Calculation of how much reinforcement is needed for the foundation. Foundation reinforcement: how much reinforcement is needed? How much reinforcement is needed for a 10x10 foundation

The calculation of reinforcement for a foundation is an important stage in its design, therefore it must be carried out taking into account the requirements of SNiP 52-01-2003 for choosing a reinforcement class, section and its required quantity.

First you need to understand why metal reinforcement is needed in a monolithic concrete base. Concrete, after gaining industrial strength, has a high compressive strength, and a much lower tensile strength. An unreinforced concrete base is prone to cracking when the soil swells, which can lead to deformation of the walls and even destruction of the entire building.

Calculation of reinforcement for slab foundation

Calculation example

A house made of aerated concrete blocks is installed on a 40 cm thick slab foundation on medium-heavy loams. Overall dimensions of the house - 9x6 meters.

Calculation of reinforcement for a strip foundation

In the main tensile load falls along the tape, that is, it is directed longitudinally. Therefore, for longitudinal reinforcement, a bar with a thickness of 12-16 mm is chosen, depending on the type of soil and wall material, and for transverse and vertical bonds it is allowed to take a bar of a smaller diameter - from 6 to 10 mm. In general, the principle of calculation is similar to the calculation of reinforcement for a slab foundation, but the spacing of the reinforcement grid is 10-15 cm, since the tensile forces strip foundation may be significantly larger.

Calculation example

The strip foundation of a wooden house, the width of the foundation is 0.4 m, the height is 1 meter. The dimensions of the house are 6x12 meters. The soil is heaving sandy loam.

1. To perform a strip foundation, two reinforcing meshes are required. The lower reinforcing mesh prevents rupture of the foundation tape during subsidence of the soil, the upper one - when it heaves.
2. The mesh spacing is 20 cm. For the construction of the foundation tape, 0.4 / 0.2 = 2 longitudinal bars are required in each layer of reinforcement.
3. The diameter of the longitudinal bar for a wooden house is 12 mm. To perform a two-layer reinforcement of two long sides of the foundation, 2 12 2 2 = 96 meters of rod is required.
4. For short sides 2 6 2 2 = 48 meters.
5. For cross-links, we select a bar with a diameter of 10 mm. Laying step - 0.5 m.
6. We calculate the perimeter of the strip foundation: (6 + 12) 2 = 36 meters. The resulting perimeter is divided by the laying step: 36 / 0.5 \u003d 72 transverse bars. Their length is equal to the width of the foundation, therefore, the total number is 72 0.4 = 28.2 m.
7. For vertical ties, we also use a D10 bar. The height of the vertical reinforcement is equal to the height of the foundation - 1 m. The number is determined by the number of intersections, multiplying the number of transverse bars by the number of longitudinal ones: 72 4 \u003d 288 pieces. With a length of 1 m, the total length will be 288 m.
8. Thus, to perform the reinforcement of the strip foundation, you will need:

• 144 meters of bar class A-I II D12;
• 316.2 meters of A-I D10 bar.
• According to GOST 2590 we find its mass. A running meter of D16 bar weighs 0.888 kg; bar meter D6 - 0.617 kg. We calculate the total mass: 144 0.88 \u003d 126.72 kg; 316.2 0.617 = 193.51 kg.

Calculation of binding wire: the number of connections can be calculated by the number of vertical reinforcement, multiplying it by 2 - 288 2 = 576 connections. Wire consumption for one connection is 0.4 meters. The wire consumption will be 576 0.4 = 230.4 meters. The mass of 1 meter of wire with a diameter of d = 1.0 mm is 6.12 g. For knitting foundation reinforcement, 230.4 6.12 \u003d 1410 g \u003d 1.4 kg of wire will be required.

For the construction of any building or structure, a reliable and solid foundation is of great importance. The durability and safety of the building will primarily depend on its quality. In order to fill with concrete and lay the reinforcement of a 10x10 monolithic foundation and not make a mistake, you should prepare a detailed estimate of the work, carefully calculating the consumption of materials, their quantity, and also the cost. Particular attention should be paid to how much reinforcement you need to purchase to securely strengthen the foundation.

How much metal reinforcement is required for the foundation is easiest to calculate using the example of a base measuring 10x10 m.

Since the reinforcement frame is one of the most expensive elements of the base, in order to avoid unnecessary costs, it is necessary to carefully calculate the consumption of reinforcement per cube or for the entire foundation. Usually in order to calculate required amount fittings used following formula: L=4xP, where:

• "L" is the amount of material that is needed for the longitudinal load-bearing reinforcement bars;
• "P" is the perimeter of the foundation.

