Abstract 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/m3 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.

中文翻译：

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珊瑚骨料海水混凝土动态直接拉伸试验与三维细观模拟研究

摘要 珊瑚骨料海水混凝土（CASC）的动态拉伸性能在珊瑚礁工程和海洋军事防御工程应用中发挥着重要作用。本研究制备了剑麻纤维含量为 3 kg/m3 的 CASC 和剑麻纤维珊瑚骨料海水混凝土 (SFCASC)。高应变速率下的动态拉伸试验使用分裂式霍普金森张力杆（SHTB）技术进行。3D 细观混凝土模型用于模拟 CASC 的动态拉伸性能。并通过实验和细观模拟揭示了CASC的破坏机制。结果表明，剑麻纤维在动态拉伸载荷下对强度和断裂能的 DIF 增长贡献很小，并且普通混凝土中的裂缝绕过骨料，而由于骨料的微泵效应和脆性和多孔珊瑚的特性，CASC中的裂缝通过骨料发展。根据试验结果建立了抗拉强度和断裂能的DIF计算模型。采用细观方法建立的数值模型可以准确预测冲击载荷作用下CASC的力学性能。模拟裂纹出现在试件中间，与试验得到的破坏模式一致，进一步验证了3D细观模型模拟CASC冲击性能的准确性。根据试验结果建立了抗拉强度和断裂能的DIF计算模型。采用细观方法建立的数值模型可以准确预测冲击载荷作用下CASC的力学性能。模拟裂纹出现在试件中间，与试验得到的破坏模式一致，进一步验证了3D细观模型模拟CASC冲击性能的准确性。根据试验结果建立了抗拉强度和断裂能的DIF计算模型。采用细观方法建立的数值模型可以准确预测冲击载荷作用下CASC的力学性能。模拟裂纹出现在试件中间，与试验得到的破坏模式一致，进一步验证了3D细观模型模拟CASC冲击性能的准确性。