Steel slag aggregate on mechanical properties and environment synergistic effect of geopolymer pervious concrete

This paper systematically elucidates the mechanism by which steel slag aggregate (SSA) influences the mechanical properties, nitrogen and phosphorus removal, and botanical compatibility of geopolymer pervious concrete (GPC). First, the effects of varying SSA admixtures on the dry density, porosity, permeability coefficient, and compressive strength of SSGPC have been investigated. Subsequently, denitrification and phosphorus removal experiments have been conducted on SSGPC, with the experimental data fitted using kinetic models. Finally, the pore pH testing and botanical compatibility experiments have been performed on SSGPC. This study pioneers the utilization of steel slag aggregate in geopolymer pervious concrete to achieve the synergistic improvement of mechanical performance, permeability, nitrogen removal, and plant adaptability, revealing the correlation mechanism between interfacial microstructure and macroscopic properties. The results indicate that increasing SSA content can simultaneously enhance the pore structure, permeability, and mechanical properties, while increasing interfacial gel content enhances strength, effectively reduces the alkalinity of the system, and improves plant survival rate.