CFRP grid embedded in mortar for strengthening of shear-critical RC beams

摘要

A carbon fibre-reinforced polymer (CFRP) grid embedded in mortar (CGM) is an innovative strengthening system that has similar benefits to fibre-reinforced polymer (FRP) strengthening systems for concrete structures, but overcomes such drawbacks as poor compatibility with concrete substrate and lack of vapour permeability. A study was conducted to investigate the effectiveness of the CGM composite system to strengthen shear-critical reinforced-concrete beams. The results show that a CFRP grid embedded in mortar is effective in enhancing the load-carrying capacity of shear-critical reinforced-concrete beams. However, the effectiveness of CGM strengthening reduces with the presence of stirrups. In addition, the CGM strengthening slightly reduces the shear strength contribution from internal stirrups. The experimental shear strength contributions were also compared with predicted values based on North American FRP design guidelines with some modifications.