Varieties and main technical characteristics of reinforcing mesh vr-1

Wire mesh VR-1

The applied wire Вр-1 is made from wire rod with a diameter of 3, 4 and 5 mm. By pulling through special rollers to create a periodic profile (punching). As a result, the periodic profile is formed by dents alternating with protrusions along the entire length of the wire. The depth of the dents is 0.15, 0.20 and 0.25 mm, respectively, of the given diameters. The lengths of the projections are 0.6, 0.8 and 1 mm in the same order.

produced with square cells of 50, 100 and 150 mm, Ø 3, 4 and 5 mm. A wire mesh with a mesh of 200X200 mm is also produced from a wire Ø 5 mm

Taking into account the elasticity of the steel used, the meshes are supplied in cards. The length of which is 2 m and the width: 0.25, 0.38, 0.5 and 1 m

On sale there are also other sizes or galvanized Vr meshes, regulated by TU.

2 Brands and classes of wire for reinforcement - products B and Bp

Another type of reinforcement for reinforcing building structures is special steel wire. It, like bar steel products, is designed to reinforce various reinforced concrete structures and their parts. Such wire is produced in 2 types and according to the relevant standards:

• a periodic profile (with alternating dents and protrusions on the surface) cold-drawn, made of low-carbon steel and intended for reinforcing conventional reinforced concrete structures - produced in accordance with GOST 6727-80;
• round and periodic profile (with dents on the surface) cold-drawn, made of carbon steel and intended for reinforcing prestressed structures made of reinforced concrete - produced in accordance with GOST 7348-81.

Reinforcement wire

According to the 6727 standard, the wire manufactured according to it is classified and divided into types as follows. All products belong to one class - Вр 1. Wire is produced in 3 nominal diameters: 3, 4 and 5 mm. In accordance with all this, it is designated. That is, for example, a product with a diameter of 4 mm is marked as follows: wire 4 Vr 1 in accordance with GOST 6727-80.

Thus, according to this standard, only 3 brands of fittings are produced. Each of them has its own mechanical properties shown in Table 1, but according to them, unlike most other types of fittings, wire Вр 1, according to GOST 6727, is not classified in any way.

Table 1.

Products Вр 1, according to standard 6727, are made from wire rod according to OST 14-15-193-86. Wire GOST 7348 is divided by type, as noted above, into round - indicated by B, periodic profile - marked by Bp. In addition, it is further subdivided according to the state of manufacture into:

• produced with tempering at applied voltage (stabilized) - mark P is put in the wire designation;
• just with a vacation - it is not indicated in any way in the marking.

According to the manufacturing accuracy, all products of the standard 7348 are divided into groups: 1, 2, and 3. Round wire (B) is produced stabilized and simply with tempering. And the periodic profile (BP) - just with a vacation. And yet the products of standard 7348, depending on their diameter and the value of the yield stress (conditional), are divided into strength classes: 1200, 1300, 1400 and 1500 (in N / mm2). This is also reflected in the wire designation. Products of standard 7348 are produced with nominal diameters of 3, 4, 5, 6, 7 and 8 mm. Mechanical properties for wire of all standard sizes and strength classes are given in table 2.

Table 2.

According to the division into types and classes, the wire of the standard 7348 is designated as follows. For example, a product with a diameter of 7 mm, having a strength class of 1300, round, stabilized and belonging to accuracy group 2, is marked: wire 7B1300 - P2 GOST 7348-81. And with a diameter of 4 mm, having a strength class of 1400, a periodic profile and belonging to accuracy group 3: wire 4 Вр 1400 - 3 GOST 7348-81.

Characteristics and advantages of the VR-1 mesh

The main elements are welded strictly at an angle of 90 degrees on special equipment using a contact welding machine. The shape of the cells is in most cases square. The cell has typical dimensions of the sides, which are 50-fold (50 by 50, 100 by 100, 150 by 150, etc.). Each manufacturer can offer different mesh sizes and bar thicknesses, but all this will be within the limits of the corresponding GOST. Manufacturing according to individual sizes is allowed.

Products can be untreated or zinc coated for corrosion protection. The thickness of the protective layer may vary. The larger it is, the higher the anti-corrosion properties and the operational period will be. Galvanized products can be used in conditions with high humidity. The VR-1 mesh with a protective coating costs several times more than the usual one. Therefore, if your budget is limited, then it is worth purchasing more budgetary options.

