CN117580812A - Cement admixture, method for producing cement admixture, and cement composition - Google Patents
Cement admixture, method for producing cement admixture, and cement composition Download PDFInfo
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- CN117580812A CN117580812A CN202280045966.XA CN202280045966A CN117580812A CN 117580812 A CN117580812 A CN 117580812A CN 202280045966 A CN202280045966 A CN 202280045966A CN 117580812 A CN117580812 A CN 117580812A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/08—Acids or salts thereof
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
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Abstract
A cement admixture comprising a material selected from the group consisting of gamma-2 CaO SiO 2 、3CaO·2SiO 2 、α‑CaO·SiO 2 And at least 1 non-hydraulic compound selected from the group consisting of calcium magnesium silicate, and calcium sulfoaluminate, wherein the content of the calcium sulfoaluminate is 0.1 to 10 mass%. It is possible to provide a cement admixture which can ensure initial strength even when cement is replaced in a large amount and which can start carbonation curing at an early stage.
Description
Technical Field
The present invention relates to a cement admixture used in the civil engineering field, the construction field, etc., a method for producing the cement admixture, and a cement composition.
Background
Since concrete uses cement in large quantities as a raw material, it is CO 2 And a large discharge amount of material. This is mainly because fossil fuel is used in large amounts to obtain combustion energy of a furnace in cement production, and besides, decarbonation reaction (CaCO) of limestone occurs 3 →CaO+CO 2 ). Reduction of CO as concrete 2 The discharge amount is an important issue as a part of global warming countermeasures.
In order to reduce CO emissions during the manufacture of concrete products 2 In the past, various studies have been made on the reduction of the amount of cement used by blending a large amount of a specific additive or an industrial by-product (such as blast furnace slag fine powder or fly ash) instead of cement.
On the other hand, the following techniques are known: by compounding with gamma-C 2 S(γ-2CaO·SiO 2 The method comprises the steps of carrying out a first treatment on the surface of the Concrete containing a non-hydraulic compound as an admixture, also called Belite gamma phase) is forcibly subjected to carbonation curing to thereby effect CO 2 Absorption, a concrete product having high durability in which the surface layer portion is densified is obtained (for example, patent document 1). Gamma-C 2 S does not undergo hydration reaction but reacts with CO 2 Reacting to produce CaCO-rich product 3 And SiO 2 Is a gel of (a). These products fill the gaps in the cement matrix, and dramatically improve the durability of the surface layer portion of the concrete product. In this case, the part of CO that is absorbed by the concrete by carbonation curing 2 While reducing the total CO in the concrete product 2 Discharge amount.
Patent document 2 proposes a concrete kneaded material containing γ -C 2 S, 1 or 2 kinds of steel-making slag powder and portland cement as powder components, and blended in such a manner that gamma-C is contained in the total content thereof 2 The total proportion of S and steel-making slag powder is 25-95% by mass, and the water-cement ratio W/C is 80-250% by mass. And describes reduction of CO by suppression of the amount of cement used 2 Discharge amount, and CO absorption by carbonation (salinization) curing 2 Thereby realizing the total CO compared with the prior general concrete 2 And (3) a precast concrete product with greatly reduced discharge amount.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2006-182583
Patent document 2: japanese patent application laid-open No. 2011-168436
Disclosure of Invention
Problems to be solved by the invention
However, if a large amount of gamma-C is blended 2 S reduces the amount of the non-hydraulic substance, industrial by-products, and hydraulic cement used, and thus reduces the initial strength, and the curing time required for releasing the concrete form becomes long, and the time required for carrying out the carbonation curing becomes long.
Patent document 1 and patent document 2 do not describe the initial strength.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a cement admixture which can secure initial strength even when cement is replaced in a large amount and which can impart excellent strength-imparting properties by carbonate (chemical) curing.
Means for solving the problems
The inventors of the present application have intensively studied to solve the above problems, and as a result, have found that the above problems can be solved by a cement admixture by containing a specific non-hydraulic compound and calcium sulfoaluminate and having a content of calcium sulfoaluminate within a predetermined range, and have completed the present invention. Namely, the present invention is as follows.
