The device of industrial or residential buildings represents the initial stage of construction. This, one can say, is the basis of the entire structure, without which it is impossible to do and it simply cannot be excluded. To make the structure stable and withstand the entire load, it is made of reinforced concrete. Actually due to the formed frame, the proper strength is ensured. But how many reinforcement per 1 m3 of concrete need to be taken so that the foundation does not begin to crumble under the influence of a constant load for a long period of time?
Rebar classification
To understand how much reinforcement should be used, it is worth knowing and what types of this building consumable material generally exist.
For the manufacture of reinforced concrete products for various purposes, different types of reinforcement are used. As a rule, its classification is divided into several groups, depending on a number of factors:
- According to the source material - steel, non-metallic.
- Based on the principle of action (in the finished design) - tense, non-tense.
- According to the production technology - rod, wire, rope.
- Based on the type of profile - smooth, rods with a curly surface (better adhesion to concrete).
- By type of installation - mesh, frame, piece fittings.
- Based on the connection method - welding, knitting.
Without knowing the classification, it is impossible to determine how many kg of reinforcement in 1 m3 of concrete will be spent on the foundation or the production of large-scale structures. Sometimes preference is given to a grid or frame, which are connected in a knitted way because of their flexibility. This quality of such reinforcement is very important because it helps prevent the destruction of reinforced concrete structures due to movements of the earth's crust.
Composite reinforcement
A few words are worth mentioning about modern know-how in the construction field. This is an analogue to metal rods, which is already widely used abroad - these are composite fibers made of glass. What is this kind of material that is in no way inferior to metal rods?
About how many kg of reinforcement in 1 m3 of concrete is optimal to use, it will be said later, but for now it’s worth a little closer to get acquainted with this modern material. Its main feature is its non-metallic origin. Although the list of functions of these rods includes the performance of particularly important tasks, steel is not used for their manufacture, as is the case with valves.
Composite fibers are made from other materials:
- glass;
- basalt;
- carbon;
- aramid.
At the same time, using synthetic fibers alone does not achieve the desired strength, and therefore the production process involves processing by incorporating thermosetting or thermoplastic polymer additives. Their presence ensures the hardness of the rods.
Subsequently, like metal reinforcement, ribs are also formed on composite consumables. In addition, in order to increase the bonding and adhesive properties during subsequent contact with concrete pouring, a special sand coating is applied to the rods. And as a result, we get a worthy alternative.
How much reinforcement goes per 1 m3 of concrete or the importance of proper calculation
Attempts to save on any building materials negatively affect the strength of buildings and other structures erected from concrete. And, ultimately, the brigade comes out sideways. And since we are talking about the foundation (mainly of a monolithic type), the stability of the entire structure will depend on its actual physical parameters.
For this reason, close attention should be paid to the foundation at the stage of its laying. And the addition of reinforcement just allows not only to increase strength, but also to give the whole structure due monolithicity. This is so important for sustainability.
And since the construction market is developing from time to time, today many construction companies are paying attention to modern solutions that fully comply with these standards.
What to consider?
How much reinforcement goes to a cube of concrete? The number of iron rods used, including their diameter, largely depends on the type of structure being erected.
This determines the weight of the material, which is necessary to solve each specific problem. For the optimum ratio of concrete and reinforcement, a number of parameters should be considered:
- a variety of base (monolithic, columnar, tape);
- the area and thickness of the planned foundation;
- rod parameters;
- construction weight;
- variety of soil.
Creation of a slab type foundation or foundation for a private wooden house with respect to solid soil using rods up to 10 mm thick. The combination of a heavier structure and weak soil requires reinforcement with a mesh with a cross section of 14-16 mm with a pitch of about 200 mm. In this case, the material itself fits into two zones (lower and upper).
So how much reinforcement is needed per cube of concrete? Having data on the height and area of the base, you can easily find out how many meters of iron rods will be required for the entire structure, depending on the brand and class of reinforcement. It is also easy to calculate the weight of the consumable.
Norms and Standards
The standard norms for the consumption of valves are calculated for different cases. Architects need to take into account all the subtleties that were given above. To everything else, it is necessary to take into account the characteristics of the concrete mixture itself:
- how many impurities are contained;
- composition of additives;
- component properties.
Buildings that differ in design features and purpose have their own requirements regarding strength indicators. And the last role is played by the number of metal rods used.
As for the calculation, how many tons of reinforcement in 1 m3 of concrete are required, this can be determined using the following standards:
- State Elementary Estimated Norms or ESP.
- Federal unit rates or FER.
- State standards or GOST.
According to the GESN standards, for every cubic meter of concrete there should be at least 200 kg of reinforcement or one ton per 5 m 3 .
The FER regulations are based on the testimony of the SPES, and therefore the requirements for these standards are similar. However, federal rates are a little softer - the number of fittings per 1 cubic meter can be within 187 kg. At the same time, this applies directly to reinforced concrete slabs with a height of not more than 2 meters and a depth of 1 m.
However, to obtain the most accurate calculations, you should use GOST 5781-82 and 10884-94. They contain all the necessary information regarding the rod and thermomechanically hardened reinforcement for reinforced concrete.
