Detail of GB/T 40399-2021

Introduction of GB/T 40399-2021

Foreword Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights. This document was proposed by the Ministry of Housing and Urban-Rural Development of the People's Republic of China. This standard is under the jurisdiction of SAC/TC 458 National Technical Committee on Concrete of Standardization Administration of China. General technical conditions for precast concrete part of prefabricated construction 1 Scope This document specifies basic provisions, raw materials and accessories, production of parts, quality requirements, test methods, inspection rules, marking and product certificate, storage and transportation of precast concrete part of prefabricated construction. This document is applicable to precast concrete parts such as precast concrete columns, precast concrete beams, precast concrete floorslabs, precast concrete wall panels, precast concrete stairs and precast concrete balconies for prefabricated construction. 2 Normative references The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies. GB 175 Common portland cement GB/T 1499.1 Steel for the reinforcement of concrete - Part 1: Hot rolled plain bars GB/T 1499.2 Steel for the reinforcement of concrete - Part 2: Hot rolled ribbed bars GB/T 1499.3 Steel for the reinforcement of concrete - Part 3: Welded fabric GB/T 1596-2017 Fly ash used for cement and concrete GB/T 5223 Steel wires for prestressed concrete GB/T 5224 Steel strand for prestressed concrete GB 8076 Concrete admixtures GB/T 8923.1 Preparation of steel substrates before application of paints and related products - Visual assessment of surface cleanliness - Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings GB/T 18046 Ground granulated blast furnace slag used for cement, mortar and concrete GB/T 20065 Screw-thread steel bars for the prestressing of concrete GB/T 27690 Silica fume for cement mortar and concrete GB 50010-2010 Code for design of concrete structures GB/T 50046 Standard for anticorrosion design of industrial constructions GB/T 50081 Standard for test methods of concrete physical and mechanical properties GB 50204-2015 Code for acceptance of constructional quality of concrete structures GB 51231 Technical standard for assembled buildings with concrete structure JGJ 1 Technical specification for precast concrete structures JGJ 52 Standard for technical requirements and test method of sand and crushed stone (or gravel) for ordinary concrete JGJ 55 Specification for mix proportion design of ordinary concrete JGJ 63 Standard of water for concrete JGJ/T 152 Technical standard for test of reinforcing steel bar in concrete JG/T 398 The grouting sleeve for rebars splicing JG/T 408 Cementitious grout for sleeve of rebar splicing 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 precast concrete part concrete product of industrial and civil buildings composed of single products or composite products of factory-made precast concrete members 3.2 honeycomb stone exposure and voids formed on the concrete surface due to lack of cement mortar 3.3 exposed steel exposure of steel bars in parts due to not being wrapped by mortar or concrete 3.4 hole void in concrete with its depth and length exceeding the protection layer thickness 3.5 crack narrow slit extending from the concrete surface to its inner part 3.6 precast concrete sandwich wall panel composite precast concrete wall panel composed of inner sandwich wall panel, sandwich layer, outer sandwich wall panel and wythe connector Note 1: It is also called sandwich wall panels for short. Note 2: It is composed of precast concrete sandwich shear wall panel and precast concrete sandwich external wall panel. 3.7 wythe connector accessories in precast concrete sandwich wall panel, for connecting inner and outer sandwich wall panels 3.8 stacking stand stand as a tool, for supporting and fixing concrete parts during storage and transportation 3.9 grouting coupler metal coupler used to connect steel bars by the force transmission of cement-based grouting material 3.10 building information modeling; BIM general term for design, construction, operation and consequence after digitally expressing the physical and functional characteristics of architectural engineering and facilities throughout their life cycle 4 Basic provisions 4.1 The design of precast concrete parts shall meet the requirements of building use function, modulus and standardization, and follow the principle of less dimensions and more combinations. 4.2 Precast concrete parts should be subjected to the integrated design of building information model (BIM) technology, and the steel bars of precast concrete parts shall be matched with reserved hole entrances and embedded parts. 4.3 The shape, dimension and weight of precast concrete parts shall meet the requirements of structural design, production, transportation and hoisting. 4.4 Reinforcement of precast concrete parts shall facilitate the connection between factory production and site. 4.5 The mold assembly, manufacture, demoulding and hoisting, surface repair, storage and transportation of precast concrete parts shall have a comprehensive and perfect quality management system, safety assurance system and assay method. 4.6 The whole production process of precast concrete parts shall be managed according to product construction drawing, which shall include template drawings, reinforcement drawings, embedded parts drawings, external veneer layout drawings and reserved holes drawings, etc.; the explanatory note in the table of the drawing shall include the list of embedded parts, the pre-pouring checklist, the checklist of products, the strength of demoulded concrete, the strength of ex-factory concrete, etc. 4.7 The technological process of precast concrete parts shall be prepared according to the characteristics of products, and the demoulding adsorption force and bearing capacity under hoisting conditions shall be checked and calculated. The demoulding adsorption force should not be greater than 300 N/m2, and the dynamic coefficient for hoisting shall be 1.5. 4.8 The inspection of concrete raw materials, steel bars, connecting sleeves, connectors, embedded parts, mold performance and product manufacturing quality shall be determined according to this document, GB 50204-2015, GB 51231 and JGJ 1. 4.9 Before hoisting and transporting precast concrete parts, the concrete strength shall be inspected. Only when it meets the design requirements and the provisions of this document can it be demoulded, hoisted and transported. 4.10 The thickness of concrete protective layer of precast concrete parts shall meet the design requirements. 4.11 Qualified precast concrete parts shall have a marking system and not be delivered to the user until a certificate is issued.

Contents of GB/T 40399-2021

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Basic provisions 5 Raw materials and accessories 6 Production of parts 7 Quality requirements 8 Test methods 9 Inspection rules 10 Marking and product certificate 11 Storage and transportation