How to twist reinforcement

Why do they knit reinforcement for the foundation?

A high-quality mesh of reinforcement allows you to maintain a certain geometric shape of the foundation when pouring concrete. Cooking it is not recommended due to disturbances in iron crystals. Regardless of how large-scale the building you are constructing, reinforcement for the foundation is an integral element. Now there are many ways to knit reinforcement for the foundation. You can do this yourself.

During construction, due attention must be paid to the foundation. A reliable foundation can withstand the enormous weight of the future building, so it needs to be reinforced with reinforcement. The strip foundation is laid along the perimeter of the building. Such a base can be chosen for any type of structure.

Strip foundation when building a house

There are four main types of foundation masonry (base, base):

• trapezoidal;
• pillow;
• stepped;
• rectangular.

The best option is a trapezoidal shape, as it better withstands the enormous load on the base. It is necessary to accurately calculate the inclination of the side face to the vertical. For a foundation made of stone or brick, it should be no more than 30°. If the base is concrete, then the angle should not exceed 45°.

What kind of reinforcement is used to knit the frame?

There are two main types of reinforcement - metal and composite. Diameter is the main indicator that determines its brand. The thicker the rods, the greater the load they can withstand. The diameter is calculated at the design stage, taking into account the mass of the future building, as well as the heaving of the soil.

When constructing a building made of concrete or brick, which is massive, the use of thick rods is required. They can handle the enormous weight of the structure. When laying the foundation, it is prohibited to use rods with a diameter of less than 12 mm - they will not withstand such a load. When building small houses and garages from gas, foam and heat blocks, you can use less thick reinforcement; rods with a diameter of 12 mm are sufficient.

Metal reinforcement for the foundation

When constructing massive structures, class A-3 is used. Rods of this brand can bend up to 90°. Much less commonly, class A-2 is used for laying foundations. When cold they can bend up to 180°.

Metal fittings

The most common type of pipe used when laying a foundation is metal reinforcement. Rods of different cross-sectional diameters are available for sale - from 12 to 40 mm. They are widely used in construction, in particular, for laying foundations for large, heavy buildings.

The cost of a product directly depends on its characteristics, namely:

• rental method,
• steel grades,
• surfaces (corrugated or smooth).

Rods with a corrugated surface have a higher price. This type has stiffening ribs, which allows the products to better adhere to concrete.

Metal fittings

Composite reinforcement refers to non-metallic rods made of different materials used in construction. For more effective adhesion to concrete, the surface of the rods is made rough or covered with sand.

The most common types of composite reinforcement:

• carbon fiber;
• basalt plastic (BBP);
• fiberglass (FRP).

Accordingly, reinforcement is produced from materials: carbon fiber is used in the production of carbon fiber reinforcement, basalt fiber is used for the production of ABP, and glass is used for ASP. They have many advantages: corrosion resistance, high specific strength, and environmental friendliness.

Schemes for distribution of reinforcement in the structure of a strip foundation frame

The optimal scheme is considered to be one in which the cross-section of the reinforcement in a strip foundation will be a rectangle. Two forces act on the base at once: the first is heaving during frost, the second is the pressure of the house. What kind of reinforcement is used for a strip foundation to compensate for these two forces?

Composite reinforcement

The material does not play a major role here. To compensate for the influence of these two forces, two reinforcement belts are installed. The first is located at the top, the second at the bottom. If the foundation is laid shallow (up to 1 meter), then this is quite enough. For a foundation that is laid deeper, a third reinforcement belt is required. High altitudes require reinforcement.

Four main patterns of tying reinforcement for strip foundations are used. Regardless of the chosen method, first of all you need to make a hook from wire, the diameter of which should be 3-4 mm. You can knit the reinforcement with wire yourself.

Wire for tying reinforcement cage

The most reliable way to knit a reinforcement cage is using wire. A less successful alternative is the use of a welding machine. The tying of the base reinforcement frame can be carried out using ordinary metal wire or wire processed by firing. The second option is preferable - thermally hardened wire becomes more flexible and durable.

Wire for tying reinforcement cage

Calculator for calculating the amount of wire for tying the reinforcement cage of a strip foundation

It is not enough to know how to knit reinforcement correctly; you also need to carry out calculations. To do this, it is necessary to take into account the following indicators:

• indentations between clamps;
• number of longitudinal reinforcement rods;
• base length;
• double sealing of corners.

A modern calculator, which you can use online, will allow you not only to determine the amount of wire for tying the frame under the foundation, but also calculate the approximate number of joints.

A reliable frame is an important element of the foundation and the building as a whole. To strengthen it, you need to use certain tools. Depending on the choice of method - manual or automatic, special devices are selected and used.

Such tools include:

• manual or semi-automatic hook;
• automatic pistol.

Hand hook for wire tying

Using these tools, you can tie reinforcement under a strip foundation. An automatic pistol is used in professional construction, as its cost is quite high. For the construction of one building, the purchase of this device is considered inappropriate. For independent work, a regular hook for tying reinforcement is suitable.

Techniques for tying reinforcement

At the moment there are four main techniques. The most convenient and fastest way is to take the wire, fold it in half and pass it under a certain area of ​​the frame. Armed with a hook, thread the wire into the loop, pull up its free end and throw it over the hook, while bending the wire slightly. We twist the ends, after several turns (3-5) we stop the manipulation, removing the hook.

