JP5305746B2 - Hydraulic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic composition which contains a coarse aggregate and has a large unit hydraulic powder quantity and which simultaneously satisfies at a high level a reduction in kneading time, an improvement of initial dispersibility, a reduction of viscosity, and an improvement of curing physical properties. <P>SOLUTION: The hydraulic composition contains a copolymer, which contains as its constituting monomers acrylic acid and a specific poly alkylene glycol acrylate-based monomer and wherein the ratio of the acrylic acid in the all constituting monomers is at least 50 mol%, a hydraulic powder, a coarse aggregate, and water, wherein the weight ratio of the water/the hydraulic powder is not more than 0.33, and the content of the coarse aggregate is 300-1,100 kg/m<SP>3</SP>. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a hydraulic composition having a water / hydraulic powder weight ratio of 0.33 or less and containing coarse aggregate.

  High-strength concrete is prepared by kneading with a composition having a small weight ratio of water / hydraulic powder compared to general-strength concrete. Such high-strength concrete generally has a long construction time, a large amount of addition for obtaining a predetermined fluidity, a high concrete viscosity, and a long time for hardening the concrete. There are a number of issues such as

By the way, conventionally, as an admixture for a hydraulic composition such as concrete, a copolymer of an unsaturated carboxylic acid monomer and a polyalkylene glycol ester monomer or a polyalkylene glycol ether monomer is used. It is known to use. In Patent Document 1, (meth) acrylic acid-based monomer, polyalkylene glycol (meth) acrylic acid ester-based monomer, polyalkylene glycol are used to improve workability and workability of high-strength concrete. An ultra-high-strength hydraulic cement composition containing a copolymer obtained by copolymerizing specific four or five types of monomers including an ether monomer so as to have a predetermined copolymerization ratio is disclosed. . Patent Document 2 discloses a polyalkylene glycol acrylate monomer and a (meth) acrylic compound having a C 3-7 oxyalkylene group introduced, with the problem of fluidity of the cement composition and kneadability of the mortar. A cement additive using an acid monomer is disclosed. Further, Patent Document 3 discloses a cement dispersant obtained by esterifying polyoxyalkylene glycols having different polyalkylene glycol lengths to a part of polyacrylic acid, with the object of having excellent fluidity and low curing delay. It is disclosed.
JP-A-6-191918 JP 2000-191357 A JP 2002-53359 A

  However, the current admixture for hydraulic composition has the same water / hydraulic powder weight as compared to kneading mortar or cement paste that does not contain coarse aggregate with a composition with a small water / hydraulic powder weight ratio. Even when the ratio is high, when concrete containing coarse aggregate is kneaded, the speed at which the surface of the coarse aggregate is coated with mortar or cement paste is slow, and it tends to take time to uniformly knead. Further improvements are desired for properties such as shortening the mixing time, reducing the amount added to ensure fluidity, optimizing the viscosity, and shortening the construction period.

  An object of the present invention is to provide a hydraulic composition containing a coarse aggregate and having a large amount of unit hydraulic powder that can simultaneously satisfy a high level of shortening the kneading time, improving initial dispersibility, reducing viscosity, and improving cured properties. Is to provide. Patent Document 1 does not specifically disclose a polymer having a structural unit derived from acrylic acid and a structural unit derived from an ester of acrylic acid and alkylene glycol. Patent Documents 2 and 3 do not discuss hydraulic compositions containing coarse aggregates.

The present invention includes a copolymer comprising a structural unit composed of acrylic acid and a structural unit represented by the following general formula (A), wherein the proportion of the structural unit composed of acrylic acid in all the structural units is 50 mol% or more. And a hydraulic powder, coarse aggregate, and water, the water / hydraulic powder weight ratio is 0.33 or less, and the content of the coarse aggregate is 300 to 1100 kg / m ³ . It relates to a hydraulic composition.

[In the formula, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average added mole number of AO, represents a number of 2 to 300, and R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Q represents an integer of 0 to 2, and r represents an integer of 0 to 1. ]

In addition, the present invention includes a structural unit composed of acrylic acid and the structural unit represented by the general formula (A), and the proportion of the structural unit composed of acrylic acid in all the structural units is 50 mol% or more. A dispersant for a hydraulic composition containing a polymer, comprising a hydraulic powder, a coarse aggregate, and water, wherein the water / hydraulic powder weight ratio is 0.33 or less, The present invention relates to a dispersant for a hydraulic composition having a coarse aggregate content of 300 to 1100 kg / m ³ .

The present invention also includes water, hydraulic powder, and coarse aggregate, the water / hydraulic powder weight ratio is 0.33 or less, and the content of the coarse aggregate is 300 to 1100 kg / m ^3. A hydraulic composition production method for producing a hydraulic composition, comprising:
A copolymer comprising a structural unit composed of acrylic acid and the structural unit represented by the general formula (A), wherein the proportion of the structural unit composed of acrylic acid in all the structural units is 50 mol% or more [hereinafter, Polymer (I)], kneading water and hydraulic powder to prepare mortar,
Kneading the mortar and coarse aggregate;
It relates to a method for producing a hydraulic composition having

  According to the present invention, it is possible to prepare a hydraulic composition that is easy to handle because the viscosity of the hydraulic composition is small and the copolymer (I) is added in a low amount without causing deterioration in strength characteristics. According to the present invention, a hydraulic composition having a high water-reducing property, quick kneading, improving the workability by lowering the viscosity of the hydraulic composition, and having excellent early strength, such as ultra-high strength concrete. Can be manufactured.

