GB/T 29416-2026Test method for the fire performance of external wall insulation systems applied to building facades (English PDF)

4.6 Measurement System

4.6.1 Overview The measurement system consists of thermocouples, a data acquisition system, a camera, wind speed measuring equipment, and a timing device.

4.6.2 Thermocouples

4.6.2.1 General Provisions The thermocouple should be a type K armored thermocouple with an outer cable diameter D of (1.5±0.025) mm, conforming to GB/T 18404, for temperature measurement. The temperature range is (0~1000)°C, and the tolerance level is Class II. Thermocouples installed on the test apparatus are divided into external thermocouples and internal thermocouples. External thermocouples should be installed on horizontal alignment lines 1, 2, and

3.The measuring points of the external thermocouples should extend (50±5) mm beyond the outer surface of the external insulation system. The allowable deviation for the temperature measurement point location is ±10mm. Internal thermocouples should be installed on horizontal alignment lines 2 and

3.The temperature measuring points of the internal thermocouples should be arranged at the midpoint of the thickness of each structural layer of the insulation layer. At the core. When the insulation layer thickness is less than 10mm, thermocouples are not required. If the system contains cavities, the temperature measuring points of the internal thermocouples should be... They are positioned at the center of each cavity thickness. The allowable deviation for the temperature measurement point position is ±10mm.

4.6.2.2 External thermocouples on horizontal level line 1, horizontal level line 2, and horizontal level line

3 The installation method of the external thermocouples on horizontal level line 1, horizontal level line 2, and horizontal level line 3 is as follows:

---On the front of the main wall, thermocouples are installed on the vertical centerline of the combustion chamber opening and 500mm and 1000mm to each side of the centerline. Five temperature measuring points are set on each of the horizontal alignment lines 1, 2, and 3 (see Figure 1a);

---On the front of the secondary wall, thermocouples are installed at positions 150mm, 600mm, and 1050mm from the outer surface of the main wall's external insulation system. Three temperature measurement points are set on each of the horizontal alignment lines 1, 2, and 3 (see Figure 1b).

4.6.2.3 Internal thermocouples on horizontal alignment lines 2 and

3 The installation method of the internal thermocouples on horizontal alignment lines 2 and 3 is as follows:

---Within the main wall external insulation system, thermocouples should be installed on the vertical centerline of the combustion chamber opening and 500mm on each side of the centerline. At a position of 1000mm, five temperature measuring points are set on each of the horizontal alignment lines 2 and 3 (see Figure 1a).

---Inside the secondary wall external insulation system, thermocouples are installed at distances of 150mm, 600mm, and 1050mm from the outer surface of the main wall external insulation system. At the position, three temperature measuring points are set on each of the horizontal alignment lines 2 and 3 [see Figure 1b].

4.6.3 Data Acquisition System The data acquisition system should record data at intervals no greater than 3 seconds.

4.6.4 Camera Two cameras with a continuous recording time of no less than 90 minutes were used to continuously record the entire experiment. The camera angles should cover the entire experiment. The overall height of the two walls of the test device should be determined. HD mode with a resolution of at least 1920×1080 is recommended for video recording.

4.6.5 Wind speed measurement equipment Wind speed can be measured using equipment such as an anemometers, with a measurement accuracy of not less than ±

0.1 m/s.

4.6.6 Timing device The measurement accuracy of the timing device shall not be less than 0.1s.

5.2 Sample Dimensions and Installation

5.2.1 Before sample installation, the base wall of the test apparatus shall be treated in accordance with the provisions of

4.2 or the design requirements provided by the client. Base It should be flat, clean, and free of oil, release agents, or other substances that may hinder adhesion.

5.2.2 The installation of the specimen should not obstruct the combustion chamber opening.

5.2.3 On the main wall of the test apparatus, the specimen installation width should not be less than 2400mm, with one side close to the specimen surface on the secondary wall; the installation height should be greater than... The specimen is positioned 7700 mm above the top of the combustion chamber opening. The specimen can be extended downwards to the ground on either side of the combustion chamber opening.

