ABSTRACT
A number of steel structures in road and railway infrastructure, oil and gas pipelines etc, are coming to the end of their design life and are in need of retrofitting or replacement; and many of these are located in regions that regularly experience freeze-thaw conditions. Due to the high strength to weight ratio and the flexibility, repairs using fibre reinforced plastics (FRPs) have recently replaced more conventional methods of repairing and strengthening steel structures, such as using steel sleeve repair (Hollaway et al,2002; Zhao et al, 2007). The use of FRP for structural repairs or strengthening has found wide applications in concrete and FRP structures, but their use for repairing steel structures is comparatively new. One of the main failure modes that characterize FRP strengthened members is the debonding failure, which is mainly governed by the weak adhesive layer that can be subjected to both shear and peeling stresses (Porter 2002).
