What does Armature a3 mean?

Classes and grades of reinforcement steel

06.06.2019

Reinforcement is used to improve the performance of concrete. It gives an increase in strength and allows you to withstand heavy loads without cracking or crumbling. Without the use of a frame made of metal rods or wire mesh, it would be impossible to construct concrete supports, bridges, underground structures and other structures.

According to purpose, reinforcement is divided into four types:

• Anchor . Used to create embedded elements in concreting.
• Constructive . Eliminates deformation of the structure and distributes loads. Thanks to this, the concrete does not settle and thermal expansion is compensated.
• Working . It is necessary to take the main load and increase strength.
• Assembly . It is used when you need to connect disparate parts into a single frame.

Product characteristics indicate where it can be used. We sell prestressed and non-prestressed reinforcement, adapted for installation in supporting and unloaded structures.

According to the installation method, longitudinal and transverse varieties are selected. The first type resists vertical cracks well, the second - inclined ones.

Classes of fittings and areas of their use

On sale you will find rods that vary in diameter, length and surface type. There are smooth and grooved varieties. For ease of designation, they were divided into classes, for each the area of ​​use and a set of characteristics, as well as the steel grade of the reinforcement, were specified.

There are the following types:

• A1 (A240, AI). One of the most common types of materials for the manufacture of reinforced concrete products is trays, floor slabs, and support elements. The diameter ranges from 6 to 40 mm. Depending on this parameter, the product is supplied in skeins or rods.
• A2 (A300, AII). The diameter reaches 80 mm. Can be used as a frame for piles. Installation in concrete increases its resistance to vertical loads.
• A3 (A 400, A III ). There are ribs on the surface of the rod. Corrugation improves adhesion to concrete. Diameter up to 40 mm. Products up to 10 mm are supplied in skeins, larger quantities in rods.
• A4 (A600, AIV). Metal elements are used as the basis for reinforced concrete products for various purposes. They are suitable for the production of parts subject to dynamic loads. It is also widely used in construction – not only civil, but also industrial.
• A5 (A800, AV). The material is created from structural low-alloy steel. The recommended area of ​​application is the creation of prestressed concrete products. Suitable for the construction of bridges and hydraulic structures.
• A6 (A1000, AVI). The characteristics allow the use of steel rods in the most critical areas - from nuclear industry facilities to dams. Since the product is expensive, it is produced upon pre-order. Provides good adhesion to concrete due to the special structure of the ribs - they are ring-shaped or crescent-shaped. Can also be used with reinforced concrete products. Reinforcement significantly extends their service life.
• A400C . Manufactured using the hot-rolled method. The diameter reaches 40 mm. It is distinguished by the presence of two ribs located longitudinally. Used in private construction, in the construction of low structures.
• A500C . Additionally strengthened by mechanical and thermal methods. Not adapted to strong dynamic loads, used with basic types of reinforced concrete products.
• A600C . It is characterized by increased resistance to corrosion due to the addition of molybdenum and vanadium to the alloy. Suitable for monolithic houses, construction in areas with high seismic activity.

Below is a table of classes and brands of fittings with the main characteristics listed.

Reinforcement class	Rolled diameter	steel grade	Mechanical properties, no less
σ T , N/mm2 yield strength	σ B , N/mm2 tensile strength	σ S , % relative. elongation	Cold bending test, C – mandrel diameter, B – rod diameter
A-I (A 240)	6-40	St3kp, St3ps, St3sp	235	373	25	180 deg C=d
A-II (A 300)	10-40	St5sp, St5ps	295	490	19	180 deg C=3d
40-80	18G2S
AC-II (AC 300)	10-32	10GT	295	441	25	180 deg C=d
A-III (A 400)	6-40	35GS, 25G2S	390	590	14	90 deg C=3d
6-22	32G2Rps
A-IV (A 600)	10-18	80C	590	883	6	45 degrees C=5d
10-32	20ХГ2Ц, 20ХГ2Т
А-V (А 800)	10-32	23Х2Г2Т, 23Х2Г2Ц	785	1030	7	45 degrees C=5d
A-VI (A1000)	10-22	22Kh2G2AYu, 22Kh2G2R, 20Kh2G2SR	980	1230	6	45 degrees C=5d

Steel grades for the production of fittings

The grade classification and classes of reinforcing steel indicate the performance characteristics. Among the most common varieties:

• 20GS . Structural low alloy steel. It lends itself well to welding, therefore it is suitable for the manufacture of reinforcing frames.
• 35GS . Another structural low-alloy variety. Well protected from aggressive environments and pressure.
• St3kp . Structural carbon of ordinary quality. Shows good adhesion to concrete and does not deteriorate due to pressure, vibration, or exposure to aggressive environments.
• 22Х2Г2АУ . The characteristics of this low-alloy structural steel make it suitable for use in both conventional and prestressed concrete structures.
• 80C . Durable material that can withstand high stress and aggressive environmental influences.

The table below shows the correspondence of the class of reinforcing steel, the grade of raw materials used in the manufacture and the profile diameter of the created rod.

Table of reinforcement classes and steel grades - steel for reinforcement according to GOST 5781-82

Profile type	Class	Diameter, mm	steel grade
Smooth profile	A1 (A240)	6-40	St3kp, St3ps, St3sp
Periodic profile	A2 (A300)	10-40, 40-80	St5sp, St5ps, 18G2S
Periodic profile	A3 (A400)	6-40, 6-22	35GS, 25G2S, 32G2Rps
Periodic profile	A4 (A600)	10-18 (6-8), 10-32 (36-40)	80С, 20ХГ2Ц
Periodic profile	A5 (A800)	10-32 (6-8), (36-40)	23Х2Г2Т
Periodic profile	A6 (A1000)	10-22	22Х2Г2АУ, 22Х2Г2Р

What determines the scope of application of fittings?

Several factors influence where a particular type of rod will be used:

• Degree of workload.
• Potential threats.
• Scope of application of reinforced concrete products or location of the reinforced building.

Before you buy a batch of steel rods, you need to understand what the loads acting on them will be - static or dynamic. The mechanical parameters of the future frame are also taken into account. If you need to connect several parts by welding, the steel must have a good level of weldability.

Source: https://spbrmk.ru/klassy-i-marki-stali-armatury/

Reinforcement A1 and A3 class differences

There are more than a dozen types of fittings on the building materials market. Despite the extensive choice, grades A1 and A3 are most often used in civil engineering. They differ in both price and characteristics, and our article will help you figure out which material is best to choose for certain purposes.

General characteristics of fittings

In order to understand how A1 reinforcement differs from A3, you need to know what properties characterize this type of rolled metal.

The profile type is divided into smooth and periodic. The first has a flat surface, and the second has longitudinal and transverse ribs protruding. The periodic profile adheres better to concrete, which increases the strength of the structure.

An equally important characteristic is the cross-sectional diameter. For each brand of reinforcement, GOST establishes acceptable dimensions. With an increase in cross-sectional diameter, both the strength of the reinforcement cage and the mass increase.

GOST also establishes the grade of steel from which the rods are made. Not only the strength of the structure depends on it, but also corrosion resistance, which is important in aggressive environments, places with high temperature changes and high humidity.

