Effects of Recycled Aggregate Content on Pervious Concrete Performance

Abstract

A recycled aggregate (RA) was prepared by crushing and sieving demolished discarded concrete pavements and was subsequently tested and analyzed to determine its various physical properties. On this basis, pervious concrete (PC) mix proportions were designed. Coarse RA particles with sizes of 5–10 and 10–20 mm were selected. Concrete specimens were prepared with a water–cement ratio of 0.3, an aggregate–cement ratio of 4.5, the substitute rates of RA with 0, 25%, 50%, 75% and a single-/double-gap-graded RA mix (mass ratio of particles with sizes of 5–10 mm to particles with sizes of 10–20 mm: 1:1, 1:2, 2:1, 2:3 and 3:2). Various properties of the RA-containing PC(RPC) were determined by analyzing the compressive strength, splitting tensile strength, effective porosity, permeation coefficient and impact and abrasion resistance of the specimens. The results showed the following: The density of the RPC decreased with an increasing RA replacement ratio. The density of the RPC prepared with a double-gapgraded RA mix was lower than that prepared with a single-gap-graded RA (particle size: 10–20 mm) mix. The permeation coefficient of the RPC increased with increasing porosity. The splitting tensile strength of the RPC was positively correlated with its compressive strength. The compressive strength of the RPC decreased with increasing porosity. The regression analysis showed that the impact and abrasion resistance of the RPC increased with increasing compressive strength. In addition, all of the RPC specimens met the strength and permeation requirements. This study can provide theoretical support for the application of RPC.