JP3206982B2 - Admixture for concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an admixture for concrete,
More specifically, the present invention relates to an admixture that improves the compaction property of concrete and shortens compaction time in a concrete molding method using centrifugal force.

[0002]

2. Description of the Related Art Conventionally, concrete products such as piles, poles, fume tubes and the like have been manufactured by compaction by centrifugal force. In order to ensure the strength of the concrete used in these products, it is essential to add a high-performance water reducing agent, for example, an admixture such as a naphthalene-based or melamine-based admixture.

[0003]

However, concrete to which a high-performance water reducing agent is added has a certain fluidity (slump value).
Is possible, but the viscosity of concrete increases,
Compaction by centrifugal force tends to decrease. Therefore, an admixture that solves this problem, that is, an admixture capable of improving the fluidity of concrete used for centrifugal molding and shortening the compaction time due to a decrease in viscosity is desired.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on the relationship between the fluidity and the viscosity of concrete using an admixture, a surfactant and the like. It has been found that the use of the surfactant in combination increases the fluidity of the concrete, significantly lowers the viscosity of the concrete, and shortens the compaction time by centrifugal force, thereby completing the present invention.

That is, the present invention relates to (1) a copolymer obtained by polymerizing the monomers shown in the following (A) and (B) and / or a metal salt of the copolymer; A compound represented by the following general formula (C) is an essential component, and the copolymer (1) and / or its copolymer
The amount of the polymer salt added to the cement was 0.10 as a solid content.
To 1.0% by weight of the compound represented by the general formula (C).
0.0025 to 0.1% by weight as solids
Certain concrete admixtures are provided. (A) A polyalkylene glycol monoester monomer having an unsaturated bond. (B) Acrylic acid monomers and / or unsaturated dicarboxylic acid monomers.

[0006]

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The present invention relates to a copolymer obtained by polymerizing the monomers shown in the above (A) and (B) and / or a metal salt of the copolymer and a compound represented by the general formula (C). As described above, the fluidity and viscosity of centrifugal concrete are improved by using the compound to be used together. This effect cannot be obtained by using each component alone, but can be obtained only by using both together as in the present invention.

In the present invention, as the monomers constituting the copolymer (1), the monomer (A) is represented by the following general formula (I), and the monomer (B) is represented by the following general formula (II) It is preferred to use one or more monomers selected from the group of monomers represented by (III) and (III).

[0009]

Embedded image

Wherein R ₃ and R _{4 are} hydrogen, methyl, (CH ₂ )
_m2 COOM ₃ , ((CH ₂ ) _m3 COO) ₂ M ₄ , (CH ₂ ) _m4 CONH (AO)
_n2 X ₂ ,

[0011]

Embedded image

[0012] _{(CH 2) m6 COO (AO} ) n5 X 5 AO: oxyalkylene group m ₁ 2 to 3 carbon atoms ~m _6: 0 to 2 integer n ₁ ~n _5: 3~500 integer M ₃ : Hydrogen, monovalent metal, ammonium group, amino group or substituted amino group M ₄ : divalent metal X _{1 to} X ₅ : hydrogen, alkyl group having 1 to 3 carbon atoms]

[0013]

Embedded image

Wherein R ₅ , R ₈ : hydrogen, methyl group R ₆ , R ₇ , R ₉ , R ₁₀ : hydrogen, methyl group, or (CH ₂ ) _m7 COOM ₅ M ₅ : hydrogen, monovalent metal , Ammonium group, amino group or substituted amino group M ₆ : divalent metal m ₇ : integer of 0 to 2].