Deviation from the norm
In some cases, when deciding how much reinforcement per cube of concrete to use, one has to deviate from the norm with respect to the amount of reinforcement. As a rule, in a big way, which is provoked not only by a human factor. The reasons for such decisions may be the following situations:
- The construction of structures on complex soils - floats, sandy soils. In addition, one should take into account the high level of humidity, the risk of an earthquake, and sudden changes in temperature. All this is a good reason to increase the amount of material in order to ensure the proper level of safety of structures.
- Subsequent operation of buildings. If we are talking about industrial buildings, where heavy equipment is located, detonation of surfaces, the constant movement of a large number of resources, then designers should pay special attention to this. Therefore, a competent calculation of the consumption of fittings is required.
- In the case when they are replaced by heavier analogues.
In general, the problem of how much reinforcement is needed per cube of concrete is solved as follows.
If a lightweight structure is erected on fairly dense soil, less reinforcement will be used. This is mainly due to the use of small diameter rods. In other words, rational calculation.
Consumable Count
As a rule, reinforcement is laid in layers at the top and bottom. Parameters such as the height and area of the concrete structure allow you to determine the length of the grid in accordance with the brand and class of the frame. To perform the correct calculation of consumables, you must know all these parameters exactly.
But is it worth it to make accurate calculations of the consumables? The answer is unequivocal - this is necessary in any case, since this allows you to avoid overpayments for excess tonnage. On the other hand, there is no need to buy a new batch of reinforcement every time in case of shortage.
Strip foundation
How many reinforcement per 1 m3 of concrete do you need for such a structure? The device of this base frame is characterized in that its height should be less than the width - this is a prerequisite. Therefore, for reinforcing, you can use metal rods of small diameter - about 10-12 mm.
First of all, it is worth considering typical patterns for reinforcing a strip foundation :
- 2 horizontal rods in the upper and lower plane;
- 3 horizontal rods in the upper and lower plane.
At the same time, choosing a reinforcement scheme, it is worth considering that the step between the rods of one row should not exceed 400 mm, and the protective layer - from 50 to 70 mm. From these schemes, it is worth choosing one that will be acceptable in each case.
Under the protective layer should be understood the distance emanating from the extreme shaft to the edge of the concrete frame. Its presence allows you to protect the reinforcement from moisture and thereby protects it from corrosion.
Calculation on a concrete example
For example, we calculate how many reinforcement per 1 m3 of concrete will be needed for a house measuring 6 x 6 m.
Let the width of the base under the house being built be 400 mm. The foundation should have two armored belts with two rows of rods. That is, for a house with 6 meters on one side, 24 linear meters of fittings will be required. The step between the vertical rods should be 500 mm, and the optimal height of the foundation (as we recall, its width is 400 mm) will be 700 mm. As for the indents from the upper and lower boundaries of concrete, this indicator will be equal to 50 mm.
Given all this, we get the length of each vertical rod - 700-50-50 = 600 mm. For a 6 x 6 m building, 61 floors will be required. To calculate the total length of the reinforcing bars, it is enough to multiply their total length by the number of floors. That is: 600 * 61 = 36600 mm or 36.6 m. Ultimately, a total of 60.6 meters of reinforcement will be required.
Tile base
In this case, two important parameters must be considered:
- class of construction;
- variety of soil.
How many reinforcement per 1 m3 of concrete in this case? If the foundation will have a relatively light wooden house structure and the probability of soil bloating at a low level, then you can use rods of medium thickness - about 10 mm in diameter. As a result, you can save an impressive amount.
At the same time, in the case when the probability of soil expansion is high or it is planned to build a house of brick or it will be a panel building (the load increases significantly), then reinforcement of at least 14-16 mm in diameter will be required for the construction of the foundation.
Example for calculation
Take for calculation the same parameters of the house - 6 x 6 meters. In the frame design, the pitch between the rods is 200 mm. Accordingly, for the house you need 62 rods. But since two stiffening belts are needed for a monolithic foundation construction (they are located in the upper and lower parts), therefore, it is worth multiplying by another 2 and as a result we get: 62 * 2 = 124 rods.
Since the parameters of the house are 6 x 6, then the length of each rod should be 6000 mm. However, the fittings are not supplied in such sizes, therefore, calculation should be carried out in linear meters, i.e. 744 running meters for two armored belts. Moreover, they must be interconnected to increase rigidity.
To do this, you need the following amount of reinforcement: 31 * 31 = 961. The thickness of the frame will be 200 mm, and it will be located 50 mm from the ground. The length of each connecting segment is 100 mm or 0.1 m. As a result of multiplication, we get: 0.1 * 960 = 96 p. M. We add everything we have and as a result we get: 744 + 96 = 840 p. M. Just so much reinforcement and required for the construction of the foundation.
In conclusion
In the end, it remains to add another important point - in the process of calculating how much reinforcement in the concrete cube fits to form the foundation, the type of concrete mixture should be taken into account. And in addition, the density of the solution must be taken into account. And this parameter, in turn, depends on the types of additives that are part of the concrete mix. That is, the lower the density of concrete, the greater the amount of reinforcement required.