Effect of Shear Stresses on Asphalt Pavement Performance and Evaluating Debonding Potential under Repeated Loading: Numerical Study

Abstract

The primary of this paper is to evaluate the potential of shear failure in asphalt pavement with the primary focus on the layer interface debonding. To fulfill this objective, a three-dimensional (3D) finite-element (FE) model is developed to calculate the stress state within the asphalt pavement structure. Five different cases of vehicle maneuvering where shear forces acting on the surface layer were selected, and pavement responses were obtained and analyzed under 100 loading cycles at three different temperatures. Results show that maximum shear stress occurred on top of the surface layer, and with receding from the surface, the stresses reduced significantly along the pavement depth. The case where the vehicle moves along the curved road section induced the highest transverse shear stress, whereas braking action caused the highest longitudinal shear stress both within the pavement layer and at the layer interface. Moreover, the maximum shear stress in both directions and all studied cases took place in somewhere within the tire imprint area. With increasing temperature, the pavement responses increased in all cases accordingly. In addition, pavement responses at the bottom of the binder course were significantly lower than those of at the bottom of the surface layer. In general, pavement responses in pavement layers were larger than their counterparts at the layer interface. Finally, the concept of interface shear ratio (ISR) is presented to evaluate the potential of debonding at the layer interface under repeated loading. According to initial results, the ISR could be considered as a promising criterion for assessing shear failure potential at layer interface.