Classification and categories of premises. The assessment and classification of fire and explosion hazard is based on the determination of the possible destructive consequences of fires and explosions at facilities, as well as the hazardous factors of these phenomena for people (RP). There are two methods for assessing the fire and explosion hazard of objects - deterministic and probabilistic. Such normative documents as “Fire Safety Standards” (NPB) and “Electrical Installation Rules” (PUE) are of a deterministic nature. The probabilistic method is based on the concept of tolerable risk and provides for the prevention of exposure of people to PPP with a probability exceeding the normative one. The normative document based on the probabilistic approach is GOST 12.1.004-91* SSBT “Fire safety. General requirements".
Even at the design stage of industrial enterprises, measures should be taken to ensure their fire safety. For example, the strength of buildings in case of fire, limiting the area of fire development, preventing its spread in the building and on the territory, the use of appropriate technological equipment that excludes the occurrence of a fire, etc.
All these requirements are laid down in building codes and regulations. In each case, all fire safety requirements are established on the basis of an assessment of the category of premises and buildings in terms of explosion and fire hazard.
The categories of premises and buildings of subordinate enterprises are determined by the relevant ministries and departments, as well as technologists of design organizations at the stage of designing buildings and structures in accordance with all-Union and departmental technological design standards or special lists approved in the prescribed manner.
The categories of explosion and fire hazard in premises and buildings are determined for the most unfavorable period in relation to fire or explosion, based on the type of combustible substances and materials in apparatus or premises, their quantity and fire hazardous properties, and features of technological processes.
According to the explosion and fire hazard, premises and buildings are divided into 5 categories: A, B, C, D, D. (Table 6.1).
When establishing the category of the room, it is necessary to know the overpressure of the explosion. The method for calculating the overpressure of an explosion for combustible gases, vapors of flammable and combustible liquids, combustible dusts is described in a number of other sources covering fire safety issues.
Characteristics of materials and structures for flammability. The fire hazard of combustible substances and materials depends on their physical and chemical properties, state of aggregation, conditions of use and storage. The fire-hazardous properties of materials are characterized, in particular, by the tendency to ignite, the peculiarity and nature of combustion, the tendency to extinguish by one or another fire extinguishing agent. The tendency to ignite is understood as the ability of a material to spontaneously ignite, ignite or smolder from various causes.
According to building codes and regulations, all building materials and structures are divided by flammability into: fireproof(non-combustible), slow-burning(flammable), combustible(combustible).
Fireproof materials are those that, under the influence of fire or high temperature, do not ignite, do not smolder or char (for example, brick, concrete without organic fillers, etc.).
fireproof structures- These are structures made of non-combustible materials.
Flame retardant materials- these are materials that, under the action of fire and high temperatures, hardly ignite, smolder or char and continue to burn or smolder only if there is a source of fire. When the source of fire is removed, their burning or smoldering stops (for example, concrete with organic fillers, wood subjected to deep impregnation with flame retardants, etc.).
Fire-resistant structures are structures made of fire-retardant, as well as combinations of combustible and non-combustible materials.
combustible materials- these are materials that, under the influence of fire or high temperatures, ignite and continue to burn or smolder after the source of ignition has been removed (for example, wood and some other materials).
Combustible structures are structures made of combustible materials and not protected from high temperatures or fire.
Table 6.1.
| Room category | Characteristics of substances and materials located (circulating) in the room |
| A (explosive-fire-dangerous) | Combustible gases, flammable liquids with a flash point of not more than 28 ° C in such an amount that they can form explosive vapor-gas mixtures, the ignition of which develops an estimated excess explosion pressure in the room exceeding 5 kPa. Substances and materials capable of exploding and burning when interacting with water, atmospheric oxygen or one with the other in such an amount that the excess design explosion pressure in the room exceeds 5 kPa |
| B (explosive-fire-dangerous) | Flammable dusts or fibres, flammable liquids with a flash point of more than 28 °C, flammable liquids in such a way that they can form explosive dust-air or vapor-air mixtures, the ignition of which develops an estimated overpressure of the explosion in the room exceeding 5 kPa |
| B (fire hazardous) | Flammable, combustible and slow-burning liquids, solid combustible and slow-burning substances and materials, substances and materials capable of only burning when interacting with water, atmospheric oxygen or one with the other, provided that the premises in which they are available or circulated do not belong to category A or B |
| G (fire hazardous) | Non-combustible substances and materials in a hot, incandescent or molten state, the processing of which is accompanied by the release of radiant heat, sparks and flames; combustible gases, liquids and solids that are burned or disposed of as fuel |
| D (fire hazardous) | Non-flammable substances and materials in a cold state |
a) the building does not belong to category A;
b) the total area of premises of categories A and B exceeds 5% of the total area of all premises or 200 m 2.
The categories of buildings C, D, D are defined similarly:
b) the total area of premises of categories A, B and C exceeds 5% (10% if there are no premises of categories A and B in the building) of the total area of all premises.
It is allowed not to classify a building as category C if the total area of the premises of categories A, B and C in the building does not exceed 25% of the total area of all premises located in it (but not more than 3500 m 2) and these premises are equipped with automatic fire extinguishing installations.
b) the total area of premises of categories A, B, C and D exceeds 5% of the total area of all premises.
It is allowed not to classify the building as category D if the total area of the premises of categories A, B, C and D in the building does not exceed 25% of the total area of \u200b\u200ball the premises located in it (but not more than 5000 m 2) and the premises of category A, B and C are equipped automatic fire extinguishing installations.
As a boundary condition for classifying premises as category B, you can use the standards, according to which objects with a fire load exceeding 5-10 2 MJ for every 10 m 2 of the area of \u200b\u200bthe premises are classified as fire hazardous. At the same time, the fire load includes combustible and slow-burning substances and materials in the room, except for building envelopes, floors and ceilings.
Fire resistance of buildings and structures. Fire resistance is understood as the ability of structural elements of buildings to resist the effects of fire, maintain their bearing capacity and strength in a fire. The fire resistance of building structures in fire conditions is characterized by the fire resistance limit.
Fire resistance limit- this is the period of time (in hours) during which the structure performs its working functions in a fire . The fire resistance limit is characterized by the presence of one of three signs:
1. Formation of through cracks in the structure;
2. An increase in temperature on the unheated, opposite to fire, surface of the structure by more than 160 °C on average or more than 180 °C at any point on this surface compared to the temperature of the structure before the test, or more than 220 °C regardless from design temperature to testing;
3. Loss of bearing capacity by the structure (collapse, deflection).
Practical methods for increasing the fire resistance of materials and structures are widely used. So, for example, an increase in the fire resistance of jelly-concrete structures can be achieved by increasing their cross section, the thickness of the protective layer; steel structures are lined with special materials; wooden structures can be impregnated with flame retardants, sheathed with roofing iron over felt impregnated on clay, etc.
