Abstract: Apparatus and methods for curing composite compositions that react with CO2. The apparatus in general includes an easily transportable and easily assembled curing structure, such as a plastic sheet housing supported by gas pressure and/or by mechanical supports. Apparatus for providing reagent CO2, for measuring water content and for removing water, and for controlling temperature, flow rates and flow directions through the curing structure. Examples of curing procedures and examples of cured materials in desired shapes are described.

Abstract: The present disclosure discloses a method and an article for improving the strength of carbonated calcium hydroxide compacts. The method includes the following steps: calcium hydroxide-rich materials, ordinary portland cement, magnesium hydroxide, pottery sand and water are mixed according to the mass ratio of 100:15-20:15-20:40-80:10-20, then the mixture was compressed, carbonated and naturally cured to obtain the carbonated compacts. The present disclosure utilizes cement hydration and magnesium hydroxide carbonation to consume the water produced by calcium hydroxide carbonation, the C-S-H gelation effect produced by cement hydration, the cementation effect of magnesium hydroxide carbonation products, the volume expansion effect of magnesium hydroxide carbonation and the gas transmission channel and internal curing effect of pottery sand further improve the carbonation degree, product gelation, thus greatly improving the strength of carbonated calcium hydroxide compacts.

Abstract: The present invention relates to a dry refractory paint precursor composition comprising, 5 to 55 wt.-% mineral filler, 20 to 45 wt.-% glass frit comprising SiO2, Na2O, B2O3 and/or Al2O3, and 0.1 to 25 wt.-% of a binder selected from waterglass, cement and mixtures thereof, all based on the total weight of the composition. The invention further relates to refractory paints comprising said compositions, and to methods for preparing said paints.

Abstract: The invention relates to a process for the preparation of a shaped composite, comprising the preparation of a mixture into which fragments of mineral wool comprising a size comprising a sugar, a non-cement silica carrier distinct from the wool, a non-cement alkali metal carrier distinct from the wool, and water, are introduced, the non-cement silica carrier and the non-cement alkali metal carrier forming, with the water, a mineral binder which gradually solidifies around the solid particles present in the mixture, and then the shaping of the mixture into a shaped composite, in particular into briquettes. The invention also relates to a process for the manufacture of mineral wool, in which a molten mass is produced which is converted into mineral wool by means of a fiberizing device, the shaped composite being introduced as vitrifiable charge into a melting chamber, such as a cupola furnace.

Abstract: The present invention discloses cementitious compositions which contain hydratable cement, limestone, or mixture thereof, having improved strength properties due to the presence of calcined clay and certain higher alkanolamines, wherein the calcined clay has an Fe2O3 content of greater than one percent (1%). Also disclosed are exemplary additives and methods for enhancing strength of cement and/or limestone compositions.

Abstract: This disclosure is related to a method of treating a formation, a wellbore, or equipment in a wellbore. The method includes introducing a soluble abrasive material into a wellbore for various oil and gas operations. The method also includes introducing an acidic solution into the wellbore to dissolve at least a portion of the soluble abrasive material to allow for more efficient removal of the soluble abrasive material from the wellbore.

Abstract: A pre-mixed mortar, stucco or masonry composition includes from 70 to 80 percent sand and from 20 to 30 percent of a light-weight cement mix composition that comprises either slag cement, Gypsum or a combination of slag cement and gypsum; Portland cement; clay; and polystyrene.

Abstract: The invention relates to a process for the production of binders by calcinating mineral raw material mixtures. In order to improve the process and the quality of the binders, it is proposed that oil shale and/or oil sand fills are converted by targeted agglomeration into particles of a certain size and consistency, wherein the water content for the mechanical stabilization of the agglomerate is adjusted to less than 25 percent and the agglomerates are calcinated to form binders at temperatures between 800 and 1500° C. under reductive conditions over the entire process with a Lambda value <1 in a vertical shaft furnace with updraft gasification. The binding properties are adjusted by the targeted addition of CaO-containing substances and/or existing sulfur fractions of the oil sands and/or oil shales are bound by means of the CaO that is present in the starting material and/or added.

