Reinforcement is an integral part of any construction. With the help of load-bearing structures reinforced, on which depends the reliability of the constructed building. Since proper use of reinforcement provides durability of reinforced concrete structures, it should be flexible, taking into account existing requirements and regulations to ensure the preservation of its mechanical properties.
What is the bent valves?
Builders have long known, that concrete structures can severely deform under load, which leads to their destruction. To, To avoid such consequences, design stronger special reinforcing cage, consisting of steel rods (smooth or grooved fittings). In some cases, this is done using a composite reinforcement, manufactured from basalt and glass fiber reinforced plastic. The reinforcing frames are used for construction of foundations, wall, overlap, stairways, colon and t.d. Due to the structure of the skeletons reliably withstand the mechanical loads.
Although the reinforcement cage is fairly sturdy construction, he still has one weak spot. It seams bars, are particularly vulnerable places in corner joints. It should be noted, that create such connections by intersecting straight rods can not be, because it is a gross violation of the norms, which are recorded in the documents of SNIP 52-01-2003 and SNB 5.03.02-03.
If done this way corner joints, this can greatly weaken the entire structure. In the future this may lead to delamination and destruction of reinforced concrete structures, such as foundations, monolithic columns, jumpers and floors. For this reason, such compounds are made by means of bending fittings. Besides, It plays an important role and the correct installation of reinforcement rods. according to the technology, each rod, which is adjacent to the armature, I must go overlap for at least 80 cm.
Bending fixtures must be performed in such a way, so as not to lose its strength properties. Only self is allowed to bend rebar, made of metal. If you are using a reinforcement of composite materials, then it is impossible to bend.
To get a reliable reinforcing frame, ply reinforcement mechanically. In this case, care should be taken, in that the fold is not sharp angle formed. Formula curvature radius rods, universal: range shall be a value in the range 10-15 diameters used reinforcement rod.
Today, manufacturers offer two types of valves: metal and fiberglass. Metal rods are rods with a ribbed or smooth surface. The ribs provide a tighter grip with concrete. This type of reinforcement is very strong and at the same time sufficiently resilient, however, metal may eventually rust. For the production of glass-fiber reinforcement is used special basalt or glass fiber. Such rods have a much lower weight and cost less. Besides, fiber is not subject to corrosion and can withstand almost any temperature. Also, such devices are sufficiently robust, and it is not easy to break. A disadvantage is the inability of such rods folding directly on the building site. Bending must be ordered from the manufacturer, which is not always convenient or beneficial.
handyman, who prefer to stick to their own fixtures, often make the following errors:
Incision in the fold. Most often, a small incision or inscription is done in order, that the work was easier. Notched rod seriously weakens the entire structure, which can lead to negative consequences.
Heating of seats fold. Often the metal is heated by a blowtorch or open flame to facilitate the bending process. This is a direct violation of the technology, since the valve must be bent in a cold state.
Bending means via unsuitable. At home, do not apply professional tools for bending. They are replaced by hammers, sledgehammers and pieces of pipe. Treated this way valves can be destroyed and can not be used in construction.
Today invented a lot of all sorts of machines for bending of reinforcement. They all work on the same principle, but they have their own design and technical features.
The most popular option is the bending machine with the central device and the thrust roller, between which the fixed armature. Bending articles is done by the third roller. Bending can be done either in a clockwise direction, and against it. With this machine, you can make the desired bend angle fixture. Rod bent to not over the entire length, but only in a certain place, It has a thrust roller, limiting bending area.
Modern Masters using two main types of bending machine:
Machines with mechanical drive.
All mechanical devices look about the same and have similar structure scheme. There is a shaft, which is arranged vertically. It is worn disc fixed on its surface and a central bending fingers. At the front of the bending machine has a special clip, in which during the bending process of the workpiece abuts.
There is a special reinforcement bending technology with the help of such devices. Rod placed between the bending and the central fingers. Then the disc starts to rotate, a rod abuts against the roller. Here comes into operation bending finger, who starts to bend the product around the central roller.
