Modern metal plants produce a large number of rolled metal for strengthening construction projects. These products have different purposes, depending on their size and strength. The most durable type of rolled metal is the I-beam. It is used in the construction of very massive structures, since the beam can easily cope with heavy loads.

Features and purpose

I-beam- This is a metal product with a cross-section in the shape of the letter “H”. It consists of two shelves and a wall connecting them. The name of this rolled metal product comes from the Latin word “taurus”. Translated into Russian, taurus means “bull”. That is, literally translated, this type of rolled metal is called a two-horned beam.

Steel is used to manufacture these products. As a rule, this is low-alloy or carbon steel, depending on the purpose of the future product. This metal is produced using the hot-rolled method.
I-beam is used in industrial and civil construction. With its help they reinforce:

1. Roofs of varying degrees of complexity.
2. Interfloor ceilings in apartment buildings.
3. Columns of complex architectural objects.
4. Steel trusses for civil and industrial buildings.
5. Mine shafts.
6. Railway carriages.
7. Bridges and other structures built on a durable steel frame.

This beam is also used to create reliable crane trestles, masts and monorails.

Advantages and disadvantages

The main advantage of this rolled metal is its strength and reliability. These characteristics are related to the cross-sectional shape of the product. After all, the cross-section in the form of the letter “H” significantly increases the rigidity of the product. If we compare an I-beam with a regular one, which has a square shape in section, then the first one will be much stronger and stiffer. The strength indicator of such products even exceeds that of channel bars.

High strength characteristics are associated with the distribution of mechanical load on the metal structure. With a cross-section in the form of the letter “H,” the load is evenly distributed over the entire beam and is not concentrated at certain points. Therefore, when using this rolled metal, the risk of rapid wear and destruction of the steel frame is eliminated. Consequently, the I-beam can be used in the construction of very massive objects subject to enormous loads. The main thing is to choose the right product sizes.

In addition to the strength characteristics, it is worth considering other advantages of using this rolled metal. The most important of them:

1. Economical. Due to its rigidity, an I-beam reliably reinforces large objects without requiring the use of auxiliary reinforcement. If you were to choose a different type of reinforcing profile, you would have to buy more of it to ensure that the structure is resistant to damage. In the case of an I-beam, this is not necessary. Consequently, you can save on rolled metal.
2. Light weight. The cross-section in the shape of the letter “H” significantly reduces the weight of this rolled metal. At the same time, its strength characteristics increase noticeably in comparison with the same characteristics of more rigid square products.
3. Resistance to bending and compression. Thanks to these advantages, the I-beam tolerates vibrations well and can be used in the construction of heavy bridges.
4. Possibility of installation by welding. Welding elements of a steel structure significantly increases the speed of work and reduces the delivery time of the project.
5. Constancy of geometric characteristics. Since the rigidity of the I-beam is determined by its shape, any changes in it would lead to a decrease in the strength of the frame and destruction of the building. This is excluded when using this rolled metal. After all, it does not deform even under too high loads.
6. Ease and economy of transportation. To transport more massive rolled metal, you would have to rent several Vehicle. In the case of this product, the amount of transport can be reduced. After all, the specific shape of the I-beam facilitates compact installation, and its low weight allows you not to worry about overload.

Like any other rolled metal product, an I-beam has not only advantages, but also disadvantages. Let's consider the main ones:

1. Poor fire resistance. If a fire breaks out at your facility, any delay in extinguishing it will have a detrimental effect on the strength of the structure. If the situation gets out of control, the building may even collapse.
2. Weak resistance to corrosion. Carbon and low-alloy steel are susceptible to rust, so these materials must be treated with protective substances. And even after proper processing, the beam is not recommended for use in conditions of high humidity (for example, for the construction of underwater bridge supports).
3. Impossibility of application on very large spans. In the absence of additional supports, the load-bearing capacity of the I-beam is noticeably reduced. You need to pay maximum attention to this feature of rolled metal when developing a project.
4. Very low torsional resistance. This disadvantage observed in all products with an open cross-section. For example, the channel and corner have it. The beam's resistance to torsion is approximately 400 times lower than that of round pipe with the same cross-sectional area. If the frame of your future object will be subject to torsion, it is better to choose a different type of rolled metal for reinforcement.

Varieties

There are I-beams for various purposes. Depending on the application, it has certain characteristics. For example, this rolled metal is produced with parallel or inclined shelves. In the first case we are talking about ordinary rolled metal, and in the second - about special ones. Products with parallel shelves are marked “U”, “W”, “D” or “K”. It means:

1. “U” is a product with narrow shelves.
2. "Sh" - rolled metal with wide shelves that can withstand heavy loads.
3. “D” is an I-beam with middle shelves.
4. "K" - products intended for the construction of columns. These beams are heavy and characterized by the highest degree of strength.

I-beams with inclined flanges also have different purposes, depending on the angle of inclination and cross-sectional area. It is marked with the letters “M” or “C”. Products marked “M” are intended for the construction of overhead tracks. The angle of inclination of its internal edges should not exceed 12%. Beams marked “C” are used to strengthen mine shafts. For these I-beams, the angle of inclination of the internal faces can reach 16%. Coefficients of 12% and 16% are the maximum values ​​for the angle of this product. They must not be exceeded during the production of rolled metal.

