Numerical simulation of effect of reclaimed asphalt pavement on damage evolution behavior of self-compacting concrete under compressive loading

The preparation of self-compacting concrete (SCC) using reclaimed asphalt pavement (RAP) to replace part of natural coarse aggregate can realize efficient recycling of resources and have achieved good economic benefits. However, the mechanism of the effect of RAP on the mechanical properties of concrete is still not clear. Therefore, a discrete element model (DEM) of SCC with different RAP contents is established. The bonding characteristics between RAP and cement paste were considered and the crushable aggregate was generated to improve the model reliability. Based on the DEM, the influence of RAP on mechanical behavior and failure mode of SCC under uniaxial compression load was analyzed. The results indicated that RAP significantly affects the total number and growth character of microcracks. The microcracks appear earlier and the total crack number decreases with RAP content ranging from 0% to 100%. Cracks are more curved and formed network damage with RAP content increase. Furthermore, the simulation result shows that RAP affects concrete's crack type under compression load. This study helps to understand effects of RAP on the damage evolution behavior of SCC and the related mechanism.