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GB/T 50046-2018 PDF in English


GB/T 50046-2018 (GB/T50046-2018, GBT 50046-2018, GBT50046-2018)
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GB/T 50046-2018: PDF in English (GBT 50046-2018)

GB/T 50046-2018
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC
P GB/T 50046-2018
Standard for anticorrosion design of industrial constructions
ISSUED ON: SEPTEMBER 11, 2018
IMPLEMENTED ON: MARCH 01, 2019
Issued by: Ministry of Housing and Urban-Rural Development of PRC.
General Administration of Quality Supervision, Inspection and
Quarantine of PRC.
Table of Contents
Foreword ... 6
1 General provisions ... 10
2 Terms ... 11
3 Basic requirements ... 12
3.1 Corrosiveness classification ... 12
3.2 General layout and architectural layout ... 17
3.3 Design service life period of protective layer ... 18
4 Structures and members ... 19
4.1 General requirements ... 19
4.2 Concrete structures ... 19
4.3 Steel structures ... 22
4.4 Steel and concrete composite structure ... 24
4.5 Masonry structure ... 24
4.6 Timberwork ... 25
4.7 Ground work ... 25
4.8 Foundations ... 26
4.9 Pile ... 28
5 Building protection ... 33
5.1 Ground and floor ... 33
5.2 Structure and component surface protection ... 43
5.3 Doors and windows ... 46
5.4 Roof ... 47
5.5 Wall ... 47
6 Structures ... 49
6.1 Storage tank and sewage treatment pool ... 49
6.2 Outdoor pipe rack ... 52
6.3 Exhaust funnel ... 52
7 Materials ... 55
7.1 General requirements ... 55
7.2 Cement mortar and concrete ... 55
7.3 Bulk of corrosion resistance ... 56
7.4 Metal ... 57
7.5 Plastic material ... 57
7.6 Wood ... 58
7.7 Resin materials ... 58
7.8 Water glass materials ... 58
7.9 Asphalt materials ... 59
7.10 Anticorrosion coatings ... 59
Appendix A Corrosion resistance properties of commonly used materials ... 61
Appendix B Physical and mechanical properties of commonly used materials
... 65
Appendix C Commonly used coating protection systems ... 67
Appendix D Testing methods for linear shrinkage of resin mortar and resin
concrete ... 75
Explanation of wording in this standard ... 78
List of quoted standards ... 79
Standard for anticorrosion design of industrial
constructions
1 General provisions
1.0.1 This standard is formulated with a view to ensuring that buildings and structures subjected
corrosive medium are used normally within the design service life.
1.0.2 This standard is applicable to anticorrosion design for buildings and structures subjected to
corrosive medium.
1.0.3 Anticorrosion design of industrial constructions shall follow the principle of combining
prevention with protection. According to the corrosiveness, environmental conditions, production
operation management level and construction and maintenance conditions of the medium
produced during the production process, the anticorrosion measures shall be taken in the light of
local conditions; protection and prevention shall be strengthened for parts that endanger personal
safety and are difficult to be maintained, as well as important load-bearing structures and
members.
1.0.4 In addition to the requirements of this standard, the anticorrosion design of industrial
constructions shall also meet the requirements of the current relevant standards of the nation.
4 Structures and members
4.1 General requirements
4.1.1 Under corrosive environment, the structural design shall meet the following requirements:
1 The structural materials shall be properly selected according to the adaptability of materials to
different mediums;
2 The structural type, arrangement and configuration shall be selected in a way that is beneficial
to improve the corrosion resistance of the structure, effectively avoid the accumulation of
corrosive mediums on the surface of the member and remove in time if any, and facilitate the
arrangement and maintenance of the protective layer;
3 The design service life of the structural members shall be determined according to the relevant
requirements of the current national standard GB 50068 Unified standard for reliability design of
building structures.
4 When the design service life of certain secondary members is different from that of major
structure, the secondary members shall be easily replaceable.
4.2 Concrete structures
4.2.1 The concrete structure and members shall be selected according to the following
requirements:
1 The frame should be placed in situ;
2 In case of corrosiveness class A (strongly corrosive), prestressed concrete structure should be
adopted for the roof truss, the roof girder and the crane beam with a working level equal to or
greater than A4;
3 In case of corrosiveness classes A and B, the column section should be of solid-web type,
rather than in an H shape with opening in the web.
4.2.2 The design of prestressed concrete structure shall meet the following requirements:
1 In case of corrosiveness classes A and B, pre-tensioned prestressed concrete structure should
be adopted; if unbonded prestressed concrete structure is adopted, the anchoring system shall be a
continuous fully-enclosed anti-corrosion system or the channels shall be grouted. The durability of
the corrosion-resistant materials shall conform to the requirements of the environment type and
design service life of the external tendon.
beam.
