Bridge bearings

Bearing the Weather

If you have any knowledge in the civil engineering department, you probably know how to build bridges to get over obstacles in the way of moving forward in life. Discarding the philosophical aspect of that sentence and focussing on the literal meaning, one has to consider every aspect and angle when it comes to bridges. This includes bridge bearings.

What is a Bridge Bearing?

In most cases, with concrete and steel bridges, an engineer must accommodate for movement, as the bridge will move slightly due to several aspects, including thermal expansion and contraction, earth movement, post-tensioning strain, load deflections and, in some cases, shrinkage. This is where bridge bearings come in to play, as they minimise the resistance of the forces resulting from these structural movements, reducing structural damage caused by these moments.

Polytetrafluoroethylene, or PTFE for short, features unique low-friction properties that, together with the durability and flexibility of natural rubber, make up the compounds of a bridge bearing. This allows for an ideal structural bearing that has many applications.

BA Type

The BA Type bearing provides a low-friction sliding movement, allowing the bearing to move in up to two directions. The PTFE compound slides on a mirror-polished stainless steel surface for minimum friction between the moving parts. Metal-backed PTFE can be used in this bearing for high-temperature applications, making this model accommodate temperatures up to 250 °C. This model has very limited rotational movement, but can withstand a load of up to 2500 kN.

BR Type

This type of bearing is made from laminated rubber and can withstand up to 3000 kN of load, making this a very strong bearing for short- and medium-span bridges. The movement and rotation limitations of this type depends on how many laminations the bearing consists of, usually limited to a total of six layers. This also limits their temperature suitability, as they are only recommended for ambient temperatures and nothing too extreme.

BAR Type

This model type offers unlimited sliding movement and a very useful, but limited, amount of rotation, being able to withstand a load of up to 250 kN. These bearings are intended for low loads and ambient temperature use only.

Now that you know of the different types of bridge bearings and their applications, you can make an informed decision for the next time you need to build a bridge. Contact Technoslide for all your bearing needs and we will provide you with the best quality for your next building project!