How to quickly knit reinforcement

How to knit reinforcement correctly

When pouring a foundation, it is very important to invest in it a high-quality reinforcing mesh, which will provide the required adhesion and hardness of the foundation. In this case, it will not be possible to make a mesh using only one rod, bending it at different angles. This requires a large amount of material and its correct connection. Experts do not recommend using welding, as the structure of the metal is disrupted and its strength is reduced. The most practical way is to knit reinforcement.

What materials and tools are used when tying reinforcement

Previously, when pouring the foundation, they used exclusively steel wire, made in accordance with the relevant GOST, in several layers. This guaranteed the necessary strength of the foundation in the future. But today there is a sufficient variety of knitting materials that can also be considered reliable.

Steel wire

Steel (or, as they say, knitting) wire is the most suitable material for tying reinforcement. In its manufacture, annealed steel with a low carbon content is used, which makes the wire quite strong, and at the same time soft. Knitting wire is divided into 2 types:

• Black. The most practical and convenient. If you purchased black wire that is not soft enough, then it should be ignited in a fire for 30 minutes, cooled, and you can start working.
• Galvanized. Very rarely, this type of wire is purchased for knitting reinforcement, since there is no oxygen flow in it, and, accordingly, corrosion processes cannot occur. Therefore, there is no need to spend extra money here.

Plastic clamps

Quite a popular consumable today that will help you quickly understand how to quickly knit any reinforcement. But it cannot be said that professional builders adhere to the majority opinion, since plastic products have a lower price, but are not able to withstand the force that steel wire can withstand.

Plastic clamps differ from knitting wire not only in their lower price, but they are also extremely easy to use - just wrap the product around the reinforcing bars, pass one end through a special eyelet and tighten. A common problem is when clamps break, for example when a construction worker steps on reinforcing bars. Therefore, for greater reliability, you should wear 2 or more layers, located in different directions.

Tools

You should not use improvised materials when knitting reinforcement, as this will not allow you to achieve high reliability of the frame, and accordingly, the foundation will not receive the required strength.

The most popular tools used for tying reinforcement:

• Hook for tying reinforcement. This tool is used quite often, since the hook for tying reinforcement has an affordable price policy and is easy to use. It has 3 varieties: simple, screw and semi-automatic.

• Knitting pliers. Not too different from a hook for tying reinforcement. They are slightly longer and have additional cutters in their design. With reversible pliers, you can use tying wire directly from the coil.

• Gun for tying reinforcement. It is a type of professional tool; it is important to purchase it only when it is necessary to knit reinforcement in large quantities for any type of foundation. The gun for tying reinforcement is lightweight and very easy to use; the tying process is fully automated and takes no more than one second. The main disadvantage is the high price.

Gun for tying reinforcement

How to knit reinforcement for a monolithic slab correctly

Monolithic foundations are used more often than standard concrete slabs. When installing this type of base, a reinforcing mesh is first made, which is then filled with concrete. The reinforcing mesh gives the concrete additional strength and allows the slab to withstand higher loads.

Ready-made frame for a monolithic slab

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How to knit reinforcement yourself or the correct sequence of knitting reinforcement for a monolithic slab:

1. The lower level of reinforcing bars is laid in a cross. It is necessary to observe the main thing correctly - to monitor the size of the cells, which should be 30*30 cm. This size cannot be exceeded, otherwise the monolithic slab will not be strong enough.
2. The joints of the slab foundation rods must be tied with steel wire using a standard tying pattern. Using a special tool, such as a hook for tying reinforcement, will greatly simplify the task.
3. The reinforcement of the lower level of the slab must have a margin in length so that it can be given a U-shape. Thus, the lower rods go into the upper level of the slab foundation.
4. The rods of the upper level of the slab or ceiling are also stacked on top of each other and tied with steel wire or plastic clamps at the points of contact.
5. The structure for a monolithic slab should be placed at a distance of 4 cm from the ground; for this, special stands are used, which can be purchased at a hardware store. The stands are made of plastic and can support frames with a fairly large weight. An example of plastic stands for the lower tier of the structure
6. To maintain the upper level of the ceiling reinforcement, special stands should be made from rods, which are called tables. It is enough to take a small piece of reinforcement and bend it in a zigzag. Now the upper tier can be conveniently installed on the resulting stands. When pouring concrete, the supports are left together with the main structure.

This method of reinforcement is used not only when pouring a slab foundation in several layers; in this way, you can make a monolithic slab with your own hands, which can later be used, for example, as a floor between floors.

Calculation of reinforcement for a monolithic slab

Having learned how to knit reinforcement for the foundation, it is necessary to calculate the material. You should know that to reinforce any surface, reinforcement with a diameter of 8 mm or 10 mm is used. For slabs of multi-storey buildings, rods with a large diameter are used - 12 mm or 14 mm.

For example, it is necessary to accurately calculate the number of reinforcing bars that will be used to reinforce a slab with a total area of ​​64 m2. For such a surface, rods with a diameter of 10 mm will be sufficient. One grid cell will have sides of 20*20 cm.

In order to find out the exact amount of reinforcement, you should divide one side of the slab (8 meters) by the side of the cell (20 cm) and multiply the result by two. Result: 80 rods. As a reserve, when calculating one side, one rod is always added, this means that the end result will be 82 rods (since there are two sides).

But the reinforced mesh has upper and lower levels, and 82 rods must be multiplied by two. You will get 164 rods of a certain diameter.

To reinforce the mesh, rods of a maximum length of 6 meters are used. Therefore, the total number of reinforcement should be multiplied by the length of one product. This means that to produce one slab with a total area of ​​64 m2, it is necessary to purchase 984 meters of reinforcement of a pre-selected diameter.

When calculating the amount of reinforcement for the mesh, you should not forget about stands, short sections for fastening two levels, as well as rods of a certain diameter that may be needed during the entire process.

How to properly knit reinforcement for a strip foundation

A strip foundation is the most practical and requires much lower costs than a monolithic pour. But this type of foundation receives a significant load from the erected building and requires correct and reliable mesh reinforcement, on which you can also save money, because strengthening the middle part of the strip foundation is not necessary.

Example of a standard strip foundation

Installation of strip foundation:

• To fill this type of foundation, formwork secured with metal pins is used. Therefore, the distance between the rods must be such that after tying them, the finished structure can be inserted into the formwork.
• The side walls of the frame are tied so that the sides of the cells are no more than 20 cm.
• After the sides are ready, short pieces of rods should be placed between them, which are also knitted using steel wire or plastic clamps.
• The resulting structure is installed inside the formwork, which also requires some skill and, preferably, two assistants.

Installation of the finished frame into the formwork

Knitting reinforcement for a strip foundation:

• One connection requires a piece of binding wire of at least 30 cm, which should be folded in half.
• A piece of wire folded in half is completely wrapped around the overlapping rods and a crochet hook is inserted into the loop.
• The other end of the wire should also be wrapped around the crochet hook.
• You can begin to rotate the crochet hook until the 2 rods are firmly fixed.
• Remove the hook from the loop.

Having become familiar with how to correctly knit reinforcement for a strip foundation, you should also pay attention to the fact that if excessive force is applied, the knitting wire can easily be torn, so you should control the movements of the tool. Also, do not leave the wire in a weakened state when the rods move freely. This will lead to insufficient structural strength.