The next technique is similar to the previous knitting method. The main difference is the formation of an O-shaped loop. After the wire is twisted securely, the hook is removed.

Algorithm for the third pattern of tying reinforcement for a strip foundation:

• we put the wire under the rods;
• insert the hook into the loop and pry up the end of the wire;
• bend it back and pull it towards you;
• scroll several times.

Techniques for tying reinforcement

According to experts, this is the most convenient technique for beginners.

There is another way to knit reinforcement for the foundation. As usual, you need to fold the wire in half and place it under the rods. After this, press it against the rod and bend the ends towards you. Insert the hook and make a few turns.

Using additional parts for spatial fixation of reinforcement

When knitting the frame, it is necessary to use additional elements. These include “frogs”, U- and L-shaped elements, clamps, and fasteners. They allow you to fix the reinforcement and its corners.

It is worth saying a few words about clamps. These are bent products in the shape of a rectangle. They are made from rods with a smooth or grooved surface. Clamps are used to distribute the load.

Knitting fiberglass reinforcement

To tie fiberglass reinforcement, wire or special plastic clamps are used. The first method is no different from knitting a standard (metal) frame. Clamps are an excellent choice for those who are new to tying reinforcement. The cost of the products is not much higher than ordinary wire. A hook or gun is also used for reinforcement.

Knitting fiberglass reinforcement

Recommendations

How to reinforce aerated concrete masonry to prevent cracks from appearing? To do this, it is necessary to correctly select the density and strength of the reinforcement. Also, the reinforcement process itself must be carried out in compliance with all requirements.

Reinforcement of brick walls is divided into three types:

• Longitudinal.
• Transverse.
• Vertical.

Proper reinforcement of walls and corners will allow you to strengthen your structure as much as possible.

The grillage reinforcement is carried out strictly according to the design. Despite the fact that it is similar to a strip foundation, the laying technology is significantly different.

Fiberglass reinforcement is quite strong, lightweight, and practically does not corrode. However, it has significant disadvantages, including low elasticity and heat resistance, a decrease in strength over time, and instability to alkalis.

Many people ask the question: is a mesh needed for floor screed? Yes, I need it. It allows you to make the floor smooth and more durable.

Coupled rebar connection is another type you may encounter. This is a separate method of connecting rods. It can be crimped or threaded. This connection allows you to withstand loads on the base.

Source: https://pobetony.expert/armirovanie/vyazat-armaturu-dlya-fundamenta

How to crochet reinforcement and other methods?

When performing work on pouring concrete foundations, builders are faced with the need to prepare a metal frame to ensure the strength of the structure. You can form a mesh from reinforcing bars in various ways:

• tying frame elements using wire with a hook, a screwdriver or a knitting gun;
• welding reinforcement together;
• securing the rods together using plastic clamps.

There is no single correct option. In practice, all methods are used, and the choice depends on the material used and the conditions at the construction site.

To understand in which case it is better to use one or another method, you should consider the positive and negative features of each.

Crochet

Crocheting reinforcement (you can read about how to do it here) has the following advantages:

• high speed of operation. With some skill, the specialist quickly tightens the knots with a hand tool at the junction of the rods. Such work is not difficult even for beginners;
• ease of repairing defects. Incorrectly applied wire can be easily untwisted or torn with wire cutters. The welding seam cannot be redone so easily - you will have to saw the joint with an angle grinder;
• You don’t need to have much experience to tie reinforcement. A novice builder quickly learns this simple procedure and after fifty knots can be considered a professional;
• You can tie the rods into a frame immediately inside the formwork;
• Labor and material costs are not high.

The disadvantages of crocheting reinforcement include the unsteadiness of the assembled frame. This problem arises when it is necessary to transfer the frame from the assembly site to the formwork. Dealing with this shortcoming is simple:

• in the case of conventional metal reinforcement, it is recommended to strengthen the connections by welding in several places;
• when using fiberglass products, install several braces around the perimeter. They will help give additional strength to the mesh.

In practice, this problem is solved simply - they knit the frame directly in the formwork so that it does not have to be moved.

In addition to a manual hook for tying reinforcement, a semi-automatic hook is also used. This device helps you get the job done much faster. A semi-automatic machine is a mechanism equipped with a reversible screw base. If the handle is pulled back, the screw begins to rotate, pulling the wire onto the joint.

You can see how to use a semi-automatic crochet hook for tying reinforcement cages in the video below. You have to get used to using such a tool, but professional workers manage to tighten the knot on the connection in one movement, which noticeably speeds up the whole process.

Welding

The technology of welding reinforcement is used in the construction of monolithic foundations for multi-story buildings. Previously, this method was considered the most reliable, but in modern conditions other methods of connecting rods are more often used.

The disadvantages of the welded method include:

• the need to involve a professional welder in the work. Paying a specialist automatically increases the estimated cost of the facility;
• the point of connection of two reinforcing bars weakens the overall strength of the structure and is a weak point;
• It is impossible to connect fiberglass reinforcement by welding;
• the most popular brand of rods for frame assembly (A-400) is not suitable for this method. You will have to order A500C brand rods separately.

Source: https://DomZastroika.ru/foundation/kak-vyazat-armaturu-dlya-fundamenta-kryuchkom.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 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.

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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 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

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 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 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

video on:

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