The utilization of ultra-high-strength concrete offers a weight reduction of concrete structures and improvements in disaster protection performance. Recently, porosity-free concrete (PFC) having the world’s highest compressive strength of 400 MPa has been developed, and its basic mechanical properties were determined; however, its impact-resistant capacity is yet to be examined. In this study, investigation of the impact resistance behavior of PFC is performed using a weight dropping impact test on a fiber-reinforced PFC beam. Steel fiber-reinforced PFC is used for preventing brittle failure, and the full plastic moment of the PFC beam cross-section is determined based on material test results. Also, the estimation of maximum response deflection is attempted by a simple plastic analysis. It was demonstrated that the response deflection could be reduced by 30–50% by increasing the steel fiber mixing rate in the PFC beam from 1 to 2%. The proposed estimation method revealed that the response deflection of the PFC beam could be estimated with an accuracy of approximately 80% considering the calculated full plastic moment when the plastic hinge is clearly formed. In the future, to establish a design procedure for the impact-resistant capacity of protective structures from steel fiber-reinforced PFC, it is necessary to conduct experimental and numerical research focusing on ultimate strength, including statistical processing.

中文翻译：

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钢纤维无孔混凝土梁在冲击荷载作用下的响应特性

超高强度混凝土的使用可减轻混凝土结构的重量并提高防灾性能。最近，开发了世界最高抗压强度400MPa的无孔混凝土（PFC），并确定了其基本力学性能；然而，其抗冲击能力还有待检验。在这项研究中，对 PFC 的抗冲击行为进行了研究，在纤维增强 PFC 梁上使用落重冲击试验。钢纤维增强PFC用于防止脆性破坏，PFC梁截面的全塑性弯矩是根据材料试验结果确定的。此外，通过简单的塑性分析尝试估计最大响应挠度。结果表明，通过将 PFC 梁中的钢纤维混合率从 1% 增加到 2%，响应挠度可以减少 30-50%。所提出的估计方法表明，考虑到塑性铰明显形成时计算出的全塑性力矩，可以估计 PFC 梁的响应挠度，准确度约为 80%。未来，为了建立钢纤维增强 PFC 防护结构抗冲击能力的设计程序，有必要进行以极限强度为重点的实验和数值研究，包括统计处理。所提出的估计方法表明，考虑到塑性铰明显形成时计算出的全塑性力矩，可以估计 PFC 梁的响应挠度，准确度约为 80%。未来，为了建立钢纤维增强 PFC 防护结构抗冲击能力的设计程序，有必要进行以极限强度为重点的实验和数值研究，包括统计处理。所提出的估计方法表明，考虑到塑性铰明显形成时计算出的全塑性力矩，可以估计 PFC 梁的响应挠度，准确度约为 80%。未来，为了建立钢纤维增强 PFC 防护结构抗冲击能力的设计程序，有必要进行以极限强度为重点的实验和数值研究，包括统计处理。