GB/T 31545-2015Portland cement for nuclear power engineering (English PDF)

Foreword

GB/T 31545-2015 was issued on 15 May 2015 by the General Administration of Quality Supervision, Inspection and Quarantine and the Standardization Administration of the People's Republic of China, and has been in force since 1 February 2016.

The document is a recommended national standard: the /T in the designation marks it as recommended rather than compulsory, which in the Chinese system means it is the method the reviewer applies.

1 Scope

China's national standard for Portland cement used in nuclear power construction. Nuclear concrete differs from ordinary structural concrete in requirements that come from the plant's hazards rather than from its loads. The containment and shielding structures are enormous continuous pours, so the heat the cement generates as it hydrates cannot escape: the interior reaches a high temperature while the surface cools, and the differential cracks a structure whose whole function is to be impermeable. The second constraint is neutron activation - trace elements in the cement become radioactive under long exposure, which turns the shielding itself into radioactive waste at decommissioning - and the third is chloride, which must be held very low to protect the reinforcement over a design life of sixty years. The standard specifies the definition, the material requirements, the strength grade, the technical requirements, the test methods, the inspection rules, and the packaging, marking, transport and storage of nuclear power cement.

This standard specifies the definition, the material requirements, the strength grade, the technical requirements, the test methods, the inspection rules, and the packaging, marking, transport and storage of Portland cement for nuclear power engineering.

This standard applies to Portland cement for nuclear power engineering.

2 Normative references

The following 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/T 176 Methods for chemical analysis of cement

GB/T 1346 Test methods for water requirement of normal consistency, setting time and soundness of the portland cement

GB/T 5483 Natural gypsum

GB/T 8074 Testing method for specific surface of cement - Blaine method

GB 9774 Sack for portland cement

GB/T 12573 Method for cement sampling

GB/T 12959 Test methods for heat of hydration of cement

GB/T 17671 Method of testing cements - Determination of strength (ISO method)

GB/T 26748 Cement grinding aids

JC/T 603 Standard test method for drying shrinkage of mortar

3 Terms and definitions

For the purposes of this document, the following term and definition apply.

3.1 Portland cement for nuclear power engineering, P.N - a hydraulic cementitious material suitable for nuclear power engineering, made by finely grinding Portland cement clinker of suitable composition together with an appropriate quantity of natural dihydrate gypsum.

5 Strength grade

The strength grade of nuclear power cement is 42.5.