GB 16776-2025Structural silicone sealants for building (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 16776-2005 "Silicone structural sealants for building" and GB 24266-2009 "Silicone structural sealants for insulating glass Compared with GB 16776-2005 and GB 24266-2009, in addition to structural adjustments and editorial changes, the main technical changes are as follows:

--- Added classification by purpose (see Chapter 4);

--- Increased the requirements and test methods for density, secant stiffness, shear properties, and alkane plasticizer content (see 5.2, 6.5, 6.11.1.2,

--- Changed the requirements for tensile modulus and thermal weight loss (see 5.2,

5.4 of GB 16776-2005);

--- Changed the requirements and test methods for the bond failure area (water-ultraviolet light) (see 5.2, 6.11.1.4, GB 16776-2005 5.2,

6.8.8 of GB 24266-2009 and 4.2.4,

5.8 of GB 24266-2009);

--- Deleted the requirements and test methods for tensile bond strength after immersion in water (see 5.2,

6.8.7 of GB 16776-2005 and GB 24266- 2009 (4.2.4, 5.8);

--- Added the cleaning method of the test substrate in the preparation of adhesion test specimens (see 6.4.1.2);

--- Changed the test method for hardness (see 6.10,

6.7 of GB 16776-2005);

1 Scope

China's mandatory national standard for structural silicone sealants for building. In a structural glazing facade the glass is held to the frame by nothing but a bead of silicone: there is no mechanical capture, and the sealant carries the wind load and the weight of the panel for the life of the building, thirty metres up. That is the whole reason this standard is mandatory and why its requirements are severe. The tensile adhesion strength is specified not as delivered but after water immersion, after ultraviolet exposure through the glass, and after heat ageing, because those are what the joint actually experiences and because adhesion failure - the silicone parting from the substrate rather than tearing itself - is the failure mode that drops a panel. Compatibility with the substrates and with the other materials in the joint is specified for the same reason.

This document specifies the classification and labeling, requirements, test methods, inspection and Inspection rules as well as marking, packaging, transportation and storage. This document is applicable to silicone structural adhesives used for the secondary sealing structure bonding of building curtain walls and insulating glass.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document.

GB/T 531.1-2008 Test method for indentation hardness of vulcanized rubber or thermoplastic rubber Part

3 Fluorescent ultraviolet lamp

GB/T 22083-2008 Classification and requirements of building sealants

GB/T 31851-2015 Detection method for alkane plasticizers in silicone structural sealants

GB/T 37126-2018 Test methods for building sealants for structural assembly

4 Classification and labeling

4.1 Classification The products are divided into single component (1) and two components (2) according to their composition. According to their uses, the products are divided into building curtain wall structural bonding (C) and insulating glass second sealing structural bonding (S). Products are divided into glass (G), aluminum (AL), and others (Q) according to the substrate used.

5 Determination of surface drying time

GB/T 13477.6-2002 Test methods for building sealing materials Part

6 Determination of fluidity

GB/T 13477.8-2017 Test methods for building sealing materials Part

8 Determination of tensile adhesion

GB/T 13477.10-2017 Test methods for building sealing materials Part

10 Determination of constant-tension adhesion

GB/T 13477.18-2002 Test methods for building sealing materials - Part

18 Determination of peel adhesion

GB/T 14682 Terminology of building sealing materials

GB/T 16422.2-2022 Plastics laboratory light source exposure test method Part