Clear faced concrete is one of the topics in the development of reinforced concrete construction technology. It is a comprehensive construction technology that covers design to construction quality, concrete mix design, finished product protection, concrete surface repair, and formwork design. At present, due to the lack of accurate definition and clear quality standards for fair faced concrete in current national regulations, there are different understandings and quality standards for fair faced concrete. The plain concrete emphasized by general construction units often refers to the concrete surface that is flat without any plastering after the formwork is removed, with uniform color, no honeycomb or rough surface, exposed reinforcement, slag inclusion, powdering, rust spots, and obvious bubbles, pursuing the surface texture and "natural color" of the concrete.
Obviously, the surface quality of concrete is a direct reflection of the success or failure of plain concrete, and the quality of formwork and release agents is the key factor affecting the surface quality of concrete.
A resin based template surface coating named template paint, which can be used as a long-term release agent for various molds such as wooden molds, bamboo molds, and steel molds. This paint has been well received by the concrete products and construction industry, solving the long-standing problems of template storage being prone to rust, concrete surface being easily contaminated, and difficulties in demolding and cleaning. The formed concrete has the surface texture of plain concrete. This article summarizes the functions, characteristics, and application technologies of this paint for reference by professionals in the concrete engineering industry.
The function and characteristics of template paint
1. Protect templates and extend their lifespan.
In concrete construction projects, most templates are stored outdoors. How to protect the templates from rusting is a major challenge in the concrete industry. This paint has excellent anti-corrosion and rust prevention properties, making it very popular. On the other hand, the isolation effect of the paint film prevents the formwork from being eroded by concrete sand and gravel and corroded by cement hydrates, thereby extending the service life of the formwork.
2. Improving the surface quality of concrete can achieve the effect of "plain concrete". The surface of the paint film is smooth, shiny and full, naturally forming porcelain glaze, which can compensate for the surface defects of the template; Meanwhile, the coating has low demolding adsorption force, making it easy to demold and clean, thus avoiding the adhesion of concrete. The surface of the concrete formed by using this paint is smooth, with a delicate touch, resembling marble, and has a glossy appearance, greatly improving the appearance quality of the concrete and revealing its "natural color", achieving the effect of plain concrete.
3. Can be used as a long-lasting release agent. This paint has good adhesion (up to 9MPa with steel), wear resistance, alkali resistance, and can be reused multiple times. The thermal decomposition temperature of the paint film is about 350. C， And it has good heat and alkali resistance (saturated calcium hydroxide 80. C soaking for 48 hours, physical and chemical properties do not decrease), so it is also suitable for steam curing environments.
