Hydraulic composition and production method of hydraulic composition hardened body

Abstract

To provide a hydraulic composition having flowability, fluidity retention property, and strength development property, and capable of reducing a carbon dioxide balance.SOLUTION: A hydraulic composition containing water, an aggregate, a powder containing a binding material and non-hydraulic powder, and a chemical admixture is such that: a mass ratio (water / binding material) of water to the binding material contained in the powder is 0.3-0.9; a content of the non-hydraulic powder in the powder is 1-100 pts.mass based on 100 pts.mass of the binding material; and a content of the chemical admixture is 0.02-1.0 pt.mass based on 100 pts.mass of the binding material.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hydraulic composition and a method for producing a hardened product of the hydraulic composition. More specifically, the present invention relates to a hydraulic composition and a method for producing a hardened product of the hydraulic composition that have fluidity, fluidity retention, and strength development properties and reduce carbon dioxide balance. [Background technology]

[0002] In recent years, efforts to achieve a carbon-neutral or carbon-negative society have been accelerating around the world. For example, Japan declared in 2020 that it would achieve carbon neutrality by 2050, and in 2021 set a target of reducing greenhouse gas emissions by 46% by fiscal 2030 (compared to fiscal 2013 levels).

[0003] For example, the construction industry is also working to reduce carbon dioxide (CO2) emissions.

[0004] Specifically, concrete is a material that emits a large amount of carbon dioxide during its production, using cement that emits a large amount of carbon dioxide. Therefore, in order to reduce carbon dioxide emissions, low-carbon cement and low-carbon concrete, which use industrial by-products such as ground granulated blast furnace slag and fly ash to reduce the amount of cement used, are known.

[0005] It has also been reported that by using a cement admixture containing a non-hydraulic compound such as γ-2CaO·SiO2 and a specified proportion of eelimite, it is possible to ensure the initial strength of concrete while imparting strength reproducibility through carbonation curing (see Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2023-28447 Summary of the Invention [Problem to be solved by the invention]

[0007] However, even when the cement admixture described in Patent Document 1 is used, there is still room for improvement in reducing the carbon dioxide balance (i.e., reducing the total amount of carbon dioxide emitted throughout the entire process of producing a hardened hydraulic composition such as a concrete product). Furthermore, there is still room for improvement in the fluidity and fluidity retention of the resulting hydraulic composition, and there is also room for improvement in the strength development of a hardened hydraulic composition produced from this hydraulic composition.

[0008] Therefore, there is a demand for the development of a hydraulic composition that can improve the reduction in carbon dioxide balance and also has improved fluidity, fluidity retention, and strength development.

[0009] In view of the above circumstances, an object of the present invention is to provide a hydraulic composition and a method for producing a hardened hydraulic composition that have improved fluidity, fluidity retention, and strength development, and that are capable of improving the reduction in carbon dioxide balance.

[0010] The carbon dioxide balance is the amount of carbon dioxide calculated by the formula: "material-derived carbon dioxide emissions (i.e., the amount of carbon dioxide generated during material production)" - "fixed CO2 amount (i.e., the amount of carbon dioxide absorbed and fixed by carbonation curing, etc.)." "Reducing the carbon dioxide balance" means reducing the total amount of carbon dioxide emitted throughout the entire process of producing a hardened hydraulic composition such as a concrete product, and therefore reducing the value of the carbon dioxide balance calculated by the formula. [Means for solving the problem]

[0011] As a result of intensive research aimed at solving the above problems, the present inventors have found that the above problems can be solved by incorporating a powder containing a binder and a predetermined proportion of a non-hydraulic powder, and a predetermined proportion of a predetermined admixture. According to the present invention, the following hydraulic composition and method for producing a hardened hydraulic composition are provided.

[0012] [1] A powder containing water, aggregate, the binder and the non-hydraulic powder described below, and the admixture described below; a mass ratio (water / binder) of the water to the binder contained in the powder is 0.3 to 0.9; The content of the non-hydraulic powder in the powder is 1 to 100 parts by mass relative to 100 parts by mass of the binder, A hydraulic composition, characterized in that the content of the admixture is 0.02 to 1.0 part by mass per 100 parts by mass of the binder. Binding material: It is a powder with hydraulic and latent hydraulic properties, and contains 5 to 70 mass% of Portland cement, 30 to 95 mass% of ground granulated blast furnace slag, and 0 to 10 mass% of gypsum based on the total mass of the binder. Non-hydraulic powder: It is a powder that does not have hydraulic properties and hardens when it reacts with carbon dioxide. Admixtures: When the total content of the structural unit 1 formed from a compound represented by the following general formula (1), the structural unit 2 formed from a compound represented by the following general formula (2), and the structural unit 3 formed from other copolymerizable monomers is taken as 100 mass%, The composition contains a water-soluble vinyl copolymer containing 50 to 99% by mass of the structural unit 1, 1 to 50% by mass of the structural unit 2, and 0 to 10% by mass of the structural unit 3.

[0013] [ka] (In general formula (1), R 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group. 4 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. 5 O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is R 5is the average number of moles of O added, and is a number from 1 to 150. x is an integer from 0 to 5. y is an integer of 0 or 1.

[0014] [ka] (In the general formula (2), R 6 , R 7 , R 8 are each independently a hydrogen atom, a methyl group, or [-(CH2) p COOM 2 ] (where [-(CH2) p COOM 2 ] is COOM 1 or other COOM 2 In this case, M1 and M2 do not exist in the group. 1 , M 2 are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine. p is an integer of 0 to 2.

[0015] [2] The hydraulic composition according to [1], wherein the content of the non-hydraulic powder in the powder is 1 to 50 parts by mass per 100 parts by mass of the binder.

[0016] [3] The powder further contains the following CO2-fixing fine powder in a range of 1 to 100 parts by mass per 100 parts by mass of the binder: The aggregate further contains the following CO2 fixation modified recycled aggregate in the range of 10 to 100 volume % of the total aggregate volume, or The hydraulic composition according to [1] above, which is both of these. CO2 fixed fine powder: The 50% particle size is 100 μm or less, and the concrete powder is a reaction product of recycled concrete powder obtained from hardened concrete and carbon dioxide gas. The modified concrete powder contains calcium carbonate and silicate. CO2 fixation modified recycled aggregate: The modified recycled aggregate is a dry or wet reaction product of carbon dioxide gas and recycled aggregate obtained from hardened concrete with a water absorption rate of more than 2.0% and not more than 10.0%, The modified recycled aggregate contains calcium carbonate and silicon dioxide.

[0017] [4] A hardening step of hardening the hydraulic composition according to any one of [1] to [3] to obtain a hardened hydraulic composition; a curing step of curing the obtained hardened hydraulic composition in an environment with a CO2 concentration of 5% or more; A method for producing a hardened hydraulic composition, comprising: [Effects of the Invention]

[0018] The hydraulic composition of the present invention has fluidity, fluidity retention and strength development properties, and further has the effect of reducing the carbon dioxide balance.

[0019] The method for producing a hydraulic composition hardened body of the present invention includes a hardening step using the hydraulic composition of the present invention and a predetermined curing step, and therefore has the effect of allowing the hydraulic composition hardened body to develop strength and reducing the carbon dioxide balance. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. Therefore, it should be understood that appropriate changes, modifications, etc. can be made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. In the following examples, % means % by mass, and parts means parts by mass, unless otherwise specified.

