Shear behaviour of recycled aggregate concrete beams with and without shear reinforcement

Abstract

An experimental study of the shear behaviour of recycled aggregate concrete (RAC) beams with and without shear reinforcement is presented. Nine full-scale simply supported beams were loaded in four-point bending tests until failure. Three different replacement ratios of coarse natural with coarse recycled concrete aggregate (0%, 50% and 100%), and three different shear reinforcement ratios (0%, 0.14% and 0.19%) were the main parameters. All natural aggregate concretes (NAC) and recycled aggregate concretes (RAC) were designed and experimentally verified to have similar compressive strength and workability. It was found that the shear behaviour and the shear strength of the beams with 50% and 100% of recycled concrete aggregate were very similar to that of the corresponding natural aggregate concrete beams. The applicability of different code provisions for shear strength predictions of the RAC beams with and without shear reinforcement was tested by comparison with test results obtained on 85 beams, 58 RAC and 27 corresponding NAC beams. The shear strength of RAC50 and RAC100 beams with and without shear reinforcement was conservatively predicted by the analyzed codes with similar reliability as for the corresponding NAC beams shear strength. At this state-of-knowledge, the application of the analyzed codes’ provisions for NAC beams shear strength can be recommended both for the RAC50 and the RAC100 beams.