GB 50205-2020 English PDF

GB 50205-2020: Standard for acceptance of construction quality of steel structures
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GB 50205-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC
P GB 50205-2020
Standard for acceptance of construction quality of
steel structures
ISSUED ON: JANUARY 16, 2020
IMPLEMENTED ON: AUGUST 01, 2020
Issued by: Ministry of Housing and Urban-Rural Development of PRC;
State Administration for Market Regulation.
Table of Contents
Foreword ... 8 
1 General requirements ... 12 
2 Terms and symbols ... 12 
2.1 Terms ... 12 
2.2 Symbols ... 14 
3 Basic requirements ... 15 
4 Materials and products approach ... 17 
4.1 General requirements... 17 
4.2 Steel sheet ... 17 
4.3 Steel profiles and pipes ... 19 
4.4 Steel castings ... 20 
4.5 Cables, tie rods and anchorage ... 22 
4.6 Welding materials ... 23 
4.7 Fasteners for connections ... 24 
4.8 Materials of spherical joints ... 26 
4.9 Profiled metal plate... 27 
4.10 Membrane materials of membrane structures ... 28 
4.11 Coating materials ... 29 
4.12 Products and others ... 30 
5 Welding engineering ... 30 
5.1 General requirements... 30 
5.2 Welding engineering of steel member ... 31 
5.3 Stud (welding nail) welding engineering ... 37 
6 Connection engineering of fasteners ... 38 
6.1 General requirements... 38 
6.2 Connection of ordinary fasteners ... 39 
6.3 Connection of high strength bolts ... 40 
7 Processing of steel parts and steel components ... 42 
7.1 General requirements... 42 
7.2 Cutting ... 42 
7.3 Rectification and formation ... 43 
7.4 Trimming of edges ... 48 
7.5 Processing of spherical joints ... 50 
7.6 Processing of steel castings ... 53 
7.7 Holing ... 55 
8 Assembling engineering of steel elements ... 57 
8.1 General requirements... 57 
8.2 Assembling and butting of components ... 57 
8.3 Assembling ... 59 
8.4 Milling of element ends and compacting of contact surface ... 61 
8.5 Shapes and sizes of steel elements ... 62 
9 Test assembling engineering of steel elements ... 70 
9.1 General requirements... 70 
9.2 Entity test assembling ... 71 
9.3 Simulation test assembling... 72 
10 Installation engineering of steel frame structures ... 73 
10.1 General requirements... 73 
10.2 Foundation and anchor bolts (anchor) ... 74 
10.3 Installation of steel columns ... 76 
10.4 Installation of steel roof truss (shelves), beam (truss) ... 79 
10.5 Installation of connection joints ... 82 
10.6 Installation of steel sheet shear wall... 83 
10.7 Installation of supports, purlins, wall frames and secondary structures ... 85 
10.8 Installation of steel platform and stairs ... 86 
10.9 Overall steel structures ... 88 
11 Installation engineering of space structures ... 90 
11.1 General requirements ... 90 
11.2 Installation of bearing and anchor bolt (anchor) ... 90 
11.3 Installation of steel grid structure and reticulated shell ... 92 
11.4 Steel pipe truss structure ... 94 
11.5 Making of cable and member ... 95 
11.6 Making of membrane element ... 97 
11.7 Installation of cable and member ... 98 
11.8 Installation of membrane structures ... 99 
12 Profiled metal sheet engineering ... 100 
12.1 General requirements... 100 
12.2 Making of profiled metal sheet ... 101 
12.3 Installation of profiled metal sheet ... 103 
12.4 Installation of fixation apparatus ... 106 
12.5 Connection construction and joints ... 108 
12.6 Metal roofing system ... 108 
13 Coating engineering ... 109 
13.1 General requirements... 109 
13.2 Anticorrosive coating painting ... 110 
13.3 Coating of connection parts and repairing of coating defects ... 112 
13.4 Fire resistant paint coating ... 114 
14 Parts projects completion acceptance of steel structures ... 115 
Appendix A Inspection items and methods of steel products ... 118 
Appendix B Inspection items of fastener connection engineering ... 122 
Appendix C Wind resistant performance testing methods of metal roofing
system ... 128 
Appendix D Procedure qualification of anticorrosive coating ... 134 
Appendix E Determination methods of fire resistant paint coating thickness138 
Appendix F Inspection and evidential testing of safety and function about sheet
structures ... 140 
Appendix G Inspection items for quality of appearance about steel structures
... 142 
Appendix H Records of inspection batches of item for quality acceptance .. 143 
Appendix J Method of quantity survey for steel structure ... 158 
Explanation of wording in this standard ... 160 
List of quoted standards ... 161 
Standard for acceptance of construction quality of
steel structures
1 General requirements
1.0.1 In order to strengthen the quality management of construction projects,
unify the acceptance of construction quality of steel structure projects, ensure
the quality of steel structure projects, this standard is hereby formulated.
