"High-strength concretes designed with conventional materials typically improve the strength of the cured concrete by reducing the water/cement ratio (w/c) using a high-range water-reducing admixture (HRWRA) and by replacing up to 15 percent of the mass of cement with . ...The addition of silica fume... allows the formed by the hydration of the cement to react and form additional calcium silicate hydrate gel that increases the strength of the paste. The design strategy used in this study involved investigating a silica-fume replacement of up to 15 percent and the use of high-range water reducers that allowed samples with w/c's as low as 0.44 to be prepared."