Mechanical properties and constitutive model of coral aggregate concrete subjected to dynamic uniaxial and triaxial compression

The dynamic compressive mechanical performance of coral aggregate concrete (CAC) has been studied by the servo-controlled true triaxial testing machine (TAWZ-5000/3000), the failure modes and the stress-strain curves were obtained under various loading conditions. The effect of strain rates and the constant lateral pressure on the strength, deformation capacity, and failure modes of CAC were analyzed according to the results obtained from the test. The results show that the lateral pressure significantly changes the failure mode while the strain rate only affects the degree. The strength and deformation capacity will improve with the increase of strain rate and lateral pressure, and the lateral pressure diminishes the strain rate effect on mechanical properties. A 5-parameter empirical dynamic failure criterion was established based on the William-Warnke criterion. Finally, a 2-stage dynamic multiaxial compressive constitutive model obeying the Weibull and Lognormal statistical distributions was established, and the model had well-fitting results with the experimental results.