Concrete B25 - material for high-strength structures: properties, composition, scope of application

Antifreeze additive for “warm” concrete and mortar according to GOST 24211-2008

MosBetonTorg LLC produces, sells and delivers high-quality M350 concrete in Moscow and the Moscow region. Today we are ready to offer our clients high-quality concrete mortar, the cost of which is optimal even for the implementation of a small project.

The price list shows the price for various brands of building mixtures. We work for you 7 days a week and 24 hours a day.

No way without cement

If we analyze the demand for basic building materials, concrete not only does not lose popularity, but becomes more widely purchased, becoming a material of mass demand. And we are not talking about large construction organizations and technologies of any kind of continuous casting; household concrete mixers are being sold out like baked goods on the holidays. Indeed, concrete is an unsurpassed material that ensures the strength and reliability of a structure, and you can make it yourself, providing or specifying characteristics depending on the specific tasks and type of construction. But first, let’s answer the most popular question for construction beginners: how much cement is required to mix concrete per 1 cubic meter?

Cube is a common abbreviation for a unit of volume, 1 cubic meter, which is used to measure ready-mixed concrete, so most reference standard tables use this particular value when recommending a percentage or fraction of components. In classic concrete, i.e. without additives, there are only four of these components, where the loose fit of crushed stone pebbles is filled with sand, mixed with a binder - cement, dissolved in water to start the reaction. Cement, without any additives, also crystallizes perfectly and becomes an artificial stone, having high strength and a large amount of shrinkage, which is regulated by adding filler and its size.

Agree, if you add a spoonful of cement to 1 cube of mixed concrete or, more commonly, a ton of this mass, there will be no strength; I think that the concrete will not even retain its shape and will crumble when it dries. If you put the standard 166 kg, with the same amount of other components, you get concrete with characteristics equal to the hundredth - “M-100”. We again increase only the amount of binder to 300 kg and get concrete grade “M-250”, i.e. capable of withstanding a load 2.5 times greater in relation to the hundredth. The dependence of the strength of the concrete mass of the product on the amount in the cement composition is practically linear, i.e. for concrete grade 300, take 300 kg. binder, for “M-450” - a little more than 450 kg. etc., getting an elementary conclusion - the more cement, the higher the grade and strength of the finished concrete.

But you shouldn’t focus only on this dependence; it’s better to take the developer’s specific values, because they take into account dozens of other factors. For example, try scattering a pile of large rubble, and then, for comparison, medium-fraction crushed stone, which cannot be stacked high, it will “float”. Consequently, the strength of concrete, its properties and grade are determined not only by the proportion of binder, but also by other factors, even the type of sand and the amount of water, taking into account which the desired characteristics are obtained. In other words, before independently preparing concrete of the calculated grade, we find out the quality of the available components and, using the tables, determine the exact amount of cement needed to mix 1 cubic meter of concrete, although its approximate mass can also be found out from a linear relationship.

Recipe m350

Let us take, for example, concrete of composition M350, as the most popular and best-selling product for concrete units. According to GOST 7473-94, the share of cement in it is 360 kg, sand – 845, crushed stone – 1075 and 170 kg of water. It seems that the simplest thing is to weigh the components with a measuring bucket and prepare concrete, but GOST stipulates the use of gravel in this brand to ensure the required strength or granite, which practically does not absorb moisture and thereby increases frost resistance. We find the crushed stone and sand we have in the reference table and find out the amount of cement required, adjusting the theoretical one to 360 kg.

Application area

Class M350 is used in any construction process, so it is very important to choose a supplier with a positive reputation.

It is not for nothing that the concrete mixture of the offered brand has a favorable price: this solution is popular among customers due to its versatility.

It applies:

• in the production of various monolithic foundations;
• during the construction of columns and beams;
• when installing pool bowls;
• in the construction of floor slabs and reinforced concrete structures.

What are the advantages of grade 350 concrete?

