Effect of Load Distribution on IC Debonding in FRP-Plated RC Beams

Abstract

Intermediate crack debonding (IC debonding) is a common failure mode for RC beams flexurally-strengthened with externally bonded FRP reinforcement. Although numerous studies have been carried out on IC debonding, the vast majority of them have been concerned with beams subjected to three- or four- point bending despite the fact that a uniformly distributed load (UDL) is a more common loading condition in practice. This paper presents the first ever finite element study into the effect of load distribution on IC debonding failure. A recently developed FE model was employed to simulate the IC debonding failure of three beams tested by other researchers under different load distributions and then to simulate the IC debonding failure of a beam under UDL. The numerical predictions are found to be in close agreement with the test re-sults and confirm the experimental observation that the IC debonding strain in the FRP plate (and hence the IC debonding moment of the strengthened section) increases as the load distribution becomes more uniform.