The polyalkylene glycol monoester of the monomer (A) used in the present invention includes, for example, triethylene glycol monoacrylate (hereinafter referred to as 3E-A), polyethylene glycol (molecular weight 200) monoacrylate (hereinafter referred to as 4E-A). A) Polyethylene glycol (molecular weight 400) monoacrylate (hereinafter referred to as 9E-A) Polyethylene glycol (molecular weight 600) monoacrylate (hereinafter referred to as 14E-A) Polyethylene glycol (molecular weight 1000) monoacrylate (hereinafter referred to as 23E-A) Polyethylene glycol (molecular weight 2000) monoacrylate (hereinafter referred to as 46E-A) Polyethylene glycol (molecular weight 4000) monoacrylate (hereinafter referred to as 92E-A) Polyethylene glycol (molecular weight 6000) monoacrylate (hereinafter referred to as 138E-A) Triethylene glycol monomethacrylate (Following 3E-M
A) Polyethylene glycol (molecular weight 200) monomethacrylate (hereinafter referred to as 4E-MA) Polyethylene glycol (molecular weight 400) monomethacrylate (hereinafter referred to as 9E-MA) Polyethylene glycol (molecular weight 600) monomethacrylate (hereinafter 14E-MA) Polyethylene glycol (molecular weight 1000) monomethacrylate (hereinafter referred to as 23E-MA) Polyethylene glycol (molecular weight 2000) monomethacrylate (hereinafter referred to as 46E-MA) Polyethylene glycol (molecular weight 4000) monomethacrylate (hereinafter referred to as 92E-MA) Polyethylene glycol monoesters such as polyethylene glycol (molecular weight 6000) monomethacrylate (hereinafter referred to as 138E-MA), polypropylene oxide monoesters, monoesters of polyethylene glycol / polypropylene oxide copolymer, and their glycols Derivatives obtained by etherifying the hydrogen at the terminal of the alkylene glycol include, for example, polyalkylene glycol monoesters having an added mole number of 500 or less, since the reactivity decreases with an increase in the mole number of the added alkylene glycol, and those glycol ends. A derivative obtained by etherifying hydrogen is preferred.

Examples of the acid having an unsaturated bond when synthesizing the polyalkylene glycol monoester include carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid;
Dicarboxylic acids and derivatives (unsaturated amides) such as maleic acid, fumaric acid, itaconic acid, citraconic acid, vinyl sulfonic acid, allyl sulfonic acid, sulfoethyl (meth)
Examples thereof include sulfonic acids such as acrylic acid and styrene sulfonic acid, and one or more selected from these groups can be used, but monocarboxylic acids, dicarboxylic acids, and derivatives thereof are more preferable.

The acrylic acid monomer of the monomer (B) used in the present invention includes acrylic acid, methacrylic acid, crotonic acid and metal salts thereof. As the unsaturated dicarboxylic acid monomer, maleic anhydride, maleic acid, itaconic anhydride, itaconic acid, citraconic anhydride, citraconic acid, fumaric acid, or a metal salt, an ammonium salt, an amine salt thereof, or Monoesters or diesters of these acids and polyalkylene glycols having 2 to 3 carbon atoms (glycol addition mole number 2 to 500) can be mentioned.

The proportion (% by weight) of the monomers (A) and (B) in the copolymer of the present invention is suitably in the range of (A) :( B) = 10-99: 90-1. More preferably, (A) :( B) = 40-99:
A range of 60 to 1 is preferred. When the monomer ratio of (A) is 10% or less, a sufficient bubble reduction effect cannot be obtained even when used in combination with the compound represented by the general formula (C).

The copolymer (1) of the present invention has a weight-average molecular weight (gel permeation chromatography / sodium polystyrene sulfonate) of 1,000 to 100,000.
Is good, and 5000 to 500,000 is more preferable. If the weight average molecular weight is less than 1,000, dispersibility is not sufficient. Also, 10
If it exceeds 00000, the cohesiveness becomes remarkable, which is not preferable.

The copolymer (1) of the present invention can be produced by a known method. For example, JP-A-59-162163
And Japanese Patent Publication No. Hei 2-11542, Japanese Patent Publication No. 2-7901, and Japanese Patent Publication No. 2-7897.

The use of the copolymers obtained by these production methods alone does not show the effect of reducing the viscosity which is the object of the present invention. In the present invention, one or more compounds represented by the general formula (C) are further used. The compound represented by the general formula (C) is an alkyldiphenyl ether sulfonate wherein R 1 and R ′ in the formula are H 2 or a saturated alkyl group having 8 to 18 carbon atoms.

The gravitational acceleration at the time of centrifugal molding of the concrete using the concrete admixture of the present invention is preferably in the range of 3G to 60G, more preferably in the range of 5G to 30G.

