Clogging of Permeable Pavements: Case Study

The use of permeable pavements has been an important tool for flood reduction and minimization of the greenhouse effect in urban centers. This type of pavement allows the passage of water and air through its layers and, when designed and applied correctly, may contribute to the reduction of surface runoff during the occurrence of peak flows. The problem with this type of pavement is the decrease in permeability that will inevitably occur due to the use over time. This is called clogging and is caused by the gradual deposition of particulate material between the voids, which originally allowed the rapid passage of water. Studies show that sealing of permeable pavements can occur between 5 and 10 years after their construction, depending on sources of pollution, punctual or diffuse, that can reach the coating layer. In this way, part of the clogging to which the pavement will be exposed can be avoided, even in the design phase, increasing its useful life. This study presents an evaluation of the sealing mechanism in some types of permeable pavements. The evaluation was carried out in the field, through the monitoring of measurements of the permeability coefficient in an area used as light vehicle parking. The measurements were carried out shortly after the work was finished and fourteen months after the release to traffic, which allowed to evaluate the level of natural reduction of the permeability coefficient and the impact on the functioning of the pavement and, in parallel with this evaluation, similar in a simulator, with the empirically accelerated clogging. The objective was to demonstrate that the deposition of residues that cause septum, in most cases, is limited to the coating layer, which would facilitate the cleaning of the pavement, recovering its main functionality, the permeability.