Research on Shear Failure of Asphalt Mixture Based on Unjamming Transition

Asphalt mixture was a composite material, and traditional theories were difficult to reveal the failure mechanism. To study the evolutionary mechanism of shear failure of asphalt mixture, this paper introduces a solid-fluid transition theory to explain the rheological behavior of asphalt mixture. A DEM (Discrete Element Method) model of the virtual biaxial test was established. The formations of shear failure, rotation angles, force chain and volume fraction were analyzed. The results showed the failure of the asphalt mixture was caused by the flow of asphalt mortar and aggregate. In the process of shear failure formation, the vortex-like structure appeared in the velocity field. There was a difference in rotation angle and force chain between the inside and outside of the failure areas. The asphalt mixture underwent an unjamming transition from a solid to a fluid in the shear areas with a decrease in volume fractions.