Competent development of fire safety instructions, taking into account the individual characteristics of a particular facility, is important. The chances of an uncontrolled fire increasing significantly if the rules are drawn up “superficially”. This increases the risk of harm to human health and property. In order to prevent accidental fires, it is important to be able to correctly determine the structural and functional purpose of buildings in terms of fire safety.

Each building in turn is divided into the following indicators:

• constructive - this parameter depends on many factors: the area and height of the building, the direction of activity, what class of functional fire hazard the industrial or warehouse buildings and other types of objects belong to
• functional - the parameter directly depends on the direction of activity carried out in the structure in question. The functional fire hazard class of a building and its parts is determined taking into account the level of safety of technological operations that can provoke a fire. The number of people for whom the building is intended is also taken into account.

Functional purpose of fire safety premises, general information

The fire safety function class is an indicator of great importance, determined based on the individual characteristics of the structure and the nuances of its operation. When classifying, they take into account the possible reaction of people if they are in the building in question, the preparedness and number of personnel, the ratio of staff to visitors, and the presence of sleeping places. They also consider the ability to navigate in evacuation passages, approximate knowledge of the layout and other indicators. They classify not only free-standing buildings, but also fire compartments. The relevant documentation specifies the following requirements: individual buildings are allowed to be classified as structures if they are functionally connected to each other. For example, a store and a warehouse where the store's products are stored.

Functional fire hazard categories

Let's consider what functional fire hazard class theaters, schools, hospitals, railway stations and other institutions belong to. How many classes are there in total?

1 class – This includes residential buildings. They are operated on an ongoing basis and must be equipped with several independent options for escape routes. In addition, such facilities should be equipped with various... Buildings in this group are characterized by the presence of rooms for rest and sleep. “F1” includes buildings where people live (temporarily, permanently), and they are divided into:

• F 1.1 – institutions for people with disabilities and preschool children (orphanages, hospitals, kindergartens)
• F 1.2 – institutions with temporary accommodation of people (hotels, sanatoriums, hostels for workers and students)
• F 1.3 – multi-apartment buildings (high-rise buildings)
• F 1.4 – individual housing building

2nd class (F2) – establishments with a high level of traffic/attendance, various entertainment organizations that provide their services in open and closed spaces. This group includes:

• F 2.1 – buildings with seating for recreation (libraries, circuses, concert halls, etc.)
• F 2.2 – museums, various dance schools, facilities where exhibition events and fairs are organized
• F 2.3 – similar to F 2.1, but programs are held in open areas (stadiums)
• F 2.4 - similar to F 2.2, but there are programs taking place in open areas

3rd grade – this includes structures operating in the area of ​​public services:

• F 3.1 – shopping centers, hypermarkets;
• F 3.2 – canteens, dumplings (catering points);
• F 3.3 – stations, airports, seaports, station structures;
• F 3.4 – medical organizations providing services both at home and in institutions;
• F 3.5 – housing and communal services, savings banks, legal and notary organizations;
• F 3.6 – sports complexes, saunas, institutions where physical education and health programs are organized, etc.

• F 4.1 – educational organizations (technical schools, colleges, etc.) with secondary education;
• F 4.2 – this group includes institutions providing higher education (academies, institutes);
• F 4.3 – scientific, design and newspaper publications, banks;
• F 4.4 – fire station.

5th grade (F5) – the last group includes the following list of buildings:

• F 5.1 – production, workshop and laboratory structures;
• F 5.2 – storage and archival structures, parking complexes intended for various vehicles;
• F 5.3 – agricultural institutions.

As the category decreases, fire safety requirements also increase. Consequently, buildings where people are constantly present or where regular mass presence is observed must be taken under special control by inspection services and designers.

Functional fire hazard class of buildings and structures - table No. 1

Class (subclass) of functional fire hazard of a building	Capacity of halls, people	Number of floors/height of structure	Material category, not higher than specified
			Walls, ceilings	Floor coverings
F1.2, F2.3, F 2.4, F3.1, F3.2, F3.6, F4.2-F 4.4, F5.1	Above 800		KM0	KM2
	300-800		KM1	KM2
	50-300		KM2	KM3
	Up to 50		KM3	KM4
F1.2, F1.3, F2.3, F 2.4, F3.1, F3.2, F3.6, F4.2-F 4.4, F5.1-F5.3		Up to 9 floors/up to 28 m	KM2-KM3	KM3-KM4
		9-17 floors/28-50 m	KM1-KM2	KM2-KM3
		Above 17 floors/from 50 m	KM0-KM1	KM1-KM2
		Regardless of number of floors
F1.1, F2.1, F2.2, F3.3-F3.5, F4.1	above 300		KM0	KM2
	15-300		KM1	KM2
	Up to 15		KM3	KM4