Based on the class of reinforcing steel and its diameter, the strength characteristics of the material are determined. GOST 5781-82 indicates for each grade and diameter the yield strength, tensile strength, relative elongation and other characteristics that will allow all calculations to be made before construction.

Characteristics and features of A1 fittings

Class A1 fittings have a smooth profile and are made of low-alloy steel (St3sp, St3ps, St3kp). The size of the produced profile can have a diameter from 6 to 40 mm. It is produced using cold rolling. Old marking A1, new A240.

The main advantage of A1 is its high corrosion resistance. It withstands sudden temperature changes and high humidity well. Also, reinforcement with a smooth profile is better welded. Disadvantages include weaker adhesion to concrete.

Features of the A1 brand:

• low price;
• less strength;
• high corrosion resistance;
• good weldability;
• poor adhesion to concrete mortar.

Characteristics and features of A3 fittings

A3 reinforcement has a periodic profile with longitudinal and transverse stiffeners. It is made by hot rolling from steel grades 35GS, 25G2S - with a diameter of 6-40 mm, and 32G2Rps - profile size from 6 to 22 mm. New marking A400, old A3.

The ribbed profile ensures good adhesion of the reinforcement frame to the concrete. This significantly increases the strength of the supporting structure. The disadvantage is lower corrosion resistance, which is why A3 brand reinforcement is not recommended for use in combination with certain types of concrete, in places with high humidity and aggressive chemical environments.

Features of the A3 brand:

• high price;
• high strength reinforcing mesh;
• good adhesion to concrete;
• low corrosion resistance.

Brand selection

The A1 and A3 fittings differ not only in characteristics, but also in price. The first one costs about 30% less than the second one, so whenever possible they try to use it. The range of applications for both brands is wide, and they are often used in combination with each other.

A1 is considered a universal solution that is considered first. It is used for the manufacture of many reinforced concrete products: slabs, rings, beams, blocks. Also, products with a smooth profile are used when pouring screeds, finishing facades and strengthening columns. It is recommended to use it for the foundation of a building in the role of constructive and installation.

A3 is used in cases where increased strength is required from reinforced concrete. It is used in the construction of bridges, dams and other massive objects.

Also, high-strength reinforcement can withstand the loads of monolithic buildings and foundations that experience high pressure. Grade A3 is also recommended for use in the manufacture of reinforced concrete floors.

In addition, it is used to strengthen the A1-based frame. The combined mesh provides high strength at an affordable price.

Combined use of reinforcement A1 and A3 when reinforcing a balcony beam.

In addition to A1 and A3 fittings, the differences of which we have already examined, enterprises also produce other brands of products that may be optimal for your task. All of them, like A3, have a periodic profile and are not so resistant to corrosion (in this regard, A1 is unique).

Grade A2 is made from steel with fewer alloying additives, which makes it cheaper but less durable. It is actively used in the construction of private houses and low-rise commercial buildings. A4, A5 and A6 are capable of withstanding enormous loads, but due to their high price, their use is justified only in highly loaded structures.

It is also important in what form you will purchase the products. It is produced in both rods and skeins. Let's figure out what the difference is. The maximum length of the rods is 12 meters. They are easier to work with, since they are easier to cut and do not need to be straightened, but there is also a drawback. After cutting the rods, scraps inevitably remain and some of the material goes to landfill. There is no such problem with skeins. In addition, they are indispensable when the design requires reinforcement mesh longer than 12 meters.

To summarize, we can say that the differences between A1 and A3 fittings make it more universal. It is suitable in most cases and will allow you to get by at a lower cost, but when high strength is required, it is better not to save money and use A3 reinforcement. If, after reading the article, you still have doubts about which brand of fittings to choose, then it is better to seek advice from a professional who will select the optimal solution for your project.

Source: https://VseoArmature.ru/vidy/otlichie-armatury-a1-ot-a3

A3 fittings - table of weights and assortment according to GOST 5781-82

Class A3 (A400) reinforcement is a type of long steel produced by hot rolling in accordance with GOST 5781-82. The surface of this product has longitudinal and transverse protrusions located along a helical line. This shape ensures effective adhesion of steel rods to the hardening concrete mixture. At the customer's request, rods of this class can have a smooth surface.

Technical characteristics and areas of application of A3 fittings

The products are made from low-alloy steel grades 35GS, 25G2S, 32G2Rps. Due to the increased manganese content, the material is resistant to low temperatures. This type of rolled product is capable of withstanding high operational static and dynamic loads. To increase the service life of fittings, galvanizing or aluminum galvanizing is usually used by hot, electrochemical or thermal diffusion methods.

Main physical characteristics:

• yield strength – 390 N/mm2;
• temporary tensile strength – 590 N/mm2;
• relative elongation – no less than 14%.

Thermo-mechanically strengthened reinforcement with similar tensile strength - 550-600 N/mm2 - is manufactured in accordance with GOST 10884-94.

Product performance properties:

• strength;
• the ability to give the required shape;
• good weldability (without restrictions) of products made from steels with low carbon content, high strength of welded joints.

Due to their technical characteristics, A3 class reinforcing bars are used:

• in monolithic construction and production of reinforced concrete products for the production of flat and spatial reinforcement frames;
• for creating metal structures for various purposes;
• for reinforcing floor screeds, paths, blind areas;
• to strengthen road surfaces;
• for the manufacture of gratings, fences, nets;

Assortment of fittings A3

Products are produced in the diameter range of 6-40 mm. The profile number of periodic profile rods indicates the nominal diameter, which is equal to the diameter of smooth rods of equal cross-sectional area. Rolled products with a cross-sectional diameter of up to 10 mm can be produced in coils or rods, more - only in rods. The coils are formed in such a way that there are no kinks. The length of the segments is 6-12 mm. The rods should not be bent by more than 0.6% of the total length.

Calculation of the mass of a batch of reinforcing bars can be done using a table that presents the theoretical masses of 1 linear meter. They are calculated based on the average density of steel, which is assumed to be 7.85 kg/m3. When multiplying the mass of a linear meter of a product of the corresponding diameter by the total footage, we obtain the weight of the batch.  

Table of cross-sectional areas and theoretical weights of 1 m of A3 reinforcement

Diameter, m	Cross-sectional area, cm2	Weight 1 m, kg	Diameter, m	Cross-sectional area, cm2	Weight 1 m, kg
6	0,283	0,222	20	3,14	2,47
8	0,503	0,395	22	3,8	2,98
10	0,785	0,617	25	4,91	3,85
12	1,131	0,888	28	6,16	4,83
14	1,54	1,21	32	8,04	6,31
16	2,01	1,58	36	10,18	7,99
18	2,54	2,0	40	12,57	9,87

Source: https://TreydMetall.ru/info/armatura-a3-tab-vesov

A500C fittings: technical characteristics and differences from A-III fittings

One of the most popular types of fittings today is A500C. The material is a rod of grade A5 with a diameter of 6 to 40 mm. This type of rolled product is produced in accordance with the requirements of GOST 52544 2006. The material refers to structural elements that are subjected to thermomechanical processing during the rolling process.

A500C fittings are considered universal due to their excellent performance characteristics. The low carbon content of steel and its thermomechanical treatment during the production of rolled products ensure ductility and improved weldability of the final product.

The material is also characterized by increased durability and viscosity. In terms of its properties, fittings of this class meet the requirements of international standards.