According to SNiP 2.01.02-85, all buildings and structures for fire resistance are divided into 8 degrees (Table 6.2). The degree of fire resistance of buildings and structures is determined by the minimum fire resistance limits of the main building structures and the maximum limits for the spread of fire over these structures.
The size of the damaged zone of the sample in the plane of the structure from the boundary of the heating zone perpendicular to it to the most distant point of damage is taken as the limit of fire propagation (for vertical structures - upwards, for horizontal structures - in each direction). Results are rounded up to the nearest 1 cm. It is allowed to take the limit of fire propagation through structures equal to zero if the size of damage to the sample in the control zone does not exceed 5 cm for vertical and 3 cm for horizontal structures. To measure the extent of damage to layered structures, it is necessary to examine all layers by opening. Damage is considered to be charring and burning of materials, as well as melting of thermoplastic materials.
Table 6.2.
Approximate structural characteristics of buildings
depending on their degree of fire resistance
| Degree of fire resistance | Structural characteristics |
| I | Buildings with load-bearing and enclosing structures made of natural or artificial stone materials, concrete, or reinforced concrete using sheet and slab non-combustible materials |
| II | Buildings with load-bearing and enclosing structures made of natural or artificial stone materials, concrete or reinforced concrete using sheet and slab non-combustible materials. It is allowed to use unprotected steel structures in the coatings of buildings |
| III | Buildings with load-bearing and enclosing structures made of natural or artificial stone materials, concrete or reinforced concrete. For floors, it is allowed to use wooden structures protected by plaster or slow-burning sheet, as well as slab materials. There are no requirements for fire resistance limits and fire propagation limits for coating elements; at the same time, wood coating elements are subjected to fire retardant treatment |
| IIIa | Buildings are predominantly with a frame structural scheme. Frame elements - from steel unprotected structures. Enclosing structures - from profiled steel sheets or other non-combustible sheet materials with slow-burning insulation |
| III b | The buildings are predominantly one-storey with a frame structural scheme. Frame elements made of solid or glued wood subjected to fire retardant treatment to ensure the required fire spread limit. Enclosing structures - from panels or element-by-element assembly, made using wood or materials based on it. Wood and other combustible materials of building envelopes must be subjected to fire retardant treatment or protected from fire and high temperatures in such a way as to ensure the required fire spread limit. |
| IV | Buildings with load-bearing and enclosing structures made of solid or glued wood and other combustible or slow-burning materials, protected from fire and high temperatures by plaster or other sheet or plate materials. There are no requirements for fire resistance limits and fire propagation limits for coating elements; at the same time, the elements of the wood coating are subjected to fire retardant treatment |
| IV a | The buildings are predominantly one-storey with a structural frame scheme. Frame elements - from steel unprotected structures. Enclosing structures - from profiled steel sheets or other non-combustible materials with combustible insulation |
| V | Buildings, for the bearing and enclosing structures of which there are no requirements for fire resistance limits and limits for the spread of fire |
As already mentioned, GOST 12.1.004-91 * SSBT “Fire safety. General requirements" provides for the determination of the probability of exposure to people of the OFP (hazardous fire factors) and its comparison with the standard probability of exposure (taken equal to):
6.3. Fire prevention measures in the design
and construction of enterprises
Achieving the required probability of exposure to PPP personnel begins with the correct design or selection of an industrial building. It is considered properly designed if, along with the solution of functional, strength, sanitary and other technical and economic problems, fire safety conditions are provided. Fire prevention in the design and construction of an industrial enterprise includes the following issues:
- increasing the fire resistance of buildings and structures;
- zoning of the territory;
- the use of fire breaks;
- the use of fire barriers;
– ensuring the safe evacuation of people in case of a fire;
- ensuring the removal of smoke from the premises in case of fire.
When planning and building an enterprise, correct consideration of the explosion and fire hazard of premises and buildings of production facilities is of great importance. All buildings and structures are grouped according to their functional purpose and categories of their explosion and fire hazard. So, at engineering enterprises, 3 zones are usually distinguished:
1. Administrative zone;
2. Production area;
3. Warehouse area.
The construction site for an industrial facility is chosen taking into account the terrain and, most importantly, the wind rose (the prevailing prevailing wind direction of the area). The enterprise is located on the leeward side in relation to the settlement.
On the territory of the enterprise, buildings of increased fire danger are located on the leeward side in relation to other objects. Between buildings it is necessary to provide fire breaks (minimum distances), excluding the possibility of transferring the flame from one building to another. These distances are taken depending on the degree of fire resistance of the protected buildings, according to Table. 6.3.
Table 6.3.
Sizes of fire breaks
When constructing an external fire wall of a higher building facing another building, the fire distances between them are not standardized.
The main part of the territory of the plant is covered by a ring road, from which direct, uncluttered entrances are arranged to all buildings.
A prerequisite is the equipment on the territory of the enterprise of a fire-fighting gas pipeline, which can either be connected to the city water supply network or have independent power from the nearest natural reservoir.
Fire-fighting water supply is provided through a looped pipeline, which makes it possible to ensure the supply of water to the fire in the event of a violation of the integrity of the pipeline on one of the branches. In order to connect fire hoses to the water supply, hydrants are installed along the entire pipeline no more than 120 ... 130 m.
Fire water pipelines are divided into external and internal. External water supply networks are divided into ring and branched (dead end).
With a ring scheme, water can circulate through the pipes in all directions. Ring networks are used, as a rule, for fire-fighting water supply of large engineering enterprises, and dead-end networks are used for small enterprises.
The internal fire water supply provides water supply from the external water supply to fight local fires in its initial stage. The water supply along the entire length has risers with fire hydrants. The water flow from the fire hydrant must be at least 2.3 l / s, and the compact part of the jet must reach the most remote point of the protected room. Fire hydrants are installed at a height of 1.33 m from the floor on all floors indoors or on stairwells, in lobbies. Cranes, together with fire hoses and trunks, are placed in special cabinets with the inscription "PK-N".
Fire barriers. In a fire, fire spreads throughout a building or structure. To limit the spread of fire from one part of the building to another and reduce the possible burning area, arrange fire barriers.
Fire barriers include:
- fire walls;
- fire barriers;
- fire protection ceilings;
– fire zones;
- vestibules-locks;
– fire doors and windows;
- fire gates, hatches, valves.
The scope of fire barriers is established by SNiP 2.01.02-85.
The same normative document quite fully reflects the requirements for the constructive solution of fire barriers.
Fire zones are three-dimensional elements of buildings that divide the building along the entire width (length) and height into fire compartments.
