Detail of GB/T 8077-2023

Introduction of GB/T 8077-2023

GB/T 8077-2023 Methods for testing uniformity of concrete admixtures 1 Scope This document describes the methods for testing uniformity of concrete admixtures. This document is applicable to high performance water reducing admixture, high efficiency water reducing admixture, normal water reducing admixture, air entraining type water reducing admixture, pumping agent, early strength agent, retarder, air-entraining agent, waterproofing agent, antifreeze, flash setting admixture and expansive agent, etc. 2 Normative references The following documents contain provisions 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 2419 Test method for fluidity of cement mortar GB/T 6005 Test sieves - Metal wire cloth, perforated metal plate and electroformed sheet - Nominal sizes of openings GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods GB/T 8075-2017 Terms of concrete admixtures GB/T 17671 Test method of cement mortar strength (ISO method) JC/T 681 Mixer for mixing mortars JC/T 729 Mixer for cement paste 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 8075-2017 and the following apply. 3.1 repeatability conditions independent testing conditions on the same test object in a short period of time in the same laboratory with the same equipment by the same operator according to the same testing method [Source: GB/T 8075-2017, 6.7] 3.2 reproducibility conditions independent testing conditions on the same test object in different laboratories with the different equipment by the different operators according to the same testing method [Source: GB/T 8075-2017, 6.8] 3.3 repeatability limit value delimiting a probability of 95% that the absolute difference of two test results is less than or equal to it under the repeatability conditions (3.1) [Source: GB/T 3358.2-2009, 3.3.9] 3.4 reproducibility limit value delimiting a probability of 95% that the absolute difference of two test results is less than or equal to it under the reproducibility conditions (3.2) [Source: GB/T 3358.2-2009, 3.3.14] 4 Test conditions 4.1 Number of tests and requirements 4.1.1 The number of tests for determination of each chemical property shall be two. The absolute difference between the two results shall be within the repeatability limit. The mean of the two test results shall be used to express the test result. If the absolute difference between the two results exceeds the repeatability limit, it is necessary to carry out the third determination in a short time, eliminate the data exceeding the repeatability limit, and take the mean of the other two data. If the third data is within the two values, the mean of the three test results shall be used to express the test result. Unless otherwise specified, if the deviations of three results all exceed the repeatability limit, the test shall be conducted again. 4.1.2 During routine production control analysis, determination of each chemical property by a single test shall be the minimum required. 4.1.3 The water used in this document shall not be lower than the requirements of Grade III water specified in GB/T 6682-2008, except the fluidity of cement paste and the water-reducing rate of cement mortar.  

Contents of GB/T 8077-2023

Foreword III 1 Scope 2 Normative references 3 Terms and definitions 4 Test conditions 4.1 Number of tests and requirements 4.2 Blank test 4.3 Ignition 4.4 Constant mass 4.5 Inspection of chloride ions (Cl-) (with silver nitrate solution) 4.6 Requirements for reagents 4.7 Requirements for data processing 5 Appearance 6 Stability 6.1 Principle 6.2 Instruments 6.3 Test procedure 6.4 Calculation and expression of results 6.5 Determination of test results 7 Solid content 7.1 Drying method 7.2 Dilution drying method 7.3 Vacuum drying method 8 Moisture content 8.1 Drying method 8.2 Vacuum drying method 9 Density 9.1 Pyknometer method 9.2 Precision densitometer method 10 Fineness 10.1 Hand sieving method 10.2 Negative pressure sieve method 11 pH 11.1 Principle 11.2 Instruments 11.3 Test conditions 11.4 Test procedure 11.5 Expression of results 11.6 Repeatability limit and reproducibility limit 12 Surface tension 12.1 Principle 12.2 Instruments 12.3 Test conditions 12.4 Test procedure 12.5 Result and calculation 12.6 Repeatability limit and reproducibility limit 13 Chloride ion content 13.1 Potentiometric titration 13.2 Ion chromatography 14 Sodium sulfate content 14.1 Gravimetric method 14.2 Ion exchange gravimetric method 15 Fluidity of cement paste 15.1 Principle 15.2 Materials and instruments 15.3 Environmental conditions 15.4 Test procedure 15.5 Expression of results 15.6 Repeatability limit and reproducibility limit 16 Water reducing rate of cement mortar 16.1 Principle 16.2 Materials and instruments 16.3 Environmental conditions 16.4 Test procedure 16.5 Result and calculation 16.6 Repeatability limit and reproducibility limit 17 Alkali content 17.1 Flame photometry 17.2 Atomic absorption spectrophotometry Annex A (Informative) Effective composition A.1 Principle A.2 Reagents and instruments A.3 Environmental conditions A.4 Test procedure Annex B (Informative) Corresponding relationship between density of pure water and temperature Annex C (Informative) Example of calculating chloride ion percentage in concrete admixture by the second derivative method C.1 Blank test and calibration of silver nitrate concentration C.2 Test of admixture sample Bibliography