Concrete for filling the foundation: composition, calculation, preparation

The foundation is the basis of the house, and the duration of operation of the entire building depends on the correctness of its structure. Therefore, the issue of filling the foundation should be shown special care. We will talk about how to prepare a concrete composition that will help build a strong and reliable base of the foundation and how to calculate the concrete on the foundation.

Table of contents:

1. What concrete is needed for the foundation - a variety of concrete compositions
2. Brand of concrete for filling the foundation: the main types of concrete brands
3. Which concrete to use for a strip foundation: Features of choice
4. Preparation and consumption of concrete for the foundation
5. Preparation and pouring concrete for the foundation

What concrete is needed for the foundation - a variety of concrete compositions

There are three main indicators of the classification of concrete mixtures:

• binder;
• density;
• The scope of application.

In relation to the first option, concrete happens:

• silicate - it is based on the use of lime, this mixture is rare and is practically not used in construction;
• Hypsum -type concrete is used to finish the ceiling and internal parts of the room, in addition, there is concrete of a gypsum -cement type, characterized by a high level of moisture resistance;
• The cement type of concrete is the most common option used both in the process of performing internal and external works;
• Polymer -cement concrete - is based on a mixed binder in the form of latex and resin;
• Clothing -type concrete - is formed from slag, not common due to the fact that it was recently invented;
• Concrete of a special composition is prepared from a certain binding substance and a special additive that provides its stability before acids, alkalis, etc.

In the ratio with density, concrete happens:

• heavy - granite or limestone is used as a filler;
• Particularly heavy - ore or barity is added to the concrete composition;
• Light - differs in the presence of light filler, a gas or foam concrete includes this class.

In the ratio with the appointment and area of \u200b\u200buse, concrete happens:

• ordinary - used in the process of building foundations, beams, plates and various kinds of ceilings;
• hydraulic - they are faced with channels, gateways, sewer structures;
• airfield concrete;
• A special type of concrete - protects the surface from radiation, high temperature or chemical exposure.

Brand of concrete for filling the foundation: the main types of concrete brands

Concrete is marked according to certain indicators, such as:

• brand, designated as m;
• concrete composition class - in;
• frost resistance f;
• moisture resistance W;
• The magnitude of mobility.

The concrete brand is the main indicator of its quality. The behavior of the concrete composition in the process of solving depends on it. In the ratio with the brand, concrete happens:

1. The concrete of brands100 and class7.5 is characterized by low quality, used at the initial stage of construction, fences, concrete pillows for arranging the foundation, wooden houses, garages and agricultural construction are built from it.

2. Brand of concrete 150 and class12.5 - the average level of quality of concrete used in the process of arranging a black screed or concrete path, in addition, the base is built from it under the arrangement of a light strip foundation, for slag -block, foam concrete buildings, in addition, is used in the construction foundation for a garage or outbuilding.

3. The concrete brand 200, and class15 is used in the process of building unloaded elements in the form of stairs or when pouring tape plates used in the construction of the foundation. This type of concrete is also called structural, since reinforced concrete slabs are made from it.

4. Concrete of brand 300 and class2.5 - the most popular and common type of concrete, its quality is at a solid average level, used in the process of filling the foundation. With the help of such concrete, cottages are poured, up to six floors high. In addition, this type of concrete is ideal for arranging a monolithic floor.

5. The concrete brand 350 in 25 is a high -quality type of concrete used during the structure of structures that require increased strength.

6. Concrete brand 400 is used in multi -storey construction.

7. Concrete brand 500 has a very rare application, banking storage facilities and special objects are built from it.

The level of compression in the process of solidification depends on the concrete class. Concrete mobility is a value denoting its fluidity in a liquid state. The high level of moisture in concrete significantly reduces its strength characteristics.

Widespread has a fairly wide interval from two to twelve units. This coefficient is taken into account if there are groundwater on a section located too close to the foundation. Frost resistance is an indicator of the amount of frost that is subjected to concrete without the loss of its qualities.

Which concrete to use for a strip foundation: Features of choice

If its strip type is selected as the foundation for the construction of the building, then you should decide on the brand of concrete, which is necessary for its fill. There are two options for acquiring concrete:

• Its purchase from the manufacturer - such concrete has the highest quality and is great for the work on arranging the foundation;
• To make the composition independently using the concrete mixer - the quality of concrete, in this case will significantly decrease, and since the foundation is the main part of the building, on which its strength depends, it is better to give preference to the first option.

We offer to get acquainted with the characteristics that affect the choice of a particular type of concrete composition:

• the total mass of the entire structure, the load on the foundation of the building, the number of floors, the basement;
• research of geological purposes, in the process of which the soil, underground waters, etc.;
• Type of foundation and base base.

It is these factors that affect the type of concrete used in the process of building the foundation.

One of the most important factors that determine the composition of the concrete solution is to determine the general load on the surface of the foundation. If you include exclusively the load, then for the building up to two floors, concrete of brand 200 and class 15 is suitable. This concrete is constructive, as it is used in the production process of reinforced concrete structures. If the construction does not have residential purposes, then concrete of brands 150 is also used. If a silicate, hyperpress brick, reinforced concrete slabs, a slag block or a expanded block is used during the construction of the house, it is recommended to use concrete of more than the twentieth class.

