Which components are part of the concrete m300. Composition and proportions of concrete m300

Commodity concrete m300 per 22.5 -it has high strength, frost resistance and water resistance. The brand of concrete m300 is widely used for the construction of monolithic foundations, walls of cellars, ceilings and staircases.

Paths, sidewalks, blind areas and open areas made of m300 concrete can be operated without additional protection from moisture and thawing (hydrophobization).

Concrete mixtures of m-300 are usually produced on the basis of gravel or granite crushed stone. The greatest durability of the construction is achieved when the m-300 concrete is closed on granite crushed stone. Some concrete plants, for the sake of economy, can produce mixtures of m-300 on limestone and dolomite.

Concrete m-300 in-22.5  - the most popular brand of concrete  among private developers. Of course, concrete grade 300 - the leader in sales in the Russian market. Our price for concrete m-250 is indicated taking into account delivery in Moscow.

You can use the calculator to calculate the required amount of concrete.

Ready-mixed concrete of the brand m300 in 22.5  finds the widest application when pouring all types of monolithic foundations: tape, pile-grillage, slab. Concrete blind areas, platforms, ramps, garden paths, ribbons of brick fences are everywhere cast from the brand m300. Also, the concrete mixture m-300 in-22.5 is used for pouring ladders, steps, retaining walls. When constructing a house, m3 concrete can be cast slabs of ceilings, walls of cellars, columns, staircases.

In the modern system of classification of concretes adopted in accordance with St SEV 1406, the class of concrete of the mark m300 - B22.5 occupies an intermediate stage, and "in the Hamburg account", it should not occur in modern design documentation.

Delivered on truck mixers 7-10 bottles. When delivering a volume less than 7 cubes to the total cost of the order, the cost of the transported "air" is added. For example: the price of 1 cube of concrete with delivery = 3500 rubles
  the cost of 7 cubes with delivery, respectively, 3500 * 7 = 24500 rubles
  when ordering 5 cubic meters, the cost is calculated as follows: 3500 * 5 + 800 rubles = 18300 rubles (where 800 rubles - the cost of delivery 2 cubes of "air", since the cost of 1 car is standard and does not vary depending on the transported cubic capacity.

Is concrete m300 suitable for the foundation of a 3-storey house 12x14m from foam blocks?

Much depends on the construction of the foundation. In general, the brand of concrete 300 provides sufficient strength for such a load. It is only necessary to consider the type of foundation, the cross-section of the tape or the thickness of the slab should provide sufficient spatial rigidity. That is, if you pour a foundation slab 20 cm thick without additional ribs, almost certainly your foundation will burst. Similarly with a tape. The height and thickness of the tape should be at least 100 * 40 cm (respectively)

We plan to fill the slab in the private house. Concrete 300 brand is suitable?

In general, in 22.5 - a frontier mark for similar types of work. If during operation your overlap is not planned to be heavily loaded with heavy objects and structures such as stoves, fireplaces, large aquariums, etc. it is quite possible to manage m300. However, we would recommend buying a higher grade concrete - M350. This is the most optimal brand for monolithic ceilings.

The concrete grade M300 is the most demanded structure in construction. When performing large amounts of work, where a lot of solution is required, it must be bought with cubes. At the same time it is quite elevated for a private builder, and the strength class of B22.5 is more than enough to build reliable load-bearing structures.

Concrete grade M300 - the best option for the construction of foundation and load-bearing structures. With its help, all the main types of work in individual construction are carried out:

• Filling the foundation for heavy fences.
• The arrangement of sewerage wells.
• Performance of screed with a capacity of up to 100 mm with reinforcement.
• Floor leveling.
• Arrangement of pavement and pavements.

The M300 is also used in production for the manufacture of concrete products - wall and foundation blocks, staircases, curbs.

