Long-Term Performance of a CFRP Strap Shear Retrofitting System

Synopsis: A shear retrofitting method for reinforced concrete (RC) beams has been developed that uses external CFRP straps to provide additional shear capacity. Research has been undertaken to develop an installation technique that allows the CFRP strap to encompass the full depth of the beam, without requiring access to the top surface of the beam. The current testing scheme investigates the durability of the CFRP strap system using the new installation technique. A long-term load test was conducted on a RC T-beam which indicated that the straps continued to provide shear capacity after 7 months under a load equivalent to 80% of the ultimate capacity of the retrofitted beam. A cyclic test conducted on another similar T-beam specimen demonstrated that after 1,000,000 cycles, under a load that varied between 0.5 and 0.8 times the ultimate retrofitted beam capacity, the straps continued to provide effective shear enhancement.