Sustainable Concrete Production Using Steel Slag: A CCD-Based Response Surface Methodology for Performance Optimization

In recent years, the sand crisis has garnered increasing attention, and researchers have investigated a variety of substitutes to mitigate the consumption of river sand. Common alternatives are industrial waste items that would otherwise need to be disposed of on land. For concrete, one such by-product that can be utilized in place of alluvial sand is steel slag (SS). The purpose of this study is to ascertain the ideal replacement percentages for the required mechanical and structural qualities by investigating the viability of using steel slag as a fine aggregate in concrete. Experimental studies were carried out using different ratios of steel slag in place of traditional fine aggregate. Compressive strength, workability, and other characteristics of the concrete mixes were evaluated. The experimental findings show that using steel slag as a partial substitute for fine aggregate has encouraging potential. The steel slag with 15% substituted showed good workability and compressive strength. Response surface methodology (RSM) Central Composite Design analysis was conducted based on the experimental data in order to create a statistical model that would predict the ultimate compressive strength based on curing and Steel slag concentrations. The result shows the high desirability with 0.995 value is obtained. The optimal curing period was found to be 55 days with 20.7164% steel slag. The maximum compressive strength found to be 40.47 MPa with good coefficient of correlation less than 1.