KR101735773B1 - Crack-reducing concrete admixture - Google Patents

Crack-reducing concrete admixture Download PDF

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KR101735773B1
KR101735773B1 KR1020160028299A KR20160028299A KR101735773B1 KR 101735773 B1 KR101735773 B1 KR 101735773B1 KR 1020160028299 A KR1020160028299 A KR 1020160028299A KR 20160028299 A KR20160028299 A KR 20160028299A KR 101735773 B1 KR101735773 B1 KR 101735773B1
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repeating unit
ether compound
concrete
formula
acid
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김보승
박광서
김정선
박광영
차철용
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주식회사 실크로드시앤티
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • C04B24/02—Alcohols; Phenols; Ethers
    • C04B24/023—Ethers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L71/00—Compositions of polyethers obtained by reactions forming an ether link in the main chain; Compositions of derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/34—Non-shrinking or non-cracking materials
    • C04B2111/346—Materials exhibiting reduced plastic shrinkage cracking

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Abstract

Disclosed is a crack-reducing concrete admixture capable of reducing interfacial tension between water and a concrete surface to prevent cracks of a concrete caused by dry-type shrinkage. More specifically, the crack-reducing concrete admixture comprises: a polycarboxylate ether-based compound; and a polyalkyl ether-based compound, wherein the polycarboxylate ether-based compound includes a copolymer including first, second, and third repeating units. The first repeating unit is derived from a compound represented by chemical formula 1, CH_2=CR_1-L_1-(CH_2CH_2O)_n1-(C=O)-R_2. The second repeating unit is derived from an unsaturated carboxylic acid, and the third repeating unit is derived from an unsaturated carboxylate. The polyalkyl ether-based compound has a hydrophile lipophile balance (HLB) of 10 to 13. The descriptions of L_1, R_1, R_2 and n1 in the chemical formula 1 are the same as described in the present specification.

Description

Crack-reducing concrete admixture < RTI ID = 0.0 >

And more particularly to a crack-reducing concrete admixture. More particularly, the present invention relates to a crack-reducing concrete admixture capable of reducing interfacial tension between water and concrete surface or between water and water to prevent cracking of concrete due to drying shrinkage.

As the main material of the building structure, concrete is one of the most used materials in construction because it has superior performance compared to other materials in terms of workability, strength, durability and maintenance, and has economical advantages.

However, concrete has the possibility of occurrence of deterioration due to various environments, materials, construction factors, etc., and if cracks occur in the concrete, the performance such as the strength and durability of the building structure is deteriorated, The psychological uneasiness of the user is generated, and further, the life and usability of the building structure are lowered, leading to a great economic loss, which is recognized as a big problem.

Cracks in concrete are caused by various factors, the most frequent occurrence of which is drying shrinkage. The drying shrinkage is caused by the volume reduction caused by the drying of the inside of the concrete due to the external movement of the water inside the concrete. Dry shrinkage is found in most concrete. When concrete members are confined, internal stress is generated due to decrease of volume of concrete, which causes cracking of concrete. This is the biggest cause of cracks in concrete and is recognized as a cause of defects.

Especially, when slab of long span, shortening of air, and precast permanent formwork for the convenience of construction are used according to the enlargement tendency of the building structure as in the present, there is a possibility that the constraining force and internal stress acting on the concrete become large, do. It is no exaggeration to say that drying shrinkage is the biggest problem that needs to be resolved in concrete structures at present. Also, as the quality of the aggregate used in the production of concrete becomes poorer, the flowability of the concrete deteriorates. As a result, cracking due to drying shrinkage is further increased due to securing workability in production of concrete and economic reasons .

On the other hand, concrete admixture is a material added to impart dispersibility and fluidity to concrete, etc. when mixing concrete, aggregate and water. These concrete admixtures are classified into mineral admixtures and chemical admixtures, and the chemical admixtures are largely classified into air entraining admixtures, water reducing admixtures, and high-performance water reducing admixtures.

Conventionally, melamine-based or naphthalene-based condensates have been mainly used as high-performance water reducing agents. However, since the polycarboxylic acid system (abbreviated as "PCA") admixture has been developed in Japan in the 1990s, it exhibits excellent dispersibility even when used in a small amount compared with existing naphthalene-based water reducing agents and sufficient workability can be maintained despite high water- Furthermore, PCA-based admixture has become popular because it has superior deformability through control of molecular structure than other kinds of admixture and can be manufactured in various forms.

