Study on the pore blocking characteristics and cleaning methods of permeable asphalt mixtures based on accelerated clogging simulation experiments

Clogging in permeable asphalt pavements compromises their functional properties. Understanding clogging characteristics and developing appropriate maintenance methods is crucial. This study integrates indoor accelerated clogging simulations with Grey Relational Analysis to investigate the factors influencing clogging behavior. Computer tomography scanning and seepage model simulations are utilized to examine the distribution of clogging materials, seepage properties, and changes in pore parameters in permeable asphalt mixtures before and after clogging. Additionally, variable frequency vibration tests are conducted to evaluate the impact of vibration frequency on clog removal efficiency. Findings show that the cementation hardening effect of clay progressively seals pores, with sand particles of 0.15 mm diameter exerting the most significant influence on clogging. Wet-dry cycles lead to an accumulation of clay cementation, resulting in a 26.1 % and 72.4 % decrease in pore channel length and volume, respectively, at depths of 0-4.2 cm. The area within this depth range is most prone to clogging, increasing pore tortuosity. Seepage behavior is primarily determined by several main interconnected pores. Vibration test outcomes indicate that frequencies between 100 and 400 Hz are optimal for disrupting cementation blockages.