GB/T 17457:2019 Ductile iron pipes and fittings - Cement mortar lining
1 Scope
This standard specifies the material, the method of application, the thickness of internal lining and the surface condition as well as the corresponding test methods of cement mortar lining for ductile iron pipes and fittings as defined in GB/T 13295-2019 and GB/T 26081-2010.
This standard is applicable to cement mortar linings which are used to improve the hydraulic properties of pipes and fittings compared to un-lined ductile iron pipes and fittings and/or to prevent corrosion damage and includes special requirements for linings of gravity sewers operating partially filled.
This standard is also applicable to linings used for the conveyance of particularly aggressive fluids, where the following solutions may be used either separately or in combination:
——an increase in the thickness of the lining;
——a change of the type of cement;
——a coating over the lining.
2 Normative references
The following referenced documents are indispensable for the application 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 201 Calcium aluminate cement
GB/T 748 Sulfate resistance portland cement
GB/T 13295-2019 Ductile iron pipes, fittings and accessories for water or gas applications (ISO 2531: 2009, MOD)
GB/T 14684 Sand for construction
GB/T 17219 Standard for safety evaluation of equipment and protective materials in drinking water system
GB/T 17671 Test method of cement mortar strength (ISO method) (GB/T 17671-1999, idt ISO 679: 1989)
GB/T 26081-2010 Ductile iron pipes fittings and accessories for sewage applications (ISO 7186: 1996, MOD)
GB/T 32488 Ductile iron pipes and fittings - Seal coats for cement mortar linings (GB/T 32488-2016, ISO 16132: 2004, MOD)
3 Materials
3.1 Cement
3.1.1 The cement used for the lining of ductile iron pipes and fittings shall meet the corresponding national standards according to their types. The general portland cement (including ordinary portland cement, portland slag cement, etc.) shall meet the requirements of GB 175, the calcium aluminate cement shall meet the requirements of GB/T 201, and the sulfate resistance portland cement shall meet the requirements of GB/T 748.
3.1.2 Unless otherwise specified, the type of cement shall be selected by the manufacturer in order to be suitable for the nature of the fluid to be transported, with due consideration to GB/T 13295-2019, Annex G, and GB/T 26081-2010, Annex D.
3.2 Sand