[1]A cement admixture comprising a material selected from the group consisting of gamma-2 CaO SiO 2 、3CaO·2SiO 2 、α-CaO·SiO 2 And at least 1 non-hydraulic compound selected from the group consisting of calcium magnesium silicate, and calcium sulfoaluminate, wherein the content of the calcium sulfoaluminate is 0.1 to 10 mass%.
[2] The cement admixture according to the item [1], wherein the content of the non-hydraulic compound is 60% by mass or more.
[3]As described above [1]]Or [2]]The cement admixture according to the above, wherein the non-hydraulic compound is gamma-2 CaO.SiO 2 。
[4] The cement admixture according to any one of the above [1] to [3], further comprising a hydraulic compound other than calcium sulfoaluminate.
[5]Cement admixtureThe production method of (1) above]～[4]The method for preparing a cement admixture according to any one of, wherein a CaO raw material and Al are prepared 2 O 3 Raw material, siO 2 Raw material, mgO raw material and SO 3 Raw materials, pulverizing them and mixing them to obtain a mixture, and heat-treating the mixture.
[6] A cement composition comprising the cement admixture according to any one of [1] to [4 ].
Effects of the invention
According to the present invention, a cement admixture which can ensure initial strength even when cement is replaced in a large amount and which can impart excellent strength-imparting properties by carbonate (chemical) curing can be provided.
Detailed Description
Hereinafter, embodiments (this embodiment) of the present invention will be described in detail. Unless otherwise specified, parts and% used in the present specification are mass basis.
[ Cement admixture ]
The cement admixture according to the present embodiment comprises a material selected from the group consisting of gamma-2 CaO SiO 2 、3CaO·2SiO 2 、α-CaO·SiO 2 And at least 1 non-hydraulic compound of the group consisting of calcium magnesium silicate, and calcium sulfoaluminate.
By combining the non-hydraulic compound and calcium sulfoaluminate, and by adjusting the content of calcium sulfoaluminate to 0.1 to 10%, a good initial strength can be maintained.
The non-hydraulic compound may be used alone or in combination of 1 or more than 2.
The components and the like will be described below.
< non-Hydraulic Compound >
The cement admixture of the present invention contains a cement additive selected from the group consisting of gamma-2 CaO.SiO 2 、3CaO·2SiO 2 、α-CaO·SiO 2 And at least 1 non-hydraulic compound selected from the group consisting of calcium magnesium silicate.
(γ-2CaO·SiO 2 )
γ-2CaO·SiO 2 Refers toFrom 2 CaO.SiO 2 Among the compounds represented, those known as low-temperature phase are those known as alpha-2 CaO. SiO as high-temperature phase 2 、α’-2CaO·SiO 2 、β-2CaO·SiO 2 Completely different substances. They are all 2 CaO.SiO 2 The crystal structure and density are different.
γ-2CaO·SiO 2 As a non-hydraulic compound, CO is produced by forcibly curing concrete containing the non-hydraulic compound as an additive by carbonation (salinization) 2 Absorption can give a concrete product having a high durability in which the surface layer portion is densified. More specifically, gamma-2 CaO.SiO 2 With CO 2 Reacting to produce CaCO-rich product 3 And SiO 2 The gel fills the gaps in the cement matrix, and the durability of the surface layer part of the concrete product is dramatically improved. Moreover, it can correspond to the part of CO absorbed by the concrete through carbonation curing 2 While reducing the total CO in the concrete product 2 The amount to be discharged is also a preferable compound from the viewpoint of environmental protection.
(3CaO·2SiO 2 )
3CaO·2SiO 2 A mineral containing CaO in pseudo wollastonite is called wollastonite (rankineite). It is a mineral with no hydration activity and stable chemical properties, but the densification effect caused by carbonation (salinization) is great.
(α-CaO·SiO 2 )
α-CaO·SiO 2 (alpha-wollastonite) is composed of CaO-SiO 2 Among the compounds represented, those known as high-temperature phase are those known as beta-CaO.SiO as low-temperature phase 2 Completely different substances. They are all CaO.SiO 2 The crystal structure and density are different.
