GOST 30244-94
Group W19
INTERSTATE STANDARD
CONSTRUCTION MATERIALS
Flammability Test Methods
Building materials. Methods for combustibility test
ISS 13.220.50
91.100.01
OKSTU 5719
Date of introduction 1996-01-01
PREFACE
PREFACE
1 DEVELOPED by the State Central Research and Design and Experimental Institute of Complex Problems building structures and structures named after V.A. Kucherenko (TsNIISK named after Kucherenko) and the Center for Fire Research and Thermal Protection in Construction TsNIISK (TsPIZS TsNIISK) Russian Federation
INTRODUCED by the Ministry of Construction of Russia
2 ADOPTED by the Interstate Scientific and Technical Commission for Standardization and Technical Regulation in Construction (INTKS) on November 10, 1993.
The following voted for adoption:
State name | Name of body government controlled construction |
The Republic of Azerbaijan | State Construction Committee of the Azerbaijan Republic |
Republic of Armenia | State Architecture of the Republic of Armenia |
Republic of Belarus | Ministry of Construction and Architecture of the Republic of Belarus |
The Republic of Kazakhstan | Ministry of Construction of the Republic of Kazakhstan |
Kyrgyz Republic | Gosstroy of the Kyrgyz Republic |
The Republic of Moldova | Ministry of Architecture and Construction of the Republic of Moldova |
Russian Federation | Ministry of Construction of Russia |
The Republic of Tajikistan | State Construction Committee of the Republic of Tajikistan |
The Republic of Uzbekistan | State Committee for Architecture and Construction of the Republic of Uzbekistan |
Ukraine | State Committee for Urban Development of Ukraine |
3 Clause 6 of this standard is the authentic text of ISO 1182-80* Fire tests - Building materials - Non-combustibility tests Fire tests. - Construction Materials. - Non-flammability test (Third edition 1990-12-01).
________________
* Access to international and foreign documents mentioned in the text can be obtained by contacting Customer Support. - Database manufacturer's note.
4 ENTERED INTO EFFECT on January 1, 1996 as a state standard of the Russian Federation by Resolution of the Ministry of Construction of Russia dated August 4, 1995 N 18-79
5 IN REPLACEMENT ST SEV 382-76, ST SEV 2437-80
6 REPUBLICATION. January 2006
1 area of use
This standard specifies test methods building materials for flammability and their classification into flammability groups.
The standard does not apply to varnishes, paints, and other building materials in the form of solutions, powders and granules.
2 Normative references
This standard uses references to the following standards:
GOST 12.1.033-81 System of occupational safety standards. Fire safety. Terms and Definitions
GOST 18124-95 Flat asbestos-cement sheets. Specifications
3 Definitions
This standard uses terms and definitions in accordance with GOST 12.1.033, as well as the following terms.
stable flame combustion: Continuous flaming combustion of the material for at least 5 s.
exposed surface: The surface of a specimen exposed to heat and/or open flame during a flammability test.
4 Basic provisions
4.1 Test Method I (Section 6) is intended to classify building materials as non-combustible or combustible.
4.2 Test method II (section 7) is intended for testing combustible building materials in order to determine their flammability groups.
5 Classification of building materials by flammability groups
5.1 Building materials, depending on the values of flammability parameters determined by method I, are divided into non-combustible (NG) and combustible (G).
5.2 Construction materials are classified as non-combustible when following values flammability parameters:
- temperature increase in the furnace is no more than 50°C;
- weight loss of the sample is not more than 50%;
- duration of stable flame combustion is no more than 10 s.
Construction materials that do not satisfy at least one of the specified parameter values are classified as combustible.
5.3 Combustible building materials, depending on the values of the flammability parameters determined by method II, are divided into four flammability groups: G1, G2, G3, G4 in accordance with Table 1. Materials should be assigned to a certain flammability group provided that all the values of the parameters established correspond to Table 1 for this group.
Table 1 - Flammability groups
Flammability group | Flammability parameters |
|||
Temperature | Degree | Degree | Duration of independent combustion, s |
|
Note - For materials of flammability groups G1-G3, the formation of burning melt drops during testing is not allowed. |
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6 Combustibility test method for classifying building materials as non-combustible or combustible
Method I
6.1 Scope of application
The method is used for homogeneous building materials.
For layered materials, the method can be used as an evaluation method. In this case, tests are carried out for each layer making up the material.
Homogeneous materials - materials consisting of one substance or a uniformly distributed mixture various substances(for example, wood, foam plastics, polystyrene concrete, particle boards).
Layered materials are materials made from two or more layers of homogeneous materials (for example, plasterboard sheets, paper laminates, homogeneous materials with fire retardant treatment).
6.2 Test specimens
6.2.1 For each test, five cylindrical samples are made of the following dimensions: diameter mm, height (50 ± 3) mm.
6.2.2 If the material thickness is less than 50 mm, the samples are made from the appropriate number of layers to provide the required thickness. In order to prevent the formation of air gaps between them, layers of material are tightly connected using thin steel wire with a maximum diameter of 0.5 mm.
6.2.3 In the upper part of the sample, a hole with a diameter of 2 mm should be provided for installing a thermocouple in the geometric center of the sample.
6.2.4 Samples are conditioned in a ventilated oven at a temperature of (60±5)°C for 20-24 hours, after which they are cooled in a desiccator.
6.2.5 Before testing, each sample is weighed, determining its mass with an accuracy of 0.1 g.
6.3 Test equipment
6.3.1 In the following description of the equipment, all dimensions, except those given with tolerances, are nominal.
6.3.2 The test setup (Figure A.1) consists of a furnace placed in a heat-insulating environment; cone-shaped air flow stabilizer; protective screen providing traction; a sample holder and a device for introducing the sample holder into the furnace; the frame on which the stove is mounted.
6.3.3 The furnace is a pipe made of refractory material (Table 2) with a density of (2800±300) kg/m, height (150±1) mm, internal diameter (75±1) mm, wall thickness (10±1) mm. The total wall thickness, taking into account the refractory cement layer fixing the electric heating element, should be no more than 15 mm.
Material | |
Alumina (AlO) | |
or silica and alumina (SiO, AlO) | |
Iron(III) oxide FeO | |
Titanium dioxide (TiO) | |
Manganese oxide (MnO) | |
Traces of other oxides (potassium, sodium, calcium and magnesium) | Rest |
6.3.5 The tube furnace is installed in the center of a casing filled with insulating material ( outside diameter 200 mm, height 150 mm, wall thickness 10 mm). The upper and lower parts of the casing are limited by plates that have recesses on the inside for fixing the ends of the tubular furnace. The space between the tube furnace and the walls of the casing is filled with powdered magnesium oxide with a density of (140±20) kg/m.
6.3.6 The lower part of the tube furnace is connected to a cone-shaped air flow stabilizer 500 mm long. The internal diameter of the stabilizer should be (75±1) mm in the upper part, (10±0.5) mm in the lower part. The stabilizer is made of sheet steel 1 mm thick. Inner surface stabilizer must be polished. The seam between the stabilizer and the furnace should be tightly fitted to ensure tightness and carefully processed to eliminate roughness. The upper half of the stabilizer is insulated with outside a layer of mineral fiber 25 mm thick [thermal conductivity (0.04±0.01) W/(m K) at 20°C].
6.3.7. The upper part of the furnace is equipped with a protective screen made of the same material as the stabilizer cone. The screen height should be 50 mm, internal diameter (75±1) mm. The inner surface of the screen and the connecting seam with the furnace are carefully processed until smooth surface. Outer part insulated with a layer of mineral fiber 25 mm thick [thermal conductivity (0.04 ± 0.01) W/(m K) at 20°C].
