Detail of GB/T 27794-2023

Introduction of GB/T 27794-2023

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. This document replaces GB/T 27794-2011 Socket type concrete conduits for electric cable. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect to GB/T 27794-2011: a) The standard name has been changed to "Precast concrete conduits for electric cable"; b) Terms and definitions have been added (see Clause 3 hereof); c) The classification, dimensions and marking of products have been changed (see Clause 4 hereof; Clause 3 of Edition 2011); d) Reinforced concrete conduits for PVC-lined, CPVC-lined, and MPP-lined electric cables have been added (see 5.9); e) The requirements for raw materials have been modified (see Clause 5 hereof; Clause 4 of Edition 2011); f) The clause “General requirements” has been added (see Clause 6); g) The technical performance requirements for gaskets for cable conduit seals have been changed (see 6.8 hereof; Annex A of Edition 2011); h) The technical requirements have been modified (see Clause 7 hereof; Clause 5 of Edition 2011); i) The test methods have been modified (see Clause 8 hereof; Clause 6 of Edition 2011); j) The joint type and detail dimensions of precast unreinforced concrete conduits for electric cables are adjusted to Annex A (see Annex A; 3.3 of the Edition 2011); k) The joint types of precast reinforced concrete conduits for electric cables have been added (see Annex B); l) The design methods for flexural performance and external pressure load of precast reinforced concrete conduits for electric cables have been added (see Annex D). 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 China Building Materials Federation. This document is under the jurisdiction of the National Technical Committee on Cement Products of Standardization Administration of China (SAC/TC 197). This document was firstly issued in 2011, and this edition is the first revision. Precast concrete conduits for electric cable 1 Scope This document specifies the classification, dimensions, marking, raw materials, general requirements, technical requirements, test methods, inspection rules, as well as marking, packaging, transportation, storage and delivery certificate of precast concrete conduits for electric cables. This document is applicable to precast concrete conduits for electric cables that are factory-prefabricated and field-installed. 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 of the referenced document (including any amendments) applies. GB 175 Common portland cement GB/T 700 Carbon structural steels 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 1596 Fly ash used for cement and concrete GB 8076 Concrete admixtures GB/T 13788 Cold rolled ribbed steel bars GB/T 14684 Sand for construction GB/T 14685 Pebble and crushed stone for construction GB/T 17431.1 Lightweight aggregates and its test methods - Part 1: Lightweight aggregates GB/T 18046 Ground granulated blast furnace slag used for cement, mortar and concrete GB/T 21120 Synthetic fibres for cement concrete and mortar GB/T 23265 Chopped basalt fiber for cement concrete and mortar GB/T 38143 Alkali-resistant glass fibres for cement concrete and mortar GB/T 50081 Standard for test methods of concrete physical and mechanical properties GB/T 50082 Standard for test methods of long-term performance and durability of ordinary concrete GB/T 50107 Standard for evaluation of concrete compressive strength GB 50119 Code for utility technical of concrete admixture GB 50164 Standard for quality control of concrete GB 50204 Code for acceptance of constructional quality of concrete structures GB/T 51003 Technical code for application of mineral admixture JC/T 946 Rubber gasket ring of concrete and reinforce concrete sewer pipes JGJ/T 12 Technical standard for application of lightweight aggregate concrete JGJ 55 Specification for mix proportion design of ordinary concrete JGJ 63 Standard of water for concrete JGJ/T 221 Technical specification for application of fiber reinforced concrete 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 precast concrete conduits for electric cable precast concrete members formed by concrete pouring (reinforced or unreinforced) and internally arranged with connecting pipe holes for electric cable laying Note: Referred to as cable conduit. 3.2 precast unreinforced concrete conduits for electric cable cable conduit made of plain concrete without steel skeleton 3.3 precast reinforced concrete conduits for electric cable electricity channel cable conduit with steel skeleton 3.4 flexible joint pipe joint of cable conduit adopting the joint type of elastic gasket ring or elastic packing sealing connection 3.5 rigid joint pipe joint of cable conduit with a joint type that uses a rigid material such as mortar to seal the connection 4 Classification, dimensions and marking 4.1 Classification 4.1.1 Cable conduits are divided into precast unreinforced concrete conduits for electric cables (code DH) and precast reinforced concrete conduits for electric cables (code DP) according to whether the steel skeleton is configured inside. Precast reinforced concrete conduits for electric cables are divided into lightweight aggregate reinforced concrete conduits for electric cables (code LDP) and ordinary reinforced concrete conduits for electric cables (code NDP) according to molding materials. 4.1.2 Reinforced concrete conduits for electric cables are divided into modified polyvinyl chloride (PVC) lined reinforced concrete conduits for electric cables (PVC-), chlorinated polyvinyl chloride (CPVC) lined reinforced concrete conduits for electric cables (CPVC-) and modified polypropylene (MPP) lined reinforced concrete conduits for electric cables (MPP-) lined according to the types of lined pipes.

Contents of GB/T 27794-2023

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Classification, dimensions and marking 5 Raw materials 6 General requirements 7 Technical requirements 8 Test methods 9 Inspection Rules 10 Marking, packaging, transportation and storage 11 Delivery certificate Annex A (Informative) Joint types and detail dimensions of precast unreinforced concrete conduits for electric cables Annex B (Informative) Joint types of precast reinforced concrete conduits for electric cables Annex C (Normative) Technical requirements for connecting rods Annex D (Informative) Design methods for flexural performance and external pressure load of precast reinforced concrete conduits for electric cables