The type 1 fire zone is made as an insert with a width of at least 12 m. The insert is a part of the building formed by type 2 fire walls that separate the insert from the fire compartments.
In one-story buildings of III-V degrees of fire resistance, in which combustible gases and liquids are not used and stored, and there are no processes associated with the formation of combustible dusts, it is allowed to provide fire zones of the 2nd type for dividing buildings into fire compartments. The fire zone of the 2nd type is a strip of coating and walls with a width of at least 6 m.
When designing fire zones, it is necessary to exclude the possibility of a fire in them. Therefore, it is not allowed to use or store combustible gases, liquids and materials in the zones, as well as provide for processes associated with the formation of combustible dusts.
It is allowed to provide openings in fire barriers provided that they are filled with fire doors, windows, gates, hatches and valves or when tambour locks are installed in them. The total area of openings in fire barriers should not exceed 25% of their area.
6.4. Fire protection organization
Organizational issues of fire safety. Successful fight against the possibility of fires and their elimination in the event of a fire is provided by a set of fire-preventive measures. These measures should prevent the occurrence of fires, create an obstacle to the spread of fire, ensure the extinguishing of the source of the fire, as well as the evacuation of people and material assets.
The timely implementation of fire prevention measures, both at the design stage and during the operation of the enterprise, is systematically supervised by the State Fire Supervision authorities.
The organization of fire protection is based on the principle of centralization of forces and means, the development of measures for the prevention and elimination of fires and fires on a single methodological basis. At present, the State fire supervision on the territory of our country is carried out by the Ministry of Civil Defense and Emergencies of the Russian Federation through the Main Directorate of Fire Protection (GUPO) and its local authorities. In accordance with the Decree "On State Fire Supervision", the following three main functions are assigned to it - organizational, control and administrative.
The organizer function allows you to:
- ensure the full readiness of fire departments;
- to ensure the interaction of the work of these parts;
- to use their technical equipment to the full extent for the prevention and elimination of fires;
- Develop fire codes and regulations.
Control functions are aimed at ensuring compliance with fire regulations and rules in the design, construction and operation of industrial enterprises.
Administrative functions allow you to influence violators of fire regulations and rules.
The work of the State Fire Supervision bodies clearly defines the tasks: improving work to prevent fires at national economy facilities, increasing the efficiency of their extinguishing, monitoring the implementation of preventive measures and established fire safety requirements.
Fire supervision solves these tasks in close cooperation with other bodies, voluntary fire brigades (teams), with freelance inspectors at state executive authorities, widely involving workers and employees of enterprises, institutions and organizations, as well as the population at the place of residence in preventive work. To carry out fire supervision means to prevent, identify and, in accordance with the procedure established by law, demand the elimination of violations of fire safety norms and rules.
At an industrial enterprise, responsibility for fire safety (observance of the necessary fire regime and timely implementation of fire prevention measures) is assigned to the heads of the enterprise, and in individual workshops, laboratories, workshops, etc., to the heads of these departments.
The heads of the enterprise are obliged to: ensure the full and timely implementation of fire safety rules and fire safety requirements of building codes in the design, construction and operation of facilities under their jurisdiction; to organize a fire brigade, a voluntary fire brigade (FPD) at the enterprise!? and the fire-technical commission (PTK) and manage them; provide for the necessary appropriations for the maintenance of the fire department, the purchase of fire extinguishing equipment and the financing of fire prevention measures; appoint persons responsible for the fire safety of divisions and facilities of the enterprise. Professional departmental fire brigades are created at large enterprises, enterprises with an increased fire hazard of technological processes or at a distance far from city fire brigades. At other enterprises, a fire-watch service is organized.
The heads of the enterprise have the right to impose disciplinary sanctions on violators of the rules and requirements of fire safety, to raise the issue of bringing those responsible for violating these rules to justice.
All workers, upon entering a job, undergo an introductory and primary (at the workplace) briefing on fire safety measures according to an approved program with appropriate registration. At objects with an increased fire hazard, classes are held on the fire-technical minimum. Refresher briefings should be held at least once a year.
For each enterprise (subdivision of the enterprise), on the basis of the "Fire Safety Rules", PPB-01-93, general facility and workshop fire instructions are developed.
Fire communication and alarm. Fire communication and signaling are widely used for quick notification of a fire that has arisen at a particular production site. Fire communication and signaling devices have a significant impact on the successful extinguishing of a fire.
Fire communication and signaling is a set of devices that allow you to quickly receive a message about a fire and quickly give the necessary orders to eliminate it.
According to its purpose, fire protection communication is divided into notification communication, dispatching and fire communication.
Technical means of security and fire alarms designed to obtain information about the state of monitored parameters at a protected facility, receive, convert, transmit, store, display this information in the form of acoustic or light signals, in accordance with GOST 25829-78 are classified by scope and functional purpose.
According to the field of application, technical means of signaling are divided into security, fire and security fire; according to their functional purpose - to technical means of detection (detectors) designed to obtain information about the state of controlled parameters, and technical means of warning intended to receive, convert, transmit, store, process and display information (SPI, PPC and annunciators). According to the principle of operation, fire detectors are divided into manual and automatic detectors. Automatic fire detectors can be thermal, responsive to rising temperatures; smoke, reacting to the appearance of smoke (aerosol combustion products); there are also flame detectors that respond to the optical radiation of an open flame.
Evacuation of people. When designing and building industrial enterprises, it is necessary to provide for emergency exits and evacuation routes for people. This allows for the organized movement of people. Saving people during a fire or other emergencies depends on how well the escape routes are chosen and arranged. Escape routes ensure the removal of people outside the building in which an accident or fire has occurred or may occur. When constructing evacuation routes for people, it is necessary to be guided by SNiP 2.01.02-85 and SNiP 2.09.02-85.
Escape routes must meet 3 conditions:
1) the shortest distance to the exit to the outside;
2) minimum exit time from the building;
3) traffic safety of people.
Escape routes include exits that lead from the premises:
1. Ground floor outside directly or through the corridor, vestibule, landing;
2. Any floor, except for the first one, to the corridor leading to the stairwell, which has its own exit to the outside or through the vestibule, separated from the adjacent corridors by partitions with doors;
3. To an adjacent room on the same floor, provided with emergency exits in accordance with clause l and clause 2.
Evacuation exits are not allowed to be provided through rooms of categories A and B and vestibule locks with them, as well as through production rooms in buildings IIIb, IV, IVa, and V degrees of fire resistance. it is allowed to provide one emergency exit through the premises of categories A and B from the premises on the same floor, in which the engineering equipment for servicing these premises is located and in which the permanent stay of people is excluded, if the distance from the most remote point of the premises to the evacuation exit from it does not exceed 25 meters.
