How to connect fittings correctly

How to correctly overlap reinforcement during tying and welding

When connecting steel rods, reinforcing a strip foundation, many people have a natural question: how to correctly overlap the reinforcement, and what its length should be. After all, the correct assembly of a metal load-bearing frame will prevent deformation and destruction of a monolithic concrete structure from the loads acting on it and increase its trouble-free service life. What are the technical features of making butt joints, we will consider in this article.

Types of lap reinforcement connections

According to the requirements of SNiP, the concrete foundation must have at least two continuous, unbroken reinforcement contours. This condition can be met in practice by joining the reinforcing rods with an overlap. In this case, connections at joints can be of several types:

• Lap without welding
• Welded and mechanical connections.

The first connection option is widely used in private housing construction due to its ease of execution, availability and low cost of materials. In this case, the common reinforcement class A400 AIII is used. The joining of overlapping reinforcing bars without the use of welding can be carried out both with and without the use of tying wire. The second option is most often used in industrial housing construction.

According to building codes and regulations, the connection of overlapping reinforcement during tying and welding requires the use of rods with a diameter of up to 40 mm. The American Cement Institute ACI allows the use of rods with a maximum cross-section of 36mm. For reinforcing rods whose diameter exceeds the specified values, the use of overlap joints is not recommended due to the lack of experimental data.

According to construction regulations, it is prohibited to overlap reinforcement when knitting and welding in areas of maximum load concentration and places of maximum stress on metal rods.

Joining overlapping reinforcing bars by welding

For country house construction, welding overlapping reinforcement is considered an expensive pleasure, due to the high cost of metal rods of the A400C or A500C brand. They belong to the weldable class. Which significantly increases the cost of materials. It is unacceptable to use rods without the “C” index, for example: the common class A400 AIII, since when heated the metal significantly loses its strength and corrosion resistance.

However, if you decide to use weldable class rods (A400C, A500C, B500C), their connections should be welded with 45 mm diameter electrodes. The length of the weld seam and the overlap itself depends on the class of reinforcement used.

Overlapping weld length

Reinforcing bar class	The length of the overlap weld in the diameters of the reinforcement being connected
А400С	8 ᴓ
А500С	10 ᴓ
В500С	10 ᴓ

Based on the data presented, it can be seen that when using steel rods of class B400C for knitting, the amount of overlap, and therefore the weld, will be 10 diameters of the reinforcement being welded. If ᴓ12 mm rods are taken for the load-bearing frame of the foundation, then the length of the seam will be 120 mm, which, in fact, will correspond to GOST 14098 and 10922.

According to American codes, reinforcing bar crosses cannot be welded. Effective loads on the base can cause possible ruptures of both the rods themselves and their connections.

Overlapping reinforcement connection when knitting

In cases of using common rods of the A400 AIII brand, in order to transfer the calculated forces from one rod to another, a connection method without welding is used. In this case, the places where the reinforcement overlaps are connected with a special wire. This method has its own characteristics and special requirements are placed on it.

Reinforcement overlap options

In accordance with the current SNiP, non-welding connection of rods during the installation of a reinforced concrete frame can be made using one of the following options:

• Overlay of profile rods with straight ends;
• Overlap of a reinforcing profile with a straight end with welding or installation throughout the entire bypass of transversely located rods;
• With curved ends in the form of hooks, loops and claws.

Such connections can be used to knit profiled reinforcement with a diameter of up to 40 millimeters, although the American standard ACI-318-05 allows the use of rods with a diameter of no more than 36 mm.

The use of bars with a smooth profile requires the use of lap joint options either by welding transverse reinforcement or using bars with hooks and tabs.

Basic requirements for making overlap joints

When performing overlapping reinforcement joints, there are rules defined by construction documentation. They define the following parameters:

• The size of the rod lining;
• Features of the location of the connections themselves in the body of the concreted structure;
• The location of adjacent bypasses relative to each other.

Taking these rules into account allows you to create reliable reinforced concrete structures and increase the period of their trouble-free operation. Now about everything in more detail.