This brand of concrete has numerous advantages:

• increased strength properties. The concrete mass does not collapse under the influence of significant compressive loads, as well as during active abrasion of the surface during operation;
• high degree of mobility. This makes it easier to carry out concrete work, and the use of special plasticizers can further increase the elasticity index;
• adjustable frost resistance. At the stage of preparing the solution, it is possible to ensure the required level of frost resistance to maintain the integrity of the monolith in difficult conditions;
• long service life. The composition of the M350 brand retains its original strength characteristics for a long time and is not destroyed under the influence of aggressive factors;
• increased density. Thanks to the effective compaction of liquid concrete, there are no cavities or air pores in the mass. This significantly increases the degree of water resistance and expands the possibilities of application;
• environmental cleanliness. For production, environmentally friendly raw materials are used, which do not have a negative impact on people after completion of the hardening process.

Thanks to these advantages, concrete grade M350 has established itself as a universal building material for structural purposes.

Our advantages

Manufacturer with reputation and reliable production.

More than 2000 satisfied customers. RBU (Germany) > 80 m3/hour each.

Guarantee of high quality raw materials and products

Control is carried out at all stages by our own certified laboratory

Accuracy and timeliness of deliveries.

Weight control. Professional logistics.

Uninterrupted and convenient delivery to any area. Pickup.

Favorable geographical location of production sites.

Favorable prices. Any form of payment.

Without intermediaries. Discounts up to 20% on purchase volume.

High level of service and 100% mutually beneficial cooperation.

Free consultations and visits. We build long-term relationships.

If you look at the price list, you can see for yourself that we offer not only the most optimal cost of building materials, but also favorable terms of cooperation.

Specifications

Class B25 is a grade of M350 concrete. Its strength is 327 kgf/cm2. This composition is used to make:

• monolithic foundations;
• beams;
• pool bowls;
• piles;
• floor slabs;
• monolithic walls;
• columns

Very often it is used in the production process for products that are very heavy - for example, reinforced concrete.

Class B25 is one of the most popular in commercial and industrial construction. This is due solely to the excellent characteristics of the mixture. It should be said that the specific gravity of such material classifies it as heavy. The designation “B25” indicates that the density of 1 m3 of the composition can easily withstand a pressure of 250 atmospheres. In this case, the integrity of the structure will not be compromised. Mobility is assessed within P2 - P4. It can be increased by using special plasticizers as additives.

Three main indicators

Frost resistance is 200 cycles of freezing and thawing of products. At the same time, the structural integrity and properties of the material are preserved. In terms of water resistance, this composition is capable of not allowing water to pass through, even if it acts on the surface under a pressure of 0.8 atmospheres. The volumetric weight or density of M350 concrete ranges from 1800 to 2500 kg/m3. Density from 2200 to 2400 kg/m3 is average.

Density is the ratio of mass to volume, which affects quality, including strength characteristics. The higher the density, the stronger the material. Pores have a significant influence on density. Strength, as mentioned above, is at the level of 327 kgf/cm2.

Main components

Grade M350 is usually produced in the form of a mixture of cement and solid filler, and one of the components may be granite or crushed gravel. Quite often, plasticizers and additives are used in the composition to increase frost resistance.

Such technical characteristics expand the scope of application of M350 concrete. And as mentioned above, it is often used for the construction of load-bearing structures that have significant weight. In addition, the material is used for pouring road slabs on airfield sites. To make a solution of class B25 you need:

• cement;
• crushed stone;
• sand;
• screening (partially replaces solid fillers);
• plasticizers;
• antifreeze additives;
• water.

It should be noted that the components may differ in their parameters and characteristics - strength, fraction size, moisture content and purity. For example, sand with a coarse, medium or fine grain fraction, calcareous or granite gravel, crushed stone and various screenings can be used as aggregates. It should be noted that this brand has an increased amount of cement and thanks to this the material hardens quite quickly.

Proportions

To prepare 1m3 of such material you will need:

1. cement M400 or M500 - 400 kg;
2. sand cleared of impurities - 752 kg;
3. solid filler – 1000 kg;
4. water – 175 liters.