Features

By its density, the composition is closer to light solutions and costs almost as cheaply. But its strength is close to heavy concretes, plus high moisture resistance:

1. Strength - 295-302 kgf / cm 2 after hardening.

2. Plasticity (workability) M300 - within the categories P2-P4.

3. Frost resistance - 100-200 cycles. This indicator can be improved with the help of calcareous crushed stone.

4. Watertightness - the norm is W4-W.

Weight will depend on how much mineral aggregates are added as a percentage. For calculations, an indicative figure of 1.8-2.4 t / m 3 is taken.

The composition of the concrete can be improved even if you make the solution yourself. To increase the plastic properties you will need a little slaked lime or liquid soap, and water absorption will reduce the water glass. But when choosing the proportions, you need to make sure that the additives by volume do not exceed 2% of the total mass.

Composition and proportions

M300 is not mentioned either under its own name or under the brand B22.5 in SNiP 52-01-2003. Manufacturers produce this mixture by separately developed technical conditions. Therefore, if you decide to buy, and do not do it yourself, it is worth asking its composition.

Concrete of grade В22,5 of mark М-300 should be made of cement of high quality not below М400. To increase the strength and increase the class to the level of B25, the use of granite gravel, limestone or gravel fraction of 5-40 mm is allowed. The main thing is that their strength is not less than 2 times higher than the M300 mark.

Different modifiers in small proportions also have a beneficial effect on the strength of structures. In addition, they allow to increase frost resistance and other characteristics, as well as cost.

If you want to get the M300 mark yourself, you can take the standard proportions of the composition of the concrete from the table (given in parts of the volume):

The resulted relation in buckets is more convenient at independent preparation of a mix «in field conditions». The quality will depend on the characteristics of the dry aggregates, and the strength of the finished structure depends on the volume of the water.

• 350 kg of cement;
• 800 kg of sand;
• 1000 kg of crushed stone;
• 200 liters of water (its amount will depend on the properties of cement and sand).

In the resulting solution, no more than 10 kg of plasticizing additives can be added to produce an M300 cube (about 2.4 tons) at the output and maintain the correct proportions of concrete.

Cost with delivery

Dry mixture, packaged in bags of 50 kg, "Peskobeton M300" can be bought for 135-150 rubles. This is an outlet for those who are not sure about the correct ratio of "home recipes", or if the delivery of a solution to the construction site is difficult. When there are no problems with access roads, it is cheaper to order a ready-made train in a special vehicle. In this case, the cost of concrete per cube with delivery will be less due to the purchased volume and lack of packaging - this will even block the cost of transport (about 10-15% of the price).

The price of B22.5 reflects the type of large-fraction aggregate, as granite is 8-10% more expensive than gravel. If you need additives that increase frost resistance or other properties, you will have to pay another 100 rubles per cubic meter, regardless of the proportions.

In the direction of increasing the price mileage can work - the further the delivery of concrete, the more expensive it will be to pay for it. Without the price, the price fluctuates between 3.5-4.5 thousand rubles. Such a run depends on whether the manufacturer has his own quarries or whether he himself has to be satisfied with the supply of raw materials from afar.

The distance between the facility and the cement plant at 10 km will increase the purchase price by 350 rubles. And every 5 km the price per 1 m 3 will increase by about 50-80 rubles. Those who are built within the Moscow Ring Road, usually do not have to pay for shipping.

At whom to buy?

Some intermediary companies that practice a "flexible pricing policy", just on the M300 brand and do the maximum wrapping, balancing the decline in prices for stronger but not too demanded types of concrete.

Much more honest in this respect are the manufacturers themselves - the cost of their products is usually calculated in direct proportion to the costs of its release plus profits. Just do not be flattered by offers with free shipping: the manufacturer will still cover its costs at your expense and well, if simply by picking up the price of concrete, rather than sacrificing it by quality.

When choosing a seller of M300 concretes, ask the manager which transport will deliver the solution to the facility. If you are offered a dump truck, look for another supplier who knows that it is possible to keep the characteristics of the composition at the level of class B22.5 only in a concrete mixer.

Construction work accompanies a person in time and space throughout its history. And if at the dawn of its existence mankind used only natural building materials such as stone, wood, adobe, then with the development of building technologies, artificial ones began to appear. And among them - concrete, without which today there is not a single modern structure.

