AbstractTo gain a better understanding of the microscopic damage mechanism of different asphalt mixtures under the action of ice swelling, the authors use the stochastic modeling method combined with MATLAB and Ansys to conduct a thermal–mechanical coupling analysis of open-graded friction course (OGFC) and asphalt concrete (AC) under continuous freezing conditions. The results show that without considering other heat sources, the internal temperature of a structure will increase with time and gradually maintain the same periodic change as the external temperature. Under the same environment, internal moisture will freeze quickly in approximately 15 s. The freezing rate is related to the size of the pores and the temperature difference between the inside and outside of the ice crystals but is less related to the gradation type of the mixture. In structural analysis, the stress and strain will increase with the porosity under the same gradation type. At the same time, the stress in the bonding surface is always approximately twice the stress value in the asphalt mortar, and the strain is less than that in the asphalt mortar. In different grading types, although the strain of OGFC is smaller than that of AC, the overall frost heave stress is significantly larger than that of AC. Therefore, this study not only provides a reference for the dynamic study of ice crystals but also reveals the internal damage mechanism of the two types of asphalt mixtures.