1、 Mobilization of raw materials and finished products

01

Basic requirements and contents

(1) Raw materials and finished products shall be provided with quality certificate, Chinese mark and factory inspection report.

(2) Steel

 1）The variety, specification and performance of steel and steel castings shall meet the current national product standards and design requirements.The quality of imported steel products shall meet the requirements of design and contract standards, and shall be attached with commodity inspection certificate.

2）The steel under one of the following conditions shall be sampled for re inspection:

a. Imported steel products;

b. Steel mixed batch;

c. Thick plates with thickness equal to or greater than 40mm and designed with Z-direction performance requirements;

d. The safety level of the building structure is grade I, and the steel used in the main load-bearing components of the long-span steel structure;

e. Design steel with re inspection requirements;

f. The quality of steel is questionable.

The re inspection results should meet the current national product standards and design requirements

(3) Welding materials

1）The variety, specification and performance of welding materials shall meet the current national product standards and design requirements.

2）The welding materials used in important steel structures shall be sampled and retested, and the re inspection results shall meet the current national product standards and design requirements.

(4) Standard fastener for connection

 1）High strength large hexagon head bolt connection pair for steel structure connection, torsion shear type high strength bolt connection pair, high strength bolt for steel grid, ordinary bolt, rivet, self tapping screw, pull rivet, shooting screw, anchor bolt (mechanical type and chemical reagent type), anchor bolt and standard accessories such as nut and washer shall be in accordance with current national products.Standards and design requirements.The inspection report of torque coefficient and tightening axial force (pretension) shall be provided with the box for high strength large hexagon head bolt connection pair and torsion shear type high strength bolt connection pair.

2）The torque coefficient of high strength large hexagon head bolt connection pair shall be rechecked according to the current national standard code for acceptance of construction quality of steel structures (GB 50205), and the inspection results shall meet the requirements.The bolts for re inspection shall be randomly selected from the bolts to be installed on the construction site, and 8 sets of connection pairs shall be selected from each batch according to the specification for re inspection.

3）The pre tension of torsion shear type high strength bolt connection pair shall be rechecked according to the provisions of the current national standard code for acceptance of construction quality of steel structures (GB 50205), and the inspection results shall meet the requirements.The bolts for re inspection shall be randomly selected from the bolts to be installed on the construction site, and 8 sets of connection pairs shall be selected from each batch according to the specification for re inspection.

4）For steel grid structure with bolt ball joints, tensile load or surface hardness test shall be carried out for connecting high-strength bolts. The value shall conform to the provisions of the current national standard “high strength bolts for bolted spherical joints of steel grid” GB / t16939 or mechanical properties of fasteners, bolts, screws and studs gb3098.1.The surface hardness of grade 8.8 high-strength bolt should be hrc21-29; the surface hardness of grade 10.9 high-strength bolt should be hrc32-36, and there should be no crack or damage.Inspection quantity: every 600 bolts of the same specification are regarded as a batch, and less than 600 bolts are still counted as one batch. Three bolts from each batch are selected as a random inspection group.

5）The tensile strength of the bolts with the minimum load inspection requirements shall meet the design requirements. When there is no design requirement, it shall meet the requirements of the current national standard mechanical properties of fasteners bolts, screws and studs (gb3098.1) or other current national product standards.The bolts for re inspection shall be randomly selected from the bolts to be installed on the construction site, and 8 sets of connection pairs shall be selected from each batch according to the specification for re inspection.

(5) Welding ball

1）The variety, specification and performance of the welding ball and the raw materials used for manufacturing the welding ball shall meet the current national product standards and design requirements.

2）Non destructive inspection shall be carried out for the welded ball weld, and its quality shall meet the design requirements. If there is no design requirement, it shall comply with the secondary quality standard specified in code for acceptance of construction quality of steel structure engineering (GB 50205). The inspection quantity: 5% of each specification shall be selected according to the quantity, and no less than 3.Welding ball weld inspection shall be carried out in accordance with the current industry standard “method for ultrasonic testing and quality classification of welded ball joint steel grid structure” JG / t3034.1.

