Aqueous compositions may be used preparing special concretes like aerated concrete or lightweight concrete. Such an aqueous composition for preparing such concretes, may combine water, a hydraulic binder, and an aggregate that is ground in the presence of a particular anionic polymer. The ground aggregate is selected from slag, fly ash, sand, and combinations thereof.

The present invention relates to a two-component composition consisting of a component A intended to be mixed, in situ, with a component B in order to form an injectable or pumpable organo-mineral compound, in particular for injection-sealing dynamic anchor bolts, comprising at least one alkali metal silicate, at least one polyisocyanate derivative and at least one cement. The component A further contains at least one polyol having a molecular mass of between 50 and 200 g/mol, at least one polymerisation catalyst comprising at least one polar function and at least one gelling agent and the component B further comprises at least one suitable

The present invention relates to a two-component composition consisting of a component A intended to be mixed, in situ, with a component B in order to form an injectable or pumpable organo-mineral compound, in particular for injection-sealing dynamic anchor bolts, comprising at least one alkali metal silicate, at least one polyisocyanate derivative and at least one cement. The component A further contains at least one polyol having a molecular mass of between 50 and 200 g/mol, at least one polymerisation catalyst comprising at least one polar function and at least one gelling agent and the component B further comprises at least one suitable

A fluidizing composition in the form of a liquid or in the form of a powder including at least one superplasticizer chosen from polycarboxylate ethers, characterized in that it includes from 1 to 20 parts by weight of at least one aromatic hydrocarbon sulfonic acid or one of its salts chosen from alkali salts, alkaline-earth salts or one of their mixtures, for 100 parts by weight of the superplasticizer. A method for preparing such fluidizing composition, a dry mortar incorporating the fluidizing composition, as well as plasters prepared from the dry mortar are also described.

A fluidizing composition in the form of a liquid or in the form of a powder including at least one superplasticizer chosen from polycarboxylate ethers, characterized in that it includes from 1 to 20 parts by weight of at least one aromatic hydrocarbon sulfonic acid or one of its salts chosen from alkali salts, alkaline-earth salts or one of their mixtures, for 100 parts by weight of the superplasticizer. A method for preparing such fluidizing composition, a dry mortar incorporating the fluidizing composition, as well as plasters prepared from the dry mortar are also described.

A curing accelerator composition for building chemical mixtures comprises a mineral constituent and a polymeric water-soluble dispersant. The mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate. The composition displays a more pronounced accelerating effect than comparative compositions in which the mineral component comprises a calcium silicate hydrate having a higher degree of crystallinity.

A curing accelerator composition for building chemical mixtures comprises a mineral constituent and a polymeric water-soluble dispersant. The mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate. The composition displays a more pronounced accelerating effect than comparative compositions in which the mineral component comprises a calcium silicate hydrate having a higher degree of crystallinity.

This invention relates to a solidifying agent for solidifying radioactive waste, and more particularly to a solidifying-agent composition for solidifying radioactive waste, including alumina cement and a gypsum powder. The solidifying-agent composition including alumina cement and a gypsum powder is capable of effectively minimizing an increase in the volume of a solidified radioactive waste product to a level satisfying physical and chemical safety regulations upon the solidification of radioactive waste.

This invention relates to a solidifying agent for solidifying radioactive waste, and more particularly to a solidifying-agent composition for solidifying radioactive waste, including alumina cement and a gypsum powder. The solidifying-agent composition including alumina cement and a gypsum powder is capable of effectively minimizing an increase in the volume of a solidified radioactive waste product to a level satisfying physical and chemical safety regulations upon the solidification of radioactive waste.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.