CHARACTERISTICS OF SILICA FUME

1. Physical Properties

Diameter is about 0.1 micron to 0.2 micron
Surface area about 30,000 m²/kg
Density varies from 150 to 700 kg/m³
When its density is about 550 kg/m³ it is the best suited as concrete additive

2. Chemical Composition

Contains more than 90 percent silicon dioxide
Other constituents are carbon, sulphur and oxides of aluminium, iron, calcium, [...]