Ready frame for strip foundation

Very often on the Internet you can find a popular way to remake a drill by installing a hook for tying reinforcement on it, which professional builders strongly disagree with. Using such a homemade tool, you will not be able to achieve the correct tension of the knitting

wire. Also, the drill is not convenient enough for installing a strip foundation; the consequence will be quickly tired hands. And there is not always access to electrical energy in places where the foundation is being poured.

Correct knitting of fiberglass reinforcement

Fiberglass reinforcement is usually called products whose structure consists of glass fibers. This type of reinforcement belongs to the category of composite reinforcement and is very popular today. In their shape, fiberglass products are practically no different from metal ones.

Tying fiberglass reinforcement using clamps

Among the advantages of fiberglass reinforcement, the following should be noted:

• Easy. The process of transportation and installation is automatically simplified.
• Elastic. If necessary, composite reinforcement can be placed in rings, which is very convenient for loading and transportation.
• Strong. In terms of its technical qualities, it is in no way inferior to metal products.
• Durable. Composite reinforcement has a long service life.

An example of tying fiberglass reinforcement with several clamps

The knitting of fiberglass reinforcement is practically no different from standard metal products. Here you should also use a crochet hook or a special gun, and knitting wire or plastic clamps as consumables.

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First, the horizontal sides of the structure are prepared, onto which vertical rods are subsequently placed. When knitting fiberglass reinforcement, it is necessary to accurately monitor the size of the cells; for greater simplicity, you can make marks in advance with a marker. The places where the reinforcement is tied must be located in the inner part of the frame. It is not enough to know how to knit fiberglass reinforcement correctly; you must also make accurate calculations.

It is necessary to pay special attention to the corners of the structure, since fiberglass reinforcement is poorly susceptible to heat, so it is not recommended to bend it yourself. More tie wire or plastic clamps should be used at the corners of the frame.

Source: https://viascio.ru/materialy/armatura/kak-pravilno-vyazat-armaturu

How to knit reinforcement for a foundation: proven methods

You need to know how to knit foundation reinforcement correctly. If this procedure is performed incorrectly, the load will be distributed unevenly, which will lead to various deformations. Proper knitting will increase the strength indicators, as well as increase the service life of the future building.

The foundation is the basis of every residential and non-residential structure, therefore it is subject to special requirements for strength and quality. In the construction of most country houses, a strip type of foundation is used. In order for the base to withstand sufficiently large loads, it must be reinforced. Special reinforcing elements in the structure will contribute to the uniform distribution of all acting forces.

In this article we will take a closer look at what materials and tools are used to strengthen the foundation. Let's look at the correct knitting procedure step by step.

Features of the foundation of country houses/cottages that you should know

There are several types of foundations for country houses, but the strip type is universal. It is suitable for the construction of buildings of various heights, as well as for construction on soils of various types. On this foundation, you can build buildings from brick, concrete panels or wooden beams. It is also distinguished by significant savings in money, since it does not require the presence of expensive materials and special equipment.

This type of foundation is a continuous concrete strip, which is located along the entire perimeter of the future building.

The geometric dimensions of the tape will vary significantly depending on the type of building, its number of storeys, the thickness of the walls and the building material from which the walls and ceilings will be built. The foundation is made as follows.

First, the reinforcing frame is prepared and laid to a certain depth. After this, it is filled with a specially prepared concrete mixture.

The foundation has a certain depth. It depends on the type of soil on which the object is built. If the top layer is quite loose and unstable, then the depth should be large enough. This parameter is calculated at the preliminary design stage.

The strip base is excellent for the construction of country cottages. Here are the main advantages thanks to which it has become so popular:

• Easy installation;
• Can be used for houses with basements and several floors;
• No specialized equipment or tools are required.

Why is the reinforcement procedure performed?

The foundation on which the building will stand must withstand the entire load. The load is distributed unevenly. In places where load-bearing walls are located, it will be most pronounced. Due to unstable soil, quite strong stress can also occur in some places.

Concrete itself is a fairly strong material, but when it is subjected to tensile forces, it becomes weak. In order to increase the ability of concrete to resist tensile forces, it is reinforced with special metal elements. As a result, a reinforced concrete structure is formed, which has high strength in both tension and compression.

The base must have the necessary strength margin to withstand various climatic and mechanical external influences. Therefore, the reinforcement procedure must be carried out efficiently and in accordance with all the necessary requirements of the relevant SNiP. The following requirements apply to reinforcing elements:

• The metal frame must be assembled and installed in such a way that none of its elements interfere with the pouring of the concrete mixture;
• The reinforcement is laid with a certain step, which is calculated during design;
• In places where the frame rods intersect each other, there must be a tight and motionless connection. The connection must not be allowed to be movable and therefore unreliable;
• The metal structure must be made of galvanized reinforcement or additionally coated with a protective layer;
• Performing any manipulations with the structure that will lead to a decrease in the load-bearing capacity is strictly prohibited.

Before we begin the procedure of strengthening the foundation, we need to understand what materials we will need. The frame is made from reinforcement of the required diameter. The frame elements are knitted in certain places using steel wire. There are metal rods and reinforcement made of a special composite material. In most cases, metal rods are used.

Metal reinforcing elements are manufactured by hot rolling at specialized enterprises. The production process is regulated by GOST-5781-82. According to it, there are six groups that differ in composition and strength. The first group is made exclusively from low-carbon steel and has relatively low strength. The larger the group, the more alloying additives there will be in the steel, and the stronger it will be.

Recommended reading:

What reinforcement should be chosen when laying the foundation of a private house

How to calculate reinforcement mesh during the construction of various objects

Products of the first group have a completely smooth surface. All subsequent groups have a corrugated surface, which provides a stronger connection with the concrete mixture.

Selecting a suitable group of reinforcement for a strip foundation

It must be done based on calculations. In most cases, products of the 3rd group with a rod diameter of 13-18 millimeters are used.

Pay attention to the letter designations that are indicated in the material labeling:

• The letter “C” indicates that rods of this type can be joined by welding. If the marking does not contain this letter, then any welding work with the material is prohibited. This will lead to a change in strength characteristics. Therefore, in most cases, frame elements are secured with wire;
• The letter “K” in the marking indicates that the products are coated with a special protective layer. This is done to protect against corrosion and aggressive environments. It is recommended to use this type for the construction of a reinforcing frame for the foundation of country houses/cottages.

In addition to the main material, the following materials are used for the manufacture of the reinforcing frame: clamps, additional racks and lintels. These elements are made from smooth metal rods of the first group.

If the height of the additional elements does not exceed 800 millimeters, then rods with a thickness of 6 millimeters will be sufficient. If the height is more than 800 millimeters, it is recommended to use rods 8 millimeters thick.

Knitting is done using steel wire, which is called knitting wire.

It is strictly prohibited to use welding to connect fittings that are not suitable for this purpose. Here are the main reasons why welding is prohibited:

• The weld seam is exposed to corrosion, which will subsequently lead to the destruction of the structure;
• Welding may be weak in some areas. When pouring concrete mixture, it may break, which will lead to the appearance of defects on the base;
• Heating the metal leads to a loss of strength properties.

