Lightening of metal structures. Lightweight metal structures. Methods for stiffening sheet metal

The exceptional properties of a metal profile pipe make it possible to use it in many areas of industry, in particular, it concerns construction industry... Lightweight metal structures are installed as frames in industrial facilities, in public buildings, shopping centers and exhibition pavilions. Columns and trusses, sheds and fences, benches and gazebos, stairs and bridges are made of pipes. Hollow today profile products quite often they are used in the residential sector for the construction of attics, various kinds of superstructures, outbuildings and even low-rise buildings.

Methods for manufacturing a profile pipe, its advantages and types

Manufacturers produce pipes profile section seamless and electrowelded. In the first case, round or faceted metal blanks are subjected to preliminary deformation - pressing or piercing. In the second case, the strip steel sheet(strip) is passed through the roll forming equipment, and the resulting closing seam is welded. Received different ways billets are finally formed on rolling mills hot, warm or cold, as a result of which the required profiles are obtained. In the future, heat treatment of products is carried out, increasing their technical and operational characteristics.

In construction, as a rule, metal profile pipes of square and rectangular section... Due to their shape and manufacturing technology, they are obtained:

• lightweight - light weight makes it easier to assemble structures;
• reliable - stiffening ribs give additional strength;
• convenient in transportation and storage - it is used less space, in comparison with round products, and does not require special fixing;
• easy to install - docking with flat surfaces is not difficult.

Metal structures made of shaped pipes allow:

• reduce the cost of construction by reducing the construction time;
• perform work in a cold period of time;
• to ease the load on the foundation;
• not to be afraid of subsidence of the building frame;
• perform complex structural elements.

The disadvantage of using a profile pipe for any metal structure can be an incorrect calculation of the loads. Therefore, specialists should be involved in the design of trusses, columns, vaults and other elements of the frame. Otherwise, the building during operation may simply "fold".

It should be noted that thick-walled pipes suitable for manufacturing load-bearing elements frame buildings, have a high cost. But the absence of the need for a massive foundation and the speed of the construction of the object in many cases are relegated to the background.

In addition to the size and shape of the section of the profile pipe, metal products differ in the type of material used. They can be made of steel, aluminum and its alloys, with a galvanized or subsequently painted surface. Aluminum pipes used for the construction of fences, facade systems, internal elements of the interior and "light" buildings, and more robust structures, for example, trusses and columns are made of steel analogs. Galvanized pipes are installed where aesthetics and reliability are required - when erecting "open" frames, in-house buildings, sports complexes, as well as in the manufacture of intake sections.

The scope of the profile pipe is so wide that it is difficult to overestimate it. But in heating and plumbing systems it is not used. There are more suitable options for them.

Rafter metal structures

Trusses made of shaped pipes have a significantly lower weight than those made of corners, channels, or T-bars. It is quite possible to assemble them on your own directly on the construction site, but only with the appropriate experience.

With the wrong technology, a curved roof may well turn out, which will not look aesthetically pleasing. And after a while, if not immediately, it will surely collapse. It should also be remembered that metal trusses from profile pipes should be laid in the event that the quality roofing lightweight modern materials will be used.

Depending on the span and shape of the roof, the trusses perform:

• triangular;
• broken;
• trapezoidal;
• with parallel belts;
• single-pitched;
• arched;
• asymmetrical.

Almost any trusses can be recreated from shaped pipes - with different forms kerchiefs, types of braces and racks, as well as support options. The assembly is carried out by welding using additional reinforcing elements at the docking joints. In addition, braces and spacers may be present in the structure of the truss, and bolts and rivets as fasteners.

The shape and dimensions of the metal structure, the location of pipes and the number of additional elements are determined by calculations that take into account the transfer and redistribution of possible permanent and variable loads.

Correctly designed and assembled trusses from shaped pipes are allowed to be used in critical areas of structures. They can serve without problems for years, but high price yet does not add to their popularity among private developers. More often, owners use shaped pipes for the installation of small buildings in their local areas.

Frame houses

In almost every locality today you can find prefabricated frame structures as shopping centers and cafes, showrooms and warehouse hangars, bus stops, covered parking lots and gas stations. Previously production workshops built from massive metal structures, and now channels and corners have been replaced with lightweight profile pipes. New technologies made it possible to expand the boundaries of frame construction and ensure the rapidity of the emergence of new buildings.

