Abstract: Method of efficiently manufacturing cement-SCM compositions having improved strength compared to cement-SCM compositions made using conventional methods. The cement-SCM compositions may contain: (A) a fine interground particulate component with (1) a hydraulic cement fraction and (2) a supplementary cementitious material (SCM) fraction; (B) a coarse particulate component comprised of coarse SCM particles not interground with the fine interground particulate component; and optionally (C) an auxiliary particulate component not interground with the fine interground particulate component or the coarse particulate component. A method of manufacturing a cement-SCM composition may be performed by: (A) intergrinding hydraulic cement (e.g.

Abstract: A flow barrier for wastewater disposal ponds or pits used in oil and gas operations. The flow barrier includes a flake component, a fiber component, and a granular component. The disposal pond flow barrier may prevent the infiltration or leakage of aqueous fluids from the wastewater disposal ponds into the surrounding environment and ecosystems. A process for manufacturing and using the flow barrier in a wastewater disposal pond is also provided.

Abstract: Method and apparatus (100) for transforming organic and inorganic solid urban waste into aggregates, comprising an extruding machine connected to a reactor. The extruding machine is formed by an extrusion cylinder (103) through which a piston circulates (104) inside an extrusion cavity (106), which comprises three sections (107, 110, 111) and is fed with a parget obtained after pre-processing the waste. The end (115) of the third section (111) is connected to the reactor (112) through an opening (114). The reactor's longitudinal shaft is formed by a rotatory steel shaft (116) in which some steel blades are arranged (108), whose ends play the roles of cutting, hammering, punching and hydraulic helix as they rotate. Between the end of the blades and the wall of the reactor, there is a clearance of more than 0.1 mm of thickness.

Abstract: The present invention is a dispersant composition for a hydraulic composition, which includes (A) a polymer compound having a naphthalene ring-containing monomer unit and (B) a specific alkylene oxide added compound represented by the general formulas (B1) to (B3), wherein a molar ratio of a total amount of the component (B) to the naphthalene ring-containing monomer unit in the component (A) is 0.4% or more and 30% or less.

Abstract: Compositions and a method for making self consolidating grouts containing fly ash, ground granulated blast furnace slag, and lime are described. No polymeric admixtures are utilized, and the 28 day cure strength of the cured gouts exceeds the minimum ASTM standards. The uncured grout exhibits slump flows between 24 and 30? without visible segregation of the components.

Abstract: A low-calcium silicate cement consists of calcium oxide, silica, alumina, and iron oxide. A preparation method of the low-calcium silicate cement consists of: subjecting raw materials to crushing, joint grinding and uniform mixing to obtain a low-calcium silicate cement raw meal; calcining the above low-calcium silicate cement raw meal at 1050-1300° C. for 30-90 min, and cooling to obtain low-calcium silicate cement clinker; and levigating the above low-calcium silicate cement clinker till a specific surface area is 400-500 m2/Kg, thereby obtaining a low-calcium silicate cement.

Abstract: A variety of cement compositions and methods of using cement compositions in subterranean formations. A method of formulating a cement composition may comprise: measuring surface area of a group of pozzolans, wherein the smallest measured surface area of the group of pozzolans and the largest measured surface area of the group of pozzolans vary by about 50% or greater. The method may further comprise selecting one or more pozzolans from the group of pozzolans. The method may further comprise adding components comprising lime and water to the selected one or more pozzolans to faun a cement composition.

Abstract: A comb polymer and use thereof for improving the processing of hydraulically setting compositions. The comb polymer has ester, amide and/or ether groups on side chains bound to a main chain and the main chain has at least one acrylic acid unit A or a salt thereof and at least one methacrylic acid unit M or a salt thereof. Processes for producing a hydraulically setting composition with longer processing time.

Abstract: Provided is an air pollution control system including: a denitration apparatus; an air heater; a precipitator; a desulfurization apparatus; a dehydrator; a spray drying apparatus provided with a spray unit that is configured to spray dehydrated filtrate supplied from the dehydrator; a flue gas introduction line through which a branch gas branched from the flue gas is introduced to the spray drying apparatus; a flue gas supply line through which a flue gas from the spray drying apparatus returns to a main flue gas duct; a solid content separator that performs a solid-gas separation on solid contents contained in the flue gas; and a kneader that performs kneading and immobilizing treatment on the separated solid contents together with an immobilization aid.

