W. R. Grace Co.-conn.

W. R. Grace Co.

Ahmad Arfaei

Ellis M Gartner

Neal Steven Berke

Ara A Jeknavorian

David Charles Darwin

Lawrence L Kuo

Leslie A Jardine

Hideo Koyata

Byong-Wa Chun

James Franklin Lambert

Joseph A Cogliano

David F Myers

Michael P Dallaire

Tariq Quadir

Paul C Scheiner

Maria C Hicks

Heyman C Duecker

JudithAnn R Hartman

Paul G Tourney

Leslie Ann Jardine

Lawrence Reeder Roberts

Xiaojia Zhang

Robert J Hoopes

A high early strength admixture for precast hydraulic cement comprises a calcium salt and a copolymer having a carbon-containing backbone to which are attached cement-anchoring members, such as carboxyl groups, and to which are also attached oxyalkylene pendant groups by linkages selected from the group consisting of amide and imide members. The copolymers used are preferably formed by reacting an acrylic polymer with ammonia or an alkoxylated amine. The calcium salt, preferably calcium nitrite, and the copolymer can be added simultaneously as one admixture, or separately. The invention relates also to methods for enhancing high early strength in concrete, cement, masonry, and mortar mixtures generally, and to precast concrete particarly, and also pertains to such hydraulic mixtures containing the calcium salt and copolymer.

High early-strength-enhancing admixture for precast hydraulic cement and

An improved hydraulic cement and resultant hydraulic cement composition which has an alkyl terminated alkoxy amine derivative of maleic acid based polymer or copolymer uniformly distributed therein.

Cement and cement composition having improved rheological properties

The present invention is directed to an imidized polycarboxylic acid polymer useful as a cement admixture, to improved cement compositions containing said polymer and to a process of forming the same.

Cement admixture product having improved rheological properties and

Polymeric additives for hydraulic cement compositions which impart to the wet cement composition greater plasticity, lower slumploss over time, and water reduction capability without the problems of air entrainment associated with prior polymeric additives of this type. The superplasticizers have a carbon backbone formed by polymerization of ethylenically-unsaturated carboxylic acids, the backbone comprising carboxylic acid grafting sites to which are covalently attached a) air detraining functional side chains, which are first polyoxyalkylene groups of the general formula

Air controlling superplasticizers

Hydraulic cement set-accelerating admixture compositions; cement compositions containing such admixtures; and methods for preparing said cement compositions. The admixture compositions comprise one or more nitroalcohols present in an amount effective to increase the set acceleration of a hydraulic cement composition. The invention further relates to a method of making a hydraulic cement composition comprising adding to a cement composition comprising a hydraulic cement binder, a nitroalcohol component in an amount effective to increase the set-acceleration of the binder, and to a cement composition comprising a hydraulic cement binder and a nitroalcohol set-accelerating agent.

Hydraulic cement set accelerators based on nitroalcohols

A rehabilitative solution for preventing or retarding the spread of corrosion of metal reinforcements in concrete, comprising a) one or more corrosion-inhibiting agent(s) and b) a impregnation-increasing amount of a penetration-enhancing agent selected from the group consisting of C.sub.1 to C.sub.20 alcohols; alkali metal salts of gluconic acid; alkyl-substituted benzene compounds; or mixtures thereof, is disclosed, along with several methods of its application for concrete rehabilitation.

Corrosion inhibiting composition for reinforced concrete and method of

New set-accelerating admixtures for hydraulic cement compositions are disclosed. These admixtures incorporate known set accelerators and certain low molecular weight glycols, e.g., glycerol and ethylene glycol, are found to be surprisingly effective in decreasing the initial set time of hydraulic cements, mortars, and concretes, and are advantageous as reduced-temperature set-accelerators. Preferred embodiments of the invention may also comprise a component selected from the group consisting of certain alkanolamines and mixtures thereof.

Hydraulic cement set-accelerating admixtures incorporating glycols

New set-accelerating admixtures for hydraulic cement compositions are disclosed. These admixtures incorporate known set accelerators and certain low molecular weight glycols, e.g., glycerol and ethylene glycol, are found to be surprisingly effective in decreasing the initial set time of hydraulic cements, mortars, and concretes, and are advantageous as reduced-temperature set-accelerators.

New set-accelerating admixtures for hydraulic cement compositions are disclosed. These admixtures incorporate set-accelerating compounds and methylol derivatives of amino acids, are found to be surprisingly effective in decreasing the initial set time of hydraulic cements, mortars, and concretes, and are particularly advantageous in reduced-temperature set-accelerators.

Hydraulic cement set-accelerating admixtures incorporating amino acid

A water-based silicon nitride powder extrusion mixture is prepared. The mixture also contains oleic acid, glycerin, methyl cellulose and a polyacrylic acid-containing polymer. The mixture can be extruded at ambient temperatures. The extrudate can be dried at low temperature and sintered to form a dense silicon nitride part.

Aqueous extrusion of silicon nitride

Hydraulic cement compositions are disclosed containing a hydraulic cement and a graft copolymer, the graft copolymer containing a polyether backbone and side chains prepared by polymerization of an ethylenically unsaturated monomers. The graft copolymer functions as a plasticizer in the cement composition.

Hydraulic cement additives and hydraulic cement compositions containing

A method of controlling the level of entrained air in hydraulic cement compositions is disclosed comprising the sequential steps of preparing a hydraulic cement composition in the form of an aqueous slurry containing an air entraining plasticizer and a defoamer, and increasing the air content of the composition by adding to said composition an air entraining agent. This method prevents undesired air entrainment, while allowing controlled amounts of air to be entrained if desired for freeze/thaw durability.

Method of controlling air entrainment in concrete compositions

An additive combination for hydraulic cement compositions is provided which advantageously provides corrosion inhibition and set acceleration, in combination with a high level of fluidity and retention of fluidity over a desired period of time. The cement additive combination comprises an alkali or alkaline earth metal nitrite and a graft copolymer plasticizer comprising a polyether backbone and side chain polymers formed by polymerization of ethylenically unsaturated monomers. Fluid hydraulic cement compositions are further provided comprising these additive combinations.

Growing community of inventors

Chelmsford, MA, United States of America

Ahmad Arfaei