Technical application of high-elastic rubber asphalt waterproof coating

For many years, the wide application of polymer modified asphalt in various waterproof engineering has fully proved its excellent performance. In addition to its characteristics of good elasticity, weather resistance, fatigue resistance and anti-aging, it also has reliable quality and economy. Sex and other advantages. The polymer modified asphalt waterproofing material comprises a polymer modified asphalt waterproofing membrane and a polymer modified asphalt waterproofing coating. The coils and coatings have their own advantages. Compared with the coils, the coating construction is simpler and more convenient. It is suitable for the base surface of any shape and can form a dense and seamless coating film. Therefore, polymer modified asphalt waterproof coatings have been widely used in various waterproof engineering and have been rapidly developed.

1. Research and development background

The application of solvent-based polymer modified asphalt waterproof coating will pollute the environment, be harmful to human health and waste a lot of resources. Therefore, it is an irresistible trend to develop water-based environmentally-friendly waterproof coatings such as high-performance water-based polymer modified asphalt waterproof coatings. For technical reasons, the traditional water-based polymer modified asphalt waterproof coating products are relatively poor in terms of mechanical properties and durability. During construction, since the traditional polymer modified asphalt coating is a one-component material, it can only be painted or rolled on the base layer, and a continuous waterproof membrane is formed after the water is volatilized; it can only be multi-pass and thin when painting. Coating has seriously affected the construction progress and increased construction costs. In order to adapt to the rapid construction and environmental protection requirements of modern buildings and infrastructure, polymer modified asphalt waterproof coatings should be developed in the direction of higher performance and more adaptability to base layer expansion or cracking deformation; construction methods should also be manually applied. The brush turns to a rapid construction process using on-site spraying of mechanical equipment and instant film formation.

At present, the rapid development of China's infrastructure construction, especially the construction of high-speed railways, highways and urban subways, has brought unprecedented opportunities for the development of high-performance waterproof coatings. Research and development of high-performance waterproof coatings and the development and promotion of new supporting construction tools have been obtained. The waterproof industry at home and abroad attaches great importance to it, and its work has achieved initial success. Internationally, the United States, Canada, and South Korea have developed such products, and the supporting spray construction equipment has also been applied; in China, some companies have begun technology research and development, production and application in this area.

2. Features and technical indicators

The high-elastic rubber asphalt waterproof coating is a new type of waterproof coating developed and promoted in the past 10 years in China and in the past 5 years. It is a kind of modified emulsified asphalt made by polymer rubber emulsion. Elastic waterproof coating, the construction adopts the method of direct spraying at the engineering site. The main features of the material are as follows:

1) The film elasticity and elongation are good, the elongation can reach 16 times of its own, and the recovery rate is over 90%. The main technical properties and indexes of the materials are shown in Table 1. The technology can solve the leakage and rust problems of the structure due to stress deformation, expansion and cracking, puncture or poor connection.

2) The coating can completely cover the base layer, and is 100% bonded to the base layer. It is not water-repellent or peel-off. It is especially suitable for parts with irregular structures or complicated shapes, and the construction is relatively simple.

3) Good environmental protection, no toxic and harmful substances such as benzene, toluene, formaldehyde, etc., no exhaust emission during production, construction and use, applicable to summary: Introduce the characteristics and main technologies of high-elastic rubber asphalt waterproof coating The index and the comparison with the traditional polymer modified asphalt waterproof coating, and the construction process and application range of the waterproof coating are described. Key words: polymer modified asphalt waterproof coating; high elastic rubber asphalt waterproof coating; spray construction; construction application of instantaneous curing confined space.

4) Instant molding, using professional spraying equipment construction, saving labor, can greatly shorten the construction period and save construction costs.

5) Adhesion is good, and it can be well bonded with various materials such as concrete, steel, wood and metal.

6) Various coating methods (spraying, brushing, and rolling), easy to construct, and can meet the operation requirements of various details such as drain, yin and yang, and cracking.

7) It can be applied on wet surfaces to speed up the construction progress of the entire general contracting project.

