Methods and systems for cementing casing in a wellbore are described. The methods include introducing a modified biopolymer into an inner diameter of the casing, reverse-circulating a cement composition in the wellbore, permitting the modified biopolymer to contact the cement composition, and terminating the reverse-circulation upon detection of an increase in pressure in pumping the cement composition. The modified biopolymer includes a reaction product of a biopolymer and an organic carbonate, and the cement composition has a pH greater than 11.

Methods and systems for cementing casing in a wellbore are described. The methods include introducing a modified biopolymer into an inner diameter of the casing, reverse-circulating a cement composition in the wellbore, permitting the modified biopolymer to contact the cement composition, and terminating the reverse-circulation upon detection of an increase in pressure in pumping the cement composition. The modified biopolymer includes a reaction product of a biopolymer and an organic carbonate, and the cement composition has a pH greater than 11.

The present invention relates to a process for preparing a particle-stabilized inorganic foam based on calcium sulfoaluminate, to a particle-stabilized inorganic foam based on calcium sulfoaluminate, to a cellular material obtainable by hardening and optionally drying the particle-stabilized inorganic foam based on calcium sulfoaluminate, and to a composition for preparing an inorganic foam formulation for providing a particle-stabilized inorganic foam based on calcium sulfoaluminate.

A set control composition for cementitious systems comprises a retarder (a) selected from (a-1) polymeric polycarboxylic acids selected from homopolymers and copolymers of ,-ethylenically unsaturated carboxylic acids; and copolymers of at least one ,-ethylenically unsaturated carboxylic acid and at least one sulfo group containing monomer; and salts thereof, whose milliequivalent number of carboxyl groups is 3.0 meq/g or higher, preferably 3.0 to 17.0 meq/g, and having a molecular weight 25,000 g/mol or less, assuming all the carboxyl groups to be in unneutralized form, (a-2) phosphonic acids and salts thereof, (a-3) low molecular weight polycarboxylic acids and salts thereof, and mixtures thereof, (b) at least one of (b-1) a borate source and (b-2) a carbonate source, wherein the carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 g.Math.L.sup.1 or more at 25 C., and organic carbonates, in a weight ratio of b) to a) in the range of 0.1 to 10, (c) a polyol having at least 3 alcoholic hydroxyl groups in its molecule, in a weight ratio of c) to a) in the range of 0.2 to 4, and (d) a dispersant. The set control composition effectively improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. The compositions show sufficient open time, i.e., the time until initial setting, good workability during said open time as characterized, for example by adequate slump flow over time, and fast setting. The invention further relates to a construction composition comprising i) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases, ii) optionally, an extraneous aluminate source, iii) a sulfate source, and iv) the set control composition. The construction composition contains 0.05 to 0.2 mol of total available aluminate, calculated as Al(OH).sub.4.sup., from the calcium aluminate mineral phases plus the optional extraneous aluminate source, per 100 g of cementitious binder i), and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0.

A limestone calcined clay cement construction composition comprises a) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases, and having a Blaine surface area of at least 3800 cm.sup.2/g; b) a supplementary cementitious material having a Dv90 of less than 200 ?m comprising (b-1) a calcined clay material and (b-2) a carbonate rock powder in a weight ratio of (b-1) to (b-2) in the range of 0.5 to 2; c) optionally, an extraneous aluminate source; d) a sulfate source; and e) a polyol. The composition contains a controlled amount of available aluminate, calculated as Al(OH).sub.4.sup.?, from the calcium aluminate mineral phases plus the optional extraneous aluminate source; and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0. The construction composition further comprises f) an ettringite formation controller. The limestone calcined clay cement construction composition is a reduced carbon footprint composition and exhibits high early strength, high final strength, sufficient open time and high durability.

A limestone calcined clay cement construction composition comprises a) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases, and having a Blaine surface area of at least 3800 cm.sup.2/g; b) a supplementary cementitious material having a Dv90 of less than 200 ?m comprising (b-1) a calcined clay material and (b-2) a carbonate rock powder in a weight ratio of (b-1) to (b-2) in the range of 0.5 to 2; c) optionally, an extraneous aluminate source; d) a sulfate source; and e) a polyol. The composition contains a controlled amount of available aluminate, calculated as Al(OH).sub.4.sup.?, from the calcium aluminate mineral phases plus the optional extraneous aluminate source; and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0. The construction composition further comprises f) an ettringite formation controller. The limestone calcined clay cement construction composition is a reduced carbon footprint composition and exhibits high early strength, high final strength, sufficient open time and high durability.

Disclosed herein is a warm mix asphalt additive comprising (a) a wax; (b) a phosphoric ester; and (c) a fatty amine. Preferably component (a) is a fatty amide wax and component (b) is a C16-C18 alkyl phosphoric ester. Also disclosed is a warm mix asphalt binder composition comprising asphalt and a warm mix asphalt additive, and methods for its preparation thereof. Additionally disclosed is a warm mix asphalt composition comprising a warm mix asphalt binder and aggregate, and methods for its preparation thereof.

Cement compositions that can capture carbon dioxide and related methods are generally described.

Cement compositions that can capture carbon dioxide and related methods are generally described.

A composite plastering material and a method of making the same are provided. The composite plastering material includes a mixture of sand-silica and Abelmoschus esculentus powder. The composite plastering material has increased compressive strength depending upon the concentration of Abelmoschus esculentus powder used. The method of making the composite plastering material includes sieving the sand-silica to produce sand-silica of a uniform particle size, mixing powdered Abelmoschus esculentus powder with the sand-silica to produce a first mixture, and mixing water with the first mixture to produce the composite plastering material. Optionally, the method may also include milling the sand-silica prior to sieving and combining the sand-silica with the Abelmoschus esculentus powder. The composite plastering material may then be plaster cast, such as by pressing the composite plastering material in a hot press and drying the resulting composite material in an oven.