The waterproof coating standard is an important guiding document for daily coating testing and construction. The national quality inspection department has successively issued or updated various testing standards for waterproof coatings, clearly regulated the production and application of waterproof coatings, and greatly improved the quality of waterproof coatings. However, the domestic standards for waterproof coatings still have some deficiencies such as poor operability of certain detection indicators (such as impermeability), unclear product types, and lack of quality control items such as mildew resistance and cracking of the coating film. By comparing some waterproof coatings and coating film standards at home and abroad, this article allows us to see that there is a big gap in the practicability of domestic and developed country standards, and provides guidance for the revision of domestic standards.
1 Introduction of waterproof coating standards at home and abroad
CHINA Waterproof Coating Standard GB/T 23445 - 2009 [1] "Polymer Cement Waterproof Coating " and JC/T 864 -2008 [2] "Polymer Emulsion Building Waterproof Coating" Test indicators: appearance, solid content, tensile Performance (no treatment, heat treatment, acid-base treatment), bonding performance, acid and alkali resistance , impermeability, impermeability and other indicators are required for the product. The standard indicators mainly focus on the test of the mechanical properties of the waterproof coating film. EU standard EN 14891 [3] "Liquid impermeable products used under tiles " test indicators: impermeability, bridging fracture, bond strength ( after ventilated and dry storage, water immersion treatment, heat curing, lime water immersion, freeze-thaw cycle After that, chlorinated water treatment). The standard examines cracking performance, mechanical properties in lime water, and chlorine water environments, and is closely related to the actual . American standard ANSI 118. 10 [4] "Used for load-bearing and bonded waterproof membranes under tile and stone paving" test indicators: anti-fungal and microbial performance, joint strength, breaking strength, dimensional stability, water resistance, Water immersion shear strength. The main advantage of the standard is that it examines the antibacterial and antimicrobial properties, and makes requirements for the storage performance of waterproof products. Japanese standard JIS A6021-2011［5］ "Coating film waterproof materials for construction" test indicators: tensile properties at different temperatures , tearing properties, heating elongation properties, solid content. This standard focuses on the impact of Japan's complex and changeable weather on performance. Singapore standard [6] "Elastic cement-based waterproof membrane" test indicators : tensile properties (no treatment, heat treatment, alkali treatment, ammonia water treatment, sodium hypochlorite solution treatment ), initial hardness, bridge fracture, chloride content, water vapor Permeability, anti-adhesion. AustraliaAustralian Standard AS 46554.1-2012［7］ "Waterproof Membrane for External Ground Use" test indicators: bond strength, dimensional stability, seam strength, tensile properties, water vapor permeability, temperature resistance, elongation at break rate (detergents, heat aging, UV treatment). This standard focuses on the change of mechanical properties in the kitchen and bathroom environment .
2 Comparison of waterproof coating standards at home and abroad
Compared with the domestic waterproof coating and coating film standards, the different detection indicators of the EU standards include: bonding strength after soaking in chlorine water/MPa≥0.5, bridging fracture≥0.75, bonding strength /MPa≥ 0.5. The different test indicators of the American standard include: antifungal and microbial performance 14 days without growth. Joint strength/MPa≥0.5. The Japanese standard stipulates that the test temperatures for tensile strength and elongation at are 23°C, -20°C, and 60°C, and there are also requirements for tear strength.
The Singapore standard stipulates that the bridge fracture is 2mm wide without cracking, and the 1mm stretching cycle is 10 times without cracking. At the same time, the tensile properties after treatment with ammonia water and sodium hypochlorite solution were tested. The Australian standard stipulates that the joint strength/MPa≥0.5, and the water vapor transmission rate of the coating film is required. Through the comparison of domestic and foreign standards, foreign standards have different requirements in terms of antibacterial and microbial properties, resistance to different temperatures, crack resistance, and resistance to chemical reagents commonly used in kitchens and bathrooms (ammonia, detergent, sodium hypochlorite solution) . The key points of foreign standards are product storage time, performance change trend affected by temperature, whether the construction is cracked, and the performance retention rate of common reagents in contact with kitchen and bathroom. Therefore, it can be concluded that foreign waterproof coating standards are more focused on simulating the performance test in the actual application process.
3 Development trend of waterproof coating standards
A standard is a unified regulation for repetitive things and concepts. It is based on the synthesis of science, technology and practical experience, and is used as a criterion and basis for common compliance after consensus among relevant parties. The development of waterproof coating standards is closely related to the development of waterproof coating industry. Green health , low-carbon environmental protection, advocating nature and other factors will be considered as the main trade-off points for waterproof coating products. At the same time, in order to promote the development of the waterproof coating industry, the formulation and improvement of standards need to be closer to reality and avoid excessive formalization [8]. Secondly, the formulation and revision of standards should be as de-enterprise-oriented as possible. Avoid the intervention of production enterprises and the suppression of some indicators. Therefore, referring to the professional experience of foreign waterproof coating standards and the development trend of the domestic waterproof coating industry, domestic waterproof coating standards will definitely develop .
4 Suggestions for revision of waterproof coating standards
By comparing the advantages and disadvantages of domestic and foreign waterproof coating standards, referring to the practical indicators of foreign standards, and combining the actual situation of the domestic waterproof industry, I suggest that the waterproof coating standards should be carried out according to Table 1.
references
［1］JC/T 864-2008 Polymer emulsion building waterproof coating［S］
［2］GB/T 23445-2009 Polymer Cement Waterproof Coating［S］
[3] EN 14891 Liquid-impermeable products for use under ceramic tiles [S]
[4] ANSI 118.10 Load-bearing, bonded waterproofing membranes for use under tile and stone paving [S]
［5］JIS A6021－2011 Coated waterproof materials for construction［S］
[6] Elastic cement-based waterproof membrane [S]
［7］AS 46554.1-2012 Waterproof membrane for external ground［S］
[8] Hong Bo. Some views on the current testing standards for waterproof coatings［J］．Guangdong Building Materials, 2005(5)
About the author: Huang Kai (born in 1986), master, engineer, mainly engaged in the research of .