As a rule, at least 2 emergency exits are provided. Evacuation exits are dispersed. The minimum distance between the most remote emergency exits from the premises should be determined by the formula:
where is the perimeter of the room,
The distance from the most remote workplace to the nearest evacuation exit from the premises to the outside or to the stairwell should be taken according to Table. 6.4.
The width of doors, corridors or passages on escape routes should be taken at the rate of 0.6 m per 100 people.
The minimum width of escape routes must be at least 1 m. The minimum width of flights of stairs must be 2.4 m. The minimum width of doors on escape routes must be 0.8 m. Emergency exit doors must open outward, in the direction of movement of people. The height of the doors to the light should be at least 2 m.
Human-caused fires have become quite frequent and widespread. Thousands of fires occur every year, 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 specific fire resistance number, according to the existing classification. Next, we will consider the classification in more detail and describe the parameters of each of the classes.
What is the degree of fire resistance?
| The degree of fire resistance of the structure | Fire safety class of the building | The maximum allowable height of the structure, cm | Permissible S floor, cm2 |
| I | So So Cl | 7500 5000 2800 | 250000 250000 220000 |
| II | Co Co Cl | 2800 2800 1500 | 180000 180000 180000 |
| III | Co Cl C2 | 500 500 200 | 10000 80000 120000 |
| IV | Without rationing | 500 | 50000 |
| V | Without rationing |
SNiP 31-01-03
This definition is understood as the ability of structures to contain the expansion of the flammable area without losing the building's ability to further exploitation. The list of these properties consists of enclosing and bearing abilities.
If the structure loses its bearing capacity, it will certainly collapse. It is under destruction that this definition is meant. As for the enclosing ability, its loss is the level of heating of materials before the formation of cracks or holes through which combustion products can spread to adjacent rooms, or heating to a temperature at which the combustion process of the material begins.
The indicator of the maximum degree of fire resistance of structures is the time interval from the moment of ignition to the appearance of signs of such losses (measured in hours). To test the performance of materials in a fire, a prototype is taken and placed in the equipment for such experiments - a special furnace. In kiln conditions, the test object is subjected to a high-temperature fire, while the material is subjected to a project-specific load.
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 the temperature increase across the surface, which is compared with the original. The structural elements of the structure made of metal have the minimum fire resistance, and the maximum resistance is reinforced concrete, in the manufacture of which cement with high fire resistance characteristics was used. The maximum value of the degree of fire resistance can reach 2.5 hours.
Also, when determining the ability of a structure to withstand fire, the limit of fire propagation is taken into account. It is equivalent to the size of damage in areas that were outside the burning zone. This indicator can be 0-40 cm.
We can safely say that the degree of fire resistance of structures directly depends on the ability of the materials used in its construction to withstand high temperatures affecting the surface in a fire environment.
According to the degree of combustion, materials are divided into 3 groups:
- Fireproof (reinforced concrete structures, bricks, stone elements).
- Slow-burning (materials from the combustible group, the resistance to fire of which is increased by processing with special means).
- Combustible (quickly ignite and burn well).
For the classification of materials, a special set of documents is used - SNIP.
How is it determined?
The degree of fire resistance is a representative of the most significant parameters of a structure, not inferior in importance to design features in terms of fire safety and functional characteristics. But what should be paid attention to in order to determine it with the utmost accuracy? To do this, you need to consider the following parameters of the structure:
- Floors.
- The actual building area.
- The nature of the purpose of the building: industrial, residential, commercial, etc.
To determine the degree of fire resistance (I, II, etc.), it is necessary to determine exclusively on regulatory documents and given in SNIP. Also, for such purposes and the design of high-rise structures, DBN 1.1-7-2002 is used, 4 DBN B.2.2-15-2005 is used to determine the fire safety of multi-storey buildings, and 9 DBN B.2.2 is used to familiarize yourself with the fire safety requirements for structures with a large number of floors. -24:2009. Only the use of special documentation will provide the most complete information about the degrees of fire resistance of buildings with different design features.
6.7.1 The degree of fire resistance, the class of constructive fire hazard, the allowable height of buildings and floor area within the fire compartment of public buildings should be taken according to table 6.9, buildings of consumer services enterprises (Form 3.5) - according to table 6.10, trade enterprises (Form 3.1) - according to table 6.11.
In this case, it is necessary to take into account the additional requirements provided for in this section for buildings of the corresponding classes of functional fire hazard.
Table 6.10
|
Degree |
Class |
Permissible |
Floor area within |
||
|
one- |
a lot of- |
||||
Table 6.11
|
Degree |
Class |
Permissible |
Floor area within |
||
| one-story | two-storey | 3 - 5-storey | |||
|
Notes 1 In one-story buildings of trade facilities, with the exception of trade facilities for paint and varnish, construction (finishing) materials, auto parts, car accessories, carpets, furniture, III degree of fire resistance, the floor area between fire walls of the 1st type can be doubled, subject to separation sales area from other premises of the store by a fire wall of the 2nd type. 2 When placing storerooms, office, household and technical premises on the upper floors of buildings of stores of I and II degrees of fire resistance, the height of buildings can be increased by one floor. |
|||||
6.7.2 In buildings of I and II degrees of fire resistance of the constructive fire hazard class C0, in the presence of automatic fire extinguishing, the floor area within the fire compartment can be increased by no more than twice as compared to those established in tables 6.9 - 6.11.
6.7.3 The floor area within the fire compartment of one-story buildings with a two-story part occupying less than 15% of the built-up area of the building should be taken as for one-story buildings in accordance with tables 6.9 - 6.11.
6.7.4 In the buildings of stations of I, II degrees of fire resistance of class C0, instead of fire walls, it is allowed to install water deluge curtains in two strands located at a distance of 0.5 m and providing an irrigation intensity of at least 1 l / s per 1 m of curtain length during operation not less than 1 hour, as well as fire curtains, screens and other devices with a fire resistance of at least E 60. At the same time, these types of fire barriers must be placed in a zone free from fire load to a width of at least 4 m on both sides of the barrier.
6.7.5 In the buildings of air terminals of the I degree of fire resistance, the floor area between the fire walls can be increased to 10,000 m², if there are no warehouses, storerooms and other premises with the presence of combustible materials in the basement (basement) floors (except for storage rooms, wardrobes for personnel and premises categories B4 and D). Storage chambers (except for those equipped with automatic cells) and dressing rooms should be separated from the rest of the basement with type 1 fire partitions and equipped with automatic fire extinguishing installations, and command and control centers with type 1 fire partitions (including translucent ones).
6.7.6 In the buildings of stations and air terminals of the I degree of fire resistance of class C0, equipped with automatic fire extinguishing installations, the floor area between the fire walls is not standardized.