In European countries, Japan and the United States, low-rise residential buildings using structures from shaped pipes are being built quite intensively, but cheaper wooden frames remain priority for our fellow citizens. But if we compare the "western" buildings with buildings erected from traditional materials (brick, concrete, solid logs), then in terms of financial and labor costs, the latter will cost more than metal-frame houses.

In fact, the cost of a structure made of shaped pipes directly depends on the materials used. In particular, the size of the section and wall thickness of pipes, methods of insulation, as well as options for interior and exterior decoration play an important role.

General principles

Vertical steel structures are installed on the foundation. It is laid below the level of soil freezing, but it is performed in a lighter version than would be required during construction load-bearing walls from traditional materials. It is allowed not to arrange a capital foundation only for temporary buildings, which sometimes can be moved from place to place or disassembled. This applies, for example, to greenhouses, seasonal sheds or greenhouses.

The frame is mounted in stages, connecting the profile pipes to each other using:

• welding;
• threaded connections;
• riveting.

Factory metal structures are assembled faster and easier, as they are completed with special fasteners, and the pipes have clear fixed dimensions. Welded joints require constant monitoring of the correct location of adjacent elements. In this case, the construction of the frame needs a more thorough and accurate approach. Installation work is carried out from the bottom up. The stability of the vertical elements is ensured by horizontal strapping and braces made of profile pipes of a smaller section.

The roofing part of the building is erected in two ways, depending on its design features. In the first case, it will be one of the elements of the general framework, and in the second - a separate structure consisting of several trusses installed on supporting posts, columns or beams.

It should be noted that the more the slope of the slopes will be chosen and the easier roofing materials, the thinner the profile pipes will be required for the installation of the roof.

The next stage in the construction of a residential building is work on the insulation of the enclosing structures. For these purposes, experts recommend using extruded foam and advise not to forget about additional insulation of metal structures so that they do not turn into a kind of cold bridges.

Simple and popular metal structures

Within the territory of garden plots owners often set up sheds for storing inventory and summer kitchens, souls and outdoor toilets using metal pipes with a profile section. Such structures are quickly erected and, if necessary, dismantled. But there are also more capital buildings that serve for years.

Fence from shaped pipes

Owners of private houses prefer solid fences that hide the site from prying eyes. But the territories of public institutions, parks and gardens are surrounded by fences made of shaped pipes, eliminating shading and providing an excellent overview. Such fences look more elegant than concrete and brick ones, and are built faster and easier.

Metal structures of fences can consist of straight or roll-formed profiles, have simple forms or combined with openwork forging elements.

The most popular option is considered to be a fencing structure consisting of square hollow pillars, a pair of horizontal and many vertical rectangular shaped pipes of small size. As with assembling a truss, the elements are welded together, but they can also be fixed using couplings or brackets.

The work is carried out in stages.

1. On a stretched level, at a distance of about three meters from each other, the locations for the installation of the pillars are outlined.
2. Pipes are dug in and concreted, or driven in.
3. The lower and upper crossbars are welded onto the pillars.
4. On horizontal elements, vertical profiles are fixed equidistantly, having the same or different length.

Metal structures are also hung on the frame made of shaped pipes, which are ready-made fence sections, manufactured in an industrial environment or independently. In this case, the same profiles, mesh or reinforcing bars can be used as filling. And sheets of corrugated board will help to hide the site from curious passers-by.

Pipes of rectangular cross-section are often installed on the canvases of wickets or gates, even with a continuous fence of the site. The advantage such a decision is the reduction of the loads on the support pillars, which makes it possible to expand the passage. In addition, the hosts will always be able to see the visitors in advance and communicate with them without opening the gate or letting in unexpected guests, which in some cases is very important.

Visors and awnings

Lightweight metal structures designed for the construction of free-standing awnings, canopies over entrances, as well as roofs for gazebos, terraces and garages are also made of shaped pipes. In their shape, they resemble metal trusses, but smaller in size and excellent in filling. They are not reinforced by a large number of struts and braces, and in some cases, when the structure consists of separately located pipes, they do not have them at all.

For arched canopies metal profiles bend, and for pitched canopies they are welded with vertical or horizontal elements at the required slope in accordance with the drawings. On ready-made structures lay lightweight roofing materials. For this, tents are often used or transparent sheets polycarbonate.

