Permeable Asphalt Pavements (PAP): Benefits, Clogging Factors and Methods for Evaluation and Maintenance-A Review.

Permeable asphalt pavement (PAP) is an efficient solution to stormwater management, allowing water to infiltrate through its layers. This reduces surface runoff and mitigates urban flooding risks. In addition to these hydrological benefits, PAP enhances water quality by filtering pollutants such as organic and inorganic materials and microplastics. However, clogging from sediment accumulation in the pavement's void structure often impairs its performance, reducing infiltration capacity. This review addresses several issues related to PAP, including the factors that contribute to pavement clogging and evaluates current and emerging maintenance strategies, including manual removal, pressure washing, regenerative air sweeping and vacuum truck utilization. Additionally, different methods of assessing clogging using innovative technology such as X-Ray Computed Tomography (CT), as well as a summary of the software used to process these images, are presented and discussed as tools for identifying clogging patterns, analyzing void structure and simulating permeability. This review identifies gaps in existing methodologies and suggests innovative approaches, including the creation of self-cleaning materials designed to prevent sediment buildup, biomimetic designs modeled after natural filtration systems and maintenance protocols designed for targeted clogging depths, to support the optimization of PAP systems and promote their adoption in resilient urban infrastructure designs in alignment with Sustainable Development Goals (SDGs).