Hydraulic composition for spraying

Abstract

To provide a hydraulic composition for spraying that suppresses the occurrence of laitance and exhibits superior discharge performance.SOLUTION: A hydraulic composition for spraying comprises a hydraulic powder, (A) a predetermined copolymer A, (B) a predetermined copolymer B, and water.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a hydraulic composition for spraying, a dispersant for the hydraulic composition for spraying, a method for producing the hydraulic composition for spraying, and a spraying method using the hydraulic composition for spraying. [Background technology]

[0002] In order to prevent the collapse of exposed ground such as during tunnel excavation, a spraying method using quick-setting concrete or quick-setting mortar, which is made by mixing concrete with an accelerating agent, is being used. In this method, the concrete to be sprayed is usually prepared in a cement, aggregate, and water metered mixing plant installed at the excavation site, and then it is transported to a conveying and spraying machine with an agitator truck. The sprayed concrete and the accelerating agent are then mixed in a line that uses the pump of the spraying machine to pneumatically pump the sprayed concrete to the discharge outlet, and a junction pipe is installed midway between the two lines to pneumatically pump the accelerating agent from the other side, and the mixture is sprayed onto the ground surface to a specified thickness as quick-setting shotcrete.

[0003] Patent Document 1 discloses high-strength wet sprayable ready mixed concrete containing a specified cement, fine aggregate, coarse aggregate, a specified cement dispersant, and water, and having a water / cement ratio of 25 to 50%, in which the cement dispersant is contained in an amount of 0.01 to 1.5 parts by weight per 100 parts by weight of cement. Patent Document 2 discloses an additive for hydraulic materials that contains a polymer compound having a (poly)oxyalkylene group, an anionic group, and a cationic group and is used for sprayed concrete, as well as a hydraulic material composition that contains the additive for hydraulic materials and a hydraulic material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-349369 [Patent Document 2] Patent Publication No. 2021-70602 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the spray hydraulic composition is sprayed onto the natural ground under high pressure, there is a risk of slag being generated by high-pressure impact. Slag is powder and water separated from mortar, etc., i.e., paste components, and often contains a large amount of water. If the generation of slag increases the amount of water locally, and concrete, etc. with low strength is produced, it may cause the concrete, etc. to spall or be unable to withstand deformation of the natural ground. In addition, since the hydraulic composition for spraying starts hardening within a few seconds after adding the quick-setting agent, it easily adheres to the pipes and nozzles of the spraying machine, and if the work is performed continuously, it gradually accumulates, causing a decrease in the discharge amount of the hydraulic composition for spraying and a phenomenon in which the discharge amount becomes unstable and pulsates, resulting in poor workability. In such cases, this can be solved by cleaning the pipes and nozzles, but the work efficiency will decrease significantly as the frequency of cleaning increases. The present invention provides a hydraulic composition for spraying that suppresses the generation of slag and has excellent discharge performance, a dispersant for the hydraulic composition for spraying, a method for producing the hydraulic composition for spraying, and a spraying method using the hydraulic composition for spraying. [Means for solving the problem]

[0006] The present invention relates to a hydraulic composition for spraying, comprising: a hydraulic powder; (A) a copolymer A (hereinafter referred to as component (A)) containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), in which the ratio of structural unit (1) to structural unit (2) in all structural units [structural unit (1) / structural unit (2)] is 50 / 50 or more and 95 / 5 or less in molar ratio; (B) a copolymer B (hereinafter referred to as component (B)) containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), in which the ratio of structural unit (1) to structural unit (2) in all structural units [structural unit (1) / structural unit (2)] is 31 / 69 or more and 49 / 51 or less in molar ratio; and water.

[0007] [ka] [In the formula, R 1a represents a hydrogen atom or a methyl group, M 1 represents a hydrogen atom or a counter ion that forms a salt.

[0008] [ka] [In the formula, R 2a represents a hydrogen atom or a methyl group, R 3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; X 1 represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group, AO represents an alkyleneoxy group having 2 or 3 carbon atoms, and n1 represents the average number of moles of AO added, which is a number of 5 to 170.

[0009] The present invention also relates to a dispersant for a hydraulic composition to be sprayed, comprising component (A) and component (B).

[0010] The present invention also relates to a method for producing a hydraulic composition for spraying, which comprises mixing a hydraulic powder, component (A), component (B), and water.

[0011] The present invention also relates to a spraying method in which the above-mentioned sprayable hydraulic composition of the present invention is sprayed onto a target surface. Effect of the Invention

[0012] According to the present invention, there are provided a hydraulic composition for spraying that suppresses the generation of slag and has excellent discharge performance, a dispersant for the hydraulic composition for spraying, a method for producing the hydraulic composition for spraying, and a spraying method using the hydraulic composition for spraying. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention relates to a sprayable hydraulic composition, and more particularly to a dispersant for the sprayable hydraulic composition, a sprayable hydraulic composition, and a spraying method using the same, which are used when spraying quick-setting concrete or quick-setting mortar on tunnels for roads, railways, and water conduits, and on slopes formed by natural ground excavation, embankment, etc. The sprayable hydraulic composition in the present invention is a general term for cement mortar and cement concrete.

[0014] The mechanism by which the hydraulic composition for spraying of the present invention inhibits the generation of slag and has excellent discharge performance is not clear, but is presumed to be as follows. It is presumed that component (A) is adsorbed to and dispersed in the hydraulic powder, imparting fluidity to the spray hydraulic composition, while component (B) is less likely to be adsorbed to the hydraulic powder, and that component (B) remaining in the water causes a depletion and coagulation action, promoting the coagulation of the hydraulic powder. It is presumed that the action of components (A) and (B) adjusts the recovery time from dispersion by external force to coagulation, thereby improving the fluidity of the hydraulic composition for spraying, thereby preventing clogging of the piping and nozzles of the spraying machine, while quickly coagulating when left to stand after spraying, thereby preventing slag. The hydraulic composition for spraying, the dispersant for the hydraulic composition for spraying, the method for producing the hydraulic composition for spraying, and the spraying method of the present invention are not limited to the above-mentioned mechanism of action.

