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: 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.

Abstract: A method for taking soil samples from horizontal boreholes. A first step involves making a substantially horizontal borehole from an entry pit to an exit pit. A second step involves towing a soil sampling apparatus through the borehole. It is preferred that the apparatus be pulled by the drill string as the drill string is withdrawn from the borehole. By using a soil sampling apparatus that is capable of taking multiple soil samples, all necessary soil sampling along the horizontal borehole may be completed in a single pass.