https://mdotwiki.state.mi.us/construction/api.php?action=feedcontributions&user=JohnsonN23&feedformat=atomMediaWiki - User contributions [en]2024-03-28T15:01:00ZUser contributionsMediaWiki 1.35.2https://mdotwiki.state.mi.us/construction/index.php?title=Dev_Page&diff=5351Dev Page2018-05-25T17:50:45Z<p>JohnsonN23: </p>
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<div><br />
<br />
Page made for testing<br />
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You are doing great Rick!<br />
-Nate</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Listserve.PNG&diff=5261File:Listserve.PNG2018-02-27T14:22:46Z<p>JohnsonN23: </p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Table_of_Contents_by_Project_Phase&diff=5260Table of Contents by Project Phase2018-02-22T14:28:58Z<p>JohnsonN23: Project life cycle</p>
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<div><span STYLE="font: 15pt arial;">'''Pre-Construction'''</span><br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/102.02_Contents_of_Proposal 102.02 Contents of Proposal]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work Contract Administration and Oversight Guidelines for Projects Containing Warranty Work]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Contract_Administration_and_Oversight_Guidelines_for_Intelligent_Transportation_Systems_(ITS)_Projects Contract Administration and Oversight Guidelines for Intelligent Transportation Systems (ITS) Projects]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency Local Agency]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Railroad_Highway_Projects Railroad Highway Projects]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Preconstruction_Meeting Preconstruction Meeting]<br /><br />
<span STYLE="font: 15pt arial;">'''Construction'''</span><br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/E-Construction E-Construction]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/E-Signature E-Signature]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/FieldManager FieldManager]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/104.01_Authority_of_the_Department 104.01 Authority of the Department]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/104.07_Contractor_Obligations 104.07 Contractor Obligations]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/104.09_Lines,_Grades,_and_Elevations 104.09 Lines, Grades, and Elevations]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/108.01_Subcontracting_of_Contract_Work 108.01 Subcontracting of Contract Work]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs) 102.18 Subletting Contract Work to Disadvantaged Business Enterprises (DBEs)]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Disadvantaged_Business_Enterprises_(DBE) Disadvantaged Business Enterprises (DBE)]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/105.01_Quality_and_Scope_of_Supply 105.01 Quality and Scope of Supply]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Materials_Quality_Assurance_Procedures_Manual Materials Quality Assurance Procedures Manual]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Hot_Mix_Asphalt_Production_Manual Hot Mix Asphalt Production Manual]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Material_Source_List_Forms_(501)-Processing_and_Approval_Procedure Material Source List Forms (501)-Processing and Approval Procedure]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/105.10_Source_of_Steel_and_Iron 105.10 Source of Steel and Iron]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/150_-_Mobilization 150 - Mobilization]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/107.12_Contractor%27s_Responsibility_for_Utility_Property_and_Services 107.12 Contractor's Responsibility for Utility Property and Services]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/107.15_Complience_with_Laws;_Environmental_Protection 107.15 Complience with Laws; Environmental Protection]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Construction_Value_Engineering_Change_Proposal_(VECP) Construction Value Engineering Change Proposal (VECP)]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/105.07_Handling_and_Transporting_Materials 105.07 Handling and Transporting Materials]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/107.19_Hauling_on_Local_Roads_and_Streets 107.19 Hauling on Local Roads and Streets]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Contractor%27s_Equipment_and_Traffic_Control Contractor's Equipment and Traffic Control]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Weight_Limit_Waivers Weight Limit Waivers]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Holiday_Traffic_Safety_Provisions Holiday Traffic Safety Provisions]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Davis-Bacon_and_State_Prevailing_Wage_Information Davis-Bacon and State Prevailing Wage Information]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures Prevailing Wage Oversight Procedures]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Apprentices_and_Trainees Apprentices and Trainees]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/LCPtracker_Supplemental_Information LCPtracker Supplemental Information]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/109.04_Progress_and_Partial_Payments 109.04 Progress and Partial Payments]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Work_Order Work Order]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions 103.02 Contract Revisions]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Extending_Project_Limits Extending Project Limits]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Project_Delays_Due_to_a_Utility_Company Project Delays Due to a Utility Company]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/108.07_Extension_of_Time_on_Work_Day_Contracts 108.07 Extension of Time on Work Day Contracts]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Quality_Initiatives_and_Adjustments Quality Initiatives and Adjustments]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions 109.05 Payment for Contract Revisions]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension 104.10 Contractor Claim for Extra Compensation or Time Extension]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Dispute_Review_Board_(DRB) Dispute Review Board (DRB) Procedures]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Processing_Sewage/Storm_Water_Damage_Claims Processing Sewage/Storm Water Damage Claims]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Notice_of_Non-Complience_with_Contract_Requirements Notice of Non-Complience with Contract Requirements]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/108.10_Liquidated_Damages 108.10 Liquidated Damages]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/102.01_Prequalification_of_Bidders 102.01 Prequalification of Bidders]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment 109.07 Final Inspection, Acceptance, and Final Payment]<br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges Construction Field Services Indirect Testing Charges]<br /><br />
<span STYLE="font: 15pt arial;">'''Post-Construction'''</span><br /><br />
[http://mdotwiki.state.mi.us/construction/index.php/Certification_Programs Certification Programs]<br /></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5258Main Page2018-02-20T15:13:44Z<p>JohnsonN23: /* Recent Minor Changes */</p>
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<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
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<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
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<br />
<center>[[File:logo.jpg|400px]]</center><br />
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<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
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<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
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[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
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[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
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[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
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==[[#Preamble|Preamble]]==<br />
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<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
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<br />
Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
<br />
<br />
{{top}}<br />
<br />
===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
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{{top}}<br />
<br />
== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
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<br />
Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
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{{top}}<br />
<br />
====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
<br />
The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/19/2018</center>||<center>2</center>||<center>[[208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)|208]]</center>||Addition of Notice of termination section.||[http://mdotwiki.state.mi.us/construction/index.php/208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)#Submittal_of_Notice_of_Termination view here]<br />
|-<br />
|<center>1/17/2018</center>||<center>7</center>||<center>[[708_-_Prestressed_Concrete|708]]</center>||Overhaul of information for section 708||[http://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238&oldid=5233 compare]<br />
|-<br />
|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
|-<br />
|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
|-<br />
|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
|-<br />
|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
|-<br />
|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
|-<br />
|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
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{{top}}<br />
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====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>2/20/2018</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight]]</center>||Updated Title VI Poster||[http://mdotwiki.state.mi.us/construction/index.php/File:MDOT_TitleVI_englishposter.pdf View Here]<br />
|-<br />
|<center>2/12/2018</center>||<center>1</center>||<center>[[104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension|104.10]]</center>||Changed contact info to Mike Deboer and added direction to Claims Database in ProjectWise||[http://mdotwiki.state.mi.us/construction/index.php?title=104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension&diff=5251&oldid=4922 compare here]<br />
|-<br />
|<center>2/6/2018</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Changed roller speed calculation from 23.36 mph to 2.36 mph||[https://mdotwiki.state.mi.us/construction/index.php/501_-_Plant_Produced_Hot_Mix_Asphalt#Roller_Speed section here]<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
|-<br />
|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
|-<br />
|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
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|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
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|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
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|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
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|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
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|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
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|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
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|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
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|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
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|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
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|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:MDOT_TitleVI_englishposter.pdf&diff=5257File:MDOT TitleVI englishposter.pdf2018-02-20T15:11:15Z<p>JohnsonN23: JohnsonN23 uploaded a new version of &quot;File:MDOT TitleVI englishposter.pdf&quot;</p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=103.02_Contract_Revisions&diff=5256103.02 Contract Revisions2018-02-13T17:25:24Z<p>JohnsonN23: auditor edit</p>
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<div><center>[http://mdotcf.state.mi.us/public/specbook/files/2012/103%20Scope%20of%20Work.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 103]</center><br />
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===[[#Construction Contract Modification Process Overview|Construction Contract Modification Process Overview]]===<br />
<br />
[http://mdotcf.state.mi.us/public/specbook/files/2012/103%20Scope%20of%20Work.pdf Subsection 103.02] Revisions to the Contract, of the 2012 Standard Specifications for Construction states:<br />
<br />
A. General. The Department reserves the right to revise the contract at any time. Revisions to the contract neither invalidate the contract nor release the surety, and the Contractor agrees to perform the work as revised. The Contractor must not proceed with the revised work until directed to do so by the Engineer, but must continue with all work unaffected by the revision.<br />
<br />
Contract modifications are the formal process by which revisions to the contract are formally authorized, approved and incorporated into the construction contract. Contract modifications are to be processed for any revisions to the contract that alters the nature, scope, cost or schedule of the project.<br />
<br />
The MDOT contract modification process will no longer differentiate between different item types, quantities and/or monetary revisions in work. Changes, extras, adjustments, time extensions, modified originals, overruns, and all other changes are all to be evaluated in the same manner. To better align former terms, new terms, and changes in the Standard Specifications for Construction, all these various different types of changes to a construction contract modification will be referred to in this document only as “revisions to the contract.” Contract revisions will include all possible work revisions that may be included on a contract modification. Contract revisions may be positive or negative in dollar value, or even have no dollar value associated. The criteria for determining approval requirements of contract modifications will consist of the total cumulative net dollar value change of all contract revisions and previously generated contract modifications with respect to the awarded contract amount.<br />
<br />
For example, an awarded contract for $10,000 with a contract modification containing the following contract revision items:<br />
<br />
* Adding more blue house paint +$1,000<br />
* Deducting yellow house paint -$900<br />
* Adding new green paint for shed +$400<br />
* Modifying the application rate for a second coat of red paint (units x rate difference) = +$300<br />
Net Contract Modification Total = +$800<br />
<br />
$800 total net cumulative contract modifications / $10,000 original contract = 8 percent<br />
<br />
So the contract modification would be evaluated as being 8 percent over awarded contract amount requiring Tier II approval as outlined in Section IV.<br />
<br />
All contract modifications will be generated and processed within the timeframes established within this document, and shall then be subject to a tiered approval process based on thresholds and criteria fully explained in Section IV.<br />
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===[[#Contract Modification Development|Contract Modification Development]]===<br />
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Once a need has been determined to revise the terms of a construction contract, the engineer will initiate the construction contract modification process per the MDOT 2012 Standard Specifications for Construction, Division 1, and as outlined below.<br />
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====[[#Revisions to the Contract|Revisions to the Contract]]====<br />
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The revision of any contract work shall be identified and processed per the procedures outlined in the MDOT 2012 Standard Specifications for Construction. The contractor and engineer must come to an agreement on the price, extent, increased units, estimated budget and/or method of payment, of any contract revision prior to commencement of the work. This agreement may consist of a lump sum, a set quantity of increased pay item units, negotiated unit price, agreement to enter a force account method of payment, and/or an estimated budget amount. The precedence of contract term revisions is outlined in the MDOT 2012 Standard Specifications for Construction ([http://mdotcf.state.mi.us/public/specbook/files/2012/109%20Measurement%20&%20Payment.pdf Subsection 109.05]). If the engineer does not receive an estimate or lump sum price quote for any work within five calendar days of their request, the contract modification shall be generated with an estimated budget and the work is performed by force account procedures. In no case shall it take longer than seven business days after commencement of any contract revision work to generate the contract modification covering the revised work and send the contract modification to the contractor for signature.<br />
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All force account work ([http://mdotcf.state.mi.us/public/specbook/files/2012/109%20Measurement%20&%20Payment.pdf Subsection 109.05]) shall require the pre-approval of the region construction engineer prior to commencing the work. A description showing when and how this prior approval was obtained must be noted directly on the contract modification document in the detailed work description area. Any contract revision that will be paid for using the force account method shall have an estimated budget created on a contract modification. Payments to contractors are based only on accepted work that meets specifications in the pay estimate process, so estimated budgets for force account work are expected to be revised and balanced as the work progresses.<br />
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====[[#Revisions to Contract Time|Revisions to Contract Time]]====<br />
<br />
Any revisions to the terms of the contract must be made in a contract modification. This includes revisions to the contract time conditions. Any revisions in work that may impact the contract time requirements must be included on the same contract modification. If it is not possible to determine the exact extent of the contract time revisions at the time the contract modification is generated, then any potential impacts to contract time should be noted directly on the contract modification. Contract modifications should indicate one of the following: that there are no contract time impacts, the exact impacts to contract time, or note that revisions included on the contract modification could impact the contract time and a future contract revision may be required to address this.<br />
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Sample: It is not currently known at this time if this non-critical path contract revision work will impact the project completion schedule; however, should the work included in this contract revision alter the project schedule, the contractor will be required to submit a revised progress schedule for approval (Subsection 108.05.A.3.b).<br />
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===[[#Generating Contract Modifications|Generating Contract Modifications]]===<br />
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====[[#General Contract Modification Information|General Contract Modification Information]]====<br />
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The following general information is required on each contract modification:<br />
<br />
*“Short Description” – Include a brief description of the contract revisions covered by this contract modification.<br />
<br />
*“Description of Changes” – Address all items below as they apply to the contract modification:<br />
<br />
<br />
A. State the original awarded contract amount.<br />
<br />
B. State the current net total contract amount. This total shall include the net sum total of all previously generated contract modifications, including the current contract modification being developed.<br />
<br />
C. State the resulting net total difference between the current net total contract amount and original awarded contract amounts (“B” minus “A” above).<br />
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D. State the resulting total net percentage change in contract amount. This shall be calculated as the total resulting changes to the contract (“C” above) divided by the original awarded contract amount (“A” above) expressed as a percentage.<br />
<br />
E. State if the project is a Federal Highway Administration (FHWA) oversight project or MDOT oversight. Also indicate if the project has consultant administration, local agency involvement or other description as may be applicable. For all FHWA oversight projects also state the name of the FHWA area engineer and date of their pre-approval for the work covered on this contract modification. See additional requirements for attaching pre-authorized FHWA [http://www.fhwa.dot.gov/programadmin/contracts/fhwa1365.cfm Form 1365] to the contract modification as detailed in [http://mdotwiki.state.mi.us/construction/index.php/Construction_Contract_Modification_Process_Overview#Requirements_for_FHWA_Review Requirements for FHWA Review].<br />
<br />
F. For all contract modifications bound for a Tier III approval process (as detailed in Section IV) this section must include a short executive summary of project changes. This summary can and should typically discuss work beyond that contained in the subject contract modification, to more fully describe how the sum of all the contract modifications brought the contract to its current status (i.e., a last minor contract revision may not be the sole reason the entire contract has now reached Tier III status, often work in previous contract revisions contributed to the total project cost increases in a more significant way). The summary should not be overly detailed and just give a general description of how and why the contract has reached the Tier III threshold, when the work was (or will be) completed, funding (if different form regular project items), and any other general information related to the project/contract revisions. This summary description of contract revisions and explanations may be used by external reviewers in their evaluation and approval of contract modifications reaching the Tier III level.<br />
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For example, contract modifications will contain summary bullet points in the “Description of Changes” area like:<br />
<br />
A. $100 awarded contract.<br />
<br />
B. $110 current net total contract (including changes in this CM).<br />
<br />
C. $10 net total change.<br />
<br />
D. Total project now 10 percent over awarded contract amount.<br />
<br />
E. MDOT oversight project.<br />
<br />
F. Tier III approval required. Contract has reached the Tier III approval threshold due to several previously approved changes (provide brief overview of specifics) that were required to safely construct the project due to changing conditions caused by the a local festival which required some work items to be performed in different project schedule phases than as originally planned. These changes also required the addition of several additional minor traffic control items needed to maintain traffic mobility through the project area. No additional contract time will be needed to complete the project as scheduled.<br />
<br />
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A full sample contract modification has been included within this document as [//{{SERVERNAME}}/images_construction/0/0b/Contract_Revison_Example_file.pdf Contract Revison Example file.pdf]<br />
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====[[#Contract Modification Item Type|Contract Modification Item Type]]====<br />
There are four basic item types used in the FieldManager software. They are described in more detail as:<br />
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'''Original Pay Items:'''<br />
*This item code is used for contract revisions that were already included in the awarded contract as a pay item, but which may need to be increased or decreased based on actual field conditions.<br />
*A detailed explanation (including answering all of items “A” through “E” in Part 3 of Section III) is required for all revisions that increase or decrease the work item in excess of $25,000. (Note this is a general guideline for minimum requirements, additional information may be required on smaller dollar value changes depending upon specific project requirements.)<br />
<br />
'''Modified Original Pay Items:'''<br />
*Modified originals are used for contract work that was included in the awarded contract as a pay item, but which may need to be duplicated within the contract for another funding category or job number within the same contract for the same item of work.<br />
*Provide a detailed explanation (including answering all of items “A” through “E” in Part 3 of Section III) for any modified original contract pay item.<br />
*Must include the following statement as part of the reason:<br />
''“The item code, item description, and unit price for this modified original have been verified against the original contract item and are correct.”'' One original work item may be used multiple times to establish multiple modified original items. Modified original items are not extra work or adjustments. Extras and adjustments are excluded from this procedure, as they must be established as extra and adjustments to other projects and categories within the respective contract.<br />
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'''Extra Work:'''<br />
*This item type is used for any contract revisions that will require the addition of a new pay item of work in FieldManager and were not included in the awarded contract.<br />
*Provide detailed explanation (including answering all of items “A” through “H” in Part 3 of Section III) for the addition of any extra work item revising the contract.<br />
*Include any required documentation to support the extra revised contract work.<br />
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'''Adjustments:'''<br />
*This category is for contract revisions that require adjustments to work items. Adjustments are defined as “a monetary revision to a contract unit price or to the entire contract.” Examples: incentive, liquidated damages, HMA quality adjustment, concrete quality adjustment, traffic control quality and compliance adjustment, soil erosion and sedimentation control adjustment, prompt pay violation adjustment, delinquent payroll adjustment, significant changes (i.e., [http://mdotcf.state.mi.us/public/specbook/files/2012/103%20Scope%20of%20Work.pdf 103.02.B] for major items of work ± 25 percent), etc.<br />
*Document the details of the contract revision adjustments and all associated impacts to the project. Provide detailed explanation (including answering all of items “A” through “H” in Part 3 of Section III) for any contract adjustment item.<br />
*The unit used for adjustments will be “DLR” (dollars) and the quantity can be ±.<br />
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====[[#Detailed Contract Modification Information|Detailed Contract Modification Information]]====<br />
The following detailed information is required for all contract modifications according to which item type (Part 2 above) is used.<br />
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* Bulleted list item<br />
Document the details of the contract revision work including responses to all applicable items listed below:<br />
<br />
A. What was done?<br />
<br />
B. Why was it done?<br />
<br />
C. Are there any offsetting items?<br />
<br />
D. Is the work expected to impact contract time or open to traffic date(s)?<br />
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E. Is this a design error or due to changed conditions?<br />
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F. Who else has reviewed the proposed contract revisions (FHWA area engineer, region construction engineer, etc)?<br />
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G. How was the price established? Document how the cost was determined and justified either by negotiated prices or force account use.<br />
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:Indented line For example:<br />
o Unit price compared to a similar project or similar items on the existing contract.<br />
o Quoted price appears to be reasonable when compared with weighted average item prices – reference year.<br />
o Force account was the only logical method due to variables/unknowns.<br />
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H. Include and attach any/all supporting documentation for the contract revision.<br />
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====[[#Balancing Quantities|Balancing Quantities]]====<br />
Work items should be balanced as soon as they are completed and not delayed until project finaling. Balancing quantities must be submitted as soon as the work items are completed, measured, and checked.<br />
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===[[#Approval Thresholds|Approval Thresholds]]===<br />
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The required approval path of contract modifications will be based on the sum of the original awarded contract, the net sum of all previously generated contract modifications, and the current proposed contract revisions compared to the original contract award amount. As shown in Figure 1, if the net total contract amount is less than or equal to 5 percent then the contract modification approval occurs at the Tier I - TSC level; if the net contract amount exceeds 5 percent of the original value but is less than or equal to 10 percent then the contract modification requires both Tier I - TSC and Tier II - Region approvals; and if the contract modification exceeds 10 percent of the original contract value then the contract modification requires Tier I - TSC, Tier II - Region and Tier III - Bureau of Field Services approvals. Contracts at the Tier III - Bureau of Field Services level may also require approval of other entities and may take longer to approve. Please note that approval of the State Administrative Board will not be required if the contract modification is approved in accordance with all the instructions included within.<br />
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[[File:103 Figure 1.jpg|500px|thumbnail|default|Figure 1 - Approval Thresholds]]<br />
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If a level of approval is reached and then subsequent contract modifications decrease the contract value to below the threshold, then the later contract modifications under the threshold can be approved with only the lower relevant approvals.<br />
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===[[#Authorization Path|Authorization Path]]===<br />
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====[[#Preparer|Preparer]]====<br />
The “prepared by signature” block of the contract modification will contain the name of the technician, project engineer, consultant or other staff that prepared the contract modification document. This signature block is considered optional and the use of this signature block will depend upon transportation service center (TSC) or consultant office policies. The preparer of the contract modification is responsible for completing all content, including all required information, determining all signatures required, routing the document to required approvers, and for determining the approval threshold requirements. Due to varying approval times, non-sequential numbered contract modifications and other issues, the threshold net contract budget amount determination will be determined by the preparer at the time of contract modification generation. The preparer shall account for both the current contract modification and all previously “generated” contract modifications (regardless of final approval or not), but shall not include any draft contract modifications that have not yet been generated for signatures.<br />
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====[[#Consultants (MDOT or LAP Contracts)|Consultants (MDOT or LAP Contracts)]]====<br />
When consultants are managing construction projects, they must complete the signature block for “consultant project manager” by having the consultant’s licensed project engineer assigned to the project sign in this signature block. Consultants shall then send the contract modification to the contractor for signature.<br />
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====[[#Contractors|Contractors]]====<br />
Once the engineer, local agency, or consultant generates the contract modification, it will be sent to the contractor for signature. The contractor shall sign and return the document to the sender within ten calendar days of transmittal. The above approval timeline is the general guideline for most contract modifications, however, for complex or large balancing modifications that may require additional time to review, the contractor may take up to a maximum of 21 calendar days to return the document. After this maximum timeframe, or if the contractor refuses to sign and return the contract modification, the engineer may then process the contract modification with “contractor failed to sign and return” noted in the contractor signature area.<br />
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====[[#Local Agency Projects|Local Agency Projects]]====<br />
The contract modification authorization procedures for local agency projects are the same as those described with the addition of a required signature by the local agency. FHWA has directed that a representative of the local agency participating on federally funded projects must have a full time representative of the local agency sign all contract modifications. This representative is not required to be an engineer, just a full time employee of the local agency, and directly accountable to the local agency. The local agency representative shall also review and authorize the contract modification within five business days of transmittal.<br />
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====[[#Requirements for FHWA Review|Requirements for FHWA Review]]====<br />
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Approval by the Federal Highway Administration (FHWA) is necessary on all contract modifications on projects overseen by their agency in accordance with FHWA’s Oversight Project Contract Modification Procedure as outlined below. The FHWA has changed the term “FHWA Oversight” to “Projects of Division Interest (PoDI)”.<br />
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The MDOT Construction/Project Engineer or full time publicly employed Local Agency person is responsible for completing [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=FHWA-1365.pdf form FHWA-1365], Record of Authorization to Proceed with Major Contract Revision (available on MDOT’s internal form page). The form is to be electronically submitted with any applicable document(s) to the respective FHWA Area Engineer that is overseeing the project to obtain the necessary approvals. Detailed instructions for completion of FHWA [http://www.fhwa.dot.gov/programadmin/contracts/fhwa1365.cfm Form 1365]are attached. Consultant project engineers are not permitted to submit FHWA [http://www.fhwa.dot.gov/programadmin/contracts/fhwa1365.cfm Form 1365] directly to the FHWA.<br />
<br />
Prior approval from FHWA is required for all major changes in work before the work commences. This approval is obtained by electronic submission of FHWA [http://www.fhwa.dot.gov/programadmin/contracts/fhwa1365.cfm Form 1365]to the FHWA Area Engineer that is overseeing the project. The area engineer will approve or comment on the submitted form and electronically transmit the form to the MDOT TSC Construction Engineer for inclusion in the project files. The completed form must be attached to the contract modification that processes the contract revisions for the major change. FHWA will typically respond within 5 working days.<br />
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====[[#Major Changes or Major Extra Work|Major Changes or Major Extra Work]]====<br />
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All major work performed prior to obtaining documented pre-approval from FHWA will be considered non participating. However, when an emergency or unusual conditions justify expediency, the area engineer may provide verbal pre-approval of the change and immediately follow-up such verbal approvals with a formal written approval. Major changes or major extra work are defined as any change that will significantly affect the cost of the project to the federal government, alter the termini, character, or scope of work.<br />
<br />
'''FHWA’s Michigan Division has further clarified the definition of major changes as noted below:'''<br />
# Any construction field issue (contract modification) that results in extra (new) work items and/or existing (original) work items that equal or exceed $50,000 in value. This includes increasing original pay items unless it is for interim or final balancing as noted below. <br />
# Any change to the termini, character, or scope of the project, regardless of the amount. Examples of these types of changes are as follows: changes in materials, changes in pavement marking types/materials, or any changes resulting in a plan revision per the MDOT Road Design Manual. <br />
# All extensions of time (interim, open to traffic, final, etc.)<br />
# Any changes to incentive requirements, liquidated damages, A+B provisions, or warranties.<br />
# Any Value Engineering Change Proposals (VECP), regardless of amount.<br />
<br />
Contract revisions (contract modifications) that do not meet the threshold criteria noted above should still be discussed with the respective FHWA Area Engineer, prior to work commencing.<br />
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====[[#Non-Major Contract Modifications|Non-Major Contract Modifications]]====<br />
Non-major contract modifications also require formal approval from FHWA, although approval in advance and completion of FHWA [http://www.fhwa.dot.gov/programadmin/contracts/fhwa1365.cfm Form 1365]are not required prior to the work being performed. <br />
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====[[#Clarifications|Clarifications]]====<br />
FHWA [http://www.fhwa.dot.gov/programadmin/contracts/fhwa1365.cfm Form 1365] is not required for contract modifications of any amount that only balance pay items to field measured quantities (interim and final balancing contract modifications). These balancing contract modifications must not contain any pay items or work that is part of a major change as defined above.<br />
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Once an extra work item is approved, the balancing of the extra work item does not require FHWA pre-approval.<br />
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Projects classified as PoDI must have FHWA approval of all (except as noted below) contract modifications and keeping your FHWA Area Engineer informed of any unusual issues early will help ensure more efficient projects and faster contract modification approval. All discussions and pre-approvals should be noted on the contract modification. <br />
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Extra work items and adjustments that are 100 percent locally or state funded do not require FHWA approval unless the work constitutes a change in the scope of work. These items are to be placed on separate contract modifications.<br />
<div style="text-align: right;">[mailto:Change?body=https://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions Email this Page]</div><br />
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===[[#Tier I - TSC Approval|Tier I - TSC Approval]]===<br />
Once all external non-MDOT signatures have been completed, the contract modification will go through Tier I - TSC level approval. For all electronic signature contract modifications, the document shall be placed in the correct job number and folder within the MDOT ProjectWise system for further MDOT approvals. Non-electronic signature documents will be physically routed and mailed with all government approval timelines tripled (see Section VI). TSC approval must consist of at least two licensed engineer signatures and these two signatures are mandatory for every contract modification without exception. The “Recommended by” signature must contain the printed name of the construction/project engineer in responsible charge of the project. The “Authorized by TSC manager” signature block must contain the name of the TSC manager. When the contract modification is returned to the TSC office from the contractor, local agency, or consultant, the construction/project engineer (or designated alternate/backup) must review and approve the contract modification within four business days of receipt. The TSC manager (or their designated alternate/backup) shall also review and authorize the contract modification within four business days of the construction/project engineer signature.<br />
<br />
For all MDOT construction contract modification documents, signature authority is allowed to be designated to a pre-established backup or alternate signer as required. Designated backups or delegated signature authority must be to a pre-established person that is an equivalent level or higher. However, even if a backup or designated alternate review and sign the document, the name on the signature block will still contain the printed name of the required approver. In this case, the construction/project engineer and TSC manager will be named as the owners of these two signature blocks and they will ultimately be responsible for the accuracy and content of the contract modification regardless of who signed. It is never acceptable to have the same person sign multiple signature blocks on the same contract modification. If a designated backup signs for a responsible party, then they must indicate so by signing and printing their name along with adding the words “for [name of person]” in the signature area. If using electronic signatures, the backup or alternate signer must enter this same text in the signature reason area as they enter their digital electronic signature.<br />
<div style="text-align: right;">[mailto:Change?body=https://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions Email this Page]</div><br />
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===[[#Tier II - Region Approval|Tier II - Region Approval]]===<br />
Contract modifications meeting Tier II - Region approval threshold level must first obtain all lower level Tier I – TSC approval signatures as outlined above. After receiving these approvals, the contract modification will then be submitted to the region construction engineer for their review and approval. The region construction engineer must respond within four business days of receipt of the contract modification from the TSC. Backup or alternate signers for the region construction engineer will also be pre-established. <br />
<div style="text-align: right;">[mailto:Change?body=https://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions Email this Page]</div><br />
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===[[#Tier III - Bureau of Field Services Approval|Tier III - Bureau of Field Services Approval]]===<br />
Contract modifications reaching the Tier III - Bureau of Field Services approval threshold, must first obtain all Tier I - TSC and Tier II - Region level signatures, and then be routed to the Construction Contracts engineer at the Bureau of Field Services for review and processing. Contract modifications, with supporting documentation, reaching this level may also be sent to the Office of Commission Audits (OCA) and the Attorney General’s Office for review and concurrence prior to authorization. Contract modifications may be indentified by OCA to be further explained. (Contract modifications at this level that do not conform to all the requirements established herein may have to also be submitted to the SAB for approval.) Estimated approval time from initial receipt of the contract modification at the Bureau of Field Services through approval will likely be in the 30-45 day time frame with all required reviews. Contract modifications reaching this threshold should be submitted promptly to begin the approval process due to the lengthy timeframes involved. Upon authorization by the Bureau of Field Services, the contract modification will be sent back to the designated contact for the construction/project engineer.<br />
<br />
Engineers at any level of the construction contract modification approval process always have the option to contact higher level approval engineers for advice or consultation on unusual contract modifications regardless of threshold levels. The same holds true for the advice or consent of other services available to engineers through the Bureau of Field Services Construction Contracts Unit in Lansing, FHWA area engineers, the Attorney General’s office and/or the Office of Commission Audits. These resources can provide a great deal of expertise to engineers which can help avoid potential contract issues. Inquiries to these areas should be routed through the region construction engineer and/or the Construction Contracts Unit to facilitate potential correlation of similar issues and/or possible statewide guidance to other engineers.<br />
<div style="text-align: right;">[mailto:Change?body=https://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions Email this Page]</div><br />
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===[[#Records Retention|Records Retention]]===<br />
<br />
Electronic records of all construction contract modifications will be stored in the MDOT ProjectWise system to ensure proper records retention criteria for document backup, archiving, and disposal schedules can be met. Consultant or local agency generated contract modifications will also be stored in the ProjectWise system by the TSC point of contact after MDOT signatures have been obtained but an electronic copy will also be emailed back to the consultant/local agency for their records and electronic storage. The use of electronic signatures changes the standard MDOT records process, as the electronic file with the digital signatures embedded into it is legally considered the original document and it must be properly retained. Questions on records retention or digital electronic signatures should be referred to the MDOT Construction Contracts Unit.<br />
<div style="text-align: right;">[mailto:Change?body=https://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions Email this Page]</div><br />
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===[[#Contract Revisions - See Also|Contract Revisions - See Also]]===<br />
<br />
====[[#FHWA Approval|FHWA Approval]]====<br />
[[File:FHWA Interaction in MDOT Project.jpg|thumb|center|500px|FHWA Interaction in MDOT Project.]]<br />
<br />
====[[#Approval Path Flow Chart|Approval Path Flow Chart]]====<br />
[//{{SERVERNAME}}/images_construction/f/f4/Appendix_A_-_Approval_Path_Flow_Chart.pdf Appendix A - Approval Path Flow Chart.pdf]<br />
<br />
====[[#Sample Contract Modification|Sample Contract Modification]]====<br />
<br />
This is the entire example Contract Modification in one PDF file.<br />
[//{{SERVERNAME}}/images_construction/8/86/Appendix_B_-_Sample_Contract_Modification.pdf Appendix B - Sample Contract Modification]<br />
<div style="text-align: right;">[mailto:Change?body=https://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions Email this Page]</div><br />
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<br />
[[Category: Construction Manual]]<br />
[[Category: Division 1]]<br />
[[Category: Section 103]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=104.10_Claim_for_Extra_Compensation_or_Extension_of_Time&diff=5255104.10 Claim for Extra Compensation or Extension of Time2018-02-13T14:36:43Z<p>JohnsonN23: /* General */</p>
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<div><div style="text-align: center;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
=[[#General|General]]=<br />
<br />
The Michigan Department of Transportation Construction Contractor Claims Procedure provides a formalized, tiered process for the submittal and review of a Contractor’s claim. The claim review process involves a formalized administrative procedure. The goal of the process is to resolve claims at the lowest possible level. This document will clarify the process and reinforce the level of attention, accountability, and urgency by the Contractor and Department in the claim process. The time durations within the procedures are intended to be maximum timeframes with any request for an extension to the durations, whether by the Contractor or the Department, documented in writing.<br />
<br />
Construction Field Services (CFS) and Region Construction Engineers will be monitoring and tracking all claims. The procedures for the reporting and tracking of claims are as follows:<br />
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* A copy of all notices of intent to file claims (MDOT and local agency) must be provided to TSC Managers and Region Construction Engineers as noted in the procedures. <br />
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* The claim information must be entered in the central office claim database after receiving Form 1953 from the Contractor.<br />
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* The Federal Highway Administration (FHWA) Area Engineer must be notified on all Projects of Division Interest (PODI) when a claim meeting is scheduled or an issue is scheduled to be presented to a Dispute Review Board (DRB). A copy of the DRB claim package is to be provided to the FHWA Area Engineer.<br />
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* All claim decision letters from the Region Office Review hearings are to be copied to both the Region Construction Engineer and the CFS Construction Contracts Engineer.<br />
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Please send all (project, region and central office) claim decision letters to the contractor by '''certified''' mail. The Return Receipt is to be placed in the project file. This documentation will be used when determining if subsequent appeals are timely. If you receive what appears to be an untimely appeal from a contractor, contact the Attorney General’s Office (517-373-1479) for recommended action.<br />
<br />
This information will replace the claim procedures in section 104 of the construction manual.<br />
<br />
If you have any questions, please contact [mailto:DeBoerM@michigan.gov Michael DeBoer], Construction Contracts Engineer, at or call him at 517-256-8368.<br />
<br />
The statewide claims spreadsheet can be found in ProjectWise, under Documents - Statewide Groups - CFS - Statewide Claims Data. <br />
<br />
{|style="margin: 0 auto;"<br />
|[[file:Claims database structure.PNG|250px|ProjectWise folder structure]]<br />
|[[File:Claims_image.PNG|1000px|Image of file]]<br />
|}<br />
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<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
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=[[#MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)|MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)]]=<br />
The [http://www.michigan.gov/documents/mdot/MDOT_Claims_Procedure_571598_7.pdf MDOT Claims Procedure Manual] is published on the MDOT website.<br />
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<br />
====[[#Claims Process Flowchart|Claims Process Flowchart]]====<br />
[[File:CLAIMS Flowchart DRAFT -SACT Review Complete.pdf|500px|thumbnail|center|Claims Process Flowchart]]<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
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[[Category:Construction Manual]]<br />
[[Category:Division 1]]<br />
[[Category:Section 104]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Claims_image.PNG&diff=5254File:Claims image.PNG2018-02-13T14:27:50Z<p>JohnsonN23: </p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Claims_database_structure.PNG&diff=5253File:Claims database structure.PNG2018-02-12T15:46:41Z<p>JohnsonN23: JohnsonN23 uploaded a new version of &quot;File:Claims database structure.PNG&quot;</p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5252Main Page2018-02-12T15:06:58Z<p>JohnsonN23: /* Recent Minor Changes */</p>
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<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
<br />
<br />
<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
<br />
<br />
<center>[[File:logo.jpg|400px]]</center><br />
<br />
<br />
<br />
<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
<br />
<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
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[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
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[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
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[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
<br />
==[[#Preamble|Preamble]]==<br />
<br />
<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
<br />
<br />
Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
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<br />
===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
<br />
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<br />
== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
<br />
<br />
Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
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<br />
====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
<br />
The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/19/2018</center>||<center>2</center>||<center>[[208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)|208]]</center>||Addition of Notice of termination section.||[http://mdotwiki.state.mi.us/construction/index.php/208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)#Submittal_of_Notice_of_Termination view here]<br />
|-<br />
|<center>1/17/2018</center>||<center>7</center>||<center>[[708_-_Prestressed_Concrete|708]]</center>||Overhaul of information for section 708||[http://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238&oldid=5233 compare]<br />
|-<br />
|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
|-<br />
|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
|-<br />
|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
|-<br />
|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
|-<br />
|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
|-<br />
|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
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====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>2/12/2018</center>||<center>1</center>||<center>[[104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension|104.10]]</center>||Changed contact info to Mike Deboer and added direction to Claims Database in ProjectWise||[http://mdotwiki.state.mi.us/construction/index.php?title=104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension&diff=5251&oldid=4922 compare here]<br />
|-<br />
|<center>2/6/2018</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Changed roller speed calculation from 23.36 mph to 2.36 mph||[https://mdotwiki.state.mi.us/construction/index.php/501_-_Plant_Produced_Hot_Mix_Asphalt#Roller_Speed section here]<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
|-<br />
|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
|-<br />
|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
|-<br />
|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
|- <br />
|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
|-<br />
|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
|-<br />
|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
|}<br />
</div><br />
{{top}}<br />
[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=104.10_Claim_for_Extra_Compensation_or_Extension_of_Time&diff=5251104.10 Claim for Extra Compensation or Extension of Time2018-02-12T15:01:45Z<p>JohnsonN23: </p>
<hr />
<div><div style="text-align: center;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
=[[#General|General]]=<br />
<br />
The Michigan Department of Transportation Construction Contractor Claims Procedure provides a formalized, tiered process for the submittal and review of a Contractor’s claim. The claim review process involves a formalized administrative procedure. The goal of the process is to resolve claims at the lowest possible level. This document will clarify the process and reinforce the level of attention, accountability, and urgency by the Contractor and Department in the claim process. The time durations within the procedures are intended to be maximum timeframes with any request for an extension to the durations, whether by the Contractor or the Department, documented in writing.<br />
<br />
Construction Field Services (CFS) and Region Construction Engineers will be monitoring and tracking all claims. The procedures for the reporting and tracking of claims are as follows:<br />
<br />
* A copy of all notices of intent to file claims (MDOT and local agency) must be provided to TSC Managers and Region Construction Engineers as noted in the procedures. <br />
<br />
* The claim information must be entered in the central office claim database after receiving Form 1953 from the Contractor.<br />
<br />
* The Federal Highway Administration (FHWA) Area Engineer must be notified on all Projects of Division Interest (PODI) when a claim meeting is scheduled or an issue is scheduled to be presented to a Dispute Review Board (DRB). A copy of the DRB claim package is to be provided to the FHWA Area Engineer.<br />
<br />
* All claim decision letters from the Region Office Review hearings are to be copied to both the Region Construction Engineer and the CFS Construction Contracts Engineer.<br />
<br />
Please send all (project, region and central office) claim decision letters to the contractor by '''certified''' mail. The Return Receipt is to be placed in the project file. This documentation will be used when determining if subsequent appeals are timely. If you receive what appears to be an untimely appeal from a contractor, contact the Attorney General’s Office (517-373-1479) for recommended action.<br />