Where to place reinforcement overlap joints when knitting

SNiP does not allow the location of overlapping reinforcement ties in areas of the greatest load on them. It is not recommended to place joints in places where steel rods experience maximum stress. It is best to place all connecting rod connections in unloaded areas of reinforced concrete, where the structure is not under stress. When pouring a strip foundation, the bypass ends of the reinforcement are placed in places with minimal torque and minimal bending moment.

If it is not technologically possible to fulfill these conditions, the length of the overlap of the reinforcing rods is taken at the rate of 90 diameters of the joined rods.

What is the amount of overlap of reinforcement when knitting?

Since the overlap of the reinforcement is determined by the technical documentation, the length of the joint connections is clearly indicated there. In this case, the values ​​can vary not only from the diameter of the rods used, but also from such indicators as:

• Nature of the load;
• Concrete grade;
• Reinforcing steel class;
• Connection points;
• Purpose of reinforced concrete products (horizontal slabs, beams or vertical columns, pylons and monolithic walls).

Splicing reinforcing bars when performing overlaps

In general, the length of the overlap of reinforcement bars during tying is determined by the influence of the forces arising in the rods, the perceived adhesion forces with concrete acting along the entire length of the joint, and the forces that provide resistance in the anchoring of the reinforcing bars.

The fundamental criterion when determining the length of the reinforcement overlap during tying is its diameter.

For the convenience of calculating the overlap of reinforcing bars when knitting the load-bearing frame of a monolithic foundation, we suggest using a table with the indicated diameter values ​​and their overlap. Almost all values ​​are reduced to 30 times the diameter of the rods used.

The amount of reinforcement inlet in diameters

Diameter of reinforcing steel A400, mm	Overlap amount
in diameters	in mm
10	30	300 mm
12	31,6	380 mm
16	30	480 mm
18	32,2	580 mm
22	30,9	680 mm
25	30,4	760 mm
28	30,7	860 mm
32	30	960 mm
36	30,3	1090 mm

Depending on the loads and purpose of the reinforced concrete products, the length of the lap joints of the steel rods changes upward:

Inlet of reinforcement depending on the purpose of reinforced concrete products

Type of load	Purpose of concrete products
Horizontal use, in diameters	Vertical use, in diameters
In compressed concrete	33.8 ᴓ	48.3 ᴓ
In stretched concrete	47.3 ᴓ	67.6 ᴓ

Depending on the grade of concrete and the nature of the load used for pouring the monolithic foundation strip and other reinforced concrete elements, the minimum recommended values ​​for the bypass of reinforcement during the binding process will be as follows:

For compressed concrete

Diameter of reinforcing steel A400 used in compressed concrete, mm	Length of overlap of reinforcing bars for concrete grades (concrete strength class), in mm
M250 (B20)	M350 (B25)	M400 (B30)	M450 (B35)
10	355	305	280	250
12	430	365	335	295
16	570	490	445	395
18	640	550	500	445
22	785	670	560	545
25	890	765	695	615
28	995	855	780	690
32	1140	975	890	790
36	1420	1220	1155	985

For stretched concrete

Diameter of reinforcing steel A400 used in tensile concrete, mm	Length of overlap of reinforcing bars for concrete grades (concrete strength class), in mm
M250 (B20)	M350 (B25)	M400 (B30)	M450 (B35)
10	475	410	370	330
12	570	490	445	395
16	760	650	595	525
18	855	730	745	590
22	1045	895	895	275
25	1185	1015	930	820
28	1325	1140	1040	920
32	1515	1300	1185	1050
36	1895	1625	1485	1315

How to position reinforcement bypasses relative to each other

To increase the strength of the foundation's load-bearing frame, it is very important to correctly position the reinforcement overlaps relative to each other in both planes of the concrete body. SNiP and ACI recommend spacing connections so that there are no more than 50% bypasses in one section. In this case, the spacing distance, as defined in regulatory documents, must be at least 130% of the length of the connecting connection of the rods.

Mutual arrangement of reinforcement bypasses in the concrete body

If the centers of overlap of the knitted reinforcement are within the specified value, then it is considered that the connection of the rods is located in the same section.

According to ACI 318-05 standards, the relative position of the connecting connections must be at a distance of at least 61 centimeters. If the distance is not maintained, then the likelihood of deformation of the concrete monolithic base from the loads exerted on it during the construction of the building and its subsequent operation increases.