6.7.7 The degree of fire resistance of canopies, terraces and galleries attached to the building may be taken one value lower than the degree of fire resistance of the building. At the same time, the class of constructive fire hazard of canopies, terraces and galleries should be equal to the class of constructive fire hazard of the building.
In this case, the degree of fire resistance of a building with a canopy, a terrace and a gallery is determined by the degree of fire resistance of the building, and the floor area within the fire compartment is determined taking into account the area of the canopies, terraces and galleries.
6.7.8 In sports halls, halls of indoor skating rinks and halls of pool baths (with and without seats for spectators), as well as in halls for preparatory classes of pools and firing zones of indoor shooting ranges (including those located under the stands or built into other public buildings ) if their area is exceeded in relation to that established in Table 6.9, fire walls should be provided between halls (in shooting ranges - a firing zone with a shooting gallery) and other premises. In the premises of the vestibules and foyers, if their area is exceeded in relation to that established in Table 6.9, instead of fire walls, translucent fire partitions of the 2nd type can be provided.
6.7.9 Buildings of classes F1.2 and F4.2 - F4.3 of I, II and III degrees of fire resistance, not more than 28 m high, it is allowed to build on one attic floor with load-bearing elements having a fire resistance rating of at least R 45 and fire hazard class K0 , when separating it from the lower floors with a fireproof ceiling of at least type 2. The enclosing structures of this floor must meet the requirements for the structures of the superstructure 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 of I and II degrees of fire resistance - no more than 2000 m², for buildings of III degree of fire resistance - no more than 1400 m². If there are automatic fire extinguishing installations on the attic floor, this area can be increased by no more than 1.2 times.
When using wooden mansard structures, as a rule, structural fire protection should be provided that ensures these requirements.
6.7.10 The degree of fire resistance, the class of constructive fire hazard and the highest height of buildings of general preschool institutions (Form 1.1) should be taken depending on the largest number of seats in the building according to table 6.12.
Table 6.12
|
Number of places |
Degree of fire resistance of the building, not lower |
Constructive fire hazard class |
Permissible |
6.7.11 Walls from the inside, partitions and ceilings of buildings of preschool educational institutions, children's health institutions and medical buildings with a hospital (class F1.1), outpatient institutions (class F3.4) and clubs (class F2.1) in class buildings constructive fire hazard C1 - C3, including with the use of wooden structures, must have a fire hazard class of at least K0 (15).
6.7.12 Three-story buildings of preschool institutions may be designed in large and major cities, except for those located in seismic areas, provided they are equipped with an automatic fire alarm with additional automatic transmission of a fire signal directly to the fire department via telecommunication lines.
6.7.13 Buildings of specialized preschool institutions, as well as for visually impaired children, regardless of the number of seats, should be designed with a constructive fire hazard class C0 not lower than II degree of fire resistance and no more than two floors high.
6.7.14 Attached walking verandas of preschool institutions should be designed with the same degree of fire resistance and the same class of constructive fire hazard as the main buildings.
6.7.15 The degree of fire resistance, the class of constructive fire hazard and the highest height of school buildings (general education and additional education for children), educational buildings of boarding schools, primary education institutions (Form 4.1), as well as bedroom buildings of boarding schools and boarding schools at schools (Form 1.1) should be taken depending on the number of students or places in the building according to table 6.13. The maximum floor area of a building is determined according to Table 6.9.
The construction of school buildings, educational buildings of boarding schools, primary vocational education institutions, as well as dormitory buildings of boarding schools and boarding schools at schools with a height of more than 9 m is allowed provided that they are equipped with an automatic fire alarm with additional automatic transmission of a fire signal directly to the NCC via wired or wireless telecommunication lines connections. The placement of these buildings should be determined based on the condition that the time of arrival of the first unit to the place of call in urban settlements and urban districts should not exceed 10 minutes, and in rural settlements - 20 minutes. Driveways and entrances to these buildings should be designed based on the need to provide access for fire departments from ladders or car lifts directly to each room with window openings on the facade.
For projected four-story, as well as reconstructed five-story school buildings, at least 50% of staircases should be smoke-free. If it is not possible to install smoke-free staircases, in addition to the estimated number of staircases, the installation of external open stairs should be provided. The number of outdoor open stairs should be taken:
One staircase with an estimated number of students and staff on the floor above the second up to 100 people;
At least one staircase for every 100 people with an estimated number of students and staff on the floor above the second more than 100 people.
Table 6.13
|
Number of students |
constructive class |
Degree |
Permissible |
|
Dormitories |
|||
|
Note - For these buildings, it should be possible to install manual retractable fire escapes. * In the regions of the Far North, the height of a one-story building on a pile foundation should be no more than 5 m. |
|||
On the fourth floor of school buildings and educational buildings of boarding schools it is not allowed to place premises for primary classes, and other educational premises - more than 25%.
The superstructure of these buildings with an attic floor during reconstruction is allowed within the normalized number of storeys. At the same time, it is not allowed to place sleeping quarters on the attic floor.
Buildings of educational buildings of secondary vocational (Form 4.1) and higher vocational education (Form 4.2) may be designed with a height of no more than 28 m.
6.7.16 Buildings of specialized schools and boarding schools (for children with impaired physical and mental development) should not be higher than 9 m.
6.7.17 The height of the placement of auditoriums, assembly halls, conference halls and halls of sports facilities without spectator seats should be taken according to Table 6.14, taking into account the degree of fire resistance, the structural fire hazard class of the building and the capacity of the hall.
Table 6.14
|
Degree |
Building constructive fire hazard class |
Number of seats in the hall |
Permissible height of the hall, m |
|
Notes 1. The maximum height of the hall is determined by the height of the floor corresponding to the bottom row of seats. 2. In the buildings of preschool educational institutions, specialized nursing homes and disabled people (non-apartment), hospitals, dormitory buildings of boarding schools and children's institutions, children's health institutions (Form 1.1), schools (Form 4.1), placement of these halls is not allowed above the second floor. |
|||
6.7.18 The degree of fire resistance, the class of constructive fire hazard and the maximum height of the buildings of entertainment and cultural and educational institutions of the functional fire hazard class F2.1 and F2.2 should be taken depending on their capacity according to table 6.15.
Table 6.15
|
Class |
Degree |
Class |
Permissible |
The largest |
|
Notes 1 In buildings of class F2.1, the maximum height of the hall, determined by the height of the floor corresponding to the lower row of seats, should not exceed 9 m for halls with a capacity of more than 600 seats. In buildings of the I degree of fire resistance of class C0, it is allowed to place halls with a capacity of up to 300 seats at a height of not more than 28 m, 150 seats - at higher elevations. |
||||
|
2 In buildings of class F2.2, the maximum height of the hall, determined by the height of the corresponding floor, should not exceed 9 m for dance In buildings of the I degree of fire resistance of class C0, it is allowed to place halls with a capacity of up to 400 seats at a height of not more than 28 m, 200 seats - at higher elevations. 3 When blocking a year-round cinema with a seasonal cinema of varying degrees of fire resistance, a type 2 fire wall must be provided between them. |
||||
When determining the capacity of the halls, the fixed and temporary places for spectators provided for by the hall transformation project should be summed up.
