Abstract:
The present invention provides an admixture composition comprising a liquid suspension of colloidal silica, siloxane, and polycarboxylate polymer cement dispersant for enhancing early age strength, finishability, and other properties in hydratable cementitious compositions such as concrete (e.g., shotcrete). An inventive method involves mixing the components together in a specific sequence, thereby to obtain a stable liquid suspension. This attainment of a stable liquid suspension is surprising and unexpected because (i) the polycarboxylate polymer cement dispersant and siloxane components are incompatible and immiscible with one another; and (ii) that colloidal silica and siloxane compound are incompatible and immiscible with one another. Yet, the present inventors achieved an additive in the form of a stable liquid suspension which can be conveniently dosed into concretes and shotcrete mixtures, to enhance early age strength, and to improve workability and rheology in terms of finishability of concrete surfaces and improved rebound performance in shotcrete applications.
Abstract:
The invention provides a waterproofing membrane which does not require a removable release sheet but which nevertheless bonds to post-cast concrete and facilitates water-tight sealing at membrane-to-membrane overlaps. The waterproofing membrane comprises a carrier and pressure-sensitive adhesive (PSA) layers, an inorganic particle layer having particulate bodies which are partially embedded in the PSA and which have an average particle size less than the average thickness of the PSA layer, and an anti-submarining nano-silica-containing coating layer attached to un-embedded portions of the inorganic particles to prevent total embedding into the PSA when the membrane is rolled or unrolled, whereby water-tight seams are facilitated between overlapped portions of adjacently installed waterproofing membranes, and whereby the water-tight seam is achieved preferably using only detailing or waterproofing tape and without the additional use of a liquid primer, mastic, or other coating.
Abstract:
The present invention provides a composition and method for modifying a hydratable cementitious composition such as concrete or mortar using at least three different, distinct carboxylate polymers, even when clay is present in the concrete or mortar that would otherwise diminish dosage efficiency of polycarboxylate polymer used as dispersant. The three polycarboxylate polymers, designated as Polymer I, Polymer II, and Polymer II, are derived from monomer Components A, B, and C wherein Component A is an unsaturated carboxylic acid, Component B is a polyoxyalkylene, and Component C is an unsaturated carboxylate ester. The component molar ratio ranges for A:B:C are different as between Polymers I and II; while a distinct component molar ratio A:B+C is identified for Polymer III. When treated with these three different polycarboxylate polymers, the hydratable cementitious composition is surprisingly enhanced in terms of initial workability and slump retention, especially if clay is present.
Abstract:
The present invention provides a fast response method and system wherein one or more comb-type polycarboxylate ether (PCE) polymers, having a cumulative adsorptivity coefficient in the range of 40%-75%, are employed as fluidizing admixtures dosed into concrete by and in automated slump monitoring and control systems which iteratively monitors and adjusts the slump of the concrete mix.
Abstract:
Disclosed are surface retarder composition and method for etching cementitious materials which achieve a desirable light “acid etch” look without using muriatic (hydrochloric) acid or sand blasting, removing the human health and environmental concerns. Formulations in accordance with embodiments disclosed herein are easier to remove from formwork or molds after demolding than conventional retarder paints. Surface retarders prevent the hydration of cement particles, which allows the uncured layer of paste next to the form to be removed such as by washing with water or other fluids, or by brushing, revealing aggregates. Also disclosed are molded cement and concrete materials or articles exhibiting such light etch.
Abstract:
Apparatus and method for measurement and monitoring of physical properties of materials, such as liquids, and more particularly to acoustic instruments, methods, and systems that automatically measure air content in real-time within liquids, including concrete, mortar, or other hydratable cementitious mix suspensions using resonant electroacoustic transducers that have their radiating surfaces in contact with the liquid.
Abstract:
The present invention provides a method and system for manufacturing cement wherein ground particles of cement and calcium sulfate are subjected to infrared sensors, laser sensors, or both, so that emanated, irradiated, transmitted, and/or absorbed energy having wavelengths principally within the range of 700 nanometers to 1 millimeter can be monitored and compared to stored data previously obtained from ground cement and sulfate particles and preferably correlated with stored strength, calorimetric, or other data values, such that adjustments can be made to the mill processing conditions, such as the form or amounts of calcium sulfate (e.g., gypsum, plaster, anhydride), or cement additive levels. The strength and other properties of cement can be thus adjusted, and its quality can be more uniform.
Abstract:
A method for grinding cement clinker particles, comprising: introducing to a composition comprising dry cement clinker particles, in a ball mill or roller mill, whereby said particles are ground to have a finer average particle size, an aqueous grinding additive composition comprising: from about 0.1 to about 15% by weight of at least one polyacrylic acid or a salt thereof; and water; and grinding the dry composition comprising the cement clinker particles and the aqueous grinding additive composition to produce a cement product having a pack set index (PSI) greater than that obtained when the polyacrylic acid is not present in the grinding additive.
Abstract:
Method for grinding a solid in a vertical roller mill (VRM) and a cement composition prepared by the disclosed methods. A method comprises grinding a solid comprising a cement clinker under a water spray in the presence of a grinding stabilizing additive, wherein the grinding stabilizing additive comprises: (i) an alkanol amino acid compound or a disodium or dipotassium salt thereof having the structural formula:
(ii) a glycol; or a mixture of (i) and (ii), wherein the water spray level is reduced by at least 5% compared to a control. Cement compositions prepared by the disclosed methods have the pre-hydration level (Wk) equal to or less than 1.5%. The values and preferred values of R1-3 are disclosed herein.
Abstract:
The present invention provides exemplary method and additive for making cementitious binders that comprise primarily ground granulated blast furnace slag (GGBFS) having excellent strength at 24 hours, with preferably little or minimal amounts of Ordinary Portland Cement (OPC). As OPC manufacture involves carbon dioxide release into the atmosphere, the use of a GGBFS-based binder composition will help to enhance sustainability practices in the construction industry and minimizing strength losses implied by deletion of OPC. Strength in the GGBFS binder composition is enhanced by an alkaline-earth activator in combination with a strength enhancing component comprising dispersant and secondary activator.