Assessing the phenomenon of clogging of pervious concrete (Pc): Experimental test and model proposition

Abstract

During rainfall, different types of sediments are transported (organic and inorganic) that end up prejudicing the hydraulic efficiency of materials such as pervious concrete (PC). Sediments tend to accumulate on the surface of the material and its internal pore structure causing a decrease in permeability. This phenomenon is known as clogging. This study aims to identify and characterize the phenomenon of clogging of PC considering laboratory and field conditions. In that sense, a PC mix and three types of sediment (sand (S), clay (C), and mixture of both (S + C)) were considered. Two types of permeability tests were adapted to induce the clogging and estimate the permeability reduction: the constant head test (laboratory), and the ASTM C1701 (field). Finally, different rates of clogging (low, medium and high) were considered. Considering the type of sediments, the finer they are the higher is the influence on the clogging phenomenon, reaching maximum permeability reductions greater than 95%. Considering the rate of clogging, the results show that low rate entails higher clogging. On the other hand, an analytical model to describe the clogging was proposed. This predicts efficiently the reduction of permeability considering the type and concentration of sediment. This model was proposed with experimental data obtained and validated with results from other investigations. The model aims to be used for engineers to design PC considering their life span and maintenance.