What is expansion joint

Expansion joints are devices that are used to allow for the heat-induced expansion and reduction that takes place in various states of weather. The expansion joint is often used in the construction of bridges and sidewalks. The joints proper may be something as simple as a caulk filled area that will give without coming open during climate changes, or some type of interlocking metal device that allows the teeth in the joint to move in response to changes in temperature and humidity levels. Expansion joints are usually placed at strategic points in the construction, making it possible for the sections to expand and contract slightly without weakening the overall structure.

Expansion joints includes:
PTFE expansion joints
Rubber expansion joints
Metallic expansion joints
Fabric expansion joints

Along with use in sections of sidewalks and bridges, expansion joints also are used with railway tracks. As with bridges, the joints are placed at key locations along the tracks and allow the metal tracks to undergo contraction and expansion as the weather changes. The end result is that the tracks remain intact and aligned properly. Using expansion joints for railway tracks helps to minimize the expense of maintenance of railways, allowing railroads to focus on other areas of operation.