Categorization of objects according to explosion and fire hazard

Categorization refers to the correlation of a structure by explosion and fire hazard to specific categories. The procedure is mandatory. It is subject to objects related to F 5.1 and F 5.2 (for example, laboratories, workshops, parking lots), as well as complex technical installations located outside the structure. Categorization is carried out only for warehouse and production facilities. The fire hazard group is established at the design stage of the structure. According to the explosion and fire hazard, premises are divided into five categories: A, B - (explosive), B (fire hazardous), D, D. The categories are established specifically for the most negatively affecting fuel, its volume, etc.

What difficulties arise in establishing a category?

There are cases when it is extremely difficult to identify the functional fire hazard class. Let's look at the example of the functional fire hazard class of a gas station. Its purpose is to sell fuel, therefore, it is an organization engaged in trade. But there are other types of gas stations where fuel is not sold, but only dispensed. From this we can conclude that the station belongs to the fifth class (F5) warehouse facilities, with equipment installed outside. The control room also belongs to F5 (a design for industrial purposes), and the store itself, installed at a gas station, belongs to F3. It is worth noting that the fire hazard class is assigned to the structure as a whole or to a separate fire sector. But, if you look at the regulations, you can find some clarifications regarding the assignment of categories. Even if there are premises with different areas of activity under the same roof, the rules will be established and put forward based on the main direction of the building in question. Or let's look at another example. The educational institution has a laboratory that belongs to F5, but the safety requirements will be put forward as for F4. For the full and safe functioning of a structure, it is important to correctly establish the functional fire hazard group and carry out preventive measures in a timely manner.

Category calculation

Category calculation is a set of computational measures that allow identifying the hazard category based on an analysis of stored, used, processed media, technological operations and installations. To perform a calculation, you must first collect information (including a plan) about the object in question. Afterwards, take measurements of the walls and ceiling heights in those areas that pose a particular danger during a fire. Next, set the temperature conditions and what material is used as the flooring. Identify the presence of special equipment intended for fire extinguishing, ventilation outlets. The purpose of the calculation is to create appropriate requirements for the area under consideration, aimed at reducing the risk of fire, and competently ensuring the protection of people and valuables in the event of its occurrence.

Features of class calculation

The functional fire hazard class of a building is determined based on many parameters. You should be guided by two main documents - 123 F3, dated July 22, 2008 and 117 F3, dated July 10, 2012. To assign a fire hazard level to a building, it is important to take into account which rooms of a certain explosive level are present more. The total volume of flammable media that can be accommodated at the facility must be established. How are calculations carried out? To identify a suitable calculation method, the one with the highest possible level of danger is selected. The probability of failure of one of the equipment is also taken into account. All elements of the unit are located indoors; during the entire shutdown time, there is a leak from the pipelines supplying the system. Next, the spilled composition evaporates. In addition, the free space of the object under study is taken into account. After this, the calculation of excess pressure begins. To identify the category, a special formula is used. Some types of categories are established based on a specific group of combustible atoms present in the building. To identify the fire hazard category for residential buildings, a calculation is not needed. Based on the class, the number of exits, inputs, fire alarm options and other points that affect the safe stay in the structure are determined.

Types of structural fire hazards

It is revealed by the degree of participation of certain building elements in the development of fire and the creation of fire hazards. This parameter is directly related to the fire hazard categories of the main load-bearing, barrier elements, for example, flights of stairs. There are 4 categories:

• C0 – structural elements are made of non-flammable materials (non-fire hazardous)
• C1 – low-flammable materials were used during construction
• C2 – residential buildings, fire resistance degree from 2 to 4
• C3 - the main part of structures (with the exception of walls, barriers, partitions, etc.) for which fire safety requirements are not imposed

Requirements for objects of different categories of functional fire hazard in one structure

Premises with categories F2-F4 are allowed to be located within 1 fire compartment, including various technical rooms. A necessary condition is at least 3 fire hydrants. Cinema complexes with a total number of seats over 300 must be separated into separate compartments and provided with individual emergency exits and staircases in the amount of 2 or more. Each structure should be equipped with:

• systems: automatic fire extinguishing, smoke protection
• alarms
• means of rescue (for individual and general use)
• warning systems, preferably above type 4
• special water supply

The differentiation of objects with different functional categories within one structure is carried out by installing fire partitions, walls and ceilings. During the development of a multifunctional structure project, an important stage is carrying out calculations. It is with their help that you can analyze the accuracy of previously approved decisions regarding space planning work.

