How to knit reinforcement for concrete

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

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 to knit reinforcement for a foundation manually

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To independently make a reinforcement cage for a strip, columnar or pile foundation, or a mesh for a floating slab, you need to learn how to correctly knit the longitudinal and transverse joints of the rods. To do this, a homemade or factory hook and knowledge of the layout of reinforcement inside concrete structures are enough.

Rules and patterns for tying reinforcement

The most complete recommendations on how to knit reinforcement by hand are given in the design manual dated 2007 by the Gvozdev Research Institute of Concrete Concrete. The knitting wire must comply with GOST 3282 (available with a coating of 0.2 - 6 mm and without it 0.16 - 10 mm), since not every wire available to a home craftsman becomes soft after annealing and retains its strength characteristics.

Experts do not recommend the use of plastic clamps, since when concrete is moved inside the formwork, the joints move along with the mixture. For slab foundations, the industry produces ready-made welded reinforcing mesh, but delivering them to the site is more expensive than individual rods.

In addition, the ends have to be strengthened manually with U-shaped elements. Therefore, for small volumes of reinforcement work in individual construction, a coil of tying wire, a hook and these instructions are quite sufficient.

The technology for how to properly knit reinforcement has the following sequence of operations:

• a piece of wire 20-25 cm is cut from the coil for rod diameters of 8 - 16 mm;
• bends in half, wraps under the overlap of the rods diagonally;
• the point of the hook is threaded into the loop;
• the wire clamp is tensioned;
• the free edge is placed on the hook bed;
• by rotating the tip of the tool, a twist of 3-4 turns is created;
• after removing the hook, the free ends are bent inside the frame;

This technology is suitable for all foundations; only the layout of the rods inside the reinforcement structures differs.

Important! When using reinforcement from 25 mm, welding of joints is a prerequisite. In this case, the crosshairs tied with twisted wire can break off under the weight of the structural material.

Strip foundation

Before making a frame from reinforcement for a strip foundation, you need to take into account the main mistakes of independent developers:

• straight rods in the corners are connected by an overlap;
• the frames stand on the concrete base on vertical rods;
• in the cross-section of a concrete structure, the reinforcement is less than 0.1%;
• The lateral protective layer is not provided; the rods come into contact with the formwork in some areas.

You cannot reinforce the corners of a strip foundation with a simple overlap of rods. Reinforcement is carried out according to special anchoring schemes presented below.

When reinforcing the tape, you should take into account the features of this foundation:

• when concreting MZLF, the reinforcement cage can be tied inside the formwork using rods, clamps and anchors;
• deep tapes are reinforced before installing the panels, since it is not difficult to penetrate inside the formwork;
• frames can be made in the building area, placed in place in the formwork, and then reinforced with L-shaped or U-shaped anchors in the corners;
• the footing reduces the minimum size of the protective layer of concrete at the base of the structure from 5 cm to 2-3 cm; to create the lower protective layer, special plastic supports are used - “glasses”;
• when extending longitudinal rods, it is necessary to ensure an overlap of 20 reinforcement diameters, but not less than 25 cm;
• It is forbidden to lay the lower chord on stones, bricks, scraps of reinforcement; only plastic or concrete spacers are allowed;
• Overlapping reinforcement connections must be spaced apart so that more than half the cross-section of the entire longitudinal reinforcement is not connected in one section.
• there is a minimum percentage of reinforcement content in the cross section of the strip foundation equal to 0.1%;

Schemes for reinforcing corners of strip foundations.

Important! Clamps (transverse horizontal and vertical rods) are necessary mainly to give the frames the necessary spatial geometry. Therefore, the reinforcement is considered structural and does not experience loads during operation. The diameter is taken to be 6 and 8 mm for lengths less than 80 cm and more than 80 cm, respectively.

More detailed information in the article: Reinforcement schemes for strip foundations.