Various concrete admixtures have been developed to prevent cracking of the concrete, for example, cracking of the concrete due to drying shrinkage. For example, a concrete admixture comprising a copolymer produced through the esterification reaction of an unsaturated carboxylic acid and an alkyl ether in which ethylene oxide or propylene oxide is introduced into the main chain or side chain can not impart sufficient crack-reducing performance to the concrete And a concrete admixture containing a mixture of a fatty acid and a polyalkylene oxide has a problem that it is expensive to manufacture due to excessive use of a fatty acid and can not impart sufficient crack reduction performance to a concrete.

To reduce the interfacial tension between water and concrete surface or between water and water to prevent cracking of concrete due to drying shrinkage.

According to one aspect,

Polycarboxylate ether compounds; And

A polyalkyl ether compound,

The polycarboxylate ether compound includes a copolymer including a first repeating unit, a second repeating unit, and a third repeating unit,

Wherein the first repeating unit is derived from a compound represented by the following formula (1), the second repeating unit is derived from an unsaturated carboxylic acid, the third repeating unit is derived from an unsaturated carboxylate,

The polyalkyl ether compound is provided with a crack-reducing concrete admixture having a Hydrophile Lipophile Balance (HLB) of 10 to 13:

≪ Formula 1 >

CH 2 = CR 1 -L 1 - (CH 2 CH 2 O) n 1 - (C = O) -R 2

In Formula 1,

And, L 1 is * - - (CH 2) m1 -O- * '(C = O) -O- * or *'

m1 is selected from an integer of 0 to 5,

R 1 and R 2 are, independently of each other, hydrogen and C 1 -C 20 alkyl; ≪ / RTI >

n1 is selected from an integer of 7 to 100,

* And * are binding sites with neighboring atoms.

According to another aspect, of the above formula 1, L 1 is * - is (CH 2) m1 -O- * ' , m1 may be a day.

According to another aspect, in the general formula (1), R 1 may be hydrogen or a methyl group.

According to another aspect, in the above formula (1), R 2 may be a C 4 -C 18 alkyl group.

According to another aspect, in the general formula (1), n1 may be selected from an integer of 50 to 60.

According to another aspect, the unsaturated carboxylic acid may be selected from acrylic acid, methylacrylic acid, itaconic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, methylglutaric acid and malic acid.

According to another aspect, the unsaturated carboxylate may be selected from methyl methacrylate, methyl acrylate, ethyl 2-hydroxyacrylate, acrylamide and vinyl acetate.

According to another aspect, the molar ratio of the first repeating unit, the second repeating unit, and the third repeating unit may be 10: 90: 1 to 40:30:30.

According to another aspect, the polycarboxylate ether compound may have a weight average molecular weight of 5,000 to 300,000.

According to another aspect, the content of the polycarboxylate ether compound may be 1 to 50 parts by weight based on 100 parts by weight of the total amount of the admixture.

According to another aspect, the polyalkyl ether compound may be represented by the following formula (2):

(2)

CH 3 - (CH 2) n2 - (OCH 2 CH 2 CH 2) n3 - (OCH 2 CH 2) n4 -OH

In Formula 2,

n2 is selected from an integer of 1 to 10,

n3 is selected from an integer of 0 to 10,

n4 is selected from an integer of 1 to 10;

According to another aspect, the content of the polyalkyl ether compound may be 10 to 70 parts by weight based on 100 parts by weight of the total amount of the admixture.

According to another aspect, the crack-reducing concrete admixture may further comprise an additive comprising at least one selected from urea, diethanolamine and triethanolamine.

According to another aspect, the content of the additive may be 1 to 40 parts by weight based on 100 parts by weight of the total amount of the admixture.

According to another aspect, the admixture may be a mono-fluid type.

The crack-reducing concrete admixture may contain a polycarboxylate ether compound having a repeating unit derived from the compound represented by Formula 1 and a polyalkyl ether compound having a hydrophilic lipophile balance (HLB) of 10 to 13 It is possible to effectively prevent the cracks in the concrete due to the drying shrinkage by reducing the interfacial tension between the water and the concrete surface or between the water present in the water and the concrete surface .

1 is a diagram showing 1 H NMR (CDCl 3 , 400 MHz) data of the monomer 1 for forming a polycarboxylate ether compound prepared in Synthesis Example 1. FIG.

The crack-reducing concrete admixture includes a polycarboxylate ether (PCE) compound and a polyalkyl ether compound.

[Polycarboxylate ether (PCE) compound]

The polycarboxylate ether compound may include a copolymer including a first repeating unit, a second repeating unit and a third repeating unit.

