Concrete density kg m3: what does this most important

The density of the concrete solution is its main quality. It is interconnected with the severity and strength of the building material. On the basis of this parameter, concrete is divided into brands / classes, which should be selected when building with their own hands various structures and structures.

Important product qualities

The density of concrete (specific gravity) is the ratio of its mass to volume. This value is always less than 100%. The instruction warns that the quality of the finished product is most dependent on this characteristic.

Note! The specific gravity of the mixture is directly related to its strength. The higher this value, the stronger the building material. The optimal values ​​of this value are provided in the factory preparation of concrete.

In amateur construction, it is very difficult to achieve standard values.

Solution classification

1. Compressive strength class is a digital expression of a feature voiced, guaranteed to be 95% guaranteed. This statement means that the quality normalized by the class is valid no less than in 95 specific cases out of a hundred.
2. The product brand is gradually becoming a thing of the past. This classification determined its characteristics, taken on the average value of the tests.

Material porosity

The inverse of the quality of concrete quality is its porosity.

1. Products of any class contain voids, only their volume changes.. Experts voice this characteristic as the ratio of the aggregate of the pores of a product to its total volume. When adding density and porosity, it turns out 100% of material strength.
2. Pores form when excess moisture evaporates during mixing.. Therefore, one should take into account the difference in the properties of a dry mix and kneaded one. It is easy to do, knowing the proportions of its components: a binder, coarse and fine filler.
3. When the setting is completed, the curing of the structure takes effect.. During this process, unbound chemically moisture evaporates.
4. After it, the mass of the finished structure becomes slightly less (hence, for example, the estimated density of concrete m300), rather than the previously laid mortar.
5. This difference depends on the water-cement ratio: the more moisture, the product will be less dense.

Note! To get the most dense, and therefore durable concrete, you need to carefully select the fractionality of the filler. This will reduce the volume of pores in the monolithic structure.

Impact of components and technologies on product density

The density of the finished product depends on the characteristics of all components of the concrete mix.

Filler and binder

1. The component that most affects the density of the batch is the filler. This happens because its volume in the mixture is the most significant.
2. When using lightweight fillers, its density is very low. Volumetric weight is also reduced.
3. The density of the material is directly influenced by its styling technology. For example, when using special vibrators, excess water and air bubbles are forced out of solution. As a result, the poured structure acquires an increased density, which means reliability and durability. Although increasing the price of work.

1. To increase the density of heavy concrete kg m3, manufacturers use a special cement: aluminous, expanding, pozzolanic. It should be borne in mind that this solution is more difficult to lay.

Other components

1. To avoid the problem of difficult styling of heavy mixes and to improve some of their other properties, plasticizers are used. They also compact fresh concrete.
2. To rid the solution of excess moisture, can be applied modern method of vacuuming. Thus, for example, the density of asphalt concrete is increased by kg m3 when laying the road bed. Vacuuming is most effective for solutions on silicate or slagosilicate cement.

Variety of solution

Based on the density (specific gravity), and hence the strength, concrete solutions differ in classes or brands.

Dense mixture

1. Particularly heavy solutions are used on special objects. Of them are made reactors and walls of nuclear power plants, as well as roads, runways of airfields, industrial floors. Such a building material is the most dense. This indicator can reach 6000 kg per m3 due to the use of special fillers. For example, metal filings.
2. Heavy or general construction concretes are the main building material for the manufacture of monolithic structures and structures. Estimation of the density of the material is carried out by its mark.

Lightweight and lightweight solutions

1. Lightweight product has a density of 1800/2200 kg / m3. It is usually used for supporting structures. For example, the density of concrete m400 kg m3 is optimal for pouring the foundation. Lightweight brands for strength M-350 / M-500, which correspond to classes B-25 / B-40.

Light types of solutions are more diverse.

1. Light types of concrete on porous fillers (pumice, expanded clay, slags) have a density of 1400/1800 kg per m3. M-100 / M-350, they correspond to the classes B-15 / B-25. Maybe such products are heat-insulating or heat-insulating structural material.
2. Light cellular analogues: gas and foam concrete, consist of a binder, water, finely ground silica filler and pore former. They have a low specific weight (500/1200 kg per m3) and low thermal conductivity. Variety brands - M-15 / M-150, they correspond to the classes B-3.5 / B-12.5. Such concrete can be used for the construction of walls or to act as thermal insulation.
3. Particularly light porous and cellular analogues. Of course, the density of concrete of 15 kg m3 is not achievable, but the producers can produce products with a specific weight of less than 500 kg per cubic meter. The strength classes of such material are B-1 / B-10. Its main task is to provide thermal insulation of buildings.

Conclusion

The density of concrete directly affects the strength and durability of the cast structure. Therefore, it is necessary to carefully approach the choice of this characteristic.

The video in this article will be useful to you and will tell more about its topic.