Elastomeric supports:
How they operate
Support and movement capacity
The elastomeric supports for bridges are construction elements comprised by elastomer layers internally reinforced with steel sheets, to create a single compact block.
They accommodate large structures, supporting different loads and permit the movements and rotations that converge in the structures so that they will not be damaged.
They have excellent mechanical features, since they take advantage of the low deformation modulus of this material (both for compression and for tangential stress effects). These features, combined with its durability and resistance, make them essential for large-scale civil works structures such as bridges, viaducts, buildings, industrial warehouses and other structures.
In order to understand its behaviour, it must be considered that rubber does not have mechanisms; in itself, it constitutes a complex mechanism, which permits the superstructure to move in all directions.
Main functions
The elastomeric supports have a multiple function, since they permit the following actions in a combined way:
1 Horizontal movements in two directions.
2 Rotations in three axes of space.
3 Absorption of vertical loads.
4 Absorption of short-term horizontal loads.
Our supports
Top quality supports
custom-made for each project
We design each module to withstand extreme conditions and we subject them to demanding quality tests.
Our elastomeric supports have been installed in infrastructures in more than 30 countries.
The quality of the materials, the meticulous design and manufacturing control, combined with a process under continual supervision and optimization have earned our prestige which has allowed us to achieve this major international presence.
We have been certified with the EC marking based on the standard EN 1337-3:2005. Likewise, we work based on other standards which include the standards: AASHTO, BS-5400, MCV-5, etc.
WHAT THEY ARE LIKE
- Inexpensive. Due to the simplicity of their design, the manufacturing versatility and the relatively low cost of the raw materials: rubber and steel.
- Effective. Because they transfer the loads in an excellent way and absorb the irregularities of the surfaces among which they are located, they absorb slopes up to 2%.
- Resistant. Because the properly designed elastomeric supports can support compression loads just as high as those required for concrete. Likewise, they withstand the deformation due to the structure stresses, which take place in the former.
- Durability. In indoor settings, natural rubber (NR) has excellent mechanical features and in the outdoors, which may also be polychloroprene rubber (CR), combined with the NR properties with major resistance against weathering and ozone; it is self-extinguishing and withstands high temperatures. Both rubbers also have the advantage of being highly compatible, which behave as one, before, during and after the vulcanization process. They also withstand extremely low temperatures up to -40 ℃.
- They hardly require maintenance. Our elastomeric supports for bridges do not corrode and only periodical monitoring is required. The supports are replaceable and they can be changed very easily.
Support types
A solution designed
for each structure
We manufacture several types of elastomeric supports based on the structure’s requirements:
Super-tilting supports (types A, B and C)
- Supports that, due to their special layout, permit rotation angles of approximately double that of the reinforced supports, type B, with the same thickness. Anchor-brace types C2, C3 and C5 can also be manufactured. Due to their major deformation, they have a lower admissible load than their officially approved counterparts.
- They are used when the rotations are very high, when it is necessary to absorb vibrations or when the differences in parallelism between the surfaces with which the support is in contact are high.
Assembly supports for lightweight loads (type A)
- They are elastomeric supports reinforced with only one plate. They have two elastomer layers between which a highly resistant steel plate is embedded. They have a fixed thickness of 10 mm.
- They are used to centre the loads of precast parts and to compensate their lack of parallelism.
- The admissible workload is 15 N/mm2 and the maximum movement is 5.6 mm.
- Above all, they are used for centering loads and the absorption of surface defects of the precast concrete parts.
Reinforced supports (type B)
- The reinforced supports are laminated supports manufactured with elastomer layers, which are embedded with high-strength steel plates, joined by a meticulous vulcanization process. They support vertical loads up to 20,000 kN, as well as movements and rotations in all directions. They are used for all types of concrete and metal bridges, buildings and industrial warehouses, as well as tanks and silos.
- The maximum workload ranges from de 10 to 15 MPa based on their size.
- The admissible movement varies from 50% to 70% of its net rubber thickness.
- They are used in metal bridges, concrete bridges, industrial warehouses, houses, tanks, silos, locks, etc.
Anchor-brace supports (types C)
- Anchor-brace supports type C2. They are reinforced supports with external faces anchor-braced to the structure to hinder movements between the support and the structure. They are designed for concrete pouring on site, welded or screwed joints between the anchor-brace plates of the supports and the structure.
- Supports with a cotter pin type C4. Similar to the ones above, but with embedded cutting disks. It prevents slippage due to the horizontal stresses.
- Embossed supports type C5. They are similar in the supports C2, but with exterior plates with a drawing. They are indicated when they will be glued with resins or mortar cement to the structure. They are mainly used in precast parts, although they can also be used for concrete pouring in situ. They should only be used for structures with not very high horizontal loads.
- They support vertical loads up to 20,000 kN, as well as movements and rotations in all directions.
- All of them except the type C5 admit guides, blocks, etc.
- They are used when the minimum vertical load does not guarantee that slippage will not occur due to lack of friction. They are also used when tensile stresses occur.
Sliding reinforced supports (teflon-coated) (type D)
- This involves a reinforced support with a vulcanized teflon surface. Their dimensions are determined based on the existing movements and stresses. They will always be associated to an upper slippage surface, which consists in a thin sheet of polished stainless steel, which will be welded to a steel plate with a significantly higher thickness, which permits them to work.
- They support vertical loads up to 20,000 kN, as well as movements and rotations in all directions.
Sliding anchor-braced supports (teflon-coated) (type E)
- It is a support anchored with a hollow-core teflon sheet embedded in a vulcanized plate to the support. Their dimensions are determined based on the existing movements and stresses. They can bear guides, blocks and all types of accessories that admit non-sliding anchor-brace supports.
- They will always be associated to an upper slippage surface, which consists in a thin sheet of polished stainless steel, which will be welded to a steel plate with a significantly higher thickness, which permits them to work.
- They support vertical loads up to 20,000 kN, as well as movements and rotations in all directions.
Non-reinforced elastomeric supports for very light loads (rubber only) (type F)
- They are only manufactured with elastomers and their admissible workload ranges from 1.5 to 5 N/mm2. They are commonly used in buildings, stairways and the roofs of industrial warehouses to support precast concrete parts, which are not too heavy. Like the elastomeric supports of type A, it is recommended that they are approx. 20 mm smaller than the work surfaces in contact with them. They are very suitable for occasional loads up to 150 kN.