Mechanical characterization of the concrete mixture, including steel slag aggregate and steel fibres

Abstract

Steel slag is a major by-product of the steel industry, its waste management poses serious environmental threats. The slag produced by the steel industries and used as an aggregate in concrete is a sustainable key for the optimal and efficient use of natural mineral resources. In the past, numerous studies have been conducted and engineering solutions have been proposed to find the desired proportion of steel slag in concrete. The present work primarily focuses on the mechanical characterization of concrete mixes adopting Steel Slag Aggregates (SSA) as a substitution for conventional Coarse Aggregates (CA). Furthermore, an optimal concrete composition has been proposed to maximise the load-bearing strength of the concrete. First, following the standard benchmarking procedure, concrete mechanical properties are obtained. Next, the effect of replacing CA (10%, 20%, 30%, and 40%) by weight with SSA in the concrete mix is studied. The required number of cubes was cast for optimisation, and mechanical characterization (compressive, split tensile, and shear tests) was performed on the M45-grade concrete with SSA. Finally, the study has been extended with the inclusion of steel fibres in the previous optimal SSA-concrete mix. The optimum steel fibre volume fraction has been determined by performing various mechanical tests on the steel fibre concrete mix. The experimental results show that SSA can significantly improve the mechanical performance of concrete. The ideal percentage to replace CA with SSA in the concrete mixture (CM2) is 30%, which improves the concrete's compressive strength, split tensile strength, and shear strength in comparison to regular concrete. Additionally, adding steel fibres to the ideal mix (CM2) has very less impact on compressive strength but increases tensile strength and shear strength.