Naturally occurring wollastonite is a low temperature phase of beta-CaO.SiO 2 。β-CaO·SiO 2 Has needle-like crystals and is used as an inorganic fibrous material such as wollastonite fiber, but the α -CaO-SiO according to the present embodiment 2 The densification effect by the carbonation (salt) is small.
(calcium magnesium silicate)
The calcium magnesium silicate is CaO-MgO-SiO 2 In the present embodiment, the total term of the compound is preferably 3CaO, mgO, 2SiO 2 (C 3 MS 2 ) Represented by magnanite (Merwinite). By using the magnofusite, densification due to promotion of large carbonation (salinization) can be achieved.
The non-hydraulic compound may be 1 or 2 or more, but is preferably contained in the cement admixture in an amount of 60% or more, more preferably 80% or more. When the content is 60% or more, a sufficient densification effect can be obtained by curing with carbonic acid (salt). The upper limit is not particularly limited, but from the viewpoint of storage stability, 95% or less is preferable.
When the number of non-hydraulic compounds is 2 or more, the total amount of the non-hydraulic compounds is 2 or more.
Among the above non-hydraulic compounds, particularly, gamma-2 CaO.SiO is preferable from the viewpoint of 2 : the pulverization phenomenon called dusting (granulation) is accompanied at the time of production, so that the energy required for pulverization is smaller than that of other compounds, and the effect of densification by long-term carbonation (salt) is large. From the obtained gamma-2 CaO.SiO 2 From the viewpoint of the effect, among the non-hydraulic compounds, γ -2 CaO-SiO 2 Preferably 50% or more, more preferably 70% or more. The upper limit is not particularly limited, and in the non-hydraulic compound, γ -2 CaO-SiO 2 It may be 100%.
(calcium sulfoaluminate)
The calcium sulfoaluminate according to the present embodiment is a calcium sulfoaluminate prepared from 3cao.3al 2 O 3 ·CaSO 4 The mineral represented is hydrated in the presence of gypsum or the like to form ettringite (3cao.al 2 O 3 ·3CaSO 4 ·32H 2 O), contributing to an increase in initial strength.
The content of calcium sulfoaluminate is in the range of 0.1 to 10 mass% as an essential requirement. When the content of calcium sulfoaluminate is less than 0.1 mass%, sufficient initial strength is not obtained, and when it exceeds 10 mass%, strength-exhibiting properties at the time of carbonate curing are lowered.
The content of calcium sulfoaluminate is preferably in the range of 0.3 to 10 mass%, more preferably in the range of 1 to 9 mass%, and particularly preferably in the range of 2 to 7 mass%. By containing calcium sulfoaluminate in these ranges, the initial strength can be improved and the strength presentation at the time of carbonate (ized) curing can be improved.
< Hydraulic Compound >
In addition to the non-hydraulic compound and calcium sulfoaluminate, the cement admixture according to the present embodiment may contain a hydraulic compound other than calcium sulfoaluminate. The hydraulic compound is not particularly limited as long as it is a hydraulic compound usually used in cement compositions, and examples thereof include those composed of 3cao—sio 2 、2CaO·SiO 2 Represented by calcium silicate, consisting of 4CaO.Al 2 O 3 ·Fe 2 O 3 、6CaO·2Al 2 O 3 ·Fe 2 O 3 、6CaO·Al 2 O 3 ·Fe 2 O 3 Indicated calcium aluminoferrite, 2CaO.Fe 2 O 3 And calcium ferrite. These hydraulic compounds may be used singly or in combination of 1 or more than 2.
[ method for producing Cement admixture ]
The cement admixture according to the present embodiment can be produced by the following method: preparation of CaO raw material, al 2 O 3 Raw material, siO 2 Raw material, mgO raw material, and SO 3 The raw materials are blended in a proper predetermined molar ratio, and they are pulverized and mixed to obtain a mixture, and the mixture is subjected to heat treatment.
Examples of the CaO raw material include calcium carbonate such as limestone, calcium hydroxide such as slaked lime, acetylene byproduct slaked lime, and fine powder produced from waste concrete blocks.
