Why do they knit reinforcement for the foundation?
A high-quality mesh of reinforcement allows you to maintain a certain geometric shape of the foundation when pouring concrete. Cooking it is not recommended due to disturbances in iron crystals. Regardless of how large-scale the building you are constructing, reinforcement for the foundation is an integral element. Now there are many ways to knit reinforcement for the foundation. You can do this yourself.
During construction, due attention must be paid to the foundation. A reliable foundation can withstand the enormous weight of the future building, so it needs to be reinforced with reinforcement. The strip foundation is laid along the perimeter of the building. Such a base can be chosen for any type of structure.
Strip foundation when building a house
There are four main types of foundation masonry (base, base):
- trapezoidal;
- pillow;
- stepped;
- rectangular.
The best option is a trapezoidal shape, as it better withstands the enormous load on the base. It is necessary to accurately calculate the inclination of the side face to the vertical. For a foundation made of stone or brick, it should be no more than 30°. If the base is concrete, then the angle should not exceed 45°.
What kind of reinforcement is used to knit the frame?
There are two main types of reinforcement - metal and composite. Diameter is the main indicator that determines its brand. The thicker the rods, the greater the load they can withstand. The diameter is calculated at the design stage, taking into account the mass of the future building, as well as the heaving of the soil.
When constructing a building made of concrete or brick, which is massive, the use of thick rods is required. They can handle the enormous weight of the structure. When laying the foundation, it is prohibited to use rods with a diameter of less than 12 mm - they will not withstand such a load. When building small houses and garages from gas, foam and heat blocks, you can use less thick reinforcement; rods with a diameter of 12 mm are sufficient.
Metal reinforcement for the foundation
When constructing massive structures, class A-3 is used. Rods of this brand can bend up to 90°. Much less commonly, class A-2 is used for laying foundations. When cold they can bend up to 180°.
Metal fittings
The most common type of pipe used when laying a foundation is metal reinforcement. Rods of different cross-sectional diameters are available for sale - from 12 to 40 mm. They are widely used in construction, in particular, for laying foundations for large, heavy buildings.
The cost of a product directly depends on its characteristics, namely:
- rental method,
- steel grades,
- surfaces (corrugated or smooth).
Rods with a corrugated surface have a higher price. This type has stiffening ribs, which allows the products to better adhere to concrete.
Metal fittings
Composite reinforcement refers to non-metallic rods made of different materials used in construction. For more effective adhesion to concrete, the surface of the rods is made rough or covered with sand.
The most common types of composite reinforcement:
- carbon fiber;
- basalt plastic (BBP);
- fiberglass (FRP).
Accordingly, reinforcement is produced from materials: carbon fiber is used in the production of carbon fiber reinforcement, basalt fiber is used for the production of ABP, and glass is used for ASP. They have many advantages: corrosion resistance, high specific strength, and environmental friendliness.
Schemes for distribution of reinforcement in the structure of a strip foundation frame
The optimal scheme is considered to be one in which the cross-section of the reinforcement in a strip foundation will be a rectangle. Two forces act on the base at once: the first is heaving during frost, the second is the pressure of the house. What kind of reinforcement is used for a strip foundation to compensate for these two forces?
Composite reinforcement
The material does not play a major role here. To compensate for the influence of these two forces, two reinforcement belts are installed. The first is located at the top, the second at the bottom. If the foundation is laid shallow (up to 1 meter), then this is quite enough. For a foundation that is laid deeper, a third reinforcement belt is required. High altitudes require reinforcement.
Four main patterns of tying reinforcement for strip foundations are used. Regardless of the chosen method, first of all you need to make a hook from wire, the diameter of which should be 3-4 mm. You can knit the reinforcement with wire yourself.
Wire for tying reinforcement cage
The most reliable way to knit a reinforcement cage is using wire. A less successful alternative is the use of a welding machine. The tying of the base reinforcement frame can be carried out using ordinary metal wire or wire processed by firing. The second option is preferable - thermally hardened wire becomes more flexible and durable.
Wire for tying reinforcement cage
Calculator for calculating the amount of wire for tying the reinforcement cage of a strip foundation
It is not enough to know how to knit reinforcement correctly; you also need to carry out calculations. To do this, it is necessary to take into account the following indicators:
- indentations between clamps;
- number of longitudinal reinforcement rods;
- base length;
- double sealing of corners.
A modern calculator, which you can use online, will allow you not only to determine the amount of wire for tying the frame under the foundation, but also calculate the approximate number of joints.
A reliable frame is an important element of the foundation and the building as a whole. To strengthen it, you need to use certain tools. Depending on the choice of method - manual or automatic, special devices are selected and used.
Such tools include:
- manual or semi-automatic hook;
- automatic pistol.
Hand hook for wire tying
Using these tools, you can tie reinforcement under a strip foundation. An automatic pistol is used in professional construction, as its cost is quite high. For the construction of one building, the purchase of this device is considered inappropriate. For independent work, a regular hook for tying reinforcement is suitable.