Abstract: The present invention relates to a manufacturing method of manufacturing lightweight construction materials using sludge waste, more specifically to a manufacturing method of manufacturing lightweight construction materials using the sludge waste which is manufactured by adding feldspar, bentonite, zeolite, loess, mica and agalmatolite to sludge waste and the lightweight construction materials manufactured thereby. According to the present invention, lightweight construction materials can be manufactured which are environmentally friendly by recycling waste sludge, can reduce energy consumption by simplifying the processes, and have superior strength and water permeability by mixing specific inorganic materials.

Abstract: The present invention is directed to plug-and-abandon operations that use plugging compositions comprising cement kiln dust, pumicite, and/or lime. An embodiment includes a method of plugging a well bore for abandonment comprising: placing a plugging composition in the well bore, the plugging composition comprising: cement kiln dust in an amount of about 5% to about 100% by weight of cementitious components, pumicite in an amount of about 5% to about 100% by weight of cementitious components, 0% to about 24% of Portland cement by weight of cementitious components, and water; and allowing the plugging composition to set and form a plug.

Abstract: The present invention relates to a paste composition for artificial marble and a method of manufacturing the artificial marble using the same, which can solve the problems of efflorescence and durability in the existing cementitious marble and the problems of thermal resistance and acid tolerance in the existing organic binder-based marble, and can provide an insulating function to the artificial marble by using an inorganic binder such as an amorphous activated aluminosilicate compound and also using a lightweight particulate porous inorganic material. The method of manufacturing the artificial marble includes preparing paste for artificial marble by mixing 10˜20 parts by weight of white cement, 3˜10 parts by weight of amorphous activated aluminosilicate, 40˜70 parts by weight of broken-stone chip, 5˜10 parts by weight of water, 0.

Abstract: Methods and compositions that comprise sub-micron alumina for accelerating setting of a cement composition. An embodiment includes a method of cementing in a subterranean formation. The method may comprise introducing a cement composition into the subterranean formation, wherein the cement composition comprises hydraulic cement, sub-micron alumina, and water. The method further may comprise allowing the cement composition to set in the subterranean formation. Another embodiment includes a cement composition that may comprise hydraulic cement, sub-micron alumina, and water.

Abstract: A lightweight composite having an activated surface contains a lightweight hollow core particle having cement grains which may be adhered to the hollow core or embedded in the surface of the hollow core. The hollow core particle may be prepared from calcium carbonate and a mixture of clay, such as bentonite, and a glassy inorganic material, such as glass spheres, glass beads, glass bubbles, borosilicate glass and fiberglass.

Abstract: The invention relates to CO2 capturing binder with an amortized environmental cost, the method of manufacture thereof by means of selecting, purifying and optimizing the carbide lime paste for use as a cementing material, and aggregates for the manufacture of lime paints and slurries, stuccos, mortars and concretes having multiple applications in the construction industry, in architectural restoration, in public works and land conditioning, object of the present invention. It is basically characterized in that the raw material is the residue in the form of sludge generated in the industrial manufacture of acetylene (C2H2) from calcium carbide (CaC2) the fundamental component of which is calcium hydroxide (Ca(OH)2) in highly reactive nanometric formations treated in a specific manner according to the invention.

Abstract: A manufactured cementitious binder including a hydraulic binder in an amount in the range of from about 40 to 75% by weight of the cementitious binder; metakaolin in an amount in the range of from about 1 to 30% by weight of the cementitious binder; silica fume in an amount up to about 15% by weight of the cementitious binder; lime kiln dust in an amount of from about 5 to 30% by weight of the cementitious binder, and a cementitious accelerator in an amount greater than about 0.1% by weight of the cementitious binder, wherein the cementitious binder provides a cementitious settable composition, when added with water and without a lightweight additive, that has a density lower than about 13 pounds per gallon and greater than about 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.

Abstract: A nanomaterial based admixture improves the fire retardancy of foam-based GFRC material to a minimum of 3 hours, creating Nano GFRC. A dispersion of nanoclay in water is prepared by heating water to 80-90 ° C., adding the desired amount of nanoclay and stirring with a magnetic stirrer for 30-45 minutes, producing a stable and uniform dispersion. Concrete is made by mixing sand, acryl, water, nanoclay solution, and cement in a bucket, adding enough water reducer to thin the mixture enough to stir, adding fibers, and mixing the composite using a rotor for about 10 minutes. Polystyrene foam is sandwiched with the prepared mixture on all sides to make the concrete. This resulting concrete is lightweight and strong, reduces CO and CO2 emissions by a factor of three compared to standard GFRC, and shows dramatic improvement in fire retardant properties.

