Permeability Measurement of Pervious Concrete by Constant and Falling Head Methods: Influence of Aggregate Gradation and Cement-to-Aggregate Ratio

Abstract

Pervious concrete (PC) has become more popular in recent years as a solution to the runoff problem. PC has a large number of voids, allowing surface water to flow freely through its structure. Strength and permeability are crucial design factors for PC, but there has been limited research examining their mutual relationship. In the studies, constant head (CH) and falling head (FH) permeability test methods were used to find the coefficient of permeability of the PC because there is no standard method for measuring it correctly and precisely in laboratory conditions. Also, the experiment aims to investigate the influence of various aggregate grading (single, two, and three particle size gradations) and cement-to-aggregate (C/A) ratios (0.20, 0.25, and 0.33) on the compressive strength (CS), split tensile strength (STS), flexural strength (FS), permeability, and porosity of PC while maintaining a constant water-to-cement (W/C) ratio of 0.34. The findings demonstrate that three particle size gradation mixes give higher CS, STS, and FS as compared to single and two particle size gradations. The porosity–permeability relationship of PC was analyzed using experimental results, and the FH and CH permeability tests were compared to determine the more reliable method. The investigation also established a novel model between the CH and FH methods, while examining the correlation between porosity and permeability.