Monolithic ceiling in the house made of aerated concrete. Calculation and device monolithic overlap

When building walls from aerated concrete there comes a time when it is necessary to take care of the erection of interfloor ceilings, they can be made of wooden beams or concrete slabs. If you compare with buildings erected from bricks, then when installing interfloor ceilings on walls of foam and gas units, you should place a reinforcing belt that will distribute loads.

The device of overlappings from a monolithic plate

A monolithic ceiling in a house made of aerated concrete can be made using a reinforced concrete slab. This technology is used today in the field of construction by private masters and professional brigades. The bases are durable and reliable, but they have an impressive weight, which should be taken into account when building walls from building blocks. In order to ensure that the plates can evenly distribute their weight and do not violate the integrity of the system, for the installation of slabs , an additional structure should be made that looks like a concrete or brick belt. In the first case, the plate is supported by a 150x250 mm tape of concrete. It is located along the perimeter of the wall. The tape is reinforced with a reinforcement, the diameter of which is 10 mm. The next stage is the pouring of concrete grade M-200.

When monolithic ceilings in the house are made of aerated concrete, a 2-cm temperature gap should be left, which should be located between the end of the reinforced concrete slab and the wall. To eliminate the cold bridges, the reinforcing belt and the plate are additionally insulated, and extruded polystyrene boards can be used. It is best to choose those that have a thickness of 50 mm. The second option, which provides for the use of a brick belt, involves holding a masonry of red baked brick. He is laid in three rows. This option is the most common when you use the distribution belt.

Brick Belt

In this case, there is no need to equip the formwork, it is sufficient to form a reinforcement frame from rods. However, before laying bricks, you should strengthen the wall blocks with reinforcement. For this, it is necessary to make grooves, laying reinforcing bars in them and filling with cement mortar. The masonry is strengthened by a masonry net, which is located between the rows. The reinforced concrete monolithic slab must go deeper into the wall by 14 cm. This will be sufficient to ensure rigidity and stability of the structure.

Features of the monolithic belt device

A monolithic ceiling in a house made of aerated concrete can provide for a monolithic reinforcing belt. For a building made of aerated concrete this part of the work is mandatory. Among other things, it performs the role of load distribution from floors, upper-floor walls and payloads from interior items, people and equipment. The reinforcement belt will compensate for the lack of aerated concrete, which is expressed in the ability to work on bending.

Despite the fact that aerated concrete is able to undergo compression, the absence of a reinforcing belt will cause an uneven load on the bearing walls. As a result, they may appear cracks, as a result of which some blocks may even burst. To install the strapping or reinforcing contour, heavy types of concrete and reinforcement should be used, the latter of which corresponds to class A III.

A monolithic ceiling in a house made of aerated concrete can have a reinforcement belt, which is equipped with one of the existing methods. It can be as follows: on the outer edge you need to mount blocks of concrete, as an alternative solution, sometimes used silicate brick. Between the edge of the floor and these products fit the reinforcement, it must be tied up. It is necessary to choose a material with square cells, the side of which corresponds to 10 cm. The outer and inner corners should be fixed with steel staples, after that reinforcing belt should be poured with concrete.

The choice of overlap for a house from a gas block

Intermediate floors in a house made of aerated concrete can be prefabricated or monolithic. They can be arranged on metal or wooden beams, using hollow plates from cellular, heavy concrete or prefabricated-monolithic structures. As a basis of overlapping, a monolithic slab can be made, which is manufactured in the construction site. Wooden and concrete floors have their advantages and disadvantages, however, taking into account the popularity of aerated concrete, which is increasingly used today in house building, the following criteria come to the fore:

• Speed of construction;
• Cost of installation;
• The cost of the material;
• Need for the use of special equipment.

The construction of aerated concrete, whose projects can be found in the article, provides for the construction of an overlap, the choice of which for maximum loads and strength characteristics, as a rule, is not relevant, because listed species provide these qualities on a level sufficient for the category of construction objects. Thus, the calculated data range from 500 to 800 kg of load per 1 m ^{2 of} area. Intermediate ceilings in a house made of aerated concrete should be made of materials that have less weight and retain strength characteristics at the proper level. They must have a long service life, low cost, resistance to external influences of chemical or natural nature.

Monolithic ceilings made of aerated concrete

Inexpensive houses made of aerated concrete can be supplemented with aerated concrete slabs that have the same characteristics and properties as walls. This choice can be called justified, especially if we take into account the thermal conductivity of the materials, which turns out to be the same. Stopping on this option, you may prefer prefabricated-monolithic structures, products that are reinforced aerated concrete slabs, or monolithic slabs. In the first case, during the installation process, reinforcement should be carried out using reinforced concrete joints.

Today, on sale, you can find slabs of overlapping aerated concrete, which are made according to individual sizes. However, the average length is 6 m, and the width is limited to a limit of 1.5 to 1.8 m. The thickness is 30 cm, the design load per 1 m ² is 600 kg. Such plates are made only by autoclaving, with their density corresponding to the D500 limit. Quite often monolithic slabs are supplemented by a groove joint, this makes it possible to obtain a tight fit of the elements to each other, while installation is carried out in the shortest possible time. In one shift, a team of 4 people will be able to perform an overlap, the area of which varies from 50 to 120 m ² .