  The copolymer (I) includes a structural unit composed of acrylic acid (hereinafter referred to as an acrylic acid unit) and a structural unit represented by the general formula (A) (hereinafter referred to as a structural unit (A)). That is, as an example of the copolymer (I), a monomer that is an ester of acrylic acid, a polyalkylene glycol from which the structural unit (A) is derived, and acrylic acid (hereinafter referred to as the monomer (A)). As a constituent monomer. Acrylic acid may form a salt. Conventionally, it is known to use a copolymer of an unsaturated carboxylic acid monomer and a polyalkylene glycol ester monomer as a hydraulic composition admixture. However, when acrylic acid is used as a monomer to be copolymerized with the polyalkylene glycol ester monomer, the polyalkylene glycol ester monomer has acrylic acid properties that are almost equivalent to those of methacrylic acid. Such an ester is more likely to be hydrolyzed than an ester of methacrylic acid, and thus was thought to have low fluidity retention and stability as a product. For these reasons, studies have been made focusing on methacrylic acid, and many studies focusing on copolymers having acrylic acid as the main chain have not been made. In the hydraulic composition containing a coarse aggregate with a small water / hydraulic powder weight ratio of 0.33 or less, the present inventors have a copolymer (I) having acrylic acid as the main chain rather than methacrylic acid. It has been found that a hydraulic composition (for example, concrete) having a low addition amount, a fast kneading property, a low viscosity and easy to handle can be prepared, and that strength characteristics are not lowered. This is because, in a region where the water / hydraulic powder weight ratio is small, the amount of the hydraulic powder per unit volume of the hydraulic composition is large, so that the amount of copolymer (I) added is relatively large and the water content is increased. Since the influence of decomposition becomes small, it is presumed that in a system in which fine particles such as silica fume are used in combination, the basicity of the hydraulic composition is lowered and hydrolysis is difficult to occur. And since the copolymer (I) contains many acrylic acid units as the main chain, the flexibility of the main chain of the copolymer is increased, so even in a state where the powder particle interval is narrow like a thick slurry, it can move. The present copolymer having a high degree (molecular mobility) can be easily adsorbed on the powder surface, and when adsorbed on the powder, it can take a bulky adsorption form instead of the molecular weight. As a result, the surface of the hydraulic powder is quickly wetted (hydrophilized) by this copolymer, so that the viscosity of the concentrated slurry is reduced and the slurry can easily coat the coarse aggregate even at a low water powder ratio. It is presumed that the mixing property of the material including the coarse aggregate is excellent.

  The acrylic acid unit has a structure represented by the following general formula (A ′). In general formula (A ′), M is a hydrogen atom or a counter ion forming a salt. Therefore, the copolymer (I) of the present invention includes a structural unit represented by the following general formula (A ′) and a structural unit represented by the above general formula (A), and the general formula in all structural units. It is a copolymer in which the proportion of structural units represented by (A ′) is 50 mol% or more.

  An example of the monomer (A) is a monoester of polyalkylene glycol and acrylic acid, and has a structure represented by the general formula (A). In general formula (A), AO represents an oxyalkylene group having 2 to 4 carbon atoms, preferably an oxyalkylene group (oxyethylene group) having 2 or 3 carbon atoms, more preferably 2 carbon atoms. n is the average added mole number of AO and represents a number of 2 to 300, preferably 5 to 150, more preferably 8 to 80, and still more preferably 10 to 40. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group, more preferably a methyl group. q represents an integer of 0 to 2, and is preferably 0. r represents an integer of 0 to 1, and is preferably 1.

  Copolymer (I) has an acrylic acid unit and a structural unit (A) as structural units, and the proportion of acrylic acid units in all the structural units is 50 mol% or more. The lower limit of the proportion of acrylic acid units in all the structural units is preferably 55 mol%, more preferably 60 mol%. The upper limit of the acrylic acid unit is preferably 95 mol%, more preferably 93 mol%, and still more preferably 90 mol%. Accordingly, the proportion of acrylic acid units in all the structural units is preferably 50 to 95 mol%, more preferably 55 to 93 mol%, still more preferably 60 to 90 mol%, and still more preferably 60 to 85 mol%. is there.

  Further, on a weight basis, the proportion of acrylic acid units in all the structural units is preferably 1.0% by weight or more, more preferably 1.5% by weight or more, still more preferably 2.0% by weight or more. More preferably, it is 2.5% by weight or more, preferably 80% by weight or less, more preferably 70% by weight or less, still more preferably 60% by weight or less, and still more preferably 40% by weight or less. Accordingly, the proportion of acrylic acid units in all the structural units is preferably 1.0 to 80% by weight, more preferably 1.5 to 70% by weight, still more preferably 2.0 to 60% by weight, and still more preferably. 2.5 to 40% by weight. In particular, when n of the structural unit (A) is a number of 8 to 80, it is preferable from the viewpoint of salt resistance and initial dispersibility to use the acrylic acid unit at such weight%.