Source: https://postroim-dachu.ru/stroitelstvo-fundamenta/kak-sdelat-nahlest-armatury-pri-vyazke-i-svarke.html

Knitting reinforcement: fastening technology, connection methods, description of diagrams and installation rules

The foundation plays an important role in the construction of any building and structure. It takes on static and dynamic loads from the building structures and everything in it. The further task of the foundation is to distribute and transfer this load to the ground.

The foundation, as an element of a building, is under constant load. The durability of a building is directly dependent on the quality of the foundation, its strength and reliability. Therefore, when talking about concreting the foundation for a building, all these factors must be taken into account.

The strip foundation structure consists of concrete, which works well in compression. The next element is the reinforcement, which is considered a kind of skeleton and works well for bending.

The combination of these two elements is called reinforced concrete. This design confidently works with dynamic and static loads. Gives the building stability, durability, strength.

Features of using strip foundations

Recently, private housing construction has been experiencing an optimized trend. Architects and designers are creating bold projects that require responsible steps from the construction industry in terms of creating new materials based on other composite binders.

Revolutionary changes in modern construction engineering have not affected the design of foundations. Here, as before, the human factor plays a big role and there is a lot of physical labor involved.

Simple designs of strip foundations are considered good form in the construction of garages, temporary buildings, outbuildings, country cottages and other construction projects.

Strip foundations have proven themselves well in temperate climates, with freezing depths of up to one and a half meters. The soils must be dry and hard. If we have a case where the soil is heaving, or a place with high humidity, it is not advisable to install such foundations.

The advantageous qualities include the simplicity of the design, which allows you to perform almost the entire range of work without special training. It is successfully combined with the technical conditions of basement floors and monolithic floors. Allows you to do without the use of heavy construction equipment.

Typically, strip foundations are installed under the external load-bearing walls of a building. The internal walls and partitions of the building also rest on a strip foundation.

Basic rules and requirements for reinforcement

There is a special method for calculating the structure of a strip foundation. All main indicators, such as: the diameter of the reinforcing bars, their number in the lower and upper chords, the distance between the working reinforcement bars, are determined by calculation.

Values ​​such as: reinforcement class for the upper and lower chords, the distance between the clamps, the overlap distance of the reinforcing bars when connecting frames, the protective layer of concrete, are assigned for structural reasons by technical specialists.

Building codes and regulations regulate the performance of reinforcement work when constructing a monolithic strip foundation. There are a number of conditions for using reinforcement of a certain class:

• the reinforcement cage must be located in such a way as not to interfere with the concreting of the foundation;
• the distance between the transverse connecting clamps is determined structurally, in accordance with the standards of construction production. They should not interfere with the penetration of the vibrator head when pouring the concrete mixture;
• When connecting reinforcing cages to each other, the rods of the working reinforcement are superimposed on each other and tightly tied together with knitting wire. Also, the hinge joint must be rigid when connecting reinforcement cages transversely;
• To prevent contact of reinforcing bars with outside air, a protective concrete layer up to 50 mm thick should be installed. This will preserve the working fittings from corrosion. The foundation will ensure the stability and strength of the structure for a long time;
• Building codes allow the replacement of reinforcing bars with different diameters. For example, four rods of working reinforcement with a diameter of 10 mm, which have a periodic profile and are located in the lower belt, are divided into two similar rods with a diameter of 20 mm. Such a replacement will not lead to a violation of the design parameters of the structure.

Tools for knitting reinforcement bars

For small volumes of private housing construction, developers use the method of manually knitting reinforcing bars into frames. This method has enough advantages, and it can be done as follows:

Knitting gun. The work productivity is very high. For large-scale construction of cottage towns, it justifies its use. It is convenient to use when reinforcement work is carried out in an open area.

Industrial hooks. This hook is placed on a wooden handle or clamped into a screwdriver. The knitting process becomes partly mechanized, but labor productivity does not increase.

With improvised means. As a rule, non-professionals use a piece of welding electrode or an ordinary nail. By first bending it with pliers, you get a simple tool that is suitable for small amounts of work.