Construction mesh VR-1 for reinforcing concrete structures has the following advantages: • Versatility. The material can be used for various construction and industrial purposes; • High quality indicators (strength, resistance to mechanical stress and other indicators); • Long service life. When used under normal conditions, the material can serve for several decades; • Economic benefit. Compared to other reinforcement building materials, mesh is relatively inexpensive.

Features of production

Since the wire BP 1 is very popular, many metal rolling enterprises are engaged in its manufacture. The latest equipment allows you to get up to several tens of meters of this product in 1 second, while performing all the notches quickly and efficiently. Drawing technology is considered to be more advanced and economical.

The production uses rolled rods made by the hot-rolled method. They are additionally processed so that the quality of the products remains at a high level. For example, the scale, if any, is very carefully and carefully removed from the surface.

Then they begin to manufacture the wire by drawing through holes (dies) on special drawing mills. These holes are gradually reduced in size and allow you to get the product of the desired cross-section. This technique involves pulling the raw material through several dies with dies of different sizes, achieving a product of even a very small cross-section.

Wire characteristics

For the manufacture of wire of type ВР1, steel 3kp, 2kp and 1kp is used. It is usually produced in skeins weighing up to 100 kg. Also, if necessary, the weight of skeins is allowed up to 1.5 thousand kg.

Wire type BP2 is produced from high-carbon steel grades 85, 80, 75 and 70. It is found in two profile options - round and periodic. According to the state of manufacture, such a wire is “with tempering” and stabilizing (“with tempering under tension”).

Among the requirements for the wire is the absence of sunsets, cracks, shells on its surface. Rust deposits and maximum deviations in diameter are allowed in accordance with GOSTs.

The use of wire helps to strengthen structures, make them stronger and more durable. LLC "Steel World" offers regular supplies of wire for the needs of your construction or production in any volume. All products are sold at manufacturer's prices, have markings and accompanying regulatory documents. By contacting us, you will receive maximum information on any questions regarding BP wire and rolled metal products. We will give a quality guarantee and ensure prompt delivery of products. Partnership with Steel World LLC will be a profitable investment with confidence in the future.

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Bp mesh types and sizes. Right choice

It is worth noting that galvanized nets are more expensive. Therefore, their use is advisable for reasons of corrosion protection. It is worth choosing such meshes for operation in an environment with increased corrosive activity. For example, for the reinforcement of hydraulic structures or the manufacture of greenhouse frames.

For reinforcing masonry, concrete floors or foundations, it is sufficient to choose a mesh without zinc coating. Low carbon steel embedded in concrete with at least a minimal protective layer will last forever. It is economically unreasonable to use galvanized mesh in these cases.

Sizes of meshes for reinforcement of the most common structures:

• armopoyas for laying in one brick - cards 2X0.25 m, Ø 3 mm, 50X50;
• for laying foam blocks - 2X0.38 m, Ø 4-5 mm, 50X50;
• for bandaging layers or masonry in 2 bricks - 2X0.5 m, Ø 3 mm, 50X50;
• reinforcement of strip foundations, grillages, concrete floors - 2X1 m, Ø 5 mm, cell 100-200. Depending on the thickness of the structure and the number of reinforcing layers.

We hope our article will help you understand what a Bp mesh is, the types and sizes that were described above. To make the right choice and save time and money. Write your comments and share your experience.

4 Old and new designations and classes of standard 5781

The currently used GOST 5781 from 1982 was introduced to replace the same standard from 1975 (5781-75). In this more ancient NTD (normative technical documentation), there are no products of class A-VI (A1000), which are in the currently used edition - standard 5781-82. And the remaining 5 classes (specified in 5781-82) of fittings in NTD 5781-75 are designated somewhat differently than now. In their marking, the second part of the designation is missing, indicated in brackets and characterizing the yield strength of the product. That is, for example:

• reinforcement A1 in the standard 5781-75 is designated simply A-I, and in 5781-82 - A-I (A240);
• A2 in these NTDs, respectively, is marked as A-II and A-II (A300);
• A3 - A-III and A-III (A400) and so on.