[0015] <Hydraulic composition for spraying> The hydraulic composition for spraying of the present invention contains a hydraulic powder, (A) a copolymer A [component (A)] which contains a structural unit (1) represented by the following formula (1) [hereinafter also referred to as structural unit (1)] and a structural unit (2) represented by the following formula (2) [hereinafter also referred to as structural unit (2)], in which the ratio of structural unit (1) to structural unit (2) in all structural units [structural unit (1) / structural unit (2)] is 50 / 50 or more and 95 / 5 or less in molar ratio, (B) a copolymer B [component (B)] which contains structural unit (1) represented by the following formula (1) and structural unit (2) represented by the following formula (2) and in which the ratio of structural unit (1) to structural unit (2) in all structural units [structural unit (1) / structural unit (2)] is 31 / 69 or more and 49 / 51 or less in molar ratio, and water.

[0016] [ka] [In the formula, R 1a represents a hydrogen atom or a methyl group, M 1 represents a hydrogen atom or a counter ion that forms a salt.

[0017] [ka] [In the formula, R 2a represents a hydrogen atom or a methyl group, R 3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; X 1 represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group, AO represents an alkyleneoxy group having 2 or 3 carbon atoms, and n1 represents the average number of moles of AO added, which is a number of 5 to 170.

[0018] In the structural unit (1) represented by formula (1), R 1a is a hydrogen atom or a methyl group, and from the viewpoint of ejection workability, a methyl group is preferred. M 1 is a hydrogen atom or a counter ion which is a salt. 1Examples of the alkali metal include sodium, potassium, and other alkali metals, magnesium, and other alkaline earth metals, ammonium ion, and organic amines such as monoethanolamine, diethanolamine, and triethanolamine. The alkali metal is preferred, and sodium is more preferred. M 1 From the viewpoint of ejection workability, sodium ion and ammonium ion are preferred, and sodium ion is more preferred.

[0019] Examples of the monomer of the structural unit (1) represented by formula (1) include (i) alkali metal salts, such as lithium salts, sodium salts, and potassium salts, of (meth)acrylic acid; (ii) alkaline earth metal salts, such as calcium salts, magnesium salts, and other salts of (meth)acrylic acid; and (iii) organic amine salts, such as diethanolamine salts and triethanolamine salts of (meth)acrylic acid. Of these, sodium salts of (meth)acrylic acid are preferred.

[0020] In the structural unit (2) represented by formula (2), R 2a is a hydrogen atom or a methyl group, and from the viewpoint of ejection workability, a methyl group is preferred. R 3a is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and from the viewpoint of discharge workability, a hydrogen atom or a methyl group is preferable. X 1 is a divalent alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group, and from the viewpoint of ejection workability, a direct bond or a carbonyl group is preferable. AO is an alkyleneoxy group having 2 or 3 carbon atoms, and includes at least one selected from an ethyleneoxy group and a propyleneoxy group, and is preferably an ethyleneoxy group. When AO contains an ethyleneoxy group and a propyleneoxy group, the ethyleneoxy group and the propyleneoxy group may be bonded in a block bond or a random bond. n1 is the average number of moles of AO to which alkylene oxide is added, and from the viewpoint of extrusion workability, it is 5 or more, preferably 8 or more, more preferably 20 or more, and from the viewpoint of extrusion workability, it is 170 or less, preferably 120 or less, more preferably 80 or less.

[0021] Examples of monomers of the structural unit (2) represented by formula (2) include monoalkoxypolyethylene glycols such as monomethoxypolyethylene glycol, monoethoxypolyethylene glycol, mono(iso)propoxyethylene glycol, monomethoxypolyethylene glycol propylene glycol, monoethoxypolyethylene glycol propylene glycol, and mono(iso)propoxyethylene glycol propylene glycol, monoalkoxypolyethylene glycol polypropylene glycol, polyethylene glycol, and polyethylene glycol polypropylene glycol, all of which have an average addition mole number of AO of 5 or more and 170 or less and have a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and esters of acrylic acid or methacrylic acid with polyethylene glycol or polyethylene glycol polypropylene glycol, and among these, esters of monomethoxypolyethylene glycol having an average addition mole number of ethyleneoxy groups to which ethylene oxide is added of 8 or more and 80 or less and methacrylic acid are preferred.

[0022] <Component (A)> Component (A) is a copolymer A containing a structural unit (1) represented by formula (1) and a structural unit (2) represented by formula (2), in which the ratio of structural unit (1) to structural unit (2) in all structural units [structural unit (1) / structural unit (2)] is 50 / 50 or more and 95 / 5 or less in molar ratio. This ratio is the ratio of the molar percentage of structural unit (1) to all structural units in component (A) and the molar percentage of structural unit (2) to all structural units. The above-mentioned ratio of the component (A) [structural unit (1) / structural unit (2)] (molar ratio) is, from the viewpoint of discharge workability, 50 / 50 or more, preferably 60 / 40 or more, more preferably 65 / 35 or more, and even more preferably 70 / 30 or more, and from the viewpoint of slag suppression, is 95 / 5 or less, preferably 90 / 10 or less, more preferably 85 / 15 or less, and even more preferably 80 / 20 or less. The ratio (molar ratio) of the structural unit (1) to the structural unit (2) in all structural units of the component (A) may be the ratio (molar ratio) of the amount of the monomer of the structural unit (1) to the amount of the monomer of the structural unit (2) in the synthesis of the component (A). Furthermore, the component (A) may be a copolymer containing one or more types of each of the structural units (1) and (2).

[0023] The component (A) can contain a structural unit (3) which does not fall under the category of structural unit (1) or structural unit (2). Examples of the structural unit (3) include structural units derived from monomers such as methyl acrylate, hydroxyethyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, hydroxymethyl acrylate, hydroxyethyl methacrylate, and hydroxymethyl methacrylate, 2-(methacryloyloxy)ethyl phosphate (HEMA-P), allylsulfonic acid, methallylsulfonic acid, and salts thereof, such as alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts. Examples of the structural unit (3) include structural units derived from monomers such as (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, 2-(meth)acrylamide-2-methasulfonic acid, 2-(meth)acrylamide-2-ethanesulfonic acid, 2-(meth)acrylamide-2-propanesulfonic acid, styrene, and styrenesulfonic acid.