Technological map of tying reinforcing bars

Let's take a closer look at the connection diagram of working reinforcement bars with clamps. This process includes the following operations:

• First of all, we will prepare the binding wire. We unwind the wire from the coil and cut it into pieces of 250-300 mm;
• With a double bent wire we wrap around the junction of the reinforcement bars;
• Insert a crochet hook into the resulting loop of wire and perform rotational movements. The reinforcement bars are tightly connected;
• after four turns, the hook is pulled out and the ends of the wire are bent around the joint.

It is allowed to make corner connections of frames in the pit only using bent reinforcement profiles.

What wire is used for tying reinforcement?

The quality of the knitting wire is reflected in the strength and rigidity of the frame joints. For all its softness, it must be strong enough and provide a tight connection. The thickness of the binding wire depends on the diameter of the reinforcement bars being connected. The most popular among developers is considered to be black annealed wire with a diameter of up to one and a half millimeters.

The wealthiest developers can afford to use tying wire with an anti-corrosion zinc coating. Such wire will delight the owner for many years.

Cost of reinforcement works

Carrying out reinforcement work includes several operations. First of all, the necessary preparations of reinforcing bars for working, structural, and connecting reinforcement are carried out.

The knitting wire is unwound from the coil and cut into pieces up to 300 mm long. Depending on the diameter of the wire, you can make a loop on one side.

After tying the individual rods into spatial frames, they take their design position. Now they are firmly fixed in the formwork, the vertical sides with spacers, and the bottom with bosses.

By performing simple calculations, you can find out how much metal was used in the manufacture of the foundation frames. The same calculations are made to determine the volume of concrete mixture that will be laid in the mass.

In each individual case, frames may differ in design features and material. The average price for knitting work is around eighteen thousand rubles per ton of reinforcement laid in the foundation.

Recommendations from experts

When making a strip monolithic foundation for an auxiliary outbuilding, bathhouse, garage, calculations for the selection of reinforcement are usually not made. Structurally, as a load-bearing structure, periodic profile reinforcement of class A 3 is used, the diameter must be at least 12 mm.

Rods made of composite materials can be used for reinforcement. In terms of quality characteristics, they are not inferior to steel ones, and in a number of indicators they are even superior. Low cost and weight, strength and durability have become the hallmark of this material.

Plastic ties are considered an excellent alternative to binding wire among advanced professionals. They provide a fairly strong connection between the rods, minimize labor costs and increase labor productivity.

Final part

It’s good when a man can do a lot of household chores with his own hands. However, builders are not born - they are made. You must have a certain amount of knowledge and experience.

One of the important and responsible structural elements of a building is the foundation. The strength and durability of the entire building, as well as the safety of residents, depend on the quality and reliability of this structural element.

Responsible construction processes should be performed by professionals, not self-taught ones. Entrust experts to do what they know how to do well.

Photo of reinforcement knitting

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Source: https://stroimaterials.ru/vyazka-armatury/

How to properly tie foundation reinforcement, necessary tools - Machine

Many people believe that only welding can secure reinforcement in the most rigid way. Everything is true and false : the fact is that the main task pursued when connecting reinforcing bars is not to impart strength to the resulting frame. It is achieved during pouring using a concrete mixture.

• The point of this operation is to fix the metal rods in the desired position and prevent their displacement relative to each other during pouring or subsequent vibration and during operation.
• Welding will cope with this task, but:

• will change the crystalline structure of the metal of the rods at the joints and reduce its strength;
• will create an overly rigid structure, which may break during vibration and subsequent operation precisely because of its rigidity;
• will require special equipment and knowledge;
• will increase the time and cost of construction.

Currently, welding of reinforcement is used exclusively in industrial construction for a limited type of objects that will stand on ground that is not prone to subsidence.

Most home craftsmen prefer knitting.

This connection method is free from all of the above disadvantages, is simple, reliable, and does not require any special knowledge or the use of expensive equipment.

In addition, when tying reinforcement for the foundation, the integrity of the metal is not compromised, and the rods themselves retain limited mobility relative to each other, which allows them to withstand vibration and loads arising during operation without any harm to themselves.

