Proceedings of the 39th IAHR World Congress 19–24 June 2022, Granada, Spain doi://10.3850/IAHR-39WC2521716X2022251 Permeable pavement clogging laboratory experiments using rainfall simulators Angélica Goya, Juan Naves, Jose Anta, Joaquín Suárez, Raquel Viturro and Alfredo Jácome Universidade da Coruña, Water and Environmental Engineering Group (GEAMA), A Coruña, Spain) angelica.goya@udc.es, juan.naves@udc.es, jose.anta@udc.es, joaquin.suarez@udc.es, raquel.viturro@udc.es, alfredo.jacome@udc.es Abstract Sustainable urban Drainage Systems (SuDS) are becoming a common solution to address the increase in flow discharges, runoff volumes and pollutants concentrations caused by urban expansion. Among them, the use of permeable pavements is nowadays widespread due to their demonstrated effectiveness in managing and treating stormwater. However, there is great uncertainty in how the clogging of permeable pavements affects their long-term performance in terms of permeability reduction and pollution removal efficiency. Therefore, this study focused first in assessing the influence of clogging on the rainfall drained through porous asphalt slabs of 0.4 m x 0.4 m x 0.15 m. The hydrology behavior and removal efficiency of the asphalt were analyzed for different scenarios and grades of clogging by adding surface sediment loads between simulated rain events. In addition, a porous layer of the asphalt analyzed was used for the retrofitting of an impermeable concrete surface of a 36 m2 full-scale street section physical model that uses the same system to simulate rain. The objective is to analyze the impact of the porous asphalt layer on the hydrology and the mobilization of pollutants under full-scale and laboratory-controlled conditions, and to compare with previous tests developed using a conventional impervious concrete pavement. Keywords: Urban drainage; SuDS; Permeable pavement; Clogging; Rainfall simulator 1. INTRODUCTION Sustainable urban Drainage Systems (SuDS) are becoming a common solution to address the increase in flow discharges and runoff volumes caused by urban growth. Among them, the use of permeable pavements is nowadays widespread due to their demonstrated effectiveness in managing and treating stormwater. However, there is great uncertainty in how the clogging of permeable pavements affects their long-term performance in terms of permeability reduction and pollution removal efficiency. The installation of permeable pavements in an urban environment involves the reception of dust and dirt coming from different sources as atmospheric deposition, organic materials, runoff, and degradation of the filter media materials themselves, in addition to other inputs. This dust and dirt, consisting of materials of different sizes, are partially retained in the porous space. In fact, the retention of these elements is a favorable process in terms of improving the quality of runoff water, because these particles are commonly associated with different pollutants, some of them listed as very dangerous such as heavy metals contained in road dust (Goya et al., 2020; Sansalone et al., 2012). However, retention also implies clogging of the permeable pavement, caused a hydraulic constrain by limiting infiltration reducing its proven effectiveness in stormwater management and treatment (Davies et al., 2002). In this study, the impact of permeable pavements on the hydrology and the mobilization of pollutants is assessed by comparing the obtained results against conventional impervious pavements. Using the physical models available at the Center for Technological Innovation in Construction and Civil Engineering (CITEEC) of the University of A Coruña, the hydrology behavior and removal efficiency of PA-16 asphalt slabs of 0.4 m x 0.4 m x 0.15 m were analyzed for different clogging scenarios by adding surface sediment loads between simulated rain events using the small-scale rainfall simulator. Then, a porous layer of the same asphalt was used for the retrofitting of an impermeable concrete surface of a 36 m 2 full-scale street section physical model that uses the same system to simulate rain (Naves et al., 2020). The overall objective is to analyze the impact of the porous asphalt layer on the hydrology and the mobilization of pollutants under laboratory-controlled conditions, comparing this with previous tests developed using a conventional impervious concrete pavement (Naves et al., 2021). 2. METHODOLOGY In this chapter, the experimental setup and procedure followed to assess the long-term clogging using porous asphalt slabs in a small rainfall simulator is described first. Then, the retrofitting of the street section 1590 ©2022 IAHR. Used with permission / ISSN-L 2521-7119