Notes

1. The distances indicated in the table should be taken: for cities and other populated areas - from the design city limits for an estimated period of 20-25 years; for individual industrial enterprises, railway stations, airfields, sea and river ports and marinas, hydraulic structures, warehouses of combustible and flammable materials, artesian wells - from the boundaries of the territories allocated to them, taking into account their development; for railways - from the bottom of the embankment or the edge of the excavation on the side of the pipeline, but not less than 10 m from the border of the road right of way; for highways - from the base of the embankment of the roadbed; for all bridges - from the base of the cones; for detached buildings - from their nearest protruding parts.

2. A detached building should be understood as a building located outside a populated area at a distance of at least 50 m from the buildings and structures closest to it.

3. The minimum distances from railway and highway bridges with a span of 20 m or less should be the same as from the corresponding roads.

4. With appropriate justification, it is allowed to reduce the distances from gas pipelines indicated in columns 3-9 (with the exception of positions 5, 8, 10, 13-16) and in column 2 only for positions 1-6 by no more than 30%, provided classifying pipeline sections to category II with 100% control of installation welded joints by X-ray or gamma rays and by no more than 50% when classifying them as category B, while the distances indicated in position 3 can be reduced by no more than 30% when condition that pipeline sections are classified as category B.

The distances indicated in positions 1, 4 and 10 for oil pipelines and oil product pipelines may be reduced by no more than 30%, provided that the nominal (calculated) thickness of the pipe wall is increased by the same percentage by which the distance is reduced.

5. The minimum distances from the axis of gas pipelines to buildings and structures for overhead installation, provided for in position 1, should be taken increased by 2 times, in positions 2-6, 8-10 and 13 - by 1.5 times. This requirement applies to sections of overhead laying over 150 m in length.

6. When buildings and structures are located at elevations higher than the elevations of oil pipelines and oil product pipelines, it is allowed to reduce the distances indicated in positions 1, 2, 4 and 10 by up to 25%, provided that the accepted distances must be at least 50 m.

7. When laying oil pipelines and oil product pipelines above ground, the permissible minimum distances from populated areas, industrial enterprises, buildings and structures to the pipeline axis should be taken as for underground oil pipelines, but not less than 50 m.

8. For gas pipelines laid in forested areas, the minimum distances from railways and roads may be reduced by 30%.

9. The minimum distances from underwater oil and petroleum product pipelines specified in position 7 may be reduced to 50% when laying these pipelines in steel cases.

10. Gas pipelines and other objects from which gas may be released or leaked into the atmosphere must be located outside the air access strips to airfields and heliports.

11. The "-" sign in the table means that the distance is not regulated.

Mushroom-shaped foundation for anchor-corner supports F 3 A5m – is a monolithic reinforced concrete structure designed for installation of overhead power line supports with a voltage of 500 kV overhead power lines based on metal supports. A mushroom-shaped foundation with an inclined post is available. This rack has embedded parts that are used for fastening directly to the support. A mushroom-shaped foundation cannot be dispensed with if the power transmission line is supposed to be 6 meters or more in height. For anchor-angular steel ones in the power industry, footrests with inclined posts are used, the axis of which is a continuation of the support belt and the guy axis. This design dramatically reduces horizontal loads on the foundation.

The foundation of a power line support in the form of a footrest F 3 A5m is a structure with a pyramidal slab and a stand. This structure is laid to a depth of 1.5 to 2.5 meters. The bearing capacity of such foundations, based on the strength of the structure, is up to 770 kN. The foundation is called mushroom-shaped because of its shape, similar to an inverted mushroom. The purpose of such a foundation is to support anchor-corner supports.

The mushroom-shaped foundation significantly increases the resistance of the power transmission line structure to wind loads. High-quality foundations made of heavy concrete can reliably protect power lines from deformation under the influence of bending loads.

