What is a reinforcement class

Reinforcement classes: marking, table of classification of reinforcing steel grades, characteristics and their application

Today, not a single large construction project that uses concrete can do without reinforcement. After all, the latter, despite its high strength, is easily damaged when working in bending and tension.

Thanks to metal rods, this drawback is eliminated, and the material that has gained sufficient strength is able to withstand significant loads of all types without harm to itself. But for each construction project, different materials and, accordingly, different classes of reinforcement will be the appropriate choice.

In one case, it is worth giving preference to thin reinforcement of one grade of steel, capable of working in an aggressive environment for years without harm. And in another you will need thick reinforcement from a different grade of steel. Let's talk about it.

Why are reinforcement classes used?

Today, metal rods are manufactured that differ in a number of factors. To display the characteristics of the material that are most important when choosing for a specific construction project, a special classification of reinforcement was developed. An experienced builder or designer only needs to look at the grade of material to accurately find out all the necessary information:

• manufacturing method;
• Class;
• diameter;
• special properties.

In the same way, when performing design or construction work, a professional can easily imagine all the loads that the material will have to withstand and accurately name the class of reinforcement that will be needed for a particular object. Let's start decoding from the very beginning.

How are fittings made?

First of all, the marking of fittings mentions the manufacturing method. For example, in the A240 brand, the letter “A” indicates that the material is hot-rolled or cold-rolled.

Another letter is “At”. It means that you are dealing with heat-strengthened reinforcement. Its cost is higher, since it is more difficult to produce.

First, the rod heats up to a temperature of 1000 degrees Celsius, after which it cools to +500 degrees in a matter of seconds. Thanks to this, the rod has much greater strength.

Therefore, it finds application in various fields, from construction, when reinforced concrete bears a large load, to mechanical engineering and furniture manufacturing.

Also in some cases the letter “B” is found. It indicates that the reinforcement is cold-formed. In addition, there is the letter “K” - ropes. This is a different specialization, but in order to be able to easily and quickly decipher the class, it will also be useful to remember this letter.

Main types of fittings

The class of reinforcing steel itself is mentioned next. There are six classes in total:

• A240;
• A300;
• A400;
• A600;
• A800;
• A1000.

In addition, in some cases there is a different designation - A1, A2 A6. But this designation is considered obsolete - it was used in the Soviet Union and it was the one that was used by the GOST in force at that time. Today, most manufacturers and buyers use a different classification of the range of fittings.

A240 is the only brand that is produced with a smooth section. Its diameter can range from 6 to 40 millimeters. Simplicity of manufacture reduces the cost of the material, but it cannot be used as a main worker - only as an auxiliary one, for example, in the manufacture of a frame. A smooth surface impairs adhesion to concrete, resulting in deterioration of the properties of reinforced concrete. Temporarily can resist stretching up to 380 megapascals.

All other classes have a periodic cross-section, that is, there are ribs on the surface that improve the quality of adhesion to concrete. For greater clarity, let’s bring all their characteristics together - the table will make it easy to select the appropriate material, as well as understand the meaning of the marking:

Class Diameter, mm Tensile strength, MPa Yield strength, not less than, MPa

A-2	10—80	500	300
A-3	6—40	600	400
A-4	10—22	900	600
A-5	10—22	1050	800
AT-4	10—40	900	600
AT-5	10—40	1000	800
AT-6	10—22	1200	1000
AT-7	10—32	1400	1200

As you can see, the diameter may vary, which allows you to select the appropriate material for each specific construction project.

How to determine the diameter?

The most important parameter is the diameter. It determines what load it can withstand, its ductility limit and a number of others. Therefore, when designating the brand of reinforcement, its diameter must be indicated. The entire classification is as follows: A200 D30. It is the last number coming after the letter D or the symbol Ø that shows the thickness of the rod.

Some meticulous buyers, when choosing a suitable material, check its actual thickness with that indicated in the passport using a caliper. They are often surprised by a serious discrepancy - the difference can be several millimeters.

However, it is worth considering that with a periodic section (that is, the presence of ribs on the rod), it is impossible to measure the nominal diameter. In narrow places it will be less than the specified value, and on the edges it will be more. Therefore, experts use the average value.

Its characteristics are indicated in the tables.

Special properties

Also, fittings are distinguished by purpose. In relatively rare cases, a metal rod must have a number of properties that make it suitable for the application. This is achieved in different ways - by adding special impurities to the alloy or by special processing. In any case, the fittings acquire unique characteristics. The presence of special properties is indicated by the letter at the end of the encoding. The following designations are usually found:

• C – weldable. Usually, when assembling a frame from reinforcement, the use of welding is extremely undesirable - overheating reduces strength and, in addition, reduces resistance to corrosion. But there is a special metal that contains additives that increase its ability to withstand negative consequences;
• K – resistant to corrosion. Thanks to special additives (chrome, tungsten and others), the fittings are able to work for many years not only in conditions of high humidity, but also in contact with an aggressive environment - alkaline, acidic, with a high oxygen content;
• SK is a reinforcement that has both of the above properties. It has a high cost, so it is used relatively rarely, only when the usual one cannot cope with difficult operating conditions.

Of course, there is a special GOST for this product that imposes special requirements on it.

What fittings are the most popular?

Experienced specialists will agree that A3 (A400) fittings have a number of qualities that make it the most popular.

To begin with, class A3 reinforcement is always produced with a corrugated surface, which allows it to be used as the main load-bearing rod in the frame.

Fitting class A-III (A400)

Different production technologies make it possible to produce any type of material: hot-rolled, cold-rolled and thermally strengthened. Therefore, choosing exactly the steel grade that is needed to perform a specific job is as easy as possible.

It is important that the range of diameters is very wide - metal rods with a thickness of 6 to 40 millimeters are produced. So, they can be used both when reinforcing small products (strip foundation for a garage or bathhouse) and when working with huge volumes of concrete (bridges, tunnels, multi-story monolithic buildings).

In addition, important advantages of the material include its resistance to high humidity and significant loads. It is durable and strong.

The ability to bend rods at an angle of up to 90 degrees without heating simplifies the process of assembling corner frames. This is extremely important - corner joints often cause serious problems for builders. Reinforcement bent at the right angle guarantees the reliability and durability of the frame even under heavy loads.

Currently, in civil and industrial construction of monolithic structures, more and more preference is given to A500C class reinforcement, due to its high strength, welding properties and ability to withstand any type of load.

