Transition from one-way to two-way shear in slabs under concentrated loads

Abstract

The long-standing problem of shear in structural concrete elements is typically studied as one-way shear in beams, or as two-way shear in slab–column connections. The problem of one-way shear in slabs, as encountered by bridge engineers when considering the concentrated live loads on slab bridges, is not described by codes. This paper reviews the literature regarding one-way slabs and wide beams failing in shear. The mechanisms of shear transfer and the existing models and code methods for one-way and two-way shear are reviewed. Subsequently, the similarities, differences and the transition zone between one-way and two-way shear, and the models representing these failure modes, are studied. This overview of the literature highlights that knowledge of one-way shear is limited to the comparison with small, heavily reinforced slender beams and of two-way shear to the comparison with slab–column connections. The transition zone between these two failure modes, which often occurs in structural concrete elements used in practice, is typically not studied. Possible solutions for the transition zone between the two failure modes are listed.