KR101972571B1 - Composition for forming concrete in hot weather and concrete formed thereform - Google Patents

Abstract

The present invention relates to a composition for forming concrete and concrete manufactured therefrom. More specifically, the present invention relates to a composition for forming concrete containing an admixture and concrete manufactured therefrom. In order to solve the problems of condensation delay and initial strength deterioration of the concrete caused by a retarder in the case of conventional concrete used in extreme hot environment, a repeating unit comprising phosphate is introduced into the admixture so that the slump maintenance performance is maximized without using the retardant, initial dispersing force deterioration is prevented, and excellent workability is provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for forming an extreme concrete and a concrete produced from the composition.

A composition for forming a concrete, and concrete produced therefrom. More specifically, in order to solve the problems of condensation delay and initial strength deterioration of the concrete caused by the retardant in the case of concrete used in the conventional extreme environment, by introducing a repeating unit containing phosphate into the admixture, To a concrete for forming a concrete containing an admixture for maximizing the slump retention performance of the concrete, preventing the initial dispersing ability from lowering, and imparting excellent workability, and a concrete made therefrom.

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.

In order to prevent such cracking of the concrete and to improve the physical properties, an admixture may be added to the composition for forming a concrete. The concrete admixture is widely used as a water reducing agent and a fluidizing agent as an additive to improve performance in concrete compositions such as cement paste, mortar, and concrete, and is mainly used for construction of structures in the civil engineering construction field. Since the concrete admixture has a large surface tension property, the addition of the additive as an additive does not adversely affect the physical properties of the concrete installation material and has an advantage of increasing the strength, because the addition of the concrete admixture to the concrete composition causes little change depending on its concentration.

The concrete admixture is generally classified into a mineral admixture and a chemical admixture, and the chemical admixture can be roughly divided into an air entraining admixture, a water reducing admixture and a high performance water reducing agent.

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.

Generally, the polycarboxylic acid-based concrete admixture has a polymer steric structure of a comb-type structure. The main chain is anionic due to an acrylic-based monomer, and the side chain is nonionic due to a polyalkylene oxide. Therefore, the electrostatic repulsive force of the main chain and the cubic effect due to the side chain lower the cohesive force in the cement. It is also known that the polycarboxylic acid-based admixture has an excellent effect on reduction of high water-reducing effect, workability and slump loss due to the synergistic osmotic effect in addition to these two effects.

On the other hand, concrete in the middle is concrete which is applied when there is a risk of slump of concrete or rapid water evaporation due to high temperature in places such as Vietnam or hollow region. Conventional methods for solving these problems are mainly to increase the unit yield, to use a coagulation retardant, or to provide a cooling system to lower the temperature of the concrete.

In general, sodium gluconate (molasses), which is conventionally used to prevent slump loss of concrete in a harsh environment, has a problem of deteriorating the quality of concrete such as coagulation delay, initial strength drop, and bleeding, .

Japanese Patent No. 2774445 discloses a concrete admixture prepared by copolymerizing a polyalkylene glycol monoester monomer and an acrylic acid monomer as a prior art relating to a concrete admixture for concrete. The concrete admixture has a polyalkylene glycol chain and low cohesive adsorption ability of the cement particles, so that the dispersibility is good, but the coagulation delay effect of the cement is weak.

In U.S. Patent No. 5,661,206, the use of a copolymer of a polycarboxylic acid compound and a copolymer of an alkoxypolyalkylene glycol mono (meth) aryl ether compound and a polycarboxylic acid compound as a fluidizing agent improves the fluidity of the cement slurry, The problem of slump reduction can be solved.

However, polycarboxylic acid-based concrete chemical admixtures composed of unsaturated polyoxyethylene side chain monomers and acid monomers such as acrylic acid or methacrylic acid, which are presently used, have a problem in that when used in a standing environment, The polycarboxylate ether (PCE) molecular structure in which the side chain is tightly closed results in a decrease in the ratio of the acid monomer having a function of adsorbing with cement, resulting in a poor adsorption performance and a loss of the initial dispersing ability of the concrete do.

Accordingly, there is a need for a composition for forming concrete containing an admixture capable of solving the above-mentioned problems and stably increasing the holding performance of the concrete in a harsh environment while preventing the initial dispersing ability from being lowered.

