JP3415419B2 - Concrete composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete composition, and more specifically, there is no delay in setting and reduction in initial strength even when a large amount of fly ash is mixed, and there is little slump loss and good strength development. It relates to a concrete composition.

[0002]

2. Description of the Related Art Fly ash, which is produced in large quantities as a by-product from a pulverized coal combustion boiler of a thermal power plant, is effectively used as a concrete admixture, but most of it is disposed of as landfill. When fly ash is used as a concrete admixture in a concrete composition, 1) the workability of the concrete composition is improved, 2) the structure of the hardened concrete is densified, and the long-term strength is increased. Resistance to soil, 3) control of temperature cracks due to self-heating to alleviate the heat of hydration of concrete, and 4) the effect of suppressing alkali-aggregate reaction. It has excellent properties as an admixture.

On the other hand, when a large amount of such fly ash is mixed with a concrete composition, there is a problem that the slump loss of the concrete composition is remarkable and the workability and the workability are significantly reduced.

Conventionally, as a method for preventing slump loss of a concrete composition in which a large amount of fly ash is mixed, it has been proposed to use a copolymer of maleic anhydride and polyoxyalkylene alkylalkenyl ether as a water reducing agent ( JP-A-8-34652). However, this proposal has a drawback in that the slump loss is insufficiently prevented under the temperature condition around 30 ° C. On the other hand, as a method for preventing slump loss of a normal concrete composition containing no fly ash, it has been proposed to use a water-soluble vinyl copolymer having slump loss-preventing performance as a water reducing agent. Examples of such water-soluble vinyl copolymers include:
1) Water-soluble vinyl copolymer obtained by copolymerizing (meth) acrylic acid salt (JP-A-1-226757, JP-A-4-209613), 2) Copolymerization of maleic anhydride and alkenyl ether Polymer and its derivatives (Japanese Patent Publication Sho 5)
No. 8-38380, JP-A-63-285140, JP-A-2-163108) and the like. However, when these water-soluble vinyl copolymers are used in a concrete composition in which a large amount of fly ash is mixed, there is a drawback in that the slump loss is insufficiently prevented by any of the water-soluble vinyl copolymers.

Further, conventionally, in a concrete composition containing a large amount of fly ash, problems such as delay of setting, reduction of initial strength, etc. occur in the strength of hardened concrete, so the amount of fly ash mixed with concrete is increased. Has its own limitations. The fly ash cement stipulated in JIS standard limits the substitution ratio of fly ash to cement to 30% at the maximum, and is not currently associated with the large use of fly ash.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a concrete composition which does not cause slump loss even when a large amount of fly ash is mixed and which exhibits good strength.

[0007]

[Means for Solving the Problems] Therefore, the inventors of the present invention have variously changed the compounding amount of fly ash, and as a result of diligently examining the slump loss preventing effect in a concrete composition by using a seed polymer, as a result, in addition to a water reducing agent. If a specific amount of a specific water-soluble vinyl copolymer is blended, even if a large amount of fly ash is blended, slump loss is small, and a concrete composition with good strength development is obtained, and effective use of fly ash. The present invention has been completed and the present invention has been completed.

That is, the present invention provides a concrete composition containing cement (C), fly ash (F), a slump loss inhibitor (AD) and a water reducing agent (HP), wherein the slump loss inhibitor is Formula (1) and Formula (2)
The repeating unit represented by (1) / (2) = 3 / 2-2
Number average molecular weight 10 having a ratio of / 3 (molar ratio) and having a hydrocarbon group substituted with a sulfonate group as an end group.
A water-soluble vinyl copolymer having a water-reducing capacity of 0 to 15,000, wherein the water-reducing agent is obtained by aqueous polymerization of monomers represented by the following formulas (5), (6) and (7). And the reaction ratio is as follows: monomer represented by formula (5) / monomer represented by formula (6) / monomer represented by formula (7) =
A water-soluble vinyl copolymer having a molar ratio of 9 to 47/2 to 16/3 to 8 and a weight ratio (F / C) of fly ash and cement of 3/7 to 6/5, and cement. Of the slump loss inhibitor [((AD) / (C +
F)) × 100] is 0.01 to 1.0, and the weight ratio (AD / HP) of the slump loss inhibitor (AD) to the water reducing agent (HP) is 0.1 to 10. The present invention provides a concrete composition.

[0009]

[Chemical 4]

(Wherein p is a number from 1 to 25, q is from 1 to 40)
, R is a number from 1 to 10, M is a hydrogen atom or a base)

[Chemical 4] (In the formula, R ¹ , R ² and R ³ represent a hydrogen atom or a methyl group, M ¹ and M ² represent an alkali metal, an alkaline earth metal, ammonium or an organic amine, and n is a number of 5 to 50. Show)

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The concrete composition of the present invention is
It contains cement (C), fly ash (F), anti-slump loss agent (AD) and water reducing agent (HP). Here, as the cement used in the present invention, normal, early early, ultra early early, moderate heat, sulfate resistance, various portland cements such as white are all mentioned, but the initial and long-term strength development is improved. In order to exert a great effect on
Ordinary Portland cement is preferred.