As SiO 2 Examples of the raw materials include silica, clay, and various silica-based dust generated as industrial by-products typified by silica fume and fly ash.
Examples of the MgO raw material include magnesium hydroxide, basic magnesium carbonate, and dolomite.
As Al 2 O 3 Examples of the raw material include bauxite, aluminum ash, and the like, and as CaSO 4 Raw material (SO) 3 Raw materials) include dihydrate gypsum, hemihydrate gypsum and anhydrite.
The raw CaO material was CO derived from non-energy during heat treatment 2 From the viewpoint of reduction of the discharge amount, it is also preferable to use one or more of acetylene by-product slaked lime, fine powder produced from waste concrete blocks, and industrial by-products containing CaO.
The heat treatment method is not particularly limited, and can be performed by a rotary kiln, an electric furnace, or the like, for example. The heat treatment temperature is not limited to a specific one, and is usually carried out in the range of about 1,000 to 1,800 ℃, and is usually carried out in the range of about 1,200 to 1,600 ℃.
The present embodiment can also use industrial byproducts including the non-hydraulic compound described above. At this time, impurities coexist. As such industrial by-products, steel-making slag and the like can be mentioned.
At some time, the raw material of CaO and SiO 2 Raw materials, mgO raw materials, al 2 O 3 Raw materials, SO 3 The raw materials contain impurities, but there is no problem within a range that does not impair the effects of the present invention. Specific examples of the impurities include Fe 2 O 3 、TiO 2 、MnO、Na 2 O、K 2 O、P 2 O 5 、B 2 O 3 Fluorine, chlorine, etc. Examples of the coexisting compounds include free calcium oxide, calcium hydroxide, calcium aluminate, calcium aluminosilicate, calcium ferrite, calcium aluminoferrite, calcium phosphate, calcium borate, magnesium silicate, and leucite (K) 2 O、Na 2 O)·Al 2 O 3 ·SiO 2 Spinel MgO.Al 2 O 3 Magnetite Fe 3 O 4 Etc.
In addition to the non-hydraulic compound, the cement admixture may contain hydraulic 2cao·sios 2 Up to 35% can be mixed.
Examples of the method for quantifying the non-hydraulic compound and calcium sulfoaluminate include a method in which a crystalline phase is identified by a powder X-ray diffraction method and then calculated from chemical analysis values, a method in which a Rietveld method (Rietveld method) using a powder X-ray diffraction method and the like are used, and in the present invention, a method in which a crystalline phase is identified by a powder X-ray diffraction method and then calculated from chemical analysis values is used.
The cement admixture according to the present embodiment preferably contains particles in which a non-hydraulic compound and calcium sulfoaluminate are present in the same particle. As a method for obtaining particles in which a non-hydraulic compound and calcium sulfoaluminate are present in the same particle, the above-described production method can be obtained by selecting an appropriate raw material composition and heat treatment conditions.
Whether or not the non-hydraulic compound and calcium sulfoaluminate are present in the same particle can be confirmed by an electron microscope or the like. Specifically, the cement admixture was embedded in a resin, and the surface treatment was performed by an argon ion beam to observe the cross-sectional structure of the particles and to perform elemental analysis, whereby it was confirmed whether or not the non-hydraulic compound and calcium sulfoaluminate were present in the same particle.
The Blaine specific surface area of the cement admixture is not particularly limited, but is preferably 1,500cm 2 The upper limit of the ratio is preferably 8,000cm or more 2 And/g or less. Of these, more preferably 2,000 to 6,000cm 2 Preferably 3,000 to 6,000cm per gram 2 And/g. By making Blaine specific surface area 1,500cm 2 At least one of the above components is excellent in separation resistance and sufficient in carbonation (salt) promoting effect. In addition, the passage is 8,000cm 2 And/g or less, the crushing power at the time of crushing can be kept from becoming large, and the economy can be realized, and the weathering can be suppressed, and the deterioration of the quality with time can be suppressed.
[ Cement composition ]
The cement composition according to the present embodiment contains the cement admixture of the present invention.