JP Registration 2774445 US registration 5661206

The present invention provides a composition for forming a concrete and a concrete made therefrom, which can maximize the holding performance of the concrete without using a retarder in a standing condition and can prevent a decrease in initial dispersibility.

Also, the present invention provides a composition for forming a concrete and a concrete made therefrom, which can provide smooth workability and minimize condensation delay, including an admixture which maximizes the retention performance, not the conception delay, .

The present invention also provides a composition for forming a concrete and a concrete produced from the composition, wherein the introduced phosphate is slowly hydrolyzed in concrete having a strong base condition to prevent slump loss of concrete by including a phosphate introduced admixture.

According to one aspect,

Aggregates, binders, admixtures and water,

Wherein the admixture comprises a polymer comprising a first recurring unit derived from a phosphate-based monomer (I) represented by the following formula (1): < EMI ID =

≪ Formula 1 >

In Formula 1,

R ₁ , R ₂ and R ₃ each independently represent hydrogen or a methyl group,

n is an average number of moles of oxyalkylene groups added and is an integer of 1 to 20;

According to another aspect, the polymer may further comprise a second repeating unit derived from an unsaturated (poly) alkylene glycol ether monomer (II) represented by the following formula (2)

(2)

In Formula 2,

R ₄ , R ₅ and R ₆ each independently represent hydrogen or a methyl group,

X represents an alkylene group or an oxyethylene group having 1 to 4 carbon atoms,

R ^a O is one or a mixture of two or more oxyalkylene groups having 2 to 20 carbon atoms,

n is an average addition mole number of the oxyalkylene group, and is an integer of 10 to 120;

According to another aspect, the weight average molecular weight (Mw) of the polymer may be from 5,000 to 100,000.

According to another aspect, the content of the first repeating unit derived from the phosphate-based monomer (I) may be 5 to 40 parts by weight per 100 parts by weight of the polymer.

According to another aspect, the content of the second repeating unit derived from the unsaturated (poly) alkylene glycol ether monomer (II) may be 30 parts by weight to 95 parts by weight per 100 parts by weight of the polymer.

According to another aspect, the polymer further comprises a third repeating unit derived from an unsaturated carboxylate, wherein the content of the third repeating unit derived from the unsaturated carboxylate per 100 parts by weight of the admixture is from 1 part by weight to 40 parts by weight Can be.

According to another aspect, the unsaturated carboxylate may comprise methyl methacrylate, methyl acrylate, ethyl 2-hydroxyacrylate, vinyl acetate, or any combination thereof.

According to another aspect, the admixture may further comprise an additive comprising urea, diethanolamine, triethanolamine or any combination thereof.

According to another aspect, the amount of the admixture may be 0.01 to 2 parts by weight per 100 parts by weight of the composition for forming a concrete.

According to another aspect, the binder is selected from the group consisting of Portland cement, crude steel Portland cement, lime cement, slag cement, blast furnace slag cement, Portland pozzolan cement, fly ash, bottom ash, gypsum cement, lime cement, Or any combination thereof.

According to another aspect, concrete produced from the above-described composition for forming a concrete is produced.

Since the composition for forming a concrete includes an admixture containing a polymer containing a first repeating unit derived from the phosphate monomer (I) represented by the following formula (1), the maintenance performance of the concrete It is possible to maximize the amount of water and to prevent the initial dispersing force from being lowered.

In addition, the composition for forming a concrete includes an admixture which maximizes the supersaturation performance, not the congealing delay, so that the workability is smooth, the delay of the coagulation is minimized, and the strength of the concrete is prevented from lowering in the extreme environment.

Also, the composition for forming a concrete includes an admixture containing a polymer containing a repeating unit derived from a phosphate monomer, and the slump loss of the concrete can be prevented because the phosphate is slowly hydrolyzed in the concrete having a strong base condition.

Also, the concrete produced from the composition for forming concrete can maximize the retention performance of concrete even when no retarder is used under severe conditions, prevent the initial dispersing force from being lowered, work smoothly in the extreme environment, And slump loss of concrete is prevented, it is possible to provide an architectural structure having high durability and high durability.

1 is a graph showing the results of slump tests of Examples 1 to 6 and Comparative Examples 1 to 3 over time.

The composition for forming a concrete includes aggregate, binder, admixture and water.

[aggregate]

The aggregate serves as a base of the composition for forming concrete, and is a mineral material for construction which can be formed into a single lump by a binder.

