Deformation joint expansion joints (temperature joints), settlement joints and seismic joints. Under the action of external factors, buildings often deform, causing cracks or even damage. Deformation joints are structural joints reserved for this situation. Deformation joints can be There are three types of expansion joints, settlement joints and anti-vibration joints.
Deformation joints can be divided into expansion joints, settlement joints, and seismic joints.
Expansion joints: building components will expand and contract due to changes in temperature and humidity. For this reason, vertical gaps are usually set in appropriate parts of the building, and the walls, floor, roof and other components of the house are disconnected from the foundation, and the building is separated into several independent parts. For the seams set to overcome the excessive temperature difference, the foundation can be disconnected from the top surface of the foundation to the roof along the structure.
Seismic joints: the joints set up to make the building more regular in order to facilitate the earthquake resistance of the structure, the foundation may not be disconnected. Its purpose is to divide the large building into smaller parts to form a relatively independent earthquake-proof unit to avoid damage caused by the uncoordinated overall vibration of the building due to earthquake.
In the seismic fortification zone, settlement joints and expansion joints must meet the requirements of seismic joints.
Settlement joint: Refers to the structural joints of the building that are set to avoid cracks in walls or other structural parts when the height of the same building is very different, the upper load is unevenly distributed, or when it is built on different foundation soils. The settlement joint divides the building into several sections, forming a system of its own, with no connection from the foundation, walls, slabs to the roof. The slit width is generally 30~70 mm. Vertical seams that completely separate the building or structure from the foundation to the top. In order to avoid uneven sinking of each section and produce cracks. It is usually set between the parts where the height of the building, the load or the bearing capacity of the foundation is very different, and at the junction of the old and new buildings.
There are many buildings that comprehensively consider these three kinds of joints, the so-called “three stitches and one”.