Abstract: A geopolymer thermal energy storage (TES) concrete product comprising at least one binder; at least one alkali activator; at least one fine aggregate with high thermal conductivity and heat capacity; and at least one coarse aggregate with high thermal conductivity and heat capacity.

Abstract: A high performance concrete composition comprising: (i) at least one Class C fly ash, (ii) at least one calcium aluminate cement, (iii) at least one aggregate, and (iv) water.

Abstract: An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

Abstract: An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

Abstract: A geopolymer thermal energy storage (TES) concrete product comprising at least one binder; at least one alkali activator; at least one fine aggregate with high thermal conductivity and heat capacity; and at least one coarse aggregate with high thermal conductivity and heat capacity.

Abstract: The present disclosure provides a geopolymer composition having a controllable setting time comprising: at least one reactive aluminosilicate; at least one retarder; and at least one alkali silicate activator solution.

Abstract: A composite binder comprises: one or more Class F fly ash materials, one or more gelation enhancers, and one or more hardening enhancers, wherein each of the one or more Class F fly ash materials comprises 15 wt. % or less calcium oxide, and wherein the composite binder is a Portland cement-free binder for concrete. Also provided are Geopolymer Composite Cellular Concretes (GCCCs) including the composite binder and methods of making these GCCCs.

Abstract: A geopolymer composite binder is provided herein, the composite binder including (i) at least one fly ash material having less than or equal to 15 wt % of calcium oxide; (ii) at least one gelation enhancer; and (iii) at least one hardening enhancer having a different composition from a composition of the at least one fly ash material.

Abstract: Three pumpable geopolymer compositions for well sealing application is disclosed herein. One pumpable geopolymer composition comprises: (i) less reactive aluminosilicate; (ii) more reactive aluminosilicate; (iii) alkaline silicate activator solution with a very low SiO2/M2O. Another pumpable geopolymer composition comprises: (i) less reactive aluminosilicate; (ii) more reactive aluminosilicate; (iii) alkaline silicate-free activator solution that may contain an alkali salt; and (iv) powdered alkali silicate glass. The third pumpable geopolymer composition comprises (i) less reactive aluminosilicate; (ii) more reactive aluminosilicate; (iii) alkaline low silicate activator solution; and (iv) powdered alkali silicate glass.

Abstract: Treatment of a radioactive waste stream is provided by adding sodium hydroxide (NaOH) and/or potassium hydroxide (KOH) together with a rapidly dissolving form of silica, e.g., fumed silica or fly ash. Alternatively, the fumed silica can be first dissolved in a NaOH/KOH solution, which is then combined with the waste solution. Adding a binder that can be a mixture of metakaolin (Al2O3.2SiO2), ground blast furnace slag, fly ash, or other additives. Adding an “enhancer” that can be composed of a group of additives that are used to further enhance the immobilization of heavy metals and key radionuclides such as 99Tc and 129I. An additional step can involve simple mixing of the binder with the activator and enhancer, which can occur in the final waste form container, or in a mixing vessel prior to pumping into the final waste form container, depending on the particular application.

Abstract: A geopolymer composite binder is provided herein, the composite binder including (i) at least one fly ash material having less than or equal to 15 wt % of calcium oxide; (ii) at least one gelation enhancer; and (iii) at least one hardening enhancer having a different composition from a composition of the at least one fly ash material.

Abstract: A geopolymer composite ultra high performance concrete (GUHPC), and methods of making the same, are provided herein, the GUHPC comprising: (a) a binder comprising one or more selected from the group consisting of reactive aluminosilicate and reactive alkali-earth aluminosilicate; (b) an alkali activator comprising an aqueous solution of metal hydroxide and metal silicate; and (c) one or more aggregate.

Abstract: A composite binder comprises: one or more Class F fly ash materials, one or more gelation enhancers, and one or more hardening enhancers, wherein each of the one or more Class F fly ash materials comprises 15 wt. % or less calcium oxide, and wherein the composite binder is a Portland cement-free binder for concrete. Also provided are Geopolymer Composite Cellular Concretes (GCCCs) including the composite binder and methods of making these GCCCs.

