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 jewelry member according to the present disclosure includes: a plurality of spherical bodies that are three-dimensionally arranged regularly and include an amorphous silicic acid; and a resin that is located in a gap among adjacent spherical bodies of the plurality of spherical bodies and includes a fluorescent dye.

A method for cutting or otherwise removing material from an inorganic substrate (e.g., a substrate formed from a cementitious material, such as concrete, or stone, etc.) includes applying an aqueous solution that includes a hardener/densifier to the inorganic substrate and/or to a removal element (e.g., a saw blade, an abrasive wheel, a grinding disk, etc.), the inorganic substrate or material removed from the inorganic substrate as the removal element removes material from the inorganic substrate. A system for removing material from an inorganic substrate includes a removal element and an aqueous solution that includes a hardener/densifier.

A method for cutting or otherwise removing material from an inorganic substrate (e.g., a substrate formed from a cementitious material, such as concrete, or stone, etc.) includes applying an aqueous solution that includes a hardener/densifier to the inorganic substrate and/or to a removal element (e.g., a saw blade, an abrasive wheel, a grinding disk, etc.), the inorganic substrate or material removed from the inorganic substrate as the removal element removes material from the inorganic substrate. A system for removing material from an inorganic substrate includes a removal element and an aqueous solution that includes a hardener/densifier.

A composition that may be used to retain moisture within fresh concrete as it cures to optimize the curing of the concrete may include one or more hardening and densifying agents (e.g., alkali metal polysilicate, colloidal silica, etc.) and one or more temporary moisture sealing agents (e.g., a wax, etc.). Additionally, such a composition may include a siliconate (e.g., a metal siliconate, such as an alkali metal siliconate like potassium methyl siliconate, etc.). The hardening and densifying agent of such a composition may penetrate the surface of fresh concrete to react with free lime, providing the fresh concrete with a strong surface. The temporary moisture sealing agent may form a moisture barrier on the surface of the fresh concrete to prevent moisture from escaping from the fresh concrete (e.g., evaporating, etc.) before the fresh concrete has sufficiently cured. The temporary moisture sealing agent may degrade within a matter of days (e.g., three days, seven days, 14 days, less than a month, etc.), facilitating its removal from the surface of the concrete once the concrete has cured and enabling further treatment of the surface without undue delay.

A composition that may be used to retain moisture within fresh concrete as it cures to optimize the curing of the concrete may include one or more hardening and densifying agents (e.g., alkali metal polysilicate, colloidal silica, etc.) and one or more temporary moisture sealing agents (e.g., a wax, etc.). Additionally, such a composition may include a siliconate (e.g., a metal siliconate, such as an alkali metal siliconate like potassium methyl siliconate, etc.). The hardening and densifying agent of such a composition may penetrate the surface of fresh concrete to react with free lime, providing the fresh concrete with a strong surface. The temporary moisture sealing agent may form a moisture barrier on the surface of the fresh concrete to prevent moisture from escaping from the fresh concrete (e.g., evaporating, etc.) before the fresh concrete has sufficiently cured. The temporary moisture sealing agent may degrade within a matter of days (e.g., three days, seven days, 14 days, less than a month, etc.), facilitating its removal from the surface of the concrete once the concrete has cured and enabling further treatment of the surface without undue delay.

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.

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.

Luminescent concrete compositions containing cement, fine aggregates such as sand, and a phosphor such as strontium aluminate. Glow-in-the-dark concrete products made therefrom and methods of producing such concrete products are also specified. The glow-in-the-dark concrete products demonstrate good mechanical strength (e.g. compressive strength) and skid resistance. The addition of phosphorescent strontium aluminate provides luminance that persists for up to 10 hours to the concrete products.

Luminescent concrete compositions containing cement, fine aggregates such as sand, and a phosphor such as strontium aluminate. Glow-in-the-dark concrete products made therefrom and methods of producing such concrete products are also specified. The glow-in-the-dark concrete products demonstrate good mechanical strength (e.g. compressive strength) and skid resistance. The addition of phosphorescent strontium aluminate provides luminance that persists for up to 10 hours to the concrete products.