6.3.8 The block, consisting of a furnace, a cone-shaped stabilizer and a protective screen, is mounted on a frame equipped with a base and a screen to protect the lower part of the cone-shaped stabilizer from directed air flows. The height of the protective screen is approximately 550 mm, the distance from the bottom of the cone-shaped stabilizer to the base of the frame is approximately 250 mm.
6.3.9 To observe the flaming combustion of the sample, a mirror with an area of 300 mm is installed above the furnace at a distance of 1 m at an angle of 30°.
6.3.10 The installation should be placed so that directed air flows or intense solar and other types of light radiation do not affect the observation of the flaming combustion of the sample in the furnace.
6.3.11 The sample holder (Figure A.3) is made of nichrome or heat-resistant steel wire. The base of the holder is a thin mesh made of heat-resistant steel. The weight of the holder should be (15±2) g. The design of the sample holder should allow it to be freely suspended from the bottom of the tube from of stainless steel outer diameter 6 mm with a hole drilled in it with a diameter of 4 mm.
6.3.12 The device for inserting the sample holder consists of metal rods that move freely within the guides installed on the sides of the casing (Figure A.1). The device for introducing the sample holder must ensure its smooth movement along the axis of the tubular furnace and its rigid fixation in the geometric center of the furnace.
6.3.13 To measure temperature, use nickel/chrome or nickel/aluminum thermocouples with a nominal diameter of 0.3 mm, an insulated junction. Thermocouples must have a stainless steel protective casing with a diameter of 1.5 mm.
6.3.14 New thermocouples are subjected to artificial aging to reduce reflectivity.
6.3.15 The furnace thermocouple should be installed so that its hot junction is located at the middle of the height of the tubular furnace at a distance of (10±0.5) mm from its wall. To install the thermocouple in the indicated position, use a guide rod (Figure A.4). The fixed position of the thermocouple is ensured by placing it in a guide tube attached to the protective screen.
6.3.16 The thermocouple for measuring temperature in the sample should be installed so that its hot junction is located in the geometric center of the sample.
6.3.17 The thermocouple for measuring temperature on the surface of the sample should be installed so that its hot junction from the very beginning of the test is at the middle of the height of the sample in close contact with its surface. The thermocouple should be installed in a position diametrically opposite to the furnace thermocouple (Figure A.5).
6.3.18 Temperature is recorded throughout the experiment using appropriate instruments.
A schematic electrical diagram of the installation with measuring instruments is shown in Figure A6.
6.4 Preparing the installation for testing
6.4.1 Remove the sample holder from the oven. The furnace thermocouple must be installed in accordance with 6.3.15.
6.4.2 Connect the heating element of the oven to the power source in accordance with the diagram shown in Figure A.6. During testing automatic control oven temperatures should not be adjusted.
Note - A new tube furnace should be heated up gradually. A stepwise mode is recommended with steps of 200°C and holding for 2 hours at each temperature.
6.4.3 Establish a stable temperature regime in the oven. Stabilization is considered achieved provided that the average oven temperature is in the range of 745-755°C for at least 10 minutes. In this case, the permissible deviation from the boundaries of the specified range should be no more than 2°C in 10 minutes.
6.4.4 After stabilizing the furnace in accordance with 6.4.3, the temperature of the furnace wall should be measured. Measurements are taken along three equidistant vertical axes. Along each axis, the temperature is measured at three points: at the middle of the height of the tube furnace, at a distance of 30 mm up and 30 mm down the axis. For ease of measurement, you can use a scanning device with thermocouples and insulating tubes (Figure A.7). When measuring, close contact of the thermocouple with the furnace wall should be ensured. The thermocouple readings at each point should be recorded only after stable readings have been achieved for 5 minutes.
6.4.5 The average temperature of the furnace wall, calculated as the arithmetic mean from the readings of thermocouples at all points listed in 6.4.4, should be (835 ± 10) ° C. The furnace wall temperature should be maintained within the specified limits until testing begins.
6.4.6 If not correct installation chimney(upside down) it is necessary to check that its orientation is consistent with that shown in Figure A.2. To do this, use a thermocouple scanning device to measure the temperature of the furnace wall along one axis every 10 mm. The resulting temperature profile, when installed correctly, corresponds to that shown with a solid line, and when installed incorrectly, corresponds to the dotted line (Figure A.8).
Note - The operations described in 6.4.2-6.4.4 should be carried out during commissioning new installation or when replacing a chimney pipe, heating element, thermal insulation, power supply.
6.5 Test performance
6.5.1 Remove the sample holder from the furnace, check the installation of the furnace thermocouple, and turn on the power source.
6.5.2 Stabilize the furnace in accordance with 6.4.3.
6.5.3 Place the sample in the holder, install thermocouples in the center and on the surface of the sample in accordance with 6.3.16-6.3.17.
6.5.4 Insert the sample holder into the oven and install it in accordance with 6.3.12. The duration of the operation should be no more than 5 s.
6.5.5 Start the stopwatch immediately after introducing the sample into the oven. During the test, record the readings of thermocouples in the furnace, in the center and on the surface of the sample.
6.5.6 The duration of the test is, as a rule, 30 minutes. The test is stopped after 30 minutes provided that temperature balance has been achieved by this time. Temperature balance is considered achieved if the readings of each of the three thermocouples change by no more than 2°C in 10 minutes. In this case, the final thermocouples are fixed in the furnace, in the center and on the surface of the sample.
If, after 30 minutes, temperature balance is not achieved for at least one of the three thermocouples, the test is continued, checking for temperature balance at 5-minute intervals.
6.5.7 When temperature balance is achieved for all three thermocouples, the test is stopped and its duration is recorded.
6.5.8 The sample holder is removed from the oven, the sample is cooled in a desiccator and weighed.
Residues that fall off the sample during or after testing (carbonation products, ash, etc.) are collected, weighed and included in the mass of the sample after the test.
6.5.9 During testing, record all observations regarding the behavior of the sample and record the following indicators:
- mass of the sample before testing, g;
- mass of the sample after testing, g;
- initial temperature of the furnace, °C;
- maximum oven temperature, °C;
- final oven temperature, °C;
- maximum temperature in the center of the sample, °C;
- final temperature at the center of the sample, °C;
- maximum sample surface temperature, °C;
- final sample surface temperature, °C;
- duration of stable flame combustion of the sample, s.
6.6 Processing results
6.6.1 For each sample, calculate the temperature increase in the oven, in the center and on the surface of the sample:
a) temperature increase in the furnace
b) temperature increase in the center of the sample
c) temperature increase on the surface of the sample.
6.6.2 Calculate the arithmetic average value (over five samples) of the temperature increase in the oven, in the center and on the surface of the sample.
6.6.3 Calculate the arithmetic average value (based on five samples) of the duration of stable flame combustion.
6.6.4 Calculate the mass loss for each sample (as a percentage of initial mass sample) and determine the arithmetic mean value for five samples.
6.7 Test report
The test report provides the following data:
- test date;
- name of the customer;
- name of the material or product;
- code of technical documentation for the material or product;
- description of the material or product indicating the composition, manufacturing method and other characteristics;
- name of each material that is integral part products, indicating the layer thickness and method of fastening (for prefabricated elements);
- method of making a sample;
- test results (indicators determined during testing according to 6.5.9 and calculated flammability parameters according to 6.6.1-6.6.4);
- photographs of samples after testing;
- a conclusion based on the test results indicating what type of material it is: flammable or non-flammable;
- validity period of the conclusion.