In addition to the width of the shelves and their angle of inclination, the I-beam is classified according to the degree of accuracy. This indicator indicates permissible deviations from dimensions during rolling (the table of dimensions and deviations is located in GOST 8239-89). The degree of accuracy is marked on the product with the letter “B” or “B”. If the beam is marked “B”, then it is a product with normal manufacturing precision. The letter "B" indicates increased accuracy. This product is suitable for complex tasks, requiring the absence of even the smallest errors. When manufacturing it, it is very important to comply with the permissible values ​​for wall deflection, blunting of outer edges and curvature of the product itself.

The state standard specifies the following accuracy criteria:

1. The permissible wall deflection is no more than 0.15.
2. The blunting of the outer edges is no more than 2.2 mm (for category “B”; for ordinary beams this indicator does not matter).
3. The curvature of the product is no more than 0.2% of its length.

The accuracy of compliance with other characteristics (the height of the I-beam, as well as the width, thickness and skew of the shelf) depends on the category of the product (“B” or “B”) and its dimensions. All these coefficients are given in the table in GOST for rolled metal with normal and increased manufacturing accuracy.

Dimensions and weight

When manufacturing an I-beam, the requirements of GOST 8239-89 must be taken into account. These requirements regulate the dimensions of products and show their dependence on each other. For example, in a finished beam the following parameters are interrelated:

• cross-sectional area;
• radii of internal curvature;
• shelf thickness;
• angle of inclination of internal edges;
• product height;
• wall thickness;
• shelf width;
• radius of curvature of the shelf;
• product weight.

The value of these characteristics is not subject to change. For example, an I-beam marked “10” has a cross-sectional area of ​​12 square meters. cm. At the same time, its other characteristics should be equal to:

• radius of internal curvature = 7 mm;
• shelf thickness = 7.2 mm;
• product height = 100 mm;
• wall thickness = 4.5 mm;
• shelf width = 55 mm;
• shelf curvature radius = 2.5 mm;
• product weight = 9.46 kg (meaning the weight of a beam 1 meter long).

When manufacturing rolled metal of this type, all listed dimensions must be observed, since they are interrelated with each other. If at least one dimensional characteristic changes (for example, the length of the wall increases or the width of the flange decreases), the strength of the beam will noticeably decrease. This means that rolled metal cannot be used in construction work oh, because he will become too unreliable. Such a beam will break under any physical or seismic loads, which will lead to the destruction of a house, bridge or other object.

According to GOST 8239-89, an I-beam can have a cross-sectional area from 12 to 138 square meters. cm (depending on the size, the I-beam is marked with the numbers “10”, “12”, “14” ... “60”). The largest product from the state standard has the following characteristics:

• radius of internal curvature = 20 mm;
• average shelf thickness = 17.8 mm;
• I-beam height = 600 mm;
• thickness of the jumper between the shelves = 12 mm;
• width of each shelf = 190 mm;
• permissible radius of curvature of the shelf = 8 mm.

With such dimensional characteristics, the weight of the product should be 108 kg per meter. As a rule, beams are produced in lengths of 4-12 meters, and their length depends on the cross-sectional area of ​​the rolled metal. The larger the area, the longer the length. But there are also exceptions. For example, if a buyer needs beams of shorter length, he can order them directly from the manufacturer.

Also, when making to order, other characteristics can be changed. If in GOST 8239-89 the maximum cross-sectional area of ​​an I-beam is specified as 138 sq. cm, this does not mean that you cannot obtain more massive products, if necessary. The state standard provides calculations within a limited range. Any other calculations are performed individually by engineers. That is, the customer contacts the manufacturer and leaves a request for the production of the products he needs. Next, the production process begins according to the following scheme:

1. Calculations of dimensional characteristics are performed. When calculating these characteristics, their relationships with each other are observed, as in the products considered in GOST. Experts also determine the permissible error rate, depending on the degree of accuracy of the product. During the work, engineers take into account not only the dimensions of the beam, but also its coefficients such as moment of inertia, static half-section moment, moment of resistance and radius of gyration. Only if all these characteristics are observed can you obtain a high-quality, durable product.
2. Drawings are being made. If you have your own drawings, you do not have to pay for this service. But keep in mind that the creation of such documentation requires very deep knowledge and experience in carrying out such work. Therefore, do not order a service from dubious specialists, focusing on low price. Remember that the strength of your I-beam and the entire structure that you are going to reinforce with beams made according to the drawings will depend on the correctness of the calculations.
3. An I-beam is manufactured in the required quantity.

Where can I buy?

If you are interested in an I-beam, you can buy it here. This is the website of our company “MS” - a metal warehouse engaged in the sale of rolled products of any type. Here you will find products with heights from 100 to 691 mm. The catalog contains products with narrow, medium, normal and wide shelves. We can also offer you column and special beams. A list of available products and their characteristics are available for viewing on the website.