3. Differences from traditional polymer modified asphalt waterproof coatings

1) Different technical performance. The traditional polymer modified asphalt waterproof coating has low solid content, poor elasticity, small elongation at break, poor resistance to bursting, and a small application temperature range. The high-elastic rubber asphalt waterproof coating has high solid content, good elasticity, and the recovery after stretching can reach more than 90%. The elongation at break is much higher than that of the traditional modified asphalt coating, and it also has excellent resistance to bursting. The capacity and application environment temperature range have also been expanded, and the low temperature resistance and high temperature resistance are better, which can meet the temperature requirements of waterproof materials for road and bridge concrete pavements. See Table 2 for the comparison of the main technical indicators of the traditional polymer modified asphalt waterproof coating and the currently sprayed high-elastic rubber asphalt waterproof coating which are based on the standard of "water emulsion asphalt waterproof coating" (JC/T408-2005).

2) Different construction methods. The traditional polymer modified asphalt waterproof coating generally adopts the method of brushing and rolling, and the brushing can not be too thick at one time, and it is necessary to apply the brushing multiple times to reach the design thickness, and each brushing can be performed after the coating film is dried. Therefore, the construction speed is slow, the construction period is long, and the film thickness is not uniform. This construction drawback seriously restricts the application development of the coating. The above-mentioned problems are overcome by the sprayable construction and rapid curing of the high-elastic rubber asphalt waterproof coating.

3) The application range is different. Conventional polymer modified asphalt coatings are generally not used in subways, tunnels, culverts, landfills, artificial lake water conservancy facilities and top surfaces due to their low physical performance and limited artificial brushing (rolling) construction process. And projects with more facades. The high-elastic rubber asphalt waterproof coating is widely used due to its excellent technical performance and construction technology using on-site spraying and instant curing.

4. Construction process

The high-elastic rubber asphalt waterproof coating has changed the construction method of traditional waterproof coating artificial painting. The construction technology of the professional spraying equipment on-site spraying ensures the uniformity of the film thickness and eliminates the influence of human factors, making the waterproof more reliable. . At room temperature, the main component and the curing agent are composed of A and B two-component materials, which are sprayed by two nozzles through the pipeline to atomize and mix at high speed. After the material is sprayed onto the base surface, the material is solidified into a film (Fig. 1 is the scene). The mechanism of instant curing of spray coating construction). The construction capacity of each spraying equipment can reach 1500~2000m2 under the premise of construction conditions on the construction base, which greatly improves the efficiency of waterproof construction. The following is a description of the construction process of the high-elastic rubber asphalt waterproof coating of the sprayed concrete base.

1) Construction sequence: brush high-elastic rubber asphalt waterproof coating + non-woven fabric for strengthening treatment in weak parts → spraying high-elastic rubber asphalt waterproof coating special primer, dosage 0.1kg/m2 → spraying 1.5mm thick high-elastic rubber asphalt waterproof coating Main waterproof, the dosage is 2.1kg/m2→ If necessary, apply the topcoat, the dosage is 0.5kg/m2.

2) Construction method

1 The base surface is dry, strong and clean. After the spraying construction requirements are met, the brush-coated high-elastic rubber asphalt waterproof coating is applied and the non-woven fabric is laid to strengthen the weak parts such as cracks and corners.

2 In order to enhance the adhesion strength of the high-elastic rubber asphalt waterproof coating, spray the matching primer first before spraying in a large area.

3 After the primer is completely cured, use a special spraying equipment to evenly spray a high-elastic rubber asphalt waterproof coating with a thickness of 1.5mm or more and a single coating to reach the design thickness.

4 After spraying high-elastic rubber asphalt waterproof coating, if the thickness is not up to standard or the local needs to be strengthened, it will be treated by brushing.

5 According to the different protection and beautification requirements of the project, you can apply top coat or other protective materials on the waterproof layer.

5, the scope of application

The excellent waterproof performance of the high-elastic rubber asphalt waterproof coating and the simple and quick process of on-site spraying make the material have a wide range of applications.

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