Modern construction technologies industrial buildings and residential buildings today, as before, among the structural elements of structures, various types of structures are used, united by one name - a beam. According to its purpose, this element of the building is intended to act as a supporting mechanism. Located on two or more building pillars, such an element takes on the load and allows you to create floor slabs, connecting the spans, is one of the main elements of the building's roof structure.

Traditionally, in the construction of buildings, beams are used that correspond to the type and purpose of the buildings, and therefore there are different kinds classifications of these elements. Most often, the classification is carried out according to the type, purpose, form and material of this structural element.

General information about the device and purpose

In construction, beams are classified, first of all, depending on how many supports it rests on:

Structurally, the simplest beam used in low-rise frame-panel housing construction for the attic floor is a solid bar rectangular, but for more demanding structures than simple country house elements that are somewhat different in shape are required that can withstand heavy loads:

In addition, special requirements are imposed on construction materials:

Most demanded in construction, when erecting roofs industrial facilities, T-shaped or I-shaped profiles are used, they are here the main elements of roof structures. This is due to the fact that this shape works most effectively under bending loads.

I-beams - in their cross-sectional shape they resemble the letter "H". Each element has its own name - the vertical parts of such a letter "H" are called shelves, and the dash connecting them is called a wall. Due to this shape, the profile is able to withstand higher loads than a rectangular material in cross section. In addition, I-beams allow the use of additional methods for increasing the strength of the structure:

• for the most critical sections of the roof, I-profiles with a thickened wall are used;
• for secondary sections, girders are used, the inner edges of the shelves, which are parallel to each other;
• to increase the rigidity of the structure, profiles with a slope on the inner edges are used.

Materials and technologies for manufacturing floor elements

Depending on the purpose of the building, the technology of its construction and the conditions for its subsequent operation of the roof, beams are classified both by the type of material used and the method of manufacturing the finished element:

1. Reinforced concrete structures:

• are made by the method of monolithic casting of the form with the obligatory use reinforcement cage in the factory, as a rule, these are T-profiles of a complex frame structure;
• monolithic structures - produced by casting the form directly on construction site when erecting buildings using monolithic frame technology.

1. Metallic:

• metal elements made by hot rolling of finished metal;
• special types of products from individual elements connected by welding;
• products from light alloys for special types of roofing - stadiums, concert halls, exhibition complexes.

1. Wooden:

• from a solid bar of various sizes;
• composite crossbars made of separate parts, connected together by an adhesive method using, as natural wood and wood-based materials - plywood, fiberboards.

Classification and marking of steel elements

The classification of steel structures is carried out and has its own alphanumeric code. Such coding makes it possible to carry out the necessary classification and take into account the elements necessary for the parameters in construction even at the stage of development of design and estimate documentation.

The basis for this type of classification is the officially approved state standards and the technical conditions by which all types of beams are classified, regardless of the material of manufacture or manufacturer.

So, in the marking of steel I-profiles, in addition to indicating their dimensions, and the height can be from 100 mm to 1000, an alphabetic code is also indicated, which indicates, for example, the dimensions of the edges of the shelves:

• "B" - means that the product has a normal width of parallel edges;
• "Ш" - indicates that the shelves have an increased width and are classified as "wide-shelf" products;
• "K" - says that such a profile can be used as a column support.

The use of wooden elements in various roof structures

In low-rise housing construction, when erecting a roof, beams are used as elements of various purposes and sizes:

The most suitable for these functions are I-beam glued wood elements, which are very strong, can withstand heavy loads and are lightweight compared to solid wood lumber. Feature of all kinds wooden structures used in the construction of the roof of the building is the use of lumber conifers for the device of rafters, spacers, the frame of partitions and hard wood for the device of overlap attic floor.

Sergey Novozhilov - an expert in roofing materials with 9 years of experience practical work in the field of engineering solutions in construction.

The field of application of welded metal beams is mainly related to construction - of which frames of structures, bridges and other metal structures are mounted... Welded I-beams are especially popular for the construction of industrial facilities, workshops and other structures with large spans.

I-beams, welded from steel, as metal structures and metal frames for construction, facilitate the structure. They are more economical in terms of the shape of the supports, because this reduces the mass of the metal used in the structure.

An I-beam or, in other words, an I-beam is manufactured in accordance with GOST 535-88. Products may differ in the size or type of shelves and walls, which is associated with the purpose of a particular type of beam in construction work.

