GB/T 9978.10-2026Fire resistance tests of building elements - Part 10: Specific requirements for structural systems (English PDF)

6.4 Loading Conditions

6.4.1 The test load values for various load-bearing components in the structural system shall be in accordance with the relevant requirements for loading in GB/T 9978.1. Sure.

6.4.2 The loading conditions of load-bearing vertical partition members in the structural system shall comply with the relevant requirements for loading conditions in GB/T 9978.4.

6.4.3 The loading conditions of load-bearing horizontal partition members in the structural system shall comply with the relevant requirements for loading conditions in GB/T 9978.5.

6.4.4 The loading conditions of beam members in the structural system shall comply with the relevant requirements for loading conditions in GB/T 9978.6.

6.4.5 The loading conditions of column members in the structural system shall comply with the relevant requirements for loading conditions in GB/T 9978.7.

6.4.6 The loading conditions shall conform to the actual loading conditions of the structural system.

6.5 Environmental Conditions The test furnace should be installed in a laboratory, and the size of the laboratory should meet the test requirements. At the start of the test, the ambient temperature should be recorded as the initial temperature. temperature.

6.6 Deviation of test conditions During the test, if the furnace temperature, furnace pressure, or ambient temperature exceeds the upper limit of the deviation of the structural system's fire-exposed conditions, the structural system under such circumstances... The test results are still considered valid.

7.1 General Rules

7.1.1 The structural system specimens selected for the test should be representative in terms of materials, structure, manufacturing process, and installation method, and should preferably be similar to those used in actual applications. The situation is consistent.

7.1.2 When installing structural system specimens within a specific support and constraint frame, it should be ensured that the installation method and the frame itself do not affect the performance of the specimens. To ensure the validity of the experimental results, it is necessary to take measures to avoid significant impacts.

7.1.3 When the structural system includes auxiliary components in practical applications, the auxiliary components should participate in the overall test as part of the test specimen, and Its installation status should be consistent with its actual usage status.

7.2 Specimen Dimensions The specimens should preferably be the actual dimensions of the structural system. If the specimens cannot be tested according to the actual dimensions, a scaled-down model can be used to test the specimens.

Note. Scaled-down model testing refers to using a model smaller than the prototype, without requiring strict similarity conditions, to verify design theory, design assumptions, and calculations. Tests whose main objective is to conduct experiments using methods are also known as small component tests.

7.3 Number of Specimens

7.3.1 For each structural system with specified support structures or constraints, at least one representative specimen shall be selected for fire resistance testing. test.

7.3.2 When a structural system is used in practical applications, changes in external factors such as load-bearing conditions, constraints, installation location, and fire location may lead to... When the fire resistance performance of the structural systems varies significantly, a sufficient number of tests should be selected based on different combinations of test conditions and numerical simulation analysis. Representative specimens were subjected to fire resistance tests.

7.4 Specimen Curing The curing of specimens shall comply with the relevant requirements for specimen curing in GB/T 9978.1.

7.5 Specimen Installation and Constraints

7.5.1 The installation of test specimens should be based on the actual usage conditions of the structural system and in accordance with the methods and procedures recommended by the client.

7.5.2 The furnace interior portion of the specimen should be installed on the furnace bottom support foundation, and should be protected against conditions such as high-temperature expansion, deformation, and movement of the specimen. Under these conditions, reliable support conditions for the specimen should be continuously ensured.

7.5.3 Constraints and support frames shall be provided to limit the high-temperature expansion, deformation and movement of the specimen.

7.5.4 All gaps between the specimen and the constraint support frame shall be sealed with fire-resistant sealing material to prevent the escape of hot fumes. Sealing operation No additional constraints should be imposed on the test specimens.

7.5.5 After the specimen is installed in the furnace, a distance of not less than 500 mm should be maintained between the perimeter of the specimen and the furnace wall.

7.5.6 The installation method of the test specimens should not affect the uniform mixing of high-temperature flue gas in the furnace and normal exhaust.

7.5.7 The support and constraint conditions of the specimen shall be described in detail in the test report and test results.

7.6 Specimen Validation Before the test, the client shall provide the laboratory with the test specimen, along with all structural details, drawings, main components, and their manufacturers and suppliers. List of suppliers. The laboratory shall conduct consistency testing on the test specimens based on the provided information and address any discrepancies as early as possible before the start of the test. The laboratory may request one or more spare specimens with the same structure for component analysis. If the structural consistency of the specimen in all directions cannot be verified before the test, and sufficient data cannot be obtained after the test, then it is necessary to rely on a commissioned contractor. When providing information, this situation should be clearly stated in the test report. The laboratory should still provide a comprehensive and detailed description of the specimen design in the test report. A correct assessment, and accurate and complete recording of its structural details.