[0024] Of all the structural units in component (A), the total proportion of structural units (1) and (2) is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and from the viewpoint of extrusion workability, for example, 100 mol% or less, even 90 mol% or less, and even 85 mol% or less. Component (A) may be a copolymer in which the total proportion of structural units (1) and (2) in all the structural units is 100 mol%.

[0025] From the viewpoint of discharge workability, the weight average molecular weight of the (A) component is preferably 20,000 or more, more preferably 30,000 or more, even more preferably 40,000 or more, and preferably 100,000 or less, more preferably 90,000 or less, even more preferably 80,000 or less, and even more preferably 70,000 or less. This weight average molecular weight was measured by GPC under the following conditions: high-speed GPC apparatus (HLC-8320GPC) Tosoh Corporation, detector: RI, column: G4000PWXL+G2500PWXL (anion), mobile phase: 0.2 M phosphate buffer / acetonitrile=9 / 1, flow rate: 1.0 mL / min., column temperature: 40°C, standard substance: polyethylene glycol).

[0026] The hydraulic composition for spraying of the present invention contains the component (A) in an amount of preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, based on the hydraulic powder in the hydraulic composition for spraying from the viewpoint of discharge workability, and from the viewpoint of slag suppression, preferably 0.3% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.15% by mass.

[0027] <(B) component> Component (B) is a copolymer B that contains a structural unit (1) represented by formula (1) and a structural unit (2) represented by formula (2), and the ratio of structural unit (1) to structural unit (2) in all structural units [structural unit (1) / structural unit (2)] is a molar ratio of 31 / 69 to 49 / 51. This ratio is the ratio of the molar percentage of structural unit (1) to all structural units in component (B) and the molar percentage of structural unit (2) to all structural units. The ratio of the component (B) [structural unit (1) / structural unit (2)] (molar ratio) is, from the viewpoint of suppressing slag production, 31 / 69 or more, preferably 34 / 66 or more, more preferably 37 / 63 or more, and even more preferably 39 / 61 or more, and from the viewpoint of suppressing slag production, is 49 / 51 or less, preferably 48 / 52 or less, and more preferably 47 / 53 or less. The molar ratio of the structural unit (1) to the structural unit (2) in all structural units of the component (B) may be the molar ratio of the amount of the monomer of the structural unit (1) to the amount of the monomer of the structural unit (2) in the synthesis of the component (B). Furthermore, the component (B) may be a copolymer containing one or more types of each of the structural units (1) and (2). The structural unit (1) contained in component (B) may be the same as or different from the structural unit (1) contained in component (A), and the structural unit (2) contained in component (B) may be the same as or different from the structural unit (2) contained in component (A).

[0028] The component (B) can contain a structural unit (3) which does not fall under the category of the structural units (1) and (2). Examples of the structural unit (3) include structural units derived from monomers such as methyl acrylate, hydroxyethyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, hydroxymethyl acrylate, hydroxyethyl methacrylate, and hydroxymethyl methacrylate, 2-(methacryloyloxy)ethyl phosphate (HEMA-P), allylsulfonic acid, methallylsulfonic acid, and salts thereof, such as alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts. Examples of the structural unit (3) include structural units derived from monomers such as (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, 2-(meth)acrylamide-2-methasulfonic acid, 2-(meth)acrylamide-2-ethanesulfonic acid, 2-(meth)acrylamide-2-propanesulfonic acid, styrene, and styrenesulfonic acid.

[0029] The total proportion of the structural units (1) and (2) in the total structural units of the component (B) is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and from the viewpoint of suppressing slag, for example, 100 mol% or less, further 90 mol% or less, and further 85 mol% or less. The component (B) may be a copolymer in which the total proportion of the structural units (1) and (2) in the total structural units is 100 mol%.

[0030] From the viewpoint of suppressing slag, the weight average molecular weight of component (B) is preferably 20,000 or more, more preferably 30,000 or more, even more preferably 40,000 or more, and preferably 150,000 or less, more preferably 120,000 or less, even more preferably 100,000 or less, and even more preferably 90,000 or less. This weight average molecular weight was measured by GPC under the following conditions: high-speed GPC apparatus (HLC-8320GPC) Tosoh Corporation, detector: RI, column: G4000PWXL+G2500PWXL (anion), mobile phase: 0.2 M phosphate buffer / acetonitrile=9 / 1, flow rate: 1.0 mL / min., column temperature: 40°C, standard substance: polyethylene glycol).

[0031] From the viewpoint of suppressing slag, the hydraulic composition for spraying of the present invention contains the component (B) in an amount of preferably 0.01 mass % or more, more preferably 0.03 mass % or more, even more preferably 0.05 mass % or more, and preferably 0.3 mass % or less, more preferably 0.2 mass % or less, even more preferably 0.15 mass % or less, based on the hydraulic powder in the hydraulic composition for spraying.

[0032] In the hydraulic composition for spraying of the present invention, the mass ratio (A) / (B) of the content of the component (A) to the content of the component (B) is preferably 0.2 or more, more preferably 0.4 or more, and even more preferably 0.45 or more, from the viewpoint of discharge workability, and is preferably 3 or less, more preferably 2 or less, and even more preferably 1 or less, from the viewpoint of slag suppression.

[0033] In the hydraulic composition for spraying of the present invention, the molar percentage A of the structural unit (1) relative to all structural units in the component (A) is 1 and the molar percentage B of the structural unit (1) relative to all structural units in the component (B) 1 Difference from (A 1 -B 1) is preferably 5 mol % or more, more preferably 12 mol % or more, and even more preferably 20 mol % or more from the viewpoints of slag suppression and extrusion workability, and is preferably 64 mol % or less, more preferably 50 mol % or less, and even more preferably 40 mol % or less from the viewpoints of slag suppression and extrusion workability.

[0034] <Hydraulic powder> The spray hydraulic composition of the present invention contains hydraulic powder. The hydraulic powder used in the spray hydraulic composition of the present invention is a powder that hardens when mixed with water, and examples thereof include ordinary Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, sulfate-resistant Portland cement, low-heat Portland cement, moderate-heat Portland cement, white Portland cement, alumina cement, and ecocement (e.g., JISR 5214, etc.). Among these, from the viewpoint of the spread of the spray hydraulic composition, cement selected from early-early-strength Portland cement, ordinary Portland cement, sulfate-resistant Portland cement, and white Portland cement is preferred, and early-early-strength Portland cement and ordinary Portland cement are more preferred.