The amount of the admixture of the present invention added to concrete is 0.10 to 1.0% as a solid content of the copolymer (1) and / or a salt thereof based on the weight of cement, and is represented by the general formula (C). range der compound is from 0.0025 to 0.1% as a solid content that
In this range, the compaction time, especially due to the decrease in viscosity, is reduced.

The admixture of the present invention is used for concrete which is compacted by centrifugal force. The concrete product to be molded is not particularly limited for use in civil engineering, construction, secondary products and the like.

The admixture of the present invention can be used in combination with known defoamers and additives (materials). For example, AE agent, AE
Water reducer, superplasticizer, high-performance water reducer, retarder, early strength agent, accelerator, foaming agent, foaming agent, water retention agent, thickener, waterproofing agent, antifoaming agent, water-soluble polymer, surfactant And hydraulic compositions using cement paste, mortar, cements constituting concrete, blast furnace slag, fly ash, silica fume and the like.

[0026]

EXAMPLES Hereinafter, the present invention will be described specifically, but the present invention is not limited to these examples. In the examples, “%” and “parts” are based on weight unless otherwise specified.

The method for producing the copolymer (1) from the monomers (A) and (B) among the admixture components used in the present invention will be described below.

Production Example 1 (Production of Copolymer AB-1) 265 parts of water was charged into a reaction vessel equipped with a stirrer, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. 50 parts of polyethylene glycol monomethacrylate (9E-ME) and 50 parts of sodium methacrylate were charged and adjusted to pH 9 with 2 parts of a 30% aqueous sodium hydroxide solution. After the replacement with nitrogen, 10 parts of a 25% ammonium persulfate aqueous solution is added to initiate polymerization.
After 3 hours of reaction and completion of polymerization, the mixture was completely neutralized with 3 parts of a 30% aqueous sodium hydroxide solution to obtain a copolymer having a molecular weight of 7,500 (AB-
1) was obtained.

Production Example 2 (Production of copolymer AB-2) 150 parts of water was charged into a reaction vessel equipped with a stirrer, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 60 ° C in a nitrogen atmosphere. 60 parts of polyethylene glycol monoacrylate (92E-A) and 40 parts of sodium methacrylate were charged and adjusted to pH 9 with 2 parts of a 30% aqueous sodium hydroxide solution. After the replacement with nitrogen, 20 parts of a 15% aqueous ammonium persulfate solution is added to initiate polymerization. 3
After completion of the polymerization, the mixture was completely neutralized with 3 parts of a 30% aqueous solution of sodium hydroxide to obtain a copolymer having a molecular weight of 32,500 (AB-
2) was obtained.

Production Example 3 (Production of Copolymer AB-3) A reaction vessel equipped with a stirrer was charged with 265 parts of isopropyl alcohol, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to the boiling point in a nitrogen atmosphere. 80 parts of polyethylene glycol monomethacrylate (92E-MA) and 20 parts of sodium acrylate were charged and adjusted to pH 8 with 2 parts of a 30% aqueous sodium hydroxide solution. After the replacement with nitrogen, 30 parts of a 10% solution of benzoyl peroxide in isopropyl alcohol is added to initiate polymerization.
After 5 hours of reaction to complete the polymerization, the mixture was completely neutralized with 3 parts of a 30% aqueous sodium hydroxide solution to obtain a copolymer having a molecular weight of 460,000 (AB
-3) was obtained.

Production Example 4 (Production of Copolymer AB-4) 100 parts of water and 70 parts of isopropyl alcohol were charged into a reaction vessel equipped with a stirrer, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to the boiling point in a nitrogen atmosphere. Charge 50 parts of polyethylene glycol monoacrylate (14E-A), 20 parts of polyethylene glycol monomethacrylate (14E-MA), 15 parts of sodium acrylate, and 15 parts of sodium methacrylate, 25%
The pH was adjusted to 7.5 with 1 part of an aqueous sodium hydroxide solution. After the replacement with nitrogen, 10 parts of a 20% ammonium persulfate aqueous solution is added to initiate polymerization. After 6 hours of reaction and completion of the polymerization, the mixture was completely neutralized with 3 parts of a 30% aqueous sodium hydroxide solution to give a molecular weight of 69000.
(AB-4) was obtained.