The bonding procedure is more practical than welding. You can simply knit the reinforcement for the foundation with your hands, but it will take a lot of effort and time, and you can also damage your hands. Therefore, it is necessary to use a minimum set of tools. You will need the following tools:

• Knitting gun. This is a special tool that allows you to quickly connect the rods. The only drawback is that it is inconvenient to use in hard-to-reach areas;

• Special crochet hook. In places where the gun cannot reach, you can use a hook. Outwardly, it looks like a curved piece of rod with a pointed tip, and on the other side there is a comfortable handle. In the absence of a knitting gun, the entire procedure can be performed with crochet;

• Pliers. If you do not have special tools, you can twist the wire at the joints of the reinforcement using ordinary pliers.

Main components of the frame and calculation of the required volume of rods

The frame structure for strengthening the foundation of the building consists of the following main elements:

• Working fittings. These are corrugated steel rods that are placed horizontally along the walls of the future building. To reinforce the strip-type base, rods with a thickness of 13 to 18 millimeters are mainly used. They are laid in several layers (two or three);
• Vertical elements. These include pieces of rods that connect the upper and lower layers of horizontal elements;
• Clamps. These are additional parts of the structure that perform a connecting function. They can be located in different planes (vertical, horizontal, transverse).

Calculation of the required amount of reinforcement is carried out at the design stage. The calculation is based on the geometric dimensions of the base tape (depth, total length, width). Depending on the depth, the number of layers of the frame also changes; this indicator is also taken into account in the calculations. The material can be sold both in meters and in kilograms. There are special reference tables for converting one value to another.

How to knit reinforcement for the foundation so that the house can stand for decades without deformation.

The procedure for assembling metal rods of various lengths into a single frame is a rather long and labor-intensive process. In order to speed it up, several people can do it at the same time. Let's look at this process step by step:

• First you need to prepare the binding wire. Cut it into pieces about 300 millimeters long;
• Then fold the cut piece in half and make a loop. It must be at least one third of the entire length;
• Next, you need to wrap the wire around the place where the steel bars are connected. Next, using a special hook, you need to pick up the loop and twist it with the free ends of the wire;
• The hook with the loop engaged is turned clockwise until the wire pulls the rods tightly together. You shouldn't use too much effort when twisting here. The wire may break if you overtighten it;
• At the final stage, the hook is pulled out, and the remaining free ends are slightly bent.

In addition to metal wire, plastic ties can also be used for ties. However, they have a number of disadvantages. They do not have sufficient strength, so when pouring concrete mixture they can easily be damaged. At sufficiently high subzero temperatures, plastic becomes less elastic and more fragile. Therefore, the assembly of the frame in winter is completely excluded.

Of course, there are also plastic puffs with a metal core that can be used in winter. They are quite expensive, so your financial costs will increase significantly.

Laying a strip foundation during the construction of country houses of various heights is one of the important stages that will determine the load-bearing strength of the entire house. Therefore, you need to know how to knit reinforcement for the foundation so that the frame is strong enough.

Source: http://blog.kpmtrade.ru/sortovoj-prokat/kak-vyazat-armaturu-dlya-fundamenta/

How to knit reinforcement correctly - ProBuildingmaterials

Construction of a house begins with laying the foundation. The main requirement for a concrete foundation is its strength. It is achieved by laying a frame of reinforcement bars tied together inside the concrete. Such a frame is called reinforcing. This article will discuss such an important stage of construction work as tying reinforcement for the foundation.

Methods

It is necessary to first consider what methods of tying reinforcement for the foundation generally exist. They differ from each other by type:

• tool;
• material;
• knitting patterns;
• type of fittings.

By type of tool - this can be either knitting reinforcement for the foundation manually or using a special tool. For the latter, special crochet hooks, screwdrivers, and special pistols , produced specifically for this operation.

The material used to connect reinforcement bars to each other is:

• tying wire is the most common and reliable technology for tying reinforcement for the foundation, because it is performed with tying a knot.
• paper clips - are wire clamps, which, unlike ligation with knitting wire, are made without tying a knot.
• small clamps made of plastic - this new material has become widespread due to its ease of installation and high knitting speed, and besides, it is not afraid of corrosion. However, such a bundle of reinforcement for the foundation causes a certain skepticism among professionals. Read more here.
• clips - made in the form of latches that fix adjacent rods to each other.
• welded connection - this old method has not become widespread, since the welded connection, due to its fragility, is susceptible to cracking during concrete pouring and does not have the necessary reliability. To perform a high-quality welded joint, you need a highly qualified welder.

Required wire

When choosing wire, the following factors must be considered:

• Manufacturing accuracy class. The accuracy class is determined by the production method. There is a wire of a higher accuracy class, its deviation of the actual size, diameter, from that declared by the manufacturer along the entire length of the wire is less than that of a wire of a lower accuracy class. However, for knitting reinforcement, the accuracy class is not particularly important.
• Wire rolling method. There are two types of rolled products: cold-rolled and hot-rolled. Cold-rolled steel is rolled out from blanks by presses without heating. With the hot rolling method, rolled steel is rolled out in a heated state, which gives greater strength.
• Which group in terms of tensile strength does the wire belong to (there are the first and second groups);
• Degree of corrosion resistance. On this basis, there is only one difference - whether there is a galvanized coating on the wire or not.

The criterion for choosing a wire is very simple, you need a wire that is called “knitting” . It has a full set of necessary characteristics: sufficient softness with the declared strength, abrasion resistance and reliability when fastened.

Galvanized wire is considered overkill.
The optimal diameter of the knitting wire is 1.2-1.4 mm. A wire with a diameter of 1.6-2 mm takes a lot of force, as a result of which construction slows down, and the piece is too weak, it will simply burst.

You need to check the rigidity of the connection of the reinforcement by touching the rods - if they are rigidly fixed, they will not move, which means everything is in order. You should not test the strength of the knot itself, otherwise there is a risk of loosening the binding.

The length of wire recommended for one knitting point is from 30 to 50 cm. The wire itself is extremely cheap - about 50 rubles. for 100 meters. To avoid running out of it at the wrong time due to loss or excessive consumption, it is recommended to buy it with a double supply. 100 rubles for 200 meters is quite inexpensive.

How to bend reinforcement correctly, all the ways

You should choose how to bend the reinforcement for the foundation based on its diameter: with your own hands is quite easy, but for thicker reinforcement you will have to use special devices, homemade or specialized.

Among homemade devices, two methods are common. The first is when an ordinary pipe of suitable diameter is installed vertically and its base is poured with concrete so that it stands firmly.

The fittings are inserted inside all the way, and now the end protruding from the pipe can be bent by simply leaning on it. If this presents certain difficulties, then a second pipe is additionally put on the free end of the reinforcement, and now, due to the increased leverage, the thick reinforcement can be easily bent.

Welding is also often used. By softening a section of the rod with heat, it becomes easy to bend. The same is done with a blowtorch and a hammer. After heating the bend point with a lamp, bend the reinforcement with a hammer.

The most radical way is to make a cut with a small grinder and then bend it completely using available tools.

Crochet

The design of the hook for these purposes may be different, but this is not so important. The meaning lies in the presence of a hook as such, because it is used to thread the wire. The rules for tying reinforcement for the foundation are shown schematically in the figure.

Pay attention to the sequence of actions:

1. Bend the wire in half;
2. Follow the arrow, as in the figure, bring it into position for threading;
3. Insert the hook into the loop that will now be wound;
4. Place the hook loop inward between the free ends of the wire;
5. Without removing the hook, twist until tightened, but do not pinch;
6. Ready!