The first repeating unit may be derived from a compound represented by the following formula (1): < EMI ID =

≪ Formula 1 >

CH 2 = CR 1 -L 1 - (CH 2 CH 2 O) n 1 - (C = O) -R 2

In Formula 1, L 1 is * - is - '(C = O) -O- * or *' (CH 2) m1 -O- *. According to one embodiment, L 1 is - - may be a (CH 2) m1 -O- * ' .

In the general formula (1), m1 may be selected from an integer of 0 to 5. m1 represents the number of - (CH 2 ) m1 -, and when m1 is 0, - (CH 2 ) m1 - becomes a single bond. According to one embodiment, m1 can be 1 or 2. According to another embodiment, m1 may be 1, but is not limited thereto.

Wherein R 1 and R 2 are, independently of each other, hydrogen and a C 1 -C 20 alkyl group; ≪ / RTI >

According to one embodiment, R < 1 > may be hydrogen or a methyl group. According to another embodiment, R < 1 > may be a methyl group, but is not limited thereto.

According to one embodiment, R 2 may be a C 4 -C 18 alkyl group. For example, R 2 may be selected from among n-butyl group, n-octanyl group, n-decyl group, n-dodecyl group and n-octadecyl group, but is not limited thereto.

In the general formula (1), n1 may be selected from an integer of 7 to 100. n1 is - (CH 2 CH 2 O) - represents the number of. According to one embodiment, n may be selected from the integers from 10 to 100. According to another embodiment, n may be selected from integers from 50 to 60. [ According to another embodiment, n may be selected from integers from 53 to 55. [

The compound represented by Formula 1 simultaneously contains a moiety derived from ethylene oxide and a moiety derived from a carboxylic acid (e.g., saturated or unsaturated fatty acid) as shown in Formula 1 below . Specifically, the compound represented by Formula 1 is characterized in that the moiety derived from ethylene oxide and the moiety derived from carboxylic acid are connected through a single bond. Therefore, when a concrete admixture containing a repeating unit derived from the compound represented by the formula (1) is used in the production of concrete, a moiety derived from a carboxylic acid in the compound during the drying shrinkage of the concrete is adsorbed on the concrete surface, It is possible to reduce the interfacial tension between the concrete surface and the concrete surface, thereby reducing the occurrence of internal stress due to the volume reduction of the concrete. Accordingly, it is possible to effectively prevent cracks from occurring in the concrete.

≪ Formula (1) >

Figure 112016022849129-pat00001

The compound represented by Formula 1 may be synthesized using a known organic synthesis method. The method of synthesizing the compound represented by Formula 1 can be easily recognized by those skilled in the art with reference to the following Examples.

The second repeating unit may be derived from an unsaturated carboxylic acid.

In the present specification, the unsaturated carboxylic acid means a carboxylic acid having a double bond or a triple bond between carbon atoms, and includes a dicarboxylic acid or a tricarboxylic acid in addition to a monocarboxylic acid.

According to one embodiment, the unsaturated carboxylic acid may be selected from acrylic acid, methylacrylic acid, itaconic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, methylglutaric acid and malic acid. For example, the unsaturated carboxylic acid may be acrylic acid, but is not limited thereto.

The third repeating unit may be derived from an unsaturated carboxylate.

In the present specification, the unsaturated carboxylate means a carboxylate having a double bond or a triple bond between carbon atoms, and includes, in addition to a monocarboxylate, a dicarboxylate or a tricarboxylate.

According to one embodiment, the unsaturated carboxylate may be selected from methyl methacrylate, methyl acrylate, ethyl 2-hydroxy acrylate, acrylamide and vinyl acetate. For example, the unsaturated carboxylate may be ethyl 2-hydroxyacrylate, but is not limited thereto.

The polycarboxylate ether compound may further include a fourth repeating unit derived from an additive. The additive may further include at least one selected from a chain transfer agent and a polymerization initiator.

The chain transfer agent may be, for example, mercaptoethanol, thioglycerol, thioglycolic acid, mercaptopropionic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2- Thiol chain transfer agents such as mercaptoethanesulfonic acid, n-dodecyl mercaptan, octyl mercaptan, and butyl thioglycolate; Halides such as carbon tetrachloride, carbon tetrabromide, methylene chloride, bromoform and bromotrichloroethane; unsaturated hydrocarbon compounds such as? -methylstyrene dimer,? -terpinene, dipentene, and terpinolene; Primary alcohols such as 2-aminopropane-1-ol; Secondary alcohols such as isopropanol; Phosphorous acid, hypophosphorous acid and its salts; Sulfurous acid, hydrogen sulfite, dithionite, meta-sulfite and salts thereof; And mixtures thereof.