Slab foundation

Since a floating slab is considered the most expensive foundation, discharged reinforcement can be used in the middle part of the structure. However, this method of saving materials requires professional calculations in special programs. Therefore, individual developers most often use reinforcement mesh with the same cell size.

Correctly knitting reinforcement into meshes is not difficult, however, amateurs who do not have experience and specialized education make mistakes:

• lack of connection at the ends - the rods of the upper and lower chords must be connected with U-shaped clamps along the entire perimeter of the slab; At the ends, the slab is reinforced with U-shaped clamps.

one mesh instead of two belts - the lower mesh works in tension solely from the weight of the building; at the slightest occurrence of frost heaving under the slab, tension zones appear near the upper plane, so the second mesh is a prerequisite for normal operation (if the slab thickness is equal to or less than 15 cm, it is allowed to use one mesh);

failure to comply with protective layers;

A special plastic cup provides the bottom protective layer.

the size of the mesh cells is too large, the cells should not exceed 40 cm, the optimal size is selected by calculation, in practice it is often no more than 20 cm.

To assemble the reinforcement frame of the slab, the upper mesh must be fixed at some distance above the lower chord. For this purpose, tables, frogs, spiders, and other elements with bent legs to rest on the lower cells and shelves supporting the top layer are used.

Spider made of reinforcement with a diameter of 8 mm.

When bending reinforcement on site, it is prohibited to heat the rods with gas welding. Bending machines or clamps must be used that provide the required bend radius. Where load-bearing walls are located, the slab foundation is reinforced with additional reinforcement, i.e. The cell pitch is halved.

In slabs with stiffening ribs under the load-bearing walls, frames are located by analogy with strip foundations and grillages. They are rigidly connected to the slab mesh and provided with standard protective layers of concrete.

More detailed information in the article: How to properly knit reinforcement for a monolithic slab.

Grillage

The external similarity of the grillage to a strip foundation leads to errors in self-reinforcement. The tape experiences tension at the base from the prefabricated loads of the cottage, and at the top from swelling of the soil. Heaving forces never act on the grillage, since it is separated from the ground by a crushable layer of polystyrene foam or an air gap of 10–20 cm. However, here a bending moment arises in the vertical direction in places where the posts are rigidly pinched into the beams.

Important! For a grillage, it is not enough to make a standard frame of longitudinal rods tied with clamps. It is necessary to further strengthen the top row near the columns (piles and pillars), and the entire lower belt.

Diagram of the correct reinforcement of the grillage/pile interface.

Recommendations on how to properly knit reinforcement joints apply only to steel rods. It is not recommended to use composite reinforcement in foundations, which, when tensile forces appear, first elongates and only then begins to absorb loads. This is fraught with the opening of cracks in the base of the upper part of the concrete foundation beams that make up the grillage.

Source: https://GidFundament.ru/rabota/kak-pravilno-vyazat-armaturu-skhema.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 properly reinforce concrete and knit reinforcement

Why reinforce concrete?

How to tie reinforcement correctly

Calculation of reinforcement for foundation reinforcement

Reinforcement is the use of reinforcement during construction to increase the strength and reliability of a structure. Let's figure out why you need to reinforce concrete and how to correctly calculate the amount of material for this process.

Why reinforce concrete?

Concrete is widely used in construction as a very durable material. But it also has disadvantages - when stretched and bent, it can crack or burst, which will significantly reduce the strength of the structure. To prevent this from happening, when pouring concrete, it is reinforced with metal rods - reinforcement. It acts as a frame that takes the pressure of the material and prevents it from collapsing.

How to tie reinforcement correctly

Concrete reinforcement is done when pouring the foundation and erecting floors. To do this, the rods are installed across the possible direction of stretching or deflection.

To achieve even greater strength, the reinforcement must be tied or welded. This is done so that when pouring the heavy solution does not displace the rods and change the shape of the structure. The connection elements must be firmly adjacent to each other so that the concrete does not separate them when poured.

Welding is considered a stronger and faster method, which, however, is rarely used in private construction because it requires experience and skill from the welder.

