Answers to common questions
By Dave Johnson, P.E.
Tack coats and pavement bonding have been garnering significant attention in the asphalt world. A number of states have already or are sponsoring research on the topic. This is a very good thing as pavement bonding is essential to quality pavement performance.
A National Cooperative Highway Research Project (NCHRP), 9-40, “Optimization of Tack Coat for HMA Placement”, investigated tack coat usage and practices that will improve pavement bonding. The final report for the project is Report 712.
Beginning in January of 2015, the Asphalt Institute (AI) and the Federal Highway Administration (FHWA) have been leading four-hour tack coat workshops for state departments of transportation around the United States.
The structure of these workshops is similar to the previously launched longitudinal joint and intelligent compaction workshops also done with FHWA. Consistent with the others, the tack coat workshop is offered to the states without a fee.