Five Major Considerations for Steel Structure Projects
Steel structure fabrication includes many aspects such as placing, numbering, cutting, and calibration. The friction surface after high strength bolt treatment, the anti-slip coefficient should meet the design requirements.
After passing the production quality inspection, rust removal and painting are carried out. Generally leave 30-50mm at the installation weld without painting temporarily
Welders must pass the examination and obtain a certificate of competency, and must weld within the scope of their examination-qualified projects and their approval. Weld seam after welding shall be in the process of welding seams and parts of the welders steel seal.
Welding materials and base material should match, full weld penetration of the first and second welding seam should be used for internal defect inspection by ultrasonic flaw detection, ultrasonic flaw detection can not make a judgment on defects, the use of radiation flaw detection.
The first time the construction unit used steel, welding materials, welding methods, etc., welding process evaluation.
When transporting steel members, the vehicle should be selected according to the length and weight of the steel members. The pivot point of the steel member on the vehicle, the length of the two extremities and the tying method should ensure that the member does not produce deformation or damage the coating.
The steel structure shall be installed according to the construction organization design, and the installation procedure shall ensure the stability of the structure and not lead to permanent deformation. When installing columns, the positioning axis of each section shall be led directly from the ground control axis. The main components of the steel structure, such as columns, beams and roof frames, shall be corrected and fixed immediately after installation in position.
The friction surface of the members handled by the factory shall be rechecked for anti-slip coefficient before installation and shall be installed only after passing.
E.Fire and Rust
The fire resistance of steel structure is poor. When the temperature reaches 550℃, the yield strength of steel drops to about 0.7 of the yield strength at normal temperature, and the structure reaches its strength design value and may be damaged.
The design should be based on the provisions of the relevant fire codes, so that the building structure can meet the requirements of the corresponding fire standards. The temperature of the steel structure should not exceed the critical temperature during the time required by the fire protection standards to ensure the normal load-bearing capacity of the structure.
Exposed steel structures may be subject to severe corrosion, most commonly rust, by the atmosphere, especially by a polluted atmosphere. This necessitates anti-corrosion treatment of the surface of the members to ensure the normal use of the steel structure. The method of anti-corrosion treatment is decided according to the surface conditions of the members and the requirements of service life.