When building with your own hands, knitting is often used. Even a not very experienced builder can use this method with some preparation. When knitting, a special wire with a diameter of 2-3 mm is used, which strengthens the structure at the intersection of the rods.

In specialized stores you can also buy a ready-made reinforcement frame, but practice shows that its connection does not give a head start either in terms of completion time or in strength.

Calculation of reinforcement for foundation reinforcement

The amount of reinforcement and other materials for binding depends on the type of foundation and its shape. For a slab foundation, it is enough to install rods with a diameter of at least 10 mm with stiffeners. The choice of diameter is influenced by the type of soil and the size of the future house: 10 mm rods are suitable for a light house standing on solid ground; for a building with several floors when built on moving soil, reinforcement of at least 15 mm will be needed.

For a slab foundation area of ​​6 by 6 meters, it is necessary to build a structure from metal rods with a pitch of 20 cm. For installation, you need to take 31 pieces of reinforcement and lay it out lengthwise and crosswise - you get 62 rods.

For a concrete slab, two reinforcement belts are needed - top and bottom - so the amount of reinforcement needs to be doubled again - 124 rods.

If you recalculate the amount of reinforcement in linear meters, then with a length of one rod of 6 meters, you need to purchase 744 linear meters of material.

The upper and lower levels are connected at intersection nodes. In this example, there are 961 of them. If the thickness of the slab is 20 cm, and the rods are inserted to a depth of 5 cm, then for a strong structure, rods 10 cm long or 96.1 linear meters of reinforcement are needed.

After installation of the structure, it is checked for compliance with the design. After this, you can pour concrete and carry out further construction work.

Source: https://rus-stroy.net/kak-pravilno-armirovat-beton-i-vyazat-armaturu/

How to knit reinforcement for a foundation: proven methods

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

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

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

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

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

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

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

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

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

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

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

Why is the reinforcement procedure performed?

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

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

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

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

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

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

Recommended reading:

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

How to calculate reinforcement mesh during the construction of various objects

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

Selecting a suitable group of reinforcement for a strip foundation

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

How to knit reinforcement correctly

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

What materials and tools are used when tying reinforcement

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

Steel wire

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

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

Plastic clamps

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

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

Tools

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

The most popular tools used for tying reinforcement:

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

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

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

Gun for tying reinforcement

How to knit reinforcement for a monolithic slab correctly

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

Ready-made frame for a monolithic slab

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

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

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

Calculation of reinforcement for a monolithic slab

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

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

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

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

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

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

How to properly knit reinforcement for a strip foundation

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

Example of a standard strip foundation

Installation of strip foundation:

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

Installation of the finished frame into the formwork

Knitting reinforcement for a strip foundation:

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

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

Ready frame for strip foundation

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

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

Correct knitting of fiberglass reinforcement

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

Tying fiberglass reinforcement using clamps

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

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

An example of tying fiberglass reinforcement with several clamps

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

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

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

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

How to properly knit reinforcement for a strip foundation: metal, composite, fiberglass

Anyone knows that the stability and durability of a building depends on how competently and accurately the foundation is laid. It takes on a static, uniformly distributed load throughout its entire service life. The deformation of linear stresses is controlled by the reinforcement located inside, and the compressive loads on the foundation are absorbed by the concrete.

Knitting reinforcement for a strip foundation is the best option for fastening the metal component of a future building. These connected metal rods of different diameters, after filling the formwork with cement concrete, retain the spatial linear contour given to it when knitting.

When concrete gains the required strength, this reinforcement allows it to maintain the desired location under load. If the fixation was carried out by welding, then when the cement concrete vibrates, the welding reinforcement seam may separate. This will create the possibility of tension within. Because of this, it may collapse prematurely.

Features of strip foundation

Strip foundations are more common than monolithic foundations. It can be used in construction from different materials, or you can make it yourself. Also, during its construction, money is simply saved. But it also has a drawback. The production of strip foundations is only suitable for dry, rocky soils. In wet, unstable soil, a device to a greater depth will not be cost-effective.