7 Test method for combustible building materials to determine their flammability groups
Method II
7.1 Scope of application
The method is used for all homogeneous and layered combustible building materials, including those used as finishing and facing materials, as well as paint coatings.
7.2 Test specimens
7.2.1 For each test, 12 samples are made, 1000 mm long and 190 mm wide. The thickness of the samples must correspond to the thickness of the material used in real conditions. If the material thickness is more than 70 mm, the thickness of the samples should be 70 mm.
7.2.2 When making samples, the exposed surface should not be processed.
7.2.3 Samples for standard testing of materials used only as finishing and facing materials, as well as for testing paint and varnish coatings, are prepared in combination with a non-combustible base. The fastening method must ensure tight contact between the surfaces of the material and the base.
Should be used as a non-flammable base asbestos cement sheets 10 or 12 mm thick according to GOST 18124.
In cases where the specific technical documentation does not provide the conditions for standard testing, samples must be manufactured with the base and fastening specified in the technical documentation.
7.2.4 The thickness of paint and varnish coatings must correspond to that accepted in the technical documentation, but have at least four layers.
7.2.5 For materials used both independently (for example, for structures) and as finishing and facing materials, samples must be made in accordance with 7.2.1 (one set) and 7.2.3 (one set).
In this case, tests must be carried out separately for the material and separately using it as finishing and cladding, with determination of flammability groups for all cases.
7.2.6 For asymmetrical layered materials with various surfaces make two sets of samples (according to 7.2.1) in order to expose both surfaces. In this case, the flammability group of the material is determined based on the worst result.
7.3 Test equipment
7.3.1 The test installation consists of a combustion chamber, an air supply system to the combustion chamber, a gas exhaust pipe, and a ventilation system for removing combustion products (Figure B.1).
7.3.2 The design of the walls of the combustion chamber must ensure stability temperature regime tests established by this standard. For this purpose, it is recommended to use the following materials:
- for the inner and outer surfaces of the walls - sheet steel 1.5 mm thick;
- for the thermal insulation layer - mineral wool slabs[density 100 kg/m, thermal conductivity 0.1 W/(m K), thickness 40 mm].
7.3.3 A sample holder, ignition source, and diaphragm are installed in the combustion chamber. The front wall of the combustion chamber is equipped with a door with glazed openings. A hole with a plug for inserting thermocouples should be provided in the center of the side wall of the chamber.
7.3.4 The sample holder consists of four rectangular frames located around the perimeter of the ignition source (Figure B.1), and must ensure the position of the sample relative to the ignition source shown in Figure B.2, the stability of the position of each of the four samples until the end of the test. The sample holder should be installed on a support frame that allows it to move freely in a horizontal plane. The sample holder and mounting parts should not overlap the sides of the exposed surface by more than 5 mm.
7.3.5 The ignition source is a gas burner consisting of four separate segments. Mixing of gas with air is carried out using holes located on the gas supply pipes at the entrance to the segment. The location of the burner segments relative to the sample and its circuit diagram are shown in Figure B.2.
7.3.6 The air supply system consists of a fan, rotameter and diaphragm and must ensure the flow of air into the lower part of the combustion chamber, uniformly distributed over its cross-section, in an amount of (10±1.0) m/min with a temperature of at least (20±2)° WITH.
7.3.7 The diaphragm is made of perforated steel sheet 1.5 mm thick with holes with diameters of (20±0.2) mm and (25±0.2) mm and located above it at a distance of (10±2) mm metal mesh from wire with a diameter of no more than 1.2 mm with a cell size of no more than 1.5x1.5 mm. The distance between the diaphragm and the upper plane of the burner must be at least 250 mm.
7.3.8 A gas outlet pipe with a cross section of (0.25±0.025) m and a length of at least 750 mm is located in the upper part of the combustion chamber. Four thermocouples are installed in the exhaust pipe to measure the temperature of the exhaust gases (Figure B.1).
7.3.9 Ventilation system to remove combustion products, it consists of an umbrella installed above the flue pipe, an air duct and a ventilation pump.
7.3.10 To measure temperature during testing, thermocouples with a diameter of no more than 1.5 mm and corresponding recording instruments are used.
7.4 Preparation for testing
7.4.1 Preparation for testing consists of carrying out calibration in order to establish the gas flow rate (l/min) that ensures the test temperature conditions established by this standard in the combustion chamber (Table 3).
Table 3 - Test mode
Distance from bottom | Temperature, °C |
|
maximum | minimum |
|
7.4.2 Calibration of the installation is carried out on four steel samples with dimensions 1000x190x1.5 mm.
Note - To provide rigidity, it is recommended that calibration samples made of sheet steel be made with flanging.
7.4.3 Temperature control during calibration is carried out according to the readings of thermocouples (10 pcs.), installed on calibration samples (6 pcs.), and thermocouples (4 pcs.), permanently installed in the gas outlet pipe (7.3.8).
7.4.4 Thermocouples are installed along the central axis of any two opposite calibration samples at the levels indicated in Table 3. The hot junction of the thermocouples should be located at a distance of 10 mm from the exposed surface of the sample. The thermocouples should not come into contact with the calibration sample. To insulate thermocouples, it is recommended to use ceramic tubes.
7.4.5 Calibration of the shaft furnace is carried out every 30 tests and when measuring the composition of the gas supplied to the ignition source.
7.4.6 Sequence of operations during calibration:
- install the calibration sample into the holder;
- install thermocouples on calibration samples in accordance with 7.4.4;
- insert the holder with the sample into the combustion chamber, turn on measuring instruments, air supply, exhaust ventilation, ignition source, close the door, record the thermocouple readings 10 minutes after turning on the ignition source.
If the temperature in the combustion chamber does not meet the requirements of Table 3, repeat the calibration at other gas flow rates.
The gas flow rate established during calibration should be used during testing until the next calibration.
7.5 Test performance
7.5.1 Three tests should be carried out for each material. Each of the three tests consists of simultaneous testing of four material samples.
7.5.2 Check the flue gas temperature measurement system by turning on the measuring instruments and the air supply. This operation is carried out with the combustion chamber door closed and the ignition source inoperative. The deviation of the readings of each of the four thermocouples from their arithmetic mean value should be no more than 5°C.
7.5.3 Weigh four samples, place them in the holder, and introduce it into the combustion chamber.
7.5.4 Turn on the measuring instruments, air supply, exhaust ventilation, ignition source, close the chamber door.
7.5.5 The duration of exposure of the sample to flame from the ignition source should be 10 minutes. After 10 minutes, the ignition source is turned off. If there is a flame or signs of smoldering, the duration of spontaneous combustion (smoldering) is recorded. The test is considered complete after the samples have cooled to ambient temperature.
7.5.6 After completing the test, turn off the air supply, exhaust ventilation, and measuring instruments, and remove samples from the combustion chamber.
7.5.7 For each test, the following indicators are determined:
- flue gas temperature;
- duration of independent combustion and (or) smoldering;
- length of damage to the sample;
- mass of the sample before and after testing.
7.5.8 During the test, the temperature of the flue gases is recorded at least twice per minute according to the readings of all four thermocouples installed in the flue pipe, and the duration of spontaneous combustion of the samples is recorded (in the presence of a flame or signs of smoldering).
7.5.9 During testing, the following observations are also recorded:
- time to reach the maximum flue gas temperature;
- flame transfer to the ends and unheated surface of the samples;
- through burning of samples;
- formation of a burning melt;
- appearance of the samples after testing: soot deposition, color change, melting, sintering, shrinkage, swelling, warping, cracking, etc.;
- time until the flame spreads along the entire length of the sample;
- duration of combustion along the entire length of the sample.
