In most concrete and steel structures accomodation must be made for relative movement between structural members in order to avoid the build-up of dangerous stresses. The source of this movement may be:
- Thermal expansion and contraction
- Permanent creep and shrinkage
- Post tensioning strain
- Live load deflections
- Earth movement
It is usually desirable to minimise the resistance forces and moments resulting from these movements and this is the primary function of Structural Bearings.
Bearing Technologies range of Structural Bearings provide this function by the most efficient methods using well proven concepts combined with modern manufacturing technology and advanced materials.
This is achieved by exploiting the unique low-friction properties of PTFE (polytetrafluoroethylene) and the flexibility, durability and versatility of natural rubber.
This brochure describes 3 of the simpler types of Structural Bearings which are suitable for relatively small movements and rotations.
This range provides low friction sliding movement in one or two directions by means of PTFE* sliding on mirror polished Stainless Steel. For high temperature applications CSB10** metal backed PTFE is used. These bearings do not provide for any significant rotation movement. The standard load range is 100kN-2500 kN. Temperatures above 250 deg C can also be accomodated by the use of special materials.
The BAR type is offered in a load range of 30kN-250kN to provide a useful though a limited amount of rotation in addition to unlimited sliding movement. These bearings are intended for ambient temperature operation only.
This is a range of Laminated Rubber Bearings catering for short to medium span structures in the nominal load range 200kN-3000kN. The movement and rotation limits depend on the number of laminations which are normally limited to 6. They are suitable for ambient temperatures only.