How much reinforcement is needed for jumpers is calculated according to a slightly different formula: L \u003d 10xP. The difference in the formulas is explained by the fact that more than twice as much is needed to create material jumpers.

In this case, fittings with diameters from 10 to 12 mm are used. The rods must have two belts, securely connected one to the other.

Each such belt is a reinforcing mesh with a cell diameter of about 20 cm. Provided that the thickness of the frame is about 20 cm, the length of the jumpers should be 25 cm.

If you make simple calculations, it turns out to be quite simple to calculate the consumption of reinforcement: 51 metal rods are needed per 10 m of the slab, each of which is 10 m long. For a perpendicular mesh, you need a similar number of rods. In total, the total consumption of reinforcing bars will be 102 bars for one belt. How many rods are needed for the second reinforcing belt, it will be even easier to count: 102x2 - 204.

Consumption of reinforcement per cubic meter of concrete

Separately, the consumption of reinforcement per m 3 of concrete should be considered. The calculation is made according to the current GOST individually in each individual case. This is due to the fact that the characteristics of the concrete itself can vary within fairly wide limits depending on the filler and additives.

To reinforce the foundation, steel ribbed reinforcement with a diameter of 8 to 14 mm is most often used. Such a surface allows for maximum adhesion to the concrete layer. A 10 by 10 foundation, on average, takes 150-200 kg of reinforcement for each cube of concrete (for columns, the consumption is from 200 to 250 kg per cube of concrete). Recently, fiberglass reinforcement has been used in the construction process. Its cost is slightly higher than the cost of a metal counterpart. But if you calculate how many such reinforcing bars are needed per m 3, most likely the use of composite reinforcement for the foundation will be much more profitable. As a rule, the cost of composite reinforcement is on average half that of steel. This is due to the fact that the consumption per cube of concrete for rods is similar, but the weight of the composite is much lower.

In order to calculate the consumption of rods per cube of concrete and not make a mistake, in principle, it is not so difficult. You only need to know how many m 3 of concrete will be used to pour the foundation. If you are afraid to make a mistake in the calculations of reinforcement per cube of concrete, you can always use the help of professionals. They will calculate with maximum accuracy the consumption of materials per m 3 of solution and, if necessary, will perform the laying of the foundation itself, as well as its reinforcement.

How much reinforcement is needed for a strip foundation 10x10

If we take a strip foundation with a side of 10 meters and one load-bearing wall in the middle, its total length will be 10x (10x4) = 50 m. With a base width of 40 cm, three reinforcing bars must be laid to lay a solid and solid foundation. And since the strip foundation must necessarily have 2 belts, you need 6 bars. We multiply this figure by the length of the rod (10 m) and get the result. In order to qualitatively reinforce the strip foundation, you will need to spend 60 m of rods. In addition, you will need to calculate the number of transverse rods. With a cell length of 50 cm, the size of the bar should be 30 cm. Thus, 90 mm of reinforcing bars will be needed on one side of the base, and since the strip foundation in question has five tapes, the final figure will be already 450 m.

How much reinforcement is needed for a 10x10 slab foundation

To create a platform, a foundation is made in the form of a slab (slab base). Before proceeding with pouring the foundation, it is necessary to pour a layer of sand with crushed stone, cover it with a small layer of mortar and lay out the reinforcement. Usually, rods with a diameter of 12 mm are used for this purpose. The cell size in this case is 20 mm and a two-belt system for laying the reinforcing layer is used.

With a base plate size of 10x10 m, ten rods are needed per linear meter. Accordingly, for 10 m - 50 pieces. Let's add 50 transverse rods here and we get the material consumption for one belt - 50 rods. Since two belts are required, we multiply the resulting number of rods by this number and get the required amount of material - 100 rods.

How much reinforcement is needed for a 10x10 columnar foundation. To reinforce the columnar foundation, reinforcing bars with a cross section of 10 to 12 mm will be required. They are installed vertically in increments of 10 to 15 cm. There are 4 rods per pole. To calculate the amount of reinforcement, you need to know the total number of all columns. You can find out this figure from the project documentation.

It's hard to imagine now everyday life without construction. Thousands of new buildings and structures are built every year all over the world. An important stage is the construction of the foundation, since the strength and stability of the structure largely depends on it. In order for the base to be stronger and more durable, its reinforcement was invented many years ago. Reinforcement allows you to increase the hardness and rigidity of the foundation. Thus, a kind of strong framework is created. In the normal state, the foundation can be destroyed. Most often this occurs as a result of compression of the structure or during tension.

