Study of the Permeability Coefficient of Pervious Concrete with Various Aggregate Grades

Abstract

Pervious concrete(PC) is a kind of green and environmentally friendly material with good permeability. It has the function of relieving the pressure of urban drainage system and promoting the harmonious coexistence between human and nature. The purpose of this study was to evaluate the effect of porosity and aggregate size on the water permeability and mechanical properties of PC. Through the volumetric method, three kinds of single-grained gravel aggregates of 5∼10mm, 10∼15mm and 15∼20mm were used to design and prepare PC with porosity of 15%, 20% and 25%. A linear fitting function and a power fitting function are found to demonstrate the correlation between the permeability coefficient and the porosity, respectively. The results showed that porosity and aggregate size are both important factors affecting the performance of PC. When the porosity is the same, the larger the aggregate size is used, the higher the permeability coefficient of PC is obtained. The permeability coefficient increases with the increase of the measured porosity. The smaller aggregate size is beneficial to increase the 28d compressive strength of PC. A power fitting function can better to characterize the correlation between the permeability coefficient and the measured porosity, and the fitting equation is Kt = 121.24 PM239 (R2=0.97).