What are the forms of composite beam bridges? What are their characteristics?

There are two types of composite beam bridges:

1. The continuous composite beam bridge with group-nailed precast slabs can greatly reduce the secondary internal force of the structure and the tensile stress of concrete caused by the shrinkage and creep effect of concrete.

2. Pre-prestress is introduced into the precast concrete slab composite beam bridge. By introducing prestress into precast concrete slab in advance, a large compressive stress preparation can be established in concrete slab in negative bending moment area, and the crack resistance of concrete in negative bending moment area can be greatly improved.

Continuous composite beam bridge with group-nailed precast slabs;

It is developed on the basis of traditional reinforced concrete slab bridge. In the early steel bridge, the reinforced concrete deck was placed directly on the steel beam.

Later, in order to avoid the excessive relative displacement between the bridge deck and the steel beam caused by the braking force of the vehicle or the accidental action of the earthquake, a small number of bolts or bent rebar connectors were set between the steel beam and the concrete slab.

With the good economic benefits of composite beam bridge gradually emerging, engineers began to consider connecting the concrete bridge deck with the steel beam in a certain way, but at the same time, it can maintain the convenience of precast slab construction, so the group-nailed precast slab composite beam bridge was born, as shown in figure 1. The common practice of group-nailed precast composite beam bridge is on the steel beam.