The dimensions of the footrests, which determine the release of series 3, assume a foundation height of F 3 A5m 3115 m. A significant part of the foundation height during installation is buried in the ground. A foundation height of 1.7 meters is considered shortened and is indicated separately in the product labeling. The solid mass of the mushroom-shaped monolithic foundation is 4500 tons. Lifting is done using special holes and hinges.

The foundation of the power transmission line support is made of heavy-duty heavy concrete of class B25, the filler of such concrete is small crushed stone. Increased frost resistance of concrete foundations grade F150-F200, water resistance W4-W6. The high class of water resistance allows the mushroom-shaped foundation F 3 A5m to have a long service life under the influence of aggressive chemical environments of water and soil. Special raised foundations are intended for use in water obstacles.

These properties allow such a support to serve for many decades without crumbling or allowing the structure to warp.

High-quality reinforcement gives foundations a margin of safety. Reinforcement is carried out with longitudinal rods made of stressed steel reinforcement of classes A-I and A-III. The rods are welded into a single frame using binding wire. The protective layer of foundation concrete - at least 30 mm - does not allow either moisture or aggressive substances to threaten the safety of the structure. The embedded parts and reinforcement products of mushroom-shaped foundations are pre-treated against corrosion with two layers of zinc-rich primer.

Product marking

The symbol consists of the designation of the product name, its standard size and additional characteristics. O – the purpose of the footrest is for corner supports on guy wires, A – for anchor-corner supports. Raised foundations are designated by the letter P.

For an example of brand decoding, consider (2100x 2100x 3115 mm) , Where:

• F – mushroom-shaped footstool;
• Number – standard size;
• A - for anchor-corner supports;
• 5 - voltage 500 kV;
• m - modernized headrest.

The weight, code and date of manufacture of the foundation are marked on each product.

Foundation installation

In areas with clay grants, a sand base 50-100 mm thick is used for the foundation. Often, crushed stone preparation is arranged under the foundation, which increases the supporting area. Under foundations for inclined racks, a crushed stone layer for soft soils is also made at an angle to the plane.

Product quality control

Ultra-precise overall dimensions of the power transmission line foundation may not be achieved during production. However, the deviation in product dimensions should not exceed 10-20 mm in length and 5-8 mm in thickness.

The main role in the foundation is played by its mass; the more massive the mushroom-shaped foundation, the greater the load it can withstand. Therefore, the deviation from its design mass should not be less than 5-7%. To ensure that the concrete foundation does not collapse prematurely, attention is also paid to the quality of its concrete surface. Like any other reinforced concrete products, power transmission line foundations should not have a large number of cracks more than 0.2 mm wide. Shells more than 1 by 2 meters in length are not allowed on the surface of the mushroom-shaped foundation. Under no circumstances should the working reinforcement of the F 3 A5m foundation block be exposed.

All embedded products located on the surface are treated with paint and varnish, and in case of operation in aggressive environments they are additionally protected. The manufacturer assigns a warranty period of 12 months from the date of commissioning, but no later than 18 months from the date of manufacture.

During the procedure batch acceptance of transmission line foundations, the strength of concrete, the compliance of reinforcement products and mounting loops, the strength of welded joints, the accuracy of overall dimensions, the thickness of the protective layer of concrete to the reinforcement, the presence and width of possible cracks are checked. Mushroom foundations are checked by inspecting each product; special attention is paid to the quality of the foundation embedded products, because it is their reliable adhesion that guarantees the stability of the support. Certifies the quality of reinforced concrete foundations F 3 A5m technical certificate, accompanying each party. It informs the consumer about the number of reinforced concrete products in the batch, the date of manufacture of the batch, the mass of the product, and also provides the final strength of the concrete and the grade of concrete for frost resistance and water resistance.

Storage and transportation

In order to keep the foundations in a condition suitable for use, attention is paid to proper storage, unloading and careful transportation. Power transmission line foundations, like many monolithic and massive reinforced concrete products, are stored in one row or according to a special storage scheme. Transportation of the product takes place either in railway cars or in high-capacity vehicles under conditions of very reliable fastening of the products.

Fire safety rules are mandatory measures that must be strictly observed. But these rules are established using certain characteristics, among which is the purpose of the functional fire hazard of the building.

To prevent fire, it is very important to correctly classify a specific building, structure, structure or fire compartment.