<br />
This information will replace the claim procedures in section 104 of the construction manual.<br />
<br />
If you have any questions, please contact [mailto:DeBoerM@michigan.gov Michael DeBoer], Construction Contracts Engineer, at or call him at 517-256-8368.<br />
<br />
The statewide claims spreadsheet can be found in ProjectWise, under Documents - Statewide Groups - CFS - Statewide Claims Data. <br />
<br />
[[file:Claims database structure.PNG|250px|ProjectWise folder structure]]<br />
<br />
<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
<br />
{{top}}<br />
<br />
=[[#MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)|MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)]]=<br />
The [http://www.michigan.gov/documents/mdot/MDOT_Claims_Procedure_571598_7.pdf MDOT Claims Procedure Manual] is published on the MDOT website.<br />
{{top}}<br />
<br />
<br />
====[[#Claims Process Flowchart|Claims Process Flowchart]]====<br />
[[File:CLAIMS Flowchart DRAFT -SACT Review Complete.pdf|500px|thumbnail|center|Claims Process Flowchart]]<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
{{top}}<br />
[[Category:Construction Manual]]<br />
[[Category:Division 1]]<br />
[[Category:Section 104]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Claims_database_structure.PNG&diff=5250File:Claims database structure.PNG2018-02-12T14:53:19Z<p>JohnsonN23: </p>
<hr />
<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=104.10_Claim_for_Extra_Compensation_or_Extension_of_Time&diff=5249104.10 Claim for Extra Compensation or Extension of Time2018-02-12T14:52:31Z<p>JohnsonN23: /* General */</p>
<hr />
<div><div style="text-align: center;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
=[[#General|General]]=<br />
<br />
The Michigan Department of Transportation Construction Contractor Claims Procedure provides a formalized, tiered process for the submittal and review of a Contractor’s claim. The claim review process involves a formalized administrative procedure. The goal of the process is to resolve claims at the lowest possible level. This document will clarify the process and reinforce the level of attention, accountability, and urgency by the Contractor and Department in the claim process. The time durations within the procedures are intended to be maximum timeframes with any request for an extension to the durations, whether by the Contractor or the Department, documented in writing.<br />
<br />
Construction Field Services (CFS) and Region Construction Engineers will be monitoring and tracking all claims. The procedures for the reporting and tracking of claims are as follows:<br />
<br />
* A copy of all notices of intent to file claims (MDOT and local agency) must be provided to TSC Managers and Region Construction Engineers as noted in the procedures. <br />
<br />
* The claim information must be entered in the central office claim database after receiving Form 1953 from the Contractor.<br />
<br />
* The Federal Highway Administration (FHWA) Area Engineer must be notified on all Projects of Division Interest (PODI) when a claim meeting is scheduled or an issue is scheduled to be presented to a Dispute Review Board (DRB). A copy of the DRB claim package is to be provided to the FHWA Area Engineer.<br />
<br />
* All claim decision letters from the Region Office Review hearings are to be copied to both the Region Construction Engineer and the CFS Construction Contracts Engineer.<br />
<br />
Please send all (project, region and central office) claim decision letters to the contractor by '''certified''' mail. The Return Receipt is to be placed in the project file. This documentation will be used when determining if subsequent appeals are timely. If you receive what appears to be an untimely appeal from a contractor, contact the Attorney General’s Office (517-373-1479) for recommended action.<br />
<br />
This information will replace the claim procedures in section 104 of the construction manual.<br />
<br />
If you have any questions, please contact [mailto:DeBoerM@michigan.gov Michael DeBoer], Construction Contracts Engineer, at or call him at 517-256-8368.<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
<br />
The statewide claims spreadsheet can be found in ProjectWise, under Documents - Statewide Groups - CFS - Statewide Claims Data. <br />
{{top}}<br />
<br />
=[[#MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)|MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)]]=<br />
The [http://www.michigan.gov/documents/mdot/MDOT_Claims_Procedure_571598_7.pdf MDOT Claims Procedure Manual] is published on the MDOT website.<br />
{{top}}<br />
<br />
<br />
====[[#Claims Process Flowchart|Claims Process Flowchart]]====<br />
[[File:CLAIMS Flowchart DRAFT -SACT Review Complete.pdf|500px|thumbnail|center|Claims Process Flowchart]]<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
{{top}}<br />
[[Category:Construction Manual]]<br />
[[Category:Division 1]]<br />
[[Category:Section 104]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=104.10_Claim_for_Extra_Compensation_or_Extension_of_Time&diff=5248104.10 Claim for Extra Compensation or Extension of Time2018-02-12T12:29:56Z<p>JohnsonN23: /* General */ updated contact info</p>
<hr />
<div><div style="text-align: center;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
=[[#General|General]]=<br />
<br />
The Michigan Department of Transportation Construction Contractor Claims Procedure provides a formalized, tiered process for the submittal and review of a Contractor’s claim. The claim review process involves a formalized administrative procedure. The goal of the process is to resolve claims at the lowest possible level. This document will clarify the process and reinforce the level of attention, accountability, and urgency by the Contractor and Department in the claim process. The time durations within the procedures are intended to be maximum timeframes with any request for an extension to the durations, whether by the Contractor or the Department, documented in writing.<br />
<br />
Construction Field Services (CFS) and Region Construction Engineers will be monitoring and tracking all claims. The procedures for the reporting and tracking of claims are as follows:<br />
<br />
* A copy of all notices of intent to file claims (MDOT and local agency) must be provided to TSC Managers and Region Construction Engineers as noted in the procedures. <br />
<br />
* The claim information must be entered in the central office claim database after receiving Form 1953 from the Contractor.<br />
<br />
* The Federal Highway Administration (FHWA) Area Engineer must be notified on all Projects of Division Interest (PODI) when a claim meeting is scheduled or an issue is scheduled to be presented to a Dispute Review Board (DRB). A copy of the DRB claim package is to be provided to the FHWA Area Engineer.<br />
<br />
* All claim decision letters from the Region Office Review hearings are to be copied to both the Region Construction Engineer and the CFS Construction Contracts Engineer.<br />
<br />
Please send all (project, region and central office) claim decision letters to the contractor by '''certified''' mail. The Return Receipt is to be placed in the project file. This documentation will be used when determining if subsequent appeals are timely. If you receive what appears to be an untimely appeal from a contractor, contact the Attorney General’s Office (517-373-1479) for recommended action.<br />
<br />
This information will replace the claim procedures in section 104 of the construction manual.<br />
<br />
If you have any questions, please contact [mailto:DeBoerM@michigan.gov Michael DeBoer], Construction Contracts Engineer, at or call him at 517-256-8368.<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
{{top}}<br />
<br />
=[[#MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)|MICHIGAN DEPARTMENT OF TRANSPORTATION CLAIMS PROCEDURE (Revised 2016)]]=<br />
The [http://www.michigan.gov/documents/mdot/MDOT_Claims_Procedure_571598_7.pdf MDOT Claims Procedure Manual] is published on the MDOT website.<br />
{{top}}<br />
<br />
<br />
====[[#Claims Process Flowchart|Claims Process Flowchart]]====<br />
[[File:CLAIMS Flowchart DRAFT -SACT Review Complete.pdf|500px|thumbnail|center|Claims Process Flowchart]]<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/104.10_Contractor_Claim_for_Extra_Compensation_or_Time_Extension Email this Page]</div><br />
{{top}}<br />
[[Category:Construction Manual]]<br />
[[Category:Division 1]]<br />
[[Category:Section 104]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Frequently_Searched_Items&diff=5247Frequently Searched Items2018-02-06T15:35:32Z<p>JohnsonN23: </p>
<hr />
<div>:[http://mdotwiki.state.mi.us/construction/index.php/Construction_Contract_Modification_Process_Overview Contract Modification] and FHWA limits (formerly FHWA BOHIM)<br />
:[http://mdotjboss.state.mi.us/webforms/WebFormsHome.htm Mdot forms search]<br />
:[http://www.michigan.gov/mdot/0,4616,7-151-9625_21539_21546---,00.html MDOT Average unit prices]<br />
:[http://www.michigan.gov/mdot/0,4616,7-151-9625_21540_36037---,00.html MDOT Design Estimating Average Unit Price]<br />
:[http://mdotcf.state.mi.us/public/trnsport/ Construction Contractor Inquiries for letting dates, item numbers, status] <br />
:[http://mdotjboss.state.mi.us/SpecProv/specProvHome.htm Frequently used special provisions] <br />
:[http://mdotcf.state.mi.us/public/design/englishstandardplans/ MDOT Standard plans]<br />
:[http://mdotcf.state.mi.us/public/tands/plans.cfm MMUTCD chapter 6] <br />
:[http://www.michigan.gov/mdot/0,4616,7-151-12965_14036---F,00.html Traffic Sign Details]<br />
:[https://mdotjboss.state.mi.us/BidLetting/BidLettingHome.htm E proposal to find plans, proposals for jobs that are let]<br />
:[http://mdotjboss.state.mi.us/BidLetting/BidLettingHome.htm Bid tabs from lettings] <br />
:[http://www.michigan.gov/mdot/0,4616,7-151-9622_11044_11367_68095---,00.html Material source guide]<br />
:[http://mdotjboss.state.mi.us/webforms/NewRevisedConstrForms.htm Check for latest MDOT Form updates]<br />
:[http://mdotwiki.state.mi.us/construction/index.php/105.10_Source_of_Steel_and_Iron Formerly Buy America BOHIM] <br />
:[http://mdotwiki.state.mi.us/construction/index.php/501_-_Plant_Produced_Hot_Mix_Asphalt HMA Inspector’s Daily report requirements - (Formerly CA (2006-07))]<br />
:[http://www.michigan.gov/documents/mdot/MDOT_DocumentationGuide_328761_7.pdf Material Documentation Guide]<br />
:[http://mdotwiki.state.mi.us/construction/index.php/102.01_Prequalification_of_Bidders Contractor Performance Evaluations procedures (MDOT Wiki)]<br />
:[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures Prevailing Wage]<br />
:[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Estimates Final Estimates]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5246Main Page2018-02-06T14:18:31Z<p>JohnsonN23: /* Recent Minor Changes */</p>
<hr />
<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
<br />
<br />
<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
<br />
<br />
<center>[[File:logo.jpg|400px]]</center><br />
<br />
<br />
<br />
<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
<br />
<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
<br />
[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
<br />
[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
<br />
[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
<br />
==[[#Preamble|Preamble]]==<br />
<br />
<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
<br />
<br />
Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
<br />
<br />
{{top}}<br />
<br />
===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
<br />
{{top}}<br />
<br />
== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
<br />
<br />
Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
<br />
{{top}}<br />
<br />
====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
<br />
The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/19/2018</center>||<center>2</center>||<center>[[208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)|208]]</center>||Addition of Notice of termination section.||[http://mdotwiki.state.mi.us/construction/index.php/208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)#Submittal_of_Notice_of_Termination view here]<br />
|-<br />
|<center>1/17/2018</center>||<center>7</center>||<center>[[708_-_Prestressed_Concrete|708]]</center>||Overhaul of information for section 708||[http://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238&oldid=5233 compare]<br />
|-<br />
|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
|-<br />
|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
|-<br />
|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
|-<br />
|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
|-<br />
|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
|-<br />
|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
<br />
{{top}}<br />
<br />
====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>2/6/2018</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Changed roller speed calculation from 23.36 mph to 2.36 mph||[https://mdotwiki.state.mi.us/construction/index.php/501_-_Plant_Produced_Hot_Mix_Asphalt#Roller_Speed section here]<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
|-<br />
|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
|-<br />
|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
|-<br />
|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
|- <br />
|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
|-<br />
|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
|-<br />
|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
|}<br />
</div><br />
{{top}}<br />
[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5245Main Page2018-02-06T14:18:01Z<p>JohnsonN23: /* Recent Minor Changes */</p>
<hr />
<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
<br />
<br />
<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
<br />
<br />
<center>[[File:logo.jpg|400px]]</center><br />
<br />
<br />
<br />
<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
<br />
<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
<br />
[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
<br />
[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
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[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
<br />
==[[#Preamble|Preamble]]==<br />
<br />
<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
<br />
<br />
Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
<br />
<br />
{{top}}<br />
<br />
===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
<br />
{{top}}<br />
<br />
== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
<br />
<br />
Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
<br />
{{top}}<br />
<br />
====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
<br />
The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/19/2018</center>||<center>2</center>||<center>[[208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)|208]]</center>||Addition of Notice of termination section.||[http://mdotwiki.state.mi.us/construction/index.php/208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)#Submittal_of_Notice_of_Termination view here]<br />
|-<br />
|<center>1/17/2018</center>||<center>7</center>||<center>[[708_-_Prestressed_Concrete|708]]</center>||Overhaul of information for section 708||[http://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238&oldid=5233 compare]<br />
|-<br />
|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
|-<br />
|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
|-<br />
|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
|-<br />
|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
|-<br />
|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
|-<br />
|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
<br />
{{top}}<br />
<br />
====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>2/6/2018</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Changed roller speed calculation from 23.36 mph to 2.36 mph||<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
|-<br />
|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
|-<br />
|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
|-<br />
|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
|- <br />
|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
|-<br />
|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
|-<br />
|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
|}<br />
</div><br />
{{top}}<br />
[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=5244501 - Plant Produced Hot Mix Asphalt2018-02-06T14:15:14Z<p>JohnsonN23: /* Roller Speed */ change in speed calculation</p>
<hr />
<div>[[File:HMA2.jpg|600px|center|Asphalt Base]]<br />
<br />
<center><span STYLE="font: 60pt arial;">'''501'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Plant Produced Hot Mix Asphalt'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/501%20Plant%20Mixed%20HMA.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 501]</center><br />
<br />
<br />
----<br />
<br />
<br />
<div style="float: left; padding-right: 10px;">{{TOC | width size = 100px }}</div><br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
<br />
===[[#Pre-Production Meeting|Pre-Production Meeting]]===<br />
<br />
A pre-production meeting should be held before work commences on a project. During this meeting, the overall goals and expectations are set for the project. It is generally the responsibility of the Engineer to outline the scope of the project and to discuss the information provided in the contract documents. It is also the responsibility of MDOT and the Contractor to discuss any unusual aspects of the project, items that are not routine construction practices.<br />
<br />
The role of each person on the project, for both MDOT and the Contractor, should be discussed and made clear. This requires that the supervisory personnel define the tasks, authority and responsibilities of each of the key individuals to be involved in the work. A list of MDOT personnel who will be assigned to the project should be provided to the Contractor.<br />
<br />
The Contractor’s representative should be familiar with the project and be able to speak with authority about what is to be accomplished. A paving schedule for the project should be presented and discussed with MDOT. Any questions about the information in the contract documents should be raised and clarification requested, if necessary. A listing of key Contractor personnel who will be assigned to the project, with clear lines of authority, should be provided to MDOT.<br />
<br />
Agreement is needed on the methods to be employed to complete the project on schedule, within specification and with minimum delays. A list of equipment that will be used on the project should be supplied to MDOT. Because continuity of the asphalt paving operation is critical to providing a quality pavement, the discussion between MDOT and the Contractor personnel should include such items as those listed below.<br />
<br />
The discussion should include the safety of those individuals working on the project, as well as the safety of the traveling public. Clear responsibility for maintenance of all traffic control devices, such as signs, pavement markings and flagging, should also be defined.<br />
<br />
The name of the individual responsible for safety for the Contractor should be provided to MDOT so that rapid and clear communications can be accomplished if safety problems occur. All personnel involved in the project must be required to comply with all safety standards applicable to the type of construction and asphalt paving work to be carried out.<br />
<br />
Sampling methods and frequencies should be discussed. Test methods to be used should be reviewed to assure that individuals understand the purpose of each test, the location of the field lab and the personnel who are to conduct the tests, the time frame for the communication of the test results and the procedures to be used if failing test results are obtained. The details of the quality control program, both on the part of the Contractor and MDOT, should be discussed so that everyone is aware of who is responsible for performing the procedures and when they will be done.<br />
<br />
Qualification of the material sampling technicians should be a pre-production meeting agenda item. Attach copies of the qualification documentation for the sampling technician to the preproduction meeting minutes for each HMA paving project where HMA sampling is required. This will help ensure that sampling technicians for the project are formally qualified by the department. Maintain and document these certifications in the project files.<br />
<br />
Communication cannot stop once the pre-production meeting is concluded. It is important that the individuals in daily charge of the project for both MDOT and the Contractor meet periodically, both on a formal and informal basis, to discuss the progress and quality of the work done to date and the progress schedule for the future. Ideally, these meetings should occur at a regularly scheduled time and can be held on the project site, or at the asphalt plant. Asphalt paving projects, like many construction projects, are not always built as originally scheduled. Changes occur because of material supply, equipment breakdown, Contractor and Subcontractor schedules and weather conditions. When such changes do occur, it is important that they be communicated between the Contractor and MDOT and between MDOT and the Contractor.<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Pre-Production Meeting Discussion Points'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
Project safety.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
Project mixture and testing Special Provisions.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
Job mix formula.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
Job mix formula adjustments, retroactive.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
Lot and sublot size.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
Random numbers.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
Sampling procedures.<br />
|-<br />
|<br />
<center>8</center><br />
|<br />
Laying out core locations and traffic control for coring.<br />
|-<br />
|<br />
<center>9</center><br />
|<br />
Laying out core locations, discuss how it will be done.<br />
|-<br />
|<br />
<center>10</center><br />
|<br />
Trial runs.<br />
|-<br />
|<br />
<center>11</center><br />
|<br />
Sequence of operations.<br />
|-<br />
|<br />
<center>12</center><br />
|<br />
Paving widths.<br />
|-<br />
|<br />
<center>13</center><br />
|<br />
Equipment required.<br />
|-<br />
|<br />
<center>14</center><br />
|<br />
Application rate of materials.<br />
|-<br />
|<br />
<center>15</center><br />
|<br />
Plant production and paver speed.<br />
|-<br />
|<br />
<center>16</center><br />
|<br />
Mixture temperature at the paver.<br />
|-<br />
|<br />
<center>17</center><br />
|<br />
Pavement density control, roller patterns.<br />
|-<br />
|<br />
<center>18</center><br />
|<br />
Weather and air temperature requirements.<br />
|-<br />
|<br />
<center>19</center><br />
|<br />
Project documentation.<br />
|-<br />
|<br />
<center>20</center><br />
|<br />
Qualifications of material sampling technicians.<br />
|}<br />
<br />
{{top}}<br />
<br />
===[[#Safety|Safety]]===<br />
<br />
HMA mixtures consist of a blend of asphalt binder and aggregates mixed in an asphalt plant. When specified, special additives may be required.<br />
<br />
The old saying “Safety is Everyone’s Business” is certainly true on an HMA paving project. Communication is one of the keys to a safe work environment. Every individual should know what is expected and know how to perform the assigned tasks. Everyone, regardless of title or job function, must be aware of the need for safe work practices. Occupational Safety and Health Administration regulations must be known, understood and followed by each person involved on the project. Safety talks are a very good way to start each day for both the Contractor and MDOT personnel. Several different organizations publish short, concise safety presentations that can be completed in two to three minutes. Daily talks are one way to continuously remind people that they are working in a potentially dangerous environment at both the plant and the paving site. If an unsafe work practice is noticed, corrective action should be taken immediately, even if the paving operation has to be shut down until the unsafe practice is corrected.<br />
<br />
The people most likely to be hurt on an asphalt paving project are those individuals who are new to this type of work. A new plant inspector can easily get burned if not aware that asphalt samples are very hot. Functioning equipment parts, high temperatures, noise and moving delivery and haul trucks all add to the possibility of an accident occurring.<br />
<br />
The street inspector can easily get hurt if they are not aware of the number of vehicles operating on the paving site. Individuals who are working around the paver are susceptible to being hit by passing traffic and have the potential to be hurt by the equipment being used in the paving operation.<br />
<br />
Safety is everyone’s business on a construction project and there is further discussion of this under Pre-Production Meeting.<br />
<br />
{{top}}<br />
<br />
===[[#Glossary of Paving Terminology|Glossary of Paving Terminology]]===<br />
<br />
<div style="float: right; padding-left: 10px;"><br />
{| class="wikitable"<br />
|-<br />
! colspan="4" |<br />
<center>'''Metric Conversion - HMA Mix Application Rates'''</center><br />
|-<br />
|<br />
<center>110 lb/syd</center><br />
|<br />
<center>60 kg/m<sup>2</sup></center><br />
|<br />
<center>25 mm</center><br />
|<br />
<center>1 in.</center><br />
|-<br />
|<br />
<center>140 lb/syd</center><br />
|<br />
<center>75 kg/m<sup>2</sup></center><br />
|<br />
<center>30 mm</center><br />
|<br />
<center>1-1/4 in.</center><br />
|-<br />
|<br />
<center>165 lb/syd</center><br />
|<br />
<center>90 kg/m<sup>2</sup></center><br />
|<br />
<center>40 mm</center><br />
|<br />
<center>1-1/2 in.</center><br />
|-<br />
|<br />
<center>190 lb/syd</center><br />
|<br />
<center>105 kg/m<sup>2</sup></center><br />
|<br />
<center>45 mm</center><br />
|<br />
<center>1-3/4 in.</center><br />
|-<br />
|<br />
<center>220 lb/syd</center><br />
|<br />
<center>120 kg/m<sup>2</sup></center><br />
|<br />
<center>50 mm</center><br />
|<br />
<center>2 in.</center><br />
|-<br />
|<br />
<center>275 lb/syd</center><br />
|<br />
<center>150 kg/m<sup>2</sup></center><br />
|<br />
<center>65 mm</center><br />
|<br />
<center>2-1/2 in.</center><br />
|-<br />
|<br />
<center>330 lb/syd</center><br />
|<br />
<center>180 kg/m<sup>2</sup></center><br />
|<br />
<center>75 mm</center><br />
|<br />
<center>3 in.</center><br />
|-<br />
|<br />
<center>385 lb/syd</center><br />
|<br />
<center>210 kg/m<sup>2</sup></center><br />
|<br />
<center>90 mm</center><br />
|<br />
<center>3-1/2 in.</center><br />
|}<br />
</div><br />
* '''AGGREGATE''' - Various hard, inert materials such as sand, gravel, pebbles, etc., used as the bulk material in asphaltic mixes.<br />
* '''ANGLE OF ATTACK''' - The angle incurred between the screed plate and the surface.<br />
* '''ASPHALT''' - A mixture of bitumen (bonding agent) and aggregate (bulk material).<br />
* '''AUGER''' - A rotating device with a broad, helical flange (flighting) used to spread paving material evenly in front of the screed.<br />
* '''AUGER SHADOWS''' - Alternate dark and light areas of compaction occurring longitudinally in the mat, representing different density and texture.<br />
* '''AUTOMATIC FEED CONTROLS''' - The standard system for maintaining a constant head of material in front of the screed by controlling the ON - OFF operation of the unit’s dual feed system.<br />
* '''AUTOMATIC GRADE AND SLOPE CONTROLS''' - The electronic/hydraulic control system that automatically maintains the elevation of one screed tow point with respect to a reference surface (grade), while maintaining the elevation of the opposite screed tow point in relation to the first with respect to gravity (slope). It is used to improve upon the levelability of the paver.<br />
* '''AUTOMATIC LEVEL CONTROL (Joint Matcher)''' - An electronic/hydraulic control system that automatically controls the elevation of the mat being placed on one side with respect to a reference surface such as an adjacent mat or cut. It is used to match the profile of the edge of a mat to that of the adjacent surface.<br />
* '''BITUMEN''' - A thick, viscous, petroleum-based substance used as bonding agent in asphaltic mixes.<br />
* '''BURNERS''' - See SCREED HEATERS.<br />
* '''COMPACTION''' - The process of increasing the density of paving material.<br />
* '''CONVEYOR''' - An endless chain and bar assembly used to move paving material from the hopper to the auger.<br />
* '''CORRUGATION''' - Washboard effect usually occurring in areas where braking and acceleration take place. It may also occur to a lesser degree in the even speed areas. It is caused by an excessively soft mix over an unstable base.<br />
* '''CRACKS''' -<br />
** '''ALLIGATOR''' - Crisscross cracks usually due to heavy traffic loads exceeding the strength of the surface over an unstable base.<br />
** '''LONGITUDINAL''' - Cracks that appear along longitudinal joints, between lanes and shoulders, and many times at the base and outer edges of ruts. These cracks result from movement along these weakened areas.<br />
** '''REFLECTION''' - Existing cracks in sub-pavement, eventually coming through an overlay, due to continued movement in the unstabilized sub-pavement.<br />
** '''SHRINKAGE''' - Random cracks appearing due to lack of traffic that would normally keep the surface sealed.<br />
** '''SLIPPAGE''' - Cracks appearing in the overlay because the surface is pushed or rolled apart by breaking traffic. This may also occur if an overlay is poorly bonded to the sub-pavement due to inadequate tack coating or improper mix design.<br />
** '''TRANSVERSE''' - Cracks perpendicular to traffic flow. In overlays of concrete, the concrete joints may reflect through surface if movement occurs along the joint. Concrete stress cracks across the pavement may also reflect through.<br />
* '''CROSS BEAM''' - A steel bar connected between the side arms for mounting the slope sensor.<br />
* '''CROWN''' - The transverse contour of a finished mat. Also used to describe the contour of the screed plate. The transition line between two different slopes (i.e., between lanes or between lanes and shoulders).<br />
* '''LEAD CROWN''' - The contour or profile from side to side of the leading edge of the screed.<br />
* '''TAIL (or ROAD) CROWN''' - The contour of the trailing edge of the screed.<br />
* '''NEGATIVE CROWN''' - Contour that is higher at the edges than at the center of a mat.<br />
* '''POSITIVE CROWN''' - Contour that is higher at the center than at the edges of a mat.<br />
* '''CUT-OFF SHOE''' - A detachable plate used to reduce the paving width of a screed.<br />
* '''DENSITY''' - Measurement of in-place pavement compaction.<br />
* '''DEPTH CRANK''' - Adjusting crank located at the rear of each side arm, used to control angle of attack of the screed.<br />
* '''EDGER PLATE''' - A vertical plate at each end of the screed used to confine the head of material.<br />
* '''ELEVATION''' - Vertical height from a reference surface.<br />
* '''FEEDERS''' - L. H. and R. H. auger-conveyor systems on a paving machine.<br />
* '''FLOATING BEAM''' - An aluminum beam, supported by a series of spring loaded shoes, towed beside the paver and used as a reference.<br />
* '''FLOW GATES''' - Adjustable plates at the rear of the hopper used to control material volume conveyed to the augers.<br />
* '''FLOOR PLATE''' - A heavy steel plate upon which the conveyors travel.<br />
* '''FREE-FLOATING SCREED''' - The screed is supported on the surface of the paving material as it passes beneath the screed plate. Material thickness under the screed will increase or decrease according to the angle between the screed plate and grade surface.<br />
* '''GRADE''' - <br />
** The base surface (road bed) over which paving is being performed. <br />
** The elevation of a fresh mat in relation to the base.<br />
** The incline of a paving surface in the direction of travel, expressed by stating the rise or fall as a percentage of horizontal distance. (Example: 6 percent grade - 6 inches (6 m) of elevation change in 100 feet (100 m) of horizontal longitudinal run).<br />
* '''GRADE CONTROL''' - A means of controlling the longitudinal elevation of a mat as it is being laid.<br />
* '''GRADE SENSOR''' - An electrical device that detects positive and negative changes in longitudinal elevation from a grade reference (i.e., wire or string line, floating beam, mat reference, adjacent mat, or curb surface).<br />
* '''HEAD OF MATERIAL''' - The volume of paving material directly in front of and along the entire lateral length of the screed.<br />
* '''HMA''' - A paving material that consists of asphalt binder and mineral aggregate.<br />
* '''HOPPER''' - The area at the front of the paving machine that receives the paving material.<br />
* '''HYDRAULIC''' - Liquid in motion under pressure, the flow of which causes work to be accomplished.<br />
* '''HYDROSTATIC TRANSMISSION''' - Power transmitted by a positive displacement pump through a liquid under pressure to a positive displacement motor.<br />
* '''INCLINOMETER''' - See SLOPE SENSOR.<br />
* '''JOINT''' - The point at which a new asphalt mat connects with one previously laid.<br />
* '''LATERAL or TRANSVERSE JOINT''' - A joint perpendicular to the direction of travel (i.e., night joint).<br />
* '''LONGITUDINAL JOINT''' - A joint parallel to the direction of travel (i.e., a joint between two "lanes" or between road and shoulder).<br />
* '''TRANSVERSE JOINT''' - A joint perpendicular to the direction of travel.<br />
* '''JOINT MATCHER''' - See AUTOMATIC LEVEL CONTROL.<br />
* '''LIFT''' - Another term for “mat”, usually used in conjunction with a thickness, such as “a 6 inch (150 mm) mat was laid in [3] 2 inch (50 mm) lifts”.<br />
* '''LINE OF SHEAR''' - The lateral line of contact in the paving material at the leading edge of the screed pre-strike-off where material divides to pass beneath the screed plate or move upward along the face of the screed into the augered material for later placement.<br />
* '''MAT''' - The material being placed by a paver/finisher.<br />
* '''MAT REFERENCE SYSTEM''' - An aluminum beam, supported by a series of spring loaded road wheels, which is towed behind the screed. It is used in conjunction with the Floating Beam to permit taking 50 percent of the longitudinal grade reference from the freshly laid mat and combining it with the average taken from the existing grade to produce the ultimate in a smooth riding surface.<br />
* '''NULL''' - A condition that exists when components are at rest.<br />
* '''“NULLED” SCREED''' - A screed resting flat on the mat and having no angle of attack.<br />
* '''“NULLED” GRADE AND SLOPE SENSOR''' - Sensors that are operating, however, they are transmitting no signal.<br />
* '''PIVOT POINT (of screed)''' - The pin mounting point of the screed frame on the rear of the side arm.<br />
* '''POT HOLES''' - Local base failure causes a pocket that further deteriorates due to containment of water as the surface collapses. Traffic bounces the broken surface out, exposing intermediate and base materials to more moisture and the abrasion of traffic.<br />
* '''PULL POINTS''' - See TOW POINTS.<br />
* '''PUSH ROLLER''' - Rollers mounted at the front of the paver to provide contact area between the paver and the asphalt truck tires.<br />
* '''PRE-STRIKE-OFF SHIELD''' - The vertical plate at the front of the screed that meters material passing beneath the screed.<br />
* '''QUARTER POINTS''' - Points on the screed midway between the center and the ends.<br />
* '''RAVELING''' - Road surface chunks away producing a very rough riding surface. Edges of pavement may completely disintegrate. The causes are usually the same as stripping, but also may include deficient mix design.<br />
* '''RIDEABILITY''' - Perceived smoothness of the finished road surface.<br />
* '''RIPPLES''' - Short frequency changes in the elevation of a mat surface.<br />
* '''RUTS''' - Troughs in the wheel tracks caused by increased compaction and/or stripping due to heavy traffic.<br />
* '''SCREED''' - The assembly towed behind the tractor, that strikes off, smooths and exerts some pre compaction on the paving material being placed.<br />
* '''SCREED EXTENSIONS''' - Attachments for increasing screed width.<br />
* '''SCREED HEATERS (Burners)''' - The devices that preheat the screed plate to a temperature approximately that of the material to be laid.<br />
* '''SCREED PLATE''' - The bottom plate of the screed.<br />
* '''SHOVING BULGE''' - Pavement that has been pushed by braking vehicles or roller.<br />
* '''SLOPE''' - The incline of a paving surface perpendicular to the direction of travel expressed by stating the rise or fall as a percentage of horizontal distance. (Example: 2 percent slope - 2 inches (50 mm) of elevation change in 100 feet (250 mm) of lateral run).<br />
* '''SLOPE CONTROL''' - A means for controlling the transverse elevation of the fresh laid mat in relation to the grade.<br />
* '''SLOPE SENSOR (Inclinometer)''' - An electrical device that detects positive and negative changes in lateral elevation using the grade controlled side of the machine as a reference.<br />
* '''STRIPPING''' - Road surface peels away producing a rough, open texture. It is usually due to debonding between the asphalt and aggregate. The cause may be heavy traffic and moisture, or lack of density (full specification compaction) when placed.<br />
* '''TOW LENGTH''' - The distance from the two point (at the front of the side arm) to the pivot point (of the screed).<br />
* '''TOW POINTS (Pull Points)''' - The points where the side arms of the screed are attached to the tractor unit.<br />
* '''UPHEAVAL''' - Swelling of sub-pavement caused by excessive heat or freezing expansion of trapped water beneath the surface.<br />
* '''VIBRATORS''' - A rotating shaft and eccentric weight assembly mounted on the screed that produces vibration.<br />
* '''WAVE''' - Long repeating changes in the elevation of the mat surface.<br />
<br />
{{top}}<br />
<br />
==[[#MATERIALS|MATERIALS]]==<br />
<br />
It is very important to know what special provisions are contained in the proposal. Mixture types to be used and the sampling and testing procedures vary depending on the specifications used.<br />
<br />
The materials used in the HMA mixtures will be shown on Form 1931 HMA Mix Design ('''''Figure 501-1'''''), and those materials will meet the requirements as specified in Tables [http://mdotcf.state.mi.us/public/specbook/files/2012/501%20Plant%20Mixed%20HMA.pdf 501-1, 501-2] and [http://mdotcf.state.mi.us/public/specbook/files/2012/904%20Asphaltic%20Materials.pdf 904-2] of the Standard Specifications for Construction.<br />
<br />
All mixtures specified for a project must have an approved mixture design before mix production can proceed.<br />
<br />
The Contractor must submit a mixture design to the MDOT Construction Field Services laboratory for approval in accordance with the HMA Production Manual.<br />
<br />
The field application of the applied mix design is called the Job Mix Formula (JMF), ('''''Figure 501-2'''''). Adjustments to the JMF will not be allowed outside the mixture limits shown in Tables [http://mdotcf.state.mi.us/public/specbook/files/2012/501%20Plant%20Mixed%20HMA.pdf 501-1 and 501-2] of the Standard Specifications for Construction.<br />
<br />
[[File:Fig501-1a1.jpg|thumb|center|600px|Figure 501-1a - Form 1931 - HMA Mix Design]]<br />
<br />
[[File:Fig501-1a2.jpg|thumb|center|600px|Figure 501-1a(Cont.) - Form 1931 - HMA Mix Design]]<br />
<br />
[[File:Fig501-1b1.jpg|thumb|center|600px|Figure 501-1b - SUPERPAVE HMA Mix Design]]<br />
<br />
[[File:Fig501-1b2.jpg|thumb|center|600px|Figure 501-1b(Cont.) - SUPERPAVE HMA Mix Design]]<br />
<br />
[[File:Fig 501-2.jpg|thumb|center|600px|Figure 501-2 - Form 1911 - Job Mix Formula (JMF)]]<br />
<br />
{{top}}<br />
<br />
===[[#Hot Mix Plants|Hot Mix Plants]]===<br />
<br />
HMA mixtures being supplied to MDOT projects must be produced at a certified facility. Plants are certified in accordance with the HMA Production Manual. This certification includes the approval of the field laboratory used for acceptance testing, the Contractor’s quality control plans (which should be available at the plant) and other plant operational requirements. The certification is normally completed by the Region Traveling Mixture Inspector (TMI) before the Contractor starts his first project in the spring. Certifications are good for one construction season only.<br />
<br />
The function of the hot mix plant is to heat the aggregates, add the asphalt cement and produce a homogenous asphalt mixture. The aggregate used to make the mix can be a single aggregate, but it is generally different sizes blended together through the cold feed bins to produce proper gradation. Asphalt cement is the material that holds the aggregate together. This material can be “neat”, unmodified or modified with polymers, rubber, latex, etc. These asphalt cements may also contain anti-strip agents.<br />
<br />
There are two basic types of asphalt mixing plants. The majority of plants used are known as drum mix plants; the other, less frequently used type, is a batch plant. The batch plant consists of the cold feed system, individual bins that hold and feed the aggregate to the drum dryer ('''''Figure 501 3'''''). This dryer heats the aggregate to the desired temperature and delivers the material to the hot bins in the tower unit. Aggregate is generally sized by means of a screen deck into two to four of these hot bins. The aggregates are then proportioned by weight into the mixer, also called the pug mill. After a short mixing process, the asphalt cement is added and the entire mixture is mixed for 30 to 45 seconds. The mix is then dumped into a truck, or transferred to a hot storage silo to be loaded into a truck later.<br />
<br />
Drum mixers come in many different types, such as parallel flow, counter flow, double barrel, drum-within-a-drum and drums with separate mixing chambers ('''''Figure 501-4'''''). Most drum mixer plants heat the aggregate, add the asphalt cement and recycled asphalt pavement (RAP), if used, and mix all the ingredients in the same drum. The other type adds the asphalt cement and RAP in a separate mixing chamber out of direct contact with the burner flame. No matter what type of plant is being used, several key items should be monitored.<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Hot Mix Plant Inspection'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
The aggregate stockpiles should be built on a clean, dry and stable foundation, with positive drainage. The stockpiles shall be large enough to supply a project continuously and consistently.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
Aggregate of different sizes should be stockpiled separate from one another.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
When using drum mix plants, the aggregate moisture content of each stockpile should be taken at least once a day and the number entered into the plant control system. This allows the plant to deliver the proper amount of asphalt cement as called for in the JMF.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
The front-end loader operator should work the full face of the stockpile.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
A scalping screen should be placed in the aggregate cold feed charging system and the RAP feed system to remove any oversize material.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
The weigh bridges on the cold feed and RAP charging conveyors must be calibrated.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
The asphalt cement in the storage tanks should be kept at a constant temperature, normally between 275°F and 311°F . The asphalt tanks and all hot asphalt lines should be insulated.<br />
|-<br />
|<br />
<center>8</center><br />
|<br />
The asphalt cement delivery system must be calibrated.<br />
|-<br />
|<br />
<center>9</center><br />
|<br />
Visible light blue emissions from the stack may indicate that the temperature of the gases inside the drum is too high and may be causing damage to the asphalt cement.<br />
|-<br />
|<br />
<center>10</center><br />
|<br />
The trucks should not be loaded by slowly driving forward while the mix is being delivered from the silo. Multiple drops of the mix are necessary.<br />
|}<br />
<br />
[[file:fig501-3.jpg|thumb|center|600px|Figure 501-3 - Typical Batch Plant]]<br />
<br />
[[file:fig501-4.jpg|thumb|center|600px|Figure 501-4 - Typical Drum Plant]]<br />
<br />
{{top}}<br />
<br />
===[[#Plant Procedures|Plant Procedures]]===<br />
<br />
Every HMA paving project must have an approved mix design for each mixture used on the project. The design may have been approved for another project; however, a JMF must be prepared for each mixture used on the project. The JMF is prepared and signed by the TMI. After production begins, the Contractor may ask for JMF adjustments. These adjustments may be allowed if there is reason for the request and as long as the resulting mixture meets the specifications for the project.<br />
<br />
It is the Contractor’s responsibility to provide quality control necessary to produce the mixture uniformly, within the limits specified in 12SP501(U) Superpave Hot Mix Asphalt Percent Within Limits (PWL) or 12SP501(V) Superpave Hot Mix Asphalt Percent Within Limits (PWL) For Capital Preventive Maintenance (CPM) Mill & Resurface Projects and CPM One Course Overlay Projects. It is MDOT’s responsibility to conduct quality assurance and verification sampling and testing to ensure conformity of the mix to 12SP501(U) Superpave Hot Mix Asphalt Percent Within Limits (PWL) or 12SP501(V) Superpave Hot Mix Asphalt Percent Within Limits (PWL) For Capital Preventive Maintenance (CPM) Mill & Resurface Projects and CPM One Course Overlay Projects.This testing is done at the field laboratory provided by the Contractor located at the asphalt plant or at an MDOT Region Lab.<br />
<br />
The MDOT plant inspector should follow the sampling and testing procedures explained in the Special Provision 12SP501(U) Superpave Hot Mix Asphalt Percent Within Limits (PWL) or 12SP501(V) Superpave Hot Mix Asphalt Percent Within Limits (PWL) For Capital Preventive Maintenance (CPM) Mill & Resurface Projects and CPM One Course Overlay Projects. It can also be provided by the TMI.<br />
<br />
The inspector will witness the Contractor taking the daily asphalt binder sample and submit to the Construction Field Services laboratory for binder certification verification testing.<br />
<br />
{{top}}<br />
<br />
===[[#Note|Note]]===<br />
<br />
HMA types will be as specified on the plans or in the proposal.<br />
<br />
Bond coat, also referred to as tack coat, is an asphalt emulsion. This is a certified product and the suppliers must be on the Certified Products List.<br />
<br />
{{top}}<br />
<br />
==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
<br />
{{#ev:youtube|2N2tE_ZOFPo|350|right|Safety Edges}}<br />
<br />
The Contractor must provide all equipment required to prepare the base and place the HMA in accordance with the plans and specifications. This equipment must be safe, environmentally acceptable and capable of producing a specification product. The typical equipment used:<br />
<br />
{| class="wikitable"<br />
|-<br />
!<br />
<center>'''Equipment'''</center><br />
!<br />
<center>'''Used For'''</center><br />
|-<br />
|<br />
Cold-milling machine<br />
|<br />
Used to remove old pavement.<br />
|-<br />
|<br />
Pressure distributor<br />
|<br />
Used for applying the bond coat.<br />
|-<br />
|<br />
HMA paver<br />
|<br />
Used for placing and spreading the HMA.<br />
|-<br />
|<br />
Rollers<br />
|<br />
Used for compacting the HMA pavement.<br />
|-<br />
|<br />
Hauling units, Trucks<br />
|<br />
Used for hauling the mix from the plant.<br />
|-<br />
|<br />
Sweepers<br />
|<br />
Used for cleaning the old surface to be paved.<br />
|-<br />
|<br />
Misc. equipment<br />
|<br />
Hand tools, level, straightedge and boards.<br />
|}<br />
<br />
This equipment should be thoroughly checked before using it on the project. The inspector may use the following checklist to record the condition of equipment. This checklist may be placed in the project files.<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="4" |<br />
'''Paver Checklist'''<br />
|-<br />
!<br />
<br />
<br />
<br />
!<br />
Yes<br />
!<br />
No<br />
!<br />
Remarks<br />
|-<br />
|<br />
Is the automation operating properly?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Is the auger control operating properly?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are the vibrators on the screed operating properly?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Does the paver have reverse pitch augers or paddles at center of paver?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Do extensions have proper vibratory action?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Does paver have properly working screed heaters?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Do extensions have approved method of heating?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Is automation ski in good condition?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Is the automation ski of proper length 30 feet +/- for all courses except last pass top course?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
10 feet +/- for last pass top course?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Does the paver have two operating warning lights?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="4" |<br />
''' Roller Checklist - Manufacturer and Roller Number -______________________________________ '''<br />
|-<br />
!<br />
<br />
<br />
<br />
<br />
!<br />
Yes<br />
!<br />
No<br />
!<br />
Remarks<br />
|-<br />
|<br />
Does the Contractor have proper number of rollers?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are the rollers of proper size?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are the rollers free from backlash?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Do the rollers steer properly?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are the king bolts in good condition on steel wheeled rollers?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are the water sprinklers in good operating condition?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are the mats or wheel scrapers in good operating condition?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Are roller wheels free of openings or projections?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Do vibratory rollers have automatic shutoff when speed is less than .5 mph?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Can VPM be locked in on vibratory rollers?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Can speed be locked in on vibratory rollers?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Do pneumatic rollers have a min. of seven wheels?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Is tire pressure as specified?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|-<br />
|<br />
Do the rollers have an operating warning light?<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|<br />
<br />
<br />
<br />
<br />
|}<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="4" |<br />
'''Distributor Checklist - Manufacturer and Distributor Number -______________________________'''<br />
|-<br />
!<br />
<center></center><br />
!<br />
<center>Yes</center><br />
!<br />
<center>No</center><br />
!<br />
<center>Remarks</center><br />
|-<br />
|<br />
Is distributor mounted on proper vehicle?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is vehicle tachometer working properly?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is distributor tachometer working properly?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Does the distributor have a capacity of at least 800&nbsp;gallons (3,000 liters)?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are flasher lights working properly?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are circulating systems working properly?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is heating system in good working condition?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is thermometer in tank working properly?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is tank clean?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is spray bar clean?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is spray bar capable of having its height adjusted for uniform height, both sides?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are nozzles proper size?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are nozzles clean?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Is hand spray working properly?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are fluid connections free of leaks?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are nozzles set at proper angles<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|-<br />
|<br />
Are guards placed on end of spray bar to protect over spray where necessary?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|}<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="4" |<br />
<center>'''Truck Checklist'''</center><br />
|-<br />
!<br />
<center></center><br />
!<br />
<center>Yes</center><br />
!<br />
<center>No</center><br />
!<br />
<center>Remarks</center><br />
|-<br />
|<br />
Do all trucks have working backup warning systems?<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|<br />
<br />
<br />
|}<br />
<br />
{{top}}<br />
<br />
====[[#Cold-Milling Machine|Cold-Milling Machine]]====<br />
<br />
Cold-milling machines shall be equipped with an automatically controlled and activated cutting drum that is capable of grade reference, maintaining transverse slope control and producing a uniformly textured surface. An approved grade referencing attachment, not less than 30 feet in length, may be used. This equipment must be capable of accurately removing the pavement surface, in one or more passes, to the required grade or cross section.<br />
<br />
{{top}}<br />
<br />
====[[#Hauling Units|Hauling Units]]====<br />
<br />
<br />
<div style="float: right; padding-left: 10px;"><br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Tarpaulin Requirements'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
Water repellent.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
Of sufficient weight and strength to resist tearing.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
Be in good condition with no holes or tears.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
Large enough to cover the top of the load and extend over sides and tailgate.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
Enough tie-down points to secure properly and prevent flapping.<br />
|}<br />
</div><br />
<br />
The hauling unit must be capable of completely protecting the mixture from the weather and ensuring that the mixture temperature is maintained during the hauling time. A release agent may be applied to the surfaces of the truck or trailer bed. Fuel oil is not to be used as a release agent.<br />
<br />
Two types of trucks are generally employed to transport the mixture: end dump and rear discharge. These trucks are loaded in the same manner directly from the silo at the plant. If temperatures warrant, the sides and bottom of the truck bed should be insulated. The insulation should be tight against the body of the bed; there should be no gaps between the side of the truck and the insulation through which air could move.<br />
<br />
Every haul truck should be equipped with a tarpaulin, which can be employed as needed to protect the mix in case of inclement weather.<br />
<br />
<br />
<br />
<br />
{{top}}<br />
<br />
====[[#Pressure Distributor|Pressure Distributor]]====<br />
<br />
Pressure distributors are used to apply a uniform application of the asphalt emulsions, normally referred to as the tack or bond coat. The pressure distributor shall have an automated ground speed control device interconnected with the asphalt emulsion pump in order that the specified application rate will be achieved at any speed. It shall be capable of maintaining the asphalt emulsion at the specified temperature. The spray bar nozzles shall produce a uniform fan spray, and the shutoff shall be instantaneous, with no dripping. Each pressure distributor shall be capable of maintaining the specified application rate within +/- 0.015 gallons/square yard for each load.<br />
<br />
{{top}}<br />
<br />
====[[#Paver|Paver]]====<br />
<br />
Pavers spread the hot mix asphalt to the desired width and thickness and produce a smooth, uniform mat texture. The paver consists of two primary parts, the tractor unit and the screed unit.<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig502-1.jpg|thumb|center|600px|Figure 502-1 - Paver Tractor Unit]]</div><br />
<br />
The tractor unit provides the motive power to the paver and to transfer the mixture from the receiving hopper on the front of the paver to the spreading augers at the back of the paver. The second unit is the paver screed. This leveling device is attached to the tractor unit at only one point on each side of the paver; it is able to float on the asphalt mixture and to provide initial mat texture and compaction to the material as it passes under it.<br />
<br />
The tractor unit receives the asphalt mixture from the haul trucks, carries that mixture back to the spreading augers, distributes the mixture across the width of the screed and pulls the screed over that mixture. The tractor unit is powered by its own engine and provides the power to move the paver forward, either on rubber tires, or crawler tracks. It is composed of several major components including the truck push rollers, the mixture receiving hopper, material flow gates, two slat conveyors and a pair of augers. See '''''Figure 502-1'''''.<br />
<br />
The paver screed is a leveling device attached to the tractor unit at only one point on each side of the paver; it is able to float on the asphalt mixture and to provide initial mat texture and compaction to the material as it passes over it.<br />
<br />
<br />
<br />
<br />
<br />
<br />
{{top}}<br />
<br />
====[[#Push Rollers|Push Rollers]]====<br />
<br />
The truck push rollers, located on the front of the paver hopper, are used to maintain contact with the tires of the truck and to push the truck ahead of the paver. The rollers must be clean and free to rotate to allow smooth forward travel of the paver. If the push rollers are not cleaned periodically and do not rotate freely, the truck tires will slide on the rollers and increase the load on the paver.<br />
<br />
