Abstract: Disclosed is a method for enhancing the performance of concrete includes, providing a cementitious mixture comprising cement and processed high calcium fly ash; wherein a processing of the processed high calcium fly ash neutralizes a cementitious reactivity of a high calcium fly ash, wherein a pozzolanic reactivity of the processed high calcium fly ash is maintained during the processing of the high calcium fly ash. The processing of the high calcium fly ash includes hydrating and carbonating the high calcium fly ash. The processing further includes excavating the high calcium fly ash from a landfill or surface impoundment after the hydrating and carbonating. Also disclosed is a portland-pozzolan blended cement mixture with clinker, gypsum, and a pozzolanic material, such as processed high calcium fly ash. After processing, the cementitious reactivity of a high calcium fly ash is neutralized, while pozzolanic reactivity of the high calcium fly ash is maintained.

Abstract: Disclosed is a method for enhancing the performance of concrete includes, providing a cementitious mixture comprising cement and processed high calcium fly ash; wherein a processing of the processed high calcium fly ash neutralizes a cementitious reactivity of a high calcium fly ash, wherein a pozzolanic reactivity of the processed high calcium fly ash is maintained during the processing of the high calcium fly ash. The processing of the high calcium fly ash includes hydrating and carbonating the high calcium fly ash. The processing further includes excavating the high calcium fly ash from a landfill or surface impoundment after the hydrating and carbonating. Also disclosed is a portland-pozzolan blended cement mixture with clinker, gypsum, and a pozzolanic material, such as processed high calcium fly ash. After processing, the cementitious reactivity of a high calcium fly ash is neutralized, while pozzolanic reactivity of the high calcium fly ash is maintained.

Abstract: Pozzolanic cement compositions and method manufacturing the same are described. These cement compositions may include a pozzolanic material and an activator based on a salt of glycolic acid, glyceric acid, malic acid, tartaric acid, malonic acid, glutaric acid, maleic acid, formic acid, acetic acid, propionic acid, or butyric acid, a retarder based on hepto-gluconates, sulfate salts, sugars, sugar acids, lignins, and/or an accelerator based on amines. The cement compositions may have less than 10% by weight Portland cement. The pozzolanic cement compositions including these activators, accelerators, and retarders can have improved properties such as longer setting time, better slump retention, and improved strength.

Abstract: A geopolymer concrete prepared by predicting a mechanical property of a geopolymer concrete formed with each of a plurality of fly ash materials, selecting as a source material for the geopolymer concrete one of the fly ash materials that yields a predicted value of the mechanical property that is equal to or greater than a target value for the mechanical property, and mixing the fly ash source material with an alkaline activator solution, a fine aggregate, and a coarse aggregate. The prediction of the mechanical property includes measuring one or more properties of each of the plurality of fly ash materials, calculating predicted values of the mechanical property for geopolymer concretes formed with each of the plurality of fly ash materials using a predetermined equation relating the one or more properties of the plurality of fly ash materials to predicted values of the mechanical property of the geopolymer concrete.

Abstract: Pozzolanic cement compositions and method manufacturing the same are described. These cement compositions may include a pozzolanic material and an activator based on a salt of glycolic acid, glyceric acid, malic acid, tartaric acid, malonic acid, glutaric acid, maleic acid, formic acid, acetic acid, propionic acid, or butyric acid, a retarder based on hepto-gluconates, sulfate salts, sugars, sugar acids, lignins, and/or an accelerator based on amines. The cement compositions may have less than 10% by weight Portland cement. The pozzolanic cement compositions including these activators, accelerators, and retarders can have improved properties such as longer setting time, better slump retention, and improved strength.

Abstract: A geopolymer concrete formed by mixing about 3% to about 43% by weight incinerator fly ash, about 3% to about 35% by weight coal fly ash, about 7% to about 38% by weight alkaline activator liquid, and about 31% to about 70% by weight aggregate. The incinerator fly ash may be derived from a solid waste incinerator facility. The alkaline activator liquid may include a sodium hydroxide solution and sodium silicate. The aggregate may include a fine aggregate, such as sand, and a coarse aggregate, such as gravel.

Abstract: A geopolymer concrete formed by mixing about 3% to about 43% by weight incinerator fly ash, about 3% to about 35% by weight coal fly ash, about 7% to about 38% by weight alkaline activator liquid, and about 31% to about 70% by weight aggregate. The incinerator fly ash may be derived from a solid waste incinerator facility. The alkaline activator liquid may include a sodium hydroxide solution and sodium silicate. The aggregate may include a fine aggregate, such as sand, and a coarse aggregate, such as gravel.