In order to avoid subsidence of the base and premature destruction, and possibly the house itself, additional compaction is performed to ensure the necessary strength of the base. If necessary, the strip foundation is supplemented with internal load-bearing lintels.

The depth at which the strip foundation is installed depends on several factors. If the upper soil layers are unstable, then the base of the base is installed below the freezing level. It can also be combined with piles. If the compaction of the base is sufficient, then there is no particular need to immerse the strip foundation below.

Types of reinforcement for tying

Before starting work, you need to decide on the fittings that are best suited. How to properly knit reinforcement for a strip foundation? Tying the strip foundation reinforcement is done with any pneumatic tool or hook. What if they are not around? An improvised tool is used. This is what is good about a strip foundation. Knitting of reinforcement can even be done using pliers.

Tying metal reinforcement

There are certain rules for mating. When choosing fittings, it is necessary to choose one that meets the requirements of GOST. During construction, a material that complies with GOST-5781-82 is often used. Has six strength classes.

It can be bent if necessary, and also welded using a welding machine. In the manufacture of the first class, low-carbon steel is used, and when the class is changed, the concentration of alloying additives increases, due to which the mechanical strength increases.

Bonding of composite reinforcement

Made from fiberglass, carbon fiber, basalt plastic. It contains fibers of carbon, basalt, as well as glass and aramid. The most common is fiberglass. It is lighter, cheaper, does not rust, does not bend, and cannot be welded with a welding machine. In the absence of welding capabilities, composite reinforcement has to be tied together. The advantage of this type is that it has low thermal conductivity.

Tying fiberglass reinforcement

Bound plastic reinforcement can be distinguished from metal reinforcement by the permissible distributed weight. When choosing fiberglass reinforcement as a reinforcing material, it is necessary to calculate the possible loads because the specific gravity it perceives is significantly different from the weight that metal reinforcement is capable of supporting. The binding process itself remains the same. The same tools and the same accompanying materials are used.

Scheme according to which reinforcement is distributed in a strip foundation

The reinforcement located in the cement concrete distributes the load. Therefore, the quality of the knitting will directly determine how long the structure will last.

Features of the frame arrangement:

• Preference is given to fittings with a diameter of at least 1 centimeter;
• The minimum distance from the frame to the inner edges of the formwork must be maintained, usually 30-50 millimeters;
• Between the rods no more than 40 centimeters;
• The elements that run lengthwise and crosswise are made from smooth rods 6-8 millimeters long;
• Between clamps 10-50 centimeters;
• Compliance with the number of tiers according to SNiP.

Calculation of wire for the frame

How to knit reinforcement on a strip foundation? It is necessary to ensure that the characteristics comply with GOST 3282-74. It is subjected to heat treatment, after which it becomes plastic without losing its strength properties. The section error is no more than 0.02 millimeters.

Types of wire separation

By processing method:

• Annealed;
• Unprocessed.

Load resistance:

By availability of protection:

• Protected;
• Not protected.

Tools for tying reinforcement

Correct knitting of reinforcement for a strip foundation implies that the nodes must be firmly fixed with wire. If this is not done, then when the cement-concrete mixture vibrates, the knots may finally come undone. This will then lead to increased loads and premature failure.

For a strip foundation, the reinforcement is knitted:

• Hands - crochet;
• Inertia hook;
• With a pistol.

Tying hook

To the question of how to properly tie reinforcement to a strip foundation, you can answer that you first need to choose a good tool.

They are small in size, suitable for tying in both hard-to-reach places and in normal circumstances. When purchasing a hook, take a closer look and try it out right away.

Homemade crochet hook

Homemade hooks are made according to a template, just like models made in production. In their production, reinforcement is used, which is sharpened on the side and bent in a vice. The handle is made from molten plastic and then screwed on. A polymer tube can also be used for the handle.

