Formwork preparation plays a major role in the final appearance of the concrete surface. The challenge is to prevent adhesion of the hardened concrete on the formwork and ensure easy cleaning of it. This can be achieved with correct application of a suitable mold release agent, which additionally improves the durability and aesthetical appearance of the concrete surface.
The following requirements are specified for the action of mold release agents (MRA):
- Easy and clean release of the concrete from the formwork
- Visually perfect concrete surfaces
- No adverse effect on the concrete quality on the surface
- Protection of the formwork from corrosion and premature ageing
- Easy application
- Lowest impact on the environment
- High level of Ecology, Health and Safety on the construction site and in the precast plant
Another important requirement, specifically for precast works is high temperature resistance when heated formwork or warm concrete is used. Unpleasant odor development is also undesirable, particularly in a precast factory. For site use, an important requirement is adequate rain or UV resistance, and possible accessibility after the mold release agent has been applied.