Freeze-thaw resistance, mechanical and transport properties of self-consolidating concrete incorporating coarse recycled concrete aggregate

The effects of coarse recycled concrete aggregate on freeze-thaw resistance, mechanical performance and transport properties of self-consolidating concrete (SCC) were investigated. Recycled concrete aggregate (RCA) was substituted for crushed coarse limestone aggregate as 0, 20, 40 and 60 wt% of limestone aggregate. Mixtures having three different water/binder (w/b) ratios (0.43, 0.48 and 0.53) were prepared. The properties of fresh concrete were determined by using the slump-flow, V-funnel and L-box tests. Compressive and splitting tensile strength, ultrasonic pulse velocity (UPV), water absorption, water sorptivity, chloride-ion penetration and freeze-thaw resistance of hardened concrete were determined. Test results indicate that in RCA containing mixtures, the viscosity of the SCC mixtures increased significantly. The compressive strength of SCC mixtures improved slightly with increasing the coarse RCA content up to 40%. In addition, water absorption and chloride-ion penetration of SCC mixtures increased slightly by the incorporation of RCA. On the other hand, the splitting tensile strength, unit weight, UPV, water sorptivity and freeze-thaw resistance of concrete decreased in RCA containing mixtures. (C) 2013 Elsevier Ltd. All rights reserved.