4.2.9 For the protection of exposed steel embedded parts and connecting parts in the concrete
structures, the following measures shall be taken according to the following requirements based on
the corrosiveness class, importance and ease of inspection and maintenance:
1 Encasing with resin or polymer-cement concrete, where the thickness of concrete
should be 30mm~50mm;
2 Mortar plastering with resin or polymer cement, where the thickness of the mortar should be
10mm~20mm;
3 Resin-bonded glass flake mastic protection, where the thickness of the mastic should be
1mm~2mm;
4 Anti-corrosion coating protection, where the thickness of the coating should be
200μm~320μm;
5 The parts may be made of corrosion-resistant metals.
4.2.10 The exposed pre-tensioned tendons shall be enclosed with resin or polymer-cement
concrete, and the thickness of the protective layer shall not be less than 50 mm. The anchored end
of the post-tensioned prestressed concrete, if exposed in arrangement, shall be encased with resin
or polymer-cement concrete. The thickness of the protective layer shall not be less than 50 mm,
and the anchored end shall be protected against corrosive medium and accumulation of water.
4.3 Steel structures
4.3.1 In case of corrosiveness class A, lattice structure should not be adopted for the important
carrying members such as the truss, columns and main beams; cold-formed thin-walled steel shall
not be used.
4.3.2 Important members and those difficult to maintain shall not be made of steel with original
surface corrosiveness class of Grade D. Protective coating with long service life or more should be
adopted
4.3.3 The cross-section of steel structural members shall be selected according to the following
requirements:
1 The members shall adopted solid web type or closed section where the section end shall be
enclosed; for hot-dip galvanizing of closed-section bars, holes shall be opened to avoid explosion;
2 Double-angle steel formed T-shaped section or double-channel steel formed H-shaped section
should not be adopted in case of corrosiveness classes A and B;
3 If members made by assembling section steels, the width of gap between the section steels
shall meet the requirements of construction and maintenance of the protective layer,
and shall comply with the current national standards GB/T 30790.3 Paints and varnishes -
Corrosion protection of steel structures by protective paint systems - Part 3: Design considerations
4.3.4 The sectional thickness of steel structural members should meet the following
requirements:
1 For members made by assembling steel plates, it should not be less than 6mm;
2 For members with closed section, it should not be less than 4mm;
3 The sectional thickness of angle steel should not be less than 5mm.
4.3.5 Hot-rolled H-shaped steel should be adopted for gabled frame members. If combination of
T-shaped steels or steel plates is adopted, it shall be subjected to double-sided continuous welds.
4.3.6 Tubular section and spherical joints should be adopted for grid structure, and shall meet the
following requirements:
1 In case of corrosiveness classes A and B, the hollow-sphere joint connected by welding shall
be used;
2 If bolted spherical joint is used, the seam between the member and the bolted sphere shall be
packed tightly with sealing materials, and the excess bolt holes shall be sealed off.
4.3.7 Isolation measures should be taken where different metal materials contact.
4.3.8 For welds of important steel members (such as trusses, columns, main beams) and closed
section members, continuous welds shall be used. The weld leg size of fillet weld should not be
less than 8mm; if the thickness of the member is less than 8mm, the weld leg size should not be
less than the thickness of the member; the stiffener shall be chamfered, and the size of the chamfer
shall meet the requirements of drainage, construction and maintenance.
4.3.9 The corrosion resistance of connecting members, such as welding rod, bolt, washer, and
joint plate, shall not be lower than the main materials. The diameter of bolt shall not be less than
12mm. Spring washers shall not be adopted. Bolts, nuts and washers shall be protected by
hot-galvanizing or hot-dip galvanizing, and subjected to the same corrosion prevention measure
with that of the major structure after installation.
4.3.10 For the contact surface at the high-strength bolted connection of the member, the
derusting grade shall not be lower than . The gap at the joint should be filled with
corrosion-resistant sealing compounds.
4.3.11 The steel column pedestal shall be placed on the concrete foundation. For the venues
where the ground is often flushed with water, the top surface of the foundation should be no less
than 300mm above the ground. In case of corrosiveness class A, the steel column pedestal and
steel column should be encased with C25 fine stone concrete, in which case the concrete thickness
is not less than 60mm, the encasing height is not less than 800mm, and the top surface slopes by
30°.