The polymerization initiator includes, for example, persulfates such as ammonium sulfate, sodium persulfate, and potassium persulfate; Hydrogen peroxide; Azo compounds such as azobis-2-methylpropionamidine hydrochloride and azoisobutyronitrile; Peroxides such as benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, t-amyl peroxy-2-ethylhexanoate, and the like, and mixtures thereof. According to one embodiment, the polymerization initiator may be t-amylperoxy-2-ethylhexanoate, but is not limited thereto.

The polycarboxylate ether compound may contain the first repeating unit, the second repeating unit, and the third repeating unit in a molar ratio of 10: 90: 1 to 40:30:30.

According to one embodiment, the polycarboxylate ether compound may have a weight average molecular weight of 5,000 to 300,000. For example, the polycarboxylate ether compound may have a weight average molecular weight of 7,000 to 100,000. According to another embodiment, the polycarboxylate ether compound may have a weight average molecular weight of 9,000 to 80,000. According to another embodiment, the polycarboxylate ether compound may have a weight average molecular weight of 10,000 to 70,000. When the weight average molecular weight of the polycarboxylate ether compound is within the above range, the dispersibility and workability of the concrete admixture are excellent.

According to one embodiment, the polycarboxylate ether compound may include, but is not limited to, a repeating unit represented by the following formula (A)

≪ Formula (A)

Figure 112016022849129-pat00002

R 11 to R 16 in the above formula (A) may be independently selected from hydrogen and C 1 -C 20 alkyl groups. According to one embodiment, R 11 to R 16 in the above formula (A) may be, independently of each other, hydrogen or a methyl group.

X in the above formula (A) may be hydrogen or a metal cation of 1 to 3 valences. According to one embodiment, X may be hydrogen, Na + , K + or Ca 2+ . When X in the above formula (A) is hydrogen or a metal cation of 1 to 3 valence, the dispersibility of concrete can be improved.

Y in the formula (A) is a C 1 -C 20 alkyl group and a C 1 -C 20 alkoxy group; And a C 1 -C 20 alkyl group and a C 1 -C 20 alkoxy group substituted with at least one selected from a hydroxyl group, a C 1 -C 20 alkyl group, and a C 1 -C 20 alkoxy group. According to one embodiment, Y in the above formula (A) may be a methyl group, an ethyl group or -OCH 2 CH 2 OH.

In formula (A), a may be an integer of 15 to 40. According to one embodiment, a may be selected from the integers from 15 to 40. [ When the value a is within the above range, the concrete fluidity, that is, the initial dispersing force and the holding force, is effective.

In formula (A), b may be an integer of 40 to 90. According to one embodiment, b may be selected from the integers from 45 to 65. [ When b is within the above range, the dispersibility of concrete can be improved.

In formula (A), c may be 0 or 1.

In formula (A), d may be an integer of 1 to 40. According to another embodiment, d may be selected from integers from 2 to 30. When d is within the above range, the holding force of concrete can be improved.

In Formula A, e may be 0 or 1.

In formula (A), f may be selected from an integer of 0 to 10. According to one embodiment, f may be selected from integers from 0 to 3.

G in the above formula (A) may be selected from an integer of 1 to 60. According to one embodiment, g may be selected from the integers from 45 to 55.

H in formula (A) may be selected from the integers from 2 to 19. According to one embodiment, h may be 10.

The content of the polycarboxylate ether compound may be 1 to 50 parts by weight based on 100 parts by weight of the total amount of the admixture. When the content of the polycarboxylate ether compound is within the above range, the concrete crack can be effectively reduced.

[Production method of polycarboxylate ether (PCE) system]

The method for producing the polycarboxylate ether compound includes the steps of: providing a composition for forming a polycarboxylate ether compound including the compound represented by Formula 1, the unsaturated carboxylic acid, and the unsaturated carboxylate; And heating the composition to form the polycarboxylate ether compound.

The step of forming the composition for forming a polycarboxylate ether compound may be carried out by stirring the compound represented by the formula (1), the unsaturated carboxylic acid and the unsaturated carboxylate at a temperature of about 80 to 130 ° C .

The content of the compound represented by the formula (1) may be selected in the range of about 70 to about 90 wt% based on the total weight of the composition for forming the polycarboxylate ether compound. According to one embodiment, the content of the compound of Formula 1 may be selected in the range of about 75 to about 85 wt% based on the total weight of the composition for forming the polycarboxylate ether compound.

The content of the unsaturated carboxylic acid may be selected in the range of about 10 to about 20 wt% based on the total weight of the composition for forming the polycarboxylate ether compound. According to one embodiment, the content of the unsaturated carboxylic acid may be selected in the range of about 13 to 17% by weight based on the total weight of the composition for forming the polycarboxylate ether compound.

