Extended finite element modeling of hot mix asphalt based on the semi-circular bending test

Semi-circular bending (SCB) test is widely used to characterize the fracture behaviors of asphalt mixtures. In this study, heterogeneous models of SCB specimens were prepared with the difference in aggregate shape. Asphalt concrete was composed of coarse aggregate and fine aggregate matrix (FAM). Extended finite element modeling (XFEM) was utilized to capture the fracture behaviors of asphalt mixtures under -10 and 20 degrees C. The initiation and propagation of cracks under different temperatures were observed. Local cracking was mainly initiated around the aggregates or on the aggregates. Statistical analysis of the failure loads and the displacements corresponding to the peak loads were obtained, and comparison was made with the laboratory test results. SCB tests with the round particles presented the greatest failure load, followed by convex, ellipse and concave particles. The effect of aggregate shape on dissipated fracture energy was the same as the effect of particle shape on failure load. Laboratory results were consistent with the simulation results, proving the reliability of the numerical model.

Automated summary

Semi-circular bending (SCB) test was conducted to characterize the fracture behaviors of asphalt mixtures with different aggregate shapes. XFEM simulation was used to observe the initiation and propagation of cracks under different temperatures. The results showed that the shape of aggregates has an effect on the failure load and dissipated fracture energy in SCB test.