Experimental simulation study on pore clogging mechanism of porous pavement

Permeability reduction caused by clogging is a major issue with porous concrete pavements. Particulate matter infiltration owing to rainwater, movement, and accumulation/deposition in the pores is the main cause of clogging in porous pavements. In this study, in order to observe the internal movement of particles in pores and the clogging evolution directly, we focus on the accumulation of transparent sodium polyacrylate beads instead of pervious concrete aggregate. The clogging process caused by particles in surface runoff entering the internal pores of porous concrete was studied, and a visualization method was applied to analyze the clogging process in porous media. The effects of the porous concrete porosity, horizontal runoff velocity, seepage velocity, and particle size distribution on the clogging development with time, clogging development rate, and particle distribution in the clogging state were studied using the control variable method. The results demonstrate that the clogging process exhibits four stages, namely rapid clogging, partial recovery, slow clogging, and clogging stability. The effects of porosity and clogging particle size on the clogging development rate are significant. Porous concrete porosity, seepage velocity, and clogging particle size all have impacts on the distributions of clogging particle in the final clogging process, while the horizontal runoff effect can be neglected. (C) 2018 Elsevier Ltd. All rights reserved.