The conditions for the development of a fire in buildings and structures is largely determined by the degree of their fire resistance. Degree of fire resistance it is called the ability of the building (facilities) as a whole to resist the destruction during the fire. Buildings and structures according to the degree of fire resistance are divided into five degrees (I, II, III, IV, V). The degree of fire resistance of the building (structures) depends on the ignition and fire resistance of the main building structures and from the propagation of fire for these structures.

By ignition, building structures are divided into non-aggravated, challenges and combustible. The construction structures made of non-aggravated materials are not mooriving. The structures made of hard-fledged materials or combined materials protected from fire and high temperatures are considered to be difficult to be designed with fire and high temperatures (for example, a fire-fighting door made of wood and coated with leaf asbestos and roofing steel).

Fire resistance of building structures is characterized by their the limit of fire resistanceunder which they understand the time in hours, after the expiration of the fire, there is 1 of 3 signs:

1. The collapse of the structure;

2. Education in the design of through cracks or holes. (Combustion products penetrate adjacent rooms);

3. Warming up the design to temperatures causing self-ignition substances in adjacent rooms (140-220 o).

Fire resistance limits:

Ceramic brick - 5 h (25 cm-5.5; 38-11ch)

Silicate brick - ~ 5 h

Concrete 25 cm thick - 4 h (cause of destruction - the presence of up to 8% water);

Wood coated with 2 cm thick (25 cm only) 1 h 15 min;

Metal structures - 20 min (1100-1200 o-metal becomes plastic);

The entrance door treated with antipiren -1 h.

Porous concrete, hollow brick have a greater fire resistance.

The smallest limit of fire resistance has unprotected metal structures, and the greatest is reinforced concrete.

According to DBN 1.1.7-2002 "Fire protection. Fire safety of construction objects ", all buildings and structures are divided into fire resistance to eight degrees (see Table 3).

Table 3.

Fire resistance of buildings and structures

Protection of wooden structures from fire:

To protect wooden structures from fire apply:

Impregnation with antipirens;

Cladding;

Stucco.

Antipirens - Chemicals designed to give wood of non-carrier properties (French Gay-Loussak Physicist.1820 Salt Ammonium).

Antipirens - reduce the velocity of gaseous products, reduce the resin yield as a result of chemical interaction with cellulose.

For impregnation of wood apply:

Phosphorous ammonium (NH 4) 2 HPO 4

Ammonium sulphate (NH 4) 2 SO4

Buru Na 2 B 4 O 7 * 10H 2 O.

Deep impregnation is made in autoclaves at a pressure of 10-15 atm for 2-20 hours.

The soaking is made in the antipiren solution at a temperature of 90 ° C for 24 hours.

The impregnation with antipirens translates the wood into the category of difficultly combined materials. Surface treatment - Warning woods for several minutes.

Facing and plaster - protect wooden structures from fire (slow heating).

Wet plaster - Flame protection 15-20 minutes.

6.7.1 The degree of fire resistance, the class of constructive fire hazard, the permissible height of the buildings and the floor area within the fire compartment of public buildings should be taken in Table 6.9, household service enterprises (F3.5) - according to Table 6.10, trade enterprises (F3.1) - Table 6.11.

It is necessary to take into account the additional requirements provided for in this section for the buildings of the respective classes of functional fire hazard.

Table 6.10

Table 6.11

6.7.2 In buildings I and II degrees of fire resistance class of the design of the constructive fire danger C0 in the presence of an automatic fire extinguishing area of \u200b\u200bthe floor within the fire compartment, no more than twice as low as installed in Tables 6.9 - 6.11 can be enlarged.

6.7.3 Floor area within the fire compartment of one-story buildings with a two-storey part, which occupies less than 15% of the building building area, should be taken as for one-storey buildings in accordance with Tables 6.9 - 6.11.

6.7.4 In the buildings of I, II degrees of fire resistance of class C0 instead of fire walls, a device of water dramet curtains in two threads located at a distance of 0.5 m and providing irrigation intensity of at least 1 l / s per 1 m length of curtains at work time Not less than 1 hour, as well as fireproof curtains, screens and other devices with the limit of fire resistance no less E 60. At the same time, the specified types of fireproof obstacles should be placed in the zone free from fire load on a width of at least 4 m in both sides of the barrier.