Techniques for tying reinforcement
At the moment there are four main techniques. The most convenient and fastest way is to take the wire, fold it in half and pass it under a certain area of the frame. Armed with a hook, thread the wire into the loop, pull up its free end and throw it over the hook, while bending the wire slightly. We twist the ends, after several turns (3-5) we stop the manipulation, removing the hook.
The next technique is similar to the previous knitting method. The main difference is the formation of an O-shaped loop. After the wire is twisted securely, the hook is removed.
Algorithm for the third pattern of tying reinforcement for a strip foundation:
- we put the wire under the rods;
- insert the hook into the loop and pry up the end of the wire;
- bend it back and pull it towards you;
- scroll several times.
Techniques for tying reinforcement
According to experts, this is the most convenient technique for beginners.
There is another way to knit reinforcement for the foundation. As usual, you need to fold the wire in half and place it under the rods. After this, press it against the rod and bend the ends towards you. Insert the hook and make a few turns.
Using additional parts for spatial fixation of reinforcement
When knitting the frame, it is necessary to use additional elements. These include “frogs”, U- and L-shaped elements, clamps, and fasteners. They allow you to fix the reinforcement and its corners.
It is worth saying a few words about clamps. These are bent products in the shape of a rectangle. They are made from rods with a smooth or grooved surface. Clamps are used to distribute the load.
Knitting fiberglass reinforcement
To tie fiberglass reinforcement, wire or special plastic clamps are used. The first method is no different from knitting a standard (metal) frame. Clamps are an excellent choice for those who are new to tying reinforcement. The cost of the products is not much higher than ordinary wire. A hook or gun is also used for reinforcement.
Knitting fiberglass reinforcement
Recommendations
How to reinforce aerated concrete masonry to prevent cracks from appearing? To do this, it is necessary to correctly select the density and strength of the reinforcement. Also, the reinforcement process itself must be carried out in compliance with all requirements.
Reinforcement of brick walls is divided into three types:
- Longitudinal.
- Transverse.
- Vertical.
Proper reinforcement of walls and corners will allow you to strengthen your structure as much as possible.
The grillage reinforcement is carried out strictly according to the design. Despite the fact that it is similar to a strip foundation, the laying technology is significantly different.
Fiberglass reinforcement is quite strong, lightweight, and practically does not corrode. However, it has significant disadvantages, including low elasticity and heat resistance, a decrease in strength over time, and instability to alkalis.
Many people ask the question: is a mesh needed for floor screed? Yes, I need it. It allows you to make the floor smooth and more durable.
Coupled rebar connection is another type you may encounter. This is a separate method of connecting rods. It can be crimped or threaded. This connection allows you to withstand loads on the base.
Source: https://pobetony.expert/armirovanie/vyazat-armaturu-dlya-fundamenta
How to 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);
In the case of reinforcement of a columnar foundation, the reinforcement cage can be bent and then fixed to the heads with special clamps. Some manufacturers already supply metal or wooden piles with special clamping brackets and couplings.
In this case, it is enough to bend the rod and insert it into the bracket. Clamp the bracket and boil it on top; you can do all this yourself, using a minimum of tools.
In the case of using smooth reinforcement, the tying process is more labor-intensive, since the hooks will constantly bend and cannot be done without a specialized tool at hand, as well as without outside help.
It is better to knit the reinforcement cage for a slab monolithic foundation from several belts. For the horizontal tier, spiral rods with a cross-section of up to 16 mm are used, and for vertical links, smooth rods with a cross-section of up to 10 mm are used. When installing the lower mesh, it is recommended to use plastic expansion joints, which will create a uniform pitch. Then, when knitting vertical rods, it is important not to forget to take them outside the foundation, due to the fact that load-bearing walls will be connected to them.
Using plastic ties for knitting is a more expensive option for replacing wire, but clamps (ties) can be found in any household. The principle of tying is similar, but the plastic for the ties is less durable. Therefore, it is better not to use force during installation.
The most popular clamps have a special core at the end of the tie; they are used to secure cables and pipes to vertical surfaces. Plastic showed excellent results when knitting with your own hands in warm weather; in cold weather it quickly loses its elasticity and bursts.
Source: https://crast.ru/instrumenty/kak-svjazyvajut-armaturu-dlja-fundamenta
Methods for tying reinforcement for foundations
A strong and high-quality reinforcing mesh is needed to maintain the spatial shape of the foundation when it is poured. Therefore, you cannot cook it - otherwise, as experts explain, “the iron crystal is damaged.” And it doesn’t matter whether a large building or a compact bathhouse is being built, only tying reinforcement for the foundation is possible, and of high quality and with the right material.
But today there are quite a lot of ways to knit reinforcement. But, in general, most often it looks like this: the network is knitted in sections outside the trench, and then these sections are simply tied to each other. You can, of course, knit at the bottom of the trench, but for this the reinforcement must be secured in advance. After all, the main thing is that it does not sink to the bottom of the trench - and for this, experienced builders use special holders (sold on the market).