The steel frame helps prevent stretching of the foundation. Today, steel bars of various thicknesses are used for reinforcement. Often they are connected with a wire into a single lattice. Use a special wire that provides knitting of the frame. In order for the metal base to be strong and reliable, you need to calculate the amount of metal. This indicator depends on the type of foundation being built. It can be columnar, tape or slab. Let us consider in more detail how much reinforcement is needed for the foundation, however, for a more accurate result, such as calculated data, you will need qualified specialist help.

How much reinforcement is needed for the column base of the building

Before erecting a columnar foundation, you will need to calculate the reinforcement. This design is lightweight, unlike a monolithic one, so the number of metal rods is small. To stiffen concrete pillars, it is recommended to take rods with a diameter of no more than 10 mm. Rods are used both horizontally and vertically. Vertical are the main ones, they are located from top to bottom along the entire length of the columns. Vertical rods should have a ribbed surface. The main function of a horizontal metal frame is the adhesion of the main frame. To reinforce each column, in most cases, no more than 4 rods are required, which are installed over the entire height.

Before ordering fittings from a supplier whose prices seem to be the most reasonable, it is necessary to carefully calculate the required footage for the foundation. Below we will show how easy it can be to deal with, and consider the calculation for various types of bases.

Number of reinforcement for different foundations

Obviously, the types of reinforced concrete bases differ not only in the volume of concrete, but also in the footage of reinforcing bars for the metal frame of the foundation. Most of the rods will be required for a slab foundation, followed by strip and pile bored foundations.

Consider the case when the foundation for the house has dimensions in terms of 6 × 6 m, and we will calculate the footage of the reinforcement.

Footage on a strip foundation

For knitting the reinforcing cage of a strip foundation, smooth rods and rods with a periodic profile are usually used. Their footage will directly depend on the width and length of the tape, as well as the perimeter of the base. Suppose that in our case the width of the tape is 300 mm, the height is 1000 mm. The step between the mounting (smooth) fittings is chosen equal to 500 mm. What kind of reinforcement is needed for the foundation - it's up to you to decide, based on the loads and soil indicators.

We consider the total length of the tape under the house 6 × 6 m (adjusted upwards - without taking into account the thickness of the tape):
6 × 4 = 24 m.
We consider the footage of the rods of a periodic profile (ribbed), provided that the tape will consist of two belts of two rods each:
24 × 2 × 2 = 96 m.
We take into account that in the corner part of the foundation, the bars will have to be bent and outlets made into a perpendicular tape 0.5 m long. In total, there will be 4 m of such outlets for each corner, or 16 m in total for the entire foundation. We add this amount to the footage of ribbed rods and get the footage of rebar of a periodic profile on the foundation:
96 + 16 = 112 m.
Now you need to calculate how many smooth rods you need. To do this, we find the number of reinforcement mates, taking into account the accepted step of 500 mm:
24/0.5 = 48 pcs.
We determine the amount of vertically and horizontally oriented transverse reinforcement (with a margin - without taking into account the thickness of the protective layer):
(0.3 + 1) × 2 = 2.6 m.
Determine the total footage of smooth rods:
2.6 × 48 = 124.8 m ≈ 125 m.
In total, this foundation will require 112 m of rods of a periodic profile, 125 m - smooth.

Footage per slab base

Ribbed reinforcement is mainly used for the slab foundation (the diameter of the reinforcement for the foundation does not play a role in the calculation of material consumption) - two grids with cells of 200 × 200 mm are formed.

To begin with, we determine the number of longitudinal and transverse rods (in our case, it is the same):
6/0.2 = 30 pcs.
The total number of rods per grid will be 2 times more:
30 × 2 = 60 pcs.
We take the length of the rods equal to 6 m (with a margin - not taking into account the value of the protective layer of concrete), so the footage of reinforcement per mesh will be:
60 × 6 = 360 m.
Accordingly, twice as many rods will be required for the entire foundation (2 grids):
360 × 2 = 720 m.
The distance between the grids can be maintained with special piece elements, and not with mounting fittings - it’s more convenient.

Footage for bored piles

Suppose that we will use piles with a diameter of 200 mm and a length of 1.5 m. The step between the supports will be 1.5 m. The pile will be reinforced with three rods of working reinforcement and two smooth clamps. The outlets used to connect the piles with the reinforced concrete grillage are taken to be 300 mm long.