[0021] (1) Hydraulic composition: The hydraulic composition of the present invention contains water, aggregate, a powder containing the binder and non-hydraulic powder, and the admixture. Furthermore, the hydraulic composition has a mass ratio of water to the binder contained in the powder (water / binder) of 0.3 to 0.9. The content of the non-hydraulic powder in the powder is 1 to 100 parts by mass per 100 parts by mass of the binder. The content of the admixture is 0.02 to 1.0 part by mass per 100 parts by mass of the binder.

[0022] Such a hydraulic composition contains a powder containing a predetermined proportion of a non-hydraulic powder and a predetermined proportion of a predetermined admixture, and thereby has fluidity, fluidity retention, and strength development properties, and can also reduce the carbon dioxide balance.

[0023] Binding material: It is a powder with hydraulic and latent hydraulic properties, and contains 5 to 70 mass% of Portland cement, 30 to 95 mass% of ground granulated blast furnace slag, and 0 to 10 mass% of gypsum based on the total mass of the binder. Non-hydraulic powder: It is a powder that does not have hydraulic properties and hardens when it reacts with carbon dioxide. Admixtures: When the total content of the structural unit 1 formed from a compound represented by the following general formula (1), the structural unit 2 formed from a compound represented by the following general formula (2), and the structural unit 3 formed from other copolymerizable monomers is taken as 100 mass%, The composition contains a water-soluble vinyl copolymer containing 50 to 99% by mass of the structural unit 1, 1 to 50% by mass of the structural unit 2, and 0 to 10% by mass of the structural unit 3.

[0024] [ka] (In general formula (1), R 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group. 4 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. 5O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is R 5 is the average number of moles of O added, and is a number from 1 to 150. x is an integer from 0 to 5. y is an integer of 0 or 1.

[0025] [ka] (In the general formula (2), R 6 , R 7 , R 8 are each independently a hydrogen atom, a methyl group, or [-(CH2) p COOM 2 ] (where [-(CH2) p COOM 2 ] is COOM 1 or other COOM 2 In this case, M1 and M2 do not exist in the group. 1 , M 2 are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine. p is an integer of 0 to 2.

[0026] In a preferred embodiment of the hydraulic composition of the present invention, the powder contains 1 to 100 parts by mass of CO2-fixing fine powder applied to 100 parts by mass of binder, or the aggregate contains 10 to 100% by volume of CO2-fixing modified recycled aggregate applied to the total aggregate volume, or both. In this way, the carbon dioxide balance can be further reduced.

[0027] (1-1) Aggregate: Examples of the aggregate include fine aggregate and coarse aggregate, and can be appropriately selected and used.

[0028] Examples of fine aggregates include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, various slag fine aggregates, and various recycled fine aggregates, but they may also contain fine particles such as clay.

[0029] Examples of coarse aggregate include river gravel, mountain gravel, land gravel, crushed stone, various slag coarse aggregates, lightweight aggregates, and various recycled coarse aggregates.

[0030] In the hydraulic composition of the present invention, the aggregate preferably further contains a CO2-fixing modified recycled aggregate in an amount of 10 to 100% by volume relative to the total aggregate volume (more specifically, the volume of aggregate using the original blend of natural aggregate). The content of this CO2-fixing modified recycled aggregate is more preferably 20 to 100% by volume, and particularly preferably 30 to 100% by volume.

[0031] Here, "original mix" refers to a mix that does not use CO2 fixation modified recycled aggregate. Furthermore, natural aggregate refers to aggregate that has not been subjected to CO2 fixation treatment. Examples of fine aggregate include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, various slag fine aggregates, and various recycled fine aggregates. Examples of coarse aggregate include river gravel, mountain gravel, land gravel, crushed stone, various slag coarse aggregates, lightweight aggregates, and various recycled coarse aggregates. In other words, "relative to the aggregate volume using natural aggregate in the original mix" refers to the volume of natural aggregate, such as river sand, as in the past. In other words, CO2 fixation modified recycled aggregate may be used in place of the aggregate previously used (100% by volume), or it may replace about 1 / 5 (i.e., 20% by volume).

[0032] CO2 fixation modified recycled aggregate is an aggregate produced by reacting CO2 in advance with calcium derived from waste materials such as waste concrete. Examples include CO2 fixation modified recycled fine aggregate and CO2 fixation modified recycled coarse aggregate.

[0033] The CO2-fixed modified recycled aggregate in the hydraulic composition of the present invention contains modified recycled aggregate, which is a dry or wet reaction product of carbon dioxide and recycled aggregate obtained from hardened concrete and having a water absorption rate of more than 2.0 and not more than 10.0%, and the modified recycled aggregate contains calcium carbonate and silicon dioxide.

[0034] It is preferable to use CO2 fixation modified recycled fine aggregate as this type of CO2 fixation modified recycled aggregate, since it contains more calcium derived from cement, fixes a larger amount of CO2 during production of the CO2 fixation modified recycled aggregate (i.e., the "amount of carbon dioxide emitted from the material" is smaller), and has a large effect in reducing the carbon dioxide balance when applied to hydraulic compositions.

[0035] This CO2 fixation modified recycled fine aggregate can be produced as follows.

[0036] First, concrete blocks are crushed or grinded to obtain a crushed or ground material. There are no particular limitations on the method of crushing or grinding, and known crushing or grinding devices, such as shot-blasting crushers, impact crushers, and mechanical grinding devices that do not require heating, can be used. The crushed or ground material is then classified to particle sizes of 0.10 to 10 mm, and particles with a water absorption rate of more than 3.0% and less than or equal to 10.0% are used as recycled fine aggregate. The water absorption rate can be controlled by the processing method of the crushing or grinding device, such as the number of shot-blasting repetitions. Next, the recycled fine aggregate is reacted with carbon dioxide at a volume concentration of 5% or more to obtain a CO2-fixing and modified recycled fine aggregate containing calcium carbonate and silicon dioxide. The reaction between the recycled fine aggregate and carbon dioxide can be performed using either a dry method or a wet method. In this manner, a CO2-fixing and modified recycled fine aggregate can be produced.

[0037] (1-2) Powder: The powder contains a binder and a non-hydraulic powder. By containing the non-hydraulic powder in this way, the hydraulic composition has strength development properties and can further reduce the carbon dioxide balance.

[0038] (1-2a) Binding material: The binder is a powder having hydraulic and latent hydraulic properties, and contains, based on its total mass, 5 to 70 mass% of Portland cement (a "hydraulic" powder), 30 to 95 mass% of ground granulated blast furnace slag (a "latent hydraulic" powder), and 0 to 10 mass% of gypsum (a "hydraulic" powder). By including such a binder, the hydraulic composition has fluidity, fluidity retention, and strength development, and furthermore, the carbon dioxide balance can be reduced.

[0039] "Latent hydraulicity" refers to a property in which a material does not harden simply by being mixed with water, but begins to harden when an alkaline irritant is also present, and "powder with latent hydraulicity" refers to a powder that exhibits this property.

[0040] Examples of Portland cement include ordinary Portland cement, moderate-heat Portland cement, low-heat Portland cement, high-early-strength Portland cement, and sulfate-resistant Portland cement.

[0041] Examples of gypsum include anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum.

[0042] In addition to the Portland cement, ground granulated blast furnace slag, and gypsum, the binder may contain other conventionally known components, such as fly ash, silica fume, stone powder, limestone powder, and an expanding agent.

[0043] As described above, the Portland cement is contained in a proportion of 5 to 70 mass % of the total mass of the binder, and preferably in a proportion of 5 to 67 mass %.