Moreover, if one roller rotates freely and the other does not, the paver may tend to change direction. Many pavers are equipped with a truck hitch that is located beside the push rollers. This hitch acts to keep the truck in contact with the paver to prevent the truck driver from inadvertently pulling away from the paver and dumping mix on the pavement in front of the paver. The hitch is controlled by the paver operator. Once the truck bed has been emptied of mix, the truck hitch is withdrawn and the truck is able to pull away from the paver.<br />
<br />
{{top}}<br />
<br />
====[[#Paver Hopper|Paver Hopper]]====<br />
<br />
The paver hopper is used to receive and temporarily hold the mixture from the trucks. The front of the hopper must be constructed in a way to minimize the spillage of mix from the hopper. The sides, or wings, of the hopper are movable. Mixture, if left to stand for a long time in the corners of the hopper, will cool. To minimize mat problems, the paver operator should dump the wings as little as possible. The paver hopper must be at least half full at the time the wings are dumped. The slat conveyors in the bottom of the hopper should not be visible when the wings are emptied. Keeping the hopper at least half full between truckloads of mix keeps the head of mix in front of the screed constant and this will reduce mat problems.<br />
<br />
{{top}}<br />
<br />
====[[#Slat Conveyor|Slat Conveyor]]====<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig502-2.jpg|thumb|center|500px|Figure 502-2 - Slat Conveyors]]</div><br />
At the bottom of the paver hopper is a set of slat conveyors. These devices are used to carry the mixture from the hopper through the paver tunnel to the back of the paver and the spreading augers. The slat conveyor on one side operates independently from the movement of the other side. Thus, the amount of mixture that can be carried back to the augers on one side can be different from the other side. This allows the paver operator to feed more or less mixture to either side of the paver. This is helpful at lane tapers, crown corrections, or in areas of wedging. '''''See Figure 502-2'''''.<br />
<br />
{{top}}<br />
<br />
====[[#Flow Gates|Flow Gates]]====<br />
<br />
At the back of the paver hopper, and over each slat conveyor, is a set of gates. These gates are used to regulate the amount of mix that can be delivered by the slat conveyors to the augers. The gates move vertically, either manually or mechanically. Depending upon the gate settings, more or less mixture is permitted to enter the tunnel. The flow gates should be adjusted to provide a uniform head of material in front of the screed. See '''''Figure 502-2'''''.<br />
<br />
{{top}}<br />
<br />
====[[#Augers|Augers]]====<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:fig502-3.jpg|thumb|center|600px|Figure 502-3 - Example of Automatic Feed Control Sensor]]</div><br />
<br />
The mix that is carried to the back of the tractor unit by the slat conveyors is deposited in front of the augers. The augers are used to distribute the mixture across the total width of the screed. The auger on each side of the paver is operated independently of the other. The auger and the slat conveyor on the same side must be operated together. At the junction of the two augers in the center of the paver, adjacent to the auger gear box, there should be a reversed pitch auger, or paddle, to tuck the mixture under the gear box and assure that the mixture at this location is the same as that across the rest of the screed. It is important that the augers carry a consistent amount of mix across the front of the screed so that the pressure on the screed is kept as constant as possible.<br />
<br />
All pavers are equipped with an automatic feed system that, when properly adjusted, supplies mixture to the paver screed to maintain a uniform head of material. For this system, a feed control sensor is used to determine the amount of mix in the auger chamber. If the volume of the mix in front of the screed falls below the desired amount, the feed sensor will engage the slat conveyors and auger system, pulling more mix back to the screed area. See '''''Figure 502-3'''''.<br />
<br />
If the feed system is set and operating properly, the slat conveyors on each side of the paver will rarely shut off. This continuous action of the slat conveyors and augers is accomplished by setting the proper position for the hopper flow gates and determining the correct speed setting for the slat conveyors and augers. Intermittent operation of the slat conveyors and auger system could cause both auger shadows and ripples in the mat behind the screed.<br />
<br />
{{top}}<br />
<br />
====[[#Screed Unit|Screed Unit]]====<br />
<br />
The screed unit, which is towed by the tractor unit, establishes the thickness of the asphalt layer and provides the initial mat texture. In addition, the screed imparts a level of compaction with the vibratory action of the screed. The screed is attached to the tractor unit at only one point on each side of the paver. This point is called the tow or pull point. This floating screed principle is employed on all modern pavers in use today.<br />
<br />
This principle allows the paver screed to average out changes in grade that are experienced by the tractor wheelbase. For the floating screed principle to work properly, it is important that the pull points on both sides of the tractor be at the same level above the ground.<br />
<br />
The combination of the screed pull point at the end of the leveling arm and the thickness control device at the screed provides for adjustments to be made to the angle of attack of the screed. See '''''Figure 502-4'''''.<br />
<br />
<center>''F1 - Angle of Attack''<br />
<br />
''F2 - Head of Material''<br />
<br />
''F3 - Paving Speed''</center><br />
[[File:Fig502-4.jpg|thumb|center|600px|Figure 502-4 - Paver Screed]]<br />
<br />
The screed is continually attempting to keep in balance all the forces acting on it. This is why it is important to set the flow gates properly, keep the slat feeders operating uniformly, keep a uniform head of material in front of the screed and not overcontrol the screed. The temperature of the mix must be kept uniform so that the viscosity of the mix does not change and influence the balance of forces acting on the screed. When a change in one force occurs, the screed will rise or fall and will change the thickness of the mat being placed.<br />
<br />
The screed should be raised and the bottom surface checked for smoothness, twisting, and excessive wear. Screed plates first wear out about four to six inches from the trailing edge.<br />
<br />
{{top}}<br />
<br />
====[[#Paver Speed|Paver Speed]]====<br />
<br />
The speed of the paver should be adjusted to give a uniform texture and coordinate satisfactorily with the rate of delivery of the mixture to the paver to provide a uniform placement rate, without intermittent operation of the paver. Paver speed is a large contributor to the smoothness of the ride on a finished pavement. Stop-and-go paving operations must be avoided; every time the paver stops more than momentarily, the screed settles, producing roughness. See '''''Figure 502-5''''' for paver speed based on yield and plant production rates.<br />
<br />
The paver speed has a major effect on the forces acting on the screed. It is good practice to keep the speed of the paver as constant as possible during the paving operations. When changing trucks, it would be best if the transfer could be done without slowing or stopping the paver. At relatively slow paving speeds, it might be possible to make the truck exchange while keeping the head of material constant. This requires the level of mix in the hopper to be kept at least even with the bottom of the flow gates. If the normal paving speed is fast, or the truck exchange is slow, it will be better to stop the paver when the transfer of trucks occurs. When one truck is emptied, it should pull away from the paver. The paver should be brought from paving speed to a stop as quickly and as smoothly as possible without jerking the paver. The next truck should then be backed toward the paver, stopping short of the paver. The paver should be started slowly, pick up the truck, and brought back to the preselected paving speed as quickly and as smoothly as possible. This procedure will minimize the change in forces acting on the screed and will result in a near-constant mat thickness.<br />
<br />
Paver speed for various production and application rates can be calculated using the following equations or selected from '''''Figure 502-5'''''.<br />
<br />
::'''V = [(Rp)(L)]/60'''<br />
<br />
::'''L = 2000/9WA'''<br />
<br />
:::where:<br />
<br />
::'''V''' = paver speed (feet/minute)<br />
<br />
::'''Rp''' = plant production rate (ton/hour)<br />
<br />
::'''L''' = length of pavement (feet) placed per ton of mix<br />
<br />
::'''60''' = converts from hours to minutes<br />
<br />
::'''W''' = width of pavement (feet)<br />
<br />
::'''A''' = application rate or yield (pounds/square yards)<br />
<br />
::2000 = converts from tons to pounds<br />
<br />
::9 = converts from feet to square yards<br />
<br />
<br />
:'''Example -'''<br />
<br />
::Given: <br />
<br />
:::Application Rate (A) = 165 pounds/square yards<br />
<br />
:::Width of Pavement (W) = 11 feet<br />
<br />
:::Plant Production Rate (Rp) = 300 ton/hour<br />
<br />
::Find: Paver Speed (V)<br />
<br />
::First find the length of 11 foot (3.35 m) width pavement that can be placed per ton of mix.<br />
<br />
:::L = 2000/9WA = 2000/[9(11)(165)] = 10 feet/ton of mix<br />
<br />
::Next calculate the paver speed.<br />
<br />
:::V = RpL/60 = [(300 ton/hr)(10 ft/ton)] / 60 min/hr = 50 ft/min<br />
<br />
----<br />
{| class="wikitable"<br />
|-<br />
! colspan="16" |<br />
Figure 502-5 - Paver Speed<br />
<br />
PLANT PRODUCTION (TONS PER HOUR) YIELD IS POUNDS PER SQUARE YARD<br />
|-<br />
|<br />
<center></center><br />
|<br />
<center>100</center><br />
|<br />
<center>125</center><br />
|<br />
<center>150</center><br />
|<br />
<center>175</center><br />
|<br />
<center>200</center><br />
|<br />
<center>225</center><br />
|<br />
<center>250</center><br />
|<br />
<center>275</center><br />
|<br />
<center>300</center><br />
|<br />
<center>325</center><br />
|<br />
<center>350</center><br />
|<br />
<center>375</center><br />
|<br />
<center>400</center><br />
|<br />
<center>425</center><br />
|<br />
<center>450</center><br />
|-<br />
|<br />
<center>100</center><br />
|<br />
<center>27</center><br />
|<br />
<center>34</center><br />
|<br />
<center>41</center><br />
|<br />
<center>48</center><br />
|<br />
<center>55</center><br />
|<br />
<center>62</center><br />
|<br />
<center>69</center><br />
|<br />
<center>76</center><br />
|<br />
<center>83</center><br />
|<br />
<center>90</center><br />
|<br />
<center>97</center><br />
|<br />
<center>104</center><br />
|<br />
<center>111</center><br />
|<br />
<center>116</center><br />
|<br />
<center>125</center><br />
|-<br />
|<br />
<center>110</center><br />
|<br />
<center>25</center><br />
|<br />
<center>30</center><br />
|<br />
<center>37</center><br />
|<br />
<center>43</center><br />
|<br />
<center>50</center><br />
|<br />
<center>56</center><br />
|<br />
<center>62</center><br />
|<br />
<center>68</center><br />
|<br />
<center>75</center><br />
|<br />
<center>81</center><br />
|<br />
<center>87</center><br />
|<br />
<center>93</center><br />
|<br />
<center>99</center><br />
|<br />
<center>100</center><br />
|<br />
<center>112</center><br />
|-<br />
|<br />
<center>120</center><br />
|<br />
<center>23</center><br />
|<br />
<center>29</center><br />
|<br />
<center>34</center><br />
|<br />
<center>40</center><br />
|<br />
<center>45</center><br />
|<br />
<center>51</center><br />
|<br />
<center>57</center><br />
|<br />
<center>62</center><br />
|<br />
<center>68</center><br />
|<br />
<center>73</center><br />
|<br />
<center>79</center><br />
|<br />
<center>85</center><br />
|<br />
<center>91</center><br />
|<br />
<center>96</center><br />
|<br />
<center>102</center><br />
|-<br />
|<br />
<center>130</center><br />
|<br />
<center>21</center><br />
|<br />
<center>26</center><br />
|<br />
<center>31</center><br />
|<br />
<center>36</center><br />
|<br />
<center>42</center><br />
|<br />
<center>47</center><br />
|<br />
<center>53</center><br />
|<br />
<center>58</center><br />
|<br />
<center>63</center><br />
|<br />
<center>68</center><br />
|<br />
<center>74</center><br />
|<br />
<center>79</center><br />
|<br />
<center>84</center><br />
|<br />
<center>89</center><br />
|<br />
<center>95</center><br />
|-<br />
|<br />
<center>140</center><br />
|<br />
<center>19</center><br />
|<br />
<center>24</center><br />
|<br />
<center>29</center><br />
|<br />
<center>34</center><br />
|<br />
<center>39</center><br />
|<br />
<center>44</center><br />
|<br />
<center>49</center><br />
|<br />
<center>54</center><br />
|<br />
<center>59</center><br />
|<br />
<center>64</center><br />
|<br />
<center>69</center><br />
|<br />
<center>74</center><br />
|<br />
<center>79</center><br />
|<br />
<center>84</center><br />
|<br />
<center>89</center><br />
|-<br />
|<br />
<center>150</center><br />
|<br />
<center>18</center><br />
|<br />
<center>23</center><br />
|<br />
<center>27</center><br />
|<br />
<center>31</center><br />
|<br />
<center>36</center><br />
|<br />
<center>40</center><br />
|<br />
<center>45</center><br />
|<br />
<center>50</center><br />
|<br />
<center>55</center><br />
|<br />
<center>59</center><br />
|<br />
<center>64</center><br />
|<br />
<center>68</center><br />
|<br />
<center>73</center><br />
|<br />
<center>78</center><br />
|<br />
<center>82</center><br />
|-<br />
|<br />
<center>160</center><br />
|<br />
<center>17</center><br />
|<br />
<center>22</center><br />
|<br />
<center>26</center><br />
|<br />
<center>30</center><br />
|<br />
<center>34</center><br />
|<br />
<center>38</center><br />
|<br />
<center>43</center><br />
|<br />
<center>47</center><br />
|<br />
<center>51</center><br />
|<br />
<center>55</center><br />
|<br />
<center>60</center><br />
|<br />
<center>64</center><br />
|<br />
<center>68</center><br />
|<br />
<center>72</center><br />
|<br />
<center>77</center><br />
|-<br />
|<br />
<center>170</center><br />
|<br />
<center>16</center><br />
|<br />
<center>20</center><br />
|<br />
<center>24</center><br />
|<br />
<center>28</center><br />
|<br />
<center>32</center><br />
|<br />
<center>36</center><br />
|<br />
<center>40</center><br />
|<br />
<center>44</center><br />
|<br />
<center>48</center><br />
|<br />
<center>52</center><br />
|<br />
<center>56</center><br />
|<br />
<center>60</center><br />
|<br />
<center>64</center><br />
|<br />
<center>68</center><br />
|<br />
<center>72</center><br />
|-<br />
|<br />
<center>180</center><br />
|<br />
<center>15</center><br />
|<br />
<center>19</center><br />
|<br />
<center>23</center><br />
|<br />
<center>26</center><br />
|<br />
<center>30</center><br />
|<br />
<center>34</center><br />
|<br />
<center>38</center><br />
|<br />
<center>42</center><br />
|<br />
<center>46</center><br />
|<br />
<center>50</center><br />
|<br />
<center>53</center><br />
|<br />
<center>57</center><br />
|<br />
<center>61</center><br />
|<br />
<center>64</center><br />
|<br />
<center>68</center><br />
|-<br />
|<br />
<center>190</center><br />
|<br />
<center>14</center><br />
|<br />
<center>18</center><br />
|<br />
<center>22</center><br />
|<br />
<center>25</center><br />
|<br />
<center>29</center><br />
|<br />
<center>32</center><br />
|<br />
<center>36</center><br />
|<br />
<center>39</center><br />
|<br />
<center>43</center><br />
|<br />
<center>46</center><br />
|<br />
<center>50</center><br />
|<br />
<center>53</center><br />
|<br />
<center>57</center><br />
|<br />
<center>61</center><br />
|<br />
<center>65</center><br />
|-<br />
|<br />
<center>200</center><br />
|<br />
<center>14</center><br />
|<br />
<center>17</center><br />
|<br />
<center>20</center><br />
|<br />
<center>24</center><br />
|<br />
<center>27</center><br />
|<br />
<center>30</center><br />
|<br />
<center>34</center><br />
|<br />
<center>37</center><br />
|<br />
<center>41</center><br />
|<br />
<center>45</center><br />
|<br />
<center>49</center><br />
|<br />
<center>52</center><br />
|<br />
<center>55</center><br />
|<br />
<center>58</center><br />
|<br />
<center>62</center><br />
|-<br />
|<br />
<center>210</center><br />
|<br />
<center>13</center><br />
|<br />
<center>16</center><br />
|<br />
<center>19</center><br />
|<br />
<center>22</center><br />
|<br />
<center>26</center><br />
|<br />
<center>29</center><br />
|<br />
<center>33</center><br />
|<br />
<center>36</center><br />
|<br />
<center>39</center><br />
|<br />
<center>42</center><br />
|<br />
<center>46</center><br />
|<br />
<center>49</center><br />
|<br />
<center>52</center><br />
|<br />
<center>55</center><br />
|<br />
<center>59</center><br />
|-<br />
|<br />
<center>220</center><br />
|<br />
<center>12</center><br />
|<br />
<center>15</center><br />
|<br />
<center>18</center><br />
|<br />
<center>21</center><br />
|<br />
<center>24</center><br />
|<br />
<center>27</center><br />
|<br />
<center>31</center><br />
|<br />
<center>34</center><br />
|<br />
<center>37</center><br />
|<br />
<center>40</center><br />
|<br />
<center>43</center><br />
|<br />
<center>46</center><br />
|<br />
<center>49</center><br />
|<br />
<center>52</center><br />
|<br />
<center>55</center><br />
|-<br />
! colspan="16" |<br />
<center>'''COMPUTED PAVER SPEEDS IN FEET PER MINUTE FOR 11 FOOT WIDTH'''</center><br />
|}<br />
<br />
{| class="wikitable"<br />
|-<br />
|<br />
<center></center><br />
|<br />
<center>100</center><br />
|<br />
<center>125</center><br />
|<br />
<center>150</center><br />
|<br />
<center>175</center><br />
|<br />
<center>200</center><br />
|<br />
<center>225</center><br />
|<br />
<center>250</center><br />
|<br />
<center>275</center><br />
|<br />
<center>300</center><br />
|<br />
<center>325</center><br />
|<br />
<center>350</center><br />
|<br />
<center>375</center><br />
|<br />
<center>400</center><br />
|<br />
<center>425</center><br />
|<br />
<center>450</center><br />
|-<br />
|<br />
<center>100</center><br />
|<br />
<center>25</center><br />
|<br />
<center>32</center><br />
|<br />
<center>28</center><br />
|<br />
<center>44</center><br />
|<br />
<center>50</center><br />
|<br />
<center>57</center><br />
|<br />
<center>63</center><br />
|<br />
<center>69</center><br />
|<br />
<center>75</center><br />
|<br />
<center>82</center><br />
|<br />
<center>88</center><br />
|<br />
<center>94</center><br />
|<br />
<center>100</center><br />
|<br />
<center>107</center><br />
|<br />
<center>113</center><br />
|-<br />
|<br />
<center>110</center><br />
|<br />
<center>23</center><br />
|<br />
<center>28</center><br />
|<br />
<center>34</center><br />
|<br />
<center>40</center><br />
|<br />
<center>45</center><br />
|<br />
<center>50</center><br />
|<br />
<center>56</center><br />
|<br />
<center>61</center><br />
|<br />
<center>67</center><br />
|<br />
<center>72</center><br />
|<br />
<center>78</center><br />
|<br />
<center>83</center><br />
|<br />
<center>89</center><br />
|<br />
<center>94</center><br />
|<br />
<center>100</center><br />
|-<br />
|<br />
<center>120</center><br />
|<br />
<center>21</center><br />
|<br />
<center>26</center><br />
|<br />
<center>31</center><br />
|<br />
<center>37</center><br />
|<br />
<center>42</center><br />
|<br />
<center>47</center><br />
|<br />
<center>52</center><br />
|<br />
<center>58</center><br />
|<br />
<center>63</center><br />
|<br />
<center>68</center><br />
|<br />
<center>73</center><br />
|<br />
<center>79</center><br />
|<br />
<center>84</center><br />
|<br />
<center>89</center><br />
|<br />
<center>94</center><br />
|-<br />
|<br />
<center>130</center><br />
|<br />
<center>19</center><br />
|<br />
<center>24</center><br />
|<br />
<center>29</center><br />
|<br />
<center>35</center><br />
|<br />
<center>38</center><br />
|<br />
<center>43</center><br />
|<br />
<center>48</center><br />
|<br />
<center>52</center><br />
|<br />
<center>57</center><br />
|<br />
<center>62</center><br />
|<br />
<center>67</center><br />
|<br />
<center>71</center><br />
|<br />
<center>76</center><br />
|<br />
<center>81</center><br />
|<br />
<center>86</center><br />
|-<br />
|<br />
<center>140</center><br />
|<br />
<center>18</center><br />
|<br />
<center>22</center><br />
|<br />
<center>27</center><br />
|<br />
<center>33</center><br />
|<br />
<center>36</center><br />
|<br />
<center>41</center><br />
|<br />
<center>45</center><br />
|<br />
<center>49</center><br />
|<br />
<center>54</center><br />
|<br />
<center>59</center><br />
|<br />
<center>63</center><br />
|<br />
<center>68</center><br />
|<br />
<center>72</center><br />
|<br />
<center>76</center><br />
|<br />
<center>81</center><br />
|-<br />
|<br />
<center>150</center><br />
|<br />
<center>17</center><br />
|<br />
<center>21</center><br />
|<br />
<center>25</center><br />
|<br />
<center>30</center><br />
|<br />
<center>34</center><br />
|<br />
<center>38</center><br />
|<br />
<center>42</center><br />
|<br />
<center>47</center><br />
|<br />
<center>51</center><br />
|<br />
<center>55</center><br />
|<br />
<center>59</center><br />
|<br />
<center>64</center><br />
|<br />
<center>68</center><br />
|<br />
<center>72</center><br />
|<br />
<center>76</center><br />
|-<br />
|<br />
<center>160</center><br />
|<br />
<center>16</center><br />
|<br />
<center>20</center><br />
|<br />
<center>23</center><br />
|<br />
<center>27</center><br />
|<br />
<center>31</center><br />
|<br />
<center>34</center><br />
|<br />
<center>38</center><br />
|<br />
<center>42</center><br />
|<br />
<center>46</center><br />
|<br />
<center>49</center><br />
|<br />
<center>53</center><br />
|<br />
<center>57</center><br />
|<br />
<center>61</center><br />
|<br />
<center>65</center><br />
|<br />
<center>68</center><br />
|-<br />
|<br />
<center>170</center><br />
|<br />
<center>15</center><br />
|<br />
<center>18</center><br />
|<br />
<center>22</center><br />
|<br />
<center>26</center><br />
|<br />
<center>29</center><br />
|<br />
<center>32</center><br />
|<br />
<center>36</center><br />
|<br />
<center>40</center><br />
|<br />
<center>43</center><br />
|<br />
<center>46</center><br />
|<br />
<center>50</center><br />
|<br />
<center>54</center><br />
|<br />
<center>57</center><br />
|<br />
<center>60</center><br />
|<br />
<center>64</center><br />
|-<br />
|<br />
<center>180</center><br />
|<br />
<center>14</center><br />
|<br />
<center>17</center><br />
|<br />
<center>21</center><br />
|<br />
<center>25</center><br />
|<br />
<center>28</center><br />
|<br />
<center>31</center><br />
|<br />
<center>35</center><br />
|<br />
<center>39</center><br />
|<br />
<center>42</center><br />
|<br />
<center>45</center><br />
|<br />
<center>49</center><br />
|<br />
<center>53</center><br />
|<br />
<center>56</center><br />
|<br />
<center>59</center><br />
|<br />
<center>63</center><br />
|-<br />
|<br />
<center>190</center><br />
|<br />
<center>13</center><br />
|<br />
<center>17</center><br />
|<br />
<center>20</center><br />
|<br />
<center>23</center><br />
|<br />
<center>26</center><br />
|<br />
<center>30</center><br />
|<br />
<center>33</center><br />
|<br />
<center>36</center><br />
|<br />
<center>39</center><br />
|<br />
<center>43</center><br />
|<br />
<center>46</center><br />
|<br />
<center>49</center><br />
|<br />
<center>52</center><br />
|<br />
<center>56</center><br />
|<br />
<center>59</center><br />
|-<br />
|<br />
<center>200</center><br />
|<br />
<center>13</center><br />
|<br />
<center>16</center><br />
|<br />
<center>19</center><br />
|<br />
<center>22</center><br />
|<br />
<center>25</center><br />
|<br />
<center>28</center><br />
|<br />
<center>31</center><br />
|<br />
<center>34</center><br />
|<br />
<center>37</center><br />
|<br />
<center>40</center><br />
|<br />
<center>43</center><br />
|<br />
<center>46</center><br />
|<br />
<center>49</center><br />
|<br />
<center>52</center><br />
|<br />
<center>55</center><br />
|-<br />
|<br />
<center>210</center><br />
|<br />
<center>12</center><br />
|<br />
<center>15</center><br />
|<br />
<center>18</center><br />
|<br />
<center>21</center><br />
|<br />
<center>24</center><br />
|<br />
<center>27</center><br />
|<br />
<center>30</center><br />
|<br />
<center>33</center><br />
|<br />
<center>36</center><br />
|<br />
<center>39</center><br />
|<br />
<center>42</center><br />
|<br />
<center>45</center><br />
|<br />
<center>48</center><br />
|<br />
<center>51</center><br />
|<br />
<center>54</center><br />
|-<br />
|<br />
<center>220</center><br />
|<br />
<center>11</center><br />
|<br />
<center>14</center><br />
|<br />
<center>17</center><br />
|<br />
<center>20</center><br />
|<br />
<center>23</center><br />
|<br />
<center>26</center><br />
|<br />
<center>29</center><br />
|<br />
<center>32</center><br />
|<br />
<center>35</center><br />
|<br />
<center>38</center><br />
|<br />
<center>41</center><br />
|<br />
<center>44</center><br />
|<br />
<center>47</center><br />
|<br />
<center>50</center><br />
|<br />
<center>53</center><br />
|-<br />
! colspan="16" |<br />
<center>'''COMPUTED PAVER SPEEDS IN FEET PER MINUTE FOR 12 FOOT WIDTH'''</center><br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
|<br />
<br />
|<br />
100<br />
|<br />
125<br />
|<br />
150<br />
|<br />
175<br />
|<br />
200<br />
|<br />
225<br />
|<br />
250<br />
|<br />
275<br />
|<br />
300<br />
|<br />
325<br />
|<br />
350<br />
|<br />
375<br />
|<br />
400<br />
|<br />
425<br />
|<br />
450<br />
|-<br />
|<br />
100<br />
|<br />
20<br />
|<br />
25<br />
|<br />
30<br />
|<br />
35<br />
|<br />
40<br />
|<br />
45<br />
|<br />
50<br />
|<br />
55<br />
|<br />
60<br />
|<br />
65<br />
|<br />
70<br />
|<br />
75<br />
|<br />
80 <br />
|<br />
85<br />
|<br />
90<br />
|-<br />
|<br />
110<br />
|<br />
18<br />
|<br />
23<br />
|<br />
28<br />
|<br />
32<br />
|<br />
37<br />
|<br />
41<br />
|<br />
45<br />
|<br />
50<br />
|<br />
55<br />
|<br />
59<br />
|<br />
64<br />
|<br />
68<br />
|<br />
73<br />
|<br />
77<br />
|<br />
82<br />
|-<br />
|<br />
120<br />
|<br />
17<br />
|<br />
21 <br />
|<br />
25<br />
|<br />
29<br />
|<br />
33<br />
|<br />
36<br />
|<br />
42<br />
|<br />
46<br />
|<br />
50<br />
|<br />
54<br />
|<br />
58<br />
|<br />
63<br />
|<br />
67<br />
|<br />
71 <br />
|<br />
75<br />
|-<br />
|<br />
130<br />
|<br />
15<br />
|<br />
19<br />
|<br />
23<br />
|<br />
27<br />
|<br />
31<br />
|<br />
34<br />
|<br />
38<br />
|<br />
42<br />
|<br />
46<br />
|<br />
50<br />
|<br />
54<br />
|<br />
58<br />
<br />
|<br />
62<br />
|<br />
66<br />
|<br />
69<br />
|-<br />
|<br />
140<br />
|<br />
14<br />
|<br />
17<br />
|<br />
21<br />
|<br />
25<br />
|<br />
29<br />
|<br />
32<br />
|<br />
36<br />
|<br />
39<br />
|<br />
43<br />
|<br />
46<br />
|<br />
50<br />
|<br />
53<br />
|<br />
57<br />
|<br />
61<br />
|<br />
65<br />
|-<br />
|<br />
150<br />
|<br />
13<br />
|<br />
16<br />
|<br />
20<br />
|<br />
23<br />
|<br />
27<br />
|<br />
30<br />
|<br />
33<br />
|<br />
36<br />
|<br />
40<br />
|<br />
43<br />
|<br />
47<br />
|<br />
50<br />
|<br />
53<br />
|<br />
56<br />
|<br />
60<br />
|-<br />
|<br />
160<br />
|<br />
12<br />
|<br />
15<br />
|<br />
19<br />
|<br />
22<br />
|<br />
25<br />
|<br />
28<br />
|<br />
31<br />
|<br />
34<br />
|<br />
38<br />
|<br />
41<br />
|<br />
44<br />
|<br />
47<br />
|<br />
50<br />
|<br />
53<br />
|<br />
56<br />
|-<br />
|<br />
170<br />
|<br />
12<br />
|<br />
15<br />
|<br />
18<br />
|<br />
20<br />
|<br />
23<br />
|<br />
26<br />
|<br />
30<br />
|<br />
33<br />
|<br />
36<br />
|<br />
38<br />
|<br />
41<br />
|<br />
44<br />
|<br />
47<br />
|<br />
50<br />
|<br />
53<br />
|-<br />
|<br />
180<br />
|<br />
11<br />
|<br />
14<br />
|<br />
17<br />
|<br />
19<br />
|<br />
22<br />
|<br />
25<br />
|<br />
28<br />
|<br />
31<br />
|<br />
34<br />
|<br />
36<br />
|<br />
39<br />
|<br />
42<br />
|<br />
45<br />
|<br />
47<br />
|<br />
50<br />
|-<br />
|<br />
190<br />
|<br />
10<br />
|<br />
13<br />
|<br />
16<br />
|<br />
19<br />
|<br />
21<br />
|<br />
23<br />
|<br />
26<br />
|<br />
29<br />
|<br />
32<br />
|<br />
34<br />
|<br />
37<br />
|<br />
39<br />
|<br />
42<br />
|<br />
44<br />
|<br />
47<br />
|-<br />
|<br />
200<br />
|<br />
10<br />
|<br />
12<br />
|<br />
15<br />
|<br />
18<br />
|<br />
21<br />
|<br />
22<br />
|<br />
25<br />
|<br />
28<br />
|<br />
30<br />
|<br />
32<br />
|<br />
35<br />
|<br />
38<br />
|<br />
40<br />
|<br />
42<br />
|<br />
45<br />
|-<br />
|<br />
210<br />
|<br />
9<br />
|<br />
11<br />
|<br />
14<br />
|<br />
17<br />
|<br />
19<br />
|<br />
21<br />
|<br />
24<br />
|<br />
26<br />
|<br />
29<br />
|<br />
31<br />
|<br />
33<br />
|<br />
35<br />
|<br />
38<br />
|<br />
40<br />
|<br />
43<br />
|-<br />
|<br />
220<br />
|<br />
9<br />
|<br />
11<br />
|<br />
14 <br />
|<br />
16<br />
|<br />
18<br />
|<br />
20<br />
|<br />
23<br />
|<br />
25<br />
|<br />
28<br />
|<br />
30<br />
|<br />
32<br />
|<br />
34<br />
|<br />
37<br />
|<br />
39<br />
|<br />
41<br />
|-<br />
! colspan="16" |<br />
<center>'''COMPUTED PAVER SPEEDS ON FEET PER MINUTE FOR 15 FOOT WIDTH'''</center><br />
|}<br />
<center>'''Figure 502-5'''<br />
'''Paver Speeds'''</center><br />
----<br />
<br />
{{top}}<br />
<br />
====[[#Screed Heaters|Screed Heaters]]====<br />
<br />
The screed is equipped with heaters, the purpose of which is to increase the temperature of the cold bottom screed plate to about 320°F (160°C). A properly heated screed, particularly at the start of the day’s paving operations, or after any extended shutdown of the paving process, provides a more uniform mat surface texture. It is necessary for the screed to be the same temperature as the mixture being placed in order to assure that the mix does not stick to the screed plate and tear the mat, causing a rough texture to the surface. To preheat the screed, the heaters are normally operated for a period of 10 minutes to 20 minutes before the commencement of the paving operation. Care should be taken to avoid overheating, which can cause permanent warping of the screed.<br />
<br />
{{top}}<br />
<br />
====[[#Crown Control|Crown Control]]====<br />
<br />
The screed on the paver can be angled at its center to provide for positive or negative crown. The amount of crown that can be introduced into the screed varies with the width of the basic screed and with the make and model of the equipment. When rigid extensions are being used in conjunction with the main screed, the crown can usually be altered at any of the points where the extensions are joined. If a hydraulically extendable screed is being used with the paver, the crown can be introduced in the center of the main screed and also at the points between the main screed and the hydraulic extensions.<br />
<br />
{{top}}<br />
<br />
====[[#Vibrators|Vibrators]]====<br />
<br />
The amount of compaction imparted to the asphalt mixture is a function of many variables. Two factors within the screed itself can contribute to the degree of compaction. The first is the frequency of vibration and the second is the amplitude of the compactive effort. The frequency of vibration is controlled by the rotary speed of the vibrator shaft. The applied amplitude is determined by the location of the eccentric weights that are located on the shaft. In general, the vibrators should be used near the maximum possible frequency.<br />
<br />
The density obtained by the paver screed is also a function of the speed of the paver. The faster the paver moves, the less time the screed sits over any particular point in the new mat, thus the amount of compactive effort applied by the screed decreases. For asphalt mixes, it can be expected that about 70 percent to 80 percent of the theoretical maximum density may be obtained as the mixture passes under the screed.<br />
<br />
{{top}}<br />
<br />
====[[#Extensions|Extensions]]====<br />
<br />
When the basic width of the paver screed needs to be changed to accommodate increased paving widths, rigid or hydraulic screed extensions can be employed. Rigid extensions come in several widths, usually 6 inch, 12 inch, 2, 3, and 5 foot sections.<br />
<br />
{{top}}<br />
<br />
====[[#Rigid Extensions|Rigid Extensions]]====<br />
<br />
In order to keep the paver in balance, where possible, the width of the rigid extensions added should be approximately equal on both sides of the screed. It is important for the screed extension to be attached securely to the main screed. Further, the extension must be set at the same elevation and angle as the basic screed to prevent the presence of a transition line, or ridge, at the intersection of the main screed and the extension. Alignment of the front edge of the extension is typically controlled independently of the alignment of the rear edge of the extension. Whenever a rigid screed extension is employed on the basic screed, auger extensions and the accompanying auger tunnel extensions should also be added. The length of the auger extensions should, in general, be the same length as the screed extensions. The distance between the end of the auger extension and the end gate should be about 12 inches.<br />
<br />
Further, whenever rigid extensions are employed, the strike off, or pre-strike off, assembly must be added to the extension and set at the same location as the strike off on the main screed. An end gate is attached to the end of the screed to restrict the outward movement of the mix around the end of the screed.<br />
<br />
Cutoff shoes can be used, if necessary, to reduce the width of mixture being placed to a width that is less than the basic main screed width.<br />
<br />
{{top}}<br />
<br />
====[[#Hydraulic Extensions|Hydraulic Extensions]]====<br />
<br />
Most paver manufacturers have developed hydraulically extendable screeds that trail the main screed on the paver. One make of paver, however, is equipped with a power extendable screed that places the extendable portion of the screed in front of the main screed. If the extensions on the extendable portion of the screed are not properly aligned with the main screed, a longitudinal mark, or ridge, will occur in the surface of the mix at the junction between the two screeds. This mark can easily be eliminated by adjusting the elevation of the extendable screed in relation to the main screed. In addition to the longitudinal mark, a mismatch in the elevation between the two screeds can also result in a possible difference in surface texture. Finally, the difference in the alignment of the two screeds can cause a difference in the degree of compaction that is obtained from the screed. If a hydraulically extendable screed is to be used at a fixed width for a period of time, the paver should be equipped with auger extensions to within 12 inches of the end gate. Some pavers may be equipped with augers that extend automatically as the screed is extended.<br />
<br />
{{top}}<br />
<br />
====[[#Ski|Ski]]====<br />
<br />
<div style="float: right; padding-left: 10px;"><br />
[[File:Fig502-5.jpg|thumb|600px]]<br />
[[File:Fig502-6.jpg|thumb|600px|Figure 502-6 - Floating Ski for Slope Control]]<br />
</div><br />
<br />
One type of reference device, termed a floating ski or beam, is a series of feet, or shoes, attached to the bottom of the floating beam. The purpose of the shoes is to allow one or more of them to pass over a high or low point in the existing surface without altering the slope of the whole beam. The grade sensor usually rides directly on the beam at its midpoint. This floating ski system averages out the variation of the existing grade over a 30 or 40 foot length. See '''''Figure 502-6'''''.<br />
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<br />
====[[#Grade Reference Controls|Grade Reference Controls]]====<br />
<br />
Automatic screed controls are employed to keep the elevation of the pull points on the paver at a more constant elevation relative to the grade reference being used. Deviations in the pavement surface are averaged out over the length of the grade reference device. There are four basic types of grade references that can be employed to maintain the elevation of the screed pull point: the erected string line, the mobile mat reference, 30 foot floating ski, and the joint matching shoe. Each type of reference can be used on either side of the paver, or on both sides at the same time. When a grade reference is used in conjunction with a slope control device, the grade reference sensor is typically positioned on the centerline side of the paver, with the slope controller determining the thickness of the mat on the outside edge of the pavement.<br />
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<br />
====[[#String Line|String Line]]====<br />
<br />
String line allows for the smoothest possible asphalt mat behind the paver screed. The elevation of the string line must be set by a survey crew and the set line must be very taut. Typically, the string is supported on metal posts at 25 foot intervals. The haul trucks and all paving personnel must keep away from the line and not disturb it in any way. Once the line is set at the proper elevation, it is imperative that the line remain untouched both before and after the paver sensor passes over.<br />
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<br />
====[[#Joint Matching Shoe|Joint Matching Shoe]]====<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig502-7.jpg|thumb|center|600px|Figure 502-7 - Joint Matching Shoe for Slope Control]]</div><br />
<br />
Another type of grade referencing device is the joint matching shoe. This device consists of a short 12 inch shoe or ski that is used to reference the grade of an adjacent piece of pavement or curb. This type of reference device is used only when the grade being sensed is relatively smooth. Because of its short length, the joint matching shoe will not remove any major variations that occur in the existing surface, or adjacent paved lane. See '''''Figure 502-7'''''.<br />
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<br />
====[[#Mobile Mat Reference System|Mobile Mat Reference System]]====<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig502-8.jpg|thumb|center|600px|Figure 502-8 - Example of a Mobile Mat Reference System]]</div><br />
<br />
The mobile reference system, illustrated in '''''Figure 502-8''''', combines the front mounted 30 foot floating beam with a 20 foot mat reference beam. The mat reference beam is spring supported on a series of wheels that roll on the mat. It responds to and averages changes in mat elevation in the same manner as the floating beam. A superstructure that spans the screed and auger areas ties the two together and supports the grade sensor. This 55 foot overall length assembly produces a mat with an exceptionally smooth riding surface. This arrangement permits an average to be taken from the grade surface and another to be taken from the freshly laid mat. These averages are combined and measured at the grade sensor near the screed tow point. A mean average is thus obtained over the entire span. This arrangement can sense and correct any change in screed elevation.<br />
<br />
This system spans a distance greater than three wire reference stakes spaced at 25 foot intervals to produce a better average reference and eliminates potential errors inducted into the mat by an improperly maintained wire reference. It can be configured for automatic grade and slope, or dual grade control, as shown in '''''Figure 502-8'''''.<br />
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<br />
====[[#Slope Control|Slope Control]]====<br />
<br />
Paving done with automatic screed controls is accomplished with a combination of grade control on one side of the paver and slope control to determine the grade on the other side of the paver. See [http://hct591jbosds790/wiki/index.php/File:Fig502-6.jpg '''''Figure 502-6'''''].<br />
<br />
The slope control operates through a slope sensor that is located on a cross beam between the two side arms on the screed. One side of the paver is controlled by the grade referencing sensor and the other side is controlled by the slope controller. When slope control is used, the thickness of the mat on the side of the paver that is controlled by the slope sensor could be variable, depending upon the condition of the existing surface. The desired degree of cross slope is dialed into the slope controller. Before the automatic screed controls are engaged, the screed must be nulled before paving starts and the proper angle of attack must be set. If the automatic controls are being used, the screed operator should not try to change the screed manually by turning the thickness control crank.<br />
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<br />
====[[#Rollers|Rollers]]====<br />
<br />
Rollers are used to compact the mixture to the required density. The Contractor will use several types of rollers and each type is used for different purposes. Three types of self-propelled rollers are currently being used: static steel wheel, pneumatic tire rollers and vibratory rollers. Fuel oil is not permitted for use on tapered joint rollers and mobile mat reference wheels.<br />
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<br />
====[[#Static|Static]]====<br />
<br />
Static steel wheel rollers normally range in weight from 3 to 6 tons and have compression drums or rolls that vary in diameter from 30 to more than 60 inches. The gross weight of the roller can be altered by adding ballast water to the roller drums.<br />
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<br />
====[[#Vibratory|Vibratory]]====<br />
<br />
Vibratory rollers come in a variety of configurations. Double-drum vibratory rollers come in single-articulated-frame and double-articulated-frame models. These vibratory rollers can be operated in any one of three modes: static, with one drum vibrating and one drum static, and with both drums vibrating. For relatively thin layers of mix, generally less than 1-1/2 inch, the vibratory roller should typically be operated in the static mode. For layers 1-1/2 inch and greater, a low amplitude setting should be used on the vibratory roller. As the layer thickness increases, it may help to increase the amplitude applied to the mix as recommended by the manufacturer.<br />
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<br />
====[[#Pneumatic|Pneumatic]]====<br />
<br />
Pneumatic tire rollers are required for initial compaction on all base and some leveling courses to knead the material into all cracks and depressions for better density. This type roller’s compactive effort is a function of the wheel load, the tire pressure, the tire design and the depth of penetration of the tires into the mix. All the tires should be the same size, ply and tire pressure. The tire pressure used depends, in part, upon the number of plies used in the tires. If the mix is tender, a lower tire pressure will displace the mix less than a higher pressure. For a stiff mix, a higher tire pressure should be used. It is very important that proper air pressure be maintained in all tires. This type of roller must be equipped with a skirt around the bottom of the roller and within 3 inches of the new surface. This skirt will help keep the tires hot by holding the heat from the mix under the roller. The tire surface must be kept hot to reduce the pick up of fines from the mixture being compacted. Rollers can also be a combination of both pneumatic and steel wheel.<br />
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<br />
====[[#Hand Tools|Hand Tools]]====<br />
<br />
Adequate hand tools, and proper equipment for cleaning and heating them, should be available for the paving operation. These tools include rakes, shovels, lutes, 10 foot straightedge, carpenter’s level and blocks and shims for supporting the screed of the paver when beginning operations at a butt joint. Not all of these tools are necessarily used on every project, or every day of a particular job. Rakes, shovels and lutes are frequently used by personnel around the paver. While the paver is operating, laborers may work, or rework, a portion of the mix to fit the paving around objects and to fill in areas that the paver does not pave adequately, or cannot reach. Non-biodegradable agents that dissolve the HMA mixture, such as fuel oil, shall not be used at the paving site.<br />
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<br />
===[[#Surface Preperation|Surface Preperation]]===<br />
<br />
<br />
====[[#Aggregate Base|Aggregate Base]]====<br />
<br />
The ride quality of the surface depends, to a great degree, upon the conditioning and preparation of the aggregate surface. The aggregate base course must meet all the requirements for moisture content, density and smoothness. The aggregate base must provide a firm foundation before paving commences. If distortion of the base course occurs during the paving operation, the mixture placement should be stopped until the condition of the base course is corrected. If the aggregate surface is left exposed to the weather, either allowed to dry out or become saturated by rain, sufficient tests must be made immediately prior to placing the mixture to ensure that density requirements are met. Raveled, dried-out surfaces must be re-compacted and restored to the proper cross section. Saturated areas must be allowed to dry prior to placing mixture. The aggregate base must be rolled after final trimming in order to pack down any loose gravel and minor dips caused by the trimmer.<br />
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<br />
====[[#Cold-Milled Surface|Cold-Milled Surface]]====<br />
<br />
The proposal and plans should be reviewed to see if the cold-milling will be for profiling, or for a specified depth. Profiling is used to establish a new cross section in the existing pavement. Milling can be accomplished in any width necessary; however, the width is typically 6.25 feet. Equipped with automatic grade and slope controls, the milling machine is capable of producing a level surface in one pass over the existing pavement. A surface that has been milled typically is very dusty and dirty. Once the pavement has dried, multiple passes of a mechanical broom are needed to remove all the residual grit from the milled surface. Care should be exercised to keep dust to a minimum. Any dust and dirt left on the milled surface will greatly affect the bond between that course and the new overlay. When cold-milling by the ton is a pay item, a weigh person will be needed. Cold-milling machines may be used to do the work involved in the pay item of removing HMA surface by the square foot (square meter).<br />
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<br />
====[[#Old HMA Pavement|Old HMA Pavement]]====<br />
<br />
Before overlaying an old HMA pavement, it should be inspected. The degree of preparation depends upon the condition of the existing surface. Slick, highly polished surfaces, potholes, old patches, cracks and joints may require repairs. At a minimum, the failed areas should be removed and replaced, the potholes properly patched, the cracks cleaned out and the ruts filled, or preferably removed by cold-milling. Proper subsurface drainage should be installed as necessary. Old patches that show signs of instability, areas with excess asphalt, or excess crack filler, and areas with loose material should be removed and repaired.<br />
<br />
At a minimum, all repairs shown on the plans shall be completed.<br />
<br />
The inspector should mark areas that will require wedging, which will usually occur when the existing pavement has depressions of 1 inch or more. Unless otherwise noted, the patching and wedging work is done with the mixture that will be used for the leveling course. The top course mixture can be used for wedging when the thickness is less than 2 inches. All horizontal and vertical surfaces that will be in contact with the new HMA mixture must be thoroughly cleaned. This can be accomplished by using a rotary broom, flushing with water, and other methods that may be required to remove clay and dirt. Vegetation and debris should be removed from joints and cracks. Cleaning of the roadway surface may be a pay item.<br />
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<br />
====[[#Old Rigid Pavement|Old Rigid Pavement]]====<br />
<br />
Before overlaying the old pavement, it should be inspected. Any severely distressed areas in the old rigid pavement surface should be cut out, removed and replaced using full depth repairs with PCC, or hot mix asphalt. Any severely spalled areas at joints should be repaired using partial-depth repair methods. Rocking slabs must be stabilized. Joints that are poorly sealed should have the old seal material removed and the joints cleaned. Some pavements may be disintegrated so badly that the fragments may have to be removed. Pavement sags and rough areas may require a wedging course. The inspector should check the entire pavement surface to ensure that all corrections are made before resurfacing work begins. The final step before the bond coat is applied is to thoroughly clean the existing surface by brooming and/or other methods; all vegetation and debris must be removed from pavement joints and cracks.<br />
<br />
Before placing the bond coat, the inspector should make certain that the surface has been swept clean of all foreign material, such as debris, leaves, dirt, etc.<br />
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<br />
===[[#Adjusting Drainage Structures|Adjusting Drainage Structures]]===<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig 502-9.jpg|thumb|400px|Figure 502-9 - Adjusting Drainage Structures]]</div><br />
<br />
One of the greatest contributors to a poor ride on an urban project is the improper adjustment of manholes. Refer to [[403 - Drainage Structures|Section 403]] of this manual for more information on adjusting drainage structure.<br />
<br />
To make a proper adjustment, the inspector should string line along the roadway after the leveling course has been placed, 15 feet either side of the structure in a longitudinal direction and in a transverse direction from the centerline to the edge of pavement, or curb line. The top of the cover should be set 1/8 inch lower than the string line, adjusted to the elevation of the planned overlay. Care must be taken to adjust the top of the cover to the slope of the planned finished roadway.<br />
<br />
The inspector should also check the structure to determine that the casting is firmly set in place. The adjacent pavement, curb, or curb and gutter, shall be replaced to the original elevation, condition and type of construction, unless otherwise provided. Refer to '''''Figure 502-9'''.'' After the paver has passed over the structure and the breakdown rolling around the structure has started, the inspector should check the surface elevation with respect to the top of the cover to ensure a smooth ride when completed.<br />
<br />
Hand raking and shaping around the cover must be completed before the material cools. It may be necessary to compact these areas by the hand tamper method. Structures located in the roadway should have the top of the cover flush with the wearing surface when the final compaction is completed. On structures in the curb line out of the traveled roadway, the top of the cover should be 3/8 inch (8 mm) below the wearing surface after final compaction is completed.<br />
<br />
Improper adjustments of catch basins can create drainage problems, which will lead to early deterioration of the roadway. Adjust catch basins after the leveling course has been placed. After the paver placing the top course has passed over the structure and the hand raking and shaping have been completed, it may be necessary to compact this area by the hand tamper method. Refer to '''''Figure 502-10'''.''<br />
<br />
[[File:Fig 502-10.jpg|thumb|center|400px|Figure 502-10 - Adjusting Drainage Structures]]<br />
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<br />
===[[#Wedging|Wedging]]===<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig 502-11.png|thumb|400px|Figure 502-11 - Wedging HMA Pavement]]</div><br />
<br />
Some old surfaces may need to be leveled or smoothed before the new surface is placed. This requires a HMA layer of varying thickness to be placed and is referred to as wedging. If the wedging course is 3 inches or less, the inspector should string line the area to be wedged to determine the limits of wedging. If the wedging is greater than 3 inches, two courses of HMA mixture may be required. The thickness of each course generally should not exceed 3 inches. This process is typically used for superelevation corrections, placing a wedging course so that the leveling and top courses can be placed at a uniform thickness. '''''Figure 502-11''''' illustrates the wedging process.<br />
<br />
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<br />
===[[#Bond Coat|Bond Coat]]===<br />
<br />
The bond coat, also called the tack coat, consists of an asphaltic emulsion applied to an existing surface to promote adhesion between the old surface and the new asphalt overlay. If a good bond is not formed between the existing surface and the new overlay, a slippage, or sliding-type, failure can easily occur. All existing pavements, including newly-constructed HMA surfaces, which are to be surfaced with HMA, will receive a bond coat application. <br />
<br />
The bond coat material must be applied with an approved distributor with a uniform spray. See '''''Figure 502-12'''.'' All nozzles on the distributor should be open and functioning. All nozzles should be turned at the same angle to the spray bar: approximately 30 degrees, depending upon the manufacturer’s recommendations. In addition, the spray bar should be set at the proper height above the pavement surface to provide for a double or triple lap of the liquid asphalt materials. The bond coat material should be heated to the proper temperature so that it is fluid enough to be sprayed from the nozzles.<br />
<br />
A bond coat is an application of an asphaltic emulsion to an existing surface as a bond or tack coat ensuring adhesion with the overlying surface and preventing displacement ahead of the roller.<br />
<br />
All existing pavements, including newly-constructed HMA widening, which are to be surfaced, should receive a bond coat application. Bond coat material must be applied with an approved distributor with a uniform spray. The existing surface texture will determine the rate of application up to the maximum rate of 0.10 gallons/square yards. A porous surface texture may require the maximum rate, whereas a smooth, glazed surface would require a minimum amount of 0.05 gallons/square yards. This minimum rate should also be used between courses as a tack coat.<br />
<br />
Before the application of bond coat, the surface must be dry and free of sand, gravel and dust. Bridge railings and piers, curb and gutter pans, and guardrails must be protected from the spray of bond coat by the use of shields. Plan the width of application to ensure having bond coat under the matching longitudinal joint. Avoid spraying adjacent completed surfaces that will remain exposed. The three essential requirements of a bond coat are:<br />
<br />
# It must be thin.<br />
# It must be uniform.<br />
# It must be cured before surfacing.<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:502-12.JPG|thumb|center|600px|Figure 502-12 - Distributor Spray Pattern]]</div><br />
Excess bond coat may create a slip plane between courses, bleed into the overlaying course and cause flushing. All traffic must be kept off of the bond coat until it is cured. Bond coats may be considered cured when your shoes tend to stick without picking up material when walking over it.<br />
<br />
Whenever the temperature of the previously placed mats falls below 170°F prior to placement of the adjacent mat, or when placing base mix and the air temperature is below 50°F, the vertical edges of the initial mat shall be coated with HMA bond coat material before the mixture is placed in the adjacent section.<br />
<br />
If trucks backing into the paver pick up emulsion, thus leaving the pavement clean, the bond coat is not cured. After curing, only traffic essential in the work should be allowed on the bond coat. The work should be planned so the bond coat is not applied too far in advance of the paving operation. Breakdowns and bad weather can create problems with large areas of bond coat that are left unsurfaced. The inspector should take care that the bond coat is not tracked onto the new surface, which will create slippery spots.<br />
<br />
The bond coat material shall be applied ahead of the paving operation for a distance of at least 1500 feet, depending upon traffic conditions, as determined by the Engineer. The surfacing or construction traffic shall not be allowed on the existing pavement until the bond coat has cured. Only enough bond coat should be applied that can be covered the same day.<br />
<br />
The uniform application of the emulsion is a function of the asphalt distributor and the skill of the operator. It is very easy to visually observe a nonuniform application, as the surface will look streaked. Things that can cause a nonuniform application are, improper temperature, improper pump speed, sprayer bar height improperly set, spray nozzles clogged, or the nozzle overlap pattern is improperly adjusted. When the inspector sees an improper bond coat application, the operation should be stopped. The Contractor would then correct the problem and show that a uniform application can be made before being allowed to continue paving on the project.<br />
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<br />
===[[#Placing HMA Mixture|Placing HMA Mixture]]===<br />
<br />
It is the Contractor’s responsibility to uniformly place the HMA mixture to the specified grade and thickness. It is the MDOT inspector’s responsibility to ensure that the Contractor is providing a specification product.<br />
<br />
If the inspector observes the Contractor not providing a specification product, the paving process should be stopped until the Contractor makes the corrections needed before being allowed to continue. All HMA lifts shall be placed, compacted, and allowed to cool to at least 130°F, or cool enough to support construction equipment without visible distortion or distress of the mat prior to placing any subsequent HMA layers.<br />
<br />
Close cooperation between the paving crew and the asphalt plant is essential in securing a satisfactory and uniform product. A fast means of communication should be established between the plant and the paving crew so that any changes to the mixture can be promptly communicated. Mixture temperature should be checked regularly when the mix arrives on the project and recorded on the load tickets.<br />
