An Elasomer is a polymeric substance obtained after vulcanization of rubber. Vulcanization is the process
of improving the propoerties of rubber by heating with sulphur. As a result of vulcanization, rubber molecules are
cross-linked with sulphur. This cross-linking makes the rubber stronger.
Greater compressive stiffness is, therefore, obtained by dividing elastomer into many layers by introducing very thin,
usually 1 to 3 mm, steel reinforcement plates between the elastomer layers and bonding the plates firmly with the
elastomer to prevent any relative movement. This has the effect of decreasing the area free to bulge without any
change in the loaded area. Hence, higher the Shape Factor, stiffer is the bearing under compressive load. Since the
elastomer expands laterally, shear stresses are set up in the elastomer by the bond forces. The steel plate, in turn,
is subjected to pure tensile stresses.
1. Requires minimum maintenance compared to all other bearings.
2. Installation is easy.
3. Permits movement of the structure in all directions, depending upon the applied forces.
4. Occupies small space.
5. Serves as a shock absorber due to anti-vibration properties of elastomer.
6. Acts as an aid to better dispersion of longitudinal forces to the approaches.