[0044] The ground granulated blast furnace slag is contained in the binder at a ratio of 30 to 95 mass % as described above, and preferably at a ratio of 30 to 92 mass %, based on the total mass of the binder.

[0045] As described above, the gypsum is contained in a proportion of 0 to 10 mass % of the total mass of the binder, and preferably in a proportion of 3 to 8 mass %.

[0046] The proportion of the total amount of Portland cement, ground granulated blast furnace slag, and gypsum in the total mass of the binder can be 50 to 100 mass %.

[0047] (1-2b) Non-hydraulic powder: The non-hydraulic powder is a powder that does not have hydraulic properties and hardens by reacting with carbon dioxide. Note that "non-hydraulic powder" means "a powder that does not harden, or hardly hardens, even when mixed with water."

[0048] Examples of non-hydraulic powders include γ-2CaO·SiO2, 3CaO·2SiO2, 3CaO·2SiO2·CaF2, and 3CaO·MgO·2SiO 2、 Examples of the silicate include α-CaO SiO2, calcium magnesium silicate, etc. Specifically, it can be at least one selected from the group consisting of γ-2CaO SiO2, 3CaO 2SiO2, α-CaO SiO2, and calcium magnesium silicate.

[0049] The content of the non-hydraulic powder is 1 to 100 parts by mass, preferably 1 to 75 parts by mass, and more preferably 1 to 50 parts by mass, relative to 100 parts by mass of the binder. By setting the content within this range, the hydraulic composition has fluidity, fluidity retention, and strength development, and further, the carbon dioxide balance can be reduced.

[0050] (1-2c) CO2 fixed fine powder: The powder preferably contains 1 to 100 parts by mass of CO2-fixing fine powder relative to 100 parts by mass of the binder. By containing this CO2-fixing fine powder, the carbon dioxide balance in the hydraulic composition can be further reduced.

[0051] The CO2-fixing fine powder has a 50% particle size of 100 μm or less and includes recycled concrete powder obtained from hardened concrete and modified concrete powder, which is a reaction product of carbon dioxide and the recycled concrete powder contains calcium carbonate and silicate.

[0052] This CO2-fixing fine powder can be produced as follows.

[0053] First, concrete blocks are crushed or ground to recover recycled concrete powder with a 50% particle size of 100 μm or less. There are no particular limitations on the method for crushing or grinding, and known crushing or grinding devices, such as shot-blasting crushers, impact crushers, and mechanical grinding devices that do not require heating, can be used. Next, the recovered recycled concrete powder is reacted with carbon dioxide at a volume concentration of 5% or more to fix CO2 to the cement-derived components contained in the recycled concrete powder, thereby obtaining modified concrete powder (CO2-fixed fine powder). The reaction with carbon dioxide can be carried out either by a dry method in which gaseous carbon dioxide is brought into contact with the recycled concrete powder, or by a wet method in which the recycled concrete powder is immersed in a solution such as water and then carbon dioxide is blown into the liquid (dispersion) to contact the powder. In this manner, CO2-fixed fine powder can be produced.

[0054] As described above, the content of the CO2-fixing fine powder is preferably 1 to 100 parts by mass, more preferably 10 to 90 parts by mass, and particularly preferably 20 to 80 parts by mass, relative to 100 parts by mass of the binder. By setting the content within such a range, the hydraulic composition has fluidity, fluidity retention, and strength development, and further reduces the carbon dioxide balance.

[0055] In the hydraulic composition of the present invention, the mass ratio of water to the binder contained in the powder (water / binder) is preferably 0.3 to 0.9. By setting the mass ratio within this range, the hydraulic composition has fluidity, fluidity retention, and strength development, and further, the carbon dioxide balance can be reduced.

[0056] (1-3) Admixture: The compatibilizer contains a water-soluble vinyl copolymer having 1 to 3 predetermined structural units.

[0057] By using such a predetermined admixture in a predetermined ratio, even in a hydraulic composition that contains a non-hydraulic powder in addition to a binder as a powder, the hydraulic composition has fluidity, fluidity retention, and strength development, and further, the carbon dioxide balance can be reduced.

[0058] In other words, in efforts to realize a carbon-free society, hydraulic composition hardened bodies such as concrete products that use non-hydraulic compounds (non-hydraulic powder, etc.) have been reported, but the use of non-hydraulic compounds tends to change the physical properties (fluidity, fluidity retention, etc.) of the hydraulic composition and reduce workability. Furthermore, there is a demand for further reduction in carbon dioxide balance. Under these circumstances, by using a predetermined admixture in a predetermined ratio in the hydraulic composition of the present invention, even when a non-hydraulic powder is contained, the composition can have fluidity, fluidity retention, and strength development, and further reduce the carbon dioxide balance.

[0059] (1-3-1) Water-soluble vinyl copolymer: The water-soluble vinyl copolymer contains structural unit 1 formed from a compound represented by the following general formula (1), structural unit 2 formed from a compound represented by the following general formula (2), and structural unit 3 formed from other copolymerizable monomers. When the total blending proportions of structural units 1 to 3 is taken as 100% by mass, the copolymer contains structural unit 1 in proportions of 50 to 99% by mass, structural unit 2 in proportions of 1 to 50% by mass, and structural unit 3 in proportions of 0 to 10% by mass. Furthermore, the content of structural unit 1 is preferably 70 to 99% by mass, the content of structural unit 2 in proportions of 1 to 30% by mass, and the content of structural unit 3 in proportions of 0 to 10% by mass.

[0060] (1-3-1a) Building block 1: Structural unit 1 is a structural unit formed from a compound represented by the following general formula (1).

[0061] [ka] (In general formula (1), R 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group. 4 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. 5 O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is R 5 is the average number of moles of O added, and is a number from 1 to 150. x is an integer from 0 to 5. y is an integer of 0 or 1.

[0062] R in general formula (1) 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group, and among these, R 1 ,R 3 is preferably a hydrogen atom.

[0063] (1-3-1b) Building block 2: Structural unit 2 is a structural unit formed from a compound represented by the following general formula (2).

[0064] [ka] (In the general formula (2), R 6 , R 7 , R 8 are each independently a hydrogen atom, a methyl group, or [-(CH2) p COOM 2 ] (where [-(CH2) p COOM 2 ] is COOM 1 or other COOM 2 In this case, M1 and M2 do not exist in the group. 1 , M 2are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine. p is an integer of 0 to 2.

[0065] M 1 , M 2 are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine, and among these, a hydrogen atom, sodium, and potassium are preferred. Since alkaline earth metals are divalent, M 1 or M 2 This indicates that 1 / 2 mole of the compound is added.

[0066] Specific examples of the compound represented by general formula (2) include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride, itaconic anhydride, etc., as well as alkali metal salts, alkaline earth metal salts (1 / 2), organic amine salts, etc. Among these, the compound represented by general formula (2) is preferably at least one selected from acrylic acid, methacrylic acid, maleic acid, fumaric acid, and alkali metal salts, alkaline earth metal salts (1 / 2), and organic amine salts thereof.

[0067] (1-3-1c) Building block 3: Structural unit 3 is a structural unit formed from another copolymerizable monomer, that is, a structural unit formed from a compound copolymerizable with the compound represented by general formula (1) and the compound represented by general formula (2).