Abstract: A geopolymer composite ultra high performance concrete (GUHPC), and methods of making the same, are provided herein, the GUHPC comprising: (a) a binder comprising one or more selected from the group consisting of reactive aluminosilicate and reactive alkali-earth aluminosilicate; (b) an alkali activator comprising an aqueous solution of metal hydroxide and metal silicate; and (c) one or more aggregate.

Abstract: A geopolymer composite binder is provided herein, the composite binder including (i) at least one fly ash material having less than or equal to 15 wt % of calcium oxide; (ii) at least one gelation enhancer; and (iii) at least one hardening enhancer having a different composition from a composition of the at least one fly ash material.

Abstract: Treatment of a radioactive waste stream is provided by adding sodium hydroxide (NaOH) and/or potassium hydroxide (KOH) together with a rapidly dissolving form of silica, e.g., fumed silica or fly ash. Alternatively, the fumed silica can be first dissolved in a NaOH/KOH solution, which is then combined with the waste solution. Adding a binder that can be a mixture of metakaolin (Al2O3.2SiO2), ground blast furnace slag, fly ash, or other additives. Adding an “enhancer” that can be composed of a group of additives that are used to further enhance the immobilization of heavy metals and key radionuclides such as 99Tc and 129I. An additional step can involve simple mixing of the binder with the activator and enhancer, which can occur in the final waste form container, or in a mixing vessel prior to pumping into the final waste form container, depending on the particular application.

Abstract: Provided in one embodiment is a method of charactering a fly ash composition, comprising determining a reactivity of the fly ash composition in a solution. The applicability of the findings to low water-to-solid ratios for the process of geopolymerization for the relationship between the amounts of fly ash reacted, and the compressive strength of a geopolymer cement is also described.

Abstract: Treatment of a radioactive waste stream is provided by adding sodium hydroxide (NaOH) and/or potassium hydroxide (KOH) together with a rapidly dissolving form of silica, e.g., fumed silica or fly ash. Alternatively, the fumed silica can be first dissolved in a NaOH/KOH solution, which is then combined with the waste solution. Adding a binder that can be a mixture of metakaolin (Al2O3.2SiO2), ground blast furnace slag, fly ash, or other additives. Adding an “enhancer” that can be composed of a group of additives that are used to further enhance the immobilization of heavy metals and key radionuclides such as 99Tc and 129I. An additional step can involve simple mixing of the binder with the activator and enhancer, which can occur in the final waste form container, or in a mixing vessel prior to pumping into the final waste form container, depending on the particular application.

Abstract: Treatment of a radioactive waste stream is provided by adding sodium hydroxide (NaOH) and/or potassium hydroxide (KOH) together with a rapidly dissolving form of silica, e.g., fumed silica or fly ash. Alternatively, the fumed silica can be first dissolved in a NaOH/KOH solution, which is then combined with the waste solution. Adding a binder that can be a mixture of metakaolin (Al2O3.2SiO2), ground blast furnace slag, fly ash, or other additives. Adding an “enhancer” that can be composed of a group of additives that are used to further enhance the immobilization of heavy metals and key radionuclides such as 99Tc and 129I. An additional step can involve simple mixing of the binder with the activator and enhancer, which can occur in the final waste form container, or in a mixing vessel prior to pumping into the final waste form container, depending on the particular application.

Abstract: A method for reducing metals using a tin or antimony porphyrin by forming an aqueous solution of a tin or antimony porphyrin, an electron donor, such as ethylenediaminetetraaceticacid, triethylamine, triethanolamine, and sodium nitrite, and at least one metal compound selected from a uranium-containing compound, a mercury-containing compound, a copper-containing compound, a lead-containing compound, a gold-containing compound, a silver-containing compound, and a platinum-containing compound through irradiating the aqueous solution with light.