JPH11157903A - Concrete composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition capable of providing concrete excellent in retaining properties of slump without deteriorating characteristics of the concrete even by using a large amount of a fly ash and good in development of the initial strength and long-term strength by compounding a water-reducing admixture together with a slump loss preventing agent having a specific structure. SOLUTION: This concrete composition contains a cement (C), a fly ash (F), a slump loss preventing agent (AD) and a water-reducing admixture (HP) and the AD is a water-soluble vinyl copolymer having recurring units represented by formulae I and 11 [(p) is 1-25; (q) is 1-40; (r) is 1-10; M is H or a base] in a ratio of (3/2) to (2/3) of formulae I/II (molar ratio), hydrocarbon groups substituted with a sulfonate group as terminal groups and 1,000-15,000 number-average molecular weight. The weight ratio of the AD based on 100 pts.wt. total amount of the C and F is 0.01-1.0 and the weight ratio of the AD based on the HP is 0.1-10. An acrylic or a methacrylic acid-based water-soluble vinyl copolymer and the like are used as the HP.

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 particularly, to a concrete composition which does not have a delay in setting and a decrease in initial strength even when a large amount of fly ash is mixed, has a small slump loss, and has 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 partially and effectively used as a concrete admixture, but is largely disposed of by landfill or the like. When fly ash is used as a concrete admixture in a concrete composition, 1) the workability of the concrete composition is improved, and 2) the structure of the concrete hardened body is densified, the long-term strength is increased, and water tightness and chemicals are increased. 3) the ability to control temperature cracking due to self-heating to alleviate the heat of hydration of concrete, and 4) the effect of suppressing the alkali-aggregate reaction. It has excellent properties as an admixture.

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

Conventionally, as a method for preventing slump loss of a concrete composition containing a large amount of fly ash, a proposal has been made to use a copolymer of maleic anhydride and polyoxyalkylenealkylalkenyl ether as a water reducing agent as a water reducing agent ( JP-A-8-34652). However, this proposal has a disadvantage that slump loss is not sufficiently prevented at a temperature around 30 ° C. On the other hand, as a method for preventing slump loss of a normal concrete composition containing no fly ash, a proposal has been made to use a water-soluble vinyl copolymer having slump loss prevention performance as a water reducing agent. Examples of such a water-soluble vinyl copolymer include:
1) A water-soluble vinyl copolymer obtained by copolymerizing (meth) acrylate (Japanese Patent Application Laid-Open Nos. 1-222657 and 4-209613) 2) Copolymerization of maleic anhydride and alkenyl ether Polymers and their derivatives
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 containing a large amount of fly ash, there is a drawback that slump loss is not sufficiently prevented by any of the water-soluble vinyl copolymers.

Conventionally, a concrete composition containing a large amount of fly ash causes problems such as a delay in setting and a decrease in the initial strength of the cured concrete. Has its own limitations. The fly ash cement specified in the JIS standard limits the replacement ratio of fly ash to cement to a maximum of 30%, and does not lead to the large use of fly ash at present.

[0006]

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

[0007]

Means for Solving the Problems The inventors of the present invention varied the blending amount of fly ash and studied the effect of preventing slump loss in a concrete composition by using a kind of polymer. If a specific amount of a specific water-soluble vinyl copolymer is blended, a concrete composition with low slump loss and good strength can be obtained even when a large amount of fly ash is blended, and the effective use of fly ash And completed the present invention.

That is, the present invention is 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 as follows: Equation (1) and Equation (2)
(1) / (2) = 3/2 to 2
/ 3 (molar ratio) having a hydrocarbon group substituted with a sulfonate group as a terminal group.
A water-soluble vinyl copolymer of 100 to 15000, and a polymerization ratio of the slump loss inhibitor to 100 parts by weight of the total of cement and fly ash (C + F) [((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 is to provide a concrete composition as follows.

[0009]

Embedded image

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

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The concrete composition of the present invention comprises:
Contains cement (C), fly ash (F), anti-slump loss agent (AD) and water reducing agent (HP). Here, examples of the cement used in the present invention include ordinary, early-strength, ultra-early-strength, moderate heat, sulfate-resistant, various portland cements such as white, and the like. In order to exert a great effect on
Ordinary Portland cement is preferred.