1.0.2 This standard is applicable to the acceptance of construction quality of
steel structure engineering of industrial and civil buildings and structures.
1.0.3 This standard should be used in conjunction with the current national
standard "Unified acceptance standard for building construction quality" GB
50300.
1.0.4 In addition to this standard, the acceptance of construction quality of steel
structure projects shall also comply with the current relevant national standards.
2 Terms and symbols
2.1 Terms
2.1.1 Part
The smallest unit that constitutes a part or component, such as a gusset sheet,
a flange sheet, etc.
2.1.2 Component
A unit composed of several parts, such as welded H-beams, steel brackets, etc.
2.1.3 Element
The basic unit of steel structure composed of parts or parts and components,
such as beams, columns, supports, etc.
2.1.4 The smallest assembled rigid unit
In the installation project of steel grid and reticulated shell structure, the smallest
installation unit except for the loose parts, which is generally divided into two
The profiled metal sheet whose longitudinal edges of the formed sheet are
profiled edges that can be overlapped with each other, whose sheets are
connected to structures through fasteners after being naturally overlapped.
2.1.16 Up standing seam metal sheet
The profiled metal sheet whose longitudinal edges of the formed sheet are
profiled edges that can be overlapped with each other and, after the sheet and
the sheet are naturally overlapped, which are crimped along the length direction
by a special machine and connected to the structure through a fixed bracket.
2.1.17 Clip-lock metal sheet
The profiled metal sheet whose longitudinal sides of the formed sheet are
profiled edges that can be overlapped with each other and the sheet-sheet
installation of which is connected to the structure through a fixed bracket, after
being clipped and pressed-in.
2.1.18 Flashing
An element having a certain shape as formed by rolling or mechanical bending
of metal sheet, which is used to seal the edges of the gaps after the roof and
wall profiled metal sheets are paved to prevent rainwater leakage.
2.1.19 Metal roofing system
The general term for the roof enclosure system composed of metal panels, fixed
brackets, bottom plates, fasteners, heat preservation, moisture proof, heat
insulation, sound insulation and other materials.
2.2 Symbols
2.2.1 Function and effect:
P - Design value of pretension of high-strength bolt;
ΔP - The loss of the pretension of the high-strength bolt;
Tch - Checking torque of high-strength bolt;
Tc - Final tightening torque of high-strength bolts;
T0 - Initial tightening torque of high-strength bolt.
2.2.2 Geometric parameters:
α - Spacing;
construction of steel structure projects shall have the requirements for the
acceptance of the construction quality of not lower than the provisions of this
standard.
3.0.4 The construction quality control of steel structure engineering shall be
carried out in accordance with the following provisions:
1 The raw materials and finished products used shall be subject to
mobilization acceptance. All raw materials and finished products involving
safety and function shall be re-inspected in accordance with the provisions
of 14.0.2 of this standard, meanwhile the sampling and sample delivery
shall be witnessed by the supervision engineer (technical person in charge
of the construction organization);
2 The quality control of each process shall be carried out according to the
construction technical standards; inspection shall be carried out after each
process is completed;
3 The handover inspection shall be carried out between the relevant trades;
it shall be inspected and approved by the supervision engineer (the
technical person in charge of the construction organization).
