Aohong, a professional manufacturer of Rubber Bearings, provides high-performance High Damping Rubber Bearings (HDRBs) designed for superior seismic isolation in bridges and buildings. These bearings combine natural or neoprene high damping rubber with reinforced steel plates to effectively absorb and dissipate seismic energy, ensuring structural safety during earthquakes. The unique rubber layers offer excellent horizontal flexibility, while the steel plates provide strong vertical load capacity, making HDRBs an ideal choice for highway bridges, railway structures, and high-rise buildings.
Structure and Composition
High Damping Rubber Bearings consist of:
- Top and Bottom Connecting Steel Plates – transfer loads securely to the structure.
- Internal High Damping Rubber Layers – provide horizontal flexibility and high energy dissipation.
- Reinforced Steel Plates – enhance vertical stiffness to support heavy loads.
- Protective Rubber Cover – improves aging resistance, protecting against UV and ozone damage.
Features of High Damping Rubber Bearings
- High Damping Capacity: Damping ratio reaches 10%–25%, eliminating the need for additional dampers.
- Superior Seismic Isolation: Reduces structural response and vibration by extending the natural vibration period.
- Excellent Durability: Service life up to 60 years, with minimal residual deformation after earthquakes.
- Stable Vertical Load Support: Supports 5 to 2000 tons, suitable for large-scale infrastructures.
- Easy Installation and Low Maintenance: Ideal for cost-effective and long-term applications.
Working Principle
By creating a flexible isolation layer, High Damping Rubber Bearings separate the superstructure from the foundation, lowering the building’s natural frequency and reducing seismic energy transfer. During an earthquake, the rubber layer undergoes shear deformation, absorbing vibration energy and converting it into heat, thereby protecting the superstructure and maintaining the safety of people and equipment. After seismic events, the bearings automatically return to their original position due to the rubber’s high elasticity.
Applications
- Bridges: Highway bridges, railway bridges, and continuous beam structures.
- Buildings: High-rise structures, industrial facilities, and precision equipment foundations.
- Infrastructure: Nuclear plants and critical engineering projects requiring advanced seismic isolation.
Specifications
Standard Sizes (Rectangular and Round)
- 200 × 300 mm to 550 × 550 mm
- Thickness: 22 mm to 150 mm
- Custom dimensions available upon request
Performance Parameters
- Shear Modulus: 0.8 MPa, 1.0 MPa, 1.2 MPa
- Temperature Range: -40 °C to +60 °C
- Damping Ratio: 10%–25%
Physical and mechanical properties of elastomer
| Characteristics | Requirements | |||
|---|---|---|---|---|
| G Modulus (MPa) | 0.7 | 0.9a | 1.15 | |
| Tensile strength (MPa) | Moulded Test Piece | ≥16 | ≥16 | ≥16 |
| Test Piece From Bearing | ≥14 | ≥14 | ≥14 | |
| Minimum Elongation at Break (%) | Moulded Test Piece | 450 | 425 | 300 |
| Test Piece from Bearing | 400 | 375 | 250 | |
| Minimum Tear Resistance (kN/m) | CR | ≥7 | ≥10 | ≥12 |
| NR | ≥5 | ≥8 | ≥10 | |
| Compression Set (%) | CR 24 h, 70 °C | ≤15 | ||
| NR 24 h, 70 °C | ≤30 | |||
| Accelerated Ageing (Maximum change from unaged value) | ||||
| Hardness (IRHD) | NR 7d, 70 °C | -5+10 | ||
| CR 3d, 100 °C | ±5 | |||
| Tensile strength (%) | NR 7d, 70 °C | ±15 | ||
| CR 3d, 100 °C | ±15 | |||
| Elongation at break (%) | NR 7d, 70 °C | ±25 | ||
| CR 3d, 100 °C | ±25 | |||
| Ozone Resistance | Elongation: 30%, 96 h | No cracks | ||
| 40±2 °C | ||||
| NR 25 pphm | ||||
| CR 100 pphm | ||||