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====[[#Placement Temperature|Placement Temperature]]====<br />
<br />
It is the Contractor’s responsibility to ensure that the mixture temperature is adequate for placement and compaction; however, if the inspector observes mixture that is either too cold or too hot, the problem should be pointed out to the Contractor and the Engineer.<br />
<br />
* Too Hot: Blue smoke rising from the mix usually indicates an overheated truckload. The temperature should be checked immediately. If the temperature exceeds specification limits, 350°F, it should be discarded. If it exceeds optimum placement temperature, but does not exceed the specification limit, the truckload is usually not discarded, but immediate steps should be taken to correct the condition.<br />
<br />
* Too Cold: A generally stiff appearance, or improper coating of the larger aggregate particles, indicates a cold mixture. Again, the temperature should be checked immediately. If it is below the specification limit, 250°F, it should be discarded. If it is within the specification limit, but below optimum placing temperature, steps should be taken immediately to correct the situation by contacting the plant.<br />
<br />
* Excess Moisture. Steam rising from the mix as it is dumped into the hopper of the spreader indicates moisture in the mix. It may be bubbling or popping as if it were boiling. The mix may also foam so that it appears to have too much asphalt.<br />
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<br />
====[[#Texture|Texture]]====<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig 502-13.jpg|thumb|500px|Figure 502-13 - Mat Texture]]</div><br />
<br />
As the first load of mixture is being spread, the texture of the unrolled surface should be checked to determine uniformity. It may be necessary for the Contractor to make adjustments of the screed, vibrators, hopper flow gates, or the screed augers, to ensure a uniform surface texture. These adjustments should be completed within the first two loads placed. Refer to '''''Figure 502-13''''' for some typical mat appearances.<br />
<br />
Nonuniform mixing shows up as spots of lean, brown, and dull appearing material within areas of rich and shiny appearance. A result of specified mix contaminated with inferior performing, non-specification mix.<br />
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<br />
====[[#Yield|Yield]]====<br />
<br />
The inspector should check the placement yield occasionally. The first yield check should be made as soon as the Contractor has completed all paver adjustments. This check is done by roughly measuring the area covered by one truckload; the tonnage placed is known from the load ticket. Dividing the tonnage placed, by the area covered, will give the yield. To convert the yield to mat thickness, the following will be helpful: 110 pounds/square yard = 1 inch of thickness. If this yield is found to be high or low from that specified on the plans, a slight adjustment of the thickness controls should be made and the yield rechecked. Once the proper yield has been obtained, only periodic checks will be required each day.<br />
<br />
<br />
'''Example:''' <br />
Specification Requirement = 165 pounds/square yards<br />
Load Ticket = 247923 pounds<br />
<br />
Area Covered: <br />
<br />
1000 feet x 11 feet / 9 = 1467 square yards<br />
'''Then:''' yield = 247923 lbs / 1467 yd<sup>2</sup> = 169 lbs/yd<sup>2</sup><br />
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<br />
====[[#Segregation|Segregation]]====<br />
<br />
Another texture problem that may be observed is caused by material segregation. If segregation is observed, the paving operation should be stopped until the problem is corrected. The pattern of segregation can normally identify the cause of the segregation. '''''Figure 502-14''''' shows some typical surface patterns and the causes.<br />
<br />
Other surface blemishes are caused by the truck backing into the paver, the screed settling when the paver stops and when the paver operator empties the hopper wings into an empty hopper. A diagnostic guide is included here to help in identifying the cause and fix for a range of segregation problems.<br />
<br />
Segregation of the aggregates in the mix may occur because of improper handling and may be serious enough to warrant rejection. Loads that have become contaminated because of spilled gasoline, kerosene, oil and the like, should not be used in the roadway.<br />
<br />
[[file:fig 502-14a.JPG|thumb|center|600px|Figure 502-14 - Material Segregation]]<br />
<br />
<center>Continuous Both Sides<br />
Paver speed too fast, or end of screed extensions too far from the end of the augers, or too much loose material built up at the end of the screed.</center><br />
<br />
[[file:fig 502-14b.JPG|thumb|center|600px|Figure 502-14(Cont.) - Material Segregation]]<br />
<br />
<center>Centerline<br />
Paver speed too fast, or reversing auger paddles missing, or lift thickness may be too thin for mixture being placed.</center><br />
<br />
[[file:fig 502-14c.JPG|thumb|center|600px|Figure 502-14(Cont.) - Material Segregation]]<br />
<br />
<center>Echelon<br />
Paver hopper is emptied before starting to unload truck, or cold mix in paver wings is emptied into empty paver hopper, or material in the trucks is segregated because of improper loading, or when using dump trucks not holding tailgate closed until load slides against it.</center><br />
<br />
----<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Segregation Diagnostic Guide'''</center><br />
|-<br />
!<br />
<center>'''Cause'''</center><br />
!<br />
<center>'''Fix'''</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Loose Streak/Streaks (Narrow) Down the Center of the Mat'''</center><br />
|-<br />
|<br />
<center>Head of Material Low</center><br />
|<br />
<center>Maintain 1/2 Auger Level</center><br />
|-<br />
|<br />
<center>Missing or Damaged Deflector Plates</center><br />
|<br />
<center>Repair or Replace</center><br />
|-<br />
|<br />
<center>Wrong Center Auger Flights/Damaged</center><br />
|<br />
<center>Replace, Try Reverse Flights</center><br />
|-<br />
|<br />
<center>Lead Crown too Low</center><br />
|<br />
<center>Adjust</center><br />
|-<br />
|<br />
<center>Pre-Strike-Off Low in Center</center><br />
|<br />
<center>Adjust to Level Across Screed</center><br />
|-<br />
|<br />
<center>Improper Auger Height</center><br />
|<br />
<center>Try Different Height Settings</center><br />
|-<br />
|<br />
<center>High Spot in Center of Existing Grade</center><br />
|<br />
<center>Increase Mat Height, Fix Grade</center><br />
|-<br />
|<br />
<center>Mix Design, Cold or Low Liquid Content</center><br />
|<br />
<center>Adjust at Plant</center><br />
|-<br />
|<br />
<center>Mix Spilled in Front of Paver</center><br />
|<br />
<center>Hopper Flashing, Truck Dumping</center><br />
|-<br />
|<br />
<center>Auger Speed and Flow Gate Setting</center><br />
|<br />
<center>Adjust Feeder Sensors/Flow Gates</center><br />
|-<br />
|<br />
<center>Inverted Crown in Screed</center><br />
|<br />
<center>Adjust, Check Mat Profile</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Loose Strip (Wide) Down the Center of the Mat'''</center><br />
|-<br />
|<br />
<center>Low PSI Main Screed Compared to Extensions</center><br />
|<br />
<center>Lower Angle of Attack Extensions</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Tight Streak (Narrow) Down the Center of the Mat'''</center><br />
|-<br />
|<br />
<center>Pre-Compaction</center><br />
|<br />
<center>Adjust Feeder Sensors/Flow Gate</center><br />
|-<br />
|<br />
<center>Lead Crown High</center><br />
|<br />
<center>Adjust Lead Crown</center><br />
|-<br />
|<br />
<center>Improper Auger Height</center><br />
|<br />
<center>Try Different Auger Heights</center><br />
|-<br />
|<br />
<center>Worn/Broken Inner Auger Flights</center><br />
|<br />
<center>Replace</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Tight Streak (Wide) Down the Center of the Mat'''</center><br />
|-<br />
|<br />
<center>High Pressure Main Screed Compared to Extensions</center><br />
|<br />
<center>Increase Angle of Attack Extensions</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Loose Strip Across Mat Repeating Pattern'''</center><br />
|-<br />
|<br />
<center>End of Load Segregation</center><br />
|<br />
<center>Maintain Higher Mix Level in Hopper</center><br />
|-<br />
|<br />
<center>Running Mix Level Low in Tunnels</center><br />
|<br />
<center>Stop Paver With Mix in Hopper</center><br />
|-<br />
|<br />
<center>Dumping Hopper Wings When Hopper Empty</center><br />
|<br />
<center>Minimum Level, Bottom of Flow Gates</center><br />
|-<br />
|<br />
<center>Segregation at Truck Loading</center><br />
|<br />
<center>Should not be Loaded in one Position</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Loose Strips Outside Edge of Mat'''</center><br />
|-<br />
|<br />
<center>In Line With Conveyors</center><br />
|<br />
<center>Lower Mix Level, Auger Height & RPM</center><br />
|-<br />
|<br />
<center>In Line With Bearing Supports</center><br />
|<br />
<center>Increase Auger RPM and/or Height</center><br />
|-<br />
|<br />
<center>At Outer Edges of Screed (Wider Width Mats)</center><br />
|<br />
<center>Add Extensions (Auger and Tunnel)</center><br />
|-<br />
|<br />
<center>Warped Screed Plate</center><br />
|<br />
<center>Replace Screed Plate</center><br />
|-<br />
|<br />
<center>Worn Spots on Screed Plate</center><br />
|<br />
<center>Re-Level With Shims</center><br />
|}<br />
<br />
{{top}}<br />
<br />
===[[#Joints|Joints]]===<br />
<br />
<div style="float: right; padding-left: 10px;">[[File:Fig 502-15.jpg|thumb|400px|Figure 502-15 - Constructing a Joint]]</div><br />
Attention needs to be directed toward joints more than any other phase of HMA construction. The subject of joints includes longitudinal joints and transverse joints, as well as the matched joint between an asphalt surface and a concrete pavement, or gutter pan. Refer to '''''Figure 502-15''''' for details of joint construction.<br />
<br />
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<br />
====[[#Transverse Joint|Transverse Joint]]====<br />
<br />
The transverse joint in all courses must be carefully constructed and thoroughly compacted to provide a smooth riding surface. When the paving operation is discontinued, a transverse joint must be constructed. Although there are several ways to construct this joint, the most common is the ramp joint. This method uses paper, canvas or burlap as the separator, making it easier to remove the mix when the paving operation starts again. If the end of the lane is to be left open overnight, a ramp joint should be used. The length of temporary taper shall be 5 feet for each inch of mat thickness.<br />
<br />
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<br />
====[[#Longitudinal Joint|Longitudinal Joint]]====<br />
<br />
One of the most important considerations in making a longitudinal joint is keeping the paver on a straight line of travel. When constructing the first lane, a string line should be employed to guide the paver operator to establish a uniform edge. The lane edge should not vary more than 1 inch in 3 feet from the established alignment. The completed centerline joint should be uniform, closed and flush with adjacent lanes.<br />
<br />
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<br />
====[[#Tapered Joint|Tapered Joint]]====<br />
<br />
The use of a tapered, overlapping longitudinal joint eliminates the requirement that all lanes be resurfaced to within one truckload of the same point of ending. The tapered longitudinal joint shall be constructed by tapering the HMA mat; the taper shall have a 1 to 12 rise and the taper shall extend beyond the normal lane width. A notch of up to 1 inch shall be placed at the top of the taper when placing HMA. The taper shall be constructed by the use of an approved strike off device attached to the screed that will provide a uniform slope and will not restrict the main screed. Bond coat shall be applied to the taper before the adjacent lane is placed. Compaction of the taper section will be required as near to final density as possible. The paver screed will be equipped with a special template strike-off and a small weighted roller for construction and compaction of this joint.<br />
<br />
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<br />
====[[#Butt Joint|Butt Joint]]====<br />
<br />
When butt joints are called for on the plans or in the proposal, construction should be as follows. Material from the existing surface is milled out to a depth as shown on the plans, or equal to the top course, across the entire width of the joint and to a length of 35 feet minimum. This should be checked using a straightedge or string line. If the depth exceeds the plan thickness by 2 inches, the Contractor must fill in the butt joint to the required thickness. Care should be taken to neatly construct the joint at a right angle to the centerline of the roadway. The joint is swept clean of all loose material and given a bond coat.<br />
<br />
On two-course projects, the first course should be reduced gradually at a rate of 1 inch in 33 feet and end at a point 33 feet or more from the butt joint. The top course will then be placed at a uniform rate.<br />
<br />
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<br />
====[[#Echelon Paving|Echelon Paving]]====<br />
<br />
If two pavers running in echelon are used, the construction of the joint is similar to the building of a joint against a cold compacted pavement. However, the amount of overlap between the first and second lanes is very important. The distance the screed of the trailing paver should extend over the uncompacted mat behind the first paver should be limited to no more than 1 inch. The screed of the second paver must be set at the same level as the screed of the first paver; this will prevent the screed of the second paver from dragging on the mix placed by the first paver. No raking of the joint is needed. The rollers behind the first paver should stay 1 foot away from the free edge toward the second paver. Once the mix from the second paver is placed against the uncompacted edge, the rollers behind the second paver will densify the joint area.<br />
<br />
When meeting either a concrete slab or gutter pan, keep the asphalt surface about 1/4 inch above the concrete after rolling. Be extremely careful when an asphalt surface is being placed on an aggregate base adjoining a slab or curb. Experience has shown that these sections generally settle after a short period of time.<br />
<br />
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<br />
====[[#Feathered Joint|Feathered Joint]]====<br />
<br />
When a feathered joint is required, it should be constructed as follows. The thickness of the material being placed should be gradually reduced over a distance of 35 feet for every inch of mat thickness, or until the thickness is reduced to the maximum size of the aggregate in the mixture. Stop the paver at this point, remove it from the roadway and remove any excess HMA material from the roadway. Trim the joint at right angles to the roadway centerline. The last meter of the HMA material should be raked and all the large stones removed, leaving the fine material. Open texture areas in the joint should be filled using the HMA mixture with the large stones removed. Once this has been done, complete the rolling of the joint.<br />
<br />
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<br />
===[[#Compaction|Compaction]]===<br />
<br />
Compaction is the single most important factor that affects the ultimate performance of a hot mix asphalt pavement. Adequate compaction of the mix increases the pavement life, decreases permanent deformation, reduces oxidation or aging of the asphalt binder, decreases moisture damage, increases strength and stability and decreases low temperature cracking. An asphalt mix that has all the desirable mix design characteristics will perform poorly, if not compacted to the proper density.<br />
<br />
It is the Contractor’s responsibility to obtain the proper pavement density. Most mixtures will compact quite readily if spread uniformly and rolled at a temperature that assures proper asphalt binder viscosity. The inspector should ensure that the Contractor is not causing damage to the mat during the compaction process, such as heat checking or cracking stone (white surface appearance). The finished mat should be smooth and free of blemishes. The number of rollers needed and the number of passes each roller needs to make will be based upon the mixture temperature and the rate at which the mixture cools.<br />
<br />
The primary compaction variables that can be controlled during the rolling process are: number of rollers, type of rollers, roller speed, number of roller passes and roller pattern. For vibratory rollers, the following can be controlled by the operator: vibration frequency, vibration amplitude and direction of travel, when frequency and amplitude are engaged according to the manufacturer’s recommendations. Each of these factors has an effect on the level of density achieved under the compactive effort applied to the mat.<br />
<br />
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<br />
====[[#Roller Speed|Roller Speed]]====<br />
<br />
The faster a roller passes over a point on the asphalt surface, the less time the weight of the roller has to work on that point; this means that less compactive effort is applied to the mixture. The roller speed selected is dependent upon a combination of factors: productivity, layer thickness and the position of the roller in the compaction process.<br />
<br />
Vibratory rollers do not have to roll rapidly to maintain production on the job. Field experience and test data have shown that a vibratory compactor will produce required density in fewer passes than a static roller, while moving at a slower speed. Depending on the material and job conditions, this can be quite dramatic.<br />
<br />
The fast rolling movements by some static roller operators may produce a good looking surface appearance, but density may suffer. The good looking surface texture can lull the operator into a false sense of security.<br />
<br />
A vibratory compactor should never exceed a rolling speed that will provide less than one impact of the drum per inch of travel. Generally speaking, this means that vibratory rollers normally operate in the 2 to 3 mph range. To exceed this one impact or more per inch of travel may produce small ripples in the mat when laying HMA. Obviously the higher the frequency, the faster the vibratory compactor may roll. There are, of course, limits to this. The important part to remember is that although it rolls slower than a static roller, the vibratory machine can usually economically reach specified density with fewer passes. Slow and steady is the key to good vibratory compaction procedures.<br />
<br />
Easy method to calculate roller speeds for proper “Impact Spacing”<br />
<br />
Rolling Speed (Impacts per foot)<br />
<br />
''VPM / Impacts per foot = feet per minute''<br />
<br />
2500 / 10 = 250 fpm<br />
<br />
2500 / 12 = 208 fpm<br />
<br />
2500 / 14 = 179 fpm<br />
<br />
Speed - fpm to mph<br />
<br />
''fpm x 0.01136 = fpm / 88 = mph'' <br />
<br />
208 fpm x 0.01136 = 208 fpm / 88 = 2.36 mph<br />
<br />
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<br />
====[[#Number of Passes|Number of Passes]]====<br />
<br />
Roller passes must be distributed uniformly over the width and length of the area being compacted. All too often, the center of the lane receives adequate coverage, while the edges receive considerably less compactive effort. The uniformity of the roller passes is just as important as the number of passes.<br />
<br />
The rolling zone is the distance behind the paver where the breakdown roller operates. Compaction must be achieved while the stiffness of the mix is low enough to allow for reorientation of the aggregate particles under the action of the rollers. A rule of thumb is that the proper level of air voids should be obtained before the mixture cools to a temperature of 176°F. To reach the required density, the quickest initial compaction should occur directly behind the lay down machine. The rolling zone should be kept as short as possible.<br />
<br />
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<br />
====[[#Pattern|Pattern]]====<br />
<br />
For each roller employed on a project, the mat width should be divided by the width of the compaction roller to determine the number of passes needed to cover the entire width being paved. A pass is defined as one trip of the roller in one direction over any one spot. Once it is determined how many passes are needed to achieve compaction at any point, the roller pattern for an area will be calculated by multiplying the number of roller passes needed for compaction by the number of rollers needed to cover the width being paved. In the longitudinal direction, the rollers should not stop at the same transverse end point with each pass of the roller; the reversal points should be staggered to prevent shoving of the mix.<br />
<br />
A slight change in direction, or curl, is beneficial at each reversal spot to further reduce the tendency of the mix to shove under the compactor and to eliminate the possibility of a bump at the point where the roller reversal occurs. The roller should not sit and wait on the hot mat. Long delays, caused by the lack of trucks, or filling the roller with water, allow the roller to indent the new mat. It is generally impossible to roll these marks out once the mat cools.<br />
<br />
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<br />
===[[#Coring|Coring]]===<br />
<br />
Once the Contractor has finished the rolling operation, the inspector will identify the locations where the density cores will be taken; these locations are randomly selected both longitudinally and transversely.<br />
<br />
Density is required across the full pavement width. If the random core location falls over a tapered joint, it should be moved to the first point that the mat is full depth. If it falls at the free edge of the pavement, the core location should be moved 2 inches in from the edge. Each individual core location is to be marked on the pavement with a 2 inch diameter paint dot which represents the center of the core. The paint dot is to be visible on the core during handling and testing.<br />
<br />
After coring is completed, the inspector should check the layer thickness for conformance to the standard specifications. [http://hct591jbosds790/wiki/index.php/File:502-16a.JPG '''''Figure 502-16'''''] shows an example of a coring documentation form.<br />
<br />
The MDOT procedure used for selecting random core locations is by using a random number generating computer program. <br />
<br />
[[File:502-16a.JPG|thumb|center|500px|Figure 502-16 - Example of Field Core Worksheet]]<br />
<br />
[[File:502-16b.JPG|thumb|center|500px|Figure 502-16 (Cont.) - Example of Field Core Worksheet]]<br />
<br />
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<br />
===[[#Surface Defects|Surface Defects]]===<br />
<br />
Surface defects are problems that occur in the asphalt mixture during, or soon after, the lay down and compaction process. These defects can be divided into two primary categories: equipment related and mixture related. At the end of this section there is a troubleshooting guide to help in assessing possible causes and fixes for surface defects.<br />
<br />
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<br />
====[[#Waves|Waves]]====<br />
<br />
The surface can have two types of waves: long waves and short waves. Long waves may correspond to the distance between truckloads and may be associated with the reversal points of the rollers. Long and short waves can be caused by a fluctuating head of material in front of the screed. Short waves can be caused by a screed in poor mechanical condition, such as too much play in the screed control connections. Very short waves, or a washboard effect, can be caused by improper operation of the vibratory roller.<br />
<br />
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<br />
====[[#Tearing|Tearing]]====<br />
<br />
There are three types of mat tearing, or pulling, of the asphalt mix, and each is described by the location of the tear: in the center of the lane, at the outside edges of the lane, or full width. These tears are usually caused by improper paver condition, or operation, by cold mix, and by attempting to lay a mat too thin compared to aggregate size.<br />
<br />
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<br />
====[[#Screed Marks|Screed Marks]]====<br />
<br />
Nonuniform mat texture can appear in the mat both transversely and longitudinally. This nonuniform texture can be caused by many factors: screed extensions not level with each other, running the hopper empty between trucks, unevenly worn screeds, cold mix, or improperly emptying the paver wings. Transverse screed marks are transverse indentations in the mat, which may occur when the paver stops between truckloads. This is caused by an improperly adjusted screed angle of attack.<br />
<br />
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<br />
====[[#Checking|Checking]]====<br />
<br />
Checking is short transverse cracks, usually 1 inch to 4 inches in length and 1 inch to 3 inches apart. Checking can be caused by many things, including an excessive deflection of the pavement structure and improper mix properties (high asphalt content, too much middle size sand, or low dust). If the surface of the mat is cooling much faster than the mixture under it, the surface will check as the hot mix is compacted.<br />
<br />
This will happen on windy days and when the mat thickness is thin, normally the wearing course.<br />
<br />
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<br />
====[[#Fat Spots|Fat Spots]]====<br />
<br />
Fat spots are isolated areas where the asphalt cement has come to the surface; these spots can occur very erratically. Bleeding (flushing) occurs when the asphalt cement comes to the surface under traffic. Fat spots can be caused by high moisture in the mixture; if the mixture is very hot, asphalt could run down to the bottom of the truck during transport and cause fat spots when dumped into the paver. Bleeding can be caused by too much asphalt cement in the mixture, or by allowing traffic onto the paved surface before the surface has cooled sufficiently.<br />
<br />
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<br />
===[[#Surface Tolerance|Surface Tolerance]]===<br />
<br />
The importance of staying within the surface tolerance for smoothness cannot be overemphasized.<br />
<br />
Irregularities in the lower courses can usually be corrected by removing or adding material. In the surface course, the entire affected area should be removed promptly and sufficient new material placed to form a true and even surface. If the required smoothness is obtained in the first course, the subsequent courses can usually be placed uniformly by simply setting the paver for the thickness desired.<br />
<br />
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<br />
====[[#Ride Quality|Ride Quality]]====<br />
<br />
<div style="float: right; padding-left: 10px;"><br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Things That Affect Ride Quality'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
Trucks backing into the paver.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
Emptying the paver wings when the hopper is empty.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
Placing segregated mixtures.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
Stopping the paver and allowing the screed to settle into the mat.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
Placing the mat too thin based upon the aggregate size.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
Improper rolling procedures.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
Improper base preparation.<br />
|-<br />
|<br />
<center>8</center><br />
|<br />
Transverse joints not being properly constructed.<br />
|-<br />
|<br />
<center>9</center><br />
|<br />
Malfunction of the paver automation.<br />
|}<br />
</div><br />
<br />
Pavement ride quality is affected by all phases of the construction process; to ensure a smooth finished product, good construction practices must be followed throughout the entire paving process. Following is a list of things that can cause a rough riding surface:<br />
<br />
A special provision for pavement ride quality measurement is included in many paving contracts. <br />
<br />
<br clear=all><br />
<br />
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<br />
===[[#Paving Inspector's Checklist|Paving Inspector's Checklist]]===<br />
<br />
Things to look for during the paving operation include:<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Trucking'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
The trucks should be loaded in multiple drops.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
The trucks should have tarpaulins.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
If required, the truck bed should be insulated.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
Trucks should stop short of the paver and be picked up by the paver.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
The dump bed should not hit the paver when dumped.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
There should be enough trucks to provide a continuous flow of mix to the paver.<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Surface Preparation'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
Ensure existing surface failures are repaired properly.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
Cracks should be cleaned.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
Joints in PCC pavement should be cleaned.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
Rough, uneven surfaces should be leveled.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
Ensure the surface is cleaned of all dust, dirt and other debris.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
Ensure the bond coat has been applied uniformly at the proper yield.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
Ensure the bond coat has broken before paving starts.<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Mixture Placement'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
If automation is required, ensure it’s on and working.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
The operator should not make manual changes while automation is working.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
The screed should be hot.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
The screed extensions should be level with the main screed.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
The augers must be extended if the screed is extended.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
Never empty the paver hopper while paving.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
Keep the level of mix in the hopper above the flow gates.<br />
|-<br />
|<br />
<center>8</center><br />
|<br />
Try to keep the paver moving at a constant speed.<br />
|-<br />
|<br />
<center>9</center><br />
|<br />
When the paver stops, do it as fast as possible.<br />
|-<br />
|<br />
<center>10</center><br />
|<br />
When the paver starts, go to paving speed as fast as possible.<br />
|-<br />
|<br />
<center>11</center><br />
|<br />
Ensure the paver speed matches mixture delivery.<br />
|-<br />
|<br />
<center>12</center><br />
|<br />
Keep the level of mix at the augers as uniform as possible.<br />
|-<br />
|<br />
<center>13</center><br />
|<br />
Ensure the flow gates are set properly.<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Compaction'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
Ensure sufficient compaction capacity is available.<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
Ensure mixture temperature is high enough for proper compaction.<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
The pneumatic roller must be skirted.<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
The breakdown roller should be as close to the paver as possible.<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
The roller pattern should be set up as soon as paving starts.<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
Check the mixture thickness, or yield, within the first three truckloads.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
The roller’s vibratory frequency should match its travel speed.<br />
|-<br />
|<br />
<center>8</center><br />
|<br />
All roller marks should be removed by the finish roller.<br />
|}<br />
<br />
{{top}}<br />
<br />
===[[#Mat Troubleshooting Guide|Mat Troubleshooting Guide]]===<br />
<br />
{| class="wikitable"<br />
|-<br />
!<br />
<center>'''Cause'''</center><br />
!<br />
<center>'''Fix'''</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Mat Tearing at Full Width'''</center><br />
|-<br />
|<br />
<center>Excessive Speed</center><br />
|<br />
<center>Correct at Machine</center><br />
|-<br />
|<br />
<center>Unstable Mix (Temp., Aggregate, etc.)</center><br />
|<br />
<center>Correct at Plant</center><br />
|-<br />
|<br />
<center>Strike-off too Low</center><br />
|<br />
<center>Raise Strike-off</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Mat Tearing at Center Only'''</center><br />
|-<br />
|<br />
<center>Lead Crown Incorrect</center><br />
|<br />
<center>Adjust as Needed</center><br />
|-<br />
|<br />
<center>Worn Screed Plate</center><br />
|<br />
<center>Replace Screed Plate</center><br />
|-<br />
|<br />
<center>Cold Screed</center><br />
|<br />
<center>Check Burners-Review Heating</center><br />
<br />
<center>Procedures</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Mat Tearing at Edges Only'''</center><br />
|-<br />
|<br />
<center>Edger Plate not Square</center><br />
|<br />
<center>Adjust as Needed</center><br />
|-<br />
|<br />
<center>Cold Material Buildup at end of Augers</center><br />
|<br />
<center>Extend Augers</center><br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Mat Tearing Quarter Points Only'''</center><br />
|-<br />
|<br />
<center>Cold Material</center><br />
|<br />
<center>Correct at Plant</center><br />
|-<br />
|<br />
<center>Aggregate Thicker Than Mat</center><br />
|<br />
<center>Check mat Depth-Correct at Plant</center><br />
|-<br />
|<br />
<center>Overloaded Augers</center><br />
|<br />
<center>Machine Adjustment-</center><br />
<br />
<center>a)Auger Speed, b) Flow Gates</center><br />
|-<br />
|<br />
<center>Extensions Incorrectly Installed</center><br />
|<br />
<center>See Machine Operator’s Manual</center><br />
|-<br />
|<br />
<center>Auger Worn Out</center><br />
|<br />
<center>Replace Augers</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Tearing Behind Main With Extensions Retracted'''</center><br />
|-<br />
|<br />
<center>Extensions too low in Front of Main</center><br />
|<br />
<center>Adjust up</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Loose Streak Center of Mat'''</center><br />
|-<br />
|<br />
<center>Insufficient Lead Crown</center><br />
|<br />
<center>Adjust as Needed</center><br />
|-<br />
|<br />
<center>Flow Gates too Low</center><br />
|<br />
<center>Adjust as Needed</center><br />
|-<br />
|<br />
<center>Worn Augers or Kickback Paddles</center><br />
|<br />
<center>Repair or Replace</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Screed Rises at Each Take-Off'''</center><br />
|-<br />
|<br />
<center>Overloaded Augers</center><br />
|<br />
<center>Educate Operator</center><br />
|-<br />
|<br />
<center>Auger Worn Out</center><br />
|<br />
<center>Repair or Replace Augers</center><br />
|-<br />
|<br />
<center>Waiting too Long Between Loads</center><br />
|<br />
<center>Inform Operator to Adjust Paver Speed</center><br />
|-<br />
|<br />
<center>Varying mix Temperature</center><br />
|<br />
<center>Inform Plant and Truck Drivers</center><br />
|-<br />
|<br />
<center>Grade Sensor Mounted at tow Point</center><br />
|<br />
<center>Move Back on Side Arm</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Screed Marks and Poor Surface Texture'''</center><br />
|-<br />
|<br />
<center>Trucks Bumping Paver/Holding Brakes</center><br />
|<br />
<center>Educate Drivers</center><br />
|-<br />
|<br />
<center>Fluctuating Head of Material</center><br />
|<br />
<center>Check Paddle Box Locations, Flow Gate Openings and Speed of Auger-Conveyor</center><br />
|-<br />
|<br />
<center></center><br />
|<br />
<center></center><br />
|-<br />
|<br />
<center>Cold Screed</center><br />
|<br />
<center>Review/Check Screed Heaters and Heating Procedures</center><br />
|-<br />
|<br />
<center>Worn Screed Plate</center><br />
|<br />
<center>Replace Screed Plate</center><br />
|-<br />
|<br />
<center>Worn Augers</center><br />
|<br />
<center>Repair or Replace Augers</center><br />
|-<br />
|<br />
<center>Lack of Vibration</center><br />
|<br />
<center>Increase Vibration at Vibrator Control and/or Reposition and Coordinate Eccentric Weights</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Transition Lines Between Main and Extensions'''</center><br />
|-<br />
|<br />
<center>Extensions set too High or Low</center><br />
|<br />
<center>Adjust Height of Extensions</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Extension Area With Voids'''</center><br />
|-<br />
|<br />
<center>Extension Starved for Material</center><br />
|<br />
<center>Install Additional Augers and Guards for Constant Extended Width – Use Kick-out Paddles for Variable Extended Widths</center><br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Bright Streak Down Center of Mat'''</center><br />
|-<br />
|<br />
<center>Too Much Lead Crown</center><br />
|<br />
<center>Make Necessary Adjustment</center><br />
|-<br />
|<br />
<center>Flow Gates too High</center><br />
|<br />
<center>Adjust as Needed</center><br />
|-<br />
|<br />
<center>Augers Worn Out</center><br />
|<br />
<center>Repair or Replace</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Ripples'''</center><br />
|-<br />
|<br />
<center>Fluctuating Head of Material</center><br />
|<br />
<center>Check Machine Adjustments, Check Material for Inconsistency</center><br />
|-<br />
|<br />
<center>Incorrect Flow Gate Adjustment</center><br />
|<br />
<center>Adjust as Needed</center><br />
|-<br />
|<br />
<center>Erratic Speeds</center><br />
|<br />
<center>Adjust Paver Speeds to Plant Output</center><br />
|-<br />
|<br />
<center>Loose or Worn Depth Crank Assembly</center><br />
|<br />
<center>Repair, Tighten or Replace</center><br />
|-<br />
|<br />
<center>Worn Augers</center><br />
|<br />
<center>Repair or Replace</center><br />
|-<br />
|<br />
<center>Trucks Holding Brakes</center><br />
|<br />
<center>Educate Drivers</center><br />
|-<br />
|<br />
<center>Poor Flow Characteristics</center><br />
|<br />
<center>Correct at Plant</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Hair Line Cracks'''</center><br />
|-<br />
|<br />
<center>Poor Rolling Procedures</center><br />
|<br />
<center>Check Roller Manufacturer Recommendations</center><br />
|-<br />
|<br />
<center>Fluctuating Head of Material</center><br />
|<br />
<center>Review Correct Procedures</center><br />
|-<br />
|<br />
<center>Excessive Speed</center><br />
|<br />
<center>Review Correct Procedures</center><br />
<br />
|-<br />
|<br />
<center>Unstable Mix</center><br />
|<br />
<center>Correct at Plant</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Poor Longitudinal Joints'''</center><br />
|-<br />
|<br />
<center>Delay in Rolling</center><br />
|<br />
<center>Improve Coordination</center><br />
|-<br />
|<br />
<center>Over-Correction of Depth Crank</center><br />
|<br />
<center>Review Correct Procedures</center><br />
|-<br />
|<br />
<center>Overloaded Augers</center><br />
|<br />
<center>Review Correct Procedures</center><br />
|-<br />
|<br />
<center>Head of Material Varying</center><br />
|<br />
<center>Operational Problems/Machine Adjustment</center><br />
|-<br />
|<br />
<center>Too Much Overlap</center><br />
|<br />
<center>Review Correct Procedures</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Poor Transverse Joints'''</center><br />
|-<br />
|<br />
<center>Incorrect Joint Preparation</center><br />
|<br />
<center>See This Manual for Recommended Procedure</center><br />
|-<br />
|<br />
<center>Fluctuating Head of Material</center><br />
|<br />
<center>Check Machine Adjustments; Check Inconsistencies in Material</center><br />
|-<br />
|<br />
<center>Incorrect Nulling Procedure</center><br />
|<br />
<center>See This Manual for Recommended Procedure</center><br />
|-<br />
|<br />
<center>Poor Rolling Operation</center><br />
|<br />
<center>See Appropriate Manufacturer’s Instructions</center><br />
|-<br />
|<br />
<center>Varying Mix Temperature</center><br />
|<br />
<center>Correct at Plant</center><br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Bleeding'''</center><br />
|-<br />
|<br />
<center>Excessive Moisture in Mix</center><br />
|<br />
<center>Correct at Plant</center><br />
|-<br />
|<br />
<center>Excessive Vibration</center><br />
|<br />
<center>Reduce Vibration</center><br />
|-<br />
|<br />
<center>Tack Coat</center><br />
|<br />
<center>Correct on Job</center><br />
|-<br />
! colspan="2" |<br />
<center>'''Screed Rides Nose Down'''</center><br />
|-<br />
|<br />
<center>Screed Depth Crank Improperly Set</center><br />
|<br />
<center>Adjust for Correct Angle of Attack</center><br />
|-<br />
|<br />
<center>Screed Depth Crank Bearings Badly Worn</center><br />
|<br />
<center>Replace Bearings</center><br />
|-<br />
|<br />
<center>Forward Area of Screed Plate Badly Worn</center><br />
|<br />
<center>Replace Screed Plate</center><br />
|-<br />
|<br />
<center>Pre-Strike-Off Set too High</center><br />
|<br />
<center>Make Adjustment as Outlined in Machine Operator’s Manual</center><br />
|-<br />
|<br />
<center>Hydraulic Screed Extensions are set too High When Retracted</center><br />
|<br />
<center>Make Adjustment as Outlined in Hydraulic Screed Extensions Operator’s Manual</center><br />
|}<br />
<br />
{{top}}<br />
<br />
===[[#Temporary Patching with HMA Mixture|Temporary Patching with HMA Mixture]]===<br />
<br />
# The HMA mixture used for patching should be the top course mixture called for on the plans, or in the proposal. However, if the project does not call for HMA mixtures, or the patching is in advance of the paving operation, any mixture readily available and approved by the Engineer can be used. The inspector should contact the Region HMA inspector for guidance.<br />
# Before placing any HMA patch, the area to be patched must be cleaned and a bond coat applied. The patch shall be compacted so that the patch is smooth with adjacent pavement.<br />
<br />
{{top}}<br />
<br />
==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
===[[#Payment|Payment]]===<br />
The amount bid for HMA may be adjusted. These adjustments are based upon the mixture acceptance test results and the pavement in-place density, and are explained in the contract special provisions.<br />
<br />
A Contractor’s payment could range from 105 percent to 50 percent of the bid price; he could be required to remove any sublot, a total lot, or even the total mixture. It is also possible to require the Contractor to remove a sublot of leveling course mixture that has already had the top course mixture placed upon it.<br />
<br />
<br />
{{top}}<br />
<br />
===[[#Documentation|Documentation]]===<br />
<br />
It is required that accurate and complete records be kept for all paving projects. This is true for both the Project Engineer and his staff and for the Contractor’s general superintendent, plant and paving superintendents and all foremen. Trying to reconstruct events at a later time without written notes and complete test data is usually frustrating and often results in conflicting opinions as to exactly what happened. One procedure should constantly be followed: if in doubt about whether the information is important or beneficial, write it down. The results of all daily and periodic tests conducted at the asphalt plant must be recorded on the appropriate MDOT form.<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''HMA Plant Test Reports'''</center><br />
|-<br />
!<br />
<center>'''MDOT Form #'''</center><br />
!<br />
<center>'''Form Title'''</center><br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1839.pdf 1839]</center><br />
|<br />
Testing Of Bituminous Mixtures (Vacuum Worksheet)<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1903.pdf 1903]</center><br />
|<br />
Daily Report of HMA Plant Inspection<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1903B.pdf 1903B]</center><br />
|<br />
Report of Quality Assurance Testing<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1903C.pdf 1903C]</center><br />
|<br />
Daily Report of Contractor's Quality Control Tests<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1905.pdf 1905]</center><br />
|<br />
Testing Of Bituminous Mixtures (Centrifuge Worksheet)<br />
|-<br />
|<br />
<center>1906</center><br />
|<br />
Verification Testing of HMA Mixtures Marshall Density and Percent Air Voids<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1907.pdf 1907]</center><br />
|<br />
Report of Compacted Bituminous Mixture Core Density & Percent Compaction<br />
|-<br />
|<br />
<center>1908</center><br />
|<br />
Verification Testing Of HMA Mixtures Theoretical Maximum Density (TMD)<br />
|-<br />
|<br />
<center>1910</center><br />
|<br />
Pycnometer Calibration Worksheet<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1912.pdf 1912]</center><br />
|<br />
Testing of Bituminous Mixtures Ignition Furnace Worksheet<br />
|-<br />
|<br />
<center>[http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1923B.pdf 1923B]</center><br />
|<br />
Sample Identification<br />
|}<br />
<br />
Information on what occurred on the paving operation must be recorded on the inspector’s daily report and should include:<br />
<br />
{| class="wikitable"<br />
|-<br />
! colspan="2" |<br />
<center>'''Paving Operation Items'''</center><br />
|-<br />
|<br />
<center>1</center><br />
|<br />
Was the bond coat applied properly?<br />
|-<br />
|<br />
<center>2</center><br />
|<br />
What was the temperature of the mix delivered?<br />
|-<br />
|<br />
<center>3</center><br />
|<br />
Did the paver have to stop and wait for trucks?<br />
|-<br />
|<br />
<center>4</center><br />
|<br />
What number and type of rollers were used?<br />
|-<br />
|<br />
<center>5</center><br />
|<br />
Was any surface distress noted?<br />
|-<br />
|<br />
<center>6</center><br />
|<br />
Document the marking of core locations.<br />
|-<br />
|<br />
<center>7</center><br />
|<br />
Document the extraction of the cores from the locations marked (random numbers, date, time, etc.).<br />
|-<br />
|<br />
<center>8</center><br />
|<br />
Document when immediate possession of the extracted cores occurs (core ID, date, time, etc.).<br />
|-<br />
|<br />
<center>9</center><br />
|<br />
Document the taking of loose mix samples from behind the paver.<br />
|-<br />
|<br />
<center>10</center><br />
|<br />
Document the completion of paving courses on lots/sublots of HMA paving material during the day.<br />
|}<br />
<br />
This will allow for a better understanding later if deficiencies develop in the performance of the final product. This information must be detailed and complete. If a conversation is held with other project personnel concerning project activity, the date and location of the conversation should be recorded. The names and titles of any people involved in the discussion should be written down, as well as the topics discussed. The outcome of each conversation must be recorded; who told whom to do what, and what was the reply?<br />
<br />
===[[#Note|Note]]===<br />
<br />
The amount bid for HMA may be adjusted. These adjustments are based upon the mixture acceptance test results and the pavement in-place density, and are explained in the contract special provisions.<br />
<br />
A Contractor’s payment could range from 105 percent to 50 percent of the bid price; he could be required to remove any sublot, a total lot, or even the total mixture. It is also possible to require the Contractor to remove a sublot of leveling course mixture that has already had the top course mixture placed upon it.<br />
<br />
{{top}}<br />
<br />
===[[#MDOT Standard Practice for Random Sampling of HMA Materials|MDOT Standard Practice for Random Sampling of HMA Materials]]===<br />
<br />
<br />
====[[#Sampling In-Place Paving Material|Sampling In-Place Paving Material]]====<br />
<br />
Determine the length of one pavement representing a sublot of material, the width of the pavement and the number of samples, (''n''), needed for each sublot. Following the example below and accompanying Table 1, pick ''n'' numbers corresponding to the length of pavement, followed by picking ''n'' numbers for width determination.<br />
<br />
<br />
'''EXAMPLE'''<br />
<br />
A sublot is defined as 1 mile for this example of in-place 12 foot wide pavement. A specified number of samples are to be taken from each sublot. Since there are 5280 feet in the sublot, pick two numbers using the random number generating calculator, which are then multiplied by 5280. In this instance, the two numbers chosen were: 0.376 and 0.529, for length and transverse offset.<br />
<br />
Thus, the samples will be taken at 1985 and 6.3 feet from the beginning of the pavement.<br />
<br />
Therefore, the first sample should be taken 1985 feet from the beginning of the pavement and 6.3 feet from the designated (right or left) edge of the pavement.<br />
<br />
This process will be repeated for additional samples.<br />
<br />
<br />
{{top}}<br />
===[[#Utilizing Reclaimed Asphalt Pavement (RAP) Millings from the Same Project When Using a Portable Hot Mix Asphalt (HMA)|Utilizing Reclaimed Asphalt Pavement (RAP) Millings from the Same Project When Using a Portable Hot Mix Asphalt (HMA) Plant]]===<br />
<br />
This section serves to provide guidance for utilizing Reclaimed Asphalt Pavement (RAP) millings from the same project when using a portable Hot Mix Asphalt (HMA) plant. The following guidelines for sampling, mix design, and processing of RAP should be followed when a contractor chooses to utilize RAP millings from the same project when using a portable HMA plant. These guidelines will be incorporated into the next version of the HMA Production Manual.<br />
<br />
<ol type="1"><br />
<li>Sampling:<br />
<ol type="A"><br />
<li>Samples to be taken a minimum of every mile in each lane by milling or coring.</li><br />
<li>Sample areas to be repaired.</li><br />
<li>Shoulder samples shall be taken if RAP from shoulder is to be used.</li><br />
<li>Samples shall be taken if visual observations show significant variations in existing pavement mat.</li><br />
<li>Sampling frequency required is based on the percentage/tonnage of RAP that will be utilized on the project.</li><br />
</ol><br />
<li>Mix Design:<br />
<ol type="A"><br />
<li>A sufficient amount of millings or cores shall be taken at each test location to ensure an adequate amount of RAP is obtained to perform a full mix design.</li><br />
<li>No paving shall occur using RAP from the project until a mix design is approved.</li><br />
</ol><br />
<li>Processing RAP:<br />
<ol type="A"><br />
<li>It is not required to have a stockpile with enough material to produce the recycled mixtures approved for the project.</li><br />
<li>RAP should be stockpiled* and tested according to existing requirements (one test per 1000 tons, minimum of three tests).</li><br />
<li>If the millings have aggregates larger than what is required for the mix design, it should be processed (crushed and/or screened) prior to stockpiling*. If aggregates larger than what is required for mix design still exist after processing, the contractor must demonstrate that additional screens are installed on the RAP feed system to ensure that the RAP being introduced into the HMA mixture contains no aggregate larger than the top size aggregate allowed in the mix design.</li><br />
<li>In addition, a RAP scalper screen is required**. The top size of the top scalping screen shall be 1.5” for top and leveling courses and 2” for base courses.</li><br />
</ol><br />
</ol><br />
<br />
&nbsp;*If approved by the engineer, in line crushing and/or screening will be allowed in lieu of processing RAP into a stockpile. The contractor must demonstrate that additional screens are installed on the RAP feed system to ensure that the RAP being introduced into the HMA mixture contains no aggregate larger than the top size aggregate allowed in the mix design.<br /> <br />
&nbsp;**If in line crushing and/or screening is being used to ensure that the RAP being introduced into the HMA mixture contains no aggregate larger than the top size aggregate allowed in the mix design a RAP scalper screen may not be required.<br />
{{top}}<br />
[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Notice_of_Non-Compliance_with_Contract_Requirements&diff=5243Notice of Non-Compliance with Contract Requirements2018-01-31T12:31:56Z<p>JohnsonN23: JohnsonN23 moved page Notice of Non-Complience with Contract Requirements to Notice of Non-Compliance with Contract Requirements</p>
<hr />
<div><center>[http://mdotcf.state.mi.us/public/specbook/files/2012/104%20Control%20of%20Work.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 104]</center><br />
<div style="text-align: center;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/Notice_of_Non-Complience_with_Contract_Requirements Email this Page]</div><br />
<br />
The purpose of the Notice of Non-Compliance with Contract Requirements ([http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165]) is to provide written notice to the Contractor to suspend operations due to one or more of the conditions within [http://mdotcf.state.mi.us/public/specbook/files/2012/104%20Control%20of%20Work.pdf section 104.01.B] of the 2012 Standard Specifications for Construction and orders corrective action to take place by a certain date. <br />
<br />
The original order is to be served at the work site to the Superintendent or Foreman who is in charge of the work. The condition to be corrected should be briefly, but clearly, stated on the [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165]. A reasonable time limit is to be allowed to permit the Contractor to correct the condition. If corrective action has not been completed within the specified time, the work operation is to be shut down without further delay. If corrective action has been taken within the allowed time, the “Notice to Resume Work” section of the [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165] is filled in and distributed as indicated on the [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165]. The purpose of this section on [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165] is to authorize resumption of work which was suspended for non-compliance with contract requirements. It is not used when there has been no suspension of work.<br />
<br />
Examples 1 and 2 below show a sample of how the form can be completed.<br />
<br />
[[File:1165 Contract Compliance Example 1.png|600px|thumbnail|center|1165 Contract Compliance Example 1]]<br />
<br />
[[File:1165 Health and Safety Example 1.pdf.png|600px|thumbnail|center|File:1165 Health and Safety Example 2]]<br />
<br />
<div style="text-align: right;">[mailto:Change?body=http://mdotwiki.state.mi.us/construction/index.php/Notice_of_Non-Complience_with_Contract_Requirements Email this Page]</div><br />
{{top}}<br />
[[Category:Construction Manual]]<br />
[[Category:Division 1]]<br />
[[Category:Section 104]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5242Main Page2018-01-19T13:16:14Z<p>JohnsonN23: /* Recent Major Changes */</p>
<hr />
<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
<br />
<br />
<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
<br />
<br />
<center>[[File:logo.jpg|400px]]</center><br />
<br />
<br />
<br />
<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
<br />
<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
<br />
[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
<br />
[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
<br />
[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
<br />
==[[#Preamble|Preamble]]==<br />
<br />
<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
<br />
<br />
Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
<br />
<br />
{{top}}<br />
<br />
===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
<br />
{{top}}<br />
<br />
== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
<br />
<br />
Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
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<br />
====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
<br />
The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/19/2018</center>||<center>2</center>||<center>[[208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)|208]]</center>||Addition of Notice of termination section.||[http://mdotwiki.state.mi.us/construction/index.php/208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)#Submittal_of_Notice_of_Termination view here]<br />
|-<br />
|<center>1/17/2018</center>||<center>7</center>||<center>[[708_-_Prestressed_Concrete|708]]</center>||Overhaul of information for section 708||[http://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238&oldid=5233 compare]<br />
|-<br />
|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
|-<br />
|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
|-<br />
|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
|-<br />
|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
|-<br />
|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
|-<br />
|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
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====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
|-<br />
|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
|-<br />
|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
|-<br />
|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
|- <br />
|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
|-<br />
|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
|-<br />
|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
|}<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)&diff=5241208 - Soil Erosion and Sedimentation Control (NPDES)2018-01-19T13:02:37Z<p>JohnsonN23: /* Submittal of Notice of Termination */</p>
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<center><span STYLE="font: 60pt arial;">'''208'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Soil Erosion and Sedimentation Control'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/208%20SESC.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 208]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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# MDOT is responsible to provide transportation services in an environmentally sensitive manner. To that end, the following Public Acts, sponsored by the Michigan Department of Environmental Quality (MDEQ) require MDOT to obtain permits and perform various environmental activities to ensure that issues related to a healthy environment are appropriately considered and enacted throughout the life of the state transportation projects and activities.<br />
