To improve the overall performance of ecological concrete for sponge city applications, orthogonal experimental design combined with single-factor tests was conducted, considering coarse aggregate size, water–binder ratio, cement content, and zeolite powder replacement as key variables. The effects of these factors on compressive strength, porosity, and permeability coefficient were systematically evaluated, and the interactions among performance indices were further analyzed through controlled single-variable experiments. The results indicate that the optimal mix proportion consists of a 1:1 combination of 10–15 mm and 15–20 mm coarse aggregates, a water–binder ratio of 0.31, a cement content of 250 kg/m³, and a zeolite powder replacement of 20%. Under this optimized mixture, the ecological concrete achieves satisfactory mechanical performance with a 28-day compressive strength exceeding 5 MPa, together with high permeability of approximately 30 mm/s. The proposed mix design demonstrates superior physical performance and provides experimental support for the optimization and engineering application of ecological concrete.
Qilin et al. (Wed,) studied this question.