A method for the preparation of industrial-scale concrete installations with improved compression strength, curling, cracking and cracking characteristics, the method comprising the addition of nanosilica particulate, and more preferably, colloidal amorphous silica, having specific size and surface area characteristics to a concrete mix after water has been added to the mix and the mix has been agitated.

A gypsum building material, characterised in that the gypsum building material comprises at least gypsum, H-siloxane and/or amorphous silicon dioxide and optionally further additives, wherein the H-siloxane is uniformly distributed in the gypsum building material and/or is applied to at least one surface of the gypsum building material, characterised in that the gypsum building material under the effect of temperatures of at least 80° C. has a longer expansion phase than a gypsum building material without H-siloxane and/or amorphous silicon dioxide, wherein the gypsum building material is otherwise of identical composition.

A gypsum building material, characterised in that the gypsum building material comprises at least gypsum, H-siloxane and/or amorphous silicon dioxide and optionally further additives, wherein the H-siloxane is uniformly distributed in the gypsum building material and/or is applied to at least one surface of the gypsum building material, characterised in that the gypsum building material under the effect of temperatures of at least 80° C. has a longer expansion phase than a gypsum building material without H-siloxane and/or amorphous silicon dioxide, wherein the gypsum building material is otherwise of identical composition.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, in the absence of an aluminium compound; wherein a mixture of polycarboxylic acids is added to the filter cake, during or after the liquefaction operation. It also relates to novel precipitated silicas and to their uses.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, in the absence of an aluminium compound; wherein a mixture of polycarboxylic acids is added to the filter cake, during or after the liquefaction operation. It also relates to novel precipitated silicas and to their uses.

A defoamed aqueous composition including 5 to 75 weight-% of at least one anionic polymer, 0.05 to 5 weight-% of at least one water insoluble liquid defoamer and 0.005 to 3 weight-% of at least one polysaccharide, based on 100 weight-% of the composition. The composition gives predictable air content in non-air entrained and air-entrained mortar and concrete.

A defoamed aqueous composition including 5 to 75 weight-% of at least one anionic polymer, 0.05 to 5 weight-% of at least one water insoluble liquid defoamer and 0.005 to 3 weight-% of at least one polysaccharide, based on 100 weight-% of the composition. The composition gives predictable air content in non-air entrained and air-entrained mortar and concrete.

Drilling fluid compositions and methods of using them are described. The drilling fluid compositions comprise nanocomposites comprising core-shell morphology, wherein the core material comprises a nanoparticle having an average particle size of about 5 nm to 100 nm, and the shell material comprises a crosslinked polymer comprising acrylamide repeat units. The nanocomposites are effective fluid loss control agents when the drilling fluids are employed in mud drilling operations.

Drilling fluid compositions and methods of using them are described. The drilling fluid compositions comprise nanocomposites comprising core-shell morphology, wherein the core material comprises a nanoparticle having an average particle size of about 5 nm to 100 nm, and the shell material comprises a crosslinked polymer comprising acrylamide repeat units. The nanocomposites are effective fluid loss control agents when the drilling fluids are employed in mud drilling operations.

Hydrophobized granular material comprising from 30 to 95% by weight of a pyrogenic mixed oxide based on silica and at least one oxide of metal M selected from of Al, Ti and Fe with the content of metal M oxide in the mixed oxide being from 01 to 10% by weight, and from 5 to 70% by weight of at least one IR-opacifier selected from the group consisting of silicon carbide, zirconium dioxide, ilmenites, iron titanates, zirconium silicates, manganese oxides, graphites, carbon blacks and mixtures thereof.