All machines differ in power and the ability to bend or that rebar. There are three groups of devices for bending:
light fittings (diameter of 3 before 20 mm):
heavy fittings (diameter of 20 before 40 mm):
extra heavy reinforcement (diameter of 40 before 90 mm).
Each of these machines is needed for a particular purpose. for example, the last group of models can be bent several bars. It is very convenient, if you need to process a large number of blanks. To date, the producers even offer universal machines, by which to bend the reinforcement armature 3 millimitrovuyu, and 90-millimitrovuyu. Some buy machines with hydraulic drive, which gives more space to work. With such a device, you can not just bend the rods, but also to create complex structures of reinforcement. If desired, the rod can be made from even ring.
This professional equipment helps to produce really high-quality armatures. Thanks to this machine, you can bend the bars even 180 degrees. Besides, preform will have no creases and folds, because of which they can not be used in construction.
Hand tools for bending of reinforcement are also popular among the masters. Manufacturers offer as a small portable model, and heavier stationary. If you need to bend rebar for their needs, You can use a special device or benders. With their help you will be able to perform simple work, for example, bent rods with a diameter of no more than 14 mm. Usually, such machines are mounted on a table or work bench, where they are convenient to use. the, who plans to make armatures on a permanent basis, such a device will not work. must purchase more expensive and professional equipment for this purpose.
Generally, machine selection for bending of reinforcement depends on two main factors. The first - is the diameter of the workpiece, and the second - the number of workpieces. If you pick the wrong device, it can cause the appearance of defects on the surface of the rod. Under the excessive influence they will break or compress like an accordion. For this reason, it is essential to immediately determine the type of reinforcement, you are going to bend, and, Based on this, choose the machine. Also, do not forget to do the right hardware configuration, to get better and more precise bending bars.
Quite often it is necessary not only to buy the valve and bring it to an object, but also to give it the desired shape. Metal, usually, sell straight rods, which then has to handle on their own. Since most artisans are not at home professional tools for bending, they have to create homemade instruments.
One of the simplest and most convenient to use a machine with a metal frame. Its surface is welded pin, designed for fitting stop. Also attached to the surface of the turntable, which can be controlled via a special lever. there are bending and center pins on this platform, thanks to which is carried out flexible. The distance between valves depends on diameter, you want to stick to. Such a device can be attached to both the surface of the table, and to the floor, but in this case you will need to do more, and legs. If the diameter of the rods 6 – 12 mm, then this attitude better than a good fix on the floor.
When, if you need a portable machine, it can be fixed on the heavy plate. Then all the design elements are securely fastened in place and will not move.
The valves are not always used for the construction of major buildings. If you are going to build a small structure, which will not create a large burden on the foundation, bending can be carried out without special devices.
Many think the question, how to bend rebar, if you can not collect even the simplest machine. In this case, the rods can be bent and his hands, but the diameter should not exceed 8 mm. Besides, should be considered, that the bending quality is not very good. Also rough handling workpieces it may otpruzhinit and harm your health.
If you do decide to bend rebar with their hands, This can be done with basic tools. for example, this can be done using two steel pipes. One of them plays the role of lever, and a second stop element. This tube can be fixed in a vise or to dig into the ground for safety. Then you can gently begin to bend the rebar until, until it reaches the desired bend.
When, if the quality of the bars you are not very important, they can be bent and non-recommended methods. In particular, you can make an incision in the fold of their heat or rod. For this often used a blowtorch. If you work alone, should fix the valve in a vise. In the presence of helper it can hold the workpiece. Bend the rebar can be heated with a hammer or own hands.
In some cases, bending of the rods is carried out through a tree. If there are two nearby trees growing nearby, they can also be used for this case.
Selecting bending method depends entirely on you. Experts strongly recommend to make bending rods for the foundation of special equipment. In this case, you get a reliable armature, that will stand severe stress. Do not skimp on this stage, because the quality of materials will depend on your safety and the lives of others.