What is heavy concrete, its composition and types
The contents
Heavy concrete is a type of solution used in steel-frame construction, mainly for pouring the Foundation of a large building. Its name he received due to the fillers that are part of it. These fillers are the most durable and reliable, why their weight increases. Hence the name – heavy concrete.
The main components ↑
As a rule, the composition of the concrete does not change, regardless of whether light or severe. Can change only individual components, which set the tone for the solution. So, the composition includes:
- Cement is one of the basic elements of the mixture. To make heavy concrete, cement is added brand M200 or M300. To the solution was the most robust, it is best to add Portland cement.
- Water. Please note, use only pure water, it should not even a small fraction of chemical admixtures and mineral additives. Clean water is the key to good concrete.
- Sand. For kneading quality of the solution is preferable to buy pure sand. Clay and others leaving it to be completely absent, as this may affect the strength of the solution.
- Filler. You can use crushed stone, gravel. However, for heavy concrete was more durable, better to use granite or other rocks, which are famous for its fortress. As an additional binder can be added to a solution of marble chips. This filler is not cheap, but holds it perfectly.
- Supplements. Using the manufacture of a solution of the additive, chemical or mineral, you can improve quality, increase strength, service life, water resistance, corrosion resistance and other important indicators.
The scope ↑
Usually heavy and super heavy concretes used in the construction of industrial scale. For example, such solutions are used for the construction of Bank vaults, military installations and other strategic facilities, service stations, Parking lots for heavy vehicles, floors in large shopping centers, nuclear power plants and other facilities. Such a solution with proper planning, able to withstand loads up to 3000kg/mThree.
The types of heavy concrete ↑
Consider what are heavy concretes:
- Having high strength. In the composition of this basically adds a special substance that gives a solution of plasticity. Also to give greater strength it is subjected to a special procedure – the vibrating.
- Concrete. This type is used when casting the reinforcement structures are particularly strong overlaps, as well as in the manufacture of concrete blocks.
- Hardens quickly. It consists of cement, with the ability to quickly stiffen and harden. So, the solution solidifies faster, reducing time to a minimum without reducing the quality.
- Hydraulic. A special kind that allows you to use it in places high humidity, and in the construction of water facilities.
- Road. Usually this type is used for road paving, but if you need a solution that can withstand heavy loads, then apply for.
- Fine-grained. The name of the solution obtained through the absence in its composition of rocks and large gravel. Most often used when you need fine work, for example, during the laying of the thin walls. The manufacturer of this kind is also regulated by GOST. Previously it was a GOST 26633-91, now it is a GOST 26633-2012.
- Decorative. This form is used in cases when you want to apply a design decision in parks. From such concrete make beautiful borders and original sculptural solutions adorning parks and promenades.
Types of concrete a lot, due to which its scope is almost infinite.
Characteristics ↑
To select high quality concrete, evaluate it according to the following criteria:
- Strength. Typically, the concrete is checked for the density compression. Hard solutions because of its purpose needs to cope with heavy loads while retaining its integrity. The solution had a maximum strength, it should be composed of cement grade M100-M800, and the best Portland cement and higher proportions of cement and water, the stronger the solution turns.
- Class of concrete. This criterion speaks to the durability of the compression concrete and the limit of its stretching. In other words, the greater the compressive strength, the better. With regard to tensile strength, it is less than the compressive strength. These indicators are identified as: compression strength indicated by the letter b and is measured in MPa, tensile strength is denoted by the index mode of BT. Thus, the higher these indicators, the better the concrete.
- Frost. Another important indicator. Because of the temperatures in the concrete accumulates water, which significantly affects the quality and durability. The solution should be frost resistant. This feature allows you to keep its original properties. Frost resistance is indicated by the letter F.
- Water resistant. The higher this number is, the longer is concrete. This figure is denoted with the letter W.
- Refractoriness. This property of concrete is particularly important when a building or any other object subjected to treatments of high temperatures, e.g. fire or explosion.
GOST ↑
Solution, like any product, has its own standard reference rules for the manufacture, performance, composition, you need to follow strictly. So, rules of manufacture of heavy concrete is GOST 26633-2012. According to GOST the solution in the standard have the following characteristics:
- The Freeze-Resistance – F500.
- Water Resistant – W6-W12.
- Shrinkage during setting – 0.15 mm 1 meter.
- Tensile strength – Bt10-Bt40.
The composition of concrete ↑
To produce a solution of high strength and with better quality on other characteristics, you need to connect the components, observing the following proportions:
- 1 part cement.
- 2 parts sand. As a rule, in heavy concretes using coarse sand. It is necessary to increase the strength, as in this case, sand is used as a binder component.
- 4 parts of filler. Fits any filler, what is the most available.
- 0.8 parts of water. The water should be clean and without impurities.
In General, the composition proportion of chemical impurities is not more than 4-5% of the total weight of the resulting mass.
Concrete fully hardens, «becomes an adult» after 28 days, provided that the room temperature was not lower than 16-18°C and the humidity does not exceed 50-60%.
The characteristics of different classes ↑
Each class, as each has its own characteristics and quality. According to GOST there are a whole range of classes of solution adopted as a global standard. The product line includes the solutions of the different class rating: B3,5; B5; B7,5; B10; B12,5; B15; B20; B25; B30; B35; C40; В45; B50; W55; B60; B70; B80; B90; 100. GOST also allows for intermediate classes, for example, is 27.5. Each of these types has its own set of properties that need to pay special attention when choosing the type of concrete. As a rule, all characteristics of these species are listed in the Guest, which guided the creation of the solution specified classes.
Superheavy concretes ↑
Heavy concrete is a type, which includes expensive and very rare components, due to which solution is most durable and increases its weight. So, this type is exclusively intended for industrial construction, why to use it in the construction of ordinary objects is not very cost effective. Therefore it is not necessary to order extra-heavy concrete for the pouring of the Foundation on the plot.
The cost ↑
The price of the solution depends on the value of its components. For example, to find clean water, gravel or sand without any admixture of clay is not a problem, but the additives that improve the quality, not just. Also the price depends on its brand. For example, the solution of mark M100 will cost 2400rub/mThree. The higher the grade, the higher the price.
Super heavy concretes are not used in home construction because of the high cost of components. It is composed of elements that are difficult to find, due to this, its value increases.
So you have a clear picture about the hard concrete, we bring you the video