When building buildings, the number of storeys exceeds five units, it is preferable to use brands of more than 300.

If the foundation is erected on sandy or rocky soil, and the construction does not have more than two floors, then the option of using low -quality concrete, brand 150 or 200 is possible. When arranging the foundation on clay or subgany soil, the quality of concrete should be higher.

Concrete is especially important during the construction of the foundation on clay soil, since this type of soil is characterized by high heaving. If the air temperature decreases sharply, clay increases in volume, thereby deforming the foundation. This is especially true for shallow foundations. The option of their deformation is possible by several centimeters, which leads to a violation of the integrity of the entire structure. In addition, these deformations occur unevenly, since clay in different areas behaves in its own way.

Since the concrete foundation is subjected to various kinds of loads, it is recommended to lay it below the level at which the soil freezes. To determine this indicator, a number of geological studies should be carried out. The average freezing of the soil is 80-100 cm.

An important factor in determining the composition of concrete for the foundation is the type of foundation itself. If the choice has stopped on the strip foundation, then its arrangement will require concrete of lower quality than for pile, for example. Pile foundations are appropriate during the construction of high -rise buildings, then concrete is poured into piles using special equipment. For this type of foundation, it is recommended to use concrete of brand 400.

A significant factor that determines how much concrete on the foundation is required is the level of groundwater of the area on which the building is planned. In addition, the basement and its presence, water bodies located near the foundation also require improving the quality of concrete. Widespread concrete is one of its qualities, which helps prevent moisture to penetrate through a concrete base. This parameter is very important in the process of arranging hydraulic structures. To increase the water permeability of the foundation, external coating waterproofing is used.

The price of concrete for the foundation is determined primarily by its quality. The higher the concrete brand, its water resistance, class - the higher the cost of the finished mixture. But, at the same time, the strength of the entire structure also increases. In high brands of concrete, more cement is used, which creates the necessary strength.

Preparation and consumption of concrete for the foundation

If it is planned to use independently prepared concrete solution, it is better to use concrete of a brand of at least 300.

The procedure for making concrete solution involves primarily the following technology, according to which the composition has different proportions.

Among the main components of a concrete solution for the foundation, they distinguish:

• cement, to the amount of one kilogram;
• sand - 3 kg;
• The filler in the form of crushed stone or gravel is 4-5 kg.

To create a concrete mixture of high quality, the brand of which is at least 300 or 400, you will need to add water to this amount of materials in an amount, half as much than the total mass of all components. For example, 8 kg of dry components will require about 4 liters of water. Upon receipt of too hard in the composition of the solution, it is allowed to dilute it a little with water. The concrete should mix well with a shovel, but do not drain from it.

Keep in mind that raw sand also contains moisture, so it is advisable to dry it before using it, if wet sand is used, then the amount of water should be reduced. In addition, it is recommended to clean the sand from extraneous impurities well, since dirty sand is poorly grasped in the solution.

Choose a small -fractional type fillers, the optimal size of crushed stone or gravel should be one two centimeters. Cement should not be acquired long before the start of construction work, since it is characterized by rapid moisture capacity, which makes it unusable. It is preferable to buy cement 10-15 days before the start of construction work.

Preparation and pouring concrete for the foundation

Before proceeding with the direct process of pouring the concrete base, a number of works aimed at calculating the concrete solution for these work should be carried out.

Each of the foundation lines is calculated separately, and then all the indications are summarized. The length of the tape is multiplied by width and height. For example, if there is a tape in the foundation, the width of which is 2 meters, a height of 2 meters, and the length is 10 meters, then in order to find out its volume 2x2x10 \u003d 40 m. 40 cubic meters of concrete solution will be required to fill this tape. Each of the tapes is calculated in this way, and then the readings are summarized.

After preparing a solution of concrete for the foundation, it is poured into pre -prepared formwork. It is better to do this in several stages, while compacting each of the layers.

With a foundation height of 100 cm, concreting occurs in four layers, each of which is 25 cm. After the first layer is flooded, it is compacted and compacted using a special device - a vibrator in concrete.

Concrete for filling the foundation should not contain air, since it negatively affects its quality. In addition, each of the layers should first be leveled before laying a new one. To do this, use a suitable flat board in size.

If we consider the calculation of concrete for pouring the foundation of the plate type, then it should accurately determine its size, and in particular: width, height and length. If the length of the plate is 10 meters, the width is 8, and the height is 0.5, then 40 cubic meters of concrete solution will be required to fill it. This foundation needs a thorough tamping of each flooded area, so it is better to entrust the work on its arrangement to professionals. The alignment process after pouring occurs from the smaller side, that is, the one that is 8 m. A wide board will be required to equalize concrete, you should take care of its compaction before alignment.

The columnar foundation involves the same calculation of the amount of concrete, which is poured with layers, each time tamped with the deep vibrator.