What to knit with? Tie wire VS plastic clamps
What is better for tying reinforcement: regular wire or fashionable plastic clamps? Let's figure it out together.
Steel wire: where to get it and how to make it yourself
Foundation binding wire is made from annealed low carbon steel. It is soft to bend and easy to use. The color is white - galvanized - and black, without any coating. By the way, interestingly, many craftsmen consider beautiful galvanized wire to be used for a foundation as a real excess - after all, there is no access to oxygen in concrete, and therefore there can be no corrosion.
Expert advice: if you suddenly bought a knitting wire in a store, but it doesn’t bend well, you don’t have to return it - just warm it up in a fire for half an hour and then cool it in the air.
What diameter should I use for wire? Experienced builders say that the most convenient and durable option is 1.2-1.4 mm. A two takes a lot of effort, but a one is too weak.
Here's how you can get hold of tying wire for a foundation. We take an old truck tire and burn it. This tire contains metal cord - it is this that is used in the new quality. The only point: tires from imported trucks may contain synthetics instead of metal. This is easy to check: use a knife to cut through the inner side, the one adjacent to the rim. Did the knife hit the metal? So, the wire will work. Didn't resist? Then the tire will simply burn in the fire, and that’s it.
Plastic clamps: pros and cons
Most builders look at the recently introduced plastic clamps with some apprehension - will they then withstand the load in the foundation? Won't they break? How reliable are they really?
And the advantages of this material, of course, are pleasing: the simplicity and speed of tying, the cost is not much more expensive than tying wire.
And the most popular in this regard today are plastic clamps with a heart made of steel wire. They are used for attaching pipes for cables to fences, and when installing perimeter security systems. They are more expensive, but they are especially convenient to use.
Another point that not everyone knows about: the foundation tied with plastic clamps cannot be left in the winter. From frost they immediately become brittle and burst.
How to knit? 4 most popular ways
A simple simple hook for tying reinforcement can be made from wire 3-4 mm in diameter - for example, from an electrode for electric arc welding. Of course, they won’t be able to knit quickly, but it’s quite tolerable. But let’s share this trick: make a nail attachment for a screwdriver - in the shape of a hook, like on a clothes hanger, and use it to tie around the reinforcement. This way everything will work out twice as fast, and your hands will get tired much less.
And the essence of the technology, how to properly knit foundation reinforcement, is simple. We place two rows of wire pendicularly.
Next, we use a homemade machine, where the reinforcement is clamped with boards and we knit it manually, or we use a gun for tying reinforcement, which can be purchased at a construction supermarket.
The main thing is that the rods do not sink to the bottom of the foundation, and to do this we either lay a brick or stick the ends of the mesh directly into the soil. Next, there are differences in how and where to bend the wire itself. Choose the method with which tying reinforcement will be more convenient for you!
Method No. 1
Here's how to knit foundation wire by hand:
- Step 1. Take the wire in your hands and fold it in half.
- Step 2. Bend around your finger about one-third of the way through the loop.
- Step 3. Now we put it on the reinforcement and insert the hook into the loop.
- Step 4. Turn the hook and grab the second end of the wire with it, pull the other end of the wire toward you.
- Step 5. Take out the hook and bend the ends. If they turn out to be long, cut them off.
How many revolutions will need to be made will be determined practically. If there is too little, the harness will be weak; if too much, the wire will break. Usually - from three to five turns.
How to knit reinforcement. Option 1
Method No. 2
Work order:
- Step 1. In this version, the wire is also folded in half.
- Step 2. Press it with your fingers to the rod and bend the ends towards you.
- Step 3. Insert the hook, twist, remove and bend the ends.
Here the wire holds much better and more reliably.
Expert advice: the most common mistake when tying reinforcement is long twists. To prevent this from happening, you just need to bend the wire before rotating the hook - so that it has time to make 3-4 turns.
Method No. 3
Work order:
- Step 1. Take a piece of wire and fold it in half.
- Step 2. Start from below.
- Step 3. Grab the loop with the hook.
- Step 4. Bend the remaining “tail” over the hook.
- Step 5. Twist the resulting loop.
How to knit reinforcement. Option 3.
Method No. 4
- But, according to reviews, the most convenient way to knit wire on reinforcement with your own hands:
- Step 1. Insert the hook into the loop and grab the other end with it - the one that you hold with your hand.
- Step 2. At the same time, bend the wire down through the hook.
- Step 3. Pull the hook towards you and twist it several times. That's all!
This method has a fairly significant advantage - the left hand remains free and you can use it to hold the reinforcement, which is very convenient.
We knit reinforcement with special guns
And they come in a wide variety - electric and battery-powered, from a variety of manufacturers. The Japanese were the first to come up with such a miracle of technology - thanks to their device, the wire on one node is twisted within a second and strictly within a certain tension force: not weakly, but not so much that it breaks.
