Versatile Metakaolin for multiple applications
Our metakaolin ranges, such as our Argical™ M and MetaStar™ series, provide a broad range of benefits when used in concrete, lime mortars and plasters.
Metakaolin is manufactured through the calcination of high purity kaolin to form an amorphous pozzolanic white mineral additive for use in concrete and specialty binder-based products. The pozzolanic reactivity of metakaolin refers to its ability to react with calcium hydroxide in specialty binder-based products. Metakaolin is also used as an additive to substitute specialty binders in concrete, renders and mortars.
When used as an additive to concrete, our metakaolin enhances performance in multiple ways. Firstly, metakaolin reduces efflorescence by reducing the porosity of the concrete and reacting with lime salts before they reach the concrete surface. Metakaolin also reduces the porosity of concrete which prevents corrosive salts and ions from attacking reinforcing metal bars. It is ideal for road and marine structures exposed to corrosive salts. Thirdly, where high strength concrete is required, metakaolin increases cured compressive strength of concrete and speeds up curing and early strength development, making it ideal for applications where high early strength is required, such as airport runways. Lastly, 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 surface finish easier.
Glass Fiber Reinforced Concrete (GFRC) is a combination of mineral components and glass fiber, obtained by a projection method. It’s the glass fiber that strengthens the concrete properties and gives GFRC its cohesion, flexural resistance and ductility. Alas, with time, lime formation within the specialty binder leads to weaker connections between the specialty binder matrix and fibers that can no longer slip. The material becomes unable to absorb the energy, which finally leads to a fatal brittle breakdown of the area (loss of ductility).
Combining lime with metakaolin provides calcium silicate hydrates (CSH), which improve the mechanical performance and durability of concrete and, by consuming lime, prevent it from spoiling the glass fiber.
Our reactive metakaolin pozzolans are ideal for achieving hydraulic set in traditional lime putty mortars and plasters and for improving the mechanical strength of floor mortars. Pozzolans are particularly helpful when applying lime putty mixes in damp, frost prone or exposed locations. Adding metakaolin pozzolans to lime putty mixes increases compressive strength which helps to offer additional protection during the carbonation period.
Metakaolin is also the perfect alternative to industrial by-product silica fume for high performance concrete.The benefits of using metakaolin in place of silica fume include:
- Improved strength, durability and workability
- Increased resistance against corrosion and chemical attacks
- Reduced alkali silica reaction (ASR) Reduced permeability, efflorescence and cracking
- Exceptional whiteness/brightness