Abstract

The paper concerns bridge spans made of steel beams combined with a concrete slab, boarding for the bridge deck slab. It also relates to bridges made of precast beams, rehabilitated with use of additional layer of a concrete slab. Effects of connection of a bridge beam with a sandwich concrete deck slab are analyzed in the work. For such composite structure there is proposed a solution in which global, resultant internal forces are separated into components imposed to the elements forming the girder i.e.: the beam and both layers of the sandwich slab. Influence of concrete creep and shrinkage on the internal forces and deflections of the composite girder is shown. Rheological processes are described with use of a model of the substitute modulus of elasticity. Numerical examples given in the paper show the effects of concrete creep and shrinkage in steel-concrete composite bridges, particularly in continuous beams.