[0012] As fly ash, of course, fly ash specified by JIS is used. Of course, fly ash generally called raw powder and cinder ash are used in general, so-called coal ash in a broad sense. You can

The water-soluble vinyl copolymer, which is a slump loss preventing agent, comprises a repeating unit represented by the formula (1) or (2) and a repeating unit represented by the formula (1) / the formula (2). Repeating unit = ratio of 3/2 to 2/3 (molar ratio),
It preferably has a ratio of 11/9 to 9/11 (molar ratio). Both repeating units may be random-bonded or block-bonded. Further, this water-soluble vinyl copolymer has a hydrocarbon group substituted with a sulfonate group as its terminal group. The terminal group may be present at one end of the copolymer composed of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), or may be present at both ends. Good. As will be described later, such an end group is a monoethylenic unsaturated group substituted with a sulfonate group in a copolymer composed of a repeating unit represented by the formula (1) and a repeating unit represented by the formula (2) It can be formed by radical addition or radical addition polymerization of a hydrocarbon monomer. Further, this vinyl copolymer has a number average molecular weight (GPC method, pullulan conversion, the same applies hereinafter) of 1,000 to 15,000, preferably 200.
It is from 0 to 10000. The repeating number of the repeating unit represented by the formula (1), the repeating number of the repeating unit represented by the formula (2), the total amount of both repeating units and the ratio of the terminal group in the water-soluble vinyl copolymer are as described above. It can be appropriately selected depending on the relationship with the number average molecular weight, but it is preferable that the total amount of both repeating units is 60% by weight or more, and 80% by weight or more of the whole. More preferably. In addition, a sulfonate group means the group which consists of sulfonate.

The repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) are each formed by copolymerizing corresponding vinyl monomers. Examples of the vinyl monomer that forms the repeating unit represented by the formula (1) include methoxypolyethoxyethyl maleic acid monoester or a salt thereof in which the number of repeating oxyethylene units is 1 to 25. Examples of the base that forms the salt include a) alkali metals such as sodium and potassium, b) alkaline earth metals such as calcium and magnesium, c) ammonium, d) organic amines such as diethanolamine and triethanolamine. Can be mentioned. Of these, an alkali metal salt of methoxypolyethoxyethyl maleic acid monoester having a repeating number of oxyethylene units of 1 to 10 is preferable.

The vinyl monomer forming the repeating unit represented by the formula (2) has 1 to 40 repeating units of oxyethylene units and 1 to 10 repeating units of oxypropylene units. , Polypropoxypolyethoxyethyl monoallyl ether. Among them, the number of repeating oxyethylene units is 10 to 35 and the number of repeating oxypropylene units is 1 to 5
Is preferred, polypropoxypolyethoxyethyl monoallyl ether.

The hydrocarbon group substituted with a sulfonate group, which is the terminal group of the water-soluble vinyl copolymer, is 1)
Substituted alkene group obtained by radical addition of monoethylenically unsaturated hydrocarbon monomer substituted with sulfonate group, 2) Radical addition of monoethylenically unsaturated hydrocarbon monomer substituted with sulfonate group Examples thereof include polysubstituted alkene groups obtained by polymerization. Among them, a) a substituted alkene group obtained by radical addition of allyl sulfonate and / or methallyl sulfonate, and b) polysubstituted alkene group obtained by radical addition polymerization of vinyl sulfonate. In any case, examples of the base that forms the sulfonate group include alkali metals, alkaline earth metals, ammonium, alkanolamines, etc. Among them, alkali metals are preferable.

Although the present invention does not particularly limit the content ratio of the hydrocarbon group substituted with a sulfonate group as a terminal group in the water-soluble vinyl copolymer, it is not limited to one molecule of the water-soluble vinyl copolymer. 1) 1 to 2 mol in the case of a substituted alkene group obtained by radical addition, 2) 3 to 3 in the case of a poly-substituted alkene group obtained by radical addition polymerization
4 mol is preferred.

The water-soluble vinyl copolymer which is the slump loss inhibitor of the present invention can be obtained by various methods.
It is advantageous to obtain it through the following first step, second step and third step. First step: a vinyl monomer represented by the following formula (3) or formula (4), a vinyl monomer represented by the following formula (3) / a vinyl monomer represented by the following formula (4) Body = 3/2 to 2/3
(Mole ratio) Copolymerization in the presence of a radical initiator, followed by radical termination to obtain a radical terminated copolymer. Second step: a step of radically activating the copolymer by adding a radical initiator to a system containing the radical-terminated copolymer. Third step: Radical addition or radical addition polymerization of one or more monoethylenically unsaturated hydrocarbon monomers substituted with a sulfonate group with respect to the radical activated copolymer to obtain a terminal. A step of obtaining a water-soluble vinyl copolymer having a hydrocarbon group substituted with a sulfonate group as a group.

[0019]

[Chemical 5]

(Where p is a number from 1 to 25 and q is 1 to 4)
0 is an integer, r is an integer of 1 to 10, and M is hydrogen or a base)

In the first step, the vinyl monomer represented by the formula (3) / the vinyl monomer represented by the formula (4) = 3/2 to 2
/ 3 (molar ratio), preferably 11/9 to 9/11
Copolymerization is carried out in the presence of a radical initiator at a ratio of (molar ratio). In this case, the vinyl monomer represented by the formula (3) is a vinyl monomer which forms the repeating unit represented by the formula (1), and the vinyl monomer represented by the formula (4) is A vinyl monomer that forms a repeating unit represented by the formula (2). The vinyl monomer represented by the formula (3) and the vinyl monomer represented by the formula (4) are copolymerized by water-based solution polymerization using water or a mixed solvent of water and a water-soluble organic solvent. You can The radical initiator used for the copolymerization reaction of both vinyl monomers may be one that decomposes at the copolymerization reaction temperature to generate a radical, but it is advantageous to use a water-soluble radical initiator. is there.

As such a water-soluble radical initiator,
Persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, 2,2-azobis (2-amidinopropane)
Dihydrochloride and the like can be mentioned. The suitable amount of these water-soluble radical initiators varies depending on the type of the water-soluble radical initiator and the vinyl monomer to be used. For example, when ammonium persulfate is used, the vinyl monomer represented by the formula (3) is used. It is preferably in the range of 0.2 to 3% by weight based on the total amount of the monomer and the vinyl monomer represented by the formula (4).

In the first step, in the radical copolymerization of the vinyl monomer described above, the reaction system is radically terminated in a timely manner to obtain a radical-terminated copolymer. Examples of the method for stopping the radical include a method in which a radical terminating agent for forcibly decomposing and eliminating the radical is added to the reaction system.