As fly ash, fly ash specified in JIS is of course used, and so-called coal ash in a broad sense including fly ash usually called raw powder and cinder ash is used. Can be.

The water-soluble vinyl copolymer as a slump loss inhibitor is obtained by replacing the repeating unit represented by the formula (1) or (2) with the repeating unit represented by the formula (1) / the formula (2). Repeating unit = 3/2 to 2/3 (molar ratio),
Preferably, it has a ratio of 11/9 to 9/11 (molar ratio). Both repeating units may be randomly linked or block linked. The water-soluble vinyl copolymer has, as its terminal group, a hydrocarbon group substituted with a sulfonate group. The terminal group may be present at one terminal 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 terminals. Is also good. As described below, such a terminal group is a monoethylenically unsaturated copolymer substituted with a sulfonic acid 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, the vinyl copolymer has a number average molecular weight (GPC method, in terms of pullulan, the same applies hereinafter) of 1,000 to 15,000, preferably 200
0-10000. In the water-soluble vinyl copolymer, the number of repetitions of the repeating unit represented by the formula (1), the number of repetitions of the repeating unit represented by the formula (2), and the ratio of the total amount of both repeating units to the terminal group are as described above. Can be appropriately selected in relation to the number average molecular weight as described above, but it is preferable that the total amount of both repeating units is 60% by weight or more of the whole, and is 80% by weight or more of the whole. More preferably, In addition, a sulfonate group means the group which consists of a sulfonate.

The repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) are each formed by copolymerizing a corresponding vinyl monomer. Examples of the vinyl monomer that forms the repeating unit represented by the formula (1) include methoxypolyethoxyethylmaleic acid monoester having 1 to 25 repeating oxyethylene units or a salt thereof. 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. No. Among them, an alkali metal salt of methoxypolyethoxyethylmaleic acid monoester in which the number of repeating oxyethylene units is 1 to 10 is preferable.

The vinyl monomer which forms the repeating unit represented by the formula (2) has 1 to 40 oxyethylene units and 1 to 10 oxypropylene units. And polypropoxy polyethoxyethyl 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
Polypropoxy polyethoxyethyl monoallyl ether is preferred.

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

The present invention does not particularly limit the content of the hydrocarbon group substituted with a sulfonate group as a terminal group in the water-soluble vinyl copolymer. 1) 1 to 2 mol for a substituted alkene group obtained by radical addition; 2) 3 to 2 for a polysubstituted alkene group obtained by radical addition polymerization.
4 moles are preferred.

The water-soluble vinyl copolymer as a slump loss inhibitor of the present invention can be obtained by various methods.
It is advantageously obtained through the following first, second and third steps. First step: The vinyl monomer represented by the following formula (3) or (4) is converted into 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) A step of copolymerizing in the presence of a radical initiator and then terminating the radical to obtain a radical-terminated copolymer. Second step: a step of adding a radical initiator to a system containing a radical-terminated copolymer to radically activate the copolymer. Third step: The radical-activated copolymer is subjected to radical addition or radical addition polymerization of one or more monoethylenically unsaturated hydrocarbon monomers substituted with a sulfonate group, and the terminal Obtaining a water-soluble vinyl copolymer having a hydrocarbon group substituted with a sulfonate group as a group.

[0019]

Embedded image

(Where p is a number from 1 to 25, and q is 1 to 4
An integer of 0, r represents an integer of 1 to 10, M represents 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
(Molar ratio) in the presence of a radical initiator. In this case, the vinyl monomer represented by the formula (3) is a vinyl monomer that forms the repeating unit represented by the formula (1), and the vinyl monomer represented by the formula (4) is It 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 aqueous solution polymerization using water or a mixed solvent of water and a water-soluble organic solvent. Can be. The radical initiator used in the copolymerization reaction of both vinyl monomers may be any one that decomposes at the copolymerization temperature to generate radicals, 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. Suitable amounts of these water-soluble radical initiators vary depending on the type of the water-soluble radical initiator and the vinyl monomer used. For example, when ammonium persulfate is used, the vinyl monomer represented by the formula (3) is used. The amount 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 above-mentioned radical copolymerization of the vinyl monomer, radical termination of the reaction system is appropriately performed to obtain a radical-terminated copolymer. Examples of the method for terminating the radical include a method of adding a radical terminator for forcibly decomposing and eliminating radicals to the reaction system.