4.4 Steel and concrete composite structure
4.4.1 In strongly and moderately corrosive environments, the following structures should not be
adopted:
1 Steel and concrete composite roof truss and crane beam;
2 Concrete composite structure with profiled steel sheet as formwork and reinforcement.
4.4.2 Steel and concrete composite beam shall meet the following requirements:
1 It shall be applicable to weakly corrosive environment of gaseous medium, and the floor is
free of the action of liquid medium;
2 The joint between the concrete flange plate and the steel beam shall be sealed.
4.5 Masonry structure
4.5.1 The selected materials for load-bearing masonry structure shall meet the following
requirements:
1 Sintered common bricks and sintered perforated bricks should be adopted for brick masonry of
which the strength grade should not be lower than MU20; if concrete common bricks are adopted,
the strength grade should be MU20, and cement mortar with a strength grade not lower than Mb10
shall be used;
2 Concrete blocks may be adopted for block masonry of which the strength grade should not be
lower than MU 15; the strength grade of grout concrete shall not be lower than Cb30; and the
strength grade of cement mortar shall not be lower than Mb10.
4.5.2 The design of load-bearing masonry structure shall meet the following requirements:
1 Masonry structure shall not be used if it is subject to a large amount of freely soluble solid
medium and alternation of drying and wetting;
2 Independent brick column shall not be used in case of corrosiveness classes A and B;
3 Solid masonry shall be used in case of corrosiveness classes A and B;
4 Reinforcement masonry member shall not be used in case of corrosiveness classes A and B.
4.6 Timberwork
4.6.1 Softwoods should be selected as timberwork materials, and laminated wood may also be
used if conditions permit.
4.6.2 The connecting pieces for timberwork should be made of corrosion-resistant non-metallic
or metallic materials.
4.7 Ground work
4.7.1 The investigation of corrosive subsoil shall meet the following requirements:
1 The investigation of contaminated soil shall be in accordance with the requirements of the
current national standard GB 50021 Code for investigation of geotechnical engineering.
2 In case of collapsibility and salt expandability of subsoil, it shall comply with the current
national standard GB/T 50942 Technical code for building in saline soil regions;
3 Assessment shall be conducted in case the medium leaked from the proposed production unit
may contaminate the subsoil and have an impact.
4.7.2 The methods for treating ground that has contaminated or potentially contaminates the site
shall comply with the following requirements:
1 If the subsoil contains hydrogen ion or sulfate ion medium, reinforcement methods with lime
soil cushion course, lime piles and lime-soil compaction piles shall not be used;
2 If the subsoil contains corrosive liquid medium, slag and fly ash shall not be used as the
cushion materials;
3 If the subsoil contains acidic liquid medium, carbonates shall not be used as the filler of
vibrosinking piles and sand-gravel piles;
4 If the corrosiveness class of contaminated soil to cement materials is A or B, the followings
should not be used: concrete-flyash crushed stone pile, rammed soil-cement pile, cement-soil
mixing method and other cement-containing reinforcement methods, while the sulfate ion medium
corrode those advisable include sulfate-resistant Portland cement or Portland cement, and common
Portland cement with admixtures;
5 Soda solution grouting shall not be used if the subsoil contains acidic medium or sulfate
medium;
6 Solidification grouting shall not be used when the pH of contaminated soil or groundwater is
less than 7, or the production process is subjected to alkaline solution action.
4.7.3 If the contaminated soil layer is not thick while showing high collapsibility and salt
expandability, soil replacement cushion method should be adopted; the cushion material should be
non-contaminated soil or non-polluting sand-gravel material. If the contaminated soil layer is thick,
the pile may be adopted to pass through the contaminated soil layer.
4.8 Foundations
4.8.1 The corrosiveness class of the foundations and foundation beams shall be determined
according to the following requirements:
1 It shall be in accordance with the requirements of the current national standard GB 50021
Code for investigation of geotechnical engineering if they are located at contaminated sites;
2 If an isolating course is arranged under the ground/floor, the corrosiveness class of medium
leaked in the production process to the foundations and the foundation beams may be determined
by lowering one class than those specified in Table 3.1.5 of this standard;
3 In case of combined action of contaminated soil, groundwater and medium leaked in
production process, it shall be determined according to the corrosiveness classes of those
mentioned above, whichever is the highest.
4.8.2 The foundation material shall be selected according to the following requirements:
1 Plain concrete, reinforced concrete or rubble concrete shall be adopted;
2 The strength grade of plain concrete and rubble concrete shall not be lower than C25;
3 The concrete strength grade of reinforced concrete should meet the requirements given in
Table 4.2.3 of this standard.
4.8.3 The embedded depth of foundation shall meet the following requirements:
1 The embedded depth shall not be less than 2m if the subsoil expands in the production process
due to the action of leaked medium such as sulfuric acid, sodium hydroxide or sodium sulfate;
3 An isolating course shall be arranged for the floor subject to chloride ion medium and the base
course ground subject to caustic alkali in strongly and moderately corrosive environment; and an
isolating course should be arranged for those mentioned in weakly corrosive environment.