Abstract: A foam concrete has constituents that include a cement, a sand, a coarse aggregate, an oil ash, a water, and a foam solution. The foam concrete has a compressive strength of at least 20 MPa, a thermal conductivity of less than 0.41 W/mK and a maximum weight of 1650 kg/m3.

Abstract: Methods and compositions are provided that related to cementing operations. Methods and compositions that include pumice and/or perlite as a replacement for fly ash.

Abstract: The present invention relates to a method for producing a binder comprising the following steps: a) providing a starting material, from raw materials, that has a molar (Ca+Mg)/(Si+Al+Fe) ratio from 1 to 3.5, a molar ratio Ca/Mg from 0.1 to 100, and a molar Al/Si ratio from 100 to 0.1, wherein constituents that are inert during the hydrothermal treatment in an autoclave are not taken into account for determination of the ratios, b) mixing the raw materials, c) hydrothermal treating of the starting material mixture produced in step b) in an autoclave at a temperature from 100 to 300° C. and a residence time from 0.1 to 24 h, wherein the water/solids ratio is 0.1 to 100, d) tempering the intermediate product obtained in step c) at 350 to 600° C., wherein the heating rate is 10-6000° C./min and the residence time is 0.01-600 min.

Abstract: The invention relates to a method for grinding an inorganic solid from the series cement clinker, pozzolan and/or raw material for cement production, where a grinding additive is added before or during grinding, and the grinding additive, based on the dry mass, comprises 6% to 80% by weight of caprolactam and 1.5% to 30% by weight of aminocaproic acid, where, based in each case on the dry mass, 0.002% to 2% by weight of the grinding additive is used, based on the total solid. Further claimed are a grinding additive and the use thereof for increasing the compressive strength of the cured product produced therewith.

Abstract: The present invention provides a composition for advanced hybrid geopolymeric functional materials possessing very broad application spectrum ranging from cementitious materials to advanced functional materials having “Inorganic-Organic Hybrid” matrix in contrast to the limited application of conventional geopolymeric materials having “Inorganic matrix” only. The invention further relates to a process for the preparation of these materials. The process obviates the need of external addition of sodium silicate which is one of the costliest and main raw materials in conventional geopolymerisation processes. Interestingly, in the present invention the sodium silicate has been synthesized in situ by designing of conditions for synergistic and simultaneous mechano-chemical reactions among the selected raw materials viz. inorganic and organic wastes under alkaline environment.

Abstract: The invention comprises a method of making a cement-based object or structure having a compressive strength greater than about 1,000 psi. The method comprises placing a cement-based material in an insulated concrete form, wherein the insulated concrete form has an R-value of at least 1.5, wherein the cement-based material comprises approximately 10% to approximately 80% by weight portland cement, and at least one of approximately 10% to approximately 90% by weight slag cement and approximately 5% to approximately 80% by weight fly ash. The invention also comprises a method of making a cement-based object or structure. The invention further comprises objects or structures made by the foregoing methods.

Abstract: Cement-SCM blends employ particle packing principles to increase particle packing density and reduce interstitial spacing between the cement and SCM particles. Particle packing reduces the amount of water required to obtain a cement paste having a desired flow, lowers the water-cementitious material ratio (w/cm), and increases early and long-term strengths. This may be accomplished by providing a hydraulic cement fraction having a narrow PSD and at least one SCM fraction having a mean particle size that differs from the mean particle size of the narrow PSD cement by a multiple of 3.0 or more to yield a cement-SCM blend having a particle packing density of at least 57.0%.

Abstract: A cementitious mixture including drinking water treatment waste (DWTW) solids, an aggregate, cement and water exhibits improved cement hydration, compressive strength and mitigated autogenous shrinkage. DWTW solids provide an internal curing agent for use with a cementitious mixture. DWTW solids are produced by a water treatment process of flocculating water to produce floc having entrained water, allowing the floc to settle out and dewatering the floc to produce DWTW solids. The DWTW solids form up to about 200 pounds per cubic yard of the cementitious mixture. The DWTW solids have a moisture content of about 5% to about 55% and a particle size of about 10 ?m to 150 ?m. The cementitious mixture may be cured to form concrete structural elements and products and masonry products. A method of using DWTW solids as an internal curing agent for cementitious mixtures produces cured concrete compositions having improved compressive strength and reduced autogenous shrinkage.

