Provided is a concrete hardener composition. The concrete hardener composition includes a sodium silicate compound, an acid compound and a balance amount of solvent. The sodium silicate compound includes sodium silicate or a mixture of sodium silicate and sodium methylsilicate. The acid compound includes acetic acid, glycolic acid, ethylenediaminetetraacetic acid, tartaric acid, nitric acid, boric acid or a combination thereof. The solvent includes water or a mixed solution of water and polyol. Based on the total weight of the concrete hardener composition, the content of silicon is between 5 wt % and 15 wt %, and the content of the acid compound is between 2 wt % and 30 wt %.

Provided is a concrete hardener composition. The concrete hardener composition includes a sodium silicate compound, an acid compound and a balance amount of solvent. The sodium silicate compound includes sodium silicate or a mixture of sodium silicate and sodium methylsilicate. The acid compound includes acetic acid, glycolic acid, ethylenediaminetetraacetic acid, tartaric acid, nitric acid, boric acid or a combination thereof. The solvent includes water or a mixed solution of water and polyol. Based on the total weight of the concrete hardener composition, the content of silicon is between 5 wt % and 15 wt %, and the content of the acid compound is between 2 wt % and 30 wt %.

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.

Provided is a concrete hardener composition. The concrete hardener composition includes a sodium silicate compound, an acid compound and a balance amount of solvent. The sodium silicate compound includes sodium silicate or a mixture of sodium silicate and sodium methylsilicate. The acid compound includes acetic acid, glycolic acid, ethylenediaminetetraacetic acid, tartaric acid, nitric acid, boric acid or a combination thereof. The solvent includes water or a mixed solution of water and polyol. Based on the total weight of the concrete hardener composition, the content of silicon is between 5 wt % and 15 wt %, and the content of the acid compound is between 2 wt % and 30 wt %.

Provided is a concrete hardener composition. The concrete hardener composition includes a sodium silicate compound, an acid compound and a balance amount of solvent. The sodium silicate compound includes sodium silicate or a mixture of sodium silicate and sodium methylsilicate. The acid compound includes acetic acid, glycolic acid, ethylenediaminetetraacetic acid, tartaric acid, nitric acid, boric acid or a combination thereof. The solvent includes water or a mixed solution of water and polyol. Based on the total weight of the concrete hardener composition, the content of silicon is between 5 wt % and 15 wt %, and the content of the acid compound is between 2 wt % and 30 wt %.

A method of making a lithium alkylsiliconate composition comprising adding an alkylalkoxysilane to a first mixture comprising lithium hydroxide and water to form a second mixture comprising a lithium alkylsiliconate and an alcohol, wherein i) the mole ratio of lithium hydroxide to alkylalkoxysilane is from 0.9 to less than 1.1 and the water is from 89 to 93 mol %, or ii) the mole ratio of lithium hydroxide to alkylalkoxysilane is from 1.1 to 1.4 and the water is from greater than 93 to 99 mole %.

A process for treating a substrate made of stone material, preferably in the form of slabs, is provided which process improves the mechanical, thermal and catalytic properties of the substrate. The process includes applying a protective coating to the outer surface of the substrate made of stone material and, to improve adhesion of the protective coating to the outer surface of the substrate, preliminarily subjecting the substrate to one or more pre-treatment steps that eliminate or reduce the presence of pollutants and porosity on the surface of the substrate. The pre-treatment of the substrate made of stone material comprises at least one step of treatment under vacuum conditions inside an autoclave, preferably under pressure conditions lower than 10.sup.2 mbar. Then, after having brought the substrate back to ambient pressure, it is possible to apply and effectively adhere the protective coating to the surface of the stone material.

Silicon dioxide-containing thermal-insulation sheet hydrophobized throughout with hardened surface, wherein the compressive stress at fracture measured on the sheet surface is higher than the compressive stress at fracture measured on the sectional surface in the middle cross section of the sheet parallel to the sheet surface, at, in each case, the same penetration depths of the measurement probe in the test specimen.

Silicon dioxide-containing thermal-insulation sheet hydrophobized throughout with hardened surface, wherein the compressive stress at fracture measured on the sheet surface is higher than the compressive stress at fracture measured on the sectional surface in the middle cross section of the sheet parallel to the sheet surface, at, in each case, the same penetration depths of the measurement probe in the test specimen.