3.0.5 Acceptance of construction quality of steel structure engineering shall be
carried out in accordance with inspection batches, item work, divisional (sub-
divisional) work on the basis of qualified self-inspection by the construction
organization. The division of item work in the divisional (sub-divisional) work of
the steel structure engineering shall be implemented in accordance with the
current national standard "Unified acceptance standard for building
construction quality" GB 50300. The steel structure item work shall be
composed of one or several inspection batches, the inspection batches of each
item work shall be divided according to the provisions of this standard;
meanwhile it shall be confirmed by the supervisor (or construction organization).
3.0.6 The qualified quality standard of the inspection batch shall meet the
following requirements:
1 The main control items must meet the quality requirements of this standard;
2 The inspection results of general items shall have 80% or more check
points (values) that meet the requirements of this standard, meanwhile the
maximum (or minimum) value shall not exceed 1.2 times the allowable
deviation value.
3.0.7 The qualified quality standards for item work shall meet the following
requirements:
1 Each inspection batch included in the item work shall meet the quality
4.2.1 The variety, specification and performance of steel sheets shall meet
the requirements of current national standards and meet design
requirements. When the steel sheet enters the site, the test pieces shall
be taken according to the current national standards, to be subject to the
testing of the yield strength, tensile strength, elongation and thickness
deviation. The testing results shall comply with the current national
standards.
Inspection quantity: All quality certification documents are inspected; the
sampling quantity is determined according to the mobilization batch and
the sampling inspection plan of the product.
Inspection method: Check quality certification documents and sampling
inspection report.
4.2.2 The steel sheet shall be subject to the witnessed sampling and
reinspection in accordance with Appendix A of this standard. The results of the
re-inspection shall meet the requirements of the current national standards and
meet the design requirements.
Inspection quantity: Inspection for all.
Inspection method: Witness the sampling and sample delivery; check the re-
inspection report.
II General items
4.2.3 The thickness of the steel sheet and its allowable deviation shall meet the
requirements of its product standards and design documents.
Inspection quantity: Spot inspection for 10% of each batch of steel sheets of
the same variety and specification; meanwhile it is no less than 3 pieces, 3
locations per piece shall be inspected.
Inspection method: Use vernier caliper or ultrasonic thickness gauge to make
measurement.
4.2.4 The flatness of the steel sheet shall meet the requirements of its product
standards.
Inspection quantity: Spot inspection for 10% of each batch of steel sheets of
the same variety and specification; meanwhile it is no less than 3 pieces, 3
locations per piece shall be inspected.
Inspection method: Use stayguy, steel ruler and vernier caliper for
measurement.
4.2.5 The surface appearance quality of the steel sheet shall not only meet the
Inspection quantity: Follow the Appendix A of this standard to carry out
inspection based on the re-inspection batch size.
Inspection method: Witness the sampling and sample delivery; check the re-
inspection report.
II General items
4.3.3 The cross-sectional size, thickness and allowable deviation of profiles and
pipes shall meet the requirements of their product standards.
Inspection quantity: Spot inspection for 10% of each batch of profiles of the
same variety and specification; meanwhile it is no less than 3 pieces, 3 locations
per piece shall be inspected.
Inspection method: Use steel ruler, vernier caliper and ultrasonic thickness
gauge for measurement.
4.3.4 The allowable deviation of the profile and pipe dimensions shall meet the
requirements of their product standards.
Inspection quantity: Spot inspection for 10% of each batch of profiles of the
same variety and specification; meanwhile it is no less than 3 pieces, 3 locations
per piece shall be inspected.
Inspection method: Use stayguy and steel ruler for measurement.
4.3.5 The surface appearance quality of profiles and pipes shall meet the
requirements of Article 4.2.5 of this standard.
Inspection quantity: Inspection for all.
Inspection method: Observation inspection.
4.4 Steel castings
I Main control item
4.4.1 The types, specifications and performance of the steel castings shall
meet the requirements of the current national standards and meet the
design requirements. When the steel castings enter the site, test pieces
shall be taken according to the current national standards, to be subject
to the inspection of the yield strength, tensile strength, elongation and
thickness deviation; the inspection results shall comply with the current
national standards.
Inspection quantity: All quality certification documents are inspec...