#: Natural Resources and Environmental Protection Act 1994 PA 451, as amended (the Act).<br />
#: Part 91 of this Act describes MDOT’s responsibilities for Soil Erosion and Sedimentation Control (SESC) measures.<br />
#: Part 31 of this Act describes MDOT’s responsibilities for the National Pollutant Discharge Elimination System (NPDES). Part 21 of Part 31 of this Act describes the regulations related to NPDES.<br />
#: Natural Resources and Environmental Protection Act 1994 PA 451, as amended.<br />
#: Part 31 of this Act describes MDOT’s responsibilities for floodplains and floodways. Any work within a floodplain requires a Floodplain Permit and compliance with the State Flood Hazard Management Plan.<br />
#: Part 301 of this Act describes MDOT’s responsibilities for inland lakes and streams. Any work below the ordinary high water elevation of an inland lake or stream requires an Inland Lakes and Streams Permit.<br />
#: Part 303 of this Act describes MDOT’s responsibilities for wetland protection. Any work within a wetland requires a State Wetland Permit. Any unavoidable wetland impacts resulting from construction activities in a regulated wetland must be properly mitigated on a no net loss basis.<br />
#: Part 315 of this Act describes MDOT’s responsibilities for dam safety. Any construction, enlargement, repair, reconstruction, alteration, removal, or abandonment of any dam requires a Dam Safety Permit.<br />
#: Part 323 of this Act describes MDOT’s responsibilities for shorelands protection and management. Any removal of vegetation, drainage alterations, land alterations or construction within flood risk, high risk erosion area, or environmental areas requires a Shorelands Protection and Management Permit.<br />
#: Part 325 of this Act describes MDOT’s responsibilities for submerged lands on the Great Lakes. Any dredging, filling, or related construction activities in, over, or adjacent to any of the Great Lakes require a Great Lakes Submerged Lands Permit.<br />
#: Part 353 of this Act describes MDOT’s responsibilities for sand dunes protection and management. Any vegetation removal, construction, or earth change within a critical dune area requires a Sand Dune Protection and Management Permit.<br />
# SESC and NPDES procedures have been established which, when properly used, will minimize erosion and sedimentation problems associated with construction projects.<br />
#: SESC: MDEQ has designated MDOT as an Authorized Public Agency (APA), which requires all earth change activities (regardless of size or location) to follow the SESC Plan (also called SESC Manual), at a minimum. The Plan is a contract document; as such, the Contractor and the Engineer are responsible for fulfilling the commitments described in the SESC Plan. As necessary, control measures may be adapted, adjusted, and added to maintain the level of erosion control to comply with the affected Natural Resources and Environmental Protection Act 1994 PA 451, as amended, and project specific permits.<br />
#: The APA designation allows MDOT to undertake earth change activities without obtaining an individual SESC permit. MDOT is subject to audits by MDEQ to determine the conformance to the SESC Plan.<br />
#: NPDES: MDOT need not obtain an NPDES permit. However, a letter of authorization from MDEQ is required. MDOT is subject to site (project) specific NPDES inspections by MDEQ.<br />
# Permits: Non-SESC/NPDES permits are normally obtained during the early preliminary engineering and/or preliminary engineering phases of projects and are to be shown in the contract documents with related pay items. The Engineer is responsible to administer the permit commitments while the Contractor performs the construction activities described in the contract. As necessary, and with the written permission of MDEQ, control measures may be adapted, adjusted, and added to maintain the level of environmental mitigation activities to comply with the intent of the permit and/or the affected Act.<br />
# Project Carryover: The Contractor is responsible to maintain SESC measures in compliance with the SESC plan until adequate ground cover is established. If it is determined adequate ground cover is not established prior to the end of a construction season, the Contractor is responsible for the maintenance of the SESC measures during the shutdown periods should there be an unusually warm period resulting in an event causing erosion and/or when a project is allowed to recommence prior to April 16. The Contractor is responsible for the removal of the SESC measures upon complete ground cover stabilization in the spring or summer of the following construction season. Stabilization is to be considered when planning the project’s completion dates.<br />
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===[[#Soil Erosion and Sedimentation Control Guidlines|Soil Erosion and Sedimentation Control Guidlines]]===<br />
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====[[#Notification|Notification]]====<br />
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While individual permits are not necessary, the Engineer is required to notify the appropriate Municipal Enforcing Agency (MEA) or County Enforcing Agency (CEA) (and County Drain Commissioner if a county drain is impacted) of the project. The MEA or CEA are to receive a copy of the preconstruction meeting minutes. See the SESC Manual for contact information.<br />
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====[[#Training|Training]]====<br />
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Those having decision making authority are required to complete SESC training and successfully pass the exam. This training is available through MSU’s Virtual University program. MDEQ’s web site for learning more about this training is: [http://www.michigan.gov/deq www.michigan.gov/deq]. The exams are offered by MDEQ. The DEQ also offers limited-seating classroom instruction for SESC training. Contact the Construction & Technology Support Area for details and scheduling.<br />
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====[[#Contractor Obligation|Contractor Obligation]]====<br />
<br />
The Contractor is responsible to construct and maintain SESC measures in keeping with the contract documents and in compliance with the SESC Manual. Site specific conditions may result in the need to adapt, adjust, and add control measures to maintain the level of erosion control to comply with the Act. The Engineer is responsible to direct these improvements.<br />
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If the Contractor is working outside the right-of-way for borrow operations, waste or disposal areas, haul roads, storage sites, or any other earth change activity affecting one acre or more or within 500 feet of a lake or stream, the Contractor must obtain an SESC permit from the applicable MEA or CEA, property owner agreement(s), and other applicable permits from MDEQ. A copy of such permits must be submitted to the Engineer.<br />
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====[[#MDEQ|MDEQ]]====<br />
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MDEQ visits project sites in reaction to complaints, due to interest, and while performing audits of MDOT’s APA status. Portions of projects found outside the SESC Manual requirements will result in requests for corrective action. Continued disregard for MDEQ concerns or gross violations may result in a Notice of Violation (NOV) being issued to MDOT. The SESC Manual describes the complaint procedure. The Engineer must direct the appropriate corrective actions for completion within five days of the NOV. If timely corrective actions are not possible, the Engineer must, within the same five days, submit a plan to MDEQ describing the proposed actions.<br />
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===[[#National Pollutant Discharge Elimination System Guidlines|National Pollutant Discharge Elimination System Guidlines]]===<br />
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====[[#Proposal|Proposal]]====<br />
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The proposal for projects subject to NPDES regulations, earth disturbances of one acre or greater will contain a Special Provision for NPDES Inspection and Response. Refer to MDEQ’s Construction Site Storm Water Manual for comprehensive NPDES procedures.<br />
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====[[#Notification|Notification]]====<br />
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For projects subject to NPDES regulations, MDEQ is to receive a Notice of Coverage (NOC) prior to the start of the project describing the project details. Development staff are to prepare the NOC and submit it to Construction and Technology Support Area. Construction and Technology staff will submit the NOC to the Bureau of Highways Engineer of Delivery for signature. Once signed, the NOC is returned to Construction and Technology for processing to MDEQ. MDEQ provides a letter of authorization. The TSC delivery staff is to complete the Notice of Termination and submit it to Construction and Technology upon project stabilization.<br />
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====[[#Training|Training]]====<br />
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Inspectors assigned to perform NPDES inspections are required to be certified Storm Water Operators (SWO). This self-training is coordinated through the Region Office and the testing is offered once per month by MDEQ. Contact the DEQ district office in your area for further details. <br />
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====[[#Administration|Administration]]====<br />
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The Engineer is to administer the contract such that the Contractor constructs and properly maintains all applicable temporary and permanent soil erosion control measures.<br />
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If the Contractor is working outside of the right-of-way for borrow operations, storage or disposal areas, haul roads or any other earth change activity affecting five acres or more, the Contractor must obtain a NPDES permit from the MDEQ. A copy of any such permit must be submitted to the Engineer prior to the start of work.<br />
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====[[#Inspection|Inspection]]====<br />
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The project’s SWO is required to perform inspection for NPDES compliance once per week, and within 24 hours after every precipitation event that results in a discharge from the right of way and ensure that any needed corrective actions are carried out. A log of the inspections and corrective actions shall be maintained on file for review and shall be retained for a period of three years from the date of the inspection or corrective action. The SWO shall document these inspections and corrective actions onto MDOT’s NPDES [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1126.pdf Form 1126]. Deficiencies must be brought to the attention of the Contractor, in writing, and this notice must include a deadline for completing the corrective actions.<br />
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====[[#Corrective Actions Deadline|Corrective Actions Deadline]]====<br />
<br />
If corrective actions are warranted, the SWO will notify the Contractor of the expected actions and provide a timely deadline. The SWO is to record this notification and subsequent corrective actions on the part of the Contractor. The corrective actions should be completed within seven calendar days. Emergency corrective actions, related to 1) sedimentation that occurs in streams, drainage structures, or watercourses, or 2) erosion that affects the support of the roadbed, or 3) the safety of the public should be completed within 24 hours.<br />
<br />
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<br />
===[[#Winter Construction Storm Water Inspection Reports | Winter Construction Storm Water Inspection Reports]]===<br />
<br />
On March 6, 2013, the Michigan Department of Environmental Quality (MDEQ) issued revised procedures for winter construction storm water inspections. MDEQ will no longer accept “frozen ground” as a weather condition for determining construction site inspection frequency. On-site inspections must be resumed within 24 hours of any change in conditions that may allow runoff to occur such as construction operations resuming, rainfall, or warming conditions that will cause snow melt. Detailed weather conditions must be recorded on Form 1126 National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC).<br />
<br />
Michigan’s Public Act 451 Storm Water Construction Regulation 323.2190 requires that construction activities on sites one acre or greater in size with a point source discharge to waters of the state be inspected once per week and within 24 hours after every precipitation event that results in a runoff from the site. During inactive periods when a construction site has been temporarily stabilized and below freezing temperatures predominate, the Certified Storm Water Operator, without performing an on site inspection, may certify on Form 1126 that weather and inactive conditions are such that runoff from the site will not occur.<br />
<br />
'''Certified Storm Water Operator Procedures'''<br />
<ol type="1"><br />
<li>In order to cease on site weekly inspections during periods of inactive earth change activity during periods of time where discharges from the site are unlikely, each of the following must occur:<br />
<ol type="A"><br />
<li>Ensure that earth change activity has ceased. Document this condition on Form 1126.</li><br />
<li>Confirm with an on site inspection that the site has temporary soil erosion and sedimentation control measures implemented to minimize discharge of sediment from the site. Document this condition on Form 1126.</li><br />
<li>Document weather conditions. Weather conditions must be consistently below freezing and unlikely to result in runoff from the site. Document this condition on Form 1126.</li><br />
</ol><br />
Once conditions 1A, 1B, and 1C are met, subsequent weekly inspection documentation may be completed without a site visit by documenting weather conditions for the site location on Form 1126.</li><br />
<br />
<li>On site inspections must resume if any of the following occurs:<br />
<ol type="A"><br />
<li>Earth change activity resumes.</li><br />
<li>Weather conditions are such that snow melt runoff or precipitation in the form of rain is likely to leave the right of way.</li><br />
<li>Weather conditions are consistently above freezing for several days in a row and the possibility exists for surface runoff, an inspection would be required.</li><br />
<li>The site becomes unstabilized.</li><br />
</ol><br />
</li><br />
<li>Once any of the conditions identified in 2A 2D occur, on site inspections shall resume within 24 hours. On site inspections must be performed weekly or within 24 hours of a precipitation event that results in a runoff from the site.</li><br />
</ol><br />
These MDEQ winter inspection requirements apply to all Local Agency Projects which are covered pursuant to the provisions of Michigan’s Permit-by-Rule (R323.2190) of Part 31.<br />
<br />
'''Detailed Reporting of Weather Conditions Affecting a Construction Site'''<br />
<br />
Warming conditions may result in runoff from the site. However, the ground may still be frozen. Typical weather condition documentation that is acceptable may be obtained from any reliable weather source. This documentation should include the reporting period and the high temperature and average for the week.<br />
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<br />
===[[#Non-Compliance Progressive Steps|Non-Compliance Progressive Steps]]===<br />
<br />
The following are suggested progressive steps to take if a Contractor fails to comply with either the SESC or NPDES regulations.<br />
<br />
* Issue a work order describing the work to be completed and the applicable deadlines.<br />
<br />
* Issue a Notice of Non-Compliance with Contract Requirements ([http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165]) for failure to respond to sedimentation and erosion control needs in a timely manner, with language describing a projected project shutdown date and/or curtailment of biweekly progress estimates if the needs still are not resolved within the appropriate time frames. <br />
<br />
* Request maintenance (direct or contract forces) to perform the work. The Contractor is subject to back charges for the costs associated for work performed by others.<br />
<br />
* In certain situations, it is possible to contract with other specialty Contractors to perform work. The Contractor may be subject to back charges for the costs associated for work performed by others.<br />
<br />
* Prepare an interim Contractor Evaluation ([http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1182W.pdf Form 1182W]) documenting problems with SESC/NPDES measures.<br />
<br />
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===[[#Submittal of Notice of Termination|Submittal of Notice of Termination]]===<br />
<br />
The purpose of this construction manual update is to clarify the requirements for submitting a Notice of Termination (NOT) when a project is completely stabilized. <br />
<br />
Part 31 of Michigan Public Act 451, the Natural Resources and Environmental Protection Act (NREPA), requires a Notice of Coverage (NOC) be submitted to the Michigan Department of Environmental Quality (MDEQ) for those projects which create an earth disturbance of five acres or more and have a storm water discharge to the waters of the state. The NOC is submitted during the project design phase. When a NOC is required, a Notice of Termination (NOT) is also required to be submitted to the MDEQ when the project is stabilized. The NOT submittal is critical for compliance with NREPA and the MDOT Storm Water Permit. <br />
<br />
Prior to NOT submittal, the region resource specialist or the region soils engineer must inspect the site and concur that it is stabilized. A site is considered stabilized when all temporary soil erosion and sedimentation control (SESC) measures have been removed, permanent SESC measures installed, and vegetation well established. SESC inspections must continue and be documented until the site is stabilized and the NOT has been submitted to the MDEQ. <br />
<br />
The region resource specialist or region soils engineer will notify the resource specialist in the Bureau of Bridges and Structures Geotechnical Section that the site has been stabilized. The resource specialist in the Bureau of Bridges and Structures will submit the NOT and distribute copies to the respective construction engineer, resource specialist, and/or region soils engineer. <br />
<br />
Once the NOT for a project has been submitted, the site will be subject to final inspection by the MDEQ to ensure the site is completely stabilized prior to MDEQ acceptance of the NOT. Further information can be found in the MDOT SESC Manual, which is available at: <br />
<br />
[http://www.michigan.gov/documents/2006_SESC_Manual_165226_7.pdf http://www.michigan.gov/documents/2006_SESC_Manual_165226_7.pdf]<br />
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==[[#MATERIALS|MATERIALS]]==<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=208_-_Soil_Erosion_and_Sedimentation_Control_(NPDES)&diff=5240208 - Soil Erosion and Sedimentation Control (NPDES)2018-01-19T13:02:14Z<p>JohnsonN23: /* GENERAL */ CMU 2017-009</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''208'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Soil Erosion and Sedimentation Control'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/208%20SESC.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 208]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
# MDOT is responsible to provide transportation services in an environmentally sensitive manner. To that end, the following Public Acts, sponsored by the Michigan Department of Environmental Quality (MDEQ) require MDOT to obtain permits and perform various environmental activities to ensure that issues related to a healthy environment are appropriately considered and enacted throughout the life of the state transportation projects and activities.<br />
#: Natural Resources and Environmental Protection Act 1994 PA 451, as amended (the Act).<br />
#: Part 91 of this Act describes MDOT’s responsibilities for Soil Erosion and Sedimentation Control (SESC) measures.<br />
#: Part 31 of this Act describes MDOT’s responsibilities for the National Pollutant Discharge Elimination System (NPDES). Part 21 of Part 31 of this Act describes the regulations related to NPDES.<br />
#: Natural Resources and Environmental Protection Act 1994 PA 451, as amended.<br />
#: Part 31 of this Act describes MDOT’s responsibilities for floodplains and floodways. Any work within a floodplain requires a Floodplain Permit and compliance with the State Flood Hazard Management Plan.<br />
#: Part 301 of this Act describes MDOT’s responsibilities for inland lakes and streams. Any work below the ordinary high water elevation of an inland lake or stream requires an Inland Lakes and Streams Permit.<br />
#: Part 303 of this Act describes MDOT’s responsibilities for wetland protection. Any work within a wetland requires a State Wetland Permit. Any unavoidable wetland impacts resulting from construction activities in a regulated wetland must be properly mitigated on a no net loss basis.<br />
#: Part 315 of this Act describes MDOT’s responsibilities for dam safety. Any construction, enlargement, repair, reconstruction, alteration, removal, or abandonment of any dam requires a Dam Safety Permit.<br />
#: Part 323 of this Act describes MDOT’s responsibilities for shorelands protection and management. Any removal of vegetation, drainage alterations, land alterations or construction within flood risk, high risk erosion area, or environmental areas requires a Shorelands Protection and Management Permit.<br />
#: Part 325 of this Act describes MDOT’s responsibilities for submerged lands on the Great Lakes. Any dredging, filling, or related construction activities in, over, or adjacent to any of the Great Lakes require a Great Lakes Submerged Lands Permit.<br />
#: Part 353 of this Act describes MDOT’s responsibilities for sand dunes protection and management. Any vegetation removal, construction, or earth change within a critical dune area requires a Sand Dune Protection and Management Permit.<br />
# SESC and NPDES procedures have been established which, when properly used, will minimize erosion and sedimentation problems associated with construction projects.<br />
#: SESC: MDEQ has designated MDOT as an Authorized Public Agency (APA), which requires all earth change activities (regardless of size or location) to follow the SESC Plan (also called SESC Manual), at a minimum. The Plan is a contract document; as such, the Contractor and the Engineer are responsible for fulfilling the commitments described in the SESC Plan. As necessary, control measures may be adapted, adjusted, and added to maintain the level of erosion control to comply with the affected Natural Resources and Environmental Protection Act 1994 PA 451, as amended, and project specific permits.<br />
#: The APA designation allows MDOT to undertake earth change activities without obtaining an individual SESC permit. MDOT is subject to audits by MDEQ to determine the conformance to the SESC Plan.<br />
#: NPDES: MDOT need not obtain an NPDES permit. However, a letter of authorization from MDEQ is required. MDOT is subject to site (project) specific NPDES inspections by MDEQ.<br />
# Permits: Non-SESC/NPDES permits are normally obtained during the early preliminary engineering and/or preliminary engineering phases of projects and are to be shown in the contract documents with related pay items. The Engineer is responsible to administer the permit commitments while the Contractor performs the construction activities described in the contract. As necessary, and with the written permission of MDEQ, control measures may be adapted, adjusted, and added to maintain the level of environmental mitigation activities to comply with the intent of the permit and/or the affected Act.<br />
# Project Carryover: The Contractor is responsible to maintain SESC measures in compliance with the SESC plan until adequate ground cover is established. If it is determined adequate ground cover is not established prior to the end of a construction season, the Contractor is responsible for the maintenance of the SESC measures during the shutdown periods should there be an unusually warm period resulting in an event causing erosion and/or when a project is allowed to recommence prior to April 16. The Contractor is responsible for the removal of the SESC measures upon complete ground cover stabilization in the spring or summer of the following construction season. Stabilization is to be considered when planning the project’s completion dates.<br />
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===[[#Soil Erosion and Sedimentation Control Guidlines|Soil Erosion and Sedimentation Control Guidlines]]===<br />
<br />
<br />
====[[#Notification|Notification]]====<br />
<br />
While individual permits are not necessary, the Engineer is required to notify the appropriate Municipal Enforcing Agency (MEA) or County Enforcing Agency (CEA) (and County Drain Commissioner if a county drain is impacted) of the project. The MEA or CEA are to receive a copy of the preconstruction meeting minutes. See the SESC Manual for contact information.<br />
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<br />
====[[#Training|Training]]====<br />
<br />
Those having decision making authority are required to complete SESC training and successfully pass the exam. This training is available through MSU’s Virtual University program. MDEQ’s web site for learning more about this training is: [http://www.michigan.gov/deq www.michigan.gov/deq]. The exams are offered by MDEQ. The DEQ also offers limited-seating classroom instruction for SESC training. Contact the Construction & Technology Support Area for details and scheduling.<br />
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<br />
====[[#Contractor Obligation|Contractor Obligation]]====<br />
<br />
The Contractor is responsible to construct and maintain SESC measures in keeping with the contract documents and in compliance with the SESC Manual. Site specific conditions may result in the need to adapt, adjust, and add control measures to maintain the level of erosion control to comply with the Act. The Engineer is responsible to direct these improvements.<br />
<br />
If the Contractor is working outside the right-of-way for borrow operations, waste or disposal areas, haul roads, storage sites, or any other earth change activity affecting one acre or more or within 500 feet of a lake or stream, the Contractor must obtain an SESC permit from the applicable MEA or CEA, property owner agreement(s), and other applicable permits from MDEQ. A copy of such permits must be submitted to the Engineer.<br />
<br />
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<br />
====[[#MDEQ|MDEQ]]====<br />
<br />
MDEQ visits project sites in reaction to complaints, due to interest, and while performing audits of MDOT’s APA status. Portions of projects found outside the SESC Manual requirements will result in requests for corrective action. Continued disregard for MDEQ concerns or gross violations may result in a Notice of Violation (NOV) being issued to MDOT. The SESC Manual describes the complaint procedure. The Engineer must direct the appropriate corrective actions for completion within five days of the NOV. If timely corrective actions are not possible, the Engineer must, within the same five days, submit a plan to MDEQ describing the proposed actions.<br />
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===[[#National Pollutant Discharge Elimination System Guidlines|National Pollutant Discharge Elimination System Guidlines]]===<br />
<br />
<br />
====[[#Proposal|Proposal]]====<br />
<br />
The proposal for projects subject to NPDES regulations, earth disturbances of one acre or greater will contain a Special Provision for NPDES Inspection and Response. Refer to MDEQ’s Construction Site Storm Water Manual for comprehensive NPDES procedures.<br />
<br />
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<br />
====[[#Notification|Notification]]====<br />
<br />
For projects subject to NPDES regulations, MDEQ is to receive a Notice of Coverage (NOC) prior to the start of the project describing the project details. Development staff are to prepare the NOC and submit it to Construction and Technology Support Area. Construction and Technology staff will submit the NOC to the Bureau of Highways Engineer of Delivery for signature. Once signed, the NOC is returned to Construction and Technology for processing to MDEQ. MDEQ provides a letter of authorization. The TSC delivery staff is to complete the Notice of Termination and submit it to Construction and Technology upon project stabilization.<br />
<br />
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<br />
====[[#Training|Training]]====<br />
<br />
Inspectors assigned to perform NPDES inspections are required to be certified Storm Water Operators (SWO). This self-training is coordinated through the Region Office and the testing is offered once per month by MDEQ. Contact the DEQ district office in your area for further details. <br />
<br />
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<br />
====[[#Administration|Administration]]====<br />
<br />
The Engineer is to administer the contract such that the Contractor constructs and properly maintains all applicable temporary and permanent soil erosion control measures.<br />
<br />
If the Contractor is working outside of the right-of-way for borrow operations, storage or disposal areas, haul roads or any other earth change activity affecting five acres or more, the Contractor must obtain a NPDES permit from the MDEQ. A copy of any such permit must be submitted to the Engineer prior to the start of work.<br />
<br />
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<br />
====[[#Inspection|Inspection]]====<br />
<br />
The project’s SWO is required to perform inspection for NPDES compliance once per week, and within 24 hours after every precipitation event that results in a discharge from the right of way and ensure that any needed corrective actions are carried out. A log of the inspections and corrective actions shall be maintained on file for review and shall be retained for a period of three years from the date of the inspection or corrective action. The SWO shall document these inspections and corrective actions onto MDOT’s NPDES [http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1126.pdf Form 1126]. Deficiencies must be brought to the attention of the Contractor, in writing, and this notice must include a deadline for completing the corrective actions.<br />
<br />
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<br />
====[[#Corrective Actions Deadline|Corrective Actions Deadline]]====<br />
<br />
If corrective actions are warranted, the SWO will notify the Contractor of the expected actions and provide a timely deadline. The SWO is to record this notification and subsequent corrective actions on the part of the Contractor. The corrective actions should be completed within seven calendar days. Emergency corrective actions, related to 1) sedimentation that occurs in streams, drainage structures, or watercourses, or 2) erosion that affects the support of the roadbed, or 3) the safety of the public should be completed within 24 hours.<br />
<br />
{{top}}<br />
<br />
===[[#Winter Construction Storm Water Inspection Reports | Winter Construction Storm Water Inspection Reports]]===<br />
<br />
On March 6, 2013, the Michigan Department of Environmental Quality (MDEQ) issued revised procedures for winter construction storm water inspections. MDEQ will no longer accept “frozen ground” as a weather condition for determining construction site inspection frequency. On-site inspections must be resumed within 24 hours of any change in conditions that may allow runoff to occur such as construction operations resuming, rainfall, or warming conditions that will cause snow melt. Detailed weather conditions must be recorded on Form 1126 National Pollutant Discharge Elimination System (NPDES) and Soil Erosion and Sedimentation Control (SESC).<br />
<br />
Michigan’s Public Act 451 Storm Water Construction Regulation 323.2190 requires that construction activities on sites one acre or greater in size with a point source discharge to waters of the state be inspected once per week and within 24 hours after every precipitation event that results in a runoff from the site. During inactive periods when a construction site has been temporarily stabilized and below freezing temperatures predominate, the Certified Storm Water Operator, without performing an on site inspection, may certify on Form 1126 that weather and inactive conditions are such that runoff from the site will not occur.<br />
<br />
'''Certified Storm Water Operator Procedures'''<br />
<ol type="1"><br />
<li>In order to cease on site weekly inspections during periods of inactive earth change activity during periods of time where discharges from the site are unlikely, each of the following must occur:<br />
<ol type="A"><br />
<li>Ensure that earth change activity has ceased. Document this condition on Form 1126.</li><br />
<li>Confirm with an on site inspection that the site has temporary soil erosion and sedimentation control measures implemented to minimize discharge of sediment from the site. Document this condition on Form 1126.</li><br />
<li>Document weather conditions. Weather conditions must be consistently below freezing and unlikely to result in runoff from the site. Document this condition on Form 1126.</li><br />
</ol><br />
Once conditions 1A, 1B, and 1C are met, subsequent weekly inspection documentation may be completed without a site visit by documenting weather conditions for the site location on Form 1126.</li><br />
<br />
<li>On site inspections must resume if any of the following occurs:<br />
<ol type="A"><br />
<li>Earth change activity resumes.</li><br />
<li>Weather conditions are such that snow melt runoff or precipitation in the form of rain is likely to leave the right of way.</li><br />
<li>Weather conditions are consistently above freezing for several days in a row and the possibility exists for surface runoff, an inspection would be required.</li><br />
<li>The site becomes unstabilized.</li><br />
</ol><br />
</li><br />
<li>Once any of the conditions identified in 2A 2D occur, on site inspections shall resume within 24 hours. On site inspections must be performed weekly or within 24 hours of a precipitation event that results in a runoff from the site.</li><br />
</ol><br />
These MDEQ winter inspection requirements apply to all Local Agency Projects which are covered pursuant to the provisions of Michigan’s Permit-by-Rule (R323.2190) of Part 31.<br />
<br />
'''Detailed Reporting of Weather Conditions Affecting a Construction Site'''<br />
<br />
Warming conditions may result in runoff from the site. However, the ground may still be frozen. Typical weather condition documentation that is acceptable may be obtained from any reliable weather source. This documentation should include the reporting period and the high temperature and average for the week.<br />
{{top}}<br />
<br />
===[[#Non-Compliance Progressive Steps|Non-Compliance Progressive Steps]]===<br />
<br />
The following are suggested progressive steps to take if a Contractor fails to comply with either the SESC or NPDES regulations.<br />
<br />
* Issue a work order describing the work to be completed and the applicable deadlines.<br />
<br />
* Issue a Notice of Non-Compliance with Contract Requirements ([http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1165.pdf Form 1165]) for failure to respond to sedimentation and erosion control needs in a timely manner, with language describing a projected project shutdown date and/or curtailment of biweekly progress estimates if the needs still are not resolved within the appropriate time frames. <br />
<br />
* Request maintenance (direct or contract forces) to perform the work. The Contractor is subject to back charges for the costs associated for work performed by others.<br />
<br />
* In certain situations, it is possible to contract with other specialty Contractors to perform work. The Contractor may be subject to back charges for the costs associated for work performed by others.<br />
<br />
* Prepare an interim Contractor Evaluation ([http://mdotjboss.state.mi.us/webforms/GetDocument.htm?fileName=1182W.pdf Form 1182W]) documenting problems with SESC/NPDES measures.<br />
<br />
{{top}}<br />
===[[#Submittal of Notice of Termination|Submittal of Notice of Termination]]===<br />
<br />
The purpose of this construction manual update is to clarify the requirements for submitting a Notice of Termination (NOT) when a project is completely stabilized. <br />
<br />
Part 31 of Michigan Public Act 451, the Natural Resources and Environmental Protection Act (NREPA), requires a Notice of Coverage (NOC) be submitted to the Michigan Department of Environmental Quality (MDEQ) for those projects which create an earth disturbance of five acres or more and have a storm water discharge to the waters of the state. The NOC is submitted during the project design phase. When a NOC is required, a Notice of Termination (NOT) is also required to be submitted to the MDEQ when the project is stabilized. The NOT submittal is critical for compliance with NREPA and the MDOT Storm Water Permit. <br />
<br />
Prior to NOT submittal, the region resource specialist or the region soils engineer must inspect the site and concur that it is stabilized. A site is considered stabilized when all temporary soil erosion and sedimentation control (SESC) measures have been removed, permanent SESC measures installed, and vegetation well established. SESC inspections must continue and be documented until the site is stabilized and the NOT has been submitted to the MDEQ. <br />
<br />
The region resource specialist or region soils engineer will notify the resource specialist in the Bureau of Bridges and Structures Geotechnical Section that the site has been stabilized. The resource specialist in the Bureau of Bridges and Structures will submit the NOT and distribute copies to the respective construction engineer, resource specialist, and/or region soils engineer. <br />
<br />
Once the NOT for a project has been submitted, the site will be subject to final inspection by the MDEQ to ensure the site is completely stabilized prior to MDEQ acceptance of the NOT. Further information can be found in the MDOT SESC Manual, which is available at: <br />
<br />
::[http://www.michigan.gov/documents/2006_SESC_Manual_165226_7.pdf http://www.michigan.gov/documents/2006_SESC_Manual_165226_7.pdf]<br />
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==[[#MATERIALS|MATERIALS]]==<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5239Main Page2018-01-17T13:46:42Z<p>JohnsonN23: /* Recent Major Changes */</p>
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<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
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<br />
<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
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<br />
<center>[[File:logo.jpg|400px]]</center><br />
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<br />
<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
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<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
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[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
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[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
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[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
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==[[#Preamble|Preamble]]==<br />
<br />
<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
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<br />
Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
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===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
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== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
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Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
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====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
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The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
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!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/17/2018</center>||<center>7</center>||<center>[[708_-_Prestressed_Concrete|708]]||Overhaul of information for section 708||[http://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238&oldid=5233 compare]<br />
|-<br />
|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
|-<br />
|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
|-<br />
|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
|-<br />
|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
|-<br />
|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
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|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
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|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
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====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
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|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
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|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
|-<br />
|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
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|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
|- <br />
|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
|-<br />
|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
|-<br />
|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
|}<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5238708 - Prestressed Concrete2018-01-17T13:38:02Z<p>JohnsonN23: /* Delivery of Structural Precast Concrete Elements */</p>
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<div><center><span STYLE="font: 60pt arial;">'''708'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Prestressed Concrete'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/708%20Prest%20Concrete%20Beams.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 708]</center><br />
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=[[#GENERAL|GENERAL]]=<br />
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Structural precast concrete members are cast in forms at a facility certified by the Prestressed Concrete Institute (PCI) that is typically a location other than their final position in the structure. Precast concrete beams are also longitudinally prestressed (bonded pre-tensioned strands) and in the case of side-by-side box beams, are transversely prestressed (post-tensioned strands) as well. Prestressing and post-tensioning of precast concrete elements allows for longer, more efficient spans than traditionally reinforced concrete members by introducing pre-compression into the concrete members. The pre-compression force is typically designed to be larger than the effect of applied loads on the element, and therefore, stresses are well controlled. <br />
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Other structural elements that are prestressed include concrete spun poles and in some cases, Prefabricated Bridge Elements and Systems (PBES) other than beams, and sound wall posts and/or panels. <br />
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Structural precast concrete elements that are not prestressed include, but may not be limited to, sound wall posts and panels, culverts, and some PBES. Although structural precast concrete elements are typically fabricated off-site, they require on-site inspection to ensure successful forming, casting, transport, handling, and placement into their final position in the structure. <br />
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==[[#Prestressed Concrete Elements|Prestressed Concrete Elements]]==<br />
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Prestressing, refers to the process of pulling steel tendons in the concrete element into tension usually before the concrete is placed in the forms. After the concrete has hardened, the stressed tendons are released and transmit a compressive stress to the concrete. This offsets tension forces on the concrete and increases the load-carrying capacity of the beam. The result is similar to pressing on the ends of a set of books in order to pick up the whole set of books at once. <br />
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===[[#Prestressing|Prestressing]]===<br />
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Prestressing is generally defined as the preloading of a structure, before application of service loads, to improve its performance in specific ways. Precast concrete elements can be prestressed by pre-tensioning or post-tensioning. Pre-tensioning and post-tensioning are subcategories of prestressing and refer to whether the strands are tensioned before concrete placement or after concrete placement, respectively.<br />
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:'''2) Pre-tensioning:''' Is typically performed at the fabrication facility by using hydraulic jacks to tension seven-wire steel strands in the beam casting bed before the concrete is placed. After the concrete has reached its minimum required release strength, the tensioned strands are released by cutting at each end, which transmits a compressive force to the concrete via bond between the strands and concrete. This offsets tensile stresses in the concrete from dead load and live load and increases the load-carrying capacity of the beam.<br />
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Pre-tensioning is typically used with beams and girders, although it can be used with other elements such as soundwall posts and panels, and other types of PBES such as precast pier caps, precast deck panels, etc. Concrete spun poles are also prestressed.<br />
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:'''2) Post-Tensioning:''' Is performed similarly to pre-tensioning but the tensioning of the strands takes place after the concrete has been placed and cured, and the post-tensioning force is distributed to the concrete via mechanical anchorages. The most common application for post-tensioning in the Department is with side by side box beams. After side by side box beams are erected the grouted keyways between the beams are filled with non-shrink grout and cured. Typically the same seven wire strand used in pre-tensioning is grouped to make a tendon and then placed transverse to the beams centerline through ducts in the intermediate diaphragms. In some cases, more rigid steel rods are used for post-tensioning instead of seven wire strands. The quantity of ducts and the number of strands per duct are proportional to the beam length and depth. After hydraulic jacks are used to tension the tendons to the proper load, the force is locked in and the ducts are filled with non-shrink grout. Post-tensioning side by side box beams reduces differential deflection between adjacent beams and allows more effective live load distribution. Post-tensioning can also be used to transmit a compressive load in pier caps, decks, and PBES in order to offset tensile forces in the element.<br />
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===[[#Beams|Beams]]===<br />
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The Department uses four general kinds of prestressed concrete beams: <br />
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*Side by side box beams <br />
*Spread box beams <br />
*AASHTO I-beams (Types I-IV) <br />
*Bulb-tee beams (e.g. Michigan 1800 beam)<br />
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Prestressed concrete beams vary in width, length, and depth. In general, deeper beams will span longer distances for the same loading conditions. Likewise, deeper beams used for the same span length may have wider beam spacing, and thus carry larger loads. <br />
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The bulb-T beam shape can be a more effective section due to its larger bottom flange that allows more prestressing strands to be used. It also features a wider top flange that makes the shape more stable during handling, transport and erection. <br />
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===[[#Concrete Spun Poles|Concrete Spun Poles]]===<br />
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Prestressed concrete spun poles are used to mount cameras and other Intelligent Transportation System (ITS) equipment at high elevations in order to provide the proper vantage point. Similar to beams, strands are pre-tensioned and then the forms are rotated at a high speed to create a pole that is hollow in the middle. <br />
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===[[#Prefabricated Bridge Elements and Systems (PBES)|Prefabricated Bridge Elements and Systems (PBES)]]===<br />
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PBES can refer to either singular precast elements such as deck panels, footings, columns, pier caps, abutments, etc., or a system that contains multiple elements such as beams with a portion of the deck already attached. The connections between PBES elements or between PBES elements and cast in place elements are of utmost importance. One of the primary advantages of prefabricated elements is the speed at which they can be constructed which minimizes disruption to traffic. If the connections are not properly laid out or constructed, significant delays can result. Therefore, it is important for connection details to be checked by both the Contractor and the Inspector on-site prior to concrete placement or connection of elements, to ensure proper fit-up. All the necessary connection details should be in the design plans. <br />
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The use of templates by the Contractor and fabricator is encouraged. At the fabricator’s plant the dimensions should be checked by both the fabricator’s quality control (QC) personnel and the department’s (QA) quality assurance personnel. The Contractor and Inspector are also encouraged to work closely with the fabricator’s QC and the department’s QA to ensure construction goes as smooth as possible. <br />
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Connection methods for PBES include, but are not limited to:<br />
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*Grouted keyways or pockets <br />
*Grouted mechanical splice sleeves <br />
*Post-tensioning <br />
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===[[#Soundwalls|Soundwalls]]===<br />
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Sound walls, or noise abatement walls, can be detailed differently but typically are constructed of two types of elements, panels and posts. Both the panels and posts may be precast and prestressed or precast with conventional steel reinforcement. <br />
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=[[#FABRICATION OF STRUCTURAL PRECAST CONCRETE|FABRICATION OF STRUCTURAL PRECAST CONCRETE]]=<br />
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==[[#Request for Information Process|Request for Information Process]]==<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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==[[#Shop Drawing Review Process|Shop Drawing Review Process]]==<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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==[[#Nonconformance Program|Nonconformance Program]]==<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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==[[#Prefabrication Meeting|Prefabrication Meeting]]==<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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==[[#Shop Inspection|Shop Inspection]]==<br />
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Quality assurance inspection is performed on most structural precast concrete elements such as prestressed beams, culverts 20 foot and greater, sound wall posts and panels, MSE wall panels, concrete spun poles, and other prefabricated bridge elements for accelerated bridge construction. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit to perform shop inspection at structural precast concrete fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 708.2. The inspector then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 708.3 for more information on the fabrication inspection process. <br />
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[[File:Fig_708.2.png|600px|thumbnail|center|Figure 708.2 - Approved for Use stamp]]<br />
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[[File:Fig_708.3.png|600px|thumbnail|center|Figure 708.3 – Structural Precast Concrete Fabrication Inspection Flowchart]]<br />
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==[[#Addressing Deficiencies|Addressing Deficiencies]]==<br />
<br />
As part of the shop inspection process, the MDOT shop inspector will note the condition of structural precast elements as they are removed from the forms, and note if corrective repairs are required prior to approving the element for use on MDOT projects. These repairs are typically done prior to being shipped to the project site, however, there are some circumstances where repairs will be required on site, so the construction inspector should be familiar with common deficiencies. The Structural Fabrication Unit has developed, with the assistance of the Materials Section, repair procedures to assist with evaluating fabricator proposed concrete repairs to fabricated structural precast concrete elements for MDOT projects. <br />
<br />
Fabricated structural precast concrete elements may contain defects from the fabrication process or can be damaged from the removal of formwork, handling, and shipping. The fabricator is required to notify the MDOT QA shop inspector of all defects and/or damages to fabricated elements and propose a repair procedure to MDOT for acceptance. MDOT will thoroughly evaluate the proposed procedure and provide a response. The repair procedure will be either be approved, rejected or approved as noted. The fabricator must receive MDOT approval before performing the repair. Structural precast concrete repairs can be generalized into the following categories:<br />
<br />
:*Minor Surface Defects (air holes, minor honeycombing, gouges etc.) See Figure 708.4 through Figure 708.06 for minor surface defects <br />
<br />
[[File:Fig_708.4.png|600px|thumbnail|center|Figure 708.4 – Minor surface defect – air holes greater than 1” in any direction]]<br />
<br />
[[File:Fig_708.5.png|600px|thumbnail|center|Figure 708.5 – Minor surface defect – rubber gasket crease]]<br />
<br />
[[File:Fig_708.6.png|600px|thumbnail|center|Figure 708.6 – Minor surface defect – honeycombing of PCI girder]]<br />
<br />
:*Major Surface Defects (moderate honeycombing, etc.) <br />
:*Minor Damages (spalls, cracks, broken corners, etc.) See Figure 708.7 through Figure 708.8 for examples of minor damages <br />
<br />
[[File:Fig_708.7.png|600px|thumbnail|center|Figure 708.7 – Minor damage – broken corner at end of PCI girder]]<br />
<br />
[[File:Fig_708.8.png|600px|thumbnail|center|Figure 708.8 – Minor damage – spalled bottom corner at the end of a box beam]]<br />
<br />
:*Other, which includes major damage and elements subject to rejection. See Figure 708.9 and Figure 708.10 for example of major deficiencies. <br />
<br />
[[File:Fig_708.9.png|600px|thumbnail|center|Figure 708.9 – Minor Damage – spalled bottom corner and exposed prestressing strands at the end of a box beam]]<br />
<br />
[[File:Fig_708.10.png|600px|thumbnail|center|Figure 708.10 – Major damage – improper consolidation of concrete and expose prestressing strands and steel reinforcement]]<br />
<br />
The repair of deficiencies to the satisfaction of the Structural Fabrication Unit, or rejection of elements for major deficiencies will occur at the fabrication facility prior to shipment to the site. It is important to note the Approved for Use stamp on all structural precast elements prior to incorporation into the project.<br />
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=[[#MATERIALS|MATERIALS]]=<br />
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<span style="color: red"> -Reserved- </span><br />
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=[[#CONSTRUCTION|CONSTRUCTION]]=<br />
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==[[#Delivery of Structural Precast Concrete Elements|Delivery of Structural Precast Concrete Elements]]==<br />
<br />
Project personnel are required to use the following procedure for acceptance of fabricated structural prestressed concrete elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.04.06.B of the Materials Quality Procedures Manual]. These structural prestressed concrete elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. If elements and the Bill of Lading arrive at the project site or the contractor’s yard without an approval stamp, the element must be rejected.<br />
<br />
Acceptance of fabricated structural prestressed concrete elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.04] of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
<br />
<ol type="A"><br />
<li>Fabrication Inspection Acceptance: Structural elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements. Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.</li><br />
<li>Visual Inspection Acceptance: The engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural elements. Additionally, the engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).</li><br />
</ol><br />
<br />
The Engineer must visually inspect the product for signs of damage that may occur as a result of shipping and handling. This visual information should be documented on the inspector’s daily report. Look for deficiencies in the beams in the form of cracks, honeycombing, spalls, or cold joints. Crack widths can be measured with a crack comparator as seen in Figure 708-11. Bring any damage to the attention of the Engineer and make a record of the damage in the daily report. Take measurements of crack width and length as well as spall measurements and photographs. Also note in the daily report when the beams arrive in good condition. If there is any concern regarding whether beams were approved for use or whether damage is acceptable, contact the [mailto:MDOT-StructuralFabrication@michigan.gov Structural Fabrication Unit].<br />
