Cementitious composition containing bottom ash as pozzolan and concretes and mortars therefrom
AssigneeLafarge Canada Inc.
InventorsDonald Stephen Hopkins, David Bridson Oates
Life of this patent
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Abstract
Ground bottom ash, a waste material derived from combustion of coal, which presents a disposal problem, replaces part of the cement in a cementitious material useful in concretes and mortars and provides compressive strengths in concretes comparable with or better than corresponding cements in which there is no replacement of cement by ground bottom ash and cements containing fly ash.
Claims17
A cementitious composition for use in concretes and mortars comprising 75 to 85%, by weight, cement and 15 to 25%, by weight, of a pozzolanic material consisting essentially of 75 to 100%, by weight, of a ground bottom ash having a particle size such that 80 to 100% pass a 45 .mu.m screen, said ground bottom ash being recovered ground agglomerates of residual mineral coal ash from burning of coal in a coal combustion boiler, and 25 to 0%, by weight, of silica fume, said cementitious composition providing a compressive strength in concretes and mortars at least comparable with the compressive strength achieved by said cement, alone or in combination with fly ash, as a cementitious composition.
A concrete or mortar composition comprising:
- i) a cementitious composition comprising 75 to 85%, by weight, cement and 15 to 25%, by weight, of a pozzolanic material consisting essentially of 75 to 100%, by weight, of a ground bottom ash having a particle size less than 50 .mu.m such that 80 to 100% pass a 45 .mu.m screen, and 25 to 0%, by weight of silica fume,
- ii) mineral aggregate selected from coarse aggregate or fine aggregate, and
- iii) water,
- said concrete or mortar composition having a water/cementitious composition ratio of 0.25:1 to 0.7:1, said ground bottom ash being recovered ground agglomerates of residual mineral coal ash from burning of coal in a coal combustion boiler said cementitious composition providing a compressive strength in said concrete or mortar composition at least comparable with the compressive strength achieve by said cement, alone or in combination with fly ash, as a cementitious composition.
In a cementitious composition comprising a cement in admixture with a pozzolanic material, the improvement wherein said pozzolanic material is a ground bottom ash having a particle size less than 50 .mu.m such that 80 to 100% pass a 45 .mu.m screen, said composition comprising about 20%, by weight, of said around bottom ash.
Dependencies are inferred from the claim text.