As the radical terminating agent, conventionally known compounds can be used, but as the radical terminating agent which can be advantageously used, 2-mercaptoethanol, 3
Examples thereof include compounds having at least two hydroxyl groups or thiol groups in the molecule, such as mercapto-1,2-propanediol. The advantage of using a compound as described above as a radical terminating agent is that it gives a radical active site when a radical initiator in the reaction of the second step described below is added to the terminal of the resulting radical-terminated copolymerization. It is possible to carry out radical addition or radical addition polymerization of the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group in the subsequent third step described later efficiently and selectively.

The suitable amount of the radical terminating agent to be added is determined depending on the molecular weight of the radical-terminated copolymer, the vinyl monomer, the aqueous solvent, and the type of the radical terminating agent. 1 with respect to the total amount of the vinyl monomer represented by the formula (3) and the vinyl monomer represented by the formula (4), which will form a radical-terminated copolymer.
˜50 mol%.

Conventionally known methods can be applied to the aqueous solution radical copolymerization itself using the vinyl monomer represented by the formula (3) and the vinyl monomer represented by the formula (4). The copolymerization reaction temperature may range from room temperature to the boiling point of the aqueous solvent, but is preferably 50 to 80 ° C.

In the second step, a radical initiator is added to the system containing the radical-terminated copolymer obtained in the first step to radically activate the copolymer. The radical initiator used in the second step may be the same as the radical initiator used in the first step.

The amount of the radical initiator used in the second step depends on the kind of the radical initiator and the kind of the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group used in the next third step. Although different, it is usually in the range of 0.1 to 5% by weight based on the radical-terminated copolymer obtained in the first step.

In the third step, a monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group is radical-added or radical-addition-polymerized to the copolymer radical-activated in the second step to give a copolymer. A water-soluble vinyl copolymer having a hydrocarbon group substituted with a sulfonate group as the terminal group of is obtained.

The present invention is not particularly limited to a sulfonic acid group-substituted monoethylenically unsaturated hydrocarbon monomer which is radical-added or radical-addition-polymerized to a radical-activated copolymer. Is for example
Examples thereof include 1) monomers mainly suitable for radical addition such as allyl sulfonate and methallyl sulfonate, and 2) monomers suitable for radical addition or radical addition polymerization such as vinyl sulfonate. In the monomers 1) and 2), examples of the base that forms a salt include the same alkali metals, alkaline earth metals, ammonium, and alkanolamines as described above for formula (1). Of these, alkali metals are preferred.

The reaction ratio between the radical-activated copolymer and the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group depends on the type of radical terminating agent used in the first step and the second step. The amount is usually 1 to 10 mol, preferably 1.5 to 5 mol with respect to 1 mol of the radical-activated copolymer, although it varies depending on the kind of the radical initiator used in Step 1.
The radical addition or radical addition polymerization itself of the radical-activated copolymer and the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group can be carried out according to a known method.

In the radical addition or radical addition polymerization of the radical-activated copolymer obtained in the second step and the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group, radical-activated Further, one molecule is radical-added or several molecules are radical-addition-polymerized per one terminal radical active site of the copolymer.
The monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group used in the present invention is another sulfonate vinyl monomer, for example, (meth) acryloyl acrylate such as 2- (meth) acryloxyethyl sulfonate. Extremely high reaction selection compared to those having sulfonic acid groups such as (meth) acrylamide sulfonates such as roxysulfonates and 2-acrylamido-2-methylpropanesulfonate, but not monoethylenically unsaturated hydrocarbon monomers The water-soluble vinyl copolymer of the present invention having a regulated terminal structure due to its property is obtained.

The water-reducing agent used in the present invention is not particularly limited, and a (meth) acrylic acid-based water-soluble vinyl copolymer, a naphthalenesulfonic acid formalin condensate, a melaminesulfonic acid formalin condensate, an aminosulfonic acid formalin condensation is used. Examples thereof include known concrete water reducing agents such as compounds, ligninsulfonic acid, hydroxycarboxylic acid and salts thereof, and among them, a (meth) acrylic acid-based water-soluble vinyl copolymer is preferable.

The (meth) acrylic acid-based water-soluble vinyl copolymer is obtained by aqueous polymerization of the monomers represented by the formulas (5) and (6) and the formula (7). A water-soluble vinyl copolymer having a reaction ratio of formula (5)
Monomer represented by the formula / monomer represented by the formula (6) / monomer represented by the formula (7) = 9 to 47/2 to 16/3 to 8
It is desirable to use a water-soluble vinyl copolymer having a (molar ratio) as a main component.

[0035]

[Chemical 6]

(Wherein R ¹ , R ² and R ³ are H or C
H ₃ is shown, M ¹ and M ² are alkali metal, alkaline earth metal, ammonium or organic amine, and n is 5 to 5
Indicates the number of 50)

Examples of the monomer represented by the formula (5) include alkali metal salts of acrylic acid and methacrylic acid, alkaline earth metal salts and alkanolamine salts. Examples of the monomer represented by the formula (6) include alkali metal salts, alkaline earth metal salts and alkanolamine salts of allyl sulfonic acid and methallyl sulfonic acid. Formula (7)
The monomer represented by is an esterified product of a polyalkylene glycol with one terminal alkyl group blocked such as methoxypolyethylene glycol and acrylic acid or methacrylic acid, and the addition mole number of the polyalkylene glycol is 5
Compounds that are ˜50.

If the reaction ratio of each monomer deviates from the above range, when the resulting water-soluble vinyl copolymer is used as a water reducing agent, dispersion fluidity becomes insufficient and slump loss becomes large. Sometimes. The reaction ratio of each monomer is calculated as follows: Monomer represented by formula (5) / monomer represented by formula (6) / monomer represented by formula (7) = 18 to 33/3 to 1
It is more desirable to set it to 0/4 to 7 (molar ratio).