As the radical terminator, a conventionally known compound can be used. As the radical terminator that can be advantageously used, 2-mercaptoethanol, 3
And 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 terminator is that a radical active site when a radical initiator in the reaction of the second step described below is added to the terminal of the obtained radical-terminated copolymer is provided. This makes it possible to efficiently and selectively perform radical addition or radical addition polymerization of a monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonic acid salt group in a third step described later.

The preferred amount of the radical terminator depends on the molecular weight of the radical-terminated copolymer, the type of the vinyl monomer, the aqueous solvent and the radical terminator. Is 1 to the total amount of the vinyl monomer represented by the formula (3) and the vinyl monomer represented by the formula (4), which forms a radical-terminated copolymer.
~ 50 mol%.

A conventionally known method 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 can range from room temperature to the boiling point of the aqueous solvent, but is preferably from 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, the copolymer radical-activated in the second step is subjected to radical addition or radical addition polymerization of a monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonic acid salt group. To obtain a water-soluble vinyl copolymer having a hydrocarbon group substituted with a sulfonate group as a terminal group.

The present invention does not particularly limit the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group to be subjected to radical addition or radical addition polymerization to a radical-activated copolymer. Is, for example,
1) Monomers 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 rate between the radical-activated copolymer and the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group depends on the type of the radical terminator used in the first step and on the second step. Is usually 1 to 10 mol, preferably 1.5 to 5 mol, per 1 mol of the radical-activated copolymer, although it depends on the kind of the radical initiator used in the above.
The radical addition or radical addition polymerization 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 with the monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group, the radical-activated A copolymer obtained by radical addition of one molecule per terminal radical active site of the copolymer or by radical addition polymerization of several molecules is obtained.
The monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonic acid group used in the present invention may be another sulfonic acid-based vinyl monomer, for example, (meth) acrylic acid such as 2- (meth) acryloxyethylsulfonate. Extremely high reaction selection as compared to those having a sulfonic acid group 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 restricted terminal structure due to its properties.

The water reducing agent used in the present invention is not particularly limited, and includes a (meth) acrylic acid-based water-soluble vinyl copolymer, a naphthalenesulfonic acid formalin condensate, a melaminesulfonic acid formalin condensate, and an aminosulfonic acid formalin condensate. Well-known concrete water reducing agents such as products, lignin sulfonic acid, hydroxycarboxylic acid and salts thereof are mentioned, and among them, (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 monomer represented by the formula (7). Water-soluble vinyl copolymer having a reaction ratio of the formula (5)
/ Monomer represented by formula (6) / monomer represented by formula (7) = 9 to 47/2 to 16/3 to 8
It is desirable that a water-soluble vinyl copolymer (molar ratio) be the main component.

[0035]

Embedded image

Wherein R ¹ , R ² and R ³ are H or C
H ₃ , M ¹ and M ^{2 each} represent an alkali metal, an alkaline earth metal, ammonium or an organic amine;
50 is shown)

Examples of the monomer represented by the formula (5) include alkali metal salts, alkaline earth metal salts and alkanolamine salts of acrylic acid and methacrylic acid. Examples of the monomer represented by the formula (6) include an alkali metal salt, an alkaline earth metal salt, and an alkanolamine salt of allylsulfonic acid and methallylsulfonic acid. Equation (7)
Is an esterified product of a polyalkylene glycol having an alkyl group blocked at one end such as methoxypolyethylene glycol and acrylic acid or methacrylic acid, and the number of moles of the polyalkylene glycol added is 5
~ 50.

