The present invention relates to pre-blend cement for general-purpose
concrete construction containing Class-F fly ash, Class-C fly ash or
slag, and less than about 5 percent (w/w) of sodium thiocyanate (NaSCN)
and/or calcium nitrate (Ca(NO.sub.3).sub.2), as a substantial replacement
for cement. The sodium thiocyanate and/or calcium nitrate are additives
for improved high early strength and accelerated setting times, thereby
allowing the concrete structure to be put into service sooner, reducing
labor cost, and allowing precast concrete and concrete masonry
manufacturers to achieve rapid form and mold turnover.