[0035] The hydraulic powder may include blast furnace slag, fly ash, silica fume, anhydrous gypsum, etc., and may also include non-hydraulic limestone fine powder, etc. As the hydraulic powder, blast furnace cement, fly ash cement, or silica fume cement, which is a mixture of cement with blast furnace slag, fly ash, silica fume, etc., may also be used.

[0036] <Aggregate> The sprayable hydraulic composition of the present invention may contain aggregate. The aggregate may be selected from fine aggregate and coarse aggregate. Examples of fine aggregates include those specified by number 2311 in JIS A 0203-2014. Examples of fine aggregates include river sand, land sand, mountain sand, sea sand, lime sand, silica sand and crushed sands thereof, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural), and recycled fine aggregate. Furthermore, examples of coarse aggregate include those specified by number 2312 in JIS A 0203-2014. For example, examples of coarse aggregate include river gravel, land gravel, mountain gravel, sea gravel, limestone gravel, crushed stones thereof, blast furnace slag coarse aggregate, ferro-nickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural), and recycled coarse aggregate. Fine aggregate and coarse aggregate of different types may be mixed and used, or a single type may be used. The sprayable hydraulic composition of the present invention may contain fine aggregate as an aggregate. The amount of fine aggregate used in the sprayable hydraulic composition of the present invention is preferably 500 kg / m 3 More preferably, 600 kg / m 3 More than 2000 kg / m 3 Less than or equal to 1700 kg / m 3 The following is the result. In the sprayable hydraulic composition of the present invention, the fine aggregate ratio is preferably 35% or more, more preferably 45% or more, and preferably 100% or less, more preferably 70% or less, and further preferably 65% ​​or less. Here, the fine aggregate ratio is the volume content of fine aggregate in the total aggregate.

[0037] <Water> The hydraulic composition for spraying of the present invention contains water. Examples of water include tap water, groundwater, lake water, and river water.

[0038] The water / hydraulic powder ratio (W / C) of the sprayable hydraulic composition of the present invention is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, from the viewpoints of suppressing adhesion to the nozzle, reducing dust, and furthermore, of expressing strength to prevent the sprayable hydraulic composition from collapsing, and is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. That is, from the viewpoints of inhibiting adhesion to nozzles, reducing dust, and exhibiting strength, the hydraulic composition for spraying of the present invention contains water in an amount of preferably 30 parts by mass or more, more preferably 35 parts by mass or more, even more preferably 40 parts by mass or more, and preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 65 parts by mass or less, relative to 100 parts by mass of the hydraulic powder. The water / hydraulic powder ratio (W / C) is the ratio of water to hydraulic powder in the hydraulic composition for spraying expressed as a mass percentage (mass%), and is calculated as (water / hydraulic powder) x 100. In addition, when the hydraulic powder includes powders selected from powders having pozzolanic action, powders having latent hydraulic properties, and stone powder (calcium carbonate powder) in addition to powders having properties that harden through hydration reactions such as cement, the amounts of these powders are also included in the amount of hydraulic powder in the present invention. In addition, when the powder having properties that harden through hydration reactions contains a high-strength admixture, the amount of the high-strength admixture is also included in the amount of hydraulic powder. This also applies to other parts by mass that are related to the mass of the hydraulic powder.

[0039] <(C) component> The hydraulic composition for spraying of the present invention may optionally contain (C) an accelerator (hereinafter also referred to as component (C)). The accelerator may be in any form, such as a powder, a liquid, or a combination of both. The accelerator is, for example, one or more accelerators selected from cement mineral-based accelerators and aluminum-based accelerators. From the viewpoints of slag suppression and discharge workability, it is preferable to use a cement mineral-based accelerator and an aluminum-based accelerator in combination with the hydraulic composition for spraying of the present invention.

[0040] The cement mineral-based quick-setting admixture of component (C) may be one or more selected from calcium aluminate, calcium sulfoaluminate, and calcium aluminate. The aluminum-based quick-setting admixture of component (C) may be one or more selected from aluminum salts including aluminum hydroxide, sodium aluminate, potassium aluminate, aluminum sulfate, aluminum chloride, potassium aluminum sulfate, potassium alum, iron alum, and ammonium iron alum. From the viewpoint of strength development, the component (C) is preferably one or more selected from calcium aluminate, calcium sulfoaluminate, calcium aluminate, sodium aluminate, and aluminum sulfate, more preferably one or more selected from calcium aluminate, calcium sulfoaluminate, and aluminum sulfate, even more preferably one or more selected from calcium aluminate and aluminum sulfate, and even more preferably one containing aluminum sulfate. Component (C) may include gypsum, alkali carbonates such as sodium carbonate, potassium carbonate, and sodium hydrogen carbonate, sodium sulfate, and calcium hydroxide.

[0041] Examples of the quick-setting agent for component (C) that can be used include Denka Tomic series, Denka Tomic US-32, Denka Tomic US-50, Denka Tomic TYPE-5, Denka Tomic TYPE-10, Denka Tomic Z, Natomic L, Natomic LSA, Natomic USS, Natomic HSS, and Denka Σ Shot V, all of which are manufactured by Denka Co., Ltd.; Pacific Shot Master series, Pacific Shot Master A, Pacific Shot Master A (for high strength), and Pacific Shot Master H, all of which are manufactured by Pacific Materials Co., Ltd.; Master Lock series, Master Lock SA161, Master Lock SA167, Master Lock SA178, Master Lock SA143, and Master Lock SA446, all of which are manufactured by Pozzolith Solutions Co., Ltd.; and Signit series, Signit P10AF, Signit L53AF, and Signit U, all of which are manufactured by Sika Japan Co., Ltd.

[0042] <Calcium aluminate> Calcium aluminate (hereinafter referred to as CA) is a compound of CaO and Al 2 O 3 It is a general term for compounds that have hydration activity and are mainly composed of CaO and / or Al. 2 O 3Compounds in which a part of the above has been replaced with alkali metal oxides, alkaline earth metal oxides, silicon oxide, titanium oxide, iron oxide, alkali metal halides, alkaline earth metal halides, alkali metal sulfates, and alkaline earth metal sulfates, etc., or CaO and Al 2 O 3 These are substances that consist mainly of these and contain small amounts of these in solid solution, and CAs may be either crystalline or amorphous.