When the reaction ratio of each monomer is out of the above range, when the obtained water-soluble vinyl copolymer is used as a water reducing agent, the dispersion fluidity becomes insufficient or the slump loss increases. 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
More preferably, it is set to 0/4 to 7 (molar ratio).

The water-soluble vinyl copolymer, which is a water reducing agent used in the present invention, is obtained by reacting each of the monomers as described above. Other monomers may be reacted for purposes as long as they are not impaired. For example, acrylamide, methacrylamide, acrylonitrile, acrylate 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 a 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 or suspension of a radical polymerization initiator is added to an aqueous solution or suspension of 0% by weight, and a solution of
It can be produced by performing a polymerization reaction for up to 5 hours.

The number-average molecular weight of the water-soluble vinyl copolymer thus produced is usually from 2,000 to 15,000, and each of the monomers represented by the formulas (5), (6) and (7) Is preferably adjusted to be in the range of 3000 to 10000. If the molecular weight is too large, the water reduction tends to decrease, and if the molecular weight is too small, the slump loss of the concrete tends to increase.

In the concrete composition of the present invention, the above-mentioned slump loss inhibitor is a weight ratio (AD) of the amount of slump loss inhibitor (AD) to 100 parts by weight of the total (C + F) of cement (C) and fly ash (F). / (C +
F) × 100)) is 0.01 to 1.0, preferably 0.1 to 1.0.
It is blended so as to be 02 to 0.5. When the weight ratio of the slump loss preventing agent in the concrete composition is smaller than the above ratio, the slump loss of the concrete composition is not improved, and when the weight ratio is larger than the above ratio, the concrete composition has A setting delay occurs.

The weight ratio (AD / HP) of the slump loss inhibitor (AD) to the water reducing agent (HP) is 0.1 to
The amount of the slump loss inhibitor 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 the weight ratio is larger than the above ratio, the fluidity of the concrete composition increases. The properties are too small 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 above-mentioned slump loss inhibitor is blended in the above-mentioned weight ratio, but when the mixing ratio of fly ash is large, the effect of the present invention is particularly large. Become noticeable. That is, it is preferable that the weight ratio (F / C) of fly ash and cement is 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 cement amount in the concrete composition is preferably from 250 to
The range of 350 kg / m ³ is preferable from the viewpoint of obtaining strength development, particularly good initial strength. Also, the amount of fly ash used is not particularly limited, but it is preferable that the unit fly ash amount in the concrete composition be in the range of 150 to 300 kg / m ³ from the viewpoints of using a large amount of fly ash and developing strength.

In preparing the concrete composition of the present invention, aggregate and water are mixed with the above components.
In general, fine aggregate (S) and coarse aggregate (G) are used in combination. Here, as fine aggregate, river sand, land sand, mountain sand,
Sea sand, crushed sand, etc. can be used, but especially fine aggregate, which has an unbalanced particle size distribution and is not suitable as ordinary concrete aggregate, also uses a large amount of fly ash and concrete By ensuring proper mixing, the fluidity of the concrete is ensured and can be suitably used as the aggregate of the present invention.

The coarse aggregate is river gravel, land gravel, mountain gravel,
Coarse aggregates such as crushed stones 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 is preferably in the range of 0.35 to 0.55. It is preferable for securing the fluidity of the concrete and a good slump value (8 to 22 cm).

[0049] In the concrete composition of the present invention, an air entraining agent may be added as required. As the air entraining agent, any of nonionic, anionic, oxyethylene, higher fatty acid and natural resin acid salt chemical compositions conventionally used as concrete air entraining agents 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 the concrete to 4.5 to 5.5%.

The concrete composition of the present invention can be used as a concrete hardening material, a quick-setting material, a high-strength admixture, a hydration accelerator, a setting agent, and other various concrete admixtures and reinforcing materials commonly used in concrete. Various fibers, steel and the like can also be used.

The method of mixing and kneading the above components is not limited, as long as the components can be uniformly mixed and kneaded. 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 0.5-1.
Adjusting to be 0 is mixing workability, flow value,
It is preferable in terms of the strength of the obtained concrete.