The content of the unsaturated carboxylate may be selected in the range of about 1 to about 10 wt% based on the total weight of the composition for forming the polycarboxylate ether compound. According to one embodiment, the content of the unsaturated carboxylate may be selected in the range of about 3 to 7% by weight based on the total weight of the composition for forming the polycarboxylate ether compound.

The step of forming the composition for forming the polycarboxylate ether compound may be carried out using a known stirring device. For example, the stirring device may be a mechanical stirrer, a double helix mixer, a high-speed emulsifier, a homogenizer, a high shear blender or an ultrasonic homogenizer. But are not limited thereto.

The composition for forming a polycarboxylate ether compound may further include a solvent. For example, the solvent may be an aromatic or aliphatic hydrocarbon such as water, benzene, toluene, xylene, cyclohexane or n-hexane, an ether compound such as tetrahydrofuran or dioxane, a ketone such as acetone or methyl ethyl ketone Compounds, alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, ethyl acetate, dimethylformamide, chloroform, methylene chloride and mixtures thereof.

The content of the solvent may be selected in the range of about 5 to 15% by weight based on the total weight of the composition for forming the polycarboxylate ether compound. According to one embodiment, the content of the solvent may be selected in the range of about 10% by weight based on the total weight of the composition for forming the polycarboxylate ether compound.

The composition for forming a polycarboxylate ether compound may further include a chain transfer agent. For a description of the chain transfer agent, reference is made to what is described herein. The content of the chain transfer agent may be selected in the range of about 0.05 to about 2 wt% based on the total weight of the composition for forming the polycarboxylate ether compound. According to one embodiment, the content of the chain transfer agent may be selected in the range of about 0.1 to about 1 wt% based on the total weight of the composition for forming the polycarboxylate ether compound.

The composition for forming a polycarboxylate ether compound may further include a polymerization initiator. A description of the polymerization initiator is given in the description of the present invention. The content of the polymerization initiator may be selected in the range of about 0.05 to about 2 wt% based on the total weight of the composition for forming the polycarboxylate ether compound. According to one embodiment, the content of the polymerization initiator may be selected in the range of about 0.1 to about 1.5 wt% based on the total weight of the composition for forming the polycarboxylate ether compound.

Wherein the step of heating the composition for forming a polycarboxylate ether compound to form the polycarboxylate ether compound comprises heating the composition for forming the polycarboxylate ether compound at a temperature of about 40 DEG C to about 100 DEG C ≪ / RTI > for 10 hours.

The method for producing the polycarboxylate ether compound may further include cooling the formed polycarboxylate ether compound and adding a pH adjusting agent to the polycarboxylate ether compound. By adding the pH adjusting agent, the pH of the concrete admixture can be adjusted to about 2.5 to about 6.5.

The pH adjusting agent may include, for example, calcium hydroxide (Ca (OH) 2), sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonium hydroxide (NH 4 OH), or a combination thereof.

Since the polycarboxylate ether compound includes a copolymer containing the compound represented by the formula (1) as a repeating unit, it can impart excellent dispersibility and workability to the concrete composition, and the polycarboxylate A moiety derived from a carboxylic acid contained in a copolymer of the ether compound is hydrolyzed by the strong alkalinity of the concrete and adsorbed on the surface of the concrete, and the moiety derived from the carboxylic acid has an interface between the water and the concrete surface It is possible to effectively prevent the concrete from cracking due to drying shrinkage by reducing the tension.

[Polyalkyl ether compound]

The polyalkyl ether compound has a Hydrophile Lipophile Balance (HLB) of 10 to 13.

The hydrophilic lipophilic ratio in the present specification is a number from 1 to 20, which is a non-dimensional number according to the Griffin grade and shows whether there is a preferential water or oil solubility. The hydrophilic lipophilic ratio describes the equilibrium of the size and strength of the hydrophilic and lipophilic groups of the compound. Numbers less than 9 tend to characterize hydrophobicity, hydrophobicity, and numbers greater than 11 tend to characterize water-soluble, hydrophilic compounds. W.C. Griffin, J. Soc. Cosmet. Chem. 1 (1949) 311; W.C. Griffin, J. Soc. Cosmet. Chem. 5 (1954) 249.

For example, the HLB of a single compound can be calculated according to Equation (1) below and the HLB of the mixture can be calculated according to Equation (2) as follows:

&Quot; (1) "

HLB = hydrophilic group molecular weight / total molecular weight 20

&Quot; (2) "

HLB X + Y = (a * HLB X ) + ((1-a) * HLB Y )

In the above equation (2)

HLB X represents the HLB of X calculated according to Equation (1) above,

HLB Y represents the HLB of Y calculated according to Equation (1) above,

a represents the fraction of X in the mixture.

