Experimental and three-dimensional mesoscopic investigation of coral aggregate concrete under dynamic splitting-tensile loading

摘要

An investigation that combines both experimental tests and mesoscopic modelling is conducted to characterize the dynamic splitting-tensile behavior of coral aggregate concrete (CAC). Static and dynamic splitting-tensile strength and failure patterns of CAC with different uniaxial compressive strength (30-70 MPa) are tested by means of MTS machine and Split-Hopkinson pressure bar device, respectively. A three-dimensional (3D) randomly mesoscopic model for the simulation of the splitting-tensile strength and failure of CAC under different strain rates (1-200 s~(-1)) is developed and validated by contrasting tested and numerical results. The experimental and numerical results indicate that the splitting-tensile strength and failure pattern are significantly affected by concrete strength and strain rate. The dynamic splitting failure mechanism that the damage outside the specimen is more serious than the inside, and the fracture in the center of the specimen is more severe than the edge, has been explained from the localized failure patterns of concrete and aggregates. Furthermore, it can be learned from the tensile dynamic increase factor of CAC is sensitive to strain rate significantly, which has a profound significance in the further investigation of reef CAC structures.