Various curing methods can be applied to the curing after the concrete is cast, and any of normal temperature curing, high temperature curing, normal pressure steam curing, and high temperature and high pressure curing can be used. It is possible to obtain a high-strength concrete hardened body by performing the combination.

[0053]

According to the concrete composition of the present invention, even if a large amount of fly ash is used, the properties of the concrete containing the fly ash are impaired by blending the specific slump loss inhibitor with the water reducing agent. In addition, it is possible to obtain concrete having excellent slump holding properties and excellent initial strength and long-term strength development.

[0054]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it should be understood that the present invention is by no means restricted to such specific Examples. In the following examples and the like, parts mean parts by weight, and% means% by weight excluding the amount of air.

Test Category 1 (Synthesis of Water-Soluble Vinyl Copolymer as Slump Loss Prevention Agent) Synthesis Example 1 132 parts (0.251 mol) of methoxypolyethoxy (p = 9) ethyl maleate monoester, polypropoxy ( r = 2) 210 parts (0.251 mol) of polyethoxy (q = 15) ethyl monoallyl ether, 8 parts (0.102 mol) of 2-mercaptoethanol and 2 parts of ion-exchanged water
60 parts were 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 charged to start 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 then 33 parts of a 30% aqueous sodium hydroxide solution was added to neutralize. The remaining catalyst and unreacted monomers are removed from the neutralized reaction solution using a cellulose tube membrane by dialysis, and the purified and dried copolymer is obtained from methoxypolyethoxy (p = 9) ethyl maleate monoester. Repeating unit formed (repeating unit represented by formula 1) / polypropoxy (r = 2) repeating unit formed from polyethoxy (q = 15) ethyl monoallyl ether (repeating unit represented by formula 2)
= 1/1 (molar ratio), molecular weight 3400, sulfur content 1.7%}. 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, and 40 parts of a 10% aqueous solution of ammonium persulfate was added to radically activate the copolymer.
142 parts (0.180 mol) of a 0% aqueous solution were charged, and the reaction was continued for 2 hours to complete the radical addition reaction. Impurities were removed from the reaction solution after the completion of the radical addition reaction 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 spectroscopy, pyrolysis gas chromatography, elemental analysis, GPC, titration and the like. As a result, the carboxyl number was 36 and the sulfur content was 3.3.
%, The ratio of each structural unit is converted to the corresponding vinyl monomer, and methoxypolyethoxy (p = 9) ethyl maleate monoester sodium salt / polypropoxy (r =
2) Polyethoxy (q = 15) ethyl monoallyl ether = 1/1 (molar ratio) water-soluble vinyl having a number average molecular weight of 3700 and having a terminal 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, the 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) ethyl maleate monoester, 376 parts of polypropoxy (r = 2) polyethoxy (q = 30) ethyl monoallyl ether (0. 251 mol), 11 parts of 3-mercapto-1,2-propanediol (0.102 mol)
And 260 parts of ion-exchanged water were charged into the flask, the atmosphere in the flask was replaced with nitrogen, and the temperature of the reaction system was maintained at 80 ° C. in a warm water bath. Next, 30 parts of a 10% aqueous solution of ammonium persulfate was charged to start 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 charged to terminate the radicals, and 33 parts of a 30% aqueous sodium hydroxide solution was further charged to neutralize. Impurities were removed from the neutralized reaction solution by dialysis in the same manner as in Synthesis Example 1, and a repeating unit formed of a purified and dried copolymer {methoxypolyethoxy (p = 9) ethyl maleate monoester (formula 1) Recurring 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 0.1.
86%｝ was obtained. Next, 740 parts of this copolymer (0.1 parts)
(00 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, and 60 parts of a 10% aqueous solution of ammonium persulfate was added to radically activate the copolymer.
208 parts (0.320 mol) of the aqueous solution was charged, and the reaction was continued for 2 hours to complete the radical addition polymerization reaction. As described above, impurities were removed from the reaction solution after the completion of the radical addition polymerization reaction by dialysis, 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 number was 26, the sulfur content was 2.0%, and the ratio of each structural unit was converted to the corresponding vinyl monomer. Methoxypolyethoxy (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 7,800 and having a terminal group formed by radical addition polymerization of sodium acid.