<br />
The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 708.11 for a sample inspection memorandum. <br />
<br />
[[File:Sample Structural Precast Concrete Memo.jpg|600px|thumbnail|center|Figure 708-11 Sample Structural Precast Concrete Memo]]<br />
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==[[#Structural Precast Concrete Field Storage|Structural Precast Concrete Field Storage]]==<br />
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Once the structural precast concrete element has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural precast concrete elements:<br />
<br />
:*Support beams off the ground to prevent moisture and deleterious material intrusion <br />
:*Support beams across the full width on two battens, each greater than 4 inches wide. Support stacked beams, one above the other along the same vertical plane at each ends of the beams. <br />
:*Support the beams on level, stable ground, avoid storing beams near side slopes, or areas near heavy construction traffic <br />
:*Do not support the beam at more than two points <br />
:*Taller, long span I-beam shapes may need to be laterally braced on site <br />
:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
:*Related items such as bearings and bridge railing should also be protected from damage, dirt, and corrosion. <br />
<br />
Ensure the lifting devices are removed once the beam has been placed in its final position on the substructure. <br />
<br />
Per Section 105 of the Standard Specifications for Construction, the Engineer reserves the right to reject any shipped product that shows visual signs of damage or does not meet specification requirements. <br />
<br />
Considerable care should be exercised when handling structural precast concrete elements. In many cases, there is no way to repair a damaged element short of re-fabrication. Prestressed beams should be kept in an upright position at all times, as the beam’s own dead weight counter acts the internal prestressing force to keep the beam stable. The method of stockpiling and transporting members is covered in detail in subsection 708.03 of the Standard Specifications for Construction. Beams shall be supported at two points no more than 3 feet (1 m) from the ends of the beams. <br />
<br />
Check beam markings and compare to the beam layout sheet in the plans. Make sure the beams are placed in the right location and direction. They may fit in more than one place but there is only one correct location and direction for each beam. <br />
<br />
Lifting devices, usually loops of seven wire strand, are cast into the member and these should be the only attachment used when moving a beam. The lifting device must have adequate capacity to lift the beams and set them in place. Never lift the beam near the center. If the beam has to be set down before being placed, never allow it to be supported at the center. Crib it under the ends. The prestressing forces pulling in on the ends of the beam hold up the dead weight of the beam. If the beam is supported or lifted at the center, the prestressing forces will cause the beam to crack. If cracks are noted to be greater than 0.006 inches, the Structural Fabrication Unit must be contacted.<br />
<br />
[[File:Fig_708-11.png|600px|thumbnail|center|Figure 708-12 Crack comparator for measuring crack width]]<br />
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==[[#Erection of Box Beams|Erection of Box Beams]]==<br />
<br />
The beam widths should be checked to ensure that box beams will fit properly on the substructure units. Beam bearing pads must be shimmed in an approved manner during erection (when necessary) to provide full bearing contact with the bottoms of the beams. This needs to be checked on every box beam. Box beams may camber more than anticipated, or may experience transverse rotation such that they do not sit flush on the sole plates, which are typically beveled to accommodate camber and vertical alignment angles. Note in the daily report when the beam erection has been completed. <br />
<br />
At expansion bearings, ensure the beams line up with the position dowel holes, and ensure the holes are filled with hot poured rubber sealant type filler at least 3 inches above the position dowels. Ensure the remainder of the hole is filled with Type H-1 grout. Ensure holes at fixed bearings are filled with Type H-1 grout. <br />
<br />
For side by side box beams, the beams should be set with spaces between them as specified on the plans or shop drawings and with the seal washers placed around the transverse post tensioning conduit holes. The space between the beams should be completely filled, full depth, with R-2 grout mortar and cured for at least 48 hours. Ensure the contractor does not grout when temperatures are below 40° F. The deck width should be measured by the Contractor as soon as the beams are set to assure that post tensioning rods or strand will be fabricated to the proper length. <br />
<br />
All hardware dimensions must be as shown on the plans or shop drawings. Tendons or rods for post-tensioning should be tensioned with calibrated jacks according to a Contractor-supplied calibration chart showing the corresponding jack pressures and elongations necessary to gradually build up to the required post-tensioning force. After the post-tensioning is complete, ensure the conduit is flushed with water, then compressed air. The tendon or rod holes will be grouted under pressure with Type E-1 grout for steel tendons or rods as described in subsection 708.03B of the Standard Specifications for Construction. <br />
<br />
'''Do not stand behind the jacking machine or rod holes during jacking procedures. If a tendon or rod snaps, it can cause serious injury.'''<br />
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==[[#Erection of I-Girders and Michigan 1800 Girders|Erection of I-Girders and Michigan 1800 Girders]]==<br />
<br />
Girder bearing pads must be shimmed (when necessary) in an approved manner during erection to provide full bearing contact with the bottoms of the girder. Beveled sole plates are also required for I-girders. This needs to be checked on every girder. Note in the daily report when the girder erection has been completed. <br />
<br />
I-Girders and especially Michigan 1800 girders can be more prone to sweep or transverse deflection. For this reason they should be rigidly blocked in place to ensure proper spacing between girders before any deck or diaphragm forming.<br />
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==[[#Erection of Spun Concrete Poles|Erection of Spun Concrete Poles]]==<br />
<br />
Spun concrete poles typically have less concrete clear cover from the outside of the element to the prestressing strands than prestressed beams. Pay particular attention to any cracking and bring it to the attention of the Engineer. During installation, the poles must only be lifted and stored using the locations and methods shown on the approved shop drawings or manufacturer’s instructions. Spun concrete poles must be safely secured after being placed in the drilled shaft installation before the concrete foundation is poured and cured.<br />
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==[[#Erection of Sound Walls|Erection of Sound Walls]]==<br />
<br />
In most cases the sound wall panels are attached to the posts using tongue and groove joints. It is important during erection that the panels are lowered slowly into position and do not crack or spall the posts. If the posts are prestressed, and contain grout pockets, the grout pockets at the ends of the posts must be filled with non-shrink grout and should be free of cracks. In order to properly inspect prestressed posts a ladder should be used to visually inspect the tops of the posts. Any cracking whether from damage or shrinkage, or spalling, should be cause for concern as the horizontal surface will be subject to moisture and chloride intrusion leading to rapid deterioration of the posts.<br />
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=[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]=<br />
<br />
There are three methods of payment for structural precast concrete elements as described below. All three methods are shown in Figure 708.03. No method of payment relieves the Fabricator or Contractor from damage due to transporting, storing on the project site, or erecting the elements. Additional information on payment can be found in Section 109 of the Standard Specifications for Construction.<br />
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==[[#Stockpile Payment|Stockpile Payment]]==<br />
<br />
See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.04.06] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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==[[#Partial Shipment Payment|Partial Shipment Payment]]==<br />
<br />
After the Fabricator has shipped a portion of the structural concrete elements to the project site verify that the shipping documentation and elements have been stamped approved for use, and inspect the product for signs of damage that may have occurred as a result of shipping and handling. If the shipping documentation and elements are stamped approved for use and there is no shipping and handling damage partial shipment payment may be made. The approved for use stamp indicates that all materials and processes during fabrication were according to specifications; a Fabrication Inspection memo will be sent to the TSC after final shipment. <br />
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==[[#Final Shipment Payment|Final Shipment Payment]]==<br />
<br />
As with partial shipments, after the Fabricator has sent the final shipment of the structural concrete elements to the project site verify that the shipping documentation and elements have been stamped approved for use, and inspect the product for signs of damage that may have occurred as a result of shipping and handling. If the shipping documentation and elements are stamped approved for use and there is no shipping and handling damage partial shipment payment may be made. The approved for use stamp indicates that all materials and processes during fabrication were according to specifications; a Fabrication Inspection memo will be sent to the TSC after final shipment. <br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Sample_Structural_Precast_Concrete_Memo.jpg&diff=5237File:Sample Structural Precast Concrete Memo.jpg2018-01-17T13:37:08Z<p>JohnsonN23: </p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5236708 - Prestressed Concrete2018-01-17T13:35:22Z<p>JohnsonN23: update 1/17/2018</p>
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<div><center><span STYLE="font: 60pt arial;">'''708'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Prestressed Concrete'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/708%20Prest%20Concrete%20Beams.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 708]</center><br />
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=[[#GENERAL|GENERAL]]=<br />
<br />
Structural precast concrete members are cast in forms at a facility certified by the Prestressed Concrete Institute (PCI) that is typically a location other than their final position in the structure. Precast concrete beams are also longitudinally prestressed (bonded pre-tensioned strands) and in the case of side-by-side box beams, are transversely prestressed (post-tensioned strands) as well. Prestressing and post-tensioning of precast concrete elements allows for longer, more efficient spans than traditionally reinforced concrete members by introducing pre-compression into the concrete members. The pre-compression force is typically designed to be larger than the effect of applied loads on the element, and therefore, stresses are well controlled. <br />
<br />
Other structural elements that are prestressed include concrete spun poles and in some cases, Prefabricated Bridge Elements and Systems (PBES) other than beams, and sound wall posts and/or panels. <br />
<br />
Structural precast concrete elements that are not prestressed include, but may not be limited to, sound wall posts and panels, culverts, and some PBES. Although structural precast concrete elements are typically fabricated off-site, they require on-site inspection to ensure successful forming, casting, transport, handling, and placement into their final position in the structure. <br />
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==[[#Prestressed Concrete Elements|Prestressed Concrete Elements]]==<br />
<br />
Prestressing, refers to the process of pulling steel tendons in the concrete element into tension usually before the concrete is placed in the forms. After the concrete has hardened, the stressed tendons are released and transmit a compressive stress to the concrete. This offsets tension forces on the concrete and increases the load-carrying capacity of the beam. The result is similar to pressing on the ends of a set of books in order to pick up the whole set of books at once. <br />
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===[[#Prestressing|Prestressing]]===<br />
<br />
Prestressing is generally defined as the preloading of a structure, before application of service loads, to improve its performance in specific ways. Precast concrete elements can be prestressed by pre-tensioning or post-tensioning. Pre-tensioning and post-tensioning are subcategories of prestressing and refer to whether the strands are tensioned before concrete placement or after concrete placement, respectively.<br />
<br />
:'''2) Pre-tensioning:''' Is typically performed at the fabrication facility by using hydraulic jacks to tension seven-wire steel strands in the beam casting bed before the concrete is placed. After the concrete has reached its minimum required release strength, the tensioned strands are released by cutting at each end, which transmits a compressive force to the concrete via bond between the strands and concrete. This offsets tensile stresses in the concrete from dead load and live load and increases the load-carrying capacity of the beam.<br />
<br />
Pre-tensioning is typically used with beams and girders, although it can be used with other elements such as soundwall posts and panels, and other types of PBES such as precast pier caps, precast deck panels, etc. Concrete spun poles are also prestressed.<br />
<br />
:'''2) Post-Tensioning:''' Is performed similarly to pre-tensioning but the tensioning of the strands takes place after the concrete has been placed and cured, and the post-tensioning force is distributed to the concrete via mechanical anchorages. The most common application for post-tensioning in the Department is with side by side box beams. After side by side box beams are erected the grouted keyways between the beams are filled with non-shrink grout and cured. Typically the same seven wire strand used in pre-tensioning is grouped to make a tendon and then placed transverse to the beams centerline through ducts in the intermediate diaphragms. In some cases, more rigid steel rods are used for post-tensioning instead of seven wire strands. The quantity of ducts and the number of strands per duct are proportional to the beam length and depth. After hydraulic jacks are used to tension the tendons to the proper load, the force is locked in and the ducts are filled with non-shrink grout. Post-tensioning side by side box beams reduces differential deflection between adjacent beams and allows more effective live load distribution. Post-tensioning can also be used to transmit a compressive load in pier caps, decks, and PBES in order to offset tensile forces in the element.<br />
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===[[#Beams|Beams]]===<br />
<br />
The Department uses four general kinds of prestressed concrete beams: <br />
<br />
*Side by side box beams <br />
*Spread box beams <br />
*AASHTO I-beams (Types I-IV) <br />
*Bulb-tee beams (e.g. Michigan 1800 beam)<br />
<br />
Prestressed concrete beams vary in width, length, and depth. In general, deeper beams will span longer distances for the same loading conditions. Likewise, deeper beams used for the same span length may have wider beam spacing, and thus carry larger loads. <br />
<br />
The bulb-T beam shape can be a more effective section due to its larger bottom flange that allows more prestressing strands to be used. It also features a wider top flange that makes the shape more stable during handling, transport and erection. <br />
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===[[#Concrete Spun Poles|Concrete Spun Poles]]===<br />
<br />
Prestressed concrete spun poles are used to mount cameras and other Intelligent Transportation System (ITS) equipment at high elevations in order to provide the proper vantage point. Similar to beams, strands are pre-tensioned and then the forms are rotated at a high speed to create a pole that is hollow in the middle. <br />
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===[[#Prefabricated Bridge Elements and Systems (PBES)|Prefabricated Bridge Elements and Systems (PBES)]]===<br />
<br />
PBES can refer to either singular precast elements such as deck panels, footings, columns, pier caps, abutments, etc., or a system that contains multiple elements such as beams with a portion of the deck already attached. The connections between PBES elements or between PBES elements and cast in place elements are of utmost importance. One of the primary advantages of prefabricated elements is the speed at which they can be constructed which minimizes disruption to traffic. If the connections are not properly laid out or constructed, significant delays can result. Therefore, it is important for connection details to be checked by both the Contractor and the Inspector on-site prior to concrete placement or connection of elements, to ensure proper fit-up. All the necessary connection details should be in the design plans. <br />
<br />
The use of templates by the Contractor and fabricator is encouraged. At the fabricator’s plant the dimensions should be checked by both the fabricator’s quality control (QC) personnel and the department’s (QA) quality assurance personnel. The Contractor and Inspector are also encouraged to work closely with the fabricator’s QC and the department’s QA to ensure construction goes as smooth as possible. <br />
<br />
Connection methods for PBES include, but are not limited to:<br />
<br />
*Grouted keyways or pockets <br />
*Grouted mechanical splice sleeves <br />
*Post-tensioning <br />
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===[[#Soundwalls|Soundwalls]]===<br />
<br />
Sound walls, or noise abatement walls, can be detailed differently but typically are constructed of two types of elements, panels and posts. Both the panels and posts may be precast and prestressed or precast with conventional steel reinforcement. <br />
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=[[#FABRICATION OF STRUCTURAL PRECAST CONCRETE|FABRICATION OF STRUCTURAL PRECAST CONCRETE]]=<br />
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==[[#Request for Information Process|Request for Information Process]]==<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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==[[#Shop Drawing Review Process|Shop Drawing Review Process]]==<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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==[[#Nonconformance Program|Nonconformance Program]]==<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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==[[#Prefabrication Meeting|Prefabrication Meeting]]==<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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==[[#Shop Inspection|Shop Inspection]]==<br />
<br />
Quality assurance inspection is performed on most structural precast concrete elements such as prestressed beams, culverts 20 foot and greater, sound wall posts and panels, MSE wall panels, concrete spun poles, and other prefabricated bridge elements for accelerated bridge construction. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit to perform shop inspection at structural precast concrete fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 708.2. The inspector then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 708.3 for more information on the fabrication inspection process. <br />
<br />
[[File:Fig_708.2.png|600px|thumbnail|center|Figure 708.2 - Approved for Use stamp]]<br />
<br />
[[File:Fig_708.3.png|600px|thumbnail|center|Figure 708.3 – Structural Precast Concrete Fabrication Inspection Flowchart]]<br />
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==[[#Addressing Deficiencies|Addressing Deficiencies]]==<br />
<br />
As part of the shop inspection process, the MDOT shop inspector will note the condition of structural precast elements as they are removed from the forms, and note if corrective repairs are required prior to approving the element for use on MDOT projects. These repairs are typically done prior to being shipped to the project site, however, there are some circumstances where repairs will be required on site, so the construction inspector should be familiar with common deficiencies. The Structural Fabrication Unit has developed, with the assistance of the Materials Section, repair procedures to assist with evaluating fabricator proposed concrete repairs to fabricated structural precast concrete elements for MDOT projects. <br />
<br />
Fabricated structural precast concrete elements may contain defects from the fabrication process or can be damaged from the removal of formwork, handling, and shipping. The fabricator is required to notify the MDOT QA shop inspector of all defects and/or damages to fabricated elements and propose a repair procedure to MDOT for acceptance. MDOT will thoroughly evaluate the proposed procedure and provide a response. The repair procedure will be either be approved, rejected or approved as noted. The fabricator must receive MDOT approval before performing the repair. Structural precast concrete repairs can be generalized into the following categories:<br />
<br />
:*Minor Surface Defects (air holes, minor honeycombing, gouges etc.) See Figure 708.4 through Figure 708.06 for minor surface defects <br />
<br />
[[File:Fig_708.4.png|600px|thumbnail|center|Figure 708.4 – Minor surface defect – air holes greater than 1” in any direction]]<br />
<br />
[[File:Fig_708.5.png|600px|thumbnail|center|Figure 708.5 – Minor surface defect – rubber gasket crease]]<br />
<br />
[[File:Fig_708.6.png|600px|thumbnail|center|Figure 708.6 – Minor surface defect – honeycombing of PCI girder]]<br />
<br />
:*Major Surface Defects (moderate honeycombing, etc.) <br />
:*Minor Damages (spalls, cracks, broken corners, etc.) See Figure 708.7 through Figure 708.8 for examples of minor damages <br />
<br />
[[File:Fig_708.7.png|600px|thumbnail|center|Figure 708.7 – Minor damage – broken corner at end of PCI girder]]<br />
<br />
[[File:Fig_708.8.png|600px|thumbnail|center|Figure 708.8 – Minor damage – spalled bottom corner at the end of a box beam]]<br />
<br />
:*Other, which includes major damage and elements subject to rejection. See Figure 708.9 and Figure 708.10 for example of major deficiencies. <br />
<br />
[[File:Fig_708.9.png|600px|thumbnail|center|Figure 708.9 – Minor Damage – spalled bottom corner and exposed prestressing strands at the end of a box beam]]<br />
<br />
[[File:Fig_708.10.png|600px|thumbnail|center|Figure 708.10 – Major damage – improper consolidation of concrete and expose prestressing strands and steel reinforcement]]<br />
<br />
The repair of deficiencies to the satisfaction of the Structural Fabrication Unit, or rejection of elements for major deficiencies will occur at the fabrication facility prior to shipment to the site. It is important to note the Approved for Use stamp on all structural precast elements prior to incorporation into the project.<br />
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=[[#MATERIALS|MATERIALS]]=<br />
<br />
<span style="color: red"> -Reserved- </span><br />
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<br />
=[[#CONSTRUCTION|CONSTRUCTION]]=<br />
<br />
==[[#Delivery of Structural Precast Concrete Elements|Delivery of Structural Precast Concrete Elements]]==<br />
<br />
Project personnel are required to use the following procedure for acceptance of fabricated structural prestressed concrete elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.04.06.B of the Materials Quality Procedures Manual]. These structural prestressed concrete elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. If elements and the Bill of Lading arrive at the project site or the contractor’s yard without an approval stamp, the element must be rejected.<br />
<br />
Acceptance of fabricated structural prestressed concrete elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.04] of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
<br />
<ol type="A"><br />
<li>Fabrication Inspection Acceptance: Structural elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements. Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.</li><br />
<li>Visual Inspection Acceptance: The engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural elements. Additionally, the engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).</li><br />
</ol><br />
<br />
The Engineer must visually inspect the product for signs of damage that may occur as a result of shipping and handling. This visual information should be documented on the inspector’s daily report. Look for deficiencies in the beams in the form of cracks, honeycombing, spalls, or cold joints. Crack widths can be measured with a crack comparator as seen in Figure 708-11. Bring any damage to the attention of the Engineer and make a record of the damage in the daily report. Take measurements of crack width and length as well as spall measurements and photographs. Also note in the daily report when the beams arrive in good condition. If there is any concern regarding whether beams were approved for use or whether damage is acceptable, contact the [mailto:MDOT-StructuralFabrication@michigan.gov Structural Fabrication Unit].<br />
<br />
The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 708.11 for a sample inspection memorandum. <br />
<br />
[[File:Fig_708-11.png|600px|thumbnail|center|Figure 708-11 Crack comparator for measuring crack width]]<br />
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==[[#Structural Precast Concrete Field Storage|Structural Precast Concrete Field Storage]]==<br />
<br />
Once the structural precast concrete element has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural precast concrete elements:<br />
<br />
:*Support beams off the ground to prevent moisture and deleterious material intrusion <br />
:*Support beams across the full width on two battens, each greater than 4 inches wide. Support stacked beams, one above the other along the same vertical plane at each ends of the beams. <br />
:*Support the beams on level, stable ground, avoid storing beams near side slopes, or areas near heavy construction traffic <br />
:*Do not support the beam at more than two points <br />
:*Taller, long span I-beam shapes may need to be laterally braced on site <br />
:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
:*Related items such as bearings and bridge railing should also be protected from damage, dirt, and corrosion. <br />
<br />
Ensure the lifting devices are removed once the beam has been placed in its final position on the substructure. <br />
<br />
Per Section 105 of the Standard Specifications for Construction, the Engineer reserves the right to reject any shipped product that shows visual signs of damage or does not meet specification requirements. <br />
<br />
Considerable care should be exercised when handling structural precast concrete elements. In many cases, there is no way to repair a damaged element short of re-fabrication. Prestressed beams should be kept in an upright position at all times, as the beam’s own dead weight counter acts the internal prestressing force to keep the beam stable. The method of stockpiling and transporting members is covered in detail in subsection 708.03 of the Standard Specifications for Construction. Beams shall be supported at two points no more than 3 feet (1 m) from the ends of the beams. <br />
<br />
Check beam markings and compare to the beam layout sheet in the plans. Make sure the beams are placed in the right location and direction. They may fit in more than one place but there is only one correct location and direction for each beam. <br />
<br />
Lifting devices, usually loops of seven wire strand, are cast into the member and these should be the only attachment used when moving a beam. The lifting device must have adequate capacity to lift the beams and set them in place. Never lift the beam near the center. If the beam has to be set down before being placed, never allow it to be supported at the center. Crib it under the ends. The prestressing forces pulling in on the ends of the beam hold up the dead weight of the beam. If the beam is supported or lifted at the center, the prestressing forces will cause the beam to crack. If cracks are noted to be greater than 0.006 inches, the Structural Fabrication Unit must be contacted.<br />
<br />
[[File:Fig_708-11.png|600px|thumbnail|center|Figure 708-12 Crack comparator for measuring crack width]]<br />
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==[[#Erection of Box Beams|Erection of Box Beams]]==<br />
<br />
The beam widths should be checked to ensure that box beams will fit properly on the substructure units. Beam bearing pads must be shimmed in an approved manner during erection (when necessary) to provide full bearing contact with the bottoms of the beams. This needs to be checked on every box beam. Box beams may camber more than anticipated, or may experience transverse rotation such that they do not sit flush on the sole plates, which are typically beveled to accommodate camber and vertical alignment angles. Note in the daily report when the beam erection has been completed. <br />
<br />
At expansion bearings, ensure the beams line up with the position dowel holes, and ensure the holes are filled with hot poured rubber sealant type filler at least 3 inches above the position dowels. Ensure the remainder of the hole is filled with Type H-1 grout. Ensure holes at fixed bearings are filled with Type H-1 grout. <br />
<br />
For side by side box beams, the beams should be set with spaces between them as specified on the plans or shop drawings and with the seal washers placed around the transverse post tensioning conduit holes. The space between the beams should be completely filled, full depth, with R-2 grout mortar and cured for at least 48 hours. Ensure the contractor does not grout when temperatures are below 40° F. The deck width should be measured by the Contractor as soon as the beams are set to assure that post tensioning rods or strand will be fabricated to the proper length. <br />
<br />
All hardware dimensions must be as shown on the plans or shop drawings. Tendons or rods for post-tensioning should be tensioned with calibrated jacks according to a Contractor-supplied calibration chart showing the corresponding jack pressures and elongations necessary to gradually build up to the required post-tensioning force. After the post-tensioning is complete, ensure the conduit is flushed with water, then compressed air. The tendon or rod holes will be grouted under pressure with Type E-1 grout for steel tendons or rods as described in subsection 708.03B of the Standard Specifications for Construction. <br />
<br />
'''Do not stand behind the jacking machine or rod holes during jacking procedures. If a tendon or rod snaps, it can cause serious injury.'''<br />
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==[[#Erection of I-Girders and Michigan 1800 Girders|Erection of I-Girders and Michigan 1800 Girders]]==<br />
<br />
Girder bearing pads must be shimmed (when necessary) in an approved manner during erection to provide full bearing contact with the bottoms of the girder. Beveled sole plates are also required for I-girders. This needs to be checked on every girder. Note in the daily report when the girder erection has been completed. <br />
<br />
I-Girders and especially Michigan 1800 girders can be more prone to sweep or transverse deflection. For this reason they should be rigidly blocked in place to ensure proper spacing between girders before any deck or diaphragm forming.<br />
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==[[#Erection of Spun Concrete Poles|Erection of Spun Concrete Poles]]==<br />
<br />
Spun concrete poles typically have less concrete clear cover from the outside of the element to the prestressing strands than prestressed beams. Pay particular attention to any cracking and bring it to the attention of the Engineer. During installation, the poles must only be lifted and stored using the locations and methods shown on the approved shop drawings or manufacturer’s instructions. Spun concrete poles must be safely secured after being placed in the drilled shaft installation before the concrete foundation is poured and cured.<br />
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==[[#Erection of Sound Walls|Erection of Sound Walls]]==<br />
<br />
In most cases the sound wall panels are attached to the posts using tongue and groove joints. It is important during erection that the panels are lowered slowly into position and do not crack or spall the posts. If the posts are prestressed, and contain grout pockets, the grout pockets at the ends of the posts must be filled with non-shrink grout and should be free of cracks. In order to properly inspect prestressed posts a ladder should be used to visually inspect the tops of the posts. Any cracking whether from damage or shrinkage, or spalling, should be cause for concern as the horizontal surface will be subject to moisture and chloride intrusion leading to rapid deterioration of the posts.<br />
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=[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]=<br />
<br />
There are three methods of payment for structural precast concrete elements as described below. All three methods are shown in Figure 708.03. No method of payment relieves the Fabricator or Contractor from damage due to transporting, storing on the project site, or erecting the elements. Additional information on payment can be found in Section 109 of the Standard Specifications for Construction.<br />
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==[[#Stockpile Payment|Stockpile Payment]]==<br />
<br />
See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.04.06] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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==[[#Partial Shipment Payment|Partial Shipment Payment]]==<br />
<br />
After the Fabricator has shipped a portion of the structural concrete elements to the project site verify that the shipping documentation and elements have been stamped approved for use, and inspect the product for signs of damage that may have occurred as a result of shipping and handling. If the shipping documentation and elements are stamped approved for use and there is no shipping and handling damage partial shipment payment may be made. The approved for use stamp indicates that all materials and processes during fabrication were according to specifications; a Fabrication Inspection memo will be sent to the TSC after final shipment. <br />
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==[[#Final Shipment Payment|Final Shipment Payment]]==<br />
<br />
As with partial shipments, after the Fabricator has sent the final shipment of the structural concrete elements to the project site verify that the shipping documentation and elements have been stamped approved for use, and inspect the product for signs of damage that may have occurred as a result of shipping and handling. If the shipping documentation and elements are stamped approved for use and there is no shipping and handling damage partial shipment payment may be made. The approved for use stamp indicates that all materials and processes during fabrication were according to specifications; a Fabrication Inspection memo will be sent to the TSC after final shipment. <br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=MediaWiki:Sidebar&diff=5235MediaWiki:Sidebar2018-01-17T12:36:33Z<p>JohnsonN23: </p>
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* Division 2 - Earthwork<br />
** 201 - Clearing|201 - Clearing<br />
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** 203 - Removing Drainage Structures, Culverts, and Sewers|203 - Removing Drainage Structures, Culverts, and Sewers<br />
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* Division 4 - Drainage Features<br />
** 401 - Culverts|401 - Culverts<br />
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** 403 - Drainage Structures|403 - Drainage Structures<br />
** 404 - Underdrain|404 - Underdrain<br />
** 405 - Pump Station Construction|405 - Pump Station Construction<br />
** 406 - Precast Three-Sided, Arch, and Box Culverts|406 - Precast Three-Sided, Arch, and Box Culverts<br />
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* Division 5 - HMA Pavements and Surface Treatments<br />
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** 605 - Contractor Quality Assurance for Concrete|605 - Contractor Quality Assurance for Concrete<br />
<br />
* Division 7 - Structures<br />
** 701 - Portland Cement Concrete for Structures|701 - Portland Cement Concrete for Structures<br />
** 702 - Mortar and Grout|702 - Mortar and Grout<br />
** 703 - Mortar and Concrete Patching Repair and Resurfacing Mixes|703 - Mortar and Concrete Patching Repair and Resurfacing Mixes<br />
** 704 - Steel Sheet Piling and Cofferdams|704 - Steel Sheet Piling and Cofferdams<br />
** 705 - Foundation Piling|705 - Foundation Piling<br />
** 706 - Structural Concrete|706 - Structural Concrete<br />
** 707 - Structural Steel|707 - Structural Steel<br />
** 708 - Prestressed Concrete|708 - Prestressed Concrete<br />
** 709 - Timber Sturctures|709 - Timber Sturctures<br />
** 710 - Waterproofing and Protective Covers|710 - Waterproofing and Protective Covers<br />
** 711 - Bridge Railings|711 - Bridge Railings<br />
** 712 - Bridge Rehabilitation, Concrete|712 - Bridge Rehabilitation, Concrete<br />
** 713 - Bridge Rehabilitation, Steel|713 - Bridge Rehabilitation, Steel<br />
** 714 - Temporary Structures and Approaches|714 - Temporary Structures and Approaches<br />
** 715 - Cleaning and Coating Existing Structural Steel|715 - Cleaning and Coating Existing Structural Steel<br />
** 716 - Shop Cleaning and Coating Structural Steel|716 - Shop Cleaning and Coating Structural Steel<br />
** 717 - Downspouts and Drains|717 - Downspouts and Drains<br />
** 718 - Drilled Shafts|718 - Drilled Shafts<br />
** 719 - Earth Retaining Structures|719 - Earth Retaining Structures<br />
** Division 7 Supplemental Information|Division 7 Supplemental Information<br />
<br />
* Division 8 - Incidental Construction<br />
** 801 - Concrete Driveways|801 - Concrete Driveways<br />
** 802 - Concrete Curb, Gutter, and Dividers|802 - Concrete Curb, Gutter, and Dividers<br />
** 803 - Concrete Sidewalk, Ramps, and Steps|803 - Concrete Sidewalk, Ramps, and Steps<br />
** 804 - Concrete Barriers and Glare Screens|804 - Concrete Barriers and Glare Screens<br />
** 805 - Hot Mix Asphalt Curb|805 - Hot Mix Asphalt Curb<br />
** 806 - Bicycle Paths|806 - Bicycle Paths<br />
** 807 - Guardrail, Guardrail Terminals, and Miscellaneous Posts|807 - Guardrail, Guardrail Terminals, and Miscellaneous Posts<br />
** 808 - Fencing|808 - Fencing<br />
** 809 - Field Office|809 - Field Office<br />
** 810 - Permanent Traffic Signs and Supports|810 - Permanent Traffic Signs and Supports<br />
** 811 - Permanent Pavement Markings|811 - Permanent Pavement Markings<br />
** 812 - Temporary Traffic Control for Construction Zone Operations|812 - Temporary Traffic Control for Construction Zone Operations<br />
** 813 - Slope Protection|813 - Slope Protection<br />
** 814 - Paved Ditches|814 - Paved Ditches<br />
** 815 - Landscaping|815 - Landscaping<br />
** 816 - Turf Establishment|816 - Turf Establishment<br />
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** 818 - Dune Grass Planting|818 - Dune Grass Planting<br />
** 819 - Electrical and Lighting|819 - Electrical and Lighting<br />
** 820 - Traffic Signals|820 - Traffic Signals<br />
** 821 - Preservation of Land Monuments and Property Corners|821 - Preservation of Land Monuments and Property Corners<br />
** 822 - Ground or Cut Centerline and Shoulder Corrugations|822 - Ground or Cut Centerline and Shoulder Corrugations<br />
** 823 - Water Mains|823 - Water Mains<br />
** 824 - Contractor Staking|824 - Contractor Staking</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=708_-_Precast_Concrete_Beams_(Prestressed)&diff=5234708 - Precast Concrete Beams (Prestressed)2018-01-17T12:34:57Z<p>JohnsonN23: JohnsonN23 moved page 708 - Precast Concrete Beams (Prestressed) to 708 - Prestressed Concrete</p>
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<div>#REDIRECT [[708 - Prestressed Concrete]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=708_-_Prestressed_Concrete&diff=5233708 - Prestressed Concrete2018-01-17T12:34:57Z<p>JohnsonN23: JohnsonN23 moved page 708 - Precast Concrete Beams (Prestressed) to 708 - Prestressed Concrete</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''708'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Prestressed Concrete'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/708%20Prest%20Concrete%20Beams.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 708]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural precast concrete members are cast in forms at a facility certified by the Prestressed Concrete Institute (PCI) that is typically a location other than their final position in the structure. Precast concrete beams are also longitudinally prestressed (bonded pre-tensioned strands) and in the case of side-by-side box beams, are transversely prestressed (post-tensioned strands) as well. Prestressing and post-tensioning of precast concrete elements allows for longer, more efficient spans than traditionally reinforced concrete members by introducing pre-compression into the concrete members. The pre-compression force is typically designed to be larger than the effect of applied loads on the element, and therefore, stresses are well controlled.<br />
<br />
Other structural elements that are prestressed include concrete spun poles and in some cases, Prefabricated Bridge Elements and Systems (PBES) other than beams, and sound wall posts and/or panels. <br />
<br />
Structural precast concrete elements that are not prestressed include, but may not be limited to, sound wall posts and panels, culverts, and some PBES. Although structural precast concrete elements are typically fabricated off-site, they require on-site inspection to ensure successful forming, casting, transport, handling, and placement into their final position in the structure. <br />
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<br />
===[[#Shop Drawing Submittal|Shop Drawing Submittal]]===<br />
<br />
Shop drawings with complete detailed dimensions are submitted to MDOT for review and approval. Approved shop drawings are required prior to the start of fabrication, but MDOT does not check every dimension for accuracy. The submission is reviewed to ensure it is complete and in general conformance with the contract plans. The Contractor is solely responsible for the correctness of shop drawings. Errors found during the review of the shop drawings will be pointed out by MDOT but undiscovered errors are the Contractor's responsibility.<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/files/englishbridgemanual/ebdm10.pdf Chapter 10 of the MDOT Bridge Design Manual]. Figure 708.1-1 and Figure 708.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
<br />
[[File:Fig 708.1-1.png|600px|thumbnail|center|Figure 708.1-1 – Shop Drawing Review Process]]<br />
<br />
<br />
[[File:Fig 708.2-1.png|600px|thumbnail|center|Figure 708.2-1 – Shop Drawing Review Process]]<br />
<br />
Allow the fabricator or supplier to work directly with MDOT Technical Review Areas to expedite the review of the shop drawings. Contact the Bridge Field Services [http://www.michigan.gov/mdot/0,4616,7-151-9623_26663_56139_56173-278981--,00.html Structural Fabrication Unit] with questions. <br />
<br />
The contractor/fabricator shall submit to the Engineer the shop drawings in electronic format according to [http://mdotcf.state.mi.us/public/specbook/files/2012/104%20Control%20of%20Work.pdf subsection 104.02] of the Standard Specifications for Construction. The Bridge Design Engineer will coordinate review of the drawings and stamp “Approved.” The approved drawings will be distributed according to the Bridge Design Manual. <br />
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<br />
===[[#Approved Shop Drawing Distribution|Approved Shop Drawing Distribution]]===<br />
<br />
Upon receipt of the approved shop drawings from the Bridge Design Engineer, the Engineer shall forward them to the Contractor.<br />
<br />
Upon receipt of the shop fabrication and erection drawings at the project office, the inspector will check each sheet against MDOT’s general plans. Particular attention should be directed to span lengths. <br />
<br />
Upon completion of the work, the contractor shall furnish the Department one set of complete set of shop drawings on a medium approved by the Department. <br />
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<br />
===[[#Prestressed Concrete Elements|Prestressed Concrete Elements]]===<br />
<br />
Prestressing, refers to the process of pulling steel tendons in the beam into tension before the concrete is placed in the forms. After the concrete has hardened, the stressed tendons are released and transmit a compressive stress to the concrete. This offsets tension forces on the concrete and increases the load-carrying capacity of the beam. The result is similar to pressing on the ends of a set of books in order to pick up the whole set of books at once.<br />
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<br />
====[[#Beams|Beams]]==== <br />
<br />
The Department uses four general kinds of prestressed concrete beams:<br />
<br />
* Side by side box beams<br />
* Spread box beams<br />
* AASHTO I-girders (Types I-IV)<br />
* Bulb-tee girders (e.g. Michigan 1800 girders)<br />
<br />
Prestressed concrete beams vary in width, length, and depth. In general, deeper beams will span longer distances for the same loading conditions. Likewise, deeper beams used for the same span length may have wider beam spacing, and thus carry larger loads.<br />
<br />
Another beam type that has occasionally been used is the bulb-T beam. This beam shape can be a more effective section due to its larger bottom flange that allows more prestressing strands to be used. It also features a wider top flange that makes the shape more stable during handling, transport and erection.<br />
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<br />
====[[#Prestressing|Prestressing]]====<br />
<br />
Prestressing is generally defined as the preloading of a structure, before application of service loads, to improve its performance in specific ways. Precast concrete elements can be prestressed by pre-tensioning or post-tensioning. Pre-tensioning and post-tensioning are subcategories of prestressing and refer to whether the strands are tensioned before concrete placement or after concrete placement, respectively. <br />
<br />
:'''1) Pre-tensioning:''' Is typically performed at the fabrication facility by using hydraulic jacks to tension seven-wire steel strands in the beam casting bed before the concrete is placed. After the concrete has reached its minimum required release strength, the tensioned strands are released by cutting at each end, which transmits a compressive force to the concrete via bond between the strands and concrete. This offsets tensile stresses in the concrete from dead load and live load and increases the load-carrying capacity of the beam.<br />
<br />
Pre-tensioning is typically used with beams and girders, although it can be used with other elements such as soundwall posts and panels, and other types of PBES such as precast pier caps, precast deck panels, etc. Concrete spun poles are also prestressed.<br />
<br />
:'''2) Post-Tensioning:''' Is performed similarly to pre-tensioning but the tensioning of the strands takes place after the concrete has been placed and cured, and the post-tensioning force is distributed to the concrete via mechanical anchorages. The most common application for post-tensioning in the Department is with side by side box beams. After side by side box beams are erected the grouted keyways between the beams are filled with non-shrink grout and cured. Typically the same seven wire strand used in pre-tensioning is grouped to make a tendon and then placed transverse to the beams centerline through ducts in the intermediate diaphragms. In some cases, more rigid steel rods are used for post-tensioning instead of seven wire strands. The quantity of ducts and the number of strands per duct are proportional to the beam length and depth. After hydraulic jacks are used to tension the tendons to the proper load, the force is locked in and the ducts are filled with non-shrink grout. Post-tensioning side by side box beams reduces differential deflection between adjacent beams and allows more effective live load distribution. Post-tensioning can also be used to transmit a compressive load in pier caps, decks, and PBES in order to offset tensile forces in the element.<br />
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<br />
====[[#Concrete Spun Poles|Concrete Spun Poles]]====<br />
Prestressed concrete spun poles are used to mount cameras and other Intelligent Transportation System (ITS) equipment at high elevations in order to provide the proper vantage point. Similar to beams, strands are pre-tensioned and then the forms are rotated at a high speed to create a pole that is hollow in the middle.<br />
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====[[#Prefabricated Bridge Elements and Systems (PBES)|Prefabricated Bridge Elements and Systems (PBES)]]====<br />
<br />
PBES can refer to either singular precast elements such as deck panels, footings, columns, pier caps, abutments, etc., or a system that contains multiple elements such as beams with a portion of the deck already attached. The connections between PBES elements or between PBES elements and cast in place elements are of utmost importance. One of the primary advantages of prefabricated elements is the speed at which they can be constructed which minimizes disruption to traffic. If the connections are not properly laid out or constructed, significant delays can result. Therefore, it is important for connection details to be checked by both the Contractor and the Inspector on-site prior to concrete placement or connection of elements, to ensure proper fit-up. All the necessary connection details should be in the design plans. <br />
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The use of templates by the Contractor and fabricator is encouraged. At the fabricator’s plant the dimensions should be checked by both the fabricator’s quality control (QC) personnel and the department’s (QA) quality assurance personnel. The Contractor and Inspector are also encouraged to work closely with the fabricator’s QC and the department’s QA to ensure construction goes as smooth as possible. <br />
<br />
Connection methods for PBES include, but are not limited to:<br />
<br />
* Grouted keyways or pockets<br />
* Grouted mechanical splice sleeves<br />
* Post-tensioning<br />
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====[[#Soundwalls|Soundwalls]]====<br />
<br />
Sound walls, or noise abatement walls, can be detailed differently but typically are constructed of two types of elements, panels and posts. Both the panels and posts may be precast and prestressed or precast with conventional steel reinforcement.<br />
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===[[#Fabrication of Prestressed Concrete|Fabrication of Prestressed Concrete]]===<br />
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====[[#Shop Inspection|Shop Inspection]]====<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
<br />
The Engineer should be notified at least one week prior to the beginning of fabrication.<br />
<br />
Quality assurance inspection is performed on most structural precast concrete elements such as prestressed beams, culverts over 10’, sound wall posts and panels, MSE wall panels, concrete spun poles, and other prefabricated bridge elements for accelerated bridge construction. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit to perform shop inspection at structural precast concrete fabrication facilities nationwide.<br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 708.2. The inspector then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 708.3 for more information on the fabrication inspection process.<br />
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[[File:Fig_708.2.png|600px|thumbnail|center|Figure 708.2 - Approved for Use stamp]]<br />
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[[File:Fig_708.3.png|600px|thumbnail|center|Figure 708.3 – Structural Precast Concrete Fabrication Inspection Flowchart]]<br />
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====[[#Addressing Deficiencies|Addressing Deficiencies]]====<br />
<br />
As part of the shop inspection process, the MDOT shop inspector will note the condition of structural precast elements as they are removed from the forms, and note if corrective repairs are required prior to approving the element for use on MDOT projects. These repairs are typically done prior to being shipped to the project site, however, there are some circumstances where repairs will be required on site, so the construction inspector should be familiar with common deficiencies.<br />
The Structural Fabrication Unit has developed, with the assistance of the Materials Section, repair procedures to assist with evaluating fabricator proposed concrete repairs to fabricated structural precast concrete elements for MDOT projects. <br />
<br />
Fabricated structural precast concrete elements may contain defects from the fabrication process or can be damaged from the removal of formwork, handling, and shipping. The fabricator is required to notify the MDOT QA shop inspector of all defects and/or damages to fabricated elements and propose a repair procedure to MDOT for acceptance. MDOT will thoroughly evaluate the proposed procedure and provide a response. The repair procedure will be either be approved, rejected or approved as noted. The fabricator must receive MDOT approval before performing the repair. Structural precast concrete repairs can be generalized into the following categories:<br />
<br />
* Minor Surface Defects (air holes, minor honeycombing, gouges etc.) See Figure 708.4 through Figure 708.06 for minor surface defects<br />
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[[File:Fig_708.4.png|600px|thumbnail|center|Figure 708.4 – Minor surface defect – air holes greater than 1” in any direction]]<br />
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[[File:Fig_708.5.png|600px|thumbnail|center|Figure 708.5 – Minor surface defect – rubber gasket crease]]<br />
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[[File:Fig_708.6.png|600px|thumbnail|center|Figure 708.6 – Minor surface defect – honeycombing of PCI girder]]<br />
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* Major Surface Defects (moderate honeycombing, etc.)<br />
<br />
* Minor Damages (spalls, cracks, broken corners, etc.) See Figure 708.7 through Figure 708.8 for examples of minor damages<br />
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[[File:Fig_708.7.png|600px|thumbnail|center|Figure 708.7 – Minor damage – broken corner at end of PCI girder]]<br />
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[[File:Fig_708.8.png|600px|thumbnail|center|Figure 708.8 – Minor damage – spalled bottom corner at the end of a box beam]]<br />
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* Other, which includes major damage and elements subject to rejection. See Figure 708.9 and Figure 708.10 for example of major deficiencies.<br />
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[[File:Fig_708.9.png|600px|thumbnail|center|Figure 708.9 – Major deficiency – spalled bottom corner and exposed prestressing strands at the end of a box beam]]<br />
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[[File:Fig_708.10.png|600px|thumbnail|center|Figure 708.10 – Major deficiency – improper consolidation of concrete and expose prestressing strands and steel reinforcement]]<br />
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The repair of deficiencies to the satisfaction of the Structural Fabrication Unit, or rejection of elements for major deficiencies will occur at the fabrication facility prior to shipment to the site. It is important to note the Approved for Use stamp on all structural precast elements prior to incorporation into the project.<br />
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==[[#MATERIALS|MATERIALS]]==<br />
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<span style="color: red"> -Reserved- </span><br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Precast Elements|Delivery of Structural Precast Elements]]===<br />
<br />
When prestressed or non-prestressed structural precast structural concrete elements arrive on the job site, inspect them before they are unloaded. Check ends of each beam for a stamp or tag stating “Approved for Use.” If the beams are delivered to the project site without an approval stamp or tag, reject the beams. If the beams are approved for use, a memorandum will be sent to the TSC from Bridge Field Services stating the approval of each beam and verification of all material certifications and test results. According to [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf Section 4.04 of the MDOT Materials Quality Assurance Procedures Manual] prestressed concrete fabrication has been approved for use by MDOT when the following two part process is met:<br />
<br />
:A. Fabrication Inspection Acceptance: Structural elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements. Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
<br />
