Pre-blend cement compositions containing non-chloride accelerators

摘要

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(NO₃)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.