Impact of recycled concrete aggregates on the strength and durability properties of pervious concrete

An investigation was designed to assess the performance of pervious concrete prepared with fly ash (FA) and recycled concrete aggregates (RCA) in place of Portland cement (PC) and natural aggregates (NA). The percentage of NA replacement with RCA was varied (0%, 50% and 100%), while the percentage of FA substitution was fixed at 10%. Various fresh (workability and consistency), mechanical (compressive strength, split tensile and shear strength), durability (abrasion resistance, freeze-thaw resistance, flexure and acid resistance) and microstructural properties of the pervious concretes were evaluated after different curing periods. The findings showed that the incorporation of RCA at different levels and partial substitution of FA was desirable pervious concrete used for structural and pavement construction purposes. The incorporation of 10% FA in addition to higher levels of RCA was found to be particularly beneficial in refining the microstructure of pervious concrete. A homogenous microstructure with dense and layered calcium silicate hydrate and calcium hydroxide was observed for the mix made with 10% FA and 100% RCA.