How to knit reinforcement
There's just one problem: these pistols are very expensive. And here Russian craftsmen get out of the situation as best they can: someone buys and then resells a pistol, someone prefers a cheap Chinese counterfeit (enough for one foundation), and someone is looking for an opportunity to rent such a pistol - and In fact, such a possibility exists.
But it doesn’t matter which method or tool you choose - the main thing is that the reinforcement is connected conscientiously. Then the foundation under the bathhouse will delight you for many years with its strength and the absence of any cracks.
Source: https://stroy-bloks.ru/sposoby-vyazki-armatury-dlya-fundamenta/
Some features of connecting the reinforcement cage for the foundation
The foundation is the support of any structure , but it also has its own elements that give strength. We are talking about a reinforcement frame that runs inside any concrete structure. Building a concrete foundation with your own hands is quite simple, but not everyone knows how to properly knit reinforcement for a strip foundation.
It is worth noting that there are quite a few different types of foundations, for the construction of which pouring concrete is used. But if the concrete solution is approximately the same for all types, then the reinforcement frame and its piping can be fundamentally different from each other .
The easiest to manufacture is a strip foundation. In addition to a reliable foundation for the house, this foundation requires a minimum of time, effort, and financial investments to create . The only significant drawback of this design is its subsidence during operation. To avoid deformation or delay its manifestation as much as possible, it is necessary to create the highest quality frame from reinforcement.
Features of strip foundation reinforcement
Unlike any other type, in a strip foundation the maximum overloads occur not on the concrete base , but on the reinforcement frame. This is due to the fact that the deformation of the foundation occurs as a punching type. Accordingly, tying reinforcement for a strip foundation is most important in the upper and lower layers. In the middle, when pushing, the concrete compresses, and the compression performance of concrete is more than good.
Properly selected fittings play an important role in this process .
All types of fittings are marked with a special designation and help determine the choice, so marking with a large letter “K” indicates that the fittings are coated with a special anti-corrosion compound.
This is not a particularly important aspect for the reinforcement that is used in the foundation frame, since it is completely filled with concrete. A more relevant marking with the letter “C” indicates that the reinforcement can be welded, and not just tied with wire.
Low-quality reinforcement is not marked in principle, but for the foundation you should not skimp on this element, since the strength and elasticity of the entire structure as a whole, as well as the operational life of the future construction, depend on it.
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Elements necessary for foundation reinforcement
When answering the question of how to properly knit reinforcement for a strip foundation, it is important to determine the list of necessary materials and tools for this process.
- The most important thing is the fittings ; they are usually sold in lengths of 3 and 6 meters. The cross-sectional dimensions, as well as the length of the reinforcing bar, are determined by the individual characteristics of the future foundation. The minimum diameter of the reinforcement is 10-12 mm; this material is used to create small buildings such as garages and sheds.
- Binding wire . It is selected from a metal with a low carbon content; in addition, to give greater elasticity, such wire is calcined over fire. It should not be too thick, as it will be difficult to bend. At the same time, too thin a wire will not provide sufficient strength and will have to be folded in several layers, which will significantly complicate the work. If the wire is difficult to bend, it can be heated again over the fire for 20-30 minutes.
- Strapping hook . This simple device can be bought at almost any hardware store; in addition, you can make it yourself from strong, inflexible wire or from the handle of an old trowel or spatula.
- Grinder with a set of cutting discs for cutting reinforcement.
In order to properly prepare the frame for pouring the foundation, the strength and efforts of one person will not be enough; you need at least one more assistant who will hold the entire structure while individual elements are tied together. Ideally, the tying of reinforcement for a strip foundation is carried out by three people. The third assistant will be especially necessary when transferring finished structures into the formwork boxes.
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Main stages, methods and rules of reinforcement
In order to understand how to properly knit reinforcement for the foundation, you need to determine the loads that it will experience . The thickness and dimensions of the entire foundation directly depend on this.
The reinforcement can be tied in three ways:
- Welding . If you have a welding machine and some experience, the process of tying the reinforcement is simplified, but the quality of such a frame is an order of magnitude worse, since at the welding points the metal becomes thinner, and therefore becomes more fragile. Such a connection is not able to withstand long-term mechanical and physical loads, especially if they are associated with vibration.
- Overlap . The individual elements of the reinforcement are joined not across, but lengthwise, with the individual ends extending at least 10-15 cm, which are subsequently wrapped with wire.
- Wire knitting is the most effective way to create a reliable frame. This method allows you to create almost any shape with an unlimited number of angles. It is important to observe the geometry of the corners when joining all the elements and try to make them as straight as possible (at 90 degrees).
When constructing small buildings, instead of wire, you can use plastic clamps , which are used to tighten reinforcement joints. This option is no worse than a wire connection, the only thing is that it is less resistant to loads and is less resistant to critical temperature changes. Frost causes plastic to become brittle and may burst.
