Functional and structural HMA overlays are widely used pavement preservation technique, where interface bonding can be one of the most important factors affecting the performance. Interface bonding is affected by various factors, including material, application, texture, and other environmental conditions. Tack coat plays a significant role considering low cost and potential damages caused by the premature failure of tack coat. Typical distresses include delamination, pot-hole, shoving and cracking. The current MnDOT specification of tack coat practice is not performance based. Much researches have been conducted on the performance of tack coat in both lab and field in recent years as the importance of tack coat performance has been realized.
For this project, the in-situ pull-off tester (e.g., interface bonding strength test equipment) will be purchased, and different road sections in the state of Minnesota and MnROAD test sections will be selected to monitor the factors affecting the interface bonding and pavement performance. The objective of this project is to the development of a test method and a performance-based specification for tack coat practice.