When placing several halls in the cinema, their total capacity should not exceed that indicated in the table.
The load-bearing structures of the roofs above the stage and the hall (trusses, beams) in the buildings of theaters, clubs and sports facilities should be designed in accordance with the requirements for the load-bearing elements of the building.
For one-story buildings of I and II degrees of fire resistance, it is allowed to use load-bearing structures for halls with a fire resistance of at least R 60. These structures can be made of wood treated with fire retardants of group I of fire retardant efficiency in accordance with GOST R 53292. At the same time, the capacity of the hall can be no more than 4 thousand seats for sports facilities with stands and no more than 800 seats in other cases, and the rest of the structures must comply with the requirements for class C0 buildings.
6.7.19 Medical institutions, including those that are part of buildings of other functional purposes (schools, kindergartens, sanatoriums, etc.), should be designed in accordance with the following requirements.
Buildings of hospitals (Form 1.1), outpatient clinics (Form 3.4) should be designed no higher than 28 m. The degree of fire resistance of these buildings should not be lower than II, the structural fire hazard class should not be lower than C0.
Hospitals
Hospital buildings with a height of up to three floors inclusive must be divided into fire sections with an area of \u200b\u200bnot more than 1000 m², above three floors - into sections with an area of \u200b\u200bnot more than 800 m² with fireproof partitions of the 1st type.
The medical buildings of psychiatric hospitals and dispensaries should be no more than 9 m high, not lower than the II degree of fire resistance of the constructive fire hazard class C0.
In rural areas, buildings of medical institutions for 60 or less beds and outpatient clinics for 90 visits per shift may be provided with chopped or block walls.
Operating units, resuscitation and intensive care units should be located in separate fire compartments. These blocks of two floors or more must have elevators for transporting fire departments, adapted for transporting immobile patients.
Ward departments of children's hospitals and buildings (including wards for children with adults) should be located no higher than the fifth floor of the building, wards for children under the age of seven and children's psychiatric departments (wards), neurological departments for patients with spinal cord injury, etc. no higher than the second floor.
It is allowed to place wards for children under the age of seven not higher than the fifth floor, provided that smoke protection and automatic fire extinguishing are installed in the building (building).
In perinatal centers, the placement of wards is allowed no higher than the fourth floor, and antenatal wards - no higher than the third floor.
Homes for the elderly and disabled should be designed in accordance with the requirements for hospitals in medical institutions.
Polyclinics
Medical institutions without hospitals are allowed to be located in one-story buildings of the III degree of fire resistance of the constructive fire hazard class C0.
Outpatient buildings for serving children are allowed to be designed no higher than:
6 floors (18 m) - in large and major cities;
5 floors (15 m) - in other cases. At the same time, it is allowed to place only administrative and household premises for the staff of the institution on the top floor.
6.7.20 Buildings of recreation facilities for summer functioning of the V degree of fire resistance, as well as buildings of children's health institutions and sanatoriums of IV and V degrees of fire resistance, should be designed only as one-story.
Buildings of summer children's health camps and tourist huts should be designed with a height of no more than two floors, buildings of children's health camps for year-round use - no more than three floors, regardless of the degree of fire resistance and the class of constructive fire hazard.
In health camps, sleeping quarters should be combined into separate groups of 40 beds. These rooms must have independent emergency exits. One of the exits can be combined with a staircase. Sleeping quarters of health camps in separate buildings or separate parts of buildings should be no more than 160 places.
6.7.21 Grandstands of any capacity of buildings of class F2.3 with the use of a space under the stands when auxiliary premises are located in it on two or more floors must be designed not lower than the I degree of fire resistance of the structural fire hazard class C0.
Ceilings under the stands must be fireproof type 2.
In case of one-story placement of auxiliary premises in the under-tribune space or with more than 20 rows for spectators in the stands, the supporting structures of the stands must have a fire resistance rating of at least R 45, fire hazard class K0, and the ceilings under the stands must be type 3 fireproof.
The supporting structures of the stands of sports facilities (Form 2.3) without the use of space under the stands and with more than 5 rows must be made of non-combustible materials with a fire resistance rating of at least R 15. At the same time, combustible substances and materials are not allowed under the stands.
6.7.22 In indoor sports facilities, the supporting structures of stationary stands (under which accommodation is not provided) with a capacity of more than 600 spectators should be made with a fire resistance rating of at least R 60 fire hazard class K0; from 300 to 600 spectators - R 45 and K0; and less than 300 spectators - R 15 and K0, K1.
The fire resistance limit of load-bearing structures of transformable stands (retractable, etc.), regardless of capacity, must be at least R 15.
The above requirements do not apply to temporary spectator seats installed on the floor of the arena during its transformation.
6.7.23 Buildings of libraries and archives should be designed no higher than 28 m.
6.7.24 Buildings of sanatoriums, recreation and tourism facilities (with the exception of hotels) should be designed no higher than 28 m.
The degree of fire resistance of the dormitories of sanatoriums with a height of more than two floors must be at least II, the class of constructive fire hazard is C0.
Two-story dormitory buildings of sanatoriums are allowed to design the III degree of fire resistance of the constructive fire hazard class C0.
The number of places in the residential buildings of sanatoriums and recreation and tourism institutions of I and II degrees of fire resistance of the fire hazard class C0 should not exceed 1000; III degree of fire resistance of fire hazard class C0 - 150; other degrees of fire resistance - 50.
Sleeping quarters designed to accommodate families with children should be located in separate buildings or separate parts of buildings, allocated with type 1 fire partitions, no more than six floors high, with evacuation exits isolated from other parts of the buildings. At the same time, sleeping quarters must have an emergency exit that meets one of the following requirements:
6.7.25 The degree of fire resistance of hotels, rest houses of a general type, campsites, motels and boarding houses with a height of more than two floors must be at least III, class of constructive fire hazard C0.
Sleeping quarters designed to accommodate families with children in general-type holiday homes, campsites, motels and boarding houses should be placed in separate buildings or separate parts of buildings, allocated with type 1 fire partitions, not more than six floors high, with evacuation exits isolated from other parts of buildings . At the same time, sleeping quarters must have an emergency exit that meets one of the following requirements:
The exit should lead to a balcony or loggia with a blank wall 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 overlooking the balcony (loggia);
The exit must lead to a passage with a width of at least 0.6 meters leading to an adjacent part of the building;
The exit should lead to a balcony or loggia equipped with an external staircase connecting the balconies or loggias floor by floor.