The amount of the cement admixture to be used is not particularly limited, but is usually preferably 5 to 80 parts, more preferably 5 to 60 parts, and still more preferably 10 to 50 parts, based on 100 parts of the total of the cement and the admixture. When the amount is 5 parts or more, the hydration heat can be reduced, and when the amount is 80 parts or less (particularly 50 parts or less), the initial strength is excellent.
The amount of water used in the cement composition of the present embodiment is not particularly limited, and may be in a usual range. Specifically, the amount of water is preferably 25 to 60 parts per 100 parts of the total of cement and the admixture. When the content is 25 parts or more, sufficient handleability can be obtained, and when the content is 60 parts or less, strength-imparting properties and carbonation (promoting) effects can be sufficiently obtained.
The cement used in the cement composition of the present embodiment is not particularly limited, and preferably contains portland cement, and examples thereof include various portland cements such as ordinary portland cement, early-strength portland cement, super-early-strength portland cement, low-heat portland cement, and medium-heat portland cement. Further, various mixed cements obtained by mixing blast furnace slag, fly ash, or silica with these portland cements, waste-use cements produced from municipal waste incineration ash, sewage sludge incineration ash, or the like, so-called environment-friendly cements (R), and filled cements (filler cement) obtained by mixing limestone powder, or the like, are exemplified. In addition, CO is also included as compared with the conventional cement 2 Low emission geopolymer cement, sulphoaluminate cement, limestone firing clay cement (LC 3). 1 or 2 or more of these can be used.
In the cement composition of the present embodiment, at a low water-cement ratio (water-binder ratio), it is advantageous to blast furnace cement and environment-friendly cement which are strongly required to be suppressed in neutralization, and particularly, it is most preferable to include blast furnace cement.
The particle size of the cement composition of the present embodiment is not particularly limited, since it depends on the purpose and use of the cement composition, and is usually preferably 2,500 to 8,000cm in terms of Blaine specific surface area 2 Preferably 3,000 to 6,000cm per gram 2 And/g. By 2,500cm 2 The strength-exhibiting property can be sufficiently obtained at a ratio of 8,000cm or more 2 And/g or less, the operability can be improved.
In the cement composition of the present embodiment, in addition to cement and the present admixture, 1 or 2 or more known additives or additives used in usual cement materials, such as aggregates of sand, gravel and the like, fine powder of blast furnace slag, fine powder of limestone, fly ash, natural pozzolan and the like, an expansive material, a rapid hardening material, a water reducing agent, an AE water reducing agent, a high performance AE water reducing agent, an antifoaming agent, a thickener, an antirust agent, an antifreezing agent, a shrinkage-reducing agent, a polymer, a clay mineral such as a setting agent and bentonite, and an additive such as an anion exchanger such as hydrotalcite, can be used in a range not to substantially impair the object of the present invention.
The cement composition of the present embodiment may be prepared by mixing the materials at the time of construction, or may be prepared by mixing a part or all of the materials in advance. The method of mixing the respective materials and water is not particularly limited, and a part of the materials may be mixed with water and the remaining materials may be mixed.
As the mixing device, any conventional device can be used, and for example, an inclined mixer, OMNI mixer, henschel mixer, V-type mixer, NAUTA mixer, and the like can be used.
Examples
The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to the following examples unless departing from the gist of the present invention.
Experimental example 1 (1-1 to 1-9)
CaO raw material and SiO 2 Raw materials, mgO raw materials, al 2 O 3 Raw materials and SO 3 The raw materials were blended so as to have the mineral proportions shown in Table 1, mixed and pulverized, and then burned at the temperatures shown in Table 1 for 2 hours to synthesize clinker, which was pulverized by a ball mill so as to have a Blaine specific surface area of 3,000cm 2 And/g, thereby producing a cement admixture.