What you need to knit reinforcement

First of all - steel wire. You can use white, galvanized, but regular black will do. There is no need to be afraid that it will collapse due to rust: if the reinforcement is laid correctly, that is, with a fairly large layer of concrete (at least 2 cm), the access of oxygen to the reinforcement elements is completely eliminated, and there will be no corrosion.

The following requirements apply to the knitting wire:

1. Cross-section from 1.2 mm to 1.6 mm (thinner wire will not be able to provide a reliable connection, and working with wire of larger diameter is very difficult).
2. The ability to bend easily and not break when twisted.
3. It is recommended to purchase wire made from low-carbon, baked steel.

As for the length of the sections into which the wire is to be cut, on average it is 20 cm. The exact value of this parameter depends on the method of connecting the reinforcement, its thickness and the experience of the craftsman.

To save money, you can use metal cords from truck tires; for this you will have to burn them.

Sometimes imported tires use plastic cord. This is easy to determine: just make a cut on the inner side facing the rim. If the knife hits the metal, everything is fine.

Those who don’t really like the process of burning tires can buy a coil of wire in the store, as well as the necessary tools.

1. There is a special hook for knitting, which you can buy in a store or make yourself.
2. This method, which is called a double-row knot, is simple because it requires minimal effort. The necessary actions are as follows:

1. The wire is bent in half and the tip of the resulting loop is slightly bent - this is necessary to make it easier to slip it under the reinforcement.
2. The loop is slipped under the rods diagonally, and its end is grabbed with a hook.
3. The free end of the wire is placed under the tip of the hook, the hook is twisted and twists the wire.

You can slightly change the procedure by applying in practice knitting reinforcement using method No. 2:

1. Make a wire loop by bending the wire.
2. Place the wire on the rods and press it with your finger.
3. Place the free ends under the rod diagonally and bend them towards you.
4. Insert the hook into the loop and twist the wire.

Method number 3:

1. The wire loop is inserted under the reinforcement from below.
2. The loop is grabbed by the hook, and the “tail” from the free ends is bent through it at a right angle.
3. You need to twist the hook.

Method number 4:

1. Again, a loop is made from the wire and threaded from below under the reinforcement.
2. The end of the wire loop is caught with a hook.
3. The tail formed from the free ends is bent over the hook and lowered so that another loop is formed.
4. You will need to twist the hook.

The last method is good because at the twisting stage it frees up your left hand, and you can use it to hold the rod. Otherwise, all four methods differ only in whether the free end of the wire is brought to the hook or vice versa, and in what is wrapped around what.

There is no fundamental difference between them: you choose the one that is more convenient, but it is worth remembering some points:

1. It is important to correctly determine the size of the loop that the hook will hook into and not make it too long. Otherwise, to tighten the wire, you will have to rotate the hook 7-8 turns, and the wire may break. The optimal number of revolutions is 3 or 4.
2. When crocheting, you need to lightly tighten the loop, but do not overdo it. Uneven tension of knots in different areas is not dangerous if it does not lead to a change in the position of the rods, but it is desirable that all knots be tightened with equal force. This will be easier to do if you use pieces of wire of the same length and tighten the knots with the same number of turns of the hook.
3. For large volumes of work, experts recommend not cutting the wire, gradually unwinding it, but cutting the entire coil at once using a grinder, then taking several rods (they will all be the same size) and bending them in half. It is easier to work with such blanks.

The remaining ends can be left, bent down or cut off. It is important that after pouring they are covered with a layer of concrete mixture at least 2 cm thick.

Additional tools

Most craftsmen also knit corner reinforcement elements with a double-row knot, although for this there is a special type of knot made with pliers.

There are other knots for tying reinforcement. But they are difficult to implement and are rarely used.

These are the cross and dead knots.

If you have a welding machine at your disposal, you can make your own original tool from a hollow steel tube with a cross-section of 1.2 cm and a drill 20 cm long, which fits freely into the tube. You will also need 2 8 mm bolts, 2 corresponding nuts and a hook made of wire with a cross-section of 6 or 8 mm.

