Influence of Shear on Rotation Capacity of Reinforced Concrete Members Without Shear Reinforcement

The influence of shear on the rotation capacity of one-way slabs without shear reinforcement is investigated in this paper by means of an experimental study. The experimental program consisted of 11 slab strips 8400 mm (331 in.) long and 450 mm (17.7 in.) thick with a flexural reinforcement ratio of 0.79%. The rotation capacity was investigated for various values of the shear span and for two types of flexural reinforcement (hot-rolled and cold-worked bars). The specimens developed shear failures with and without yielding of the flexural reinforcement and one specimen failed in flexure with rupture of the tensile reinforcement. The results clearly show that the rotation capacity at failure is governed by shear. Based on the test results, and considering the principles of the critical shear-crack theory (CSCT), an analytical expression is proposed to estimate the rotation capacity of one-way members without transverse reinforcement accounting for shear.