Développement du système de connexion dans les poutres mixtes (acier-béton)

Abstract

The safety of the composite beams depends primarily on the effectiveness of the connection system because the majority of the ruptures occur at the steel-concrete interface. Therefore, it is necessary to develop new connection systems of major simplicity of implementation in site, more powerful, economic and competitive that those of traditional shear connectors. In this thesis, we proposed a new shear connector, called (I-shape shear connector). The geometry of this connector is appropriate to resist shear forces and prevent vertical separation between the steel beam and the concrete slab. Moreover, this shear connector has the advantage of its facility of manufacture by cutting of IPE or IPN steel profile and its facility of fixing by welding. Push-out tests and finite element modeling have been performed to characterise and to obtain a better understanding of the mechanical behaviour of this new shear connector. The analysis of the experimental and numerical results made it possible to propose an empirical equation able to evaluate the ultimate shear resistance of the proposed shear connector. The results of numerical modeling of composite beams showed that the I-shape shear connector can ensure steel-concrete connection in the case of simply supported composite beams. However, the experimental procedure remains always necessary to confirm the effectiveness of the proposed shear connector in the case of the continuous composite beams.