Abstract: The present disclosure describes a self-consolidating concrete (SCC) mixture having a compressive strength of at least 25 MPa at 28 days of age. In accordance with one embodiment, there is provided an SCC mixture, comprising: a mixture of coarse aggregate (CA), fine aggregate (FA), very fine aggregate (VFA), cementitious materials including Portland cement or Portland limestone cement, an ASTM C494 Type F polycarboxylate ether high range water reducer, and water, wherein the VFA has a particle size distribution in which 95% to 100% passes a 2.5 mm sieve and in which 20% to 100% passes a 75 ?m sieve.

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: An additive composition for mortars, exterior insulation finish systems, self-leveling compounds and joint compounds is disclosed. The additive composition contains a nitrogen-containing polymer and a reactive agent capable of forming a crosslinking reaction with the nitrogen-containing polymer. Small amounts of the additive composition contained in a product cannot only increase one or more properties of the product but can also minimize the use of redispersible polymers in the product.

Abstract: Plaster compositions including at least one cement having a first particle distribution and a first mode, at least one non-reactive fine aggregate having a second particle size distribution and a second mode, at least one non-reactive coarse aggregate having a third particle size distribution and a third mode, and an unmodified, hydrophilic, starch. The first mode is greater than the second mode and less than the third mode. The combination of cement, non-reactive fine and coarse aggregates and unmodified, hydrophilic, starch produces a plaster composition having favorable properties suitable for use in providing exposed aggregate finishes used in water reservoirs, pools, and stucco finishes.

Abstract: A process for preparing a setting and hardening accelerator for mineral binders includes the following steps: a) reacting a calcium compound CV with a silicon compound SV, and b) adding an acidic compound having a molecular weight of not more than 200 g/mol, more particularly 40-100 g/mol.

Abstract: Hydraulic cement compositions that include a carbonate compound composition, e.g., a salt-water derived carbonate compound composition containing crystalline and/or amorphous carbonate compounds, are provided. Also provided are methods of making and using the hydraulic cements, as well as settable compositions, such as concretes and mortars, prepared therefrom. The cements and compositions produced therefrom find use in a variety of applications, including use in a variety of building materials and building applications.

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: A cementitious composition capable of forming high early strength cement when admixed with water may comprise, for each 100% by weight, no more than about 60% by weight C3S, at least about 4% by weight C2S, and between about 7% and about 11% by weight SO3, wherein the cementitious composition has a particle size distribution such that substantially all of its particles are of a size of about 10 microns or smaller. A cementitious composition may have a ratio of weight % SO3 to weight % Al2O3 of at least about 1.5 and a particle size distribution such that substantially all of its particles are of a size of about 10 microns or smaller. An apparatus and method for making such a cementitious composition are also described.

Abstract: A subterranean grouting method including (a) placing a sample of a grout mixture within a test container, (b) separating a sand component from the sample, (c) determining if the grout mixture exhibits a thermal conductivity within a predetermined thermal conductivity range based upon a proportion of the sand component within the sample, and (d) upon determining that the grout mixture exhibits a thermal conductivity with the predetermined thermal conductivity range, securing a conduit within a subterranean bore with the grout mixture, wherein (a), (b), (c), and (d) are carried out proximate each other at a job site.

Abstract: Provided is a fiber reinforced cement based mixed material capable of securing high tensile strength and high toughness even after development of a crack. A fiber reinforced cement based mixed material contains cement, a mineral admixture, water, a chemical admixture, aggregate particles, and fibers, the aggregate particles contained in the fiber reinforced cement based mixed material in a proportion of 50 to 95% in terms of a weight ratio to the total weight of the cement and the mineral admixture, wherein a mean particle diameter of the aggregate particles is 0.2 to 0.8 mm, and at least some of the fibers is formed to be a bumpy fiber having asperities formed in the surface thereof, and a ratio (h/H) of a depth h of each of recessed portions among the asperities of the bumpy fiber to a smallest cross-sectional diameter H thereof is 0.05 to 0.8.

Abstract: An additive composition for mortars, exterior insulation finish systems, self-leveling compounds and joint compounds is disclosed. The additive composition contains a nitrogen-containing polymer and a reactive agent capable of forming a crosslinking reaction with the nitrogen-containing polymer. Small amounts of the additive composition contained in a product not only can increase one or more properties of the product but can also minimize the use of redispersible polymers in the product.

