KR20180086148A - Hydraulic composition - Google Patents

Abstract

The present invention provides a hydraulic composition containing an AE agent and water-soluble cellulose ether, which has excellent frost damage resistance and experiences little bleeding. The hydraulic composition comprises at least the AE agent, the water-soluble cellulose ether, a defoamer, cement, water, and an aggregate. The AE agent contains a fatty acid-based surfactant consisting of: a fatty acid represented by general formula (1), an alkali metal salt of the fatty acid represented by general formula (1), a lower alkylamine salt of the fatty acid represented by general formula (1) or a lower alkanolamine salt of the fatty acid represented by general formula (1); and a nonionic surfactant consisting of a polyoxyethylene phenyl ether represented by general formula (2). In formula (1), R^1 is a C12-C24 alkyl or alkenyl group. In formula (2), R^2 is a C8 or C9 alkyl group and n is an integer of 1 to 50.

Description

Hydraulic composition {HYDRAULIC COMPOSITION}

The present invention relates to a hydraulic composition, and more particularly, to a hydraulic composition having excellent anti-freeze property and less bleeding.

Water-soluble cellulose ethers have been used for the purpose of separating the hydraulic composition such as concrete, resistance to bleeding, imparting fluidity, and the like.

However, in the hydraulic composition to which the water-soluble cellulose ether is added, the air amount of the hydraulic composition may become excessively large in order to carry out air bubbles during the kneading of the hydraulic composition due to the surfactant action of the water-soluble cellulose ether.

Since the diameter of the air bubbles of the air introduced by the water-soluble cellulose ether is large and is not a bubble effective for anti-rotatory properties, an operation of removing coarse bubbles by using an antifoaming agent has been carried out.

Further, in order to ensure the anti-dissolution properties of the hydraulic composition, fine bubbles having a diameter of about 25 to 250 탆 are required to be carried in the hydraulic composition, and an air entraining agent such as an air entraining agent is usually used.

As described above, in the case of a hydraulic composition using a water-soluble cellulose ether, it is necessary to use a defoaming agent for the purpose of defoaming air from the water-soluble cellulose ether to a predetermined amount of air. The defoaming agent is a water-soluble cellulose ether- Not only air but also fine bubbles originating from AE are removed.

With respect to the above-mentioned problems, for example, use of O-2,3-dihydroxypropyl cellulose having a low air entraining property has been proposed as a water-soluble cellulose ether (Patent Document 1).

A method of using a hollow microsphere instead of AE has also been proposed (Patent Document 2).

In addition, a useful AE system for a cement composition using fly ash has been proposed (Patent Document 3).

Japanese Patent Application Laid-Open No. 6-206752 Japanese Patent Laid-Open No. 8-59327 Japanese Patent Laid-Open No. 8-59320

However, in the method of Patent Document 1, the use of O-2,3-dihydroxypropylcellulose makes it possible to satisfy the toughness, but since the thickening property in the hydraulic composition is insufficient, the material separation resistance, There is a possibility that the effect and the fluidity-imparting effect are lower than that of ordinary cellulose ether.

On the other hand, in the method of Patent Document 2, since the fluctuation of the amount of air in each batch is large, it is difficult to control the amount of air, and furthermore, the hollow microspheres are expensive, which leads to high cost.

In addition, the method of Patent Document 3 is not sufficient in terms of bleeding, maintenance of the air amount, and the like.

SUMMARY OF THE INVENTION The object of the present invention is to provide a hydraulic composition comprising an AE agent and a water-soluble cellulose ether having excellent anti-freeze properties and little bleeding.

DISCLOSURE OF THE INVENTION The inventors of the present invention have made intensive investigations in order to achieve the above object. As a result, they have found that a hydraulic composition having excellent anti-dissolution properties and low bleeding can be obtained by using a specific AE agent and a water-soluble cellulose ether, .

That is,

What is claimed is: 1. A water absorbent composition comprising at least an AE agent, a water-soluble cellulose ether, a defoaming agent, a cement, water and an aggregate, wherein the AE agent comprises a fatty acid represented by the following general formula (1) A fatty acid surfactant comprising a lower alkylamine salt of a fatty acid represented by the following general formula (1) or a lower alkanolamine salt of a fatty acid represented by the following general formula (1) A nonionic surface active agent comprising polyoxyethylene phenyl ether,

(In the formula, R ¹ represents an alkyl group or an alkenyl group having 12 to 24 carbon atoms.)