Abstract: The present invention relates to a cement-free alkali-activated binder. More particularly, the present invention relates to a cement-free alkali-activated binder having a novel combination ratio, which can improve the compressive strength of mortar and concrete in which the cement-free alkali-activated binder is used as a binding material instead of cement, and which can solve the low field applicability of mortar and concrete in terms of quick setting characteristics, fluidity loss, economic efficiency and the like, and to mortar or concrete comprising the same. The cement-free alkali-activated binder can improve field applicability by controlling the content and combination ratio of an alkali activator included in the cement-free alkali-activated binder, and can solve the problems of the toxicity of cement, the carbon dioxide (CO2) produced during the manufacturing of cement and the exhaustion of natural resources due to the production of cement.

Abstract: Disclosed are a system, a method and/or composition of environment friendly composite construction material. In one aspect, a method includes providing a mixture of a pozzolanic material and/or a kaolin clay with an activator solution to form an alumino-silicate cementitious material through a resulting geo-polymerization process. The alumino-silicate cementitious material is in the form of a paste. The method also includes processing the alumino-silicate cementitious material to transform the alumino-silicate cementitious material that is in the form of the paste to a form of a powder of the alumino-silicate cementitious material. The method further includes mixing the alumino-silicate cementitious material which is in the form of the powder with water to control a workability of the alumino-silicate cementitious material.

Abstract: The present invention provides settable compositions and methods of using settable compositions that comprise a hydraulic cement; a partially calcined kiln feed comprising SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, Na2O, and K2O; metakaolin; and water.

Abstract: A method of servicing a wellbore in a subterranean formation, comprising preparing a cement composition comprising water and a cementitious material, wherein the cementitious material further comprises blast furnace slag, vitrified shale, calcium sulfate hemi-hydrate or combinations thereof, and placing the cement composition in the wellbore. A cement composition comprising water and a cementitious material, wherein the cementitious material further comprises blast furnace slag, vitrified shale, calcium sulfate hemi-hydrate or combinations thereof. A cement composition comprising water and a cementitious material, wherein the cementitious material further comprises blast furnace slag.

Abstract: The present invention provides for a refractory aggregate composition comprising an improved calcium aluminate clinker having the formula CnAx wherein C is calcium oxide and A is aluminum oxide, wherein n is an integer from about 1 to about 12, wherein x is an integer from about 1 to about 24, and wherein said clinker has from zero to less than about fifty weight percent C12A7, and including a source of barium that is substituted for calcium in said calcium aluminate clinker. Analogs, derivatives and hydrates of the improved calcium aluminate clinker are provided. A refractory composition and a sprayable refractory composition are disclosed comprising the improved calcium aluminate clinker. A method for improving the insulating character and/or penetration resistance of a liner in contact with molten aluminum in an aluminum manufacturing process or during aluminum transport is provided.

Abstract: It is an object of the invention to provide a cement admixture that can form concrete having a sufficient self-healing capability and satisfactorily maintaining its self-healing capability for prolonged periods. The cement admixture of the invention contains an expanding material and an alumina-silicate with swelling properties. The cement admixture is combined with cement to form a cement composition. The cement composition is mixed with water and an aggregate to provide concrete with an excellent self-healing capability.

Abstract: A manufactured cementitious binder including a hydraulic binder in an amount in the range of from about 40 to 75% by weight of the cementitious binder; metakaolin in an amount in the range of from about 1 to 30% by weight of the cementitious binder; silica fume in an amount up to about 15% by weight of the cementitious binder; lime kiln dust in an amount of from about 5 to 30% by weight of the cementitious binder, and a cementitious accelerator in an amount greater than about 0.1% by weight of the cementitious binder, wherein the cementitious binder provides a cementitious settable composition, when added with water and without a lightweight additive, that has a density lower than about 13 pounds per gallon and greater than about 11 pounds per gallon and a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.

