AbstractThis study proposed a three-dimensional (3D) multiscale modeling method to investigate the responses of asphalt pavement subjected to coupled temperature-stress fields. In this method, finite element models of asphalt pavement at two different scales, i.e., the macroscale (pavement level) and mesoscale (mixture level), were developed separately and connected through a two-way coupled approach, including a homogenization (upscaling) procedure and a mapping (downscaling) procedure. X-ray computed tomography (CT) scanning technology was adopted to acquire realistic mesostructure images of asphalt concrete, and a digital image processing technology was employed to reconstruct its 3D mesoscale representative volume element model from these CT images. Both thermal and mechanical properties of asphalt concrete at the two scales were considered in the multiscale simulation. Also, actual climatic data sets, including air temperature history, solar radiation history, and mean wind speeds, were incorporated into the computation. The results showed that the developed multiscale method furnishes an in-depth insight into the thermomechanical behaviors of asphalt pavement at different length scales under both tire loading and realistic environmental factors. The consideration of coupled temperature-stress fields varying with time has a significant impact on the accurate determination of the critical responses within asphalt pavement. Because the developed method is capable of simultaneously taking into account multiple factors, including mixture component properties and mesostructures, pavement structures, tire loads, and climatic information, it can be expected to serve as a mechanistic tool for facilitating and enhancing the analysis and design of asphalt pavement.