Fibre reinforced polymer shear reinforcement for concrete members: behaviour and design guidelines

This paper describes an experimental program conducted to examine the structural performance of fibre reinforced polymer (FRP) stirrups as shear reinforcement for concrete structures. A total of ten large-scale reinforced concrete beams were tested to investigate the contribution of the FRP stirrups in a beam mechanism. The ten beams included four beams reinforced with carbon fibre reinforced polymer (CFRP) stirrups, four beams reinforced with glass fibre reinforced polymer (GFRP) stirrups, one beam reinforced with steel stirrups, and one control beam without shear reinforcement. The variables were the material type of stirrups, the material type of the flexural reinforcement, and the stirrup spacing. Due to the unidirectional characteristics of FRP, significant reduction in the strength of the stirrup relative to the tensile strength parallel to the fibres is introduced by bending FRP bars into a stirrup configuration and by the kinking action due to inclination of the diagonal shear crack with respect t...