If you have not yet decided on the choice of rolled metal supplier, check out the advantages of our company. They attract new clients to us every day. Our main advantages:

1. Cooperation with leading metal plants of the Russian Federation. We do not purchase goods from dubious persons, so we can confidently say that we sell high-quality rolled metal products.
2. Big choice products. You will find an I-beam of any size in the catalog, therefore, you do not have to wait for its production. In addition, we have many other types of metal products, not just beams. If you are a professional builder, you know that when constructing a large project, I-beams alone will not be enough. You will have to buy fittings and other rental products. By collaborating with us, you will do this at the same time, without delaying construction work and without overpaying for delivery.
3. Affordable prices. Since we take goods directly from metal plants, and not through intermediaries, we do not have to purchase them at a higher price. Accordingly, our clients receive rolled metal at the manufacturer’s price.
4. Operational support. If you don't know which I-beam is suitable for your needs, ask our specialist for help. He will find you a product with optimal characteristics.
5. Promotions and sales that allow you to save on your purchase.
6. Useful additional services. We not only sell rolled products, but also weld and cut them.

To order an I-beam, check the cost of the product and wait for delivery. If you indicated an address in St. Petersburg, we will deliver the goods by our own car. In other cases, the products will be sent by a transport company suitable for you.

The photos used in the article are for illustration purposes and do not represent images of the company's products.

What is an I-beam? In simple terms, this is a beam that has a certain shape and is made of special profile steel. Depending on the design features, it may look like the letter “H”.
This primary view steel structures, which are used in the construction of both industrial buildings and civil buildings. In order for all structures and floors of buildings to meet certain requirements, it is necessary to know what dimensions, weight and design features. This article will help you understand all these subtleties.

The most common application of steel I-beams is in the construction of buildings, industrial warehouses, bridges, aircraft hangars, pipelines and other structures. This is due to the fact that the metal consumption of beams, due to the selection of the required dimensions and weight, as well as the selected cross-section in a certain way, is always much more effective than that of a simple hot-rolled beam.

They are also used in construction (as floor elements), in the automotive industry, as well as in the construction of columns, overhead tracks, and road overpasses. But the most common application is the use of these beams in the installation of large span frames in the construction of industrial buildings.

Main advantages

In order for the rigidity and load-bearing capacity of an I-beam structure to exceed the capabilities of a rolled profile, an I-beam of 30 or 20 should be used. Most often, beams are produced from rolled metal with a size of no more than 60B.

The weight of the resulting structure is reduced compared to a rolled one by up to 10% when choosing beam 30, which is quite easy to select the required length.

One bistal I-beam can include different grades of metal: they began to make those that are more stressed from high-strength steel, and those that are less stressed from low-carbon steel. This significantly affected the price; such designs began to cost much less.

It should be noted that the waste-free use of I-beams is possible, since it is possible to order the I-beam as needed. Experts estimate that by reducing waste you can save up to 15%.

Dimensions of I-beams with characteristics (range)

All required dimensions I-beams, if necessary, can be found in special GOSTs. This document describes the main characteristics and geometric dimensions for different items. A list is compiled from all the presented items, which is called an assortment. By looking at this assortment, you can find out what I-beams exist, as well as a description of their main parameters. The assortment also introduces some “axioms”, which are certain immutable truths, and they must be known and remembered:

• The cross-section of the I-beam must always be the same as the parameters indicated in the drawings. The designation and existing standards must be presented in a form that everyone can understand.

• The dimensions that are given in the I-beam assortment tables must coincide with their nominal dimensions (here we mean all the main parameters, such as mass, weight and cross-sectional area), and, of course, other physical characteristics must be the same.

• Accuracy must be observed in rolling I-beams. They are divided into two different types. Increased accuracy - B and normal accuracy - B. If other rolling options appear, then this is not acceptable and is considered in in this case substandard I-beam.

Determination of sizes, as well as types of I-beams, is determined by rental numbers, which can be represented by the following numbers: 10, 12, 14, 16 and so on.

Weight calculation

To determine the weight of an I-beam, you definitely need to know its two components. You should know its number, which must comply with GOST, and be in the assortment table, which indicates the main design parameters. There you can also find out about its mass and cross-section.

But you need to remember that the tables indicate only the conditional mass of the I-beam. To be more precise, the tables indicate the mass of just one linear meter. If you need to calculate the I-beam (required quantity), then you will have to do it yourself. In this case, you can use the tabular data that is indicated in the assortment of I-beams.

An example for calculating the weight of the required amount of I-beam

Let’s say that you have 3 meters of I-beam number 10. Open the weights table and find the necessary data: a linear meter of I-beam 10 conventionally weighs 9.46 kilograms. All you have to do is multiply on a piece of paper or using a calculator the amount of I-beam you have (in our example - 3 meters) by the found value of the conditional weight of a linear meter (9.46), the resulting result will mean the total weight of the I-beam (in our example - 28.38 kg).

So, everyone understands that in order to carry out practical calculations it is necessary to have reference data on the conditional weight of a linear meter (in accordance with GOST), which is contained in the table of I-beams.

