Investigation of Thermal Conductivity and Gamma Radiation Shielding Properties of Cement Containing BaSO₄ and H₃BO₃

In this study, the thermal conductivity and gamma radiation shielding properties of cement composites were investigated by incorporating barium sulfate (BaSO₄) and boric acid (H₃BO₃) into cement mixtures. Barium sulfate, due to its high atomic number and density, enhances gamma-ray shielding, while boric acid contributes to reducing thermal conductivity of the composites. Cement mortar samples were prepared with a constant 5 wt.% H₃BO₃ and varying BaSO₄ contents (5, 10, 15, and 20 wt.%). Thermal conductivity measurements revealed a significant reduction compared to reference samples without additives, decreasing from 1.728 W/mK in the control sample to 0.2345 W/mK in the sample with 20 wt.% BaSO₄. Gamma-ray sheilding properties were experimentally determined using a NaI detector in the energy range of 121–1528 keV, and results were found to be in good agreement with theoretical XCOM calculations. The incorporation of BaSO₄ effectively reduced the half-value layer (HVL), confirming its contribution to enhanced gamma shielding. Microstructural analyses (SEM-EDX) demonstrated homogeneous distribution of both BaSO₄ and H₃BO₃ within the cement matrix. These findings indicate that BaSO₄ and H₃BO₃ additives can improve both thermal insulation and gamma radiation shielding in cement-based materials, making them promising candidates for applications in radiation-prone environments.