For strip foundation

The strip foundation reinforcement has two patterns for laying rods:

• system of 4 rods : two at the base of the foundation, two at the top (used if the width of the foundation does not exceed 50 cm),
• system of 6 rods : an additional longitudinal rod is placed between the two main ones (used in cases where the foundation width is more than 50 cm).

Bent reinforcement is laid at the corners, and the ends should protrude from the corner by at least 40 cm. The reinforcement connection nodes should be located from each other at a distance of no more than 60 bar diameters .
For example, if 12 mm reinforcement is used, then the strapping should be every 72 cm or more often. How to choose reinforcement for a strip foundation?

For columnar

This is a foundation that is placed on pillars that act as piles.
Bound reinforcement for the foundation is placed inside the pillars before pouring. The tying of reinforcement for a columnar foundation is the same as for a strip foundation - either 4 rods, or 6 for large columnar foundations.

For vertical rods in this type of foundation, 12 mm reinforcement is used, since this is a vertical foundation. The cross rods can be thinner and smoother.

For wooden houses, it is allowed to use longitudinal and vertical reinforcement thinner than 12 mm. Sometimes, for the foundation of small wooden buildings, a welded frame is constructed from vertical rods connected with hoops like a barrel. This is incorrect, because with this bonding method you can only use welding, and this is not a completely reliable method. We have already talked about this above.

For slab

A reinforcement frame for a foundation can take the form of a two-dimensional plane, a mesh formed from reinforcement bars. The second option is volumetric, in the form of two meshes of intersecting reinforcement, located one above the other and connected by transverse rods.

Reinforcement - from 12 mm and above, up to 16 in private housing construction. The mesh cell size is 200x200 mm. The distance from the lower reinforcement belt to the pillow (or insulation) is 50 mm. The top belt is also protected from external influences by a 50 mm layer of concrete.

Cost calculation (price for work and materials)

Let's take as an example a strip foundation 10 by 10 meters. This is the perimeter of the house. In addition, there will be a foundation for internal load-bearing walls - two walls of 10 meters each. It turns out 60 m.p. foundation.

How much reinforcement and tying wire will be required with the right approach?
Let's say the foundation is less than 50 cm wide - it will use a scheme with four longitudinal rods. In this case, in 1 linear meter of the foundation the following will be used:

• 4 longitudinal rods. That means at 60 mp. will be 240 meters.
• 4 vertical. With a foundation height of, say, 50 cm, their height will be no more than 45 cm. 4 x 45 cm = 1.8 m. In 60 meters of the foundation - 108 m.
• 4 transverse. With a foundation width of 45 cm, the width of the transverse ones will not exceed 35 cm. 4 x 35 cm = 1.40 m. In 60 meters of the foundation - 84 m.

How much is it?

For longitudinal rods we use 12 mm reinforcement costing 25-30 r/m.p.
240 x 35(30) =6000 (7200) For vertical and transverse rods, take 6-8 mm costing 12-16 r/m.p. (108+84) x 12(16)=2304 (3072)

So, the purchase of reinforcing rods for this foundation will cost from 8304 to 10072 rubles.

Now let's calculate the required amount of wire. 4 ties for a 4-bar foundation per 1 m.p. This, based on a maximum consumption of 50 cm per tie, is 2 meters of wire per meter of structure.

We have 60 meters, so we need 120 meters of wire. 1 m of wire with a diameter of 1.2 mm weighs 9 grams, respectively, 120 m of wire with a diameter of 1.2 mm weighs about 1 kg, which costs about 50 rubles.

The wire is cheap, so you can and should buy it with a double supply - 240 meters for 100 rubles.

All that remains is to calculate the cost of installation and tying of the frame. As a rule, it is not calculated separately and is included in the total cost of pouring the foundation. In the regions, such work is cheaper, but the price range is approximately the same - 1000-2000 rubles per cubic meter. This price includes the construction of a trench, installation of formwork, binding of the frame, pouring concrete and removing the formwork.

The total length of the foundation we are calculating is 60 meters, width 0.4 m, height 0.5 m. Let's calculate the volume: 60 x 0.4 x 0.5 = 12 m3. With this volume, the cost of foundation work will be 12,000 - 24,000 rubles.

Source: https://isss.ru/raznoe/kak-pravilno-vyazat-armaturu.html

Knitting reinforcement: methods, patterns, norms and rules of knitting for beginners

12.10.2018

Knitting reinforcement is one of the main stages of work to create a reinforcement frame. By connecting the reinforcement, a reinforcing structure is created, thanks to which the concrete receives greater strength in both compression and tension.

If the rods are connected incorrectly, the finished monolithic structure will not receive the design strength.

In order to avoid this, we will look at how to knit reinforcement correctly, observing all the rules and regulations, and what tool can be used to do the work; this will be useful for novice reinforcement makers and for experienced builders.

Methods of knitting reinforcement

Let's consider all the existing ways to connect reinforcement. Each of the options is good in some way, and is used by builders, depending on the type of building and design requirements. There are 3 ways to connect rods; with their help, a strong and reliable metal frame is created:

1. Wire knitting.
2. Welding.
3. Plastic clamps.

These methods of tying reinforcement have their own characteristics. Each of them is correct and is applied depending on the requirements and the material used. When reinforcing a strip foundation for a private house, the reinforcement is often connected by welding rather than tied with wire. But which option is the best?

Advantages and disadvantages of welding connections

Despite the fact that these are different technologies, the right choice can save money and time on construction, without sacrificing structural strength. The method of connecting elements by welding was previously considered one of the most reliable and effective. However, such technology is not always appropriate. Usually it was used when installing bulky frames that strengthen the foundation for multi-story buildings and large cottages.

This method has some disadvantages:

1. You need to have skills in working with a welding machine, otherwise you need to spend money on the services of a professional welder. In this case, the cost increases.
2. Welding points are the weak point of the structure. There the strength of the frame becomes lower.
3. The method is not suitable if you use fiberglass reinforcement. In addition, the A-400 (A-3) fittings, which are the most popular, cannot be connected by welding. Only rods with the index “C” are suitable for work, for example: A500C reinforcement.

Therefore, in modern monolithic construction, welding has been replaced by viscous welding. For private and residential houses, construction of a bathhouse, garage or other buildings, this is the best option for connecting reinforcement.

Pros and cons of joining using the knitting method

Why is this method so good? It has the following positive aspects:

1. Speed ​​of work completion. Knitting with wire takes little time, it is simple and does not require skills. However, if you do it manually, the process slows down. Next we will look at how to quickly knit reinforcement.
2. Ease of troubleshooting. When working with welding, it will be more difficult to eliminate errors; you will have to take a grinder and cut the welding seam. The wire can be simply bitten off with wire cutters or unwound with a crochet hook.
3. You don't need to be a professional to knit reinforcement.
4. The reinforcement process can be performed in formwork.
5. The cost of work is much lower.

An example of knitting a mesh of reinforcement with wire.

If we talk about shortcomings, we note the precariousness of the finished frame. True, this is not a big problem. The structure will be strong, the only problem is that when the frame is moved into the formwork it begins to loosen, in this case it is possible to tack the reinforcement in several places by welding.

To solve this problem with fiberglass reinforcement, you need to attach several braces to make the structure more rigid and stable. By bending, the tension in the knitting areas changes, the frame moves. Therefore, you need to be careful when installing it in the formwork.

It is better to knit the reinforcement in the formwork or above it if the strip foundation is being reinforced.