Now you can easily navigate the classification developed for fittings, you know about the main properties of this valuable building material, which means that without any problems you will select exactly the products that will be the best option for a particular object. You won’t have to overpay when purchasing material or sacrifice the reliability of the structure being built.

Source: https://VseoArmature.ru/vidy/klass-armatury

What is fittings?

|Reinforcement|What is reinforcement?

Date: January 11, 2019

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The development of the construction industry requires the development of new materials that meet modern requirements. Ensuring the strength of foundations and building frames is associated with the use of special elements, which are the subject of the article. Reinforcement is an integral part of reinforced concrete that compensates tensile stresses.

For reinforced concrete structures and products, steel elements are used, united by frames that have increased strength when exposed to tensile forces. Depending on the type of material used, there are also non-metallic types of reinforcement used for special purposes.

In various types of reinforced concrete products, steel reinforcement for concrete is used, the parameters of which are determined at the design stage. It differs in strength characteristics, chemical composition, production technology, diameter, profile, principle of use.

Let us dwell in detail on these structural elements. Let's look at what reinforcement is, its types, what its properties are, and its scope of application.

Steel rebar is a traditional type of reinforcement material

Necessity of application

Let's look at what it is used for and how it works in a foundation or building structure.

Concrete is known as a building material with high strength and long service life. The concrete mass, while maintaining its integrity, absorbs compressive forces, but is susceptible to tensile loads and shears. They cause cracks and loss of integrity.

The use of reinforced concrete has improved the operational characteristics of objects. The monolithic reinforced concrete mass includes corrugated steel rods that have a high degree of adhesion to concrete. When making reinforced concrete, a reinforcement contour is first formed and then poured with concrete. The resulting design is distinguished by a set of characteristics:

• Increased strength
• High degree of plasticity.
• Vibration resistant.
• Resistant to deformation.
• Not susceptible to corrosion processes.

The buildings are constructed from concrete reinforced with reinforcement. How much reinforcement is needed in concrete? It increases strength characteristics, compensates for perceived forces that:

• stretching of a reinforced structure;
• compression of a reinforced concrete structure or product;
• transverse shear of the concrete mass.

Reinforcement - linearly extended elements in a reinforced concrete structure, designed to absorb tensile (mainly) and compressive forces

Concrete reinforcement had a positive effect on improving performance by providing increased adhesion between the grooved metal bars and the concrete mass.

As a rule, reinforcement bars are located vertically and horizontally in concrete, which makes it possible to compensate for perpendicularly directed loads acting on the reinforced concrete structure. In products and structures made of concrete, various types of steel rods are used, differing in design features and properties.

General classification

The reinforcement used in the construction industry are steel bars classified into different types. They differ in the following characteristics:

• Section profile.
• The nature of perceived effort.
• Principle of application.
• Appointment.
• Features of distribution in the concrete mass.
• Method of production.

Based on the area of ​​use, transverse and longitudinal reinforcement can be distinguished

Varieties

Let's look at each feature. According to the profile used, the following rods are used:

• having transverse protrusions evenly distributed over the surface, located at an equal angle to the longitudinal axis of the rod. The corrugation ensures adhesion to the concrete mass;
• having a round cross-section. They are used as connecting rods.

Depending on how the reinforcement works in the foundation or reinforced concrete structure, the rods differ in the nature of the perceived forces acting:

• In the transverse direction. The use of transverse elements prevents the formation of angled cracks resulting from shear stress.
• Longitudinal. The rods compensate for tensile forces and ensure the strength of products in stretched areas. The longitudinally located elements also absorb compressive loads, ensuring the integrity of the concrete structure.

Reinforcement rods are divided into types according to the principle of operation. Rods can be in concrete in different states:

• pre-stressed. This reduces deflections and prevents cracking.
• in a free (not tense) manner. Their use involves concreting in a natural state without pre-tensioning.

Reinforcing mesh is often used to reinforce slabs

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Concrete reinforcement is made with rods that differ in purpose. The following rods are used:

• Workers who perceive stress from the mass of the structure and external forces.
• Distribution rods with a grooved profile. This ensures force compensation and the integrity of the concrete structure.
• Mounting elements with which the reinforcement frame is assembled. They help maintain the position of the steel mesh or spatial contour during concreting.
• Fasteners that act as anchors. Used as embedded parts.
• Structural, installed in areas where there is a possibility of additional stress.

When performing frame and mesh type reinforcement, working rods are used in conjunction with mounting and distribution rods.

According to the chosen installation method, the following reinforcements are applied:

• piece reinforcement installed during assembly using welding. Round elements or rods with a corrugated surface are used;
• mesh reinforcement representing a structure pre-assembled using binding wire for welding;
• frame type. It differs in spatial form.

We can conclude that the construction of reinforced concrete structures is impossible without the use of material such as reinforcement

Depending on the manufacturing method, reinforcement elements are used in the form of:

• The most common type of rods is hot rolled rods. The marking of fittings corresponds to various classes differing in mechanical characteristics. It may include the letters A, B or K and a number, for example A400 or A500. The rod elements are made from low-alloy steels saturated with carbon and alloying additives. This ensures resistance to corrosion processes, ductility, and strength characteristics.
• Rope or wire produced by the cold-drawn method. Reinforcement elements of this type are used in a tensioned, prestressed state and are characterized by high strength. The special features of the ropes are increased strength, high adhesion to the concrete mass, and reliable compensation of bending forces.

A separate variety is non-metallic rods made from fiberglass or polymer composites containing carbon, basalt or glass fibers. They are susceptible to bending forces, subject to combustion, and do not affect electromagnetic radiation. Differs from steel bars:

• Reduced weight.
• Corrosion resistant.

Reinforcement has become widely used in the construction industry

Application area

The areas of use of steel products used to strengthen concrete are quite wide:

• construction of foundations, load-bearing walls, floors of residential buildings;
• construction of industrial facilities;
• construction of special hydraulic structures (power stations, piers), as well as underground structures;
• installation of support columns for various highways;
• implementation of construction measures to strengthen plaster, perform screed;
• production at reinforced concrete enterprises of shaped structures made of reinforced concrete (floor elements, foundation blocks, beams, rings);
• arrangement of airfield structures, pedestrian zones, road surfaces;

Reinforced concrete is used for construction activities in areas with increased seismic activity and cold climatic conditions.

The markings of the fittings used for each of the listed applications are different. It includes an abbreviation consisting of certain letters and numbers. Let's look at this in more detail.