The water-soluble vinyl copolymer, which is the water reducing agent used in the present invention, is obtained by reacting each of the monomers as described above. In this case, the effect of the present invention is obtained. Other monomers may be reacted for the purpose within a range that does not impair them. For example, acrylamide, methacrylamide, acrylonitrile, acrylic acid ester and the like are usually used in an amount of 15 mol% or less of the total amount of monomers.

The water-soluble vinyl copolymer, which is the water reducing agent used in the present invention, contains the monomers represented by the formulas (5), (6) and (7) in a predetermined ratio. Concentration 10-4
An aqueous solution of a radical polymerization initiator was added to a 0% by weight aqueous solution or suspension, and the mixture was stirred at 50 to 70 ° C. for 3 hours in a nitrogen gas atmosphere.
It can be produced by carrying out a polymerization reaction for up to 5 hours.

The water-soluble vinyl copolymer thus produced usually has a number average molecular weight of 2,000 to 15,000, but each monomer represented by the formula (5), the formula (6) and the formula (7). It is preferable to adjust the ratio to be in the range of 3000 to 10000. If the molecular weight is too high, the water reducing property tends to decrease, and if the molecular weight is too low, the slump loss of concrete tends to increase.

In the concrete composition of the present invention, the slump loss preventing agent is the weight ratio of the slump loss preventing agent (AD) to 100 parts by weight of the total of the cement (C) and the fly ash (F) (C + F) ((AD / (C +
F) × 100)) is 0.01 to 1.0, preferably 0.
It is blended so as to be 02 to 0.5. When the weight proportion of the slump loss inhibitor in the concrete composition is smaller than the above proportion, the slump loss of the concrete composition is not improved, and when it is larger than the above proportion, the concrete composition is A delay in setting occurs.

The weight ratio (AD / HP) of the slump loss inhibitor (AD) to the water reducing agent (HP) is 0.1 to 0.1.
The blending amount of the slump loss preventing agent is adjusted so as to be 10, preferably 0.15 to 5.0. When the weight ratio of the slump loss inhibitor to the water reducing agent is smaller than the above ratio, the fluidity of the concrete composition becomes too large, and when it is larger than the above ratio, the flowability of the concrete composition is increased. It becomes too difficult to obtain the desired slump.

In the present invention, the mixing ratio of fly ash and cement is not particularly limited as long as the slump loss preventing agent is blended in the above weight ratio, but the effect of the present invention is particularly effective when the mixing ratio of fly ash is large. It will be noticeable. That is, it is preferable to set the weight ratio (F / C) of fly ash and cement to 3/7 or more, particularly 3/7 to 6/5, from the viewpoint of strength development, use of a large amount of fly ash, and the like.

The amount of cement used is not particularly limited, but the unit amount of cement in the concrete composition is 250-250.
The range of 350 kg / m ³ is preferable from the viewpoint of obtaining strength development, particularly good initial strength. The amount of fly ash used is not particularly limited, but it is preferable that the amount of unit fly ash in the concrete composition is in the range of 150 to 300 kg / m ³ from the viewpoints of large use of fly ash, strength development, and the like.

Further, in the preparation of the concrete composition of the present invention, the above components are mixed with aggregate and water,
As the aggregate, it is general to use fine aggregate (S) and coarse aggregate (G) together. Here, as fine aggregate, river sand, land sand, mountain sand,
Sea sand, crushed sand, etc. can be used, but especially for fine aggregate that is not suitable as an aggregate for normal concrete because the particle size distribution is unbalanced, the above-mentioned large amount of fly ash and the accompanying concrete With proper mixing of the above, the fluidity of concrete can be secured and it can be suitably used as the aggregate of the present invention.

Coarse aggregates include river gravel, land gravel, mountain gravel,
Coarse aggregate such as crushed stone can be used regardless of the type of various aggregates.

The use weight ratio (S / G) of the fine aggregate (S) to the coarse aggregate (G) in this aggregate is not particularly limited, but it is in the range of 0.35 to 0.55. It is preferable for securing the fluidity of concrete and a good slump value (8 to 22 cm).

An air entraining agent may be added to the concrete composition of the present invention, if necessary. As the air entraining agent, any one having a chemical composition of nonion type, anion type, oxyethylene type, higher fatty acid type or natural resin acid salt type, which has been conventionally used as an air entraining agent for concrete, can be used. In the concrete composition of the present invention, by adjusting the addition ratio of the air entraining agent,
It is desirable to adjust the air entrainment amount of concrete to 4.5 to 5.5%.

In addition to the concrete composition of the present invention, it is also used as a concrete admixture for various kinds of concrete such as a quick-hardening / quick-setting material, a high-strength admixture, a hydration accelerator, and a setting modifier, and a reinforcing material, which are used in ordinary concrete. Various fibers, steel, etc. can also be used.

There is no limitation on the method of mixing and kneading the above components, as long as they can be uniformly mixed and kneaded, and the order of addition of the components is not particularly limited, but the weight ratio of water to cement (C) is not limited. (W / C) is 0.5 to 1.
It is necessary to adjust so that it becomes 0, mixing workability, flow value,
It is preferable in terms of strength of the obtained concrete.

For the curing after the concrete is poured, various curing methods can be applied, and any of room temperature curing, high temperature curing, normal pressure steam curing and high temperature and high pressure curing can be adopted. It is also possible to combine them to obtain a higher-strength concrete hardened body.

[0053]

EFFECTS OF THE INVENTION The concrete composition of the present invention contains the above-mentioned specific slump loss preventive agent together with a water reducing agent, so that even if a large amount of fly ash is used, the characteristics of concrete containing fly ash are impaired. In addition, it is possible to obtain concrete having excellent slump retention and good initial strength and long-term strength development.