:B. Visual Inspection Acceptance: The engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural elements. Additionally, the engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must visually inspect the product for signs of damage that may occur as a result of shipping and handling. This visual information should be documented on the inspector’s daily report. Look for deficiencies in the beams in the form of cracks, honeycombing, spalls, or cold joints. Crack widths can be measured with a crack comparator as seen in Figure 708-11. Bring any damage to the attention of the Engineer and make a record of the damage in the daily report. Take measurements of crack width and length as well as spall measurements and photographs. Also note in the daily report when the beams arrive in good condition. If there is any concern regarding whether beams were approved for use or whether damage is acceptable, contact [http://www.michigan.gov/mdot/0,4616,7-151-9623_26663_56139_56173---,00.html Bridge Field Services].<br />
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[[File:Fig_708-11.png|600px|thumbnail|center|Figure 708-11 Crack comparator for measuring crack width]]<br />
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Per [http://mdotcf.state.mi.us/public/specbook/files/2012/105%20Control%20of%20Materials.pdf Section 105] of the Standard Specifications for Construction, the Engineer reserves the right to reject any shipped product that shows visual signs of damage or does not meet specification requirements. <br />
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Considerable care should be exercised when handling structural precast concrete elements. In many cases, there is no way to repair a damaged element short of re-fabrication. Prestressed beams should be kept in an upright position at all times, as the beam’s own dead weight counter acts the internal prestressing force to keep the beam stable. The method of stockpiling and transporting members is covered in detail in [http://mdotcf.state.mi.us/public/specbook/files/2012/708%20Prest%20Concrete%20Beams.pdf subsection 708.03] of the Standard Specifications for Construction. Beams shall be supported at two points no more than 3 feet (1 m) from the ends of the beams.<br />
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Check beam markings and compare to the beam layout sheet in the plans. Make sure the beams are placed in the right location and direction. They may fit in more than one place but there is only one correct location and direction for each beam.<br />
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Lifting devices, usually loops of seven wire strand, are cast into the member and these should be the only attachment used when moving a beam. The lifting device must have adequate capacity to lift the beams and set them in place. Never lift the beam near the center. If the beam has to be set down before being placed, never allow it to be supported at the center. Crib it under the ends. The prestressing forces pulling in on the ends of the beam hold up the dead weight of the beam. If the beam is supported or lifted at the center, the prestressing forces will cause the beam to crack.<br />
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Once the structural precast concrete element has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural precast concrete elements:<br />
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* Support beams off the ground to prevent moisture and deleterious material intrusion<br />
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* Support beams across the full width on two battens, each greater than 4 inches wide. Support stacked beams, one above the other along the same vertical plane at each ends of the beams.<br />
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* Support the beams on level, stable ground, avoid storing beams near side slopes, or areas near heavy construction traffic<br />
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* Do not support the beam at more than two points<br />
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* Taller, long span I-beam shapes may need to be laterally braced on site<br />
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* Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity.<br />
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* Related items such as bearings and bridge railing should also be protected from damage, dirt, and corrosion.<br />
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Ensure the lifting devices are removed once the beam has been placed in its final position on the substructure.<br />
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====[[#Erection of Box Beams|Erection of Box Beams]]====<br />
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To ensure that box beams will fit properly on the substructure units; the beam widths should be checked. Beam bearing pads must be shimmed (when necessary) in an approved manner during erection to provide full bearing contact with the bottoms of the beams. This needs to be checked on every box beam. Box beams may camber more than anticipated, or may experience transverse rotation such that they do not sit flush on the sole plates, which are typically beveled to accommodate camber and vertical alignment angles. Note in the daily report when the beam erection has been completed.<br />
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At expansion bearings, ensure the beams line up with the position dowel holes, and ensure the holes are filled with hot poured rubber sealant type filler at least 3 inches above the position dowels. Ensure the remainder of the hole is filled with Type H-1 grout. Ensure holes at fixed bearings are filled with Type H-1 grout.<br />
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For side by side box beams, the beams should be set with spaces between them as specified on the plans or shop drawings and with the seal washers placed around the transverse post tensioning conduit holes. The space between the beams should be completely filled, full depth, with R-2 grout mortar and cured for at least 48 hours. Ensure the contractor does not grout when temperatures are below 40° F. The deck width should be measured by the Contractor as soon as the beams are set to assure that post tensioning rods or strand will be fabricated to the proper length.<br />
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All hardware dimensions must be as shown on the plans or shop drawings. Tendons or rods for post-tensioning should be tensioned with calibrated jacks according to a Contractor-supplied calibration chart showing the corresponding jack pressures and elongations necessary to gradually build up to the required post-tensioning force. After the post-tensioning is complete, ensure the conduit is flushed with water, then compressed air. The tendon or rod holes will be grouted under pressure with Type E-1 grout for steel tendons or rods as described in [http://mdotcf.state.mi.us/public/specbook/files/2012/708%20Prest%20Concrete%20Beams.pdf subsection 708.03B] of the Standard Specifications for Construction. <br />
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'''Do not stand behind the jacking machine or rod holes during jacking procedures. If a tendon or rod snaps, it can cause serious injury.'''<br />
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====[[#Erection of I-Girders and Michigan 1800 Girders|Erection of I-Girders and Michigan 1800 Girders]]====<br />
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Beam bearing pads must be shimmed (when necessary) in an approved manner during erection to provide full bearing contact with the bottoms of the beams. Similar to box beams, beveled sole plates are also typically required for I-girders. This needs to be checked on every beam. Note in the daily report when the beam erection has been completed. <br />
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I-Girders and especially Michigan 1800 girders can be more prone to sweep or transverse deflection. For this reason they should be rigidly blocked in place to ensure proper spacing between beams before any deck or diaphragm forming. <br />
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====[[#Erection of Spun Concrete Poles|Erection of Spun Concrete Poles]]====<br />
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Spun concrete poles typically have less concrete clear cover from the outside of the element to the prestressing strands than prestressed beams. Pay particular attention to any cracking and bring it to the attention of the Engineer. During installation, the poles must only be lifted and stored using the locations and methods shown on the approved shop drawings or manufacturer’s instructions. Spun concrete poles must be safely secured after being placed in the drilled shaft installation before the concrete foundation is poured and cured.<br />
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====[[#Erection of Sound Walls|Erection of Sound Walls]]====<br />
<br />
In most cases the sound wall panels are attached to the posts using tongue and groove joints. It is important during erection that the panels are lowered slowly into position and do not crack or spall the posts. If the posts are prestressed, and contain grout pockets, the grout pockets at the ends of the posts must be filled with non-shrink grout and should be free of cracks. In order to properly inspect prestressed posts a ladder should be used to visually inspect the tops of the posts. Any cracking whether from damage or shrinkage, or spalling, should be cause for concern as the horizontal surface will be subject to moisture and chloride intrusion leading to rapid deterioration of the posts.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
There are three methods of payment for structural precast concrete elements as described below. All three methods are shown in Figure 708-03. No method of payment relieves the Fabricator or Contractor from damage due to transporting, storing on the project site, or erecting the elements. Additional information on payment can be found in [http://mdotcf.state.mi.us/public/specbook/files/2012/109%20Measurement%20&%20Payment.pdf Section 109] of the Standard Specifications for Construction.<br />
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===[[#Stockpile payment|Stockpile payment]]===<br />
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After the Contractor has requested stockpile payment and the TSC has verified that all of the paperwork has been properly submitted (e.g. proof for full payment to subcontractors) contact the Bridge Field Services Structural Fabrication Unit to verify that the stockpiled materials meet project specifications and/or fabricated elements have been approved for use up to the date of the request. The [http://www.michigan.gov/mdot/0,4616,7-151-9623_26663_56139_56173-278981--,00.html Structural Fabrication Unit] will then send the TSC notification that stockpiled materials requested for payment are in conformance with the project specifications. <br />
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===[[#Partial Shipment Payment|Partial Shipment Payment]]===<br />
<br />
After the Fabricator has shipped a portion of the structural concrete elements to the project site verify that the shipping documentation and elements have been stamped approved for use, and inspect the product for signs of damage that may have occurred as a result of shipping and handling. If the shipping documentation and elements are stamped approved for use and there is no shipping and handling damage partial shipment payment may be made. The approved for use stamp indicates that all materials and processes during fabrication were according to specifications; a Fabrication Inspection memo will be sent to the TSC after final shipment.<br />
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===[[#Final Shipment Payment|Final Shipment Payment]]===<br />
As with partial shipments, after the Fabricator has sent the final shipment of the structural concrete elements to the project site verify that the shipping documentation and elements have been stamped approved for use, and inspect the product for signs of damage that may have occurred as a result of shipping and handling. If the shipping documentation and elements are stamped approved for use and there is no shipping and handling damage partial shipment payment may be made. The approved for use stamp indicates that all materials and processes during fabrication were according to specifications; a Fabrication Inspection memo will be sent to the TSC after final shipment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=Main_Page&diff=5231Main Page2018-01-16T20:48:41Z<p>JohnsonN23: /* Recent Major Changes */</p>
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<div>[http://www.michigan.gov/mdot www.michigan.gov/mdot]<br />
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<center><span STYLE="font: 40pt arial;">'''CONSTRUCTION MANUAL'''</span></center><br />
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<center>[[File:logo.jpg|400px]]</center><br />
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<center><span STYLE="font: 30pt arial;">'''Bureau of Field Services'''</span></center><br />
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<center><span STYLE="font: 15pt arial;">'''Construction Field Services Division '''</span></center><br />
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[[File:DI-06215-039.jpg|800px|thumb|center|Construction work on the US-127 Sound Wall between Grand River ave and Lake Lansing Rd.]]<br />
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[[File:DI-06239-007.jpg|300px|thumb|Underground sewer pipe being put in under I-75 for Plaza.]]<br />
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[[File:DI-05767-052.jpg|300px|thumb|Construction work on the US-23 Flex Route.]]<br />
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==[[#Preamble|Preamble]]==<br />
<br />
<br />
This manual provides guidance to administrative, engineering, and technical staff. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. Engineering judgment is necessary to allow decisions to account for unique site-specific conditions and considerations to provide high quality products, within budget, and to protect the public health, safety, and welfare. This manual provides the general operational guidelines; however, it is understood that adaptation, adjustments, and deviations are sometimes necessary. Innovation is a key foundational element to advance the state of engineering practice and develop more effective and efficient engineering solutions and materials. As such, it is essential that our engineering manuals provide a vehicle to promote, pilot, or implement technologies or practices that provide efficiencies and quality products, while maintaining the safety, health, and welfare of the public. It is expected when making significant or impactful deviations from the technical information from these guidance materials, that reasonable consultations with experts, technical committees, and/or policy setting bodies occur prior to actions within the timeframes allowed. It is also expected that these consultations will eliminate any potential conflicts of interest, perceived or otherwise. MDOT Leadership is committed to a culture of innovation to optimize engineering solutions. <br />
The National Society of Professional Engineers Code of Ethics for Engineering is founded on six fundamental canons. Those canons are provided below.<br />
Engineers, in the fulfillment of their professional duties, shall:<br />
::#Hold paramount the safety, health, and welfare of the public.<br />
::#Perform Services only in areas of their competence.<br />
::#Issue public statement only in an objective and truthful manner.<br />
::#Act for each employer or client as faithful agents or trustees.<br />
::#Avoid deceptive acts.<br />
::#Conduct themselves honorably, reasonably, ethically and lawfully so as to enhance the honor, reputation, and usefulness of the profession.<br />
<br />
<br />
This manual has been revised throughout to incorporate changes brought about by the release of the 2012 Standard Specifications for Construction and by progress in equipment, construction practices, and materials. The format has been established to follow the standard specification outline with divisions and sections set up to facilitate revision and addition of new information as needed.<br />
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Additional information about the Wiki Construction Manual and submitting revision suggestions is located in the [[Help:Contents]] page.<br />
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===[[#MDOT Mission Statement|MDOT Mission Statement]]===<br />
Providing the highest quality integrated transportation services for economic benefit and improved quality of life.<br />
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== General Information ==<br />
===[[#Current News|Current News]]===<br />
With the first release of the MDOT Wiki Construction Manual there are bound to be some errors. If you find an error on a page please contact the Content Manager for that particular Division located [[Help:Contents#Content_Suggestions|here]] in the [[Help:Contents|Help page]]. Some sections are still undergoing content revisions, most have been identified by the Content Managers and are noted as such in the Wiki Constrution Manual.<br />
<br />
<br />
Content will be revised frequently and a way to monitor what changes have occured recently is by using the [[Special:RecentChanges|Recent changes]] page. This page will show all major and minor edits along with new users that were created. Pretty much everything that goes on in the Construction Manual. For a more specific listing of content changes you will want to see the [[Main_Page#Recent_Major_Changes|Recent Major Changes]] page or [[Main_Page#Recent_Minor_Changes|Recent Minor Changes]] page which contain manually updated lists of content changes for specific sections of the Construction Manual.<br />
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====[[#Recent Major Changes|'''Recent Major Changes''']]====<br />
<br />
The table below is a list of Major changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:orange; color:black"<br />
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!Updated!! Division !! Section !! Summary !! What Changed<br />
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|<center>1/16/2018</center>||<center>7</center>||<center>[[707_-_Structural_Steel|707]]||Overhaul of information for section 707||[http://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230&oldid=5186 compare]<br />
|-<br />
|<center>12/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Engineer_Certification_Program| Engineer Certification]]</center>||Updated Engineer Certification List||[//{{SERVERNAME}}/images_construction/a/ac/Eng_Record_Cert_list_12-19-17.pdf Linked Here]<br />
|-<br />
|<center>12/12/2017</center>||<center>1 Supplemental</center>||<center>[[Plans,_Proposal,_Input,_Review_and_Evaluation|Plans, Proposal, Imput, Review and Evaluation]]</center>||Update about Post Construction Information||[http://mdotwiki.state.mi.us/construction/index.php/Other#Post-Construction_Reviews View Here]<br />
|-<br />
|<center>12/7/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal|102.02]]</center>||Updated Boilerplate Progress Clause Template||[http://mdotwiki.state.mi.us/construction/index.php/File:Boilerplate_Progress_Clause_Template_12-6-17.docx View Here]<br />
|-<br />
|<center>11/27/2017</center>||<center>Main Page</center>||<center>Main Page</center>||New Preamble for Construction Manual||<br />
|-<br />
|<center>11/27/2017</center>||<center>1 Supplemental</center>||<center>[[e-Construction#Standard_Naming_Convention_for_Documents|Standard Naming Convention]]</center>||New format for Standard Naming Convention||<br />
|-<br />
|<center>11/3/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Testing Charges]]</center>||Updated LDPR coding||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View here]<br />
|-<br />
|<center>11/2/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction|E-Construction]]</center>||Updated table for file naming||[http://mdotwiki.state.mi.us/construction/index.php/E-Construction#e-Construction.2FPaper_File_System View table here]<br />
|-<br />
|<center>11/1/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency|Local Agency]]</center>||Updated coding information for SIGMA||[http://mdotwiki.state.mi.us/construction/index.php/Local_Agency#CHARGING_TIME_TO_LOCAL_AGENCY_PROJECTS View Here]<br />
|-<br />
|<center>10/26/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Added new section for Special Markings for Cold Weather||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#Temporary_Special_Markings_for_Cold_Weather View Here]<br />
|-<br />
|<center>10/19/2017</center>||<center>8</center>||<center>[[811_-_Permanent_Pavement_Markings|811]]</center>||Updated Paint pricing for 2017||[http://mdotwiki.state.mi.us/construction/index.php/811_-_Permanent_Pavement_Markings#UNIFORM_PRICE_ADJUSTMENT.2C_REGULAR_DRY_PAINT_AND_LOW_TEMPERATURE_WATERBORNE_PAINT View Updated Table Here]<br />
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|<center>9/21/2017</center>||<center>1</center>||<center>[[Materials_Quality_Assurance_Procedures_Manual|Materials Quality Assurance Procedures Manual]]</center>||2017 Summary of Revision to the manual||<br />
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|<center>9/14/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#Project_Administration:_MDOT_Oversight_Folder|Local Agency]]</center>||Guidance on new folder in ProjectWise||<br />
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|<center>9/6/2017</center>||<center>1</center>||<center>[[LCPtracker_Supplemental_Information|LCPtracker Tracker]]</center>||New Page specifically for LCPtracker||<br />
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|<center>8/24/2017</center>||<center>1</center>||<center>[[102.14_Construction_Progress_Schedule|102.14]]</center>||Moved progress form 1130 to new section 102.14||<br />
|-<br />
|<center>7/11/2017</center>||<center>1</center>||<center>[[108.01_Subcontracting_of_Contract_Work#Construction_Subcontract_Process|108.1]]</center>||Changed email for 1302A Forms||[mailto:MDOT-ConstructionSubcontracts@michigan.gov New email address here]<br />
|-<br />
|<center>6/20/2017</center>||<center>1 Supplemental</center>||<center>[[Construction_Field_Services_Indirect_Testing_Charges|Construction Field Services Indirect Testing Charges]]</center>||New coding content||[http://mdotwiki.state.mi.us/construction/index.php/Construction_Field_Services_Indirect_Testing_Charges#Inappropriate_Use View Coding Guidelines here]<br />
|-<br />
|<center>6/16/2016</center>||<center>1 Supplemental</center>||<center>[[FieldManager|FieldManager]]</center>||Addition of CMU 2017-003, Electronic Read only Files||[http://mdotwiki.state.mi.us/construction/index.php?title=FieldManager&diff=4895&oldid=4836 View Here]<br />
|-<br />
|<center>4/25/2017</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal#Progress_Clause| 102.02]]</center>||Update according to CA 2015-11 with Boiler progress update.||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal&diff=4631&oldid=4454 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1</center>||<center>[[Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work|Contract Admin]]</center>||Added content according to CA 2015-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Contract_Administration_and_Oversight_Guidelines_for_Projects_Containing_Warranty_Work&diff=4616&oldid=4544 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>2</center>||<center>[[205_-_Roadway_Earthwork#Cost_Over_Runs_From_Off_Site_Disposal_of_Soil|205]]</center>||Added content in accordance with CA 2008-01||[http://mdotwiki.state.mi.us/construction/index.php?title=205_-_Roadway_Earthwork&diff=4609&oldid=4268 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[104.07_Contractor_Obligations#Project_.26_Worksite_Safety|104.07]]</center>||Added Content according to CA 2013-12, Workers Safety||[http://mdotwiki.state.mi.us/construction/index.php?title=104.07_Contractor_Obligations&diff=4605&oldid=4570 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#Force Account Work|109.05]]</center>||Made adjustments to implement form 1101-SP109||[http://mdotwiki.state.mi.us/construction/index.php?title=109.05_Payment_for_Contract_Revisions&diff=4603&oldid=4588 Compare It]<br />
|-<br />
|<center>4/5/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications|Prevailing Wage]]</center>||Added Section for Prevailing Wage Classification from CA 2007-15||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#Prevailing_Wage_Classifications View Here]<br />
|}<br />
</div><br />
A definition to the types of changes that you might see in the Construction Manual can be found under [[Content_Revision_Procedures#Types_of_Changes|Content Revision Procedures, Types of Changes]].<br />
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<br />
====[[#Recent Minor Changes|'''Recent Minor Changes''']]====<br />
The table below is a list of Minor changes. <br />
<div style="overflow:auto; height:200px; width:700px"><br />
{| class="wikitable" style="background:yellow; color:black"<br />
|-<br />
!Updated!! Division !! Section !! Summary !! What Changed<br />
|-<br />
|<center>1/16/2018</center>||<center>1</center>||<center>[[108.05_Progress_of_the_Work|108.05]]</center>||Moved content from 102.14 to 108.05||<br />
|-<br />
|<center>1/10/2018</center>||<center>1</center>||<center>[[102.02_Contents_of_Proposal_-_Progress_Clause|12.02]]</center>||Renamed page and moved structures progress clause to this section||[http://mdotwiki.state.mi.us/construction/index.php?title=102.02_Contents_of_Proposal_-_Progress_Clause&diff=5189&oldid=5182 View Comparison]<br />
|-<br />
|<center>1/4/2018</center>||<center>1 supplemental</center>||||Separated "other" page into separate pages|| <br />
|-<br />
|<center>12/20/2017</center>||<center>1</center>||<center>[[102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)#DBE_Performance_Indicators|102.18]]</center>||Updated content related to Commercially Useful Function (CUF). Part of CMU 2017-005||[http://mdotwiki.state.mi.us/construction/index.php?title=102.18_Subletting_Contract_Work_to_Disadvantaged_Business_Enterprises_(DBEs)&diff=5162&oldid=4910 Compare It]<br />
|-<br />
|<center>12/4/2017</center>||<center>1 Supplemental</center>||<center>[[Dispute_Review_Board_(DRB)|Dispute Review Board]]</center>||Update to page and ProjectWise directions||<br />
|-<br />
|<center>11/28/2017</center>||<center>1 Supplemental</center>||<center>[[E-Construction#e-Construction.2FPaper_File_System|e-Construction]]</center>||Updated examples for Calc forms||<br />
|-<br />
|<center>11/2/2016</center>||<center>1</center>||<center>NA</center>||Removed 'Disincentive' from manual language||<br />
|-<br />
|<center>10/26/2017</center>||<center>1</center>||<center>[[103.02_Contract_Revisions|103.02]]</center>||Moved ''Contract Modification Process Overview'' page to ''103.02 Contract Revisions||[http://mdotwiki.state.mi.us/construction/index.php/103.02_Contract_Revisions View Here]<br />
|-<br />
|<center>10/25/2017</center>||<center>7 Supplemental</center>||<center>[[Division 7 Supplemental Information#Division_7_Supplemental_Information|Division 7 Supplemental Information]]</center>||Updated notification contact information for bridge deck pours and concrete deck overlays||[https://mdotwiki.state.mi.us/construction/index.php?title=Division_7_Supplemental_Information&diff=5064&oldid=4970 View Update]<br />
|-<br />
|<center>10/23/2017</center>||<center>1</center>||<center>NA</center>||Changed language from "Approved for Traffic" to "Open to traffic"||<br />
|-<br />
|<center>10/11/2017</center>||<center>8</center>||<center>[[803_-_Concrete_Sidewalk,_Ramps,_and_Steps#MEASUREMENT_AND_PAYMENT|803]]</center>||Added illustration of sidewalk measurement and payment||[//{{SERVERNAME}}/images_construction/7/72/Road_Design_Manual_Chapter_6_-_ADA_Ramp_payment_items.pdf See Here]<br />
|-<br />
|<center>9/26/2017</center>||<center>1</center>||<center>[[Prevailing_Wage_Oversight_Procedures|Prevailing Wage Oversight Procedures]]</center>||Updated Posters to add USERRA Poster||[http://mdotwiki.state.mi.us/construction/index.php/Prevailing_Wage_Oversight_Procedures#JOBSITE_POSTING View Here]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Pay_Item_Selection|109.07]]</center>||Updated according CA 2015-06||[http://mdotwiki.state.mi.us/construction/index.php?title=109.07_Final_Inspection%2C_Acceptance%2C_and_Final_Payment&diff=4622&oldid=4591 Compare It]<br />
|-<br />
|<center>4/24/2017</center>||<center>1</center>||<center>[[Disadvantaged_Business_Enterprises_(DBE)#Disadvantages_Business_Enterprises_.28DBE.29|Disadvantaged Business]]</center>||Updated content according CA 2014-13||[http://mdotwiki.state.mi.us/construction/index.php?title=Disadvantaged_Business_Enterprises_%28DBE%29&diff=4620&oldid=4571 Compare It]<br />
|-<br />
|<center>4/21/2017</center>||<center>1 Supplemental</center>||<center>[[Local_Agency#PROJECT_ADMINISTRATION_MDOT-LET_LOCAL_AGENCY_PROJECTS|Local Agency]]</center>||Updated content according to CA 2009-16||[http://mdotwiki.state.mi.us/construction/index.php?title=Local_Agency&diff=4618&oldid=4574 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[501_-_Plant_Produced_Hot_Mix_Asphalt|501]]</center>||Updated content from CA 2006-07||[http://mdotwiki.state.mi.us/construction/index.php?title=501_-_Plant_Produced_Hot_Mix_Asphalt&diff=4614&oldid=4250 Compare It]<br />
|-<br />
|<center>4/20/2017</center>||<center>5</center>||<center>[[502_-_HMA_Crack_Treatment#GENERAL|502]]</center>||Added update from CA 2009-03 to CM||[http://mdotwiki.state.mi.us/construction/index.php?title=502_-_HMA_Crack_Treatment&diff=4611&oldid=3361 Compare It]<br />
|-<br />
|<center>4/19/2017</center>||<center>1 Supplemental</center>||<center>[[Certification_Programs#Review_Procedure|Cert Programs]]</center>||Added text from CA 2014-03||[http://mdotwiki.state.mi.us/construction/index.php?title=Certification_Programs&diff=4607&oldid=4311 Compare It]<br />
|- <br />
|<center>4/5/2017</center>||<center>6</center>||<center>[[603_-_Concrete_Pavement_Restoration#Removing Old Concrete|603]]</center>||Added text update from CA 2013-09||[http://mdotwiki.state.mi.us/construction/index.php?title=603_-_Concrete_Pavement_Restoration&diff=4429&oldid=4017 Compare It]<br />
|-<br />
|<center>3/28/2017</center>||<center>1</center>||<center>[[109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans|109.07]]</center>||Added links from CA 2009-20||[http://mdotwiki.state.mi.us/construction/index.php/109.07_Final_Inspection,_Acceptance,_and_Final_Payment#Final_Marked_Plans View Here]<br />
|-<br />
|<center>3/27/2017</center>||<center>1</center>||<center>[[109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS|109.05]]</center>||Updated reference to CFR and included link||[http://mdotwiki.state.mi.us/construction/index.php/109.05_Payment_for_Contract_Revisions#DOCUMENTING_PRICE_NEGOTIATIONS View Here]<br />
|}<br />
</div><br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5230707 - Structural Steel2018-01-16T19:53:57Z<p>JohnsonN23: /* Shop Inspection */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
<br />
On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
<br />
The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
<br />
Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
<br />
It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
<br />
When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
<br />
For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
<br />
All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
<br />
If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
<br />
The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
<br />
The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
<br />
The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
<br />
Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
<br />
When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
<br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
<br />
When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
<br />
[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
<br />
Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
<br />
<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
<br />
All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
<br />
[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
<br />
The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
<br />
[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
<br />
Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
<br />
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====[[#Deck Drains|Deck Drains]]====<br />
<br />
After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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<br />
====[[#Shear Developers|Shear Developers]]====<br />
<br />
Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
<br />
New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
<br />
When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
<br />
::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
<br />
Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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<br />
===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
<br />
[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
<br />
All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
<br />
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<br />
===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
<br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
<br />
Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
<br />
[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
<br />
[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
<br />
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<br />
====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
<br />
The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
<br />
Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
<br />
Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
<br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
<br />
Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
<br />
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<br />
===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
<br />
====[[#Welder Certification|Welder]]====<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
<br />
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====[[#Pile Welding|Pile Welding]]====<br />
<br />
Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
<br />
Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
<br />
Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
<br />
:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
<br />
:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
<br />
:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
<br />
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<br />
===[[#Implementation Examples|Implementation Examples]]===<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
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====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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<br />
==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
===[[#Stockpile Payment|Stockpile Payment]]===<br />
<br />
See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5229707 - Structural Steel2018-01-16T19:53:37Z<p>JohnsonN23: /* Delivery of Structural Steel */</p>
<hr />
<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
<br />
<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
<br />
Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
<br />
:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
<br />
:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
<br />
:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
<br />
:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
<br />
:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
<br />
Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
<br />
:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
<br />
If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
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Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
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[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
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{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
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Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
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[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
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All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
<br />
Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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====[[#Welder Certification|Welder]]====<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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===[[#Implementation Examples|Implementation Examples]]===<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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===[[#Stockpile Payment|Stockpile Payment]]===<br />
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See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5228707 - Structural Steel2018-01-16T19:52:54Z<p>JohnsonN23: /* Welding Piles, Falsework, Form Supports and Accessories */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
<br />
[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
<br />
Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
<br />
<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
<br />
All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
<br />
The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
<br />
[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
<br />
Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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<br />
====[[#Shear Developers|Shear Developers]]====<br />
<br />
Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
<br />
New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
<br />
When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
<br />
::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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<br />
===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
<br />
[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
<br />
All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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<br />
===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
<br />
Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
<br />
[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
<br />
[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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<br />
====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
<br />
The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
<br />
Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
<br />
Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
<br />
Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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<br />
===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
<br />
====[[#Welder Certification|Welder]]====<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
<br />
Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
<br />
Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
<br />
Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
<br />
:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
<br />
:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
<br />
:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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<br />
===[[#Implementation Examples|Implementation Examples]]===<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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<br />
==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
===[[#Stockpile Payment|Stockpile Payment]]===<br />
<br />
See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5227707 - Structural Steel2018-01-16T19:50:59Z<p>JohnsonN23: /* C. Welding for Form Supports and Accessories */</p>
<hr />
<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
<br />
[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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<br />
==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
<br />
===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
<br />
[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
<br />
[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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<br />
==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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<br />
===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
<br />
Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
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::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
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Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
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Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
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[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
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{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
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Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
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[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
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All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
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[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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===[[#Implementation Examples|Implementation Examples]]===<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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===[[#Stockpile Payment|Stockpile Payment]]===<br />
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See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5226707 - Structural Steel2018-01-16T19:50:43Z<p>JohnsonN23: /* Implementation Examples */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
<br />
[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
<br />
All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
<br />
[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
<br />
New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
<br />
When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
<br />
::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
<br />
[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
<br />
All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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<br />
===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
<br />
[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
<br />
[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
<br />
Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
<br />
Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
<br />
Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
<br />
:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
<br />
:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
<br />
:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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===[[#Implementation Examples|Implementation Examples]]===<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
===[[#Stockpile Payment|Stockpile Payment]]===<br />
<br />
See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5225707 - Structural Steel2018-01-16T19:26:01Z<p>JohnsonN23: /* GENERAL */</p>
<hr />
<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
<br />
[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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<br />
==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
<br />
===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
<br />
[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
<br />
[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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<br />
==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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<br />
===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
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::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
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Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
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Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
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[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
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{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
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Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
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[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
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All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
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[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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===[[#Stockpile Payment|Stockpile Payment]]===<br />
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See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5224707 - Structural Steel2018-01-16T19:25:00Z<p>JohnsonN23: /* Turn of Nut Tightening */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
<br />
All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
<br />
[[File:Fig707.6.png|500px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
<br />
New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
<br />
::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
<br />
[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
<br />
All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
<br />
Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
<br />
Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
<br />
Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
<br />
:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
<br />
:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
<br />
:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
===[[#Stockpile Payment|Stockpile Payment]]===<br />
<br />
See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5223707 - Structural Steel2018-01-16T19:24:14Z<p>JohnsonN23: /* MEASUREMENT AND PAYMENT */</p>
<hr />
<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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<br />
===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
<br />
[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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<br />
==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
<br />
===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
<br />
[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
<br />
[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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<br />
==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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<br />
===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
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::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
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Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
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Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
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[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
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{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
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Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
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[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
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All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
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[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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===[[#Stockpile Payment|Stockpile Payment]]===<br />
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See subsection 109.04 of the Standard Specifications for Construction for stockpile payment requirements. Additionally, see subsection [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.07 (Structural Steel) or 4.06.06 (Lighting, Signal and Sign Support Structures)] of the MQAP manual for QAI’s responsibilities for verifying stockpile payment.<br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5222707 - Structural Steel2018-01-16T19:16:14Z<p>JohnsonN23: /* Additional Specifications */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
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[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|500px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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<span style="color: red"> -Reserved- </span><br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Fig707.15.png&diff=5221File:Fig707.15.png2018-01-16T19:15:44Z<p>JohnsonN23: JohnsonN23 uploaded a new version of &quot;File:Fig707.15.png&quot;</p>
<hr />
<div>Figure 707.15 – Foundation Piling Record</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5220707 - Structural Steel2018-01-16T19:14:56Z<p>JohnsonN23: /* Welding Piles, Falsework, Form Supports and Accessories */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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<br />
===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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<br />
==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
<br />
===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
<br />
[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
<br />
[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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<br />
===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
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::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
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Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
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Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
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[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
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{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
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Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
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[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
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All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
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[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|500px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|900px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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<span style="color: red"> -Reserved- </span><br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Fig707.14.png&diff=5219File:Fig707.14.png2018-01-16T19:14:17Z<p>JohnsonN23: JohnsonN23 uploaded a new version of &quot;File:Fig707.14.png&quot;</p>
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<div>Figure 707.14 - Sample Welder Certification Test Report</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5218707 - Structural Steel2018-01-16T19:12:47Z<p>JohnsonN23: /* Electrode Storage */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
<br />
[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
<br />
All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
<br />
[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
<br />
Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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<br />
====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
<br />
New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
<br />
When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
<br />
::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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<br />
===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
<br />
[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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<br />
===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|800px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
<br />
[[File:Fig707.12.png|800px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
<br />
[[File:Fig707.13.png|800px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
<br />
The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|900px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
<br />
Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
<br />
Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
<br />
Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
<br />
:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
<br />
:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
<br />
:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|900px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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<br />
==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
<span style="color: red"> -Reserved- </span><br />
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<br />
[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Fig707.12.png&diff=5217File:Fig707.12.png2018-01-16T19:12:08Z<p>JohnsonN23: </p>
<hr />
<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5216707 - Structural Steel2018-01-16T19:11:04Z<p>JohnsonN23: /* Welder Qualification */</p>
<hr />
<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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<br />
===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
<br />
[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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<br />
==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
<br />
===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
<br />
[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
<br />
[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
<br />
Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
<br />
::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
<br />
::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
<br />
Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
<br />
:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
<br />
The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
<br />
The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
<br />
The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
<br />
The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
<br />
The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
<br />
[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
<br />
Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
<br />
:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
<br />
:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
<br />
:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
<br />
:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
<br />
:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
<br />
:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
<br />
The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
<br />
Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
<br />
Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
<br />
Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
<br />
At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
<br />
In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
<br />
Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
<br />
As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
<br />
:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
<br />
Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
<br />
Flame cutting is not allowed to bring members and connections into proper alignment. <br />
<br />
If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
<br />
Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
<br />
On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
<br />
The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
<br />
It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
<br />
When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
<br />
For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
<br />
If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
<br />
The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
<br />
The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
<br />
When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|500px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
<br />
All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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<br />
===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|600px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
<br />
[[File:Fig707.12.png|600px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
<br />
[[File:Fig707.13.png|600px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
<br />
The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
<br />
Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
<br />
Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|900px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|900px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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<span style="color: red"> -Reserved- </span><br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5215707 - Structural Steel2018-01-16T19:10:43Z<p>JohnsonN23: /* Bridge Welding in the Field */</p>
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<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
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<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
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<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
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==[[#GENERAL|GENERAL]]==<br />
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Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
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Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
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[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
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[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