  Since the ratio of acrylic acid units in all structural units is 50 mol% or more, the ratio of structural units (A) is 50 mol% or less. The lower limit of the proportion of the structural unit (A) in all the structural units is preferably 5 mol%, more preferably 7 mol%, still more preferably 10 mol%. The upper limit of the proportion of the structural unit (A) is preferably 45 mol%, more preferably 40 mol%. Therefore, the ratio of the proportion of the structural unit (A) in all the structural units is preferably 5 to 50 mol%, more preferably 7 to 45 mol%, and still more preferably 10 to 40 mol%.

  Copolymer (I) can also contain structural units derived from monomers other than acrylic acid and monomer (A) (other monomers), but in all the structural units, acrylic acid units and The total proportion of the structural units (A) is preferably 92 mol% or more, more preferably 93 mol% or more, further 94 mol% or more, and even more preferably 95 mol% or more. Examples of monomers derived from other structural units include unsaturated monocarboxylic acids such as methacrylic acid, and metal salts, ammonium salts and organic amine salts thereof; alkoxy obtained by adding 1 to 500 mol of alkylene oxide to alcohol. Esters of (poly) alkylene glycol and unsaturated monocarboxylic acids such as methacrylic acid; 1-500 mol adducts of alkylene oxide to unsaturated monocarboxylic acids such as methacrylic acid; (meth) allyl alcohol, glycidyl ( Allyls such as (meth) allyl ether; vinyl ethers or allyl ethers such as methoxypolyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether; maleic acid, maleic anhydride Unsaturated dicarboxylic acids such as acid, fumaric acid, itaconic acid and the like, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; half esters and diesters of the unsaturated dicarboxylic acids and alcohols; Half ester or diester of an alkoxy (poly) alkylene glycol to which 1 to 500 mol of alkylene oxide is added and the unsaturated dicarboxylic acid; the unsaturated dicarboxylic acid and glycol or a polyalkylene glycol having an addition mole number of 2 to 500 Half esters, diesters; and the like.

  In addition, the hydraulic composition of the present invention can be used alone as the copolymer (I), but from the viewpoint of retainability, other than the copolymer (I) known as a component of the admixture for hydraulic composition. (Co) polymer [hereinafter referred to as (co) polymer (II)], but in the total of copolymer (I) and (co) polymer (II), copolymer ( The proportion of I) is preferably 50 to 99% by weight, more preferably 70 to 98% by weight, and still more preferably 80 to 97% by weight in terms of effective component. As the (co) polymer (II), a polycarboxylic acid-based (co) polymer known as a dispersant for hydraulic powder or a (co) polymer having a phosphate group (salt) is used alone, Alternatively, two or more of each can be used. Examples of the (co) polymer (II) include a copolymer of methacrylic acid and the monomer (A), a copolymer of acrylic acid and polyalkylene glycol methacrylate, a copolymer of methacrylic acid and polyalkylene glycol methacrylate, and the like. Can be mentioned. The (co) polymer means a polymer and / or a copolymer.

  Moreover, the polymer which has a phosphoric acid group or its salt among (co) polymer (II) includes the polymer which has a polyoxyalkylene group and a phosphoric acid group. For example, the polymer of Unexamined-Japanese-Patent No. 2006-052381 is mentioned. Specifically, a polyalkylene glycol monoester monomer introduced with an average of 3 to 200 moles of an oxyalkylene group having 2 to 3 carbon atoms, di-[(2-hydroxyethyl) methacrylic acid] ester phosphate, And a copolymer with mono (2-hydroxyethyl) methacrylate ester.

  When the water / hydraulic powder weight ratio is preferably 0.20 or less, more preferably 0.15 or less, the hydraulic composition is used in the hydraulic composition from the viewpoint of good kneadability ( It is preferable to use only the copolymer (I) as a co) polymer, that is, a polymer admixture, particularly a dispersant, and satisfy the balance of kneadability, initial fluidity, low viscosity, and fast curing. From the viewpoint, the copolymer (I) is more preferably one type.

The weight average molecular weight of the copolymer (I) is preferably from 1,000 to 200,000, more preferably from 10,000 to 100,000, and still more preferably from 20,000 to 60,000, from the viewpoint of initial dispersibility. This weight average molecular weight is measured by a gel permeation chromatography (GPC) method under the following conditions.
[GPC conditions]
Column: G4000PWXL + G2500PWXL (Tosoh)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 1.0mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.5mg / mL
Reference material: Polyethylene glycol equivalent

  The copolymer (I) can be produced by a known polymerization method such as solution polymerization or bulk polymerization using a monomer component and an initiator. It can also be synthesized by a polymer reaction method. Incidentally, the polymer reaction method is a method of obtaining a graft copolymer by polymerizing an unsaturated carboxylic acid and then performing an esterification reaction with a polyalkylene glycol compound.