3）The welded spherical joints shall be welded into test pieces according to the design specification of balls and their matching steel pipes, and the axial tension and compression bearing capacity tests shall be conducted. The test failure load value is more than or equal to 1.6 times of the design bearing capacity.Inspection quantity: in each project, 600 welding balls of the same specification with the most unfavorable stress are taken as a batch, and less than 600 balls are still counted as a batch, and 3 balls from each batch are selected as a random inspection group.

(6) Bolt ball

1）The variety, specification and performance of the bolt ball and the raw materials used for manufacturing the bolt ball joint shall meet the current national product standards and design requirements.

2）The bolt ball shall be free from over burning, cracks and wrinkles.Inspection quantity: 5% for each specification, and no less than 5 pieces.

3）The tensile strength guarantee load test shall be carried out for the bolt ball joint according to the maximum bolt hole thread of the ball specified in the design. When the design bearing capacity of the bolt is reached, the bolt hole, thread and sealing plate are still intact.Inspection quantity: in each project, 600 welding balls of the same specification with the most unfavorable stress are taken as a batch, and less than 600 balls are still counted as a batch, and 3 balls from each batch are selected as a random inspection group.

(7) Grid member

1）The tensile strength of the connecting weld between the steel pipe of the rod and the sealing plate or cone head shall comply with the provisions of the current industry standard “bolt ball joint of steel grid” jg10 or “standard for quality inspection and evaluation of grid structure” jgj78.Inspection quantity: 300 bars of the same specification shall be taken as a batch. If less than 300 bars are still counted as a batch, 3 bars from each batch shall be randomly selected.

2）The butt welds at both ends of the steel pipe of the member shall be subject to non-destructive inspection, and its quality shall meet the design requirements. If there is no design requirement, it shall comply with the secondary quality standard specified in code for acceptance of construction quality of steel structure engineering (GB 50205), and 20% of the number of welding seams of the rod joint shall be inspected.The welding seam inspection of rod shall be carried out in accordance with the current industry standard “ultrasonic testing and quality classification method for welded joints of space truss with bolt ball joints” (JG / t3034.2).

(8) Sealing plate, cone head and sleeve

1）The variety, specification and performance of the sealing plate, cone head and sleeve and the raw materials used for manufacturing the sealing plate, cone head and sleeve shall meet the current national product standards and design requirements.

2）The appearance of sealing plate, cone head and sleeve shall be free of cracks, over burning and oxide scale.

(9) Metal profiled plate

1）The varieties, specifications and properties of metal profiled plates and raw materials used for manufacturing metal profiled plates shall meet the current national product standards and design requirements.

2）The varieties and specifications of profiled metal flashing plate, corner plate and spare parts as well as the performance of waterproof and sealing materials shall meet the current national product standards and design requirements.

(10) Coating materials

1）The varieties, specifications and properties of anti-corrosive coatings, diluents and curing agents for steel structures shall meet the current national product standards and design requirements.

2）The variety and technical performance of fire retardant coating for steel structure shall meet the design requirements, and shall be tested by a qualified testing organization, in accordance with the provisions of the current national standards.

(11) Others

1）The variety, specification and performance of rubber pad for steel structure shall meet the current national product standards and design requirements.

2）The variety, specification and performance of other special materials involved in steel structure engineering shall meet the current national product standards and design requirements.

02

Verification method

(1) According to the structural design of the unit project, design change documents and raw material batching summary table, check whether the raw materials are consistent with the type and specification of raw materials in the factory certificate (commodity inspection certificate) and test report, whether sampling is carried out in batches, and whether the sum of batches represented by sampling is consistent with the actual consumption.

(2) Check whether the test (re inspection) results of raw materials or finished products meet the requirements of standards, specifications and procedures.

