This standard specifies the test apparatus, test-piece preparation, test operation, judgment of the residue length after test-piece combustion, judgment criteria and test report of difficult-flammability test for building materials.
This standard is applicable to the determination of difficult-flammability for building materials.
2 Normative References
The following documents contain provisions which, through reference in this standard, become provisions of this standard. For dated references, subsequent amendments to (excluding correction contents), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents apply. For undated references, the latest edition of the normative document referred to applies.
GB 8624-1997 Classification for Burning Behavior of Building Materials
GB/T 8626-1988 Test Method of Flammability for Building Materials
GB/T 8627-1999 Test Method for Density of Smoke from the Burning or Decomposition of Building Materials
3 Test Apparatus
The test apparatus of this method mainly include the combustion vertical furnace and test equipments.
3.1 Combustion vertical furnace
The combustion vertical furnace mainly comprises the combustion chamber, burner, test-piece support, air steady-state flow layer, gas flue and other parts. The overall dimension is 1020mm×1020mm×3930mm (see Figure 1 and Figure 2).
3.1.1 Combustion chamber
The combustion chamber consists of the furnace wall and furnace door, and the internal spatial dimension is 800mm×800mm×2000mm. The furnace wall is a thermal insulation sandwich structure and the structure form is detailed in Figure 2.
The furnace doors are divided into the upper door and lower door, which are connected with hinge and furnace body respectively, and the structure is similar to that of the furnace wall. The two doors are closed with the furnace body by means of hand wheels and fixed screw rods.
There are observation windows set in the upper furnace door and the back wall of the combustion chamber.