(Wherein R ² represents an alkyl group having 8 or 9 carbon atoms, and n represents an integer of 1 to 50)

2. The hydraulic composition of claim 1, wherein the water-soluble cellulose ether is hydroxypropylmethylcellulose or hydroxyethylmethylcellulose,

(A / B) of the mole fraction (A) of the methoxy group-substituted hydroxypropyl group to the mole fraction (B) of the non-methoxy group-substituted hydroxypropyl group in the hydroxypropyl methylcellulose, Is from 0.2 to 1.0,

Wherein the ratio (A / B) of the mole fraction (A) of the methoxy group-substituted hydroxyethyl group to the mole fraction (B) of the non-methoxy group substituted hydroxyethyl group in the hydroxyethyl methylcellulose is 2.0 to 3.0 2,

5. The hydraulic composition according to any one of 1 to 4, wherein the AE agent is contained in an amount of 0.0001 to 0.5% by mass based on the cement,

6. A hydraulic composition according to any one of < RTI ID = 0.0 > 1-5, < / RTI &

.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a hydraulic composition which is excellent in anti-freeze property and has little bleeding.

Hereinafter, the present invention will be described in detail.

The hydraulic composition of the present invention contains at least an AE agent, a water-soluble cellulose ether, a defoaming agent, cement, water and an aggregate, wherein the AE agent is a fatty acid represented by the following general formula (1), a fatty acid represented by the following general formula (1) A fatty acid-based surfactant comprising an alkali metal salt, a lower alkylamine salt of a fatty acid represented by the following general formula (1) or a lower alkanolamine salt of a fatty acid represented by the following general formula (1) And a nonionic surfactant comprising polyoxyethylene phenyl ether represented by the following general formula (1).

In the general formula (1), the alkyl group or alkenyl group having 12 to 24 carbon atoms represented by R ¹ may be either linear or branched.

Specific examples of the fatty acid represented by the general formula (1), myristic acid (having 1 to 4 carbons, R ^1: a carbon number of 13), penta to acids (carbon number of 15, R ^1: a carbon number of 14), palmitic acid (carbon atoms 16, R ^1, : having a carbon number of 15), Mar taught acid (carbon atoms 17, R ^1: a carbon number of 16), stearic acid (carbon number 18, R ^1: a carbon number 17), oleic acid (carbon number 18: R ^1: a carbon number of 17 and double bond number 1), linoleic acid (Carbon number 18: R ¹ : carbon number 17, number of double bonds 2), linolenic acid (carbon number 18: R ¹ : carbon number 17, number of double bonds 3)

Specific examples of the alkali metal salts of fatty acids represented by the formula (1) include sodium salts and potassium salts. Specific examples of the lower alkylamine salts of fatty acids include triethylamine salts, diisopropylethylamine salts and the like. Specific examples of the lower alkanolamine salts of fatty acids include monoethanolamine salts and triethanolamine salts.

Particularly, as the fatty acid surfactant, tall oil fatty acid saponification, oleic acid saponite and linoleic acid saponification which are a mixture of oleic acid, linoleic acid, palmitic acid and stearic acid are preferable, and tall oil fatty acid saponification is more preferable. As the saponification, sodium saponification is preferable.

On the other hand, in the nonionic surfactant of the general formula (2), the alkyl group having 8 or 9 carbon atoms for R ² may be either straight chain or branched chain.

Examples of the straight-chain alkyl group having 8 or 9 carbon atoms include an n-octyl group and an n-nonyl group.

Examples of the alkyl group having 8 or 9 carbon atoms in the branched chain include isooctyl, isononyl and the like.

Specific examples of the nonionic surfactant include polyoxyethylene phenyl ether such as polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether.

The addition mole number (n) of ethylene oxide can improve the air entraining performance and is 1 to 50 in view of reducing the amount of the AE agent used. Considering the tendency that the solubility in water is lowered, 30 is preferable.

