Temperature field and thermal stress meso-distribution of asphalt mixture based on DEM thermo-mechanical analysis

To accurately characterise the meso properties of low-temperature cracking of asphalt mixtures, a virtual thermal stress restrained specimen test (TSRST) was established based on thermo-mechanical analysis in discrete element method (DEM). The virtual TSRST method was established to analyse the variation of the temperature field and thermal stress inside the specimen, and the mechanism of cracking development of asphalt mixtures was investigated through the distribution of meso contact forces of the specimen. It is found that the virtual test results are highly consistent with that of the laboratory test. During the cooling process, the maximum contact tension occurs within the aggregate, followed by the aggregate-mortar interface and the interior of the mortar. Considering the higher bonding strength of the aggregate, the aggregate-mortar interface would be the weakest area in the structure. With scoped stress concentration, most of the cracks occur close to the ends of the specimen.