Ceilings made of concrete: installation of floors, formwork

The installation of ceilings is a mandatory part of the construction of any building. As a material for the formation of the ceiling, and in some cases, in combination and the floor of the second floor, is best suited monolithic concrete. This is the most durable and durable option, which is used both for the construction of multi-storey buildings, and for private construction.

Concrete structures have a huge margin of safety, which allows not to worry about the reliability and seismic resistance of the building. Since the overlap is mostly on weight, this circumstance comes at an opportune moment. If the overlap also plays the role of the floor for the second floor, then its strength will also directly depend on the amount of furniture and equipment that will be in the upper part of the building.

If you decide to give preference to reinforced concrete structures, it is quite reasonable to think about their own installation - thus, you will save a significant amount of funds for the services of specialists. In this article you will be given detailed instructions on how to make a ceiling of concrete with your own hands. With its help, you can independently form the basis for the ceiling in low-rise and private construction.

Installation of floors

Monolithic overlap is poured in the form of a solid slab, which will have a uniform structure throughout the entire period of operation. It does not contain connecting seams and is not subject to partial draft, as is often the case with prefabricated structures.

Also, concrete structures of this type are distinguished by a relatively low price - since the slab is formed on an independent basis, its cost is an order of magnitude lower than the factory analogues. The disadvantage of this technology is a large mass - a monolithic plate has no voids, which greatly increases its weight.

The inability to create tension reinforcement significantly increases the consumption of reinforcement for the cube of the concrete floor, which also exacerbates this drawback. Preferring monolithic overlap, it is necessary to ensure that the bearing capacity of the walls and the base was designed for future loads.

It should also be noted that the filling of floors with concrete takes a long period of time, which includes the preparatory process and the time of complete solidification of the concrete solution. It is not possible to speed up the process of polymerisation of the cement composition in any way, which should be considered if the timing of the work is the priority.

Formwork assembly

• Wood is the most commonly used material for formwork - it is easy to process and install.. The use of metal formwork is also appropriate, but it will not be so convenient and can cause a lot of difficulties during the installation process. The minimum thickness of the boards should be at least 20 mm, the cross-section of the cross-bar - at least 40 mm;

Note! The exact thickness of the material is determined on site, based on the thickness of the fill and the components of the mixture. On average, the weight of 1 cubic meter of heavy concrete is about 3 tons. In this case, the main thing is the reliability of the assembled box.

• On the boards, every half meter, it is necessary to drive the cross member, which will play the role of connecting ribs. Boards should be firmly fixed to the solution could not squeeze them. Their height is calculated based on the thickness of the future overlap, which can be from 15 to 20 cm;
• There are supports under the box, one for each square meter - they will bear the brunt of the uncured slab and must be thick enough not to deform the concrete solution under pressurebut. In addition to the standard location, the props must also necessarily be located at the junction points of the shields.

Note! The bottom of the supporting columns should not sink under the weight of the plate. To avoid this, simply lay under it a wide piece of wood that will distribute the weight over the ground surface.

Reinforcement

The reinforcement cage of the monolithic slab has a two-layer structure, and consists of upper and lower grids. The strongest pressure will be at the bottom of the plate, since the workload is directed from the top down.

To compensate for the tension load, the lower part of the frame is assembled from reinforcement with a cross section of at least 12 mm. For structural reinforcement of the upper part, you can use reinforcement with a smaller section.

Cells of the reinforcing network should be from 15 to 20 cm. It is possible to connect the wires to each other with a knitting wire with a section of 2 to 3 mm or by means of electric welding.

The frame is welded or tied to the fixtures from the side of the walls or columns, if any. The distance between the top and bottom should be at least 10 cm - homemade metal struts are used to provide the necessary clearance.

Also the frame should not fall directly on the formwork - the protective layer of concrete above the reinforcement should be at least 2 cm.

Note! The information is based on data from SNiP 2.03.01-84 “Concrete and reinforced concrete structures”

Fill

The material for pouring the slab is a mixture of sand, cement and filler, which is often crushed stone. Also, today polystyrene concrete and foam concrete floors, which have less weight and more effective thermal insulation, are becoming popular.

The first option is more suitable for self-pouring, since it does not require the purchase of additional equipment in the form of a steam generator - you just need to buy polystyrene granules in the store. You can purchase ready-made heavy concrete - the concrete grade for a monolithic ceiling should be no lower than M200.

When unloading concrete, it is important not to allow it to accumulate in one area - it is necessary to evenly distribute the mass over the entire area of ​​the formwork. The brand of concrete for the overlap of polystyrene concrete must be at least D500 (for self-production, 410 kg of M400 cement and 170 liters of water are added per 1 cubic meter of polystyrene).

When self-manufactured, heavy concrete is mixed from cement, sand and crushed stone in a ratio of 1: 2: 3 based on the weight of the components. Crushed stone can be replaced with expanded clay, to ease the weight and improve the insulating characteristics. Water should be added as little as possible, but it should be enough to create a homogeneous mass.

Total

Самостоятельное бетонирование перекрытий позволит вам сэкономить существенное количество средств и создать бесшовную поверхность. В дальнейшем установить дополнительные элементы или удалить погрешности вам поможет резка железобетона алмазными кругами и алмазное бурение отверстий в бетоне (см.также статью «Железобетонные перекрытия – виды и изготовление»).

More information on this topic can be obtained by viewing the video in this article.