Abstract: A foamed concrete having a density from 100 to 800 kg/m3 including by mass relative to the total mass of the concrete: a cement; water; from 0.01 to 5% of a water-reducing agent, plasticizer or superplasticizer; from 0.45 to 5% of a foaming agent relative to the amount of water; from 0.01 to 5% of a water-soluble calcium salt; inorganic particles from 0.1 to 300 ?m in size; the ratio of foaming agent to calcium salt being from 0.3 to 0.8; the foamed concrete including 10% or more by mass of slag.

Abstract: A method for manufacturing a concrete pole, includes steps of preparing a mold with PC steel bars; preparing a concrete composition comprising cement 19˜21 weight percent, Pozzolanic material 3˜5 weight percent, fine aggregate 25˜40 weight percent, natural stone aggregate 30˜45 weight percent, chemical admixture 0.3˜0.4 weight percent, inorganic pigment 0.4˜1.0 weight percent, and water 6˜7 weight percent; pouring the concrete composition into the mold; shaping the poured composition into a hollow pole; curing the shaped pole by steam at a temperature range from 75° C. to 85° C. from 6 to 8 hours; removing the mold from the cured pole; and grinding the outer surface of the pole so that the pattern and color of the natural stones are exposed on the outer surface.

Abstract: A foamed concrete having a density from 100 to 800 kg/m3 including by mass relative to the total mass of the concrete: a cement; water; from 0.01 to 5% of a water-reducing agent, plasticizer or superplasticizer; from 0.45 to 5% of a foaming agent relative to the amount of water; from 0.01 to 5% of a water-soluble calcium salt; inorganic particles from 0.1 to 300 ?m in size; the ratio of foaming agent to calcium salt being from 0.3 to 0.8; excluding foamed concretes including 10% or more by mass of slag.

Abstract: A process for the production of a hydraulic binder, includes co-grinding a clinker and 0.1 to 5% by dry mass relative to the mass of clinker, of a material including more than 15% by mass of calcium silicate hydrate relative to the solid fraction of the material.

Abstract: A method of sequestering a greenhouse gas is described, which comprises: (i) providing a solution carrying a first reagent that is capable of reacting with a greenhouse gas; (ii) contacting the solution with a greenhouse gas under conditions that promote a reaction between the at least first reagent and the greenhouse gas to produce at least a first reactant; (iii) providing a porous matrix having interstitial spaces and comprising at least a second reactant; (iv) allowing a solution carrying the at least first reactant to infiltrate at least a substantial portion of the interstitial spaces of the porous matrix under conditions that promote a reaction between the at least first reactant and the at least second reactant to provide at least a first product; and (v) allowing the at least first product to form and fill at least a portion of the interior spaces of the porous matrix, thereby sequestering a greenhouse gas.

Abstract: A calcium sulfoaluminate-based concrete with a permeability of less than 1000 Coulombs. Rapid-setting low chloride-ion permeability calcium sulfoaluminate (CSA) cements and concretes include CSA and a suitable polymer such as a sol-gel derived, organic-inorganic, silica based hybrid coating solutions of polystyrene-butylacrylate polymers containing active silanol groups protected by hydroxyl groups containing polyalcohol, or other polymers. Such polymers may be added as powders or as liquid in the finish mill. Other rapid-setting low chloride-ion permeability (CSA) cements and concretes include CSA with selected particle size distributions, and do not require use of any polymer. These CSA cements and concretes have low chloride-ion permeability, high early strength, fast setting times, low-shrinkage, and high freeze-thaw resistance.

Abstract: A method of producing a mainly carbonate bonded article includes a step of providing an alkaline granular material having one or more alkaline earth metal silicate phases. The method includes a step of compacting the granular material to obtain a compact of the granular material. The porosity of the compact is smaller than or equal to 37% by volume. The intrinsic permeability of the compact is at least 1·10?12 cm2. The method also includes a reacting step arranged to form at least 5% by weight of carbonates (CO32?), by reacting the granular material with carbon dioxide in the presence of water, thus transforming the compact into the article. In the reacting step, the compact, being unsaturated with moisture at the beginning of the reacting step, is brought in an atmosphere having carbon dioxide. The atmosphere is at a temperature of at least 70° C. and at a pressure of at least 0.5 MPa. The pressure is also higher than the saturated vapor pressure of water at the temperature.

