A composite beam bridge combines steel members (plate beams, box beams, or truss beams) with reinforced concrete components through shear connectors to create a unified structural system. Originally used primarily for simply-supported bridges, this technology now extends to continuous beams, cable-stayed bridges, suspension bridges, and tied arch bridges.

The composite design separates beam ribs from bridge panels through longitudinal joints, creating a combined section that is constructed in stages. Beam ribs are erected first, followed by prefabricated panels, with final concrete casting creating the complete structure.

I-section steel beams form the core of medium and small span bridges, offering cost-effective production and installation. These can utilize rolled or welded steel sections, with asymmetric designs reducing upper flange dimensions.

Box-shaped cross-sections provide superior torsional rigidity and stability compared to I-section designs. This configuration enhances crossing capacity while minimizing traffic disruption during construction.

Steel trusses replace solid beams, offering improved permeability and aesthetics. These designs feature greater beam heights and more complex joint construction requirements.

Integration with concrete piers creates structures with large headroom, excellent seismic performance, and enhanced aesthetics. These designs eliminate falling beam risks while maintaining bridge floor smoothness.

• Combined section design increases stiffness while reducing steel requirements
• Reduced noise compared to all-steel bridges
• Easy adjustment of slope and superelevation
• Requires reliable shear transfer devices between steel and concrete components
• Flexible shear transfer options including diagonal reinforcement and capped bolts

• Construction efficiency: Lightweight steel components simplify erection
• Reduced dead load: Lighter than concrete alternatives, easing foundation requirements
• Material optimization: Steel handles tension while concrete resists compression
• Cost savings: Particularly significant for long-span applications
• Versatility: Suitable for highway and railway bridges