Prediction of Bulk and Interface Failure Potential in Asphalt Pavements under Multi-Axial Stress States

This paper investigated the failure potential in asphalt pavements under multi-axial stress states. A 3-D finite element (FE) pavement model was developed to predict the stress states in the pavement under moving tire loading. The calculated stress states were evaluated using Mohr-Coulomb criteria, respectively, for the bulk asphalt material and the interface between asphalt layers. The study results indicate that it is important to consider multi-axial stress states when considering the failure at pavement near-surface and layer interface. The failure potential at pavement near-surface varies depending on the depth and the horizontal location with respect to the tire. This indicates that "what appeared to be surface cracking" could initiate at the pavement surface or at some distance below pavement surface. At the layer interface, the maximum longitudinal shear stress was located at the tire center when the tire was approaching or leaving, while the maximum transverse shear stress was located at the tire edge. However, the longitudinal shear stress causes the greater failure potential due to the smaller confinement.