GB/T 9776-2022Calcined gypsum (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules for Standardization Documents" drafting.

This document replaces GB/T 9776-2008 "Building Gypsum". Compared with GB/T 9776-2008, except for structural adjustments and editorial changes In addition, the main technical changes are as follows.

a) Delete the terms and definitions of flue gas desulfurization gypsum and phosphogypsum (see 3.2.1 and 3.2.2 of the 2008 edition);

b) Changed the terms and definitions of desulfurized building gypsum and phosphorus building gypsum (see 3.4, 3.5, 3.4.1, 3.4.2 of the 2008 edition);

c) The classification has been changed (see 4.1, 4.1 of the 2008 edition);

d) The raw materials have been changed (see Chapter 5, Chapter 5 of the 2008 edition);

e) The composition has been changed (see 6.1, 6.1 of the 2008 edition);

f) The physical and mechanical properties have been changed, the fineness index has been canceled, and the dry strength index has been added (see 6.2, 6.2 of the 2008 edition);

g) Changed the radionuclide limit (see 6.3, 6.3 of the 2008 edition);

h) Added content requirements for restricted ingredients (see 6.4);

i) Added pH requirements (see 6.5);

j) The composition test method has been changed (see 8.1, 7.3.1 of the 2008 edition);

k) Delete the test method for fineness (see 7.3.2 of the 2008 edition);

l) The test method for dry strength has been added (see 8.3.3);

m) Changed the type inspection (see 9.2, 8.1.2 of the 2008 edition);

n) The determination method of water-soluble chloride ion content has been added (see Appendix A).

1 Scope

This document specifies the classification and labeling, raw materials, technical requirements, test methods, inspection rules and packaging, marking, transportation of plaster of construction. and storage.

This document applies to building gypsum made from natural gypsum, flue gas desulfurization gypsum and phosphogypsum, and building stone made from other industrial by-product gypsum Paste can refer to implementation.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 5483-2008 Natural Gypsum

GB/T 5484-2012 Chemical analysis methods for gypsum

GB 6566 Limits of radionuclides in building materials

GB/T 6682 Analytical laboratory water specifications and test methods

GB/T 17669.1-1999 General test conditions for building plaster

GB/T 17669.3-1999 Determination of Mechanical Properties of Building Gypsum

GB/T 17669.4-1999 Determination of physical properties of building gypsum paste

GB/T 23456-2018 Phosphogypsum

GB/T 36141 Phase Composition Analysis Method of Building Gypsum

GB/T 37785 flue gas desulfurization gypsum

JC/T 2073 Determination method of phosphorus and fluorine in phosphogypsum

3 Terms and Definitions

The following terms and definitions apply to this document.

3.2 Construction plaster (3.1) made from natural gypsum