Performance and runoff coefficient of permeable concretes subjected to heavy rainfall simulations

Abstract

The use of permeable concrete pavements can mitigate flooding in densely populated areas by serving as a functional and sustainable mechanism for surface water absorption and drainage. However, it is found that the performance of the pavement is often limited to low and moderate flows and that the absorption capacity of the concrete matrix decreases as the flow rate increases. Therefore, the present study was developed aiming to evaluate the potential to reduce runoff in permeable concrete pavements subjected to simulations of successive events of heavy rainfall. For this purpose, 2 binary combinations of coarse aggregates were used, varying the cement consumption and the water/cement (w/c) ratio. The samples were submitted to simulations of heavy and sequential rainfall, with evaluation of the volume of water absorbed and the runoff. The mechanical and hydraulical properties of the permeable pavements were evaluated, as well as the characteristics of the area and volume of the internal and superficial pores. Among the results, specific weight stands out as the parameter that showed the highest linear correlation with the mechanical and hydraulic behavior of the specimens. It was also found that the runoff coefficient had a moderate negative linear correlation with the average pore size of the surface of the pavement. Finally, the permeable concrete pavements investigated were found to have the potential to reduce surface runoff in densely populated areas that are prone to frequent flooding, thus playing a critical role in mitigating the problems associated with stormwater runoff.