Modélisation du comportement à rupture (peeling-off) de poutres BA renforcées soumises à un essai de flexion 4 points

The flexural strength of a reinforced concrete beam can be increased by bonding a fiber-reinforced polymer sheet to the tension face. This method of flexural strengthening has emerged very popular around the world 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. The first step for a successful, safe and economic design of flexural strengthening using FRP composite at the bottom of the beam is then to predict such failure and to take it into account in design. In this paper, a 3D finite element model using the commercial program; ABAQUS, is presented for the simulation of concrete cover separation failures. A nonlinear finite element analysis was carried out to predict ultimate loading capacity and the failure mode of RC beams in a four-point bending setup. In order to validate this modeling, 15 RC beams were tested in a four-point bending set-up. Comparisons between the predictions of the numerical model and test results show a very good agreement.