Good afternoon, dear guests and subscribers of the "Build for myself" channel!
I witnessed a verbal skirmish, when a team of shabashniks made a house according to the project, but it seems that they didn't :-))) All the people involved in the construction gathered at the unfinished building.
When designing the house, experts tore apart the monolithic belt in the staircase window, and the masons, thinking that this should not be done - they broke a large window into two small ones, making a belt in the middle inseparable.
An engineer standing nearby laughed at the builders and said: "The task for this belt is completely different."
Naturally, the owner did not like the windows, the builders had to disassemble everything and cut off part of the armopoyas.
In general, this topic is much broader than it might seem at first glance. In this article, I will reveal a little more about the use of monolithic belts than the title of this article says, and I think that this information will not be superfluous at all.
The fact is that a monolithic belt is a generalized name for reinforced belts of various purposes. One and the same structural element, depending on the purpose and place of application, has a completely different purpose.
A reinforced monolithic belt, in fact, is the same beam as a monolithic strip foundation, and if we consider the structure of the house as a whole, then both of these elements: the foundation, like the belt of the lower part of the building and the monolithic belt from the top - give the structure spatial rigidity and prevent the building from losing geometry in case of any movement soil.
But, there is one key BUT!
To make the belt work for its intended purpose - to ensure the necessary rigidity, the reinforced monolithic belt must be loaded, i.e. carry the load from the upper structures. That is why, designers never make seismic belts under the mauerlat of the rafter system, but they must lay floor slabs on them. The mass of the roof is not enough for the belt to start working on a tensile force, so the structure can be deformed during foundation settlement and when the belt is inoperative as follows:
The belt remains in place with the entire roof, and the crack from the sagging foundation opens to a monolithic belt, leaving it intact.
Thus, in the case of the construction of a monolithic belt in order to resist seismicity and increase the rigidity of the entire structures for work in extreme situations - from above it is imperative to press it with plates, walls, mansard floor, etc.
In addition, such a reinforced belt should be continuous (it should not be interrupted by arched openings, or attic, or staircase or under-roof windows !!!)
This was considered the first type of belts, solving a huge problem - rigidity of the structure.
Now, we are gradually moving on to a completely different purpose of monolithic belts - belts for load distribution. Here, the armopoyas has a completely different task - to evenly distribute the load from the overlying structures.
For example, a house is built of aerated / foam concrete. These are materials that cannot accept concentrated loads without deformation and are weak enough for crushing. Therefore, without fail, a load distribution - a monolithic belt - is constructed under the floor slabs.
It is this type of belts that has nothing to do with stiffening belts and can be performed locally, where both the Mauerlat and the floor slabs are supported.
The distribution belt can be torn in any places where there is no concentrated load, for example:
- staircase window, where there are no floor slabs;
- side walls (under the pediment), which do not carry the roof truss system.
The second important point when it is not recommended to break a monolithic belt is the use spacer rafter system. These are the types of roofs that rely on walls with a horizontal thrust force action vector:
Here, just a part of the closed monolithic belt parallel to the plane of the rafters will take on the load of the residual thrust, working in tension:
Conclusion
When arranging a monolithic belt, it is important to understand the purpose. A belt designed for rigidity is more expensive due to the larger diameter of the working reinforcement and it cannot be torn under any circumstances. A monolithic belt for load distribution is cheaper, but the stiffness of the building will be low, especially if a shallow foundation was used, whose cross-section is much smaller than the recessed one.
Most designers kill two birds with one stone, placing all tasks on one belt - so also possible, but this is not an axiom, sometimes they have to be done separately and it all depends on what he wants customer!
That's all, I will be grateful if the article became useful to you!
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