4 An isolating course shall be arranged for sodium silicate concrete ground and block ground
built with sodium silicate mastic or mortar.
5.1.5 The materials of the isolating course of ground/floor shall meet the following
requirements:
1 The isolating course shall be corrosion resistant, integrate and tight;
2 Where the surface course thickness is less than 30mm and the combined course is made of
rigid materials, flexible materials shall not be adopted for the isolating course.
3 For integral ground/floor made of resin-bonded mortar, resin-bonded fine stone concrete,
self-leveling resin emulsion coatings, etc., and block ground/floor built with resin-bonded mastic
or mortar, the isolating course shall be made of resin fiber reinforced plastic with a thickness of no
less than 1mm and a resin content of no less than 45%.
5.1.6 Fine stone concrete with a strength grade not lower than C30 shall be used as the troweling
course materials of integral ground/floor made of resin-bonded mortar, resin-bonded fine stone
concrete or coatings, etc.
5.1.7 The materials and structure of cushion course of the ground/floor shall meet the following
requirements:
1 The cushion course materials shall be concrete.
2 Under the action of acidic medium or sulfate ion medium, the reinforcement layer of the
ground foundation shall not be made of materials such as trinity mixture fill, quadruple mixture
fill, lime soil and slag. The requirements for compacted fill ground shall meet the relevant
requirements of the current national standard GB 50037 Code for design of building ground.
3 For indoor ground cushion course, the strength grade of concrete should not be lower than C20,
and its thickness should not be less than 120 mm. For outdoor ground cushion course, the strength
grade of concrete should not be lower than C25, and its thickness should not be less than 150 mm.
For integral ground made of resin-bonded mortar, resin-bonded fine stone concrete, coatings, etc.,
the strength grade of concrete for its cushion course should not be lower than C30 and the
thickness of concrete should not be less than 200mm.
4 Reinforced concrete cushion course should be adopted for outdoor ground, large-area
ground/floor, resin-bonded fine stone concrete ground/floor, resin-bonded mortar ground/floor,
self-leveling resin emulsion coating ground/floor, the ground/floor subject to impact and abrasion
of large-sized means of conveyance, or where the foundation may be subject to uneven
deformation. The reinforcement shall be a two-way reinforcing mesh with rebars in a diameter of
not less than 10 mm and a spacing of not more than 200 mm. If single-layer reinforcement is
adopted for the cushion course, the rebars should be 50mm from the upper surface; if double-layer
reinforcement is adopted, the rebars in the upper layer should be 50mm from the upper surface,
and those in the lower layer should be 30mm from the lower surface.
5 The reinforced concrete cushion course shall be reinforced and poured section by section, and
the length of each section should not be greater than 30m. The length of each section can be
appropriately increased if technical supporting measures are available, while the rebars shall be
kept continuous and number of expansion joints on the ground/floor shall be minimized.
6 In areas with frozen outdoor soil, an anti-frost heave layer with a thickness of no less
than 300mm shall be arranged under the outdoor ground cushion course; the indoor anti-frost
heave layer shall be arranged in accordance with relevant provisions of the current national
standard GB 50037 Code for design of building ground.
7 A moisture-proof layer shall be provided under the cushion course of integral ground/floor
made of resin-bonded mortar, resin-bonded fine stone concrete, coatings, etc.; a waterproof layer
shall be provided where the groundwater level is high.
5.1.8 Precast floor slabs shall be provided with reinforced fine stone concrete casting course.
Reinforcing mesh shall be configured for fine stone concrete which shall have a strength grade not
lower than C30, and a thickness not less than 40mm. The rebars should be in a diameter of not less
than 4mm, spacing not greater than 200mm, and 20mm from the upper surface.
5.1.9 Ground and floor drainage shall meet the following requirements:
1 The ground/floor subject to liquid medium shall slope toward the drainage ditch or floor drain
to facilitate discharge. The discharging slope of the bottom course ground should not be less than
2% and that of the floor shall not be less than 1%. The bottom course ground should be sloped
with subsoil, and the floor should be sloped with the troweling course;
2 The drainage ditch and floor drain shall be arranged at a position where the liquid can be
quickly discharged. The length of the discharging slope should not be greater than 9m. The length
of the discharging slopes in various directions should not differ greatly;
3 The inner wall of the drainage ditch shall not be less than 300mm from the edge of the walls
and columns.
4 The floor drain center shall not be less than 400mm from the edge of the walls, columns,
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.