[0068] Examples of compounds that form this structural unit 3 include esters of unsaturated monocarboxylic acids such as (meth)acrylic acid and alcohols having 1 to 30 carbon atoms, amides of the above unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms, monoesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid and alcohols having 1 to 30 carbon atoms, diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid and alcohols having 1 to 30 carbon atoms, unsaturated sulfonic acids (salts) such as vinyl sulfonate, (meth)allyl sulfonate, and styrene sulfonic acid, vinyl aromatics such as styrene and vinyl toluene, dienes such as butadiene and isoprene, and unsaturated amides such as (meth)acryl(alkyl)amide and N,N-dimethyl(meth)acrylamide.

[0069] The water-soluble vinyl copolymer is not particularly limited in terms of its mass average molecular weight, but the mass average molecular weight can be set to 5,000 to 500,000, preferably 7,500 to 400,000, and more preferably 10,000 to 300,000. By setting the mass average molecular weight within such a range, the hydraulic composition has fluidity, fluidity retention, and strength development, and further, the carbon dioxide balance can be reduced.

[0070] More specifically, the water-soluble vinyl copolymer may be one in which the number n in general formula (1) is 1 to 150, the compound represented by general formula (2) is at least one selected from acrylic acid, methacrylic acid, maleic acid, fumaric acid, and their alkali metal salts, alkaline earth metal salts (1 / 2), and organic amine salts, and further, the content of structural unit 1 is 70 to 99 mass%, the content of structural unit 2 is 1 to 30 mass%, and the content of structural unit 3 is 0 to 10 mass%, and the mass average molecular weight is 5,000 to 500,000.

[0071] The water-soluble vinyl copolymer may be used alone or in combination.

[0072] The content (addition amount) of the admixture is preferably 0.02 to 1.0 part by mass with respect to 100 parts by mass of the binder.

[0073] The admixture may contain, in addition to the water-soluble vinyl copolymer, other components than the water-soluble vinyl copolymer, such as a dispersing component such as lignin sulfonate, a retarding component made of an oxycarboxylate such as gluconate or a sugar such as sucrose, a hardening accelerator component, an antifoaming component, an air-entraining component, and an antiseptic component.

[0074] (1-4)Wed: There are no particular limitations on the water, so long as it can be used as mixing water for hydraulic compositions (mortar or concrete), and tap water, groundwater, recycled water, etc. can be used as appropriate.

[0075] (1-5) Other additives: The hydraulic composition may further contain other additives as appropriate within the range that does not impair the effect. Examples of such other additives include setting retarders such as sugars and oxycarboxylates, dispersants such as sodium lignin sulfonate, antifoaming agents such as oxyalkylene compounds, hardening accelerators such as alkanolamines, shrinkage reducers such as polyoxyalkylene alkyl ethers, thickeners such as cellulose ether compounds, preservatives such as isothiazolinone compounds, and rust inhibitors such as nitrites.

[0076] The content of the other additives can be, for example, 0 to 10 parts by mass relative to 100 parts by mass of the binder.

[0077] (2) Manufacturing method of cured hydraulic composition: The method for producing a hydraulic composition hardened product of the present invention comprises a curing step of hardening the hydraulic composition of the present invention to obtain a hydraulic composition hardened product, and a curing step of curing the obtained hydraulic composition hardened product in an environment with a CO2 concentration of 5% or more. Since this method for producing a hydraulic composition hardened product comprises a curing step using the hydraulic composition of the present invention and a predetermined curing step, the hydraulic composition hardened product has strength development and can reduce the carbon dioxide balance.

[0078] (2-1) Curing process: The hardening step is a step of hardening the hydraulic composition of the present invention to obtain a hardened hydraulic composition. As a method for hardening the hydraulic composition, a conventionally known method can be appropriately adopted.

[0079] The hydraulic composition can be prepared by a conventionally known method.

[0080] (2-2)Curing process: In the curing step, the hardened hydraulic composition obtained in the hardening step is cured (carbonation curing) in an environment with a CO2 concentration of 5% or more (i.e., a volume concentration of carbon dioxide of 5% or more). In this way, the hardened hydraulic composition can absorb and fix carbon dioxide.

[0081] There are no particular limitations on the carbon dioxide concentration (CO2 concentration) as long as it is 5% or more, and it can be, for example, 5 to 100%.

[0082] When the hydraulic composition is installed in a predetermined location as a hardened body (concrete product), it can also fix atmospheric carbon dioxide for a long period of time. However, if the carbon dioxide concentration (volume concentration) is less than 5%, the amount of absorbed carbon dioxide is too small, and the carbonation curing period until the desired carbon dioxide reduction amount is achieved tends to be long. [Example]

[0083] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0084] (Water-soluble vinyl copolymer) The water-soluble vinyl copolymers P-1 to P-13 and rP-1 to rP-2 contained in the admixture are shown in Table 1 below.

[0085] [Table 1]

[0086] In Table 1, the compounds forming the structural units 1 to 3 constituting the water-soluble vinyl copolymers P-1 to P-13 and rP-1 to rP-2 are as follows. X-1: α-methacryloyl-ω-methoxypoly(n=130)oxyethylene X-2: α-methacryloyl-ω-methoxypoly(n=45)oxyethylene X-3: α-methacryloyl-ω-methoxypoly(n=23)oxyethylene X-4: α-methacryloyl-ω-methoxypoly(n=9)oxyethylene X-5: α-methacryloyl-ω-hydroxypoly(n=68)oxyethylene X-6: α-methacryloyl-ω-hydroxy-oxypropylene poly(n=45)oxyethylene X-7: α-(3-methyl-3-butenyl)-ω-hydroxypoly(n=53)oxyethylene X-8: α-(3-methyl-3-butenyl)-ω-hydroxypoly(n=10)oxyethylene X-9: α-methallyl-ω-hydroxypoly(n=113)oxyethylene X-10: α-allyl-ω-methyl-poly(n=33)oxyethylene X-11: Hydroxyethyl acrylate Y-1: methacrylic acid Y-2: Acrylic acid Y-3: Maleic anhydride Z-1: Sodium methallyl sulfonate Z-2: Methyl acrylate

[0087] The methods for producing the water-soluble vinyl copolymers P-1 to P-13 and rP-1 to rP-2 are described in the following Production Examples 1 to 13.

[0088] (Production Example 1) Synthesis of Water-Soluble Vinyl Copolymer P-1: A 1000 mL round-bottom flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel was charged with 296.9 g of ion-exchanged water, 324.0 g of α-methacryloyl-ω-methoxypoly(n=130)oxyethylene, 36.0 g of methacrylic acid, and 2.9 g of 3-mercaptopropionic acid, and the mixture was dissolved uniformly with stirring. After that, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C in a warm water bath.

[0089] Next, 42.8 g of 3.5% hydrogen peroxide solution was added to the reaction system to initiate the polymerization reaction. The temperature of the reaction system was maintained at 65°C and the polymerization reaction was carried out for 2 hours. Thereafter, 14.3 g of 3.5% hydrogen peroxide solution was further added to the reaction system, and the temperature of the reaction system was maintained at 65°C and the polymerization reaction was carried out for 2 hours.

[0090] A 30% aqueous solution of sodium hydroxide was added to the reaction system to adjust the pH to 7, and the concentration was further adjusted to 40% with ion-exchanged water to obtain a reaction mixture.

[0091] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found to have a mass average molecular weight of 65000. This reaction product was designated as water-soluble vinyl copolymer P-1.

[0092] (Production Examples 2 to 9, 14 to 15) Synthesis of water-soluble vinyl copolymers P-2 to P-9, rP1 to rP2: Water-soluble vinyl copolymers P-2 to P-9 and rP1 to rP2 were synthesized in the same manner as in Production Example 1 above, except that the type and amount of each structural unit was changed and the amount of 3-mercaptopropionic acid was changed so as to obtain the desired mass average molecular weight, as shown in Table 1.

