Fresh and hardened properties of self-compacting concrete incorporating PVA-treated recycled aggregate

Abstract

In this paper, an experimental study was undertaken to improve the fresh and hardened characteristics of normal (NS) and high strength (HS) self-compacting concrete (SCC) mixes made with recycled aggregate (RA). An easy-to-perform treatment method was proposed to enhance RA properties: in this method, RA was first subjected to partial removal of adhered mortar, then treated with polyvinyl alcohol (PVA) solution for 24 hours. A series of SCC mixes, varying in w/c ratio and coarse aggregate type, including natural aggregate (NA), recycled aggregate (RA), and treated recycled aggregate (TRA), were prepared for this investigation. All mixes were investigated in their fresh state using slump flow and J-ring tests, and in their hardened state using compressive strength, splitting tensile strength, and modulus of elasticity tests. The results demonstrated that the proposed treatment method is reliable in terms of improving the properties of RA. With the exception of the passing-ability test for RA concrete mixes, all tested SCC mixes met the self-compactibility and segregation resistance criteria. Additionally, the investigated hardened properties of TRA self-compacting concrete mixes were improved significantly by using the proposed treatment method compared with those of untreated RA concrete mixes.