Shear strength of concrete-encased composite structural members

This study investigates the shear strength of composite steel and concrete members in which the steel shape is fully encased in concrete. Two types of shear failure-diagonal shear and shear bond-are examined in this study. Th rough understanding of these failure modes, a new approach is proposed to p redict the shear capacities of composite members. Major parameters investig ated include steel flange width, shear reinforcement, concrete strength, an d applied axial load. To evaluate the accuracy of the proposed approach, a verification analysis is made by comparing shear capacities predicted by th e proposed approach with previous test results. Furthermore, the shear capa cities predicted by the proposed approach are also compared with those obta ined by American and Japanese provisions. The results of the analysis and c omparison indicate that the proposed approach yields satisfactory predictio n of shear strength and provides a rational explanation on the mechanism of shear bond failure. A new term, the critical steel flange ratio, is introd uced to distinguish the shear bond failure from the conventional diagonal s hear failure.