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: The present invention relates to acid-soluble cement compositions that comprise cement kiln dust (“CKD”) and/or a natural pozzolan and associated methods of use. An embodiment includes a method of cementing comprising: placing an acid-soluble cement composition in a subterranean formation, wherein the acid-soluble cement composition comprises a hydraulic cement, a component selected from the group consisting of CKD, pumicite, and a combination thereof, and water; allowing the acid-soluble cement composition to set; and contacting the set acid-soluble cement composition with an acid to dissolve the set acid-soluble cement composition.

Abstract: Methods and compositions are disclosed that comprise interground perlite and hydraulic cement. An embodiment provides a method of cementing comprising: providing a settable composition comprising perlite, hydraulic cement, and water, wherein the perlite and hydraulic cement are interground prior to combination with the water to form the settable composition; and allowing the settable composition to set.

Abstract: A vertebroplastic cementitious composition includes a solid phase including Portland cement and a biocompatible additive which is a plasticizer and a hardening accelerant, wherein the amount of additive is between about 1% and about 15% by weight relative to the Portland cement; and an aqueous liquid phase, wherein the ratio of the solid phase to the liquid phase is between about 3 g/ml and about 6 g/ml. Methods of forming such compositions, treatment methods using such compositions and cementitious implants including such compositions are also described.

Abstract: The invention concerns a process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound and a process for the preparation of a hardening accelerator composition by reaction of a calcium compound with a silicon dioxide containing component under alkaline conditions, in both cases the reaction of the water-soluble calcium compound with the water-soluble silicate compound being carried out in the presence of an aqueous solution which contains a water-soluble comb polymer suitable as a plasticizer for hydraulic binders. The invention concerns also a composition of calcium silicate hydrate and comb polymer, its use as hardening accelerator and for the reduction of the permeability of hardened compositions.

Abstract: A cement composition, and a process for producing a cement composition, wherein the cement composition has the Sr content of 0.065 mass % to 1.0 mass % and the MgO content of greater than 1.0 mass % to 3.0 mass %. The process for producing a cement composition comprises a step (A) of adjusting the basic raw material units of raw materials selected from the group consisting of limestone, silica stone, coal ash, clay, blast furnace slag, soil generated by construction work, sewage sludge, hydrocake and iron sources so that the cement composition has the Sr content of 0.065 mass % to 1.0 mass % and the MgO content of greater than 1.0 mass % to 3.0 mass %, blending the adjusted raw materials and burning to produce cement clinker, and a step (B) of mixing the cement clinker with gypsum and an admixture of limestone and blast furnace slag followed by grinding.

Abstract: Methods and compositions that protect cement compositions from corrosion, particularly from wet carbon dioxide, are provided. A soluble salt additive is provided to react with reaction products generated during the reactions that occur when cement is exposed to wet carbon dioxide. The soluble salt reacts to form an insoluble salt that forms a protective layer on the surface of the cement that protects it from further corrosion from exposure to wet carbon dioxide.

Abstract: Methods and compositions are provided that relate to weighted elastomers. The weighted elastomers may comprise an elastomer and a weighting agent attached to an outer surface of the elastomer. An embodiment includes a method of cementing that comprises providing a cement composition containing cement, water, and a weighted elastomer. In addition, the cement composition may be introduced into a subterranean formation and allowed to set therein.

Abstract: To provide a method and facility for enabling CO2 gas generated in a cement manufacturing facility to be separated and recovered at a high concentration. To this end, according to the present invention, the calcination of a cement material and the recovery of CO2 gas generated in a calciner are performed by one of the following steps of: [1] superheating the cement material before calcination to at least the calcination temperature thereof in a superheating furnace and then mixing the superheated cement material with a new cement material before calcination in a mixer/calciner; [2] mixing, in the mixer/calciner, the cement material before calcination with a part of high-temperature cement clinker discharged from a cement kiln; and [3] using an externally heated calciner.

Abstract: A rotary kiln includes a stationary burner and at least one electrode configured to apply an electric field and/or voltage to a flame supported by the stationary burner. The electric field may contain the flame and/or accelerate combustion to shift most heat transfer from the flame from radiation heat transfer to convective heat transfer.

