Steel is a not a burning building materials, it has seismic, Flexural Properties. In practical applications, steel can be either relative increase in loading capacity of the building, can meet the needs of aesthetic style of architectural design, also avoided the defects of concrete and other construction materials cannot be bent, stretched, so favored by the construction industry of steel, single-layer, multi-layer, skyscrapers, workshop, storeroom, waiting room, Terminal is common with steel. However, the steel as a construction material in fire prevention and some of the pitfalls to avoid, and its mechanical properties, yield point, tensile strength and elastic modulus of temperature increases and sharp decline.
Steel structures normally would lose its bearing capacity in the 450~650℃ temperature, large deformation, resulting in bent steel columns, beams, and as a result too large deformations and are unable to use, generally without the protection of the fire resistance of steel structures for about 15 minutes.
This length of time is also associated with the component heat speed. Steel materials to overcome the lack of fire in the actual application, must be fire retardant, the purpose of which is to increase the fire resistance of steel structures to design specification limit. Prevent deformation in the steel in the fire to heat up rapidly collapse, a variety of measures, is the key according to the different situations in different ways, such as thermal insulation, refractory steel barrier to direct flame burning, slow down heat transfer delay steel temperature, strength weakening, and so on. But whatever the method, the principle is the same.