At the end of the tube, 2 holes with a diameter of 8 mm are drilled, nuts are welded to them and bolts are screwed in. The drill is inserted into the tube, after which the bolts are tightened so that their ends fit into the drill flange.

A hook is welded to the end of the drill, and a finished tool is obtained.

Now all that remains is to pull the tube, the drill will begin to rotate and twist the wire.

If you want to fully automate the knitting process, you can use a screwdriver with a hook attached to it. Just be sure to set its speed to minimum. It is not recommended for an inexperienced craftsman to use a drill for this purpose due to its high rotation speed.

There are knitting guns that can reduce human participation to a minimum and reduce the time required to complete the work. The gun is powered by an electric motor, which pulls the wire wound on a bobbin located in the housing.

This is a fairly expensive tool, so its purchase is only advisable if viscous reinforcement is done professionally. Another disadvantage of the gun is the short battery life and the fact that it cannot be used in hard-to-reach places, as well as for tying corner elements.

Other methods of tying reinforcement

When creating a foundation for small objects, composite reinforcement is sometimes used, which can be knitted using plastic clamps.

Among the advantages are the ease of performing the work, their absolute safety, and minimal risk of corrosion. Among the disadvantages, it should be mentioned that walking on reinforcement connected in this way is strictly prohibited. Plastic clamps cannot be used at sub-zero temperatures.

Another way to knit composite reinforcement is with clips made of heavy-duty plastic. The knitting technology is extremely simple: the rod is pressed into the gap of the clip until it clicks. But it is impossible to correct the mistake made and remove an incorrectly installed rod without damaging the clip.

Plastic fasteners are not used for metal fittings.

Safety precautions when tying reinforcement

To minimize the risk of injury, the following simple rules should be followed when working with rebar and tying wire:

1. When cutting rods or wire with a grinder, be sure to wear safety glasses or a mask that will protect your face from sparks and small metal fragments.
2. To avoid damaging your hands, work with the knitting wire only in thick gloves. It is advisable to use clothing that covers the body as much as possible.
3. When moving near the reinforcement frame, do not lean on the bars.
4. Do not walk on or stand on the rods. When working with a large area of ​​reinforcement frame (for example, under a floating foundation of a house), use wooden walkways placed on top of the reinforcement for movement. There should be no foreign objects on the walkways.

Despite its apparent simplicity, this work requires skill, and at first mistakes cannot be avoided. It is better to purchase wire with a reserve and, before starting knitting, practice a little on a piece of reinforcement. The training will take some time, but the experience gained will help you subsequently create an impeccable reinforcement frame.

Source: https://regionvtormet.ru/okrashivanie/kak-pravilno-svyazat-armaturu-dlya-fundamenta-neobhodimye-instrumenty.html

Technology of tying reinforcement for foundations - simple and correct methods of tying and installing reinforcement for various types of foundations

Almost any large structure begins with the construction of a foundation. But not many people know that for the reliability and durability of the foundation, it must be reinforced with building reinforcement. Therefore, many who plan to build their own house on their own involuntarily ask the question: how to knit reinforcement correctly?

Moreover, this process is very complex and requires patience and attention, special skills, as well as certain knowledge in construction work.

Essentially, reinforcement is designed to add flexibility to a concrete structure, making it more resilient. The fact is that under the influence of large loads of concrete, the reinforcement takes over. But without reinforcement, a concrete structure will actually be very fragile and unreliable.

As a rule, the reinforcement process is quite labor-intensive and can be done in two common ways: wire knitting or welding. Of course, both of these methods are good, but each has its own specific nuances.

Methods of knitting reinforcement

As a rule, knitting reinforcement with your own hands is the most common way of making a frame structure in prepared formwork. The knitting process itself can be performed in various ways. So the most common and simplest way to knit reinforcement is to knit with a special hook designed for this purpose.

You can also use a special gun, or alternatively use a screwdriver with a hook on the end, or you can also use pliers. At this stage, it is important to correctly and securely tie the reinforcement bars together with wire.

It should be noted that in the process of connecting reinforcement rods it is allowed to use welding, especially if it is smooth reinforcement that does not have any “notches” on it. It is very difficult to crochet such reinforcement with high quality, so in such cases it is recommended to use welding equipment, and the crocheting process is greatly simplified.