Specifics of marking

Marking of reinforcement makes it possible to use steel bars to solve specific problems related to strengthening concrete structures.

The characteristics of the product are determined by the thickness of the rod used, however, the main mechanical properties of the reinforcement depend on the manufacturing process

The individual designation of the fittings contains in capital letters:

• A – characterizes thermally strengthened products produced by cold-rolled or hot-rolled methods.
• B – corresponds to steel rods deformed in a cold state.
• K – designation of corrosion resistance of galvanized elements.
• C – the possibility of using electric welding to connect rods.
• T is an index denoting steel hardened by thermal or mechanical means.

The digital designation of the reinforcement is in the form of numbers characterizing the fluidity of the material, indicated in megapascals. As the value of the indicator increases, reliability and strength characteristics increase. Thermally strengthened steel rods are marked with the designation from A240 to A1000.

The rods are divided into classes designated A1–A4:

• A1 – characterizes rods with a diameter of 4-40 mm, made of St3 steel, used for mounting and distribution rods;
• A2 – denotes corrugated rods, the diameter of which is 10-80 mm, made from carbon steels St5, St18;
• A3 – rods with a cross section of 6-40 mm, made of low-alloy steel 25, 32, 35. They are widely used for standard reinforced concrete structures;
• A4 - combines reinforcement elements of a corrugated, smooth shape, with a diameter of 6-32 mm, containing alloying additives. The rods are made from high-strength materials 20ХГСТ, 20ХГ2Ц, 30ХГ2С, used for structures connected by welding.

The correct choice of marking of reinforcement elements determines how reinforcement works in concrete. Product markings may include the diameter of the bar. For example, the index A600 T Ø20 means that it is a corrugated rod with a diameter of 20 mm made of low-alloy heat-strengthened cold-rolled steel with a fluidity of 600 megapascals.

Conclusion

The material in the article introduces the design features and types of reinforcement elements that are an integral part of reinforced concrete. The correct choice of steel rods guarantees the strength of the concrete mass over a long period of time.

On the website: Author and editor of articles on the website pobetony.ru
Education and work experience: Higher technical education. 12 years of experience in various industries and construction sites, 8 of which were abroad.

Other skills and abilities: Has the 4th group of electrical safety clearance. Perform calculations using large data sets.

Current employment: For the last 4 years he has been acting as an independent consultant for a number of construction companies.

Source: https://pobetony.ru/armirovanie/armatura-eto/

Classes and types of building reinforcement

Concrete itself has high compressive strength, but tensile strength is 10-15 times less, and this can be compensated for by placing reinforcement in it. The combination of these two materials makes it possible to obtain products that have excellent characteristics for both the first type of load and the second.

Construction fittings

First of all, construction reinforcement is divided into classes, set depending on the steel used. Here are some examples of such markings - A240, A400C, A600, A600K, A800, A800SK and A1000 . Additional letters in the designation have their own meaning.

So C stands for welded by electric welding , and K indicates resistance to corrosion under voltage .

The absence of these letter indices in the marking indicates that the reinforcement is non-weldable and not resistant to corrosion cracking.

Knitting reinforcement without markings

Most of these products are now produced without the C marking, which means they should be mounted together with wire. When welded, such reinforcement will become brittle at the joint. Among other things, during production, reinforcement can be subjected to additional heat treatment, which increases the strength characteristics of the steel. Such improved fittings are A.

Reinforcement is usually supplied in three types - coils, rods and in the form of welded mesh . It is usually produced as a coil with a diameter of less than 10 mm; with a larger diameter it is produced in rods. At the moment, products of 10-12 mm are most in demand. And the last type is used for reinforcing slabs, floors, walls and foundations, etc., and is a welded structure.

Steel reinforcement by type, profile and application

In addition to classes, reinforcement can be divided depending on the method of its production - rod, wire and rope . The rod is made from rolled steel, and it is the most common in both private and industrial construction. The range of diameters of such fittings is from 6 mm to 0.8 meters.

Rope fittings

A much rarer type, mostly used for reinforcing masonry and having a small cross-section, from 3 to 5 mm, is wire reinforcement. It is made from cold drawn wire. For this purpose, ordinary quality wire is used, but high-strength wire is also in demand and even mandatory in the production of prestressed reinforcement.

Rope reinforcement is used in a stressed, that is, tensioned, form and copes well with bending loads. Thanks to this, concrete structures are significantly strengthened. Also, the service life of such fittings can be extended using special lubricants or polymer coatings.

Classification by profile divides reinforcement into only two groups - periodic and smooth . A periodic profile requires the presence of special stiffening ribs, which, among other things, increase the adhesion of the reinforcement to concrete. Moreover, here we can note three subspecies depending on the type of corrugation - ring, crescent and mixed . Well, the smooth profile, in accordance with its name, has no ribs, the rods are smooth and have a round cross-section.

The purpose of the reinforcement according to the loads it accepts is also important - transverse and longitudinal . The transverse one will prevent cracks from appearing in reinforced concrete products from oblique, shearing stresses on the structure, and the longitudinal one will be useful in structures with a large compressive load, taking on part of the load.

Innovation

Composite reinforcement

Relatively recently, a new type of reinforcement has appeared - non-metallic , also known as composite, polymer and fiberglass . It is produced on the basis of glass fiber with special polymer additives based on epoxy resins. Visually, it consists of rods with a spiral cross-section and a rather small diameter of up to 12 mm.

Now such fittings have already partially found their application in industry, but it is too early to talk about mass application. In private construction, they are not yet used at all. Considering the above circumstances, talking about the prospects for the practical operation of such products can be very vague. No voluminous statistics have yet been accumulated on this issue, and how it will behave under different conditions is not known for certain.

Source: https://nerudnye-spb.ru/blog/klassy-i-vidy-stroitelnoj-armatury

Steel reinforcement: GOST, size, purpose:

Today, the construction of any building or technical structure cannot be completed without the use of concrete mortar. The reinforced frame of the structure greatly increases the strength of the structure, preventing cracking and destruction of concrete buildings. Modern rolled metal products offer various types of steel construction reinforcement for the formation of reinforced concrete structures for various purposes.

Main characteristics of steel reinforcement

To absorb tension and strengthen compressed zones of concrete structures is the main purpose of construction reinforcement. To implement this function, reinforcing bars are manufactured with the highest possible strength and ductility. To obtain a high-quality product, metal rolling enterprises increase the strength properties of raw materials:

• regulate the chemical composition of steel, increasing the content of carbon and chemical additives;
• in a cold state, steel is strengthened by twisting, drawing, stretching, flattening and other methods;
• heat treatment is applied;
• several methods are combined.