Lightweight metal structures are widely used in the construction of pre-fabricated buildings and structures, and their use allows you to reduce material costs and speed up the process of building objects. Manufacturers suggest using hot-rolled or cold-rolled metal profiles, which are produced by stamping. Modern LSTK technology It is used for the rapid construction of buildings, which are characterized by a wide range of applications, long service life and increased strength.
The main advantages of using lightweight metal structures for the construction of prefabricated structures include:

high quality metal structures at an affordable cost;
durability and reliability;
strength and durability;
versatility and mobility;
resistance to corrosion processes, mold and fungi due to the presence of a special protective anti-corrosion coating;
wide range of applications in industry, agriculture and house construction.

Construction and installation works are carried out in any weather and at any time of the year due to the absence of a "wet" finish, and all structural elements are assembled quickly and easily using bolts anchor type and self-tapping screws.

Features of production and construction.

When developing a project for a building made of metal structures, the target application, the customer's needs, the expected operational load and the need for insulation are taken into account. Modern high-quality materials are used as insulation. thermal insulation materials, namely foam, extruded polystyrene foam, mineral and basalt wool, fiberglass.

Due to the compactness of all metal structures, they are quickly and conveniently delivered to the construction site, which reduces the cost of their transportation. The erection of buildings from lightweight metal structures does not require the arrangement of an expensive monolithic foundation, as in capital construction, therefore, the total production costs for construction are reduced.

Scope of application of lightweight metal structures.

In agriculture, such buildings are intended for storing vegetables and grain crops, and insulated rooms are used for breeding and raising poultry and animals. When developing a project, the creation of certain climatic conditions, pad engineering communications, ventilation system and air conditioning, artificial lighting and the need for insulation.

Buildings made of lightweight metal structures are distinguished by their strength and lightness, fast erection of the frame, walls and roof, so today they are used for construction country houses, summer cottages and cottages. This is a profitable investment, since the cost of the work is significantly lower compared to capital construction.
Technology for the construction of objects from lightweight metal structures

For the construction of prefabricated buildings used innovative technology LSTK, which consists in the use of durable lightweight profiles, which can be load-bearing, guide and hat. Of them, not only the frame of the structure itself is erected, but also walls, roof ceilings, and a shallow tape or pile is used as a foundation.

The choice of foundation depends on the type of soil, the depth groundwater and climatic conditions of the area. Using this technology, you can build objects of any shape and complexity: straight-walled, arched, polygonal and hipped roof. They differ from each other in design and shape, but they all have high strength, versatility, durability and reliability.

For effective protection from corrosion, the surface of metal structures is covered with protective anti-corrosion compounds ( polymeric materials, enamel or primer). The construction of structures from lightweight metal structures fully complies with the requirements fire safety, state standards and environmental friendliness.

Lungs steel structures- this is new round development in the field of industrial construction. Buildings made of light steel thin-walled structures are strong and reliable, their construction is 25-40% more profitable than conventional traditional structures, and design feature allows you to implement complex and original projects.

Light steel structures

There are two types of steel structures:

• LSTK - light steel thin-walled structures
• LMK - light metal structures

LSTK is a lightweight version of a metal building, thickness steel profile is 0.2-0.4 mm, while it is possible to build warehouse and industrial premises that will be earthquake-resistant and durable.

LMK are metal buildings with used metal up to 4 centimeters thick. These are solid and reliable structures that are built for different areas of human life.

Prices for light steel structures today vary and depend on the region of construction. In the central regions Russian Federation the construction of steel buildings is cheaper due to the high concentration of manufacturing plants, the presence of competition and, accordingly, more favorable offers. The average cost of one ton of metal structures is 50,000 - 79,000 rubles.

An interesting feature can be called a simple commissioning of the facility. Since LSTK and LMK constructions are not traditional, that is, capital structures made of stone and concrete, the registration and commissioning process takes place in a simplified mode, without paperwork.

Lightweight steel thin-walled structures: technology

LSTK is more popular in Russia, as the technology assumes simple and quick installation steel frame, which you can do yourself with your own hands.

The technology originated in 1950 in Canada. The availability of building material and the low cost of building construction quickly popularized thin-walled structures in Japan, Scandinavia, and North America.

Stages of construction of a prefabricated building:

• Design.
• Foundation preparation (any shallow deepening).
• Ordering a metal frame.
• Mounting.
• Putting the building into operation.

