Use of Carbon Fibre Textile to Control Premature Failure of Reinforced Concrete Beams Strengthened with Bonded CFRP Plates

Abstract

The present study examines the performance of rectangular simply supported reinforced concrete (RC) beams with externally bonded reinforcement (EBR) made of carbon fibre-reinforced polymer (CFRP) plates. The load-carrying capacity of these CFRP EBR beams can be influenced by the strengthening of their ends, which controls the premature end failure occurring when the anchorage length of the plates or the shear span/depth ratio are low. Different basic techniques are proposed to prevent this brittle failure: use of clamps at the ends of the beam, bonding of lateral perpendicular or inclined strips and U-wrapping of shear spans with carbon fibre textile. The debonding mode of failure has systematically taken the place of the concrete cover separation mode. Lateral bonding of CFRP strips and U-wrapping using carbon fibre textile are particularly efficient for the control of debonding cracks and delay the premature end failure of the beams. The load-carrying capacity is enhanced, and the ductility is increased.