Elkem Microsilica® for Fibre cement

The world is changing to asbestos free. Learn more about the benefits of Elkem Microsilica® for fibre cement production.

The world is changing to asbestos free. It all started in the 1970s in Australia, Europe, North America and Japan. Elkem has been there from the start with an environmentally responsible additive for the fibre cement industry.

What is Elkem Microsilica® ?

Elkem Microsilica consists of sub-micron, amorphous , non-porous spheres of silicon dioxide (silica, SiO2) and small agglomerates of these. The average particle size of the spheres is about 0.15 micron. Although some of the spheres exist as single entities, most of them form primary agglomerates with typical particle range 0.1 - 1 micron.
Microsilica also contains some larger, secondary agglomerates typically 5 - 50 micron. They are easily broken down to primary agglomerates when the microsilica is mixed with water.

Benefits of Elkem Microsilica®

 •As an extremely reactive pozzolan, Elkem Microsilica forms additional binder and therefore strengthens the fibre cement product.
 •As an ultrafine material, microsilica increases the packing density of the fibre cement matrix.
 •The ultra-fine Elkem Microsilica particles form a more refined pore structure, with lower over-all porosity consisting of smaller pores, and thereby enhance the durability of the fibre cement product.
 •In the fresh state, Elkem Microsilica aids in binding water and thereby enhances the plasticity of the fresh mix.
 •Increases the bending strength of fibre reinforced cement
 •Improves the freeze-thaw properties of fibre cement

Product grades
Elkem Microsilica® is classifed according to different grades, which reflect the material analyses and properties.
For fibre cement Elkem recommends:
 •Powder - Grade 940 
 •Slurry - Emsac® 500