Sustainable use of steel slag as coarse aggregate and its influence on mechanical, durability properties, and microstructure of concrete

Construction materials are dealing with new challenges due to increased resource exploitation by globalized infrastructure. Research has consequently documented various waste management techniques that are focused on environmentally sustainable principles. The coarse steel slag aggregate (CSSA) can be reused as aggregate in cement concrete mixes. Hence, this experimental work considers an opportunity to investigate the effect of partial substitution of natural coarse aggregate (NCA) by CSSA for 20%, 40%, and 60% for the M40 grade concrete mix. The workability, mechanical, durability, and microstructural properties of concrete with CSSA were compared with NCA concrete on a 28-day curing. The 40% substitution of NCA by CSSA was found as the optimum ratio for the improvement in mechanical strength. Also, up to 20% of the substitution of CSSA satisfies the RCPT, water penetration, and acid attack (10% concentrated HCl acid) requirement given by standard codes.