The final decision will be taken into account when drawing up fire safety rules for a particular organization. If it is determined incorrectly, these rules may be grossly violated, as a result of which the chances of a fire will increase significantly. Identification of the functional purpose occurs according to three characteristics, the most important of which is the functional fire hazard class of buildings (structures, etc.).

Safety class, as defined

The functional fire hazard class of buildings is a classification characteristic identified by the purpose and details of use of specific buildings.
Features of production technology and fire hazard are also taken into account.
The need for correct identification of the destination has been identified. Further, the section itself is divided into classes using special criteria.

Fire resistance degree

Data on this degree for construction must be recorded in the relevant documentation.

Structural fire hazard class

It is determined by the degree of influence (columns, crossbars, coatings, fire barriers, etc.) on the spread of fire during a fire.

Functional fire hazard class

We will consider the list of signs with the help of which the class number is identified below. You need to know that the building and its parts, which are connected by a common function, are divided into different classes depending on the method of its operation and on how safe it is for people to stay there during a fire. This takes into account their age, physical health, the likelihood of being in a sleeping state, and the approximate number of people concentrated inside.

Classification

There are five classes of functional fire safety in total.

First

These are buildings that are intended for permanent or temporary residence of the population. These, as a rule, are operated around the clock, and the composition of the people inside and their physical health are sometimes completely different. For structures of this type, the presence of sleeping rooms is standard, which means that the possibility of sleeping people exists.
Buildings of this class are required to have several fire barriers and independent escape routes (by law). Designation – F1.

• So, immediate examples. F1.1.
• Institutions for preschool children, non-apartment-type houses for the elderly, non-apartment houses for people with disabilities, boarding houses intended for sleeping, as well as dormitory buildings for children's institutions. F1.2.
• Hotel complexes, motels, boarding houses, student or work dormitories, dormitories of sanatoriums and holiday homes, campsites. F1.3.
• Multi-apartment residential buildings. F1.4.

Single-family residential buildings, semi-detached residential buildings.

Second

• Refers to cultural and leisure places of recreation, entertainment institutions, in which there is always a large crowd of people. F2.1.
• Theater halls and cinemas, halls for concerts, special buildings with stands for watching sporting events, libraries, as well as other establishments with a designated number of possible visitors. F2.2.
• Exhibition halls, museums, dance halls and dance floors located in indoor areas. F2.3.
• Institutions that are in category F2.1., located in open space. Institutions that are in category F2.2., located in open space.

Third

It includes that part of enterprises that is engaged in the service sector. Despite the considerable number of personnel, buildings of this category are characterized by a predominant number of visitors (rather than employees). This category is labeled F3. It includes a number of institutions.

• F3.1. Retail outlets (shopping centers, department stores, shops, hyper- and supermarkets, etc.).
• F3.2. Public catering points.
• F3.3. Railway, bus, sea, river stations, as well as airports.
• F3.4. Multidisciplinary medical institutions providing services to patients in the institution and at home.
• F3.5. Enterprises providing household and utility services (post office, savings bank, notary office, office of a legal services company, transport agencies, beauty salons, hairdressers, ateliers, institutions providing dry cleaning services, etc.). Religious institutions (churches, temples, mosques, etc.), as well as ritual institutions that are not designed for a certain number of visitors.
• F3.6. Sports and recreational complexes, training facilities that do not have viewing areas for spectators, baths and saunas, sanitary facilities, which include showers, dressing rooms, washrooms and restrooms, sanitary rooms, smoking rooms, etc.

Fourth

It has the designation F4 and includes educational institutions, research / design organizations.

• F4.1. Primary, middle and high schools, out-of-school educational institutions, colleges, vocational schools.
• F4.2. Institutes and universities, institutions for advanced training and further recertification.
• F4.3. Banking organizations, offices, business centers, publishing houses, editorial organizations, information bureaus, design institutions, management bodies.
• F4.4. Fire protection facilities (fire stations).

Fifth

The latter, class F5, includes buildings for economic and industrial purposes, warehouse buildings, buildings, and so on.

• F5.1. Buildings aimed at production activities, laboratories and various workshops.
• F5.2. Premises aimed at providing warehouse services, unrepaired car parks without specialized maintenance, book storage, institutions storing and recording archival papers. Agricultural buildings.

The legislative framework

All classes of premises are determined by 123 - F3, dated July 22, 2008, “Technical Regulations on Fire Safety Requirements” and 117 – F3, dated July 10, 2012, “Introducing Amendments to the Federal Law.” Guided by these two fundamental documents, the classes and subclasses of the building are determined.

