GB/T 13477.21-2022Test method for building sealants - Part 21: Determination of color change after laboratory accelerated weathering procedures (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 of Standardization Documents" drafted. This document is part 21 of GB/T 13477 "Test methods for building sealing materials". GB/T 13477 has issued the following part.

1.Provisions for test substrates;

2.Determination of density;

3.Method for determining the extrudability of sealing materials using standard equipment;

4.Determination of extrudability of single-component sealing materials in original packaging;

5.Determination of surface dry time;

6.Determination of mobility;

7.Determination of low temperature flexibility;

8.Determination of tensile adhesion;

9.Determination of tensile adhesion after immersion in water;

10.Determination of fixed elongation adhesion;

11.Determination of set-stretch adhesion after immersion in water;

12.Determination of adhesion after stretching-compression cycles at the same temperature;

1 Scope

GB/T 13477.21-2022 is the Chinese national standard on test method for building sealants - part 21: determination of color change after laboratory accelerated weathering procedures, in the field of construction materials and building. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 11 July 2022 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 February 2023. Classification: ICS 91.100.50, CCS Q24. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

2 Normative references

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

GB/T 3978 Standard Illuminator and Geometric Conditions

GB/T 3979-2008 Measurement method of object color GB/T 5698 Color Terms

GB/T 7921-2008 Uniform color space and color difference formula

GB/T 8170-2008 Numerical Rounding Rules and Representation and Judgment of Limit Values

GB/T 9086 Standard whiteboard for colorimetric and photometric measurement

GB/T 13477.1 Test methods for building sealing materials - Part

GB/T 14682 Terms of Building Sealing Materials

GB/T 16422.2-2014 Plastics Laboratory Light Source Exposure Test Method Part

3 Terms and Definitions

The terms and definitions defined in GB/T 3978, GB/T 5698, and GB/T 14682 apply to this document.

4 Principles

The sealant was made into a test piece, and the color difference value of the test piece before and after artificial accelerated weathering was used to characterize the degree of color change of the test piece.

5 Test conditions

5.1 Laboratory Standard Test Conditions Temperature (23±2)°C, relative humidity (50±5)%.

5.2 Specimen placement conditions Standard laboratory test conditions for clean, ventilated, protected from light that do not contain chemicals that may cause discoloration of the sealant.