What else do you need to know

To understand what an I-beam shelf is, just look at its drawing. If you look at it carefully, you can see that it only has two shelves. And the design of the shelves itself is such that they look absolutely identical to each other. As for their sizes, they are also determined by existing GOSTs.

For shelves in I-beams, their dimensions also matter. First of all, these are parameters such as the width of the entire shelf and its thickness. Typically, reference information on these two parameters can also be found in the assortment of I-beams.

Important parameters when calculating loads

As is already clear from the drawings, the cross-section of the I-beam should form a characteristic figure of a certain shape. It has already been stated earlier that the cross-sectional shape is similar to the letter “H”.

But for professionals, in order to obtain an I-beam calculation, this characteristic does not play an important role. Here, a parameter such as cross-sectional area comes to the fore. This information can often also be found in the relevant GOST standards; it is indicated in the assortment of I-beams.

How much does an I-beam 30 weigh?

To answer this question and find out how much it will weigh this type metal products, it is best to refer to the I-beam weight table or look at GOST. The assortment determines how much just one linear meter of the product of interest weighs.

The weight of an I-beam 30 according to GOST is a kind of standard that all manufacturers, without any exceptions, producing rolled metal products must follow.

This state of affairs is very satisfactory for all consumers. In this case, if there is a standard, then you can order a certain brand of product and be sure that the dimensions and other characteristics will be the same for I-beams from different manufacturers. For the most part, the mass of an I-beam implies the weight of one linear meter.

If you follow the parameters and indicators specified in GOST, then the weight of I-beam 30 will be equal to 36.5 kg, and the weight of I-beam 20 - 21 kg per linear meter.

With the weight of the I-beam, everything seems to be clear, but sometimes, in addition to the weight, it is necessary to obtain information on other characteristics metal structures. In this case, if there is a drawing, it is better to navigate according to it.

Let us present some values ​​of weights of one linear meter of different I-beams from the assortment table.

I-beam 10 - 9.46 kg one linear meter

I-beam 12 - 11.5 kg one linear meter

I-beam 14 - 13.7 kg one linear meter

I-beam 16 - 15.9 kg one linear meter

I-beam 18 - 18.4 kg one linear meter

I-beam 20 - 21 kg one linear meter

I-beam 24 - 27.3 kg one linear meter

I-beam 30 - 36.5 kg one linear meter

Drawing - a clear presentation of information in a visual form

The use of drawings when performing calculations is convenient because the information does not look confusing, but is presented in a visual and understandable form. All symbols are very easy to read and recognize.

Using these designations, you can subsequently easily understand the reference information in the table of I-beams, because they are built in accordance with the symbols. Thus, symbols are associated with geometric characteristics and dimensions, which, in turn, are associated with physical parameters, which the I-beam has.

For example, consider the basic designations for characterization:

h - basically this letter most often denotes the height of the structure. Very often, it happens that some builders replace the concept of I-beam height with width. If people have been working with each other for a long time, then, of course, they understand that the width of an I-beam means its height. But when they say the width of an I-beam, and at the same time name the parameter of its height, it sounds very illiterate.

b - this letter indicates the width for the I-beam shelves. This concept also very often undergoes transformation in the mouths of builders, and most often, you can hear “width of edges”. This name is also incorrect, so it’s better to immediately get used to saying it correctly - the width of the I-beam shelves.

s - confusion often occurs here, but it would be more correct to call this parameter the thickness of the I-beam walls.

t - it should be especially emphasized that this parameter means the average thickness of the I-beam flange. You definitely need to remember this, because often in different places of the beam there can be a different slope between the internal faces. In other words, the beam may have different thicknesses in different places, small at the end of the flange and slightly thicker in those places where the flange comes into contact with the I-beam wall.

If you look in reference books, then under this letter designation they indicate exactly the average thickness of the shelf, which is measured in certain places.

R - this letter describes the radius of the internal rounding of I-beams. This designation arose during the manufacturing process of I-beams. Since the internal edges of the shelf are connected not at an angle, but with the help of a slight rounding. This rounding and its radius are also specified in GOST.

r is also a radius, but it indicates the curvature of the shelf. The outer edge of the flange of the described I-beam is a flat surface, and the inner edge is made with a slight rounding at the transition to the end of the flange. The radius of this rounding is indicated in GOST, and is also presented in the assortment table as reference information about dlutaurs. Each number of the corresponding I-beam has its own radius of curvature for the shelf.

Thus, knowing all the characteristics and parameters of metal beams (in particular I-beams), you can easily carry out various calculations for construction needs. And if the correct calculation of the I-beam is made, this means that all structures in which I-beams will be used will be very reliable and in demand.

I-beam is metallic profile, made of carbon and low-grade steels, a wooden or fiberglass beam with a cross-section in the shape of the letter H. I-beams are used in the construction industry, bridge and shipbuilding. During the construction of residential and industrial buildings, it is needed for the installation of ceiling beams. How to choose a profile and what to consider when installing it in order to get a durable structure?

I-beam structural form

Types of I-beams and their main characteristics

Due to the great demand for I-beam products with the most different characteristics their production has been established not only from steel, but also from other materials - wood, aluminum, reinforced concrete, fiberglass. In private housing construction, including multi-storey ones, shaped metal, welded and wooden I-beams are most often used.

