CRFP contribution to shear capacity of strengthened RC beams

An experimental investigation was conducted to study the effect of composite carbon fabric shear reinforcement on the ultimate strength and behaviour of a reinforced concrete beam in the absence of the stirrup in the shear span. A total of fourteen reinforced concrete beam with or without composite carbon fabrics were tested in a load system by a point load at one-third of the clear span. The results indicate that the ultimate strength of the beam increased with an increase of the strengthening surface. The effect of the composite fabric reinforcement on the reinforced concrete beam was variable. The shear capacity of strengthened reinforced concrete beam is not the simple superposition of the shear strength due to concrete plus the shear strength due to steel stirrups and the additional shear capacity due to the composite fabrics. Almost all the beams failed in shear but the beams strengthened by composite fabrics at full depth of the beam failed in flexure. After analysing the experimental results, an analytical model to predict the shear contribution of the strengthened RC beam was proposed in this work. The values obtained by the analytical model have shown a close agreement to experimental results.