Determination of fire resistance is important extremely in construction and the industry. Understand ability of designs and materials during certain time without destruction as fire resistance to maintain influence of high temperatures. Not only to maintain, but in certain cases both to limit spread of fire and to keep the necessary functional performance.
Instruction
1. All construction materials and designs on inflammability are divided into three groups: fireproof, fire-resistant and combustible. Fireproof materials under the influence of fire or high temperature do not ignite. All this natural and artificial inorganic materials, plaster boards, mineral wool boards. Fire-resistant call those materials which under fire exposure smolder, and after removal of source of fire stop decay. It is asphalt concrete, gipsobetonny designs, wood subjected to deep impregnation by fire-retarding agents.
2. It is obvious that combustible materials under the influence of fire or high temperatures ignite and continue to burn after removal of source of fire. All this organic materials: wood, peat, tar, felt, paper.
3. However there is number of the construction materials which visually do not have naked flame at ignition, but capable to do harm to health flow products, emitting toxic gas.
4. The limit of fire resistance comes at emergence of any of signs: education in designs of cracks, rise of temperature on not warmed surface, loss by design of bearing capacity or full combustion of material.
5. Limits of fire resistance of materials or designs are defined by their fire tests. The standard fire is reproduced in the special furnaces which are laid out by refractory brick. The sample of design or material is established in the furnace and remains there after switching off of the furnace until when temperature in all measurement points does not begin to go down. Then on that time which the sample of design or construction material had spent in furnaces without damages the experts determine fire resistance limits by the above-stated description. The obtained data are used in construction when selecting materials and designs.