Presliding Shear Failure in Prestressed RC Beams. I: Partial-Interaction Mechanism

Abstract

Despite significant experimental, numerical and analytical research, the shear behavior of reinforced concrete members remains one of the least well understood mechanisms in reinforced concrete. Because of the complexity of shear behavior, empirical or semiempirical analysis approaches have typically been developed and these are widely employed in codes of practice. As with all empirical models, they should only be applied within the bounds of the tests from which they were derived which restricts the wide application of innovative materials as expensive testing must be performed to adjust existing empirical formulae or develop empirical formulae specific to the new materials. There is, therefore, a strong need to develop a generic, mechanics-based model to describe shear failure, which is the subject of this paper. The model is based on the mechanics of partial interaction, that is, slip between reinforcement and adjacent concrete which allows for crack formation and widening and is commonly referred to as tension-stiffening and slip across sliding planes in concrete associated with shear failure, which is referred to as shear friction.