Abstract: A hydraulic binder includes a Portland clinker having a Blaine specific surface of 4000 to 5500 cm2/g, from 2.5 to 8% of sulphate expressed by mass of SO3 relative to the mass of clinker, from 1.5 to 10% of calcium nitrite and/or calcium nitrate expressed as anhydrous mass relative to the mass of clinker and from 15 to 50% of a mineral addition including calcium carbonate by mass relative to the total mass of binder.

Abstract: The present invention relates to acid-soluble cement compositions that comprise cement kiln dust (“CKD”) and associated methods of use. An embodiment provides a method of cementing comprising: providing an acid-soluble cement composition comprising a kiln dust and water; allowing the acid-soluble cement composition to set to form an acid-soluble hardened mass; and contacting the acid-soluble hardened mass with an acid.

Abstract: The invention comprises a method of making a cement-based object or structure having a compressive strength greater than about 1,000 psi. The method comprises placing a cement-based material in an insulated concrete form, wherein the insulated concrete form has an R-value of at least 1.5, wherein the cement-based material comprises approximately 10% to approximately 80% by weight portland cement, and at least one of approximately 10% to approximately 90% by weight slag cement and approximately 5% to approximately 80% by weight fly ash. The invention also comprises a method of making a cement-based object or structure. The invention further comprises objects or structures made by the foregoing methods.

Abstract: A hydraulic binder including in parts by mass: (a) 40 to 70 parts of a Portland clinker; (b) 30 to 60 parts of fly ash; (c) optionally up to 30 parts of an inorganic material other than clinker or than fly ash; (d) 2.5 to 15 parts of an alkali metal salt expressed in parts of equivalent-Na2O relative to 100 parts of fly ash; and (e) 2 to 14 parts of sulphate expressed in parts of SO3 relative to 100 parts of clinker; the fly ash having a Dv97 less than or equal to 40 ?m, and the sum of (a), (b) and (c) being equal to 100.

Abstract: Hydraulic binder comprising: at least one first calcium aluminosilicate derivative with a fineness of less than 6000 Blaine, slag microparticles with a fineness of greater than or equal to 6000 Blaine in an amount of between 1 and 35% of the total weight of the binder, preferably of between 5 and 15%, at least one source of calcium sulphate and at least one base in an amount of less than or equal to 1% of the total weight of the binder.

Abstract: Hydraulic cements, such as Portland cements and other cements that include substantial quantities of tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and/or tetracalcalcium alumino-ferrite (C4AF), are particle size optimized to have increased reactivity compared to cements of similar chemistry and/or decreased water demand compared to cements of similar fineness. Increasing hydraulic cement reactivity increases early strength development and release of reactive calcium hydroxide, both of which enhance SCM replacement and 1-28 day strengths compared to blends of conventional Portland cement and one or more SCMs, such as coal ash, slag or natural pozzolan. Decreasing the water demand can improve strength by decreasing the water-to-cement ratio for a given workability. The narrow PSD cements are well suited for making blended cements, including binary, ternary and quaternary blends.

Abstract: The present description is directed to a cement or cementitious mixture that includes fly ash, zinc oxide and borate. Importantly, the cementitious mixture includes greater than 50% of fly ash by weight, or alternatively greater than 75% by weight of fly ash, or still further alternatively greater than 90% or 95% by weight of fly ash. Zinc oxide is incorporated in the cementitious mixture at levels of 2.5% and greater, or alternatively at the amounts of about 5 to 20% zinc oxide. Finally, a borate compound in needed for use as a set retarder.

Abstract: Fly ash contaminated with activated carbon is treated to neutralize the activated carbon by placing the contaminated fly ash in a rotary mill and introducing ozone. The result is that entrained air in concrete made from activated fly ash will contain greater than 4 percent entrained air.