Features of connecting reinforcement with plastic clamps

The main advantages of this method are that it does not require special skills, it has a high speed of work, and reliable fixation of the reinforcement.
The disadvantages of this method are the following:

1. Price. For large volumes, the wire will be more economical.
2. Speed ​​of work (when compared with other methods of knitting).
3. Correction. You made a mistake somewhere, you will have to bite off the clamp, it becomes unusable, but the wire can be tied up.
4. Reliability. It is not advisable to move around a structure connected with plastic clamps.
5. Temperature. They burst at subzero temperatures.

Based on these data, we can say that this method is more suitable for private construction, with small volumes, and it is also suitable for people who want to do the reinforcement themselves with their own hands.

Tools for tying reinforcement, technology for working with them

Nobody does the work manually. It's practically impossible. There are special tools for this purpose that speed up and simplify the process. Each tool has its own characteristics of use. The following devices are available for tying reinforcement:

1. Hand hook.
2. Knitting gun.
3. Screwdriver.
4. Ticks.

Each of the tools has its own pros and cons, we will consider them, as well as the technology for their use, and based on these data and the opinion of an expert (a reinforcement specialist with 10 years of experience), we will summarize and choose the best option for tying reinforcement.

How to crochet reinforcement correctly?

The peculiarity of the work is that it is done manually. At first, the process will be lengthy, as you need to get better at it. The hook is made of steel, and the handle is made of wood or plastic. The cost of such a hook is 1 thousand rubles.

There are even automatic hooks on sale, but reviews about them are mixed. Some note the short lifespan, others say that it is difficult to twist wire 2 mm or more thick.

There are several options for connecting knots when crocheting reinforcement. Let's look at the most popular ones.

Simple crochet rebar tie knot

The most common and simplest knot is performed as follows:

1. To connect the rods to each other, you need to take a wire 15–20 cm long and bend it in half.
2. The bent wire is bent again, but not completely, you should get a hook.
3. We insert the wire under the reinforcement that needs to be tied.
4. Next comes the hook itself. You need to insert it into the resulting loop and hook the free end of the wire.
5. One revolution is made. It is important to hold the free end.
6. Pulling the hook towards you, twist the wire until it comes off.

Step-by-step diagram for making a simple crocheted reinforcement knot.

Note! In order not to buy a crochet hook, you can make it yourself. You will need a piece of steel rod, and the handle can be made of plastic or wood. Having done it once, you can constantly use the knitting tool. See step-by-step instructions for making a hook with your own hands here.

"Dead Knot"

This unit is used for reinforcing structures consisting of reinforcement bars and clamps, such as beams and columns. Since it reliably fixes the reinforcement into the corner of the clamp, reinforcement specialists called it a “dead” knot. To quickly and efficiently perform such a knot, you need to practice a lot. Consider the instructions for executing the node:

1. We take a wire 20–40 cm long, its size depends on the diameter of the reinforcement used, and bend it in half.
2. We run the wire, loop forward, under the bottom of the reinforcement to the left of the clamp, leaving 2–4 cm to complete the knot.
3. We bring the wire to the top of the clamp and bend it again under the bottom of the reinforcement.
4. Insert the hook into the loop and hook the free end of the wire.
5. We pull the hook towards ourselves and at the same time make several turns until we feel that the wire is clamped, or until the loop comes off.

Scheme of tying reinforcement with a “dead” knot using a hook.

It should be noted! In order for this knot to reliably fix the reinforcement into the corner of the clamp, the wire should be pressed as tightly as possible to the reinforcement and the corner of the clamp, otherwise the tie will turn out to be unreliable.

You can check the quality of the assembly by tugging the clamp with your hand; if it wobbles, it is done incorrectly or is not fully tightened. We tighten it or make an additional tie with a simple knot.

When performing reinforcement of complex structures, for example, semicircular beams, nodes can be combined. First, a “dead” knot is made, and then two simple crosswise ones, as in the photo below.

Special gun for mating

This is an ideal tool for tying reinforcement. It makes the process much faster and easier. It is most convenient to assemble a metal frame with it. The only caveat is that such a unit is not cheap. That's why it is used on large-scale construction projects. The minimum cost is 30 thousand rubles.

It looks like a regular drill. Only a roll of wire is inserted into it. To tie, you need to point the gun at the joint and pull the trigger. He will do the knitting himself in a matter of seconds. This is the simplest and most affordable option for tying reinforcement.

On a note! It takes 9 seconds to make 1 knot tied with a hook. If you take an automated hook, it will take 7 seconds. And tying with a gun takes only 1 second per 1 knot.

But this method also has its disadvantages:

1. Not everywhere they can get to perform mating.
2. Price.
3. When you fix the reinforcement, you can no longer untie the knot with a crochet hook.
4. You cannot knit large-diameter reinforcement.

Using a screwdriver with a hook

To speed up the process and make it automated, a modernized screwdriver is used. It is enough to insert a homemade hook into it. A slate nail is suitable for this purpose. It is clamped into the screwdriver and is ready to go.

The principle of its operation is no different from the previous version. The only difference is that the process is significantly accelerated. And if the screwdriver has a speed adjustment, then it is adjusted so that when the wire is stretched to maximum, it does not break.

Tying reinforcement with pliers

This method of knitting is good because it saves wire during the work, due to the fact that you can knit into one, and you don’t have to make loops, as for a crochet hook.

Of the minuses it should be noted:

1. Requires more practice for speed knitting.
2. The knitting speed is 2 times less than that of a hook.
3. When knitting with 2 wires, the result is a rigid knot with a sharp end; you must wear special shoes, otherwise you can pierce your leg.

Source: https://VseoArmature.ru/armirovanie/vyazka-armatury

How and with what to properly knit reinforcement for the foundation

The combination of concrete with reinforcement provides any reinforced concrete structure with strength and durability. In order for the finished metal frame to last a long time and withstand serious loads, you need to know how to knit reinforcement.

Using special knitting wire

To quickly and reliably make the strapping, a special baked steel wire of round section with a diameter of 0.8 to 1.2 mm is used to fasten the reinforcing elements. It bends easily, fits tightly to the joint, and stretches well (that is, it does not tear when knitting).

When working with such material, the knitter does not require any special skills. This method is successfully used both for tying the reinforcement of a reinforced concrete monolithic slab and for the reinforcing frame of any foundation.

How to quickly knit reinforcement, what materials, tools and equipment will be required for this.

Application of hooks

To work with wire, you can use: a manual crochet hook (it can be easily purchased at any hardware store), a homemade hook for tying reinforcement, a semi-automatic mechanical hook (more expensive than a regular manual one) or a crochet hook made using a screwdriver.

How to make a hook for tying reinforcement:

Option #1:

We take a thick electrode or a metal rod of a suitable diameter, sharpen one end of it and bend it at the desired angle. We bend the handle from the second end of the rod (if desired, you can wrap it with electrical tape). The hook for tying reinforcement with your own hands is ready.

Option #2:

The material for production is a metal rod, both ends of which are sharpened. On one end of the rod we place a round wooden blank for the handle (with a drilled hole in diameter slightly smaller than the diameter of the rod); We bend the second end of the rod to the required (convenient) angle.

Option #3:

An old screwdriver (or a construction awl) is suitable as a starting material, the metal end of which is sharpened. Then we bend it to the required angle and get a hook for knitting reinforcement with a comfortable handle.

