Insights

When designing and constructing buildings, it is important to take into account and correctly calculate possible loads. In particular, this applies to large private houses, as well as multi- and low-rise buildings, shopping and business centers, warehouses and other commercial buildings. Expansion joints, which divide one structure into separate blocks, are an obligatory element in such cases. Thanks to this approach, it is possible to reduce the risks of damage to the structure from temperature extremes, seismic activity and other factors. In large buildings, their presence is a necessity, since several significant factors affect the integral structure.

Purpose and types

If you look at it, the expansion joint is a void in the wall, floor, foundation. This is the free space between individual blocks, which can increase or decrease depending on the influence of external factors, thereby preventing the appearance of cracks or other defects in the main structure.

Depending on the purpose of the def. seams can be divided into several categories:

• temperature;

• seismic;

• shrinkage;

• sedimentary.

Each option has its own characteristics that must be considered when choosing the appropriate option. Quite often, combined methods are used to maximize protection from external factors and prevent damage to a building or other structure.

Expansion joints

With temperature changes, cracks of various depths and lengths may appear in the structure. The reason is the change in physical parameters with temperature jumps, the phenomenon is especially acute with sharp drops. Expansion joints help prevent the phenomenon. Some people mistakenly believe that it is advisable to use them only in places with sharp temperature fluctuations or a large difference between winter and summer temperatures, but in practice this is not the case. It is necessary to use expansion joints even within the city with a temperate climate. Any temperature fluctuations can contribute to the appearance of a crack and then further destruction of the building. A similar phenomenon is caused by the ability of concrete and other materials to deform when the temperature changes.

Expansion joints are not used for foundations as the temperature in the soil tends to be more stable. Sharp jumps are excluded.

Seismic joints

They are used only in regions with seismic activity. Designed to protect the house from collapse during an earthquake, volcanic eruption, tsunami or other similar earth vibrations. The main feature of anti-seismic joints is that the entire building consists of separate isolated blocks. This approach allows you to prevent the collapse of the building in an earthquake. In other words, individual blocks in the form of large cubes can be displaced without harm to the rest of the modules, thereby preventing a collapse.

Sedimentary joints

Sedimentary expansion joints are most often used in the construction of houses of different storeys. It is best to consider the necessity of their application with a specific example. If on one side the building has 5 floors, and on the other - only 3, then the pressure in different parts will be different. As a result, ground pressure and shrinkage will also be different. Uneven pressure can provoke the appearance of stress inside walls and floors, which will subsequently lead to the destruction of structural elements.

Sedimentary joints are located vertically along the entire height of the building. The presence of an expansion joint makes it possible to strengthen the building. During construction, not only the walls are separated, but also the foundation. Thanks to this approach, the destruction of the building due to the difference in pressure and the influence of other external factors is excluded.

Shrinkage joints

They are used less often than other types. They are used when using a monolithic concrete frame. As the concrete hardens, it can crack. Over time, these cracks under the influence of moisture and other factors can increase in size, which leads to weakening of the structure and even its destruction. Shrinkage joints prevent the appearance of cracks in the monolithic frame, but they are used only until the end of the concrete hardening.

The need for application

Reinforced concrete is considered one of the best modern building materials. It is characterized by high strength and durability, although it can also be destroyed under the influence of various factors. The presence of an expansion joint allows you to prevent destruction during deformation of reinforced concrete caused by temperature fluctuations and other factors.

To eliminate the possibility of damage, expansion joints divide the structure into blocks. When stress or excessive pressure occurs in one part, the factors of influence do not apply to other structural parts, therefore, the likelihood of cracks and other defects is excluded. The width of the seams is calculated individually in each case. The flowability of the soil, the amount of precipitation, the amplitude of temperature fluctuations, etc. are taken into account.

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