Knitting wire consumption per 1 ton of reinforcement - how to calculate

The reinforcement bars connected to each other form a reinforcing frame, which serves as the “skeleton” of the reinforced concrete structure. The most common material used to connect rods is wire. Calculations of its consumption should be carried out individually for each reinforced structure.

Two types of wire

Knitting wire is produced from metal blanks by drawing. There are two main types of knitting wire: regular tinned and fired. To tie reinforcement in foundations and other reinforced concrete structures, the second type is used.

To prepare the wire, it is treated with thermal hardening, which gives it flexibility and resistance to the harmful effects of the environment, and also makes it less plastic, which greatly increases the strength of the material and, consequently, the wire assembly.

Stores offer galvanized and non-galvanized material. Both can be used to tie reinforcement, although galvanized binding wire (GOST) will be more resistant to aggressive environments.

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Main product parameters

The wire used for tying reinforcement for concrete can be supplied to the customer in coils or wound on spools. In this case, the weight of such a skein or reel is specified by the requirements of the regulatory document. Thus, the standard states that the minimum weight of a skein or reel in which wire with a diameter of 1.1–2 mm is supplied should be:

• 2 kg (if the product has a zinc coating);
• 8 kg (without zinc coating).

High-quality wire has standardized rigidity and can withstand a greater number of bends

The consumer, by prior agreement with the manufacturer, can order skeins whose weight will be 0.5–1.5 tons. Only one piece of the product can be wound onto skeins of binding wire for reinforcement, regardless of their weight. Unlike skeins, spools can contain up to 3 such sections.

The shipping documents for a batch of binding wire for reinforcement indicate only the weight, and the length can only be determined approximately. The standard does not stipulate this parameter, and determining the length of the product in a coil or on a reel is also made more difficult by the fact that even the regulatory document states that the diameter of the wire supplied to the customer may differ from the nominal one downwards.

An example of an accompanying invoice for a batch of binding wire

Tolerances for maximum deviations in the diameter of a binding wire with a cross-sectional size of 1.1–2 mm, depending on the manufacturing accuracy, are in the range of 0.05–0.12 mm. In order to determine how many meters of a product there are in a coil, you must first find out what specific gravity it has (in other words, how much 1 linear meter of wire of a certain diameter weighs). A quick and accurate method for determining this parameter is to divide the mass of a pre-weighed piece of product by its length. To find out how many meters of knitting wire for reinforcement are in a skein, it is enough to divide the total weight of the skein by the resulting value.

Permissible deviations of wire diameter according to GOST

The second method for determining the total length of wire in a coil is purely calculational and allows you to calculate fairly approximate parameters. Knowing the nominal diameter of the wire in a coil, which may differ from the actual value of its cross-section in a larger direction, the weight of one meter of the product is determined by the formula. Taking into account these errors, the calculated weight of one meter of binding wire for reinforcement will be less than its actual value. This means that the actual length of the product in the skein will be greater than that obtained when performing calculations.

The error between the actual and calculated values ​​will be even greater if the coil contains zinc-coated wire. In such cases, the increase in error is due to the fact that the density of zinc, which coats the surface of the wire, is less than that of steel (the density of steel is 7850 kg/m3, while the density of zinc is 7133 kg/m3). To accurately determine the length of galvanized wire in a coil, complex calculations are required taking into account the thickness of the protective layer, which can also vary along the entire length of the product. This is why such calculations will always produce values ​​with varying degrees of accuracy.

Minimum weight of a piece of wire on a reel

In practice, to determine the weight of one linear meter of both coated and not coated with a protective layer of zinc binding wire for reinforcement, the same formula is used M = qx S xh, where:

• M – weight of one linear meter of wire, measured in kg;
• q is the density of the metal from which the wire is made;
• S is the cross-sectional area of ​​the wire, measured in m2;
• h – product length.

The cross-sectional area of ​​the wire, which is a circle of a certain diameter (d), is calculated by the formula S = 3.14 x d2/4.

