Deterioration of FRP-to-Concrete Bond under Failure Loading

Characteristics of FRP-to-concrete bond are observed to deteriorate under cyclic loads. Deterioration has been observed under load conditions which result in a stress range in the bonded FRP of only 4% of the material capacity. Current design recommendations and “accepted practice” often neglect this detrimental effect. The clear effects of bond deterioration under fatigue loading are demonstrated for moderate-scale laboratory specimens and in full-scale specimens recovered from a forty-year old interstate highway bridge. The results suggest additional limit states that must be considered when even relatively small fatigue loads are present.