Abstract
Sprayed steel fiber recycled concrete (SSFRC) is a new type of green composite building material. This study examines the impact of water-cement ratio, recycled aggregate (RA) replacement rate, and steel fiber (SF) volume ratio on concrete properties such as slump, compressive strength, and bending strength. To accomplish this, 9 orthogonal experimental designs with 3 factors and 3 levels are utilized. The primary and secondary order of factors affecting the slump, compressive strength, and bending strength of fresh concrete are obtained by analyzing experimental data. To calculate the mix ratio, the mathematical model is obtained by controlling single factor variables and fitting relationships of relevant factor data based on the analysis results of the significance of orthogonal experiments. By investigating the replacement rates of 0%, 50%, and 100% RA, we examined the ideal sand content for SSFRC. The slump values of 24 mix ratio tests were analyzed, leading to the identification of the optimal outcomes associated with sand content percentages of 49%, 51%, and 53%. Finally, we obtained the calculation method for the mix ratio of SSFRC. Based on the example calculation and verification presented in this article, it can be concluded that the mix design method proposed for SSFRC is accurate, simple, convenient, and practical.