On a note! The photo will help you easily make hooks for tying reinforcement.

Tying reinforcement with a screwdriver significantly speeds up and facilitates the work. We clamp a hook for wire tying reinforcement, made from a thick nail, into the chuck. By adjusting the rotational force of the screwdriver, you can easily achieve the required joint density. How to knit the reinforcement cage: with homemade tools or purchased ones (or both) - decide for yourself.

How to crochet

The methods of tying reinforcement are quite simple and understandable. Scheme of step-by-step knitting of reinforcement:

1. We cut the wire into pieces (we select the size experimentally depending on the diameter of the rods).
2. Fold the prepared piece in half.
3. We bend the double workpiece around the intersection of the reinforcing bars.
4. Insert the hook into the loop and place the loose ends on it.
5. Rotate the hook (usually 3-4 rotational movements are enough) until a tight twist is obtained.

Attention! You can tie the reinforcement using the above technology using any type of hook.

There is another way to crochet reinforcement - overlapping.

1. We cut a piece of wire twice as long as in the first case.
2. Fold the piece in half and in half again.
3. We place the double bend on the top bar.
4. We place two double pieces under the lower bar and lift it up.
5. We insert the hook into the loop and press the two free ends to it.
6. Rotate the hook and crimp the joint. If we use a mechanical hook, then with force we pull the handle towards ourselves. We obtain a tight twist due to the fact that the translational motion is converted into a rotational motion by means of a worm gear.

Using a knitting gun

A gun for tying reinforcement greatly simplifies the work of creating any reinforcing frame.

Convenience and advantages of use:

• a cassette with knitting wire is inserted inside the device;
• it is supplied automatically;
• the knitting gun is powered by a built-in battery;
• correct knitting of reinforcement with minimal use of manual labor;
• An automatic gun for tying reinforcement allows you to make all twists with the same tension.

But such a convenient and useful device has disadvantages:

• impossibility of carrying out work in hard-to-reach places;
• a gun for tying reinforcement is expensive, so its use is economically justified only when carrying out large volumes of work.

Table with approximate prices for the main models available for sale on the construction market:

Reinforcement model Ø (mm) Unit production time (sec) Number of units from one battery charge Estimated price (RUB)

GS308-6512	6,5÷12	0,8	1000	19000÷21000
GS308-1016	10÷16	0,8	1000	22000÷24000
GS24T	6÷24	0,8	1000	26000÷28000
GS34T	8÷34	0,8	1000	28000÷30000
RT308V	4÷19	0,8	1100	31000÷35000
BM400	10÷29	1,0	2000	44000÷46000
BM200	9÷21	0,85	2000	28000÷30000
KW-0039	10÷22	0,8	1200	47000÷54000
RDL40	12÷32	0,9	3000	43000÷45000
RDL20	9÷21	0,9	3000	41000÷43000
PVA-32	6÷18	1,6	450	44000÷45000

Pliers and pliers

For tying, ordinary pliers, pliers (with slightly blunt cutting edges) and special pliers for tying reinforcement (manual or automatic) are often used.

Knitting reinforcement with pliers and pliers according to production technology is no different from fastening reinforcing bars using hooks. The only difference is that there is no need to form a wire loop.

Strapping using electric welding

Advantages:

1. A fairly reliable way to tie reinforcing bars.
2. High speed of work completion.
3. Less labor-intensive process than hand knitting.

Flaws:

1. Under the influence of high temperature during welding, the physicochemical properties of steel change (the crystalline structure of iron is disrupted). At the joints, the bending and tensile strength of the reinforcing bar is significantly reduced. Ultimately, this leads to a decrease in the reliability of the entire reinforcing frame.
2. The use of welding significantly increases the rigidity of the frame made of reinforcing bars. When compacting the solution with vibrators, there is a risk of deformation or destruction of rigid welded joints.
3. The frame metal in the area of ​​welding seams is more susceptible to corrosion, which reduces the durability of the entire reinforced concrete structure.
4. To carry out welding work, special equipment is required.
5. The site where such work is carried out must be connected to the power supply, which is not always possible (especially during suburban construction).
6. Work can only be carried out by a qualified specialist (welder). How firmly and reliably the frame made from steel reinforcement is knitted depends on his experience and qualifications.

Tying with metal staples

The reinforcement can be tied using special metal staples.

Advantages:

• high speed of connection execution;
• no tool is required for tying reinforcement (everything is done by hand);
• the work can be done even by an untrained person;
• equal density of connected compounds.

Flaws:

• the need to purchase a set of special staples for the production of tying reinforcement of a certain diameter;
• limited area of ​​application: only for fastening simple cross connections;
• insufficient fastening strength (mainly suitable for light horizontal structures, for example for reinforcing screeds).

Tying with plastic clamps

Knitting reinforcement using plastic clamps is a simple and convenient method for creating a reinforcement frame.

Pros:

• plastic is not subject to corrosion;
• ease of installation;
• high knitting speed;
• low cost;
• there is no need to use special tools.

Minuses:

• work cannot be carried out at subzero temperatures (plastic becomes brittle);
• the strength of the connections is questioned by many professionals;
• a fairly large elongation coefficient of plastic can lead to a decrease in the rigidity of the reinforcing frame (or a violation of the geometry).

Some recommendations for knitting the reinforcement cage of the foundation

The rules on how to knit reinforcement for a strip foundation and for a monolithic slab are the same. The length of a standard reinforcing bar is 6 meters. Very often they have to be joined. The overlap of the reinforcement during tying should be 40÷50 cm, the rods should be tied together evenly in 3-4 places.

The same requirements apply when strengthening corners and junctions with L-shaped and U-shaped additional reinforcing elements.

Knitting a metal frame from reinforcement for a strip foundation can be done not only in the formwork, but also in separate fragments (made in a place convenient for you), which are then lowered into a box.

Important! It is necessary to tie the reinforcement of individual fragments together.

The combination of reinforcement for the foundation and the correct choice of its diameter are the main factors influencing the strength of the foundation of the future structure. When tying reinforcement for the foundation, special attention must be paid to the tightness of all connections.

This video will help you understand how to properly knit foundation reinforcement:

In custody

How to tie reinforcement to a foundation or under a floor screed: using a gun for tying reinforcement or a regular homemade hook, the decision is yours and depends on the amount of work and financial capabilities. The main thing is to follow the rules and technology, then the reinforcing frame will be reliable and durable.

Source: https://zamesbetona.ru/armirovanie/kak-vjazat-armaturu.html

How to knit reinforcement - a detailed description of patterns and methods

In construction, reinforcement is the name given to interconnected elements that, when worked together with concrete, create a more advanced material – reinforced concrete. Thanks to reinforcement, beams and slabs better withstand tensile stresses, and compressed structures increase strength. To obtain the desired effect, the reinforcement fragments are connected to each other. Due to the method of connection, the method is called binding.

How to knit reinforcement

Since reinforcement in the form of steel rods is mainly used in the construction of foundations and main walls, their connection to absorb compressive or tensile stresses is mandatory. In mass construction, the welding and tying method is used for connections, in individual construction, usually only tying. In this case, the reinforcement is knitted using:

• knitting wire;
• reinforcement clamps.

The term “knitting wire” means round wire made of low-carbon steel in accordance with GOST 3282-74. It can be regular or heat-treated (marked “O”), coated or uncoated. The thickness of the zinc coating determines the class of the material.

