Elastic behaviour of composite box girder bridges

The experimentally observed behaviour of five, one-twelfth scale, wide-flange single-cell composite steel–concrete box girders with both box- and trough-shaped steel sections is described and compared with the behaviour predicted by a folded plate analysis.The folded plate method accurately predicts the elastic strains in such girders when subjected to uniformly distributed load but seriously underestimates the elastic deflections.No significant differences were observed between the structural behaviour of composite box girders with a closed box steel section and girders with a trough-shaped steel section.Aspects of the design of single-cell composite box girders where existing standards result in satisfactory structural behaviour are identified. Tentative design guides are proposed for some aspects of the design of such girders where no guidelines appear to exist at present.