The degree of fire resistance of buildings and structures, a table of indicators of these values \u200b\u200bis needed in order to know at what temperature the structure is destroyed by fire. Now the number of fires caused by careless handling of fire has increased, so you need to know the level of fire resistance of various objects.
What is the fire resistance of a building, what does it depend on and what does this indicator affect?
The intensity of the spread of fire depends on the fire resistance of the object and its structures. All building materials according to the change in characteristics in a fire are divided into:
- non-combustible;
- slow-burning;
- combustible.
Fire resistance is the ability of a building to withstand the action of an open flame for a certain period of time, during which its performance characteristics, such as thermal conductivity, bearing capacity of supports, resistance to fire, are maintained. To determine this indicator, you need to know the periods during which the structure is destroyed to a state where it cannot be restored.
Fire resistance of buildings is an important parameter that must be taken into account in the design and construction of buildings and structures. The fire resistance of a house depends on the level of fire resistance of its structures.
To determine the fire resistance limit, calculations or practical methods are used that make it possible to obtain these indicators from the test results. After comparing the values, a conclusion is made about the state of the building and a classification is assigned to it. When assessing the fire protection of an object, it must be taken into account that its calculation is based on the classification according to category C (support structures, flights of stairs). After that, it is determined whether the building complies with building codes in terms of the degree of resistance to combustion.
A fire is an uncontrolled process of burning and flame growth, which is accompanied by the destruction of property and creates a danger to the health and life of people in this area. Combustion is a chemical process of converting combustible substances into combustion products, it is accompanied by the release of fire, toxic gases, heat, which is carried out as a result of the oxygen oxidation reaction.
Fires are divided according to their intensity into the following types:
- Separate, arising in one structure. The movement of people and equipment across the area between such fires can be carried out without means of fire protection.
- Continuous, which is a simultaneous strong burning of several structures in one area. The movement of people and equipment across the area of a continuous fire cannot occur without fire protection equipment.
Determination of fire resistance limit
The fire resistance limit of a material is the time during which it retains its characteristics during combustion. The incombustibility limit of materials depends on the protective coating layer, profile cross-section, the level of fire resistance of building materials, and the ability to maintain their parameters during combustion. The degree of fire resistance is characterized by such factors:
- fire resistance;
- fire resistance level;
- level of fire spread.
There are limiting fire resistance standards:
- Loss of technological characteristics due to collapse or the appearance of limiting deformations is marked with the Latin letter R.
- Loss of integrity due to damage or holes through which combustion products and fire enter the outside. Designated with the letter E.
- Loss of insulating function as a result of an increase in surface temperature. Designate I.
The following limiting indicators are regulated for load-bearing structures according to the degree of resistance to fire:
- beams, racks, arches, trusses loss of bearing capacity - R;
- load-bearing walls and ceilings - loss of bearing capacity R and integrity E;
- exterior walls of a building that are not considered load-bearing - loss of integrity E;
- internal walls and partitions - loss of integrity E and the ability to thermal insulation I;
- internal walls and fences - loss of bearing capacity R, integrity E and insulating characteristic I.
How to determine the degree of fire resistance?
The classification of buildings according to the degree of fire resistance depends on:
- the number of floors in this building;
- the area of its territory;
- production processes or other activities that are carried out at the facility;
- characteristics and degree of flammability of materials used in the construction of the facility.
The fire resistance of a structure characterizes the duration of the period during which these structures were tested by flame. The resistance of objects to fire is regulated by SNiP, where there are 5 degrees of resistance of buildings to fire.
All buildings are divided into 5 categories:
- Explosive and fire hazardous, they carry out technical processes associated with the appearance of fire, combustible gases, flammable liquids with a flash limit of up to + 28ºC.
- Structures where work is carried out using flammable liquids with a flash limit greater than +28ºC, which can create explosive substances and, when burned, an explosion pressure of more than 5 kPa occurs.
- Objects where production processes take place using flammable liquids and solid materials that, when combined with oxygen, can burn. This is a fire category.
- Structures where technological actions are carried out using non-flammable materials in a hot form.
- Objects where production processes with the use of solid non-combustible substances take place.
Types of fire resistance degrees
The larger the number of storeys and the area of the structure, the higher the required degree of fire resistance of the building should be. Residential facilities are built of brick, concrete, stone, they are classified as 1st degree.
Residential buildings made of bricks and concrete panels belong to the 2nd degree. Residential buildings with a metal frame are classified as grade 3. The lining of these structures is made of non-combustible materials. The 4th degree includes objects that have a wooden frame, i.e. it is assigned to a wooden house. Class 5 includes all other houses that are prone to fire. Given this classification of buildings, the design and construction of buildings is carried out.
It happens that the house has a low classification in terms of fire resistance. Then its partitions, floors, load-bearing structures are treated with a non-combustible coating that protects them from fire. You can also cover the house with non-combustible materials. With the help of these comprehensive measures, the fire resistance of residential buildings is increased. In residential buildings of 1st, 2nd and 3rd degrees, partitions are installed that can contain a fire for at least 45 minutes, and in houses of 4th degree - 15 minutes.
If the structure is built of sandwich panels, then a heater is installed between them. This material can withstand frost, so they are used in construction in regions with a cold climate. The material is used for the construction of rapidly erected houses, it is easy to install.
Sandwich panels are safe for human health, have excellent sound insulation and high fire resistance. The fire resistance limit of this substance depends on its thickness: the thicker the material, the longer it will be able to withstand fire. It is impossible to build houses of the 1st degree of fire resistance from sandwich panels.
Consider the resistance of a brick building to fire. Brick houses have the highest fire safety rate, so they are classified as 1st degree. The indicator depends on the building material from which the structure is made. Brick is a non-combustible material, it does not smolder, does not deform from a fire, so it is often chosen for the construction of residential buildings. Such material will ensure the safety of people and property in the event of a fire.
Thus, any building material has its own fire resistance index, therefore, when choosing them for the construction of a building, one should take into account the characteristics of materials and structural elements that will make up the object under construction.
Degrees of fire resistance: table
Table of indicators of fire resistance of structures:
This table shows the dependence of the indicator on the fire characteristics of walls, columns, beams, runs of landings and other structures of the house. Knowing this indicator, designers carry out the project, create schemes, conduct calculations, develop the design of a residential building, taking into account fire safety requirements.
The degree of resistance to fire is an important parameter, which is determined during construction work and after its completion. It is very important for builders to know that this or that building structure has its own degree of fire resistance. How to determine the fire resistance of a building, you will learn from this article.