The AE agent used in the present invention may contain at least the fatty acid surfactant and the nonionic surfactant. If either the fatty acid surfactant or the nonionic surfactant is used alone, the bubble space coefficient of the hydraulic composition becomes larger than 250 mu m, so that sufficient anti-dissolution ability can not be obtained.

The ratio of the fatty acid surfactant to the nonionic surfactant in the AE agent is preferably in the range of 1 to 99: 99 to 1, more preferably 20 to 20, in terms of the mass ratio of the fatty acid surfactant: nonionic surfactant. More preferably 80:80 to 20, still more preferably 40 to 60:60 to 40.

The amount of the AE agent used is preferably from 0.0001 to 0.5% by mass, more preferably from 0.001 to 0.3% by mass, based on the cement, though it depends on the desired air amount and the kind of the material used in the hydraulic composition.

Examples of the water-soluble cellulose ether include hydroxypropylmethylcellulose, hydroxyethylmethylcellulose and the like. The water-soluble cellulose ether is preferably non-ionic, and may be used singly or in combination of two or more kinds, depending on the purpose.

In hydroxypropyl methylcellulose, the degree of substitution (DS) of the methoxy group is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, and the number of moles of substitution (MS) of the hydroxypropoxy group is preferably 0.1 to 0.6 , More preferably from 0.1 to 0.5.

In hydroxyethyl methylcellulose, the substitution degree (DS) of the methoxy group is preferably 1.0 to 2.2, more preferably 1.3 to 1.9, and the number of moles (MS) of the hydroxyethoxy group is preferably 0.1 to 0.6 , And more preferably from 0.2 to 0.4.

The degree of substitution of the alkyl group and the number of moles of the hydroxyalkyl group of the water-soluble cellulose ether can be determined by converting a value that can be measured by the degree of substitution analysis of hypromellose (hydroxypropylmethylcellulose) described in the 17th Japanese Pharmacopoeia Can be obtained.

The ratio (A / B) of the mole fraction (A) of the methoxy group-substituted hydroxypropyl group to the mole fraction (B) of the non-methoxy group-substituted hydroxypropyl group in hydroxypropyl methylcellulose is preferably from the viewpoint of maintaining the air amount , Preferably 0.2 to 1.0, more preferably 0.3 to 0.8, still more preferably 0.3 to 0.7.

The ratio (A / B) of the mole fraction (A) of the methoxy group substituted hydroxyethyl group to the mole fraction (B) of the non-methoxy group substituted hydroxyethyl group in hydroxyethyl methylcellulose is preferably from the standpoint of maintaining the air amount Is 2.0 to 3.0, more preferably 2.2 to 2.8.

(A) of the methoxy group substituted hydroxyalkyl group in which the hydroxyl group of the hydroxyalkyl group (hydroxypropyl group, hydroxyethyl group) is further substituted with a methoxy group, and the mole fraction (A) of the methoxy group substituted hydroxyalkyl group As a method for analyzing the molar fraction (B) of the alkyl group, as described in Marcomolecules, 20, 2413 (1987) and Fibers Journal, 40, T-504 (1984), a method in which a water-soluble hydroxyalkylalkyl cellulose is hydrolyzed After decomposition, neutralization, followed by reduction with sodium borohydride, filtration and purification, acetylation, and mass spectrometry using ¹³ C-NMR, liquid chromatography, and gas chromatography were carried out at 150 to 280 ° C The temperature is raised at a rate of 2.5 ° C per minute, and the temperature is maintained at 280 ° C for 10 minutes.

The molar fractions (A) and (B) of the present invention were calculated based on the hydroxyalkyl groups substituted with only one of the hydroxyl groups at positions 2, 3 and 6 of each glucose ring. Therefore, the fact that any of the hydroxyl groups at positions 2, 3 and 6 of the glucose ring is already substituted by a hydroxyalkyl group, and the hydroxyl group of the hydroxyalkyl group is further substituted by a hydroxyalkyl group, the mole fractions (A) and ), It is not an object of calculation.

The aqueous solution viscosity of the water-soluble cellulose ether at 2 ° C at 20 ° C is preferably 10 to 200,000 mPa · s, more preferably 50 to 100,000 mPa · s at 20 rpm of the BH type viscometer from the viewpoint of bleeding reduction , Still more preferably 100 to 50,000 mPa · s.