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Strapping process
To assemble the frame, you need to calculate the dimensions of the formwork . Ideally, the frame is woven so that 5 cm above and below does not reach the edge of the formwork. It is placed in the box on brick fragments, and the upper edge of the fill is marked on the formwork. Modern hardware stores offer special plastic expansion joints, on which the finished structure can also be laid.
The pattern of tying reinforcement depends on the formwork that needs to be poured. In the process of connecting individual elements, reinforcement bars are placed at an angle of 90 degrees and connected with a piece of wire .
For one harness, take approximately 20-30 cm of wire , which is folded in half to form a loop at the end. The loose ends are passed through the loop and tightened, thereby forming a knot.
The remaining wire is wrapped around the joint, or after securing the knot well, the excess is cut off.
A crochet hook is necessary for pulling the wire out of the loop; without it, your hands quickly get tired, and in addition there is a risk of injury.
In addition to the hook, you can use more modern automatic equipment, however, a tying gun is quite expensive, and it is not profitable to buy it at once, but you can look for stores that rent equipment.
The strength of the foundation depends on the integrity of the reinforcement when knitting the frame.
Therefore, it is important to calculate the maximum straight length of the foundation and, based on this, select individual rods. If necessary, branches are drawn vertically upward from the main frame for the foundation in order to attach the walls of the house to them in the future.
Vertical branches are knitted using the same technology as the frame for the foundation, and then laid out at least in each of the corners of the future building. Ideally, the vertical parts of the structure are placed under window openings, as well as in the middle of blank walls.
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Adviсe
In addition to knowledge of how to properly knit reinforcement for a strip foundation, a few more secrets that not all professional craftsmen are told about can be useful. In particular these are:
When laying a frame made of reinforcement, it must be thoroughly cleaned with a wire brush to remove dirt and possible rust deposits. Otherwise, the adhesion of the metal frame to the concrete mortar is not guaranteed.
If you need to bend a long reinforcing rod, you only need to use a hammer, as well as a rectangular shape along which the rod will be bent.
To create a horizontal frame, reinforcement with a ribbed surface is used, and for vertical structures, smooth rods are better suited, along which the poured concrete flows down without any problems without leaving voids with small air bubbles.
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Conclusion
In general, tying reinforcement to create a frame for a concrete strip foundation is a very simple process that anyone can do, especially if you need to make a frame that is simple in terms of geometry. It is worth noting that the cost of such work from professionals is estimated at very little money. Sometimes, it is even more expedient to pay for tying reinforcement for the foundation than to waste your own time, given the need for the help of several people.
Source: http://dachaorg.ru/vyazka-armaturi-dlya-lentochnogo.php
How to tie reinforcement for a foundation?
Reinforcement cage indicating strapping locations
In all modern foundations, construction is not complete without the use of reinforcement - interconnected metal rods that absorb tensile stresses when used in conjunction with concrete. The frame creates vertical and horizontal belts, serves to increase the strength of the structure and uniformly distribute loads.
If the reinforcement is weakly or incorrectly connected, it will creep apart, thereby compromising the integrity of the foundation. This will lead to its slow destruction. Tying the rods together is quite simple, but highly specialized specialists know well how to properly knit reinforcement for the foundation.
The frame connection scheme is almost the same for all types of foundations, except for columnar wooden or metal ones, where a frame is formed on top of the pile head using reinforcement or beams.
They are connected to the head and welded, in which case the rods or wire rod have to be bent at a specific angle.
Tying reinforcement for the foundation according to all the rules
Sketch of the technology for correctly creating connections between reinforcing bars and crocheting
It is quite possible to knit reinforcement using available materials. But it is worth noting that correctly tying the rods together does not guarantee compliance with all building codes and high-quality installation. Since the pattern of knitting the frame depends on the type of foundation, its size, thickness and type of material used. Therefore, you need to take into account several key rules:
- If mesh is used as a reinforcement frame, then the strapping must be overlapped.
- Taking into account the type and cross-section of the reinforcement, it is necessary to calculate the length of the bypass at the connection points.
- The rods must be bent strictly at a certain angle and evenly.
- The grade of concrete and working conditions at the joint are taken into account. The minimum overlap length is at least 25 cm.
If reinforcement is carried out at a height of 3 meters or more, then scaffolding or scaffolding is indispensable. The strapping technology turns out to be more complex, due to existing safety rules for working at height. Tying is carried out in three stages:
- First prepare the reinforcement and tie slings to it.
- Raise to the required height, level and place in plastic guides.
- Tie the rods using any of the listed technologies.
Work at height should be carried out only with several workers at a time, provide insurance and control the process of lifting the rods and then installing them in the specified places. Doing this yourself without insurance is strictly prohibited.
The cost of strapping is relatively low, since craftsmen can process several square meters of frame in an hour. And when using special knitting tools, it’s even faster. And they guarantee the quality of the knitting of the rods and compliance with all construction standards, especially since the rods will be bent with special pliers.
instructions
Source: http://hopper-time.ru/kak-delat-obvyazku-armatury-dlya-fundamenta/
Tying the reinforcement of a strip foundation - Do-it-yourself foundation
The foundation is the main part of any house. Its service life, and therefore the comfortable living of its residents, largely depends on what the foundation will be. You can build a strong and reliable house only by knowing how to tie reinforcement when constructing the foundation of a building.
