Popular concrete b 20 - stability and strength class

Construction is one of the most developing areas in the modern world, and every year experts create new types of building materials with a better set of characteristics than the previous ones. And if we say that it is still used more often, then this, of course, concrete products, a guarantee of durability and reliability for any structure.

Properties of concrete B 20

As we have said, modern construction is difficult to imagine without the participation of concretes of different brands. The most popular in civil and industrial construction sites is B-20 concrete. Preference is given to this artificially created material because of the ideal combination of its cost and quality. This is especially true of private construction, as the whole working process is done by hand.

Concrete B 20, which corresponds to grade 250 (according to new construction standards is marked as C16 20 concrete), is manufactured in concrete plants and delivered to construction sites in special mixer machines. During transportation, the solution is continuously mixed and fed to the construction site without losing its properties.

Consider the basic technical characteristics of concrete in 20:

• Strength in compression (20 MPa) after 28 days. A certain indicator of the strength of concrete is achieved by using components of a given quality.

Note! Only full compliance with the proportional ratio of ingredients in the mixture can give the maximum result. Any slightest deviation leads to a loss of properties, experienced builders and designers know about it, so the stage of creating the mixture is clearly controlled.

• Frost resistance (designation F) of products and structures of this class of material varies in the range of F100, F150, F200. The number after the letter indicates the number of cycles of alternate freezing and thawing of the test sample under laboratory conditions. To increase the rate of frost resistance, special additives are introduced into the concrete.
• The specific weight of concrete М250 is about 2.3 tons per cubic meter. This figure characterizes the density of the product, and depends on the percentage of air inclusions and hardened mass, after evaporation of water, which is part of the mixture.
• Concrete brand C16 20 may be watertight in the range from W2 to W. The permeability of the samples is checked by exposing a water column to a test sample under high pressure before infiltration.
• Another indicator is the modulus of elasticity. To determine this characteristic, the mixture is subjected to reduce the time of hardening treatment with heat in autoclaves.

Grade C16 20 with a draft of a mixture of up to 4 cm and a filler of a maximum fraction of 40 mm has an elastic modulus of 394 kgf / sq. Cm and, respectively:

• Fractions of 80 mm - 424 kgf / sq. Cm.
• Fractions of 120 mm - 445 kgf / sq. Cm), etc.

Application area

The high physico-technical characteristics and advantages of concrete B 20 ensure its widespread use in various areas of the construction industry and for various products:

• Construction of buildings of various scale, including large-sized. In the construction of tall buildings, the strength of structures that have to withstand serious loads is very important.

Note! The use of a particular brand of concrete is strictly regulated by the SNiP and GOST "Building materials", "Reinforced concrete structures". Replacing the mark in the section with the recommendation of these documents is allowed only after coordination with the project organization and approval by the architectural control bodies.

• Prefabricated production of concrete foundation blocks and slabs designed for medium load.

Note! The construction of buildings and structures from prefabricated reinforced concrete significantly reduces construction time, but requires the use of specialized equipment.

• Device pads, tracks, blind area. Concrete B20 copes well with the aggressive effects of environmental conditions and can withstand loads from the movement of vehicles.

Making concrete mix

To create high-quality concrete of the appropriate brand, the process technology and the percentage ratio of the ingredients of the mixture should be strictly observed.

The composition of concrete M 250

The instruction for preparing the concrete mixture B20 gives the following calculation of the production composition per 1 m3 (1000 l):

• The main cementitious element is 360 kg.
• Fillers:

• Sand (humidity 5-6%) - 536 kg.
• Crushed stone (humidity 1%) - 1141 kg.

• Water - 133l.
• Additives affecting frost resistance, plasticity, water resistance:

• Plasticizing C 3 - 3.085 kg (35% concentration).
• Plasticizing LST- 3.6 kg (20% concentration).
• Air entrapment START –0.72 kg (1% concentration).

The cost of building material

The price of B20 grade concrete directly depends on the additives added to the mixture and the quality of coarse aggregate. Concrete on granite rubble will be more expensive than on gravel. Important and reputation of the manufacturer. The newest equipment works on large concrete nodes and the standards of GOST are strictly observed.

On average, the cost of 1 m3 of concrete mix with indicators F150-200, W2-4 well-known manufacturers (OOO Obrey, Garant Beton, company BSU No. 5) will be 3,400–3,500 rubles.

Conclusion

We hope that the above information was useful to you, and decide to remind you of several important points. First, to obtain high-quality products with proper strength, you should use a grade not lower than 200 (for residential buildings).

Secondly, it is better to knead the mortar with the help of a concrete mixer, this reduces the construction time and makes the whole process easier for you (the workers). In the presented videos in this article you will find additional information on this topic.