The amount of the water-soluble cellulose ether to be added is preferably 0.01 to 5 kg, more preferably 0.05 to 3 kg, and still more preferably 0.1 to 2 kg, per 1 m 3 of the hydraulic composition, from the viewpoint of bleeding reduction and fluidity.

Examples of the defoaming agent include defoaming agents such as oxyalkylene type, silicone type, alcohol type, mineral oil type, fatty acid type, fatty acid ester type and the like.

Specific examples of oxyalkylene antifoaming agents include polyoxyalkenes such as (poly) oxyethylene and (poly) oxypropylene adducts; Diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene 2-ethylhexyl ether, higher alcohols having 8 or more carbon atoms, and secondary alcohols having 12 to 14 carbon atoms. (Poly) oxyalkylene alkyl ethers such as propylene adduct; (Poly) oxyalkylene (alkyl) aryl ethers such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3- Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol; (Poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol oleate, ethylene glycol distearate, and polyoxyalkylene oleate; (Poly) oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolauric acid ester and polyoxyethylene sorbitan trioleic acid ester; (Poly) oxyalkylene alkyl (aryl) ether sulfuric acid ester salts such as polyoxypropylene methyl ether sodium sulfate and polyoxyethylene dodecyl phenol ether sodium sulfate; (Poly) oxyalkylene alkyl phosphates such as poly (oxyethylene) stearyl phosphate; (Poly) oxyalkylene alkylamines such as polyoxyethylene laurylamine; Polyoxyalkylene amides, and the like.

Specific examples of the silicone antifoaming agent include dimethyl silicone oil, silicone paste, silicone emulsion, organic modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), and fluorosilicone oil.

Specific examples of the alcoholic defoaming agent include octyl alcohol, 2-ethylhexyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.

Specific examples of the mineral oil defoaming agent include kerosene and liquid paraffin.

Specific examples of fatty acid defoaming agents include oleic acid, stearic acid, and alkylene oxide adducts thereof.

Specific examples of the fatty acid ester defoaming agent include glycerin monolysinoleate, alkenyl succinic acid derivatives, sorbitol monolaurate, sorbitol trioleate, natural wax, and the like.

Among them, in the present invention, it is preferable to use an oxyalkylene-based defoaming agent from the viewpoint of defoaming performance.

The amount of the antifoaming agent to be added is preferably 0.01 to 30 mass%, more preferably 0.1 to 20 mass%, and still more preferably 1 to 10 mass%, based on the water-soluble cellulose ether, from the viewpoint of air volume control.

Examples of the cement include various types of cements such as Portland cement, crude steel Portland cement, medium heat Portland cement, blast furnace cement, silica cement, fly ash cement, alumina cement, and hardened steel portland cement.

The content of the cement is preferably from 270 to 800 kg per 1 m 3 of the concrete when the hydraulic composition is concrete and from 1 to 3 kg of the mortar when the hydraulic composition is mortar from the viewpoint of securing strength, to be. Examples of the concrete include ordinary concrete, high fluidity concrete and heavy fluidized concrete. Examples of the mortar include tile-attached mortar, repair mortar, and self-leveling material.

Examples of the water include tap water and seawater, and tap water is preferable from the standpoint of salting out.

The water / cement ratio (mass%) in the hydraulic composition is preferably 30 to 75 mass%, more preferably 45 to 65 mass% from the viewpoint of material separation.

Aggregates include fine aggregates and coarse aggregates.

As the fine aggregate, river sand, mountain sand, land sand, crushed sand and the like are preferable.

The grain size (maximum grain size) of the fine aggregate is preferably 5 mm or less.

As the coarse aggregate, strong gravel, mountain gravel, land gravel, crushed stone and the like are preferable.

The grain size (maximum grain size) of the coarse aggregate is larger than the grain size of the fine aggregate, preferably not more than 40 mm, more preferably not more than 25 mm.

The content of the fine aggregate is preferably from 400 to 1,100 kg, more preferably from 500 to 1,000 kg, per 1 m 3 of the concrete when the hydraulic composition is concrete, and preferably from 1 to 3 kg of the mortar when the hydraulic composition is mortar Preferably 500 to 2,000 kg, more preferably 600 to 1,600 kg.