The Gosstroy of Russia recommends the use of A500S grade in reinforced concrete structures instead of and along with At-IIIS (GOST 10884-81) and A-III grades 35GS and 25G2S (GOST 5781-82) reinforcement of the same diameter.

Explanation of markings

The letter A in the marking indicates that this type of material belongs to hot-rolled steel and is thermally and mechanically reinforced. The letter C indicates the possibility of using welding to connect elements. The number 500 in the marking indicates the yield strength of the material.

Delivery form

Rolled products of class A500C are supplied in two forms: in the form of coils or rods. If the cross-sectional diameter is up to 6 mm, the material is formed into coils, from 6 to 12 mm it is supplied in coils or rods at the request of the client. If the diameter is more than 12 mm, rolled products are sold only in the form of rods.

Production

Fittings of this class are produced under the control of GOST R 52544-2006 and STO-ASChM 7-93. Low-carbon steel grades 35G2S and 35GS are used as the manufacturing material. carbon is no more than 0.22%. For the production of A500C, two methods are used: cold drawn and hot rolled.

In the first case, wire and rolled reinforcement is created, in the second - rod reinforcement. It should be noted that rolled products of the second type are characterized by higher strength. The raw materials for A500C contain fewer alloying components than analogues, which ensures a more favorable cost of the final product.

Application

A500S reinforcement is widely used in the construction industry when creating reinforced concrete structures, pouring foundations, etc. The material is used to reinforce or strengthen load-bearing structures (in accordance with GOST 10884-94) or simple reinforced concrete structures (in accordance with GOST 5781-81).

Advantages

The A500C has many advantages, we will list the main ones:

• increased design resistance to loads, which provides a quantitative reduction in the consumption of reinforcement for creating structures;
• profitability due to the low cost of thermomechanical processing of the material;
• increased strength and ductility due to the absence of hardening in the welding zone;
• unification - that is, the possibility of replacing fittings of classes A240, A300 and A400.

Difference between A500C and A-III

The type of reinforcement that will be used in the construction of a new building is selected at the project development stage. For residential buildings weighing up to 80 tons, A3 rolled steel is mainly used. This category includes fittings A400 and A500C. These classes are often considered the same or very similar, but they have significant differences:

• Scope of application. Both classes are used for repair and finishing, construction, production of reinforced concrete products, creating frames, etc. The difference between A500C and A3 (A400) is that the first class can be used in both loaded and unloaded structures, and the second - in areas of high stress.
• Appearance. Rolled products of class A500C have a profile with crescent-shaped protrusions that do not intersect with the longitudinal ribs. This shape provides higher plastic and strength characteristics. Also, thanks to the profile, the material does not have stress concentrators at the intersections of longitudinal and transverse ribs. Different manufacturers offer different versions of this material, which may differ in the angle of inclination of the crescent-shaped elements in relation to each other and the distance between them.
• Welding capability. A3 reinforcement, produced by the hot-rolled method from high-carbon type 25GS steel, complies with GOST 5781-82. The fluidity index of the product is 400 N/mm2, which is specified in the A400 marking. This material cannot be welded. To connect individual elements, only knitting wire can be used (as fastenings at seams).

We have collected all the main characteristics by which these two classes of rolled metal can be compared in the table below:

Rolled products of class A400 (A-III) can be replaced with A500C without re-calculating the project. Reverse replacement is allowed only in case of additional recalculations. This provides a significant increase in the strength and reliability of the structure, and also increases its service life. By choosing A500C class rental, you can reduce the amount of required material by an average of 10%. Reducing the volume of working reinforcement allows you to reduce the final cost of the project.

Source: https://www.stroymetall.ru/stati/osobennosti-armatury-a500s/

Difference between fittings A1 and A3. Characteristics and application in construction

Reinforcement is the basis of concrete walls, screeds and columns. This important element experiences all the main loads and bending moments, preventing deformation and destruction of the concrete base.

Metal rods of different diameters, which have a circular cross-section, are used as reinforcement. There are two main types of reinforcing metal rods: A1 and A3.

To understand the difference between A1 and A3 fittings, as well as their scope of application, it is necessary to familiarize yourself with their main characteristics and consider their advantages and disadvantages.

Explanation of markings

Marking of reinforcing bars is usually done using letter designations. The letters indicate the exact method by which the reinforcement was produced. So, for example, the presence of the letter A in the name indicates that the product was made using the hot or cold rolling method.

If we compare both methods, it is worth noting that the steel obtained by cold rolling has increased strength characteristics and has greater hardness. The number usually denotes the degree of fluidity of the steel used in the reinforcement; it determines the main difference between the grades of metal. The yield coefficient depends on the maximum stress, which causes the metal to begin to deform.

That is, the higher this indicator, the greater the strength of the rod itself. So, for example, A440 steel has a greater safety margin compared to A240.

When building structures made of reinforced concrete, it is necessary to achieve the best strength of the entire structure, using elements with minimal mass. One solution is to reinforce the structure using a steel frame, for the assembly of which reinforcement of various cross-sectional diameters is used. It can be in the form of skeins or rods.

Each type of reinforcement, regardless of its profile, can be subjected to separate temperature treatment. This can be understood by the addition of “At” at the end of the abbreviation. The reinforcement metal can be cleaned of excess impurities and have a uniform distribution of carbon, which increases the quality of welded joints (a “C” is added to the abbreviation). Copper can be added to the metal in an amount of up to two percent to improve its anti-corrosion properties (at the end of the abbreviation “K”).

Difference between fittings A1 and A3

The main types used in construction are A3, as well as A1 reinforcement, GOST 30136-94. Sometimes you can find other names. For example, A1 fittings are often found under the name A240, and A3 – A400.

The weight of reinforcement A1 and A3 is approximately the same, however, the main difference between these types of reinforcement is that A1 has a smooth surface, and A3 has a corrugated surface. Corrugation provides better contact with concrete. Due to the presence of a corrugated surface on A3, it has better reinforcing qualities compared to smooth reinforcement A1.

The disadvantages of A3 include the appearance of additional stresses due to the need for an additional rolling cycle, which is necessary to form a corrugated surface.

Another disadvantage is the reduction in the effective cross-section of the reinforcement with a constant weight per linear meter, as well as a higher cost due to the complexity of its production. Strength decreases by 6% with an asymmetrical position of the corrugation pattern compared to round reinforcement.

There are differences between reinforcement A1 and A3 in terms of the type of steel used. Typically, steel with a low carbon content in its composition is used for the manufacture of materials. For the manufacture of A3 reinforcement, steels with increased ductility and low carbon content are used. A1 reinforcement is made from stiffer and harder steels. Also, according to GOST, variety A1 should not have corrugation.

The cross-sectional diameter of the reinforcement bars, regardless of the profile, usually varies between 8-25 millimeters. When constructing larger structures, such as bridges and high-rise buildings, reinforcement with a diameter of 40 millimeters is used. The composition of the material with a smaller cross-section includes mild steel that is more deeply purified from impurities. For large diameter fittings, any type of steel with a low carbon content can be used.

Application of fittings

Let's talk about the difference between A1 and A3 fittings in terms of application. A1 is widely used for reinforcing concrete structures in any form, be it a mesh or a complex frame. Smooth reinforcement is also actively used in the construction of any structures that have an auxiliary value (fences, products in the form of gratings, fences, etc.).

