How to tie reinforcement correctly - Metals and their processing

How to knit reinforcement for the foundation correctly, what tools and materials are needed for tying reinforcement

It is important to reinforce a shallow strip foundation, since this compensates for the loads acting on it during the operation of the building. Concrete has great compressive strength, but shear loads or causing tension can easily destroy its structural integrity.

The resistance of concrete to tension is 50 times less than to compression. The use of reinforcement turns ordinary concrete into a completely new material, which allows the strip foundation to become very resistant to tension.

Therefore, it is important to determine what reinforcement is needed for a strip foundation and calculate it.

As you know, the foundation is the main component of any building. The service life, and, therefore, comfortable living in the house, largely depends on what it will be like. It is possible to build a reliable and comfortable house; the main thing is to know the rules for tying reinforcement when building the foundation for a house and not to violate it.

Everything is interconnected here. The foundation is the guarantor and basis of the safety of the entire building, and the frame made of reinforcement bars is the main component of the longevity and strength of the foundation. This allows the reinforced concrete base to be tightly bound.

Reinforcing iron bars have the function of resisting all tensile loads; they increase the forces of compression zones. Mounting fittings are also capable of fastening the working rods in the frame.

The main task of the reinforcement frame is to prevent deformation and cracking of concrete under the weight of the building, as well as the influence of soil heaving forces. This means that properly assembled reinforcement will prevent the destruction of the building itself and its foundation. From all of the above, it follows that the importance of not violating the foundation knitting technology is paramount.

Preparation for the process of tying reinforcement

It is worth noting right away that the independent knitting process is not easy; it is much easier if you have at least one assistant. In addition, another assistant is needed to lay and move the finished structure into its place. Before the mating process itself, you need to make some preparation for this operation:

determine what reinforcement is used for the strip foundation;
calculate the reinforcement for a strip foundation;
purchase and deliver materials to the construction site;
buy annealed wire with a diameter of 0.8−1 mm;
cut the reinforcement to the required sizes.

If you need to create a monolithic strip foundation, then it would be logical to prepare reinforcement boxes of a square shape in cross-section and with a side length of 350-400 mm. If dimensions allow, then the length of the boxes should be about 3 meters .

Typically, fittings in the construction market or warehouse are 3-6 meters long. For this reason, it will be easy to lay iron rods on the long sides of the boxes, but you will have to cut it into squares (350-400 mm).

In addition, you need to make a supply of cutting wheels, and also buy or rent an angle grinder (angle grinder).

Main tool

Among other things, it is very important to create a working tool for such a task as tying reinforcement - this is a hook. It can be made from a steel electrode or a trowel; it is also sold in a hardware store. The main thing is that the hook is made of very strong wire, and its bend is 90 degrees. The reinforcement is knitted from annealed low-carbon steel, so this wire will bend easily and will not break.

If the wire bends reluctantly, it should be held for about 30 minutes over an open fire and then cooled. You should not use very thick wire , since it is quite difficult to bend it, and thin wire will have to be folded in half. For the process of knitting reinforcement, a wire 30-40 cm long, which is bent in half, is perfect.

How to properly reinforce a foundation

Before you start creating reinforcement for a strip foundation, you need to calculate the actual loads of the building. This will answer the question of which reinforcement to use. It is important to choose the right diameter and install it in a certain step. For example, when reinforcing such a foundation for a garage, it is allowed to use reinforcement with a diameter of 12 mm, but a similar diameter is not suitable for a residential building.

Reinforcement is carried out so that the metal structures are located inside the base, but are no closer than 5 cm to the outer surface. The reinforcement scheme assumes that the reinforcement is placed as a frame, with the rods being laid in increments of 10-25 cm.

the method of fastening is important . It is best to connect the reinforcement with wire, since welding will make the metal thin in the weld area.

The reinforcement pattern can be horizontal or vertical . When using a vertical scheme, the reinforcement must be laid in pairs with a step of 30 cm, and with a horizontal scheme - with a step of 200 cm. It is very important to use a vertical scheme at the joints.

