Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

A method of preparing an admixture for a plasterboard is disclosed. An admixture prepared by the method and a composition for forming a plasterboard containing the admixture are also disclosed. The method includes sulfonation of polystyrene using sulfuric acid to give an admixture including a sulfonated polystyrene (SPS)-based compound of formula 1 below. The admixture enables regulation of properties of a plasterboard, such as foam size, flowability, and setting time, by regulating a degree of sulfonation (DS) of the SPS-based compound:

##STR00001##

A method of preparing an admixture for a plasterboard is disclosed. An admixture prepared by the method and a composition for forming a plasterboard containing the admixture are also disclosed. The method includes sulfonation of polystyrene using sulfuric acid to give an admixture including a sulfonated polystyrene (SPS)-based compound of formula 1 below. The admixture enables regulation of properties of a plasterboard, such as foam size, flowability, and setting time, by regulating a degree of sulfonation (DS) of the SPS-based compound:

##STR00001##

A method of preparing an admixture for a plasterboard is disclosed. An admixture prepared by the method and a composition for forming a plasterboard containing the admixture are also disclosed. The method includes sulfonation of polystyrene using sulfuric acid to give an admixture including a sulfonated polystyrene (SPS)-based compound of formula 1 below. The admixture enables regulation of properties of a plasterboard, such as foam size, flowability, and setting time, by regulating a degree of sulfonation (DS) of the SPS-based compound:

##STR00001##

Cement compositions for primary cementing of well bores where a liquid mixture of pre-hydrated cementitious particles are combined with cement particles to form a cement composition. The pre-hydrated cementitious particles are encapsulated with the hydration product and are capable of being stored in a liquid for one day or longer

Cement compositions for primary cementing of well bores where a liquid mixture of pre-hydrated cementitious particles are combined with cement particles to form a cement composition. The pre-hydrated cementitious particles are encapsulated with the hydration product and are capable of being stored in a liquid for one day or longer

The present application relates to a mixture comprising at least one compound A selected from glyoxylic acid, salts thereof, and condensation or addition products of glyoxylic acid or salts thereof; and at least one polyhydroxy compound B. Furthermore, the present application relates to a construction material composition comprising said mixture, and to the use of said mixture for modifying the hardening of inorganic binder containing building material formulations, and/or for producing building products.

The present application relates to a mixture comprising at least one compound A selected from glyoxylic acid, salts thereof, and condensation or addition products of glyoxylic acid or salts thereof; and at least one polyhydroxy compound B. Furthermore, the present application relates to a construction material composition comprising said mixture, and to the use of said mixture for modifying the hardening of inorganic binder containing building material formulations, and/or for producing building products.

A set control composition for cementitious systems comprises (a) an amine-glyoxylic acid condensate, and (b) at least one of (i) a borate source and (ii) a carbonate source. The carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 gL.sup.−1 or more, and organic carbonates. The set control composition improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. Due to the retarding action of the set control composition, the dosage of dispersant(s) necessary to obtain a desired flowability of the cementitious system can be reduced.