Concrete m 300 - general data and characteristics. dry

At this stage in the development of the construction industry, concrete M300 can be called the most common. In fact, it is a transitional mark from lightweight compounds to heavy concrete. In industry, it is used in the construction of workshops and general-purpose facilities; in residential construction, concrete 300 is used everywhere, from filling foundations and ceilings to building fences and pavements.

Characteristics and subtleties of choice

All such compounds are labeled in accordance with GOST 26633-91.

But this composition is developed relatively recently and, although it is produced, guided by the same GOST, but with separate technical conditions.

• No matter how strange it may sound, but in the classic document ST SEV 1406-78 there is also no class B22.5 to which concrete 300 must correspond. Therefore, one can often find class B25 for concrete M300.
• Despite these oddities, this brand is produced and used everywhere, both in the serial, multi-storey, and in the private segment of the market. This strength is quite enough for the construction of the vast majority of buildings. Manufacturers love it at a relatively low cost, and consumers for a decent price / quality ratio.

Tip: for the manufacturer to obtain a certificate is not a big deal. As already mentioned, clear standards GOST for this product does not exist, and production according to specifications can be carried out with certain tolerances, so when buying, pay attention to the composition.

Properties and specifications

If you take a clear physical characteristics, the class of concrete grade 300 corresponds to B22,5.

But thanks to additives and the use of different types of filler can be brought to B25.

• As is known, the brand or class of the composition is assigned depending on the load that the prototype is able to withstand. According to the norms, this brand maintains 295 - 300 kg / cm ?.
• If you do not take into account the special additives, the characteristics of concrete grade 300, can be seriously changed using different types of coarse aggregate. As it is known, 3 types of crushed stone are used in production, it is lime, gravel and the most expensive and high-quality granite.

• The cold resistance of the running gear ranges from F100 to F200. The lowest frost resistance characteristics are shown with lime-filled mortars, respectively, the highest for crushed granite. Gravel rubble gives averaged results.
• Approximately the same can be said about the indicators of water resistance. On average, for the M300, they are equal to W4 - W6. The ratios are the same; crushed stone shows W4, granite W6. But this is not the limit, as frost resistance and water resistance can be increased by an order of magnitude through the use of special additives.
• One of the main characteristics of the solution is its mobility or plasticity. It is denoted by the letter "P" and a digital ratio of 1 - 5.
• Concrete 300 must have a plasticity P2 - P4. There are manufacturers who promise to make a composition with mobility P6, be careful of such labeling does not exist. Using additives can bring to P5, but not more.

Tip: if you order a ready-made solution, check that it is not diluted with water directly at the facility. Thus, the turnover will increase, but M300, after solidification, will turn into M150 or M200.

• Adding water is dangerous because the cement will take a strictly defined amount of moisture, the rest of the water will gradually evaporate, leaving voids in the array. As a result, the monolith fortress falls by an order of magnitude.

Dry mixes

Nowadays, dry mixes made on the basis of concrete recipes of 300 are widely used in private construction.

In the domestic version they are called sand concrete.

• They can be used without filler, and with the addition of rubble. In addition to their high qualities, they are also convenient because the instruction only requires adding water and stirring.
• The price of these mixtures ranges from 120 to 150 rubles per pack of 50kg. The mixture is packed in bags with a capacity of 20-50 kg. This is certainly more expensive than the cost of the finished solution, but it is convenient in private construction.

Composition and preparation

In the factory, the concrete of the brand 300 includes a standard set of cement, sand, crushed stone, which are naturally diluted with water.

At the request of the customer, additives can be added to enhance certain characteristics.

• Cement is used by two grades M400 or M500, the varieties of rubble have already been said. As for the sand, it should, if possible, be clean, sifted, without impurities. Water is taken weak acidity.
• The classic proportions of 300 concrete are not a big secret, you can find them in the tables below.. Here you need to pay more attention to the quality of the components. If you need to pour a high-quality foundation for a large house, then you should spend money on a solution that contains M500 cement and crushed granite.

• As for the question - how to make concrete brand 300 with your own hands, it is quite possible at home. In addition to the above mentioned components, we advise you to get a concrete mixer and a deep electric vibrator. From experience, it can be said for sure that it is impossible to mix and properly fill in large volumes of the solution without these tools.
• Undoubtedly, complex additives for the preparation of the solution are good, but it is advisable to use them when it comes to the installation of important, important objects with a constant load.

• If you need to fill the foundation for an easy country house, concreted fence posts or make a blind area around the house, then it is quite possible to do with old-fashioned methods.
• So the plasticity of the solution is increased by adding a small amount of hydrated lime.. For these purposes, you can use detergent for dishes or soap solution of high concentration. Water resistance increases if you add liquid potash glass, and the setting speed increases if you add PVA glue. But do not forget that additives are made within 2% of the amount of cement.

The video in this article shows how to make concrete 300 with your own hands.

Conclusion

Подытоживая статью, хочется ответить на вопрос, сколько стоит 1 куб бетона марки 300. Если брать в среднем с доставкой на расстояние до 50км, цена колеблется в пределах 4 – 4,5 тысяч рублей. Но не забывайте, что кроме собственно транспортных расходов, стоимость может изменяться от вида наполнителя и количества присадок (см.также статью «Бетон 200: характеристики и область применения»).