7.6 Processing of test results
7.6.1 After completion of the test, measure the length of the segments of the undamaged part of the samples (according to Figure B3) and determine the residual mass of the samples.
The part of the sample that is not burned or charred either on the surface or inside is considered intact. Soot deposition, change in sample color, local chipping, sintering, melting, swelling, shrinkage, warping, change in surface roughness are not considered damage.
The measurement result is rounded to the nearest 1 cm.
The undamaged part of the samples remaining on the holder is weighed. The weighing accuracy must be at least 1% of the initial mass of the sample.
7.6.2 Processing the results of one test (four samples)
7.6.2.1 The temperature of the flue gases is taken equal to the arithmetic mean of the simultaneously recorded maximum temperature readings of all four thermocouples installed in the flue pipe.
7.6.2.2 The length of damage to one sample is determined by the difference between the nominal length before testing (according to 7.2.1) and the arithmetic mean length of the undamaged part of the sample, determined from the lengths of its segments, measured in accordance with Figure B.3.
The measured lengths of the segments should be rounded to 1 cm.
7.6.2.3 The length of damage to samples during testing is determined as the arithmetic mean of the damage lengths of each of the four tested samples.
7.6.2.4 Damage by mass of each sample is determined by the difference between the mass of the sample before testing and its residual mass after testing.
7.6.2.5 Damage by mass of samples is determined by the arithmetic average value of this damage for four tested samples.
7.6.3 Processing the results of three tests (determination of flammability parameters)
7.6.3.1 When processing the results of three tests, the following parameters of the flammability of the building material are calculated:
- flue gas temperature;
- duration of independent combustion;
- degree of damage along the length;
- degree of damage by weight.
7.6.3.2 The flue gas temperature (, °C) and the duration of spontaneous combustion (, s) are determined as the arithmetic average of the results of three tests.
7.6.3.3 The degree of damage along the length (, %) is determined by the percentage ratio of the damage length of the samples to their nominal length and is calculated as the arithmetic mean of this ratio from the results of each test.
7.6.3.4 The degree of damage by mass (, %) is determined by the percentage ratio of the mass of the damaged part of the samples to the initial one (based on the results of one test) and is calculated as the arithmetic mean value of this ratio from the results of each test.
7.6.3.5 The results obtained are rounded to whole numbers.
7.6.3.6 The material should be classified as flammability group in accordance with 5.3 (Table 1).
7.7 Test report
7.7.1 The test report provides the following data:
- test date;
- name of the laboratory conducting the test;
- name of the customer;
- name of the material;
Code of technical documentation for the material;
- description of the material indicating the composition, manufacturing method and other characteristics;
- the name of each material that is an integral part of the layered material, indicating the thickness of the layer;
- method of making a sample, indicating the base material and method of fastening;
- additional observations during testing;
- characteristics of the exposed surface;
- test results (flammability parameters according to 7.6.3);
- photograph of the sample after testing;
- conclusion based on test results about the flammability group of the material.
For materials tested in accordance with 7.2.3 and 7.2.5, indicate the flammability groups for all cases established by these paragraphs;
- validity period of the conclusion.
APPENDIX A (mandatory). INSTALLATION FOR TESTING BUILDING MATERIALS FOR NON-COMBUSTIBILITY (Method I)
APPENDIX A
(required)
1 - bed; 2 - insulation; 3 - fire-resistant pipe; 4 - magnesium oxide powder; 5 - winding; 6 - damper; 7 - steel rod; 8 - limiter; 9 - sample thermocouples; 10 - stainless steel tube; 11 - sample holder; 12 - furnace thermocouple; 13 - insulation; 14 - insulating material; 15 - asbestos cement pipe or similar material; 16 - seal; 17 - air flow stabilizer; 18 - Sheet steel; 19 - draft protection device
Figure A.1 - General form installations
1 - fire-resistant pipe; 2 - nichrome tape
Figure A.2 - Furnace winding
Thermocouple in the center of the sample; - thermocouple on the surface of the sample;
1 - stainless steel tube; 2 - mesh (mesh size 0.9 mm, wire diameter 0.4 mm)
Figure A.3 - Sample holder
1 - wooden handle; 2 - weld seam
Furnace thermocouple; - thermocouple in the center of the sample; - thermocouple on the surface of the sample;
1 - furnace wall; 2 - mid-height of the constant temperature zone; 3 - thermocouples in protective casing; 4 - contact of thermocouples with the material
Figure A.5 - Relative position of the furnace, sample and thermocouples
1 - stabilizer; 2 - ammeter; 3 - thermocouples; 4 - furnace windings; 5 - potentiometer
Figure A.6 - Electrical diagram installations
1 - fire-resistant steel rod; 2 - thermocouple in a protective casing made of aluminous porcelain; 3 - silver solder; 4 - steel wire; 5 - ceramic tube; 6 - hot layer
Figure A.7 - Thermocouple scanning device
Figure A.8 - Temperature profiles of the furnace wall
APPENDIX B (mandatory). INSTALLATION FOR TESTING BUILDING MATERIALS FOR FLAMMABILITY (Method II)
APPENDIX B
(required)
1 - combustion chamber; 2 - sample holder; 3 - sample; 4 - gas-burner; 5 - air supply fan; 6 - combustion chamber door; 7 - diaphragm; 8 - ventilation tube; 9 - gas pipeline; 10 - thermocouples; 11 - exhaust hood; 12 - viewing window
Figure B.1 - General view of the installation
1 - sample; 2 - gas-burner; 3 - holder base (sample support)
Figure B.2 - Gas burner
1 - undamaged surface; 2 - the border between damaged and undamaged surfaces; 3 - damaged surface
Figure B.3 - Determination of sample damage length
UDC 691.001.4:006.354 | ISS 13.220.50 | ||
Key words: building materials, flammability, test methods, classification by flammability groups |
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Electronic document text
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2008
To determine the likelihood of a flame occurring, the flammability of substances and various materials is of primary importance. This characteristic defines the category fire danger structures, premises, production; allows you to choose the right means to eliminate outbreaks.
The flammability group of all material components of an object determines the success of fire fighting and minimizes the likelihood of casualties.
Features of various substances
It is known that substances can be in different states of aggregation, which are important to consider when determining the flammability group. GOST provides for classification based on quantitative indicators.
If a substance can burn, the flammability group G1 is more optimal for fire safety than G3 or G4.
Has flammability great importance for finishing, heat-insulating, building materials. On its basis, the fire hazard class is determined. Thus, plasterboard sheets have a flammability group of G1, stone wool– NG (does not burn), and polystyrene foam insulation belongs to the G4 flammability group, and the use of plaster helps reduce its fire hazard.
Gaseous substances
When determining the flammability class of gases and liquids, standards introduce such a concept as a concentration limit. By definition, this is the maximum concentration of a gas in a mixture with an oxidizer (air, for example), at which a flame can spread from the point of ignition to any distance.
If such a limit value does not exist and the gas cannot spontaneously ignite, then it is called non-flammable.
Liquid
Liquids are called flammable if there is a temperature at which they can ignite. If the liquid stops burning in the absence external source heating, it is called low-flammability. Non-flammable liquids do not ignite at all air atmosphere under normal conditions.
Some liquids (acetone, ether) may flash at 28 ℃ and below. They are considered especially dangerous. Liquids that ignite at 61…66 ℃ and above are classified as flammable (kerosene, white spirit). Tests are carried out in an open and closed crucible.
Solid
In the field of construction, the most relevant is the determination of the flammability group of solid materials. It is preferable to use substances of the flammability group G1 or NG, as they are the most resistant to ignition.
