Development of fracture-energy based interface bond test for asphalt concrete

The behavior of the interface between adjacent pavement layers is one of the most important factors affecting pavement performance. Despite the importance of interface behavior between different pavement layers, there are few guidelines that can be used for construction, and the selection of tack coat type, application rate, and placement is usually based on empirical judgment. This paper presents a new fracture-energy based Interface Bond Test (IBT), which can be a practical method to evaluate the bond between pavement layers. The results of laboratory and field studies demonstrate the ability of the test to distinguish between samples produced with different tack coat application rates and modified versus unmodified tack coat material. Results from the IBT test were also compared with direct tension tests, and similar trends were found to exist.