Experimental and Three-dimensional Mesoscopic Simulation Study on Coral Aggregate Seawater Concrete with Dynamic Direct Tensile Technology

摘要

The dynamic tensile properties of coral aggregate seawater concrete (CASC) play a substantial role in reef engineering and marine military defense engineering applications. CASC and sisal fiber coral aggregate seawater concrete (SFCASC) with sisal fiber content of 3 kg/m(3) were prepared in this study. The dynamic tensile test under high strain rate was carried out using the Split Hopkinson Tension Bar (SHTB) technology. The 3D mesoscopic concrete model was used to simulate the dynamic tensile properties of CASC. And the destruction mechanism of CASC was revealed from the experiment and meso-simulation. The results showed that sisal fiber contributes little to the DIF growth of strength and fracture energy under dynamic tensile loading, and the cracks in the common concrete bypass the aggregate, while the cracks in the CASC develop through the aggregate due to the micro pumping effect of the aggregate and the characteristics of brittle and porous coral. The DIF calculation models of the tensile strength and fracture energy were established according to the test results. The numerical model established by the mesoscopic method can accurately predict the mechanical properties of CASC under impact load. The simulated crack appeared in the middle of the specimen, which was consistent with the failure pattern obtained by the test, and further verified the accuracy of the 3D meso model for simulating the impact performance of CASC.