The mineral composition was obtained by a method of identifying a crystal phase by a powder X-ray diffraction method and then calculating each crystal phase from a chemical analysis value. In the cement admixture, in addition to the non-hydraulic compound and calcium sulfoaluminate,comprises beta-2 CaO.SiO 2 As hydraulically setting compounds. Here, a scanning fluorescent X-ray analyzer "ZSX Primus IV" manufactured by the company Rigaku was used as a fluorescent X-ray apparatus, and a full-automatic multi-purpose X-ray diffraction apparatus "SmartLab" manufactured by the company Rigaku was used as a powder X-ray diffraction apparatus.
With this cement admixture, 50 parts by mass of a cement admixture (admixture addition rate 50% by mass) was used in 100 parts by mass of a cement composition containing cement and a cement admixture, and mortar was prepared in a room at 20 ℃ with 50 parts by mass of water (water/cement composition to 50% by mass) and cement composition/sand ratio=1/3 (mass ratio) with respect to 100 parts by mass of the cement composition. Demolding after 1 day of mold frame storage, and heating at 20deg.C with relative humidity of 60%, and CO 2 The carbonation curing was carried out at a concentration of 5% for 28 days until the age of the material, and the compressive strength was measured.
(use of materials)
CaO raw material: calcium carbonate (reagent 1 grade)
SiO 2 Raw materials: silicon dioxide (reagent 1 grade)
MgO raw material: magnesium oxide (reagent 1 grade)
Al 2 O 3 Raw materials: alpha-alumina (reagent grade 1)
SO 3 Raw materials: calcium sulfate dihydrate (reagent grade 1)
Sand: JIS standard sand
And (3) cement: ordinary Portland Cement manufactured by Denka Co., ltd., specific gravity 3.15, blaine specific surface area 3,300cm 2 /g
Water: tap water
< evaluation method >
Compressive strength: the compressive strength was measured immediately after demolding at 1 day of age of the material and after accelerating carbonation of the cured material for 28 days according to JIS R5201 "physical test method of Cement".
TABLE 1
TABLE 1
Experimental example 2 (2-1) to (2-3)
The cement admixture prepared in each of examples 1 to 4 was heat-treated at 1100℃for 1 hour, left to stand at room temperature, and pulverized and subjected to the same heat treatment repeatedly until the content of the non-hydraulic substance in the cement admixture by XRD became the values shown in Table 2. The test was performed in the same manner as in experimental example 1. The results are shown in Table 2.
TABLE 2
TABLE 2
Experimental example 3 (3-1)
CaO raw material and SiO 2 The raw materials were mixed at a molar ratio of 2:1, mixed and pulverized, and then fired at 1400℃for 2 hours, and pulverized by a ball mill to a specific surface area of Blaine of 3,000cm 2 /g, thereby obtaining gamma-2 CaO.SiO 2 . Further, gamma-2 CaO.SiO 2 Firing at 1100℃for 1 hour, standing to room temperature, pulverizing, and repeating the same heat treatment until gamma-2 CaO. SiO was not confirmed by XRD 2 Is a peak of (2). In the case that only beta-2 CaO.SiO can be confirmed 2 After the peak of (2), the mixture was pulverized into a powder of 3,000cm in terms of Blaine specific surface area by using a ball mill 2 /g, thereby obtaining beta-2 CaO.SiO 2 。
In addition, caO raw material and Al 2 O 3 Raw materials, SO 3 The raw material, namely, calcium sulfate dihydrate, was blended at a molar ratio of 3:3:1, mixed and pulverized, and then fired at 1300 ℃ for 2 hours, and pulverized by a ball mill to a specific surface area of Blaine of 3,000cm 2 And/g, to obtain calcium sulfoaluminate.
The obtained gamma-2 CaO.SiO 2 、β-2CaO·SiO 2 80 parts, 15 parts and 5 parts of calcium sulfoaluminate are mixed respectively to prepare the cement admixture. The test was performed in the same manner as in experimental example 1, and the results are shown in table 3. In the cement admixture column of table 3, "+" indicates that constituent minerals are mixed separately.
TABLE 3
TABLE 3 Table 3
From the results shown in Table 1, it is clear that the cement composition using the cement admixture of the present invention can ensure the initial strength and can be cured by carbonation (salinization) at an early stage. In addition, by using gamma-2 CaO.SiO 2 As a non-hydraulic compound, the compressive strength becomes high. Further, when the content of calcium sulfoaluminate is in an appropriate range, the compressive strength becomes further high.