6.7.5 In the buildings of the IR levels of fire resistance, the floor area between fire walls can be increased to 10,000 m², unless warehouses, storerooms and other rooms with combustible materials are not located in the basements (base) floors with combustible materials (except for storage, dressing room and premises. Categories B4 and D). Storage cameras (other than those equipped with automatic cells) and the wardrobe should be separated from the rest of the basement from the basement 1go-type firefields and equip automatic fire extinguishing plants, and the commanding accommodation points are fire-fighting partitions of the type (including translucent).

6.7.6 In the buildings of the station and airproofs of the I degree of fire resistance of the C0 class, equipped with automatic fire extinguishing installations, the floor area between fire walls is not rationed.

6.7.7 The degree of fire resistance attached to the building of canopies, terraces and galleries is allowed to take one value lower than the degree of fire resistance of the building. At the same time, the class of constructive fire danger of canopies, terraces and galleries should be equal to the class of structural fire danger of the building.

In this case, the degree of fire resistance of the building with a canopy, a terrace and gallery is determined by the degree of fire resistance of the building, and the floor area within the fire compartment is taking into account the area of \u200b\u200bcanopies, terraces and galleries.

6.7.8 In the sports halls, the halls of indoor rollers and the halls of the baths of pools (with places for the audience and without them), as well as in the halls for the preparatory sessions of pools and firing areas of indoor ties (including those located under the podium or built into other public buildings ) If they are exceeded, the fire walls installed in table 6.9 should be provided between Hall (in ties - a fire zone with a rifle gallery) and other rooms. In the premises of the lobby and the lobby, when they exceed them in relation to installed in table 6.9 instead of fire walls, it is possible to provide translucent fire-fighting partitions of the 2nd type.

6.7.9 Buildings of classes F1.2 and F4.2 - F4.3 I, II and III degrees of fire resistance, a height of no more than 28 m is allowed to extend in one attic floor with carrier elements having a limit of fire resistance at least R 45 and the fire hazard class K0 , when separating it from the lower floors, fireproof overlap is not below the 2nd type. The enclosing structures of this floor must meet the requirements for the designs of the building of the building.

At the same time, the attic floor should be additionally separated by fire walls of the 2nd type. The area between these fire walls should be: for buildings I and II degrees of fire resistance - no more than 2000 m², for buildings III degree of fire resistance - no more than 1,400 m². If there are automatic fire extinguishing installations on the attic floor, this area can be increased no more than 1.2 times.

When applying wooden structures, the attic should be provided, as a rule, constructive fire protection providing these requirements.

6.7.10 The degree of fire resistance, the class of constructive fire danger and the largest height of the children's pre-school institutions of general type (F1.1) should be taken depending on the largest number of places in the building on Table 6.12.

Table 6.12.

6.7.11 Walls on the inside, partition and overlapping buildings of preschool educational institutions, children's health facilities and medical buildings with the hospital (class F1.1), ambulatory-polylic institutions (class F3.4) and clubs (class F2.1) in class buildings Constructive fire danger C1 - C3, including using wooden structures, should have a fire danger class not lower than K0 (15).

6.7.12 Three-storey buildings of children's preschool institutions is allowed to be designed in large and largest cities, except for those located in seismic areas, subject to their equipment with automatic fire alarms with an additional automatic transmission of a fire signal directly in the fire protection division by telecommunication lines.

6.7.13 Buildings of specialized pre-school institutions, as well as for children with violation of vision, regardless of the number of places, it is necessary to design a class of constructive fire danger C0 not lower than II degree of fire resistance and no more than two floors height.

6.7.14 Aged Pleasure Persons of Pediatric Pre-school Institutions should design the same degree of fire resistance and the same class of constructive fire danger as the main buildings.

6.7.15 The degree of fire resistance, the class of constructive fire hazard and the largest height of school buildings (general education and additional education of children), educational buildings of the Shkolnternatov, primary education institutions (F 4.1), as well as the bedroom buildings of the school and boarding schools in schools (F 1.1) should be taken Depending on the number of students or places in the building according to Table 6.13. The maximum area of \u200b\u200bthe floor of the building is determined by Table 6.9.

