During the hydration of Portland cement, the tri- and di- calcium silicate phases (C2S and C3S) react with water to form calcium silicate hydrate (CSH) gel and calcium hydroxide (lime). The lime component is significantly soluble in water, and it does not contribute to set cement strength. Pozzolanic additives contain silica, and sometimes also alumina, which react with the lime to form insoluble phases that significantly increase the strength and chemical resistance of the cement, whilst at the same time reducing its permeability.
Metakaolin products have very strong pozzolanic reactivity and they are the most effective pozzolan for strength enhancement, improving both the compressive and flexural strength of the set cement. They are available in both dry and convenient non-settling slurry forms. To find the product adapted to your needs go to our metakaolin page.
Uncalcined diatomite is a natural pozzolan consisting of amorphous silica.
Perlite is a natural volcanic glass with can be used as an extender but also posseses also pozzolanic properties, so slurries extenders.
All of our products are supported by a high standard of technical service and research and development from a team of highly experienced scientists and specialists.