Environmental and economic factors encourage the use of industrial by-products. The main objective of this study was to identify an alternative for natural aggregates which are becoming scarce. Steel slag is an industrial by product obtained from the steel manufacturing industry. It is a non-metallic ceramic material formed from the reaction of flux such as calcium oxide with the inorganic non-metallic components present in the steel scrap. Most of the volume of concrete comprises of aggregates. Therefore, replacing either fully or partially with steel slag will lead to environmental benefits and waste reduction of industrial by-products and also contribute to sustainable development. In this study, it is proposed to utilize the steel slag as full replacement of conventional coarse aggregate and partially as fine aggregate in the varying percentage of 0% to 50%. For this investigation, M30 grade of concrete was designed and specimens were cast and tested at 7 days and 28 days for compressive strength, tensile strength and flexural strength. From the test results, the optimum mix was obtained in which fine aggregate was replaced with 10% steel slag and coarse aggregate with 100% steel slag which showed better compressive strength, split tensile strength and flexural strength.