[0093] However, for the water-soluble vinyl copolymer P-5, the concentration was adjusted to 20% with ion-exchanged water after adjusting the pH.

[0094] (Production Example 10) Synthesis of Water-Soluble Vinyl Copolymer P-10: A 1000 mL round-bottom flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel was charged with 137.3 g of ion-exchanged water and 449.1 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53 mol)oxyethylene, and after dissolving uniformly with stirring, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was maintained at 60°C in a warm water bath.

[0095] Next, 27.6 g of a 3.5% aqueous solution of hydrogen peroxide was added dropwise over 3 hours, and simultaneously, an aqueous solution prepared by uniformly dissolving 31.2 g of acrylic acid in 93.5 g of ion-exchanged water was added dropwise over 3 hours, and simultaneously, an aqueous solution prepared by dissolving 1.6 g of L-ascorbic acid and 3.4 g of 3-mercaptopropionic acid in 45.0 g of ion-exchanged water was added dropwise over 4 hours.

[0096] Thereafter, the temperature of the reaction system was maintained at 60°C for 2 hours to complete the polymerization reaction. Thereafter, a 30% aqueous solution of sodium hydroxide was added to the reaction system to adjust the pH to 7, and the concentration was adjusted to 50% with ion-exchanged water to obtain a reaction mixture.

[0097] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found to have a mass average molecular weight of 71000. This reaction product was designated as water-soluble vinyl copolymer P-10.

[0098] (Production Examples 11 and 12) Synthesis of Water-Soluble Vinyl Copolymers P-11 and P-12: Water-soluble vinyl copolymers P-11 to P-12 were synthesized in the same manner as in Production Example 10, except that the type and amount of each structural unit was changed as shown in Table 1, and the amount of 3-mercaptopropionic acid was changed so as to obtain a predetermined mass average molecular weight.

[0099] (Production Example 13) Synthesis of water-soluble vinyl copolymer P-13: A 1000 mL round-bottom flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel was charged with 353.9 g of α-allyl-ω-methyl-poly(n=33)oxyethylene and 35.0 g of maleic anhydride, and after uniformly dissolving with stirring, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was maintained at 80°C in a warm water bath.

[0100] Next, 7.7 g of azobisisobutyronitrile was added to the reaction system to initiate a radical polymerization reaction. After stirring for 1 hour, 3.8 g of azobisisobutyronitrile was further added to the reaction system, and the radical polymerization reaction was carried out for 4 hours.

[0101] The copolymer obtained was hydrolyzed by adding water to obtain a 40% aqueous solution of a water-soluble vinyl copolymer.

[0102] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found to have a mass average molecular weight of 29000. This reaction product was designated as water-soluble vinyl copolymer P-13.

[0103] (mass average molecular weight) The weight average molecular weight of each of the water-soluble vinyl copolymers P-1 to P-13 and rP-1 to rP-2 was measured by gel permeation chromatography (GPC) under the following conditions. <Measurement conditions> Apparatus: Shodex GPC-101 (Showa Denko) Column: OHpak SB-806M HQ + SB-806M HQ (Showa Denko) Detector: Differential refractometer (RI) Eluent: 50mM sodium nitrate aqueous solution Flow rate: 0.7mL / min Column temperature: 40 degrees Sample concentration: Eluent solution with a sample concentration of 0.5% by mass Standard materials: polyethylene glycol, polyethylene oxide (Agilent)

[0104] (admixture) Next, the constituent components and content ratios (mass%) of admixtures AD-1 to AD-10 and rAD-1 to rAD-5 are shown in Table 2 below.

[0105] [Table 2]

[0106] In Table 2, the components Q-1 to Q-4 other than the water-soluble vinyl copolymer that constitute the admixture are as follows: Q-1: Sodium gluconate (Kishida Chemical, reagent) Q-2: Sucrose (Kishida Chemical, reagent) Q-3: Sodium lignosulfonate (manufactured by Borregard, product name: Borresperse NA) Q-4: Melamine-based dispersant (Takemoto Oil & Fat, product name: Polfine MF)

[0107] Preparation of admixtures (AD-1 to AD-10, rAD-1 to rAD-2): The water-soluble vinyl copolymers and the other components were mixed in the proportions shown in Table 2 in terms of active ingredients, and ion-exchanged water was then added. In this way, 20% aqueous solutions of admixtures AD-1 to AD-10 and rAD-1 to rAD-2 were prepared.

[0108] Preparation of admixtures (rAD-3 to rAD-5): The "components other than the water-soluble vinyl copolymer" shown in Table 2 were mixed in the proportions shown in Table 2, and ion-exchanged water was then added. In this manner, 20% aqueous solutions of admixtures rAD-3 to rAD-5 were prepared.

[0109] (Examples 1 to 24, Comparative Examples 1 to 18) (1) Hydraulic composition (mortar composition): First, ordinary Portland cement (density 3.16 g / cm) was mixed in a mixer specified in JIS R5201 with the mix proportions (mortar mix) shown in Table 3. 3) or high-early-strength Portland cement (density 3.14 g / cm 3 ), blast furnace slag powder #4000 (density 2.89 g / cm 3 ) or blast furnace slag powder #6000 (density 2.89 g / cm 3 ), anhydrous gypsum or dihydrate gypsum, non-hydraulic powder, and carbonated admixture LEAF (manufactured by Denka Co., Ltd., density 3.09 g / cm) whose main component is γ-2CaO·SiO2. 3 ), fine aggregate (Oigawa River land sand 2.5 mm cut, density 2.57 g / cm 3 ), CO2 fixed fine powder (density 2.59g / cm 3 ), CO2 fixation modified recycled fine aggregate (density 2.37g / cm 3 ) were added in order, and then the mixture was dry mixed for 10 seconds.

[0110] Next, each admixture shown in Table 2 and an antifoaming agent (AFK-2 (trade name) manufactured by Takemoto Yushi Co., Ltd.) were added to the mixing water (however, the admixture and antifoaming agent were considered to be part of the mixing water, and the amount of antifoaming agent added was 0.01 part by mass per 100 parts by mass of binder), and this mixing water was charged into a mixer and mixed for 180 seconds to obtain a hydraulic composition.

[0111] The admixtures were added in the range of 0.12 to 1.00 parts of active ingredient relative to the binder, as shown in Tables 6 and 7. The amount of admixture added was adjusted so that the mortar flow was within 220±10 mm. The antifoaming agent was added so that the air content of the mixed mortar was 2% or less.

[0112] The CO2-fixing fine powder and CO2-fixing modified recycled fine aggregate were specifically as follows: The CO2-fixing fine powder had a 50% particle size of 100 μm or less, included modified concrete powder, which was a reaction product of recycled concrete powder obtained from hardened concrete with carbon dioxide, and contained calcium carbonate and silicates. Furthermore, the CO2-fixing modified recycled fine aggregate was particles with a particle size of 0.10 mm to 10 mm, of which 85% or more were 5 mm or less, included modified recycled aggregate, which was a dry or wet reaction product of carbon dioxide and recycled aggregate obtained from hardened concrete with a water absorption rate of more than 3.0% but not exceeding 10%, and contained calcium carbonate and silicon dioxide.

