Effect of black sand as a partial replacement for fine aggregate on properties as a novel radiation shielding of high-performance heavyweight concrete

To defend against harmful gamma radiation, new types of materials for use in the construction of heavyweight concrete (HWC) are still needed to be developed. This research introduces new materials to be employed as a partial replacement for fine aggregate (FA) to manufacture high-performance heavyweight concrete (HPHWC). These materials include hematite, black sand, ilmenite, and magnetite, with substitution ratios of 50% and 100% of FA. In this research, the hardening and fresh characteristics of HPHWC were obtained. Concrete samples' Gamma -ray linear attenuation coefficient was evaluated utilizing a gamma source of Co -60 through the thicknesses of 2.5, 5, 7.5, 10, 12.5, and 15 cm. High temperatures were studied for HPHWC samples, which were exposed to up to 700 degrees C for two hours. Energy -dispersive x-rays and a scanning electron microscope carried out microstructure analyses. Magnetite as an FA attained the lowest compressive strength of 87.1 MPa, but the best radiation protection characteristics and the highest density of 3100 kg/m3 were achieved. After 28 days, the attenuation efficiency of concrete mixtures was increased by 6.5% when fine sand was replaced with black sand at a ratio of 50%. HPHWC, which contains hematite, black sand, ilmenite, and magnetite, is designed to reduce environmental and health dangers and be used in medicinal, military, and civil applications.