[0043] Examples of crystalline substances of CA include CaO, C, Al 2 O 3 If A is the compound, then C3A, C14A5 with an alkali metal as a solid solution, CA, C12A7, and C11A7·CaF 2 , C4A·Fe 2 O 3 , and C3A3·CaSO 4 In addition, these compounds, for example, Na 2 OK 2 O, Li 2 It may contain O. Amorphous calcium aluminate is preferred because of its good quick setting property.

[0044] The calcium aluminate used in the present embodiment may be contaminated with trace amounts of alkali metals and / or alkaline earth metals from industrial raw materials, and some CAs containing these alkali metals and / or alkaline earth metals may be produced. However, the presence of such small amounts of alkali metals and / or alkaline earth metals is not limiting in any way.

[0045] Calcium Aluminate CaO / Al 2 O 3 The molar ratio is not particularly limited, but in consideration of the very early strength development, the molar ratio is preferably 2.0 to 3.0, more preferably 2.2 to 2.8. If the molar ratio is 2.0 or more, the very early setting properties can be improved, and if it is 3.0 or less, good long-term strength development is easily obtained.

[0046] The Blaine specific surface area of ​​calcium aluminate (hereinafter simply referred to as "Blaine") is 4,000 cm 2 / g or more 8,000cm 2 / g or less, and 2 / g or more 7,000cm 2 / g or less. 2 / g or more 8,000cm 2 / g or less, early strength development is likely to be obtained, and the handleability of the mortar and / or concrete when sprayed can be improved.

[0047] <Alum> Alum is effective for promoting the loss of fluidity immediately after mixing of cement mortar or cement concrete, and for promoting strength development for about one day. There is no particular limitation on the alum, and any alum such as potassium alum, chrome alum, iron alum, ammonium alum, sodium alum, and natural alum can be used or used in combination. In particular, it is preferable to include at least one selected from the group consisting of potassium alum, sodium alum, and ammonium alum as a material for losing the fluidity of cement mortar or cement concrete.

[0048] <Gypsum> As the gypsum, any of anhydrous, hemihydrate, and dihydrate gypsum can be used. Among these, anhydrous gypsum is preferred from the viewpoint of good strength development. From the viewpoint of early strength development, the particle size of gypsum is set at 2,000 cm2 in terms of Blaine specific surface area. 2 / g or more is preferable, and 3,000 cm 2 / g or more 6,000cm 2 The Blaine specific surface area value in this specification can be determined in accordance with JIS R 5201 (physical testing method for cement).

[0049] <Calcium hydroxide> Calcium hydroxide is an effective material for reducing the initial fluidity and ensuring long-term strength. There are no particular limitations on calcium hydroxide, but it includes hydrated lime produced when quicklime is hydrated and carbide slag produced when carbide is hydrated. Commercially available calcium hydroxide can also be used, and any of the above can be used in combination.

[0050] The Blaine specific surface area of ​​calcium hydroxide is 5,000 cm 2 / g or more 15,000cm 2 / g or less, and 2 / g or more 13,000cm 2 / g or less. 2 / g or more 15,000cm 2 / g or less, rapid setting properties and long-term strength development can be ensured, and good early strength development can be easily obtained.

[0051] <Alkaline carbonate> The alkali carbonate refers to an alkali metal carbonate salt, which can significantly improve the setting property and early strength development of the powdery quick-setting admixture. The alkali carbonate is not particularly limited, but examples thereof include lithium carbonate, sodium carbonate, sodium sesquicarbonate, potassium carbonate, sodium bicarbonate, and sodium hydrogen carbonate. Sodium carbonate, potassium carbonate, sodium sesquicarbonate, sodium bicarbonate, and sodium hydrogen carbonate are particularly effective for setting and early strength development, and it is also possible to combine one or more of these. Preferably, at least one selected from the group consisting of sodium carbonate, sodium sesquicarbonate, sodium bicarbonate, and potassium carbonate is used.

[0052] When the spray hydraulic composition of the present invention contains component (C), the spray hydraulic composition of the present invention contains component (C) in an amount of preferably 4% by mass or more, more preferably 5% by mass or more, even more preferably 6% by mass or more, and still more preferably 7% by mass or more, based on the hydraulic powder in the spray hydraulic composition, from the viewpoint of slag suppression, and preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less, from the viewpoint of ejection workability.

[0053] <(D) component> The hydraulic composition for spraying of the present invention may optionally contain a clay mineral (D) (hereinafter referred to as component (D)). The clay mineral of component (D) may be a cation-exchangeable layered silicate. One example of such a clay mineral may be one or more clay minerals selected from smectite and bentonite. Smectite is a group of cation-exchangeable layered silicates belonging to clay minerals, and examples of natural products include montmorillonite, which is well known as the main component of bentonite, as well as beidellite, hectorite, saponite, nontronite, etc., and examples of synthetic products include swelling fluorine-based micas, etc. Among these, the clay mineral contained in the spray hydraulic composition of the present invention is preferably a clay mineral selected from bentonite, saponite, hectorite, and montmorillonite, more preferably a clay mineral selected from bentonite and montmorillonite, and even more preferably bentonite, from the viewpoint of suppressing adhesion to the nozzle. The content of the clay mineral selected from bentonite, saponite, hectorite and montmorillonite in the clay minerals contained in the hydraulic composition for spraying is preferably 60 mass% or more, more preferably 100 mass%, and further preferably the content of bentonite is 100 mass%.

[0054] The clay mineral of component (D) is preferably a clay mineral having a swelling degree of 10 mL / 2 g or more and 50 mL / 2 g or less, from the viewpoint of suppressing adhesion of the spray hydraulic composition to the nozzle.

