Estimation of friction contribution in the behavior of steel-concrete composite beams with flexible shear connectors

Abstract

A shear connector, developed to be applied to a composite beam whose steel profile is a thin-walled box profile, displayed much greater flexibility than the conventional welded shear connector, leading to particular issues in the composite beam behaviour. One of these issues is the role played by friction at the interface between the steel profile and the slab which, under particular circumstances, may be relevant for serviceability limit states and also for ultimate limit states. The Brazilian and American Standards do not yet recognize the friction contribution in the behaviour of composite beams, though they recognize this contribution in composite slabs. This paper presents the experimental tests carried out with and without friction contribution on simple supported composite beams with flexible connectors and the numerical models developed to simulate the behaviour of the tested beams. The experimental tests revealed significant increases in strength and stiffness of the composite beam due to friction contribution and the comparisons between numerical and experimental results displayed good correlations.