An important point is the quality of mixing of all components to achieve homogeneity of the mass. A poorly mixed mass reduces the strength of the material. Improvement of properties occurs due to the introduction of various additives. To prevent freezing of concrete in the winter, an anti-freeze additive is added.

Its strength and quality depend on the precise observance of proportions in concrete. Table 1 shows the proportions that must be adhered to.

Table 1. – Proportions of components in class B25

Best price from MosBetonTorg LLC

Concrete is sold throughout Moscow and the Moscow region. In order to buy the required solution, study the price list, select the required brand and agree on the volume with the company’s managers.

Over 10 years of high-quality work, thousands of companies and private customers have become clients of MosBetonTorg LLC. Every year we improve and develop our activities and today we offer not only a wide range of concrete products, but also an individual approach to each client.

Strength and brand

Before analyzing the composition itself, we need to figure out what the concrete grade B25 actually means?

• Grade is an indicator that characterizes the resistance of a material to compressive load . Usually the brand is designated by the index M with a digital designation of the tensile strength of concrete in kgf/cm2. Thus, if, for example, we use composition M 400 (also the very popular concrete C25 30), then we can talk about a strength of 400 kgf/cm2.
• However, recently the brand has been used less and less often to indicate the properties of a material . It was replaced by such a parameter as class. This value represents the compressive strength (in MPa) guaranteed in 95% of cases.

Sample testing

Note! Determination of the class and grade of material is carried out experimentally. To do this, cubes 150x150x150 mm are cast from a standard solution with precisely maintained proportions, dried for 28 days and tested under pressure.

• Today, GOST 26633-91 establishes the relationship between grades and classes of concrete used in construction (the table is given in the article below). If we take these characteristics into account, concrete B25 corresponds to grade M350 (strength - 25 MPa or 327 kgf/cm2).

The ratio of class, strength and brand

How is it produced?

Concrete can be made at a building materials factory or at home, strictly observing the proportions. In the first option, the buyer is provided with the technical conditions and regulatory documents according to which the mixture was made. When preparing at home, builders focus on maintaining the ratios of dry components and quality control of raw materials. The composition includes: cement of different brands, crushed stone or gravel, sand. M350 concrete proportions:

• 1 (M400):3.1:1.5;
• 1 (M500):3.6:1.9.

Compliance with proportions is an important condition for preparing a high-quality solution.
Additional ingredients are added to enhance properties if necessary. Their number is calculated by the builder or a competent person. Lastly, add water. Its consumption depends on the required consistency. On average, the ratio of cement to water is 1:0.5, respectively. You can mix the components either manually or in a concrete mixer.

Preparation of concrete m350

Figure 3. Preparation of concrete M350
Concrete class B25 is applicable in the construction of many buildings and no matter what kind of construction is underway - it is important to prepare the solution correctly. If you plan to prepare the mixture yourself, the main thing is to know the correct proportions, requirements for each component and stock up on a concrete mixer for the job. It will be difficult to mix the solution yourself - due to the presence of crushed stone in it, the solution will be difficult to stir.

The stages of preparing concrete M 350 are as follows:

• mix the dry ingredients until the coarse aggregate is added in the bowl of the concrete mixer;
• then water is gradually introduced and the mixture is constantly stirred;
• Next, the necessary plasticizers and additives are introduced into the mixture, giving it the necessary properties and characteristics.

Afterwards, the solution is poured into the structure itself, the mold is poured, and everything is thoroughly moistened with water. The main thing to remember is that the prepared solution should be poured within the next couple of hours after preparation, from the moment it is mixed with water.

If at the moment it is not possible to prepare the solution yourself, such work can be ordered from the factory. But the cost of the solution will be an order of magnitude higher in this case, because it is not only the cost of the components, but also the services for preparing the mixture. Plus, the company’s profit, as well as transportation costs.

It is important to remember that if you are not sure that you can make the solution yourself, then it is best to order services from a construction company. In this case, you are guaranteed to receive a high-quality solution prepared in accordance with all the rules and procedures.