Meso-scale fracture modelling and fracture properties of rubber concrete considering initial defects

With the massive incorporation of rubber, the fracture damage mechanism of rubberized concrete is more complex than that of ordinary concrete. This paper studies the damage fracture process of rubberized concrete. Based on the panoramic microstructure scanning images of rubberized concrete, mesoscale parameters such as microcracks and pore initial defects inside rubberized concrete are collected. The numerical model of rubberized concrete three-point bending beam is built based on the real mesoscale structure. The fracture process of rubberized concrete containing initial cracks is simulated under quasi-static loading. The results indicate that the number of microcracks at the aggregate-mortar interfacial transition zone (ITZ) decreased and the pore content increased with the increase of rubber content. The mesoscopic numerical model of rubberized concrete based on the real mesoscopic structure of rubberized concrete has good applicability and accuracy. The fracture toughness of concrete shows a trend of increasing and then decreasing with the increase of rubber content, and the fracture toughness reaches the maximum at 10% of rubber admixture. The simulation results yielded dimension -independent tensile strength and fracture toughness values.