Progress in research on the mechanisms of clogging behavior and its influencing factors in porous asphalt pavements

Porous asphalt (PA) pavement has proven to be an effective solution for mitigating a range of ecological and environmental challenges associated with urbanization, including issues related to water, noise, heat, and light. However, clogging issues significantly deteriorate the functionality of PA pavement, resulting in unsatisfactory performance expectations. In relation to this, the review paper presents a comprehensive investigation on void clogging behaviors in PA pavement, examining its theoretical foundations, research methodologies, and key findings, aims at securing more advanced designs to clogging resistant and improving the efficiency of de-clogging maintenance techniques. Firstly, based on research developments over the past decade, the mechanisms underlying void clogging in PA pavement are revealed. Secondly, research methods employed to study clogging behavior are introduced across macro to micro scale lengths, and their respective advantages and limitations are critically analyzed. Thirdly, major factors influencing void clogging are identified, and the potential coupled effects of these factors are systematically analyzed. Finally, future research directions are suggested. The analysis indicates that void clogging in PA pavement is a complex, long-term process governed by the coupled interaction of material, environmental, and load-related factors. Recent advancements—such as X-ray computed tomography (CT), image processing, numerical simulation, ground-penetrating radar, and 3D printing—have significantly enhanced the quantitative analysis of clogging behavior. Internal factors such as void structure and aggregate gradation determine the initial anti-clogging capacity, whereas external factors—including clogging material characteristics, rainfall intensity, and traffic load—further deepen clogging. Moreover, the coupled effects of these individual factors warrant further investigation. Notably, the relative size relationship and interaction between clogging particles and voids play a critical role in the early stages of clogging, with particle-to-void size ratios between 0.6 and 0.8 showcasing the most significant influence. • Research methodologies evolving from macroscopic to microscopic scales were reviewed. • The mechanisms of porous asphalt pavement clogging were synthesized and clarified. • Key factors and their coupled effects influencing void clogging were systematically examined. • Future research directions for understanding and mitigating clogging were proposed.