When choosing which wire to knit the reinforcement with, you should pay attention to the grade of concrete and the operating conditions of the structure. In this case, mechanical properties are taken into account.

So, if tying reinforcement for the foundation is supposed to be done manually, it is better to choose a thinner option, since without a special tool, thick wire for tying reinforcement requires significant effort.

In addition to industrially produced low-carbon wire, it is permissible to use metal cord from car tires. When tires are burned, the metal cord is released and simultaneously undergoes heat treatment, which makes it easier to work with in the future. This option of knitting material is acceptable only for small volumes of work and individual low-responsibility construction.

Plastic clamps, regular and with a steel core, are also applicable. They are usually used for fiberglass reinforcement.

The use of clamps is permissible in cases where liquid concrete will not be subjected to mechanical loads during the hardening process (they will not walk on it, stack heavy things, or load it with other building materials).

This option is applicable for low-rise buildings, since during the process of pouring a large mass of concrete mixture, the fastenings can move along with the reinforcement. The displacement disrupts the functioning of the frame and leads to a change in the design strength of the structure.

How to knit reinforcement for a foundation

Depending on the chosen material for knitting, various fixation methods are used. The simplest situation is with plastic clamps. They are wrapped around the joint as far as the length allows and tightened.

To correctly knit reinforcement for a strip foundation, you will need a tool. Depending on the reinforcement tying pattern, the rods are distributed over the future pouring field.

If you plan to create a foundation, some of the rods are stuck into the prepared base (rammed sand and gravel backfill), this makes the work easier. After completing the connecting work, the frame is raised above the ground on special stands. This is necessary to prevent corrosion of metal elements protruding from the concrete. To connect the rods use:

1. special pliers for tying reinforcement; 
2. crochet hook, homemade or industrial production; 
3. a curved hook made of a thick nail or dowel, inserted into the chuck of a drill (screwdriver). Thanks to this mechanized hook, wire twisting is done faster and with less manual force.  
4. semi-automatic hook for tying reinforcement. A mechanism with a leg and a spring return mechanism pulls the wire and makes several rotational movements. This happens thanks to the spiral grooves on the hook leg, which, when pulled back, provide rotation and return to its previous position.  

The use of such tools is advisable for small amounts of work, for example, when building your own house, where tying reinforcement with your own hands is done over a short period of time (when preparing the foundation for a frame or brick structure or installing a fence on a concrete base).

A do-it-yourself hook for tying reinforcement is made from a used electrode, nail or other suitable metal rod of the required strength.

Professional tool for tying reinforcement

When creating a large volume of reinforcement for reinforced concrete structures (professional activities, large private construction), instead of manual or semi-automatic tools, it is better to use an automatic, so-called gun for tying reinforcement. This useful device was invented in Japan; it allows you to tighten the wire at the connection of the rods with the required force in a matter of seconds.

The operating principle of the device is shown in the video.

Source: https://stroy-okey.ru/house/foundation/kak-vjazat-armaturu-podrobnoe-opisanie-shem-i-sposobov/

How to knit reinforcement

Hello, dear readers! Our interview will be devoted to an unusual job that, despite its simplicity, many are afraid to do themselves, namely how to knit reinforcement correctly . Today, the veil of secrecy of this matter will be lifted for us by a young, but despite this very experienced, foreman Nikolai Nikolaevich, who has built many objects.

Hello, Nikolai Nikolaevich. We have a number of questions for you, perhaps they sound simple and unprofessional, but we are not yet familiar with the correct names and terminology.

— Good evening, dear readers! I will try to answer all your questions as clearly and completely as possible. So, let's begin.

Why is reinforcement knitted in most cases rather than welded? Is the connection of reinforcement by welding different from a mechanical connection?

— Reinforcement, in most cases, is knitted, not welded. Because during a welded connection, the composition of the steel changes, resulting in weak spots in the reinforcement bars. Another disadvantage of a welded joint is the completion time, in comparison with the so-called mechanical method (actually, viscous).

Also, a lot depends on the experience of the welder, and if he is “green”, then in most cases the structure will not be able to fulfill its main purpose - to withstand the load.

However, welded joints are often used in the construction of panel buildings, due to the fact that the construction of such houses mainly uses complex teams (installers, welders, carpenters, concrete workers) and it is not economically profitable to take a separate specialty, reinforcement workers.

As for knitting, this is a simple and fairly quick way to attach reinforcement that does not require special skills; this method is most often found in monolithic construction. Knitting performs the same function as a welded joint, only with the help of a knitting wire. In any case, both welding and bonding should perform the same function. The main thing is that when pouring the reinforcement frame with concrete, the reinforcing bars do not change their position and shape. They do not impart strength to the product - strength is ensured due to the integrity of the structure poured with concrete.

What are the necessary tools and materials for knitting?

— Wire is the most important element when performing knitting work, since the quality of the assembly and specifically the fixation of the reinforcement, and, consequently, the final product, depends on the quality of the wire . When knitting, burnt wire with a diameter of 1 mm, always of round cross-section, is usually used.

The difference between baked and unburnt wire is that the first bends well, fits tightly to the reinforcement and has the property of ductility (i.e. it does not break when knitting), unlike the second, untreated, which bends hard and often breaks and breaks when tying a knot. . If they bring it unfired, then don’t even try to use it, since it is virtually impossible to knit with it.

Also, for tying reinforcement (mechanical fastening), you need a hook , or collets, and plastic bosses (fasteners).

Ordinary hook

Automatic hook

Knitting gun

Boss (retainer)

— This is a plastic part that is placed between the reinforcement and the formwork to create a protective layer. Without them, the reinforcement may touch the formwork and, after pouring, will stick out from the concrete and, accordingly, rust, lose strength and destroy the structure.

Please tell us about each tool - describe its advantages, disadvantages, when should it be used (a simple hook, a homemade hook, a screw hook, a gun)?

-As for each tool individually, it’s up to everyone to determine who is used to working with what. The most common tool is a hook or collet. The gun is good on horizontal surfaces where you don’t have to crawl into hard-to-reach places. The advantage of a pistol is the speed of work.

The disadvantage is that they are extremely inconvenient for knitting in hard-to-reach places, the battery also drains quickly and wire consumption is higher. Speaking of hooks, the most popular is the homemade hook . If you decide to get serious about tying, then it’s better to make a hook for tying reinforcement yourself. It is made from corrugated reinforcement, and a bearing is installed in the handle to facilitate rotation.

A magazine hook is only good for training, as they are usually short and quickly rust, which makes a terrible sound and reduces the speed of work. There are semi-automatic (screw) hooks , but I don’t like working with them: there are pieces of wire tails left, then technical supervision comes and forces you to redo all the debris in the ceiling.

And he’s doing the right thing, because maybe you’ve noticed rusty stripes appearing on the surface of the ceiling on your or your friends’ ceilings? This is nothing more than wire or hackwork by a craftsman who, when creating a protective layer, did not put bosses under the frame when pouring concrete into the reinforcement.

Does the knitting method differ depending on the part of the house - wall, foundation, ceiling?

— In theory, there are many ways of knitting, but in practice the two main ones are one loop for an overlap connection and 2 loops for a butt connection. Almost everything is knitted with one loop, even the corner elements, although in theory, the corner elements are knitted with a different knot. The loop is good for its simplicity and reliability - you can learn it in literally five minutes, and it’s hard to make a mistake.

How long does it take to knit reinforcement?