Having understood what an I-beam is, it is easy to understand that due to its shape it has a high load-bearing capacity and rigidity with a low specific gravity (30 times more than a square beam with the same area). Its horizontal surfaces - shelves - are load-bearing and serve as supporting platforms that distribute the load and prevent the beam from warping or tipping over.

Floors made from I-beam elements are distinguished by their strength, which is especially important for the further installation of a roofing or flooring base.

It is noteworthy that the strength of adjacent I-beam elements is summed up, and those stacked on top of each other are quadrupled.

The important parameters by which the required type of I-beam is determined are:

• dimensions and cross-sectional area;
• linear meter weight;
• axial moment of resistance and inertia;
• static moment and radius of gyration.

I-beam as a ceiling beam

Subtleties of choosing metal I-beams

As a rule, a metal I-beam is made from carbon and low-alloy steel, the grade of which is indicated in the designation. Metallurgical plants are required to produce it in accordance with regulatory documents that specify the basic requirements for chemical composition material, geometric parameters and permissible deviations from the norm. The division of rolled metal into subspecies with different characteristics allows it to be used as widely and rationally as possible.

Assortment of metal beams - dimensions and markings

According to GOST 8239-89, the standard size of an I-beam is determined by the height of its wall: for example, profile number 10 has a distance between flanges of 100 mm, and standard size 60 has 600 mm.

In addition to the number indicated in the material marking, there are several other types of I-profiles. So, they are distinguished:

• according to the location of the shelves - with a slope of the internal edges and with parallel shelves;
• by production method - made by hot rolling (hot rolled) and welded from steel sheets (welded);
• manufacturing accuracy - increased accuracy (marked with the letter B) and normal accuracy (letter B).

I-beam assortment

A metal I-beam, the slope of the internal faces of which is from 6 to 12%, is considered classic and, in turn, is classified according to its purpose into ordinary and special rolled metal. The range of special I-beams is regulated by GOST 19425–74 and applies to beams for overhead tracks (M series) and for the reinforcement of mine shafts (C series).

I-beams with a parallel arrangement of the internal edges of the shelves are manufactured in accordance with the current GOST 26020-83 or the technical specifications of a large manufacturer STO ASChM 20-93. Depending on the design features, there are the following types of beams:

• normal beams “B” (characterized by a height of up to 1000 mm, a shelf width of up to 320 mm);
• wide-shelf “W” (height – up to 1000 mm, width – up to 400 mm);
• columnar “K” (differ in the width of the shelf, approximately equal to the height of the profile).

The length of a standard metal profile ranges from 4 to 12 m (I-beams with parallel flanges can be 13 meters long), however, upon agreement with the customer, they can be manufactured in longer lengths.

Features of welded I-profile

Since manufacturers produce hot-rolled steel with a size of no more than 60B, a welded I-beam is used for structures that require exceptionally high rigidity and load-bearing capacity. According to TU U 01412851.001-95, they are also marked according to the height of the I-beam wall, so there are standard sizes from 45BS (height 445 mm) to 200BS (height 2010 mm). The letter marking for hot-rolled products also applies to welded ones.

Welded beam production

The technology of their production from sheet metal more economical than rolling steel slabs, but is a rather complex process. The quality and reliability of a welded I-beam largely depends on the equipment used and strict compliance with all operations:

• workpieces of the required thickness must be cut on CNC machines or thermal cutting equipment;
• elements of the future I-beam in modern factories are welded on automated lines using hydraulic clamping elements;
• the finished product is subject to mandatory editing, which eliminates thermal deformation, after which it acquires a strictly observed geometry.

The production of low-carbon steel blanks, the use of outdated equipment, violation of technological methods, and low qualifications of the welder lead to the fact that I-beams made by handicraft have reduced operational capabilities.

When choosing a material, you should contact reliable suppliers whose products are not inferior in mechanical properties to their hot-rolled counterparts.

At the same time, welding can be used to produce multi-flanged I-beams and beams of variable cross-section. This allows you to select optimal area sections and reduce the excessive safety margin of structures. Also, welded products can be made of a certain length, with specified cutouts and holes, using different grades of steel (bistal beams), thanks to which the customer receives a more technologically advanced and economical form of supports.

Welded I-beams of variable section and with perforation

Advantages and disadvantages of using an H-profile

In Russia and the CIS countries alone, there are more than 20 metallurgical plants, many of which are giants, producing millions of tons of rolled steel per year. I-beams occupy the lion's share of this volume, since they are distinguished by universal characteristics:

• the most rational form for beam elements in terms of metal consumption;
• excellent indicators of wear resistance and strength of structures made from them;
• the presence of state standards and technical conditions dictating the quality parameters of products;
• solidity and absence of welds in hot-rolled I-beams - for especially critical metal structures;
• a variety of characteristics and properties of welded I-beams - to lighten beam structures, reduce the load on the foundation and reduce the cost of the construction project.

