Shear critical reinforced concrete beams strengthened with CFRP straps

This paper reports on the strengthening of shear critical reinforced concrete beams with pre-stressed Carbon Fibre Reinforced Polymer (CFRP) straps. The straps can be used to enhance the shear capacity of beams and to change the mode of failure from shear to flexure. In the experimental programme, reinforced concrete cantilever beams were tested with or without straps for a particular shear span to depth ratio. The main parameters that were varied during the experiments were: the number of straps, the strap location, the level of pre-stress and the existing crack state. The experimental results are presented and discussed and conclusions drawn regarding the potential shear capacity enhancement, the stiffness improvement and the change in failure mode due to the presence of the straps.