Reinforced concrete (RC) structures under blast loading can occur severe structural damage, including cratering, spalling, and breaching. And these damages could cause danger to the personnel and equipment. In this study, ultra-high toughness cementitious composite (UHTCC) with significant strain-hardening behavior (ultimate tensile strain >3%) was utilized to improve the blast resistance of construction structure. The UHTCC square slabs with a side length of 2000 mm were tested under contact explosions. The cratering and spalling damage of slabs were investigated. A total of six slabs (three RC slabs and three UHTCC slabs) under three different weight of TNT charge (2 kg, 4 kg, and 5 kg) were tested. The results showed the UHTCC slabs presented excellent blast resistance compared with RC slabs. The existing empirical predictions were employed to explore the damage mode of UHTCC slabs compared with the experimental results. The suitability and accuracy of the predictions were discussed. The structured and unstructured discretizations with different mesh size were used in the finite element (FE) model. The simulation results from the unstructured discretizations show better agreement with the experimental results than that from the structured discretizations. The effect of mesh size on the damaged area, damaged depth, deflection-time curves of the slab and the eroded volume fraction were compared and discussed. In addition, the sensitivity analysis of input parameters in the numerical model were conducted. the maximum failure strain, the compressive strength and the mass density of UHTCC were employed as the input parameters to investigate and discuss their effects on the value of output parameters, which include the damaged area, damaged depth and maximum deflection of UHTCC slab.

爆炸荷载作用下的钢筋混凝土 (RC) 结构可能会发生严重的结构损坏，包括弹坑、剥落和破裂。这些损坏可能会对人员和设备造成危险。在这项研究中，利用具有显着应变硬化行为（极限拉伸应变 >3%）的超高韧性水泥基复合材料 (UHTCC) 来提高建筑结构的抗爆能力。边长为 2000 mm 的 UHTCC 方板在接触爆炸下进行了测试。研究了板坯的缩孔和剥落损伤。在三种不同重量的 TNT 装药（2 公斤、4 公斤和 5 公斤）下，总共测试了六个板坯（三个 RC 板坯和三个 UHTCC 板坯）。结果表明，与 RC 板相比，UHTCC 板具有优异的抗爆性。与实验结果相比，利用现有的经验预测来探索 UHTCC 板的损伤模式。讨论了预测的适用性和准确性。在有限元 (FE) 模型中使用了具有不同网格尺寸的结构化和非结构化离散化。非结构化离散化的模拟结果比结构化离散化的模拟结果更符合实验结果。对比讨论了网格尺寸对破坏面积、破坏深度、板坯挠度-时间曲线和侵蚀体积分数的影响。此外，还对数值模型中的输入参数进行了敏感性分析。最大破坏应变，