Since the polyalkyl ether compound has a hydrophilic lipophilic ratio of 10 to 13, it may be a water-soluble and hydrophilic compound.

The concrete admixture containing the polyalkyl ether compound can prevent the poly (alkyl ether) compound from offsetting the attractive force (hydrogen bond) acting between water and water when the water present in the capillary of the concrete evaporates in the capillary, It is possible to effectively prevent cracking of the concrete.

 According to one embodiment, the polyalkyl ether compound may have a hydrophilic lipophilic ratio of about 12.

According to one embodiment, the polyalkyl ether compound may be represented by the following general formula (2), but is not limited thereto:

(2)

CH 3 - (CH 2) n2 - (OCH 2 CH 2 CH 2) n3 - (OCH 2 CH 2) n4 -OH

N2 in Formula 2 may be selected from an integer of 1 to 10. According to one embodiment, n2 may be selected from integers from 2 to 5.

N3 in Formula 2 may be selected from an integer of 0 to 10. According to one embodiment, n3 may be selected from integers from 0 to 3.

N4 in Formula 2 may be selected from an integer of 1 to 10. According to one embodiment, n4 may be selected from integers from 2 to 5.

According to another embodiment, if the polyalkyl ether compound has a hydrophilic lipophilic ratio of 10 to 13, the polyalkyl ether compound may have a structure in which n2, n3 and n4 in the general formula (2) Selected compounds.

According to one embodiment, the polyalkyl ether compound may include one or more compounds selected from the compounds represented by the general formula (2).

According to another embodiment, the polyalkyl ether compound is CH 3 - (CH 2) 3 - (OCH 2 CH 2) 2 -OH , and CH 3 - (CH 2) 3 - (OCH 2 CH 2 CH 2) 2 - (OCH 2 CH 2) may comprise a mixture of 2 -OH.

The content of the polyalkyl ether compound may be 10 to 70 parts by weight based on 100 parts by weight of the total amount of the admixture.

The polyalkyl ether compound can be synthesized using a known organic synthesis method.

The crack-reducing concrete admixture may further comprise an additive comprising at least one selected from urea, diethanolamine and triethanolamine. The additive serves to impart moisture retention to the admixture to delay evaporation of water in the concrete.

According to one embodiment, the additive may be urea.

The content of the additive may be 1 to 40 parts by weight based on 100 parts by weight of the total amount of the admixture. When the content of the additive is within the above range, the moisture retention of the admixture is increased and the water evaporation in the concrete can be delayed.

The crack-reducing concrete admixture may contain a polycarboxylate ether compound having a repeating unit derived from the compound represented by Formula 1 and a polyalkyl ether compound having a hydrophilic lipophile balance (HLB) of 10 to 13 It is possible to effectively prevent the cracks in the concrete due to the drying shrinkage by reducing the interfacial tension between the water and the concrete surface or between the water present in the water and the concrete surface .

According to one embodiment, the crack-reducing concrete admixture may be a mono-fluid type. That is, the crack-reducing concrete admixture is one-pack type and excellent in long-term stability, so that it is easy to store and can be efficiently managed, thereby reducing maintenance and maintenance costs.

The crack-reducing concrete admixture may be prepared by adding a polycarboxylate ether compound, a polyalkyl ether compound and an additive to a reactor equipped with a stirrer and a thermometer and stirring at room temperature (25 ° C) for 1 hour.

In the present specification, the C 1 -C 20 alkyl group means a linear or branched aliphatic hydrocarbon monovalent group having 1 to 20 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, isobutyl, sec-butyl A tert-butyl group, a pentyl group, an iso-amyl group, a hexyl group, and the like. In the specification, the C 1 -C 20 alkylene group means a divalent group having the same structure as the C 1 -C 20 alkyl group.

The C 1 -C 60 alkoxy group in the present specification means a monovalent group having the formula: -OA 101 (wherein A 101 is the above C 1 -C 60 alkyl group), and specific examples thereof include methoxy group, ethoxy group , Isopropyloxy group, and the like.

Hereinafter, crack-reducing concrete admixtures according to one embodiment of the present invention will be described in more detail with reference to Synthesis Examples and Examples. In the following Synthesis Examples and Examples, "A was used instead of A ", the molar equivalents of A and B were the same.

