Exploring the unjamming transition of meso‐mechanical shear failure behavior in asphalt mixture

Asphalt pavement is widely used in transportation systems due to its superior comfort, rapid construction, and convenient maintenance, while also being confronted with the problem of shear failure damage. Herein, two-dimensional virtual models of asphalt mixture specimens are constructed based on the discrete element method for the virtual biaxial compression test to elucidate the underlying mechanisms behind shear failure damage. The results demonstrate that the increase in volumetric strain due to shear dilation signifies the onset of the unjamming transition, whereas the emergence of shear failure zones and vertical cracks reflects its manifestation in asphalt mixtures. Confining pressure has an inhibitory effect on the development of the unjamming transition, whereas temperature promotes its progression. The emergence of heterogeneous structures and the evolution of the force chain network into a disordered and branched structure are manifestations of the unjamming transition in the displacement field and force chain system. The outcome offers novel insights into the prediction and understanding of shear failure behavior in asphalt mixtures, establishing a fundamental framework for analyzing failure evolution and its influencing factors.