As an example, let's calculate the length of a coil of knitting wire weighing 8 kg and having a diameter of 1.1 mm.

• Cross-sectional area: S=3.14 x 0.00112/4 = 0.00000095 m2.
• Weight of one linear meter of the product: M=7850 x 0.00000095 x 1 = 0.00745 kg.
• Length of wire in a coil: L=8/0.00745 = 1073 m.

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Purpose of hardware

Wire for connecting reinforcement plays a key role in the construction of monolithic concrete structures. The main purpose of this material is to link reinforcing elements into a spatial or flat frame. This type of product is used for the production of:

• chain-link mesh;
• ropes;
• masonry mesh;
• prickly hardware;
• to carry out packaging work.

Use of wire for tying reinforcement

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Methods for determining the required wire mass

To purchase metal products, you need to convert the resulting footage into kilograms. To do this, you can use an online calculator or table.

Table of mass of 1 m of binding wire of various diameters

The minimum weight of wire products in coils and coils put on sale must comply with GOST 3282-74

The maximum weight of hardware in a coil is 1500 kg. Each skein should consist of only one piece.

Diameter selection

When determining the optimal diameter, the following recommendations should be considered:

• products with a diameter of 0.3-0.8 mm are not suitable for tying reinforcing bars;
• 1.0-1.2 mm – products most popular in private housing construction;
• 1.8-2.0 - such hardware is used to create powerful reinforcing structures.

In conditions of high humidity and when exposed to other negative atmospheric factors, galvanized products of significant diameter are used.

How to calculate

It is necessary to calculate the wire consumption for connecting reinforcement individually. Construction experts give various recommendations for determining the average wire consumption. Some argue that one ton of base requires 10 to 15 kg of raw materials. Other craftsmen recommend purchasing 15–20 kg of knitting hardware for the same amount of metal.

Consumption of tying wire per 1 ton of reinforcement

In the case of the length of the segment required to form a knot, the opinions of professionals also differ. Some believe that a piece 10–15 cm long is enough to knit a knot, others believe that the required consumption is 30–50 cm for this formation.

The main recommendation is that the amount of wire for tying the reinforcement should be twice the obtained value. The increased consumption is due to frequent interruptions during the work process.

Proper use of the hook

Node formation process:

• A piece of 30 cm wire is folded in half and the intersection point of the reinforcing bars is clasped so that the loop on the bend is opposite the tails.
• The hook is inserted into the loop, catches the tails and rotates to wrap the ends around the loop.
• The resulting knot is tightened with force, without breaking the wire.
• The hook is removed from the loop, the remains are trimmed.

Screw hooks are used, which are classified as semi-automatic devices. The tip rotates progressively in the device. If you pull the hook towards you, the tip turns and the wire is tightened. The worker makes minimal effort, and the time to create a knot is reduced by 3 to 5 seconds.

The wire is also folded in half, the hook is inserted into the loop, the end is wrapped around the loop and the hook is pulled towards itself. Turning the handle ensures tightening.

Settlement operations

Simple calculations allow you to calculate the consumption of tying wire for reinforcement with a fairly high level of accuracy. When calculating, the following characteristics should be taken into account:

Comparative table of the required amount of reinforcement and tying wire for different types of foundations

• diameter of main rods;
• thickness of knitting raw material;
• the number of nodes in which the tying should be carried out.

Increased consumption of wire material is observed at the intersections of several horizontal and vertical rods. In the middle part of the metal structure, knitting through the joint is allowed. All overlapping joints located at the edges of the structure are subject to mandatory strapping.

The length of the metal product required to form one knot is calculated experimentally - by performing a trial strapping.

