Mechanical Response Analysis of Asphalt Concrete Overlay Placed on Asphalt Pavement Considering Cross-Anisotropic Pavement Materials

Pavement materials, including unbound layers and asphalt concrete (AC) have been recognized cross-anisotropic materials. This research is conducted to investigate the effects of road materials cross-anisotropy on mechanical response of AC overlay over asphalt pavement with or without cracking existing in the underlying layer. To facilitate this study, series of three-dimensional (3D) finite element model (FEM) of cross-anisotropic asphalt pavement with AC overlay are developed. The FEM simulations are applied to analyze and compare the surface deflection as well as critical stress and strain on AC overlay in different levels of cross-anisotropy. The numerical results reveal that cross-anisotropic properties of road materials have important effects on the mechanical response of AC overlay: the cross-anisotropic structure has more potential to suffer from failure, which has been currently neglected. It’s indicated that cross-anisotropic properties of road materials should be considered in asphalt pavement overlay design.