The content of the coarse aggregate is preferably 600 to 1,200 kg, more preferably 650 to 1,150 kg per cubic meter of concrete when the hydraulic composition is concrete.

The aggregate percentage (volume percentage) in the aggregate is preferably 30 to 55% by volume, more preferably 35 to 55% by volume, still more preferably 30 to 55% by volume, in view of fluidity or sufficient strength when the hydraulic composition is concrete By volume is 35 to 50% by volume.

Also, the fine aggregate ratio (volume%) = volume of fine aggregate / (volume of fine aggregate + volume of coarse aggregate) × 100.

In the hydraulic composition of the present invention, since a high flow retentivity is obtained with a small amount of water, a water reducing agent can be added as needed.

Examples of the water reducing agent include lignin type, polycarboxylic acid type, and melamine type.

Specific examples of the lignin-based water reducing agent include ligninsulfonic acid salts and derivatives thereof.

Specific examples of the polycarboxylic acid-based water reducing agent include polycarboxylic acid ether-based, polycarboxylic acid ether-based and crosslinked polymer complexes, polycarboxylic acid ether-based and oriented polymer complexes, polycarboxylic acid ether- , A polyether carboxylic acid based polymer, a maleic acid copolymer, a maleic acid ester copolymer, a maleic acid derivative copolymer, a carboxyl group-containing polyether group, a polycarbonate-containing polyamide polymer having a terminal sulfone group, Graft copolymers, polycarboxylic acid-based compounds, and polycarboxylic acid ether-based polymers.

Specific examples of the melamine-based water reducing agent include melamine sulfonic acid formalin condensates, melamine sulfonic acid salt condensates, melamine sulfonic acid salt polyol condensates and the like.

The addition amount of the water reducing agent is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, based on the cement, from the viewpoint of fluidity of the hydraulic composition.

In the hydraulic composition, other AE agents may be used in combination as needed in order to secure a predetermined amount of air and to obtain durability of the hydraulic composition.

Other AE agents include AE agents such as anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, rosin surfactants, and the like.

Examples of the anionic surfactant system include a carboxylic acid type, a sulfuric acid ester type, a sulfonic acid type, and a phosphoric acid ester type.

Examples of the cationic surfactant system include an amine salt type, a primary amine salt type, a secondary amine salt type, a tertiary amine salt type, and a quaternary amine salt type.

Examples of the nonionic surfactant system include an ester type, an ester type, an ether type, an ether type, and an alkanolamide type.

Examples of the amphoteric surfactant system include an amino acid type and a sulfobetaine type.

Examples of the rosin surfactant system include abietic acid, neoabietic acid, palustric acid, pimaric acid, isopimaric acid, and dehydroabietic acid.

In order to control the physical properties of the hydraulic composition (fresh concrete or fresh mortar) immediately after kneading, the hydraulic composition of the present invention may contain a coagulation accelerator such as calcium chloride, lithium chloride or calcium formate, or a coagulation promoter such as sodium citrate or sodium gluconate Delay agents can be used as needed.

Further, in the hydraulic composition of the present invention, an expansion agent of a high phosphorus system or a lime-based resin can be added as needed in order to prevent shrinkage due to curing and drying and cracking accompanying temperature stress due to heat of hydration reaction of cement.

The hydraulic composition of the present invention described above can be produced by a conventional method.

For example, water-soluble cellulose ether, antifoaming agent, cement and aggregate (fine aggregate, coarse aggregate) are put into a forced biaxial kneading mixer, and dry mixing is performed. Thereafter, water, a water reducing agent and an AE agent are added and kneaded to obtain a hydraulic composition. The AE agent is used in consideration of the amount of defoamer used so that the air amount is 4.5 + 1.5%.

In the present invention, the bubble space coefficient of the hydraulic composition is preferably 25 to 250 占 퐉, more preferably 25 to 230 占 퐉, from the viewpoint of anti-skid properties. In addition, the bubble interval coefficient can be measured by, for example, an air void analyzer (AVA; trade name) manufactured by Autorun Instruments.