 [Example]

Synthetic example

Synthesis Example 1: Synthesis of polycarboxylate ether compound 1

CH 2 = C (CH 3) -CH 2 - (CH 2 CH 2 O) 53 -H ( weight-average molecular weight: 2,400) 0.2 mol, CH 3 -O- (C = O) - (CH 2) 10 CH 3 0.2 mol and LiOH as a catalyst were placed in a reactor equipped with a stirrer and a thermometer and heated at 100 to 120 ° C for 7 hours to obtain monomer 1 (CH 2 = C (CH 3 ) -CH 2 -) for forming polycarboxylate ether compound 465 g (yield: 89%) of (CH 2 CH 2 O) 53 - (C = O) - (CH 2 ) 10 CH 3 was obtained. The obtained monomer 1 for forming a polycarboxylate ether compound was confirmed by NMR. The results are shown in Fig.

81 wt% of monomer 1 for forming polycarboxylate ether compound, 14.7 wt% of acrylic acid, 5 wt% of ethyl 2-hydroxyacrylate, 0.3 wt% of 2-mercaptoethanol as chain transfer agent, and t- 1.2 weight% of peroxy-2-ethylhexanoate was gradually added dropwise, and the mixture was stirred at 95 캜 for 6 hours. After the completion of the reaction, the temperature was cooled to 60 DEG C, and then caustic soda was added in the atmosphere to adjust the pH to 4.5 to obtain 802 g of a polycarboxylate ether compound, 50% solids content (yield: 90% MW): 34,000, viscosity: 400 ± 50 cps).

Example 1

(Preparation of Concrete Admixture 1)

15 parts by weight of the polycarboxylate ether compound 1 prepared in Synthesis Example 1, CH 3 - (CH 2 ) 3 - (OCH 2 CH 2 ) 2 -OH and CH 3 - (CH 2 ) 3 - (OCH 2 CH 2 CH 2) 2 - (OCH 2 CH 2) 2 -OH in the mixture (weight ratio = 3: 1, a hydrophilic non-lipophilic (HLB) = 12) 45 parts by weight, 5 parts by weight of urea as an additive Were placed in a reactor equipped with a stirrer, and the mixture was heated and stirred at RT for 1 hour to prepare a concrete admixture 1.

(Preparation of composition 1 for concrete formation)

Using the concrete admixture 1, a composition 1 for forming a concrete was prepared with the composition shown in Table 1 below.

Comparative Example 1

(Preparation of Concrete Admixture A)

Except that a polycarboxylate ether compound (manufactured by Silk Road Co., Ltd., trade name: WRE-500, weight average molecular weight: 42,000) was used in place of the polycarboxylate ether compound 1 The concrete admixture A was prepared using the same method as that of the admixture 1.

(Preparation of Composition A for Concrete Formation)

Using the concrete admixture A, a composition A for concrete formation was prepared with the compositions shown in Table 1 below.

W / B
(%) S / A
(%) Weight unit (kg / m 3 ) AD (%) water bookbinder Fine aggregate Coarse aggregate cement 51.4 48 180 350 835 915 One%

※ W / B: Water / Binder (Cement)

※ S / A: Fine aggregate / coarse aggregate

※ AD: Based on the total weight of the binder, the addition amount of concrete admixture (based on 20% solids content)

※ Cement (Chimahata cement, Sungshin Cement Co., Ltd.)

Evaluation Example 1: Evaluation of Shrinkage Reduction Rate

The above-mentioned concrete compositions 1 and A were used to prepare concrete, and the concrete was used to form a specimen based on the " Method for Producing a Test Specimen for Testing the Concrete Strength " specified in KS L 5105, (Tokyo Sokki Kenkyujo Co., Ltd .; Type: PMFL-1) was attached to a length change test mold (10 x 10 x 40 cm) after being dipped and molded in water for 24 hours. 60-2LT) was embedded and connected to DATA LOGGER to measure shrinkage for 45 days. The shrinkage reduction ratio was calculated based on the following equation (3) based on the shrinkage amount of the concrete of Comparative Example 1. [ The results are shown in Table 2 below.

