Steel structure we should have learned, and now many high-rise buildings, factory buildings, warehouses, office buildings, hall are using this building structure. The construction of the main structure of the steel structure to ensure that the building has a good earthquake, wind, deformation resistance, but also to reduce the construction time and reduce construction costs. However, despite the steel structure has so much, but must pay attention to is that the corrosion resistance of steel and fire performance is relatively long, in the construction of steel structure must pay attention to the use of fire retardant coating.
First, the steel structure is simple to manufacture, the construction period of short steel structure used in the material is simple and is finished, the processing is relatively simple, and can use mechanical operation, therefore, a large number of steel structures are generally made in specialized metal structure components, accurate Higher degree. Components in the site assembly, you can use simple installation of ordinary bolts and high-strength bolts, and sometimes can be assembled in the ground and welding into a larger unit re-hoisting, Chongqing steel structure to shorten the construction period. In addition, the built-in steel structure is also relatively easy to alter and reinforcement, with a bolt-connected structure can also be demolition as needed.
Second, the weight of light steel structure, although the density of steel than concrete and other building materials, but the steel structure is stronger than the reinforced concrete structure, because the strength and density of steel ratio is much larger than the concrete. With the same span to bear the same load, steel roof truss up to no more than reinforced concrete roof trusses 1/3 to 1/4, cold-formed thin-walled steel roof truss even close to 1/10, to provide a convenient condition for lifting. Lightweight is also an important advantage for structures requiring long-distance transport, such as construction of mountainous and remote areas in inconvenient transportation.
Third, the strength of the material is high, the plasticity and the toughness of the steel and other building materials such as concrete, masonry and wood compared to the strength is much higher. Therefore, it is particularly suitable for large and large span components and structures. Steel also has a good plasticity and toughness characteristics. Good plasticity, the structure in the general conditions will not be due to overload and suddenly broken; toughness, the structure of the dynamic load of strong adaptability. Good energy absorption and ductility also make the steel structure has excellent seismic performance. On the other hand, since the strength of the steel is high, the cross-section of the member is small and the wall is thin, and the pressure is required to satisfy the stable requirement, and the strength can not be sufficiently exerted.
Fourth, the material is uniform, and the assumptions of the mechanical calculation are in line with the internal structure of the steel is relatively close to the homogeneous and isotropic, and in a certain range of stress is almost completely elastic. Therefore, the actual force of steel structure and engineering mechanics calculation results are more consistent. Chongqing steel structure engineering steel in the smelting and rolling process quality can be strictly controlled, material fluctuation range is small.
Fifth, of course, any kind of material is not perfect, the corrosion resistance of steel and fire resistance is more lack of protection in the structure of the cost of reinforced concrete than high. However, in the absence of corrosive media in the general plant, the components after a thorough rust and coated with qualified paint, corrosion problem is not serious. In recent years, the resistance to atmospheric corrosion of steel has good resistance to rust, has been gradually applied, and achieved good results. When the steel is subjected to 100 ℃ radiant heat for a long time, the strength does not change much. It has certain heat resistance, but when the temperature is above 150 ℃, it must be protected with the insulation. Steel is not fire, the important structure must pay attention to take fire prevention measures. For example, use vermiculite, vermiculite spray or gypsum board to protect.