According to one embodiment, the aggregate contained in the composition for forming a concrete may include a fine aggregate and a coarse aggregate. In the present specification, fine aggregate means an aggregate having a particle size of 100% passing through a 5 mm sieve of a standard net. In this specification, a coarse aggregate means aggregate having a particle size of 100% remaining in a standard 5 mm sieve.

According to one embodiment, the fine aggregate may comprise crushed sand, natural sand, washing yarn, recycled aggregates having a particle size of 0.01 mm to 5 mm, or any combination thereof. According to another embodiment, the fine aggregate may be crushed sand but is not limited thereto.

According to one embodiment, the coarse aggregate may comprise crushed stone, crushed slag, natural gravel, crushed gravel, recycled aggregates having a particle size of 5 mm to 25 mm, or any combination thereof. According to another embodiment, the coarse aggregate may be crushed gravel but is not limited thereto.

According to one embodiment, the aggregate comprises fine aggregate and coarse aggregate, wherein the fine aggregate comprises crushed sand, natural sand, wash cloth, recycled aggregate having a particle size of 0.01 mm to 5 mm, or any combination thereof, The coarse aggregate may include crushed stone, crushed slag, crushed gravel, recycled aggregate having a particle size of 5 mm to 25 mm, or any combination thereof.

According to one embodiment, the amount of the aggregate may be 60 to 90 parts by weight based on 100 parts by weight of the total amount of the composition for forming a concrete. When the amount of the aggregate is less than 60 parts by weight based on 100 parts by weight of the total amount of the composition for forming a concrete, the concrete compression strength is increased when the concrete is produced from the composition for forming a concrete, If the content is more than 90 parts by weight based on 100 parts by weight of the total amount of the composition for forming a concrete, separation between the aggregate and the binder may occur and the concrete quality may be deteriorated.

According to one embodiment, the fine aggregate fraction (S / a) in the composition for forming a concrete may be 35% to 65%. According to another embodiment, the fine aggregate fraction (S / a) in the composition for forming a concrete may be 35 to 55%. According to another embodiment, the fine aggregate fraction (S / a) of the composition for forming a concrete may be 45% to 50%. Here, the fine aggregate ratio (S / a) is a percentage of the absolute volume of fine aggregate (S) to the total aggregate (fine aggregate + coarse aggregate, a). If the fine aggregate ratio (S / a) of the composition for forming a concrete is less than 35%, the amount of unit and the amount of cement are decreased, resulting in poor workability and a problem of being separated from other materials as rough concrete If the fine aggregate ratio (S / a) of the composition for forming a concrete exceeds 65%, there arises a problem that drying shrinkage, settling crack, plastic shrinkage crack, and the like increase.

[Binding material]

The binder improves and maintains the adhesive force between the aggregate (for example, fine aggregate or coarse aggregate) contained in the composition for forming a large crate, thereby imparting durability and strength to the concrete.

According to one embodiment, the binder is selected from the group consisting of Portland cement, crude steel Portland cement, lime cement, slag cement, blast furnace slag cement, Portland pozzolan cement, fly ash, bottom ash, gypsum cement, lime cement, silica fume, Or any combination thereof.

According to another embodiment, the binder may include, but is not limited to, Portland cement, slag cement, blast-furnace slag cement, or any combination thereof.

According to one embodiment, the content of the binder may be 1 part by weight to 50 parts by weight based on 100 parts by weight of the total amount of the composition for forming a concrete. When the content of the binder is within the range of 100 parts by weight based on the total amount of the composition for forming a concrete, the manufacturing cost of the concrete can be reduced and the water tightness can be increased.

According to one embodiment, the water-binder ratio (W / B) of the composition for forming a concrete may be 20% to 60%. According to one embodiment, the water-binder ratio (W / B) of the composition for forming a concrete may be 40% to 50%. Here, the water-binder ratio (W / B) means the percentage of the absolute weight with respect to the amount of water (W) relative to the binder (B). If the water-binding material ratio (W / B) of the concrete forming composition is less than 20%, the fluidity of the concrete produced from the concrete-forming composition may deteriorate, and the water- B) is more than 60%, the durability and strength of the concrete produced from the composition for forming a concrete may be lowered.

[Admixture]

1. Polymers included in the admixture

The admixture includes a polymer containing a first repeating unit derived from the phosphate monomer (I) represented by the general formula (1).

