Evaluation of top-down crack propagation in asphalt pavement under dual tire loading

Abstract

Top-down cracking (TDC) has been recognized worldwide and is regarded as a major type of asphalt pavement distress. In this study, fracture mechanisms behind the TDC propagation and fatigue life of pavements were investigated under dual tire loads using finite element (FE) analysis. By considering the most influencing factors on TDC propagation, stress intensity factors (SIF), including KI and KII, were calculated at critical transverse locations. According to Modes I and II SIF, a greater SIF indicates a faster rate of TDC propagation. The SIF results indicated that considering temperature gradient in asphalt concrete (AC) layer is necessary in determination of critical SIF, and KI and KII are not distributed uniformly within the AC depth. In addition, TDC growth rate significantly depends on AC thickness and base layer type. Finally, the number of load repetitions for TDC propagation rate at different transverse locations is predicted based on Paris’ law equation.