[0054]

EXAMPLES Examples will be given below to make the constitution and effects of the present invention more concrete, but the present invention is not limited to the examples. In the following Examples and the like, "part" means "part by weight" and "%" means "% by weight excluding the amount of air".

Test Category 1 (Synthesis of Water-Soluble Vinyl Copolymer as Slump Loss Inhibitor) Synthesis Example 1 Methoxypolyethoxy (p = 9) ethyl maleic acid monoester 132 parts (0.251 mol), polypropoxy ( r = 2) polyethoxy (q = 15) ethyl monoallyl ether 210 parts (0.251 mol), 2-mercaptoethanol 8 parts (0.102 mol) and ion-exchanged water 2
60 parts was charged into a flask, the atmosphere in the flask was replaced with nitrogen, and the temperature of the reaction system was kept at 80 ° C. in a warm water bath. Next, 30 parts of a 10% aqueous solution of ammonium persulfate was added to initiate radical polymerization, and the polymerization reaction was continued for 8 hours. Then, 40 parts of a 20% aqueous solution of 2-mercaptoethanol was added to stop radicals, and 33 parts of a 30% aqueous sodium hydroxide solution was added to neutralize. Copolymers {methoxy polyethoxy (p = 9) ethyl maleic acid monoester obtained by removing residual catalyst and unreacted monomer from the neutralized reaction solution by dialysis using a cellulose tube membrane, and purifying and drying. Repeating unit formed (repeating unit represented by formula 1) / polypropoxy (r = 2) polyethoxy (q = 15) repeating unit formed from ethyl monoallyl ether (repeating unit represented by formula 2)
= 1/1 (molar ratio), a molecular weight of 3400, and a sulfur content of 1.7%} were obtained. Next, 300 parts of this copolymer (0.
(088 mol) and 675 parts of ion-exchanged water were charged into another flask, and the atmosphere in the flask was replaced with nitrogen. The temperature of the reaction system was maintained at 70 ° C. in a warm water bath, 40 parts of a 10% aqueous solution of ammonium persulfate was added to radically activate the copolymer, and then 2 parts of sodium methallylsulfonate were added.
142 parts (0.180 mol) of 0% aqueous solution was added and the reaction was continued for 2 hours to complete the radical addition reaction. Impurities were removed from the reaction solution in which the radical addition reaction was completed by dialysis as described above, and a purified and dried water-soluble vinyl copolymer (AD-1) was obtained. The water-soluble vinyl copolymer (AD-1) was analyzed by NMR, ICP emission spectral analysis, thermal decomposition gas chromatography, elemental analysis, GPC, titration, etc., and had a carboxyl value of 36 and a sulfur content of 3.3.
%, The ratio of each constitutional unit is converted into corresponding vinyl monomers, and methoxypolyethoxy (p = 9) ethyl maleic acid monoester sodium salt / polypropoxy (r =
2) Water-soluble vinyl having a number average molecular weight of 3700 and having a ratio of polyethoxy (q = 15) ethyl monoallyl ether = 1/1 (molar ratio) and having an end group formed by radical addition of sodium methallylsulfonate. It was a copolymer.

Synthesis Example 2 and Comparative Synthesis Examples 1 and 2 In the same manner as in Synthesis Example 1, a water-soluble vinyl copolymer (AD-
2), (ad-1), and (ad-2) were obtained. The contents of the water-soluble vinyl copolymer are summarized in Tables 1 and 2.

Synthesis Example 3 132 parts (0.251 mol) of methoxypolyethoxy (p = 9) ethylmaleic acid monoester, 376 parts of polypropoxy (r = 2) polyethoxy (q = 30) ethyl monoallyl ether (0. 251 mol), 3-mercapto-1,2-propanediol 11 parts (0.102 mol)
Then, 260 parts of ion-exchanged water was charged into the flask, the atmosphere in the flask was replaced with nitrogen, and the temperature of the reaction system was kept at 80 ° C. in a warm water bath. Next, 30 parts of a 10% aqueous solution of ammonium persulfate was added to initiate radical polymerization, and the polymerization reaction was continued for 8 hours. Then, 55 parts of a 20% aqueous solution of 3-mercapto-1,2-propanediol was added to terminate radicals, and 33 parts of a 30% aqueous sodium hydroxide solution was added to neutralize. Impurities were removed from the neutralized reaction solution by the same dialysis as in Synthesis Example 1, and a repeating unit formed from the copolymer {methoxypolyethoxy (p = 9) ethyl maleic acid monoester purified and dried (in formula 1) Repeating unit shown) / Repeating unit formed from polypropoxy (r = 2) polyethoxy (q = 30) ethyl monoallyl ether (repeating unit represented by formula 2) =
1/1 (molar ratio), molecular weight 7400, sulfur content 0.
86%} was obtained. Next, 740 parts of this copolymer (0.1
00 mol) and 675 parts of ion-exchanged water were charged into another flask, and the atmosphere in the flask was replaced with nitrogen. After keeping the temperature of the reaction system at 70 ° C. in a warm water bath and introducing 60 parts of a 10% aqueous solution of ammonium persulfate to radically activate the copolymer, 20% of sodium vinylsulfonate was further added.
208 parts (0.320 mol) of an aqueous solution was added and the reaction was continued for 2 hours to complete the radical addition polymerization reaction. Impurities were removed from the reaction solution in which the radical addition polymerization reaction was completed by dialysis as described above, and the product was purified and dried to obtain a water-soluble vinyl copolymer (AD-3). When the water-soluble vinyl copolymer (AD-3) was analyzed in the same manner as in Synthesis Example 1, the carboxyl value was 26, the sulfur content was 2.0%, and the ratio of each structural unit was converted into each corresponding vinyl monomer. , Methoxy polyethoxy (p = 9) ethyl maleic acid monoester sodium salt / polypropoxy (r = 2) polyethoxy (q = 30) ethyl monoallyl ether = 1/1 (molar ratio) and vinyl sulfone It was a water-soluble vinyl copolymer having a number average molecular weight of 7800 and having an end group formed by radical addition polymerization of sodium acid salt.

