The correct proportions of concrete M300. Composition and proportions of concrete m300

Comments:

• Specifications M300
• Proportions of components

Those who build a house with their own hands are extremely interested in the correct proportions of M300 concrete.

They are filled with structures that experience significant mechanical stress:

• tape, columnar and other foundations;
• floor slabs;
• monolithic walls;
• stairs;
• roadbed and similar platforms;
• walls and bottoms of hydraulic structures.

This universality of concrete contributes to its characteristics, as it is able to withstand low temperatures and high pressures and withstand the effects of corrosive environments. To learn about the properties of this brand, you need to talk more about them.

Specifications M300

According to the frost resistance, concrete belongs to the class F200: it can withstand, without breaking down and without losing strength, 200 cycles of frost-defrosting. It would seem that this is a weak indicator, and the concrete product will last only for several years of operation, but this is not so. The frost resistance class is set for a water-saturated solution. And impregnate it with liquid is difficult, because the class of water resistance M300 - W6. This means that a concrete slab 15 cm thick will become an impenetrable barrier to water, supplied with a pressure of 6 kgf / cm 2. Otherwise, the 15-cm bottom of the pool, flooded with concrete M300, withstands a 60-meter thick water.

In addition to these characteristics, amateur developers may be interested in the indicators of a concrete solution:

• by mobility;
• on strength.

As for the latest specification, the M300 marking assumes that the product of this brand can withstand a pressure of 300 kg / cm 2. Concrete with a mobility class from P2 to P4 can be poured into shapes of different configurations, since the solution settles quite well under its own weight.

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Proportions of components

You can also make a concrete mortar M300 in the home. To get a quality mix for construction, it is important to comply with the requirements that are imposed on its components. You should know that the recipe for this mixture assumes that the filler will be rubble:

• granite;
• lime;
• gravel.

For the production of concrete, a filler is used, the transverse dimensions of the pebbles in which should be within 1-2 cm. The optimal fraction of sand is 1.5-2 mm.

Concrete M300 is the most popular and frequently occurring brand with a wide range of applications. Due to the density of this material, it is used when laying roadbeds and aerodrome covers, bridges, foundations and much more.

Concrete is an artificial stone, which includes water, cement, small and large aggregates. It is difficult to imagine a construction site without this material. There is a misconception that this material is the same everywhere, has no varieties, is identical in characteristics and properties. In fact, this is not so. There are many varieties and brands of this product, and in each specific case it is necessary to select the appropriate type. Usually this is done using the generally accepted property of strength. It is denoted by the capital letter M and a numerical value. The range of brands begins with M100 and ends with M500.

The composition of this concrete is similar to a number of brands located towards it.

Characteristics

• Components - cement, sand, water and rubble;
• Proportions: 1 kg of M400 cement accounts for 1.9 kg. sand and 3.7 kg of rubble. For 1 kg. cement M500 is 2.4 kg. sand, 4,3 kg. rubble;
• Proportions based on volumes: 1 serving of cement M400, sand - 1.7 servings, gravel - 3.2 servings. Or 1 portion of cement M500, sand - 2.2 servings, crushed stone - 3,7 servings.
• Volumetric composition per 1 liter. cement: 1.7 liters. sand and 3.2 liters. rubble;
• Class - B22.5;
• On average, of 1 liter. cement leaves 4.1 liters. concrete;
• Density of concrete mix - 2415 kg / m3;
• Frost resistance - 300 F;
• Water resistant - 8 W;
• Workability - P2;
• Weight 1 m3 - about 2.4 tons.

Application

Areas of application:

• construction of walls,
• the device of various types of foundations of monolithic type
• can be used for the manufacture of stairs, pouring areas.

Manufacturing

Various types of fillers are used for the M300:

• gravel,
• limestone,
• granite.

To obtain a mixture of this brand, cement type M400 or M500 is used.

In order to get a high-quality product as a result, it is necessary to strictly adhere to the technology of mixing the solution, to use exclusively benign fillers and to adhere precisely to the prescribed proportions of all components.

Many amateur builders, trying to save money or from the principle, do not purchase the prepared concrete mixes, but manufacture them themselves. To produce this building material is not difficult and does not require special skills.

In all cement solutions, the volume of water is selected as half of the amount of cement. Thus, a portion of water is 0.5.

It is very important to diligently dilute first the cement solution, and then the concrete itself to a homogeneous mass. In this case, the cooked product will be high quality and reliable.

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.

Concrete is an indispensable material in construction. But many still think that concrete - he and in Africa concrete, that is, always and everywhere the same. But this is far from the case. Concrete is divided into numerous classes and brands for different indicators. The most common indicator is the strength of concrete, which is indicated by the letter M and the numerical value (M150, M200, M300, etc.).

Why M 300?

Concrete M300 - this is the most common brand of concrete with the widest range of use. The density of concrete M300 allows it to be used in the construction of road and airfield pavements, bridges, foundations, a variety of concrete structures, hydraulic structures and so on.

Composition of concrete M300 does not differ much from the brands close to it. The same cement, water, sand and filler. For the preparation of concrete M300 different types of fillers are used:

• gravel,
• limestone,
• granite.

To mix concrete of this brand, cement M400 or M500 is used. In order to get high-quality concrete, you need to adhere to the technology of mixing the solution, use only high-quality fillers and strictly observe the proportions of the composition.

Self-cooking

Many amateur builders do not in principle want to buy ready-made concrete mixes, as they strive to do everything themselves. I must say that to cook concrete M300 own handsis not difficult.

The proportions for the preparation of M300 concrete are as follows. If you have M400 cement, then you need to take: cement - 1 part, sand - 1.9 parts and crushed stone - 3.9 parts. The proportions are based on the mass.

Calculation by volume

If it is more convenient for you to calculate the amount of materials by volume, you should take 1 part of cement M400, 1.7 parts of sand and 3.2 parts of gravel.

If you want to make concrete from the brand of cement M500, then the proportions need others. For the manufacture of concrete M300 from cement grade M500 will require: cement 1 part, sand 2.4 parts and rubble 4.3 parts, this is the ideal output for concrete on.

Proportions by volume: 1 part of cement, 2.2 parts of sand and 3.7 parts of crushed stone.

In any cement mortar of water, half of the amount of cement is taken. That is, water should always take 0.5 part.

In order to help you, we will provide a calculator for online counting that will show how much material you need, and on this basis you can count.