The invention discloses a calcium-alumino-silicate-hydrate nano-seeds suspension and preparation method thereof. The preparation method of calcium-alumino-silicate-hydrate nano-seeds suspension includes the following steps: dropwise adding the aqueous solution of calcium source, the aqueous solution of silicon source and the aqueous solution of aluminum source to the solution of polycarboxylate superplasticizer, and adjusting the pH value to 10.0˜13.5, and continuously stirring to obtain the calcium-alumino-silicate-hydrate nano-seeds suspension. The beneficial effect in the present invention is: the calcium-alumino-silicate-hydrate nano-seeds has small particle size, good dispersion stability, and it can effectively improve the early hydration and mechanical performance of cement-based materials, and has good application prospects; the preparation process is simple, without washing, drying, ultrasonic dispersion and other subsequent processes, suitable for large-scale production.

A process for producing a setting and/or curing accelerator for mineral binders is characterized in that a mineral solid is subjected to milling in a liquid medium.

A strength enhancing admixture for cementitious and/or pozzolanic compositions including, based on the total dry weight of the admixture, calcium silicate hydrate in an amount of from about 0.5 to about 94 weight percent, and: i) at least one alkanolamine in an amount of from about 0.5 to about 55 weight percent; ii) at least one inorganic accelerator in an amount of from about 0.5 to about 85 weight percent; and iii) at least one carbohydrate in an amount of from about 0.5 to about 50 weight percent; wherein the calcium silicate hydrate includes a product of a reaction of a water-soluble calcium compound with a water-soluble silicate compound in presence of a water-soluble dispersant; and wherein the at least one inorganic accelerator includes any inorganic accelerator(s) other than calcium silicate hydrate.

A strength enhancing admixture for cementitious and/or pozzolanic compositions including, based on the total dry weight of the admixture, calcium silicate hydrate in an amount of from about 0.5 to about 94 weight percent, and: i) at least one alkanolamine in an amount of from about 0.5 to about 55 weight percent; ii) at least one inorganic accelerator in an amount of from about 0.5 to about 85 weight percent; and iii) at least one carbohydrate in an amount of from about 0.5 to about 50 weight percent; wherein the calcium silicate hydrate includes a product of a reaction of a water-soluble calcium compound with a water-soluble silicate compound in presence of a water-soluble dispersant; and wherein the at least one inorganic accelerator includes any inorganic accelerator(s) other than calcium silicate hydrate.

The invention discloses a calcium-alumino-silicate-hydrate nano-seeds suspension and preparation method thereof. The preparation method of calcium-alumino-silicate-hydrate nano-seeds suspension includes the following steps: dropwise adding the aqueous solution of calcium source, the aqueous solution of silicon source and the aqueous solution of aluminum source to the solution of polycarboxylate superplasticizer, and adjusting the pH value to 10.0˜13.5, and continuously stirring to obtain the calcium-alumino-silicate-hydrate nano-seeds suspension. The beneficial effect in the present invention is: the calcium-alumino-silicate-hydrate nano-seeds has small particle size, good dispersion stability, and it can effectively improve the early hydration and mechanical performance of cement-based materials, and has good application prospects; the preparation process is simple, without washing, drying, ultrasonic dispersion and other subsequent processes, suitable for large-scale production.

Disclosed is a composite gypsum board comprising a board core comprising set gypsum sandwiched between face and back cover sheets. The composite gypsum board also comprises an intermediate sheet between the board core and the face cover sheet, with a thin, dense gypsum layer disposed between the intermediate sheet and the face cover sheet. Optionally, a second dense gypsum layer can be disposed between a first major side of the board core and the back cover sheet. Also disclosed is a method of preparing a composite gypsum board in which an intermediate sheet is applied over a dense gypsum layer disposed on a face cover sheet. A back cover sheet is applied to the other major side of the board core, with a second dense gypsum layer optionally disposed therebetween.

Disclosed is a composite gypsum board comprising a board core comprising set gypsum sandwiched between face and back cover sheets. The composite gypsum board also comprises an intermediate sheet between the board core and the face cover sheet, with a thin, dense gypsum layer disposed between the intermediate sheet and the face cover sheet. Optionally, a second dense gypsum layer can be disposed between a first major side of the board core and the back cover sheet. Also disclosed is a method of preparing a composite gypsum board in which an intermediate sheet is applied over a dense gypsum layer disposed on a face cover sheet. A back cover sheet is applied to the other major side of the board core, with a second dense gypsum layer optionally disposed therebetween.

Disclosed is a composite gypsum board comprising a board core comprising set gypsum sandwiched between face and back cover sheets. The composite gypsum board also comprises an intermediate sheet between the board core and the face cover sheet, with a thin, dense gypsum layer disposed between the intermediate sheet and the face cover sheet. Optionally, a second dense gypsum layer can be disposed between a first major side of the board core and the back cover sheet. Also disclosed is a method of preparing a composite gypsum board in which an intermediate sheet is applied over a dense gypsum layer disposed on a face cover sheet. A back cover sheet is applied to the other major side of the board core, with a second dense gypsum layer optionally disposed therebetween.

Disclosed is a composite gypsum board comprising a board core comprising set gypsum sandwiched between face and back cover sheets. The composite gypsum board also comprises an intermediate sheet between the board core and the face cover sheet, with a thin, dense gypsum layer disposed between the intermediate sheet and the face cover sheet. Optionally, a second dense gypsum layer can be disposed between a first major side of the board core and the back cover sheet. Also disclosed is a method of preparing a composite gypsum board in which an intermediate sheet is applied over a dense gypsum layer disposed on a face cover sheet. A back cover sheet is applied to the other major side of the board core, with a second dense gypsum layer optionally disposed therebetween.

A process for producing a setting and/or curing accelerator for mineral binders is characterized in that a mineral solid is subjected to milling in a liquid medium.