Flexural response of rc beams failing in shear

In this paper, an analytical model to determine the flexural response of simply supported RC beams under four-point bending tests failing in flexure and shear is presented. The model is able to provide load-deflection curves, including also the shear contributions, which are determined assuming a kinematic rigid plastic model able to consider different strength contributions such as the concrete, the dowel action, and transverse reinforcement with progressive yielding. For each contribution, a physical explanation is provided to link the strength evaluation with a specific kinematic evolution for the determination of the overall response of RC beams under combined shear and flexural loads. An extensive comparison with the experimental data available in the literature is made to check the reliability of the simplified proposed model to predict also the complete flexural response of beams including postpeak resistance when shear failure is attained. The comparisons revealed good agreement between the experimental and analytical results. The proposed model can be simply used for manual calculations of the flexural response of RC beams that fail in flexure or shear.