The foundation of any structure during operation is subjected to significant loads. Therefore, its strength and stability are extremely important.
With the help of reinforcement, these characteristics are significantly improved, with less weight, the structure acquires greater stability. Any type of foundation must be designed in such a way that it meets all the necessary requirements. This applies to its reliability and durability, resistance to mechanical stress and climatic influences.
The main load-bearing building materials for the construction of a structure are concrete and steel.
The properties of materials are fundamentally different: steel is much harder and stronger than concrete, but the latter is almost a hundred times cheaper.
Their combination makes it possible to obtain lightweight building material with increased strength. This composite material is reinforced concrete .
The characteristics of concrete determine the location of the steel components in it.
These are usually the locations that are most susceptible to bending and stretching .
Some believe that the foundation of a building works exclusively in compression, and the reinforcement of the foundation of the tape type is not so necessary. You can agree with this if rocky soils serve as the foundation of the foundation.
However, much more often the soil is not a solid monolith, and there are many factors that force it to work in bending.
Different density of its surface layers can cause shrinkage;
Concrete structures under the action of the resulting stress begin to collapse - cracks form, the foundation shrinks. These processes not only worsen the appearance of the structure, but can cause its destruction.
In other words, it is better not to save on the reinforcement of the foundation, since the subsequent repair of the home and its restoration will cost many times more.
What is the essence of the reinforcement process? This is the creation of a reliable spatial framework, consisting of transverse and longitudinal reinforcement, special knitting wire and reinforcing clamps.
Along the entire length of the foundation metal rods from 6 to 12 meters long ...
It is precisely such a longitudinal reinforcement that resists tension.
Such reinforcement is usually carried out along the lower and upper edge of the structure from concrete. The laying scheme is carried out according to the calculation made in advance. It is made taking into account all potential loads, including its own weight, the impact of climatic factors - wind and snow.
Indicators of the bearing capacity of the soil are taken from geological surveys, along the geological section.
When dealing with reinforcement, it is important to remember the need for a concrete protective layer. This is the distance between the reinforcement bar itself and the side surface of the foundation itself.
This layer is very important. It protects the metal from the aggressive action of groundwater and air. In order for reinforced concrete to cope well with the task assigned to it, metal reinforcement must be located inside the cement mass.
The use of transverse structural reinforcement involves use of vertical and horizontal metal rods .
Their function is as follows:
For this, iron reinforcement with a cross section of at least 6 millimeters is used.
Often corners are reinforced from scraps and the remnants of reinforcement, because of which it is necessary to overlap the rods. They are connected by welding or special butt joints.
In this case, the ends of the smooth-profile reinforcement are bent in the form of loops, legs and hooks. The ends of rods with a periodic profile do not need this.
In welded joints of joints use special overlays-staples, in mechanical connections crimp and threaded couplings are used.
It is important to pay attention to the fact that it is strictly forbidden to reinforce corners with a simple overlap.
Otherwise, the immobility and integrity of the resulting corner is not guaranteed.
T-shaped and angular joining of frames is carried out by three different methods: curved clamps of the form P and G or special legs.
There are detailed instructions that can be followed when strengthening the foundation. The procedure is as follows.
Install formwork , then from the inside it is covered with parchment. Before laying the frame, it is necessary to make a special sand and gravel cushion, or foundation .
You can do without it, but then you will have to use special supports, which should be placed under the bottom row of rods. The distance from the sand cushion to the iron rods should be at least seven centimeters.Building bricks placed on the edge do an excellent job with the functions of such supports.
Reinforcing rods are driven into the trench: their length must be equal to the height of the intended base, and not less than five millimeters separate them from the formwork itself.
The initial, bottom row of reinforcement is laid, consisting of approximately 2-4 metal rods.
They are overlapped, the distance between them should be about 30 cm. The size of the overlap itself is at least 50 sections of reinforcing rods.
When mounting the top layer , the indent is five to six centimeters. The rods are distributed strictly evenly over the entire width of the foundation being erected. The rods forming the upper row should not be located above the gaps between the lower rods.
If reinforcement with different sections is available, then thicker rods should be used at the corners and at the bottom. The transverse auxiliary rods are bent into a frame. They must be located at a distance of up to 80 centimeters.
The lower and upper row, together with the jumpers, are attached to the pins driven into the ground at right angles. To increase the strength and reliability of the structure, the individual rods are connected at right angles (cage).
For this, a special hook is created, which is connected with a special soft wire. Electric welding is not used for this. This is because this process changes the performance characteristics of the steel alloy. The resulting seams will be too thin, and the connection of the rods will not be reliable enough.
An exception is only fittings specially designed for welding, which have a special marking C.
At the end of the process it is necessary to make special holes for ventilation . They serve not only to prevent the development of decay processes, but also to increase the shock-absorbing working qualities of the structure.
Next, the process of pouring concrete begins, after which the obligatory waterproofing of the foundation is carried out.
If all the above conditions and requirements are met, the structure will be stable and strong.
Quality of metal reinforcement in in many ways determines the strength and stability of the building.
Therefore, the choice of fittings should be taken seriously.
First of all, pay attention to the marked product marking . The "C" index indicates that this material is to be welded. Marking with the letter "K" explains that this rolled product is quite immune to corrosion caused by high stress.
If at least one of these symbols is missing on the reinforcing bars, they are categorically unsuitable for arranging the foundation.
For strengthening the strip foundation, it is better to use rods, having transverse protrusions and stiffeners. Their presence provides them with much more reliable contact with the concrete mixture. Smooth rods cannot carry loads in the same way, so they are usually used when constructing a frame. rods with a cross section of 12 mm are preferred for reinforcement.
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