The alkyl diphenyl ether sulfonate of the general formula (C) used in the examples is shown below.

[0033]

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Materials used for concrete mixing

[0035]

[Table 1]

Material W: Tap water C: Central ordinary Portland cement Specific gravity = 3.16 S: Kinokawa river sand Specific gravity = 2.56 G: Takarazuka crushed stone Specific gravity = 2.62 s / a: Sand / sand + gravel (volume ratio) Concrete properties Test method The slump was adjusted to 3 ± 1 cm by adding the admixture of the present invention and a comparative admixture in the concrete composition shown in Table 1. Thereafter, 13 kg of concrete was put into a mold having a diameter of 20 cm and a height of 30 cm, and compacted by centrifugation. The strength of the hardened concrete was measured by the compaction time and the degree of concrete compaction was visually observed.・ Centrifugation conditions Gravity acceleration 5G for 1 minute, then 15G for 2 minutes, then 30G
, 2 minutes, 4 minutes, and 6 minutes later. -Concrete tightening degree X: Gravel exposure, inner and outer surfaces are extremely poor in smoothness △: Inner and outer surfaces are slightly inferior in smoothness ○: Smoothly tightened The test results are shown in Table 2.

[0037]

[Table 2]

Note) * 1: 28 samples of 4 minutes at 30 G under the above-mentioned centrifugation conditions
Strength after 2 days * 2: Naphthalenesulfonic acid formalin condensate sodium salt (Mighty 150, manufactured by Kao Corporation) * 3: There is no concrete flow effect, and a predetermined slump cannot be obtained.

[0039]

EFFECTS OF THE INVENTION The admixture of the present invention has a remarkable reduction in air bubbles on the surface of a concrete product produced by a concrete molding method by centrifugal force, and the surface appearance is significantly improved. Repair work can be streamlined.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C04B 24/00-28/36 CAS

Claims (3)

(57) [Claims] 1. A copolymer obtained by polymerizing the monomers shown in the following (A) and (B) and / or a metal salt of the copolymer, and (2) a general formula represented by the following general formula: The compound represented by (C) as an essential component, and the copolymer of (1) and / or a salt of the copolymer.
0.10-1.0 weight as solids added to cement
%, Addition of the compound represented by the general formula (C) to cement
A concrete admixture having a solid content of 0.0025 to 0.1% by weight . (A) A polyalkylene glycol monoester monomer having an unsaturated bond. (B) Acrylic acid monomers and / or unsaturated dicarboxylic acid monomers. Embedded image 2. The admixture for concrete according to claim 1, which is used for concrete molded by applying a centrifugal force of a gravitational acceleration of 3 G to 60 G. 3. A monomer (A) having the following general formula (I):
3. The concrete admixture according to claim 1, wherein (B) is at least one monomer selected from the group consisting of monomers represented by the following general formulas (II) and (III). Embedded image Wherein R ₃ and R _{4 are} hydrogen, a methyl group, (CH ₂ ) _m2 COOM ₃ , [(C
H ₂ ) _m3 COO] ₂ M ₄ , (CH ₂ ) _m4 CONH (AO) _n2 X ₂ , _{(CH 2) m6 COO (AO} ) n5 X 5 AO: oxyalkylene group m ₁ 2 to 3 carbon atoms ~m _6: integer n ₁ of 0~2 ~n _5: 3~500 integer M _3: hydrogen, Monovalent metal, ammonium group, amino group or substituted amino group M ₄ : divalent metal X _{1 to} X ₅ : hydrogen, alkyl group having 1 to 3 carbon atoms] [Wherein, R ₅ and R ₈ : hydrogen, methyl group R ₆ , R ₇ , R ₉ , R ₁₀ : hydrogen, methyl group, or (CH ₂ ) _m7 COOM ₅ M ₅ : hydrogen, monovalent metal, ammonium group , Amino group or substituted amino group M ₆ : divalent metal m ₇ : integer of 0 to 2]