Recycling of steel slag aggregates for the development of high density concrete: Alternative & environment-friendly radiation shielding composite

The present study aims in developing high density radiation shielding composite using induction furnace (IF) steel slag as an aggregate (coarse/fine) in concrete. IF steel slag is incorporated in concrete specimens (Mix a - 0% of slag, Mix b - 40% of slag as coarse aggregate, Mix c - 40% of slag as coarse aggregate and 100% as fine aggregate) of size 150 x 150 x 50 mm were fabricated. The presence of various iron (Fe) phases such as hematite, iscorite and almandine in IF steel slag composite were confirmed by XRD analysis. Presently, these types of materials are obtained from natural resources are in use for gamma radiation shielding. Density and compressive strength were studied, further concrete blocks were subjected to irradiation using gamma radiation sources such as 137Cs (0.662 MeV) and 60Co (1.17 and 1.33 MeV). Concrete specimen morphologies and structural changes of before and after irradiation have been studied using SEM and XRD analysis. The results show that replacement of 40% as coarse aggregate and 100% as fine aggregate of slag in concrete increases the density and compressive strength of conventional concrete from 2.38 g cm-3 to 2.85 g cm-3 and 27.20 N mm-2 to 29.38 N mm-2 respectively. Gamma Attenuation Factor (GAF), Linear Attenuation Co-efficient (LAC) and Half Value Layer (HVL) are better than the conventional concrete. Mix c can be a cost-effective alternate composite for radiation shielding studies and can reduce the exploitation of natural resources.