Welded and hot-rolled metal products have many advantages, but there are also some disadvantages that must be taken into account at the design stage:

• low resistance of the H-shaped beam to torsion (400 times less than that of a round beam);
• shortage of hot-rolled I-beams of large standard sizes and their forced replacement with welded profiles;
• the need for additional reinforcement of welded I-beams used as loaded elements;
• unreasonably high metal consumption and a large amount of waste when using beams of length and thickness determined by GOST, and not by the customer.

You can purchase rolled beams directly from intermediaries selling rolled metal products or manufacturers, but welded products most often need to be ordered in advance.

Application of I-beam metal

Intensive development construction industry necessitated the need to improve and rationalize methods for manufacturing metal I-beams, due to which the scope of their application has significantly expanded. Today, the I-beam is used both in low-rise private construction and in large commercial and industrial projects, as well as in heavy engineering.

I-beam in the form of a hangar roof truss

Where is H-shaped rolled steel used?

In the course of theoretical and experimental studies, it was proven that I-beams optimally absorb bending loads, therefore, it is advisable to use them in the form of load-bearing elements:

• metal floor beams of buildings;
• column metal structures;
• bridge structures;
• overhead tracks;
• frame structures of cars, cars, excavators, etc.;
• reinforcement frame of mine walls.

A wide-flange I-beam can be used for beams, columns and rods of moderately loaded trusses, while a column-type I-beam is installed only for large spans and significant loads (in the photo there is a column-type I-beam).

Column I-beam

Calculation of a steel I-beam - what is important to consider

To minimize waste, lighten the structure, thereby reducing labor and material costs without compromising the strength of the building, professional calculation of I-beams is necessary. This service is provided by architectural and design bureaus or construction companies.

In simple cases, the calculation can be done independently, but it is recommended to check its results with a specialist.

The initial data for solving the problem of choosing a profile according to the load-bearing capacity are several indicators:

• the distance between the inner edges of shorter walls (span length);
• standard and design load (normative data are taken from the tables of the relevant GOST, and design data are determined by multiplying them by the beam pitch (from 0.8 to 1.2 m));
• the number of I-beams connected in one beam (if it is composite), and their orientation relative to the load;
• design resistance (a parameter depending on the steel grade, usually the average value Ry = 210 MPa is taken).

By calculating the required moment of axial resistance, you can accurately determine the I-beam number (this is also done using tables).

Installation of ceilings on metal I-beams

Regardless of whether a new building is being constructed or an old one is being reconstructed, the installation of the floor must be carried out according to a surface drawing that gives a detailed idea of ​​the future structure. It is forbidden to increase the pitch between the I-beams by a distance greater than the calculated one, since savings at this stage are fraught with negative consequences.

Advantages of I-beam floors

The supports for the I-beam are metal, reinforced concrete or brick columns And load-bearing walls. When installing, be sure to use a building level - this will help avoid problems when installing the formwork. It is also important to ensure sufficient support area - for this, the beams must extend more than 20 cm onto the wall.

On the supporting surfaces it is necessary to fix a plywood sheet of the calculated thickness for formwork for pouring monolithic concrete slab. It is necessary that its thickness be at least 1/35 of the stepping distance. After installing the support system (it is usually made of metal struts or wooden beams, 1-2 pieces per square meter), it is important to check the strength beam floor with its own weight, trying to detect the slightest vibrations of the surface.

When arranging large spans, sometimes there is a need to join I-beams - GOST as such does not exist for this operation, however, there is a corresponding requirement in SP 16.13330.2011 “Steel Structures”.

According to it, docking can be done in one of three ways:

• butt welding of milled ends;
• on plates with welded or welded joints;
• with the help of flanges that absorb tensile force with bolts, while compressive force through the pressing of the flange surfaces.

Options for making installation joints

Fastening unit of an I-beam to a column using linings and a bolted connection

It should be remembered that metal beams are susceptible to corrosion, so they need to be protected with paint and varnish coatings.

Wooden I-beams - assortment and practical application

The feasibility of using I-beams made of wood raises many doubts. In particular, many are perplexed as to how they differ from simple wooden beams. The answer to these doubts lies again in the special design of the I-beam, which in this case consists of two wooden shelves and a plywood wall - due to this, it is able to withstand a bending load several times greater than a monolithic beam with a simple cross-section.

Wooden I-beams - a new product on the building materials market

Types and sizes of wooden profiles

The range of this building material is quite well developed and allows it to be used as a load-bearing element not only for floors and rafter systems, but also for wall and roof frames. Thus, the following series of wooden I-beams are distinguished:

• glued (BDK) – the beam is glued together from structural elements using synthetic resins under high pressure and is intended for use in short spans;
• glued reinforced (BDKU, BDKU-L) – thanks to the increased flange width (64 mm), beams of this series have sufficient area for nailing and can be used on long spans;
• glued wide (BDKSH, BDKSH-L) – they have an even wider flange (89 mm), so the series is intended for use in structures experiencing extremely high loads, rafter systems or on extra-long spans;
• reinforced wall (SDKU, SDKU-L) - this type of beams is used in the wall frame as its basis;
• wide wall (SDKSH, SDKSH-L) - racks with this marking are used for the manufacture of wall panels.

