Density of reinforced concrete: types, density calculation
The density of reinforced concrete is one of the most importantcharacteristics of this material, which is a particularly strong structure. He has many advantages, but there is also a disadvantage, expressed in a significant weight. With this, professionals are reconciled at the design and construction stage of facilities. This feature of reinforced concrete must also be taken into account when dismantling the structures, in the process of their dismantling.
In practice, reinforced concrete found widedistribution not only in the field of industry, but also in the field of private construction. Prepare a mixture for the formation of reinforced concrete construction can be independently, as well as bind the reinforcement, using a special wire. The result is a durable and durable construction.
The main types of reinforced concrete
The density of reinforced concrete can vary, to whichwill affect the composition of the solution. Then the weight depends on the density. The concrete is classified precisely from this characteristic, among others it should be noted:
- especially heavy;
- heavy;
- lightweight;
- light reinforced concrete.
The density of reinforced concrete in the first case is limited to a value of 2500 kg / m3, which is an impressive value. In civil construction this type of reinforced concrete is not used. The composition can contain the following placeholders:
- magnetite;
- limonite;
- barite.
The density of reinforced concrete
In heavy concrete, the density is somewhat lower, it is 2200 kg / m3 . Among the ingredients of such material, morethe usual gravel, crushed stone, as well as other. The density of reinforced concrete will be even lower if it is a question of lightweight concretes. This is a heavy concrete with metal fittings and through planes. At the same time, the parameter of interest is 1800 kg / m3.
Density of lightweight concrete
Lightweight concrete has a density of 500 kg / m3. This parameter is characteristic of 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 method of pouring. If the liquid mixture is compacted with vibrating machines, the density will increase by 100 kg / m3.
Calculation of density
The density of reinforced concrete, whose types weredescribed above, can be determined if the basis of taking the proportions of the solution in terms of mass. From the calculation it is necessary to exclude liquid, which in 28 days will completely disappear from the massif. This will give an accurate value of the monolith density.
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 / m3, while for the M-250 brand this value will vary from 2390 to 2405 kg / m3. 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 / m3 respectively.
If you need a specific gravityreinforced concrete, then you should be aware that the reinforcement scheme also affects the weight of the 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 valve. After that, you can perform mass calculations. Depending on the purpose and shape of reinforced concrete, rods of different diameters can be used. As for their laying, they can be located at a certain distance from each other.
In order to know the density of monolithicreinforced concrete, there is no special precision, therefore the number of reinforcement can be taken approximately. Thus, in the manufacture of concrete tracks and blinds, an 8 mm reinforcement with a cell size of 200 mm is usually used. In one square meter of material will contain 16 m of rods, and if the density of steel is 7850 kg / m3, then the weight of the reinforcement will be 6.3 kg.
When it comes to horizontal beams with a support,plates and foundations, the diameter of the reinforcement usually varies from 12 to 16 mm. The size of the cell decreases to 180 mm, and the total length remains the same. In this case, the weight of the reinforcement will be a limit from 14 to 25.2 kg. For cantilever beams and slabs, the diameter of the reinforcement is a limit of 16 to 18 mm, this is true if the size of the cells is equal to 130 mm. Total length of reinforcement per 1 m3 of reinforced concrete will be 49 m, in this case the reinforcement mass will vary from 77.3 to 97.8 kg.
Density of additional structures
It will be fair to consider also the variant withvertical walls and columns. In this case, the diameter of the reinforcement can be equal to the limit of 14 to 18 mm with a cell 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 quantity of reinforcement is known anddensity indicators, it will be possible to determine the weight of one cubic meter of reinforced concrete. From the cube is determined the average volume, which deals with steel rods. In the end, the volume of concrete is obtained, then the numbers are multiplied by the specific weight for each material, and the results are added.
Calculation of density on the example of a strip reinforced concrete foundation
The density of reinforced concrete (kg / m3) can be calculatedon 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 armature 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 m3.
Thus, pure concrete will take 0.997 m3. To calculate the weight of reinforcing bars,multiply the values: 0.003x7850, in the end it will be possible to get 23.6 kg, while the mass of concrete should be calculated, multiplying 0.997x2400. Calculations will make it clear that the mass of concrete is 2392.8 kg. After the values have been summed, we can obtain the density of reinforced concrete, these calculations will look like this: 23.6 + 2392.8 = 2416 kg / m3. These manipulations are carried out at the design stage of loads on the base of the building.
Information on the density of concrete
The density of reinforced concrete and concrete should beknown builders. If the first value was described in detail above, then the second one should be discussed. The main working index for concrete is the reaction to homogeneity and compression, as well as strength. These characteristics regulate the density, which is a physical indicator, determined by the method of dividing the mass per volume.
In construction, it is common to use the average value of this parameter, because it is influenced by various factors, among which:
- quality and size of the filler;
- variety of filler;
- composition of water;
- degree of granularity of sand.
Density of the main types of concrete
The average density is used in determining the characteristics and is considered ranges over which the material is divided into 4 types. For example, heavy concrete has a density higher than 2500 kg / m3. This composition is created from fillers,iron ore, scraps of steel, magnesite, and for construction works of the traditional plan is not used. Such a high density is necessary for protection, therefore, such 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 / m3. This version of the material is used in the roleheat-insulating fillers. A more complete understanding of the differences in concrete by density, grades and species, as well as an approximate area of use, can be assessed by reading the information below.
Particularly heavy concrete, which was discussed above, can have the following brands: M550, M600, M700, M800, M900, M1000. Heavy concrete has a density in the range from 1800 to 2500 kg / m3, material for supporting structures is usedby type of foundation. The brands of such concrete can look as follows: M350, M450, M500. Lightweight concrete has a density in the range from 500 to 1800 kg / m3, brands can be determined by the following designations: M200, M250, M300. Particularly lightweight concrete has a density of 500 kg / m3, and their brands look as follows: M15, M50, M75, M100, M 150. This kind of material is used to create a heat-insulating layer and build walls.
Conclusion
Reinforced concrete is a combination of steel and concrete,which has unique properties. Strength, reliability and durability of the material allowed it to become widespread in the field of construction. When designing a structure, many characteristics are taken into account, as one of them is the density of reinforced concrete, t / m3 or kg / m3 - these are the physical quantities in which it is customary to measure this parameter. For example, if you know the density, which is equal to 2200 kg / m3, then you can translate this value in tons more per cubic meter. In this case, this value is 2.2.