Durable and ductile, not susceptible to corrosion under a layer of concrete, withstanding temperature changes, time-tested steel building reinforcement is used both in the construction of low-rise residential buildings and in the construction of complex industrial and technical structures.

Types of reinforcement products

According to their purpose, fittings are divided into 4 types:

• Working. It absorbs tensile forces that arise in reinforced concrete structures under the pressure of external loads and its own weight.
• Distribution. It is a reinforcement mesh or frame connected by wire or welding. By tying the rods together, it prevents the working base from shifting during concreting and is intended to distribute a uniform load between the elements of the working reinforcement.
• Clamps. They are used when assembling the frame, protecting against the appearance of cracks near the supports in the beams.
• Assembly room. Used when concreting or assembling a frame to ensure the correct position of clamps and working reinforcement. It does not take any loads and is usually removed upon completion of work.

Types of building reinforcement

According to the orientation in the structure, it is divided into transverse and longitudinal. Transverse reinforcement binds concrete in the compressed and tensile zones of the structure to prevent the formation of inclined cracks near the supports. Longitudinal reinforcement, perceiving compressive and tensile stress, prevents vertical cracking in the tensile zone of the structure.

According to the conditions of use, it is divided into prestressed and non-prestressed reinforcement. Only working reinforcement that has been pre-tensioned to increase the strength of a reinforced concrete structure can be prestressed. Tensioning the reinforcing bars, reducing deflections and reducing the weight of the structure, prevents the formation of cracks and reduces the amount of steel reinforcement.

Reinforcement manufacturing methods

According to production technology, reinforcement for reinforced concrete buildings is of two types:

• Hot rolled rod. Reinforcement with any diameter, supplied in steel rods up to 13 meters long or in coils weighing up to 1.3 tons.
• Cold drawn wire. In the process of pulling (drawing) steel through the holes of drawing mills, the wire or rods change their cross-sectional shape and dimensions. A longer and more expensive production process, which results in high-quality reinforcement with a thickness of no more than 5 mm.

Hot-rolled steel reinforcement is significantly less expensive than cold-drawn steel reinforcement and has a higher level of corrosion resistance. Hot-rolled reinforcement bars are used more often and to increase strength they undergo subsequent thermal and mechanical treatment. This type of reinforcement is divided into 2 types according to the shape of the surface:

1. Smooth – metal rods with a smooth surface. Used for mounting the frame.
2. Periodic profile (corrugated) - rods with transverse protrusions and longitudinal ribs on the surface, twisted along a helix.

When casting reinforced concrete products or buildings, recesses and surface protrusions provide better adhesion of concrete to the reinforcement frame.

Classification of fittings

The strength of reinforcing bars depends on the steel alloy from which they are made. Reinforcement is classified according to its mechanical properties. Today there are several types of marking of steel construction reinforcement by class:

• A240 A-I.
• A300 A-II.
• A400 A-III.
• A600 A-IV.
• A800 AV.
• A1000 A-VI.

Class A240 (A-I) produces smooth fittings, other classes are produced with periodic corrugated profiles. Special properties, production method or purpose of fittings are indicated in the marking of finished products with additional indices. Thermo-mechanical treatment is designated “At”, hardening by drawing is designated “Ab”. For regions of the Far North, frost-resistant reinforcement is marked “c”. Increased resistance to corrosion is designated “K”, and rods for welding are marked “C”.

Requirements for the strength of steel reinforcement are determined by GOSTs, which set yield limits for each class. For hot-rolled rod reinforcement GOST 5781, rod reinforcement strengthened by thermomechanical method is produced in accordance with GOST 10884. In accordance with the requirements of GOST, steel reinforcement cannot have holes, membranes, cracks or sunsets on its surface. Steel reinforcement bars are produced with a diameter from 6 mm to 80 mm.

Marking of finished products in production includes a class, an additional index and painting of the ends of the rods with a color corresponding to the brand. The class designation looks like this: At400S or At800KS.

Steel for the production of reinforcing bars

Low-alloy and carbon steel grades are used in the production of reinforcing bars. By changing the amount of chemicals, the alloy is given certain properties. Aluminum, silicon, manganese, nitrogen, chromium, boron, titanium, and zirconium are used as alloying additives.

Adding, for example, manganese to the alloy increases the rigidity of the material without reducing its elasticity. By changing the crystal lattice, silicon increases the density of steel rods, which improves the performance properties of the reinforcement, but makes it difficult to weld the elements. The strength of steel increases significantly when carbon is added to the alloy.

But an overdose of this substance impairs the ductility of building reinforcement.

The steel grade of the reinforcement is specified by the customer. If there are no brand requirements in the order, the manufacturer agrees it with the recipient, or the plant determines it at its own discretion.

Frequency of use

12 mm reinforcement made of steel class A3500C is in wide demand. Welding can be used to fasten plastic ribbed rods of this type. 12 mm reinforcement bars give the frame higher strength.

Application of construction reinforcement

Flat or three-dimensional structures made of steel rods are connected to each other by electric welding, knitting wire or special reinforcement clamps. The high-quality adhesion of flat reinforcing meshes (grids) and volumetric frames to concrete depends on its strength and shrinkage amount, as well as on the type of surface and cross-sectional shape of the reinforcing bars. Reliable adhesion of concrete and reinforcement is ensured by three factors:

1. Mechanical engagement of protrusions and surface irregularities of reinforcement with concrete.
2. Frictional forces arising on the surface of reinforcing bars when they are compressed by concrete during the shrinkage process.
3. Adhesion (gluing) of a reinforcing surface to concrete due to the viscosity of the cement mortar.

Currently, any concrete structure has a strong, reliable steel reinforced “skeleton”. Modern office or commercial buildings, residential or technical buildings, power plant dams or bridges are constructed using cast-in-place concreting technology.

Source: https://www.syl.ru/article/338402/stalnaya-armatura-gost-razmer-naznachenie

What is fittings needed for?

Reinforcement is a metal product in the form of a rod. Reinforcing bars are considered important elements of construction. They are obtained by rolling steel at metallurgical plants, subjecting them to high temperatures.

Waste is removed from the steel and impurities are added, reducing carbon levels and increasing the strength of the rods. After manufacturing, the fittings are subjected to inspections and compliance with GOST.

The production and sale of fittings are areas of high demand, as they are used in civil and industrial construction. This article will help you consider in more detail what reinforcement is.

