Abstract The main purpose of this research is to develop the heavyweight concrete with the density of more than 5.0 gm/cm3 for using in the radiation shielding applications. The 2n mixing theory, with kneading and lapping mechanism, was applied to develop the heavyweight concrete using iron powder and balls for aggregates. The mixing proportion of the heavyweight concrete was designed to prevent the segregation of heavy aggregates and give the required workability for the compaction. The density of heavyweight concrete was 5.06 gm/cm3, about the double of ordinary concrete (2.35 gm/cm3). The shielding test was done for γ-ray and neutron using two different emission sources for each. 137Cs and 60Co were used for γ-ray; and, 241Am-Be and 252Cf for neutron. The analytical models were developed for the attenuation percentage of the γ-ray and neutron. Attenuation coefficients were calculated for the comparison study from both the experimental and analytical results. The attenuation coefficient ratio of the heavy weight concrete to the ordinary concrete was about 2.1 for the γ-ray and only about 1.28 for the neutron. The experimental results satisfied with the analytical models. It is concluded that the density of concrete and passing distance are dominant for shielding the γ-ray. However, the passing distance is more dominant than the density of concrete in the case of neutron. The heavy concrete with its density of more than 5.0 gm/cm3 was successfully implemented in the shielding application.

中文翻译：

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用2n混合理论开发用于屏蔽应用的重质混凝土

摘要 本研究的主要目的是开发用于辐射屏蔽应用的密度大于5.0 gm/cm3的重质混凝土。应用2n混合理论，采用捏合和研磨机制，开发以铁粉和球为骨料的重质混凝土。重质混凝土的混合比例旨在防止重骨料的离析，并为压实提供所需的和易性。重质混凝土的密度为 5.06 gm/cm3，约为普通混凝土（2.35 gm/cm3）的两倍。对γ射线和中子分别使用两种不同的发射源进行屏蔽试验。137Cs和60Co用于γ射线；和，241Am-Be 和 252Cf 中子。为γ射线和中子的衰减百分比开发了分析模型。根据实验和分析结果计算衰减系数用于比较研究。重混凝土与普通混凝土的衰减系数比对γ射线约为2.1，对中子约为1.28。实验结果与解析模型一致。得出的结论是，混凝土的密度和通过距离是屏蔽γ射线的主要因素。然而，在中子的情况下，通过距离比混凝土的密度更占优势。密度超过 5.0 gm/cm3 的重混凝土在屏蔽应用中得到了成功实施。重混凝土与普通混凝土的衰减系数比对γ射线约为2.1，对中子约为1.28。实验结果与解析模型一致。得出的结论是，混凝土的密度和通过距离是屏蔽γ射线的主要因素。然而，在中子的情况下，通过距离比混凝土的密度更占优势。密度超过 5.0 gm/cm3 的重混凝土在屏蔽应用中得到了成功实施。重混凝土与普通混凝土的衰减系数比对γ射线约为2.1，对中子约为1.28。实验结果与解析模型一致。得出的结论是，混凝土的密度和通过距离是屏蔽γ射线的主要因素。然而，在中子的情况下，通过距离比混凝土的密度更占优势。密度超过 5.0 gm/cm3 的重混凝土在屏蔽应用中得到了成功实施。在中子的情况下，通过距离比混凝土的密度更占优势。密度超过 5.0 gm/cm3 的重混凝土在屏蔽应用中得到了成功实施。在中子的情况下，通过距离比混凝土的密度更占优势。密度超过 5.0 gm/cm3 的重混凝土在屏蔽应用中得到了成功实施。