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AssigneeNew Jersey Institute of Technology
InventorsJohn W. Liskowitz, Methi Wecharatana, Chai Jaturapitakkul, Anthony E. Cerkanowicz, deceased
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The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points.
A method for increasing the early rate of strength gain of a hardenable mixture containing fly ash comprising exposing fly ash to an aqueous slurry of an alkaline material prior to incorporation of the fly ash in a hardenable mixture, wherein the fly ash is characterized by at least 99% of the particles having a particle size of less than 20 microns and having a fineness defined by a fineness modulus of less than about 600, wherein the fineness modulus is calculated as the sum of the percent of fly ash retained on sieves of 0, 1, 1.5, 2, 3, 5, 10, 20, 45, 75, 150, and 300 microns.
A hardenable mixture comprising cement and a preformed slurry of fly ash, alkaline material and water, wherein the fly ash and alkaline material together are about 5% to about 60% by weight of cementitious materials in the hardenable mixture, wherein the cementitious materials comprise cement and fly ash, and wherein the fly ash the fly ash is characterized by at least 99% of the particles having a particle size of less than 20 microns and having a fineness defined by a fineness modulus of less than about 600, wherein the fineness modulus is calculated as the sum of the percent of fly ash retained on sieves of 0, 1, 1.5, 2, 3, 5, 10, 20, 45, 75, 150, and 300 microns.
Dependencies are inferred from the claim text.