Externally bonded hybrid carbon/glass FRP strips for shear strengthening of RC deep beams

Abstract

The experimental study on the shear strengthening the efficacy of a recently introduced hybrid carbon/glass fiber reinforced polymer (FRP) for reinforced concrete (RC) deep beams has been presented in this study. The hybrid carbon/glass FRP combined the benefits of the constituent materials, specifically, strength and ductility properties provided by carbon and glass FRP, respectively. A total of four deep RC beams with shear span-to-effective depth ratio (a/d) of 1.6 were constructed and tested under three-point bending considering the amount of FRP reinforcement ratio as a test variable. One unstrengthened beam was used as a reference, while three beams were strengthened with different reinforcement ratios of externally bonded (EB) hybrid carbon/glass FRP. The test results revealed the successful application of the EB hybrid carbon/glass FRP for strengthening of RC deep beams critical in shear. The increase in the load-carrying capacity of up to 17.9% was obtained. Moreover, the strengthening system has enhanced the deformational characteristics of the strengthened deep RC beams.