[Example]

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Materials used]

(1) AE agent; Table 1

(2) water-soluble cellulose ethers; Table 2

(3) Defoamer 1; SN Deformer 14HP, an oxyalkylene-based defoaming agent from Sanofo Chemicals

    Defoamer 2; AGITAN299, an oxyalkylene antifoaming agent manufactured by MUNZING CHEMIE GmbH

(4) Cement (C); Usually Portland cement (Pacific cement), density; 3.16 g / cm3

(5) water (W); tap water

(6) fine aggregate (S); A sand having a maximum particle diameter of 5 mm, an absorption coefficient of 2.79%, a density of the reference paper of 2.57 g / cm < 3 >

(7) Coarse aggregate (G); A gravel having a maximum particle diameter of 25 mm, an absorption ratio of 1.45%, a density of the test piece of 2.60 g / cm < 3 >

(8) water reducing agent 1; Master pozzolith No. 70, a complex of ligninsulfonic acid and polyol manufactured by BASF Japan

    Water reducing agent 2; Master LeoBuild 4000, a melamine sulfonic acid compound manufactured by BASF Japan

[Examples 1 to 15 and Comparative Examples 1 to 5]

[Concrete mixing]

The water-soluble cellulose ether, defoaming agent, cement, fine aggregate and coarse aggregate shown in Table 2 were placed in a forced biaxial kneading mixer having a capacity of 60 liters and subjected to dry mixing for 30 seconds. Then, water, a water reducing agent and the AE agent shown in Table 1 were added and kneaded for 90 seconds to obtain two kinds of mixed concrete shown in Table 3 below. The mixing ratio of concrete per batch was 40 liters.

The water-soluble cellulose ether was used in an amount as shown in Table 4. The antifoaming agent was used in an amount of 5% by mass based on the water-soluble cellulose ether. The amount of the water reducing agent used was 4.5% In case of Leath No. 70, 0.25% by mass with respect to cement and 2.00% by mass with respect to cement in case of Master LeoBuild 4000 were used.

Formulation 1; Typical concrete formulation

Formulation 2; High Flow Concrete Formulation

The following evaluations were carried out on the concrete produced in Examples 1 to 15 and Comparative Examples 1 to 5. The results are shown in Tables 4 to 6. However, the air amount (A ₃₀ ) and the air amount maintenance ratio (A ₃₀ / A ₀ ) after 30 minutes of standing were evaluated only for Examples 10 to 15 and Comparative Examples 4 to 5.

〔Assessment Methods〕

1. Concrete temperature

The material temperature was adjusted so that the kneading temperature of the concrete was 20 ± 3 ° C.

2. Amount of air

The air amount (A ₀ ) immediately after kneading and the air amount (A ₃₀ ) after standing for 30 minutes were defined as follows, and the ratio was defined as an air amount maintenance ratio (A ₃₀ / A ₀ ).

· Amount of air immediately after kneading (A ₀ )

Air volume obtained by a test conducted in accordance with JIS A 1128 using concrete immediately after kneading.

· Amount of air after 30 minutes of standing (A ₃₀ )

The air volume obtained by the test conducted in accordance with JIS A 1128 after remanufacturing the concrete left to stand for 30 minutes after kneading.

3. Slump test

The test was conducted in accordance with JIS A 1101.

In the case of compound 1, a fluidity evaluation was carried out by a slump test.

4. Slump Flow Test

The test was conducted in accordance with JIS A 1150.

In the case of compound 2, the fluidity was evaluated by a slump flow test.

5. Freezing and thawing test

The test was carried out in accordance with Method A of JIS A 1148-2010, and the relative dynamic modulus of elasticity was measured up to 300 cycles. It was judged that the relative dynamic elasticity modulus at the time of 300 cycles was more than 60%.

6. Air gap coefficient

And the air gap analyzer (AVA; trade name, manufactured by Autopilot Co., Ltd.) was used to measure the air gap coefficient as an index of freezing and thawing resistance. And water were mixed at a ratio of glycerin / water = 83/17 at a mass ratio in advance to prepare a solution for AVA measurement.