Reinforcement is needed for the strength and durability of concrete and is used in any construction process. The resistance of concrete to tension is much less than to the compression factor. Thanks to the corrugated surface, the reinforcement is well fixed in concrete and reduces its deformation.

Reinforcement is a metal product in the form of a rod

Pure concrete does not have high strength properties, and to increase its durability, concrete and reinforcement are combined in reinforced concrete. Reinforced concrete structures are designed to reliably strengthen the building in comparison with conventional concrete:

• reinforcement protects concrete from sudden temperature changes;
• strength increases with simultaneous exposure to compression and tension factors;
• reinforcement prevents the formation of concrete cracks.

Reinforcement is also used in the foundation. It takes on all types of loads from higher structures and therefore must be as durable as possible. Additionally, the foundation is affected by ground movements and frost heaving. The reinforcement in the foundation acts as an effective protection and helps resist concrete deterioration.

General classification of fittings: types

Depending on the type of material made, reinforcing bars are:

1. Metal. Traditional fittings are made from metals; they have high heat resistance. During the reinforcement process, it can be bent and welded.
2. Composite. They are made of glass, basalt and carbon fibers. The most popular fiberglass reinforcement is that it does not conduct electricity and is not subject to corrosion.

Metal fittings

Depending on the manufacturing method, the fittings can be:

1. Rod . Such fittings are used most often. The diameter of the rods is from 6 to 80 mm, they are manufactured by cold and hot rolling, serve as a frame for reinforced concrete structures and can be:

• Smooth. No protruding bends on the surface.
• Periodic profile. They consist of periodic small projections along the entire perimeter.

1. Wire . The size of this reinforcement reaches 10 mm. It is made by cold drawing rods through a series of holes of decreasing diameter. As a result, the wire reinforcement rods narrow in diameter and increase in length.
2. Ropeway . The fittings are made of wire. The diameter of high-strength rope rods is from 6-15 mm. There should be no broken wires or dents.

Depending on the installation, the fittings are divided into three types:

• Piece . Used in formwork for private construction of small-scale work. Individual elements are used in frames and reinforcement meshes.
• Reinforcement mesh . Ready-made interlacing of vertical and horizontal rods for the foundation and floor slabs.
• Frame . Frame structures are designed to reinforce columns and beams.

The choice of a specific type of reinforcement depends on the location and method of its application.

Reinforcing mesh 50x50x3 mm in cards

Reinforcing products (reinforcement): types and application

And reinforcing products are structures assembled from reinforcing components, both finished and semi-finished. With the help of reinforcement, the frame of reinforced concrete elements is assembled.

And a ready-made reinforcing structure allows you to minimize labor costs in the manufacture of reinforced concrete products.

:
1. Reinforcement products: classification and types.
2. Knitted reinforcement mesh.
4. Reinforcement frames.
5.

Prestressed reinforcement products.
6. Other reinforcement products.

Reinforcement products: classification and types

A wide variety of products requires their classification, so → building reinforcement (you can order it using the link) is classified according to various characteristics and applications, here are the main ones:

By profile:

• periodic profile fittings. The rods have corrugations - transverse protrusions located on the surface of the metal base at an angle to its longitudinal axis;
• fittings with a smooth profile. The surface of the rods is smooth, they have a round cross-section.

Periodic reinforcement profile and smooth

According to the nature of the loads, the reinforcement can be:

• transverse. Such rods prevent the formation of inclined cracks, the appearance of which is caused by oblique shear stress near the supports;
• longitudinal The products absorb tensile stresses, preventing the appearance of vertical cracks in the material. In reinforced concrete products operating in compression, the loads are distributed between the longitudinal reinforcement and concrete.

Transverse and longitudinal reinforcement

According to the principle of operation, reinforcing products can be:

• non-stressed. They are used for the manufacture of reinforced concrete products during the construction of small structures where the frame does not experience high loads;
• tense. Such reinforcement is pre-tensioned , which makes it more resistant to high loads. Resists the appearance of cracks and deflections. Used for the construction of reinforced concrete structures of increased strength. The diameter of the rod ranges from 5 to 35 mm.

According to their purpose, the fittings are divided into:

• working Fittings that are installed according to calculations. Takes on external loads, as well as stresses arising under the influence of the structure’s own weight.
• assembly - used for assembling the reinforced concrete frame. Due to this, during concreting, the position of the working reinforcement rods remains unchanged. Installed for technological reasons for ease of frame assembly;
• constructive (distributive). To install such reinforcement, preliminary calculations are not required. It is installed for practical purposes where random force impacts may occur. These are corrugated products that ensure precise load distribution, so that the position of the working rods does not change during operation;
• anchor - embedded parts;

Example of reinforcement cage

There are the following types of reinforcing products :

• reinforcing mesh. They can be welded and knitted;
• frames. They are divided into spatial and flat;
• prestressed reinforcement products (ropes and bundles with and without anchors);
• piece products (clamps, mounting loops, embedded elements).

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Let's look at all these types in more detail.

Welded reinforcement mesh

The most common products are welded reinforcement mesh. They are made of rods (wires), cross-shapedly connected to each other at the intersection points using spot welding.

Welded mesh is made from rods with a cross-section of more than 3 mm or from reinforcing wire. They can be:

• flat (if the diameter of the transverse rods is 10 mm or more, and the longitudinal rods are 5 mm or more)
• or rolled, if the cross-section of the rods is less than the specified values.

Cells can be rectangular or square.

Flat reinforcement mesh

Conventionally, grids are divided into:

If the diameter of each element does not exceed 10 mm, the design is considered lightweight . If the cross-section of the elements in at least one direction exceeds this indicator, the product is included in the heavy .

Rods (wire) going in the same direction must always have the same cross-section.

The designs also differ in the location of the working fittings . It can be used in one direction or in both. In the first case, distribution fittings are installed in a perpendicular direction.

Rolled mesh with rectangular cells

The length of the nets can be up to 9 m. The width depends on the type of product: for light ones - 0.65-3.8 m, for heavy ones - 0.65-3.05 m.

Welded mesh is used to reinforce reinforced concrete elements, road surfaces and brickwork; arrange → screeding of cement floors (the link describes the construction of cement-sand screeds). It is used when laying the foundation of buildings and structures, in the manufacture of frames for greenhouses in crop production and cages in animal husbandry. Decorative and functional fences are made from it.