Video on the topic: Crocheting reinforcement

Work technology

Knitting of reinforcement for a strip foundation is carried out using the following technology:

• Formwork made of wood or other materials is installed, and a fishing line is stretched inside it to indicate the upper plane of the foundation.
• At the bottom, 5 cm in height is marked, from this level the layout of longitudinal rods and ligation of joints begins. Bricks are placed at the bottom to ensure that this condition is met, and vertical reinforcing elements are stuck into the ground. The steel rods are also spaced 5 cm from the formwork walls.
• Longitudinal elements are made solid for a length of 6 m. A bunch of rods are allowed to overlap 25 - 35 cm if the foundation is strip. The slab is long. Metal rods are placed around the perimeter, and the upper and lower reinforced belts are tied onto them.
• Concrete is poured in layers after the knitting is completed, and vibration is used to expel air bubbles.

The reinforcement cage can be knitted in sections outside the formwork and sequentially installed inside the trench, but installation in this way requires more workers. Debris and foreign objects are not allowed in the nodes; there should be no protruding loops or uneven tightening with free ends of the wire in the connection.

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How to calculate the amount of tying wire per ton of reinforcement

Calculation of tying wire for reinforcement is based on the following data:

• Construction type . For a heavy structure, the number of strapping elements will be greater than for light structures.
• Type of reinforcing bar . As the diameter of the main rod increases, the amount of binding wire decreases, and as it decreases, it increases.

According to SNiP data, the consumption rate of tying wire when assembling a reinforcing frame is 30 cm per connection unit or 4 kg per ton of reinforcement. To more accurately calculate the amount of material, it is necessary to calculate the number of joining points of embedded products. Based on practical experience, steel bars weighing 100 kg will require from 0.9 to 1.3 kg. The consumption of tying wire per 1 ton of reinforcement should be from 9 to 13 kg. To tie 1 ton of steel bars with a diameter of 28 or 32 mm, you will need about 7 kg of wire, 8 mm - 12 kg.

The most accurate data can be obtained by creating a trial harness. Or use the formula for calculating the length of one turn:

2 x 3.14 (Pi) x cross-sectional radius of reinforcement x 1.03

Count the number of strapping knots and multiply by the length of one turn with a margin. Please note that when transferring the rods you need to make a double connection. Then convert the resulting linear meters into kilograms using the following table:

IMPORTANT! The table shows the weight of wire without zinc coating

Concrete consumption in the manufacture of various structures: calculations and standards

As a rule, calculations of concrete solution costs are contained in the design documentation. However, if you are building your house, outbuilding and other buildings yourself, then you will have to carry out the calculations yourself. The cost of concrete work depends on their correctness.

Concrete costs depend on the type of structure being made.

How to make calculations for the foundation of a house

The amount of concrete costs depends on the type of foundation chosen.

Slab base

Such a foundation is a monolithic slab, poured under the entire house.

In this case, you need to know the area of ​​the building and the thickness of the base.

1. Let's give an example. It is necessary to pour a slab foundation, 10 cm (0.1 m) thick, under the house, measuring 9 × 9 m.
2. The area of ​​the slab is: 9∙9=81 m2.
3. We calculate the filling volume: 81∙1=8.1 m3. Calculations for concrete screed are carried out in the same way.

This instruction did not take into account the stiffening ribs at the bottom of the foundation, which ensure its stability and rigidity.

They intersect and break the base into squares.

1. For a 9x9 m foundation, ribs must be laid every 3 m.
2. Their thickness is equal to the thickness of the slab itself, in our case it is 10 cm.
3. The total number of ribs is 6 (3 across and 3 along), the length of each of them is 9 m.
4. Consequently, their total length is 54 m. With a width and height of the ribs of 0.1 m, their volume is: 54∙1∙0.1=0.54 m3.

We add both numbers and get the result - 8.64 m3 of solution.

Tape base

Tape base.

The rate of concrete consumption per 1 m3 of such a foundation is also calculated simply.

For this purpose, you need to know the width, length, depth and height of the ground part of the base.

1. Our example will be the same building with sides measuring 9 × 9 m. Its perimeter is 9 ∙ 4 = 36 m. Let the width of the base be 40 cm (0.4 m), the depth of 1 m, and the ground part 50 cm (0.5 m).
2. In other words, the total height of the base is 1+0.5=1.5 m.
3. We calculate the volume of the foundation: 36∙4∙1.5=21.6 m3.