However, despite this, crocheting reinforcement is considered the most reliable way to connect corrugated reinforcement rods.

Knitting wire

Knitting wire for tying reinforcement is of no small importance. As a rule, such wire has corresponding requirements that apply to it. First of all, this concerns compliance with GOST or standard, but in practice, most often, such wire has the corresponding GOST 3282-74 - “Low-carbon steel wire for general purpose.” Technical conditions".

It should also be noted that the thicker the reinforcement, the thicker the binding wire should be. For example, reinforcement with a diameter of 18 mm is not acceptable. use wire with a diameter of 1.2 mm.

Of course, tying reinforcement for the foundation is the most important stage in the manufacture of the foundation. Since the reliability and durability of the foundation depends on the correct alignment.

It is important to understand that very large weight loads are constantly placed on the foundation, so the reinforcement structure connected inside the concrete evenly distributes the entire load over the entire area of ​​the monolithic structure.

Do it yourself or order it?

If you have any difficulties in creating a reliable and high-quality frame from reinforcement, you can familiarize yourself with numerous and detailed photos of tying reinforcement, which show all the different nuances that may arise during the tying process.

In order for the foundation of a building to last for a very long time, it is necessary to properly strengthen it with reinforcement by tying reinforcement rods together. Of particular importance is the strength of tying the reinforcement wires together, otherwise it will negatively affect the foundation.

But if such work turns out to be difficult or overwhelming for you, then in this case it is definitely worth turning to qualified specialists. Yes, you will have to pay a certain amount of money for such a service, but in this case you will be able to save your time, and the quality of the work of the craftsmen will be at a very high level.

Also, specialists have everything they need to carry out such work; they will be able to reliably perform work of any complexity and in a fairly quick time. As a rule, such specialists not only knit the reinforcement, but also make the formwork and fill it with concrete.

Photo of tying reinforcement for the foundation

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Source: https://materialexpert.ru/texnologiya-vyazki-armatury-dlya-fundamenta/

How to properly knit and bend reinforcement for foundations: installation technology

Reinforcement cage indicating strapping locations

In all modern foundations, construction is not complete without the use of reinforcement - interconnected metal rods that absorb tensile stresses when used in conjunction with concrete. The frame creates vertical and horizontal belts, serves to increase the strength of the structure and uniformly distribute loads.

If the reinforcement is weakly or incorrectly connected, it will creep apart, thereby compromising the integrity of the foundation. This will lead to its slow destruction. Tying the rods together is quite simple, but highly specialized specialists know well how to properly knit reinforcement for the foundation.

The frame connection scheme is almost the same for all types of foundations, except for columnar wooden or metal ones, where a frame is formed on top of the pile head using reinforcement or beams.

They are connected to the head and welded, in which case the rods or wire rod have to be bent at a specific angle.

Three methods of tying reinforcement cages

Schematic representation of reinforcement tying technology methods

To form the metal frame of the base, three strapping methods are used:

1. Welding. At first glance, welding is the simplest and most effective way to connect reinforcement, but in practice everything looks different. During welding, the metal is heated to high temperatures and deformed, which results in a partial loss of rigidity. You also have to hire a professional welder who knows about the properties of the metal and can avoid burning it, and this is an additional financial expense. There is also a risk of destruction of the welding site during operation of the industrial vibrator. Difficulties arise if you bend metal close to the welding site.
2. Connection using bent wire or plastic clamps (ties). This method is popular among many developers, since the connection can be made with your own hands in a matter of minutes. If flexible wire is used, then a special tool must be used to connect the links. Plastic clamps are more reliable than wire, but are more expensive. The connection diagram is similar, only then you have to bend the rods at the required angle.
3. Overlapping. This method involves overlapping reinforcement with further fixation with wire. It is practiced more for horizontal belts made of mesh, and a vertical smooth rod is used inside the joint.

Any of the above methods can be implemented with your own hands. In this case, you have to bend the metal, which is quite problematic, given the rigidity of the reinforcement and its minimum diameter for horizontal chords of 12 mm.

