Atlas Bearing™ 278
Atlas Bearing™ 278 is a 70 Shore A Neoprene (CR) bearing pad designed to evenly transfer load from beams to supports in bridge bearing and structural applications. It delivers 2250 psi min. tensile strength and 300% min. elongation with a compression set of 35% max. (22 hours @ 212°F). The material meets AASHTO M251-06 and AASHTO LRFD Section 18.2, and is rated to -40°F cold temperature per ASTM D2137.
Key Properties
- Durometer / Hardness (Shore A): 70 — ASTM D2240
- Tensile Strength: 2250 min. psi — ASTM D412
- Compression Set, 22 Hours @ 212°F: 35% max. — ASTM D395B
- Elongation: 300% min. — ASTM D412
- Cold Temperature: -40°F — ASTM D2137
- Ozone, 100 PPHM, 20% Strain, 100 Hours @ 104°F: No cracks — ASTM D1149
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Material / Substrate | Neoprene (CR) | — |
| Color | Black | — |
| Thickness | 1/8″, 1/4″, 1/2″ | — |
Mechanical Properties
| Property | Value | Test Method |
| Durometer / Hardness (Shore A) | 70 | ASTM D2240 |
| Tensile Strength | 2250 min. psi | ASTM D412 |
| Elongation | 300% min. | ASTM D412 |
| Compression Set, 22 Hours @ 212°F | 35% max. | ASTM D395B |
Thermal Properties
| Property | Value | Test Method |
| Cold Temperature | -40°F | ASTM D2137 |
Aging Performance — Heat Aging (70 Hours @ 212°F)
| Property | Value | Test Method |
| Durometer / Hardness Change | +15 | ASTM 573 |
| Tensile Change | -15% max | ASTM 573 |
| Elongation Change | -40% max | ASTM 573 |
Environmental Performance
| Property | Value | Test Method |
| Ozone, 100 PPHM, 20% Strain, 100 Hours @ 104°F | No cracks | ASTM D1149 |
Regulatory / Compliance Data
| Property | Value | Test Method |
| AASHTO M251-06, Polyisoprene, Grade 2 | Meets | — |
| AASHTO LRFD Bridge Construction Specification, Section 18.2 | Meets | — |
Compliance
- AASHTO M251-06 (Plain and Laminated Elastomeric Bridge Bearing Pads, Polyisoprene, Grade 2) — Compliant
- AASHTO LRFD Bridge Construction Specification, Section 18.2 — Compliant
- Bridge bearing pads for pre-cast and pre-stressed concrete structural applications requiring maximum firmness and AASHTO compliance
- Bearing pads for buildings with structural steel beams or steel-reinforced concrete under high compressive load
- Isolation and load distribution pads for industrial machinery and heavy equipment foundations where minimal pad deflection is required
- Railway tie pads demanding maximum resistance to permanent deformation
- Bearing and isolation elements in buildings, arenas, tunnels, and civil infrastructure requiring firm, stable load transfer
Common industries: Bridge and infrastructure construction, structural engineering, civil construction, railway, industrial equipment.
Atlas Bearing™ 278 is the firmest grade in the Atlas Bearing™ series at 70 Shore A, engineered for bridge bearing and structural applications requiring maximum resistance to deformation under compressive load.
It is suited for pre-cast and pre-stressed concrete structures, steel-framed buildings, industrial machinery and heavy equipment foundations, railway tie pads, and civil infrastructure where the bearing pad must maintain geometry and load distribution performance under sustained high structural loads. Its 70 Shore A durometer provides the greatest dimensional stability in the Atlas Bearing™ series.
The material meets AASHTO M251-06 for plain and laminated elastomeric bridge bearing pads (polyisoprene, grade 2) and AASHTO LRFD bridge construction specification Section 18.2. Ozone resistance is confirmed at 100 PPHM, 20% strain, 100 hours at 104°F with no cracks per ASTM D1149. Heat aging at 212°F for 70 hours yields hardness change of +15, tensile change of -15% max., and elongation change of -40% max.
Compliant with AASHTO M251-06 and AASHTO LRFD Section 18.2.
What differentiates Atlas Bearing™ 278 from softer grades in this series?
Atlas Bearing™ 278 is the firmest grade in the Atlas Bearing™ series at 70 Shore A, providing the greatest resistance to deformation under sustained structural compressive load. It is the appropriate selection for bridge bearing and structural applications where high load magnitudes require a stiffer pad that maintains geometry and load distribution performance over the service life of the structure.
Why is compression set an important consideration for elastomeric bearing pads?
Compression set measures how well an elastomer recovers its original thickness after sustained compression. In a bridge bearing or structural pad, high compression set means the pad permanently flattens under long-term structural load, reducing its ability to accommodate movement and distribute load evenly — potentially compromising structural integrity. Atlas Bearing™ 278 is rated at 35% max. compression set (22 hours @ 212°F per ASTM D395B), consistent with AASHTO requirements for elastomeric bearing pads.
What is the cold temperature rating for Atlas Bearing™ 278?
Atlas Bearing™ 278 is rated to -40°F cold temperature per ASTM D2137, as listed on the TDS.
Is Atlas Bearing™ 278 suitable for bridge and structural infrastructure applications?
Yes. Atlas Bearing™ 278 meets AASHTO standard specification M251-06 for plain and laminated elastomeric bridge bearing pads (polyisoprene, grade 2) and AASHTO LRFD bridge construction specification Section 18.2, as stated on the TDS.
How should Atlas Bearing™ 278 be specified?
Specify grade (Atlas Bearing™ 278), thickness, compliance requirements (AASHTO M251-06 / AASHTO LRFD Section 18.2), dimensional tolerances, and finished format.