Fittings GOST 5781

At the same time, the mechanical properties and other parameters of the reinforcement remained unchanged. Obviously, the new designation is much more informative, since it contains information about one of the most important mechanical characteristics of the product - the yield point. That is, an additional indication in the designation of the reinforcement A1 of the alphanumeric index A240 means that its yield strength is 24 kgf / mm2, for A2 the "supplement" in brackets A300 - 30 kgf / mm2, for A3 its A400 - 40 kgf / mm2.By the way, using such a "double" new designation of the standard 5781-82, many often name and write only the second part of the marking of the reinforcement of this GOST. That is, referring to products A1, indicate for them the brand "A240", A2 - "A300", A3 - "A400".

The 5781-75 standard, in turn, replaced the 5781-61 standard. In this GOST, in general, there were only 4 classes of fittings, designated in the same way as in NTD 5781-75: products A1 were marked as A-I, A2 - A-II, A3 - A-III and A4 - A-IV. That is, there was no second part of the current labeling either: for products А-I there is no А240 in brackets, for А-II - there is no А300, for А3 - А400 and А-IV - А600. In addition, the standard 5781-75 does not contain special-purpose fittings for products of class A-II, designated in the NTD from 1975 as Аc-II, and from 1982 - Аc300.

The mechanical properties of fittings of standard 5781-61 were the same as those of those currently produced according to NTD 5781-82. That is, the yield point:

• the А-I had the same as the А240 produced today - 24 kgf / mm2;
• A-II like A300 - 30 kgf / mm2;
• for А-III, as for the current fittings А3 (А400) - 40 kgf / mm2;
• and to А-IV, as in the A600 - 60 kgf / mm2.

Ultimate tensile strength:

• the А-I had the same as the А240 produced today - 38 kgf / mm2;
• for A-II, like for A300 - 50 kgf / mm2;
• for А-II, I as for the current fittings А3 (А400) - 60 kgf / mm2;
• and to А-IV, as in the A600 - 90 kgf / mm2.

Elongation in%:

3 History of reinforcement and modifications of its bar products

The needs of the construction industry are gradually but invariably changing. From year to year, she needs more and more technologically advanced, and sometimes completely new materials. Scientific and technological progress also does not stand still - new substances and alloys are being developed, as well as technologies for their production and production of building materials. In addition, existing materials and methods of their production are constantly being improved.

Metal fittings

Thus, it is believed that metal reinforcement was first used in 1802. The history of the construction of reinforced concrete structures dates back to the middle of the 19th century. And in the form in which we today know and use fittings, they appeared in the middle of the XX century. In the current millennium and century, fittings have also undergone a number of changes. Thus, completely new products in terms of quality and characteristics have appeared on the construction market. This applies to rod composite polymer products, the classes and grades of which are discussed above. It is produced in accordance with GOST 31938-2012, which has been put into effect in the Russian Federation since 01.01.2014. This standard has the status of being introduced for the first time.

Since these 2 types of bar reinforcement began to be produced relatively recently and according to completely new, only introduced standards, which have not yet been introduced and, most likely, will not, at least in the foreseeable near future, make any changes, then and their designations, as well as their classification, are currently fully consistent with those indicated in the GOSTs on them. But 2 other types of bar reinforcement, the classes and brands of which are also discussed above, have been manufactured and used for a relatively long time - at least since the beginning of the second half of the last century. Even GOSTs for them were developed back in the USSR. We are talking about products of standards 5781 and 10884.

These GOSTs, after their first edition and introduction into force, were first repeatedly revised and then completely republished again. At the same time, the marking and even the classification of fittings manufactured according to standards 5781 and 10884 changed from time to time. Currently, we use the latest editions of these GOSTs from 1982 and 1994, respectively, since their validity has been extended to the present. Accordingly, the products currently being produced according to them have brands and classes exactly the same as those indicated in these standards.

Understanding Reinforcement Meshes

Reinforcing mesh is a metal product made of steel wire of various diameters. The wire is cut into pieces of a certain size and welded strictly perpendicular to each other. Depending on the class and purpose of the finished product, the wire for manufacturing can be used in different ways. It can be cold-rolled mesh BP-1 made of special steel with a low carbon content or hot-rolled mesh made of grade A-III or A-I.

You need to pay your attention to the designations in the form: grid VR-2, grid VR-3, etc. This is not a type of wire, but the corresponding strength class.

