The expansion joint in brickwork is an artificially created crack between monolithic layers. People who do not know anything about building and resistance assume that this should not happen, and that houses without cracks are the most durable. But builders know that artificially created shifts in the seams increase the seismic resistance and strength of structures.
Assignment of expansion joint
Why do I need a expansion joint in brickwork? Logically, it can be assumed that to increase the strength of the building, protection from deformation and destruction.
How does it happen? The structure of the building is divided into compartments, special attention is paid to the corners, the division occurs by gaps, which just represent expansion joints. They are filled with a special hermetic material, which helps to increase strength, eliminating the possibility of cracks in walls and window openings, strong and uneven subsidencenew premises.
How to understand if they are needed? Often needed. This need is primarily determined by external conditions and geometric parameters. In Russia, the climate is conducive to a sharp change in temperature, a large difference in these indicators depending on the time of year. Since the country is large, that is, regions prone to unstable ground, the manifestation of dangerous weather conditions, seismological instability. All this affects the construction, because the building must comply with a number of rules and regulations, so that you do not have to rebuild and equip a new room every time. A properly designed structure will last for many years and save the life and he alth of the owners.
There are two types of seams. Necessarily design documentation for construction must contain information about their location and purpose.
Seam classification
There are two types of seams:
- Temperature horizontal expansion joint in brickwork, which is necessary due to regular changes in ambient temperature and the difference in indicators in the room and on the street, because this causes the expansion or contraction of the layer between the bricks.
- Shrinkage is used to reduce the effects of subsidence of the foundation of a new building, especially needed in places with high soil activity seismically unstable areas.
They have an identical design, but differ in purpose.
Views
Deposit seamsthe most popular, because very often the subsidence of the structure occurs unevenly along the entire length and there is a risk of destruction of the building for this reason. These seams are made from the base of the foundation to the beginning of the roof. When erecting, it must be taken into account that all seams must be dried, and the shear thickness should not exceed 1/4 brick.
The thickness of the expansion joint in brickwork: knot 10-20 millimeters, it replaces part of the vertical.
An urgent need arises when an old wall is adjacent to a new one, when connecting two parts of a building, building on ground with uneven settlement, and erecting structures in dangerous areas, that is, those where earthquakes, hurricanes, etc. regularly occur.
Temperature-shrink seams deserve special attention. Why? Because they protect buildings from the appearance of cracks, destruction associated not only with changes and temperature changes, but also with shrinkage. In summary, they are relatively versatile.
Usually they are used when there is a strong temperature difference between winter and summer, for example, as it happens in Russia. Their thickness depends on the time of year and temperature during the installation process and is specified in the code of building codes and regulations (SNiP).
Requirements of SNiP
This set of rules sets standards for the design of masonry and reinforced masonry structures. But all requirements are subject to change and do not apply in dynamic and seismic areas where the ground is unstable.
Basicthe rules for designing and creating an expansion joint in brickwork (SNiP) are as follows:
- Seams that are in places connecting the masonry with steel or reinforced concrete structures must match exactly. If necessary, make additional expansion joints in the brickwork.
- Shrinkage joints are recommended to be created when there is a risk of uneven subsidence of the structure, that is, when the soil is unreliable. In order to determine this, you need to do calculations using special formulas.
- The rules for expansion and shrinkage joints also indicate that it is necessary to provide a tongue, which is filled with any elastic material. Explanation: a tongue is a protrusion on one side of the seam and a depression on the other, in other words, a shift to create an empty space. This is done so that the wall is not blown through and is resistant to a hurricane.
- The rules for laying such seams are negotiated very sparingly. The location is taken according to SNiP as the maximum length of the intermediate area between them. When creating an expansion joint in brickwork, it is not recommended to take a distance less than that specified in SNiP.
Building Protection Technology
Usually, the protection of structures is organized through several technologies and activities. There is a set of recommended rules on this topic, which was mentioned above.
This article talks about protection technology by creating expansion joints - this is a fairly effective and time-tested method. There are modern implemented technologies,which are at the stage of experimental testing, therefore it is better to use either temperature, or shrinkage, or a combined technique. It is worth choosing depending on the type of building, soil and climate.
Strength, stability and reliability are the three pillars of building protection and proper organization of construction. It all starts with the design stage, where you need to study the area, the climate and weather depending on the time of year, the purpose of the room, the activity of its use and the load. The expansion joint in the masonry ensures that all available and recommended levels of structural safety are met.
All this, one way or another, affects the safety and integrity of the building.
Conclusions
Summing up, it is worth noting that the structures of buildings are exposed to the destructive effects of the external environment, such as temperature changes, desiccation by the sun's rays. Rain, s alt, snow and wind, exposure to moisture coming from inside the building, earthquakes, severe weather events can all cause cracking and failure. It is dangerous financially, socially, and in terms of life - people can suffer. Therefore, at the design stage, pay attention to such an important stage as the creation of an expansion joint in brickwork.