Knitted reinforcement mesh

If the volume of construction work is small, then reinforcing mesh is sometimes knitted by hand from soft wire after annealing, the cross-section of which is 0.8-1.0 mm. For knitting, special reinforcement cutters are used, the teeth of which are slightly blunted so as not to bite the wire during work.

Knitted reinforcement mesh

The meshes are tied manually in the following cases:

• when the rods cannot be connected by welding (for example, in the manufacture of non-standard structures);
• for the purpose of enlarging the product on the construction site;
• when performing urgent work, when finished reinforcing products cannot be delivered to the site within the required time frame;
• for small volumes of reinforcement, when there is no point in using → a welding machine (how to work with a welding inverter is described in the link);
• when the reinforcement is made from non-weldable steel rods or waste wire.

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To speed up the process of manual knitting and increase its productivity, the joints of the rods are fastened not with wire, but with clamps made on an automatic machine.

Reinforcement frames

There are 2 types of such structures:

In frames of the first type, the transverse rods are located in the same plane. The number of longitudinal rods can be different, and according to this indicator, frame structures can be 2-, 3-, or 4-branch.

They are used to produce spatial reinforcement cages for reinforcing reinforced concrete elements that are tensile or bending and have a narrow cross-section of reinforcement.

The joints of the rods are fastened by resistance welding using high-performance multi-electrode welding equipment.

Flat reinforcement cage

A feature of spatial reinforcement frames is the arrangement of transverse rods in different planes. Structures are assembled from various reinforcing products and elements - rods, meshes, flat frames, embedded elements, etc. The joints are connected to each other by welding or knitting.

To give the products additional rigidity, steel strips, angles or square rods are used instead of rods.

Volumetric reinforcement frame

Advantages of using ready-made frames:

• saving time. Ready-made structures allow you to complete work faster without wasting time on soldering and knitting reinforcement;
• complete absence of reinforcement waste;
• reliability of the design. Frames manufactured using specialized equipment in a factory are stronger and more stable than structures assembled on a construction site;
• the ability to select the necessary parameters. The frames are manufactured taking into account the required dimensions for a specific object and do not require modification on site.

In addition, the number of people involved at a construction site is reduced, since when delivering finished structures, specialists in the production of reinforcement cages are not needed.

Prestressed reinforcement products

Non-tensioned reinforced concrete structures are reinforced with meshes and frames. Prestressed products are strengthened with ropes and reinforcement bundles. The elements are tensioned in the following ways:

• on the stops. The products are concreted after stretching them onto special forms and fixed with clamps. After the mixture has hardened, the clamps are removed;
• on concrete. Channel formers (pipes, rods) are installed in the formwork, the cross-section of which is 10-15 mm larger than the diameter of the product. 2-3 hours after concreting they are removed, reinforcement is inserted into the hole and tensioned;
• electromechanically. An alternating current of the required frequency is passed through the fittings. Due to thermal expansion, the product lengthens, and after cooling it shortens, transferring the compressive force to the concrete.

Prestressed concrete products are durable and effectively withstand dynamic loads.

Source: https://chonemuzhik.ru/armiruyushhie-izdeliya-armatura-vidy-i-primenenie.html

Classification and types of building reinforcement, properties

The development of the modern housing market and other facilities requires the creation of new building materials that meet modern conditions. An increase in the number of floors in buildings leads to an increase in the requirements placed on construction reinforcement used to strengthen the building frame and foundation. Based on the type of material from which this building product is made, a distinction is made between steel and non-metallic reinforcement.

Steel construction reinforcement

According to the manufacturing method, metal fittings are divided into:

• core;
• wire;
• cable car

Bar reinforcement

One of the most common types is hot-rolled bar construction reinforcement. According to mechanical characteristics, this type of fittings is divided into classes with designations - A400, A500, and so on.

When using rebar to strengthen a foundation, it is tied rather than welded to avoid creating extreme stress centers at the welding points.

Rod reinforcement is made of carbon or low-alloy steels. The introduction of alloying additives into reinforcing steel makes it possible to increase:

• resistance of metal products to corrosion cracking in contact with concrete solutions;
• strength;
• plastic.

Alloy steel reinforcement is used for the construction of buildings in areas with high seismic activity, in regions with cold climates, for the construction of critical facilities and in structures operating with variable loads.

Thermal or thermomechanical hardening operations make it possible to bring the mechanical properties of carbon steel reinforcement closer to the similar characteristics of low-alloy steel. Thermally strengthened reinforcement is marked At.

According to performance characteristics, the reinforcement is divided into weldable - marking C and resistant to corrosion cracking - marking K.

Wire and rope reinforcement

Wire reinforcement is made from cold-drawn wire of ordinary quality or high-strength. For the production of prestressed reinforcement, only high-strength metal products are used.

Rope reinforcement is usually used in a prestressed form. Located in the body of the foundation slab, the rope reinforcement, due to its high strength, successfully absorbs the bending moment from the soil resistance to the load.

To extend their service life, reinforcing ropes are protected with lubricant or a special sheath made of polymer materials.

Non-metallic construction reinforcement

An alternative to metal reinforcement is the result of the introduction of new technologies - composite reinforcement. Otherwise it is called fiberglass or polymer. The basis of this building product is fiberglass, to which polymers based on epoxy resins are added.

Fiberglass reinforcement in appearance consists of rods with a continuous spiral relief with a diameter of up to 12 mm. This is a modern, promising material that has found application in many areas of industry.

In road construction, non-metallic composite reinforcement is used:

• in the production of concrete slabs used for the construction of in-building and temporary bypass roads;
• for reinforcing asphalt concrete pavement of highways, eliminates rutting, prevents the formation of cracks, ensures the integrity of the pavement during its guaranteed service life;
• for the construction of embankments on weak foundations - soils with high humidity, swamps, strengthening the banks of reservoirs;
• in the construction of highway driveways and temporary roads.

In industrial and civil engineering, composite reinforcement is used for:

• reinforcement of structures for various purposes made of heavy, light - cellular and porous, fine-grained concrete; temperature operating conditions of such buildings can range from -70°C to +100°C;
• production of flexible connections in layered brickwork;
• repair of damaged surfaces of brick and concrete buildings.

This group of fittings is also used for:

• strengthening bridge structures;
• installation of enclosing structures;
• runway structures;
• construction of berths, dry docks, to strengthen the coastal zone;
• creating structures that are constantly exposed to aggressive, corrosive environments.