Classification and labeling

There are different types of I-beams.

With parallel flange edges:

• normal (beam B - 20B and further);
• wide-shelf / wide (beam Ш - 20Ш and further);
• columnar (beam K - 20K and further).

Wide flange beams apply, as the name implies, for load-bearing structures as guide supports.

Column beams They are distinguished by an impressive thickness of lintels and shelves, thanks to which they are resistant to significant loads.

Beams with a slope of the edges of the shelves are of the following types:

• ordinary I-beams(beam B with a slope of the inner edges of the shelves of 6-12%);
• special (beams M and C);
• bridge or monorail beams(beams M - I-beams for overhead tracks with a slope of the inner edges of the shelves up to 12%): 18M, 24M, 30M and more;
• special building bulk and (C beams - I-beams for reinforcing mine shafts with a slope of the inner edges of up to 16%): 14C, 20C and further. The assortment of such I-beams is determined in accordance with GOST 19425-74.

The number in the marking of steel I-beams is its height, measured in centimeters.

Low alloy beams

They are manufactured in accordance with GOST 19281. Low alloy steel beams widely applicable in industry and construction. These beams are T-sections.

A metal beam belongs to a special type of high-quality rolled metal and is mainly used to create large-span structures of industrial buildings, which can significantly reduce total load on the base of the structure. Today it is one of the most important components of any work site, bridges, floors and other types of metal structures.

Each type of this product has its own individual characteristics, which allows you to do right choice... It must meet the requirements for technical specifications to be able to create the required design. V modern construction metal beam is widely used. Its choice is carried out according to such criteria as the size of the walls, shelves and type.

A metal beam is manufactured in two main types. The main difference is different form its cross-sections are a T-beam and an I-beam. A T-beam, when viewed from the end, resembles the letter "T", while an I-beam - the letter "H" or double inverted letters "T", for which, incidentally, it got its name. The main area of ​​application of both is as load-bearing floors of buildings and structures for various purposes.

In construction, a metal beam helps to redistribute the load on the supporting structures. They then evenly transfer it to the metal, which is a kind of skeleton of the building, which is gradually filled with other structural building materials... That is why special requirements are imposed on the workmanship of this element. The classification of this type of rolled metal is made on the basis of technical characteristics:

by the form it has;

by the thickness of the shelves and walls;

depending on the location of the edges of the shelves;

according to the material that was used for its production.

In addition, the metal beam differs in purpose and manufacturing method.

The beam can be called a kind of bar, which has the most different sizes and section. It was created specifically to be able to distribute the load on the supporting structures evenly along the entire perimeter of the building under construction. Recently, metal has become widespread, which is widely used in the construction of overpasses, bridges, hangars, warehouses, not to mention industrial and civil facilities.

An important point when making a choice for construction is the correct calculation of a metal beam. Regardless of the material, type of section and type of structure, its calculation is carried out according to one algorithm. First compiled design scheme, then internal efforts are determined. The next step is to select the cross-section of the beam based on internal forces, and at the final stage, all the results obtained are checked. Verification allows you to increase or decrease the cross-section in order to achieve the optimum degree of strength.

- the type of rolled steel most often used in the creation of load-bearing structures. The cross-sectional shape reminiscent of the letter "H" provides the I-beam with significant rigidity. For the manufacture of these steel products, "black" carbon steels or low-alloyed type 09G2S are used. There are two ways to manufacture H-shaped products: hot rolling and welding.

Hot rolled I-beam classification

According to the sectional shape, the hot-rolled I-beam is divided into two groups: with a slope of the inner edges of the shelves (manufactured according to GOST 8239-89 and 19425-74 for special types) and with parallel edges of the shelves (GOST 26020-83).

I-beam with a slope of the inner edges of the flanges

Products manufactured in accordance with GOST 8239-89 have a permissible edge slope of no more than 12%. Rolling accuracy: high ("B") and normal ("C").

Special-purpose beams (GOST 19425-74) are used for:

• "M" - structures of overhead tracks (the slope of the inner edges of the shelves is not more than 12%);
• "C" - reinforcement of mine shafts (the slope can reach 16%).

I-beams with parallel flange edges

The range of these products includes rolled products with dimensional parameters:

• height - 100-1000 mm;
• shelf width - 55-400 mm.