Classification
The intensity of the combustion process and the conditions under which it occurs determine the likelihood of a fire intensifying and an explosion occurring. The outcome of the incident depends on the totality of the properties of the feedstock.
General division
According to the national fire and explosion hazard standard, substances and various materials made from them are divided into the following groups:
- absolutely non-flammable;
- difficult to burn;
- flammable.
They cannot burn in air, which does not exclude interaction with oxidizing agents, with each other, and with water. Consequently, some members of the group pose a fire hazard under certain conditions.
Compounds that are difficult to combust include those that burn when ignited in air. As soon as the source of fire is eliminated, the burning stops.
Under certain conditions, flammable substances ignite on their own or in the presence of a fire source and continue to burn intensely.
The classification of flammability of construction raw materials and products is discussed in a separate updated standard. National construction standards take into account the categories of all types of products used in work.
According to this classification, non-combustible building materials (NG) are divided into two groups depending on the test mode and the values of the indicators obtained.
Group 1 includes products in which the temperature inside the oven increases by no more than 50 ℃. The reduction in sample mass does not exceed 50%. The flame does not burn at all, and the heat released does not exceed 2.0 MJ/kg.
Group 2 NG includes materials with the same indicators of temperature increase inside the furnace and weight loss. The difference is that the flame burns for up to 20 seconds, the heat of combustion should not be more than 3.0 MJ/kg.
Flammability classes
Combustible materials are examined according to similar criteria and are divided into 4 groups or classes, which are designated by the letter G and the number next to it. For classification, the values of the following indicators are taken into account:
- temperature of gases released with smoke;
- degree of size reduction;
- amount of weight reduction;
- flame retention time without a combustion source.
G1 refers to a group of materials with a smoke temperature not exceeding 135 ℃. The loss of length is 65%, weight loss is 20%. The flame itself does not burn. Such construction products are called self-extinguishing.
G2 includes a group of materials with a smoke temperature not exceeding 235 ℃. The loss of length is 85%, weight loss is 50%. Self-combustion lasts no more than 30 seconds.
G3 includes materials whose smoke temperature does not exceed 450 ℃. The loss of length is more than 85%, weight loss is up to half. The flame itself burns for no more than 300 seconds.
The G4 flammability group includes materials with a smoke temperature exceeding 450 °C. The loss of length exceeds 85%, weight - more than 50%. Self-combustion lasts more than 300 seconds.
It is acceptable to use the following prefixes in the name of each flammability group in order of increasing digital index:
- weak;
- moderately;
- Fine;
- highly flammable materials.
The given flammability indicators, along with some other characteristics, must be taken into account when developing project documentation, budgeting.
The ability to generate smoke, the toxicity of combustion products, the speed of possible fire spread, and the likelihood of rapid ignition are also of great importance.
Class confirmation
Samples of materials are tested in laboratories and open area according to standard methods separately for non-combustible and combustible building materials.
If the product consists of several layers, the standard requires testing for the flammability of each layer.
Determinations of flammability are carried out using special equipment. If it turns out that one of the components is highly flammable, then this status will be assigned to the product as a whole.
The installation for carrying out experimental determinations should be located in a room with room temperature, normal humidity, and without drafts. Bright sunlight or artificial light in the laboratory should not interfere with readings from the displays.
Before starting to study the sample, the device is checked, calibrated, and warmed up. Then the sample is fixed in the holder of the internal cavity of the furnace and the recorders are immediately turned on.
The main thing is that no more than 5 seconds have passed since the sample was placed. The determination is continued until a temperature balance is achieved, at which the changes do not exceed 2 °C over 10 minutes.
At the end of the procedure, the sample along with the holder is removed from the oven, cooled in a desiccator, weighed and measured, assigning them to the flammability group NG, G1, and so on.
Flammability test method
All building materials, including finishing, facing, paint and varnish coatings, regardless of homogeneity or multi-layering, are tested for flammability using a single method.
Pre-prepare 12 units of identical samples with a thickness equal to the actual values during operation. If the structure is layered, samples are taken from each surface.
The samples are then kept at room temperature and normal ambient humidity for at least 72 hours, weighing periodically. Aging should be stopped when constant weight is reached.
The installation has standard design, consists of a combustion chamber, an air supply system and the removal of released gases.
The samples are placed in the chamber one by one, measurements are taken, weight loss, temperature and amount of gaseous products released, and burning time without a flame source are recorded.
By analyzing all the obtained indicators, they determine the level of flammability of the material and its belonging to a certain group.
Application in construction
When constructing buildings, several different types building materials: structural, insulating, roofing, finishing with different purposes and loads. All products must have certificates available and be presented to potential buyers.
You should familiarize yourself with the parameters characterizing safety in advance and know exactly what each abbreviation and numbers can mean. The law requires use for frames construction ceilings only materials of flammability group G1 or NG.
GOST 30244-94 establishes methods for testing building materials for flammability and classifying them according to flammability.
The standard does not apply to varnishes, paints, and other building materials in the form of solutions, powders and granules.
The standard uses the following terms and definitions:
Sustained flaming combustion - continuous flaming combustion of materials for at least 5 s.
Exposed surface - the surface of the sample that is exposed to heat and/or open flame during a flammability test.
Building materials, depending on the values of flammability parameters determined by method I (intended to classify building materials as non-combustible or combustible), are divided into non-combustible and combustible.
Building materials are classified as non-combustible with the following values of flammability parameters:
temperature increase in the furnace is no more than 50°C;
sample weight loss no more than 50%;
Duration of stable flame combustion is no more than 10 s.
Construction materials that do not satisfy at least one of the specified parameter values are classified as flammable.
Combustible building materials, depending on the values of flammability parameters determined by method II (intended for testing combustible building materials in order to determine their flammability groups, are divided into four flammability groups: G1, G2, G3, G4. Materials should be assigned to a certain flammability group when provided that all parameter values set for this group correspond.
Table 3.1
Note. Flammability groups G1 and G2 are equated to the group of low-combustible building materials according to the classification adopted in GOST 12.1.044-89 and SNiP 2.01.02-85*.
Date of publication: 2014-10-30; Read: 1336 | Page copyright infringement
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13 Federal Law dated July 22, 2008 No. 123-FZ
The fire hazard of building materials is characterized by the following properties:
- flammability;
- flammability;
- ability to spread flame over a surface;
- smoke generating ability;
- toxicity of combustion products.
Based on flammability, building materials are divided into combustible (G) and non-combustible (NG).
Construction materials are classified as non-combustible with the following values of flammability parameters, determined experimentally: temperature increase - no more than 50 degrees Celsius, sample weight loss - no more than 50 percent, duration of stable flame combustion - no more than 10 seconds.
Construction materials that do not satisfy at least one of the parameter values specified in Part 4 of this article are classified as flammable. Combustible building materials are divided into the following groups:
1) low-flammable (G1), having a flue gas temperature of no more than 135 degrees Celsius, the degree of damage along the length of the test sample is not more than 65 percent, the degree of damage along the mass of the test sample is not more than 20 percent, the duration of independent combustion is 0 seconds;
2) moderately flammable (G2), having a flue gas temperature of no more than 235 degrees Celsius, the degree of damage along the length of the test sample is not more than 85 percent, the degree of damage along the mass of the test sample is not more than 50 percent, the duration of independent combustion is no more than 30 seconds;
3) normal-flammable (NG), having a flue gas temperature of no more than 450 degrees Celsius, the degree of damage along the length of the test sample is more than 85 percent, the degree of damage along the mass of the test sample is not more than 50 percent, the duration of independent combustion is no more than 300 seconds;
4) highly flammable (G4), having a flue gas temperature of more than 450 degrees Celsius, the degree of damage along the length of the test sample is more than 85 percent, the degree of damage along the mass of the test sample is more than 50 percent, and the duration of independent combustion is more than 300 seconds.