[0055] The swelling degree of the clay mineral of component (D) is preferably 10 mL / 2g or more, more preferably 20 mL / 2g or more, and preferably 50 mL / 2g or less, more preferably 45 mL / 2g or less, and even more preferably 40 mL / 2g or less, from the viewpoints of suppressing adhesion of the spray hydraulic composition to the nozzle and reducing dust. This degree of swelling is measured according to the swelling test method for bentonite (powdered) in JBAS104:77 of the Japan Bentonite Industry Association. That is, 2.0 g of sample adjusted to 8.0% moisture by mass is added in about 10 separate portions to a 100 mL stoppered measuring cylinder containing 100 mL of distilled water. The next addition is made after the previous addition has settled to the bottom of the measuring cylinder. After leaving it for 24 hours, the apparent volume of the swollen sample mass at the bottom of the measuring cylinder is read from the graduations on the measuring cylinder and expressed as the degree of swelling (mL / 2g).

[0056] When the hydraulic composition for spraying of the present invention contains component (D), the hydraulic composition for spraying of the present invention contains component (D) in an amount of preferably 0.03 mass % or more, more preferably 0.04 mass % or more, even more preferably 0.05 mass % or more, and preferably 7 mass % or less, more preferably 5 mass % or less, even more preferably 3 mass % or less, based on the hydraulic powder in the hydraulic composition for spraying, from the viewpoints of slag suppression and discharge workability.

[0057] The hydraulic composition for spraying of the present invention may optionally contain, as necessary, one or more of the following (excluding those corresponding to components (A) and (B)): high-performance water-reducing agents, high-performance AE water-reducing agents, water-reducing agents including AE water-reducing agents and fluidizing agents, expansive agents, hardening accelerators, hardening retarders, polymers for cement, foaming agents, waterproofing agents, rust inhibitors, shrinkage reducing agents, pigments, fibers, water repellents, efflorescence inhibitors, thickeners, etc.

[0058] Target surfaces for the sprayable hydraulic composition of the present invention include roads, railways, tunnels such as water conduits, slopes formed by natural ground excavation and filling, underground spaces, and concrete structures to be repaired by a spraying method.

[0059] <Dispersant for spraying hydraulic compositions> The present invention provides a dispersant for a hydraulic composition to be sprayed, comprising component (A) and component (B). In the dispersant for the spray hydraulic composition of the present invention, preferred embodiments of the components (A) and (B) are the same as the preferred embodiments of each component described above in the spray hydraulic composition of the present invention.

[0060] The dispersant for hydraulic composition for spraying of the present invention contains the component (A) in an amount of preferably 15% by mass or more, more preferably 25% by mass or more, and even more preferably 35% by mass or more from the viewpoint of discharge workability, and in an amount of preferably 75% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less from the viewpoint of slag suppression.

[0061] The dispersant for hydraulic composition for spraying of the present invention contains the component (B) in an amount of preferably 15% by mass or more, more preferably 25% by mass or more, and even more preferably 35% by mass or more from the viewpoint of slag suppression, and in an amount of preferably 75% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less from the viewpoint of ejection workability.

[0062] In the dispersant for hydraulic composition for spraying of the present invention, the mass ratio (A) / (B) of the content of the component (A) to the content of the component (B) is preferably 0.2 or more, more preferably 0.4 or more, and even more preferably 0.45 or more, from the viewpoint of discharge workability, and is preferably 3 or less, more preferably 2 or less, and even more preferably 1 or less, from the viewpoint of slag suppression.

[0063] In the dispersant for a hydraulic composition for spraying of the present invention, the molar percentage A of the structural unit (1) relative to all structural units in the component (A) is 1 and the molar percentage B of the structural unit (1) relative to all structural units in the component (B) 1 Difference from (A 1 -B 1 ) is preferably 5 mol % or more, more preferably 12 mol % or more, and even more preferably 20 mol % or more from the viewpoints of slag suppression and extrusion workability, and is preferably 64 mol % or less, more preferably 50 mol % or less, and even more preferably 40 mol % or less from the viewpoints of slag suppression and extrusion workability.

[0064] The dispersant for hydraulic composition for spraying of the present invention can be used for preparing the above hydraulic composition for spraying of the present invention. The dispersant for hydraulic composition for spraying of the present invention is used so that the ratio (mass%) of the (A) component and the (B) component to the hydraulic powder in the above hydraulic composition for spraying of the present invention is the content of the (A) component and the (B) component described in the above hydraulic composition for spraying of the present invention.

[0065] <Method of manufacturing hydraulic powder for spraying> The present invention provides a method for producing a hydraulic composition for spraying, which comprises mixing a hydraulic powder, component (A), component (B), and water. The method for producing the sprayable hydraulic composition of the present invention may be a method for producing the sprayable hydraulic composition by mixing hydraulic powder, the dispersant for the sprayable hydraulic composition of the present invention, and water. In the method for producing the hydraulic composition for spraying of the present invention, the preferred aspects of the hydraulic powder, component (A), component (B) and water are the same as the preferred aspects of each component described above in the hydraulic composition for spraying of the present invention. In producing the hydraulic composition for spraying of the present invention, the optional components described above in the hydraulic composition for spraying of the present invention can be mixed. The preferred amounts of these components to be mixed can be understood by replacing the preferred contents of each component in the above-mentioned hydraulic composition for spraying of the present invention with the mixed amounts. A specific example of a method for producing a hydraulic composition for spraying will be described in detail in the spraying method of the present invention.

[0066] <Method of producing dispersant for hydraulic composition to be sprayed> The present invention provides a method for producing a dispersant for a hydraulic composition to be sprayed, which comprises mixing component (A) and component (B). In the method for producing the dispersant for hydraulic composition to be sprayed of the present invention, the preferred aspects of the components (A) and (B) are the same as the preferred aspects of each component described above for the dispersant for hydraulic composition to be sprayed of the present invention. In producing the dispersant for hydraulic composition to be sprayed of the present invention, any optional components described above for the dispersant for hydraulic composition to be sprayed can be mixed. The preferred amounts of these components to be mixed can be understood by replacing the preferred contents of each component in the dispersant for hydraulic compositions to be sprayed of the present invention with the mixed amounts.