Reinforcement technology

For knitting, you need to use wooden formwork, securing glassine to its walls with a construction stapler. Glassine is needed to prevent the wood from absorbing moisture from the cement solution.
The upper level of filling the solution is indicated by a stretched fishing line.
Pieces of brick are laid at the bottom of the pit, so the reinforcement will be located 5 cm from the ground.
The reinforcement frame should retreat from the wall of the pit by the same 5 cm. This will allow the frame to be located completely inside the concrete. This increases the strength of the foundation.
It is best to reinforce a strip foundation with solid reinforcement without unnecessary connections.
The reinforced frame is assembled like this: metal rods are driven in around the perimeter of the entire base, and then the upper and lower belts are tied to them.

This work is done using a special hook and wire.
Concrete is poured in layers.
Each layer must be compacted with a special tamper so that eliminate voids.

If you want the reinforcement of your strip foundation to be of high quality and reliable , it is important to place the rods at an angle of 90 degrees to each other, having previously calculated the entire structure.

So, as you can see, the process of creating reinforcement is very important and will require some skills. But the main thing is to follow the technology (make calculations and use high-quality material) and adhere to the basic canons of tying reinforcement, which will certainly extend the life of the house.

Source: https://plita.guru/vidy/lentochniy/kak-pravilno-vyazat-armaturu-dlya-fundamenta.html

How to properly tie foundation reinforcement, necessary tools - Machine

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

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

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

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

Most home craftsmen prefer knitting.

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

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

What you need to knit reinforcement

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

The following requirements apply to the knitting wire:

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

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

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

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

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

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

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

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

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

Method number 3:

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

Method number 4:

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

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

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

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

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

Additional tools

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

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

These are the cross and dead knots.

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

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

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

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

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

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

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

Other methods of tying reinforcement

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

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

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

Plastic fasteners are not used for metal fittings.

Safety precautions when tying reinforcement

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

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

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

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

How to properly tie foundation reinforcement

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

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

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.
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.
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 knit 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.

Source: https://MyTooling.ru/instrumenty/kak-pravilno-svjazyvat-armaturu-dlja-fundamenta

Tying reinforcement for a strip foundation - performing the work correctly

The foundation part, built correctly, is considered one of the determining factors in the long operational period of the entire facility.

The strength indicator of this foundation depends on well-executed reinforcement, the main stage of which is considered to be tying reinforcement for the strip foundation.

If you carefully study the technological features of the work, prepare everything you need, then each of you will be able to arrange a power frame base. When a team of builders is involved in such types of work, you can monitor the correctness and quality of their actions.

The need to reinforce a strip foundation

The foundation structure is designed to withstand the load forces created by the object. It tolerates evenly distributed pressure best.

However, during practical operation, the load is often distributed unevenly, which creates internal stresses in the foundation. The reasons may be heaving of the soil composition, errors in design, resulting in different weights of individual structural elements.

Concrete has good resistance to axial compression and weaker resistance to tensile strength. Steel reinforcing bars are distinguished by their ductility and perfectly compensate for the indicated disadvantage of concrete mortar, creating protection for metal rods from corrosive formations.

During the operational period, a concrete monolith that resists compression and steel that resists tension can resist various loads with maximum effect, preventing the entire structure from collapsing.

Knitting reinforcement for a strip foundation can increase the strength indicator and help save financial resources - by reducing the volume of the foundation base, the cost of raw materials is reduced.

Knit reinforcement or weld

Knitting reinforcement for the foundation is performed using:

wire knitting material. The technology of this type of installation is reliable and popular. There are many options for tying with wire, but many prefer knotting;
threaded and crimp type couplings. Application possible in areas of mechanical joints;
steel clips. Metal rods are connected without making wire knots;
clamps and clamps made of plastic material. With such devices, installation work is carried out easily and quickly, the fasteners are resistant to corrosion. But not all builders approve of the use of such fasteners.

Many people ask the question: to knit or weld reinforcement for the foundation? The second method is faster, but there are certain compelling reasons to ignore it:

The reinforcing steel at the connection points overheats greatly. Metal loses up to fifty percent of its strength if it is processed by welding. This feature is very important when tying reinforcement for foundation corners, because in such places all the negative differences of this method most often appear;

if the fixation of the supporting elements is performed rigidly (by a welding unit), then the load forces on the frame base act unevenly. At the points of rigid couplings, stresses of an anomalous nature are created;
if a mistake is made during the assembly process, you will have to use new material for the frame;
Working with a welding machine requires special skills and the cost of paying for electrical energy.