The first repeating unit

The polymer includes a first repeating unit derived from the phosphate monomer (I) represented by the general formula (1).

≪ Formula 1 >

In Formula 1,

R ₁ , R ₂ and R ₃ each independently represent hydrogen or a methyl group,

n is an average number of moles of oxyalkylene groups added and is an integer of 1 to 20;

According to one embodiment, the content of the first repeating unit derived from the phosphate-based monomer (I) may be 5 to 40 parts by weight. For example, the content of the second repeating unit may be 10 parts by weight to 30 parts by weight, or 20 parts by weight to 25 parts by weight. If the content of the first recurring unit is less than 5 parts by weight, the dispersibility of the concrete may be deteriorated. If the content of the first recurring unit exceeds 40 parts by weight, the copolymerization reactivity may be lowered.

Since the polymer includes the first repeating unit derived from the phosphate monomer (I) represented by the above formula (1), the structure in which the phosphate group is introduced into the polycarboxylate ether (PCE) And even when the side chain monomer ratio is increased, the adsorption performance against the cement can be remarkably increased due to the strong negative charge of the phosphate group, and thus the maintenance performance can be stably enhanced while preventing the initial dispersion power from lowering even if the ratio of the side chain monomer is increased .

In the first recurring unit derived from the phosphate monomer (I) represented by the general formula (1), the phosphate group is hydrolyzed gradually over time in concrete having a strong base condition, thereby preventing the slump loss of the concrete.

The phosphate monomer (I) 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

According to one embodiment, the polymer may further comprise a second repeating unit derived from the unsaturated (poly) alkylene glycol ether monomer (II) represented by formula (2)

(2)

In Formula 2,

R ₄ , R ₅ and R ₆ each independently represent hydrogen or a methyl group,

X represents an alkylene group or an oxyethylene group having 1 to 4 carbon atoms,

R ^a O is one or a mixture of two or more oxyalkylene groups having 2 to 20 carbon atoms,

n is an average addition mole number of the oxyalkylene group, and is an integer of 10 to 120;

According to one embodiment, the average addition mole number n of the oxyalkylene group in the formula (2) may be 10 to 120. For example, in Formula 2, the average addition mole number n of the oxyalkylene group may be 20 to 100. If n is less than 10, the hydrophilicity of the obtained copolymer tends to be lowered and the dispersing performance tends to be lowered. When n is more than 120, copolymerization reactivity may become poor.

The polyalkylene glycol contained in the unsaturated polyalkylene glycol ether monomer (II) is not particularly limited and may be, for example, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, polyethylene polybutylene glycol, and the like. However, polyethylene glycol or polyethylene polypropylene glycol containing an oxyethylene group having high hydrophilicity as an essential component is preferable, and polyethylene glycol is most preferable.

According to one embodiment, the unsaturated (poly) alkylene glycol ether monomer (II) represented by the general formula (2) may be represented by the following type of unsaturated group (n is an integer of 10 to 120 essence):

<PEG-1>

<PEG-2>

<PEG-3>

The unsaturated (poly) alkylene glycol ether monomer (II) represented by the general formula (2) is not limited to the above three types of polyethylene glycol (PEG) but may be any one satisfying the general formula (2).

The composition for forming concrete according to one embodiment comprises a first repeating unit derived from the phosphate monomer (I) represented by the formula (1) and a second repeating unit derived from the unsaturated (poly) alkylene glycol ether monomer (II) Based on the total weight of the composition.

For example, the polymer may include a second repeating unit derived from an unsaturated (poly) alkylene glycol ether monomer (II) represented by PEG-1 in the chemical structure and a phosphate group-containing monomer (I) And a second repeating unit derived from the first repeating unit.

In another example, the polymer may include a second repeating unit derived from an unsaturated (poly) alkylene glycol ether monomer (II) represented by PEG-2 in the chemical structure and a phosphate group-containing monomer (I ). &Lt; / RTI &gt;

As another example, the polymer may include a second repeating unit derived from an unsaturated (poly) alkylene glycol ether monomer (II) represented by PEG-3 in the chemical structure and a phosphate group-containing monomer (I ). &Lt; / RTI &gt;

According to one embodiment, the content of the second repeating unit derived from the unsaturated (poly) alkylene glycol ether monomer (II) may be 30 parts by weight to 95 parts by weight per 100 parts by weight of the polymer. For example, the content of the second repeating unit may be 40 to 80 parts by weight, or 50 to 70 parts by weight. If the content of the second repeating unit is less than 30 parts by weight, the dispersibility of the concrete may deteriorate. If the content of the second repeating unit exceeds 95 parts by weight, the copolymerization reactivity may be lowered.

