Fire endurance time and fire prevention measures of steel structures

Fire endurance time and fire prevention measures of steel structures

Steel is a non combustible building material with seismic and flexural properties. In practical applications, steel can not only relatively increase the load capacity of buildings, but also meet the aesthetic modeling requirements of architectural design. It also avoids the defects of building materials such as concrete that cannot be bent or stretched. Therefore, steel structures are favored by the construction industry. It is common to use steel structures for single-storey, multi-storey, skyscrapers, factories, warehouses, waiting rooms, and waiting halls.

However, as a building material, steel has some unavoidable defects in terms of fire protection. Its mechanical properties, such as yield point, tensile strength, and elastic modulus, can sharply decline due to temperature increases, which in turn leads to building collapse. Therefore, fire protection measures must be taken for steel structure buildings.

Fire endurance time of steel structures

Steel structures usually lose their bearing capacity at temperatures of 450-650 degrees Celsius, causing significant deformation, leading to bending of steel columns and beams. As a result, it is impossible to continue using due to excessive deformation. Generally, unprotected steel structures have a fire resistance limit of about 15 minutes. The length of this time is also related to the speed at which the component absorbs heat.

Fire prevention measures for steel structures

1. Fireproof coating.

2. Fireproof board cladding.

3. Flexible fireproof blanket covering.

4. Concrete or metal mesh shall be coated with mortar.