The main components of the concrete mix are cement (binder), sand (fine aggregate), crushed stone (large aggregate) and water.

And depending on what cement is used, and in what proportions the components are mixed, the strength, waterproofness, frost resistance and other parameters of the concrete mix depend.

Concrete mixture: its components and their characteristics

Cement. Characterized by the brand in the range from M100 to M600, indicating its strength. For example, the M400 withstands a load of 400 kg / cm³. The most popular brands M300, M400, M500 are used in industrial, transport and individual construction, as well as in repair work.

Sand. For concrete M300 and below, fine and medium sand with a grain size (fractions) of 1 to 2.5 mm is used. For other grades, the sand fraction can reach 3.5 mm.

Crushed stone. Large aggregate of concrete mix with fractions from 5 to 70 mm. Depending on the rock used, gravel may be gravel, granite or lime.

Water. It should not contain harmful impurities (tap, river, rain, snow). If the litmus paper is not painted in water in red, then this water can be used.

For concrete, it also created its own classification by brand and class. The main brands lie in the range from M100 to M600, depending on the brand of cement and its quantity in the mixture. The brand characterizes the compressive strength and is measured in kgf / cm² (1 kg force - the force with which a body weighing 1 kg presses 1 cm²). For the calculation of reinforced concrete structures, the strength of concrete is more convenient to characterize by its class. For the translation of the mark in the class there are tables of ratios approved by GOST.

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Concrete: characteristics, application

The main characteristics of the concrete are its frost resistance and water resistance. M300, possessing these qualities, is also highly resistant to erasure, and, unlike higher grades, does not grasp so fast that it can be transported over long distances (important quality). All these properties of the M300 together with the ideal price-quality ratio have made this brand the most consumed in the market of concrete products.

In individual construction for the preparation of several cubes of concrete M300, you can make an independent calculation of its components.

Let's start with choosing a brand of cement. To do this, we use the Bolomea-Scrumtaev formula: Rb = A x Rt x (D / B - 0.5), where Rb is the strength of the concrete; A is a factor that takes into account the quality of aggregates (0.4 - 0.6); Rc - cement brand; Ц / В - cement-water ratio.

Table 1

For cement M400 we get: 0.5 x 400 x (2 - 0.5) = 200 x 1.5 = 300 (close to the tabulated value of 294).

For the M500, we get: 0.5 x 500 x (1.67 - 0.5) = 250 x 1.17 = 292.5

When choosing other grades, the ratio of C / B varies significantly, which adversely affects the optimal density of concrete, so consider the proportions of sands and crushed stone for cement brands M400 and M500.

There are normative proportions of concrete M300, indicated in the collection of documents "SNiP 82-02095". In particular, the following standards for cement consumption are specified:

table 2

In the same document we find the ratio of sand and gravel:

Table 3 (for concrete M300)

Suppose that for the basement under the garage at the dacha it is necessary to prepare 6.4 cubic meters of concrete M300 from cement M400.

For one cube of solution it is necessary to take:

• cement (table 2) - 600 kg;
• sand (Table 3) - 1.9 x 600 = 1140 kg;
• rubble (table 3) - 3.7 x 600 = 2220 kg;
• water (table 1) - 300 (15 buckets of 20 liters).

To obtain the total amount of material, multiply each result by 6.4. The calculation is over. Standards from the Internet and a calculator - that's all the tools for calculating the mixture.

Concrete is a ghost that does not occur in any normative document, is concrete m300. Although it is the transition stage between light and heavy solutions. By the standards of class B22.5 does not exist. But this does not prevent the widespread sales and use of this material for the manufacture of foundations, crossbars, fences, sewerage wells and concrete blocks.

It is due to the wide distribution that the characteristics of this type of concrete should be considered in more detail. What will be discussed in the following material.

