These values are typical for concrete containing about 600-650 lb/yd3 of
cement with a w/cm < 0.40.
The "strength trap" is the situation in which strength achieved with
silica-fume concrete will greatly exceed most project specifications. This
factor may cause concrete producers and contractors to relax their control
over the concrete production and curing. While strength may be adequate for
structural design, rapid chloride permeability values may not be within
specifications.
The Silica Fume Association
38860 Sierra Lane, Lovettsville, VA 20180
Tel: 540.257.4224 Fax: 540.822.9456