(3) Check whether the project name in the certificate and test (re inspection) report is consistent with the actual project, whether the technical data meet the standard requirements, whether the test method and calculation conclusion are correct, whether the test items are complete, and whether they conform to the principles of test before use, acceptance before concealment.

(4) Check whether there is calculation sheet and design visa for the replacement of raw materials or finished products, and whether the calculation results meet the requirements of current standards and specifications.

03

Principle of verification

In case of any of the following situations, the project is approved as “not meeting the requirements”.

(1) There is no factory certificate or test report for raw materials or finished products.

(2) The varieties, specifications and design documents of raw materials or finished products are inconsistent, and there is no replacement design visa.

(3) The sampling inspection quantity of raw materials or finished products is insufficient, or the performance test items are not complete, or a certain performance index is unqualified, and the re inspection is not carried out according to the provisions, and the identification treatment is not conducted.

(4) The technical indexes of imported steel products are not up to the corresponding domestic steel technical standards and have not been identified.

2、 Steel structure welding engineering

01

Basic requirements and contents

(1) The matching of welding materials such as welding rod, welding wire, flux, electroslag welding nozzle and base metal shall meet the design requirements and the current industry standard “technical specification for welding of steel structures of buildings” (jgj81).Welding rod, flux, flux cored wire, welding nozzle, etc. shall be baked and stored according to the provisions of product instructions and welding process documents before use.

(2) The welder must pass the examination and obtain the qualification certificate.The welder with certificate must carry out welding in the qualified items and the scope of approval.

(3) Welding procedure qualification shall be carried out before fabrication and installation of steel structure members if one of the following conditions is met:

   1）Steel products used in steel structure engineering for the first time in China (including steel grades consistent with standards but different types and supply status of microalloyed strengthening elements, or domestic production of foreign steel grades);

   2）Welding materials used in steel structure engineering for the first time in China;

   3）It is the first time for construction enterprises to adopt the combination conditions of various parameters such as steel type, welding material, welding method, joint form, welding position, post weld heat treatment method, welding process parameters and prognosis thermal measures adopted by the construction company.

(4) According to the design requirements, ultrasonic flaw detection shall be used for internal defects inspection of grade I and II welds with full penetration. If ultrasonic flaw detection can not judge the defects, radiographic inspection shall be adopted. The classification and detection method of internal defects shall comply with the current national standard “manual ultrasonic wave inspection methods and classification of flaw detection results for steel welds” (GB 11345) or “radiographic inspection of steel fusion welded butt joints”Photography and quality classification (gb3323).

   The internal defect classification and flaw detection method of welded spherical node grid frame weld, bolt ball node grid frame weld and circular tube T, K, Y-shaped joint welding seam shall comply with the current industry standard JGJ / t3034.1 and JGJ / t3034.2, respectively.Technical specification for welding of building steel structure (jgj81).

The quality grade and defect classification of grade I and II welds shall meet the requirements in the table below.

 1、 Grade II weld quality grade and defect classification

(5) For T-joint, cross joint, corner joint and other butt and corner joint joint that require penetration, the weld leg size shall not be less than t / 4 (t is the thickness of the thin plate, the same below); the weld leg size of the connecting weld between the web plate and the upper flange of crane beam or similar components designed with fatigue check calculation requirements shall be t / 2, and shall not be greater than 10 mm.The allowable deviation of weld leg size is 0 ~ 4mm.Inspection quantity: all data shall be inspected; 10% of similar welds shall be sampled and no less than 3.

(6) The weld surface shall be free of defects such as crack and weld bead.There shall be no surface porosity, slag inclusion, arc pit crack, arc scratch and other defects on the first and second level welds, and no undercut, incomplete welding, root shrinkage and other defects shall be found in the first level weld.See quality control (construction) table 4.1.8.4-13 for appearance inspection report of weld surface.Inspection quantity: 10% of each batch of similar components shall be sampled, and no less than 3 pieces; among the components inspected, 5% of each type of weld shall be sampled, and no less than 1 piece; each inspection shall be conducted at 1 place, and the total number of spot checks shall not be less than 10.