Why do you need a metal frame?
Everything is interconnected. The foundation serves as the basis and guarantor of the safety of the structure, and the frame made of reinforcing bars is the main component of the strength and longevity of the foundation. It connects its elements to a reinforced concrete base.
Iron rods of working reinforcement perform the function of resisting tensile loads and increasing the forces of compression zones. Mounting reinforcement fastens the working rods of the frame.
the task of the reinforcement frame is to prevent cracking and deformation of concrete under the weight of the structure and the influence of soil heaving forces, and this means preventing the destruction of the foundation and building. From what was written above it follows that the question of how to knit reinforcement for the foundation is not at all idle.
What types of fittings are there and what are they made from?
What is a reinforcing bar for a foundation? These are metal rods, the length of which is 6 meters or more, with a cross-section of 6 mm. The size of the cross-section of the reinforcement rods determines its strength - the larger it is, the stronger the frame.
The rods can be smooth or have ribs, edges, and various notches. They strengthen the connection of metal with concrete mortar. With a smooth rod it is half as much as with a grooved one.
When constructing buildings that require a super-strong foundation, rigid frames consisting of channels or metal corners are ideal.
Connection of reinforcing bars
To ensure that the reinforcement bars do not change the size of the fastening step calculated according to the technology, they are fixed to each other.
The tying of the reinforcement rods is done by hand knitting or by welding. The question of how to knit the reinforcement for the foundation is one of the fundamental ones when constructing the foundation of a building.
Electric welding
This method is the main one for connecting reinforcement bars, although it has a number of serious disadvantages:
When exposed to high welding temperatures, the strength of the reinforcing bar decreases.
When pouring concrete mortar and compacting it, there is a risk of breaking welded joints.
When constructing large projects, it will be necessary to hire the required number of welders with certain experience.
Manual strapping
Knitting reinforcement for the foundation is also possible manually. It is carried out with steel wire having a diameter of 0.8-1.2 mm.
Tying with pliers
The most affordable way. With a wire folded in half, at the point of intersection of the rods, tighten their connection using pliers. Then its ends are fixed.
Knitting with a screwdriver or crochet
There are two main methods of knitting: overlapped joints using one loop and joints using two loops. In practice, all connections are knitted using one loop. The loop attracts with its simplicity and reliability, as well as the ability to learn this method within a short period of time.
How to knit reinforcement with a special crochet is written below. The wire is folded in half, its loop is put on the hook, the ends of the contact point of the rods are fixed, then they are laid on the hook. When it rotates, the wire twists.
The hook rotates manually. To speed up work, it can be inserted into a screwdriver chuck. When it is turned on, the hook begins to rotate and twist the wire.
Tying reinforcement bars with clamps and staples
Reinforcement rods can be tied with staples made from round wire. The work is done by hand, but this method has a number of advantages:
Compared to hand knitting, the speed of work is increased by 3 times.
High stable connection density.
The work can be performed by any untrained person after a short study of the process.
Simple calculation of the required material.
Tying reinforcement using plastic clamps has worked well. These methods are used in the construction of foundations for cottages, country houses, and bathhouses. Here is the answer for dacha developers to the question of how to knit reinforcement for the foundation.
Tying with a knitting gun
On large construction sites, knitting guns are used to speed up and facilitate work.
The gun is aimed and installed in the desired location, the button is pressed, and the reinforcement bars are automatically knitted with maximum density. There are battery-powered devices, and there are mechanical ones. The wire in both is supplied from a reel, which is changed at the end of the reel.
Advantages of working with a pistol:
Ease and convenience in work.
The connection occurs in 1-2 seconds.
There is no waste of knitting wire.
There are also certain disadvantages when working with a pistol:
The overall construction costs increase due to the high price of the gun and consumables for it.
Requires a trained person to operate the gun.
Impossibility of using the tool in hard-to-reach places of the frame.
How to use different strapping methods
How to knit reinforcement so that the base frame is strong and reliable? If rods with a diameter of no more than 25 mm are used to reinforce the foundation, they are fastened using wire, staples or spot welding. Arc welding is used if the diameter of the rods exceeds 25 mm.
How to knit strip foundation reinforcement? Very simple. Where the reinforcement bars form an angle of 90° with each other, they are wrapped around them with wire and twisted using wire cutters. Where the rods overlap each other, they are twisted with wire in three places.
It is better to knit the frame for the strip base in place, since the wire can stretch under mechanical stress. At least 50% of reinforcing bar intersections must be connected. Properly performed work guarantees the durability and strength of the strip foundation.
Slab reinforcement
How to knit reinforcement for a slab so that it can withstand all the loads acting on it (and there are several of them, and they are directed along and across it)? The slab may be subject to torsional loads. They press on her in different directions.
