Dynamic triaxial compressive response and failure mechanism of basalt fibre-reinforced coral concrete

Abstract

The dynamic triaxial mechanical properties of basalt fibre-reinforced coral aggregate concrete (BFRCAC) were studied using the split Hopkinson pressure bar device with an active confining. The results revealed that the dynamic triaxial compressive strength and dynamic triaxial elastic modulus of BFRCAC increase with an increase in strain rate and confining pressure. The increase in confining pressure reduces the strain rate effect of the dynamic triaxial compressive strength and dynamic triaxial elastic modulus, and the increase in strain rate reduces the confining pressure effect of the dynamic triaxial compressive strength and dynamic triaxial elastic modulus. Furthermore, the critical strain of BFRCAC increases with an increase in the strain rate but decreases with an increase in the confining pressure. The confining pressure reduces the damage degree of BFRCAC; as a result, the failure mode of BFRCAC changes from longitudinal splitting failure to shear failure. The increase in the confining pressure and strain rate reduces the pull-out length of basalt fibre (BF). The addition of BF improves the strain rate effect of the dynamic mechanical properties of coral aggregate concrete (CAC), reduces the failure degree of CAC, and increases the shear failure characteristics of CAC.