The commonly used steel structures in the construction industry have many advantages such as light weight and recyclable materials. However, due to the inability of steel itself to withstand high temperatures, it affects the safety of steel structure buildings and hinders the development of steel structure manufacturers.
1. Application of fire-resistant and weather resistant steel in construction. Generally, steel has poor fire resistance, but relevant technical means can be used to change the material composition of the steel, add specific components, alter the microstructure and metallographic structure of the steel, and improve the fire resistance and weather resistance of the steel itself. This is fire-resistant and weather resistant steel. When the temperature reaches 600 ℃, the strength of this steel decreases by less than 30%. In addition, due to its excellent fire resistance, the thickness of the protective layer can be appropriately reduced during construction, and even anti rust paint can be omitted, which can save some costs. The application of fire-resistant and weather resistant steel is the fundamental solution and should be vigorously promoted. At present, many companies in China can produce fire-resistant and weather resistant steel for construction, which provides a good material source for steel structure buildings.
2. Adopt structural forms and components with strong fire resistance. The fire resistance performance of pure
steel structures is relatively poor, but they can be appropriately combined with concrete to form mixed components, or reinforced concrete structures can be directly used in some key areas. For example, steel reinforced concrete columns can be used for columns, which can effectively improve the fire resistance limit. Moreover, the larger the diameter of the steel pipe, the longer the fire resistance time. A circular steel reinforced concrete column with a diameter of 500mm can meet a fire resistance time of 3 hours when coated with 15mm thick insulation and fireproof coating. However, for components with high fire safety requirements such as floor slabs and stairs, reinforced concrete structures should still be used as much as possible.
3. Adopt a reasonable fire-resistant structural treatment plan for steel components. The fireproof construction method of steel structures should be reasonable, sturdy, economical, easy to construct, and conducive to decoration. When the enclosure or partition components of the non combustible material are on the same axis as the steel components, the non combustible wall itself can be used to provide fire protection for the steel components without the need for a separate fire protection layer. Reasonable fire-resistant construction methods should be adopted for exposed steel components.
4. Implement effective fire prevention methods. The commonly used fire prevention methods for steel structures include concrete external protection, external steel wire mesh cement mortar, external fireproof board, and spraying fireproof coating. External concrete protection involves completely wrapping steel components with concrete, and structural steel bars should also be installed in the concrete to prevent concrete from falling off. Steel wire mesh cement mortar fire prevention is a traditional construction method that uses metal mesh to apply 50 # mortar as a protective layer. External fireproof board can be wrapped around steel components with non combustible materials such as fiber-reinforced cement board, gypsum board, calcium silicate board, vermiculite board, etc.
The fire resistance of steel structures depends on the steel material. Steel itself does not burn and has good heat resistance. Based on the physical properties of steel, steel structures, as a green and environmentally friendly building structure, have become quite popular in developed countries. Do not let fire resistance hinder the progress of steel structure manufacturers. We should actively take various effective measures to improve the fire resistance of steel structures and accelerate their development.