To prevent fracture of the rod or divergence of the connection, it is better not to use welding. Therefore, it is necessary to connect reinforcing bars using wire. The rods are tied with double wire at the junction and tightened with pliers or a crochet hook.
You already know how to knit reinforcement for the foundation. Which method is better to choose?
Cook or knit reinforcement?
Fittings are a set of parts connected to each other. Together with concrete, it is used in all reinforced concrete buildings.
Still, more often than not, reinforcement bars are knitted rather than welded. Welding leads to a change in the composition of the steel, and this weakens the joints of the reinforcement rods. In large-scale work, welding connections lengthen the completion time of the task compared to mechanical bonding.
An experienced welder is required to perform welding work. A young worker who does not have the necessary skills can only cause harm.
Mechanical tying is a simple method of connecting reinforcement bars to each other. The worker performing this task does not require special skills. Both knitting and welding perform the same function, but the result is achieved in different ways.
The main thing is that after tying or welding the joints and pouring the concrete solution, the reinforcement bars remain in their proper places. Their presence does not increase the strength of the foundation; it is ensured by the integrity of the concrete base, but here the reinforcement plays an important role.
How to knit reinforcement for the foundation so that it ensures the integrity and longevity of the foundation of the building is written in this article. Each developer decides which method to use independently. The main thing is to adhere to all the rules and recommendations and strictly follow them. The result is a strong and reliable reinforced concrete foundation.
Source: https://postroifundament.ru/obvyazka-armaturyi-lentochnogo-fundamenta.html
Tying the strip foundation reinforcement
The foundation is the main part of any home. Its service life, and therefore the comfortable living of its residents, largely depends on what the foundation will be. You can build a strong and reliable house only by knowing how to tie reinforcement when constructing the foundation of a building.
How to crochet reinforcement and other methods?
When performing work on pouring concrete foundations, builders are faced with the need to prepare a metal frame to ensure the strength of the structure. You can form a mesh from reinforcing bars in various ways:
- tying frame elements using wire with a hook, a screwdriver or a knitting gun;
- welding reinforcement together;
- securing the rods together using plastic clamps.
There is no single correct option. In practice, all methods are used, and the choice depends on the material used and the conditions at the construction site.
To understand in which case it is better to use one or another method, you should consider the positive and negative features of each.
Crochet
Crocheting reinforcement (you can read about how to do it here) has the following advantages:
- high speed of operation. With some skill, the specialist quickly tightens the knots with a hand tool at the junction of the rods. Such work is not difficult even for beginners;
- ease of repairing defects. Incorrectly applied wire can be easily untwisted or torn with wire cutters. The welding seam cannot be redone so easily - you will have to saw the joint with an angle grinder;
- You don’t need to have much experience to tie reinforcement. A novice builder quickly learns this simple procedure and after fifty knots can be considered a professional;
- You can tie the rods into a frame immediately inside the formwork;
- Labor and material costs are not high.
The disadvantages of crocheting reinforcement include the unsteadiness of the assembled frame. This problem arises when it is necessary to transfer the frame from the assembly site to the formwork. Dealing with this shortcoming is simple:
- in the case of conventional metal reinforcement, it is recommended to strengthen the connections by welding in several places;
- when using fiberglass products, install several braces around the perimeter. They will help give additional strength to the mesh.
In practice, this problem is solved simply - they knit the frame directly in the formwork so that it does not have to be moved.
In addition to a manual hook for tying reinforcement, a semi-automatic hook is also used. This device helps you get the job done much faster. A semi-automatic machine is a mechanism equipped with a reversible screw base. If the handle is pulled back, the screw begins to rotate, pulling the wire onto the joint.
You can see how to use a semi-automatic crochet hook for tying reinforcement cages in the video below. You have to get used to using such a tool, but professional workers manage to tighten the knot on the connection in one movement, which noticeably speeds up the whole process.
Welding
The technology of welding reinforcement is used in the construction of monolithic foundations for multi-story buildings. Previously, this method was considered the most reliable, but in modern conditions other methods of connecting rods are more often used.
The disadvantages of the welded method include:
- the need to involve a professional welder in the work. Paying a specialist automatically increases the estimated cost of the facility;
- the point of connection of two reinforcing bars weakens the overall strength of the structure and is a weak point;
- It is impossible to connect fiberglass reinforcement by welding;
- the most popular brand of rods for frame assembly (A-400) is not suitable for this method. You will have to order A500C brand rods separately.
Source: https://DomZastroika.ru/foundation/kak-vyazat-armaturu-dlya-fundamenta-kryuchkom.html
How to properly knit reinforcement for a strip foundation
When building a house, at the stage of pouring the foundation, there comes a moment called reinforcement. To implement it, you need to be able to knit reinforcement. It is possible to order a ready-made structure, but such a foundation will be 10% more expensive.
It’s easier to learn how to knit reinforcement yourself than to overpay extra money, but to do this you need to know how to properly knit reinforcement for a strip foundation. But at this stage many questions always arise, the answers to which will be given in this article.
