Research on the Application of Steel-UHPC Composite Bridge Decks in Suspension Bridges

This paper conducted three sets of full-scale mechanical tests on steel-UHPC composite bridge deck structural components, comparing the mechanical performance of steel-UHPC composite bridge decks under different slotting conditions. It analyzed the crack development patterns and the influence on ultimate bearing capacity under bending loads. The results indicate that the presence of slots has relatively minor effects on the flexural performance of composite slabs, while the ultimate bearing capacity is more closely related to the mechanical properties of the steel beams. The bending behavior of prefabricated composite slabs can be divided into three stages: in the elastic stage, the structure exhibits high flexural stiffness with minimal deflection, and deflection increases linearly with load while concrete cracking progresses slowly; in the plastic deformation stage, the neutral axis of the composite slab shifts upward, leading to accelerated deflection and rapid concrete cracking; in the failure stage, the load increment is small while the mid-span deflection increases significantly, and the curve tends to flatten, demonstrating pronounced ductility characteristics.