So, is it possible to weld reinforcement for the foundation rather than knit it? There are situations when tying the foundation with reinforcement without welding is not carried out:

if the foundation contains embedded elements. Such parts are mounted at points where the maximum load on the concrete structure is expected. Embeds are welded onto the reinforcement skeleton to provoke a uniform redistribution of the load;
if there is a need to fix longitudinal connections. At the overlap points of the reinforcement, double layers are created that must be welded. The rods are not fastened end-to-end, since the sections will not be enough for a strong connection.

Materials and tools for tying reinforcement

Considering that the reinforcing belt imparts stability to the entire structure, absorbing a significant share of the load, a lot depends on its quality performance.

How to properly knit reinforcement for a strip foundation? It is generally accepted that steel rods are needed to create a frame base. Builders prefer to use the following types of reinforcing steel, divided into:

manufacturing materials. Iron bars are considered a classic option, repeatedly tested in practice. They are divided into six groups according to strength level; the material is bent and welded. Composite rods contain fibers of basalt, carbon, glass and aramid. This type of material is lighter in weight, reasonable in cost, does not rust, bend or be welded;
profiles. Smooth profile is more often used instead of jumpers for connections. Rod grease, which has a periodic profile, is distinguished by its relief, which improves adhesion to the solution.

For proper knitting you will need special tools. If you follow the rules of knitting, you can achieve a more reliable connection than welding. The strength indicator in the connecting nodes will not decrease, the help of an experienced welder is not required, all work is carried out directly in the formwork structure or in the immediate vicinity.

What is more convenient for knitting reinforcement? The frame is assembled manually or using appropriate tools.

Let's figure out how you can tie the reinforcement for the foundation. When carrying out such work you can use:

knitting gun. The fastest method. The device is inconvenient to work in hard-to-reach areas, and it also consumes large quantities of wire intended for knitting. The main disadvantage of the tool is its high cost. If you use Chinese-made devices, then one gun is enough for 1 base;
crochet for knitting. It resembles a curved and sharpened nail, which has a handle instead of a head. On the Internet you can find materials on how to knit reinforcement with a screwdriver, using such a hook as an attachment. Industrial-made screw hooks work effectively, but they slow down the process, leaving long tails;
folk remedies. For small working volumes and the absence of special tools, it is permissible to use pliers or a homemade hook prepared from a suitable nail. The quality of the work will not be the best; such a scheme for tying reinforcement for a strip foundation will not provide the required strength.

Structural rods are distinguished according to their purpose:

working rods. Longitudinal reinforcement elements located along the strip base;
clamps. There are transverse, vertical and horizontal, I connect the frame structure into one whole.

To know how to correctly knit reinforcement for the construction of a foundation for a private house, you need to know a certain scheme of work:

use composite or greasy rods with a diameter of 11 - 14 or 12 - 18 mm, a periodic type profile;
the rods are laid out with an overlap and connected by horizontal elements. For a shallow foundation, two layers of 2–4 rods are sufficient; in other structures, three layers are used. The gaps between the rods should not exceed thirty to forty centimeters;
vertical elements support the upper and lower layers, placing them in increments of forty to ninety centimeters. The load on them is small; material with a diameter of 6 – 11 mm is suitable for manufacturing;

protection against corrosion is provided. The frame must be completely filled with concrete; it must be separated from the upper edge of the formwork by at least six to eight centimeters. When laying the foundation for a private house, a hook is used to tie the reinforcement.

We already know how to knit reinforcement correctly. How much will it take to build a foundation? The volume of material is determined based on:

foundation dimensions;
diagram determining how to tie steel rods. It includes the number of layers and longitudinally located rods across the entire width.

Types of ties of various sections of the foundation

To build your own home you will have to be patient and attentive. Time and funding should not be saved, as troubles may arise during operation.

We know how to tie the reinforcement with our own hands along the length of the foundation tape. Everything is done quite simply, you just need to maintain the amount of overlap. But how to properly knit the corners of a foundation structure?

There are two ways to knit warp corners:

between a pair of structures located perpendicularly;
at the junction of two walls.

There are several technologies available to implement each option. When knitting sections at corners use:

hard paws. A rectangular foot similar to a poker is placed on the rod. The length of the bent section is determined by at least 35 diameter values or more. The bent parts of the rods are connected at the corner sections with “claws”;
L-shaped clamps are used. In principle, the actions resemble the previous version, but it is not the legs that are prepared, but L-shaped ends with a side of at least 50 rod diameters. One side is fixed to the wall frame, the second - to a perpendicular wall. The internal rods must be connected to the external ones. The clamps are arranged in increments equal to three quarters of the height of the basement walls;
use clamps in the shape of the letter “P”. A pair of elements are prepared for each corner, their sides are equal to 50 reinforcement diameters. The clamp is welded to a pair of rods located parallel and to one crossing them.