Advantages of composite reinforcement compared to metal:

• the specific gravity of these products is four times less than the density of steel reinforcement;
• higher resistance to corrosion, rotting, warping;
• material savings due to the possibility of using smaller profiles compared to steel ones;
• higher resistance to chemical effects of acids, alkalis, sea water;
• increasing the reliability and durability of constructed structures;
• the ability to carry out installation work without the involvement of heavy construction equipment.

Other types of classification of reinforcement according to various criteria

There are many types of classification of building reinforcement; we list the main defining features.

Classification by profile:

• reinforcement of a periodic profile - the rods have transverse protrusions evenly distributed over the surface at an angle to the longitudinal axis, which are called corrugations, designed to increase the level of adhesion to concrete;
• reinforcement with a smooth profile - rods with a round cross-section and a smooth surface.

According to the nature of the loads perceived, the reinforcement is divided into the following types:

• transverse - these building products prevent the appearance of inclined cracks that arise from oblique shear stresses near the supports;
• longitudinal, which absorbs tensile stresses and prevents the formation of vertical cracks in stretched zones. In structures operating in compression, longitudinal reinforcement together with concrete takes on part of the load.

According to the principle of operation, reinforcement is divided into non-tensioned and stressed. Prestressed reinforcement is subjected to pre-tensioning, which during operation of the structure allows to reduce deflections, prevent the appearance of cracks, reduce metal consumption, and, consequently, the weight of the entire structure.

According to their purpose, fittings are divided into:

• working - serves to accept external loads and stresses from the structure’s own weight;
• distribution - corrugated reinforcement, designed to accurately distribute the load, which allows you to maintain the position of the working rods in their original form;
• mounting - used for assembling a frame, this type of reinforcement helps maintain the desired position of the rods during the concreting process; it can take the form of a mesh or frame;
• anchor - embedded parts;
• structural - a type of reinforcement that is installed without preliminary calculations, solely based on practical considerations, in places where random force impacts may occur.

When constructing grids and frames, distribution and mounting fittings are used in combination with working fittings.

According to the method of distribution, the reinforcement is:

• piece, which are round rods or another profile, assembly of such reinforcement is carried out directly at the construction site by welding;
• reinforcing mesh - ready-made welded or bonded reinforcing products;
• reinforcement frames.

Pipeline fittings have their own classification, and the following main types are distinguished:

• shut-off valves, which are designed to shut off the flow of the working medium in the pipeline. Types of shut-off valves: gates, valves, gate valves, etc.
• control valves - based on the name, this type of pipeline valves regulates the parameters of the working environment.
• safety fittings, for example, safety valves, prevent accidents by establishing a critical value for the state of the medium.

New technologies for reinforcing concrete structures

A new type of reinforcement of concrete structures, such as the use of fiber fiber, is rapidly gaining popularity. Although the use of fiber is not a new idea. The distant ancestors of fiber-reinforced concrete can be considered building mixtures, to which straw, reeds, and sheep's wool were added to give them increased strength.

Modern types of fiber fibers include:

• Steel fiber is a piece of low-carbon wire with ends of a special configuration, which ensures strong adhesion of steel fibers to concrete. Steel fiber-reinforced concrete is used for the production of slabs for airfield runways, for high-speed highways, in shotcrete, anti-landslide structures, in the construction of earthquake-resistant objects, bank vaults, and is used for the construction of self-leveling floors.
• Polypropylene fiber is small fibers of certain sizes, evenly distributed throughout the entire volume of the concrete structure. This group of reinforcing materials significantly increases the operational properties of the structure, preventing the formation of shrinkage cracks, increases the compactability of concrete during vibration and the resistance of materials to temperature fluctuations. This fiber is used to produce leveling solutions. It increases the bending and tensile strength of the material and reduces delamination.
• Alkali-resistant glass fiber is used to prevent the opening of tensile cracks, reduce shrinkage deformation and creep rates, increase moisture resistance, frost resistance, and impact strength.
• Polyamide fiber is a synthetic fiber of the latest generation. Used for additional (secondary) strengthening of concrete structures. It is highly resistant to alkaline environments, solvents, and has high abrasion resistance. The fiber is introduced into the concrete mixture along with sand.

Due to its high melting point, polyamide fiber can be used to construct structures with the required high fire resistance.

• Basalt fiber - pieces of complex basalt fiber of a certain length. They look like friable monofilaments - monofilaments. The introduction of this reinforcing material, due to its high strength, can significantly increase the important properties of concrete: resistance to abrasion, impact, spalling, and temperature fluctuations. Basalt fiber is perfectly distributed throughout the entire volume of concrete, providing high sound insulation, heat insulation and dielectric properties of mortars.

The presence of basalt fiber in concrete makes it possible to reduce stress concentration in places weakened by the presence of structural defects in concrete - shells and microcracks.

The variety of reinforcement products offered by manufacturers indicates the expanding use of new, advanced materials that can bring the construction industry to a completely new qualitative level.

Source: https://www.navigator-beton.ru/articles/klassifikatsiya-i-vidy-stroitelnoj-armatury.html

Class A1 fittings, main characteristics and areas of application

The popularity of rolled metal products increases every year. One of these is class A1 fittings. Nowadays, almost no construction project . Widely used to create reinforced concrete products, as well as metal structures and parts. Rolled metal is produced in accordance with state standard 5781−82.

Characteristics of fittings a1

According to GOST, A1 reinforcement is called steel reinforcement or A240. This is the most correct and accurate name for this material among professional consumers and customers. In the technical language of standard 5781, which contains a classification of all manufactured reinforcing and ordinary steels, as well as prestressed reinforced concrete structures, this designation is deciphered as a1 reinforcement.

The division into classes is made according to one of the mechanical characteristics of reinforcing steel, namely the yield strength. The value 240 is indicated after the index, A, and means the yield strength in kgf/mm2, multiplied by 10, therefore, its value for this material is 24 kgf/mm2.

The steel in question is made only with a smooth profile without corrugation on the surface of a properly manufactured circular section. Externally, such reinforcement resembles steel wire or rod.

A1 fittings are manufactured exclusively from hot-rolled steel and carbon steel st3. Therefore, this grade is most in demand both for reinforcement and as ordinary rolled metal in the manufacture of other types of structures. Steel 3 is the most flexible, ductile, and best weldable.

This range has 14 standard sizes ranging from 6 to 40 millimeters in diameter. Diameters up to 12 millimeters are made using rods or skeins; large products are made only in the form of rods.

