Multi-objective optimization of the mix proportion for dune sand concrete based on response surface methodology

Abstract

Dune sand (DS) concrete (DSC) has attracted increasing attention due to the scarce of river sand and the abundance and low cost of DS. To promote more construction applications of DS, this study provides an optimization method of the mix proportion for DSC with DS to fine aggregate (D/F) ratio, basalt fiber (BF) dosage, water to cement (W/C) ratio and sand to aggregate (S/A) ratio as factors. 36 groups of dune sand concrete (DSC) were designed by the central composite design (CCD) method. Response surface method (RSM) was applied to explore the individual and interactive effects of above factors on slump, cubic compressive strength and splitting tensile strength. Desirability function was used to determine the mix ratio of concrete of different strength grades with the optimal overall performance, followed by verifications with a series of experiments. The results showed that the models established by the RSM were effective and can accurately predict the performance of DSC. W/C ratio, D/F ratio, sand to aggregate (S/A) ratio and BF dosage had significant effects on the workability and mechanical properties of concrete. Slump was affected by D/F ratio, W/C ratio, BF dosage and S/A ratio in descending order of significance, compressive strength by W/C ratio, D/F ratio, BF dosage and S/A ratio, and splitting tensile strength by W/C ratio, BF dosage, D/F ratio and S/A ratio. The optimal mix proportions for C30-C40 DSC were obtained by desirability function, and verified by experiments. The research results of this paper contribute to obtain engineered DSC.