Investigation of ferrochrome slag utilization in wet mix shotcrete: Mechanical strength and radiation shielding performance

Abstract

In this study, wet-mix shotcrete specimens were produced by substituting natural aggregate (NA) with ferrochrome slag aggregate (FS). Volumetrically, the amount of NA was reduced by 25%, 50%, 75% and 100% and a corresponding amount of FS aggregate was added. The physical, mechanical, durability and radiation shielding properties of the specimens were analysed. The gamma radiation performance was determined using energies 133Ba, 137Cs, 60Co and 22Na (ranging from 276.5 keV to 1332.5 keV) and a high-purity germanium HPGe detector system. The neutron radiation performance of the shotcrete specimens was obtained using FLUKA simulation. The WinXCOM interface was used for theoretical calculations, while the FLUKA Monte Carlo code was used for simulation calculations, and the data obtained were compared. It was observed that shotcrete mixtures having up to 50% ferrochrome slag aggregate showed a significant increase in mechanical properties. In radiation shielding performances, linear attenuation coefficient (μ), half-value layer (HVL), Tenth-value layer (TVL), mean free path (MFP) and radiation protection efficiency (RPE) parameters increased with increasing ferrochrome slag aggregate ratio, while mass attenuation coefficient (μ⁄ρ) values remained almost constant. It was experimentally determined that the 5 cm thickness shotcrete produced had RPE values of 75% and 50% at low (276.4 keV) and high (1332.5 keV) energies, respectively. It was concluded that the use of 50% ferrochrome slag aggregate has a positive effect on the mechanical properties of shotcrete mixtures. Additionally, ferrochrome slag-reinforced shotcrete is a good gamma and neutron radiation shielding material.