[0067] <Spraying method> The present invention provides a spraying method in which the sprayable hydraulic composition of the present invention is sprayed onto a target surface. In the spraying method of the present invention, a hydraulic composition for spraying obtained by mixing hydraulic powder, component (A), component (B) and water may be mixed with a quick-setting agent (C), and the hydraulic composition for spraying mixed with the quick-setting agent (C) may be sprayed onto an object. In the spraying method of the present invention, preferred embodiments of the hydraulic powder, component (A), component (B), water and other optional components are the same as those described in the sprayable hydraulic composition of the present invention. The spraying method of the present invention can be applied to the embodiments described in the spray hydraulic composition of the present invention. The preferred contents of each component in the spray hydraulic composition of the present invention can be replaced with the preferred mixing amounts of each component and applied to the spraying method of the present invention.

[0068] The spraying method of the present invention is preferably a method in which the hydraulic composition for spraying and the quick-setting agent (C) are separately pumped and mixed together, or a method in which water is added to the powder quick-setting agent before the quick-setting agent is mixed together and mixed with the hydraulic composition for spraying, and the quick-setting agent slurry is sprayed. Either a dry spraying method or a wet spraying method can be used. The dry spraying method includes a method in which hydraulic powder and aggregate are mixed, air pumped, water and the quick-setting agent (C) are mixed together, and sprayed in a wet state. The wet spraying method includes a method in which hydraulic powder, aggregate, and water are mixed and kneaded, air pumped, and the quick-setting agent (C) is mixed together and mixed, and sprayed. In any spraying method, the components (A) and (B) can be mixed with the hydraulic powder or mixed with water before use.

[0069] The spraying method of the present invention will be described in detail with reference to a specific example. However, the spraying method of the present invention is not limited to this specific example. For example, the spray hydraulic composition produced in the spraying method of the present invention may be produced by the method described in the above-mentioned method for producing the spray hydraulic composition of the present invention. In the spraying method of the present invention, first, a hydraulic powder, component (A), component (B), and water are mixed together to produce a hydraulic composition for spraying. The water / hydraulic powder ratio (W / C) of this hydraulic composition for spraying [the mass percentage (mass %) of water and hydraulic powder in the hydraulic composition for spraying] is preferably 30 mass % or more, more preferably 35 mass % or more, even more preferably 40 mass % or more, from the viewpoints of discharge workability and slag suppression, and is preferably 80 mass % or less, more preferably 70 mass % or less, even more preferably 65 mass % or less.

[0070] In the present invention, the hydraulic powder, component (A), component (B), water, and other optional components can be mixed by a known method. For example, the hydraulic powder, component (A), component (B), and water can be mixed simultaneously. A mixing mixer such as a pan-type forced mixer, a two-shaft forced mixer, or a tilting mixer can be used to mix these components.

[0071] In the present invention, a hydraulic composition for spraying can be produced by optionally adding an accelerating agent (C) and / or a clay mineral (D) to a hydraulic composition obtained by mixing hydraulic powder, component (A), component (B) and water. The mixing of the hydraulic composition with the accelerating agent (C) and / or the clay mineral (D) can be carried out, for example, by a general spraying method in which the hydraulic composition and the accelerating agent (C) and / or the clay mineral (D) are mixed together by pneumatic pressure delivery.

[0072] In the spraying method of the present invention, the thus prepared hydraulic composition for spraying is sprayed onto an object. The spraying method of the present invention can be carried out by using conventional spraying equipment. The spraying equipment may be any equipment that can perform spraying without any problems, and for example, Arriba Corporation's product name "Arriba 280" or the like can be used for pumping the hydraulic composition, and Chiyoda Manufacturing Co., Ltd.'s product name "Natocrete" or the like can be used for pumping the (C) quick-setting agent and / or (D) clay mineral, and the two can be mixed to prepare a hydraulic composition for spraying, which can then be sprayed. EXAMPLES

[0073] In the examples and comparative examples, hydraulic compositions for spraying were produced according to the formulations shown in Table 1. Copolymer A and copolymer B shown in Table 2, and (C) an accelerator and (D) a clay mineral shown in Table 3 were used to produce the hydraulic compositions for spraying.

[0074] [Table 1]

[0075] The ingredients in Table 1 are as follows: W: Tap water C: Hydraulic powder, ordinary Portland cement (two-type mixture: Taiheiyo Cement / Sumitomo Osaka Cement = 1 / 1, mass ratio) Density 3.16g / cm 3 S: Fine aggregate (S): Joyo mountain sand density 2.55g / cm 3

[0076] <Component (A) and Component (B)> Details of copolymer A as component (A) and copolymer B as component (B) are shown in Table 2. The weight average molecular weights of components (A) and (B) were measured according to the above-mentioned method for measuring weight average molecular weight. In Table 2, the structural unit (1) is methacrylic acid [in the formula (1), R 1a is a methyl group, M 1 is a sodium salt compound. The structural unit (2) is ω-methoxypolyethylene glycol monomethacrylate [in the formula (2), R 2a is a methyl group, R 3a is a methyl group, X1 is a carbonyl group, and n1 is a value shown in the table. In addition, the molar percentage A of the structural unit (1) relative to all structural units in copolymer A 1 and the molar percentage B of structural unit (1) relative to all structural units in copolymer B 1 Difference from (A 1 -B 1 ) is 26 mol %.

[0077] [Table 2]

[0078] In addition, the (C) accelerator and (D) clay minerals in Table 3 are as follows. <Component (C): Accelerator> Calcium aluminate-based accelerator: A powder accelerator whose main component is calcium aluminate Aluminum sulfate: Fujifilm Wako Pure Chemical Industries, Ltd. <(D) Ingredient: Clay minerals> Kunigel GS: Bentonite, manufactured by Kunimine Kogyo Co., Ltd., swelling ratio 33mL / 2g

[0079] (1) Preparation of hydraulic composition for spray application A mortar mixer as specified in "JIS R 5201 Physical Testing Methods for Cement" was used to prepare the sprayable hydraulic composition. At 22°C, 200g of water in which (A) Copolymer A and (B) Copolymer B shown in Table 2 were dissolved, 400g of hydraulic powder, and 1054g of fine aggregate were added to the mixing bowl of a mortar mixer, and the mixture was stirred at low speed for 2 minutes. (C) Accelerator shown in Table 3 and (D) Clay Mineral as required were added to the mixture in the ratio shown in Table 3, and the mixture was stirred by hand for 5 seconds to obtain a hydraulic composition for spraying. The blending amounts of (A) Copolymer A and (B) Copolymer B in Table 3 are all blending amounts of active ingredients. The water used for mixing was 0°C, and the other materials were 20°C, and a hydraulic composition for spraying at 15 to 17°C was obtained.