Note! This calculation does not take into account partitions.

If they are in the project, you should sum up the volume of tapes for them and the volume of the main foundation.

Columnar foundation

Parameters taken into account during calculations.

To determine the cost of concrete for arranging such a foundation, you need to know the number, height and cross-section of the supports.

First, the mixture consumption per column is calculated, then the figure is multiplied by their number.

1. When calculating the area of ​​a support with a circular cross-section, the formula S=3.14∙R∙ is used. The letters mean: S is the required area, and R is the radius of the section.
2. If the pillars are rectangular in shape, the area is calculated by multiplying their two adjacent sides.
3. When the area of ​​the support is found, it should be multiplied by the height of the supports and their number. This way you will find the volume of concrete you need.

Reinforcement consumption

The reinforcement is counted by determining its total length.

When pouring a structure with a reinforced frame, you should also calculate the cost of materials for it.

Twig frame

To calculate the frame, you just need to measure the entire length of the reinforcement.

The consumption of binding wire per 1 m3 of concrete is determined as follows.

1. First, the connection method is determined. It can be like this: the transverse and longitudinal rods of the lower belt are fixed, then vertical rods are screwed to them. And the transverse and longitudinal reinforcement of the upper chord is already fixed to them.
2. This means that at the intersection points of two horizontal and one vertical rods there will be 2 wire connections.
3. To tie one intersection point of the reinforcement, 15 cm of tying wire is required. At the same time, it folds in half, therefore, it needs 30 cm for one connection.

Volumetric reinforcement

Volumetric reinforcement using fiber fibers is being used more and more widely. Unlike metal analogues, they are distributed evenly throughout the solution, increasing its astringent qualities and resistance to delamination.

Fiber consumption per 1m3 of concrete is given in the table.

Waterproofing

Deep penetration waterproofing compounds are often used for concrete structures.

Note! For example, the consumption of Penetron per 1 m3 of concrete is not so great, but it prevents the penetration of moisture through the base.

In addition, the composition increases the strength and frost resistance of concrete.

This waterproofing is available in dry form. It consists of special cement, finely ground quartz sand and active chemical additives.

Penetron consumption per 1 m2 of concrete varies from 0.8 to 1.2 kg, which depends on the degree of roughness of the base.

Standards applied in production

The photo shows the consumption of materials for different factory-made concretes.

Concrete consumption rates in production are applied in accordance with the requirements of State Standard No. 14.322/83.

They reflect the maximum volume of solution that can be used to produce units of products or work. When drawing up standards, technologists take into account the useful consumption of material, its losses and waste. Based on them, the price of the products is determined.

In factories, the required volume of mixture for the production of a certain product is found by calculation or graphic-analytical method.

1. The calculation method uses drawings and technical documentation. The consumption coefficient of concrete during its compaction is also taken into account.
2. With the graphic-analytical method, real material costs are compared with protocol figures. Next, graphs are made and analyzed by computer programs.

Conclusion

It is extremely important to know the exact cost of the solution when carrying out work, be it the consumption of aerated concrete blocks per 1 m2 or mixtures for monolithic structures. This determines how you organize the construction process.

The video in this article will give you more food for thought.

Page 2

The drying time of concrete (or, to be precise, the time it takes to gain strength) is precisely the factor that significantly slows down any construction. And the main difficulty in this case is the fact that reducing this time can only be achieved by carrying out rather complex and costly activities.

Below we will describe what happens to the solution when it dries, and also provide a number of recommendations for optimizing this process.

Adjusting the moisture content of the material is an important factor in ensuring its performance

Drying concrete correctly

Main stages

Until the solution has set, it can be leveled

To understand how to dry concrete as quickly as possible and without loss of quality, you need to understand what happens inside the solution itself after pouring. If you do not take into account the chemical component (it is of interest only to professionals), then several stages can be roughly distinguished. For ease of analysis, we have compiled them into a single table:

Note! It is not worth artificially accelerating the course of these stages: if the solution loses moisture before the cement reacts with it, then part of the material will remain without hydration.

