Study on Mesoscopic Mechanics of Recycled Asphalt Mixture in the Indirect Tensile Test

Reclaimed asphalt pavement (RAP) mainly contains asphalt binder and aggregates, and the RAP materials used in paving roads could save virgin materials. This paper studied the following: asphalt mixture with different RAP material contents was prepared; then the indirect tensile test was carried out, and the mesoscopic model of the recycled asphalt mixture was reconstructed digitally. Discrete element method (DEM) of indirect tensile test was carried out to analyze the mechanical properties of recycled asphalt mixture in mesoscopic perspective. The results showed that there were some gaps between the simulation result of the digital specimen model and the test value of the recycled asphalt mixture, but the velocity vector and the law of force chain development of the recycled asphalt mixture could be explained in mesoscopic perspective. It proved that the virtual simulation test of the mechanical test was effective. The damage process of recycled asphalt mixture was analyzed in mesoscopic perspective, and the unification of mechanical response and macroscopic appearance was completed. Meanwhile, the simulation method of mesoscopic mechanics was an effective supplement to traditional tests, and guided tests method theoretically.