The present invention relates to calcium-containing, porous, mineral materials having a sulfate content of not more than 1.5% by weight and a biopolymer content in the range of 0.001 to 5.00% by weight, each relative to the total weight of the materials, a method for producing these materials with the aid of biopolymers as stabilizers and the use of biopolymers for producing sulfate-poor calcium-containing, porous, mineral materials.

The present invention relates to calcium-containing, porous, mineral materials having a sulfate content of not more than 1.5% by weight and a biopolymer content in the range of 0.001 to 5.00% by weight, each relative to the total weight of the materials, a method for producing these materials with the aid of biopolymers as stabilizers and the use of biopolymers for producing sulfate-poor calcium-containing, porous, mineral materials.

The present invention provides means capable of imparting high temporal stability to a hardening aid solution which serves as a raw material and capable of imparting high strength and high quality stability to a hardened body of the self-hardening material, in the hardened body of the self-hardening material that contains a ceramic powder containing Si element at least on the surface thereof. The present invention relates to a hardening aid solution containing Si element, an alkali, and a dispersing medium, wherein the dispersing medium contains water; a dissolution concentration of the Si element is 20000 mass ppm or more; the number of moles of the alkali present in 1 kg of the dispersing medium is 2 mol/kg or more; an absolute value of an amount of change in a dissolution concentration of Si element in a solution obtained by diluting the hardening aid solution by 2 times based on the mass using an aqueous KOH solution having a concentration of 3 mol/L is 2000 mass ppm or less, between before and after a heat dissolution test including heating the solution at a solution temperature of 80° C. for 5 hours, and then allowing the solution to stand in an ambient environment at 25° C. for 1 hour; and the hardening aid solution is used for hardening a powder containing a ceramic powder containing Si element at least on the surface thereof.

The present invention provides means capable of imparting high temporal stability to a hardening aid solution which serves as a raw material and capable of imparting high strength and high quality stability to a hardened body of the self-hardening material, in the hardened body of the self-hardening material that contains a ceramic powder containing Si element at least on the surface thereof. The present invention relates to a hardening aid solution containing Si element, an alkali, and a dispersing medium, wherein the dispersing medium contains water; a dissolution concentration of the Si element is 20000 mass ppm or more; the number of moles of the alkali present in 1 kg of the dispersing medium is 2 mol/kg or more; an absolute value of an amount of change in a dissolution concentration of Si element in a solution obtained by diluting the hardening aid solution by 2 times based on the mass using an aqueous KOH solution having a concentration of 3 mol/L is 2000 mass ppm or less, between before and after a heat dissolution test including heating the solution at a solution temperature of 80° C. for 5 hours, and then allowing the solution to stand in an ambient environment at 25° C. for 1 hour; and the hardening aid solution is used for hardening a powder containing a ceramic powder containing Si element at least on the surface thereof.

The invention relates to a geopolymer grout for protecting prestressing reinforcements, the geopolymer grout comprising metakaolin, fly ash and an activator mixture, the activator mixture comprising sodium hydroxide and sodium silicate, wherein the molar ratio Na.sub.2O:SiO.sub.2 of the sodium silicate is between 0.40 and 0.70.

The invention relates to a geopolymer grout for protecting prestressing reinforcements, the geopolymer grout comprising metakaolin, fly ash and an activator mixture, the activator mixture comprising sodium hydroxide and sodium silicate, wherein the molar ratio Na.sub.2O:SiO.sub.2 of the sodium silicate is between 0.40 and 0.70.

Methods of cementing include providing a geopolymer cement composition that includes a monophase amorphous hydraulic binder material (MAHBM), a metal silicate, an alkaline activator, and a carrier fluid, introducing the geopolymer cement composition into a subterranean formation, and allowing the geopolymer cement composition to set in the subterranean formation. The MAHBM includes silica or alumina core particulates coated with an amorphous calcium silicate hydrate.

Methods of cementing include providing a geopolymer cement composition that includes a monophase amorphous hydraulic binder material (MAHBM), a metal silicate, an alkaline activator, and a carrier fluid, introducing the geopolymer cement composition into a subterranean formation, and allowing the geopolymer cement composition to set in the subterranean formation. The MAHBM includes silica or alumina core particulates coated with an amorphous calcium silicate hydrate.

The present invention relates to the field of cementitious compositions. Particularly, the invention concerns an alkaline-activated fly ash cementitious composition and the use of this composition as a binder in concrete production.

The present invention relates to the field of cementitious compositions. Particularly, the invention concerns an alkaline-activated fly ash cementitious composition and the use of this composition as a binder in concrete production.