As a result, areas of uneven structure are formed within the thickness of the monolith, seriously reducing the strength of the concrete structure.

Dependence of strength on time and temperature

Factors influencing the process

So, we have characterized the main stages of the process. However, as we know from practice, the time required to dry the solution may vary.

What does it depend on?

• The first parameter that needs to be taken into account is the composition of the material. If necessary, various agents are added to the solution that can speed up hardening without compromising quality. Naturally, the price of the structure in this case increases significantly, which is why hardeners are not used en masse.

Note! The additive can work both in natural conditions and when heated.

In the second case, the most economical would be to use finely ground slag (approximately 25% of the total mass of Portland cement).

• The next factor is the humidity of the surrounding air. Of course, in a dry climate, dehydration of the solution will occur more quickly, but as we know, this will lead to the removal of water, which is necessary for hydration of the cement. Consequently, accelerating the process can lead to deterioration in the quality of the product or structure.

Dusting and cracking of the surface when drying out in the sun

• Finally, temperature is also important. With additional heating, the rate of polymerization increases due to the fact that the activity of the reaction between cement and water increases. Due to this, it is possible to either speed up construction or compensate for the decrease in temperature during the cold season.

In the cold, the material practically does not dry: additional heating is needed

• When talking about temperature conditions, we must not forget about frost. When the liquid freezes, the drying process of concrete practically stops. Moreover, the resulting internal ice, due to an increase in volume, expands the pores in the material, which leads to its premature destruction.

Recommendations for speeding up drying of concrete

When constructing a building with our own hands, we are often limited in time, but we do not want to sacrifice quality. That is why the question of how to quickly dry concrete without losing strength is of interest to many.

Here are some recommendations you can give:

• The less moisture there was initially, the faster it will leave the solution. It is for this reason that for non-responsible concreting (leveling the base under the foundation, pouring unloaded screeds, garden paths, etc.) a very thick solution is used.
• The reaction rate directly depends on the particle size: the smaller they are, the larger the contact area with water. Thus, by using finely dispersed binders and fillers, we can reduce the time required for concreting.

High-curing composition

Note! Finely ground cement is slightly more expensive than standard cement, and it is more difficult to find.

• If we are ready for financial investments, then we can modify the material at the stage of preparing the solution. To do this, we either prepare it based on quick-hardening cement, or add chemical modifiers (soda, potash, potassium chloride, sodium nitrite, etc.).

A separate group consists of thermal methods:

• Firstly, to prepare the solution, you can use water preheated to +60–800C. This will promote rapid setting and reduce the period of initial strength gain.
• Secondly, concrete formworks with high thermal insulation properties should be used. This way, the heat accumulated in the concrete will last much longer.

Steaming in autoclaves (in the photo - serial production of aerated concrete)

• Finally, in the industrial production of building concrete blocks, heat and moisture treatment is used. 8-12 hours in an autoclave with hot steam can effectively replace several weeks of drying in the open air.

Conclusion

Speeding up the drying of concrete to reduce construction time is only necessary if you know how to compensate for the loss of strength of the material. You should be very careful here, since a lack of water in cement can have a very negative impact on the reliability of the structure and its service life. This problem is covered in more detail in the video in this article.

masterabetona.ru

Calculation for floor slab

When constructing a floor slab, a mesh is usually laid in the upper and lower chords. Working reinforcement rods are placed along the length of the slab. They will be combined into a grid using structural rods. The number of transverse rods must be at least three per meter. Accordingly, they are usually laid in 300 mm increments. A mesh of reinforcing wire is usually placed at the top of the slab. To find out the number of nodes, it is enough to find the designed grids in the drawings and count all the intersections of the longitudinal and transverse rods.

Both grids are combined into a spatial frame using vertical frames. Typically, 3-4 frames are installed for a length of two meters. They can be located along the entire length of the structure or only at the ends in an area equal to 1.4 times the length of the slab. How many nodes are in the frame can also be found from the drawings. In order to calculate the total number of connection points, you need to sum the nodes:

• nets;
• frames;
• places where meshes and frames are connected.