Knitting reinforcement with your own hands

With all the variety of specialized construction tools, not all private developers have the opportunity to buy or rent them. Knitting rods does not require expensive tools; moreover, you can do it yourself.

To do this, you need to purchase steel binding wire. It is quite flexible and durable, has a diameter of 2-3 mm. To bend it, you will have to use pliers or a specially made hook, which subsequently twists around the reinforcement and fixes it. Some craftsmen who perform reinforcement with their own hands sometimes use a screwdriver as a simpler and easier way to knit. If you knit with wire, you will need:

• One of the options for knitting the base frame using a hook. Craftsmen sometimes use a screwdriver as an easier way to tie reinforcement bars with their own hands. Cut a piece of wire about 30 cm long. You can do more if you don’t mind it, but the ends will get in the way (including excess waste);
• then fold the wire in half to increase rigidity and strength;
• bend it diagonally around the reinforcement joint and make a small loop;
• Place the hook in the loop and twist clockwise evenly, without unnecessary effort, until it becomes difficult to wrap or the connection becomes strong enough. The main thing is not to use force, since it is easy to break the wire and then you will have to start all over again;
• Cut off the ends of the wire with pliers and discard.

In the case of reinforcement of a columnar foundation, the reinforcement cage can be bent and then fixed to the heads with special clamps. Some manufacturers already supply metal or wooden piles with special clamping brackets and couplings.

In this case, it is enough to bend the rod and insert it into the bracket. Clamp the bracket and boil it on top; you can do all this yourself, using a minimum of tools.

In the case of using smooth reinforcement, the tying process is more labor-intensive, since the hooks will constantly bend and cannot be done without a specialized tool at hand, as well as without outside help.

It is better to knit the reinforcement cage for a slab monolithic foundation from several belts. For the horizontal tier, spiral rods with a cross-section of up to 16 mm are used, and for vertical links, smooth rods with a cross-section of up to 10 mm are used. When installing the lower mesh, it is recommended to use plastic expansion joints, which will create a uniform pitch. Then, when knitting vertical rods, it is important not to forget to take them outside the foundation, due to the fact that load-bearing walls will be connected to them.

Using plastic ties for knitting is a more expensive option for replacing wire, but clamps (ties) can be found in any household. The principle of tying is similar, but the plastic for the ties is less durable. Therefore, it is better not to use force during installation.

The most popular clamps have a special core at the end of the tie; they are used to secure cables and pipes to vertical surfaces. Plastic showed excellent results when knitting with your own hands in warm weather; in cold weather it quickly loses its elasticity and bursts.

matings:

Tying reinforcement for the foundation according to all the rules

Sketch of the technology for correctly creating connections between reinforcing bars and crocheting

It is quite possible to knit reinforcement using available materials. But it is worth noting that correctly tying the rods together does not guarantee compliance with all building codes and high-quality installation. Since the pattern of knitting the frame depends on the type of foundation, its size, thickness and type of material used. Therefore, you need to take into account several key rules:

1. If mesh is used as a reinforcement frame, then the strapping must be overlapped.
2. Taking into account the type and cross-section of the reinforcement, it is necessary to calculate the length of the bypass at the connection points.
3. The rods must be bent strictly at a certain angle and evenly.
4. The grade of concrete and working conditions at the joint are taken into account. The minimum overlap length is at least 25 cm.

If reinforcement is carried out at a height of 3 meters or more, then scaffolding or scaffolding is indispensable. The strapping technology turns out to be more complex, due to existing safety rules for working at height. Tying is carried out in three stages:

1. First prepare the reinforcement and tie slings to it.
2. Raise to the required height, level and place in plastic guides.
3. Tie the rods using any of the listed technologies.

Work at height should be carried out only with several workers at a time, provide insurance and control the process of lifting the rods and then installing them in the specified places. Doing this yourself without insurance is strictly prohibited.

The cost of strapping is relatively low, since craftsmen can process several square meters of frame in an hour. And when using special knitting tools, it’s even faster. And they guarantee the quality of the knitting of the rods and compliance with all construction standards, especially since the rods will be bent with special pliers.

instructions

Source: https://FundamentClub.ru/armirovanie/kak-pravilno-vyazat-armaturu.html

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

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/

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.

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