What types of expansion joints are there?

We often see gaps in our daily life. For example, a building that was originally in good condition may have gaps after a period of time. There are many reasons for the appearance of gaps, such as the influence of temperature. As we all know, objects expand when heated and contract when cooled. When the temperature changes rapidly, gaps will appear in many places. People call them expansion joints. There are mainly the following types of expansion joints.

What types of expansion joints are there?

Deformation joints are a general term for expansion joints, settlement joints and seismic joints. Buildings often deform under the influence of external factors, leading to cracks or even damage. Expansion joints are structural joints reserved for this situation.

Expansion joint: Building components will expand and contract due to changes in factors such as temperature and humidity. To this end, vertical gaps are usually set at appropriate locations of the building to disconnect the walls, floor slabs, roof and other components of the house from the foundation and separate the building into several independent parts. In order to overcome the excessive temperature difference, the foundation can be disconnected without breaking the joint, and the structure can be disconnected from the top surface of the foundation to the roof.

Earthquake-proof joint: A joint set up to make the building more regular and to help the structure resist earthquakes. The foundation does not need to be continuous. Its purpose is to divide large buildings into smaller parts, forming relatively independent earthquake-proof units, to avoid damage caused by the uncoordinated vibration of the entire building due to earthquakes.

In seismic fortification areas, settlement joints and expansion joints must meet the requirements for seismic joints.

Settlement joint: refers to a building structural joint set up to avoid cracking of walls or other structural parts due to uneven settlement when the height of the same building varies greatly, the upper load is unevenly distributed, or it is built on different foundation soils. Settlement joints divide the building into several sections, forming a self-contained system with no connection between the foundation, walls, floor slabs and roof. The seam width is generally 30 to 70 mm. A vertical joint that completely divides a building or structure into sections from the foundation to the top. This is to avoid cracks caused by uneven sinking of each section. It is usually set between parts of a building with very different heights, loads or foundation bearing capacities, as well as at the junctions between new and old buildings.