During installation, the most important point is to agree on the timing of the production of slabs, the time of the crane rental and the period of material transportation to the site. If the house has walls made of aerated concrete, then as an overlap it is possible to use prefabricated-monolithic plates, which are assembled from T-shaped blocks. Lightweight reinforced concrete beams are used , the length of which is 7 m, and the height is 20 cm. The weight of the structure is approximately 120 kg, which makes it possible to install without using construction equipment. The distance between the beams should be 68 cm, which provides support to the beam on each side, this is true if the block length is 60 cm.

When installing the first row, one side of the floor block will rest on the supporting wall of the building. The joints formed between the blocks will look like grooves, they are filled with concrete, its class must correspond to B20. Once all the overlapping blocks are in place, you must tie the reinforcing mesh, which is poured into the 5-cm layer of concrete. Full of his grasp will happen in 4 weeks, but partially load the design can be after 7 days.

Which floors to choose for a house from a gas block

If you are thinking about the question of what kind of overlap is better for a house from a gas block, then it is worth paying attention to wood. It is the most preferred option for lightweight wall blocks. Such overlappings are lighter than concrete ones, they put less pressure on the walls during operation, the design becomes more simple. Among other things, the cost of wooden logs, taking into account delivery and installation will be less than the cost of reinforced concrete slabs. A costly tap is not necessary to hire, because everything can be done without the use of equipment. Using wooden floors, it can be noted that the installation is more simple. To do this, it will be sufficient to make the reinforcement belt, as in the case of concrete slabs. It will be laid beams. The legs are covered with an antifungal composition before installation, they will be supported by walls. They are wrapped with a roofing felt or any other waterproofing material. It is recommended that the end of the beam be swept, the angle should be 60 °. In parallel, the heater is laid. Between the wall and the end is left a 2-cm gap, which is necessary for temperature expansion. Wooden logs are laid in the wall, they should be deepened by 15 cm.

Dimensions and cost of aerated concrete blocks

Aerated concrete blocks, the sizes and the price for a piece which will be specified further, are used in building today more often. The cost per piece is 130 rubles. The more massive the blocks are, the faster it will be possible to complete the construction. The material for the erection of walls will cost between 3,100 and 3,600 rubles. Per cubic meter. The standard length is 600 or 625 mm, the width can be equal to 250, 300, 375, 400 or 500 mm. As for the height, it can be equivalent to 200 and 250 mm. Aerated concrete blocks (sizes and price per piece are discussed in the article) can also be designed for partitions. This material is sold at a price of 3200 rubles. Per cubic meter. The basic height and length remain the same as in the above case, but the width can be 50, 75, 100, 125 and 150 mm.

Calculation of the maximum bending of the plate

The maximum thickness of the monolithic ceiling for the aerated concrete walls of the house was mentioned above. The design load per 1 m ^{2 is} also known, which is why it is possible to calculate the maximum bending of the plate. To do this, you need to know the design resistance of concrete, the design resistance of the reinforcement and the class of rods of the reinforcement. The first parameter is equal to Rb = 7.7 MPa, the second is Rs = 365 MPa, whereas the class of reinforcement used is A400C.

The distance from the edge of the plate to the reinforcement is 35 mm, the maximum bending moment should be calculated by the following formula: M = q * L 2 2/11. M = 695 * 2.52 / 11 = 395 kg / m. If the overlap has a lower reinforcing mesh, then it must meet the conditions under which am is less than ar. The second parameter is normative and is 0.440. Whereas am is M / (Rb * b * h02), here b is the overlap width, which is 6 m, while h0 is the distance from the center of gravity of the reinforcement to the edge of the plate, which is 0.045 m. In this case, am equals 395 / (77000 * 6 * 0.0452) = 0.042. The value of 0.042 is greater than 0.440. If am is greater than ra, then there is a need to increase the brand of concrete or increase the cross-section of the reinforcement.

Proceeding from the above, it can be argued that the calculation of a monolithic overlap can be carried out by yourself.

Why use a monolithic overlap

Despite the fact that today there are several varieties of floors for aerated concrete walls, monolithic ones have many advantages. They are chosen not at all less than the wooden prefabricated-monolithic ones. The device of monolithic overlapping is expedient, after all such constructions:

• Are economical;
• Durable;
• Easy to install;
• Fireproof.

It should be noted also the wide availability of materials for the work. The only thing that should be paid attention is that self-prepared concrete in private construction is not suitable. It is recommended to order it, because in production there are certain requirements and standards controlled by the state. If you do the concrete yourself, then you can not guarantee that it will meet the standards, it will be reliable and durable.

The monolithic overlapping device can be accompanied by some difficulties, which are expressed in the fact that the concrete will have to be raised to a greater height. Therefore, there is a need to rent a concrete pump. The difficulties are also expressed in the fact that it will be necessary to equip the entire formwork throughout the area. It is made of a durable and high-quality material that will be able to undergo the weight of a concrete mix. One square meter will account for 500 kg, this is true if the concrete layer is 15 cm.

Conclusion

Concrete slabs are equipped with formwork made of materials that must have a certain margin of safety, because the load will increase when pouring from a concrete pump. Experts advise using a square beam with a side of 100 mm for this purpose. As an alternative solution, there are plywood panels, the thickness of which varies from 18 to 20 mm. Once the formwork is ready, you should make sure it is level with the help of the building level.