[0058]

[Table 1]

In Table 1, type a of the condition 1: type of the vinyl monomer which forms the repeating unit represented by the formula (1) type b of the condition 1: the type of the repeating unit represented by the formula (2) Kind of vinyl monomer to be formed Kind a / kind b (molar ratio) of condition 1: vinyl monomer to form a repeating unit represented by formula (1) / represented by formula (2) Condition 2: Type of radical terminator used Condition 3: Type of radical monomer used to form a repeating unit used for radically activating a radical-terminated copolymer Type of Initiator Type of Condition 4: Type of Monoethylenically Unsaturated Hydrocarbon Monomer Substituted with Sulfonate Group Used for Forming Terminal Group Amount of Use in Condition 4 (Mole): Radical Activated 1 mol of copolymer Charged Monoethylenically Unsaturated Hydrocarbon Monomer Substituted with Sulfonate Group for Water

A-1: Methoxypolyethoxy (p = 9)
Ethyl maleic acid monoester sodium salt a-2: Methoxy polyethoxy (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, analysis value 1: ratio (molar ratio) of (repeating unit represented by formula (1) / repeating unit represented by formula (2)) Analysis value 2: number of radical-terminated copolymers Average molecular weight Analytical value of 3 mol%: number of moles of monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group forming a terminal group per molecule of water-soluble vinyl copolymer Weight of analytical value 3 %: Ratio of hydrocarbon group substituted with a sulfonate group as a terminal group in water-soluble vinyl copolymer (% by weight) 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 maleate monoester, 210 parts of polypropoxy (r = 2) polyethoxy (q = 15) ethyl monoallyl ether (0 part) .251 mol), 2-acrylamido-2-methylpropanesulfonic acid sodium salt 29
Parts (0.126 mol) and 350 parts of ion-exchanged water were charged into a flask, the atmosphere in the flask was replaced with nitrogen, and the temperature of the reaction system was maintained at 80 ° C. in a warm water bath. Next, 30 parts of a 10% aqueous solution of ammonium persulfate was charged to start 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 the mixture. Impurities were removed from the neutralized reaction solution by the same dialysis as in Synthesis Example 1, and a purified and dried water-soluble vinyl copolymer group (ad-3) was obtained. 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 and the sulfur content was 5.2%. When converted to a monomer, methoxypolyethoxy (p = 9) ethyl maleate monoester sodium salt / polypropoxy (r =
2) Polyethoxy (q = 15) ethyl monoallyl ether / 2-acrylamide-methylpropanesulfonic acid sodium salt = 1/2/1 (molar ratio): a water-soluble vinyl copolymer having a number average molecular weight of 9200. Was.

Comparative Synthesis Example 4 132 parts (0.251 mole) of methoxypolyethoxy (p = 9) ethylmaleic acid monoester, 210 parts of polypropoxy (r = 2) polyethoxy (q = 15) ethylmonoallyl ether (0 part) .251 mol), 8 parts (0.102 mol) of 2-mercaptoethanol and 2 parts of ion-exchanged water
60 parts were 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 charged to start radical polymerization, and the polymerization reaction was continued for 12 hours to complete the polymerization. And 30% sodium hydroxide aqueous solution 3
Three parts were charged and neutralized. Synthesis Example 1 from neutralized reaction solution
The 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 carboxy value was 40, and the ratio of each structural unit was methoxypolyethoxy (p = 9) in terms of the corresponding vinyl monomer. ) Ethyl maleic acid monoester sodium salt / polypropoxy (r = 2) polyethoxy (q = 1
5) It was 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 methallylsulfonate and 345 parts of ion-exchanged water were charged into a flask, and the atmosphere in the flask was clarified. The temperature of the reaction system was maintained at 60 ° C. in a warm water bath by purging with nitrogen.
Next, 20 parts of a 20% aqueous solution of ammonium persulfate was charged to start radical polymerization, and the polymerization reaction was continued for 4 hours to complete the polymerization. And 48% aqueous sodium hydroxide solution 1
8 parts were charged and neutralized. Synthesis Example 1 from neutralized reaction solution
The impurities were removed by dialysis in the same manner as described above, and a purified and dried water-soluble vinyl copolymer (HP-1) was obtained. When the water-soluble vinyl copolymer (HP-1) was analyzed in the same manner as in Synthesis Example 1, the carboxyl number was 182 and the sulfur content was 2.9.
% By weight, and the ratio of each structural unit is represented by 15% by weight of sodium methacrylate in terms of the corresponding vinyl monomer.
(0.14 mol), methoxypolyethoxy (n = 23)
Ethyl methacrylate 50% by weight (0.05 mol), sodium methallylsulfonate 15% by weight (0.1%).
09), which was a water-soluble vinyl copolymer having a number average molecular weight of 5,000.

