IMERYS is a supplier of high quality pozzolanic minerals and perlite to the building and construction industry throughout the world.
Metakaolin is manufactured by the calcination of kaolin to form an amorphous pozzolanic white mineral additive for use in cement based products.
The pozzolanic reactivity of Metakaolin is its ability to react with calcium hydroxide in cement based products.
MetaStar™ 501 a high quality concrete additive. Metastar™ is a Metakaolin, with controlled and consistent pozzolanic activity that can be used to enhance the performance of concrete products.
Metakaolin in Concrete
Metakaolin reduces the porosity of concrete, a feature that can allow a reduction in the “cover” of concrete needed to protect reinforcing bars from corrosion. Road and marine structures exposed to corrosive salts are good examples where Imerys Metakaolin can be used to advantage.
Where high strength concrete is required, Imerys Metakaolins increase cured compressive strength of concrete and also speed up curing and early strength development. This makes Imerys Metakaolins suitable for use in applications where high strength is required quickly, such as airport aprons.
Efflorescence is a common problem affecting concrete, caused by lime salts forming calcium carbonate on the surface of the concrete. Imerys Metakaolins can reduce efflorescence by reducing the porosity of the concrete and reacting with the lime salts before they reach the concrete surface.
Metakaolin can also be used to modify the handling properties of wet concrete, particularly benefiting the viscosity profile and reducing the tendency to bleed, making leveling and achieving a good suarface finish easier.
Metakaolin in Glass Fiber Reinforced Concrete (GFRC)
GFRC is a combination of mineral components and glass fibre, obtained by a projection method.
Glass fibre strengthens concrete properties and gives GFRC cohesion, flexural resistance and ductility.
Normally with time, lime formation within the cement, leads to weaker connections between the cement matrix and the fibres which cannot slip anymore. The material is not able to absorb the energy and finally leads to a fatal brittle breakdown of the pieces (loss of ductility).
Combining lime with Metakaolin gives calcium silicate hydrates (CSH), which improve the mechanical performance and the durability of concrete and, by consuming lime, prevent it spoiling glass fibre.
All of our products are supported by a high standard of technical service, product development and research from a team of highly experienced scientists and specialists in the building & construction industries.