Construction of schools of schools, educational buildings of the Shkolnternatov, institutions of primary vocational education, as well as the beds of the school of the school and boarding schools with a height of more than 9 m is allowed under the condition of their equipment with automatic fire alarms with an additional automatic transmission of a fire signal directly in the TSUS on the telecommunications lines of wired or wireless Communication. The placement of these buildings should be determined on the basis of the condition that the arrival time of the first division to the call site in urban settlements and urban districts should not exceed 10 minutes, and in rural settlements - 20 minutes. Arrangements and entrances to these buildings should be designed based on the need to ensure the access of fire units from auto expensive or auto lifts directly into each room with window openings on the facade.

For the designed four-storey, as well as the reconstructed five-storey buildings of schools at least 50% of the staircases should be provided for unnecessary. In case of the impossibility of a device of unnecessary staircases, in addition to the calculated amount of stair cells, a device of external open stairs should be provided. The number of outdoor open stairs should be taken:

One staircase with the calculated number of students and staff on the floor above the second to 100 people;

At least one staircase for every 100 people with the calculated number of students and staff on the floor above the second more than 100 people.

Table 6.13

On the fourth floor of the buildings of schools and educational buildings of the Shkolnternatov, it is not allowed to place premises for primary classes, and the rest of the training premises - more than 25%.

The superstructure of the specified buildings in the attic floor during reconstruction is allowed within the normalized floors. At the same time, sleeping rooms are not allowed on the attic floor.

The buildings of educational buildings of secondary vocational (F 4.1) and higher professional education (F 4.2) is allowed to design a height of not more than 28 m.

6.7.16 The buildings of specialized schools and schools (for children with violation of physical and mental development) should be no higher than 9 m.

6.7.17 The height of the placement of audiences, acts, conference facilities and hare premises of sports facilities without visual sites should be taken in Table 6.14, taking into account the degree of fire resistance, the class of constructive fire danger of the building and capacity of the hall.

Table 6.14.

6.7.18 The degree of fire resistance, the class of constructive fire danger and the greatest height of the buildings of spectacular and cultural and educational institutions of the functional fire hazard class F2.1 and F2.2 should be taken depending on their capacity in Table 6.15.

Table 6.15

When determining the capacity of rooms, it is necessary to summarize stationary and temporary places for the audience, provided for by the project transformation.

When placed in a cinema of several halls, their total capacity should not exceed the specified in the table.

The supporting structures of coatings over the scene and the hall (farm, beams) in buildings of theaters, clubs and sports facilities should be designed in accordance with the requirements for the bearing elements of the building.

For single-storey buildings I and II degree of fire resistance, the use of carrier structures of hall coating structures with the fire resistance estimate is not less than R 60. The specified structures are allowed to perform from wood to be treated with flame retardant compositions I group of flame retardant efficiency according to GOST R 53292. With this room, the hall can be no more 4 thousand places for sports facilities with ribunes and no more than 800 places in other cases, and the remaining structures must comply with the requirements for C0 buildings.

6.7.19 Medical institutions, including those who are part of the buildings of other functional purposes (schools, children's preschool institutions, sanatoriums, etc.), should be designed in accordance with the following requirements.

Hospital buildings (F1.1), ambulatory-polylic institutions (F3.4) should be designed not higher than 28 m. The degree of fire resistance of these buildings should be not lower than II, the class of structural fire hazard is not lower than C0.

Hospitals

Hospital buildings up to three floors with a height of up to three floors inclusively, it is necessary to separate the fire sections with an area of \u200b\u200bnot more than 1000 m², above three floors - on the section area of \u200b\u200bno more than 800 m² by firefight 1go type.

Therapeutic housings of psychiatric hospitals and dispensaries should be high no more than 9 m, not lower than II degree of fire resistance class of constructive fire hazard C0.

In the countryside, the building of therapeutic institutions for 60 and less beds and outpatient canceric institutions for 90 visits to shift are allowed to provide with chopped or broomable walls.

Operational blocks, resuscitation and intensive care departments should be located in independent fire compartments. These blocks in two floors and more should have elevators for transporting fire units adapted to transport non-clean patients.