LSTK advantages:

• Low cost.
• Ease of assembly.
• Durability and wear resistance.
• Fast installation.
• Independence from climatic conditions, the ability to build in cold and wet weather.
• Seismic stability of the structure.
• Good heat saving properties.
• No shrinkage on the foundation.

What is LSTK made of?

LSTK buildings are built from profiles that are made of high-strength galvanized steel. The entire production cycle is automated, in the presence of design documentation, the metal rolling plant will prepare every detail of the future building with the necessary holes and markings.

Construction from LSTC is not costly, since from the zero stage it is possible to save well on the construction of the foundation and, in the final stage, on insulation. LSTK is suitable for the construction of a residential building, cottage, greenhouse, hangars and many other structures.

Video

Publisher:"Budivelnik"

The year of publishing: 1978

Language: Russian

Pages: 112

Introduction

Chapter 1. Curved profiles - the new kind highly economical rolled metal for construction

The struggle to reduce the weight of metal structures, to increase their strength, reliability and durability has led to the creation of a new type of rolled steel - roll-formed sections. Bent profiles are corrugated sheets of various configurations: z-shaped, trough-shaped, closed and other sections of a part of almost unlimited length and constant thickness in all cross-sectional elements.

There are several ways to obtain bent profiles, namely: punching, press bending and broaching. However, the use of these methods of manufacturing curved profiles does not make it possible to obtain profiles long length, width and thickness. In addition, these methods are inefficient and lead to big losses metal, the process of obtaining profiles with a complex configuration cross section very difficult The narrow range in length, width and thickness of the original blanks and the high cost of roll-formed profiles obtained by stamping, bending on presses or broaching sharply limit the scope of their application.

It became possible to eliminate the aforementioned shortcomings of bent profiles when manufacturing them using a fundamentally new method and constructively new equipment. Such equipment turned out to be similar to rolling special roll-forming units. Roll-formed profiles obtained on these mills are called roll-formed rolled profiles. From the point of view of manufacturing technologies, the fundamental difference between bent and hot rolled sections is their production from the initial billet in the cold state and the invariability of the cross-sectional area during the forming process. Equipment for the production of roll-formed rolled sections is less complicated than rolling or pressing, its production is cheaper, and maintenance is easier and simpler. Capital investments and operating costs in organizing the production of roll-formed rolled sections are significantly less than in other types of metal forming, and the initial costs are recouped in a short time.

Roll-formed profiles are manufactured by continuous profiling of sheets, strips and strips on roll-forming units different types... The profiling process consists in sequentially changing the truss of the cross-section of the original workpiece (strip, fin, tape) when it passes through a series of pairs of driven horizontal and vertical (idle) rolls (rollers) rotating towards each other.

Chapter 2. Lightweight metal structures from closed bent profiles

Particularly promising is the use of bent profiles in lightweight frames of building buildings.

The main advantage of bent-welded closed profiles (GSP) in comparison with others is the following:

1) the economy of characteristics by weight, due to the favorable distribution of material over the sections of structural elements and a decrease in design factors as a result of a decrease in the volume of auxiliary and connecting parts;

2) the possibility of using a sheet of small thickness (2-3 mm compared to 5-6 mm in structures from conventional profiles) due to increased corrosion resistance and local resistance. The same abilities make it possible to effectively use steels of increased and high strength for GSP;

3) reduced vulnerability of structural elements made of closed profiles during transportation and installation due to the absence of protruding edges;

4) improvement performance due to increased corrosion resistance and reduced outer painted surface of structures, etc.

Feasibility studies show that GSPs are very effective in rod systems and practically give the same mass indicators as pipes.

In the works of the UkrPSK Institute, it is proposed to create low-element trusses in order to simplify the nodes and reduce the design factors.

In light, lightly loaded structures, along with closed bent-welded sections, it is advisable to use open bent sections. So, in roof trusses with a span of 12-18 m for light roofs and in other lattice structures that perceive relatively small loads, the use of open bent profiles gives metal savings up to 20-30%. With an increase in spans, the effectiveness of the application open profiles decreases and with spans of more than 24 m, significant savings in metal cannot be achieved.In this case, savings are possible only when using closed bent-welded profiles.

Experience has shown that good decisions circuits, structures, assemblies, selected section shapes, welding technologies, etc. make it possible to create truly progressive building metal structures for medium and heavy loads, in many cases successfully competing with tubular ones, and sometimes even surpassing them.

