Shear Strengthening of Reinforced Concrete Beams Using Externally Applied Composite Fabrics

This paper describes a study of 12 under-reinforced concrete T-beams that were tested to determine the effectiveness of using externally applied composite fabrics as a method of increasing a beams's shear capacity. Woven composite fabrics made of aramid, E-glass, and graphite fibers were bonded to the web of the T-beams using a two-component epoxy. The three different fabrics were chosen to allow various fabric stiffnesses and strengths to be studied. The beams were tested in flexure, and the performance of eight beams with external shear reinforcement was compared to results of four control beams with no external reinforcement. All the beams failed in shear and those with composite reinforcement displayed excellent bond characteristics. For the beams with external reinforcement, increases in ultimate strength of 60 to 150 percent were achieved.