Bridge expansion joints

1. Adapt to bridge deformation
During use, bridges will deform due to temperature changes, vehicle loads, concrete shrinkage and creep. Expansion joint steel can provide a retractable space. For example, when the temperature rises, the bridge structure will expand, and the steel can stretch to avoid excessive internal stress in the bridge structure due to thermal expansion. On the contrary, when the temperature drops, the steel can shrink to adapt to the shortening of the bridge, effectively preventing cracks or damage to the main structure of the bridge.
When vehicles pass through the bridge, vibration and impact loads will be generated. Expansion joint steel can buffer the impact of these loads on the bridge structure to a certain extent, so that the expansion device of the bridge can flexibly adapt to dynamic deformation, ensuring that the bridge still maintains good structural integrity when vehicles travel frequently.
2. Ensure driving comfort and safety
Bridge expansion joint steel helps to maintain the flatness of the bridge deck. If there is no expansion joint steel or the expansion joint device fails, the bridge deck may have height differences and misalignment at the expansion part. When vehicles travel on such a bridge deck, they will be bumpy, affecting driving comfort. The steel section can keep the bridge deck relatively flat during the expansion and contraction process through its reasonable structural design, so that vehicles can pass smoothly through the expansion joints of the bridge.
From the perspective of driving safety, a flat expansion joint can prevent the vehicle from losing control due to sudden bumps. At the same time, the good load-bearing capacity of the steel section can prevent the expansion joint from being damaged under the load of the vehicle, and avoid dangerous situations such as vehicle tires getting stuck or stuck.
3. Protect the main structure of the bridge
As a key component of the bridge expansion device, the expansion joint steel section can prevent rainwater, debris, etc. from entering the main structure of the bridge. Without the effective protection of the expansion joint steel section, rainwater and other structural parts may penetrate into the beam body, piers and other structural parts of the bridge, causing durability problems such as steel corrosion and concrete corrosion.
It can also disperse the vehicle load, evenly transfer the force of the vehicle on the expansion joint to the main structure of the bridge, and avoid damage to the bridge structure due to excessive local stress. For example, when some large trucks pass through the bridge, the steel section can reasonably distribute its huge axle weight to protect the bridge structure from excessive concentrated stress.
The steel grades are generally Q355B, Q390B, etc., and the fixed length is 6-12 meters, etc.