(7) The welding procedure qualification shall be carried out by the construction unit for the welding of the welding nails and steel, and the results shall meet the design requirements and the provisions of the current national standards.Porcelain rings should be baked according to the product instructions.Welding procedure qualification report and baking record shall be provided.

(8) After welding, bending test shall be carried out for the stud, and there shall be no visible crack in the weld and heat affected zone.Inspection quantity: 10% of each batch of similar components shall be sampled, and no less than 10 pieces shall be inspected; among the inspected components, 1% of the number of welding pins shall be inspected for each piece, but not less than 1.

02

Verification method

(1) Check whether the quality certificate of welding materials and the varieties and specifications of welding materials are consistent with the structural design and design change documents of the unit project.

(2) Check whether the welder’s qualification certificate and its approval scope and validity meet the requirements.

(3) Check whether the welding process test, weld non-destructive testing, weld leg size and weld surface quality of steel member welding engineering meet the requirements of design and relevant standards, specifications and regulations.

(4) Check whether the welding process test and bending test of welding stud and steel meet the requirements of design and relevant standards, specifications and regulations.

(5) Check whether the sum of the sampling batches in the inspection report is consistent with the actual quantity.

03

Principle of verification

In case of any of the following situations, the project is approved as “not meeting the requirements”.

(1) There is no quality certificate for the welding materials entering the site, or the varieties and specifications of the welding materials are inconsistent with the design.

(2) There is no welder qualification certificate or its approval scope and validity period do not meet the requirements.

(3) The welding engineering of steel members failed to provide the inspection report of welding process test, weld nondestructive test, weld leg size and weld surface quality according to the design requirements.

(4) Welding procedure test and bending test report of welding stud and steel are not provided according to design requirements in stud (stud) welding engineering.

(5) In addition, the inspection report was not in accordance with the inspection standards.

(6) The sum of the batches represented by the sampling samples in the inspection report is less than the actual quantity.

3、 Connection engineering of solid parts

01

Basic requirements and contents

(1) When ordinary bolts are used as permanent connecting bolts and there are design requirements or doubts about their quality, the minimum tensile load of bolts shall be retested. The test method shall be in accordance with the current national standard “code for acceptance of construction quality of steel structures” (GB 50205), and the results shall meet the requirements.Inspection quantity: 8 for each specification.

(2) According to the current national standard “code for acceptance of construction quality of steel structures” (GB 50205), the manufacturer and installation unit of steel structure shall carry out the anti sliding coefficient test and re inspection of friction surface of high strength bolt connection respectively. The friction surface of components treated on site shall be tested separately for anti sliding coefficient of friction surface, and the results shall meet the design requirements.Inspection quantity: three groups of test pieces per batch.See table 4.1.8.4-15 for the test report of anti sliding coefficient of friction surface.

(3) The final tightening torque inspection shall be conducted within 1 hour and 48 hours after the final tightening of high strength large hexagon head bolt connection pair. The inspection results shall comply with the provisions of the current national standard code for acceptance of construction quality of steel structures (GB 50205).Inspection quantity: spot check 10% according to the number of nodes, and no less than 10; 10% and no less than 2 bolts for each inspected node.

(4) After the final tightening of the high-strength bolt connection pair of torsion shear type, the number of bolts not unscrewed in the final tightening shall not be greater than 5% of the number of bolts in the node, except that the special wrench cannot be used for the final screwing of the connection pair.Torque method or angle method shall be used for final tightening and marking of all torsional shear type high-strength bolt connection pairs which have not been screwed off, and the final tightening torque shall be checked according to the current national standard code for acceptance of construction quality of steel structures (GB 50205).Inspection quantity: spot check 10% according to the number of nodes, and there should be no less than 10 nodes. The final tightening torque should be checked for all the torsional shear type high strength bolt connection pairs whose plum heads have not been unscrewed.

