A Study on the Utilization of Activated Steel Slag as Partial Replacement of Cement in Concrete

Steel slag is an industrial by-product of steel manufacturing, characterized as highly calcareous, siliceous and ferrous. They are found to be useful in many fields, such as road construction, asphalt concrete, agricultural fertilizer, and soil improvement. Due to its ever increasing production and hazardous effects due to dumping of slag there is a need to study its effect on mortar and concrete with higher replacement ratios. The chemical composition of steel slag showed potential for use as cementitious component. However, the increased initial setting time and low early strength limits its widespread application in cement and concrete industries. This paper explores the use of partially replacing cement with locally available steel slag activated with chemicals for making of cement mortar. The effects of steel slag fines on the initial setting time and compressive strength of cement mortar were studied. The suitability of steel slag using various chemical activators on improving the compressive strength and initial setting were also evaluated. The results showed that 18% steel slag fines and 4 % Na2SO4 results similar results to that of OPC.