Characteristics of steel structure and key points of material selection

1. Save construction period: the installation time of steel structure is short, and the construction steel structure components used for the project can be manufactured in a large scale and assembled on the spot, which can greatly shorten the construction time of the project and save time.

2 Enlarge reasonable indoor space: because the compressive strength of steel and the compressive strength against scoliosis are 1.5 times that of concrete, the cross-section can be reduced under the condition of equivalent compressive strength, thus increasing the reasonable space.

3 Recyclability: The engineering data of steel structure buildings can be recycled, which reduces a lot of urban waste.

4 The seismic grade function is good, because the steel frame structure belongs to the flexible structure and has light weight, which can effectively reduce the earthquake echo and disaster impact analysis, and is beneficial to the seismic grade.

5 Poor flame retardancy: the heat transfer coefficient of steel is far greater than that of concrete structure, and its fire protection function is also far worse than that of reinforced concrete. When the ambient temperature reaches 600 ℃, the steel frame structure will basically lose all its stiffness and strength. Therefore, fire resistance is taken as an important part in steel structure buildings.

6 Poor corrosion resistance: because the iron atoms on the surface of steel and the air in the air will form air oxidation rust, rust can cause stress, thus harming the safe use of steel structures and shortening the service life of steel structures, so reasonable anti-corrosion measures can be taken to ensure the service life of steel structures.

Key points of data variety

The steel shall have excellent assurance of compressive strength, tensile strength and S, P and C contents. The steel used shall have a steel quality inspection report, and its variety, specification, model and function shall comply with the provisions of China's product implementation standards, and its composition shall also comply with relevant requirements. On the premise that the surface quality of steel meets the current relevant standards in China, it should also meet the following requirements: when there are rust, black spots and other problems on the surface of steel, the defect depth should not exceed 1/2 of the negative deviation coefficient of the steel thickness; The welding wire flux on the connection data shall have the product quality qualification certificate and comply with China's regulations. The welding core shall not fall off, the welding core shall not be rusted, and the flux shall not be damped back. The purity of gas protection shall meet the construction technical regulations. When carbon dioxide is used as gas protection, the purity of carbon dioxide shall not be less than 99.5%, and its moisture content shall be less than 0.05%. The original spraying materials shall be provided with factory certificates and instructions, and shall comply with the national industrial standards and design key points. The color of architectural coatings shall be used according to the design key points. If necessary, a sample can be made. The technical functions of fire protection data shall meet the requirements of project construction and conform to the relevant provisions of technical standards through the inspection of the National Reliability Testing Center. The adhesive strength and tensile strength of the fire protection data shall be tested during use, and shall comply with the relevant provisions of the national industrial standards. The specification, variety and data of profiled sheet metal sheet shall conform to the design scheme and relevant standards of current national standards.