A building construction product with an electroconductive surface, the building construction product comprising a core with one or more surfaces covered by an electroconductive paper comprising carbon fibers, the electroconductive paper being attached to the one or more surfaces of the core. Methods and materials for producing the building construction products with an electroconductive surface and products and methods for shielding an area from electromagnetic waves.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

Gypsum board having improved performance is obtained by controlling the distribution of starch in the gypsum core of the board and the gelling temperature of the starch. Starch migration in the board is controlled by the degree of acid-modification, to adjust the starch viscosity profile. The starch gelling temperature is controlled by chemical modification of the starch —OH groups.

A synchronous single-liquid grouting slurry, its technology and application for large diameter shield engineering under water-rich, high-pressure and weak soil strata conditions, comprising raw materials: 1050-1200 parts of gold tailing, 420-480 parts of silicate cement clinker, 220-240 parts of fly ash, 45-120 parts of waste clay brick, 65-95 parts of slag, 25-45 parts of limestone tailing, 70-80 parts of steel slag, 30-45 parts of silica fume, 15-22 parts of desulfurized gypsum, and 9-15 parts of quick-setting and early-strength composite additive. The invention controls the d.sub.50, d.sub.85 and d.sub.95 of the material particles as 35-40, 42-48 and 50-55 μm, respectively. Gold tailing with the particle size of 120-600 μm being used as the fine aggregate, their volume fractions are 40-60%. The slurry production technique, comprising crushing-sieving-superfine ball milling-homogenization-particle size classification-variable speed mixing being developed. The shield tail eight-point grouting technique is being developed for filling.

A synchronous single-liquid grouting slurry, its technology and application for large diameter shield engineering under water-rich, high-pressure and weak soil strata conditions, comprising raw materials: 1050-1200 parts of gold tailing, 420-480 parts of silicate cement clinker, 220-240 parts of fly ash, 45-120 parts of waste clay brick, 65-95 parts of slag, 25-45 parts of limestone tailing, 70-80 parts of steel slag, 30-45 parts of silica fume, 15-22 parts of desulfurized gypsum, and 9-15 parts of quick-setting and early-strength composite additive. The invention controls the d.sub.50, d.sub.85 and d.sub.95 of the material particles as 35-40, 42-48 and 50-55 μm, respectively. Gold tailing with the particle size of 120-600 μm being used as the fine aggregate, their volume fractions are 40-60%. The slurry production technique, comprising crushing-sieving-superfine ball milling-homogenization-particle size classification-variable speed mixing being developed. The shield tail eight-point grouting technique is being developed for filling.

A gypsum board is provided, including, a set gypsum core disposed between two cover sheets, the set gypsum core including a gypsum crystal matrix formed from at least water, stucco, and a foam, and the foam is formed from a blend of a first surfactant, a second surfactant and a third surfactant and water. Each surfactant is a distinct composition from the other surfactants.

A gypsum board is provided, including, a set gypsum core disposed between two cover sheets, the set gypsum core including a gypsum crystal matrix formed from at least water, stucco, and a foam, and the foam is formed from a blend of a first surfactant, a second surfactant and a third surfactant and water. Each surfactant is a distinct composition from the other surfactants.

A gypsum wallboard panel comprises: a gypsum core; and a paper cover sheet disposed on the gypsum core, the paper cover sheet comprising pulp fiber and an uncooked starch in an amount of at least 2% by weight of the pulp fiber.