Parallel flange I-beam types

• "B" are normal. This type of rolled metal is in demand in the construction of structures with lattice-type columns.
• "Sh" (20SH-100SH) - wide-shelf. The width of the shelves is equal to the height. These products absorb compressive forces in structures with small columns.
• "K" (20K-40K) - columnar;
• "D" - additional series I-beams.

The same types of hot-rolled products with parallel flange edges are manufactured, in addition to the 26020-83 standard, according to the technical specifications of STO ASChM 20-93. In some cases, their dimensional parameters do not coincide; differences are especially common in large-sized products.

General characteristics of hot rolled I-beams

Flexural and compressive strength is characteristic of these products. The use of an I-beam in construction allows avoiding shifts, shrinkage, and cracking during the operation of buildings.

Hot rolling is the main method for producing I-beams. The process is highly productive and allows for good dimensional accuracy. The disadvantage is the presence of scale on the surface. Such products are manufactured on expensive and difficult to set up rail and structural mills. Slabs or squares (for small assortments) are used as blanks (depending on the size of the final product).

The strength characteristics of products are influenced by:

• steel grade - for the manufacture of products for critical purposes and / or intended for work in harsh climatic conditions low-alloy steels of 09G2S type are used;
• total length of the structure;
• the type of cross-section (with parallel flange edges or with a slope of the inner edges);
• the method of fixing the beam and the type of load.

The main disadvantages of rolled products with an H-shaped section:

• the tendency of the used steel grades to corrosion, which makes necessary protective measures - galvanizing or painting;
• the bearing capacity decreases significantly with increasing span length.

Differences and general characteristics of hot-rolled I-beams and channels

The main difference between these two types of structural shapes is the shape of the profile, which affects the strength and the scope of application:

• With the H-shaped configuration of the section, the shelves protrude on both sides of the wall at the same distance. Due to this, the wall works practically only in compression, the forces tending to twist the I-beam are small or absent. Wall rigidity is provided on both sides.

Attention! In the construction of large-sized buildings, I-beams are preferred to create large-span ceilings that experience high loads.

• The shelves protrude from one side of the wall, therefore they play the role of one-sided levers. Significant twisting forces can occur in the product. If it is necessary to increase the rigidity, the walls of the two channels are welded to obtain an I-beam-like product. In terms of strength characteristics, it is not much inferior to a hot-rolled I-beam with similar dimensional parameters. In addition to welding, rivets or bolts are used to connect the walls. When installing the channel as load-bearing beam it can be welded into a box reinforced with steel plates. However, the creation of such products is a very laborious process. Advantages of the channel: ease of installation in places of abutment to other elements, lower cost compared to an I-beam. Basically, these products are used in private low-rise construction, in the construction of garages and outbuildings.

When comparing an I-beam and a channel, their common feature can be distinguished: these products are not designed for significant forces applied perpendicular to the plane of the wall.

Welded I-beam: production features and main characteristics

In certain cases, a welded beam is a more profitable option compared to a hot-rolled analogue. These products are widely used in the construction industry: in the construction of residential buildings, industrial and public facilities, infrastructure facilities.

Stages of manufacturing a welded I-beam

• Cut open steel sheets into strips of the required dimensions.
• Cutting edges on a special machine. This operation is needed to improve penetration.
• With the help of special equipment, the workpieces are placed on the conveyor of the assembly mill, positioned and fixed.
• Submerged-arc welding is carried out on a special machine, on which sets of welding heads moving along the portal are placed.

Attention! The peculiarity of the process taking place on modern automatic lines, lies in the fact that its quality is constantly monitored laser system... If defects are found, they are eliminated, and the check is repeated.

• Editing, drilling and facing on CNC machines.
• Cleaning with a shot blasting machine from rust, dirt, oil.
• Can be overpainted.

Advantages of a welded I-beam

• Depending on the area of ​​application, the product can be made with variable profile thicknesses, from two types of steel for shelves and walls - less and more expensive, - with perforations that reduce weight. Such options make it possible to reduce the cost of products while maintaining strength in the loaded areas.
• I-beam in frame structures reduces the weight of the structure, which allows the use of a less massive foundation.
• The use of these products makes it possible to create complex architectural forms.

