Optimizing cost and strength by utilization of blast furnace slag aggregate and recycled concrete sand in concrete using response surface models

Abstract

The utilization of waste materials in concrete is crucial for sustainable construction, as it can contribute to environmental conservation and enhance concrete properties. Waste management and sustainable construction poses significant challenges in the construction industry. While numerous studies have focused on environmental conservation, only a limited number have explored the use of Blast furnace slag aggregate (BFSA) as coarse aggregate and recycled concrete sand (RCS) as fine aggregate to optimize cost and concrete properties using response surface models. In this study, response surface methodology (RSM) based on central composite design (CCD) was employed to evaluate the impact of BFSA (0-50%) and RCS (0-100%) replacement parameters on cost, compressive strength. ANOVA was used to verify the accuracy of the generated models. The RSM regression equations demonstrated high R2 values exceeding 0.8 for all responses, indicating that the models could explain variability in the responses. The cost and compressive strength were found to be a suitable relation with BFSA and RCS replacement levels. In conclusion, RSM can help reduce costs by incorporating waste materials into concrete without significantly impacting concrete properties.