Types of bridge expansion joints
Engineers will choose different types of expansion joints based on factors such as bridge span and load-bearing capacity.
1.Rubber expansion joint
Just like inserting a “soft cushion” with good elasticity in the gap of the bridge deck, its core principle is to absorb the expansion and contraction deformation of the bridge through the elastic deformation of rubber material. Suitable for small and medium span bridges with minimal expansion and contraction.
Advantages: Low cost, fast installation, rubber will gently “rebound” when the vehicle passes by, providing good driving comfort.
Disadvantages: The material is prone to aging and has poor durability, requiring regular replacement.
2.Modular expansion joint
Composed of two rows of interlocking high-strength profiled steel and rubber materials. It absorbs the deformation and displacement of the beam through rubber strips, while directly bearing and transmitting wheel loads using profiled steel. It is the preferred choice for large-span bridges such as cross river bridges and highway bridges.
Advantages: Strong bearing capacity, large displacement (the length difference between large-span bridges in winter and summer can reach tens of centimeters), good durability, and the ability to adapt to complex bridge deformation requirements.
Disadvantages: The production and installation process is complex, the cost is high, and there is a risk of rubber sealing tape aging and steel fracture, requiring regular maintenance.
3.Comb tooth expansion joint
It is mainly composed of steel comb plates, anchoring systems, and connecting bolts, and adapts to the expansion and contraction deformation of the bridge through the rigid support and deformation capacity of steel components. Suitable for occasions with extremely high requirements for driving comfort and load-bearing capacity.
Advantages: High strength, large bearing capacity, good structural rigidity, good durability, and better driving comfort.
Disadvantages: High cost of steel components, limited expansion and contraction, and difficulty in production and installation.
4.Seamless expansion joint
On the surface, there are no obvious gaps. By laying a layer of special asphalt or resin material at the gaps of the bridge deck, it is possible to expand and contract the bridge deck while achieving a seamless connection. Suitable for small and medium span bridges, bridge joints with small expansion, and scenarios with high requirements for driving comfort and waterproof performance.
Advantages: Good continuity, high driving comfort, good waterproofing, easy installation, and convenient maintenance and replacement.
Disadvantages: Limited expansion and contraction (0-100mm), high requirements for construction technology and material quality.