8.1 Temperature Measurement

8.1.1 Furnace Thermocouples The following are the regulations for the number, location, and arrangement of thermocouples used for temperature measurement inside the test furnace.

a) The thermocouples used to measure the temperature inside the furnace should be uniformly distributed in three dimensions, and the temperature value of the heated space in the test furnace should be reflected in real time through the measurement and control system. Thermocouples should be evenly distributed within a range of (100±10) mm from the surface of the specimen, and the number of thermocouples should be based on the minimum rule of containing the specimen. The surface area of the specimen should be calculated based on no less than one specimen per

1.5 m^2. For special parts of the specimen (such as nodal areas), the required number of specimens may be adjusted accordingly. Increase the number of thermocouples.

b) The thermocouples shall not be directly impacted by the burner flame, and their placement shall be at least [distance] from all side walls, bottom surface, and top surface of the furnace. 450mm.

c) The thermocouple is securely fixed to ensure that it does not move during the fire resistance test.

d) At the start of the test, the number (n) of effective thermocouples in the furnace should not be less than the minimum number required in 8.1.1a). During the test, if If individual thermocouples are damaged, reducing the number of effective thermocouples in the furnace to (n-1), no measures need to be taken, and the test can continue; if If the number of effective thermocouples in the furnace is less than (n-1), damaged thermocouples should be replaced promptly to ensure effective thermocouple operation throughout the entire test. The number of thermocouples is always no less than (n-1).

e) The operating status of the thermocouples should be checked before each test, and any damaged, worn or malfunctioning thermocouples should be replaced in time.

f) The thermocouple's sensing end should not be embedded in or in contact with the test piece. Otherwise, appropriate failure criteria should be established or clear provisions should be added. Additional information will be provided to minimize its impact.

8.1.2 Test Specimen Thermocouple

8.1.2.1 Back-side thermocouple For specimens containing partition components such as walls and floors, thermocouples should be installed on the unexposed side of the specimen to monitor temperature changes on that side. The requirements and arrangement of thermocouples shall comply with the relevant provisions of GB/T 9978.1 regarding unexposed thermocouples. During the test, any suspected high-temperature points should be measured using a movable thermocouple, and the method of use should comply with GB/T 9978.1. The relevant requirements for mobile thermocouples in China.

8.1.2.2 Internal thermocouple When it is necessary to obtain the internal temperature of a test specimen or special accessory, an internal thermocouple may be used, and its usage method should be based on the individual building component. The actual functional classification conforms to the relevant requirements for internal thermocouples in GB/T 9978.1.

8.1.3 Ambient temperature thermocouple To measure ambient temperature, the thermocouple (or platinum resistance thermometer) should be installed within (1000±500) mm of the unexposed surface of the specimen, but not... It should be affected by thermal radiation from the specimen and/or the test furnace.

8.2 Pressure Measurement

8.2.1 The pressure measuring probe should be installed in a location that facilitates the measurement and monitoring of the furnace pressure, and should not be located on the flue gas pipe or directly exposed to the flame airflow. The impact point should be positioned correctly. The probe measuring tube should be kept horizontal to ensure that the pressure measurement points inside and outside the furnace are at the same height. If using a "T" shaped probe... The measuring probe and the "T"-shaped branch pipe should be kept horizontal. The output of the furnace pressure measuring instrument should be kept at the indoor ambient temperature.

8.2.2 There should be no fewer than four pressure measuring probes, two of which should be placed at a neutral pressure at a height of 500mm above the bottom of the furnace in the heating space. On a plane, at corresponding positions within the same horizontal plane, one is used to measure and control the pressure inside the furnace, and the other is used to measure the pressure of the former. The probes were calibrated. The other two probes were positioned 100mm below the top of the heating space inside the furnace, corresponding to each other on the same horizontal plane. Different locations.

Note. The neutral pressure plane refers to the theoretical interface where the pressure inside and outside the furnace is equal.

8.3 Deformation Measurement

8.3.1 Deformation measuring instruments are used to measure the deformation rate and total deformation of specimens during fire resistance tests, or the total deformation after the test.

8.3.2 Load the specimen 15 minutes before the fire resistance test. After the specimen deformation stabilizes, the measured deformation value shall be taken as the deformation value of this test. Midnight.

8.3.3 Among all the individual building components included in the specimen, relevant components are selected as the objects for measuring deformation and displacement. The measurement of deformation and displacement... Multiple measurements should be taken at different locations on the selected component, and the measurement accuracy should reach

0.1 mm.

8.3.4 The deformation measurement of load-bearing vertical partition members in the structural system shall comply with the relevant provisions of GB/T 9978.4 regarding deformation measurement. Require.

8.3.5 The deformation measurement of load-bearing horizontal partition members in the structural system shall comply with the relevant requirements for deformation measurement in GB/T 9978.5.

8.3.6 The deformation measurement of beam members in the structural system shall comply with the relevant requirements for deformation measurement in GB/T 9978.6.

8.3.7 The deformation measurement of column members in the structural system shall comply with the relevant requirements for deformation measurement in GB/T 9978.7.

8.3.8 Deformation measuring instruments should preferably be installed in locations unaffected by the high temperatures inside the furnace. When deformation measuring instruments may be exposed to high temperatures, they should be... Materials less susceptible to high-temperature interference are used, and fire protection measures can be implemented to protect the deformation measuring instrument, ensuring the validity of the measurement data. In the structure... During the fire resistance test of the system, effective measures should be taken to prevent the deformation measuring instrument from being damaged by high temperature.

8.3.9 High-temperature strain gauges may be selectively placed at key locations on the specimen to continuously collect deformation data throughout the entire process from the start of stress on the specimen until failure. data.

8.4 Fire resistance integrity monitoring The instruments used for measuring the fire resistance integrity of the specimens shall comply with the relevant requirements for fire resistance integrity observation in GB/T 9978.1.

8.5 Image Acquisition

8.5.1 Image acquisition instruments can be used to observe and record the overall or local deformation characteristics of the specimen and the changes in the fireproof protective layer during the fire resistance test. The cracking and detachment process can be used to record unexpected events inside the furnace.

8.5.2 The field of view of the image acquisition instrument can cover the entire specimen or only a key local part of the specimen, but it should ensure that the observe...