[0058]

[Table 1]

In Table 1, type a of condition 1: type of vinyl monomer that forms the repeating unit represented by formula (1) type b of condition 1: repeating unit represented by formula (2) Type of vinyl monomer to be formed Type 1 of condition 1 / Type b (molar ratio): Vinyl monomer to form repeating unit represented by Formula (1) / Indicated by Formula (2) Vinyl monomer that will form repeating units (molar ratio) Type of condition 2: Type of radical terminating agent used Type of condition 3: Radical used to radically activate the radical terminated copolymer Type of Initiator Type of Condition 4: Type of Monoethylenically Unsaturated Hydrocarbon Monomer Substituted with Sulfonate Group Used to Form End Groups Amount of Condition 4 Used (Mole): Radical Activated 1 mol of copolymer The molar number of mono-ethylenically unsaturated hydrocarbon monomers substituted by sulfonate group to

A-1: methoxypolyethoxy (p = 9)
Ethyl maleic acid monoester sodium salt a-2: methoxypolyethoxy (p = 3) Ethyl maleic acid monoester sodium salt b-1: Polypropoxy (r = 2) polyethoxy (q =
15) Ethyl monoallyl ether b-2: polypropoxy (r = 2) polyethoxy (q =
30) Ethyl monoallyl ether t-1: 2-mercaptoethanol t-2: 1,2-ethanediol t-3: 3-mercapto-1,2-propanediol s-1: ammonium persulfate s-2: 2 2'-azobis [2-methyl-N- (2-
Hydroxyethyl) propionamide c-1: methallylsulfonic acid sodium salt c-2: allylsulfonic acid sodium salt c-3: vinylsulfonic acid sodium salt

[0061]

[Table 2]

In Table 2, the ratio (molar ratio) of analysis value 1: (repeating unit represented by formula (1) / repeating unit represented by formula (2)) analysis value 2: number of radical-terminated copolymers Mol% of average molecular weight analysis value 3: Addition number of moles of monoethylenically unsaturated hydrocarbon monomer substituted with sulfonate group forming an end group per molecule of water-soluble vinyl copolymer Weight of analysis value 3 %: Proportion (% by weight) of hydrocarbon groups substituted with sulfonate groups as terminal groups in the water-soluble vinyl copolymer Analysis value 4: Number average molecular weight of water-soluble vinyl copolymer

Comparative Synthesis Example 3 66 parts (0.125 mol) of methoxypolyethoxy (p = 9) ethyl maleic acid monoester, 210 parts (0) of polypropoxy (r = 2) polyethoxy (q = 15) ethyl monoallyl ether. .251 mol), 2-acrylamido-2-methylpropanesulfonic acid sodium salt 29.
(0.126 mol) and 350 parts of ion-exchanged water were charged in a flask, the atmosphere in the flask was replaced with nitrogen, and the temperature of the reaction system was kept at 80 ° C. in a warm water bath. Next, 30 parts of a 10% aqueous solution of ammonium persulfate was added to initiate radical polymerization, and the polymerization reaction was continued for 10 hours to complete the polymerization. Then, 17 parts of a 30% aqueous sodium hydroxide solution was added to neutralize. Impurities were removed from the neutralized reaction solution by the same dialysis as in Synthesis Example 1, and purified to obtain a dried water-soluble vinyl copolymer group (ad-3). When the obtained water-soluble vinyl copolymer (ad-3) was analyzed in the same manner as in Synthesis Example 1, the carbonyl value was 23, the sulfur content was 5.2%, and the proportion of each constitutional unit was equivalent to that of the corresponding vinyl monomer. Converted to a monomer, methoxypolyethoxy (p = 9) ethyl maleic acid monoester sodium salt / polypropoxy (r =
2) A water-soluble vinyl copolymer having a number average molecular weight of 9200 and having a ratio of polyethoxy (q = 15) ethyl monoallyl ether / 2-acrylamido-methylpropanesulfonic acid sodium salt = 1/2/1 (molar ratio). It was

Comparative Synthesis Example 4 132 parts (0.251 mol) of methoxypolyethoxy (p = 9) ethyl maleic acid monoester, 210 parts (0) of polypropoxy (r = 2) polyethoxy (q = 15) ethyl monoallyl ether. .251 mol), 2-mercaptoethanol 8 parts (0.102 mol) and ion-exchanged water 2
60 parts was charged into a flask, the atmosphere in the flask was replaced with nitrogen, and the temperature of the reaction system was kept at 80 ° C. in a warm water bath. Next, 30 parts of a 10% aqueous solution of ammonium persulfate was added to initiate radical polymerization, and the polymerization reaction was continued for 12 hours to complete the polymerization. And 30% sodium hydroxide aqueous solution 3
3 parts were charged to neutralize. Synthesis Example 1 from neutralized reaction solution
Impurities were removed by dialysis in the same manner as described above, and a purified and dried water-soluble vinyl copolymer (ad-4) was obtained. When the water-soluble vinyl copolymer (ad-4) was analyzed in the same manner as in Synthesis Example 1, the carboxyl value was 40 and the ratio of each constitutional unit was represented by each corresponding vinyl monomer. Methoxypolyethoxy (p = 9) ) Ethyl maleic acid monoester sodium salt / polypropoxy (r = 2) polyethoxy (q = 1
5) A water-soluble vinyl copolymer having a number average molecular weight of 3500 and having a ratio of ethyl monoallyl ether = 1/1 (molar ratio).

