Technology for connecting reinforcement bars for the foundation: how to knit correctly and with what, building codes

The correct connection of reinforcement bars is essential to constructing a strong foundation for any kind of structure. These bars, also referred to as rebar, give concrete foundations the required strength and structural integrity. Complying with building codes and standards as well as ensuring the stability of the foundation depend on knowing how to tie these bars together correctly.

Usually, steel wires or specialty ties composed of the same material as the rebar are used to connect reinforcement bars. Tying rebar entails fastening intersecting bars together at predetermined intervals to make sure the spacing complies with engineering requirements. Rebar tying, also referred to as knitting, is a crucial technique for preserving the foundation’s structural integrity under a range of loads and circumstances.

The right methods and supplies for tying reinforcement bars are determined by building codes. The purpose of these codes is to guarantee construction sites are safe, long-lasting, and follow engineering principles. They outline the kind and gauge of wire that should be used, how far apart the ties should be spaced along the bars, and how to secure the ties in order to achieve the best results.

When tying rebar for foundations, proper training and experience are crucial. To avoid structural flaws and potential hazards, engineers and construction workers need to be aware of the precise requirements specified in building codes. Builders can ensure that the foundation will meet regulatory standards and endure over time by closely adhering to these guidelines.

Rules and requirements

The primary focus is on selecting the appropriate type and cross-section of reinforcement, creating a diagram, and ensuring that there is enough overlap at corners, high-load areas, and rod overlaps. In line with building codes:

• The connections are evenly distributed throughout the frame with a maximum distance of 61 cm from each other.
• Reinforcing joints are not placed at corners and similar high-load areas of the frame. An exception is made when the reinforcement overlaps at least 90 diameters from the cross-section of the rods.
• No more than 50% of all rods are connected in one connection point.
• The anchorage points are reinforced with additional transverse reinforcement, including smooth.
• All cross-shaped overlaps are tied with clamps or wire.

The final requirement receives special attention because strapping keeps the frame monolithic and removes the possibility of rods shifting during concrete pouring and hardening as well as during structure operation.

Tools, their pros and cons

The following are used to streamline and expedite work:

• Hand crochet hook, store-bought or homemade. Despite its simplicity and relatively slow speed, this tool is considered the most convenient and versatile. After selecting a hook with the desired bend and a couple of tests, the output always results in a reliable connection, regardless of the ease of access to the knot.
• Screw Semi-Automatic Crochet Hook with Handle, rotating and tightening the wire when pulling the tip. This tool is worth buying for large volumes of work and limited time and budget (costing several times more than a regular hook, a semi-automatic hook is still cheaper than a gun).
• Screwdriver with a nozzle made of a curved nail, electrode or wire about 4 mm thick. Using a screwdriver significantly speeds up work, but working with it requires skill and constant monitoring. For obvious reasons, a battery-powered model with the ability to adjust the speed is better suited for harnessing.
• Automatic hook gun, loaded with solid wire spools, tying knots in a fraction of a second. Due to the high price, its use is justified only with a large number of connections (from a thousand or more); if desired, the gun can be rented. There are no complaints about the reliability of the connections obtained; the only disadvantages of the gun include the price, the need for special reels (some imported models can break when threaded with ordinary wire) and the impossibility of tying knots in hard-to-reach places. In addition, the gun is not used when connecting rods of non-standard diameter.
• Ticks, selectable for small number of connections.

How to make a hook with your own hands?

Experts in the field create multiple hand hooks in varying sizes, featuring a practical handle and bend. Strong wire or an electrode that is 4 mm thick is used to make tiny hooks; the rod is bent multiple times with pliers after the surface has been cleaned.

An old handle (preferably wooden or plastic), two nuts, lock washers, or bearings, and a length of no more than fifty centimeters are the materials needed to make homemade hooks for tying thicker wires. Taking a corrugated rod is worthwhile because the steel’s strength justifies the time it takes to clean the protrusions.

Pliers are used to give the working part the desired shape; the two bends’ angles are chosen experimentally and range from 90 to 140 °. The hook’s bend can be altered if preferred, but both bends are made in the same plane.

Knitting methods

The amount of connections and the worker’s experience determine the tool and knitting technology. In certain situations, it’s better to rent or buy an automatic or semi-automatic tool rather than trying to tie a few knots with pliers or a hook.

Crochet

There are several general guidelines to adhere to when grabbing wire loops with any kind of hook, including:

• Cutting pieces of wire taking into account the cross-section of the reinforcement itself and the method of connection. For complex loops and thick rods, pieces up to 30-40 cm long will be required, when tying rods of a standard section and conventional grips – 15-20. You should check the length that is comfortable for you in advance.
• Fold the piece in half and wrap it around the rods at least once.
• Hooking and pulling the free ends of the wire with a hook, if necessary, holding.
• Fast turning of the first ones and slow turning of the last ones.
• Mandatory connection reliability check.

Crucial! Pressure on the connecting rods, not tension on the knitting wire itself, is used to verify the knot’s dependability. Both the frame and individual rods remain stationary when correctly tightened.

You can quickly and accurately learn how to crochet reinforcement by watching this video:

Simple knot

When selecting this option:

1. a piece of wire 15-20 cm long is bent in half, bent into a loop at the end and tucked under the reinforcement;
2. after this, the hook grabs the end and makes one turn;
3. then the loop is tightened and crocheted to the end.

Note: Although the method is regarded for its dependability and simplicity, it necessitates control over the wire’s free ends during the initial scrolling step.