How is obtuse corners of the foundation strengthened? In such situations, the outer rods are bent to the required angle, with additional ones attached to them to strengthen the structure. The internal rods are connected to the external ones.

To lay reinforcement in areas where walls adjoin, almost the same methods are used - overlapping and both types of clamps.

Basic rules for performing reinforcement

So, why knit a frame and how to do it correctly? When performing such work, adhere to the following recommendations:

material of class A400 and higher is used as working rods;
Welding should not be used, as it makes the sections weak;
metal rods must be tied together in corner areas; welding is prohibited at these points;
clamps should not be made from smooth reinforcement;
in order for the metal to have reliable protection against corrosion, the protective layer of concrete on either side of the rod must be at least four centimeters;

longitudinally placed rods are fastened with an overlap of at least twenty sizes of their cross-section and equal to a length of 25 centimeters;
if reinforcing bars are placed frequently, it is necessary to control the size of the filling components of the concrete solution so that they do not settle among the bars, contributing to the formation of void areas.

Some people are interested in what will happen if they just put reinforcement in the foundation without a bond. Let's be honest - you should not experiment, because this will have a negative impact on the subsequent operation of the facility.

Source: https://betonov.com/fundament/lentochnyj/vyazka-armatury-pod-lentochnyj-fundament.html

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 properly knit reinforcement for a foundation: several options

Before you start knitting rods when creating a frame for the base of a building, many questions arise. How to knit reinforcement for the foundation correctly? Or is it better to use welding? It is necessary to understand this issue in detail.

Disadvantages of welding

First you need to remove all doubts about knitting using welding. There are advantages to choosing wire connection as the main method for attaching reinforcement to the foundation. But the welding method is much more dangerous, and more complicated, requiring equipment, special knowledge and design calculations.

For this method, you need to attract a specialist to the construction site and install electricity. This method is less reliable. To strengthen the foundation, the welder must go through several dozen connections, and he will not be able to check every seam. When a compound is heated, the metal becomes brittle and its chemical structure changes.

It becomes less bendable and stronger, which is precisely why reinforcement is installed in the base to withstand such loads.

For the frame, special marked reinforcement is used, marked “C” - this means that this class allows elements to be welded. Using welding, it is not always possible to reach the right places, so sometimes you have to switch to an alternative method. Wire knitting is much more efficient and convenient, and it costs several times less. Now we need to consider: how it is more convenient to tie the reinforcement, and what materials will be needed.

What to use for knitting?

The standard is to use baked steel wire. Some builders prefer galvanized ones; this will protect the structure from corrosion, but when pouring a foundation, this does not matter (it already seals the entire frame). If you purchased wire that has not been fired, then you will have to do it yourself. You need to make a fire, put the wire, it will glow red, then you just need to let it cool.

In shape, all rods should have a round cross-section; such wire is easier to knit. A suitable diameter is 1 or 2 mm, it depends on the load and the thickness of the reinforcement itself. If a strip foundation is used for the house, then you need to take a wire with a larger size. If you want to save money on buying wire, you can use old tires from a car, only a truck. In order to get the metal, you need to burn the tires.

Nowadays plastic clamps are used quite often; their functions are similar to metal, but they are also more expensive, but they save time.

What tool will you need?

You can use many tools to knit reinforcement; one of the simplest is a hook. This is not only the simplest, but also the most widely used method. You don’t have to buy a hook in a store; you can make it yourself. Although the method is simple, when you need to make a lot of knots, your hands get tired quickly.

There is another type of hook - semi-automatic. It is only supplemented with a spiral, thanks to which it rotates when the handle moves. You can also make an attachment for a drill, then the process will go even faster.

This method is often used for significant volumes of work, when knitting meshes, but it is not suitable for a strip base made of reinforced concrete.

You can purchase or rent a special pistol. This is a professional tool that knits joints with high quality. All tools except the last one are inexpensive and quite suitable for the job.

