Influence of CFRP on the shear strength of RC and SFRC beams

The mechanical properties and the crack control characteristics of concrete are significantly improved by the addition of steel fibres. In certain cases, there may be still need for further improvements in the mechanical properties or cracking characteristics. There exist various methods for strengthening structural members, one of which is the use of fibre reinforced polymers (FRP). The focus of this study is on the influence of carbon FRP (CFRP) strengthening on the shear behaviour of reinforced concrete (RC) and steel fibre reinforced concrete (SFRC) beams without web reinforcement. For this purpose, three series - a series of RC beams and two series of SFRC beams - consisting of nine test specimens in total were tested under three-point loading. The behaviours of test specimens were examined in the context of strength, stiffness and ductility. It was found that the strength and ductility of both RC and SFRC beams can be improved by the CFRP strengthening while it does not have a significant effect on the stiffness.