What are the fire protection measures for steel structure buildings?
Introduction: Steel is a non-combustible building material, which has the characteristics of earthquake resistance and bending resistance. In practical applications, steel can not only increase the load capacity of buildings, but also meet the needs of architectural design aesthetic modeling, and also avoid the defects of concrete and other building materials that cannot be bent and stretched. Therefore, steel is favored by the construction industry. , Single-storey, multi-storey, skyscrapers, factories, warehouses, waiting rooms, waiting halls, etc. are all made of steel. However, as a building material, steel has some unavoidable defects in fire prevention. Its mechanical properties, such as yield point, tensile strength and elastic modulus, will drop sharply with the increase of temperature. The steel structure usually loses its bearing capacity at a temperature of 450 degrees Celsius to 650 degrees Celsius, and a large deformation occurs, resulting in the bending of steel columns and steel beams. As a result, due to excessive deformation, it cannot continue to be used. The fire resistance limit is about 15 minutes. The length of this time is also related to the rate at which the component absorbs heat. In order to overcome the deficiencies of fire protection in practical application of steel structure materials, fire protection treatment must be carried out, the purpose of which is to increase the fire resistance limit of steel structure to the limit range specified in the design specification. There are various measures to prevent the steel structure from rapidly heating up and deforming and slumping in a fire. The key is to take different methods according to different situations, such as using heat insulation and refractory materials to block the flame and directly burn the steel structure to reduce the speed of heat transfer. Delay the time for the temperature rise and strength weakening of the steel structure, etc. But no matter what method is adopted, the principle is the same. Therefore, the author believes that in reality, the four fire protection measures for steel structures must be paid attention to. 1. Outer layer. As the name implies, it is to add an outer layer to the surface of the steel structure and use the spraying method to construct. On-site spraying of steel structure surface with special spraying equipment“Jinma steel structure fireproof slurry (single component)”To form a protective layer, the thickness of the fireproof slurry can be designed according to the fireproof requirements, which can meet the fire resistance limit of more than 2 to 3 hours. It is a fireproof slurry with good performance and high cost performance on the market. 2. Water-filled water jacket. Filling the hollow steel structure with water is the most effective protective measure against fire. This method keeps the steel structure cooler in a fire, and water circulates within the steel structure, absorbing the heat of the material itself. The heated water can be recirculated after cooling or piped into cool water to replace the heated water. 3. Shield. The steel structure is set in the wall or ceiling composed of refractory materials, or the components are hidden in the gap between two walls, as long as a little refractory material is added or no increase, the purpose of fire prevention can be achieved. This is the most economical method of fire protection. 4. Intumescent material. The steel structure fireproof coating is used to protect the components. This method has the advantages of good fireproof and heat insulation performance, and the construction is not limited by the geometric shape of the steel structure. Generally, no auxiliary facilities need to be added, and the coating quality is light and has a certain aesthetic decoration effect. It belongs to modern advanced fire protection technology measures. At present, high-rise steel structure buildings are increasing day by day, especially some super high-rise buildings, which use steel structure more widely. Once a fire accident occurs in a high-rise building, the fire cannot be extinguished in a short period of time. This requires us to increase the fire protection of building materials in building design to enhance its fire resistance limit and formulate necessary emergency response inside the building. programs to reduce casualties and property damage.