Effect of Aggregate Gradation on Compressive Strength and Permeability of Recycled Pervious Concrete under Freeze-thaw Cycles

Freeze-thaw cycle deterioration of recycled pervious concrete (RPC) is a key durability issue facing road infrastructure. Elucidating the performance deterioration mechanisms of RPC under freeze-thaw cycles is of significant importance for promoting its resource utilization. Based on the particle interference theory, this study designed three typical gradation schemes for recycled aggregates (RAs): continuous gradation, discontinuous gradation, and single gradation, to investigate the effects of aggregate gradation on the compressive strength and permeability of RPC under freeze-thaw cycles. The research demonstrates that RPC prepared with discontinuous-graded RAs shows the most significant advantage in enhancing compressive strength, while that with continuously-graded RAs exhibits the most stable resistance to freeze-thaw cycles. Freeze-thaw cycles increase the permeability coefficient of RPC, with single gradation and continuous gradation exerting the strongest influence on the permeability performance after 25 and 50 freeze-thaw cycles, respectively. At the same time, the correlation between compressive performance and permeability coefficient of G1-G6 reclaimed RPC with intermittent gradation is the best under 25 and 50 freeze-thaw cycles. This study systematically investigates the impacts of three typical gradation schemes on the compressive strength and permeability of RPC, providing valuable experimental data and theoretical insights for the application of RAs in pervious concrete.