内埋炸药下超高韧性水泥基复合材料的抗爆性能

为研究超高韧性水泥基复合材料(ultra-high toughness cementitious composites, UHTCC)在内埋炸药爆炸下的抗爆性能和损伤破坏规律，对不同炸药埋深下的UHTCC和高强混凝土(high-strength concrete, HSC)进行了内埋炸药抗爆实验。得到了两种材料靶体的破坏状态，并利用接触爆炸的实验结果计算出了两种材料的抗爆性能参数。结果表明，在相同条件下，UHTCC抗爆性能优于高强混凝土。为了进一步探究UHTCC的抗压强度、抗拉强度以及拉伸韧性对靶体在内埋炸药下抗爆性能的影响，首先，采用改进的K&C模型对炸药埋深为40 mm的超高韧性水泥基复合材料靶体进行数值模拟，模拟结果与实验结果基本吻合，并根据数值模拟的结果得到了爆炸冲击波沿靶体径向衰减速度大于轴向衰减速度这一规律，验证了数值模型的有效性；然后，通过调整改进K&C模型中与抗压强度、抗拉强度以及拉伸韧性相关的参数，数值预测了不同抗压强度、抗拉强度以及拉伸韧性下UHTCC靶体的破坏状态，发现增强UHTCC的韧性可以有效防止靶体发生整体性破坏，增大UHTCC的抗拉强度可以减小靶体迎爆面的开坑直径，增大UHTCC的抗压强度对减小开坑直径效果不明显。

Anti-explosion tests and numerical simulations of ultra-high toughness cementitious composites subjected to blast by embedded explosives

To study the blast resistance and damage rule of ultra-high toughness cementitious composites (UHTCC) subjected to blast by embedded explosives, blast resistance tests of embedded explosives were carried out on UHTCC and high-strength concrete (HSC) with different embedded depths of explosives. The damage patterns of the targets of the two materials were obtained. Using the test results of contact explosion, the blast resistance parameters of the above two materials were calculated. The test results show that UHTCC has better blast resistance than high-strength concrete under the same test conditions. To further explore the influence of compressive strength, tensile strength and tensile toughness on the blast resistance of UHTCC targets to embedded explosives, the improved K&C model was used to numerically simulate the UHTCC target subjected to blast by explosives with an embedded depth of 40 mm. The simulation results were basically consistent with the experimental results. According to the results of numerical simulation, the rule that the attenuation speed of the explosion shock wave along the radial direction of target was greater than that along the axial direction was obtained, which verified the validity of the model. Then, by adjusting the parameters related to the compressive strength, tensile strength and tensile toughness in the modified K&C model, the damage patterns of the UHTCC targets with different compressive and tensile strengths and tensile toughness were predicted. It is found that enhancing the toughness of UHTCC can effectively prevent the target from undergoing overall damage, increasing the tensile strength of UHTCC can reduce the cratering diameter of the blasting surface, and increasing the compressive strength of the material has no obvious effect on reducing the cratering size. These studies can provide a basis for the application of UHTCC materials in protection engineering.