First, the fire resistance of the building is poor and easy to collapse. Most of the color steel plate buildings use steel structure, and the fire temperature can reach 800 ~ 1000 ℃ in case of fire, which is far beyond the critical temperature of 500
℃ when the steel structure loses its static equilibrium stability. Under the condition of bearing load, the exposed steel structure will deform quickly, causing local damage and causing the overall collapse of the building. The ordinary color steel sheet
room will lose the bearing capacity and collapse about 10 minutes after the fire, which is not conducive to personnel evacuation and rescue materials.
Second, the core material is easy to ignite and spread rapidly. Most of the core filling materials of color steel plate are polyurethane, polystyrene and other flammable and combustible materials, with low ignition point and poor flame retardancy. Once high-temperature sparks, wire short-circuit beads or open fire are encountered, they will immediately burn, and the honeycomb structure of the material will increase the contact surface with air, resulting in violent combustion. Such buildings often have large space and lack of fire separation facilities. In case of fire, there are many ways to spread, and the fire develops rapidly, which is easy to form large area combustion and three-dimensional combustion.
Third, the narrow passageway in the building affects the evacuation. In order to pursue the use area, many users have not set aside the safety passageway and evacuation space that meet the requirements of the specification, and some even occupy the safe evacuation passageway to build color steel room. Once a fire occurs, the evacuation is hindered, and the consequences are unimaginable.
Fourth, the combustion products are toxic and difficult to escape. The polystyrene and polyurethane used in the core filling of color steel plate are polymer materials. The combustion will produce a lot of thick smoke, and contain a lot of toxic gases such as carbon monoxide and hydrogen cyanide. It has strong toxicity and irritation, and is easy to cause casualties of fire escape personnel and fire fighting personnel.
Fifthly, there are many disadvantageous factors in the fire and it is difficult to put out the fire. In the process of putting out the fire of color steel building, water and fire extinguishing agent can only be sprayed on the outer surface of color steel plate, and can not directly act on the combustor in the interlayer.