The resulting amount of wire should always be rounded up, as it tends to burst. This happens especially often when working with wire with a diameter of less than 1.2 mm.

Pros and cons of joining using the knitting method

1. The knitting process is less expensive than welding reinforcement.
2. It does not require a qualified welder, equipment, or significant energy consumption, especially when it is not yet available on site.
3. It only takes one day to train an experienced rebar knitter.
4. The knitting technology leaves the frame some freedom of movement when pouring concrete and processing it with vibrators. In this case, the reinforcing bars occupy positions in which there are no significant mechanical stresses that threaten to break.

1. Poor-quality strapping, the implementation of which was not monitored by the technical supervisor of the work, can give too much freedom to the rods. In this case, the geometric parameters of the frame may be distorted during pouring until the reinforcement reaches the surface, which is unacceptable.

There are 2 calculators on the page - one is less accurate, but you can easily and quickly get the result, the other (below) is more accurate, but additional information is required for the calculation.

Use these tying wire calculators to roughly calculate the amount of wire required, depending on the amount of reinforcement being tied.

When building foundations, walls, floors and other concrete works today, reinforcement is used, and to connect reinforcing bars at their intersections, fixation is required; the most commonly used method of connecting reinforcement is tying the reinforcement with tying wire.

The weight of the wire depends on its thickness. For tying reinforcement in private housing construction, 1.2-2mm wire is used; it rarely makes sense to use thicker ones, because It holds the knot well, but thicker ones cost more and are much more difficult to twist.

This calculator allows you to quickly estimate approximately how much wire you need to buy in kilograms, because it is in kg. The wire is indicated by the sellers and most likely no one will measure it in meters. The calculation is made based on the consumption rate as a percentage of the consumption of wire reinforcement with a diameter of 1.2 mm as the most commonly used.

To calculate how much binding wire is needed more accurately, you need to take into account all the intersections of the rods; this is not too difficult, especially if the structure is reinforced with meshes with a certain cell. At each point where two horizontal rods and one vertical one intersect, there are two tying wire connections in each row, i.e. do not forget to multiply intersections in one row by 2. Knitting the mesh is allowed in a checkerboard pattern, i.e. through one joint, but the two outer rows of each side must be knitted each intersection.

By counting and indicating the number of intersections in the calculator window below, you will get the approximate amount of wire in kg required to perform the reinforcement. The calculation is made taking into account the thickness of the binding wire, which must be selected from the list. The more accurately you count the number of intersections, be careful.

The binding process occurs as follows:

• the wire is folded in half;
• they bring it under the crosshairs of the fittings;
• the ends are inserted into the loop on the hook;
• twist clockwise.

It is better to bend the twisted ends down. Their position, of course, does not affect anything, but some representatives of technical supervision pay attention to this.

It is better to remove broken wire or broken ends from the formwork. The remaining metal debris will subsequently lead to the formation of rust spots on the surface of the structure.

Large diameter wires are easier to twist with wire cutters. Some builders use more reliable homemade hooks. And large construction organizations prefer to work with automatic pistols, which reduce the time it takes to complete the work.

Regardless of the tool chosen, the connections must be reliable. Displacement of reinforcement during concrete pouring is unacceptable.

If a frame is being made for structures with a light load, then the reinforcement can be secured using plastic clamps. In this case, no tools are needed; the clamps are simply tightened by hand.

Subtleties of calculations

There are no established standards or recommendations for wire consumption for fixing rods. The indicators depend on the dimensions of the frame and the diameter of the reinforcement. But it’s quite difficult to determine with 100% accuracy the amount of wire that will be required for a particular object. In this regard, most often you have to take material with a good supply. As a rule, experienced specialists recommend purchasing material at least 1.5 times more than necessary. This is due to the fact that during the work process, when tying knots, a rupture and loss of wire may occur. In addition, with a diameter of 1.2 mm, material is consumed faster.