Steel structure engineering supervision control points

(1) Engineering material quality points:

1) Check the appearance quality and quality certification materials of steel, welding materials, bolts, bolts and other materials used in the project.
2) Urge the construction unit to carry out witness sampling and inspection of the shaped steel base metal, representative welded specimens, bolts, etc. according to the Provisions of the Ministry of Construction on the implementation of witness sampling and inspection of housing construction projects and Municipal infrastructure projects and the requirements of the standard, and the test unit shall issue a qualified test report with witness sampling.
3) Urge the construction unit to reasonably organize the supply of materials to meet the needs of continuous construction, strengthen the material management system such as transportation, storage, inspection and acceptance of on-site materials, and take protective measures such as moisture, dew and pollution prevention.
① Steel: should be clearly selected according to the design requirements of the steel grade, reference standard number, chemical composition and physical performance indicators. The supplier of raw materials shall provide complete warranty certificate and material test report. The variety, specifications and performance of steel and steel castings shall meet the current national product standards and design requirements, and the quality of imported steel shall meet the requirements of the design and contract standards. The supervisor shall require the steel structure contractor to submit the quality certification documents, Chinese marks and inspection reports to the supervisor for examination, and the supervision engineer shall inspect all of them.
② Welding materials: the varieties, specifications and performance of welding materials should meet the current national product standards and design requirements. The supervisor shall require the steel structure contractor to submit the quality certification documents, Chinese marks and inspection reports to the supervisor for examination, and the supervision engineer shall inspect all of them. The welding materials used in important steel structures were sampled and reinspected. The supervising engineer shall check the reinspection report.
(3) Fasteners for connection standard parts: steel structure engineering commonly used fasteners are high-strength bolts (divided into large hexagonal type and torsional shear type), ordinary bolts, anchor bolts, anchor bolts and other fastening standard parts, its variety, specifications, performance, etc., should meet the current national product standards and design requirements. The supervisor shall require the steel structure contractor to submit the product quality certification documents, Chinese marks and inspection reports to the supervisor for examination, and the supervision engineer shall inspect all of them.
(4) Welding balls: The supervisor shall require the contractor to provide the quality certification documents of the raw materials used for welding balls, Chinese marks and inspection reports, and non-destructive inspection reports of welding balls. The diameter, roundness and wall thickness reduction of welded ball were checked by calipers and metal thickness gauges.
⑤ Bolt ball: The supervisor shall require the contractor to provide quality certification documents, Chinese marks and inspection of raw materials used for welding balls. Check the surface quality of the bolt ball with a 10x magnifying glass. Spot check bolt ball thread size, diameter, roundness, center line Angle of adjacent two bolt holes and other dimensions.
⑥ Metal molding plate: metal molding plate, metal flooding plate, corner plate and spare parts and raw materials used, their varieties, specifications, performance, etc., should meet the current national product standards and design requirements. The Supervisor shall require the contractor to provide quality certification documents, Chinese marks and inspection reports of the products. Spot check the size deviation, surface and coating quality of the pressed metal plate (10x magnifying glass can be used).
⑦ Coating materials: The supervisor shall require the contractor to provide the product quality certification documents, Chinese marks and inspection reports of the materials. The variety and technical performance of the steel structure anticorrosive coating materials and fireproof coatings should meet the design requirements, and the fireproof coatings should be tested by qualified inspection institutions in line with the provisions of the current national standards, and confirmed by the local fire management department.
The control of raw materials and finished products of steel structure engineering is the key to ensure engineering quality certification, and is also one of the control points. The quality specifications and performance of all raw materials and finished products should meet national product standards and design requirements, and the quality certification documents and inspection reports of product positioning should be fully checked as the main control items.
⑨ For the welding materials used in the project, there should be a complete quality certificate, and bake according to the requirements of the manual before use. The supervising engineer shall check the validity of the quality certificate and the baking record of the welding material. Check the welder qualification certificate, including whether the examination qualification items can cover the actual welding content, and whether the qualification certificate is within the validity period. Check that the welding process assessment report item covers all joints of the project. Ultrasonic inspection must be carried out for first and second grade welds. For welds requiring pre-welding or post-welding heat treatment, the temperature between the welding passes during the entire welding process shall not be lower than the preheating temperature, and the preheating width on both sides of the weld shall not be less than 1.5 times the thickness of the welds. And should not be less than 100mm.
⑩ Supervision should be butt weld residual height, edge bite, surface welding nodules, shrinkage; Check the weld Angle size and the surface quality of the edge of the fillet weld by not less than 20%, and make inspection records. For stud welding supervisor should check the welding process evaluation report and porcelain ring baking record. After stud welding, the supervisor shall, together with the quality inspection personnel of the construction unit, select 10% of the similar components (no less than 10 pieces), and check 1% of the number of bolts for each piece to carry out bending test. After bending at 30° Angle, observe with the square and the naked eye, and all sides of the stud should be bent and fused with the welding part.
11. If the welding process evaluation is effective, the welding material quality certification documents are complete, the weld surface quality meets the requirements of the specification, the welding related dimensions meet the requirements of the drawings, the weld is qualified by non-destructive inspection, and there is an effective inspection report, the stud welding bending test is qualified and there is an inspection report, and the supervision inspection is qualified, the steel structure welding is qualified.