Over the years, polymer modified asphalt has been widely used in various waterproofing projects, which has fully proved its excellent performance, in addition to its good elasticity, strong weather resistance, fatigue resistance, anti-aging and other characteristics, but also has the advantages of reliable quality and economy. Polymer-modified asphalt waterproof materials include polymer-modified asphalt waterproof coils and polymer-modified asphalt waterproof coatings. Coils and coatings have their own length, compared with coils, paint construction is simpler and more convenient, suitable for any shape of the substrate, can form a dense and seamless coating film. Therefore, polymer modified asphalt waterproof coating has been widely used in a variety of waterproofing projects, and has been rapidly developed.
1, research and development background
solvent-based polymer modified asphalt waterproof coating applications will pollute the environment, harmful to human health and waste a lot of resources, so the development of water-based environmentally friendly waterproof coatings such as high-performance water-based polymer modified asphalt waterproof coating is the trend. Due to technical reasons, traditional water-milk polymer modified asphalt waterproof coating products are relatively poor in terms of aesthetics and durability. During construction, because the traditional polymer modified asphalt coating is a single-part material, can only be painted or rolled on the grass, to be evaporated water after the formation of a continuous waterproof film; In order to adapt to the rapid construction of modern buildings and infrastructure and environmental protection requirements, polymer modified asphalt waterproof coatings should be developed in a direction with higher performance and greater adaptability to grass-roots telescopic or cracking deformation;
The rapid development of China's infrastructure construction, especially high-speed railway, highway and urban subway construction, 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 highly valued by the waterproof industry at home and abroad, and its work has begun to bear fruit. Internationally, the United States, Canada, South Korea has developed such products, supporting spraying construction equipment has also been used;
2, characteristics and technical indicators
is sprayed high-bullet rubber asphalt waterproof coating is nearly 10 years abroad, nearly 5 years of domestic research and development to promote a new waterproof coating, is made of polymer rubber emulsion by a special process of emulsified asphalt modified into an elastic waterproof coating, construction to take a direct spray at the project site. The main features of the material are as follows:
1) coating elasticity and elongation rate is good, elongation can reach 16 times, recovery rate of more than 90%, the main technical properties and indicators of the material see Table 1. The technology can solve the problem of leakage and rust caused by stress deformation, expansion cracking, puncture or broken connection.
2) coating can be completely covered with the base, with the grass 100% bonding, do not run water, do not peel, especially suitable for special shape structure or complex shape of the site, the construction is relatively simple.
3) Good environmental protection, no benzene, toluene, formaldehyde and other toxic and harmful substances, in the production, construction and use of no exhaust gas emissions, can be applied to the summary: introduced the characteristics of the current spray high-bomb rubber asphalt waterproof coating, the main technical indicators and the comparison with the traditional polymer modified asphalt waterproof coating, and the waterproof coating construction process and application scope is described. Keywords: polymer modified asphalt waterproof coating, high-bullet rubber asphalt waterproof paint, spray construction, instant curing of closed space construction applications.
4) instantaneous molding, the use of professional spraying equipment construction, labor savings, can greatly shorten the duration, save construction costs.
5) good adhesion, and concrete, steel, wood, metal and other materials can be well bonded.
6) coating methods are diverse (spraying, brushing, rolling coating), simple construction, and can meet a variety of details such as drains, yin and yang corners, cracking parts and other operating requirements.
7) can be constructed on wet surfaces, speeding up the construction progress of the entire package project.
3, and traditional polymer modified asphalt waterproof coating difference
1) technical performance is different. Traditional polymer modified asphalt waterproof coating solid content is low, elasticity is poor, fracture elongation is small, anti-top cracking ability is poor, the application environment temperature range is small. Now sprayed high-bullet rubber asphalt waterproof coating solid content is high, good elasticity, elasticity can reach more than 90%, fracture elongation rate than the traditional modified asphalt coating improved a lot, but also has excellent resistance to top breaking, the application of environmental temperature range has also been expanded, low temperature resistance and high temperature resistance is better, can meet the road bridge concrete pavement waterproof material temperature requirements. The implementation of the "water-milk asphalt waterproof coating" (JC/T408-2005) standard of traditional polymer modified asphalt waterproof coating and the current spray of high-bullet rubber asphalt waterproof coating of the main technical indicators compared to Table 2.
2) construction methods are different. Traditional polymer modified asphalt waterproof coating generally use brushing and rolling coating method, a brush can not be too thick, need to paint many times to achieve the design thickness, each brush to wait for the coating film drying before carrying out, so the construction speed is slow, long duration, film thickness is not uniform, this construction disadvantage seriously restricts the application of the coating development. The above problems are overcome by the characteristics of spraying high-bullet rubber asphalt waterproof coating for spraying construction and rapid curing.
3) the scope of application is different. Traditional polymer modified asphalt coatings are generally not used in subways, tunnels, culverts, landfills, artificial lake water conservancy facilities and projects with more roofs and facades due to low physical performance indicators and restrictions on the construction process of artificial brushing (rolling coating). Now sprayed high-bullet rubber asphalt waterproof coating because of its excellent technical performance and the use of on-site spraying, instant curing of the construction process, its application is more extensive.
4, construction process
now sprayed high-bullet rubber asphalt waterproof paint has changed the traditional waterproof paint artificial brush construction method, the use of professional spraying equipment on-site spraying construction process, to ensure the uniformity of film thickness, eliminate the influence of human factors, make waterproof more reliable. At room temperature, A and B two-component materials are composed of main agent and curing agent, which are sprayed with atomization and high-speed mixing by two nozzles, respectively, and the material is instantly cured into film after injection to the substing (Figure 1 is the process of instant curing molding for site spray construction). Each spraying equipment can reach 1500-2000m2 per day under the premise that the construction base has the construction conditions, which greatly improves the efficiency of waterproof construction. Below, the waterproofing project of concrete base is used as an example to describe the construction process of the waterproof coating of high-bullet rubber asphalt.
1) Construction order: brush high-bullet rubber asphalt waterproof paint and non-woven cloth in the weak parts for enhanced treatment→ spray high-bullet rubber asphalt waterproof paint special primer, dosing 0.1kg/m2→ spraying 1.5mm thick high-bullet rubber asphalt waterproof coating for main waterproofing, dosing 2.1kg/m2→ if necessary brush paint, dosing 0.5kg/m2.
2) Construction method
(1) substation dry, strong, clean, to meet the construction requirements of spraying, the use of brush-coated high-bullet rubber asphalt waterproof paint and laid non-woven fabric, cracking, corners and other weak parts to strengthen treatment.
(2) in order to enhance the adhesion strength of high-bounce rubber asphalt waterproof coating, spray the matching primer before spraying a large area.
(3) primer spraying is completely cured, the use of special spraying equipment to evenly spray high-bullet rubber asphalt waterproof paint, thickness of more than 1.5mm, a spray to achieve the design thickness.
(4) spraying high-bullet rubber asphalt waterproof coating, if the thickness is not up to standard or local need to be strengthened, then the brush coating method is used.
(5) according to the different protection and beautification needs of the project, can be coated with paint or other protective materials on the waterproof layer.
5, application range
now sprayed high-bullet rubber asphalt waterproof paint excellent waterproof performance and site spray construction simple and fast process methods combined, making the material application is very wide.