Main characteristics and properties

GOST 5781 specifies such material parameters as cross-sectional area, weight of 1 meter of profile and permissible maximum deviations from the specified parameters. The design mass is calculated based on the nominal diameter without deviations at a steel density of 7850 kilograms per cubic meter. The smallest diameter of 6 millimeters has a mass of 0.222 kilograms, and the diameter of 40 millimeters has a mass of almost 10 kilograms.

According to the standard, the permissible weight deviations for rods are:

• +9 to -7 percent of 1 meter of theoretical weight for diameters 6 and 8 millimeters.
• diameters from 10 to 14 millimeters allow deviations of +5 to -6 percent.
• from 16 to 28 millimeters, maximum deviations range from +3 to -5%.
• with diameters from 32 to 40 millimeters, deviations range from +3 to -4 percent.

The ovality of a smooth material should not be greater than the sum of the permissible diameter deviations. The curvature of the rolled product should not exceed 0.6 percent of the measured length. There are other mechanical properties, including flexural elongation of 25 percent, and the tensile strength of the reinforcement is 373 newtons per square millimeter.

There are also requirements for the surface quality of finished steel reinforcement. There should be no cracks, flaws or other defects. Individual prints, sagging, slight rust, scaliness and rippling are allowed.

Due to its properties, this material is used in many areas , including:

1. Reinforced concrete reinforcement;
2. Reinforcement of higher class steel reinforcement;
3. For mutual fixation and hardening of the surface of the product;
4. As a means of monolithic construction such as dams, mines, bridges, airfields and other objects.

If the load on the reinforced concrete allows, then the steel reinforcement product is used independently. It is usually used to strengthen columns, foundations, beams and panels. A thin product with a diameter of 6 and 8 millimeters is used as a wire for tying and fastening building meshes, reinforced frames, reinforcement of concrete screeds and floors, as well as plaster.

In addition, fittings of this brand are actively used for the production of decorative, load-bearing, frame and other metal structures, parts for them and various equipment and technological equipment. It is used wherever ordinary rolled metal made of St3 steel is used.

A1 reinforcement is known for its mechanical and technological properties, as well as strength characteristics. This allows this material to be used in various construction and industrial applications, including strengthening reinforced concrete and foundations. Independent use of reinforcement is also allowed subject to permissible loads and high-quality manufacturing.

Source: https://tokar.guru/metallicheskie-izdeliya/armatura/armatura-klassa-a1-i-ee-osobennosti.html

Construction fittings. Types of construction fittings for the home

mistigri

The article is an introduction to the article Reinforcement work in the construction of a private house and, together with it, complements the article Technology of concrete work. The article presents the types and classification of building reinforcement used for the construction of a private house. The classification of reinforcement by class of reinforcing steel, by type of supply depending on diameter, manufacturing technology of building reinforcement, by reinforcement profile and type of strengthening is described in detail.

Scheme of operation of reinforced concrete products

The resistance of concrete to tension is 10-15 times less than to compression; to absorb tensile forces, reinforcement is placed in concrete, and thus reinforced concrete products are obtained, which, combining the properties of steel and concrete, work perfectly in tension and compression.

Reinforced concrete operation diagram

Steel consumption in standard reinforced concrete structures ranges from 50-80 kg per 1 m3 of concrete. In particularly critical structures, this figure can reach up to 125 kg per 1 m3 of concrete, which is practically never found in private construction.

Currently, reinforcement for reinforced concrete products in Ukraine is produced in accordance with DSTU 3760:2006 “Rolled reinforcement for reinforced concrete structures”.

Classification and types of building reinforcement

Construction reinforcement according to reinforcing steel class

A240 (Al), A400C (Alll), A500C (All), A600 (At-IV), A600C (At-IVC), A600K (At-I), A800 (At-V), A800K (At-), A800SK and A1000 (At-Vl).

Classification of fittings

Note: Old class names of fittings (which suppliers sometimes use for marking) are indicated in parentheses.

Reinforcing bars (reinforcement) are divided into:

• Weldable (indicated by index C);
• Resistant to stress corrosion cracking (indicated by index K);
• Non-weldable (without index C);
• Not resistant to corrosion cracking (without K index).

It should be noted that at present, the industry produces the majority of reinforcing bars without the “C” index. It is not recommended to weld such reinforcement, since at the welding site it becomes brittle, which reduces the strength of the frame. During installation, such reinforcement is tied with wire.

In private construction, the following classes are most popular: A240 (Al) - transverse reinforcement; A400С (Аll), А500С (Аll) - longitudinal and transverse reinforcement.  

Delivery of reinforcing steel with a diameter of less than 10 mm (so-called wire rod) is carried out in coils. With a diameter of 10 mm or more - rods, length from 6 to 12 m or measured length (this type of delivery is more common for private construction). The most popular: fittings with a diameter of 12mm and fittings with a diameter of 10mm.

They also produce reinforcement in the form of welded mesh, intended for reinforcing floor slabs, foundations, walls, etc.

Wire fittings

Rod reinforcement

Frame meshes

 Manufacturing technologies for building reinforcement

• Rod. Produced from hot rolled steel. It is most widespread in private and industrial construction A-I (A240), A-III (A400), with a diameter of 6 to 80 mm.
• Wire. Hot-drawn steel is used less frequently, mainly for reinforcing masonry walls (Br-I and BI), with a diameter of 3-5 mm.

 According to the reinforcement profile:

• Periodic profile, has special ribs (notches, corrugations), which improves adhesion to concrete and ensures the joint work of steel and concrete. It can be ring-shaped, sickle-shaped, mixed.

Reinforcement profile type

• Smooth steel, without special notches.

Smooth reinforcement

 By type of strengthening of building reinforcement:

• Hot-rolled reinforcement is not subjected to further hardening after production; the required mechanical properties are ensured by the chemical composition of the steel.
• Thermally strengthened reinforcement, reinforcement subjected to heat treatment to increase strength properties (increasing the strength characteristics of reinforcing steel by hardening it).

Summarizing all of the above, it can be noted that in the construction of a private house, hot-rolled or thermally strengthened rods of class A240 (Al), A400C (All), A500C (All) with a diameter of 6 mm to 25 mm are most often used for reinforcing load-bearing and non-load-bearing reinforced concrete structures ( foundations, beams, floors, lintels, etc.).

Wire reinforcement of class BP-I with a diameter of 3-5 mm is also used to reinforce masonry walls.

Source: http://www.builderclub.com/statia/armatura-stroitelnaya-vidy-stroitelnoy-armatury-dlya-doma