Pozzolanic Additive as a replacement of cement based binders
The calcined layered silicate Metapor® is a reactive additive with small amounts of expanded glass based on amorphous alumosilicate. Metapor® forms calcium alumo-silicate hydrates with calcium hydroxide and water by a pozzolanic reaction. This additional proportion of aluminate-containing, strength-giving phases can positively influence the compressive strength, flexural strength, spatial stability and bonding of the aggregate in concretes, mortars and plasters. In several scientific studies, a reduction of the porosity of the hardened concrete structure could be proven through the use of Metapor®.
Improved compressive strength and durability
Metapor® can significantly improve the properties of mineral building materials and also plastics. Metakaolin is therefore used in concrete, mortar and render. Binder systems based on hydrated lime are characterised by high permeability and compatibility with limestones and other natural building materials. However, the mechanical properties as well as the chemical resistance are rather low. A partial replacement of hydrated lime by Metapor® leads to a significant improvement of these properties. The calcined layered silicate Metapor® is produced during the production of Poraver® expanded glass without the use of additional energy. It is available as a fine powder in bags, big bags or as bulk material.
• Very high and fast activity in the lime-binding process
• Use as substitute for binder results in material savings
• Densification of the material structure
• Increased strength in mineral systems
• Improved rheological properties of materials
• Low swelling-shrinking behaviour
• Improved resistance against sulphate attack
Metakaolin containing expanded glass as reactive additive
Bulk density in kg/m³: 350 kg/m³ ±150*
Moisture content: < 0,5 M.-%
Specific surface (BET) according to
DIN ISO 9277: ca. 3,5 – 9,5 m²/g
* The bulk density may vary due to air inclusions in the material.
Metapor® has a cement-like average particle size of approximately 10 μm and thus, when introduced into cement paste, contributes to the filling of the aggregate´s voids in the microstructure. In addition, several scientific studies have shown a reduction in porosity of hardened concrete by the use of metakaoline. With a lower porosity, chloride migration can be reduced, resistance to the penetration of damaging media increased and thus the durability of the concrete improved. Detailed technical data and the chemical analysis are available on request.