Edge girder floor beams with a composite concrete deck slab and overlay is highly efficient for steel superstructures. This section has been used from very short spans to main spans reaching 2000 feet. Orthotropic deck and split deck configurations are options for greater spans and widths. Orthotropic decks and boxes with overlay are used heavily in Europe and Asia even on relatively short spans. In the U.S., orthotropic construction is not cost competitive unless the span is beyond the viability of the composite cross-section.

Steel Superstructure Configurations

Illustration: Steel Superstructure Configurations