A3 reinforcement, which is corrugated, is mainly used for the construction of simple, lightweight and high-strength frame structures made of concrete. This variety is not used in the construction of structures that perform an auxiliary function.

Source: https://FB.ru/article/353712/otlichie-armaturyi-aia-harakteristiki-i-primenenie-v-stroitelstve

A3 fittings: characteristics, price, corrugated

Construction reinforcement is used as an indispensable element of reinforced concrete structures. It is a metal product (rolled metal product) in the form of a rod made of steel (carbon or low-alloy).

It is used to strengthen concrete (hence the name, another term is “reinforcement”) if it experiences tensile or compressive forces.

Reinforcement is used almost everywhere during construction work, during the construction of both monolithic and prefabricated reinforced concrete structures. The chemical composition of the steel used is determined according to GOST.

Product classification

Depending on the properties and qualities of the manufacturing material, as well as the method of creating the reinforcement, there are several classifications, and they also characterize a different type of product (including construction products).

By manufacturing method:

• hot rolled;
• cold rolled.

According to the nature of the surface (profile) of the rod:

According to operational features:

• Strained;
• Unstressed.

The most important characteristic is determined by the composition of the steel from which the products are made. There are several strength classes of reinforcement, each of which can use more than one grade of steel.

Varieties by strength class:

• A-I (A240);
• A-II (A300);
• A-III (A400);
• A-IV (A600);
• A-V (A800);
• A-VI (A1000).

The classification given first (AI A-VI) corresponds to that given in GOST, and the second corresponds to international designations.

Reinforcement of all specified strength classes can also be thermally strengthened, then it is defined as “At” (At400, for example).

Also, one or another type of product can be given additional properties, made more corrosion-resistant (then there is a “K” in the name), or more suitable for welded joints (then, respectively, “C”).

For example, A3 A500 reinforcement, easy to weld, will be called A500C, based on the steel grade.

Product Features

This product class is one of the most frequently used, along with class A1 (mounting fittings). How different the A1 and A3 fittings are, the differences in their application will be described below.

A3 reinforcement is used in construction, since its shape provides better adhesion to concrete - A3 reinforcement is corrugated (there are two longitudinal protrusions-ribs, as well as transverse ribs along the entire length of the rod).

This type of product is also called periodic.

Class A1 reinforcement – ​​produced with a smooth profile and used to form a reinforcement frame or mesh. It should be noted that products of all stiffness classes starting from A2 are made corrugated, with different textures of transverse ribs.

In addition, A3 reinforcement is also much stronger (higher strength class and, in addition, a relatively larger diameter).

In the manufacture of A3 reinforcement, high-alloy steels with various impurities are used, which determines the scope of application in construction, the formation of ceilings/floors and high-rise construction.

A1 fittings are made from low-alloy carbon steel.

It is more resistant to aggressive environments or chemical influences, therefore it can be used in the construction of special structures (for example, in the mining industry or oil refining industry).

It is also noted that it is easy to weld and the weld seam is not subject to destruction.

There are cases when A1 reinforcement can be used; A3 class is also acceptable - for example, when forming the foundation of a private house. Here only the diameter of the product will play a role.

Technical characteristics of A3 reinforcement may vary depending on the grade of steel, the diameter of the rod or the texture of the rib pattern.

First of all, different types of A3 fittings may differ in the grade of steel they are made of. So it could be steel grades 35GS, 25G2S or 32g2Rps.

More modern analogues of these steel grades are also used, corresponding to international designations - A400s and A500s (indicated - “Armature A3 A500s”)

GOST reinforcement A3 stipulates that rod products of this class are produced with a nominal rod diameter from 6 to 40 mm.

GOST 5781 82 for A3 reinforcement provides an approximate weight of 1 meter of this product from 0.22 to 7.99 kg and a cross-sectional area from 0.28 to 10.18 cm2.

Knowing these parameters, you can accurately calculate the weight of the necessary products for domestic construction (for example, when building a foundation), and therefore the cost of the required amount of material.

In addition, different types of patterns of transverse ribs of A3 reinforcement can be used, which also affects the scope of its application. The pattern can be crescent-shaped or ring-shaped.

Reinforcement with a ring pattern is used to form massive concrete structures - it has better adhesion to concrete.

Products with a crescent pattern are more resistant to tearing, therefore they are used for the construction of thin-walled structures.

Nuances of choice

When purchasing this type of product, you should pay attention to the availability of all the necessary documentation and relevant certificates from the seller.

In addition, they contain complete information that allows you to accurately determine what type of product is being purchased.

If the seller does not provide documents, the fittings may turn out to be of poor quality and not meeting established standards.

It should be noted that the certificate of conformity of A3 fittings is not mandatory from the point of view of law. But the seller who has such an A3 fittings certificate will be in an advantageous position.

The presence of a certificate means that A3 corrugated fittings (or products of any other type in general) have passed a series of tests for compliance with GOST in terms of quality indicators.

For example, a certificate for fittings 12 A3 (quality certificate) will contain the name of the seller, a list of standards to which the product meets, the results of an analysis of the chemical composition of the steel and its grade, the mechanical properties of the steel and the weight of a specific delivery.

Visually, you need to make sure that there are no chips or painted areas on the rod, as this affects the adhesion to concrete. Also, the permissible curvature of the reinforcement per one meter (but not more than 7 mm) has been standardized.

It is quite acceptable to buy A3 fittings that have rust on them - this is not a sign of defective material and is acceptable for metal structures of this type. A3 8 mm reinforcement can be supplied not in rods but in special coils.

The price of A3 fittings will primarily depend on the diameter and weight.

Thus, A3 reinforcement with a diameter of 10 mm, regardless of the steel grade, can cost about $56 per meter.

In another option, by weight (which is standard), class 12 A3 reinforcement (A400c steel) costs an average of $560 per ton. Rebar 16 A3 (A500s steel) will cost $500 per ton on average.

Application of products (video)

Source: http://HomeBuild2.ru/stroitelnye-materialy/armatura-a3.html

Armature

Reinforcement is a type of building material used for the manufacture of monolithic structures. It also has such names as: construction reinforcement, corrugated reinforcement, steel reinforcement, A3 reinforcement, A500s reinforcement.

AREAS OF APPLICATION

Construction of buildings and structures, production of reinforced concrete structures (slabs, etc.), bridge construction, production of foundations, floors of private houses, production of reinforcing mesh.

DIAMETERS AND TYPES OF PRODUCTS

Reinforcement from factories in the Russian Federation is supplied hot-rolled and cold-deformed with quality certificates, manufactured according to regulatory documents GOST 5781, GOST R52544, GOST 10884, GOST 6727, according to TU, STO ASChM 7-93. The form of delivery from factories is bars of measured and unmeasured lengths and coils (coils).

Reinforcement in coils is made with a diameter of 5 to 12 mm, internal diameter 400-900 mm, external 800-1250 mm, height 600-2000 mm, weight varies from 800 kg to 3000 kg.

Reinforcement in rods is made with a diameter of 5 to 40 mm, rod length; standard measured 6m, 9m, 11.7m, 12m and unmeasured from 4 to 11.7 meters. Manufacturing plants have the ability to produce fittings of any other length, at the request of the customer.