Abstract: The present invention relates to the production of ternesite clinkers containing 20 to 100% by weight C5S2$ and less than 15% by weight C4A3$, and to the use of ternesite as an additive to Portland cement or Portland composite cement, and to a binder containing 20 to 95% by weight Portland cement (clinker) and 80 to 5% by weight ternesite (clinker).

Abstract: The present invention relates to a self-neutralising type of calcium hydroxide (Ca(OH)2) preparation for use in dentistry. More specifically, it relates to a self-neutralising type of calcium hydroxide preparation which is formulated in such a way that it can be used in dentistry by being mixed, in a cement clinker, with an active siliceous substance, bismuth oxide (Bi2O5), silica, sulphur trioxide and aluminum oxide/ferric oxide and the like. One aspect of the present invention provides a self-neutralising type of calcium hydroxide preparation comprising an active siliceous substance and bismuth oxide, and this self-neutralising type of calcium hydroxide preparation is characterized in that it comprises silica, sulphur trioxide and aluminum oxide/ferric oxide.

Abstract: The present invention contemplates a cementitious additive that contains electric-arc furnace dust (EAFD) and a precursor as a replacement for up to about 30% of the cement in concrete. The additive includes about 50% by weight EAFD and about 50 wgt. % of precursor. The precursor includes about 55 wgt. % silica, about 10 to 20 wgt. % lime, about 2 to 5 wgt. % soda, about 5 to 15 wgt. % potash, about 2 to 6 wgt. % alumina and about 1 to 3 wgt. % magnesia. The method also contemplates the step of homogenizing the electric-arc furnace dust (EAFD) and precursor to produce engineered dust (ED) and then replacing up to 30% of the cement with a mixture referred to as ED i.e. homogenized EAFD and precursor.

Abstract: The invention comprises a method of making a cement-based object or structure having a compressive strength greater than about 1,000 psi. The method comprises placing a cement-based material in an insulated concrete form, wherein the insulated concrete form has an R-value of at least 1.5, wherein the cement-based material comprises approximately 10% to approximately 80% by weight portland cement, and at least one of approximately 10% to approximately 90% by weight slag cement and approximately 5% to approximately 80% by weight fly ash. The invention also comprises a method of making a cement-based object or structure. The invention further comprises objects or structures made by the foregoing methods.

Abstract: Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Abstract: CO2-sequestering formed building materials are provided. The building materials of the invention include a composition comprising a carbonate/bicarbonate component. Additional aspects of the invention include methods of making and using the CO2-sequestering formed building material.

Abstract: The invention comprises a method of forming a slab on grade. The method comprises placing a first layer of insulating material horizontally on the ground and placing plastic concrete for a slab on grade on the first layer of insulating material. The plastic concrete is then formed into a desired shape having a top and sides. A second layer of insulating material is placed on the top of the plastic concrete and the first and second layers of insulating material are left in place until the concrete is at least partially cured. The second layer of insulating material is then removed. The product made by the method is also disclosed. A slab on grade is also disclosed.

Abstract: Hydraulic cements, such as Portland cements and other cements that include substantial quantities of tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and/or tetracalcalcium alumino-ferrite (C4AF), are particle size optimized to have increased reactivity compared to cements of similar chemistry and/or decreased water demand compared to cements of similar fineness. Increasing hydraulic cement reactivity increases early strength development and release of reactive calcium hydroxide, both of which enhance SCM replacement and 1-28 day strengths compared to blends of conventional Portland cement and one or more SCMs, such as coal ash, slag or natural pozzolan. Decreasing the water demand can improve strength by decreasing the water-to-cement ratio for a given workability. The narrow PSD cements are well suited for making blended cements, including binary, ternary and quaternary blends.

Abstract: The invention comprises a method of making a cement-based object or structure having a compressive strength greater than about 1,000 psi. The method comprises placing a cement-based material in an insulated concrete form, wherein the insulated concrete form has an R-value of at least 1.5, wherein the cement-based material comprises approximately 10% to approximately 80% by weight portland cement, and at least one of approximately 10% to approximately 90% by weight slag cement and approximately 5% to approximately 80% by weight fly ash. The invention also comprises a method of making a cement-based object or structure. The invention further comprises objects or structures made by the foregoing methods.