Abstract: Synthesis gas is more effectively produced from the underground gasification of coal from a coal seam when the casing lining is cemented with a cementitious slurry containing a cementitious material, graphite and an aluminum silicate, such as metakaolin. The cementitious slurry of the cement mix sets as a cement sheath at bottomhole static temperatures less than or equal to 65° C. The set cement may withstand extreme dry heat temperatures which are greater than or equal to 800° C.

Abstract: A durable concrete composition includes a cementitious material comprising cement and ground expanded perlite, coarse aggregate, fine aggregate, and sufficient water for adequate workability. The resulting concrete displays a number of superior properties to conventional concrete, including extremely high thermal resistance coupled with high strength, low chloride ion permeability, and good early strength. The ground expanded perlite is a readily available material and the finished concrete is extremely cost effective for applications where a high strength structural concrete must withstand high temperatures. The mixture can be handled and placed by conventional methods and is compatible with existing conventional concrete additives.

Abstract: A self-repairing concrete includes urea-formaldehyde resin polymer micro-capsules, in which the urea-formaldehyde resin polymer micro-capsules are mixed for a fixed function of micro-cracks. The quality mixture ratio is: concrete/micro capsules/water=100:1-15:15-50. The manufacturing method is weighing a full amount of water in a container, adding urea-formaldehyde resin polymer micro-capsules, stirring, until fully dispersed microcapsules; pouring the water into the mixing container, adding the corresponding quality of cement; stirring; adding sand and gravel filling materials, conducting worksite watering, ? volume for each time, vibrating, and air exhausting; until the paste filling mold.

Abstract: The present invention relates to materials used for building products, construction projects, structural objects, mechanical devices and other materials applications. Specifically, the present invention concerns composite materials made with reinforcing elements in a binder matrix material. A method of strengthening materials is described that uses high volumes of reinforcing elements, which can be easily dispersed and uniformly distributed, consisting of large diameter fibers, miniature rods or other similar geometric shapes with a diameter or thickness between 0.05 mm and 20 mm where the reinforcements are incorporated either as short, randomly distributed elements or long, continuous aligned arrays.

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 brick comprises a thermoplastic material, such as high density polyethylene (HDPE), and a cement-containing material. The brick may be made by mixing thermoplastic material and dry, uncured cement-containing material. This mixture is placed in a mold. The mold is heated while the mixture is compressed to melt or soften the thermoplastic material and to bind the particulate material in the mold into the shape of a brick. After the hardened brick is removed from the mold, the surface of the brick may be sprayed with water to cure cement-containing material on the surface of the brick.

Abstract: Synthetic fibers, such as polypropylene fibers, are mixed in a shrinkage compensating concrete to provide restraint in lieu of conventional steel reinforcement used in a shrinkage compensating concrete. While the synthetic fibers have a low elastic modulus and low strength, they act to restrain expansion of the concrete in the same way that conventional steel rebar does. In addition, only a small amount of the synthetic fibers are needed to restrain the expansion. As a result, shrinkage compensating concrete can be used in more varied applications, and can be provided more quickly, easily and inexpensively. Construction time requirements and expenses of concrete structures are correspondingly reduced.

Abstract: Disclosed is a counterweight which is filled with a heavy-weight concrete containing, instead of currently used iron ores, a heavy-weight aggregate that scarcely causes the material segregation from cement paste and which can be produced at a low cost and is effectively enhanced in the filling factor of heavy-weight concrete into a case. A counterweight 6 comprises a case 62 and heavy-weight concrete filled therein, wherein the heavy-weight concrete contains a heavy-weight fine aggregate containing 20 mass % or more of aggregate particles having particle diameters of less than 0.15 mm and 20 mass % or more of aggregate particles having particle diameters of 2.5 mm to less than 5 mm.

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: The invention relates to a method and system for monitoring and adjusting both air content and rheology (e.g., slump, slump flow) properties of a hydratable concrete mix contained within a concrete mixer. The system simultaneously tracks dosage of both rheology-modifying admixture (e.g., polycarboxylate polymer cement dispersant) and air control agent or “ACA” (e.g., air entraining agent) by reference to at least four nominal dose response (“NDR”) curves or profiles, which at least four NDR profiles are based on the respective behaviors of each of the ACA and rheology-modifying agent on air content and rheology.

