Why do modern buildings use steel structures

　　With the continuous growth of my country's steel production, the steel structure system has greatly promoted the rapid development of the construction industry. Why are more and more buildings (especially high-rise buildings) using steel structures? Xiao believes that more and more buildings are constructed with steel structures due to the four excellent properties of steel structures, which are light, fast, good and economical.
1 Light: The steel structure has the characteristics of light weight and good stress performance. Compared to concrete and wood, steel has the smallest ratio of density and strength. For example, under the same load strength conditions, the weight of a steel roof truss is only 30% or even 25% of the same concrete roof truss. The weight of the steel structure house is about 50% of the reinforced concrete house, but the usage area is about 4% of the reinforced concrete house.
2 Fast: The steel structure is processed and produced by the factory, which has the characteristics of mass production and high precision of finished products. The construction method of factory manufacturing and on-site high-strength bolt installation can effectively shorten the construction period and create conditions for reducing costs and giving full play to the economic benefits of investment. Under the same conditions, the steel structure project is only 1/3~1/2 of the reinforced concrete structure.
3 Good: The steel structure material has good performance and high reliability. The steel has uniform texture, isotropy, large elastic modulus, good plasticity and toughness, and is an ideal elastic plastic body. Therefore, the steel structure will not be suddenly broken and damaged due to accidental overloading or partial overloading. It can accommodate vibration loads. The calculation model can reflect the mechanical properties of steel well, and the analysis is accurate and reliable.
[4] Province: From the perspective of the current material price, the cost of steel structure is higher than that of concrete structure, but the construction speed of steel structure is about 50% faster than that of concrete structure, which will save a lot of time and cost; steel structure is more expensive than concrete structure. The overall weight of the structural house is more than 50% lighter, and the cost of foundation processing and transportation will be reduced. Building a house is a systematic project, including many links such as design, manufacture, transportation, installation, maintenance and management. Therefore, on the whole, the steel structure is more "saving".