Concrete m300 - technical specifications

The actual class corresponding to the concrete M300, B22.5. Increase the strength of the future product to the B25 index by:

• use of high quality cement;
• appropriate additives;
• filler;

To make the product more durable as a filler, granite rubble is used. Increasing water resistance and frost resistance is achieved by introducing additives into the composition of the mass. They regulate the properties of the solution, leading to the desired consumer result.

The strength of the product is characterized by an indicator of resistance to the load of 269-300 kg / cm2.

The plasticity of the concrete mass must be in the A2-P4 aisles. These are the optimum conditions for workability. In some cases, the parameter is allowed to expand to P1-P5. To feed the mixture with trays or other capacity, the plasticity of P3 is used. In the presence of the ABN system, the P4 indicator is required.

The frost resistance of structures from the concrete in question is from F100 to F200. When forming the mixture, it must be remembered that calcareous aggregates reduce this index.

Resistance to water destruction is W6. Some suppliers promise even a mark on water resistance W10. With this indicator it is worthwhile to take an interest in other properties, due to the reduction of which they achieved a similar result.

The grasping of the concrete mix occurs rather quickly. Therefore this type of material is not transported over long distances. It is best to manufacture in a construction site.

Composition and proportions of concrete m300

Not only the preparation of concrete requires knowledge of proportions. Knowing the right relationships, you can control the cooking process and, accordingly, the properties of the future material.

To prepare the mortar, M400 or M500 cement is used.

The following may be used as a filler:

• gravel;
• limestone;
• broken brick;
• sand with clay impurities;

The last two options are peculiar to handicraft making. The use of this type of aggregate reduces the performance characteristics, depending on the quality of the material. In the factory production, crushed stone is used, ranging from 5 to 40 mm in size.

Mixing occurs in the following proportions:

Purified water is added to the volume of 0.5 of the volume of cement. Although the occurrence of this component depends on the moisture content of the sand and the cement mass. If the humidity of the environment increases, the amount of liquid is reduced.

First, cement and sand are mixed. Sand mass is pre-sieved from dirt and debris. After mixing, water is poured in. Pour in water gradually, constantly mixing the mixture. It is necessary to monitor the viscosity, otherwise the consistency may be inappropriate for the product. Lastly, a large aggregate is added to the solution.

For sites with difficult access of machinery and machines carrying composite components, use ready-made dry mixes. They are packaged in bags of 25 or 50 kg. The composition already includes all elements, including those forming certain characteristics, additives.

Although it is much more convenient to produce concrete m300 in the construction site, it is better to order the mixture. In this case, high quality products and the correct characteristics of future designs will be ensured.

Concrete M300 - one of the most common and claimed brands of concrete. It is this concrete that is used for the work on pouring foundations of private structures, fences, stairs, beams, piles. M300 differs from other brands with its technical and operational characteristics, as well as its cost. In addition, it is not difficult to do it in the conditions of independent construction with the use of simple tools.

Operational properties

Before considering the main technical characteristics, it should be noted that the M300, like most other brands, is gaining full strength for a long time, about six months. However, approximately 95-98% of the main changes occur within a period of up to 28 days from the moment of mixing of cement and water. It is this time that is set as the age of the mixture to determine the main characteristics.

Scope of concrete compounds - building structures, in which a significant load is assumed. Therefore, the main property of concrete is the ability to resist the load - strength. This characteristic is inherent in the designation of the brand for strength.

What does the M300 mean?

The standard specific gravity of 1m3 is 1800-2500 kg. This indicator is directly related to the density. This characteristic depends, in the main, on the type of crushed stone that is part of its composition and varies from 1800 (using limestone) to 2500 kg / m3 (if rubble is made of granite, granodiorite and similar rocks). Such M300 allows to classify it to heavy types, it indicates its high strength, frost resistance and water resistance.

In addition to the filler rock, the weight and density are strongly influenced by the application method and the presence of air cavities in the concrete. Reducing the density below the above-mentioned boundaries indicates a violation of the manufacturing technology, laying and the strength of the construction of such concrete will also not be calculated.