For materials belonging to flammability groups G1-GZ, the formation of burning melt drops during testing is not allowed (for materials belonging to flammability groups G1 and G2, the formation of melt drops is not allowed). For non-combustible building materials, other fire hazard indicators are not determined or standardized.
By flammability of combustible building materials (including floor carpets) depending on the value of the critical surface density heat flow are divided into the following groups:
1) hardly flammable (B1), having a critical surface heat flux density of more than 35 kilowatts per square meter;
2) moderately flammable (B2), having a critical surface heat flux density of at least 20, but not more than 35 kilowatts per square meter;
3) flammable (HF), having a critical surface heat flux density of less than 20 kilowatts per square meter.
According to the speed of flame spread over the surface, combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:
1) non-propagating (RP1), having a critical surface heat flux density of more than 11 kilowatts per square meter;
2) weakly propagating (RP2), having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;
3) moderately spreading (RPZ), having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;
4) highly propagating (RP4), having a critical surface heat flux density of less than 5 kilowatts per square meter.
According to their smoke-generating ability, combustible building materials, depending on the value of the smoke generation coefficient, are divided into the following groups:
1) with small smoke generating ability(D1), having a smoke generation coefficient of less than 50 square meters per kilogram;
2) with moderate smoke-generating ability (D2), having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;
3) with high smoke-forming capacity (S), having a smoke generation coefficient of more than 500 square meters per kilogram.
Based on the toxicity of combustion products, combustible building materials are divided into the following groups in accordance with Table 2 of the appendix to this Federal Law:
1) low-hazard (T1);
2) moderately dangerous (T2);
3) highly dangerous (HH);
4) extremely dangerous (T4).
Depending on the fire hazard groups, building materials are divided into the following fire hazard classes -
| Fire hazard properties of building materials | Fire hazard class of building materials depending on groups | |||||
| KM0 | KM1 | KM2 | KM3 | KM4 | KM5 | |
| Flammability | NG | G1 | G1 | G2 | G2 | G4 |
| Flammability | — | IN 1 | IN 1 | AT 2 | AT 2 | AT 3 |
| Smoke generating ability | — | D1 | D3+ | D3 | D3 | D3 |
| Toxicity of combustion products | — | T1 | T2 | T2 | T3 | T4 |
| Flame propagation over flooring surfaces | — | RP1 | RP1 | RP1 | RP2 | RP4 |
Fire hazard properties of building materials Fire hazard class of building materials depending on groups
materials KM0 KM1 KM2 KM3 KM4 KM5
Flammability NG G1 G1 G2 G2 G4
Flammability - B1 B1 B2 B2 B3
Smoke generating ability - D1 D3+ D3 D3 D3
Toxicity of combustion products - T1 T2 T2 T3 T4
Flame spread over the surface for flooring - RP1 RP1 RP1 RP2 RP4
The flammability group is a conditional characteristic of a certain material, reflecting its ability to burn. In relation to drywall, it is determined by conducting a special flammability test, the conditions of which are regulated by GOST 3024-94. This test is also carried out for other finishing materials, and based on the results of how the material behaves on test bench, it is assigned one of three flammability groups: G1, G2, G3 or G4.
Is drywall flammable or non-flammable?
All building materials are divided into two main groups: non-combustible (NG) and combustible (G). To qualify as non-combustible, the material must meet a number of requirements that are imposed on it during the testing process. A sheet of drywall is placed in an oven heated to a temperature of about 750 ° C and kept there for 30 minutes. During this time, the sample is monitored and a number of parameters are recorded. Non-combustible material must:
- increase the oven temperature by no more than 50 °C
- give a steady flame for no more than 10 s
- decrease in weight by no more than 50%
Plasterboard sheets do not meet these requirements and are therefore classified in group G (flammable).
Drywall flammability group
Combustible building materials also have their own classification and are divided into four flammability groups: G1, G2, G3 and G4.
The table below illustrates the standards that a material must meet to receive one of the four groups.
The specified parameters refer to samples that have passed the test using Method II, according to GOST 3024-94. This method involves placing the sample in a combustion chamber, in which it is exposed to a flame on one side for 10 minutes so that the temperature in the furnace ranges from 100 to 350 ° C, depending on the distance from the bottom edge of the sample.
In this case, the following characteristics are measured:
- Flue gas temperature
- The time it takes for the flue gases to reach their highest temperature
- Weight of the test sample before and after the test
- Dimensions of damaged surface
- Does the flame spread to that part of the samples that is not heated?
- Duration of burning or smoldering both during heating and after completion of exposure
- Time it takes for the flame to spread to the entire surface
- Does the material burn through?
- Is the material melting?
- Visual change appearance sample
Having collected and analyzed all the above indicators obtained in laboratory conditions, the material is assigned to one or another flammability group. Based on the figures that were recorded when testing a gypsum board sheet with dimensions of 1000x190x12.5 mm according to Method ll described above, it was found that the flammability group of plasterboard is G1. According to this group, the temperature of its flue gases does not exceed 135 °C, the degree of damage along the length of the sample is no more than 65%, damage by weight is no more than 20%, and the self-combustion time is zero.
Watch a visual process of testing drywall for flammability in the following video:
Fire hazard class
Standard partitions on a metal frame made of plasterboard sheets with an average density of 670 kg/m³ and a thickness of 12.5 mm according to GOST 30403-96 belong to fire hazard class K0 (45). This means that when an unloaded material was exposed to fire for 45 minutes, no vertical or horizontal damage was recorded in it, and there was no combustion or smoke formation.
At the same time, in practice, the load-bearing capacity of a single-layer plasterboard partition is lost after just 20 minutes of fire exposure to the surface of the material. In addition, it should be taken into account that Fire safety The specific plasterboard partition will depend on its design. Is it installed on metal carcass or at wooden sheathing whether there is a layer of insulation inside and whether it is flammable.
In addition to fire hazard and flammability, such characteristics as toxicity group of combustion products, smoke-generating ability group and flammability group are also applicable to plasterboard.
In terms of toxicity of combustion products, gypsum plasterboard sheets are classified as low-hazard (T1). The smoke-forming ability of a material characterizes it as having a low smoke-forming ability (D1) with a smoke generation coefficient of no more than 50 m²/kg (smoke optical density). For comparison, wood during smoldering has a value of this coefficient equal to 345 m²/kg. Flammability group for plasterboard B2 - moderately flammable materials.
Read also:
Fire-technical classification of building materials, structures, premises, buildings, elements and parts of buildings is based on their division according to properties that contribute to the occurrence of dangerous fire factors and its development - fire danger, and according to the properties of resistance to the effects of fire and the spread of its dangerous factors - fire resistance.
CONSTRUCTION MATERIALS
Building materials are characterized only by fire hazard.
The fire hazard of building materials is determined by the following fire-technical characteristics: flammability, flammability, flame spread over the surface, smoke-generating ability and toxicity.
Flammability of building materials.
Construction materials are divided into non-flammable (NG) And flammable (G). Combustible building materials are divided into four groups:
- G1(low flammability);
- G2(moderately flammable);
- G3(normally flammable);
- G4(highly flammable).
Flammability and flammability groups of building materials are established according to GOST 30244.
Flammability of building materials.
