Shear resistance and cracking behaviour of SFRC beams with and without axial load

In order to evaluate the fibre effect and the synergetic effect of fibres and stirrups on the flexural shear resistance and diagonal cracking behaviour of a tunnel segment, a series of experiments is conducted. Different from the conventional testing method, inclined supported beams subjected to combined action of flexure, shear and axial compression are used to simulate the loading condition of the tunnel segment. The results indicate that steel fibres can enhance the ultimate shear resistance greatly, reduce the strain of tension steel and decrease the diagonal crack width. The combined use of steel fibres and stirrups shows a significant positive composite effect on the load-carrying capacity and the failure pattern of the inclined supported beams. The addition of 50 kg/m³ steel fibres can transform the brittle diagonal shear failure pattern of reinforced concrete beams into a ductile flexural failure pattern. The results may also apply to the shear resistance of column elements.