02

Verification method

(1) Check whether the product varieties and specifications in the product ex factory certificate and test report are consistent with the structural design of the unit project, the design change documents and the raw material batching summary table, whether sampling is carried out according to batches, and whether the sum of batches represented by sampling is consistent with the actual consumption.

(2) Check whether the minimum tensile load of common bolts is rechecked according to the design requirements.

(3) Check whether the anti sliding coefficient re inspection report of the connection friction surface of high strength large hexagon head bolt connection pair and torsion shear type high strength bolt connection pair meets the requirements.

(4) Check whether the construction torque inspection report of high-strength large hexagon head bolt connection pair and torsion shear type high-strength bolt connection pair meets the requirements.

03

Principle of verification

In case of any of the following situations, the project is approved as “not meeting the requirements”.

(1) There is no factory certificate or test report for the incoming products.

(2) The varieties, specifications and design documents of the products entering the site are inconsistent, and there is no replacement design visa.

(3) The minimum tensile load of common bolts was not retested according to the design requirements.

(4) There is no re inspection report on the anti sliding coefficient of the connection friction surface or the construction torque test report for the connection pairs of high-strength large hexagon head bolts and torsional shear type high-strength bolts.

(5) The sampling quantity or test results do not meet the requirements.

4、 Steel structure installation works

01

Basic requirements and contents

(1) The allowable deviation of the overall perpendicularity and overall plane bending of the main structure of the steel structure shall comply with the provisions of the current national standard code for acceptance of construction quality of steel structures (GB 50205).Inspection quantity: check all the main facades.For each elevation inspected, at least one middle column should be selected in addition to two columns of corner columns.

(2) After the completion of steel grid structure assembly and roof engineering, the deflection value should be measured respectively, and the measured deflection value should not exceed 1.15 times of the corresponding design value.Inspection quantity: for steel grid structure with span of 24m and below, one point of bottom chord Center shall be measured; for steel grid structure with span above 24m, one point at center of bottom chord and quartering point of bottom chord span in all directions shall be measured.

02

Verification method

(1) Check whether the overall perpendicularity and overall plane bending or deflection of the main structure of the steel structure meet the standard requirements.

(2) Check whether the deflection value of the main structure of the steel grid meets the design requirements.

03

Principle of verification

In case of any of the following situations, the project is approved as “not meeting the requirements”.

(1) The overall perpendicularity and overall plane curvature of the main structure of the steel structure do not meet the standard requirements.

(2) The deflection value of the main structure of the steel grid does not meet the design requirements.

5、 Steel Structure Painting Engineering

01

Basic requirements and contents

(1) The anti-corrosive coating, coating times and coating thickness shall meet the design requirements.When there is no requirement for coating thickness in the design, the total thickness of dry coating film: outdoor should be 150 μ m, and the allowable deviation is – 25 μ M.The allowable deviation of dry film thickness of each coating is – 5 μ M.Inspection quantity: spot check 10% according to the number of components, and the number of similar components shall not be less than 3.

(2) The thickness of thin coating fire retardant coating shall meet the design requirements of fire resistance.The thickness of the thick fire retardant coating, 80% or more of the area should meet the design requirements of the fire resistance limit, and the thickness of the thinnest part should not be less than 85% of the design requirements.Inspection quantity: spot check 10% according to the number of similar components, and no less than 3 pieces.

02

Verification method

(1) Check the design documents and test reports, and check whether the dry film thickness of anti-corrosion coating meets the requirements.

(2) Check whether the quantity meets the requirements.

03

Principle of verification

In case of any of the following situations, the project is approved as “not meeting the requirements”.

(1) The dry film thickness of anti-corrosive coating and fireproof coating does not meet the requirements.

(2) The inspection quantity does not meet the requirements.