Fair faced concrete is one of the topics in the development of reinforced concrete construction technology. It is a comprehensive construction technology from design to construction quality, concrete mix proportion design, finished product protection, concrete surface repair and formwork design. At present, because the current national specifications have no accurate definition and clear quality standards for fair faced concrete, there are different understandings and quality standards for fair faced concrete. The fair faced concrete emphasized by general construction units often refers to that no plastering is made after the formwork is removed, the concrete surface is flat, the color is uniform, there is no honeycomb and pitted surface, exposed reinforcement, slag inclusion, pulverization, rust spots and obvious bubbles, and the surface texture and "natural color" of the concrete are pursued.
Obviously, the surface quality of concrete is the direct reflection of the success of fair faced concrete, and the quality of formwork and release agent is the key to the surface quality of concrete.
The resin type formwork surface coating named formwork paint can be used as a long-term release agent for various molds such as wood mold, bamboo mold, steel mold and so on. The paint has been welcomed by the concrete products and construction industry, which has solved the problems that have plagued the industry for a long time, such as easy rust of formwork storage, easy pollution of concrete surface, difficult demoulding and mold cleaning, and the formed concrete has the surface texture of fair faced concrete. This paper summarizes the function, characteristics and application technology of the paint, which can be used as a reference for people in the concrete engineering industry.
Function and characteristics of template paint
1. Protect the formwork and prolong its service life.
In concrete construction engineering, most of the formwork are stacked in the open air. How to protect the formwork from rust is a big problem in the concrete industry. The paint has excellent corrosion and rust resistance, so it is very popular. On the other hand, due to the isolation effect of the paint film, the formwork is free from the abrasion of concrete sand and gravel and the corrosion of cement hydrate, so as to prolong the service life of the formwork.
2. Improve the surface quality of concrete and achieve the effect of "fair faced concrete". The paint film has good surface finish, bright and plump, naturally forms enamel, and can make up for the defects on the surface of the formwork; At the same time, the film has low demoulding adsorption force, easy demoulding and cleaning, and avoids the adhesion of concrete. The concrete formed with the paint has smooth surface, fine hand feel, marble like and shiny, which greatly improves the appearance quality of the concrete, fully shows the "natural color" of the concrete and achieves the effect of fair faced concrete.
3. It can be used as a long-term release agent. The paint has good adhesion (the bonding strength with steel is up to 9Mpa), wear resistance and alkali resistance, and can be reused for many times. The thermal decomposition temperature of the paint film is about 350. C. It also has good heat resistance and alkalinity (saturated calcium hydroxide 80. C soaking for 48h, physical and chemical properties do not decline), so it is also suitable for steam curing environment.