The present invention relates to the use of a soluble magnesium compound for adjusting, in particular reducing, the viscosity of an aluminum sulfate suspension.

An aqueous dispersion and uses therefor. The aqueous dispersion includes a Component (a), Component (b) and Component (c). Where Component (a) is a polymer prepared by the polymerization of monomers comprising a vinyl ester and an ethylene, where Component (b) is an acrylate-based polymer and where Component (c) is water. A film that is formed from the aqueous dispersion has a glass transition temperature of less than or equal to −7° C. The aqueous dispersion the polymer of the Component (a) has a pot life of longer than or equal to 4 hours after being mixed with cement. Where Component (a) is present in an amount of higher than 35%, based on the total weight of the aqueous dispersion and Component (b) is present in an amount of less than or equal to 20%, based on the total weight of the aqueous dispersion.

A dispersant composition includes a) at least one polymer constituted of monomers having naphthalene ring and/or melamine; b). at least one polymer having carboxylic acid and/or phosphoric acid group and/or any group that is hydrolyzed into carboxylic or phosphoric; and c). at least one polymer having a structure of Formula I: ##STR00001##
R.sup.1 is hydrogen or alky group having carbon number not less than 1, cycloalkyl or cycloalkenyl group having carbon number not less than 3, alkenyl group having carbon number not less than 2, aryl group having carbon number not less than 6; R.sup.2 is hydrogen or alky group having carbon number from 1 to 3; A is alkylene group having carbon number from 3 or 4; m and n are positive numbers wherein m is more than n and the sum of m and n is more than 9 and less than 12. Also provided is a method of using the dispersant composition in a mortar or concrete, and the weight percentage of the dispersant composition is from 0.01% to 2.5% based on the weight of cement in mortar. Further provided is an aqueous composition including the dispersant composition.

A dispersant composition includes a) at least one polymer constituted of monomers having naphthalene ring and/or melamine; b). at least one polymer having carboxylic acid and/or phosphoric acid group and/or any group that is hydrolyzed into carboxylic or phosphoric; and c). at least one polymer having a structure of Formula I: ##STR00001##
R.sup.1 is hydrogen or alky group having carbon number not less than 1, cycloalkyl or cycloalkenyl group having carbon number not less than 3, alkenyl group having carbon number not less than 2, aryl group having carbon number not less than 6; R.sup.2 is hydrogen or alky group having carbon number from 1 to 3; A is alkylene group having carbon number from 3 or 4; m and n are positive numbers wherein m is more than n and the sum of m and n is more than 9 and less than 12. Also provided is a method of using the dispersant composition in a mortar or concrete, and the weight percentage of the dispersant composition is from 0.01% to 2.5% based on the weight of cement in mortar. Further provided is an aqueous composition including the dispersant composition.

The invention relates to an aerogel concrete mixture containing a photocatalyst, a photocatalytically active high-performance aerogel concrete obtainable therefrom and a method for producing same.

The present invention relates to a process for preparing a metal-chelate retarder by a sol-gel method. The method comprises the following steps: weighing calcium nitrate tetrahydrate, aluminum nitrate nonahydrate and ferric nitrate nonahydrate according to a certain mass ratio and adding them into deionized water; placing the mixed solution on a magnetic stirrer and stirring the mixed solution evenly; adding citric acid monohydrate or gluconic acid, ethylene glycol or glycerol, and placing the mixed solution into a water bath to react to obtain the metal-chelate retarder. The process of the present invention has a reliable principle, overcomes the defects of long production period, complex preparation and the like of the existing retarders, has the advantages of simple process operation, cheap and easily available raw materials, and short production period. The prepared retarder has wide temperature adaptation range and adjustable thickening time, is suitable for large-scale industrial production, and has a wide market application prospect.

The present invention relates to a process for preparing a metal-chelate retarder by a sol-gel method. The method comprises the following steps: weighing calcium nitrate tetrahydrate, aluminum nitrate nonahydrate and ferric nitrate nonahydrate according to a certain mass ratio and adding them into deionized water; placing the mixed solution on a magnetic stirrer and stirring the mixed solution evenly; adding citric acid monohydrate or gluconic acid, ethylene glycol or glycerol, and placing the mixed solution into a water bath to react to obtain the metal-chelate retarder. The process of the present invention has a reliable principle, overcomes the defects of long production period, complex preparation and the like of the existing retarders, has the advantages of simple process operation, cheap and easily available raw materials, and short production period. The prepared retarder has wide temperature adaptation range and adjustable thickening time, is suitable for large-scale industrial production, and has a wide market application prospect.

A cement composition is provided. The cement composition comprises: a microcapsule and cement. The microcapsule is provided with a core-shell structure having i) a core containing a water-repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell of a silicon-based network polymer containing a silica unit. The microcapsule is included at 0.01 to less than 0.5 parts by weight per 100 parts by weight of the cement. Thus, it is possible to provide a cement composition that can provide a cured product having high strength, as well as excellent air content stability, substance penetration prevention, drying shrinkage, and freeze-thaw resistance.

An admixture composition for use in cementitious compositions for improving the properties of the cementitious composition wherein the admixture composition comprises at least a polycarboxylate type comb-polymer dispersant and a hydroxyl amine compound selected from EDIPA (N,N-bis (2 hydroxypropyl)-N-(hydroxyethyl) amine) and optionally one or more polyhydroxyalkyl ethyleneamine compounds.

An admixture composition for use in cementitious compositions for improving the properties of the cementitious composition wherein the admixture composition comprises at least a polycarboxylate type comb-polymer dispersant and a hydroxyl amine compound selected from EDIPA (N,N-bis (2 hydroxypropyl)-N-(hydroxyethyl) amine) and optionally one or more polyhydroxyalkyl ethyleneamine compounds.