The kneaded concrete was passed through a sieve having an eye size of 5 mm to obtain a mortar for evaluating the bubble interval coefficient, and 20 ml of the mortar was collected in a dedicated syringe. About 2000 ml of water was poured into the measuring column, and the bubbles attached to the wall surface of the column were removed with a brush. 250 ml of the AVA measuring solution prepared above was injected into the bottom of the column using a special apparatus. After the injection, a shale for collecting bubbles was installed in the vicinity of the water surface of the column and fixed to the measurement part. 20 ml of the mortar collected in the syringe was injected into the bottom of the column, and the mortar was stirred for 30 seconds to sufficiently discharge the entrained air of the mortar into the liquid. By measuring the discharged bubbles with time, the bubble interval coefficient was measured.

(Mortar ratio) and the volume occupied by the paste (paste volume ratio) excluding the volume occupied by the aggregate of 5 mm or more from the total volume of the concrete in addition to the air amount of the fresh concrete are required in calculating the bubble interval coefficient. The mortar volume ratio and paste volume ratio were calculated from the following formulas (I) and (II).

V mortar ratio (%) = [(V _B + V _W + V _S ) / 1000] × 100 (I)

(%) = [(V _B + V _W ) / 1000] x 100 (II)

V _B : Volume of cement (= cement unit weight (kg) / specific gravity of cement)

V _W : Volume (same as unit quantity) of liquid additive such as water, AE agent and water reducing agent

V _S : Volume of aggregate less than 5 mm (= unit mass of fine aggregate / specific gravity of fine aggregate)

7. Compressive strength

According to JIS A 1108, the concrete of 28 days old was subjected to a compressive strength test. The dimensions of the specimen were φ10 × 20cm.

8. Bleeding rate

The test was conducted in accordance with JIS A 1123.

As shown in Tables 4 and 6, it can be seen that by using the AE agent of the present invention, a concrete having a small bubble space coefficient was obtained even when a defoaming agent was used in combination.

Further, it was confirmed that the concrete having the relative elastic modulus of 60% or more and the bleeding ratio of 1.5% or less was excellent in anti-freeze and bleeding reduction effects.

Further, as shown in Table 6, a water-soluble cellulose ether having a ratio (A / B) of a mole fraction (A) of methoxy group substituted hydroxyalkyl groups to a mole fraction (B) of a predetermined nonmetethoxy substituted hydroxyalkyl group It was confirmed that the air amount was maintained at a good level.

On the other hand, as shown in Table 5, when the AE agent is used as in Comparative Examples 1, 2, 4 and 5, the bubble interval coefficient becomes large, and therefore, the anti-freeze property is remarkably bad.

In addition, in the case of Comparative Example 3, since the water-soluble cellulose ether was not used, it was found that the bleeding rate was extremely high at 5.2%.

Claims (6)

AE agent, water-soluble cellulose ether, antifoaming agent, cement, water and aggregate,
Wherein the AE agent is selected from the group consisting of a fatty acid represented by the following general formula (1), an alkali metal salt of a fatty acid represented by the following general formula (1), a lower alkylamine salt of a fatty acid represented by the following general formula (1) 1), and a nonionic surfactant comprising a polyoxyethylene phenyl ether represented by the following general formula (2): wherein R < 1 > Hydraulic composition.

(In the formula, R ¹ represents an alkyl group or an alkenyl group having 12 to 24 carbon atoms.)

(Wherein R ² represents an alkyl group having 8 or 9 carbon atoms, and n represents an integer of 1 to 50) The hydraulic composition according to claim 1, wherein the water-soluble cellulose ether is hydroxypropylmethylcellulose or hydroxyethylmethylcellulose. 3. The method according to claim 2, wherein the ratio of the mole fraction (A) of the methoxy group-substituted hydroxypropyl group to the mole fraction (B) of the non-methoxy group-substituted hydroxypropyl group in the hydroxypropyl methylcellulose A / B) is 0.2 to 1.0. The method according to claim 2, wherein the ratio (A / B) of the mole fraction (A) of the methoxy group-substituted hydroxyethyl group to the mole fraction (B) of the non-methoxy group substituted hydroxyethyl group in the hydroxyethyl methylcellulose is 2.0 to 3.0. The hydraulic composition according to any one of claims 1 to 4, wherein the AE agent is contained in an amount of 0.0001 to 0.5 mass% based on the cement. The hydraulic composition according to any one of claims 1 to 4, wherein the void space coefficient is 25 to 250 탆.