The application of nuclear technologies simulates the development of radiation shielding materials. Traditional heavy-weight concrete used for radiation shielding is limited in practical construction due to the poor mechanical properties and durability. This study developed a PVA fiber-reinforced ultra-high performance concrete (UHPFRC) with magnetite as heavy aggregates used for radiation shielding. Due to the scientific skeleton design, UHPFRC exhibits superior mechanical properties, with compressive strength and flexural strength reaching up to 121.9 MPa and 23.2 MPa, respectively. The microstructure of UHPFRC was investigated in detail and the results revealed that the incorporation of PVA fibers refined the pore structure of UHPFRC. The interfacial transition zone between magnetite aggregates and cementitious matrix in UHPFRC was much denser than that in traditional concrete due to the low water to binder ratio. The gamma and neutron radiations shielding capacity of UHPFRC were evaluated by the combination of actual measurement and simulation. By introducing light nuclei and refining the pore structure, the incorporation of PVA fibers improved the neutron radiation shielding capabilities of UHPFRC by 5.1%.

中文翻译：

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PVA纤维增强超高性能混凝土的微观结构及辐射​​屏蔽特性


核技术的应用模拟了辐射屏蔽材料的发展。传统用于辐射屏蔽的重混凝土由于力学性能和耐久性较差，在实际施工中受到限制。本研究开发了一种以磁铁矿为重骨料的 PVA 纤维增强超高性能混凝土（UHPFRC），用于辐射屏蔽。由于科学的骨架设计，UHPFRC表现出优异的力学性能，抗压强度和抗弯强度分别高达121.9 MPa和23.2 MPa。对 UHPFRC 的微观结构进行了详细研究，结果表明 PVA 纤维的掺入细化了 UHPFRC 的孔结构。由于水胶比低，UHPFRC 中磁铁矿骨料和胶凝基体之间的界面过渡区比传统混凝土中的界面过渡区致密得多。通过实测与模拟相结合的方式评估了UHPFRC的伽马和中子辐射屏蔽能力。通过引入轻核和细化孔隙结构，PVA纤维的掺入使UHPFRC的中子辐射屏蔽能力提高了5.1%。