Combustible building materials are divided into three groups based on flammability:
- IN 1(flammable);
- AT 2(moderately flammable);
- AT 3(highly flammable).
Flammability groups of building materials are established according to GOST 30402.
Spread of flame over the surface of building materials.
Combustible building materials are divided into four groups according to the spread of flame over the surface:
- RP1(non-proliferating);
- RP2(low spreading);
- RP3(moderately spreading);
- RP4(highly spreading).
Groups of building materials for flame propagation are established for the surface layers of roofs and floors, including carpets, in accordance with GOST 30444 (GOST R 51032-97).
Smoke-forming ability of building materials.
Combustible building materials are divided into three groups according to their smoke-generating ability:
- D1(with low smoke-generating ability);
- D 2(with moderate smoke-generating ability);
- DZ(with high smoke-generating ability).
Groups of building materials according to smoke-generating ability are established according to GOST 12.1.044.
Toxicity of building materials.
Combustible building materials are divided into four groups based on the toxicity of combustion products:
- T1(low hazard);
- T2(moderately dangerous);
- TK(highly dangerous);
- T4(extremely dangerous).
Groups of building materials based on the toxicity of combustion products are established according to GOST 12.1.044.
BUILDING CONSTRUCTION
Building structures are characterized by fire resistance and fire hazard.
The fire resistance indicator is fire resistance limit, the fire hazard of a structure is characterized by Class her fire danger.
Fire resistance limit of building structures.
The fire resistance limit of building structures is established by the time (in minutes) of the onset of one or sequentially several signs of limit states, standardized for a given structure:
- losses bearing capacity (R);
- loss of integrity (E);
- loss of thermal insulation ability (I).
Fire resistance limits of building structures and their symbols installed according to GOST 30247.
In this case, the fire resistance limit of windows is established only by the time of loss of integrity (E).
Fire hazard class of building structures.
Based on fire hazard, building structures are divided into four classes:
- KO(non-fire hazardous);
- K1(low fire hazard);
- K2(moderate fire hazard);
- short circuit(fire hazardous).
The fire hazard class of building structures is established according to GOST 30403.
The Technical Code of Standard Practice establishes the fire-technical classification of building materials, products, structures, buildings and their elements. The regulatory act regulates the classification of materials, products and structures by fire hazard depending on fire-technical characteristics, as well as determination methods.
The fire hazard of building materials is determined by the following fire-technical characteristics or their combination:
Flammability;
Flammability;
Spread of flame over the surface;
Toxicity of combustion products;
Smoke generating ability.
Building materials, depending on the values of flammability parameters determined according to GOST 30244, are divided into non-combustible
and flammable. For building materials containing only inorganic (non-flammable) components, the characteristic is “flammability”
not determined.
Combustible building materials are divided depending on:
1. Values of flammability parameters determined according to GOST 30244 into flammability groups:
G1, slightly flammable;
G2, moderately flammable;
G3, normally flammable;
G4, highly flammable.
2. Values of critical surface heat flux density according to GOST 30402 for flammability groups:
B1, flame retardant;
B2, moderately flammable;
B3, highly flammable.
3. B values of critical surface heat flux density according to GOST 30444 into groups for flame propagation:
RP1, non-distributing;
RP2, weakly spreading;
RP3, moderately spreading;
RP4, highly spreading.
4. Lethal effect of gaseous combustion products from the mass of material per unit volume of the exposure chamber
according to GOST 12.1.044 into groups according to the toxicity of combustion products:
T1, low hazard;
T2, moderately dangerous;
T3, highly hazardous;
T4, extremely dangerous.
4. Values of the smoke generation coefficient according to GOST 12.1.044 into groups according to smoke generation ability:
D1, with low smoke-generating ability;
D2, with moderate smoke-generating ability;
D3, with high smoke-generating ability.
Flammability group– this is a classification characteristic of the ability of substances and materials to.
When determining the fire and explosion hazard of substances and materials (), there are :
- gases– these are substances whose saturated vapor pressure at a temperature of 25 °C and a pressure of 101.3 kPa exceeds 101.3 kPa;
- liquids– these are substances whose saturated vapor pressure at a temperature of 25 °C and a pressure of 101.3 kPa is less than 101.3 kPa. Liquids also include solid melting substances whose melting or dropping point is less than 50 °C.
- solids and materials– these are individual substances and their mixed compositions with a melting or dropping point greater than 50 ° C, as well as substances that do not have a melting point (for example, wood, fabrics, etc.).
- dust– These are dispersed solids and materials with a particle size of less than 850 microns.
One of the indicators of fire and explosion hazard of substances and materials is flammability group.
Substances and materials
According to GOST 12.1.044-89, in terms of flammability, substances and materials are divided into the following groups ( excluding construction, textile and leather materials):
- Non-flammable.
- Low-flammability.
- Flammable.
Non-flammable – these are substances and materials that are unable to burn in air. Non-flammable substances may be fire and explosion hazards (for example, oxidizers or substances that release flammable products when interacting with water, air oxygen, or with each other).
Low-flammability – these are substances and materials that can burn in air when exposed to an ignition source, but are unable to burn independently after it is removed.
Flammable – these are substances and materials that can spontaneously ignite, as well as ignite when exposed to an ignition source and burn independently after its removal.
The essence of the experimental method for determining flammability is to create temperature conditions conducive to combustion and assess the behavior of the substances and materials under study under these conditions.
Solid (including dust)
The material is classified as non-flammable if the following conditions are met:
- the arithmetic mean change in temperature in the oven, on the surface and inside the sample does not exceed 50 °C;
- the arithmetic mean value of mass loss for five samples does not exceed 50% of their mean value of the initial mass after conditioning;
- the arithmetic mean value of the duration of stable combustion of five samples does not exceed 10 s. The test results of five samples in which the duration of stable combustion is less than 10 s are taken equal to zero.
Based on the value of the maximum temperature increase (Δt max) and mass loss (Δm), materials are classified:
- flame retardant: Δt max< 60 °С и Δm < 60%;
- flammable: Δt max ≥ 60 °C or Δm ≥ 60%.
Combustible materials are divided depending on the time (τ) to reach (t max) into:
- hardly flammable: τ > 4 min;
- average flammability: 0.5 ≤ τ ≤ 4 min;
- flammable: τ< 0,5 мин.
Gases
In the presence of concentration limits flame propagation gas is classified as flammable ; in the absence of concentration limits for flame propagation and the presence of a self-ignition temperature, the gas is classified as flame retardant ; in the absence of concentration limits for flame propagation and auto-ignition temperature, the gas is classified as non-flammable .
Liquids
If there is an ignition temperature, the liquid is classified as flammable ; in the absence of an ignition temperature and the presence of a self-ignition temperature, the liquid is classified as flame retardant . In the absence of flash points, ignition, self-ignition, temperature and concentration limits for flame propagation, the liquid is classified as non-flammable . Flammable liquids with a flash point of not more than 61 ° C in a closed crucible or 66 ° C in an open crucible, phlegmatized mixtures that do not have a flash in a closed crucible are classified as flammable . Particularly dangerous These are flammable liquids with a flash point of no more than 28 °C.
Classification of building materials
Determination of the flammability group of a building material
The fire hazard of building, textile and leather materials is characterized by the following properties:
- The ability to spread flame over a surface.
- Smoke generating ability.
- Toxicity of combustion products.
Building materials, depending on the values of flammability parameters, are divided into groups into non-combustible and combustible (for floor carpets the flammability group is not determined).
NG (non-flammable)
Based on test results using methods I and IV (), non-combustible building materials are divided into 2 groups.
