초록 ▼

A synthetic Class C fly ash results from a substantially homogeneous blend of about 40-60% by weight of a Class F fly ash and about 60-40% by weight of cement kiln dust (CKD). This new fly ash can replace about 25-50% by weight of portland cement in conventional formulations with coarse and fine agg

A synthetic Class C fly ash results from a substantially homogeneous blend of about 40-60% by weight of a Class F fly ash and about 60-40% by weight of cement kiln dust (CKD). This new fly ash can replace about 25-50% by weight of portland cement in conventional formulations with coarse and fine aggregate for making general purpose concrete and particularly ready-mix concrete with comparable compressive strength and like properties.

대표청구항 ▼

In a settable composition for producing general purpose concrete which comprises per cubic yard of the concrete to be produced an admixture of about 400-750 lbs. Portland cement, about 1600-2000 lbs. coarse aggregate of a size of at least about ⅜inch, and sufficient fine aggregate of a size less tha

In a settable composition for producing general purpose concrete which comprises per cubic yard of the concrete to be produced an admixture of about 400-750 lbs. Portland cement, about 1600-2000 lbs. coarse aggregate of a size of at least about ⅜inch, and sufficient fine aggregate of a size less than ⅜and minor amounts of optional additives to yield one cubic yard when the admixture is combined with water equal to about 40-70% by weight of said cement, the improvement wherein more than about 25% up to about 50% by weight but not more than about 200 lbs. of said Portland cement is replaced with a homogeneous blend of (a) a fly ash having a combined content of silica, alumina and ferric oxide exceeding 70% and a calcium oxide content of less than 10% and (b) cement kiln dust, said blend having a combined content of silica, alumina and ferric oxide higher than about 50% but less than about 70% and a calcium oxide content higher than 10%.