[0113] (Method for manufacturing CO2 fixation modified recycled fine aggregate) The concrete blocks were crushed and ground using a known crusher to obtain crushed and ground material. After crushing and grinding, a 2m 3 1.8 t of water and 200 kg of recycled fine aggregate, which was obtained by classifying the crushed and ground material into particles of 0.10 mm to 10 mm, were added to the container and stirred.

[0114] During stirring, carbon dioxide gas was injected into the bottom of the container at a rate of 150 L / min. The recycled fine aggregate was reacted with carbon dioxide gas until the pH reached 8.6 or less while measuring the pH with a pH meter, yielding a reaction product containing CO2-fixed and modified recycled fine aggregate.

[0115] After the reaction, the reaction product containing CO2 fixation and modified recycled fine aggregate was removed and excess water was removed using a sieve with a nominal mesh size of 0.1 mm. The reaction product was then further air-dried to obtain CO2 fixation and modified recycled fine aggregate.

[0116] (Method of manufacturing CO2 fixation fine powder) The CO2 fixation fine powder was produced in the same manner as in the above-mentioned CO2 fixation and modified recycled fine aggregate manufacturing method, except that recycled concrete powder (50% particle size of 100 μm or less) was used instead of recycled fine aggregate, and a polypropylene twill filter was used instead of a sieve. The twill filter had a thickness of 1.06 mm and an air permeability of 500 cc / cm. 2 / min, vertical strength 300kgf / cm 3 , horizontal 200kgf / cm 3 The following was used.

[0117] [Table 3]

[0118] In Table 3, pc-1, pc-2, sr-1, sr-2, se-1, and se-2 are as follows. pc-1: Ordinary Portland cement pc-2: High-early-strength Portland cement SR-1: Fineness is 4100 cm 2 / g of ground granulated blast furnace slag SR-2: Fineness is 5900 cm 2 / g of ground granulated blast furnace slag se-1: Anhydrous gypsum (manufactured by Fujifilm WAKO) se-2:2 water gypsum (manufactured by Fujifilm WAKO Co., Ltd.)

[0119] In addition, in Table 3, "carbon dioxide emissions derived from materials" was calculated from the CO2 intensity of each material. The CO2 intensity of each material (carbon dioxide emissions derived from materials) is shown in Table 4 below.

[0120] [Table 4]

[0121] Table 5 shows the proportions (by mass) of cement, blast furnace slag powder, and gypsum in the binder, as well as the content of non-hydraulic powder (content of non-hydraulic powder per 100 parts by mass of binder), the content of CO2-fixing fine powder (content of CO2-fixing fine powder per 100 parts by mass of binder), and the content (by volume) of CO2-fixing modified recycled fine aggregate in the fine aggregate.

[0122] [Table 5]

[0123] The obtained hydraulic composition was measured for mortar flow (mm), compressive strength (28-day strength), and CO2 fixation amount (kg / m 3 ) were measured as follows, and each evaluation (strength evaluation, retention evaluation, CO2 balance reduction rate evaluation) was performed. The evaluation results are shown in Tables 6 and 7.

[0124] (Mortar Flow) The hydraulic compositions were measured immediately after mixing and 30 minutes after mixing in accordance with JIS R5201 without dropping. In Tables 6 and 7, the mortar flow value immediately after mixing is shown in the "0 minute" column, and the mortar flow value 30 minutes after mixing is shown in the "30 minute" column. The mortar flow at 0 minutes was adjusted to 220±10 mm using admixtures. When the mortar flow at 0 minutes was not within the range of 210±10 mm even when the amount of admixture added was 1.00 parts by mass or more relative to the binder, the strength and retention ratings were rated "D."

[0125] (Compressive strength (28 days)) A cylindrical tinplate concrete specimen molding formwork (product name "Summit Mold", Sumitomo Cement Co., Ltd., formwork bottom diameter 50 mm, formwork height 100 mm) was prepared, and the mortar composition was filled into this formwork using a two-layer filling method. Thereafter, air curing was carried out indoors at 20°C. Then, two hours after preparation of the mortar composition, the surface of the mortar composition filled into the formwork was smoothed, and polyethylene wrap was placed on this surface to prevent moisture evaporation. Sealed curing was carried out until the material reached an age of two days, and a specimen (hardened mortar) was obtained.

[0126] After sealed curing, the specimen (hardened mortar) was removed from the formwork and subjected to carbonation curing for up to 5 days using a high-concentration accelerated carbonation curing tank (manufactured by Marui Co., Ltd.) that can control temperature, humidity, and CO2 concentration. The carbonation curing conditions were 20°C, 60% RH, and a CO2 concentration of 60%.

[0127] After carbonation curing, the specimens were again cured in air at 20°C until they were 28 days old, and the compressive strength (28-day strength) of the specimens was measured.

[0128] The compressive strength (28-day strength) of the specimens was measured in accordance with JIS-A1108.

[0129] (strength ratio) The ratio (%) of each measured compressive strength (28-day strength) to the standard strength was calculated using the formula: each compressive strength / standard strength × 100, and this was used as the strength ratio. In Examples 1 to 11 and Comparative Examples 1 to 3, the compressive strength (28-day strength) of Comparative Example 4 was used as the standard strength. In Examples 12 to 15 and Comparative Examples 5 and 6, the compressive strength (28-day strength) of Comparative Example 7 was used as the standard strength. In Examples 16 to 18 and Comparative Example 8, the compressive strength (28-day strength) of Comparative Example 9 was used as the standard strength. In Examples 19 to 20 and Comparative Examples 10 to 12, the compressive strength (28-day strength) of Comparative Example 13 was used as the standard strength. In Examples 21 to 23 and Comparative Examples 14 and 15, the compressive strength (28-day strength) of Comparative Example 16 was used as the standard strength. In Example 24 and Comparative Example 17, the compressive strength (28-day strength) of Comparative Example 18 was used as the standard strength.

[0130] (Strength evaluation) Strength evaluation was performed based on the strength ratio results. The evaluation criteria are as follows: If the mortar flow at 0 minutes was not within the range of 210±10 mm even when the amount of admixture added was 1.00 parts by mass or more relative to the binder, it was given a grade of "D." S: Intensity ratio is 120% or more A: When the intensity ratio is less than 120% and is 110% or more B: Intensity ratio is less than 110% and more than 100 C: Intensity ratio is 100% or less

[0131] (Retention Assessment) The mortar flow value after 30 minutes from immediately after mixing was evaluated according to the following evaluation criteria. Note that if the mortar flow at 0 minutes was not within the range of 210±10 mm even when the amount of admixture added was 1.00 parts by mass or more relative to the binder, it was given a "D". S: When the mortar flow value after 30 minutes is 190 mm or more A: If the mortar flow value after 30 minutes is less than 190mm and more than 175mm B: When the mortar flow value after 30 minutes is less than 175 mm and more than 160 mm C: When the mortar flow value after 30 minutes is less than 160 mm and more than 140 mm D: If the mortar flow value after 30 minutes is less than 140 mm

[0132] (CO2 balance reduction rate evaluation) First, a cylindrical tinplate concrete specimen molding formwork (product name "Summit Mold", Sumitomo Cement Corporation, formwork bottom diameter 50 mm, formwork height 100 mm) was prepared, and a mortar composition (hydraulic composition) was filled into this formwork using a two-layer filling method. Thereafter, air curing was carried out indoors at 20°C. Then, two hours after preparation of the mortar composition, the surface of the mortar composition filled into the formwork was smoothed, and polyethylene wrap was placed on the surface to prevent moisture evaporation. Sealed curing was carried out for up to two days, and a specimen (hardened mortar that is a hardened hydraulic composition) was obtained as the hardened mortar composition (hardened mortar body) (hardening process).

