A plurality of set stabilizer particles including: a particle core including 50 to 98 wt. %, preferably 70 to 98 wt. % or 70 to 95 wt. %, calcium sulfate dihydrate and 0.05 to 10 wt. %, preferably 0.5 to 5 wt. %, hydrophobic material selected from wax and/or siloxane, and a coating on the particle core, the coating including a dehydration-preventing substance selected from sugars, dextrins, and polyhydroxy alcohols, such as glycerol or polyglycols, at a ratio of about 5 to 25 parts by weight of dehydration-preventing substance per 100 parts by weight of calcium sulfate dihydrate. Methods of making and using the set stabilizer particles are also disclosed.

A plurality of set stabilizer particles including: a particle core including 50 to 98 wt. %, preferably 70 to 98 wt. % or 70 to 95 wt. %, calcium sulfate dihydrate and 0.05 to 10 wt. %, preferably 0.5 to 5 wt. %, hydrophobic material selected from wax and/or siloxane, and a coating on the particle core, the coating including a dehydration-preventing substance selected from sugars, dextrins, and polyhydroxy alcohols, such as glycerol or polyglycols, at a ratio of about 5 to 25 parts by weight of dehydration-preventing substance per 100 parts by weight of calcium sulfate dihydrate. Methods of making and using the set stabilizer particles are also disclosed.

The present invention relates to the use of modified fibers in oilfield applications, particularly in borehole cementing. Said fibers have crystallization seeds attached to their surfaces thereby improving the mechanical strength and ductility of borehole cements.

Fibers with crystallization seeds attached to its surface, method of making such composite fibers by surface treatment of fibers followed by either treating such fibers with premade crystallization seeds or by precipitation and direct crystallization of seeds onto pretreated fibers. Controlling and tuning the properties of inorganic binder compositions with fiber-bound crystallization seeds and thereby generating inorganic binder compositions with tailor-made characteristics.

The present invention relates to a construction chemical composition comprising Portland cement, a water retention agent, a dispersing agent, and a hardening accelerator comprising calcium-silicate-hydrate, as well as a mortar composition containing said construction chemical composition. Although the composition is based on Portland cement it has a pull-off strength after 6 h meeting the DIN requirements and can therefore be used as a fast setting tile mortar.

The present invention relates to a construction chemical composition comprising Portland cement, a water retention agent, a dispersing agent, and a hardening accelerator comprising calcium-silicate-hydrate, as well as a mortar composition containing said construction chemical composition. Although the composition is based on Portland cement it has a pull-off strength after 6 h meeting the DIN requirements and can therefore be used as a fast setting tile mortar.

The present invention relates to the use of modified fibers in oilfield applications, particularly in borehole cementing. Said fibers have crystallization seeds attached to their surfaces thereby improving the mechanical strength and ductility of borehole cements.

The invention concerns a process for the preparation of a calcium silicate hydrate and ettringite containing hardening accelerator composition by reaction of a water-soluble calcium compound, silicate compound, aluminum compound and a sulfate compound, wherein the molar ratio of silicon to sulfate is from 2/1 to 30/1 and the reaction of the four compounds being carried out in the presence of an aqueous solution which contains a comb polymer suitable as a plasticizer for hydraulic binders. Also concerned are the use of said accelerators in building material mixtures, the building material mixtures containing said accelerators and a process for the preparation of a sprayable binder composition in which said accelerators are used.

The invention concerns a process for the preparation of a calcium silicate hydrate and ettringite containing hardening accelerator composition by reaction of a water-soluble calcium compound, silicate compound, aluminum compound and a sulfate compound, wherein the molar ratio of silicon to sulfate is from 2/1 to 30/1 and the reaction of the four compounds being carried out in the presence of an aqueous solution which contains a comb polymer suitable as a plasticizer for hydraulic binders. Also concerned are the use of said accelerators in building material mixtures, the building material mixtures containing said accelerators and a process for the preparation of a sprayable binder composition in which said accelerators are used.

The present invention describes a hardening accelerating admixture for hydraulic binders, the accelerator being based on transition metal silicate hydrates having the general formula: aMe.sub.xO.sub.y bMO cAl.sub.2O.sub.3 SiO.sub.2 dH.sub.2O 1) whereMe represents a transition metal whose molar coefficient a is in a range between 0.001 and 2, preferably between 0.01 and 1; M represents an alkaline earth metal whose molar coefficient b is in a range between 0 and 2, preferably between 0.3 and 1.6; The molar coefficient c for Al.sub.2O.sub.3 is in a range between 0 and 2, preferably between 0.1 and 1; H.sub.2O represents the hydration water of the silicate hydrate whose molar coefficient d can vary within a wide range between 0.5 and 20; x and y can both be equal to 1 or different, depending on the valence of the transition metal, given that the valence of the oxygen atom in the metal oxide is equal to 2.