"Dead Knot"

When assembling frames with a lot of clamps—typical for beams, columns, and protrusions—this strapping technique is used. Reliability is one of the benefits of using a "dead knot" to join rods; drawbacks include complexity and comparatively high wire consumption (up to 40 cm as opposed to the typical 15-20 cm) as well as the need for specific training and experience.

Using this tying, sequentially:

1. pieces of wire 20-40 cm long are folded in half;
2. the wire is directed in a loop forward, under the bottom of the rods, to the left of the clamp or curved section – about 3-4 cm should remain at the edges;
3. In the same loop, the wire is wound to the top of the clamp and bent under the bottom of the rods;
4. the hook is inserted into the loop, catches the free ends and turns several times, until the wire breaks or is completely pinched.

With a pistol

It’s crucial to double-check the reinforcement scheme before using this tool because knots secured with a gun are nearly impossible to untie.

The plan of action is straightforward: pull the trigger and aim the gun, which is tucked in with wire, towards the docking unit. Every action takes between one and two seconds.

Once all of the open spaces have been traversed, a different tool can be used to tie each of the challenging knots.

Screwdriver

The screwdriver selection is the primary focus; ideally, this tool works at slightly higher speeds in the beginning and at lower speeds towards the end of the tightening process. The nozzle is a regular nail bent at an angle; other mating rules remain unchanged.

With pincers

The benefit of this technique is thought to be the preservation of wire, which is wound into tiny balls and held in the non-working hand rather than being cut into pieces. The plan of action is straightforward: one end is pushed under the rods, and pincers grab the other. Bite off the excess after turning the pliers once or twice after connecting the two ends in the jaws.

Regarding a note. Professional knitting skills determine how quickly you can knit when using pliers, but generally speaking, this method works best for connecting a small number of knots (otherwise your hands will simply get tired).

For your article on "Technology for connecting reinforcement bars for the foundation," the following is a succinct and straightforward main thesis statement: It is important to understand how to connect reinforcement bars correctly when building a strong foundation. This article discusses the proper methods and supplies for tying rebar in accordance with building codes. By being aware of these techniques, both builders and homeowners can make sure their foundations fulfill the durability and safety standards that are necessary for any structure to remain stable over time.

Knots and twists – diagrams

There are various methods for tying rods, which vary depending on the kind of knot and the angle of access. Typically, when tying by hand:

1. The areas connecting the horizontal reinforcement to each other are tied with diagonal double loops, with 2-3 turns of the ends until there are no backlashes.
2. Connection nodes of vertical and horizontal reinforcement are fixed with cross-shaped or mutually diagonal loops. The ends are scrolled at least 3, but not more than 5 times.

Knitting materials and their selection

The following tools are used to join and secure the rods:

• Annealed or galvanized wire with a diameter in the range of 1.2-1.4 mm (thinner brands are torn, thick ones are more difficult to twist). An exception is made for frames made of rods with a cross-section of 16-18 mm, tied with wire 1.6 mm thick (10% of the diameter of the reinforcement itself). When the thickness of the rods is more than 18 mm, which is rare in general, it is easier to double the binding wire.
• Screw couplings, holding reinforcement with a cross-section over 25 mm.
• Plastic clamps, quite reliably fixing the frame under small and medium dynamic loads and optimal for knitting composite types of reinforcement.
• Durable plastic clips, perpendicular fastening rods of composite reinforcement.
• Reinforcement clamps – embedded polymer elements providing sufficient thickness of the concrete layer and holding the rods in the desired position.

Citation. Wire that is both flexible and robust is known to be a universal connector. It is chopped into 25–30 cm length pieces or put into guns on specialized reels to expedite the process.

When using an automatic pistol or lacking expertise, the average wire consumption for reinforcement of 1 m 3 is 75 p.m. Despite their many benefits, plastic clamps are thought to be less dependable when subjected to high dynamic loads, so extra caution should be used when compacting concrete with deep vibrators or pouring a large volume of mortar.

Average price for work

An estimate of the cost to assemble and tie a frame using individual expert rods.3000–3300 rubles per m² are teams. The cost of work could go up if the facility configuration is complicated.

The starting cost for reinforcing horizontal structures is 150 rubles/m2, while the vertical cost is 180 rubles/m2 when using pre-made meshes or single-row frames.

A professional tying gun can be rented for 800-100 rubles per day, with a deposit of 25,000–30,000 rubles required.

Any construction project must ensure a solid and long-lasting foundation. In this process, the technology that joins the reinforcement bars is essential. The structural integrity of the foundation is guaranteed by builders by appropriately fastening these bars together.

Specific instructions on how to connect reinforcement bars are provided by building codes. The purpose of these codes is to guarantee structural integrity and safety. Following these guidelines ensures that the foundation can resist environmental stresses and the passage of time in addition to being required by law.

Regarding the process of tying reinforcement bars, there are a few approaches that are frequently employed. The decision is frequently influenced by the construction team’s preferences as well as the design specifications. The aim is always the same, whether you use sophisticated automatic tying machines or manual tying tools: to firmly bind the bars together in compliance with engineering specifications.

For those who are in charge of tying reinforcement bars, the appropriate education and experience are crucial. This guarantees that the procedure is executed accurately and effectively. It’s important to tie the bars together in a way that improves the foundation’s overall strength and stability, not just to tie them together.

In summary, a crucial component of construction is the technology used to join reinforcement bars for foundations. Through adherence to building codes, application of suitable tying techniques, and proficient execution, constructors can produce foundations that are not only compliant but also sturdy and dependable. This meticulous attention to detail creates the foundation for long-lasting, safe structures that satisfy present and future requirements.

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