Modular Expansion Joint

◆◆ Advantages of Modular Expansion Joints:

1. Strong Deformation Adaptability: Featuring a modular combined design, it can be flexibly assembled according to the bridge's expansion and contraction requirements, adapting to large expansion and contraction amounts (usually ranging from 80mm to 1200mm or even larger). Meanwhile, it can simultaneously adapt to the longitudinal, transverse, and vertical deformations of bridges, and has strong adaptability to complex bridge types such as skew bridges and curved bridges.

2. High Load-Bearing Capacity: High-strength steel is used as the supporting frame, and components such as edge beams and middle beams have high bending and compressive strength. It can withstand repeated rolling by heavy-duty vehicles, making it suitable for bridges with large traffic volumes such as expressways and urban main roads.

3. Excellent Sealing and Waterproof Performance: Rubber strips are embedded in the grooves of section steel to form multiple sealing barriers, which effectively prevent rainwater and debris from seeping into the internal structure of the bridge and reduce the risk of steel bar corrosion and concrete damage.

4. Significant Shock Absorption and Buffering Effect: The elastic connection between modules can absorb the impact force generated by vehicle operation, reduce bridge vibration noise, and improve driving comfort and safety.

5.Convenient and Efficient Construction: With modular prefabricated production, on-site installation only requires splicing and fixing according to the design position, which reduces the workload of on-site welding and pouring and shortens the construction period.

6. Easy Maintenance and Replacement: When a certain module is damaged, it can be disassembled and replaced individually without removing the entire expansion joint, reducing maintenance costs and the impact on traffic.

7. Good Durability: The surface of steel is usually treated with hot-dip galvanizing or anti-corrosion coating, and the rubber strips are made of anti-aging materials. It can be used for a long time in an environment of -40℃ to +60℃, with a service life generally reaching 15-20 years.

◆◆ Application Scenarios of Modular Expansion Joints

1.Expressways: Modular expansion joints can adapt to the displacement of bridges caused by factors such as temperature changes, shrinkage, and creep. Therefore, they are widely used in the construction of expressway bridges, ensuring the smoothness and safety of vehicle operation.

2.Urban Roads: In the bridge projects of urban roads, modular expansion joints also play an important role. They can effectively reduce the vibration and noise generated when vehicles pass by, improve driving comfort, and at the same time protect the bridge structure from erosion by rainwater and debris.

3.Various Types of Buildings: In addition to bridges, modular expansion joints are also widely used in the design and construction of various types of buildings. They can provide a certain deformation space, prevent the building structure from stress damage caused by temperature changes, and thus enhance the stability and seismic capacity of the structure.

4.Areas with Complex Climatic Conditions: In areas with complex climatic conditions and large bridge deformation, modular expansion joints, relying on their flexible expansion adjustment capability, can better cope with bridge deformation and ensure the safety and durability of bridges.

In summary, relying on its advantages such as strong load-bearing capacity, good waterproof performance, long service life, and high driving comfort, modular expansion joints can play an important role in a variety of scenarios.

Installation Method of Modular Expansion Joints

1. Construction Preparation:

- Entrust professional manufacturers or construction teams; welders must hold valid certificates to work.

- Compile installation plans and operation guidelines.

- Prepare equipment such as generators, vibrators, and electric welders.

- Conduct on-site surveys, mark the boundaries of reserved grooves, check the pre-embedded and reserved conditions, and confirm rectification measures with relevant parties if there are defects.

2. Setting-out and Cutting of Reserved Grooves:

- After the bridge deck pavement is completed, conduct setting-out according to the design drawings or previous marks.

- Sprinkle water within 1m on both sides of the reserved groove edges before cutting; rinse after cutting. Cut the asphalt surface layer at a uniform speed along the edge lines to ensure the edges are neat, straight, and aligned with the original reserved grooves.

3. Groove Cleaning and Reinforcement Adjustment:

- Remove debris, clean concrete from the surface of pre-embedded reinforcements, roughen the groove bottom, and rinse off scum with a high-pressure water gun. Address issues such as excessively wide structural joints or insufficient groove depth.

- Correct and adjust pre-embedded reinforcements; if reinforcements are missing or broken, perform rebar planting in accordance with regulations and conduct pull-out tests.

4. Installation of Expansion Devices:

- Verify the factory-reserved expansion gap based on the installation temperature, fix it with limit clamps or positioning angle steels, and adjust if it fails to meet requirements.

- Check the straightness of section steel by pulling lines, align the device’s centerline with the centerline of the reserved groove gap, hoist the device into the reserved groove, and lift it at the designated lifting points to prevent deformation.

- Use a 3m straightedge to check the height difference between the device’s top surface and the bridge deck; the device’s top surface should be 1-2mm lower than the bridge deck asphalt layer.

- Position the device after adjusting its planar position and elevation. First, spot-weld both ends, then spot-weld pre-embedded reinforcements and anchor reinforcements at 1m intervals.

- Conduct fixed welding after rechecking the elevation: spot-weld from the middle to both ends, recheck the elevation and planar position, and perform supplementary welding if there are no errors.

- After welding, use a grinding wheel cutter to remove temporary fixing parts, then grind and apply anti-corrosion treatment to the removed areas.

- For on-site splicing of expansion devices longer than 12m, adopt staggered splicing (staggered length > 80mm, bevel treatment for splicing surfaces), reinforce with stiffening plates via fillet welding, and ensure the distance between displacement boxes after splicing does not exceed the design value.

5. Reinforcement Installation and Binding:

- After welding, thread reinforcements into the device’s anchor rings and bind them according to design requirements. If horizontal transverse reinforcements are inserted in sections, ensure the lap length meets design standards. Arrange surface anti-crack reinforcement meshes (if designed) according to drawings.

6. Concrete Pouring:

- Install firm formwork on both sides of the expansion joint to prevent formwork displacement during pouring. After final cleaning and rinsing of the joint groove, pour concrete; avoid concrete contaminating the pavement or flowing into the joint opening and control box.

7. Rubber Sealing Strip Installation:

- Embed the rubber strip from one end to the other, or symmetrically from the middle to both ends. Avoid bidirectional extrusion to prevent mid-section bulging, and ensure the strip’s lips fit tightly with the inner wall of the section steel.

8. Concrete Curing and Acceptance:

- Sprinkle water on the concrete surface for curing until it reaches sufficient strength. After the concrete solidifies and meets strength standards, check whether the expansion joint’s flatness, centerline position, and gaps meet requirements.

1. What are your main products?

Our main products include:  Anti-Seismic Flexible Pipelines ；Bridge Bearings；Bridge Expansion Joints ；Sealants ； Waterstops

2. Can you provide customized products?

Absolutely! We offer tailored solutions based on your project’s specific requirements, covering everything from material selection (such as NBR, EPDM, and more) to structural design. All custom orders come with detailed technical drawings and professional installation guides to ensure seamless implementation.

3. What certifications does your company possess?

We hold ISO certifications for quality, environmental, and occupational health management systems, ensuring strict compliance with GB/T 17955-2019 and other national standards.

4. Do you offer installation support?

Yes, we provide after-sales support, including remote video guidance for installation.