The density of reinforced concrete is one of the important characteristics of this material, which is a particularly strong structure. It has many advantages, but there is a disadvantage, expressed in significant weight. Professionals put up with this at the stage of design and construction of facilities. This feature of reinforced concrete must also be taken into account when disassembling structures, in the process of dismantling them.
In practice, reinforced concrete is widely used not only in industry, but also in private construction. You can prepare the mixture for the formation of a reinforced concrete structure yourself, as well as knit reinforcement using a special wire. The result is a durable and sturdy construction.
The main varieties of reinforced concrete
The density of reinforced concrete can vary, which will be affected by the composition of the solution. Whereas weight depends on density. Reinforced concrete is classified precisely from this characteristic, among others it should be distinguished:
- especially heavy;
- heavy;
- lightweight;
- lightweight reinforced concrete.
The density of reinforced concrete in the first case is limited to 2500 kg / m 3, which is an impressive value. In civil engineering, this type of reinforced concrete is not used. The composition may contain the following placeholders:
- magnetite;
- limonite;
- barite.
Reinforced concrete density
For heavy concrete, the density is slightly lower, it is 2200 kg / m 3. Among the ingredients of such material is more familiar gravel, crushed stone, as well as others. The density of reinforced concrete will be even lower when it comes to lightweight concrete. It is heavy concrete with metal reinforcement and through planes. In this case, the parameter of interest will be 1800 kg / m 3.
Lightweight concrete density
Lightweight concrete has a density of 500 kg / m 3. This parameter is peculiar to expanded clay, cellular, perlite and polystyrene concrete. This material is reinforced with reinforcement. The average density of reinforced concrete depends not only on the composition, but also on the pouring method. If the liquid mixture is still compacted using vibrating machines, the density will increase by 100 kg / m 3.
Density calculation
The density of reinforced concrete, the types of which were described above, can be determined if we take the proportions of the solution in units of mass as the basis. From the calculation, liquid should be excluded, which after 28 days will completely disappear from the array. This will allow you to get the exact value of the density of the monolith.
Sometimes builders use averaged data if the brand of concrete is known. For example, for the M-200 brand, the density will vary from 2385 to 2400 kg / m 3, while for the M-250 brand this value will vary from 2390 to 2405 kg / m 3. For grades M-300, M-350 and M-400, the density will be in the range from 2400 to 2415; from 2405 to 2420 and from 2410 to 2430 kg / m 3, respectively.
If you need specific gravity of reinforced concrete, then you should know that the reinforcement pattern also affects the weight of a cubic meter. It is important not only the number of rods, but also their cross section. These parameters allow you to determine the internal volume occupied by the reinforcement. After this, mass calculations can be made. Depending on the purpose and shape of the reinforced concrete, rods of different diameters can be used. As for their installation, they can be located at a certain distance from each other.
In order to find out the density of monolithic reinforced concrete, special accuracy is not necessary, so the number of reinforcement can be taken tentatively. Thus, in the manufacture of concrete walkways and blind areas, 8 mm reinforcement with a mesh size of 200 mm is usually used. One square meter of material will contain 16 m of rods, and if the density of steel is 7850 kg / m 3, then the weight of the reinforcement will be 6.3 kg.
When it comes to horizontal beams with a support, slabs and foundations, the diameter of the reinforcement usually varies from 12 to 16 mm. The cell size decreases to 180 mm, while the total length remains the same. In this case, the mass of the reinforcement will be the limit from 14 to 25.2 kg. For cantilever beams and floor slabs, the diameter of the reinforcement is from 16 to 18 mm, this is true if the mesh size is 130 mm. The total length of reinforcement per 1 m 3 of reinforced concrete will be 49 m, in this case, the weight of reinforcement will vary from 77.3 to 97.8 kg.
Density of additional structures
It will also be fair to consider the option with vertical walls and columns. In this case, the diameter of the reinforcement may be equal to the limit of 14 to 18 mm with a mesh size of 130 mm. The total length remains the same, but the weight will be equal to the limit from 59.2 to 97.8 kg.
As soon as the number of reinforcement and density indicators are known, it will be possible to determine the weight of one cubic meter of reinforced concrete. From the cube, the average volume that is engaged in steel rods is determined. In the end, the volume of concrete is obtained, then the numbers are multiplied by the specific gravity for each material, and the results are added up.
Density calculation on the example of a strip reinforced concrete foundation
The density of reinforced concrete (kg / m3) can be calculated using the example of a strip foundation, which is made of concrete grade M-300. In this case, 16 mm rods were used. At the first stage, the volume occupied by the reinforcement in a cubic meter of material is determined. To do this, use the following calculations: π · r2 · L = 3.14 · (0.008) 2 · 16 = 0.003 m 3.
Thus, clean concrete will occupy 0.997 m 3. To calculate the mass of reinforcing bars, you should multiply the values: 0.003x7850, in the end you will be able to get 23.6 kg, while the mass of concrete needs to be calculated by multiplying 0.997x2400. Calculations will make it clear that the mass of concrete is 2392.8 kg. After the values are summed, you can get the density of reinforced concrete, these calculations will look like this: 23.6 + 2392.8 = 2416 kg / m 3. These manipulations are carried out at the stage of designing the loads on the base of the building.
Concrete Density Information
The density of reinforced concrete and concrete should be known to builders. If the first value was described in detail above, then the second is still worth talking about. The main performance indicator for concrete is the response to uniformity and compression, as well as strength. The listed characteristics are regulated by density, which is a physical indicator determined by the method of dividing mass by volume.
In construction, it is customary to use the average value of this parameter, because it is influenced by various factors, among which:
- quality and size of the filler;
- type of filler;
- water composition;
- granularity of sand.
The density of the main varieties of concrete
The average density is used in determining the characteristics and is considered the ranges over which the material is divided into 4 types. For example, heavy concrete has a density above 2500 kg / m 3. This composition is created from fillers, iron ore, steel scrap, magnesite, and is not used for construction work of a traditional plan. Such a high density is necessary for security, so this concrete is used for the construction of special structures. The minimum average density is estimated by an indicator that is lower than the value of 500 kg / m 3. This version of the material is used as heat-insulating fillers. A more complete understanding of the differences in concrete in density, grades and types, as well as an approximate area of use, can be assessed by reading the information below.
Particularly heavy concrete, which was discussed above, may have the following grades: M550, M600, M700, M800, M900, M1000. Heavy concretes have a density in the range from 1800 to 2500 kg / m 3, material for supporting structures is used according to the type of foundations. Brands of such concrete can look as follows: M350, M450, M500. Lightweight concrete has a density ranging from 500 to 1800 kg / m 3, grades can be determined by the following designations: M200, M250, M300. Particularly lightweight concrete has a density of 500 kg / m 3, and their grades are as follows: M15, M50, M75, M100, M 150. This type of material is used to create a heat-insulating layer and build walls.