For example, the functional fire hazard class of a boiler room is F5.1, since this is an industrial premises, but by checking existing equipment, the category of the premises is checked empirically and assigned, depending on the results obtained, A - the most dangerous or D - the least dangerous.

It is worth remembering that laboratories and workshops located in buildings of categories F1–F4 belong to F5.

It can be difficult to determine which category a particular building belongs to, for example, a garage, but usually for a garage it is F5.2

In conclusion, we will re-emphasize the importance of correctly determining the functional purpose of a particular enterprise, putting forward new arguments. It is on the basis of the class that fire requirements are formed, which often determine the number of entrances and exits from the building.
In addition, based on these data, the possible presence of a fire alarm, the finishing of evacuation routes and many other factors affecting the safety of stay in a particular building are established.

Mushroom footrest foundation F 3-2 A - This is a mushroom-shaped reinforced concrete product, the pin of which is not inclined to the axis of the base. Belongs to the group of upright foundations. Let us recall that the installation of intermediate or intermediate-corner power transmission line supports with the fastening of elements to each other using guy wires is carried out only with the use of special foundation structures of type F and supporting elements. The choice of one type of foundation or another is determined by the conditions of the site on which the power lines will be built, in accordance with specific engineering-geological and hydrogeological studies, as well as technical and economic calculations. The monolithic base ensures operational safety, reliability and durability of power lines.

F 3-2 A serves to transfer loads from higher-lying nodes to the natural foundation. The operation of mushroom-shaped foundations is carried out in dry and water-saturated soils, as well as in conditions of critically low temperatures (estimated down to -40 degrees), seismicity up to 9 points on the Richter scale and exposure to groundwater of varying degrees of aggressiveness. The depth of foundations is determined by the properties and characteristics of the soil under specific operating conditions, as well as the loads determined by the characteristics of the power line support.

1. Marking writing options

It is allowed to record markings in different ways:

1. F 3-2;

2. F 3.2.

2. Main scope of operation

Mushroom footrests F 3-2 A are used for direct installation of power transmission line supports, type VL, with a rated voltage of 35-500 and 750 kW. The preparation of a pit in ordinary soils is carried out with drilling machines to the design level (the instructions for this type of work contain the conditions of SNiP), in rocky, permafrost and frozen soils - the development of the area is carried out with explosions and jackhammers. The pit must be drained, the bottom is covered with a layer of sand.

Please note that the installation of upright foundation structures in winter must be completed in a short time to prevent freezing of the bottom of the pit. The installation of the support is carried out in various ways, each of which requires the elimination of rotational and other displacements of the foundation. For this purpose, braking devices are used. The soil is thoroughly compacted, while the backfill soil must be protected from freezing. A competent approach to the construction of foundations will allow you to obtain a reliable and durable structure.

3. Marking designation

According to the termsSeries 3.407-115 form the marking of unified foundations. The designation allows you to correctly classify products by type and brand. The code includes the following data:

1. F – foundation (type of product);

2. 3 – standard size;

3. 2 – for supports with shoes having 2 holes;

4. a - under the anchor-corner support.

Foundation F 3-2 A has the following dimensional data:

Length = 1800 ;

Width = 1800 ;

Height = 2700 ;

Weight = 3130 ;

Volume of concrete = 1,25 ;

Geometric volume =8,748 .

4. Basic materials for manufacturing

They produce uprightfoundations F 3-2 A by vibration molding method in metal permanent formwork. For production, rigid structural concrete is used, the strength class of which is B27.5. In addition, concrete is frost-resistant (grade F150-200), waterproof (grade W4-8), and also with high crack resistance properties. Increasing the quality of plasticity and resistance to the external environment is achieved with the help of special additives, which are introduced into the concrete mixture in strict proportions. The parameters of the materials are regulated by the current standard.

Foundation structures operate under conditions of significant destructive loads, so they are reinforced with welded reinforcement frames made of small- and large-grade steel of class A-100 and A-300 and rolled sheet metal. Flat meshes are produced using reinforcement of different diameters. Embedded fastening parts - bolts - are introduced into the body of the slab. To lift a reinforced concrete structure to a height, it is equipped with sling loops. All metal components are subjected to anti-corrosion treatment. For this purpose, zinc-rich primers are used.