Screwdriver with hook

Using a screwdriver or other semi-automatic tool will speed up the work process and may also help relieve your hands. By tying the reinforcement of a strip foundation with your own hands, you put in more effort, and this can significantly affect your productivity in case of large volumes of work.

The hook is located on the leg. During operation, the hook catches the wire, pulls it upward with force, and the leg, turning, makes revolutions and twists the ends of the wire. The operation is performed until the required tightening of the knot is achieved.

Knitting gun

It is the best tool for the highest quality fastening. But it is quite expensive. It is used by professional builders who cannot afford to waste time. The device has a replaceable spool on which the wire is wound. These coils charge the device.

Binding with wire cutters

Another way to knit strip foundation reinforcement with your own hands. It is used when it is necessary to tie several wire knots because working with pliers for a long time will make your hands very tired. For large volumes of work, it is much more preferable to use another tool.

Rules for fastening rods

According to this scheme, you can tie the reinforcement:

• The wire is tied in half.
• A hook is inserted through the loop.
• On the reverse side, the end is wrapped around the intersection and also placed in the hook.
• The wire twists.

Recommended rules and methods of work when knitting:

• The rods are pulled up, twisted, the ends are bitten off with wire cutters;
• The wire twists several turns when it is tightly stretched;
• The rods and clamps are tied.

Using paper clips, staples, clamps

If necessary, speed up the knitting using the above-mentioned materials. In these situations, knitting is done by hand without using a tool. Rods with a small diameter can be tied with self-tightening plastic clamps. Universal devices suitable for any sections. They are light, installed by hand and do not smudge. Do not forget that they have low strength and can be damaged at low temperatures.

Advantages of staples and other fasteners of the same type:

• Productivity increases;
• The density of connected nodes increases;
• Easy to use.

Step-by-step instruction

Before knitting, you need to set up the formwork, concrete it, you need to purchase materials, deliver them and perform a number of other preparatory steps.

Start of reinforcement

List of actions for reinforcement and binding:

• Sorting;
• Cleaning from dirt;
• If necessary, align the rods;
• Cutting into pieces of the required size;
• Tying reinforcement blanks in the plane of the frame;
• Connecting planes to each other.

The diameter of the selected reinforcement and wire is selected based on the total load and the expected dimensions of the strip foundation.

Laying the finished reinforcement cage

Before installation, you need to prepare the base and place the formwork. Then comes the installation of two belts, which are then both concreted.

Action diagram:

• Driving in fixing rods;
• Sequential stacking of blocks;
• Checking elements.

Core mating

The best options are considered to be a rectangular or square strip foundation. For maximum stability, the reinforcement is made in a square, at 90 degrees. At the corners of the foundation, the production process becomes a little more complicated due to the use of bent rods. The workpieces are attached with bundles (clamps), and reinforcements are attached at the joints. To increase the strength of the house, the reinforcement is bent and overlapped using clamps.

Helpful Tips:

• Pay attention to the reinforced corners of the foundation;
• Use clamps so that the reinforcement cage does not come into contact with the soil and formwork;
• Use metal of the required quality without rust;
• Knit reinforcement with overlaps;
• If the wire is not flexible enough, place it in the fire for half an hour.

Using additional parts for spatial fixation of reinforcement

You should not assume that the use of fixing devices when constructing a strip foundation can be neglected. They form a “protective layer” that will help protect your foundation from corrosion and premature destruction. This seemingly trifle will save the building and a huge amount of money.

Another great tool is staples, which are used to tie together rebar intersections. They are very elastic and act in a springy manner. They have a diameter from 2 to 4 millimeters.

When building a strip foundation, it is necessary to take work with reinforcement very seriously. Be extremely careful! It is very important to choose high-quality materials that do not have rust, and when working, strictly follow the technological sequence so that your home lasts a long time. If in doubt, it is better to leave this work to professionals.

Source: https://1beton.info/maloetazhnoe/fundament/vyazka-armaturi-pod-lentochniy-fundament

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/