Abstract: An embodiment of the present invention comprises a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising unexpanded perlite, cement kiln dust, and water; and allowing the settable composition to set. Another embodiment of the present invention comprises a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising ground unexpanded perlite, Portland cement interground with pumicite, and water; and allowing the settable composition to set. Yet another embodiment of the present invention comprises a settable composition comprising: ground unexpanded perlite; cement kiln dust; and water.

Abstract: Described herein is a cementitious article and a method of making using a water-based manufacturing system that incorporates a closed-loop or partially closed loop water recycling system and an alkali removal process. The system, as such is environmentally friendly, saves resources, such as water and other raw materials, and reduces waste disposal. The system further provides for a cementitious article having a low alkali content. Articles prepared by one or more processes described herein have characteristics that include a low apparent density, high strength and high freeze-thaw performance as compared with an article of the same general formulation but made from a comparative manufacturing system that does not include an alkali removal process. Articles described herein are suitable for use as building products, such as siding, the underlayment panel, board, trim, fascia, roofing, decking, and fence.

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: Reduced-carbon footprint concrete compositions, and methods for making and using the same, are provided. Aspects of the reduced-carbon footprint concrete compositions include CO2-sequestering carbonate compounds, which may be present in the hydraulic cement and/or aggregate components of the concrete. The reduced-carbon footprint concrete compositions find use in a variety of applications, including use in a variety of building materials and building applications.

Abstract: A lightweight artificial stone system comprises a plurality of artificial stones, each of the artificial stones formed of at least some portion of cement, expanded glass, and styrene, the lightweight artificial stones having a density in the range of between about 30 and 70 pounds per cubic foot, each of the stones having six sides and including a first height dimension and a second width dimension, each of the height and width dimensions having a length unit being substantially a multiple of two, each of the stones having four ninety degrees corners and four of the six sides having a smooth surface to provide tight, cement-free seams between adjacent stones, the tight, cement-free seams inhibiting viewing of structure behind said plurality of artificial stones, each of the stones being of such a light weight so as to be held in position in the system by a lath-less and cement-free adhesive.

Abstract: Methods and compositions are provided that relate to weighted elastomers. The weighted elastomers may comprise an elastomer and a weighting agent attached to an outer surface of the elastomer. An embodiment includes a method of cementing that comprises providing a cement composition containing cement, water, and a weighted elastomer. In addition, the cement composition may be introduced into a subterranean formation and allowed to set therein.

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: An embodiment of the present invention comprises a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising unexpanded perlite, cement kiln dust, and water; and allowing the settable composition to set. Another embodiment of the present invention comprises a method of cementing comprising: placing a settable composition into a well bore, the settable composition comprising ground unexpanded perlite, Portland cement interground with pumicite, and water; and allowing the settable composition to set. Yet another embodiment of the present invention comprises a settable composition comprising: ground unexpanded perlite; cement kiln dust; and water.

Abstract: The heat conductivity of a cementitious roadway is improved by adding into the cementitious concentration a powder mixture of a tin alloy or a tin and other powder. Preferably, the alloy is a tin-niobium alloy. Alternatively, a tin powder and a niobium powder are admixed into the composition. Where the powders are used each of the components are present in a 50:50 weight ratio. The powder admixture can also be incorporated into an aqueous latex topcoat for application to a road surface.

Abstract: A dry mortar mixture based on at least one hydraulic and/or latently hydraulic binder which in the made-up and not yet cured state has firm properties is claimed. The novel dry mortar mixture is characterized in that it contains at least one representative of a dispersant and at least one compound having superabsorbent properties. This mixture makes it possible to carry over the advantages of known tile adhesives for horizontal application to vertical application possibilities.

Abstract: Mixed cement containing mainly ground granulated blast furnace slag with an alumina ratio of 12 to 17.5 mass % and Portland cement, wherein a ratio of mixture of the ground granulated blast furnace slag is made 10 to 60 mass % and wherein plaster having a specific surface area of 7000 cm2/g or more is mixed in by a ratio of 2 to 4 mass % converted to SO3 mass. By using this mixed cement as a concrete material, it is possible to suppress expansion of the concrete even if in contact with soil containing residual sulfates over a long period.

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.