Armature 12. Building fittings: production, weight, price

Armature is a steel product, having the form of a long rod with a circular cross-section. The main purpose of this type of high-quality rolled metal is to improve the quality of concrete structures. There are several types of reinforcement, each of which is produced in strict accordance with the GOST standards.

Appointment

Concrete - the material is unusually strong for compression. The structures cast from it are able to withstand enormous weight without any harm to themselves. However, unfortunately, the stretch is very fragile, just like the bend. Because of this feature of concrete in the construction of buildings and structures, many problems can arise: cracking of the foundation and walls as a result of the influence of spring sheaves, the destruction of the floors due to too high vertical loads, etc. The tensile strength of concrete is only 10-15 % Of compressive strength.

This problem is also addressed by metal fittings. The coefficient of thermal expansion became close to the same index of concrete. This makes it possible to use materials in the complex. The most popular in low-rise construction is the armature of 12 mm in diameter. Concrete structures, reinforced with frames bound from it, are characterized by high compressive strength and, at the same time, acceptable for stretching.

When building foundations, which account for the main load during spring whipping, the use of reinforcement is a mandatory condition. Often this kind of rolled metal is used in the construction of walls (reinforcement masonry, upper hardness belt). Fittings in the form of a grid are used for pouring floors and screeds. Apply it and in the manufacture of concrete paths, blind areas, etc. When erecting multi-storey buildings, as well as houses on problematic grounds, a reinforcement of 16 mm and thicker is more often used.

Among other things, this type of rolled metal also improves such an indicator as the fatigue strength of concrete, as well as the resistance of structures to mechanical influences from the outside.

Material of manufacture

Since the reinforcement is a very important element of the reinforced concrete structures of the building, special requirements are imposed on its quality. The raw material for the production of rolled metal of this type is a special reinforcing steel. To improve its mechanical properties, it is alloyed with manganese and silicon. To impart special strength to the reinforcement, titanium and chromium are treated.

Variety in diameter

In the construction can be used reinforcement of different thicknesses. In this respect, there are certain standards established by the SNiP regulations. So, for example, for foundations of buildings with very light frame-panel walls erected on stable soils, rods with a diameter of 10 mm can be used. When building private houses of almost all other types, as already mentioned, a 12 mm armature is used.

Kinds on a way of manufacturing

Production of reinforcement 12 mm (steel), as well as rods of any other thickness, is carried out using two main technologies:

• By hot rolling the steel. Such products are called pivot.
• By drawing the steel in a cold state. This is the so-called wire look.

Manufacture of fittings of 12 mm - the process is not too complicated, but requires the use of special equipment and the exact observance of all put technologies.

Ready-made frames and nets are produced at specialized enterprises. The procedure for their manufacture includes the following steps:

• If the raw material is supplied in reels, unwinding is performed.
• Correction of wire or rods is carried out.
• The armature is cut into pieces of the required length. This and previous operations are performed on special right-cutting machines.
• Next is the assembly of the frame elements or the mesh. This operation is performed on special welding machines. In some cases, the elements are connected by manual welding.

Sometimes reinforcing skeletons and nets are made and directly in the process of building buildings (usually low-rise). In this case, the structure can be welded or wire bound. The first method is less time-consuming. When using the second, a more durable frame is obtained. The fact is that in the welding places, steel subsequently rusts faster.

Type of surface

On this basis, only two types of reinforcement 12 mm are distinguished:

• Smooth, representing ordinary rods or wire of circular cross-section.
• Corrugated. On the surface of such an armature there are transverse (usually sickle-shaped) and longitudinal ribs. This design allows significantly improve the adhesion of the frame elements to concrete.

Types of working conditions

In frames the following types of reinforcement are usually used:

• Distributive;
• Working (actually 12 mm rods);
• Installation;
• Clamps.

According to the operating conditions, the 12 mm armature is divided into:

• Stressed. It is used when special strength of concrete construction is needed (in earthquake-prone areas, in ceilings of high-rise buildings, in exposed parts of bridges, etc.).
• Non-straining. Fits without tension. Used in conventional concrete structures.

Weight of reinforcement 12 mm

When building small private buildings, the amount of metal rolling required is usually calculated in running meters. Manufacturers often sell rebar for weight. This can cause some difficulties in the calculations. In order to find out how many kilograms of reinforcement are needed in this or that case, the weight of the running meter should be multiplied by the necessary length of the material. The first indicator depends on the type of reinforcement and is determined by special tables.

Thus, the weight of reinforcement 12 mm (manufactured in accordance with GOST) is 0.89 kg / linear meter. Suppose, for the erection of a house requires 25 m of hire. Therefore, you need to buy 25 x 0.89 = 22.25 kg of rods.

Marking and Valve Cost

Smooth rolled metal 12 mm is marked with the letter А1, corrugated without perforation - А3. Also on the labeling you can find out the way of manufacturing the reinforcement (A - hot rolled, B - cold-worked) and the grade of used steel (figures). The product may be delivered in coils or bars. For example, the designation of reinforcement "A3-A500S" is deciphered as follows:

• The material has a corrugated surface (A3),
• Made by hot rolling (A),
• Grade of steel - 3PS (A500C)

The price of metal rolling of this type depends primarily on its thickness, as well as on the brand. How much can the armature cost 12? The price for rods of this diameter - hot-rolled (the most popular variety) - varies from 22 to 29 thousand rubles per ton for different suppliers. Of course, when buying, you should ask the seller for a certificate of compliance with GOST. Marking on the armature is usually made already during the rental. If this was not done in the manufacture of rods and rods, their ends are marked with indelible paint. So, for example, steel A500S is marked white and blue, A600C - yellow and white, etc. You can find out the exact match for other types of rod by special tables.

Thus, the armature - one of the most popular types of rolled metal in the market - can be produced in different ways from different steel grades, have a smooth or corrugated surface, be thick or thin. 12 mm rods are among the most popular variety. At their purchase, as well as at acquisition of any other armature, it is necessary to pay attention first of all on marking and type of a surface.