Effect of temperature field on damage initiation in asphalt pavement: A microstructure-based multiscale finite element method

The present study developed a microstructure-based multiscale finite element (FE) method to investigate the effect of temperature fields on the damage initiation within the asphalt pavement under traffic loading. Three heat transfer mechanisms that dominate the temperature distribution in the pavement structure, i.e., thermal radiation, convection, and conduction, were considered in the multiscale modeling. Both mechanical and thermal properties of asphalt concrete (AC) on two physical length scales, namely, global (pavement level) and the local (mixture level) scales, were included in the computation and connected via a homogenization process. A digital image processing (DIP) technology was adopted to establish the local-scale representative volume element (RVE) model that interpreted the realistic heterogeneity of the AC microstructure, and a bilinear cohesive zone model was employed to model the damage initiation in the RVEs. The results showed that the developed multiscale FE model provided an insight into the damage behavior of asphalt pavement subjected to temperature fields varying with time on both the global and local scales, indicating the importance of considering temperature fields in pavement structural analysis. By means of the presented method, the influence of temperature fields, pavement structures, mixture microstructures and component properties, and interface behavior between mortar matrix phase and coarse aggregates on the pavement damage initiation could be rationally taken into account in the analysis. In light of these benefits, the presented approach can be expected to be utilized as a mechanistic tool for improving the performance prediction and evaluation as well as mixture and structural design of asphalt pavements.