The ward branches of children's hospitals and buildings (including chambers for children with adults) should be placed not higher than the fifth floor of the building, chambers for children under seven years old and children's psychiatric departments (chambers), neurological branches for patients with spinal injury, etc. d., not higher than the second floor.

It is allowed to post the chambers for children under seven years not higher than the fifth floor under the condition of the device in the building (body) of the air protection and automatic fire extinguishing.

In perinatal centers, the accommodation of the chambers is allowed not above the fourth floor, and the prenatal chambers are not higher than the third floor.

Houses for the elderly and disabled should be designed in accordance with the requirements for the hospitals of therapeutic institutions.

Polyclnickles

The medical institutions without hospitals are allowed to be placed in single-storey buildings III degree of fire resistance of the C0 structural hazard class.

Ambulatory-band buildings for children service is allowed to be designed no higher:

6 floors (18 m) - in large and largest cities;

5 floors (15 m) - in other cases. At the same time, on the upper floor it is allowed to post only the premises of the administrative destination for the staff of the institution.

6.7.20 The buildings of recreation agencies of the summer functioning of V degree of fire resistance, as well as the buildings of children's health facilities and sanatoriums IV and V degrees of fire resistance should be designed only by one-storey.

The buildings of summer children's health camps and tourist huts should design a height of no more than two floors, the building of children's warm-round health camps - no more than three floors, regardless of the degree of fire resistance and class of constructive fire danger.

In recreation camps, bedrooms should be combined into separate groups of 40 seats. These premises must have independent evacuation outputs. One output can be combined with a staircase. Sleeping facilities of wellness camps in separate buildings or individual parts of the buildings should be no more than 160 seats.

6.7.21 The stands of any capacity of the facilities of class F2.3 using the subband when placing auxiliary premises in it on two or more floors should be designed not lower than I degree of fire resistance class of the C0 structural hazard.

Overlapping under the ribunes should be fire-fighting 2nd.

With one-storey placement of auxiliary premises in the prematurity or with the number of rows for the audience on the stands, more than 20 carrying structures of the tribune must have the limit of fire resistance at least R 45, the fire hazard class K0, and the overlap under the podium should be fire-fighting 3rd.

The carrying structures of the ribune of sports facilities (F2.3) without using the prebno-space and with the number of series more than 5 should be made of non-combustible materials with the limit of fire resistance at least R 15. It does not allow combustible substances and materials under the ribunes.

6.7.22 In indoor sports facilities, the supporting structures of stationary stands (under which the placement of premises) with a capacity of more than 600 viewers should be performed with the fire resistance estimate of at least R 60 fire hazard class K0; from 300 to 600 viewers - R 45 and K0; A less than 300 spectators - R 15 and K0, K1.

The limit of fire resistance of the carrier structures of transformable tribunes (retractable, etc.), regardless of the capacity, should be at least R 15.

These requirements do not apply to temporary audience places installed on the semi arena during its transformation.

6.7.23 Library and archives should be designed not higher than 28 m.

6.7.24 The buildings of sanatoriums, recreation and tourism institutions (except, hotels) should be designed not higher than 28 m.

The degree of fire resistance of sleeping hulls of sanatoriums with a height of more than two floors should be no lower than II, the class of constructive fire danger - C0.

The two-storey bedrooms of the sanatorium are allowed to design III degrees of fire resistance class of the C0 structural fire hazard.

The number of places in residential buildings of sanatoriums and recreation facilities and tourism I and II degrees of fire resistance of the C0 fire hazard class should not exceed 1000; III degree of fire resistance of the fire hazard class C0 - 150; The remaining degrees of fire resistance - 50.

Sleeping rooms designed to accommodate families with children should be placed in separate buildings or individual parts of buildings isolated by type 1-type firefares, no more than six floors having isolated from other parts of building evacuation outputs. At the same time, sleeping rooms must have an emergency exit corresponding to one of the following requirements:

6.7.25 The degree of fire resistance of hotels, relaxation homes, campgrounds, motels and boarding houses with a height of more than two floors should be not lower than III, the class of constructive fire hazard C0.

