Creep behaviour modelling of a composite steel–concrete section

Long term behavior modelling of steel–concrete composite beams requires the use of the time variable and the taking into account of all the sustained stress history of the concrete slab constituting the cross section. In this context, a research contribution of the time-dependent behavior of composite sections under the creep influence of a concrete slab is presented in the present work. The concrete creep influence upon the composite section strength is taken into account as part of the concrete linear viscoelasticity. Thus, by considering the assumption of a complete composite connection made up of a steel beam and concrete slab, with no slip at the interface, and owing to the irreversible law of concrete, we obtain an analytical model, based upon a system of two differential linear equations governing the long term behavior of composite beam cross sections in bending. Results obtained from the application of the suggested model to a steel–concrete composite beam are satisfactory.