AVAS EXPORT-IMPORT - building materials, cementy, příměsi a přísady do betonu

similar products


Dispersed silica powder


SIOXID is the trade name of dispersed silica powder of gray color and extremely fine in size. SIOXID is made by condensation of silica fumes - it is extracted from the off-gases from ferrosilicon furnaces.

Physical data

SIOXID has bulk density of approximately 150 to 250 kg.m-3. The specific density is approx. 2.20 g.cm-3. In the interests of easier and more effective handling and transportation the powder is compacted by micro-pelletizing and its bulk density is increased to 400-500 kg.m-3.

The fineness of the flue-dust emission measured in the specific surface (so called BET method) is approx. 15 000 - 30 000 m2.kg-1. The diameter of the individual particles is 0.1-0.2lm


SIOXIDis added into concrete to enhance its strength, wear resistance, resistance against chemical degradation and corrosion.

There are also other practical applications of condensed silicon dioxide. It is used as a component of cement mixtures, pre-cast units mixtures, heat-resistant materials and other construction units and materials where it serves as a substitute for asbestos. Small quantities of SIOXID can be also found in special cements that are used as pigments and additives in the production of paper and plastic, as a grout component and other special applications.


Chemical analysis

SiO2 min. 85 % weight
Al2O3 max. 2 %
CaO + MgO max. 5 %
K2O + Na2O max. 3 %
annealing loss max. 3 %

Compared with the technical characteristics of products that are produced abroad, SIOXID corresponds similar foreign products such as Fesil Silica, Microsilica, Micropoz, atc.

noncompacted do 230 kg/m3

Weight 1 big-bag
noncompacted 300 - 350 kg


Test results showed an extremely positive influence of SIOXID on important properties of concrete and mortar as strength, water resistance, resistance to aggressive environments, the ability to eliminate alkaline expansion, etc.

Packing and transport

SIOXID is normally delivered in big bags with the net content of 300 kilograms. On a customer's demand the product can be supplied in pelletized form. Sioxid must be kept away from moisture.


OFZ a.s.,


Alšova 694
334 41 Dobřany
tel.: 377 224 862, 377 422 542
fax: 377 237 661, 377 220 720
e-mail: avas@avas-concrete.com