Construction materials are classified as non-combustible group I
- temperature increase in the oven no more than 30 °C;
- duration of stable flame combustion – 0 s;
- calorific value not more than 2.0 MJ/kg.
Construction materials are classified as non-combustible group II with the following arithmetic average values of flammability parameters according to methods I and IV (GOST R 57270-2016):
- temperature increase in the oven no more than 50 °C;
- weight loss of samples no more than 50%;
- the duration of stable flame combustion is no more than 20 s;
- calorific value not more than 3.0 MJ/kg.
Allowed to be classified as non-flammable group I without testing the following building materials without painting their outer surface or with painting the outer surface with compositions without the use of polymer and (or) organic components:
- concretes, mortars, plasters, adhesives and putties, clay, ceramic, porcelain stoneware and silicate products (bricks, stones, blocks, slabs, panels, etc.), fiber cement products (sheets, panels, slabs, pipes, etc.) with the exception of in all cases of materials manufactured using polymer and (or) organic binder fillers and fiber;
- inorganic glass products;
- products made from alloys of steel, copper and aluminum.
Building materials that do not satisfy at least one of the above specified values of parameters of I and II groups of non-combustibility belong to the group of combustibles and are subject to testing according to methods II and III (GOST R 57270-2016). For non-combustible building materials, other fire hazard indicators are not determined or standardized.
Combustible building materials, depending on the values of flammability parameters determined by method II, are divided into four flammability groups (G1, G2, G3, G4) in accordance with the table. Materials should be classified into a certain flammability group provided that all arithmetic mean values of the parameters specified in the table for this group correspond.
G1 (low flammable)
Low flammable – these are materials with a flue gas temperature of no more than 135 °C, the degree of damage along the length of the test sample is not more than 65%, the degree of damage along the mass of the test sample is not more than 20%, and the duration of spontaneous combustion is 0 seconds.
G2 (moderately flammable)
Moderately flammable – these are materials with a flue gas temperature of no more than 235 °C, the degree of damage along the length of the test sample is no more than 85%, the degree of damage along the mass of the test sample is no more than 50%, and the duration of independent combustion is no more than 30 seconds.
G3 (normally flammable)
Normally flammable – these are materials with a flue gas temperature of no more than 450 °C, a degree of damage along the length of the test sample of more than 85%, a degree of damage along the mass of the test sample of no more than 50%, and a duration of independent combustion of no more than 300 seconds.
G4 (highly flammable)
Highly flammable – these are materials with a flue gas temperature of more than 450 °C, a degree of damage along the length of the test sample of more than 85%, a degree of damage along the mass of the test sample of more than 50%, and a duration of independent combustion of more than 300 seconds.
Table
| Material flammability group | Flammability parameters | |||
| Flue gas temperature T, °C | Degree of damage along length S L, % | Damage level by weight S m, % | Duration of independent combustion t c.g, s | |
| G1 | Up to 135 inclusive | Up to 65 inclusive | Up to 20 | 0 |
| G2 | Up to 235 inclusive | Up to 85 inclusive | Up to 50 | Up to 30 inclusive |
| G3 | Up to 450 inclusive | Over 85 | Up to 50 | Up to 300 inclusive |
| G4 | Over 450 | Over 85 | Over 50 | Over 300 |
| Note. For materials belonging to flammability groups G1-G3, the formation of burning melt drops and (or) burning fragments during testing is not allowed. For materials belonging to flammability groups G1-G2, the formation of a melt and (or) melt drops during testing is not allowed. | ||||
Video, what is a flammability group
Sources: ; Baratov A.N. Combustion – Fire – Explosion – Safety. -M.: 2003; GOST 12.1.044-89 (ISO 4589-84) System of occupational safety standards. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination; GOST R 57270-2016 Construction materials. Combustibility test methods.
The fire hazard of building materials is characterized by the following properties:
- Flammability;
- Flammability;
- The ability to spread flame over a surface;
- Smoke generating ability;
- Toxicity of combustion products.
By flammability building materials are divided into combustible (G) and non-combustible (NG).
Construction materials are classified as non-combustible with the following values of flammability parameters, determined experimentally: temperature increase - no more than 50 degrees Celsius, sample weight loss - no more than 50 percent, duration of stable flame combustion - no more than 10 seconds.
Construction materials that do not satisfy at least one of the parameter values specified in Part 4 of this article are classified as flammable. Combustible building materials are divided into the following groups:
- Low-flammable (G1), having a flue gas temperature of no more than 135 degrees Celsius, the degree of damage along the length of the test sample is not more than 65 percent, the degree of damage along the mass of the test sample is not more than 20 percent, the duration of independent combustion is 0 seconds;
- Moderately flammable (G2), having a flue gas temperature of no more than 235 degrees Celsius, the degree of damage along the length of the test sample is not more than 85 percent, the degree of damage along the mass of the test sample is not more than 50 percent, the duration of independent combustion is not more than 30 seconds;
- Normally flammable (NG), having a flue gas temperature of no more than 450 degrees Celsius, a degree of damage along the length of the test sample of more than 85 percent, a degree of damage along the mass of the test sample of no more than 50 percent, and a duration of independent combustion of no more than 300 seconds;
- Highly flammable (G4), having a flue gas temperature of more than 450 degrees Celsius, a degree of damage along the length of the test sample of more than 85 percent, a degree of damage along the mass of the test sample of more than 50 percent, and a duration of independent combustion of more than 300 seconds.
For materials belonging to flammability groups G1-GZ, the formation of burning melt drops during testing is not allowed (for materials belonging to flammability groups G1 and G2, the formation of melt drops is not allowed). For non-combustible building materials, other fire hazard indicators are not determined or standardized.
By flammability combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:
- Refractory (B1), having a critical surface heat flux density of more than 35 kilowatts per square meter;
- Moderately flammable (B2), having a critical surface heat flux density of at least 20, but not more than 35 kilowatts per square meter;
- Highly flammable (HF), having a critical surface heat flux density of less than 20 kilowatts per square meter.
By flame propagation speed on the surface, combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:
- Non-propagating (RP1), having a critical surface heat flux density of more than 11 kilowatts per square meter;
- Low propagation (RP2), having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;
- Moderately spreading (RPZ), having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;
- Highly propagating (RP4), having a critical surface heat flux density of less than 5 kilowatts per square meter.
By smoke-generating abilities of combustible building materials, depending on the value of the smoke generation coefficient, are divided into the following groups:
- With low smoke-generating ability (D1), having a smoke generation coefficient of less than 50 square meters per kilogram;
- With moderate smoke-generating ability (D2), having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;
- With high smoke-generating capacity (SCP), having a smoke generation coefficient of more than 500 square meters per kilogram.
By toxicity combustion products, combustible building materials are divided into the following groups in accordance with Table 2 of the Appendix to this Federal Law:
- Low hazard (T1);
- Moderately dangerous (T2);
- Highly hazardous (HH);
- Extremely dangerous (T4).
Depending on the fire hazard groups, building materials are divided into the following: Fire hazard classes:
| Fire hazard properties of building materials | Fire hazard class of building materials depending on groups | |||||
| KM0 | KM1 | KM2 | KM3 | KM4 | KM5 | |
| Flammability | NG | G1 | G1 | G2 | G2 | G4 |
| Flammability | — | IN 1 | IN 1 | AT 2 | AT 2 | AT 3 |
| Smoke generating ability | — | D1 | D3+ | D3 | D3 | D3 |
| Toxicity of combustion products | — | T1 | T2 | T2 | T3 | T4 |
| Flame propagation over flooring surfaces | — | RP1 | RP1 | RP1 | RP2 | RP4 |
