Steel Slag as Sand Replacement in Concrete: A Systematic Review of Fresh, Mechanical, and Durability Properties

The sand crisis has received growing attention in recent years, and a number of substitutes have been examined by researchers in order to reduce the use of river sand. Typical substitutes are industrial by-products that would otherwise require land for waste disposal. Steel slag (SS) is one such by-product that can be used as a replacement for alluvial sand in concrete. A comprehensive review of the effects of sand replacement by SS on physical, mechanical, and durability properties of concrete is presented in this study. The primary objectives of this study are to (1) evaluate the impact of varying proportions of SS as a sand substitute on the mechanical and durability properties of concrete, (2) identify the optimal percentage of SS replacement to achieve enhanced performance, and (3) address the existing knowledge gap regarding the sustainability of using SS in concrete applications. A systematic review of the available data revealed the promising application of SS as sand replacement in concrete with enhanced concrete strength and durability. Considering all aspects of concrete applications, the optimum level of SS replacement is reported in a range from 30% to 60%, meeting concrete's physical, mechanical, and durability expectations. The findings also show further research is needed to determine the durability of SS concrete (SSC) for different intended applications.