If we talk about the diameters most often used in construction, we can note the following sizes: 10 mm, reinforcement 12 mm, 16 mm, 25 mm.

ASSORTMENT AND CLASSIFICATION OF FITTINGS

The fittings are divided into classes and have alphanumeric designations:

A - for example A500C, AT800 where A - means hot-rolled or thermomechanically strengthened reinforcing bars. B500С where B means that this is cold-deformed reinforcing bar. C - this rolled product is weldable, the numbers 400, 500, 800 mean a yield strength of at least 400 N/mm, 500 N/mm, 800 N/mm.

Reinforcement A-I (A240) is hot-rolled steel of round section which has a smooth profile and is produced with a diameter from 6 mm to 80 mm.

Reinforcing bars of class A240 are manufactured with a diameter of up to 12 mm inclusive in coils (coils) and rods (length 6m, 9m, 11.7m, unmeasured length), reinforcement diameters from 14 to 40 are manufactured only in rods.

In the manufacture of class AI reinforcing steel, the following grades of steel are used: boiling steel St3kp, semi-quiet steel St3ps, calm steel St3sp.

Reinforcement AIII (A400) is a steel periodic profile of circular cross-section with a corrugated surface, which is manufactured according to GOST 5781-82 from structural low-alloy steel grades: steel 35GS and steel 25G2S with the addition of alloying elements such as manganese and silicon. Produced in diameters from 6 to 80 mm. In the USSR it was the main type of reinforcement used for reinforced concrete products.

The disadvantage of the reinforcement is that arc welding is prohibited for steel 35GS according to SNiP 2.03.01-84, due to a decrease in the ductility of the steel at the welding points, as a result of high heat input, which can lead to the destruction of reinforced concrete structures during the construction process.

Refusal to weld when performing construction work forces us to provide significant reserves for the cross-section of reinforcement, which leads to the use of more meters of rolled reinforcing bars and an increase in cost.

A500S reinforcement is hot-rolled thermomechanically strengthened reinforcing steel, initially manufactured according to STO ASChM 7-93 by the Severstal plant and other factories in accordance with GOST R 52544-2006. At the moment, or more precisely, since July 2016, the only regulatory document remains GOST 52544-2006, which regulates the production of steel reinforcement class A500C. Produced in diameters from 4 to 40 mm.

Compared to A400 fittings, it has a number of advantages. This is strength and flexibility due to an increased yield strength of at least 500 N/mm2. Lower cost due to the absence of alloying elements in steel. The profile does not have intersection points of longitudinal and transverse ribs, the presence of which can lead to the formation of fatigue cracks.

Increased weldability allows the use of arc welding when installing and laying reinforcement.

Profile of fittings A500SProfile of fittings A400

A500 fittings are manufactured at the Tula TMPZ plant by hot rolling from high-carbon quality steel grade 76, which is used in the manufacture of rails and complies with TU 093311-313-36554501-2014.

The following types of workpieces are used for the production of this reinforcement - a steel square or a decommissioned rail. Profile dimensions from 8 mm to 22 mm, mechanical characteristics and weight of 1 meter of length correspond to GOST 52544-2006.

The distinctive feature and disadvantages of this reinforcement is that it is laid without arc welding, that is, it is overlapped or using mechanical connections, and the cross-shaped connections of the rods are made knitted. Also, this reinforcement breaks when the bending stress exceeds 40°.

The reinforcement is used in the form of individual rods, as well as as part of knitted reinforcement frames and meshes, in monolithic reinforced concrete structures of buildings and structures of any purpose and level of responsibility in accordance with GOST 54257. The advantages of this reinforcement are that it has increased corrosion resistance compared to class A500C.

REINFORCEMENT GOSTS

GOST 10884 this GOST divides reinforcing steel into classes depending on the mechanical properties of the strength class - which corresponds to the yield strength measured in newtons per mm2 square millimeter and operational characteristics - indices C, K where C (weldable), and K (resistant to corrosion cracking) . Examples of these products are reinforcing steel: class At1200, class At1000K, class At500S, class At600, class At400S, class At600S, class At1000K, class At600K, class At800, class At800L, class At1000.

GOST 5781 This GOST subdivides steel reinforcement depending on its mechanical properties. Developed in the USSR and until recently it was the main type of reinforcement for reinforced concrete products.

Class A-I (A240), class A-II (A300), class A-III (A400), class A-IV (A600), class A-V (A800), class A-VI (A1000).

Steel reinforcement of class A-I (A240) is made only smooth, and classes A-II (A300), A-III (A400), A-IV (A600), A-V (A800) of periodic profile and smooth (at the request of the consumer ), and steel class A-VI (A1000) - only periodic profile.

GOST 52544 This GOST applies to reinforcing bars of class A500s and B500S (where A500s is hot-rolled steel without thermomechanical or other subsequent processing, and B500s is mechanically and thermomechanically strengthened rolled steel). At the moment, fittings produced in accordance with this GOST are the most common and popular in the construction industry.

TYPES OF FITTINGS

Steel reinforcement - metal

• corrugated reinforcement - round reinforcement with a periodic profile: made of reinforcing steel - steels used in production are st3, 35gs, 25g2s, class a500s, a400, a500, a300, a600, a800, a1000
• smooth reinforcement - has a round cross-section and a smooth profile surface: made of reinforcing steel - steel used in production is St3, class A240

Composite reinforcement - plastic

• fiberglass
• basalt-plastic

Main parameters and dimensions

The nominal diameter and cross-sectional area, the weight of 1 meter of length of reinforcing bars, permissible deviations in weight relative to a linear meter must correspond to those indicated in the table.

Nominal diameter of rolled products, dн, mm	Nominal cross-sectional area Fн, mm2	Weight of rolled products 1 m long
Nominal, kg, theoretical weight/DO	Permissible deviations, %
6	28.3 Fn, mm2	TV = 0.222, DO = 0.204-0.239	±8%
8	50.3 Fn, mm2	TV = 0.395, DO = 0.363-0.426
10	78.3 Fn, mm2	TV = 0.617, DO = 0.586-0.647	±5%
12	113 Fn, mm2	TV = 0.888, DO = 0.843-0.932
14	154 Fn, mm2	TV = 1.21, DO = 1.149-1.27
16	201 Fn, mm2	TV = 1.58, DO = 1.501-1.643	±4%
18	254 Fn, mm2	TV = 2.00, DO = 1.92-2.08
20	314 Fn, mm2	TV = 2.47, TO = 2.371-2.568
22	380 Fn, mm2	TV = 2.98, DO = 2.86-3.099
25	491 Fn, mm2	TV = 3.85, TO = 3.696-4.004
28	616 Fn, mm2	TV = 4.83, DO = 4.636-5.023
32	804 Fn, mm2	TV = 6.31, DO = 6.057-6.562
36	1018 Fn, mm2	TV = 7.99, DO = 7.67-8.309
40	1256 Fn, mm2	TV = 9.86, DO = 9.465-10.254

Rebar diameters, types, classes, price per ton

Our Metal Base sells fittings and offers to buy fittings of classes a500s, 35gs, 25g2s, a500, a400, a240, at wholesale prices. We have corrugated, smooth and composite steel reinforcement in stock in any quantity.

With us you can find out the price per meter or price per ton for fittings of any type and diameter, as well as get a calculation of the cost of your order. The fittings can be purchased for delivery or pickup.

