Artificial aging test of building sealing materials

Building sealing materials are a type of functional building materials that can withstand joint displacement to achieve airtightness and watertightness and are embedded in building joints. It is of great significance to improve the sealing, energy saving, waterproofing, sound insulation, dustproof and other functions of buildings.
Artificial aging test of building sealing materials can be carried out through various artificial aging tests to measure the color change of sealant after artificial accelerated aging, determine the contamination of sealing materials in building joints to porous substrates (such as marble, limestone, sandstone or granite), and measure the bonding performance of sealing materials after exposure to heat, artificial light and water circulation, providing a reliable basis for selecting and evaluating the quality of sealants.
Zhongke Testing and Reliability Experiment Center has the capabilities of environmental testing and reliability performance testing of various building materials, products and components, and provides professional artificial aging testing services for building sealing materials.

1. Sealing materials can be divided into two categories according to their strength: shaped sealing materials (sealing strips, pressure strips, etc.) and non-shaped sealing materials (sealing paste or caulking paste, etc.). Amorphous sealing materials can be divided into plastic sealing paste, elastic-plastic sealing paste and elastic sealing paste according to their raw materials and their properties.
2. Sealing materials can be divided into polysulfide, polyurethane, silicone, chloroprene rubber, butyl rubber, acrylic glue, etc. according to their chemical composition. At present, the three types that are used in large quantities on the market are silicone, polyurethane, and polysulfide.

1. Determination of adhesion
Bond the sealing material sample between the surfaces of two parallel glass plates to make a specimen. After the specimen is exposed to a cycle of artificial light and water at the specified temperature, the specimen is stretched to the specified width. After maintaining the tensile state for the specified time, check the bonding or cohesive failure mode of the specimen.
2. Determination of color change
The sealant is made into a test piece, and the color difference value of the test piece before and after artificial accelerated weathering is used to characterize the degree of color change of the test piece.
3. Determination of contamination of porous substrates
Measures the visible contamination of a porous substrate caused by a joint sealant material under specified conditions. The sealing material is filled between two porous substrates and solidified to form a test specimen. The specimen is compressed (or not compressed) and subjected to accelerated aging treatment by heat and/or low temperature and/or light radiation, and the test specimen is evaluated after the aging treatment.
By visually observing the changes on the surface of the substrate, measuring the maximum and minimum contamination width and depth, and recording the contamination phenomena on the outer surface of the substrate and inside the body.

GB/T 13477.21-2022 Test methods for building sealing materials Part 21: Determination of color changes after artificial accelerated weathering
GB/T 13477.17-2022 Test methods for building sealing materials Part 21: Determination of adhesion after exposure to heat, artificial light through glass and water
GB/T 13477.20-2017 Test methods for building sealing materials Part 20: Determination of contamination
ISO 11431:2002 Building construction - Welded products - Determination of the adhesive/bonding properties of sealants after exposure to heat, water and artificial light through glass
ISO 16938-1:2008 Building construction Determination of staining of porous substrates by joint sealants Part 1: Compression test