— I haven’t heard of such a norm, everything is according to ability. Also, the speed of knitting greatly depends on the design: knitting an overlap is much faster than an arch with curved elements.

Is there a certain standard for wire consumption?

— As such, there is no standard for one unit; there is an expense for the design. This norm is calculated in the project documentation for the facility, based on the fact that one knot requires 20 cm of wire if crocheted, and if with a pistol, then the consumption will be greater. It is very difficult to calculate the consumption, for example, for a wall or ceiling separately, since some of the knots will break and will need to be bandaged, and a lot depends on the craftsman.

Manufacturers of knitting guns claim that with this device all knots will be tightened with the same force! How important is it to tighten the knots with the same force?

— What is important for us is not the same clamping force of the rods, but that they do not change position and the structure itself does not change when pouring the form with concrete, since if changed, the protective layer will be of the wrong thickness and, in the future, cracks and rust will appear on the concrete.

In general, the same tightening force of knots is nothing more than an advertising ploy by pistol manufacturers, because it is not so important.

But all the same, when we crochet, you shouldn’t deliberately “squint” and tighten with deliberately different forces - such experiments can cost you dearly, so we tighten more or less evenly and everything will be fine.

What will be the strength of the structure if it is connected incorrectly, with insufficient force, or in this case the connection will burst altogether?

— If one connection breaks, it’s okay. I repeat - the most important thing for us is that the structure does not change shape when poured. But still, the correct knitting of reinforcement will determine the strength of the structure.

What other methods of fastening reinforcement do you know?

— I heard about two more methods - metal clips and tying reinforcement with plastic clamps. Unfortunately, I didn’t work with them, and I didn’t hear anything like that from my friends. Apparently, these methods are not widely used for some reason. I myself am a follower of the “classics”: I knit with an ordinary crochet, as it is simple and fast and I don’t use all these newfangled innovations such as screw hooks, paper clips and guns.

Thank you, Nikolai Nikolaevich, for your story about this work.

- Please! Contact me, I will always be happy to answer any of your questions.

Source: https://vseostroyke.by/kak-pravitno-vyazat-armaturu/

How to knit reinforcement for beginners: methods, norms and rules, frame for the foundation

There are only two ways to attach reinforcement to a frame: electric welding and knitting. We will not open a debate about which one is preferable. Let’s just say that knitting does not reduce the strength of the working rods.

Any welding weakens the metal because it creates local stresses in it. This negatively affects the reliability of the entire structure.

Compared to welding, knitting work is more labor-intensive.

Despite this, in private construction with its small volumes it is better to choose them. Especially when it comes to such critical structures as foundations and floor slabs.

articles:

In this article we will tell novice builders how to knit reinforcement correctly. Let's look at the tools, materials and technologies used for this work. We hope that the information received will help you confidently handle metal, assembling strong and reliable frames.

Crochet technology

There is nothing complicated in this operation. After doing it several times, you will quickly get used to it.

The essence of the method is as follows: the intersection of the rods is covered with steel wire folded in half. The crochet hook is inserted into the loop and the other free end is grabbed with it. After this, the tool is rotated until it is tightened. The ends of the wire are bent inside the frame.

The craftsmen know one little secret that guarantees tight contact: after not tightening the loop a little, you need to pull it towards yourself and only then tighten it to the end.

Scheme for knitting reinforcement using a hook

Working with a screwdriver is not fundamentally different from crocheting. The advantage is higher speed and less labor intensity. When using a screwdriver, do not forget to set the rotation speed of its chuck to minimum.

You should not knit reinforcement with an electric drill. The large inertia of this tool does not allow you to accurately determine the moment of completion of tightening.

Methods for connecting steel rods and the main types of nodes are shown in the diagram below.

Materials

To assemble the frame, special annealed wire is used. It is durable, but at the same time quite soft. This allows you to tighten the knots without the risk of tearing it. The recommended diameter of this material depends on the cross-section of the reinforcing bars and ranges from 1.0 to 1.4 mm.

Cheap wire comes without coating and is called black. It is more resistant to corrosion and has a protective layer of zinc.

Knitting wire is produced in two versions: in coils and measured (in segments). Working with a skein is more difficult because it has to be cut into pieces by hand. The measuring material can be used immediately. Wire with loops at the ends is especially convenient.

Norms and rules for performing work

Guidelines for the design and manufacture of reinforcement cages are contained in two regulatory documents. GOST 10922-2012 specifies technical conditions for knitted and welded connections of reinforced concrete structures. The set of rules SP 52-101-2003 regulates the requirements for the design of frames.

Based on these standards, standard patterns for tying reinforcement under a strip foundation, dimensions of overlaps, diameters of the reinforcement used and other rules for the execution of work have been developed.

When joining rods on straight and corner sections, the length of the overlaps is important. SNiP sets this parameter depending on the diameter of the working fittings (in millimeters):

• 300 mm for rods with a diameter of 10 mm;
• 380 for 12 mm;
• 480 for 16 mm;
• 580 for 18 mm;
• 680 for 22 mm;
• 760 for 25 mm.

Knitting the strip foundation frame

The estimated number of longitudinal rods (diameter 12-18 mm) are placed at the bottom of the trench on supports (bosses) 4-5 cm thick. The distance between them depends on the size of the foundation and can range from 5 to 20 cm. If the standard length of one steel rod (6 meters) is not enough for the entire “ribbon,” then several rods are used. They are connected to each other, observing the regulatory overlap.

Supports for reinforcement cage

Clamps made of smooth or corrugated steel with a diameter of 8-10 mm are attached vertically to the working rods. According to building codes, the pitch of the clamps must be at least 3/8 of the height of the foundation (20-50 cm).

Having installed the clamps, the upper chord of the working reinforcement is attached to them with wire, observing the design distance between the rods.

At corners and junctions, clamps are placed more often (1/2 step), and the working reinforcement is bent, connecting to the rods of the intersecting section of the “ribbon”.

The length of the bend must be at least 50 diameters of the working reinforcement.

Making a reinforcement cage in a trench is labor-intensive and inconvenient work. That's why experienced builders use this simple device.

Having laid the longitudinal whips on wooden stands, clamps and the lower belt of the working rods are tied to them. The finished structure is transferred and placed in a trench.

Assembly of the reinforcement frame of a monolithic slab is simpler than that of a strip foundation. The design here consists of two flat meshes. The lower rods are laid perpendicularly with a given pitch and connected to each other. Then, at the points of their intersections, stands made of steel rods are placed and the upper mesh is screwed to them.

Stand for mounting the upper frame of a monolithic slab

In recent years, fiberglass reinforcement has begun to be used to assemble frames.

You can knit it in several ways:

• annealed steel wire;
• plastic zip ties;
• plastic clips.

Approximate prices

The cost of tying reinforcement, as estimators say, “sits” in the total price of 1m3 of reinforced concrete. In square or linear meters it is calculated individually for each type of structure. In this case, it is necessary to take into account various parameters (the width and height of the grillage, the thickness of the slab, the cross-section of the reinforcement, the level of complexity of the frame, etc.).

For approximate calculations, builders use prices in rubles per 1 ton of metal used. Today in 2017 it averages from 20 thousand rubles.

Source: https://greensector.ru/stroitelstvo-i-remont/kak-vyazat-armaturu-dlya-nachinayushhikh-sposoby-normy-i-pravila-karkas-pod-fundament.html