Abstract: A manufactured cementitious binder includes a hydraulic binder in an amount in the range of from 40 to 75% by weight of the cementitious binder; metakaolin in an amount in the range of from 1 to 30% by weight of the cementitious binder; silica fume in an amount up to 15% by weight of the cementitious binder; limestone in an amount of from 5 to 30% by weight of the cementitious binder, and a cementitious accelerator in a controlled amount of at least 0.5% by weight of the cementitious binder, the cementitious binder providing a cementitious settable composition when added with water, wherein for a density lower than 13 pounds per gallon and of at least 11 pounds per gallon obtained without a lightweight additive, said cementitious settable composition exhibits a 24 hour compressive strength at 100 F, as hardened, of at least 500 psi.

Abstract: The various embodiments of the present invention relate generally to high strength foam materials and methods of making the same. More particularly, various embodiments of the present invention relate to high strength foam materials comprising pozzolans, such as cenospheres derived from fly ash. An embodiment of the present invention comprises, a pozzolan foam material comprising a pozzolan, an alkali, a silicate, and an organosilicon compound. Various embodiments of the present invention are directed to strong, lightweight materials that are environmentally-friendly and can be economically manufactured.

Abstract: A clay plaster formulation and application. The clay plaster is a mixture of various clays, and aggregate. This plaster is both functional and decorative and is for use on new and existing construction.

Abstract: A lightweight ready-mix concrete composition that contains 8-20 volume percent cement, 11-50 volume percent sand, 10-31 volume percent prepuff particles, 9-40 volume percent coarse aggregate, and 10-22 volume percent water, where the sum of components used does not exceed 100 volume percent. The prepuff particles have an average particle diameter of from 0.2 mm to 8 mm, a bulk density of from 0.02 g/cc to 0.64 g/cc, an aspect ratio of from 1 to 3. The slump value of the composition measured according to ASTM C 143 is from 2 to 8 inches. After the lightweight ready-mix concrete composition is set for 28 days, it has a compressive strength of at least 1400 psi as tested according to ASTM C39.

Abstract: The invention provides a cement composition resistant to carbon dioxide including a hollow element for trapping carbonation products. The hollow element can be an additional component added to the cement composition, this component is made of hollow spherical or quasi spherical particles as cenospheres, sodium-calcium-borosilicate glass, silica-alumina microspheres, or a combination thereof. Or the hollow element is a spherical or quasi spherical void made in the set cement, for example by foaming the cement composition with a gas as air, nitrogen or a combination thereof. Use of such cement composition in carbon dioxide application is disclosed. Additionally, a method to cement a part of a borehole in presence with carbon dioxide is disclosed, a method to repair a part of a borehole in presence with carbon dioxide is disclosed using the above cement composition and a method to plug a part of a borehole in presence with carbon dioxide is disclosed.

Abstract: The present invention provides settable compositions that comprise water and cement kiln dust. The settable compositions optionally may comprise an additive that comprises at least one of the following group: fly ash; shale; slag cement; zeolite; metakaolin; and combinations thereof. The settable compositions optionally may be foamed with a gas. Methods of cementing also are provided that comprise: providing the settable composition; introducing the settable composition into a location to be cemented; and allowing the settable composition to set therein. The location to be cemented may be above ground or in a subterranean formation.

Abstract: Cementing compositions and methods of cementing in a subterranean formation are provided. The cement composition includes a hydraulic cement, lightweight beads, and a desegregating agent for inhibiting segregation of the beads. The lightweight beads may be, for example, cenospheres, glass spheres, and ceramic spheres. The desegregating agent comprises a particulate substrate such as precipitated silica. It also comprises a polar molecule producing chemical disposed on the particulate substrate. Preferably, the polar molecule producing chemical is absorbed on the particulate substrate. The polar molecule producing chemical comprises at least one of a polar molecule producing acid such as glacial acetic acid, a salt of such an acid, and an acid anhydride. The method of cementing includes forming a pumpable slurry using the cement composition, pumping the slurry into a subterranean formation, and allowing the slurry to set.

Abstract: A ship bottom paint additive to prevent or reduce marine life attachment to the bottoms of ships, and ship bottom paint comprises a mixture of coal ash and diatom earth or beer yeast diatom earth wherein the coal ash is preferably fly ash and the diatom earth or beer yeast diatom earth is preferably a dry powder. The additive is a mixture may have a weight ratio within the range of about 3:1 to 7:1, and may be comprised of about 2.25–10% by weight coal ash and about 0.375–5% by weight diatom earth or beer yeast diatom earth.