  Known polymerization initiators can be used, such as persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; hydrogen peroxide; azobis-2-methylpropionamidine hydrochloride, azoisobutyronitrile, and the like. Azo compounds; peroxides such as benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide and the like can be preferably used.

  The hydraulic composition of the present invention is a hydraulic composition such as concrete containing a copolymer, hydraulic powder, coarse aggregate, and water.

The hydraulic composition of the present invention preferably has a unit hydraulic powder amount of 500 kg / m ³ or more. The unit hydraulic powder amount is more preferably 800 kg / m ³ or more, more preferably 1000 kg / m ³ or more, and still more preferably 1250 kg / m ³ or more. The unit hydraulic powder weight is preferably 2200 kg / m ³ or less, more preferably 2000 kg / m ³ or less, more preferably 1800 kg / m ³ or less, 1500 kg / m ³ or less is more preferable and more. Thus, the unit hydraulic powder quantity is preferably 500~2200kg / m ^3, more preferably 800~2000kg / m ^3, more preferably 1000~1800kg / m ^3, even more preferably from 1250~1500kg / m ^3.

  Examples of the hydraulic powder used in the present invention include Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate and their respective low alkali types), belite cement (for example, low heat Portland cement (manufactured by Taiheiyo Cement). ) High flow cement (manufactured by Taiheiyo Cement)), various mixed cements (blast furnace cement, silica fume cement, fly ash cement), and eco-cement (manufactured by Taiheiyo Cement). Among these, from the viewpoint of suppressing hydrolysis of the copolymer (I), medium heat cement, belite cement and silica fume cement are preferable.

Fillers such as stone powder (calcium carbonate powder), blast furnace slag (brain value 3000 to 10000 cm ² / g), fly ash and the like can be used in combination with the hydraulic powder.

The hydraulic composition of the present invention can contain fine particles such as silica fume. Silica fume includes zirconia fume, alumina fume, and titanium fume. A product previously mixed with cement, such as the silica fume cement, can also be used. Particles has a specific surface area (BET method) 5 m ² / g or more, further 10 to 30 m ² / g, is preferably even more 12~28m ² / g. In the present invention, it is preferable to use cement mixed with 8 to 20% by weight of silica fume as the hydraulic powder. Silica fume is ferrosilicon, fused zirconia, and an average particle size of about 0.1 μm, mainly composed of amorphous silicon dioxide collected from the exhaust gas generated when an electric arc furnace is used to produce metallic silicon. Very fine spherical fine particles. The component is 80% by weight or more of amorphous SiO ₂ , and Al ₂ O ₃ , Fe ₂ O ₃ , CaO, TiO _2, etc. are included as minor components.

  By containing fine particles such as silica fume, the basicity of the hydraulic composition is lowered and hydrolysis of the copolymer (I) is suppressed. Furthermore, it is thought that there exists an effect which suppresses aggregation of microparticles | fine-particles by interaction with copolymer (I). The filling between the material particles by the fine particles, the ball bearing effect between the material particles, and the pozzolanic reaction improve the kneadability and the strength of the cured body.

  The hydraulic composition of the present invention contains coarse aggregate. The coarse aggregate is preferably mountain gravel, land gravel, river gravel, or crushed stone. Among these, from the viewpoint of improving the strength, it is more preferable to use hard sandstone having a high strength of the coarse aggregate. Fine aggregates can also be contained as aggregates, and fine aggregates are preferably mountain sand, land sand, river sand, and crushed sand, and light aggregates may be used depending on the application. The term “aggregate” is based on “Concrete Overview” (published on June 10, 1998, published by Technical Shoin). Coarse aggregate means an aggregate (a civil engineering concrete standard specification) that remains 85% or more by weight on a sieve having an opening of 5 mm. The fine aggregate refers to an aggregate that passes through a sieve having a mesh size of 10 mm and passes through a sieve having a mesh size of 5 mm by 85% or more by weight (Construction Standard Specification for Japan Society of Civil Engineers).

In the hydraulic composition of the present invention, the content of the coarse aggregate is 300 to 1100 kg / m ³ and 350 to 1100 kg / m ³ from the viewpoints of shrinkage when the hydraulic composition is cured and strength after curing. m ³ is preferable, 600 to 1050 kg / m ³ is more preferable, 700 to 1000 kg / m ³ is still more preferable, and 800 to 950 kg / m ³ is particularly preferable. Also preferably 115~500L / m ³ (volume per hydraulic composition 1 m ³ (l)) is on a volume basis, more preferably 130~500L / m ^3, more preferably 200~450L / m ^3, 250~ 450 is more preferable.

  The volume ratio of fine aggregate to coarse aggregate (fine aggregate / (fine aggregate + coarse aggregate) volume ratio, sometimes referred to as s / a) is preferably 0.08 to 0.60, 0 .10 to 0.55 is more preferable, 0.12 to 0.40 is still more preferable, 0.12 to 0.30 is still more preferable, 0.12 to 0.30 is still more preferable, and 0.12 to 0 .16 is even more preferred.