You can order metal via email, WhatsApp, feedback form and by phone.

Source: https://ros-met.com/armatura/

A3 fittings: characteristics, weight, diameter, GOST:

When carrying out any construction or repair work, one of the main materials is A3 reinforcement. It is used as load-bearing reinforcement in the construction of reinforced concrete structures, to strengthen various metal structures. The main task of such products is to improve the strength of concrete products.

Types of fittings

Reinforcement is a rolled metal product. Depending on its purpose, conditions of use and type of steel, it is divided into six classes. One of them is A3 (A400) fittings. There are two types of reinforcement profiles: smooth (constant cross-section) and corrugated (ribbed).

The smooth profile is mainly produced according to individual orders. Corrugated reinforcement A3 has two longitudinal ribs, which are made at equal intervals at the same angle to the longitudinal line of the rod, and two transverse protrusions. Thanks to the periodic profile, better adhesion of the reinforcing bar to the concrete is ensured.

Production methods

A3 reinforcement is manufactured by hot rolling. If the products are additionally hardened by heat treatment, the result is thermally strengthened reinforcement, designated At.

When cold, reinforcing bars can be strengthened by drawing. Such rods are used for the production of prestressed reinforced concrete structures.

The letter C is added to the name of the fittings suitable for welding; the letter K is resistant to corrosion cracks.

Diameter

A3 reinforcement can have the following rod diameters: from 6 mm to 40 mm. In this case, products from 6 mm to 10 mm are produced in coils, which are then unwound and cut into pieces 6 meters long, or in the form of rods. With a diameter of 12 mm and above, reinforcement is produced only in the form of rods 12 m long. In the construction of buildings and structures, A3 reinforcement 12 mm, 14 mm, 18 mm is most often used. As mentioned above, reinforcement products are produced in coils or in the form of rods.

The marking of various reinforcing bars must include their diameter, reinforcement class and GOST number according to which they are manufactured. For example, 10-A-3 GOST 5781-82 - this is how an A3 reinforcement rod with a diameter of 10 mm is designated.

A3 fittings: weight

In most cases, the amount of material required is calculated in linear meters. But for delivery to the work site, a weight calculation is often required, and you also need to know what volume the A3 reinforcement has. Weight is calculated based on the diameter of the product.

Diameter, mm	Quantity m in 1t	Area, sq. cm	Weight 1 m, t
Rod d=6	4 504,50	0,283	0,000222
Rod d=8	2 531,65	0,503	0,000395
Rod d=10	1 620,75	0,785	0,000617
Rod d=12	1 126,13	1,131	0,000888
Rod d=14	826,45	1,540	0,001210
Rod d=16	632,91	2,010	0,001580
Rod d=18	500,00	2,540	0,002000
Rod d=20	404,86	3,140	0,002470
Rod d=22	335,57	3,800	0,002980
Rod d=25	259,74	4,910	0,003850
Rod d=28	207,04	6,160	0,004830
Rod d=32	158,48	8,040	0,006310
Rod d=36	125,16	10,180	0,007990
Rod d=40	101,32	12,570	0,009870

Technical requirements

For the production of class A3 fittings, carbon or low-alloy steel grades 35GS or 25G2S are used. In terms of chemical composition, carbon steel must comply with GOST 380.

When producing low-alloy steel, the presence of carbon is necessary: ​​35GS - from 0.3% to 0.37%, 25G2S - from 0.2% to 0.29% and manganese: 35GS - from 0.8% to 1.2%, 25G2S – from 1.2% to 1.6%. In addition, the composition of the 35GS brand also includes sulfur - 0.045% and phosphorus - 0.04%.

In addition, the addition of titanium during manufacturing is allowed: from 0.01% to 0.06%.

Mechanical characteristics of class A3 fittings:

• The yield strength is not less than 40 kgf/sq.m. mm.
• Temporary tensile strength is not less than 60 kgf/sq.m. mm.
• Relative elongation – 14%.

On the entire surface of the reinforcing bar, including protrusions and ribs, cracks, ruptures, rolling sunsets and caps are not allowed.

Application area

The fittings are used for civil construction of buildings and structures, industrial construction. A3 reinforcement is the most common and popular class, especially for use in massive and heavy structures. Scope of use:

• Construction of metal structures.
• For reinforcing concrete products.
• Strengthening floors and walls of buildings and structures.
• Reinforcement of reinforced concrete products.

Such products are used for reinforcing concrete in order to give it additional rigidity, as well as for the production of various welded metal structures: grilles for windows and doors, metal fences, reinforcing mesh.

The use of reinforcing bars extends the operational life of buildings. The strength and durability of the structures being built depends on the quality of the reinforcement used. A3 has good technical indicators, such as strength, elasticity of steel, and its weldability.

A3 reinforcement is also used for monolithic concreting.

Rods of size d=10 mm are used as the main reinforcement when used in low-rise construction, and as clamps for beams and crossbars in high-rise construction. A3 with a diameter of 12 mm is used in main load-bearing structures, foundations and monolithic walls. Due to its larger diameter, it has a smaller laying step - 20 cm. For the foundation, rods of at least 10 mm in size are used. The larger the diameter of the reinforcing bars, the stronger the foundation frame.

A3 fittings: GOST standards

A3 reinforcement is produced in accordance with GOST 5781-82 “Hot-rolled steel for reinforcement of reinforced concrete structures”.

Since the quality of the resulting product depends on the source raw material, and the strength and reliability characteristics of future buildings and structures depend on it, GOST imposes strict requirements on steel, which is used for the manufacture of reinforcement products.

At3 reinforcement is produced in accordance with GOST 10884-94 “Thermomechanically strengthened reinforcing steel for reinforced concrete structures.” It replaced the previously valid GOST 10884-81 “Reinforcement rod steel thermomechanically and thermally strengthened with periodic profile.”

A400S and A500S fittings

One of the most popular types of A3 fittings can be called A400C and A500C. Such products are produced with diameters ranging from 6 mm to 36 mm and lengths up to 11.7 m. The composition includes titanium, silicon, chromium, which significantly increases the strength of steel.

The scope of use of these types of reinforcement is the reinforcement of reinforced concrete products. When bars are arranged longitudinally in concrete, reinforcing bars protect it from cracks and work in tension.

With transverse cracking, they prevent inclined cracking from forming and work on compression.

Comparative table of characteristics of A500C and A400C fittings

Mechanical properties and scope	А500С	А400С
Tensile strength, N/sq. mm	600	590
Ultimate fluidity, N/sq. mm	500	390
Relative extension, %	14	14
Bending angle with a mandrel diameter equal to 3 rod diameters	180 degrees	90 degrees
Calculated tensile strength 6 - 8 mm, N/sq. mm	450	355
Calculated tensile strength 10 - 40 mm, N/sq. mm	450	365
Calculated compressive resistance, N/sq. mm	450	—
Calculated resistance, N/sq. mm	500	390
Use at sub-zero temperatures	Up to 55 degrees	Up to 40 degrees
Using arc tack welding of cruciform joints	Maybe	Not allowed

Most buildings and structures are currently being constructed from reinforced concrete products or monolithic concrete. The use of reinforcement is an integral part of this process.

With the development of new technologies, this material is also being improved, and more high-tech varieties are appearing. The use of A3 fittings will continue to be constant in the future; its demand is only increasing. When A3 reinforcement is used in a building structure, its quality increases significantly.