[0133] After sealed curing, the specimen (hardened mortar) was removed from the formwork and subjected to carbonation curing for up to 5 days using a high-concentration accelerated carbonation curing tank (manufactured by Marui Co., Ltd.) that can control temperature, humidity, and CO2 concentration (curing process). The carbonation curing conditions were 20°C, 60% RH, and a CO2 concentration of 60%. During this carbonation curing, the specimen was left uncovered and carbonation was carried out from all sides.

[0134] After carbonation curing, the specimens were removed from the curing tank and quickly transferred to a furnace at 105°C for two days of drying. After drying, the specimens were all crushed and then further crushed in a ball mill to particles of 150 μm or less to obtain a crushed product. This crushed product was used as the analytical sample.

[0135] (CO2 fixed amount (kg / m 3 )) To confirm the amount of CO2 fixed by carbonation curing, the total carbon content (C (%)) in the analytical sample was measured using a total organic carbon meter ("TOC-L" manufactured by Shimadzu Corporation and a solid sample combustion device "SSM-5000A"). The measurement conditions were a sample weight of 50 mg and a combustion temperature of 900°C. From the obtained total carbon content, the carbon content of the analytical sample (1 m ) was calculated using the following formula: 3 ) and then calculate the CO2 fixation rate (%) in the sample (kg / m 3 ) by carbonation curing to determine the amount of CO2 fixed (kg / m 3 ) was calculated. Formula: CO2(%)=C(%)×44 / 12

[0136] The CO2 fixation rate is the percentage of the sample weight after heat treatment. The CO2 fixation rate due to carbonation curing was calculated by subtracting the amount of carbon detected from the materials used to prepare the mortar composition and the added components (admixtures, antifoaming agents).

[0137] CO2 fixed amount (kg / m 3 ), the "CO2 balance" was calculated using the formula: carbon dioxide emissions derived from the material (see Table 3) - amount of CO2 fixed. Furthermore, the "difference in CO2 balance reduction" was calculated using the formula: reference CO2 balance - CO2 balance of each example and comparative example. Based on this difference in CO2 balance reduction, the CO2 balance reduction rate was evaluated using the following evaluation criteria. S: The difference in CO2 balance reduction is 30 kg / m 3 If it is more than A: The difference in CO2 balance reduction is 30 kg / m 3 Less than 10kg / m 3 If it is more than B: The difference in CO2 balance reduction is 10 kg / m 3 Less than 0kg / m 3 If it is super C: The difference in CO2 balance reduction is 0 kg / m 3 If:

[0138] [Table 6]

[0139] [Table 7]

[0140] In Tables 6 and 7, "CO2 balance" is a value calculated using the formula: carbon dioxide emissions derived from materials (see Table 3) - CO2 fixation amount. Furthermore, "difference in CO2 balance reduction" is a value calculated using the formula: reference CO2 balance - CO2 balance of each Example and Comparative Example. However, for Examples 1 to 11 and Comparative Examples 1, 2, and 3, the reference CO2 balance is the CO2 balance of Comparative Example 4. For Examples 12 to 15 and Comparative Examples 5 and 6, the reference CO2 balance is the CO2 balance of Comparative Example 7. For Examples 16 to 18 and Comparative Example 8, the reference CO2 balance is the CO2 balance of Comparative Example 9. For Examples 19 to 20 and Comparative Examples 10, 11, and 12, the reference CO2 balance is the CO2 balance of Comparative Example 13. For Examples 21 to 23 and Comparative Examples 14 and 15, the reference CO2 balance is the CO2 balance of Comparative Example 16. In Example 24 and Comparative Example 17, the CO2 balance in Comparative Example 18 is used as the reference CO2 balance.

[0141] In Tables 6 and 7, the amount of admixture added indicates the amount of components in the admixture excluding water.

[0142] (Examples 25-26, Comparative Examples 19-20) (2) Hydraulic composition (concrete composition): Next, a hydraulic composition (concrete composition) was prepared as follows.

[0143] First, ordinary Portland cement (density 3.16 g / cm) was mixed in a forced twin-shaft mixer with a nominal volume of 50 L under the mixing conditions shown in Table 8 in a temperature-controlled room at 20°C and humidity of 80%. 3 ) or high-early-strength Portland cement (density 3.14 g / cm 3 ), blast furnace slag powder #4000 (density 2.89 g / cm 3 ), gypsum, and non-hydraulic powder carbonate admixture LEAF (manufactured by Denka Co., Ltd., density 3.09 g / cm 3 ), CO2 fixed fine powder (density 2.59g / cm 3 ), CO2 fixation modified recycled fine aggregate (density 2.37g / cm 3 ), fine aggregate (Oigawa River land sand, density 2.59 g / cm 3 ), coarse aggregate (Okazaki crushed stone, density 2.68g / cm 3) were added in order, and then the mixture was dry mixed for 10 seconds.

[0144] Next, the admixtures shown in Table 2, an air-entraining agent (AE-200 (trade name) manufactured by Takemoto Yushi Co., Ltd.), and an antifoaming agent (AFK-2 (trade name) manufactured by Takemoto Yushi Co., Ltd.) were added to the mixing water (the admixtures, air-entraining agent, and antifoaming agent were considered to be part of the mixing water, and the amount of antifoaming agent added was 0.0005 parts by mass per 100 parts by mass of binder), and the mixing water was poured into a mixer and mixed for 90 seconds. In this way, 30 L of concrete composition was prepared.

[0145] The amounts of admixtures and air-entraining agents were adjusted so that the target air content was 4.5%±1.0% and the target slump was 18cm±2.5cm (however, the amount of air-entraining agent added was 0.002 to 0.200 parts by mass per 100 parts by mass of binder). The temperatures of the mixed concrete compositions were adjusted before preparation so that they would all be within the range of 20°C±2°C. The temperatures of the mixed concrete compositions were measured in accordance with JIS-A1156.

[0146] [Table 8]

[0147] In Table 8, the materials used in the mortar composition are the same as those used in the mortar composition, but for example, pc-1, pc-2, sr-1, and se-1 are as follows: The carbon dioxide emissions were calculated in the same manner as the "carbon dioxide emissions derived from materials" for the mortar composition. pc-1: Ordinary Portland cement pc-2: High-early-strength Portland cement SR-1: Fineness is 4100 cm 2 / g of ground granulated blast furnace slag se-1: Anhydrous gypsum (manufactured by Fujifilm WAKO)

[0148] Table 9 shows the proportions (by mass) of cement, blast furnace slag powder, and gypsum in the binder, as well as the content of non-hydraulic powder (content of non-hydraulic powder per 100 parts by mass of binder), the content of CO2-fixing fine powder (content of CO2-fixing fine powder per 100 parts by mass of binder), and the content (by volume) of CO2-fixing modified recycled fine aggregate in the fine aggregate.

[0149] [Table 9]

[0150] The resulting hydraulic composition (concrete composition) was measured for slump (cm), air content, compressive strength (28-day strength), and CO2 fixation amount (kg / m 3 ) were measured as follows, and each evaluation (strength evaluation, retention evaluation, CO2 balance reduction rate evaluation) was performed. The evaluation results are shown in Table 10.

[0151] The methods for measuring slump (cm), air content, and compressive strength are shown below.

[0152] (slump) Measurements were made in accordance with JIS-A1101 for the concrete composition immediately after mixing and for the concrete composition that had been left to stand in the mixing vessel for 30 minutes immediately after mixing.

