Shear and moment capacity of reinforced steel-fibre-concrete beams

Abstract

Synopsis An analytical approach for predicting the shear and moment capacity of reinforced steel-fibre-concrete (RSFC) beams is proposed. Recent plasticity analyses for shear capacity of reinforced concrete beams are extended to RSFC beams by including the contribution of the fibres. Moment capacity is derived using the usual sectional analysis and fully plasticized stress blocks and forces. By establishing relevant capacities for a given beam loaded over a range of span/depth ratios, the capacity and governing mode of failure can be predicted. The observed failure loads and modes of failure for 22 test beams agree well with the predictions. Data presented in the literature are also analysed and compared. The present approach allows for direct comparison between the efectiveness of stirrups and fibres as shear reinforcement. The results suggest that fibres can replace stirrups partially or wholly as long as parity in the shear reinforcement factor is maintained.