Impact of use of steel slag as coarse aggregate and wastewater on fresh and hardened properties of concrete

Present research is focused on replacement of ingredients of concrete with recycled material and wastewater to compensate the increasing demand of natural resources. Steel slag is an industrial by-product which has a potential of being utilized as a partial replacement to coarse aggregate in concrete. The present research investigates the impact on fresh and hardened properties of the concrete when the natural coarse aggregate is replaced in ratios of 15%, 25%, 50%, 75% and 100% with steel slag aggregate and wastewater is reused during the making of concrete. It is found that 50% replacement of basalt aggregate with steel slag aggregate indicates improvement in compressive strength, flexural strength and modulus of elasticity of concrete by 33%, 9.8% and 22% at the age of 28 days respectively. SEM analysis, ultrasonic pulse velocity and rapid chloride permeability tests indicate dense microstructure and enhanced durability. Therefore, this study shows the possible reuse of steel slag as coarse aggregate and wastewater in concrete.