[0153] (air volume) The concrete composition immediately after mixing was measured in accordance with JIS-A1128.

[0154] (Compressive strength) Test specimens were prepared in the same manner as for the mortar compositions, and their compressive strength (28-day strength) was measured in accordance with JIS-A1108.

[0155] (CO2 balance reduction rate evaluation) A cylindrical resin concrete specimen molding form (product name "Plamold", Sumitomo Cement Corporation, formwork bottom diameter 100 mm, formwork height 200 mm) was prepared, and a concrete composition (hydraulic composition) was filled into this formwork using a two-layer filling method. Thereafter, air curing was carried out indoors at 20°C. Two hours after the preparation of the concrete composition, the surface of the concrete composition filled into the formwork was smoothed, and polyethylene wrap was placed over the surface to prevent moisture evaporation. Sealed curing was carried out for up to two days, and a specimen (hardened concrete body, which is a hardened hydraulic composition body) was obtained as the hardened concrete composition (hardened concrete body) (hardening process).

[0156] After sealed curing, the test specimen (hardened concrete) was removed from the formwork and subjected to carbonation curing for up to 9 days using a high-concentration accelerated carbonation curing tank (manufactured by Marui Co., Ltd.) capable of controlling temperature, humidity, and CO2 concentration (curing process). The carbonation curing conditions were 20°C, 60% RH, and a CO2 concentration of 60%. During this carbonation curing, the test specimen was left uncovered, and carbonation was carried out from all sides.

[0157] After carbonation curing, the specimens were removed from the curing tank and roughly crushed in a glove box adjusted to RH 11%, then promptly transferred to a furnace at 105°C. They were then dried for two days. After drying, the specimens were all crushed and further crushed to particles of 150 μm or less in a ball mill. This crushed material was used as the analytical sample.

[0158] (CO2 fixed amount (kg / m 3 )) To confirm the CO2 fixation rate by carbonation curing, the amount of carbon in the analytical sample was measured using a total organic carbon meter (TOC-V and solid sample combustion device SSM-5000A manufactured by Shimadzu Corporation). The measurement conditions were a sample weight of 50 mg and a combustion temperature of 900°C. The carbon content of the analytical sample (1 m ) was calculated from the obtained total carbon content using the following formula: 3 ) and then calculate the CO2 fixation rate (%) in the sample (kg / m 3 ) by carbonation curing to determine the amount of CO2 fixed (kg / m 3 ) was calculated. Formula: CO2(%)=C(%)×44 / 12

[0159] The CO2 fixation rate is the percentage of the sample weight after heat treatment. The CO2 fixation rate due to carbonation curing was calculated by subtracting the amount of carbon detected from the materials used in the concrete composition and the added components (admixtures, air-entraining agents, and antifoaming agents).

[0160] For the other measurement methods, the same methods as those for the mortar composition were used, and the evaluation was carried out according to the same evaluation criteria.

[0161] The evaluation of the retention was carried out according to the following criteria: The slump 30 minutes after mixing was evaluated according to the following criteria. S: If the slump is 15.5 cm or more after 30 minutes A: If the slump is less than 15.5 cm after 30 minutes

[0162] [Table 10]

[0163] In Table 10, "CO2 balance" is a value calculated using the formula: carbon dioxide emission amount (see Table 8) (i.e., carbon dioxide emission amount derived from material) - CO2 fixation amount. Also, "difference in CO2 balance reduction amount" is a value calculated using the formula: reference CO2 balance - CO2 balance of each example and comparative example. However, for Examples 25 to 26 and Comparative Example 19, the CO2 balance of Comparative Example 20 is used as the reference CO2 balance.

[0164] (result) As shown in Tables 6, 7, and 10, the hydraulic composition of this Example has fluidity, fluidity retention, and strength development, and can further reduce the carbon dioxide balance. Furthermore, according to the method for producing a hardened hydraulic composition of this Example, it is found that by using the hydraulic composition of this Example, the hardened hydraulic composition has strength development and can reduce the carbon dioxide balance. [Industrial Applicability]

[0165] The hydraulic composition of the present invention can be used as a material for mortar, concrete, etc. The method for producing a hardened hydraulic composition of the present invention can be employed as a method for producing a hardened hydraulic composition such as mortar or concrete.

Claims

1. The composition comprises water, aggregate, a powder containing the binder and the non-hydraulic powder described below, and the admixture described below, a mass ratio (water / binder) of the water to the binder contained in the powder is 0.3 to 0.9; The content of the non-hydraulic powder in the powder is 1 to 100 parts by mass per 100 parts by mass of the binder, A hydraulic composition characterized in that the content of the admixture is 0.02 to 1.0 parts by mass per 100 parts by mass of the binder. Binding material: This powder has hydraulic properties and latent hydraulic properties, and contains 5 to 70 mass% of Portland cement, 30 to 95 mass% of ground granulated blast furnace slag, and 0 to 10 mass% of gypsum based on the total mass of the binder. Non-hydraulic powder: It is a powder that does not have hydraulic properties and hardens when it reacts with carbon dioxide. Admixtures: When the total content of the structural unit 1 formed from a compound represented by the following general formula (1), the structural unit 2 formed from a compound represented by the following general formula (2), and the structural unit 3 formed from other copolymerizable monomers is taken as 100 mass%, The water-soluble vinyl copolymer contains 50 to 99% by mass of the structural unit 1, 1 to 50% by mass of the structural unit 2, and 0 to 10% by mass of the structural unit 3. 【Chemical 1】 (In general formula (1), R １ , R ２ , R ３ are each independently a hydrogen atom or a methyl group. ４ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. ５ O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is R ５ is the average number of moles of O added, and is a number from 1 to 150. x is an integer from 0 to 5. y is an integer of 0 or 1. 【Chemistry 2】 (In general formula (2), R ６ , R ７ , R ８ are each independently a hydrogen atom, a methyl group, or [—(CH ２ ) ｐ COOM ２ ](However, [-(CH ２ ) ｐ COOM ２ ] is COOM １ or other COOM ２ In this case, the group M １ , M ２ does not exist. １ , M ２ are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine; and p is an integer of 0 to 2.

2. 2. The hydraulic composition according to claim 1, wherein the content of the non-hydraulic powder in the powder is 1 to 50 parts by mass per 100 parts by mass of the binder.

3. The powder further contains 1 to 100 parts by mass of the following CO ２ Contains fixed fines or The aggregate further contains the following CO in the range of 10 to 100% by volume based on the total aggregate volume: ２ Contains fixed modified recycled aggregate, or The hydraulic composition according to claim 1, wherein the hydraulic composition is both of these. CO ２ Fixed micro powder: The 50% particle size is 100 μm or less, and the modified concrete powder is a reaction product of recycled concrete powder obtained from hardened concrete and carbon dioxide gas, The modified concrete powder contains calcium carbonate and silicate. CO ２ Fixed modified recycled aggregate: The modified recycled aggregate is a dry or wet reaction product of carbon dioxide gas and recycled aggregate obtained from hardened concrete and having a water absorption rate of more than 2.0% and not more than 10.0%, The modified recycled aggregate contains calcium carbonate and silicon dioxide.

4. a hardening step of hardening the hydraulic composition according to any one of claims 1 to 3 to obtain a hardened hydraulic composition product; The obtained hardened hydraulic composition was subjected to CO ２ A curing process in which the solution is cured in an environment with a concentration of 5% or more; A method for producing a hardened hydraulic composition, comprising:

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