5.2.4 On the secondary wall of the test apparatus, the specimen installation width should not be less than 1200mm, with one side close to the specimen surface on the main wall; the installation height should be the same as... The samples on the main wall were installed at the same height.

5.2.5 At the corner where the main wall and the secondary wall meet, the test specimens shall be prepared according to the actual construction of the external insulation system or as required by the testing client. Install.

5.2.6 The edges of the specimen around the combustion chamber opening shall be protected in accordance with the actual application structure of the external insulation system or the requirements of the test commissioning party. When the external insulation system is constructed without any opening protection measures in practical applications, the edges of the sample around the combustion chamber opening should remain uniform. Unprotected state.

5.2.7 When the external insulation system includes horizontal structural joints in actual application, the structural joints shall be constructed in accordance with the actual requirements specified by the testing commissioning party. The joints should be spaced out, and at least one horizontal structural joint should be provided at (2400±50) mm above the combustion chamber opening.

5.2.8 When the external insulation system includes vertical structural joints in actual application, the structural joints shall be constructed in accordance with the actual requirements specified by the testing commissioning party. The design should be spaced out, and a vertical structural seam should be provided extending upwards from the centerline of the combustion chamber opening, with its position relative to the centerline. The allowable deviation is ±100mm.

5.2.9 When the external insulation system is designed with fire-resistant barriers in practical applications, the fire-resistant barriers on the test specimens shall meet the requirements of the testing client. The distance between the two isolation strips should reflect the actual installation situation.

5.2.10 When the external insulation system is constructed with a keel in practical applications, the installation position of the keel should avoid the horizontal alignment line 1 and the horizontal alignment line 2. The distance between the upper edge of line 2 and horizontal alignment line 3 and horizontal alignment line 1, horizontal alignment line 2 and horizontal alignment line 3 should not be less than 100mm.

5.3 Basic performance characteristics of the specimen Before conducting fire resistance tests according to this document, the basic performance characteristics of the specimens shall be determined in accordance with the following provisions.

a) Test the combustion performance of the specimens according to GB 8624;

b) Test the apparent density of the insulation material used in the test specimens according to GB/T 6343;

7.4 Experimental Observation and Recording

7.4.1 After the heat source is ignited, the temperature of the external thermocouples on horizontal level line 1 should be measured and recorded. When the recorded temperature of any thermocouple is higher than the specified value, the temperature of the thermocouples should be recorded. The time when the initial temperature (T0) is.200°C and the duration reaches 30s is the start time of the experiment (ts).

7.4.2 During the test, the time when the combustion state of the sample and the stability of the system change should be observed and recorded. Combustion states include.

a) Complete combustion;

b) Continuously visible flame condition;

c) External flame spread, i.e., the temperature of any external thermocouple on horizontal level line 1, horizontal level line 2, or horizontal level line 3;

d) The internal flame propagation status, i.e., the temperature of any internal thermocouple on horizontal level line 2 and horizontal level line 3;

e) Condition of burning debris. System stability includes the occurrence of phenomena such as damage, peeling, and collapse of the entire or part of the sample, and the time it takes for these phenomena to occur.

7.5 Test Time The test duration should be 60 minutes. The heat source typically burns out within 30 minutes.

7.6 Early termination of the experiment The test should be terminated under the following conditions.

a) Safety risks to personnel and equipment arise;

b) The flame height of the external insulation system sample reached the horizontal level line 3, and the flame height lasted for 10 seconds.

8.Post-test inspection Within 24 hours after the test, while the testing apparatus has cooled naturally, the condition of the specimens should be inspected, including cracking, melting, deformation, and other defects. Layering and other phenomena may occur, but areas blackened or faded by smoke should not be considered. Depending on the inspection needs, some coverings on the sample may be removed. The following should be done. Records.

a) If smoldering is present, after 24 hours of testing, inspect the areas of the specimen damaged by smoldering in both the vertical and horizontal directions;

b) The extent of flame propagation on the sample surface in both vertical and horizontal directions;