The letter L at the end of the marking means that the beam is made of high-strength LVL timber, which gives it strength that is 1.25–1.5 times higher than usual. The standard length of beams is 6 m, while the BDKU-L and BDKSH-L series are available in lengths from 6.5 to 8 m. Their height range looks like this: 241 mm, 302 mm, 356 mm, 406 mm, 457 mm.

I-beam frame building

Installation of the overlap of their I-beams

Advantages of a wooden I-beam

Of course, the I-beam system wooden structures cannot fully replace metal and reinforced concrete, but they remain a leader among modern and reliable building materials thanks to a number of technical and performance characteristics:

• versatility of use - such I-beams are suitable for the construction of frame, brick, block and wooden houses;
• low weight of the support rod (a 6-meter beam weighs on average about 40 kg), allowing installation without the use of special equipment;
• high speed installation and its simplicity - an experienced installer can cover the entire house in a day using simple carpentry tools;
• a wide selection of production series and a solid range of sizes;
• low thermal conductivity and water resistance (subject to sufficient drying of the wood).

The conditional disadvantages of a wooden I-beam include the dependence of its reliability on production conditions: the quality and type of wood from which the supporting parts and racks of the beam are made, the heat resistance and ductility of the adhesive mass, the accuracy of geometric dimensions and assembly of elements.

In addition, wood is considered a relatively unstable material, the strength of which may vary throughout the entire operational period.

Calculation options and material installation

Just as in the case of metal I-beams, the selection of the dimensions of a wooden I-beam is carried out based on the design and standard load, operating conditions, beam spacing and span length. In some cases, it is permissible to use tabular data offering ready-made technical solutions. However, due to the special responsibility of the overlapping and truss structures, it is recommended to check these parameters with a professional architect.

Table 1: Selection of the standard size of a wooden I-beam when installing a floor

Table 2: Selection of the standard size of a wooden I-beam when installing inclined rafters

I-beams are installed using temporary fasteners, which are later replaced with stationary ones.

It is prohibited to operate the surface until the piping has been installed and permanent fastenings have not been installed. Carefully calculated and competently assembled I-beam structures are distinguished by reliability, durability and high load-bearing capacity.

- one of the types of rolled metal. Its feature is its high load-bearing capacity due to the N-shaped section that characterizes the product. With the help of this product you can significantly increase the reliability of the building structure. The elasticity property of an I-beam provides a margin of structural flexibility and a low compressibility coefficient.

Due to the possession of these properties, the I-beam helps to provide high resistance to loads and significant mechanical stress. The function of the I-beam frame helps to increase the reliability and service life of the structure being built, as well as its service life.

Externally, this type of rolled metal product is a bar of steel alloy, which cross section similar to the letter "n". The structure has an upper and lower belt, which are connected to each other through a wall. The shelves on the beam can be located either parallel or at some angle relative to each other. Depending on this angle of inclination, the purpose of the product itself changes.

Thus, the wide-flange design is quite widespread. For its production, the cold and hot rolling method is used. Low-alloy and carbon steels are used for their production.

The weight and dimensions of the I-beam correspond to GOST 8239-89. Their heights are as follows: 10 cm, 12 cm, 14 cm, 16 cm, 18 cm, 19 cm, 20 cm, 24 cm, 27 cm, 30 cm, 36 cm, 45 cm (see table). High-quality rolled products have a very small error, which must be taken into account when purchasing these products. Depending on the accuracy of dimensions and weight per 1 m, I-beams are classified as high-precision products - A and ordinary accuracy - B.

Corresponding to the assortment, I-beams can be from 4 to 13 m long:

• measured length (I-beam length length);
• multiple measured lengths (6 meters and 12 meters of I-beam in one pack);
• measured length with a remainder of up to 5% of the mass of the entire batch;
• of unmeasured length.

Many people wonder what the weight of an I-beam should be. The weight of an I-beam can be calculated using the formula:

where g = 9.81 m/s2 is the acceleration of gravity, m is the specific weight of a linear meter of the beam.

GOST 8239-89 is a regulation for the dimensions and weight of an I-beam, created to avoid misunderstandings. In this main document you can find technical requirements, acceptance rules, testing methods, labeling, storage, packaging and exact weight of the finished product.

The table reflects the size of the I-beam, the theoretical mass of the beam, that is, the weight per linear meter. At the same time, do not forget that the weight is indicated per 1 linear meter with a slope of the internal edges of 6-12%. Each manufacturer has its own special I-beam tables. They contain information about the required product parameters, production method, wall thickness, technical specifications, weight, grade of rolled metal from which it is produced.

According to the conventions, the following parameters can be determined:

• h – the height of the product itself;
• b – shelf width;
• S – wall thickness;
• t is the average thickness of the shelves.

I-beams are divided into normal (B–25 B1), wide-flange (30Ш1), column 30K2, etc. Beams start from H-100 mm to H-1000 mm. If the H of the I-beam exceeds these values, or is less, then they are produced only by special order. The size of the beam is the distance separating its outer flanges.