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

Comparative Synthesis 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 dialysis in the same manner as in Synthesis Example 1, purified, and dried. Thus, a water-soluble vinyl copolymer (rf-2) was obtained.

Test Category 3 (Preparation and evaluation of concrete) Preparation of concrete Under a mixing condition shown in Table 3, a 50-liter pan-type forced mixer was mixed with ordinary Portland cement (C) (specific gravity =
3.16, Brain value = 3350), Fly ash (F) (specific gravity = 2.23, Brain value = 3340), fine aggregate (S) (land sand (from Shizuoka) specific gravity = 2.59, FM =
2.75) and coarse aggregate (G) (crushed stone (Ibaraki product) specific gravity =
2.64, GFM = 6.66) were sequentially charged and kneaded for 15 seconds. Next, the anti-slump loss agent prepared in Test Category 1 and the water reducing agent prepared in Test Category 2 were mixed together and added simultaneously with water. Table 4 shows the types of the slump loss inhibitor and the water reducing agent used here and the amounts used. The amounts of the water reducing agent and the slump loss inhibitor were adjusted so that the target slump value of the concrete composition was 18 ± 1 cm. Further, under the blending conditions shown in Table 3, the air amount adjusting agent was added together with the mixing water so that the air amount was 4.0 to 5.0 in each case.

[0069]

[Table 3]

Evaluation method Each concrete was at room temperature 20 ° C., humidity 80% and room temperature 30.
It was prepared under temperature and humidity conditions of 80 ° C. and 80% humidity. Under each temperature and humidity condition, the slump value was measured immediately after kneading of each concrete, after 30 minutes, after 60 minutes and after 90 minutes. Further, the compressive strength under curing in water at 20 ° C. for 28 days was measured. The measurement was performed according to JIS-A1101, JIS-
A-1108 was performed. The results are shown in Tables 4 and 5.

In Tables 4 and 5, Formulation: Formulation conditions of concrete shown in Table 3 Temperature: Temperature condition at the time of measuring slump change over time Use amount: Solid content conversion Water reducing agent / type: Water reducing agent prepared in test category 2 Water-soluble vinyl copolymer as water-reducing agent, amount used,%: 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 × 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-%: The weight percentage of the amount of the slump loss inhibitor (AD) used to the total (C + F) of the cement (C) and the fly ash (F) (AD x 100)
/ (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 Slump after / slump immediately after kneading) × 100

[0072]

[Table 4]

[0073]

[Table 5]

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

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

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

2) Normal Portland cement 300 kg /
m^Three, Fly ash 227kg / m^Three, Fine aggregate 495kg / m
^ThreeAnd coarse aggregate 1024 kg / m^Three, Water 176kg / m^Three, Sura
0.26 kg / m^Three, Water reducing agent
(HP-1) 1.53 kg / m ^ThreeConcrete set consisting of
Adult.

3) Ordinary Portland cement 300 kg /
m^Three, Fly ash 281kg / m^Three, Fine aggregate 445kg / m
^ThreeAnd coarse aggregate 1009 kg / m^Three, Water 176kg / m^Three, Sura
0.32 kg / m^Three, Water reducing agent
(HP-1) 1.74 kg / m ^ThreeConcrete set consisting of
Adult.

