All of the standard specifications shown are essentially prescription
specifications that do not address the performance of the silica fume in a
particular application. Basically, silica fume complying with these
specifications will be similar to silica fume that has been used in the past
on a wide variety of projects and that is described in the research
literature.
Do not rely on these specifications to predict concrete performance if you
have a particularl application. There is no substitute for testing with
your local materials to determine if a particular silica fume will meet the
needs of your project.
Note also that silica fume that does not comply with these specifications
may perform very well in some applications. In particular, the requirement
that these specifications contain for a minimum silicon dioxide content of
85 percent may not be necessary for all uses.
ASTM C 1240, Silica Fume for Use as a Mineral Admixture in Hydraulic- Cement
Concrete, Mortar, and Grout. AASHTO M 307, Microsilica for Use in Concrete
and Mortar. CSA (Canadian Standards Association) A 23.5, Supplementary
Cementing Materials.
The Silica Fume Association
38860 Sierra Lane, Lovettsville, VA 20180
Tel: 540.257.4224 Fax: 540.822.9456