Effect of Water Head, Gradation of Clogging Agent, and Horizontal Flow Velocity on the Clogging Characteristics of Pervious Concrete

Abstract

Permeability is an important index to estimate the working performance of pervious concrete. The previous studies show that pervious concrete clogs due to the ingress of the sediments and organic particles under the action of water flow. The clogging effect limits the permeability of pervious concrete. Three clogging effect factors were studied through the lab experiments in this paper, including the clogging agent gradations, the upper water heads, and the horizontal flow velocity. In addition to the traditional permeability coefficient testing method, based on Ohm’s law, the electric resistivity method was introduced to quantify the relative permeability before and after adding clogging materials. Besides, the qualitative research was conducted on the effectiveness of the high-pressure water-cleaning method and an analytical study was made on modeling the clogging process. The high-pressure water-cleaning method can significantly alleviate the clogging effect of porous concrete, especially when solving the problems caused by small particles (d<.315 mm). It is found that a clay-sand mixture is the most harmful to the pervious concrete.