Fibre-reinforced polymer (FRP) wraps are being used more often to repair and strengthen concrete members. When placed on members other than columns, the bond, which connects the wrap to the member, is the component which ensures composite action. If this connectivity fails at the wrap-concrete interface, the wrap no longer contributes to the load resistant capacity of the member. Although wraps have performed well in short-term lab and field investigations, their performance as a durable material for concrete repairs is still uncertain. In this paper, the durability of the bond connecting the wrap to concrete is examined. The wrap was installed on opposite sides of 70x75x300-mm concrete prisms. The prisms were subjected to three types of exposure conditions (temperature cycling, freeze thaw cycling and alkaline solutions) and several exposure durations. Both carbon and glass fibre reinforced wraps were tested. The standard pull-off test (53-mm diameter dollies) was used to determine the effect of the various exposure conditions and durations on the bond connecting the wrap to the concrete. Failure planes were also photographed and closely examined to identify modes of failure and the degree of connectivity of the wrap to the concrete prior to failure. Initial results show that freeze-thaw cycling had the largest adverse effect on the bond strength of the wrap and that full connectivity between the wrap and the concrete was seldom achieved using the recommended wet lay-up procedure.
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