Stormwater management using pervious geopolymer concrete with recycled aggregates: Leaching potential and contaminant removal efficiency

Pervious geopolymer concrete (PGC), known for its high hydraulic permeability and pollutant adsorption, has emerged as a sustainable solution to mitigate stormwater runoff, pollutant transport, and reduce the global warming potential (GWP) of pavements. Its sustainability can be further enhanced by incorporating recycled concrete aggregate (RCA). This combined use of geopolymer binders and RCA to produce pervious geopolymer recycled aggregates concrete (PGRAC) remains underexplored. This study evaluates the performance of PGRAC in improving stormwater quality, assessing both contaminant leaching and removal. Experimental parameters included binder blends, design porosity, and RCA content. Mechanical and hydraulic tests confirmed that all mixes achieved adequate performance for pavement use. All mixes exhibited low leaching potential for most heavy metals, below regulatory limits, except for Boron. Mixes with 10 % porosity and 100 % RCA demonstrated superior contaminant removal due to enhanced pore structure, but were more susceptible to clogging. Overall, PGRAC demonstrated strong sustainability potential. • Pervious concrete pavement of various proportions of recycled waste was developed. • Experiments showed lower heavy metals leaching potential than regulatory thresholds. • Fly ash increased the leaching potential of certain heavy metals. • Contaminant removal efficiency declined over time due to pore clogging. • Removal efficiency was strongly influenced by the inclusion of recycled aggregates.