Sleeping rooms designed to accommodate families with children in a common type of recreation, camping, motels and boarding houses should be placed in separate buildings or individual parts of the buildings allocated by the type 1-type firefares, no more than six floors having isolated from other parts of buildings. Evacuation outputs . At the same time, sleeping rooms must have an emergency exit corresponding to one of the following requirements:

The output should be conducted on a balcony or loggia with a deaf simpleness of at least 1.2 meters from the end of the balcony (loggia) to the window opening (glazed door) or at least 1.6 meters between glazed openings, which go to the balcony (loggia);

The output should lead to a transition of a width of at least 0.6 meters leading to the adjacent part of the building;

The output should be on the balcony or loggia, equipped with an outer staircase, a substantive connecting balconies or loggia.

SNB.2.02.01-98 "Fire and Technical Classification of Buildings, Building Constructions and Materials"

Fire resistance- This is the ability of building structures to resist the effect of fire for a certain time while maintaining operational functions.

Fire resistance is characterized by the limit of fire resistance.

Fire resistance limitbuilding structures are characterized by limit states normalized by temporary features:

Carrier ability (R)

Integrity (E)

Heat insulating capacity (I)

(For example: Rei120K0 - the object retains its integrity, carrying the ability, thermally insulating ability for 120 minutes, incomperable)

By fire hazard, building structures are divided into 4 classes:

K0) not fire hazardous

K1) little fire hazardous

K2) moderately fire hazardous

K3) fire hazard

Depending on the limit of fire resistance, 8 degrees of fire resistance (1st is best, the 8th worst)

1st degree of fire resistance: carrier walls R120K0, internal wallsre150K0, marches and staircasesre30K0.

Category A) Explosive - combustible gases (GG), flammable liquids (LVZ) with a flash point of not more than 28 ° C, combustible fluids in such a quantity that can form explosive steam-gas-high mixtures, when ignited by the calculated excessive pressure of the explosion explosion, exceeding 5 kPa. Substances and materials capable of exploding and burning when interacting with water or with each other in such a quantity that the estimated excessive pressure of the explosion in the room exceeds 5 kPa.

Category B) Explosion hazard - combustible dust or fibers, flammable liquids (LVZ) with a flash point of more than 28 ° C, combustible fluids in such a quantity that can form explosive dust or pair-gas-high mixtures, with the ignition of which the calculated excessive pressure of explosions in the room develops exceeding 5 kPa.

Category B) (divided by B1, B2, B3, B4) Fire hazard-flameless liquids (LVZ), combustible fluids and difficult to combustible fluids, solid combustible and difficult combustible substances and materials (including dust and fibers) capable of interacting with Water, oxygen, air or to burn with each other.

G1) combustible gases, flammable liquids (LVZ), combustible fluids, solid combustible and difficult combustible substances and materials used as fuel.

Г2) non-combustible substances and materials in hot, split or molten state, the processing process of which is accompanied by the release of radiant heat, sparks and flames.

Fire barriers

Appointment of fire prevention obstacles: stop the spread of fire.

Fire barriers:

The fire wall - crosses perpendicular to the entire building, ranging from zero mark and ending with the roof, and it appears on the roof (0.3-0.6) m. The limit of fire resistance is 150 minutes.

Fireborne partition - blows within one room. Fire resistance limit 150 min.

Firetage floors - opposes the spread of fire vertically.

The fire belt protects the fire does not cover the building outside.

Fire doors - can be metal, wooden upholstered steel steel.

Fire hatches.

Fireproof windows (tempered glass, triplex, reinforced glass)

Tambour-gateway.

Water curtains (dramet system).

Fire curtain.

Ways evacuation.

SNB 2-02-01 "Evacuation of people from buildings and facilities in the fire"

Evacuation paths are used to ensure the evacuation of all people located in the building of the building through evacuation exits without taking into account fire fighting and anti-fire protection.

Outputs are evacuation if they are from the premises:

The first floor - outwardly or through the corridor and the lobby, the corridor and the staircase outside.

Any overground floor is directly in the staircase or in a corridor leading to a staircase, having an output directly outside or through the lobby separated from the adjacent corridors doors.

The basement or basement is directly outward or on the staircase, or in the corridor leading on the staircase. At the same time, the staircase must have a way out directly, or be isolated from overlying floors.

In the neighboring room on the same floor, secured, according to paragraphs A, B, C.

If a fire occurs, people must leave the building during the time, which is determined by the shortest distance from the place of the fire before entering out.