Secondly, the brand of frost resistance. This characteristic is designated as FXXX, where XXX is the number of cycles of freezing and thawing without loss of strength properties (grade by strength). Concrete M300, produced according to the classic recipe, has a class of frost resistance around F150. You can increase it in the following ways:

• introduction of additives in the mixture that prevent the formation of air bubbles;
• removal of air from the mixture by seals, vibrators;
• by decreasing the water content of the mixture. However, such a measure leads to a deterioration of another characteristic - the level of mobility;
• use for filling granite rubble instead of lime.

Third, the brand is waterproof. The designation is WXX, where XX is the figure showing the MPa pressure 10-1, which is required for water to pass through the thickness of the concrete at 15 cm. In M300, this value is W5-W6, i.e. such concrete should not pass water at a pressure of 0.5-0.6 MPa, which is equal to 5-6 atmospheres ... Improve this feature by using hydrophobic cement, special additives, taking measures to compact the mixture.

Fourth, mobility, otherwise called workability. It is designated as ПХ, where Х - figure from 1 to 5. For concrete poured by means of pumping equipment, the most suitable mobility will be П4 - П5. Mobility depends on the amount of water in the mixture, the presence of additives - plasticizers.

Property sheet

Combining all the characteristics discussed, for the M300 concreting strength, you can create a summary table of properties:

Table 3 - Properties of M300

For the convenience of production, the proportions of concrete m300 are indicated, as a rule, in a volume ratio. The classic recipe looks like this:

Table 4 - Batch formulation

The table gives the weight composition for obtaining 1 cc. m of concrete. As you can see, the higher the brand of cement, the higher the consumption of materials per 1m3 of the mixture, but less the consumption of the cement itself.

To obtain a high quality building material, it is necessary to use sand of fraction 1.5-3 mm. The sand must be uniform, without clay particles. It is better to use river sand from the bends of rivers with a rapid current - it is cleaner. In case of using quarry sand, it should be washed. Crushed stone must have dimensions from 5 to 20 mm. The best for the production of concrete is a granite gravel.

Many owners of land are often taken to produce concrete with their own hands. For small volumes and for non-strict requirements for strength characteristics, such a measure is fully justified.

Tools

To make the concrete mixture M300 with your own hands, you need a concrete mixer and hand tools.

Concrete mixer - the type of this mechanism and the volume of its drum depends on the required amount of concrete mixture. For the manufacture of pedestrian paths, pouring small areas in the yard, it will be enough concrete mixers with a drum capacity of 60-80 liters.

When constructing the basement of the garage, baths, utility rooms, the single capacity of the concrete mixer should be already 100-120 liters, and in order to prepare the right amount of concrete for the erection of a buried or slab foundation of a residential house, a base under a stone fence requires a more solid machine - 150-250 liters.

A hand tool is a shovel for loading loose components, buckets for pouring water into a mixer, measuring tanks for exact compliance with the proportions of the composition.

Measuring tanks can be made from buckets, previously weighed in them sand, cement and crushed stone, counting the required number of buckets for one batch.

Production procedure

Production should be carried out in the following order.

Pour into the mixer approximately ¾ of all the water required for the calculations. Turn the rotation of the drum or blades (depending on the type of concrete mixer). Add the correct amount of cement to the working volume. As a result of mixing water and cement, cement milk will be obtained, which has better adhesion properties. The next additive composition - crushed stone, and lastly - sand.

There is no fundamental difference in the order of adding ingredients, but the experience of the builders shows that this order reduces the mixing time and improves the homogeneity of the mixture. Stirring should last at least 5 minutes. The achievement of the desired quality and the end of the procedure can be judged from the fact that it is impossible to determine the original color of the particles of rubble and sand in the mixture - they all have acquired the color of the cement mortar.

When using the prepared concrete, it must be remembered that from the moment of contact of water and cement, the process of formation of solid bonds began, ie, the mixture began to solidify, therefore it is necessary to work quickly and continuously. The time of solidification of concrete decreases with increasing ambient temperature and the components of the mixture.