4) Ordinary Portland cement 250 kg /
m^Three, Fly ash 207kg / m^Three, 563 kg / m fine aggregate
^ThreeAnd coarse aggregate 1021 kg / m^Three, Water 176kg / m^Three, Sura
1.67 kg / m of antiproliferative agent (AD-1)^Three, Water reducing agent
(HP-1) 0.41 kg / m ^ThreeConcrete set consisting of
Adult.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 133/14 C09D 133/14 135/02 135/02 (C04B 28/02 18:08 24:26) 103: 30 103: 46 (72) Inventor Masaru Kaneko 2-4-2 Daisaku, Sakura City, Chiba Prefecture Inside the Central Research Laboratory, Chichibu Onoda Co., Ltd. (72) Inventor Koichi Soeda 2-4-2 Daisaku, Sakura City, Chiba Prefecture Chichibu Onoda Noda Co., Ltd. Inside the research institute (72) Inventor Masahiro Iida 2-5 Minatomachi, Gamagori-shi, Aichi Prefecture Takemoto Yushi Co., Ltd. (72) Inventor Mitsuo Kinoshita 2-5 Minatomachi, Gamagori-shi, Aichi Prefecture Takemoto Yushi Co., Ltd. Tomoo Takemoto Yushi Co., Ltd. 2-5 Minatomachi, Gamagori-shi, Aichi Prefecture

Claims (5)

[Claims] 1. A cement (C), a fly ash (F), a slump loss inhibitor (AD) and a water reducing agent (H)
P) -containing concrete composition, wherein the slump loss inhibitor comprises repeating units represented by the following formulas (1) and (2): (1) / (2) = 3/2 to 2/3 ( Molar ratio), and having a hydrocarbon group substituted with a sulfonate group as a terminal group.
000 water-soluble vinyl copolymer, and the polymerization ratio of the slump loss inhibitor based on 100 parts by weight of the total of cement and fly ash (C + F) [((AD) / (C +
F)) × 100] is 0.01 to 1.0, and the weight ratio (AD / HP) of the slump loss preventing agent (AD) to the water reducing agent (HP) is 0.1 to 10 Concrete composition. Embedded image (Where p is a number from 1 to 25, q is a number from 1 to 40, r is 1
A number of 10 to 10, M represents a hydrogen atom or a base) 2. The concrete composition according to claim 1, wherein the slump loss inhibitor 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) A step of copolymerizing in the presence of a radical initiator and then terminating the radical to obtain a radical-terminated copolymer. Second step: a step of adding a radical initiator to a system containing a radical-terminated copolymer to radically activate the copolymer. Third step: The radical-activated copolymer is subjected to radical addition or radical addition polymerization of one or more monoethylenically unsaturated hydrocarbon monomers substituted with a sulfonic acid salt group, and sulfone is added as a terminal group. A step of obtaining a water-soluble vinyl copolymer having a hydrocarbon group substituted with an acid base. Embedded image (Where p, q, r and M are the same as above) 3. The slump loss inhibitor is a water-soluble vinyl copolymer which has been radically terminated by adding a compound having at least two hydroxyl groups and / or thiol groups in the molecule in the first step. The concrete composition according to claim 2. 4. The method according to claim 3, wherein the slump loss inhibitor is a monoethylenically unsaturated hydrocarbon monomer substituted with a sulfonate group in an allyl sulfonate salt, a methallyl sulfonate salt and a vinyl sulfonate salt. The concrete composition according to claim 2 or 3, wherein the concrete composition is a water-soluble vinyl copolymer using a monoethylenically unsaturated hydrocarbon monomer substituted with one type of sulfonate group selected from the group. 5. The water reducing agent is a water-soluble vinyl copolymer obtained by aqueous polymerization of monomers represented by the following formulas (5), (6) and (7), The ratio of the monomer represented by the formula (5) / the monomer represented by the formula (6) /
Monomer represented by the formula (7) = 9-47 / 2 to 16 / 3-
The concrete composition according to any one of claims 1 to 4, wherein a water-soluble vinyl copolymer having a molar ratio of 8 (molar ratio) is a main component. Embedded image (Wherein, 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 5 to 50)
Indicates the number of