Elastomer Expansion Joint

Elastomeric expansion devices are classified into zinc sheet expansion joints, TST gravel elastic expansion joints, and others. TST gravel elastic expansion joints are formed by heating and melting the specially made elastoplastic material TST, then pouring it into cleaned and heated gravel. The gravel is used to bear vehicle loads, while the TST elastomer meets the requirements for expansion and contraction capacity.
In addition, there are ultra-tough elastomeric seamless expansion joints, whose materials mainly include ultra-tough elastomeric seamless expansion joint mixtures, expansion strips, and galvanized steel. The mixture consists of flexible resin binders and rubber particles.
The elastomeric expansion joint can also be referred to as an elastic expansion joint, a rubber expansion joint, a TST elastic expansion joint, and so on.

◆◆ Characteristics of Elastomeric Expansion Joints

The main characteristics of elastomeric expansion joints include the following:

1.Simple Structure: The structure of elastomeric expansion joints is relatively simple. TST (Asphalt-Rubber) macadam can be directly paved at the bridge joint, forming a continuous structure with the adjacent bridge deck pavement, resulting in a smooth and seamless bridge deck surface.

2.Convenient and Efficient Construction: During construction, the installation of elastomeric expansion joints is relatively convenient. Traffic can be opened once the pavement has cooled down. Additionally, in cases where expansion joints need to be replaced, construction can be carried out on one side of the bridge, without affecting the normal traffic flow on busy road sections.

3.Strong Elastic Rebound Force: This type of expansion joint can adapt to repeated displacements caused by temperature changes and loads, and exhibits excellent low-temperature flexibility and high-temperature stability. It does not become brittle at -40℃ nor flow or deform at 80℃, making it suitable for use in all climatic zones.

4.Excellent Sealing and Waterproof Performance: Since the joint and the bridge deck pavement are integrated into a single unit, elastomeric expansion joints possess superior sealing and waterproof properties. Meanwhile, they also feature resistance to acid and alkali corrosion.

5.Deformation and Vibration Absorption: Elastomeric expansion joints can absorb deformations and vibrations from various directions, providing a smooth and comfortable driving experience while reducing noise and vibration.

6.Low Cost and Durability: Compared with traditional expansion joints, elastomeric expansion joints have lower costs. They are also durable and require minimal maintenance, delivering significant economic and social benefits.

In summary, elastomeric expansion joints, with their unique advantages, have been widely applied in bridge engineering.

◆◆ Application Scope of Elastomeric Expansion Joints

The application scope of elastomeric expansion joints is relatively wide, specifically as follows:

1.In Terms of Bridge Span: Applicable to small and medium-span bridges, i.e., reconstruction or new construction projects of expansion joints for bridges with a span of ≤ 30 meters; it is not very suitable for long-span bridges.

2.In Terms of Road Type: Applicable to road sections with high requirements for driving comfort, such as urban arterial roads, expressways, and viaducts. It can also be used in concrete structures that require expansion joints, including highways, municipal roads, and parking lots.

3.In Terms of Bridge Shape: Capable of meeting the expansion and deformation requirements in the horizontal, vertical, and longitudinal directions of curved bridges, sloped bridges, skewed bridges, and wide bridges, and has strong adaptability to bridges of various shapes.

4.In Terms of Temperature Zones: Different types of elastomeric expansion joints are suitable for different temperature zones. For example, elastomeric expansion joints made of neoprene are suitable for areas with temperatures ranging from -25℃ to +60℃, while those made of natural rubber are suitable for areas with temperatures ranging from -40℃ to +60℃. Due to their excellent performance, some elastomeric expansion joint materials can be applied in areas with large temperature differences and all climate zones in China.

5.In Terms of Special Projects: Applicable to expansion joints of ballasted and ballastless track bridges in high-speed railways, which can meet the expansion and contraction needs of bridge girders and slabs caused by temperature changes, load effects, and other factors.

◆◆ Installation Method of Elastomeric Expansion Joints

1.Construction Preparation: Confirm that the position and dimensions of the expansion joint meet the design requirements; the base layer shall be flat, clean and free of oil stains. Prepare elastomeric materials, auxiliary materials, and tools such as cutting tools, joint-cleaning tools, and compaction tools.

2.Base Layer Treatment: Rinse off laitance and oil stains in the expansion joint area with a high-pressure water gun. Ensure the concrete strength of the base layer is ≥ C30 and the flatness error is ≤ 5mm/2m.

3.Joint Groove Treatment: Clean up debris in the joint and ensure it is dry. Cut or fill to adjust if the joint width is uneven. Lay foam boards or waterstops at the bottom of the joint and fix them; apply primer on both sides of the joint groove to enhance adhesion.

4.Material Injection: Mix elastomeric components in proportion and stir evenly. Inject slowly in layers from one end; after each injection, perform initial compaction to expel air and ensure dense filling.

5.Compaction and Shaping: Use a scraper to level and initially compact along the joint opening. Conduct secondary compaction with a vibrator or roller before initial setting (approximately 10-20 minutes) to eliminate voids.

6.Cover Layer Installation: Install stainless steel plates or concrete cover layers, adjust them to be flush with the road surface, and fix them with anchor nails or adhesives. Fill the joints with sealant for waterproofing.

7.Curing: Close traffic as required by the material to avoid heavy pressure. Cure at room temperature for 24-48 hours; appropriately extend the curing time in low-temperature and humid environments.

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.