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Concrete for foundation

The construction of any building begins, of course, with the foundation. If you are going to build a foundation with your own hands for a house, you need to choose the type of foundation and choose the right materials. One of the most important materials for the construction of the foundation is concrete. The reliability of the foundation of the future house will depend on its brand, the quality of cooking and pouring.

Monolithic foundations have become the most popular of all types of foundations in recent decades. This is explained by the efficiency and versatility of the monolith application for different types of foundation structures.

Concrete is one of the most durable building materials, without which no construction can do. The main property of concrete is compressive strength. This indicator will depend on the brand of concrete. The strength of concrete can be increased by using special additives in concrete.

Brand of concrete for the foundation

The following concrete grades are used in construction: M50, M75, M100, M150, M200, M250, M350, M400. The concrete class is determined by the compressive strength, which corresponds to the concrete grade.

Stamp	Class	Strength, kg/cm2
M75	B5	65
M100	B7,5	98
M150	B10	131
M200	B15	196
M250	B20	262
M350	B25	327
M400	B30	393

To determine which concrete is needed for the foundation, it is necessary to analyze the following indicators:

the basement and the type of the underground part of the building: piles, tape, will there be a basement
what will be the load on the entire concrete structure and the total weight of your house
the location of the site, the water table, the nature of the soil, etc.

Each of these factors will influence the choice of a particular brand of concrete. If you are thinking of building a wooden house, then Concrete M200 is quite suitable for you. With increasing loads, for example, when using cinder blocks and silicate gas, it is better to use concrete grades M250 and M300. For the construction of the foundation for a brick house, concrete M350 is used.

The composition of concrete for the foundation

Concrete for the foundation consists of cement, sand, water and crushed stone of a fine fraction. These materials need to be taken with different grains, then the mixture will evenly fill all the voids. The fewer gaps there are, the less sand and cement will then be needed to eliminate them. Also, to improve the physico-chemical and mechanical properties, other components are added to the concrete solution, such as: polypropylene fiber, antifreeze additives in concrete, plasticizers, hydrophobizers.

Proportions of concrete for the foundation

For the construction of a stronger foundation, experts recommend using concrete of a grade not lower than M200. The proportions of concrete for the foundation in the ratio of 1:4:4 are considered the highest quality. This means that a mixture of a unit of cement, approximately 4 units of sand and 4 units of gravel is taken. There should be no additional impurities in the concrete solution (for example, soil, various oils, grass or clay).

Preparation of concrete for the foundation

Concrete mortar can be purchased ready-made or prepared independently on the construction site. The concrete mixture is prepared in concrete mixers. This is much faster than manually, and the concrete at the same time becomes 50% stronger. Crushed stone, sand, cement are poured into the concrete mixer and after a short mixing, water is added. Mixing is carried out for 2 minutes in concrete mixers with an inclined axis and 1 min. — in concrete mixers with a horizontal axis.

Concrete reinforcement

During the construction of monolithic foundations, concrete must be reinforced. Concrete reinforcement betrays the strength of the concrete structure, prevents displacement, cracking and deformation of concrete. The service life of the foundation itself depends on the correct reinforcement. Polypropylene fiber, metal fiber, reinforcing mesh are used for concrete reinforcement.

If non-removable formwork systems are used in the construction of the foundation, then the reinforcement will be preceded by the installation of the formwork. After the formwork has been installed, a steel frame is arranged, which consists of fittings and special fasteners (retainers of the protective layer). For the construction of the formwork, you can also use spring clamps for reinforcement – chirosa. This is an indispensable element of repeated use for fixing the formwork, which prevents its opening during the construction of a monolithic frame structure.

The reinforcement for the foundation is fastened together with a wire or a special bracket for the reinforcement. For the convenience of working with fittings, we recommend using high-quality machines for bending and cutting Afacan fittings.

Pouring concrete

A concrete solution is poured into the installed formwork with a reinforcing frame. The consistency of the concrete mortar should be such that the concrete is well poured, and not filled up. It is important when pouring concrete to avoid large breaks between laying portions of concrete. Concrete under the foundation should be thoroughly compacted by vibration. For this purpose, a deep vibrator for concrete is used. Then it is rammed to remove voids and covered with a polyethylene film.

On fresh concrete, you can perform the first layer of waterproofing. Immediately after stripping, a solution of a dry waterproofing mixture of a penetrating type can be applied.

The applied solution penetrates deeply into the structure of concrete, protects it from leaks and the effects of aggressive media. Waterproofing of the coating type is applied after the foundation has completely dried (after 27 days). Bitumen mastics are used as a coating waterproofing. Coating waterproofing allows you to create an elastic layer on the surface of concrete, which is resistant to low temperatures and UV radiation.