502 - HMA Crack Treatment
HMA Crack Treatment on Roads With Centerline or Shoulder Corrugations (Rumble Strips)
If a transverse crack that will be routed or sawed intersects a corrugation (rumble strip), stop the reservoir six inches short of the corrugation. Overband crack fill the remaining six inches, as well as the crack within the corrugation. If there are secondary cracks within the corrugation, limit the overband to the primary crack; the overband width should not exceed four inches. If the longitudinal joint located within a corrugation requires overbanding, apply the overband continuously along the longitudinal joint. If there are secondary cracks, limit the overband within the corrugation to the primary longitudinal crack and do not exceed four inches in width. Allow a maximum overband thickness of ½ inch when overband crack filling within a corrugation.
Field blended liquid mixture for overband (Alternate 1) is no longer allowed. All overband material must be from the Qualified Products List (Alternative 2).
a. Stand Alone Overband Crack Fill
b. Micro-Surfacing Preparation – Industry recommends a delay period of 3 days between overband pretreatment and placement of micro-surfacing.
c. Chip Seal Preparation– Industry recommends a delay period of 7-14 days between overband pretreatment and placement of chip seal.
d. Paver Placed Surface Seal Preparation – It is recommended to allow 14 days between overband pretreatment and paver placed surface seal.
e. HMA Ultra-Thin Overlay Preparation– It is recommended to allow 14 days between overband pretreatment and ultra-thin overlay.
Overband Crack Fill and HMA Crack Treatment are now paid for by the lane mile (Lnmi). All shoulder work is considered incidental. A lane mile is defined in the Lane Mile Inventory document which can be found online at http://www.michigan.gov/mdot/0,4616,7-151-9621_15757---,00.html