Test Category 2 (Synthesis of Water-Soluble Vinyl Copolymer as Water-Reducing Agent) Synthesis Example 4 67.4 parts (0.62 mol) of sodium methacrylate,
100 parts (0.09 mol) of methoxypolyethoxy (n = 23) ethyl methacrylate, 32 parts (0.20 mol) of sodium methallyl sulfonate and 345 parts of ion-exchanged water were charged into the flask, and the atmosphere in the flask was changed. After nitrogen substitution, the temperature of the reaction system was maintained at 60 ° C. in a warm water bath.
Next, 20 parts of a 20% aqueous solution of ammonium persulfate was added to initiate radical polymerization, and the polymerization reaction was continued for 4 hours to complete the polymerization. And 48% sodium hydroxide aqueous solution 1
8 parts was added to neutralize. Synthesis Example 1 from neutralized reaction solution
Impurities were removed by the same dialysis as in (1), and purified to obtain a dried water-soluble vinyl copolymer (HP-1). When the water-soluble vinyl copolymer (HP-1) was analyzed in the same manner as in Synthesis Example 1, the carboxyl value was 182 and the sulfur content was 2.9.
% By weight, and the ratio of each structural unit is 15% by weight of sodium methacrylate when expressed by the corresponding vinyl monomer.
(0.14 mol), methoxypolyethoxy (n = 23)
50% by weight of ethyl methacrylate (0.05 mol), 15% by weight of sodium methallyl sulfonate (0.
09) which is a water-soluble vinyl copolymer having a number average molecular weight of 5,000.

Comparative Synthesis Example 5 Polyethoxyethyl monoallyl ether (q = 5, r = 0 in the above formula (4)) 334 parts (1.20)
Mol) and 100 parts of water are charged into a flask, the atmosphere in the flask is replaced with nitrogen, and the temperature of the reaction system is 95 ° C. in an oil bath.
Kept at. Next, an aqueous solution prepared by dissolving 139.3 parts (1.20 mol) of maleic acid and 14.2 parts of ammonium persulfate in 225 parts of water was added over 120 minutes. After the addition was completed, another 14.2 parts of 20% ammonium persulfate aqueous solution was added to 20 parts.
Added in minutes. After the addition was completed, the temperature was kept at 95 ° C. for 100 minutes to complete the polymerization. Then, 40% sodium hydroxide aqueous solution was added to neutralize. Impurities were removed from the neutralized reaction solution by the same dialysis as in Synthesis Example 1, and purified to obtain a dried water-soluble vinyl copolymer (rf-1).

Comparative Synthetic Example 6 Using a concrete water-reducing agent commercially available as an aqueous solution of polyethoxyethyl monoallyl ether, maleic anhydride and styrene copolymer, impurities were removed by the same dialysis as in Synthetic Example 1, purification and drying were carried out. To obtain a water-soluble vinyl copolymer (rf-2).

Test Category 3 (Concrete Preparation and Evaluation) -Concrete Preparation Under the mixing conditions shown in Table 3, a 50-liter pan-type forced mixer was used and ordinary Portland cement (C) (specific gravity =
3.16, Blaine value = 3350), fly ash (F) (specific gravity = 2.23, Blaine value = 3340), fine aggregate (S) (land sand (Shizuoka) specific gravity = 2.59, FM =
2.75) and coarse aggregate (G) (crushed stone (Ibaraki) specific gravity =
2.64 and GFM = 6.66) were sequentially added and kneaded for 15 seconds. Next, the slump loss inhibitor prepared in Test Category 1 and the water reducing agent prepared in Test Category 2 were added together with the mixing water. Table 4 shows the types of the slump loss preventing agent and the water reducing agent used here, and the amounts thereof used. The amounts of the water reducing agent and the slump loss preventing agent were adjusted so that the target slump value of the concrete composition was 18 ± 1 cm. In addition, in the compounding conditions of Table 3, an air amount adjusting agent was added together with the mixing water so that the air amount was 4.0 to 5.0 in each example.

[0069]

[Table 3]

Evaluation method Each concrete has a room temperature of 20 ° C., a humidity of 80% and a room temperature of 30.
It was prepared under the temperature and humidity conditions of 80 ° C and 80% humidity. Under each temperature and humidity condition, the slump value was measured immediately after kneading each concrete, after 30 minutes, after 60 minutes, and after 90 minutes. Furthermore, the 28-day compressive strength under 20 degreeC water curing was measured. The measurements are JIS-A1101 and JIS-, respectively.
It carried out according to A-1108. The results are shown in Tables 4 and 5.

In Tables 4 and 5, mix: mix condition of concrete shown in Table 3 temperature: temperature condition at the time of measuring slump temporal change amount used: solid content water reducing agent / type: water reducing agent prepared in test category 2 Water-soluble vinyl copolymer water reducing agent as used as: -Amount:%: Weight percentage of the amount of water reducing agent (HP) used relative to the total (C + F) of cement (C) and fly ash (F) (HP x 100 / (C + F) ) water reducing agent, the amount, kg / m ^3: concrete 1 m ³ of water reducing agent usage slump loss preventing agent-type: water-soluble vinyl copolymer slump loss preventing agents as slump loss preventing agent prepared in test Category 1 -Amount /%: Weight percentage (AD x 100) of the amount of slump loss inhibitor (AD) used with respect to the total (C + F) of cement (C) and fly ash (F)
/ (C + F)) slump loss preventing agents, usage · kg / m ^3: slump loss preventing agent amount in the concrete 1 m ³ AD / HP: weight ratio slump residual ratio of slump loss preventing agents for water reducing agent: (90 min Later slump / slump immediately after kneading) x 100

[0072]

[Table 4]

[0073]

[Table 5]

As is clear from Tables 4 and 5, if a certain amount of the above-mentioned slump loss preventing agent is used in addition to the water reducing agent, slump loss is small even when a large amount of fly ash is blended, and the strength developing property is high. It can be seen that a good concrete composition can be obtained.

Preferred examples of the concrete composition of the present invention are listed below.