We calculate the required number of piles, taking into account the previously obtained value of the perimeter of the base (24 m) and the step between the supports:
24/1.5 = 16 pcs.
We consider how many ribbed rods are needed per pile:
(1.5 + 0.3) × 3 = 5.4 m.
All piles will take:
5.4 × 16 \u003d 86.4 m ≈ 87 m of rods of a periodic profile.
To form the frame, smooth rods bent into a circle will be used. We consider the length of this circle (with a margin - according to the diameter of the pile):
3.14 × 0.2 = 0.628 m.
At least two such clamps per pile are required:
0.628 × 2 = 1.256 m.
For all 16 bored piles of smooth rods you will need:
1.256 × 16 = 20.096 m ≈ 20 m.
In total, for the foundation we have chosen, 87 m of rods of a periodic profile are needed, 20 m - smooth.

At the end of the article

It would seem that finding out the required amount of reinforcement is very simple! But be careful when calculating, double-check your calculations several times! It is much cheaper to immediately order the required footage than to buy more later.

The foundation serves as a support for the building, its main supporting structure, which perceives and evenly distributes the load from the structure erected above it over the base. Usually, strip, slab or pile foundations are used for the construction of residential buildings. The choice of the type and thickness of the foundation is determined by the structure of the soil and the design features of the building being erected.

How much reinforcement is needed for the foundation, is decided on the basis of the calculation performed for each individual building.

If the calculation is made incorrectly and the foundation is not strong enough, then the house may squint and collapse. On the other hand, an unjustified increase in the capacity of the foundation greatly increases the cost of construction, which is also not welcome.

The number and diameter of the reinforcement, the way it is laid and the strapping step depend on the type of foundation and the characteristics of the site.

Calculation of reinforcement for a solid (slab) foundation

A solid (slab) foundation is most often used in the construction of residential buildings. Its strength directly depends on the diameter of the reinforcement. If a light house is being built on soil with good stability, then a steel reinforcing bar with a cross section of 10 mm is suitable for the foundation, if a heavy structure is being erected on soft soil, then the reinforcement should be at least 14–16 mm.

To find out how much reinforcement is needed for the foundation, you need to proceed from the following data:

• in a solid foundation, the reinforcing cage is mounted over the entire area in the form of cells of 15–20 cm;
• 5 bars of reinforcement are consumed per 1 m of foundation, that is, 50 bars 10 m long are required for a foundation measuring 10 × 10 m;
• the strapping of the slab foundation is carried out with two reinforcing belts, therefore, the number of rods should be doubled and the required number of rods for transverse strapping should be added;
• to fasten the elements of the reinforcing structure, a knitting wire is used, which must also be included in the calculation.

A strip foundation is capable of providing the necessary stability of a building in conditions of soft soils, but in comparison with other types of foundations, it requires a significant consumption of materials and large labor costs. Such a foundation is made in the form of a tape located around the perimeter of the house and under the bearing walls. Reinforcement allows you to increase the strength of the structure and its service life. For this purpose, a reinforcing bar 10–12 mm in diameter is suitable.

The following parameters are taken into account in the calculation:

• The length and width of the foundation base - for example, we take a strip foundation 40 cm under a house measuring 10 × 10 m, in which there is one internal load-bearing wall, in this case the total length of the strip foundation is 4 × 10 + 10 = 50 m.
• The number of rods per unit length - in order for the foundation to turn out to be strong enough, 3 rods must be laid in it.
• Number of belts - the foundation is tied with a minimum of two belts, so a total of 4 rods are required. In total, 40 rods 10 m long are needed for the foundation tape.
• The pitch of the cells in the reinforcing cage of the foundation should not be more than 50 cm - for the transverse strapping, another 30 m of reinforcement will be required for each foundation tape.
• Then you need to multiply the resulting amount of reinforcement by the number of foundation tapes.

Calculation of reinforcement for columnar foundations

When calculating reinforcement for columnar foundations, the following provisions are taken into account:

• for tying columnar foundations, you can use reinforcement from 10 mm;
• 4 rods are needed for 1 square section column, 3-4 rods for a round section column;
• the bars are installed vertically to the entire depth of the foundation, evenly distributing them around the perimeter;
• horizontal piping of columnar foundations is carried out in increments of no more than 50 cm.

Usually, all calculations are performed at the design stage and take into account all possible loads that an ignorant person may simply not be aware of.

We hope that our article will help you avoid mistakes when arranging the foundation.