Abstract: The present invention relates to subterranean operations, and more particularly, to settable fluids comprising vitrified shale and hydrated lime and methods of using such settable fluids in subterranean applications. In an exemplary embodiment, the settable fluids of the present invention may be used as a displacement fluid. In another exemplary embodiment, the settable fluids of the present invention may be used as a drilling fluid.

Abstract: Blended cement compositions for mixture with aggregate and water to prepare cementitious products. Such blended cement compositions contain cement, calcined diatomaceous earth, calcined kaolin, fiberous material and reactive vinyl acetate co-polymers, with or without talc and/or bentonite or their functional equivalents. Admixtures for blending into cement to create such blended cements or their read-mix equivalents contain calcined kaolin, calcined diatomaceous earth, fiberous material and reactive vinyl acetate co-polymers, with or without talc and/or bentonite or their functional equivalents.

Abstract: A machinable light weight sisal-based concrete structural building material and a method of making the same are disclosed. The material includes short sisal fibers in a range from about 22% (v/v) to about 33% (v/v); a cement in a range from about 12% (v/v) to about 22% (v/v); and perlite in a range from about 51% (v/v) to about 59% (v/v). The method includes the steps of mixing an amount of cement with an amount of perlite to form a solid mixture; adding water and mixing water with the solid mixture to form a sludge; adding an amount of sisal fibers and mixing the sisal fibers into the sludge to form an uniform final composition; and pouring the final composition into a mold and setting the final composition to a solid form structural building material. The produced structural building material can be machined, screwed, cut, and nailed.

Abstract: A method for stabilizing gravel, sand, crushed stone, rock and concrete structures which have cracks by injecting a pumpable, low viscous aqueous aerated concrete with a pore volume of at least 20% by volume into the cracks at a low pressure and then increasing the pressure so that the entrained air bubbles escape and sedimentation and hydration occur.

Abstract: The present invention relates to subterranean operations, and more particularly, to settable fluids comprising vitrified shale and hydrated lime and methods of using such settable fluids in subterranean applications. In an exemplary embodiment, the settable fluids of the present invention may be used as a displacement fluid. In another exemplary embodiment, the settable fluids of the present invention may be used as a drilling fluid.

Abstract: The invention relates to a novel cement-bound material with a mineral binding agent, a mineral filler and/or mineral aggregates. Said cement-bound material has a proportion of a mass hydrophobing agent comprised of stearates, siliconates, silanes or siloxanes ranging from 0.5 to 20 wt. % with regard to the weight of the mineral binding agent. The cement-bound material also has a proportion of a corrosion inhibitor, which is capable of migrating and which is comprised of nitrites, benzoates, amio alcohols or of sodium monofluorophosphates ranging from 01. to 20 kg per m3 of the active substance, and/or has a proportion of flexible fibers.

Abstract: Cementitious compositions comprising pozzolonic materials, alkaline earth metals, and a catalysts to catalyze the reaction between the pozzolonic materials and the alkaline earth metals.

Abstract: A method for producing hardened cellular concrete having normal compressive strength by producing tiny, unconnected, pre-pour, air-filled bubbles during mixing of cement, cementitious substitutes, sand, coarse aggregates, water, fiber, a surfactant, aluminum flakes or powder, calcium formate, and magnesium silico fluoride and then producing additional tiny, unconnected, post-pour, hydrogen-filled bubbles to replace those air-filled bubbles which are destroyed while pouring the fresh concrete during the casting operation. Only as much matrix is added to the coarse aggregate as is needed to engulf the aggregates while enabling the aggregate particles to be in contact.

Abstract: Cement compositions comprising flexible, compressible beads, processes for preparing such cement compositions, and methods of cementing in subterranean formations using such cement compositions. One or more flexible, compressible beads are mixed with the cement before pumping the cement into a well bore. The flexible, compressible beads are preferably composed of an elastomeric material such as a copolymer of methylmethacrylate and acrylonitrile; a terpolymer of methylmethacrylate, acrylonitrile, and dichloroethane; a styrene-divinylbenzene copolymer; and polystyrene. The flexible, compressible beads may be heated to expand the beads before mixing with the cement such that the ensuing cement composition will have a desired density. Non-flexible beads such as spherulites may also be added to the cement compositions.