Abstract: Partial oxidation of crumb rubber derived from environmental hazardous waste tires yields surface treated crumb rubber which are used as blending stocks for making rubberized concrete with substantially improved mechanical strength as compared to the conventional rubberized concrete. The chemically more active rubber surface becomes hydrophilic, so it interacts with the hydrophilic surface of surrounding cement matrix much stronger. The mechanically improved rubberized concrete is more versatile than conventional rubberized concrete.

Abstract: The present invention relates to a method for recycling waste water from a stainless steel slag treatment process wherein stainless steel slag is brought into contact with water, in particular to neutralize the free lime contained therein, thereby producing said waste water. This waste water contains heavy metals, including at least chromium, and has a pH higher than or equal to 11. In accordance with the invention, it is used as production water for manufacturing mortar and/or concrete. In this way, the heavy metals, which are dissolved in the waste water and thus readily available, become bound in the newly formed cement phases so that they are prevented from leaching. Moreover, it has been found that the workability of the fresh mortar or concrete and also the quality of the final mortar or concrete materials is not negatively affected by the use of this alkaline waste water and that an accelerated setting could be achieved during the first hours.

Abstract: Hydraulic cements, such as Portland cements and other cements that include substantial quantities of tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and/or tetracalcalcium alumino-ferrite (C4AF), are particle size optimized to have increased reactivity compared to cements of similar chemistry and/or decreased water demand compared to cements of similar fineness. Increasing hydraulic cement reactivity increases early strength development and release of reactive calcium hydroxide, both of which enhance SCM replacement and 1-28 day strengths compared to blends of conventional Portland cement and one or more SCMs, such as coal ash, slag or natural pozzolan. Decreasing the water demand can improve strength by decreasing the water-to-cement ratio for a given workability. The narrow PSD cements are well suited for making blended cements, including binary, ternary and quaternary blends.

Abstract: A method for reducing the particle size of a pozzolanic material includes providing a pozzolanic material having an initial particle size and heating the pozzolanic material to cause a portion of the particles to at least partially fracture. Fracturing the particles creates a plurality of fissures that define sub-particles within the particles. The method also includes processing the fractured pozzolanic material to separate the sub-particles, thereby yielding the pozzolanic material having reduced particles.

Abstract: The invention comprises a method of making a cement-based object or structure having a compressive strength greater than about 1,000 psi. The method comprises placing a cement-based material in an insulated concrete form, wherein the insulated concrete form has an R-value of at least 1.5, wherein the cement-based material comprises approximately 10% to approximately 80% by weight portland cement, and at least one of approximately 10% to approximately 90% by weight slag cement and approximately 5% to approximately 80% by weight fly ash. The invention also comprises a method of making a cement-based object or structure. The invention further comprises objects or structures made by the foregoing methods.

Abstract: A concrete mixture that includes aggregates, water and cement can include heavy oil ash instead of or in addition to a portion of the cement. In one embodiment, the heavy oil ash originates from heavy fuel oil burned in a power generation plant. The weight of the heavy oil ash used in the concrete mixture can be from greater than 0 to about 10% of the weight of the cement.

Abstract: Inorganic polymer compositions and methods for their preparation are described herein. The compositions include the reaction product of a reactive powder, anhydrous calcium sulfate, an activator, and optionally a retardant. The reactive powder includes fly ash and no more than 10% by weight portland cement. The anhydrous calcium sulfate is present in an amount of 2% or greater by weight of the reactive powder. Also described herein are building materials including the compositions.

Abstract: Hydraulic cements, such as Portland cements and other cements that include substantial quantities of tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and/or tetracalcalcium alumino-ferrite (C4AF), are particle size optimized to have increased reactivity compared to cements of similar chemistry and/or decreased water demand compared to cements of similar fineness. Increasing hydraulic cement reactivity increases early strength development and release of reactive calcium hydroxide, both of which enhance SCM replacement and 1-28 day strengths compared to blends of conventional Portland cement and one or more SCMs, such as coal ash, slag or natural pozzolan. Decreasing the water demand can improve strength by decreasing the water-to-cement ratio for a given workability. The narrow PSD cements are well suited for making blended cements, including binary, ternary and quaternary blends.