Why it is not recommended to weld reinforcement
The initial stage of laying reinforcement can begin with welding the elements, but only by tack welding using a low current. This will speed up the process of creating an armored belt, but then with all the joints the reinforcement under the strip foundation must be knitted mechanically or manually.
Important! Complete welding of the armored belt is prohibited, since the resulting seams will be very fragile and more susceptible to corrosion.
For example, metal that has class A3 cannot be welded at all, since it has stiffeners inside that can easily be damaged, thereby reducing the load-bearing capacity of the base.
Welding may not save much on materials and time, but the quality characteristics of the foundation will be compromised, which should never be allowed to happen.
Reinforcement tying options
The tying of the reinforcement helps the elements move relative to each other, that is, it does not aim at a completely rigid structure. Knitting should be done only according to technology, since an incorrectly carried out process will lead to the fact that during pouring concrete the rods may separate and it will be quite difficult to repair such an area.
At the moment, several methods are known that show how to knit reinforcement for strip foundations and other foundations:
One joint of reinforcement can be connected in 2 minutes. Since the gun has a battery, its charge is enough for 450 joints, depending on the power. The battery can be fully charged in 30 minutes.
The use of such guns greatly speeds up the work time for tying reinforcement, and also helps make this process enjoyable. The unit can often be simply rented rather than purchased. Since it is quite possible to knit rods with a cross-section of up to 19 mm using a knitting machine, making a strip foundation yourself will not cause any difficulties.
What is the principle of tying reinforcement?
After the preparation work for pouring the foundation is completed, it is time to tie the armored belt. To create a high-quality structure, the knitting must comply with building codes:
- The pitch of the frame is determined depending on the load that will come from the building.
- Reinforcement rods are laid out at a distance of 20 to 40 cm.
- For transverse reinforcement, the step is equal to half the height of the formwork, but not more than 30 cm.
- The armored belt is mounted on a 5 cm layer of bricks.
- The frame must be buried 5 cm relative to the top of the foundation.
- The optimal wire for knitting has a cross-section from 8 to 14 mm.
- The reinforcement rod for the armored belt must be at least 60 cm long.
- The rods, which require bending as a result of tying, are buried into the wall by at least 4 cm.
- The corners of the frame do not require as frequent knitting as the straight parts.
- The rods located in the corners are fixed in two planes.
Reinforcement knitting technologies
In order to know how to tie reinforcement for a strip foundation in one way or another, you need to know exactly the technical characteristics of the house, its purpose and dimensions, as well as what types of binding are used for the corresponding foundation. There are several types of installation of armored belts:
- Hand knitted. The process begins by unwinding the wire and bending it in half. Next, the prepared piece of wire is wound around the finger, approximately one-third of the loop. Next, you need to insert a hook into it after the reinforcing rod is placed on the frame. When the hook rotates, the tying wire is grabbed from the reverse side and pulled towards itself. After all the manipulations, the hook must be removed from the loop, and the free ends must be trimmed if they are too long. Usually, for greater reliability, twisting is repeated in the same place about 5 times, otherwise the ligament may separate.
- Short twist. The wire is also bent in half, with the ends pressed against the frame. After this, the hook is inserted and a rotation is made, the remaining ends are trimmed. The twists should be as short as possible. During the twisting process, you need to make 4 turns, in order for this to work, you need to bend the wire.
- Pickup from below. The process of this option is very simple: the wire, as before, is bent twice, the hook is wound from below and grabs the loop. The remaining wire is formed into a loop and twisted. Thus, without much difficulty, a high-quality reinforcement frame is obtained with a minimum of effort.
- With one hand. This option is the simplest for tying reinforcement, which you can do yourself. The loop is prepared in the same way as in previous cases. A hook is threaded through it and the other end of the wire is grabbed. In parallel with this action, a deflection should be performed, which will help pick up the wire. The end of the wire is pulled towards itself and twisted about two to three times. Thus, it turns out that all actions are performed with only one hand. Using this option, you can produce reinforcing tape in the shortest possible time.
In addition to the presented types of reinforcement tying, there are two more that are well suited for tying reinforcement for strip foundations:
- Flat - represents the fixation of reinforcing bars in one plane, which is horizontal.
- Spatial - used specifically for tying an armored belt for a strip foundation. The result is a spatial grid that can withstand significant loads.
Knitting reinforcement for strip foundations
Many mistakes are made at this stage, so first you should familiarize yourself with them so as not to repeat them in the future:
- Straight rods in the corners are connected by overlap.
- The frame stands on vertical rods.
- A cross-section of the base shows that the presence of reinforcement there is less than 0.1%.
- There is no side protective layer, and the rods sometimes come into contact with the formwork.
To properly reinforce a strip foundation, you need to take into account all the features of such a foundation:
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;
The slab is reinforced at the ends with U-shaped clamps.
A special plastic cup provides the bottom protective layer.
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