However, for widespread implementation, it is first of all necessary to develop a single point of view regarding the entire problem.Unfortunately, not all organizations share the opinion about the advisability of widespread use of roll-formed profiles. Much attention paid to pipes, disbelief in the effectiveness of the use of roll-formed sections, in a number of cases, the negative impact of tonnage planning to a one-sided approach to assessing the coefficient of the specific labor intensity of factory fabrication of structures to a large extent inhibits the development of an important direction of metal construction.

Chapter 3. Bent corrugated profiles in metal structures

In metal lightweight structures, various corrugated bent profiles are widely used as ready-made parts that speed up installation, improve appearance, reduce construction time and reduce the cost of it. These profiles can have corrugations of various shapes: semicircular, rectilinear, trapezoidal, triangular with a blunt top, etc. The wide assortment of corrugated sheets used until recently was a consequence of the fact that consumers made them for their own needs using existing equipment. In the absence of any unification for the production of profiles that differ from each other in the shape of the corrugations, it was necessary a large number of profile rolls or dies, the production of which took a lot of time and high-quality steel.

To reduce the number of profile sizes, reduce the cost of their development, accelerate production and provide consumers, unification and standardization of corrugated profiles were carried out. Two standards have been developed for corrugated roll-formed rolled sections GOST 9234-73 and GOST 10551-75, which cover all profiles currently produced for various industries. In order to reduce the number of profiles made from galvanized billets, to unify their dimensions, a standard is being developed for galvanized corrugated sheet steel, which is mainly used in construction.

When developing the standards, materials were used about the needs of the national economy in corrugated profiles, the range of profiles used in construction and industry and the range of corrugated profiles mastered by metallurgical and machine-building plants. It should be noted that in last years not only the product range has significantly expanded, but also the need for corrugated roll-formed sections has grown.

Chapter 4. Perforated bent profiles in metal structures

Recently, in our country and abroad in various industries and construction, bent perforated rolled profiles are becoming more and more widespread.

The use of such profiles in various sectors of the economy can reduce metal consumption by 18-20%, speed up the assembly and installation of structures, eliminate welding works during installation, reduce labor intensity installation works... The assembly of metal structures from perforated profiles is a modern and rational construction system.

Bent perforated profiles include profiles in which there are holes of various shapes and sizes, applied along the entire length with a certain step (modulus) of perforation.

Perforated profiles, depending on their application, should be divided into two large groups: profiles for prefabricated structures and profiles for special purposes.

The first group includes perforated angular and channel section profiles, bolted connection which in various combinations allows you to obtain lightweight metal structures of all kinds and purposes.

The most important advantages of this group of perforated profiles are their lightness, the ability to fast assembly without the use of welding, multiple use of the same profiles in collapsible structures for various purposes other. These profiles, which are universal building material are called quick assembly profiles.

The second group includes profiles of a special shape, which are used only in certain structures. Perforated profiles are the basis integrated system code structural elements for the manufacture of all kinds of metal structures in construction, warehouse, transport and production equipment.

Chapter 5. Lightweight panel spans and enclosing structure from bent profiles

Construction is one of the main consumers of roll-formed rolled sections. The use of such profiles makes it possible to obtain the most perfect solutions for building elements, both in terms of architectural and aesthetic and technical and economic indicators. Work is underway to further improve the designs of panel bindings in industrial and administrative buildings in order to facilitate the structures of bindings, increase labor productivity in their manufacture, improve working conditions inside premises by increasing illumination, improving the architecture of buildings In industrial and civil construction in Czechoslovakia, bent profiles are widely used various configurations up to 2 mm thick: open, semi-closed, closed with elements of double thickness and a large number of bending points.

When developing an assortment of profiles for panel bindings, the technology of manufacturing them on existing roll-forming units was taken into account, as well as the technology of manufacturing bindings at metalwork factories to speed up the assembly of structures, reduce their cost and ensure a good appearance.

Compound open types bent profiles into closed ones in the conditions of metal structures factories are most acceptable by the method of electric arc welding. However, this welding method is inefficient.

Architectural and structural elements made of lightweight profile steel are widely used in modern construction in the form of metal window and display cases, glass-metal doors, staircases and balconies, door frames guides for sliding doors and partitions.

The assortment includes open, semi-closed and closed cross-sectional shapes, as well as with elements of double thickness. The individual profiles are perforated.

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