Bending-shear response of self-consolidating and high-performance reinforced concrete beams

The shear strength and the fracture behavior of self-compacting reinforced concrete (RC) beams were investigated. Beams with and without shear reinforcement (stirrups) made with self-consolidating as well as normal vibrated concrete (both ordinary and high-performance) were tested in four-point bending considering four shear arm ratios (a - shear span/d - distance from extreme compression fiber to centroid of tension reinforcement = 1.5, 2.5, 3.5, 4.5). The response of RC beams was assessed based on the results of crack patterns, load at first cracking, ultimate shear capacity, and failure modes. Comparisons with similar tests on normal vibrated concrete beams show that self-compacting concrete beams exhibit similar shear strength associated with a more brittle behavior. Finally, the code-based shear resistance predictions for RC beams are considered. While Eurocode 2 predictions exhibit, in terms of shear strength, a lower bound of the experimental results, the crack spacing is not accurately predicted by code specification.