The content of aggregate in the hydraulic composition of the present invention (the total amount of fine aggregate and coarse aggregate) is preferably 400~2000kg / m ^3, more preferably 600~1800kg / m ^3, 700~1400kg / m ³ is more preferable, and 800 to 1200 kg / m ³ is still more preferable. Examples of the hydraulic composition of the present invention include ultra high strength concrete containing coarse aggregate.

The hydraulic composition of the present invention, age of 1 day strength 25 N / mm ² or more, further 30 N / mm ² or more and even more 40N / mm ² or more. The material age 1 day strength is measured based on JIS A1108. In order to achieve such a material one-day strength, the water / hydraulic powder weight ratio is reduced, the cement type is selected, the acrylic acid unit of the copolymer (I) is adjusted, and the early strengthening agent In combination.

The hydraulic composition of the present invention preferably contains fibers such as synthetic fibers from the viewpoint of preventing explosion when the cured body is exposed to a flame or the like and heated. Examples of the fiber include synthetic fibers having a length of 6 to 50 mm in which the volume decreases or decomposes and volatilizes by being softened or melted at 100 ° C. and a diameter of 5 to 500 μm. When the cured body is heated, the fiber is reduced in volume or decomposed and volatilized, so that distortion due to expansion of the cured body due to heating can be alleviated and explosion of the cured body can be prevented. Examples of synthetic fibers include polyacetal fibers, nylon fibers, aramid fibers, polyester fibers, acrylic fibers, vinylon fibers, synthetic fibers such as polypropylene fibers and polyethylene fibers, and regenerated fibers such as rayon fibers. Of these, polyacetal fibers are preferred. From the viewpoint of obtaining high-strength concrete having a fiber content of 0.01 to 5.0% by volume, further 0.05 to 3.5% by volume, and 80 N / mm ² or more based on the hydraulic composition, 0.1 to 5.0% by volume. It is preferable to use 3.5% by volume.

  The hydraulic composition of the present invention contains an expansion material from the viewpoint of suppressing self-shrinkage while maintaining the strength after curing in a region where the shrinkage of the hydraulic composition and the weight ratio of water / hydraulic powder are small. Is preferred. As the inflatable material, those defined in JIS A 6202 can be used. Specifically, the expansion material chosen from the expansion material which has calcium sulfoaluminate as a main component, and the expansion material which has quicklime as a main component is mentioned. The expansion material is preferably used in an amount of 1 to 30 parts by weight, further 3 to 20 parts by weight, and further 5 to 15 parts by weight with respect to 100 parts by weight of the hydraulic powder (especially cement).

  The hydraulic composition of the present invention can also contain other additives (materials) other than the copolymer (I). For example, resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, alkylbenzene sulfonic acid (salt), alkane sulfonate, polyoxyalkylene alkyl (phenyl) ether, polyoxyalkylene alkyl (phenyl) ether sulfate (salt) ), Polyoxyalkylene alkyl (phenyl) ether phosphates (salts), protein materials, AE agents such as alkenyl succinic acid and α-olefin sulfonate; oxy such as gluconic acid, glucoheptonic acid, alabonic acid, malic acid, citric acid Delayers such as carboxylic acids, dextrins, monosaccharides, oligosaccharides, polysaccharides, etc .; foaming agents; thickeners; silica sand; AE water reducing agents; calcium chloride, calcium nitrite, calcium nitrate , Cal bromide Soluble calcium salts such as um, calcium iodide, chlorides such as iron chloride and magnesium chloride, sulfates, potassium hydroxide, sodium hydroxide, carbonates, thiosulfates, formic acid (salts), alkanolamines, etc. Strengthening agent or accelerator; foaming agent; resin acid (salt), fatty acid ester, oil and fat, silicone, paraffin, asphalt, wax, etc. waterproofing agent; fluidizing agent; dimethylpolysiloxane, polyalkylene glycol fatty acid ester, mineral oil Antifoaming agents such as oils and fats, oxyalkylenes, alcohols and amides; antifoaming agents; high-performance water reducing agents such as melamine sulfonic acid formalin condensates and aminosulfonic acids; nitrites, phosphates, zinc oxide Rust preventives such as: Alkylene oxide adducts of alcohols having 1 to 4 carbon atoms, polyalkylene glycols having an average molecular weight of 400 to 10,000, etc. Reducing agent: Cellulose type such as methylcellulose and hydroxyethylcellulose, natural product type such as β-1,3-glucan and xanthan gum, polyacrylic acid amide, polyethylene glycol, ethylene oxide adduct of oleyl alcohol or vinylcyclohexene diepoxide Water-soluble polymers such as synthetic systems such as reactants; polymer emulsions such as alkyl (meth) acrylates.