[0080] (2) Evaluation (2-1) Evaluation of norovirus incidence rate 1500 g of the spray hydraulic composition obtained in (1) was sprayed onto a wooden board 18 cm away from the nozzle of a powder / granule conveying device (Breath Rider, model number K-40, manufactured by Breath Co., Ltd.) using the powder / granule conveying device. The pressure of the compressor connected to the powder / granule conveying device was 0.6 MPa, and the diameter of the nozzle was 3.5 cm. For those that did not produce slag, the mortar paste components and a small amount of fine aggregate were observed to flow down directly below the sprayed area, while for those that did produce slag, the mortar paste components and a small amount of fine aggregate were observed to flow down directly below the sprayed area. The mass of the spray hydraulic composition that fell directly below the wooden board and the mass of the spray hydraulic composition that adhered 8 cm from the bottom of the wooden board were measured, and the slag generation rate (%) was calculated using the following formula (1). It can be said that the lower the slag generation rate, the more slag generation is suppressed when the spray hydraulic composition is sprayed on the target surface. Slag generation rate (%) = 100 × (mass of the spray hydraulic composition that fell directly below the wooden board + mass of the spray hydraulic composition that is attached 8 cm below the wooden board) / (total mass of the spray hydraulic composition) (1)

[0081] (2-2) Nozzle survival rate 1500 g of the spray hydraulic composition obtained in (1) was sprayed onto a wooden board 18 cm away from the nozzle of a powder / granule conveying device (Breath Rider, model number K-40, manufactured by Breath Co., Ltd.) using the powder / granule conveying device. The pressure of the compressor connected to the powder / granule conveying device was 0.6 MPa, and the diameter of the nozzle was 3.5 cm. The sprayed hydraulic composition was all collected and the mass was measured, and the nozzle remaining rate (%) was calculated using the following formula (2). In the following formula (2), the amount of the spray hydraulic composition charged into the spraying device was 1500 g. It can be said that the lower the nozzle remaining rate, the more the ejection failure is suppressed when the spray hydraulic composition is sprayed. Nozzle remaining rate (%)=100×(mass of hydraulic composition for spraying charged into spraying device−mass of hydraulic composition for spraying sprayed) / (mass of hydraulic composition for spraying charged into spraying device) (2)

[0082]

Table 3

Claims

1. A hydraulic composition for spraying comprising: (A) a copolymer A (hereinafter referred to as component (A)) containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), in which the ratio of the structural unit (1) to the structural unit (2) in all the structural units [structural unit (1) / structural unit (2)] is 50 / 50 or more and 95 / 5 or less in molar ratio; (B) a copolymer B (hereinafter referred to as component (B)) containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), in which the ratio of the structural unit (1) to the structural unit (2) in all the structural units [structural unit (1) / structural unit (2)] is 31 / 69 or more and 49 / 51 or less in molar ratio; and water. 【Chemistry 1】 [In the formula, R １ａ represents a hydrogen atom or a methyl group, M １ represents a hydrogen atom or a counter ion that forms a salt. 【Chemistry 2】 [In the formula, R ２ａ represents a hydrogen atom or a methyl group, R ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; X １ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, AO represents an alkyleneoxy group having 2 or 3 carbon atoms, and n1 represents the average number of moles of AO added and is a number of 5 to 170.

2. 2. The hydraulic composition for spraying according to claim 1, further comprising (C) an accelerator (hereinafter referred to as component (C)).

3. 3. The hydraulic composition for spray application according to claim 2, wherein component (C) is at least one selected from calcium aluminate and aluminum sulfate.

4. The hydraulic composition for spraying according to any one of claims 1 to 3, further comprising (D) a clay mineral.

5. Molar percentage A of structural unit (1) relative to all structural units in component (A) １ and the molar percentage B of the structural unit (1) relative to all structural units in the component (B) １ Difference from (A １ -B １ 5. The hydraulic composition for spraying according to claim 1, wherein the content of 5 mol % or more and 64 mol % or less of the total content of the sintered body is ...

6. A dispersant for a hydraulic composition to be sprayed, comprising: (A) a copolymer A which contains a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), and the ratio of the structural unit (1) to the structural unit (2) in all the structural units [structural unit (1) / structural unit (2)] is 50 / 50 or more and 95 / 5 or less in molar ratio; and (B) a copolymer B which contains a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), and the ratio of the structural unit (1) to the structural unit (2) in all the structural units [structural unit (1) / structural unit (2)] is 31 / 69 or more and 49 / 51 or less in molar ratio. 【Chemistry 3】 [In the formula, R １ａ represents a hydrogen atom or a methyl group, M １ represents a hydrogen atom or a counter ion that forms a salt. 【Chemistry 4】 [In the formula, R ２ａ represents a hydrogen atom or a methyl group, R ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; X １ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, AO represents an alkyleneoxy group having 2 or 3 carbon atoms, and n1 represents the average number of moles of AO added and is a number of 5 to 170.

7. A method for producing a hydraulic composition for spraying, comprising mixing a hydraulic powder, (A) a copolymer A containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), in which the ratio of the structural unit (1) to the structural unit (2) in all the structural units is 50 / 50 or more and 95 / 5 or less in molar ratio (structural unit (1) / structural unit (2)), and (B) a copolymer B containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), in which the ratio of the structural unit (1) to the structural unit (2) in all the structural units is 31 / 69 or more and 49 / 51 or less in molar ratio, and water. 【Chemistry 5】 [In the formula, R １ａ represents a hydrogen atom or a methyl group, M １ represents a hydrogen atom or a counter ion that forms a salt. 【Chemistry 6】 [In the formula, R ２ａ represents a hydrogen atom or a methyl group, R ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; X １ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, AO represents an alkyleneoxy group having 2 or 3 carbon atoms, and n1 represents the average number of moles of AO added and is a number of 5 to 170.

8. A spraying method, comprising spraying the hydraulic composition for spraying according to any one of claims 1 to 5 onto a target surface.

Images