Behavior of high-performance RC composite corbels with inclined stirrups

Abstract

In the present work, a new modified arrangement for shear reinforcement in corbels is proposed. Inclined, rather than horizontal, alignment of stirrups was studied. In addition, the performance of composite corbels incorporated with the usual and proposed alignments of the shear reinforcement were investigated. The experimental work consisted of testing 12 specimens. Four corbels are non-composite and eight are composite with two shapes of rolled steel, namely, WF and tapered WT sections. Two values of shear span to depth ratio (av/d) have been considered, which are 0.70 and 1.0, to study both when shear is dominant and when bending moment is dominant. The behavior of the tested specimens was discussed in terms of the history of loading, first cracking load, failure load, ductility, toughness, and history of the first crack development. It was found that the proposed configuration of shear reinforcement improved the ductility and toughness with respect to the conventional arrangement by 16% and 38%, respectively, for av/d value of 0.70, and 55% and 64%, respectively, for an av/d value of 1.0. Furthermore, the results revealed that using the composite corbel with the proposed alignment rather than RC corbel improved the ductility and toughness by 35%–80% and 45%–173%, respectively, for av/d = 0.70. The values for corbels with av/d = 1.0 are 38%–101% and 67%–88%, respectively. Moreover, tests revealed that the composite WF-steel corbel with diagonally aligned stirrups showed relative performance indicators (with respect to the conventional corbel) for av/d = 0.7 of 82%, 98%, 105%, and 273% for the first cracking load, failure load, ductility, and toughness, respectively. The respective values for av/d = 1.0 were 111%, 115%, 138%, and 188%, respectively.