  The hydraulic composition of the present invention has a water / hydraulic powder weight ratio [weight ratio of water to hydraulic powder in the slurry, usually abbreviated as W / P. Abbreviated as C. ] Is 0.33 or less, preferably 0.25 or less, more preferably 0.20 or less, further 0.18 or less, and further preferably 0.15 or less. From the viewpoint of the viscosity reducing effect, the kneading speed improving effect of the hydraulic composition, and the flow retention, the water / hydraulic powder weight ratio is preferably 0.07 to 0.25, preferably 0.08 to 0.20 is more preferable, 0.08 to 0.18 is still more preferable, and 0.08 to 0.15 is still more preferable. In addition, when a hydraulic composition contains microparticles | fine-particles and / or an expansion | swelling material (For example, when using hydraulic powder with which microparticles | fine-particles and / or an expansion | swelling material were mix | blended), hydraulic powder, microparticles | fine-particles, and / or an expansion | swelling material. W / P or W / C is calculated using the total amount of and the amount of hydraulic powder.

According to the present invention, the coarse aggregate contains a copolymer (I), a hydraulic powder, a coarse aggregate, and water, and has a water / hydraulic powder weight ratio of 0.33 or less. The dispersing agent for hydraulic compositions whose content is 300-1100 kg / m < ³ > is provided. Such a dispersant preferably contains 80 to 100% by weight, further 90 to 100% by weight, and further 95 to 100% by weight of the copolymer (I) in terms of effective component.

Further, according to the present invention, water, hydraulic powder, and coarse aggregate are contained, the water / hydraulic powder weight ratio is 0.33 or less, and the content of the coarse aggregate is 300 to 1100 kg / m ^3. A hydraulic composition production method for producing a hydraulic composition, comprising:
A step of kneading copolymer (I), water and hydraulic powder to prepare mortar;
Kneading the mortar and coarse aggregate;
A method for producing a hydraulic composition having the following is provided: The copolymer (I) is 0.01 to 5.0 parts by weight, more preferably 0.05 to 4.0 parts by weight, and still more preferably 0.1 to 100 parts by weight of the hydraulic powder in terms of effective component. It is preferable to use ~ 3.0 parts by weight. The copolymer (I) can be used in an aqueous solution. The concentration of the copolymer (I) in the aqueous solution and the amount of the aqueous solution used are such that the ratio of the copolymer (I) to the hydraulic powder is in the above range. Can be set as appropriate. The kneading time in the step of kneading copolymer (I), water and hydraulic powder to prepare mortar is 0.5 to 3 minutes when the water / hydraulic powder weight ratio exceeds 0.33 to 0.25. Is preferred, 1.5 to 10 minutes is preferred when it exceeds 0.25 to 0.15, and 3 to 30 minutes is preferred when it is 0.15 or less. The step of kneading the mortar and the coarse aggregate is preferably 1 to 4 minutes when the water / hydraulic powder weight ratio is 0.33 or less. When the water / hydraulic powder weight ratio exceeds 0.33 to 0.25, the coarse aggregate may be kneaded in the step of preparing the mortar to adjust the hydraulic composition. The completion of the kneading can be judged by confirming that the mortar or hydraulic composition becomes uniform visually and the mortar attached to the kneader has fluidity.

  As the kneader used in the mortar preparation step and the mortar and coarse aggregate kneading step, a tilting barrel mixer, a pan-type mixer, a forced biaxial mixer, a dicross mixer, etc. can be used. Among them, a forced biaxial mixer (for example, IHI) It is preferable to use a DAM60) or a dicross mixer (for example, WHQ-60A manufactured by Kitagawa Iron Works).

Production Example 1
6118 g of water was charged into a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube and reflux condenser, the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 78 ° C. under a nitrogen atmosphere. Next, a monomer solution in which 5100 g of methoxypolyethylene glycol monoacrylate and 631 g of acrylic acid were mixed and dissolved in 2300 g of water, 33 g of 3-mercaptopropionic acid dissolved in 177 g of water, and 31 g of ammonium persulfate dissolved in 179 g of water 3 Each was dropped over 1.5 hours. After completion of the dropwise addition, 15 g of ammonium persulfate dissolved in 75 g of water was added dropwise over 0.5 hours. Thereafter, the temperature was maintained at 78 ° C. for 1 hour, followed by aging to complete the polymerization reaction. By neutralizing the resultant with a 48% aqueous sodium hydroxide solution, a copolymer having a pH of 5.5, a weight average molecular weight of 41,600, and a molecular weight distribution (weight average molecular weight / number average molecular weight) of 1.21 (A An aqueous solution of -1) was obtained.

Production Examples 2 to 10 and Comparative Production Examples 1 to 5
The kind and ratio of the monomer were changed as shown in Table 1, and a copolymer was produced according to Production Example 1.

The symbols in the table have the following meanings.
AA: Acrylic acid MAA: Methacrylic acid PEGA: Polyethylene glycol acrylate PEGMA: Polyethylene glycol methacrylate EOp: Average number of moles of ethylene oxide added

Example 1 and Comparative Example 1
Using the copolymers of Table 1, concrete was produced according to Formulation 1 of Table 2 and evaluated. The results are shown in Table 3.

