Composite' means that the steel structure of a bridge is fixed to the concrete structure of the deck so that the steel and concrete act together, so reducing deflections and increasing strength. This is done using 'shear connectors' fixed to the steel beams and then embedded in the concrete. Shear connectors can be welded on, perhaps using a 'stud welder', or better still on export work, by fixing nuts and bolts.

Shear connectors, correctly spaced to resist the loads, make the concrete work 'compositely' with the steel.

Usually the steel carries its own weight and that of the wet concrete. But when the concrete is 'cured' and has acquired its full strength, then all future loads (traffic, surfacing, wind, water, pressure, seismic loads) are shared by the steel/concrete composite.

The concrete is good in compression, while the steel is good in tension and compression. This composite bridge design can be used in the following ways:

1. Simple Beam Bridges - On short spans (8m, 10m, 15m and then more expensively up to 24m), bridges can be made from a number of beams under the roadway straight across the gap. The bridges benefit the most from composite action.

2. Over Truss Bridges - These are similar to simple beam bridges but for longer spans, from say 18m up to approx 100m. The deck is still on top of the steel structure, so goes into compression when deflected.

3. Transoms on any type of bridge - Transoms go from side to side across a bridge and carry the deck loads to strong steel frames on either side. This is usually on 'open top' through truss bridges or 'closed-top' through truss bridges.

4. Decking - In a normal steel building the concrete can act together with steel decking, the steel decking taking the place of the regular steel reinforcing bars within the concrete. However in a bridge, the underside of the decking is liable to corrode over time, so is not counted as part of the reinforcement. It is just used as 'lost formwork'.

Zhenjiang Tongkai Mechanical Engineering Co., Ltd. is a company specializing in the production and selling of steel bridges, steel structures and other machined parts. The company's main products include bailey bridge, modular steel bridges, steel truss bridges, steel arch bridge and steel structures; Tongkai products are widely used in various industries with their excellent quality and advanced design. We not only have a large sales market in China, but also are exported to Southeast Asia, Africa, South America and other regions.

The company has a wealth of management personnel, skilled design and experienced construction team, proficient in the application of CAD, MIDAS CIVIL, SolidWorks software; With a purpose of " first quality, promptly delivery, customer first, reputation as the base”, we will provide you with a variety of products. Our products, regardless of the size of the project, are all can be customized according to customer requirements and structural drawings. We have the strength to do better for you with a reasonable price, first-class quality, first-class service and first-class reputation!

After several years of production, operation and exploration, Tongkai has established its own

quality management system, which has passed ISO9001: 2015 quality system certification, EN1090 EU CE certification, and ISO3834 welding certification. Tongkai always implements the concept of customer value creation, customize products for customers to meet the needs of different customers, and continuously provides customers with solutions and technologies to solve problems.