As is clear from the results in table 2, the compression strength is increased by setting the content of the non-hydraulic compound in the cement admixture to 50 mass% or more, and the compression strength is further increased by setting the content to 60 mass% or more.
Further, as can be seen from the results of Table 3, even when gamma-2 CaO. SiO 2 、β-2CaO·SiO 2 Physical mixing with calcium sulfoaluminate can also give good compressive strength, but for CaO raw material and SiO 2 Raw materials, mgO raw materials, al 2 O 3 Raw materials and SO 3 The cement admixture produced by mixing, pulverizing and heat-treating the raw materials has a higher compressive strength even with the same composition.
Industrial applicability
The cement admixture of the present invention is useful as a cement admixture particularly for use in the civil engineering field, the construction field and the like, and can be preferably used as a cement composition.
Claims (6)
1. A cement admixture comprising a material selected from the group consisting of gamma-2 CaO SiO 2 、3CaO·2SiO 2 、α-CaO·SiO 2 And at least 1 non-hydraulic compound selected from the group consisting of calcium magnesium silicate, and calcium sulfoaluminate, wherein the content of the calcium sulfoaluminate is 0.1 to 10 mass%.
2. The cement admixture according to claim 1, wherein the content of the non-hydraulic compound is 60% by mass or more.
3. The cement admixture according to claim 1 or 2, wherein the non-hydraulic compound is gamma-2 CaO-SiO 2 。
4. The cement admixture according to any one of claims 1 to 3, further comprising a hydraulic compound other than calcium sulfoaluminate.
5. A method for producing the cement admixture according to any one of claims 1 to 4, wherein a CaO raw material and Al are prepared 2 O 3 Raw material, siO 2 Raw material, mgO raw material and SO 3 Raw materials, pulverizing them and mixing them to obtain a mixture, and heat-treating the mixture.
6. A cement composition comprising the cement admixture according to any one of claims 1 to 4.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021-134146 | 2021-08-19 | ||
| JP2021134146A JP7181355B1 (en) | 2021-08-19 | 2021-08-19 | Cement admixture, method for producing cement admixture, and cement composition |
| PCT/JP2022/031072 WO2023022172A1 (en) | 2021-08-19 | 2022-08-17 | Cement admixture, method for producing cement admixture, and cement composition |
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| CN117580812A true CN117580812A (en) | 2024-02-20 |
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| CN202280045966.XA Pending CN117580812A (en) | 2021-08-19 | 2022-08-17 | Cement admixture, method for producing cement admixture, and cement composition |
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| Country | Link |
|---|---|
| JP (1) | JP7181355B1 (en) |
| CN (1) | CN117580812A (en) |
| TW (1) | TW202323218A (en) |
| WO (1) | WO2023022172A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2024181324A1 (en) * | 2023-02-28 | 2024-09-06 | デンカ株式会社 | Co2 fixation method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006182583A (en) * | 2004-12-27 | 2006-07-13 | Kajima Corp | Surface densified mortar or concrete and method for producing the same |
| WO2015170685A1 (en) * | 2014-05-07 | 2015-11-12 | 電気化学工業株式会社 | Cementing composition, cementing method and well drilling method |
| JP7060935B2 (en) * | 2017-09-26 | 2022-04-27 | デンカ株式会社 | Weed control material and how to use it |
-
2021
- 2021-08-19 JP JP2021134146A patent/JP7181355B1/en active Active
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2022
- 2022-08-17 CN CN202280045966.XA patent/CN117580812A/en active Pending
- 2022-08-17 WO PCT/JP2022/031072 patent/WO2023022172A1/en active Application Filing
- 2022-08-18 TW TW111131065A patent/TW202323218A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| TW202323218A (en) | 2023-06-16 |
| JP2023028447A (en) | 2023-03-03 |
| WO2023022172A1 (en) | 2023-02-23 |
| JP7181355B1 (en) | 2022-11-30 |
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