The different sizes of I-beams correspond to the difference in the linear meter of one beam and the number of meters in one ton. In accordance with the profile number, the total weight of the rolled metal is calculated, provided that the weight of 1 m of rolled metal is known. With a beam weight of 45 and a linear meter weight of 66.5 kg, it has a length in a ton of 15.04 m.

The range of I-beams is as follows:

• hot rolled double flange. Such products are manufactured according to European standards with parallel edges. Thanks to the presence of wide edges, the product acquires additional strength. The hot rolling method reduces the labor intensity of the process, therefore its cost is quite affordable and accessible to different categories of the population. The most common area of ​​their application is frame and large-panel construction, mechanical engineering, shipbuilding;
• hot rolled normal. Such beams are used most often and are suitable for all kinds of construction with varying degrees of load. The purchase of an I-beam is considered the most appropriate for the construction of metal structures than the use of bulky sheet metal and angles;
• hot rolled with a slope of internal edges. Most often, such products are used under loads that create transverse bending. This helps create the maximum degree of rigidity along the horizontal axis. For their manufacture, ordinary carbon steel is used.

A beam is a composite linear element of a supporting structure that has at least two points of support (supports at both ends) and bends. The use of a beam is aimed primarily at distributing the weight load of the entire structure. The most common use is the horizontal use of a beam, which compensates for the vertical lateral load. And the weight pressure of the beam itself is compensated by vertical elements, the horizontal surface of which is the fulcrum for the beam. Subsequent compensation falls on the structural supports if there are no additional intermediate elements. Thus, mutual compensation of weight loads makes it possible to ensure the stability and reliability of the entire structure.

Types of beams in construction

In the photo: I-beams in the roofing structure

There are a large number of official classifiers of building structural elements. The two most objective classification schemes will be presented below.

Classification of building beams by type of material

• A steel beam is a transverse or longitudinal element of a supporting structure, made of special, carbon or low-alloy steel by hot or cold rolling. The main advantage of steel beams: the optimal degree of strength when working in bending. They are used in the construction of structures that involve an increased weight load or a high degree of danger: overhead tracks, mine shafts, and so on.

• The reinforced concrete beam is building element linear type, used in a supporting structure in order to redistribute weight and increase the stability of the entire structure and consisting of a composite material: a concrete matrix reinforced with steel reinforcement. Reinforced concrete beams are a cheaper analogue of steel beams and are used on objects with a standard weight load: residential construction, construction of industrial buildings.

In the photo: reinforced concrete beam for the construction of a bridge

• A wooden beam is an element of a load-bearing wooden or other lightweight structure made of wood. Widely used for the construction of residential and commercial structures made of wood.

On the picture: wooden beam in the overlap device

Classification of building beams by type of end section

• Rectangular section. Suitable for use in short spans.
• “L”-type section. It is suitable for use in the design of building facades.
• Standard and gable T-beams (T-type section). Ideally suited for spans middle length. IN
• I-beam. They have increased stability and are used for long spans.
• “V”-type section. Used as additional element to strengthen the supporting structure.
• “VT”-type section. Use as purlins.

I-beams, in turn, are divided into subcategories:

• I-beam with parallel flange edges. Standards and sizes are presented by GOST 26020-83.
• Standard I-beam with an angle of inclination of the flange edges from 6 to 12%. Standards and sizes are presented by GOST 8239-89.
• Special I-beam, standards and dimensions are presented by GOST 19425-74. They are divided into two subtypes with markings: “M” - I-beam has an angle of inclination of the edges up to 12%; “C” - the I-beam has an angle of inclination of the edges of up to 16%.

Separately, it is necessary to consider such an element of the supporting structure as a crossbar (sometimes called a crossbar beam). The crossbar in the vast majority of cases is reinforced concrete and, unlike a standard beam, is an integral element of the frame (the beam is an independent structural element). The crossbar is widely used in formwork construction.

Calculation of beam strength when working in bending

To calculate the deflection strength of a beam (that is, determining the weight that a given element of the supporting structure can withstand without the occurrence of deformations and other factors leading to the destruction of the structure), it is necessary to take into account whole line factors, the main of which are:

• Beam length. The shorter the beam, the greater the load it can withstand.
• The material from which the beam is made. Steel is the most durable material.
• Cross section of the beam (area and shape). The larger the area, the greater the permissible bending load.
• A method of securing a beam to a supporting structure. Much depends on the shape of the section. The I-beam is attached most firmly.

For calculation maximum load For bending, resistance formulas are used. To simplify the process, you can use an online calculator, which allows you to get a fairly accurate value based on the entered data.

Recommendations for choosing construction beams and erecting structures

• The main factor when choosing a beam for the construction of a supporting structure is the calculation of the weight of the maximum load under the influence of transverse vertical forces. However, in areas with unstable climatic conditions and a high degree of seismological hazard, it is necessary to calculate the effect of transverse horizontal forces.
• I-beam profiles may be marked with the following letters: B, Ш, K. Explanation: B – standard, Ш – wide-flange and K – column I-beam, respectively.

Select the optimal beam profiles during construction to ensure the durability and reliability of the structure!