(1) Concrete mix 1

W: tap water C: silica fume premix cement (manufactured by Taiheiyo Cement; density = 3.07 g / cm ³ )
S: Hard sandstone crushed sand (fine aggregate, density = 2.57 g / cm ³ )
G1: Kansai Shinwa crushed stone (coarse aggregate, density = 2.61 g / cm ³ , coarse grain ratio FM = 7.12)
G2: Kansai Shinwa crushed stone (coarse aggregate, density = 2.61 g / cm ³ , coarse grain ratio FM = 6.74)
E: Expanding material Σ2000 (manufactured by Denki Kagaku Kogyo; density = 3.07 g / cm ³ )
PA: Fiber Polyacetal fiber (white hair made by Daiwabo Polytec Length: about 10 mm, density 1.40 g / cm ³ (actual value))
W / P = W / (C + E)
In addition, content of a coarse aggregate is (433 + 433) = 866kg / m < ³ >, (433 / 2.61 + 433 / 2.61) = 332L / m < ³ >.

(2) Preparation of concrete According to compounding 1, cement and fine aggregate were put into a 30 liter forced biaxial mixer and kneaded for 30 seconds. The water containing the copolymer (cement dispersing agent) described in Table 1 was added thereto, and kneaded for 360 seconds (6 minutes) to prepare a mortar paste. Further, gravel was added here and kneaded for 120 seconds (2 minutes) to obtain concrete.

(3) Evaluation method About each prepared concrete, the slump flow and the compressive strength after 1 day of age were measured according to JIS A1101 and JIS A1108, respectively. The concrete kneading speed was judged from the property change at the mortar stage, and in order to evaluate the viscosity of the concrete, the L flow speed was measured 10 minutes after mixing. The L flow rate is a value measured by the L-type flow test method, and the larger the L flow rate, the lower the viscosity of the concrete and the better the workability. The results are shown in Table 3.

(note)
1)% by weight is% by weight of the effective amount of the dispersant for the cement. The cement dispersant is used as a 30% by weight aqueous solution, and the amount of water in the aqueous solution is included in the amount of kneading water.
2) Comparative Example 1-5 is a comparison of concrete prepared and having the same fluidity (slump flow value) as Example 1-2. Even if the fluidity is the same, Example 1-2 is superior in kneading properties, viscosity, and cured physical properties.

In the table, cement dispersants C-1, C-2, D-1, and D-2 are as follows.
C-1: Copolymer A-2 / Copolymer B-3 = 50/50 (weight ratio) mixed system C-2: Copolymer A-2 / Copolymer B-2 = 80 / 20 (weight ratio) mixed system D-1: copolymer A-2 / copolymer B-2 = 20/80 (weight ratio) mixed system D-2: copolymer B-2 / copolymer Polymer B-4 = 50/50 (weight ratio) mixed system

Example 2 and Reference Example Using the copolymers A-2 and B-1 in Table 1, concrete was produced according to Formulation 2 and Formulation 3 in Table 4 and evaluated. The results are shown in Table 5.

(1) Concrete mix 2 and mix 3

W: tap water C: normal Portland cement (manufactured by Taiheiyo Cement / Sumitomo Osaka Cement = 1: 1 (weight ratio); density = 3.16 g / cm ³ )
S: Mountain sand from Joyo (fine aggregate, density = 2.55g / cm ³ )
G1: Torigatayama Lime Crushed Stone 2010 (Coarse aggregate, density = 2.72 g / cm ³ , coarse grain rate FM = 6.92)
G2: Limestone 1005 from Torigatayama (coarse aggregate, density = 2.72 g / cm ³ , coarse grain rate FM = 5.87)
W / P = W / C
The content of the coarse aggregate, compounding 2 (729 + 182) = 911kg / m 3, (729 / 2.72 + 182 / 2.72) = 335L / m 3, Formula 3 similarly, 911kg / m ^3, 335 L / m ³ .

(2) Preparation of Concrete In Example 2 and Comparative Example 2, cement, fine aggregate, and gravel were added to a 30 liter forced biaxial mixer according to Formulation 2 and air-kneaded for 10 seconds. Water containing the copolymer (cement dispersant) A-2 or B-1 shown in Table 1 was added thereto and kneaded for 120 seconds (3 minutes) to obtain concrete.

  Moreover, in Reference Example, cement, fine aggregate, and gravel were added to a 30 liter forced biaxial mixer according to Formulation 3 and air-kneaded for 10 seconds. Water containing the copolymer (cement dispersant) A-2 or B-1 shown in Table 1 was added thereto and kneaded for 90 seconds (1.5 minutes) to obtain concrete.

(3) Evaluation method About each prepared concrete, the slump flow and the compressive strength after 1 day of age were measured according to JIS A1101 and JIS A1108, respectively. Regarding the concrete kneading speed, it was judged from the change in properties. In addition, in order to evaluate the viscosity of the concrete in Formula 2, the time required to reach 50 cm of the slump flow was measured. The results are shown in Table 5.

1)% by weight is the% by weight of the effective amount of the dispersant for the cement. The cement dispersant is used as an aqueous solution having a concentration of 23% by weight, and the amount of water in the aqueous solution is included in the amount of kneading water.

