Using interface shear characteristics to evaluate the residual performance of asphalt pavements

Asphalt pavement interface is considered to provide adhesion between two asphalt mixture courses. However, the relationship between shear characteristics of interface and residual performance of asphalt pavement still requires further research. This study investigated the effect of traffic loading, service time and distress type on the shear characteristics of asphalt pavement interface. Leutner shear test was conducted on the cylindrical specimens drilled from highway field, and the specimens are divided according to locations, service time and distress types. Shear strength, fail displacement and flexibility of interface were employed to characterize shear characteristics respectively. The results indicate that, among the locations, interface of rutting locations show the lowest shear strength, fail displacement and flexibility. Moreover, the shear characteristics decrease along with increase of interface’s service time. Interface of specimens with 4-years-service time showed the similar shear characteristics with interface of rutting locations. It demonstrated that the pavement that had served for 4 years had a risk of distress due to the interface shear characteristics loss, which suggests that the residual performance of this pavement was inadequate. Alternatively, the shear characteristics at rutting location are better than that of upheaval location. This research shows a possible way of evaluating residual performance and distress risk of pavement based on interface shear characteristics, which may contribute to the future pavement evaluation and maintenance.