The higher the number, the larger the diameter of the rods will be, and, accordingly, the higher the strength class. The rods can be either smooth or with a grooved surface. The ribbed wire mesh will provide a stronger bond to the concrete mix.

The products are manufactured at specialized enterprises, which have the necessary machines and additional equipment for welding. Finished products with a small diameter and mesh size are rolled up. Thicker products are sold in cards of a specific size. Each card must have documentation and appropriate quality certificates.

All characteristics and geometrical dimensions of the product must comply with GOST:

• Standard cell sizes from 50 to 50 millimeters, up to 200 to 200 millimeters;

• One meter of netting made from the thinnest wire should weigh approximately 0.5 kilograms, and from the thickest wire 3.7 kilograms. Small deviation is allowed (50-80 grams); • The width of the card or roll is not more than 150 millimeters, and the length of one sheet is 200 millimeters. As you already understood, the main material for making meshes is metal wire Вр-1. It is widely used in both the construction and industrial sectors. It can be made of steel of various grades, as well as with the addition of impurities of other metals (zinc, aluminum and others).

6 main groups of classification

In GOST, on the basis of which a reinforcing mesh is produced for strengthening concrete structures, seven main classification groups are spelled out. Let's take a closer look at each of them.

1. The first group distributes products along the main section of the bar: • Light type. This category includes products made from rods no more than 5 millimeters thick. The main step of reinforcing concrete structures must correspond to the basic values ​​(10-30 centimeters). If necessary, it can be changed up or down, but there must be a technical and economic justification for this; • Heavy type. Here, rods with a thickness of 12 to 40 millimeters are used for production. If the reinforcement has previously passed the heat treatment procedure for strengthening, then rods with a diameter of 10 mm or more can be used.
2. Second group. Distribution relative to the position of the distribution and main working valves. There are only two varieties here: • Working rods can be located both along and across, and the bars of the distribution type must be strictly perpendicular to the grid itself; • The working bars are located far and wide at once.
3. The third group for classification is carried out according to technical characteristics: • First class. These are heavy structures with a large wire thickness (mesh BP -6). The working rods are located longitudinally and have a larger cross-section than that of the distribution elements; • Second class. It is also considered heavy with a fairly large thickness of the rods. Working fittings are located along and across; • Third class. Another type of heavy mesh, only here the working rods are across; • Fourth grade. These products are already considered lightweight. They are made from fairly thin wire and have small mesh sizes; • Fifth grade. The light type, where the cross bars are mounted with a slight offset.
4. • In rolls. If the mesh is light with a wire thickness of less than 5 millimeters, then it is twisted into rolls of a certain length. Rolls are very convenient for transportation, as well as they are easy to cut and undergo other machining; • In cards. If the thickness of the wire from which the mesh is made is more than 5 millimeters, then twisting it into a roll is already problematic. Therefore, it is supplied in flat maps of appropriate geometric dimensions.
5. Fifth group by main purpose: • Masonry mesh. It has a large rod thickness (6 mm and more). Its main purpose is to strengthen brick or block masonry, as well as to strengthen the foundations of houses and industrial structures. It comes mainly in cards with different widths. For reinforcing walls made of bricks or blocks, the width should be 380 - 640 millimeters. And for partitions, the width should be about 110-250 mm. In order to make it convenient to carry out the reinforcement of walls and partitions, the cards should be no more than two meters long; • Reinforcing mesh. It is made of wire with a thickness of 3 to 6 mm. The shape of the cells can be either rectangular or square. For conventional mesh, smooth rods are used, and for road products, corrugated and thicker rods are used; • Rabitz. These are special products that are made by twisting wires of various diameters (from 1.5 to 5.5 millimeters). The main material is black or galvanized wire. The main purpose of these products is the construction of fences, enclosures and animal cages. It is widely used for household purposes.
6. The sixth classification group - according to the accuracy class of the welded joint: • Normal accuracy. Here, too high requirements are not imposed on the quality of welded seams; • Increased accuracy. In this case, the welds are stronger and of better quality.

Recommended reading:

2 Classification and varieties

Reinforcement wire is classified into varieties according to such parameters as:

• the presence or absence of a protective coating;
• heat treatment;
• strength class.

Depending on the presence of a protective coating, the material is divided into two types: made of ordinary low-carbon steel and galvanized. The coating is applied by hot-dip galvanizing, which involves holding the coils of wire in a bath of molten zinc.

