Coupled Thermomechanical Damage Behavior Analysis of Asphalt Pavements Using a 2D Mesostructure-Based Finite-Element Method

Abstract

To investigate the damage behavior of asphalt pavements under the combination of temperature fields and traffic loadings, a two-dimensional (2D) mesostructure-based finite-element method was developed. Temperature fields in an asphalt pavement at midday and midnight of summer and winter seasons were considered according to real air temperature data of an inland city in China. The mesostructure of the asphalt concrete layer was established based on digital image processing (DIP) technology from the cross-section image of an asphalt mixture specimen. A multiscale simulation approach was employed to link the mechanical behaviors of the asphalt concrete layer at different length scales. During the simulation, the traffic and temperature loadings were applied to the macroscale pavement model; subsequently, the strain responses and temperature distributions were extracted from critical positions of the pavement and transferred to the mesoscale model. In addition, the thermal expansion/contraction behavior of the asphalt mixture was taken into account. In this way, the stress distributions and damage behavior of the asphalt pavement induced by both the traffic tire loadings and temperature variations were well simulated while considering the heterogeneous features of the asphalt mixture. The results showed that the thermal expansion/contraction induced by the temperature changes had a significant influence on the maximum principal stress distributions within the asphalt layer, which further can influence the damage behavior of the asphalt pavements. In particular, significant thermal stress caused by the temperature variation appeared on the top of the asphalt concrete (AC) layer in the winter, and the thermal expansion/contraction can affect remarkably the pavement responses at midnight in the winter.