Abstract: A mixture for making gaseous concrete includes Portland cement, slaked lime, ash, aluminum gas forming material, dispersed reinforcing fiber, water, and as the gas forming material and the dispersed reinforcing fiber, it contains aluminated glass fiber, with the following ratio of components in mass %: Portland cement 30-34, Slaked lime 3-4, Ash 18-22, Aluminated glass fiber 1-5, water 37-42, Hemihydrate gypsum 0.4-0.5.

Abstract: This invention relates to a new class of chemical admixtures for hydraulic cement compositions such as pastes, mortars, grouts and concretes. The cement compositions are comprised of ordinary Portland cement, blended cements, or non-Portland cements made with Supplementary Cementitious Materials. The admixtures contain complexes of metals with derivatives of hydroxycarboxylic acids, and improve properties of cement compositions, including setting, hardness, compressive strength, shrinkage, and freeze-thaw resistance. The invention discloses a method for improving the properties of hydraulic cements by adding the disclosed chemical admixtures to cement compositions, and also discloses methods of preparing said admixtures.

Abstract: The invention relates to a hydraulic binder, comprising K, Ca, aluminosilicates, as well as optionally Li, Na, and Mg, wherein the binder comprises the following components: a) a latently hydraulic aluminosilicate glass with a ratio of (CaO+MgO+Al2O3)/SiO2>1 and b) an alkali activator of the empirical formula (I) a(M2O)*x(SiO2)*y(H2O)??(I) wherein M=Li, Na, K, a=0-4, and x=0-5 and y=3-20, wherein the molar ratio of Ca/Si is <1, the molar ratio of Al/Si is <1, and the molar ratio of M/Si is >0.1. Furthermore, it relates to binder matrices, mortars, concrete adhesives, and metal anodes made of such binder.

Abstract: The invention provides a carbon dioxide-resistant hydraulic cement composition. The inventive composition comprises a Portland cement, Class C fly ash and water. The Class C fly ash is present in the composition in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in the composition. In another aspect, the invention provides a method of cementing in a carbon dioxide environment. In yet another aspect, the invention provides a method of enhancing the recovery of a hydrocarbon fluid from a subterranean formation.

Abstract: Hydraulic cements, such as Portland cements and other cements that include substantial quantities of tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and/or tetracalcalcium alumino-ferrite (C4AF), are particle size optimized to have increased reactivity compared to cements of similar chemistry and/or decreased water demand compared to cements of similar fineness. Increasing hydraulic cement reactivity increases early strength development and release of reactive calcium hydroxide, both of which enhance SCM replacement and 1-28 day strengths compared to blends of conventional Portland cement and one or more SCMs, such as coal ash, slag or natural pozzolan. Decreasing the water demand can improve strength by decreasing the water-to-cement ratio for a given workability. The narrow PSD cements are well suited for making blended cements, including binary, ternary and quaternary blends.

Abstract: Partial oxidation of crumb rubber derived from environmental hazardous waste tires yields surface treated crumb rubber and a gas condensate which are used as blending stocks for making rubberized concrete with substantially improved mechanical strength as compared to the conventional rubberized concrete. The chemically more active rubber surface becomes hydrophilic, so it interacts with the hydrophilic surface of surrounding cement matrix much stronger. The gas condensate co-produced in the partial oxidation reactor consists of mainly active sulfur oxides (R—SOx—R) and serves as an excellent bonding agent to further enhance the bonding strength between the partially oxidized rubber particles and the cement mixes. The mechanically improved rubberized concrete is more versatile than conventional rubberized concrete.

Abstract: Embodiments disclose method and compositions that comprise cement kiln dust and rice husk ash. An embodiment comprises a method of cementing comprising: placing a settable composition into a subterranean formation, the settable composition comprising cement kiln dust, rice husk ash, and water; and allowing the settable composition to set.

Abstract: Method for suppressing antagonistic hydration reactions in Portland fly ash cement involves the use of unponded fly ash that is pre-hydrated, preferably as an aqueous slurry wherein fly ash, preferably having an alkaline earth metal oxide of at least 10% by weight, is soaked, whereby the hydration reaction of the resultant mixed fly ash and cement is accelerated when these components are mixed together with water to hydrate the cement. Blended Portland cement/fly ash compositions of the invention will also have higher early strength as well as shorter set time compared to untreated blends.