  In Formulation 2 (W / P = 0.30), Example 2-1 using A-2 as a cement dispersant has the same amount of addition using B-1 as Comparative Example 2-1 and fluidity. Is superior in all of concrete viscosity, kneading property, and cured material properties as compared with Comparative Example 2-2, which has a larger addition amount. On the other hand, in Formulation 3 (W / P = 0.45), A-2 had excellent cured properties, but there was no difference in the kneading time with the cement dispersant.

Example 3
Using the copolymer A-2 in Table 1, concrete was produced according to the formulation 4 in Table 6 and evaluated. The results are shown in Table 7.

(1) Concrete mix 4

W: tap water C: silica fume premix cement (manufactured by Taiheiyo Cement; density = 3.07 g / cm ³ )
S: Hard sandstone crushed sand (fine aggregate, density = 2.57 g / cm ³ )
G1: Kansai Shinwa crushed stone (coarse aggregate, density = 2.61 g / cm ³ , coarse grain ratio FM = 7.12)
G2: Kansai Shinwa crushed stone (coarse aggregate, density = 2.61 g / cm ³ , coarse grain ratio FM = 6.74)
W / P = W / C
s / a = (S / 2.57) / (S / 2.57 + G1 / 2.61 + G2 / 2.61)
The contents of coarse aggregate are (186 + 186) = 372 kg / m ³ and (186 / 2.61 + 186 / 2.61) = 143 L / m ³ .

(2) Preparation of concrete According to compounding 4, cement and fine aggregate were put into a 30 liter forced biaxial mixer, and kneaded for 30 seconds. The water containing the copolymer (cement dispersant) A-2 shown in Table 1 was added thereto and kneaded for 1500 seconds (25 minutes) to prepare a mortar paste. Further, gravel was added here and kneaded for 180 seconds (3 minutes) to obtain concrete.

(3) Evaluation method About the prepared concrete, the slump flow was measured according to JISA1101. The results are shown in Table 7. As a result, a hydraulic composition having a good slump flow can be obtained even with a system with little water of W / P = 0.08.

1)% by weight is the% by weight of the effective amount of the dispersant for the cement. The cement dispersant is used as a 30% by weight aqueous solution, and the amount of water in the aqueous solution is included in the amount of kneading water.

Claims (6)

Copolymer (I) comprising a structural unit composed of acrylic acid and a structural unit represented by the following general formula (A), wherein the proportion of structural units composed of acrylic acid in all structural units is 50 mol% or more [ Hereinafter referred to as copolymer (I)], hydraulic powder, coarse aggregate, water, silica fume, and synthetic fiber,
The water / hydraulic powder weight ratio is 0.07 to 0.25,
The unit hydraulic powder amount of the hydraulic powder is 800 kg / m ³ or more,
The content of the coarse aggregate is 300 to 1100 kg / m ³ .
Hydraulic composition [however, (co) polymer (II) other than copolymer (I) selected from polycarboxylic acid (co) polymers and (co) polymers having phosphoric acid groups (salts) In the case of containing [hereinafter referred to as (co) polymer (II)], the proportion of copolymer (I) in the total of copolymer (I) and (co) polymer (II) is converted into an effective component 50 to 99% by weight. ].

[In the formula, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average added mole number of AO, represents a number of 2 to 300, and R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Q represents an integer of 0 to 2, and r represents an integer of 0 to 1. ]   The hydraulic composition of Claim 1 which contains a copolymer (I) 0.01-5.0 weight part with respect to 100 weight part of hydraulic powder in conversion of an effective part.   The hydraulic composition of Claim 1 or 2 which contains a synthetic fiber 0.01 to 5.0 volume% with respect to a hydraulic composition.   Furthermore, the hydraulic composition of any one of Claims 1-3 containing an expansion | swelling material.   The ratio of the sum total of the structural unit which consists of acrylic acid in the structural unit of the said copolymer, and the structural unit represented by General formula (A) is 92 mol% or more, Any one of Claims 1-4. Hydraulic composition. Copolymer (I) comprising a structural unit composed of acrylic acid and a structural unit represented by the following general formula (A), wherein the proportion of structural units composed of acrylic acid in all structural units is 50 mol% or more [ Hereinafter referred to as copolymer (I)] , a dispersant for a hydraulic composition, comprising hydraulic powder, coarse aggregate, water, silica fume, and synthetic fiber, / Hydraulic powder weight ratio is 0.07 to 0.25, the unit hydraulic powder amount of the hydraulic powder is 800 kg / m ³ or more, and the content of the coarse aggregate is 300 to 1100 kg / Dispersant used for hydraulic composition of m ³ [however, other than copolymer (I) selected from polycarboxylic acid (co) polymer and (co) polymer having phosphoric acid group (salt) In the case of containing (co) polymer (II) [hereinafter referred to as (co) polymer (II)] Total in I) and (co) polymer (II), the proportion of the copolymer (I) is 50 to 99 wt% effective content basis. ].

[In the formula, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average added mole number of AO, represents a number of 2 to 300, and R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Q represents an integer of 0 to 2, and r represents an integer of 0 to 1. ]