Failure mode analyses of fibre reinforced polymer plated reinforced concrete beams

Externally-bonded fibre reinforced polymers are now routinely used for increasing the strength of a concrete beam in flexure and this method is very popular for the repair of structures. Nevertheless, this type of reinforcement may cause a premature and brittle failure such as plate end interfacial debonding or concrete cover separation. This paper is concerned with the failure by concrete cover separation; in other words by peeling-off. This mode involves the tearing-off of the concrete cover along the level of tension steel reinforcement starting from a plate end. In this paper, experimental work and numerical analyses of four types of reinforced concrete beams have been carried out. A nonlinear finite element analysis using the commercial program ABAQUS was carried out to predict ultimate loading capacity and the failure mode of RC beams in a four-point bending setup. A series of 4 RC beams strengthened with FRP sheets at the bottom were tested to failure under a four-point bending load. By comparing numerical results with experimental ones, the proposed finite element model has been validated and can be used for further prediction of this type of failure.