Varieties of welded I-beams produced by modern manufacturers

• Assortment similar to the assortment of rolled I-beams "B", "Sh", "K" with parallel flange edges, manufactured in accordance with GOST 26020-83 and STO ASChM 20-93. Welds for ordinary lightly loaded I-beams are performed according to the 2nd category, according to GOST 23118-99 or SP-53-101-98. TK seams (double-sided angular without bevel edges) must comply with GOST 8713-79.
• Special products made according to customer's drawings.
• Lightweight perforated beams with "windows" in the walls, allowing to lighten the structure while maintaining strength.
• Variable section products.
• Beams with shelves of various widths.
• For work in harsh conditions, with planned cyclic and variable loads, products are made reinforced with stiffeners.

I-beam marking according to GOST

Products of the H-shaped profile are marked as follows:

• the two initial digits indicate the profile height in centimeters;
• the letter index indicates the type of profile in accordance with the width of the shelf - "B", "W", "K".

The marking of a welded I-beam usually contains:

• manufacturer's code;
• cross-sectional dimensions in mm: height x wall thickness, width x shelf thickness;
• the leg in mm and the design of the waist seams are designated by letters - "O" (one-sided seam), "D" (two-sided), "P" (with full penetration of the wall);
• the type of rolled I-beam is indicated in brackets, for which a welded analogue was made to replace, this parameter is optional in the marking;
• cipher regulatory document to which the welded profile corresponds.

An example of designation is DZT 174x8 200x12 6O (20K2) DSTU BV.2.6.-75: 2008, where:

• enterprise code - DZT;
• wall section - 174x8 mm;
• shelf section - 200x12 mm;
• one-sided waist seam with 6 mm leg;
• the product is similar in size to the rolled I-beam 20K2;
• regulatory document - DSTU BV.2.6.-75: 2008.

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The most demanded type of product is steel beam, the information about which we will try to set out in as much detail as possible on this page of our site.

Beam, I-beam

Beam is made most often from carbon steel, even from low-alloy steel. It is widely used in civil and industrial construction. beams are classified according to their main purpose: for example, a column beam (K), a beam for overhead tracks (M), as well as by the method of production (hot-rolled steel beam). Beams also differ in such characteristics as the thickness of the wall and flanges and the location of the flange edges. The beam assortment corresponds to GOST 8239-89, GOST 19425-74, GOST 26020-83 and STO ASChM 20-93.

I-beam has a short name - I-beam, by which this product is most often called. Such a product has a cross-section in the shape of the letter "H". The I-beam is produced in two ways: hot rolled and welded. more popular and in demand is considered a beam produced by the hot rolling method, that is, a hot-rolled I-beam. Therefore, hot-rolled steel I-beams prevail in our assortment.

I-beam steel beam quite favorably differs from other types of beams - it significantly surpasses them in strength, degree of wear resistance. The I-beam perfectly tolerates temperature changes and can be used in the construction of buildings in which constant heating of the premises is not expected.

Where did the I-beam find its application?

A beam is a very important type of rolled metal for construction, both industrial and civil. Often it is she who is the basis of the entire metal structure. I-beam beam It is widely used in the construction of column structures, floors, bridges, overpasses, mines and other structures that must be highly durable and withstand heavy loads. Steel beams are also used in other industries, such as mechanical engineering, car building.

What sizes and types are the I-beam

I-beam can be of various lengths - the minimum length of the beam is 4 meters, the maximum is 12 meters. The beam has a height of 10 to 100 centimeters. What length and height the beam will be depends on its purpose.

The inner edges of the beam flanges can be parallel and sloped. Types of beams with sloped flange faces:

• Beam ordinary
• Special beam

The slope of the edges of a conventional beam should not exceed 12% (its minimum value is 6%). Special beam There are two types, which are usually denoted by letters: C and M. Type C beam is used in the construction of mine racks, and also with its help the shafts of mines are reinforced. For the construction of overhead tracks, a special I-beam of type M is used.

A beam with parallel flange edges is of the following types:

• Normal beam (type B; for example - beam 20 B1, beam 30 B2, beam 40 B1)
• Wide-flange beam (type W)
• Column beam (type K)

• Beam of unmeasured length
• Beam of measured length
• A beam of length that is a multiple of the measured
• A beam of length, which is a multiple of the measured, with a remainder of up to 5%

I-beam beam may vary in strength, on the basis of which its final cost is formed. You can order a beam from a warehouse with delivery by calling the phone numbers listed on the website. By purchasing this product from us, you can be sure that the items you need are always available in stock, which means that deliveries will be made in as soon as possible... We look forward to working with you.