The number of evacuation outputs from buildings is determined by the calculation, but is at least two.

Elevators are not routes of evacuation.

The width of the evacuation paths should be at least 1 meter, and the doors on the evacuation paths of at least 0.8 m, the height of at least 2 m.

For buildings 1, 2, 3 degrees of fire resistance, the evacuation time of people from the doors of the most remote premises before the outlook is received:

From the premises located between the two staircase cells and two outer outputs:

1. From the premises of buildings of any categories with an exit to a dead-end corridor (0.5 minutes).

   The external evacuation doors of the buildings should not have constipation that cannot be opened from the inside during the fire.

If it is necessary, the device of constipation on the doors under the condition of maintaining value is allowed to a device of electromagnetic closers that are automatically operational or manually.

Fires arising from human fault have become quite frequent and common. Thousands of ignition occur annually, which is the cause of a number of unpleasant consequences. Therefore, in the construction of structures, the degree of fire resistance of the building is of great importance. Each erected object is assigned a certain number of fire resistance, according to the existing classification. Look further in more detail, consider the classification and describe the parameters of each of the classes.

What is the degree of fire resistance?

Snip 31-01-03

Under this definition, the ability of structures to restrain the expansion of the flammable area without losing the building of the ability of further operation. The list of these properties consists of enclosing and bearing abilities.

If the construction will lose the carrying ability - it will certainly collapse. It is under the destruction that this definition is meant. As for the enclosing ability, its loss is considered to be the level of heating materials before the formation of cracks or holes, through which combustion products will be able to spread into adjacent rooms or heating to a temperature at which the process of burning material begins.

An indicator of the limit degree of fire resistance of structures - the time interval from the moment of the formation of fire before the occurrence of signs of such losses (measured in hours). For testing indicators in a fire, an experienced sample is taken and placed in equipment for such experiments - a special oven. Under the conditions of the furnace, on the subject of tests, the heat of high temperature is affected, and the material is assigned a load characteristic of a specific project.

The degree of fire resistance, when determining its limit, also depends on the ability to increase the temperature at individual points or the average value of increasing temperature indicators over the surface, which is compared with the original. The minimum impedance of fire exposure is the elements of the structure of the structures made of metal, and the maximum - reinforced concrete, in the manufacture of which cement was used with high characteristics of fire resistance. The maximum value of the degree of fire resistance can reach 2.5 hours.

Also, when determining the ability of the structure, the limit of fire is taken into account in the calculation. It is equivalent to the size of damage on the plots that were outside the burning zone. This indicator can be 0-40 cm.

It can be safely argued that the degree of fire resistance structures directly depends on the ability of materials that are used in its construction, to withstand high temperatures affecting the surface in the fire environment.

According to the degree of combustion, materials are divided into 3 groups:

• Non-controlled (constructions from reinforced concrete, brick, stone elements).
• Eating (materials from the group combustible, the fire resistance to which is raised by processing with special means).
• Burned (quickly flammable and burn well).

For the classification of materials, a special arch of documents is used - SNiP.

How defined?

The degree of fire resistance is a representative of the most significant parameters of the structure that is not inferior to the importance of the design features from the point of view of fire safety and functional characteristics. But what to pay attention to to determine with the utmost accuracy? To do this, we need to consider such parameters of the structure:

• Floors.
• The real area of \u200b\u200bthe building.
• Description of the building of the building: industrial, residential, commercial, etc.

To determine the degree of fire resistance (I, II, etc.), it is necessary to be determined exclusively on the regulatory documents and listed in SNiP. Also, DBN 1.1-7-2002 are used for such purposes and design, 4 dBN B.2.2-15-2005 is used to determine the fireproofing of multi-storey facilities, and 9 DBN B.2.2 is used to familiarize with fire safety requirements to facilities with a large number of floors. -24: 2009. Only the use of special documentation will allow the most complete information about the degrees of fire resistance of buildings with different constructive features.

The degree of fire resistance of buildings required by the limits of fire resistance of the PTR building structures. Fire Danger of Building Materials

The degree of fire resistance of buildings required by the limits of fire resistance of the PTR building structures.
Fire risk of building materials.

Table 3.

Table 4.

Table 5.

Table6