The expression fire resistance refers to the ability of certain elements of a building to maintain strength in a fire. Moreover, fire resistance has its own limit, which is determined in hours, i.e. specific figures to the fire hazard of the building. It is generally accepted that the degree of fire resistance is denoted by Roman values: I, II, III, IV, V.
Fire resistance is divided into two types:
- Actual (SOF). How is it defined? Mainly according to the result of technical and fire examination of building structures. Also, calculations occur based on regulatory documents. The level of resistance to fire is clearly regulated and known. In accordance with official information, the SOF is calculated.
- Required (SOtr). This concept includes the level of resistance to fire in the minimum value. In order for a building to meet all safety requirements, the structure must comply with them. This degree of fire resistance is determined on the basis of regulatory documents that have industry and specialized values. In this case, the key role is played by the direct purpose of the building, its area, the availability of fire extinguishing equipment, the number of floors, and so on.
To consolidate all this, consider an example. To make the building comply with the requirements of the PB, the SOF must be greater than or equal to SOtr. The limit of fire resistance occurs at the moment when the building completely or partially does not fulfill its functionality in case of fire. This happens when compartments or cracks form in a building. Directly through them, the flame penetrates into neighboring rooms, the surface heats up to 140-180 ° C, and also if the bearing parts of the building are completely eliminated.
Method for determining fire resistance
Appropriate tests are carried out to determine the limits of fire coverage, as well as the damage caused by burning. This is implemented in practice as follows: a fire is arranged in specially equipped furnaces. The furnace is processed exclusively with refractory bricks. Inside the furnace, kerosene is burned using special nozzles. Using thermal vapors, the temperature inside the furnace is controlled. With all this, the operation of the nozzles must be carried out so that they do not come into contact with thermal vapors and do not come into contact with the surface of the structure. So, based on the basic rules, then the calculation of the degree of fire resistance has two tasks:
- Thermotechnical.
- Statistical.
In order to determine the degree of fire resistance, it is important to first obtain an architectural design. Next, you need to adhere to the standard scheme.
As for the scheme, it looks like this:
- Turning to the fire department, they will conduct an examination on fire resistance. If deficiencies are found, they should be corrected immediately.
- Already at the stage of drawing up sketches, the degree of fire resistance will be indicated. And for this, you should contact only competent architects who will take into account all these nuances.
In practice, this whole process, by definition of fire resistance, looks like this:
- The fire resistance limit is calculated in hours or minutes. The countdown should begin from the moment of a critical situation, when the structure does not withstand the test, namely, it collapses or its integrity is violated.
- One of five steps is taken for calculation.
- Included in these calculations/calculations is the flammability level of the various materials used in the construction of the building.
- To accurately determine fire resistance, it is not enough to have superficial information. Here it is important to have a complete picture even for such structures as: additional staircases, flights of stairs, partitions and all other structures. Even the material from which these structures are made is taken into account.
- It would also be useful to study additional and mandatory materials that relate to the rules for ensuring the fire resistance of reinforced concrete structures. As a basis, for example, you can take the manual to the SNiP dated January 21, 1997 "Fire Prevention".
- Thus, to determine fire resistance, a wide range of planning and technological aspects are taken into account. But at the same time, one should not forget about the primary fire extinguishing means - fire extinguishers.
As a result, you need to make a list of requirements for the building, which are found out in the process of determining the fire resistance. The documentation and the design of the building are taken as the basis.
SNiP
In most cases, structures and buildings have type 1 walls, i.e. fire compartment. As for the minimum fire resistance threshold of a building, it is 25. As a result, it is allowed to use unprotected metal structures.
Building codes allow the use of drywall as a facing material. This to some extent increases the fire resistance of the building.
If we talk about building materials and the degree of their combustibility, then they are divided into 3 groups:
- Non-combustible.
- Fire resistant.
- Fireproof.
If you are building a frame, it is better that it be made of non-combustible material. For buildings from 1 to 5, combustible materials can be used, but not in the lobbies. This is important, because plus everything building materials are divided into classifications such as:
- Smoke generating.
- Toxic.
Below we consider an algorithm for calculating the degree of fire resistance of a building and premises of different types. Based on this, you can find out the basic requirements for certain buildings.
residential buildings
The fire resistance index of the house has 5 degrees. According to these degrees, a characteristic is given for each building material from which the house was built. The following are the structural characteristics of residential buildings:
- For residential buildings, preference is given to non-combustible materials.
- Construction is best done from concrete blocks, stone or brick.
- To insulate walls, roofs and other structures, use fire-resistant material.
- Roofing should be made of materials that are resistant to fire, namely: slate, corrugated board, metal tiles or tiles.
- Ceilings are made of reinforced concrete slabs.
- If the floors are wooden, then they should be covered with non-combustible materials, such as non-combustible boards or plaster.
- The wooden truss system must be treated with impregnations that prevent the spread of fire.
For insulation, it is not necessary to use non-combustible materials. You can use items that are resistant to fire categories G1 and G2.
Public buildings
The degree of fire resistance of public buildings is divided into 5 groups: I, II, III, IV, V. So, according to the class of constructive fire hazard of a building, the following are determined:
- I-C0.
- II-C0.
- III-C0.
- IV-C0.
- V is not numbered.
With regard to the permissible height of the room in meters and the area for the fire compartment, the following data are available here:
- I-75m;
- II-C0-50, C1-28;
- III-C0-28, C1-15;
- IV-CO-5-1000 m 2 ;
- C1-3m-1400 m 2;
- C2-5m-800 m 2.
Speaking of clubs, pioneer camps, hospitals, preschools and schools, they often use wooden partitions, ceilings and walls. Their processing must be carried out with fire-resistant materials.
Industrial buildings
- Metallurgical.
- Instrumental.
- Chemical.
- Weaving.
- Repair and others.
And for such establishments, the degree of fire resistance is more important than ever. In addition, some work with toxic and explosive substances that can have a negative impact on humans and the environment.
Production buildings are also divided into 5 stages. Fire resistance is determined based on the building materials used. Hence the conclusion: the degree of fire safety of an industrial building directly depends on the fire resistance of the building materials used.
Warehouses
As a rule, those warehouses that are made of wooden materials are considered the most vulnerable. However, if they are treated with plaster and special impregnations, then their degree of fire resistance increases. Also for this purpose, concrete or ceramic tiles are used.
For warehouses, swollen paints or polymer foam are considered the most effective. Their action prolongs the period of raising the critical temperature.
In general, a number of measures are being taken to increase the degree of fire resistance of premises built of wood. Aluminum doors can also be installed in them, and glass blocks instead of wooden windows.
So, it is worth noting that before determining the fire resistance of a building, it is important to take into account the characteristics and purpose of each building, as well as methods and materials that have different specifics.
Loading...