Durability of CFRP Sheet Reinforcement through Exposure Tests

Synopsis: Over the last few years, the use of composite materials has become an increasingly popular method of repairing and strengthening ageing civil engineering structures. However, despite the efficiency and attractiveness of this technique, its market progression has been impaired by the relative lack of knowledge on the longterm behavior of the FRP materials themselves and, by extension, on the behavior of the structures strengthened with such products. The authors are conducting a 10-year exposure test program on FRP products, and this paper provides midway results from the first 5 years of exposure data. There was no significant change in the tensile strength of the CFRP laminates after a 5-year exposure, however in-plane shear strength showed a slight decrease. Bending strength of matrix resin also decreased in the early exposure stage. The results suggest a reduction of the bonding properties between carbon fibers and resin.