ABSTRACT
This study investigates the long-term behaviour of porous asphalt (PA) that retrofitted a 36 m2 laboratory full-scale street section, focusing on filtration and clogging processes. Throughout 11 experiments with increasing accumulative sediment loads up to 5.5 kg/m2, the evolution of surface permeability, water levels inside the asphalt, water flows, turbidity, and total suspended solid (TSS) concentrations were analysed. Sediment loads, representing dry-weather build-up, were applied to the asphalt surface, followed by simulated 30-min 80 mm/h rain events. Findings revealed an average permeability reduction rate of 4,717 mm/h per kg/m2. Surface clogging appeared from a cumulative load of 4.0 kg/m2, but the asphalt effectively managed rainfall with only marginal variations in flows and water levels, except for the vicinities of gully pots. The PA demonstrated a sediment retention efficiency of 93%, showing a significant decrease in turbidity and an increase in TSS concentrations once the asphalt became clogged. Comparison with the previous work emphasized the scalability and reliability of small-scale test results for analysing permeability evolution and retention efficiency, but such tests overlook real-world heterogeneities compromising the representativeness of water and sediment fluxes. The experimental dataset provides novel and valuable data for developing models to accurately simulate permeable pavements towards better urban planning, design, and maintenance.
HIGHLIGHTS
The full-scale model setup was successfully used for monitoring the evolution of filtration and clogging processes in porous asphalt (PA).
PA exhibited strong sediment retention, with a clear correlation between clogging and the reduction in permeability.
Despite surface clogging and increased TSS concentrations, water flow and levels remained stable, demonstrating the asphalt's resilience in managing rainfall.