Source: https://www.syl.ru/article/312499/armatura-a-harakteristiki-ves-diametr-gost

Difference between A3 and A500S fittings

APEX METAL sells A3 and A500C fittings from leading Russian manufacturers of the following types:

• rods with a nominal diameter of 6 - 40 mm;
• skeins (coils) 6 - 10 mm.

Rebar of class A3 and A500C is produced on medium- and small-section mills using the hot rolling method. To do this, a workpiece of the required cross-section is heated in a methodical furnace and sent first to the roughing and then to the finishing group of stands. After the geometry is formed according to the technological map, the finished product is either wound into coils on a special winder, or cooled, cut into rods of the required length and packaged.

The difference between one class of rolled rod and another is that they are produced according to different standards: A3 is manufactured in accordance with GOST 5781-82, A500S - in accordance with STO ASChM 7-93 and TU. GOST requirements are more stringent than those of TU, ​​in addition, there is a key difference - the use of alloying elements in the chemical composition of steel.

A500C fittings are made from semi-quiet or calm steel with a carbon content of 0.14-0.22, where 3 is a conventional number and it is marked with Art. 3sp/ps. A3 fittings are made from low-alloy steel 35GS and 25G2S; you will see the difference between them just below.

Important! On January 1, 2018, the interstate standard GOST 34028-2016 came into force, replacing the previously existing GOST 5781-82.

Characteristics and differences between steel 25G2S and 35GS

We are often asked the question, which A3 reinforcement is better to buy and what is the difference between 25G2S and 35GS steel? The main difference between the grades is the percentage of alloying elements, but you need to know that in both steels there should be less than 0.3% nickel, chromium and copper, phosphorus - up to 0.04%, maximum sulfur concentration - 0.045%). Reinforcement 25G2S has better weldability; it can be welded manually, which is of great practical value in the construction industry; 35GS is used mainly for tying into frames.

Distinctive features A3 fittings, art. 25g2s Armature A3, st. 35gs

Weldability	weldable	conditionally weldable
Chemical composition, in%
C (carbon)	0,20 — 0,32	0,30 — 0,37
Mn (manganese)	1,20 — 1,60	0,80 — 1,20
Si (silicon)	0,60 — 0,90	0,60 — 0,90

Theoretical weight 1 meter

Diameter of reinforcement (A3 and A500C), mm Weight of 1 meter of reinforcement (A3 and A500C), kg

6	0,222
8	0,395
10	0,617
12	0,888
14	1,210
16	1,580
18	2,000
20	2,470
22	2,980
25	3,850
28	4,830
32	6,310
36	7,990
40	9,870

Welding fittings

Price list for A500C reinforcement in rods and coils with a diameter of 10, 12, 14, 16, 25, 28 mm, made from st. 3 sp/ps for the construction of buildings and structures.

Knitting reinforcement

Prices for AIII reinforcing bars with a diameter of 10, 14, 16, 18, 20 mm, made from 35GS steel for tying metal frames using T/O wire.

Source: https://apex-metal.ru/articles/armatura_a3_a500s_otlichiya/

A500S fittings: steel grade and quality determination

A500S fittings are one of the most popular types of fittings today. These are special A5 brand rods, whose diameter ranges from 6 to 40 millimeters. When producing this type of material, the requirements of GOST number 52544 2006 are observed. These are structural elements that are subjected to heat treatment during the production of such a part as A500C reinforcement; we will consider what this is further .

Basic information and terms

The main material is steel, with a carbon content of 22%. Thanks to this number of initial components, the strength characteristics of the final product are improved. Production costs, as well as raw material consumption, are significantly reduced. Fastening between the joints is organized using arc welding.

The scope of application is quite wide:

1. For frame connections, when reinforced concrete products are produced.
2. For private construction, in the case of monolithic concreting.

The use of the material in practice involves the participation of bending machines.

Such products can withstand tensile loads, this is a positive characteristic. This promotes the use of products for structures with prestressing and thin walls. A universal type of material, one of the most popular. This is the A500 C reinforcement, the steel grade for which is carefully selected.

What features does the fittings have?

Marking with letters and numbers A3 is considered obsolete. A more correct designation for rental is A400. But often in practice the old version is used. GOST 5781-82 regulates technical conditions with basic characteristics. The varieties of carbon steel used in production have their own designations - 25G2S and 35GS. The difference between A300 and A400 in the main parameters leads to a decrease in ductility and an increase in the fragility of welded joints.

The demand for A3 is more than logical, taking into account the following points:

• High strength.
• Using knitting wire or clamps to connect frames.

Areas with high stress also do not exclude the possibility of using such types of reinforcement. They purchase reinforcement for the construction of various types of structures:

1. Pillars.
2. Columns.
3. Supports.
4. Foundations.

A3 and A500C: the difference between classes

The model range includes corrugated rods, whose diameter ranges from 6 to 40 millimeters. The total length will be up to 11.7 meters. Both varieties represent a group of hot-rolled products. Profile A3 has the following features:

• Ring appearance.
• Along the perimeter, the ribs are located more often.
• The design is characterized by the intersection of transverse protrusions and two longitudinal ones.

The rod and concrete form better joints with such adhesion. This contributes to the operation of products for monolithic structures made of reinforced concrete. For welding work, the most convenient will be the sickle-shaped A500C, characterized by sparser protrusions.

The first letter in the marking is needed to indicate the manufacturing technology and type of product. The letter A is used for heat-strengthened, hot-rolled products.

The following numbers characterize the type of steel that was used for production. If the rolled product has special properties, use another letter at the end.

1. C - this means that the rods require the use of electric arc welding.
2. K show high resistance to corrosion.
3. T says thermomechanical strengthening was applied to the steel.

Often, additional numbers are included in the marking to indicate the specific diameter of the A500C fittings, for which GOST is installed separately.

About the cost

The cross-section and mass remain almost the same for all types of such reinforcement. Only the manufacturer's markings and the specific profile lead to some differences in appearance. The prices themselves are determined by several parameters:

• Delivery terms.
• Batch volume. The larger it is, the more profitable the purchase will be.
• Seasonality. The summer season contributes to an increase in operating costs.
• Demand for a certain diameter, 12 millimeters remains the most popular size. This is important when choosing A500C fittings; what class - A1 or A3 - is decided by the buyer.

The difference in price also depends on the content of alloying components. The fewer there are, the cheaper the product costs. With a cross section of up to 6 millimeters in diameter, the product sales form is coils. But in most cases they sell cutting rods up to 12 meters long. Without proper recalculation, it is not recommended to simply replace A3 with A500 C. At the same time, the welded type of material is considered more universal.

Recommended reading:

Which foundation reinforcement to choose: types of material and calculation of the required quantity

Simple and proven methods of tying reinforcement for the foundation of a house

Additional benefits of using reinforcement

Permission for welding using electric arc devices is the main advantage that the 500 C fittings have. This possibility is indicated by the last letter in the marking.

A small amount of alloying components also helps to improve weldability. On average, modern technologies contribute to savings of more than 10% in production. Moreover, when compared with other existing classes. With a mandrel diameter, the bending angle can reach up to 180 degrees for A500C reinforcement, the price per ton for which also depends on this.

