One of the most important elements of any homeis the foundation. If you do it correctly, the structure will not become useless in a short time. High level of reliability and durability is characteristic of the slab basement, therefore it is more often than others the house craftsmen and builders choose it.
Но если пользоваться услугами специализированных companies, they will ask for such a design more than a third of the cost of the building. On your own experience, you can make sure that the cost of this part of the building is not so high. You can complete the slab foundation by yourself.
When is it used?
Monolithic foundation - slab that fitsfor the construction of residential and non-residential buildings. This applies to those buildings that will not have a basement. As one of the main advantages is the fact that under the floor do not have to lay logs, as the concrete can act as a finished draft coating.
Such a base is distinguished by seismic resistance, high strength and is not washed away by water, because the area is quite large. This construction under the house would be appropriate if there is a problem soil on the plot.
Technology features
Monolithic foundation - a slab that can becreated by one of the two technologies. If the structure is planned to be made monolithic, then you must first install the formwork, and then assemble the reinforcement cage. Concrete poured into one approach. When the foundation is planned to be prefabricated, it is constructed from reinforced concrete slabs, the seams of which are poured with concrete. The design does not require formwork, as well as the installation of reinforcement cage.
But this approach has its drawbacks:You can not achieve the desired thickness, because the plates are made at the factory and have certain parameters. In fact, such a structure will not be monolithic, which makes it less durable. For laying plates will need a crane. If the soil has irregularities, it will be quite difficult to lay the products, it is necessary to level them, which is almost impossible to do manually.
How to make a plate
Monolithic slab under the foundation is made according totechnology, which provides for the preparation of the pit of the desired depth and size. A layer of sand or rubble is poured into the bottom, and communications are laid, for example, water and sewage pipes. A concrete screed is placed on top. It is necessary to warm this structure, and then install the formwork, as well as the reinforcement cage. The slab at the next stage can be filled with concrete.
Determination of slab thickness
The thickness of the foundation slab depends on whichthe house you are planning to build. The heavier the building, the thicker the slab should be. If the construction is shallow, the thickness should not exceed 30 cm. However, the foundation can be made deep. In this case, its thickness will be 1.5 m.
For private construction usually usedfoundation, the thickness of which is not more than 40 cm. Foundation plates are poured with M-200 concrete. The mobility of the solution should be P-3, and resistance to cold is equal to the limit of F200. It is important to take into account the marking of water resistance, which should not be less than W8.
Stages of construction
The first step in the construction of slab foundationwill mark the territory. In order to make it easier to work with the formwork, it is necessary to add about one meter to the sides of the pit. The platform must be leveled: this is the only way to normalize the pressure on the plate, which should be uniform. The bottom of the pit is leveled, it is important to get rid of drops and bumps.
For the formation of the drainage system is necessarydig transverse trenches through which water will be drained. Geotextiles are laid on the bottom of the trench. Then you should put the plastic pipes with perforations. All this is filled with small fraction rubble, and then covered with geotextile.
Installation of formwork
The foundation slab is poured into the formwork.She knocked around the perimeter of the boards. The outer side must be strengthened with struts. As soon as the fence is ready, you must make a pillow, which consists of a layer of sand and gravel. Such preparation is necessary for the removal of moisture from the structure and soil depreciation. The pillow can have a thickness ranging from 15 to 30 cm.
If the ground is wet, you can addfine fraction rubble. Preparation is well compacted. On the sand should not be a trace of the shoe. After you need to do waterproofing. It is necessary to prepare a solution of sand and cement, which poured the pillow. The thickness of this layer will be 5 cm. After that, the waterproofing can be laid in the form of rolled material, for example, roofing felt. It is laid with an overlap on the formwork.
After the waterproofing is ready, you canproceed to the reinforcement. For this, fittings are used, welding is excluded. The rods are strung with wire. In the next step, you can start pouring the base plate. It is better to order a car with a ready-made mortar, in this case you will be able to work out concrete at a time, it will turn out to be homogeneous and not covered with cracks.
Thickness calculation
Самый простой расчет толщины осуществляется by summing the gap between the reinforcing mesh, the thickness of the reinforcement and the concrete layer. The optimal value is 30 cm. The end result is determined by the composition of the soil and the uniformity of the rocks. You must consider the width of the sand cushion and the drainage layer.
For slab foundation, remove the toplayer of soil and dig a pit, the depth of which can be 0.5 m. This value is determined taking into account the fact that rubble is located in a layer of 20 cm and sand is 30 cm. If you add up the available data, then you can understand that the minimum thickness of the slab the foundation can not be less than 60 cm. This figure varies depending on the characteristics of the soil and the weight of the future construction.
For a brick building the slab may be thicker by 5see the same reason for the house of foam concrete. If the building has a second floor, and the walls are made of brick, then the thickness of the monolithic slab can be increased to 40 cm. This value can be greater, depending on the configuration of the structure and its weight. When building a two-story house of foam concrete, it can be 35 cm.
An example of the calculation of the volume and thickness
If you intend to carry out the calculation of the platefoundation, you can determine the amount of concrete to fill. For this, the sole area is multiplied by the thickness. You can deal with the calculation, referring to a specific example. If the house has a size of 10 x 10 m, and a monolithic foundation is 0.25 m thick, the slab volume will be 25 m3. This value is obtained by multiplying the three figures mentioned.
If you are planning to build a foundation slabwith your own hands, you need to know how much concrete is needed for the work. It is necessary to take into account the installation of stiffeners, which are necessary to ensure resistance to deformation. They will be located along and across the slab at a distance of 3 m, forming squares. For the calculation should determine the height and length of the ribs. The last figure is 10 m. A total of 8 edges will be required, so the total length will be 80 m. For rectangular edges, the volume will be 16 m.3. This value is obtained as follows: 0.25 x 0.8 x 80. For trapezoidal ribs, the lower base is 1.5 times the thickness of the foundation, and the upper is 0.8.
Plates for the tape bases
Slab foundations are also calledfoundation cushions and are used as the foundations of low-rise buildings foundations. With their help, it is possible to extend the life of the supporting foundation and distribute the load between the elements. Such an approach to building a building is especially relevant if the soil tends to sink in the winter period. The foundation blocks have a rectangular shape, so the load on the soil from the bottom of the product increases with each laid next.
If the base is too high, thenload on the ground may occur subsidence structures, which will lead to distortion of the geometry of the building. The only sure way out of this situation would be to reduce the load on the soil. This can be done by reducing the mass of the foundation structure or increasing the area. For the second method, belt plates were invented, which act as an adapter between the soil and the foundation blocks.
Finally
Фундамент, в основе которого лежит плита, is a solid foundation. It contains reinforced concrete, which is laid over the entire area of the building. Such structures are very durable and have less pressure on the ground. But such advantages have only that monolithic foundation, the thickness of which is determined taking into account the depth of laying and loads, the nature of the soil, as well as the weight of concrete.
