Enhancing hydraulic and environmental performance of interlocking pervious concrete pavement systems through layer configuration optimization

The hydraulic performance of pervious pavement systems (PCPS) depends on the hydraulic interaction between the layers that compose them, considering both permeability and the ability to remove pollutants. This interaction is more important than the isolated permeability of the surface layer. However, there is limited knowledge on how these interactions between layers influence overall system efficiency, particularly concerning tortuosity and the risk of internal erosion. This study aims to evaluate the hydraulic performance and pollutant removal capabilities of interlocking pervious concrete pavement systems (PCPS) by analyzing the influence of different boundary layer configurations. Twelve configurations, including one reference and eleven variations, were tested to examine the hydraulic interactions and compatibility between layers. The results showed that all simulated PCPS configurations exhibited higher permeability than the reference. Among the two-layer systems, the FS-B configuration demonstrated the highest permeability (0.23 mm/s), while the FS-A-B configuration excelled among the three-layer systems (0.19 mm/s). These findings emphasize the importance of the maximum grain diameter in the bottom layer, where larger diameters (19 mm) enhanced system permeability. Additionally, the study highlights that hydraulic interaction among layers, rather than just the surface material's permeability, is crucial for overall system efficiency. Furthermore, the systems effectively reduced turbidity by 71% (FS-SD-B) and ammoniacal nitrogen by 96% (FS-A-B) compared to the reference. These findings suggest that optimizing granular layer configurations can enhance both hydraulic and environmental performance, positioning PCPS as a viable solution for sustainable urban drainage systems. The research provides valuable insights into the design and construction of PCPS, emphasizing the importance of material selection and layer configuration in achieving optimal hydraulic performance and pollutant removal (equilibrium). The configuration of layers directly influences tortuosity, which explains hydraulic efficiency. Additionally, turbulent flow due to the accumulated hydraulic gradient can lead to erosion processes and the movement of fines, clogging the pores of the layers and contributing to an overall loss of permeability. • All simulated PCPS configurations had higher permeability than the reference. • FS-B configuration achieved the highest permeability among two-layer systems. • PCPS effectively reduced turbidity and ammoniacal nitrogen levels. • Hydraulic interaction among layers is crucial for overall system efficiency. • Optimized PCPS configurations enhance sustainable urban drainage performance.