New insights on the development of sustainable pervious concrete using sand replacing paste volume – technical, economical, and environmental analysis

Several studies in the literature report the use of fine aggregates in pervious concrete. In all reported cases, pervious concrete (PC) consistently demonstrates a reduction in the total porosity, leading to changes in hydraulic and mechanical properties. This could compromise the desired material efficiency, leading to a reduction in its environmental efficiency. In this laboratorial-scale study, the feasibility of producing sustainable PC by partially replacing paste volume by sand, in percentages up to 59%, without significant alteration in the total porosity was assessed. A fixed-porosity methodology was employed, adjusting cement paste volume to maintain constant total porosity across mixtures, regardless of sand incorporation levels. This methodological advance could provide new insights into the production of sustainable PC, and highlights the precise effect of sand on its mechanical and hydraulic properties, as well as its economic and environmental aspects. Obtained results demonstrated the fixed-porosity methodology could be considered a powerful tool to evaluate the effect of fine aggregates in PC, contributing to the development of more sustainable solutions. Specifically, the feasibility of producing PC with sand replacing paste volume up to 38% without changes in the total porosity was demonstrated. The OPC consumption was reduced by approximately 100 kg/m 3 , costs were reduced up to 25% while maintaining compressive strength and GHG emissions were reduced between 16.7-30-7% when compared to conventional PC. • Paste volume can be replaced up to 38% by sand in pervious concrete without significant changes in physical, mechanical, and hydraulic properties; • About 100 kg/m 3 of Portland cement can be saved using sand without changes in the mechanical properties; • A reduction of up to 25% in the production cost of pervious concrete using sand replacing paste volume was achieved; • Significant improvements in the sustainability of pervious concrete were yielded. • Multi-criteria evaluation demonstrates that coarse aggregate grain size influences the optimum fine aggregate content.