The construction of industrial buildings or residential buildings is the initial stage of construction. This, one might say, is the basis of the whole structure, without which it is impossible to do and it simply cannot be excluded. In order for the structure to be stable and withstand the entire load, it is made of reinforced concrete. Actually, due to the formed frame, proper strength is ensured. But how much reinforcement per 1 m3 of concrete should be taken so that the foundation does not begin to crumble under the influence of a constant load over a long period of time?
Rebar classification
To understand how much reinforcement should be used, it is worth knowing 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 intoseveral groups, depending on a number of factors:
- According to the source material - steel, non-metal.
- Based on the principle of operation (in the finished structure) - strained, non-tensioned.
- According to production technology - rod, wire, rope.
- Based on the type of profile - smooth, rods with a figured surface (better adhesion to concrete).
- By installation type - mesh, frame, piece reinforcement.
- Based on the method of connection - welding, knitting.
Without knowing the classification, it is impossible to determine how many kg of reinforcement per 1 m3 of concrete will be spent on creating a foundation or producing large-scale structures. Sometimes preference is given to a mesh or frame, which are connected in a knitted way due to their flexibility. This quality of such reinforcement is very important, because it helps to prevent the destruction of reinforced concrete structures due to movements of the earth's crust.
Composite rebar
A few words worth mentioning about modern know-how in the construction industry. We are talking about an analogue of metal rods, which is already widely popular abroad - these are composite fibers made of glass. What is this kind of material, in no way inferior to metal rods?
About how many kg of reinforcement per 1 m3 of concrete it is optimal to use will be said later, but for now it’s worth getting a little closer acquainted with this modern material. Its main feature is non-metallic origin. Although the list of functions of these rods includes the performanceespecially responsible tasks, for their manufacture steel is not used, as is the case with fittings.
Composite fibers are made from other materials:
- glass;
- bas alt;
- carbon;
- aramid.
At the same time, the use of synthetic fibers alone does not achieve the desired strength and therefore the production process involves processing by including thermosetting or thermoplastic polymer additives. Their presence makes it possible to ensure the hardness of the rods.
Subsequently, like metal fittings, ribs are also formed on composite consumables. In addition, in order to increase the binding 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 correct calculation
Attempts to save on any building materials have a negative impact on the strength of buildings and other structures erected from concrete. And, ultimately, the brigade is sideways. And since we are talking about a foundation (mainly of a monolithic type), then the stability of the entire structure will depend on its actual physical parameters.
For this reason, the foundation should be given close attention at the stage of laying it. And the addition of reinforcement just allows not only to increase strength, but also to give the entire structure proper solidity. This is so important in order to ensuresustainability.
And since the construction market develops 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 rebar goes into a cube of concrete? The number of iron bars used, including their diameter, depends largely on the type of structure being erected.
This also determines the weight of the material that is needed to solve each specific task. For the optimal ratio of concrete and reinforcement, a number of parameters should be taken into account:
- variety of base (monolithic, columnar, tape);
- area and thickness of the planned foundation;
- rod parameters;
- structure weight;
- variety of soil.
Creating a slab-type base or foundation for a private wooden house in relation to solid soil, rods up to 10 mm thick are used. The combination of a heavier structure and weak soil requires reinforcement with a mesh with a cross section of 14-16 mm in increments of about 200 mm. In this case, the material itself is placed in two belts (lower and upper).
So how much reinforcement is needed per cube of concrete? Having available data on the height and area of \u200b\u200bthe base, you can easily find out how many meters of iron bars 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
Standard Rebar Consumption Ratesdesigned for different occasions. Architects need to take into account all the subtleties that were given above. In addition, it is necessary to take into account the characteristics of the concrete mix itself:
- how many impurities it contains;
- composition of additives;
- component properties.
Buildings, which differ in design features and purpose, have their own requirements regarding strength indicators. And the number of metal rods used plays an important role here.
As for the calculation of how many tons of reinforcement per 1 m3 of concrete is required, this can be determined using the following standards:
- State elemental estimated norms or GESN.
- Federal Unit Rates or FER.
- State standards or GOST.
According to the norms of the GESN, for each cubic meter of concrete there should be at least 200 kg of reinforcement or one ton per 5 m3.
