External bonded shear reinforcement for T-section beams

Strengthening reinforced concrete (RC) beams in shear using carbon fibre-reinforced polymer (CFRP) has been found to enhance, significantly, the shear capacity of existing RC beams. In previous studies the use of steel plates bonded externally to the RC beams was found to improve the shear performance of these beams. Most of the previous work was conducted on RC beams having rectangular sections. The main objective of this paper is to gain a better understanding and enhance the experimental database of shear behaviour of RC T-beams strengthened with externally bonded reinforcement (EBR) systems. The present study encompasses some of the important parameters such as direction of EBR fibre alignment and the strengthening materials made of carbon-fibre sheets, steel plates or steel bars for shear strengthening. The contribution of EBR to the shear capacity of the T-beams was computed using three design codes and compared with the experimental output. A series of RC T-beams was tested experimentally with the CFRP and steel strips carefully aligned and spaced. A reference T-beam and a rectangular beam were tested as well to explore the effect of the internal shear reinforcement and the existence of the flange on the shear capacity of the beam.