The invention comprises a cementitious material comprising a natural pozzolan selected from hyaloclastite, sideromelane or tachylite, wherein the natural pozzolan has a volume-based mean particle size of less than or equal to 40 μm. The cementitious material also comprising an aqueous alkaline activating solution suitable for forming a geopolymer. A method making a cementitious material is also disclosed.

Method for creating a brake pad with a block of friction material, in which sodium hydroxide and sodium silicate are dissolved in water, the aqueous solution of sodium hydroxide and sodium silicate is mixed with commercial metakaolin until a wet paste is obtained, the wet paste is formed and dried until a dried geopolymeric aggregate is obtained, the aggregate is ground to a powder, the dried ground aggregate is used as an exclusive or almost-exclusive inorganic geopolymeric binder in a friction material compound and the raw compound is hot-molded under a pressure greater than a water saturation pressure at the molding temperature.

The invention relates to methods for manufacturing an inorganic polymer object from a precursor wherein the precursor consists of one or more or comprises one or more selected from the group consisting of gibbsite-containing bauxite, gibbsite containing residue of the Bayer process, thermally processed gibbsite-containing bauxite, and thermally processed gibbsite-containing residue of the Bayer process, the method comprising the steps of alkaline-activating said precursor, mixing the precursor, shaping the mixed precursor and hydrothermally curing the shaped precursor at a temperature between 70° C. and 350° C.

The invention is directed to a mine tailing and fly ash containing construction material having improved compressive strength and water resistance. The mine tailing and fly ash containing material includes mine tailing, fly ash, an alkali solution comprising sodium hydroxide and, optionally, calcium hydroxide, and water. The invention further provides a geopolymerization method of forming a mine tailing and fly ash containing construction material.

Geopolymer cement slurries, cured geopolymer cements, and methods of making cured geopolymer cement and methods of using geopolymer cement slurries are provided. The geopolymer cement slurry comprises cement precursor material, Saudi Arabian volcanic ash, and an aqueous solution. The Saudi Arabian volcanic ash comprises SO.sub.3, CaO, SiO.sub.2, Al.sub.2O.sub.3, Fe.sub.2O.sub.3, MgO, and K.sub.2O.

The invention relates to methods for manufacturing an inorganic polymer object from a precursor wherein the precursor consists of one or more or comprises one or more selected from the group consisting of gibbsite-containing bauxite, gibbsite containing residue of the Bayer process, thermally processed gibbsite-containing bauxite, and thermally processed gibbsite-containing residue of the Bayer process, the method comprising the steps of alkaline-activating said precursor, mixing the precursor, shaping the mixed precursor and hydrothermally curing the shaped precursor at a temperature between 70° C. and 350° C.

The invention is directed to kits, compositions, tools and methods comprising a cyclic industrial process to form biocement. In particular, the invention is directed to materials and methods for decomposing calcium carbonate into calcium oxide and carbon dioxide at an elevated temperature, reacting calcium oxide with ammonium chloride to form calcium chloride, water, and ammonia gas; and reacting ammonia gas and carbon dioxide at high pressure to form urea and water, which are then utilized to form biocement. This cyclic process can be achieved by combining industrial processes with the resulting product as biocement. The process may involve retention of calcium carbonate currently utilized in the manufacture of Portland Cement.

The invention is directed to kits, compositions, tools and methods comprising a cyclic industrial process to form biocement. In particular, the invention is directed to materials and methods for decomposing calcium carbonate into calcium oxide and carbon dioxide at an elevated temperature, reacting calcium oxide with ammonium chloride to form calcium chloride, water, and ammonia gas; and reacting ammonia gas and carbon dioxide at high pressure to form urea and water, which are then utilized to form biocement. This cyclic process can be achieved by combining industrial processes with the resulting product as biocement. The process may involve retention of calcium carbonate currently utilized in the manufacture of Portland Cement.

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.

A method of manufacturing geopolymer tubes comprises forming a geopolymer composition comprised of an aluminosilicate source and an alkali activator, wherein the geopolymer composition has a fluid consistency and a shear thinning index of greater than 1.05, transferring the geopolymer composition into a tubular mold, rotating the mold to shear and distribute the composition onto the inner wall of the mold until the geopolymer composition reaches non-flowable consistency, and curing the geopolymer in the mold to form geopolymer tubes. A method for making geopolymer tubes with the disclosed geopolymer composition comprises shearing the geopolymer composition in a tubular mold at a high rotational speed to significantly reduce apparent viscosity to form the tubular shape, at least in the initial process stage. A ceramic tube made from the geopolymer composition of the present invention is used as a membrane or adsorbent for filtration applications.