This slide presents a comparison of some of the physical and chemical
characteristics of silica fume, fly ash, and portland cement.
Note that the surface area measurements for silica fume are done using a
nitrogen absorption method (BET) while those for fly ash and portland cement
are typically done using an air permeability method (Blaine).
Note also that the pozzolanic activity testing was done using a constant
water content for the silica fume mixtures rather than a constant flow.
The Silica Fume Association
38860 Sierra Lane, Lovettsville, VA 20180
Tel: 540.257.4224 Fax: 540.822.9456