Behavior of Reinforced High‐Strength‐Concrete Corbels

Results of an experimental investigation on the behavior of corbels made with high‐strength concrete in excess of 40 MPa are presented. A total of 16 life‐size corbels were tested, two of which were unreinforced. The primary variables of the investigation were presence of horizontal force, reinforcement ratio, and shear‐span‐to‐depth $(a/d)$ ratio. Silica‐fume and high‐range water‐reducing admixtures were used to obtain the high‐strength concrete. All 14 reinforced concrete corbels failed in a stable manner. The primary steel yielded before failure in all cases but one. The behavior of the corbels during testing and the analysis of results indicate that high‐strength concrete may be rationally incorporated into designs of corbels. The truss analogy model provided relatively accurate strength predictions compared with the American Concrete Institute's procedure. The code limit of 5.5 MPa (800 psi) for maximum average shear stress limits the full use of the available shear strength of high‐strength corbels.