With the continuous progress of modern economy, the construction of cities is not backward.With the vigorous rise of high-rise buildings and the rise of building height, more and more people begin to pay attention to steel structure, because steel structure building has many advantages, such as high strength, light weight, good seismic performance, short construction period, low foundation cost, less occupied area of structure and high degree of industrialization.However, compared with the concrete structure, a significant weakness of steel structure is easy to conduct heat. When the surface temperature of steel reaches 400 ℃, its strength and elastic modulus will decrease significantly, while when the temperature reaches 600 ℃, the strength of steel for steel structure is almost zero.The fire resistance limit of bare steel is usually only 15-30 minutes. According to the requirements of China’s code for fire protection design of buildings, the fire resistance limits of main load-bearing components of buildings, such as columns, beams, walls and floors, are 0.5-3.0 hours respectively.Our country has clearly stipulated that fire prevention measures must be taken on steel structure, and the acceptance can only be passed if the corresponding national standards are met. 

There are various fire prevention treatment methods for steel structures. In the past, the methods of cast-in-place concrete outer layer, fire-retardant brick, gypsum board or hollow pipe internal water filling cooling were used in the past.Now more and more are used to spray fire retardant coating, anti-corrosion coating, fluorocarbon paint method to protect steel structure.Because of its good fire and heat insulation performance, the construction is not limited by the structure geometry, generally does not need to add auxiliary facilities, and the coating is light in weight, and has certain aesthetic decoration function, so it has been widely used.