1) Ordinary Portland cement (specific gravity =
3.16, Blaine value = 3350, same below) 250kg
/ M ³ , fly ash (specific gravity = 2.23, Blaine value = 3340, the same applies below) 153 kg / m ³ , fine aggregate (land sand (Shizuoka) specific gravity = 2.59, FM = 2.75, and so on) ) 643 kg / m ³ and coarse aggregate (crushed stone (Ibaraki) specific gravity =
2.64, GFM = 6.66, the same applies hereinafter) 1005 kg /
m ^3, water 176 kg / m ^3, slump loss preventing agent (AD-
1) 0.12 kg / m ³ , water reducing agent (HP-1) 0.73 kg
/ M ³ concrete composition.

2) Normal Portland cement 300 kg /
m³, Fly ash 227kg / m³, Fine aggregate 495kg / m
³And coarse aggregate 1024 kg / m³, Water 176kg / m³, Sura
Antiprosthesis (AD-2) 0.26kg / m³, Water reducing agent
(HP-1) 1.53kg / m ³Concrete set consisting of
A product.

3) Ordinary Portland cement 300 kg /
m³, Fly ash 281 kg / m³, Fine aggregate 445kg / m
³And coarse bone agent 1009kg / m³, Water 176kg / m³, Sura
Antiprosthesis (AD-3) 0.32kg / m³, Water reducing agent
(HP-1) 1.74 kg / m ³Concrete set consisting of
A product.

4) Ordinary Portland cement 250 kg /
m³, Fly ash 207kg / m³, Fine aggregate 563kg / m
³And coarse aggregate 1021 kg / m³, Water 176kg / m³, Sura
Antiprosthesis (AD-1) 1.67kg / m³, Water reducing agent
(HP-1) 0.41kg / m ³Concrete set consisting of
A product.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI // (C04B 28/02 C04B 18:08 Z 18:08 24:26 H 24:26 B A) 103: 30 103: 30 103 : 46 103: 46 (72) Inventor Katsuko Kaneko 2-4-2 Daisaku Sakura, Chiba Prefecture Chichibu Onoda Central Research Institute (72) Inventor Koichi Soeda 2-4-2 Daisaku Sakura City, Chiba Chichibu Onoda Central Research Institute, Inc. (72) Inventor Masahiro Iida 2-5 Minatomachi, Gamagori-shi, Aichi Takemoto Yushi Co., Ltd. (72) Inventor Mitsuo Kinoshita 2-5 Minatomachi, Gamagori-shi, Aichi Takemoto Yushi Co., Ltd. 72) Inventor Tomoo Takahashi 2-5 Minatomachi, Gamagori-shi, Aichi Within Takemoto Oil & Fat Co., Ltd. (56) Reference JP-A-10-17346 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 24/26

Claims (4)

(57) [Claims] 1. Cement (C), fly ash (F), slump loss inhibitor (AD) and water reducing agent (H).
P) containing a concrete composition, wherein the slump loss preventing agent has repeating units represented by the following formulas (1) and (2): (1) / (2) = 3/2 to 2/3 ( Number average molecular weight 1000 to 15 having a hydrocarbon group substituted with a sulfonate group as a terminal group.
000 water-soluble vinyl copolymer, and the water reducing agent is a water-soluble vinyl copolymer obtained by aqueous solution polymerization of monomers represented by the following formulas (5), (6) and (7). And the reaction ratio of the monomer is represented by the formula (5) / the monomer represented by the formula (6) / the monomer represented by the formula (7) = 9 to 47 /
It is a water-soluble vinyl copolymer having a molar ratio of 2 to 16/3 to 8 and a weight ratio of fly ash and cement (F /
C) is 3/7 to 6/5, and the weight ratio [((AD) / (C + F)) × 10 of the slump loss inhibitor to 100 parts by weight of the total of cement and fly ash (C + F).
0] is 0.01 to 1.0, and the weight ratio of the slump loss inhibitor (AD) to the water reducing agent (HP) (AD / H
P) is 0.1-10, The concrete composition characterized by the above-mentioned. [Chemical 1] (In the formula, p is a number from 1 to 25, q is a number from 1 to 40, and r is 1
The number of -10, M represents a hydrogen atom or a base) (In the formula, R ¹ , R ² and R ³ represent a hydrogen atom or a methyl group, M ¹ and M ² represent an alkali metal, an alkaline earth metal, ammonium or an organic amine, and n is a number of 5 to 50. Show) 2. The concrete composition according to claim 1, wherein the slump loss preventing agent is a water-soluble vinyl copolymer obtained through the following first step, second step and third step. First step: vinyl monomer represented by the following formula (3) / vinyl monomer represented by the following formula (4) = 3/2 to 2/3
(Mole ratio) Copolymerization in the presence of a radical initiator, followed by radical termination to obtain a radical terminated copolymer. Second step: a step of radically activating the copolymer by adding a radical initiator to a system containing the radical-terminated copolymer. Third step: Radical addition or radical addition polymerization of one or more monoethylenically unsaturated hydrocarbon monomers substituted with a sulfonate group to the radical-activated copolymer to produce sulfone as a terminal group. A step of obtaining a water-soluble vinyl copolymer having a hydrocarbon group substituted with an acid group. [Chemical 3] (In the formula, p, q, r and M are the same as above) 3. The slump loss inhibitor is a water-soluble vinyl copolymer radical-terminated in the first step by adding a compound having at least two hydroxyl groups and / or thiol groups in total in the molecule. The concrete composition according to claim 2. 4. The slump loss preventing agent comprises an allyl sulfonate, a methallyl sulfonate and a vinyl sulfonate as the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group in the third step. The concrete composition according to claim 2 or 3, which is a water-soluble vinyl copolymer using a monoethylenically unsaturated hydrocarbon monomer substituted with one kind of sulfonate group selected from the above.