Will the fire protection of steel structures affect the safe use of buildings?
In steel structure design, steel structure buildings have the advantages of high strength, light weight, good seismic performance, high degree of industrialization, and fast construction speed. However, the heat-resistant defects of steel have a negative impact on the safety of steel structures. Therefore, the fire protection of steel structures directly affects the safety and use of buildings.
The fire is burning out of control and steel is a good building material but poor fire resistance. Unprotected building steel components suffer from strength reduction and creep at high fire temperatures. The strength of construction steel remains unchanged below 260°, and the strength begins to decrease from 260° to 280°. When it reaches 400°, the yield phenomenon of steel disappears and the strength drops obviously. When the temperature reaches 450°~500°, the strength drops rapidly due to the internal recrystallization of the steel.
Fire protection design content and measures
The fire protection design of the steel structure factory building firstly determines the fire hazard category of the factory building according to the production nature, process, raw materials and product types of the factory building, and reasonably determines the layout of the factory building, fire protection partition, smoke prevention partition, fire resistance level and fire resistance limit of components. Carry out necessary fire separation, and set up reasonable safety evacuation and smoke prevention and exhaust facilities. Design content includes architectural design, structural design and equipment design.
Fire prevention measures for steel structures include: spraying (smearing) fireproof paint, covering fireproof boards and flexible felt insulation materials, and wrapping concrete metal mesh with mortar or masonry.
The classification of steel structure fire retardant coatings is divided into ordinary steel structure fire retardant coatings (for general industrial and civil buildings) and special steel structure fire retardant coatings (for special projects) according to the objects of use. According to the site, it can be divided into outdoor steel structure fireproof coatings and indoor fireproof coatings. According to the dispersion medium, it can be divided into water-based and solvent-based steel structure fireproof coatings. According to the fire mechanism, it is divided into intumescent and non-expandable steel structure fire retardant coatings, and intumescent fire retardant coatings are divided into thin and ultra-thin types.