Abstract: An activated carbon molded body, more particularly in honeycomb form and for use as an adsorption filter, can be produced from a mixture including activated carbon, water, novolak powder, clay, cellulose ether, liquid starch, wax, polyacrylamide and soap, by a procedure involving thoroughly mixing the constituents, extruding the mixture to form a monolithic molded body and cutting same to size, drying the body and effecting pyrolysis thereof. The adsorption filter produced therefrom can be regenerated by electrical heating under specified conditions.

Abstract: The present invention provides lightweight cement compositions, and methods for cementing in a subterranean formation using such cement compositions. The cement compositions comprise hydrated lime, vitrified shale, and sufficient water to form a slurry. Optionally, other ingredients may be included in the compositions.

Abstract: This invention relates to a formulation with the addition of low density additives of volcanic ash, hollow ceramic microspheres or a combination of microspheres and volcanic ash or other low density additives into cementitious cellulose fiber reinforced building materials. This formulation is advantageously lightweight or low density compared as compared to current fiber cement products without the increased moisture expansion and freeze-thaw degradation usually associated with the addition of lightweight inorganic materials to fiber cement mixes. The low density additives also give the material improved thermal dimensional stability.

Abstract: The present invention concerns a cement slurry with high permeability and good compressive strength, comprising a solid fraction constituted by: 35% to 80% (by volume) of particles with a mean size in the range 100 microns (&mgr;) to 800 &mgr;; 0% to 15% (by volume) of particles with a mean particle diameter in the range 0.1 microns to 10 microns; and 10% to 40% (by volume) of particles with a mean particle diameter in the range 20 &mgr; to 50 &mgr;; a fraction of said-solid particles being constituted by a cement, and preferably a further fraction by self-destructive particles; a liquid fraction in a water/solid ratio in the range 38% to 50% by volume; and a percentage of cells, provided by a gas or a liquid which is not miscible with water, in the range 30% to 60% of the final volume of the slurry.

Abstract: The present invention provides a lightweight clay which can be easily molded into a given shape, exhibits proper lightweight characteristics and storing characteristics, and can be manufactured at a low cost, and a manufacturing method thereof. In such a lightweight clay and the manufacturing method thereof, an average particle size of the organic hollow micro spheres is set to a value which falls within a range of 15 to 150 &mgr;m and, an addition quantity of the organic hollow micro spheres is set to a value which falls within a range of 0.1 to 6 weight % with respect to a total quantity of the lightweight clay, and whiteness degree(WL) measured in accordance with JIS L 0803 is set to not less than 50.

Abstract: A molded product which has a high strength and which is excellent in surface smoothness and freezing damage resistance. It comprises a fiber-reinforced cement molded OK product which has a bulk specific gravity of from 0.9 to 1.2, and which comprises, by mass, from 2 to 15% of hollow particles, from 1 to 40% of an inorganic admixture having pores which are open to the surface, from 5 to 70% in total of cement and/or lime, from 0 to 50% of slag, from 0 to 50% of gypsum, from 20 to 60% of a quartzite powder, from 0 to 20% of micro silica, from 0 to 30% of an inorganic aggregate other than the above components and from 2 to 30% of cellulose fibers.

Abstract: Methods and compositions for forming permeable cement sand screens in well bores are provided. The compositions are basically comprised of a hydraulic cement, a particulate cross-linked gel containing an internal breaker which after time causes the gel to break into a liquid and water present in an amount sufficient to form a slurry.

Abstract: A method is provided for incorporating a foaming agent into mixtures of particulates and then forming a foam within the mixture to increase the flowability of the particulates. A method is also provided for excavating solid particulates, incorporating a foaming agent into mixtures of solid particulates, and then forming a foam within the mixture to increase the flowability of the particulates. The particulates can be transported through pipelines or boreholes. Examples of particulates include, but are not limited to, mine tailings, ores, sand, coal, soils, clays, silts, aggregates, and mixtures thereof.

Abstract: A method of protecting a cementitious mixture from freeze damage is provided. The method consists of incorporating an entrainment air composition into the cementitious mixture to form air voids in the concrete, and further adding an effective agent for nucleating ice, preferably, in the air voids, such that upon the freezing of concrete formed from the cementitious mixture, ice is nucleated in the air voids. In one embodiment, the air entrainment composition includes ceramic shells, which could be impregnated with an agent for nucleating ice such as metaldehyde.

Abstract: In the preparation of aqueous cement compositions containing a plasticizer, such as an EO/PO polymerontaining 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.