The fittings also have other distinctive characteristics that you should familiarize yourself with in advance:

1. Low cost production.
2. Production of products with savings in steel volumes.
3. Increased strength and ductility. There are no fragile places leading to the destruction of the entire structure.

The relevance of reinforcement increases for compressed elements. The saturation of columns with metal elements is reduced, and therefore there is less likelihood of corrosion. This type of fittings can be used instead of similar diameters A1 and A3. In the manufacture of critical structures, the material is used due to thermal, thermotechnical hardening.

Operation in Russia and main features

In Russia, this material was not only released for the first time, but also new standards were drawn up regulating the specifics of production. During the production process, samples are selected from each bundle of rods for which separate tests are carried out.

Because of this, production costs increase to some extent. But the percentage of misgrading is lower as a result. The result is high-quality A500C fittings; which class to choose is up to the customers to decide.

But when determining the fluidity of products, it is still almost impossible to avoid mistakes. Therefore, a special profile was developed, designated A500SP. Thanks to the use of this profile, it becomes easy to determine which class the reinforcement belongs to. Adhesion to the concrete mixture also improves during practical use.

The grip with the new profile is 20% better. The rigidity of the reinforcement increases by 30%. The limit of insertion of rods into profiles becomes larger.

Technological recommendations are described in a special document developed separately for fittings of this type.

During perestroika, the amount of reinforcement produced in coils decreased significantly. The production of diameters 6 and 8 millimeters has practically reached zero. Production capacities were freed up, which were then converted to create wire rods.

The following methods are used for so-called anchoring. If necessary, you can combine methods with each other:

• The end of the rod, supplemented with special devices.
• Additional rods, mounted or welded.
• A claw or hook placed at the end of a rod.
• Carrying out direct anchoring with a straight rod.

It is not recommended to bend the bars at the end when it comes to using compressed reinforcement.

Depending on the diameter of the reinforcement, the length of the anchorage can be reduced. The way the procedure is performed also influences the decisions that the masters make.

A500S reinforcement – ​​knitting technology

To create a frame, use regular wire or clamps. In the latter case, owners have the following advantages:

1. A simple mechanism for creating connections.
2. Quality.
3. Strength.

Flexibility and ease of use are characteristic of steel wires, in the manufacture of which low-carbon steel is used. The method of surface treatment is determined by the color design of the products. The white color suggests that zinc was used. Black confirms the absence of any additional types of processing.

1.2-1.4 millimeters is the recommended diameter of the wire used. Then strength and reliability remain at a sufficient level.

Tie wire is cheaper than PVC clamps. But plastic elements also have additional advantages:

• Connections made as easy as possible to create.
• High speed of work.
• Strength indicator.

The original geometry indicators are preserved even if the load is maximum. Of the negative aspects, there is only weak protection against the effects of negative aspects. If you leave such a frame in the cold, the clamps will break or the elasticity will decrease.

An acceptable option is plastic clamps with steel cores. This option can often be seen inside cable pipelines and pipes with low-current networks.

Knitting reinforcement with a hook is usually performed in four common ways. The main differences lie in the reliability of elements and connections, and the speed of creating frames. The use of special guns reduces the speed of construction of any structures. The economic effect will also be positive with this decision.

The reinforcement is knitted at the same time as the foundation is created. Thanks to this approach, the structure is strong and rigid, quite reliable. The use of welded joints is abandoned; they do not tolerate increased loads well. When choosing a welding method, you need to evaluate all factors, positive and negative sides.

Welding is the most popular method for those who want to connect any elements into a frame. After all, the material itself is highly weldable. Only in some cases welding will not be as rational a solution as knitting.

If the reinforcement has a diameter of 16 millimeters or more, then welding is allowed without fear of changing the original characteristics. At 10-14 millimeters, this option is also acceptable, but only if there are no seismic loads in the area. Otherwise, the plates will begin to move, which leads to the destruction of the entire structure.

The A500C fittings have a wide range that can be selected for almost any situation. But complex engineering and geological conditions and high loads impose some restrictions on the use of welded joints. Welding is used for buildings with a small amount of shrinkage. The situation is associated with the absence of dynamic oscillations.

Economic efficiency reaches its maximum in the case of large volumes of work. High-rise monolithic structures are often equipped with frames manufactured at specialized enterprises. This helps to reduce the costs of construction itself, and the costs of further work are also reduced. For welding, frames with meshes are assembled at the construction site if the amount of work is small. The solution is based on the customer with his current needs.

conclusions

A500S fittings are the most modern development in the direction of fittings. This class of products differs from others when it comes to the visual component. The structure has no longitudinal ribs; it is complemented by three profiles or a large number of them.

If cold forming is used for steel, then the advantage is the use for the production of welded mesh with the absence of scale. In this case, conventional welding with electrodes for connection is prohibited.

But even the susceptibility to corrosion can be easily circumvented if you choose the material and construct the structure wisely.

Source: http://blog.kpmtrade.ru/sortovoj-prokat/armatura-a500s/

A1 fittings and A3 fittings. What is the difference

There are many types of steel reinforcement. The most commonly used fittings are a3 and a1. The article talks about the differences between them, which material is more often used for certain jobs.

Characteristics of fittings

• Profile type. It can be smooth or periodic, with longitudinal and transverse ribs. The ribbing improves adhesion to the concrete mortar, which increases the strength of the structure. Smooth reinforcement is much easier to weld.
• Diameter of rods. The larger it is, the higher the strength. It must be remembered that along with the cross-section there is an increase in the mass of the reinforcement frame.

  In some situations this can be quite important.

• Steel grade. The strength and anti-corrosion properties of the product depend on it. Corrosion resistance is important if the structure is located in an aggressive environment, places with sudden and large temperature changes and where there is high humidity.

In GOST 5781-82, for each grade and diameter, the characteristics of steel reinforcement are indicated, based on which calculations are made before construction.

Features of a1 fittings

Distinctive features and advantages:

• The profile is smooth.
• Made of low-alloy steel (St3sp, St3ps, St3kp).
• The diameter of the reinforcing bars ranges from 6 to 40 mm.
• Has high corrosion resistance.
• Tolerates sudden changes in temperature and high humidity.
• Easy to weld.

Flaws:

• Poor adhesion to concrete mortar. However, for many jobs it is sufficient or does not play a significant role.

The old marking of the fittings is A1, the new one is A240. It is used for finishing facades, strengthening columns, for foundations and in reinforced concrete products (slabs, rings, beams, etc.).

Features of A3 fittings

Distinctive features and advantages:

• Profile – with transverse or longitudinal ribs.
• Steel grades - 35GS, 25G2S and 32G2Rps.
• Diameter for rods made of steel 35GS, 25G2S from 6 to 40 mm.
• Diameter for rods made of steel 32G2Rps from 6 to 22 mm.
• Good adhesion to concrete and increased structural strength.

Flaws:

• Low corrosion resistance.
• High price compared to A1 fittings. A3 fittings are approximately 30% more expensive than A1.

The old marking is A3, the new one is A400.
It is used where increased strength is needed: in the construction of bridges, dams, in monolithic buildings where there are high loads and pressure. Often, fittings of both types are combined with each other.

Source: https://cxemok.ru/poleznoe/1666-armatura-a1-i-armatura-a3-chem-otlichayutsya.html