1. Production:
The production of steel structures includes many steps such as layout, marking, cutting, and calibration. The anti slip coefficient of the friction surface treated with high-strength bolts should meet the design requirements.
After passing the quality inspection, rust removal and painting shall be carried out. Generally, leave 30-50mm at the welding seam for temporary non painting.
2. Welding:
Welders need to pass the examination and obtain a certificate of qualification, and they need to perform welding within the scope of their examination qualification and recognition. After welding, the welder's steel seal must be stamped on the weld seam and the designated area specified in the process.
The welding material should match the base material, and the first and second level welds with full penetration should be inspected for internal defects using ultrasonic testing. When ultrasonic testing cannot make a judgment on defects, radiographic testing should be used.
The welding process evaluation shall be carried out for the steel, welding materials, welding methods, etc. used by the construction unit for the first time.
3. Transportation:
When transporting steel components, vehicles should be selected based on their length and weight. The pivot point, length of extension at both ends, and binding method of steel components on the vehicle should all be specified The component does not deform or damage the coating.
4. Installation:
The installation of steel structures should be carried out according to the construction organization design, and the installation procedures should be The stability of the structure and the ability to prevent long-term deformation. When installing the column, the positioning axis of each section of the column must be directly led up from the ground control axis. After the main components such as columns, beams, and roof trusses of steel structures are installed in place, they must be immediately calibrated and fixed.
The friction surface of the components processed by the factory must be retested for anti slip coefficient before installation, and can only be installed after passing the inspection.
5. Fire and rust prevention:
The fire resistance of steel structures is poor. When the temperature reaches 550 ℃, the yield strength of the steel decreases to approximately 0.7 of the yield strength at normal temperature, indicating that the structure has reached its strength design value and may undergo damage.
When designing, the building structure should meet the requirements of corresponding fire prevention standards in accordance with relevant fire prevention regulations. Within the time required by fire safety standards, the temperature of the steel structure should not exceed the critical temperature The normal load-bearing capacity of the structure.
Exposed steel structures may be severely corroded by the atmosphere, especially polluted air, and more commonly rust. This requires anti-corrosion treatment of the surface of the components The normal use of steel structures. The method of anti-corrosion treatment is determined based on the surface conditions and service life requirements of the components.
