A heat insulating material includes an aerogel that has macro-pores and meso-pores. A method for manufacturing a heat insulating material, including: a sol preparation step of adding a gelling agent into sodium silicate such that a molar ratio of the gelling agent relative to NaO.sub.2 is 0.1 to 0.75, and adjusting a sol into which macro-pores are introduced by leaving unreacted Na and non-cross-linked oxygen in a siloxane skeleton; an impregnating and gelling step of impregnating a nonwoven fabric fiber structure with the sol to form a composite of hydrogel-nonwoven fabric fiber; a hydrophobizating step of mixing the formed composite of hydrogel-nonwoven fabric fiber with a silylating agent to modify a surface thereof; and a drying step of removing a liquid contained in the surface modified composite of hydrogel-nonwoven fabric fiber by drying under a temperature and pressure lower than respective critical values.

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.

A full-fiber burner brick and a preparation method thereof, comprising mixing alumina crystal fiber and amorphous ceramic fiber with both of them being a combination of fibers of different lengths gradations, and moreover adding fine powder fillers of different particle size gradations and supplementing other additives. This enables the internal structure of the product more uniform, increases the bulk density of the product, and also benefits the suction filterability of fiber cotton blank, and is conducive to forming and improving the strength of the blank. The surface of the brick body is further provided with a coating, which can effectively protect the cotton fiber of the brick body fiber from harsh environments, improve its high temperature resistance, and help to extend the service life of the burner brick.

A coating composition is described, for use in the foundry, in particular comprising particulate, amorphous silicon dioxide (SiO.sub.2) and an aqueous phase having a pH of at most 5, and also coated, waterglass-bound foundry molding elements, especially coated, waterglass-bound foundry molds and foundry cores, which each comprise a coating composition of the invention. Further described is the use of a coating composition of the invention for producing a coating on a waterglass-bound foundry molding element and a method for producing a waterglass-bound foundry molding element (mold or core) coated with a water-containing refractory coating. Likewise specified is a kit whose contents include a coating composition of the invention.

A coating composition is described, for use in the foundry, in particular comprising particulate, amorphous silicon dioxide (SiO.sub.2) and an aqueous phase having a pH of at most 5, and also coated, waterglass-bound foundry molding elements, especially coated, waterglass-bound foundry molds and foundry cores, which each comprise a coating composition of the invention. Further described is the use of a coating composition of the invention for producing a coating on a waterglass-bound foundry molding element and a method for producing a waterglass-bound foundry molding element (mold or core) coated with a water-containing refractory coating. Likewise specified is a kit whose contents include a coating composition of the invention.

The present disclosure discloses a modified calcium silicate board, and belongs to the technical field of floors and decorative boards. A modification method comprises steps of: dipping a calcium silicate board in a silicon dioxide solution with a solid content of 95% or more, completely absorbing the silicon dioxide solution until the calcium silicate board is saturated, and drying the dipped calcium silicate board; and carrying out sizing hardening on any surface of the modified calcium silicate board to obtain the calcium silicate board, so as to enable the triamine impregnated paper to be directly laminated with the calcium silicate board in a hot-pressing manner, and enable the surface bonding strength to reach 1 MPa; wood veneers, fireproof plates and other materials are subjected to coldbonding, the peeling strength of the product meets the requirements, and the practicability of the calcium silicate board is effectively improved.

The present disclosure discloses a modified calcium silicate board, and belongs to the technical field of floors and decorative boards. A modification method comprises steps of: dipping a calcium silicate board in a silicon dioxide solution with a solid content of 95% or more, completely absorbing the silicon dioxide solution until the calcium silicate board is saturated, and drying the dipped calcium silicate board; and carrying out sizing hardening on any surface of the modified calcium silicate board to obtain the calcium silicate board, so as to enable the triamine impregnated paper to be directly laminated with the calcium silicate board in a hot-pressing manner, and enable the surface bonding strength to reach 1 MPa; wood veneers, fireproof plates and other materials are subjected to coldbonding, the peeling strength of the product meets the requirements, and the practicability of the calcium silicate board is effectively improved.

The disclosure provides a ceiling tile including a curable coating composition including 10-50 vol. % inorganic binder, based on the total volume of solids in the dry coating composition, wherein the inorganic binder is an alkali metal silicate or an alkaline earth metal silicate and 50-90 vol. % inorganic filler, based on the total volume of solids in the coating composition, wherein the binder and the filler are not the same and the coating is substantially free of an organic polymeric binder. The ceiling tiles have a backing side and an opposing facing side, and a cured coating layer disposed on the backing side of the panel, the backing side being directed to a plenum above the fibrous panel in a suspended ceiling tile, the cured coating layer including the curable coating composition of the disclosure.

The disclosure provides a ceiling tile including a curable coating composition including 10-50 vol. % inorganic binder, based on the total volume of solids in the dry coating composition, wherein the inorganic binder is an alkali metal silicate or an alkaline earth metal silicate and 50-90 vol. % inorganic filler, based on the total volume of solids in the coating composition, wherein the binder and the filler are not the same and the coating is substantially free of an organic polymeric binder. The ceiling tiles have a backing side and an opposing facing side, and a cured coating layer disposed on the backing side of the panel, the backing side being directed to a plenum above the fibrous panel in a suspended ceiling tile, the cured coating layer including the curable coating composition of the disclosure.

Systems and methods for treating concrete, which includes the steps of wetting a surface of concrete with colloidal silica, allowing time for the colloidal silica to penetrate the concrete surface, and cutting the surface of the concrete with a bladed or segmented tool wherein the longitudinal blade or edge portion is positioned approximately at an angle between 30 degrees and 90 degrees relative to the surface of the concrete.