&Quot; (3) "

Shrinkage reduction rate (%) = shrinkage amount of concrete of Comparative Example 1 - shrinkage amount of concrete of Example 1 / shrinkage amount of concrete of Comparative Example 1 100

Concrete admixture Shrinkage (mm) Shrinkage reduction rate (%) Example 1 One 306 34.5 Comparative Example 1 A 467 -

As can be seen from the above Table 2, it can be confirmed that the concrete admixture of Example 1 gives excellent crack reduction performance to the concrete as compared with the concrete admixture of Comparative Example 1. [

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (15)

Polycarboxylate ether compounds; And
A polyalkyl ether compound,
The polycarboxylate ether compound includes a copolymer including a first repeating unit, a second repeating unit, and a third repeating unit,
Wherein the first repeating unit is derived from a compound represented by the following formula (1), the second repeating unit is derived from an unsaturated carboxylic acid, the third repeating unit is derived from an unsaturated carboxylate,
The polyalkyl ether compound is a crack-reducing concrete admixture having a hydrophilic lipophile balance (HLB) of 10 to 13,
≪ Formula 1 >
CH 2 = CR 1 -L 1 - (CH 2 CH 2 O) n 1 - (C = O) -R 2
In Formula 1,
And, L 1 is * - - (CH 2) m1 -O- * '(C = O) -O- * or *'
m1 is selected from an integer of 0 to 5,
R 1 and R 2 are, independently of each other, hydrogen and C 1 -C 20 alkyl; ≪ / RTI >
n1 is selected from an integer of 7 to 100,
* And * are binding sites with neighboring atoms. The method according to claim 1,
In Formula 1, L 1 is * - (CH 2) m1 -O- * ' and, m1 is 1, reducing crack the concrete admixture type. The method according to claim 1,
In the formula (1), R 1 is hydrogen or a methyl group. The method according to claim 1,
In the formula (1), R 2 is a C 4 -C 18 alkyl group, a crack-reducing concrete admixture. The method according to claim 1,
In the above formula (1), n1 is an integer of 50 to 60, and the concrete admixture is a crack-reducing concrete admixture. The method according to claim 1,
Wherein the unsaturated carboxylic acid is selected from the group consisting of acrylic acid, methylacrylic acid, itaconic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, methylglutaric acid and malic acid. The method according to claim 1,
Wherein the unsaturated carboxylate is selected from methyl methacrylate, methyl acrylate, ethyl 2-hydroxyacrylate, acrylamide and vinyl acetate. The method according to claim 1,
Wherein the molar ratio of the first repeating unit, the second repeating unit, and the third repeating unit is 10: 90: 1 to 40:30:30. The method according to claim 1,
The polycarboxylate ether-based compound has a weight average molecular weight of 5,000 to 300,000. The method according to claim 1,
Wherein the content of the polycarboxylate ether compound is 1 to 50 parts by weight based on 100 parts by weight of the total amount of the admixture. The method according to claim 1,
Wherein the polyalkyl ether compound is a crack-reducing concrete admixture represented by the following formula (2)
(2)
CH 3 - (CH 2) n2 - (OCH 2 CH 2 CH 2) n3 - (OCH 2 CH 2) n4 -OH
In Formula 2,
n2 is selected from an integer of 1 to 10,
n3 is selected from an integer of 0 to 10,
n4 is selected from an integer of 1 to 10; The method according to claim 1,
Wherein the content of the polyalkyl ether compound is 10 to 70 parts by weight based on 100 parts by weight of the total amount of the admixture. The method according to claim 1,
Wherein the additive further comprises at least one additive selected from urea, diethanolamine and triethanolamine. 14. The method of claim 13,
Wherein the content of the additive is 1 to 40 parts by weight based on 100 parts by weight of the total amount of the admixture. The method according to claim 1,
Wherein the admixture is a mono-fluid type, a crack-reducing concrete admixture.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113950489A (en) * 2019-06-05 2022-01-18 丝路C&T有限公司 Method for producing admixture for gypsum board, admixture produced thereby, and composition for forming gypsum board comprising the admixture
KR102651298B1 (en) 2023-07-06 2024-03-25 효성중공업 주식회사 Admixture composition for reducing cracking of concrete using glycerin industrial byproduct
KR102686411B1 (en) * 2023-07-17 2024-07-19 주식회사 부흥건설화학 Admixture for concrete and concrete having the same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100770707B1 (en) * 2001-10-16 2007-10-29 다케모토 유시 가부시키 가이샤 Process for preparing allyletherester monomer and cement dispersing agent

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100770707B1 (en) * 2001-10-16 2007-10-29 다케모토 유시 가부시키 가이샤 Process for preparing allyletherester monomer and cement dispersing agent

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113950489A (en) * 2019-06-05 2022-01-18 丝路C&T有限公司 Method for producing admixture for gypsum board, admixture produced thereby, and composition for forming gypsum board comprising the admixture
KR102651298B1 (en) 2023-07-06 2024-03-25 효성중공업 주식회사 Admixture composition for reducing cracking of concrete using glycerin industrial byproduct
KR102686411B1 (en) * 2023-07-17 2024-07-19 주식회사 부흥건설화학 Admixture for concrete and concrete having the same

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