FER regulations are based on the readings of the HESN, and therefore the requirements for these standards are similar. However, federal prices are a little softer - the amount of reinforcement per 1 cubic meter can be in the range of 187 kg. At the same time, this applies directly to reinforced concrete slabs with a height of no 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 rod and thermomechanically strengthenedreinforcement for reinforced concrete structures.
Deviation from the norm
In some cases, when deciding how much rebar to use per cube of concrete, one has to deviate from the norm in terms of the amount of rebar. As a rule, in a big way, which is provoked not only by the human factor. Reasons for such decisions may be the following situations:
- Construction of structures on difficult soils - quicksand, sandy soils. In addition, high humidity levels, the risk of earthquakes, and sudden temperature changes should be taken into account. All this is a good reason to increase the amount of material in order to ensure the proper level of safety of structures.
- The 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 amount of resources, then designers should focus on this increased attention. Therefore, a competent calculation of the consumption of reinforcement is required.
- In the case when they are replaced by heavier counterparts.
In general, the problem of how much reinforcement is needed per cube of concrete is solved as follows.
If a light structure is erected on fairly dense soil, then 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 determinemesh length in accordance with the brand and class of the frame. To perform the correct calculation of consumables, you need to know all these parameters exactly.
But is it worth making accurate calculations of consumables? The answer is unequivocal - in any case, it is necessary, since it allows you to avoid overpaying for excess tonnage. On the other hand, there is no need to buy a new batch of rebar each time in case of a shortage.
Strip foundation
How much reinforcement per 1 m3 of concrete is needed for such a structure? The device of this base frame is different in that its height must be less than the width - this is a prerequisite. Therefore, metal rods of small diameter can be used for reinforcement - about 10-12 mm.
First of all, it is worth considering typical strip foundation reinforcement schemes:
- 2 horizontal rods in the upper and lower planes;
- 3 horizontal rods in the upper and lower planes.
When choosing a reinforcement scheme, it is worth considering that the step between the bars of one row should not exceed 400 mm, and the protective layer should not exceed 50 to 70 mm. Of these schemes, you should choose the one that will be acceptable in each case.
Under the protective layer should be understood the distance emanating from the extreme rod 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 specific example
For example, let's calculate how much reinforcement per 1 m3 of concrete will be needed for a 6 x 6 housem.
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 reinforcement will be required. The step between the vertical bars should be 500 mm, and the optimal height of the foundation (as we remember, its width is 400 mm) will be 700 mm. As for the indents from the upper and lower boundaries of the concrete, this figure will be equal to 50 mm.
Taking into account all this, we get the length of each vertical rod - 700-50-50=600 mm. For a building measuring 6 x 6 m, 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 overlaps. That is: 60061 \u003d 36600 mm or 36.6 m. Ultimately, 60.6 meters of reinforcement will be required in total.
Slab base
In this case, two important parameters must be taken into account:
- building class;
- variety of soil.
How much reinforcement per 1 m3 of concrete in this case? If a relatively light wooden house structure is located on the foundation and the probability of swelling of the soil is low, then rods of medium thickness can be used - 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 heaving is high or it is planned to build a brick house or it will be a panel building (the load increases significantly), then the foundation construction will requirereinforcement not less than 14-16 mm in diameter.
Calculation example
Let's take the same parameters of the house for calculation - 6 x 6 meters. In the frame structure, the pitch between the bars is 200 mm. Accordingly, 62 rods are needed for the house. But since two stiffening belts are required for the monolithic foundation structure (they are located in the upper and lower parts), therefore, it is worth multiplying by another 2 and as a result we get: 622=124 rods.
Since the parameters of the house are 6 x 6, the length of each rod should be 6000 mm. However, the reinforcement is not supplied in such dimensions, therefore, the calculation should be carried out in running meters, that is, 744 linear meters for two armored belts. Moreover, they must be interconnected to increase rigidity.
This will require the following amount of reinforcement: 3131=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: 0.1960=96 p.m. required for the construction of the foundation.
As a conclusion
Finally, it remains to add one more important point - in the course of calculating how much reinforcement in a cube of concrete fits to form a foundation, one should take into account the type of concrete mixture. And in addition, it is necessary to take into account the density of the solution. And this parameter, in turn, depends on the types of additives that are part of the concrete mix. Thatyes, the lower the density of concrete, the more reinforcement will be required.