DIY knitting

How to tie reinforcement for a foundation correctly? The procedure itself is not as complicated as it might seem. After an hour of work, the hands themselves will remember all the actions, and the work will proceed automatically. For knitting you will need a 20 cm piece of wire; it needs to be bent in half, but not all the way. After this, it should be carried diagonally to the intersection of the two rods. The pieces of wire are connected, a hook is inserted, they need to be twisted clockwise several times until it stops.

Some people like to do the tying twice - crosswise, this is a completely useless activity, and more time and material are spent. A connection with similar strength may be needed when laying only a strip foundation.

Tying rules

When working, you must follow certain rules:

any strapping must provide the necessary level of fixation to the rods;
the main task is to immobilize the reinforcement and ensure the correct shape of the frame before pouring the foundation;
the reinforcement must be inside the base and not extend beyond it;
to protect the reinforcement from moisture, air and soil, a layer of stone, approximately 50 mm, is used;
if the height of the structure is large, it is better to use spacers; they will prevent the frame from touching the walls of the trench;
if the nodes are fastened with plastic clamps, you need to use pliers for a stronger connection;
plastic can be installed only before the onset of frost; it will not withstand negative temperatures.

These are the basic rules that should be followed when tying foundation reinforcement to ensure a reliable and durable connection.

Selection of fittings

The metal frame is made up of rods with a round cross-section. They can be smooth or ribbed, which provides better adhesion to the mixture. Such rods can be from 5 to 30 mm, usually 8 or 16 mm are used. Smooth rods are used for the transverse plane, and ribbed rods for the longitudinal line.

Fiberglass reinforcement consists of heat-resistant resin with fiberglass filler. Such fittings are easy to transport and tie. It is also made smooth or ribbed, it can withstand any load.

How to knit rods correctly?

What is a frame? This is a shell with cells; when poured with the mixture, concrete does not flow, there are no bubbles or the appearance of voids. If you want to assemble the frame correctly, you need to know how to tie the reinforcement. Here you need wire or clamps.

If transverse rods are used, pallets will also be required (they are installed immediately before starting work; you need to calculate the pitch of the cells in advance). You can install cup holders after installing the frame. The choice of window spacing depends on the building; it is taken from 150 to 350 mm. Sometimes a distance of up to 600mm is maintained. The longitudinal rods must be laid out on the selected segment and marked with a marker.

Next, the jumpers are attached at an angle of 90 degrees. These rods can also have a smooth surface. It is better to attach the jumpers from the bottom of the frame. All clamps are tightened tightly; the nodes should not diverge after pouring. First, the first row of the reinforcement mesh is laid out, then the remaining layers are applied. The corners need to be fastened especially well.

For such connections, you can buy ready-made parts or knit them manually.

It is strictly forbidden to cook corners. The rods can be fastened together with wire or clamps. Wire knitting is, of course, more difficult, but it is also used more often, providing the required structural strength. There is another option - this is knitting reinforcement by spot welding, which is quite difficult and time-consuming. It is used mainly for mounting rods with a diameter of 24 mm.

Knitting metal rods

It is worth considering the basic steps when knitting metal structures:

Take a wire 1.5 mm in diameter and a hook or pliers. Such a tool is required for high-quality fastening of elements. You can also choose a screwdriver or a drill with a special attachment. A hook made independently or purchased in a store is used as a nozzle.
The rods are attached using the same principle as fiberglass. To avoid jumpers sticking out of the ground, you need to lay plastic pallets. It is very important to carry out the correct binding; this affects not only the quality of the foundation as a whole, but also the strength of the building in the future.
To connect the frame, you need to take a piece of wire 25-30 cm (it must be pre-burnt), wrap it around two rods to make a loop.
A hook is inserted into it and scrolled clockwise to the end. The basic rule is not to twist the connection too much, the wire may break and the procedure will have to be repeated again.
Knitting corners is carried out according to general rules, but there is a nuance - the bend of the rods is at a right angle. But a too even angle is also not desirable, so they must be rounded using a reinforcement bending machine.

As you can see, there are many nuances in knitting reinforcement for the foundation, but correct execution of all stages of work will allow you to quickly and reliably create a metal frame, thereby strengthening the foundation for the building. If you have a question about how to properly knit reinforcement for the foundation, the video will help in this difficult task. Fortunately, today there are enough such videos.

Source: https://profundamenti.ru/armirovanie/kak-pravilno-vyazat-armaturu-dlya-fundamenta-neskolko-variantov.html

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 tie foundation reinforcement