Evaluation of self-consolidating concrete shear strength by means of push-off test

Self-consolidating concrete (SCC) can be characterised by its flowability, stability and passing ability. Although SCC tends to have a more uniform microstructure in the concrete–reinforcement interfacial transition zone, the reduction of the nominal size and coarse aggregate content in the concrete mix may adversely affect its shear strength. Therefore, the aim of this research was to evaluate the shear strength of SCC by means of push-off tests of 45 specimens, produced with one conventional concrete and two SCC mixtures, with two different coarse aggregate contents (reference and reduced by 30%). The transverse reinforcement ratio ranged from 0.46% to 2.28%, using closed stirrups crossing the shear plane. The increase of reinforcement ratio resulted in improvements in shear strength for specimens with one, two and three stirrups, while specimens with four and five stirrups had a premature failure owing to concrete crushing near the notch. No significant difference in shear strength was identified owing to concrete type or coarse aggregate. The experimental results were also compared with codes estimates, and Eurocode 2 presented the best fit to experimental results when compared with the American code ACI 318 and the Canadian standard CSA A23.3.