The material with a protective coating is divided into two classes - 1C and 2C. The differences between them are in the thickness of the galvanized layer, in the material of class 2C the protective layer is much thicker: for comparison - 155 against 85 g / m2 in a wire with a diameter of 6 mm. An alternative to galvanized materials is MNZHKT wire made of a copper-nickel alloy, but its use in construction is unjustified due to its high cost.

Galvanized wire VR-1

By the type of hardening, the reinforcing wire is classified into untreated and annealed (it has the letter O in the marking). The essence of heat treatment is to heat the material to a predetermined temperature in a blast furnace and then cool it down. As a result of annealing, the crystal structure of the metal changes and the internal stress of the steel is destroyed, which provides increased elasticity and mechanical strength of the wire.

Depending on the strength class, the products are classified into two groups B-1 (normal) and B-2 (high strength). The difference between them lies in the grade of the alloys used, low-carbon steel is used for the manufacture of B-1 wire, for B-2 - steel with an increased amount of alloying components. The V-2 material is used to connect frames made of prestressing reinforcement, while class B-1 is intended for the installation of non-stressed structures.

2.1 Sizes and weights

The diameter of the material depends on the presence of a protective coating - galvanized wire is produced in diameters of 0.2-6 mm, without coating - 0.16-10 mm. From the factory, products are delivered in coils (weight from 15 to 250 kg) or spools (500-1500 kg). The coil should consist of one piece of wire, the coil should be no more than 3 pieces.

We give a table knitting wire weight of 1 meter, BP brand, the most demanded on the market:

• VR-1 (diameter 1 mm) - weight 0.012 kg;
• VR-2 (diameter 2 mm) - weight 0.025 kg;
• VR-3 (diameter 3 mm) - weight 0.06 kg;
• VR-4 (diameter 4 mm) - weight 0.1 kg;
• VR-6 (diameter 6 mm) - weight 0.23 kg.

A characteristic feature of the BP brand is the presence of corrugated walls, due to which the adhesion (adhesion) of the material to the reinforcement bars increases, which has a positive effect on the overall strength of reinforced concrete structures.

Wire "Kazachka

Recently, wire for tying reinforcement with rings, also called "Kazachka", has become widespread on the market. It is available in 8, 10, 12 and 14 cm lengths, at the ends of which there are rings for a crochet hook. The connection of the fittings "Kazachkoy" is performed much faster than the standard analogue, since there is no need for cutting and self-forming rings. The material is supplied in the form of bobbins, consisting of 1-5 thousand pieces.

2.3 How to knit?

To assemble the frame from 10-14 mm reinforcement bars, use a wire with a diameter of 1.2-1.4 mm. If the material has poor elasticity, the bay must be kept in a fire for 20-30 minutes, and then allowed to cool at natural temperature. It is possible to use products of a smaller diameter, however, in this case, when performing the connection, you will need to bend it twice.

You will need a special tool - a crochet hook, which can be manual or mechanical. A hand hook can be bought for 100-300 rubles, or you can make it from a trowel or a paint roller, bending and sharpening their end.

Crochet reinforcement instructions

Reinforcing wire is knitted quite simply - a 30 cm length is folded in half, at a distance of 1/3 of the loop, the wire bends around the finger and slips under the overlap of the reinforcement. A hook is inserted into the loop, after which the free end of the material is bent through the reinforcement and inserted into the hook bed.

Further, by rotating the tool, the connection is tightened. The number of turns of the hook is determined by eye so that the connection is strong enough, but not overtightened.

In the process of manufacturing the frame of reinforced concrete structures, it is necessary to observe a protective layer of concrete 3-5 cm thick.Here, instead of special supports, you can use cut rings of plastic plumbing pipes with a diameter of 4-5 cm.

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Manufacturing and differences of grids Вр

The production of Bp mesh is based on the welding of cross rods, pre-cut from wire. The applied automatic spot welding makes it possible to obtain a strong and high-quality connection.

As a rule, Bp meshes used for reinforcing concrete goods are produced directly at the production of reinforced concrete products themselves. This saves a lot of money and produces meshes of the right size if deviations from standards are required. At the same time, the demand for such nets in other spheres of the national economy justifies the growth of production aimed at a wider range of consumers.