W.r. Grace & Co. -conn.

University of Illinois

Gcp Applied Technologies Inc.

Ara A Jeknavorian

Chia-Chih Ou

Leslie A Jardine

Ahmad Arfaei

Josephine Ho-Wah Cheung

Christon L Hill

Neal Steven Berke

Hideo Koyata

Byong-Wa Chun

Charlotte Porteneuve

Ellis M Gartner

Felek Jachimowicz

Lawrence R Roberts

David Charles Darwin

Byong-wa Chun

Benita Dair

Kevin J Folliard

Ying Hai Chen

Jennifer Ann Lewis

Lawrence L Kuo

Eric P Koehler

David F Myers

Kati Hazrati

Xuan Zhang

Dany Vincent

Ding Feng Shen

Craig T Walloch

Eric Dananche

JudithAnn R Hartman

James Franklin Lambert

Robert T Taylor

Milind V Karkare

Lawrence Reeder Roberts

Leslie Ann Jardine

Darrick B McGuire

Ivana Jovanovic

Glen Kirby

Darrick B Mcguire

Charlotte B Porteneuve

Ying Chen

Zhang Xuan

Surface retarder coating compositions of the invention are based on the use of at least one non-Ordinary Portland Cement (non-OPC) binder and at least one OPC set retarder agent, which are provided in powder form that can be mixed with water at the construction site. The coating is applied onto the surface of a mould or formwork using roller or spray equipment, and concrete can then be cast within 30-60 minutes against the coating. The OPC set-retarding agent operates to retard setting of the concrete so that it can be de-moulded the next day and its surface can be removed using a high pressure water spray to reveal aggregate embedded beneath the removed surface.

Composition and method for obtaining exposed aggregates in surfaces of moulded concrete and other cementitious materials

The invention provides 'thixotropy' monitoring, by measuring the reversible, time-dependent reduction in viscosity occurring when concrete is subjected to mixing, and employs a mixing drum and conventional slump monitoring equipment as used on ready-mix trucks. In one embodiment, the drum is rotated until concrete is completely mixed; the speed is altered, such as by increasing it to a predetermined level; and the energy required to rotate the drum (ER) is monitored; the maximum (ER-MAX) and minimum (ER-MIN) values are recorded in computer memory; and these values are compared to pre-determined (target) values. Rheology factors (including viscosity, yield stress, and/or thixotropy) can be adjusted accordingly by adding liquid component(s) into the mix. This method, suitable for delivery of highly fluid concrete speed such as SCC, can involve transit and placement rheology targets during monitoring.

Method for monitoring thixotropy in concrete mixing drum

The present invention discloses additive compositions, cementitious compositions, and methods for controlling air in cementitious compositions in which colloidal nano-particles are used for stabilizing a water-dispersible defoamer within a cement-dispersant-containing aqueous additive formulation for modifying hydratable cementitious compositions such as cement or concrete.

Stabilized defoamers for cementitious compositions

The present invention relates to dispersants such as superplasticizers for hydratable cementitious compositions, and more particularly to methods for achieving variable degrees of longer slump life in concrete and mortar without loss of stability. This is achieved by using two admixture systems. The first admixture composition has multi-components for achieving initial-slump-enhancement, later-slump-retention, and limiting initial slump. The second admixture composition has the later-slump-enhancing component. Alternatively, conventional water reducers or superplasticizers can be employed initially, followed by the later-slump-enhancing admixture composition.

Slump retention in cementitious compositions

An exemplary surface active agent admixture composition of the invention comprises (1) a first surface active agent comprising a betaine, an alkyl or aryl or alkylaryl sulfonate, or mixture thereof; and (2) a second surface active agent comprising a nonionic oxyalkylene-containing polymer surfactant. The present invention therefore provides a system for ensuring the presence in a hydratable cementitious composition (when hardened) a sufficient air volume and sufficient air void fineness and consistency. Further exemplary admixture compositions may comprise one or more plasticizers and one or more clay activity-modifying agents. Cementitious compositions and methods for modifying cementitious compositions, which incorporate the above-mentioned surface active agent combination, are also described. The invention provides the ability to adjust and stabilize air void systems in hydratable cementitious compositions, while allowing conventional air entraining agent (AEA) dosage practices to be followed.

Air management in cementitious mixtures having plasticizer and a clay-activity modifying agent

Methods and compositions of the invention involve the use of crude intermediate fermentation broth, derived from industrial glucose fermentation processes prior to completion of purification steps, as additives and admixtures for cementitious compositions.

Gluconate broth for cement and concrete admixture

Comb polymers are used as dispersants to increase the stability of colloidal suspensions containing multivalent or high concentrations of monovalent ions. Stabilized colloidal suspensions and methods of forming stabilized colloidal suspensions are described, including suspensions containing ceramic precursors or bioactive agents useful in forming ceramic substrates or pharmaceutical compositions, respectively.

Controlled dispersion of colloidal suspension by comb polymers

Exemplary compositions comprise at least one aldopentonic acid, such as xylonic acid; and further comprise a lignin, a lignosulfonic acid or its salt, an additional sugar acid such as a aldohexonic acid or salt, a conventional admixture (such as a polyacrylate superplasticizer, a corrosion inhibitor, a set retard, a set accelerator, etc.), or a mixture thereof. Exemplary methods for obtaining microbiologically or enzymatically converted sugar acids are also described herein.

Beneficiated water reducing compositions

An exemplary admixture system for cementitious compositions, comprises a polycarboxylic acid type water reducer and a tertiary amine defoamer having an average molecular weight of 100-1500 and more preferably 200-750. The defoamer permits a stable admixture formulation and helps to achieve a controllable level of entrained air in a concrete mix. Cementitious compositions and methods for modifying the same, using the tertiary amine defoamers, are also described herein.

Defoamer for water reducer admixture

In the preparation of aqueous cement compositions containing a plasticizer, such as an EO/PO polymer-containing plasticizer, or EO/PO comb polymer-containing plasticizer, and further containing clay, such as a smectite clay, which expands when in contact with water, the step of providing an agent operative to modify the clay whereby the plasticizer absorbing capability of the clay is reduced. In exemplary methods of the invention, the plasticizer is an EO/PO (e.g., oxyalkylene) plasticizer and preferably an EO/PO comb polymer, and the clay-activity-modifying agent may comprise an inorganic cation, an organic cation, a polar organic molecule capable of being absorbed by the clay, a clay dispersant (such as a polyphosphate), or a mixture thereof. For clay-activity-modifying agents which comprise a cation or a polar organic molecule, the agent is preferably added to the clay before water is introduced to the clay. For clay dispersant agents and some organic cations such as quaternary amines (which have a strong affinity for cationic exchange with the clay), the agent may be added before, during, or after water is introduced to the clay.

Admixture for optimizing addition of EO/PO plasticizers

Admixture and method for optimizing addition of EO/PO superplasticizer to concrete containing smectite clay-containing aggregates

Exemplary emulsion admixture for use in hydraulic cement compositions formed by emulsifying an antifoaming agent, surfactant, and a comb polymer having a carbon-containing backbone to which are attached cement-anchoring members and oxyalkylene groups. A method of making a stable emulsion admixture comprising the comb polymer, as well as a hydraulic cement composition comprising the admixture, are also described.

Emulsified comb polymer and defoaming agent composition and method of

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

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Chelmsford, MA, United States of America

Ara A Jeknavorian