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===[[#Request for Information Process|Request for Information Process]]===<br />
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The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
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See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
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The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
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The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
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Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
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Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
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[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
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[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
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Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
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::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
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::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
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Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
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:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
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The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
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:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
<br />
<br />
'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
<br />
All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
<br />
There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
<br />
All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
<br />
[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
<br />
The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
<br />
[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
<br />
Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
<br />
After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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<br />
====[[#Shear Developers|Shear Developers]]====<br />
<br />
Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
<br />
::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
<br />
Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
<br />
New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
<br />
When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
<br />
::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
<br />
Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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<br />
===[[#Welder Qualification|Welder Qualification]]===<br />
<br />
Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
<br />
Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
<br />
Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
<br />
[[File:Fig707.7.png|900px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
<br />
All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
<br />
[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
<br />
[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
<br />
{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
<br />
Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
<br />
[[File:707.10 page 1.png|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
<br />
All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
<br />
Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
<br />
[[File:Fig707.11.png|600px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
<br />
[[File:Fig707.12.png|600px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
<br />
[[File:Fig707.13.png|600px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
<br />
The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
<br />
The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
<br />
Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
<br />
[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
<br />
Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
<br />
Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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<br />
===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
<br />
Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
<br />
[[File:Fig707.14.png|900px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
<br />
Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
<br />
Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
<br />
Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
<br />
Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
<br />
Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
<br />
:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
<br />
:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
<br />
:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
<br />
:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
<br />
[[File:Fig707.15.png|900px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
<br />
:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
<br />
:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
<br />
:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
<br />
Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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<br />
==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
<br />
<span style="color: red"> -Reserved- </span><br />
<br />
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<br />
[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=707_-_Structural_Steel&diff=5214707 - Structural Steel2018-01-16T19:09:30Z<p>JohnsonN23: /* Bridge Welding in the Field */</p>
<hr />
<div><br />
<center><span STYLE="font: 60pt arial;">'''707'''</span></center><br />
<br />
<center><span STYLE="font: 40pt arial;">'''Structural Steel Construction'''</span></center><br />
<br />
<center>[http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf 2012 STANDARD SPECIFICATIONS FOR CONSTRUCTION - SECTION 707]</center><br />
<br />
<br />
==[[#GENERAL|GENERAL]]==<br />
<br />
Structural steel construction involves the fabrication, handling, erection, bolting and welding of steel members used in structural applications. Most structural steel for Department projects is comprised of bridge elements – plate girders and rolled beams, intermediate and end diaphragms, connection plates and stiffeners, cover plates, beam bearings, pin and hanger assemblies and foundation piling. All these elements can be further defined as primary or secondary members, per 707.01 of the MDOT Standard Specifications for Construction. Structural steel may be in the form of plate, rolled or bent shapes, hollow structural shapes, tube railing, steel deck grating, modular expansion joints, bars and pins, etc. Structural Steel also includes other highway appurtenances such as sign and lighting support structures, tower lighting units, mast arm traffic signal supports, and bridge mounted signs. <br />
<br />
Structural steel elements are typically fabricated at steel fabricators around the country, who must be certified by the American Institute of Steel Construction (AISC) to the appropriate level for the work being conducted. Bolting, welding, and coating of structural steel takes place both at fabrication shops and in the field, depending on the application. The Structural Fabrication Unit of Bridge Field Services oversees the department’s QA program for fabrication of structural steel, and should be consulted for any issues that arise out of structural steel fabrication. <br />
<br />
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<br />
<br />
===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
It is the responsibility of the MDOT Design Project Manager (PM) to ensure their project’s shop drawings are being reviewed by all applicable technical reviewers. This process is outlined in [http://mdotcf.state.mi.us/public/design/englishbridgemanual/ Chapter 10 of the MDOT Bridge Design Manual]. Figure 707.1-1 and Figure 707.1-2 below summarize MDOT’s electronic shop drawing review process and provides a listing of shop drawings to be reviewed with annotations indicating which MDOT Review Areas need to be involved in their review. Note that this shop drawing listing is general in nature and is applicable for most projects; however, exceptions may apply on a case by case basis and it is the responsibility of the PM to ensure the shop drawings are being reviewed by all applicable parties.<br />
<br />
[[File:Fig707.1-1.png|900px|thumbnail|center|Figure 707.1-1 – Shop Drawing Review Process]]<br />
<br />
[[File:Fig707.1-2.png|900px|thumbnail|center|Figure 707.1-2 – Shop Drawing Review Process]]<br />
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<br />
==[[#FABRICATION OF STRUCTURAL STEEL|FABRICATION OF STRUCTURAL STEEL]]==<br />
<br />
===[[#Request for Information Process|Request for Information Process]]===<br />
<br />
The Structural Fabrication Request for Information Process can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_RFI_Process_120415_510630_7.pdf here].<br />
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===[[#Shop Drawing Review Process|Shop Drawing Review Process]]===<br />
<br />
See subsection 104.02, Plans and Working Drawings, of the MDOT Standard Specifications. The Shop Drawing Review Process may be found [http://www.michigan.gov/documents/mdot/MDOT_Shop_Drawing_Review_Process_041513_471762_7.pdf here].<br />
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===[[#Nonconformance Program|Nonconformance Program]]===<br />
<br />
The Structural Fabrication Nonconformance Program can be found [http://www.michigan.gov/documents/mdot/MDOT_Structural_Fabrication_Nonconformance_Policy_080414_464586_7.pdf here].<br />
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===[[#Prefabrication Meeting|Prefabrication Meeting]]===<br />
<br />
The Structural Fabrication Unit will conduct a prefabrication meeting with the fabricator when deemed necessary. Prefabrication meetings are generally scheduled when the fabrication is more complex in nature or the fabricator is new to working with the Department but can be held for any project.<br />
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===[[#Shop Inspection|Shop Inspection]]===<br />
<br />
Quality assurance inspection is performed on all structural steel fabricated for the Department during all phases of the fabrication process. See the Materials Acceptance Requirements Table in the MQAP manual or project specific special provisions for acceptance requirements. The Department’s quality assurance program is implemented by Bridge Field Service’s Structural Fabrication Unit and utilizes vendor Quality Assurance Inspectors (QAI) to perform shop inspection at structural steel fabrication facilities nationwide. <br />
<br />
Throughout the fabrication process the shop inspector will inspect the materials and fabricated elements for conformance to Department specifications, collect all documentation regarding the fabrication, and verify Buy America provisions were met. If problems arise during the fabrication, the shop inspector will contact the Structural Fabrication Unit for resolution. Once fabrication is complete and the elements are ready to be shipped to the project site, the shop inspector will stamp the elements as well as the shipping documents “Approved for Use”. See Figure 707.1. The QAI then submits all fabrication documentation to the Bridge Field Services Structural Fabrication engineer for placement into the corresponding ProjectWise folder. See Figure 707.2 for the structural steel fabrication inspection flowchart.<br />
<br />
[[File:Fig707.2.png|600px|thumbnail|center|Figure 707.1: "Approved For Use" Stamp (MDOT)]]<br />
<br />
[[File:Fig707.3.png|900px|thumbnail|center|Figure 707.2 - Steel Fabrication Inspection Flowchart]]<br />
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<br />
==[[#CONSTRUCTION|CONSTRUCTION]]==<br />
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<br />
===[[#Delivery of Structural Steel|Delivery of Structural Steel]]===<br />
<br />
Project personnel are required to use the following procedure for acceptance of fabricated structural steel elements that are required to have “Fabrication Inspection” as the basis of acceptance in accordance with section [http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05.08.B or 4.06.06.B] of the Materials Quality Assurance Procedures Manual. These structural steel elements must not be shipped from the fabricator to the project or contractor’s yard without approval by the shop inspector at the time of loading. Fabricated structural steel elements include, but are not limited to, the following: <br />
<br />
::*Structural steel for bridges (plate, rolled, hollow structural shape, bridge tube railing, steel deck grating, modular expansion joints, etc.); <br />
<br />
::*Highway structures (sign structures, tower lighting units, and mast arm traffic signal) <br />
<br />
Acceptance of fabricated structural steel elements consist of satisfactory shop inspection by the MDOT shop inspector in accordance with the applicable sections ([http://www.michigan.gov/documents/mdot/MDOT_MQAP_Manual_5_Section_D_307110_7.pdf 4.05 and 4.06]) of MDOT’s Materials Quality Assurance Procedures Manual (MQAP) and satisfactory visual inspection in the field by the engineer. The following two part process has been added to the MQAP to clarify the acceptance process:<br />
<br />
:#Fabrication Inspection Acceptance: Structural steel elements must be inspected by the shop inspector after they are loaded for shipping. The elements must be stamped “Approved for Use” prior to shipping if they meet contract requirements (see Figure 707.1).Additionally, the shop inspector must stamp at least five copies of the Bill of Lading that is prepared by the fabricator. The approval stamp is for use by the Department and does not relieve the contractor of their responsibility to meet contract requirements.<br />
:#Visual Inspection Acceptance: The Engineer must collect one copy of the stamped Bill of Lading and use it to verify the delivered structural steel elements. Additionally, the Engineer must verify that the elements are stamped and visually inspect them for signs of damage that may have occurred as a result of shipping and handling. This visual inspection should be documented in the Inspector’s Daily Report (IDR).<br />
<br />
The Engineer must inspect fabricated structural elements delivered to the project site with a stamped Bill of Lading and approval stamp as stated in Part 2 of the acceptance process stated above. The Engineer reserves the right to reject any shipped element that shows visual signs of damage or does not meet specification requirements in accordance with section 105 of the MDOT Standard Specifications for Construction. The Engineer must notify the Structural Fabrication Unit of any elements arriving on site that do not meet the standard specifications. <br />
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The Engineer must reject fabricated structural steel elements delivered to the project site without being stamped and without a stamped Bill of Lading. Note that only large structural steel elements will be individually stamped. Packaged structural steel elements (containers of fasteners, pallets of diaphragms/ bridge sign connections, etc.) will only be stamped on the outside of the package in multiple locations. Therefore, it is very important that the Engineer verify the material prior to the containers/pallets getting opened and separate, unstamped elements become scattered throughout the project site. The Engineer is instructed to contact the Structural Fabrication Unit immediately whenever an element or Bill of Lading arrives on the project site without the approval stamp. <br />
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The Engineer may make stockpile payments for fabricated structural steel elements in accordance with section 109 of the MDOT Standard Specifications for Construction. These elements can be stored at the fabrication facility or at the construction site. If the elements are stored at the construction site then they must be inspected by the Engineer as stockpiling occurs since the approval stamp ink could wash off. The Engineer must then mark the accepted structural steel elements in another more permanent way. <br />
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The Engineer should contact the Structural Fabrication Unit if project personnel have any questions regarding the acceptability of structural steel elements shipped to the project site. The Structural Fabrication Unit must review all proposed corrective action to structural steel elements not meeting specifications prior to approval. <br />
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The Structural Fabrication Unit will send a fabrication inspection memorandum via ProjectWise link to the project office at the end of each project. This memorandum is not the basis of acceptance, but rather a brief summary of the fabrication inspection for the project. The project office should use it as a reference when requesting fabrication information from the Structural Fabrication Unit. All fabrication records are stored in the project folder in ProjectWise. See Figure 707.3 for a sample inspection memorandum. <br />
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[[File:Fig707.4.png|500px|thumbnail|center|Figure 707.3 – Sample Steel Fabrication Memo]]<br />
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===[[#Structural Steel Field Storage|Structural Steel Field Storage]]===<br />
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Once the structural steel has been accepted on the job site, the inspector should verify that the material is stored properly prior to installation. Below is a list of items the inspector should check regarding storage of structural steel elements: <br />
<br />
:*Padding adding must be used to prevent paint damage when chains or cables are used to brace or erect structural steel. The padding will minimize coating damage and resulting corrosion due to handling operations. <br />
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:*Structural steel should be stored on adequate supports to preserve its shape and quality. <br />
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:*Members are to be stored in an upright position and should be thoroughly braced to avoid overturning, which may damage the member itself, adjacent members or material, or injure personnel in the immediate vicinity. <br />
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:*Members should be so arranged that depressions, troughs, and similar "moisture traps" are eliminated and the blocking should be high enough so that the steel members don't come in contact with the ground or sit in ponded water or mud. This will keep the structural steel dry and free of corrosion until it is erected. <br />
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:*Related items such as bearings, bridge railing, sign structures and tower lighting units should also be protected from damage, dirt, and corrosion. <br />
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:*All related hardware (bolts, nuts and washers, etc.) must be stored in sealed containers that will keep them free of dirt and moisture until the point that they are installed. The inspector must reject any hardware that shows signs of corrosion prior to installation. <br />
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===[[#Erection of Structural Steel|Erection of Structural Steel]]===<br />
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====[[#Erection Plan|Erection Plan]]====<br />
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The inspector should review and understand the erection plan and the location and orientation of match-marked pieces. These markings are usually placed on the end of a member and will be erected with this marking in the same location as shown on the erection diagram.<br />
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====[[#Falsework|Falsework]]====<br />
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Falsework is a form of temporary support and may be required in the erection of steel for some projects. Often it is required at beam splices, usually on long spans or when special erection procedures are called for. A drawing of the proposed falsework must be submitted by the Contractor and approved by the Engineer. Such approval does not relieve the Contractors responsibility for design adequacy. The inspector should ensure that the falsework is assembled as shown on the approved drawings and that all bolted and welded connections are properly completed. See section 714 of the MDOT Construction Manual for more on falsework and temporary structures.<br />
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===[[#Erection Process|Erection Process]]===<br />
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====[[#Masonry Plates|Masonry Plates]]====<br />
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Placement of masonry plates is the first step in the erection process. These plates are placed on the concrete bridge seats of abutments and piers as shown on the plans. The inspector will see that concrete surfaces are perfectly flat at bearing locations and, if necessary, see that all high spots are ground to provide full bearing under each plate. Check plates to see they are not warped. The inspector should check the bearing of each individual plate by applying pressure to corners of the plate. Thin elastomeric sheets should be placed under the masonry plates when so designated on the plans. Low spots under edges of plates should not be filled with grout as this thin layer often will not bond and will deteriorate under load and weathering action. <br />
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Masonry plates and expansion rockers will be match-marked to the centerline of bearing line previously marked on the concrete bearing surface by the instrument crew. If masonry plates are not center marked, it will be necessary for the inspector to establish these marks on each unit. In doing this, locate the match line by using anchor bolt holes as the center. When erecting each unit, these marks will match the centerline of bearing lines previously placed on the bridge seat. On projects where sole plates are welded to the bottom flange of WF-beams or plate girders, it will be necessary to shift the entire beam to align marks. <br />
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At the time of erection, machine finished bearing surfaces will be coated with a commercial grade lubricant suitable for bearings. <br />
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In considering suspended span ends, the required opening should be maintained at the moving end. It makes little difference what the opening is under a field welded stay plate because it will never move. Where the plans call for expansion joints at independent backwalls, a check should also be made at the backwalls to verify enough beam end clearance to accommodate the maximum expansion. <br />
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Use the Offset Dimension for Rocker Tilt chart (see Figure 707.5) to adjust for temperature. <br />
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[[File:Fig707.5.png|900px|thumbnail|center|Figure 707.5 – Offset Dimensions for Rocker Tilt]]<br />
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====[[#Horizontal Stabilization|Horizontal Stabilization]]====<br />
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As wide flange beams and plate girders are erected, sufficient horizontal stabilization must be provided for each beam to prevent the beam from tipping over due to construction or wind loading. Common methods for achieving horizontal stabilization are listed below. This is an important phase of erection and may prevent serious accidents and damage to steel beams caused by high winds or crane booms striking erected sections. <br />
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:*Bolting beams to piers or abutments <br />
:*Placing diaphragms as the erection progresses <br />
:*Placing falsework <br />
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====[[#Erection Sequence|Erection Sequence]]====<br />
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Give particular attention to cantilevered center spans. End diaphragms and lateral bracing on skewed bridges will be placed as erection progresses to ensure proper fit or to determine assembly problems at the earliest phase possible. These members are, in effect, control members and must be placed in proper sequence. Project inspectors should insist that skewed diaphragms be placed at the time each stringer is set and before any final bolting of intermediate diaphragms. If the fabrication and design are correct, all the steel should fit. At no time should already connected diaphragms or bracing be disconnected to allow for easier fit up of successive elements. This could result in the erected elements becoming unstable. <br />
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Flame cutting is not allowed to bring members and connections into proper alignment. <br />
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If reaming is required to bring members and connections into proper alignment, it must be approved by the Engineer. Reaming is the process of using specialized tools to enlarge and already drilled hole in the steel elements. Excessive reaming could result in an ineffective bolt in that location to properly joint the materials. <br />
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Excessive pressure should not be used to force members into place, particularly on diaphragm assembling. Sweep can be forced into the main member by diaphragms forced into place when the length of the diaphragm has as little as a ½” error. This develops across the structure to a large sweep. When the bridge components do not appear to assemble correctly, a careful check must be made to determine if the pieces are properly match-marked. <br />
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====[[#Camber|Camber]]====<br />
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On wide flange beam and plate girder spans, the normal sag which occurs when the beam is loaded is necessary to be offset by either fabricating a camber in a beam or thickening the concrete haunch over the beams. Sometimes a combination of both is used. Also, beams may not be true to line and variances in elevation have to be provided for. Therefore, a convenient method of establishing the finished grade before casting concrete is desirable. <br />
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The superstructure plans for steel bridges may show a construction camber diagram sketch and another indicating top of screed elevations with slab thickness ordinates. <br />
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Plan camber of structural steel beams is built into the member with a small tolerance permitted as shown on the plans. The fabrication is checked by the shop inspector working under the Structural Fabrication Unit to see that the members are fabricated to the tolerance permitted. The camber in the shop is usually measured with the beam on its side. Estimated reduction in camber is then tabulated on the plans to cover camber loss due to the weight of the member, forms and reinforcing steel; welding of stud shear connectors; and the deflection from the weight of the concrete deck. <br />
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It is the Contractor's responsibility to erect the beams within the permitted camber tolerance. Any corrective work to obtain this camber is the Contractor's responsibility. Any proposed corrective work should be reviewed by the Structural Fabrication Engineer before approving. <br />
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When camber varies from the plan, it should be possible to adjust haunches and/or top of slab grades to allow for discrepancies. <br />
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For deck replacement projects, that slab and screed elevations are based on the beam camber completely returning after bridge deck removal. This is not always the case, and it is important to ensure the beams are surveyed after deck removal, and the results compared to the original camber diagram to determine if slab and screed grade adjustments are required. <br />
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====[[#Bolted Field Splices|Bolted Field Splices]]====<br />
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All field splice plates should be shipped in the assembled and drilled position, except that they are moved back one-half joint. The plates are brought forward on the beams to their final position. Occasionally, ironworkers inadvertently take the plates off, thus creating considerable difficulties. All plates, including the flanges, are required to be match-marked and it should be possible to determine the location and orientation of each plate. The fabrication plants CNC drill some parts of the girders to use as templates then do a laydown assembly. During this assembly, they will use the templates to match drill the other parts of the connection and match mark the parts. The match-marking scheme used should be shown on the approved shop drawings. If the plate hole alignment is difficult to achieve and they appear to require reaming, a mismatch should be suspected. <br />
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If minor hole misalignment occurs, the Engineer will be consulted regarding corrective measures to be used. Often the main splice plates on girder splices appear to be slightly out of alignment. When this occurs, the plates need to be inverted or rotated according to the match-marking. Never ream on main girder splice plates, as the connection is design to be slip critical. <br />
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The inspector will observe reaming operations to ensure the correct size reamer is being used. Also, holes will be reamed perpendicular to the member faces and all burrs will be removed. Members should be tightly clamped together to prevent metal chips from getting between surfaces. <br />
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The joint should be straight edged or string lined during the final bolting operation and adjustments made as required in grade or alignment to ensure straightness at the splice. <br />
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The slope of surfaces of bolted parts in contact with the bolt head and nut will not exceed 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20, a smooth beveled washer will be used to compensate for the lack of parallelism. <br />
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Prior to assembling, all joint surfaces, including those under the bolt head, nut, or washer must be free of oil, grease, burrs, dirt, or other foreign material that would prevent the solid seating of the parts. On shop painted steel, a carefully controlled coating of zinc rich primer has been applied to all faying (i.e., contact or friction) surfaces. These surfaces would have been masked during subsequent coating applications per subsection 716.03.B.2 of the MDOT Standard Specifications for Construction. Ensure no other coating is applied to these surfaces prior to bolting. <br />
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When making bolted attachments to existing structural steel, the contact surfaces on the old steel should be blast cleaned and prime coated with zinc rich paint as called for on the plans or in the specifications. <br />
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====[[#High Strength Steel Bolts, Nuts, and Washers|High Strength Steel Bolts, Nuts, and Washers]]====<br />
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When high strength structural bolts and nuts are used, a hardened washer must be placed under the nut or bolt head, whichever element is being turned. Bolts, nuts, and washers supplied for shop painted or galvanized members must be galvanized. See Table 707.2 for a brief description of high strength bolts, nuts and washers used for structural applications.<br />
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[[File:Table707.2.png|900px|thumbnail|center|Brief description of high strength bolts, nuts and washers used for structural applications.]]<br />
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===[[#Turn of Nut Tightening|Turn of Nut Tightening]]===<br />
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Bolt verification testing is required to be performed on all projects requiring turn of nut tightening per [http://mdotcf.state.mi.us/public/specbook/files/2012/707%20Str%20Steel%20Construction.pdf subsection 707.03.D.7.c of the MDOT Standard Specifications for Construction]. This testing is done to ensure that the contractor has sufficient knowledge and ability to complete turn of nut tightening correctly by using a device that measures bolt tension in conjunction with Table 707.3. Bolt verification testing is conducted by the Structural Fabrication Unit and the inspector should schedule the testing prior to any field bolting taking place.<br />
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'''Table 707.3 Minimum Bolt Tension for ASTM A325 Bolts'''<br />
{| class="wikitable"<br />
|-<br />
! Bolt Diameter (in)!! Minimum Bolt Tension (lbs.), (a)<br />
|-<br />
| 1/2|| 12050<br />
|-<br />
| 5/8|| 19200<br />
|-<br />
| 3/4|| 28,400<br />
|-<br />
| 7/8|| 39,250<br />
|-<br />
| 1|| 51,500<br />
|-<br />
| 1-1/8|| 56,450<br />
|-<br />
| 1-1/4|| 71,700<br />
|-<br />
| 1-3/8|| 85,450<br />
|-<br />
| 1-1/2|| 104,000<br />
|}<br />
''a. Equal to 70% of specified minimum tensile strength of bolts.''<br />
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All bolts must be tightened by the turn-of-nut method. Typically a hardened washer is placed under the head of bolt and the head is turned. Tightening may be required to be completed by turning the nut because of bolt placement and wrench operation clearances. In that case the washer must be placed under the nut. Impact wrenches, if used, must be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in a maximum of ten seconds. If tightening takes longer than 10 seconds the nut or bolt may be damaged and too much of the galvanized coating will be removed.<br />
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There will first be enough bolts brought to a snug tight condition to ensure that the joint parts are brought into full contact with each other. Snug tight is defined as the tightness attained by a few impacts of an air impact wrench or the full effort of a person using an ordinary spud wrench. Note that when the plates or parts being bolted cannot be drawn into full contact by "snug tightening" bolts, a few temporary bolts should be fully tightened to force the surfaces into contact. These temporary bolts should then be marked for removal and replacement. The remainder of the bolts should then be snugged and tightened. Then remove and replace the bolts tightened to force surface contact.<br />
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All bolts in the joint will be tightened by first the snugging and then by applying the applicable amount of nut rotation as specified in Table 707.4.<br />
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[[File:Table707.4.png|900px|thumbnail|center|Nut Rotation from Snug Tight Condition ]]<br />
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The element being turned, either the nut or the bolt, will be marked after snugging to visually verify the proper rotation has been achieved. The marking should be done with a felt tip ink pen (do not use keel, chalk or soap stone) according to the scheme shown in Figure 707.6.<br />
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[[File:Fig707.6.png|900px|thumbnail|center|Figure 707.6 Typical Turn of Nut Marking System ]]<br />
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Tightening will progress systematically from the most rigid part of the joint to its free edges. During this operation there will be no rotation of the part not being turned by the wrench. This usually requires the stationary element being restrained by a spud wrench. After tightening, the bolt must be at least flush with the nut to verify full engagement of all threads of the nut and to ensure proper bolt/nut capacity. All bolts and nuts that have been snug tightened only may be removed and reused. Bolts and nuts that have been tightened beyond the snug stage must not be reused if loosened or removed.<br />
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====[[#Deck Drains|Deck Drains]]====<br />
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After the steel is erected, the inspector will check the deck drain locations to ensure that water will not be drained directly over some members, such as diaphragms, and that they extend well below the bottom flanges of the beams or girders.<br />
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====[[#Shear Developers|Shear Developers]]====<br />
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Shear developers are used to provide a composite section between the concrete deck and the steel beams supporting it. They are in the form of steel studs and are welded to beam flanges at the spacing shown on the plans. This composite section generally allows the designer to reduce the beam size required, as a portion of the deck is considered part of beam, thus increasing its moment of inertia. <br />
Stud shear developers are certified in the same manner as electrodes and must be selected from the Qualified Products List. <br />
Defective stud welds can usually be attributed to four main causes:<br />
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::*Welding on contaminated coatings (oil, grease etc.), wet, or moist beams with damp ferrules. <br />
::*Welding with insufficient amperage. <br />
::*Welding with a stud gun that is out of adjustment (arc length and plunge). <br />
::*Welding too close to the flange edge. <br />
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Before welding studs to the beams, the specifications require that all coatings be removed by grinding in the weld area and that all moisture, oil, grease, or other dirt be removed. <br />
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New operators have a tendency to tip the studs slightly, increasing the chances of producing defective welds. Also, they sometimes do not hesitate long enough to allow the weld metal to cool. <br />
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When the welding operation is delayed due to rain, the flange surface must be dry before commencing welding and any connection ferrules which were dampened due to the rain must be replaced with dry ones. <br />
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::*Prior to the welding operation, it is advisable for the Engineer to discuss with the Contractor the procedure which will be used to repair all studs which lack a full 360°fillet. The Contractor can repair defective studs by manually adding either a fillet weld to each stud that lacks weld metal, using E7015, E7016, or E7018 electrodes, or by adding new studs adjacent to the defective ones. <br />
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=====[[#Testing Studs|Testing Studs]]=====<br />
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Studs are tested by ringing with a hammer. To test the studs, the inspector should allow cooling before testing. The first two studs welded will be bent to a 30 degree angle without breaking the weld. If the weld breaks, repairs will be made and the next set of studs tested along with the studs that were repaired. The rest of the studs on that beam can then be checked for proper welding. Sufficient tests should be made to insure proper procedures are being followed (bend over additional studs). If a weld defect is found, the stud may be bent to an angle of 15 degrees away from the defect. If no weld break occurs, the stud is acceptable. No welding will be done when the temperature of the base material is below 32 °F (0C) or when the surface is wet or exposed to rain or snow.<br />
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===[[#Welder Qualification|Welder Qualification]]===<br />
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Structural welding or welding repair work requires all welders to be tested through the [http://www.michigan.gov/documents/mdot/Welder_Qualification_Program_Portfolio_071014_462432_7.pdf MDOT Welder Qualification Program]. The field welder must present Form 0396 “Welder Qualification Test Report” (See Figure 707.7) stating qualification according to AWS D1.5 Bridge Welding Code within the previous two-year period. The Project Engineer will contact the Structural Fabrication Unit to arrange for welder qualification testing if the Contractor does not currently have a Department qualified welder available. The Engineer reserves the right to require a confirming qualification test during work progression. <br />
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Field welders must be qualified in the welding process, position, method, electrode classification, base metal type, and the maximum electrode diameter actually being used to perform the work. <br />
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Welders qualified using a 3/8” thick test plate are allowed to weld material up to 1” in thickness but if the welder is tested using a 1” thick test plate, they are not limited in the thickness of material they can weld. <br />
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[[File:Fig707.7.png|900px|thumbnail|center|Figure 707.7Sample Welder Qualification Test Report]]<br />
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All welding falls into one of two categories: either fillet (F) series or groove (G) series. Fillet welding is encountered when any two structural shapes or plates are joined by lapping or butting together without any joint preparation and, conversely, groove welding requires a specified root opening. Because groove welding requires a greater skill and the welder qualification test is somewhat more severe than the fillet weld test, MDOT grants automatic qualification for certain (F) positions, provided the welder has passed a corresponding or higher (G) qualification test (see Figure707.8 and Figure707.9 for position descriptions). The following Table 707.5 is furnished to assist in ascertaining which positions automatically qualify other positions. <br />
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[[File:Fig707.8.png|900px|thumbnail|center|Figure 707.8 - Fillet Weld (F) Positions]]<br />
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[[File:Fig707.9.png|900px|thumbnail|center|Figure 707.9 - Groove Weld (G) Positions]]<br />
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{|<br />
|-<br />
| [[File:Table707.5.png|900px|frame|left|Table 707.5 Welder Qualification Type and Position Limitations]]<br />
|-<br />
|*Position of welding: F = Flat, H = Horizontal, V = Vertical, OH = Overhead <br />
|-<br />
|*Note that welding in a vertical downward direction is never permitted, only vertically in the upward direction (starting at the bottom and working towards the top). <br />
|}<br />
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===[[#Bridge Welding in the Field|Bridge Welding in the Field]]===<br />
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Field welding will be performed according to subsection 707.03.D.8 of the MDOT Standard Specifications for Construction and the current American Welding Society (AWS) Bridge Welding Code D1.5. All field welding must be completed in accordance with [http://www.michigan.gov/documents/mdot/Form_0395_D1_5_Field_Welding_Plan_060515_494948_7.docx Form 0395 - AASHTO / AWS D1.5 Field Welding Plan] which has been approved by the Structural Fabrication Unit (see Figure 707.10). Field welding is not allowed unless shown on the plans or authorized by the Engineer.<br />
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[[File:707.10 page 1.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 1]]<br />
[[File:707.10 page 2.jpg|500px|thumbnail|center|Figure 707.10 Sample Approved Weld Procedure Specification (WPS) page 2]]<br />
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All structural field welding will be done by the Shielded Metal Arc Welding (SMAW) process using E7018 electrodes. Gas Metal Arc Welding (GMAW) and other gas shielded processes are prohibited. Submerged Arc Welding (SAW) and Flux Cored Arc Welding (FCAW) may be allowed for field welding when approved by the Engineer. <br />
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====[[#Electrode Storage|Electrode Storage]]====<br />
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Proper storage and use of electrodes is critical. Care must be taken to ensure no moisture is picked up in the coating of the electrodes as this can add hydrogen to the coating and cause discontinuities in the weld. Electrodes exposed to the atmosphere upon removal from drying or storage ovens (see Figure 707.11) or hermetically sealed containers (see Figure 707.12) must be used within two hours, or re-dried at a minimum temperature of 500° F for a minimum of two hours. Electrodes can only be re-dried once, and any electrode that becomes wet cannot be re-dried. Electrodes taken from a hermetically sealed container or drying oven that are not going to be used within two hours should be stored in a portable oven, also known as a “hot box” (see Figure 707.13), at a minimum temperature of 250° F. The welder should take out only as many electrodes from the hot box as can be used within that two hour period of time. <br />
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[[File:Fig707.11.png|600px|thumbnail|center|Figure 707.11 Drying and Storage Oven]]<br />
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[[File:Fig707.12.png|600px|thumbnail|center|Figure 707.12 Hermetically Sealed Electrode Containers]]<br />
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[[File:Fig707.13.png|600px|thumbnail|center|Figure 707.13 Hotboxes for Electrode Storage]]<br />
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====[[#Weld Joint Preparation|Weld Joint Preparation]]====<br />
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The first step in making a sound weld is to make sure the joint is correctly cleaned and then preheated prior to welding. Cleaning the joint can be accomplished by using a stiff wire brush. All surfaces to be welded must be free from all loose or thick scale, slag, rust, moisture, grease, or other contaminants. Mill scale that can withstand a vigorous wire brushing, or anti-spatter compound may remain prior to welding. <br />
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The pieces to be joined should be checked for flatness, straightness and dimensional accuracy. Likewise, alignment, root opening, fit-up and joint preparation should be examined. Finally, process and procedure variables should be verified, including electrode size and type and equipment settings. These variables should be listed in the weld procedure (WPS). <br />
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Preheating is the required practice of providing localized heat to the weld zone. The preferred method of preheating is by the use of a manual torch and the required preheat temperature varies based on the thickness of the base metal (see Table 707.6). Preheat shall be applied for a distance of 3 inches in all directions from the weld joint and should be verified by the welder using a temperature indicating stick. Bridge welding is not permitted when the ambient temperature is below 40 degrees Fahrenheit.<br />
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[[File:Table707.6.png|900px|thumbnail|center|Table 707.6 - Minimum Preheat Temperatures]]<br />
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Welds should be cleaned between every pass and after the final pass. A finished weld should have a clean appearance. Cleaning is typically accomplished by using a stiff wire brush in conjunction with a chipping hammer to remove slag and splatter. The grinder is also a very common and useful tool for cleaning. Grinders are to be used with care to avoid doing more harm than good to both finished welds and the base metal. <br />
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====[[#Weld Inspection|Weld Inspection]]====<br />
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Once the welding has been completed the welds must be tested for acceptability according to subsection 707.03.d.8.c of the MDOT Standard Specifications for Construction. The contractor is responsible for the non-destructive testing of the welds. Personnel qualified as Level II or Level III in accordance with the American Society for Nondestructive Testing (ASNT), Recommended Practice No. SNT-TC-1A must perform all the testing and provide a copy of their qualification to the inspector. If welds are found to be unacceptable, the welds must be repaired and retested. Consult the Structural Fabrication Unit of Bridge Field Services with any questions regarding non-destructive testing.<br />
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<br />
===[[#Welding Piles, Falsework, Form Supports and Accessories|Welding Piles, Falsework, Form Supports and Accessories]]===<br />
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Welding on piles, falsework, form supports and other accessories will be performed according to the current American Welding Society (AWS) Structural Welding Code D1.1. All welders performing this type of welding must be certified through the [http://www.michigan.gov/documents/mdot/MDOT_Certified_Weld_Testing_Agency_Program_082312_396129_7.pdf MDOT Welder Certification Program] which is administered by the Structural Fabrication Unit. The field welder must present Form 5620 - Welder Certification Test Report (See Figure 707.14) stating qualification according to AWS D1.1 Structural Welding Code within the previous two-year period. <br />
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[[File:Fig707.14.png|900px|thumbnail|center|Figure 707.14 - Sample Welder Certification Test Report]]<br />
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====[[#Pile Welding|Pile Welding]]====<br />
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Steel piles are utilized in a variety of bridge foundation designs, and pile lengths beyond 50 feet are typically spliced in the field as needed. For the most critical designs, such as piles considered primary members or integral abutment piles, full penetration butt welds around the entire perimeter of the pile section are required. Lesser applications may allow the use of commercially available mechanical pile splicers. The pile splice requirements are based on the criticality and redundancy of the member in combination with the loading condition. <br />
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Piles are considered to be primary members if they are part of the substructure, extend above ground level, or if they are designed to carry live load and act as primary load path members. Piles deemed primary will be shown on the plans. The most common use of piles as primary members are pile bent piers, which utilize driven piles as columns. They are inherently less redundant than piers supported by pile groups tied by a pile cap on grade; therefore, the use of mechanical pile splicers is not acceptable. Full penetration butt welds and 100 percent Ultrasonic Testing (UT) is required for acceptance of primary members. <br />
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Integral abutment designs rely on the flexibility of a single row of piles to accommodate thermal expansion and contraction of the bridge superstructure. Due to the lateral forces associated with this movement, full penetration butt welds are necessary to ensure the full section capacity of the pile is developed through the welded splice. Piles used for integral abutments are not deemed to be primary members, however, require greater Quality Control (QC) by the Contractor and Quality Assurance (QA) by MDOT. <br />
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Pile foundations designed for high capacity service loads, tension loads, or extreme events (vessel impact, deep scour, etc.) may also require full penetration butt welded splices, and not allow for pile splicers. A determination of the pile’s criticality and the foundation’s redundancy will be made on a case by case basis. Pile splicing requirements will be detailed in the project plans and the specifications will address QC/QA requirements in the same manner as integral piles. <br />
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Full penetration butt welding in the field requires significantly more time than the use of pile splicers for typical steel piles. Changes to the specifications were made to require 100% UT for primary members, yet still ensure acceptable full penetration butt welds on other critical pile.<br />
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=====[[#Additional Specifications|Additional Specifications]]=====<br />
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:*Special Provision for Pile Splicing (SP705 (A)) that completely revises the pile splicing specifications. Subsection 705.03.C.2.d of the 2012 Standard Specifications for Construction is replaced in its entirety with the Special Provision for Pile Splicing. <br />
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:*Special Provision for Quality Control Plan for Welding Foundation Piling Splices (SP705 (B)) requiring Contractors to provide a welding QC plan. This establishes the QC requirements the Contractor must follow. However, MDOT is still responsible for QA by visually inspecting field welds to the maximum extent practicable and documenting the number of splices and QA checks on form 1161L. MDOT reserves the right to UT welds in the event the QA process determines inadequate QC by the Contractor. <br />
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:*[http://www.michigan.gov/documents/mdot/Field_Manual_for_Pile_Welding_407880_7.pdf Field Manual for Pile Welding] to assist construction staff in understanding basic terminology and principles associated with field welding and inspection. This is an excellent resource for field staff overseeing pile welding. Included in the field manual are descriptions of weld processes, types of welds, welding equipment, inspection procedures, common weld discontinuities, pre- approved welding procedure specifications and photographs of acceptable and non-acceptable welds. <br />
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:*Form 1161L Foundation Piling Record, LRFD has been revised to accommodate the pile welding changes and establish a method for QA. See Figure 707.15. <br />
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[[File:Fig707.15.png|900px|thumbnail|center|Figure 707.15 – Foundation Piling Record]]<br />
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====[[#Implementation Examples|Implementation Examples]]====<br />
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:*Primary Member Piles–Steel H-Piles or Cast-In-Place (CIP) shells used as primary members typically pile bent piers. Require full penetration buttwelds AND 100 percent UT for acceptance in accordance with the Special Provision for Pile Splicing. The pay item Splice, Steel Pile is applicable to this scenario; however, the costs for all UT testing shall also be included in the pay item. <br />
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:*Integral Abutment or other High Capacity Piles–Steel H-Piles or CIP shells used for integral abutment or other high capacity foundations require full penetration buttwelds and must be done in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The 100 percent UT requirement for acceptance does not apply unless deemed necessary by the Engineer; however, alternate splice details (pilesplicers) are not allowed for integral or other high capacity piles. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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:*Standard Steel Piles – Steel H-Piles or CIP shells used for non-integral abutments, piers, or other elements as shown in the project plans and specifications, that are not considered primary structural members (typically pile bent piers) may be spliced with the alternate splice details (mechanical pilesplicers). A full penetration buttweld is not required; however, all welding must be performed in accordance with the Special Provision for Pile Splicing and the Special Provision for Quality Control Plan for Welding Foundation Piling Splices. The pay item Splice, Steel Pile is applicable to this scenario, and weld acceptance is visually based (see the Field Manual for Pile Welding). <br />
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=====[[#C. Welding for Form Supports and Accessories|C. Welding for Form Supports and Accessories]]=====<br />
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Certified and Qualified welders may weld supports and attachments to steel girders if approved by the Engineer, in compression areas only. This may include support angles for permanent metal deck forms or attachments to facilitate bridge deck concrete forms. '''Welding in tension zones is not permitted''' and in these cases straps that run across the top flange must be used in lieu of welding to the top flange. Tension zones coincide with areas with no shear studs, with the exception of horizontally curved girders which have shear studs along the full length of the girders. In these cases the tension zones should be noted on the design plans. If there are any questions about the limits of tension zones or compression zones, consult with the bridge designer or Bridge Field Services.<br />
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==[[#MEASUREMENT AND PAYMENT|MEASUREMENT AND PAYMENT]]==<br />
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<span style="color: red"> -Reserved- </span><br />
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[[Category:Construction Manual]]</div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:707.10_page_2.jpg&diff=5213File:707.10 page 2.jpg2018-01-16T19:06:34Z<p>JohnsonN23: </p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:707.10_page_1.png&diff=5212File:707.10 page 1.png2018-01-16T19:06:09Z<p>JohnsonN23: </p>
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<div></div>JohnsonN23https://mdotwiki.state.mi.us/construction/index.php?title=File:Fig707.7.png&diff=5211File:Fig707.7.png2018-01-16T19:03:21Z<p>JohnsonN23: JohnsonN23 uploaded a new version of &quot;File:Fig707.7.png&quot;</p>
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<div>Figure 707.7Sample Welder Qualification Test Report</div>JohnsonN23