Optimizing the sustainability assessment, mechanical properties and drying shrinkage of concrete containing groundnut shell ash using RSM modeling

The past decade has seen increased research interest on the possible alternatives to cement in concrete and mortar, with materials that are environmentally friendly, economical, and socially inherent. However, recycling, reusing, and regenerating methods may be used to harness the potential benefits of agricultural/industrial wastes as alternatives. The utilization of these recyclables as supplementary and alternative resources yields notable energy conservation and a reduction in cement consumption, thus contributing to the mitigation of carbon dioxide (CO₂) emissions in the environment. Moreover, groundnut shell ash (GSA) is utilized as a substitution for cement in the mixture. The proportion of cement substitution with GSA ranged from 0% to 20% in order to examine the characteristics of concrete and mortar. Concrete samples were cast and tested at 7th, 14th, 28th, and 90th days. Cube, cylinder, and prism specimens were cast for assessing the compressive, flexural, and splitting tensile strengths of concrete consistently. It was discovered that the highest compressive and splitting tensile strengths were 13.39% and 12.69%, respectively, over the control at 90 days, and the flexural strength was 10.64% at 28 days of curing over the control for 10% GSA cement replacement. Also, the water absorption, and drying shrinkage dropped with the increased content of GSA. Besides, the utilization of GSA in the mixture has reduced the embodied carbon. Furthermore, utilizing ANOVA, response prediction approaches were produced at a 95% significance level. The models demonstrated R² ranging from 96 to 99%. Therefore, the research study’s findings indicate that the addition of GSA in concrete positively affects the concrete and mortar properties and recommends a 10% substitution of cement in the mixture.