An aqueous oil-in-water emulsion containing a propylethoxysilane oligomer mixture or a mixture of a propylethoxysilane oligomer mixture and octyltriethoxysilane in a weight ratio of 3:1 to 1:3, at least one emulsifier or an emulsifier system, at least one content of a 2-aminoethanol and water is used as an addition in the production of hydraulically setting cement mixtures such as mortar, screed or concrete for reduction of the shrinkage characteristics.

An aqueous oil-in-water emulsion containing a propylethoxysilane oligomer mixture or a mixture of a propylethoxysilane oligomer mixture and octyltriethoxysilane in a weight ratio of 3:1 to 1:3, at least one emulsifier or an emulsifier system, at least one content of a 2-aminoethanol and water is used as an addition in the production of hydraulically setting cement mixtures such as mortar, screed or concrete for reduction of the shrinkage characteristics.

Disclosed are a rock similar material satisfying a water-induced strength degradation characteristic and a preparation method and use thereof. The rock similar material satisfying the water-induced strength degradation characteristic includes an aggregate, a cementing material, and an additive, where the aggregate includes quartz sand, barite powder, and bentonite, and the cementing material includes cement and gypsum.

Disclosed are a rock similar material satisfying a water-induced strength degradation characteristic and a preparation method and use thereof. The rock similar material satisfying the water-induced strength degradation characteristic includes an aggregate, a cementing material, and an additive, where the aggregate includes quartz sand, barite powder, and bentonite, and the cementing material includes cement and gypsum.

The invention provides a low density cement composition. The composition includes a cement component, a glass sphere component, a bentonite component, a fine calcium carbonate component, a medium calcium carbonate component, a silica sand component, and a silica flour component.

The invention provides a low density cement composition. The composition includes a cement component, a glass sphere component, a bentonite component, a fine calcium carbonate component, a medium calcium carbonate component, a silica sand component, and a silica flour component.

Migration of formation solids in a wellbore is restrained by feeding a slurry, comprising water, a viscosifier, and a concentration of cement clinker particles, into the wellbore, and hydrating the clinker particles in the wellbore. The clinker particles are kept in suspension during the hydrating, and upon completion of the hydrating the hydrated clinker particles form a hardened cement consisting of a permeable structure of interconnected hydrated clinker particles. A layer of degradable lost circulation material (LCM) may be employed to separate the slurry with clinker particles from the formation surrounding the wellbore during hydrating of the clinker particles.

Migration of formation solids in a wellbore is restrained by feeding a slurry, comprising water, a viscosifier, and a concentration of cement clinker particles, into the wellbore, and hydrating the clinker particles in the wellbore. The clinker particles are kept in suspension during the hydrating, and upon completion of the hydrating the hydrated clinker particles form a hardened cement consisting of a permeable structure of interconnected hydrated clinker particles. A layer of degradable lost circulation material (LCM) may be employed to separate the slurry with clinker particles from the formation surrounding the wellbore during hydrating of the clinker particles.

A process for producing a ceramic catalyst involves the steps of: a) providing functional particles having a catalytically inactive pore former as a support surrounded by a layer of a catalytically active material, b) processing the functional particles with inorganic particles to form a catalytic composition, c) treating the catalytic composition thermally to form a ceramic catalyst, wherein the ceramic catalyst comprises at least porous catalytically inactive cells which are formed by the pore formers in the functional particles, which are embedded in a matrix comprising the inorganic particles, which form a porous structure and which are at least partly surrounded by an active interface layer comprising the catalytically active material of the layer of the functional particles.

An SCR catalyst produced in by this method has an improved NO.sub.x conversion rate compared to a conventionally produced SCR catalyst.

A process for producing a ceramic catalyst involves the steps of: a) providing functional particles having a catalytically inactive pore former as a support surrounded by a layer of a catalytically active material, b) processing the functional particles with inorganic particles to form a catalytic composition, c) treating the catalytic composition thermally to form a ceramic catalyst, wherein the ceramic catalyst comprises at least porous catalytically inactive cells which are formed by the pore formers in the functional particles, which are embedded in a matrix comprising the inorganic particles, which form a porous structure and which are at least partly surrounded by an active interface layer comprising the catalytically active material of the layer of the functional particles.

An SCR catalyst produced in by this method has an improved NO.sub.x conversion rate compared to a conventionally produced SCR catalyst.