Abstract Heavy-weight conventional concretes are traditionally used for shielding against nuclear radiations. However, mechanical properties and durability of conventional concrete are reported to be far less than that of ultra-high-performance concrete (UHPC) made with ultrafine materials and fibers without coarse aggregate ensuring a highly densified microstructure. Recently, many studies are reported in the literature focusing on the development of UHPC mixtures and evaluation of their performance in terms of mechanical properties and durability characteristics. The information pertaining to the performance of UHPC mixtures against nuclear radiation is lacking in the literature. In the present study, five mixtures of heavy-weight ultra-high-performance concrete (HWUHPC) were considered by partially replacing the sand with hematite powder that had ultrafine particles and about two times heavier than the sand. The dry density of the HWUHPC mixtures varied from about 2600 kg/m3 to 2900 kg/m3, all satisfying the requirement of minimum dry density for being considered under heavy-weight category. Although the HWUHPC mixtures had different dry densities, their mechanical properties did not vary significantly and showed no adverse effect of the replacement of sand. The radiation shielding increased with increase in the dry density of the HWUHPC mixtures. However, the radiation shielding of the HWUHPC was found to be higher as compared to that of the heavy-weight conventional concrete having same dry density, indicating that the denseness of the microstructure also improves the radiation shielding besides the density of concrete.

中文翻译：

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重质超高性能混凝土对核辐射的屏蔽性能

摘要 重质常规混凝土传统上用于屏蔽核辐射。然而，据报道，传统混凝土的机械性能和耐久性远低于由超细材料和纤维制成的超高性能混凝土（UHPC），而没有粗骨料确保高度致密的微观结构。最近，文献中报道了许多研究，重点是 UHPC 混合物的开发及其在机械性能和耐久性特性方面的性能评估。文献中缺乏有关 UHPC 混合物抗核辐射性能的信息。在目前的研究中，五种重质超高性能混凝土 (HWUHPC) 混合物被考虑通过用具有超细颗粒且比沙子重约两倍的赤铁矿粉末部分代替沙子。HWUHPC 混合物的干密度从大约 2600 kg/m3 到 2900 kg/m3 不等，均满足考虑在重量级类别下的最小干密度要求。尽管 HWUHPC 混合物具有不同的干密度，但它们的机械性能没有显着变化，并且没有表现出替代砂的不利影响。辐射屏蔽随着 HWUHPC 混合物干密度的增加而增加。然而，发现 HWUHPC 的辐射屏蔽比具有相同干密度的重型常规混凝土的辐射屏蔽更高，