The third repeating unit

According to one embodiment, the polymer may further comprise a third repeat unit 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-hydroxyacrylate and vinyl acetate. For example, the unsaturated carboxylate may be ethyl 2-hydroxyacrylate, but is not limited thereto.

According to one embodiment, the content ratio of the third recurring unit which may be additionally contained is not particularly limited as long as the effect of the present invention is not impaired. However, the third repeating unit derived from the unsaturated carboxylate per 100 parts by weight of the polymer The content of the unit may be 1 to 40 parts by weight.

According to one embodiment, the weight average molecular weight (Mw) of the polymer may be from 5,000 to 100,000. For example, the weight average molecular weight of the polymer may be from 10,000 to 60,000. When the weight average molecular weight of the polymer is less than 5,000, the dispersing performance is lowered. When the weight average molecular weight is more than 100,000, the polymerization efficiency may be lowered.

Other units

The polymer contained in the admixture may further include a fourth repeating unit derived from 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-hexyl mercaptan, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and butyl thioglycolate; Halides such as carbon tetrabromide, methylene chloride, 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 a mixture thereof.

The polymerization initiator includes, for example, persulfates such as ammonium sulfate, sodium persulfate, and potassium persulfate; Hydrogen peroxide; Azobis-2-methylpropionamidine hydrochloride, azoisobutyronitrile (AIBN), 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'- Methoxy-2,4-dimethylvaleronitrile), and the like; Butyl peroxypivalate, 1,1'-bis- (bis-t-butylperoxy) cyclohexane, t-amylperoxy-2-ethyl Peroxides such as hexanoate, and mixtures thereof. According to one embodiment, the polymerization initiator may be t-amylperoxy-2-ethylhexanoate, but is not limited thereto.

According to one embodiment, the amount of the polymer may be 1 part by weight to 99 parts by weight, for example 1 part by weight to 50 parts by weight, based on 100 parts by weight of the total amount of the admixture. When the content of the polymer is within the above range, the concrete cracks can be effectively reduced.

2. Admixture additive

 The admixture may further comprise a blending additive comprising at least one selected from urea, diethanolamine and triethanolamine. The admixture additive imparts moisture retention to the admixture to delay evaporation of water in the concrete.

According to one embodiment, the admixing additive may be urea.

The content of the admixture 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 admixture 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 admixture contains both a polycarboxylate ether compound containing a repeating unit derived from the compound represented by the formula (1) and a polyalkyl ether compound having a hydrophilic lipophile balance (HLB) of 10 to 13 at the same time , It is possible to effectively prevent cracking of concrete due to drying shrinkage by imparting excellent dispersibility and workability maintenance performance to a concrete forming composition and reducing interfacial tension between water and concrete surface or water present on water and concrete surface .

According to one embodiment, the admixture may be a mono-fluid type. That is, the admixture is a one-pack type, has excellent long-term stability, is easy to store, can be efficiently managed, and can reduce maintenance and maintenance costs.

The 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.

The content of the admixture may be 0.01 to 2 parts by weight based on 100 parts by weight of the total amount of the composition for forming a concrete. When the content of the admixture is within the above range with respect to 100 parts by weight of the total amount of the composition for forming a concrete, it is possible to improve the fluidity of the concrete and to prevent the concrete from cracking.

As an example of the method for producing the above-mentioned admixture, a method of producing an admixture containing a polymer containing the first repeating unit and the second repeating unit as an admixture according to one embodiment comprises mixing the phosphate-based monomers (I), (S210) adding a mixture of an unsaturated polyalkylene glycol ether monomer (II) represented by the formula (2), a chain transfer agent and a solvent into a reactor and stirring at 25 to 100 ° C; Adding the polymerization initiator to 0.01 part by weight to 1.0 part by weight based on 100 parts by weight of the mixture while stirring the mixture for 1 hour to 10 hours (S220); (S230) holding the polymerization initiator at the same temperature condition for 30 minutes to 2 hours at the completion of the addition of the polymerization initiator; And adjusting the pH to 3 to 8 with at least one selected from a monovalent metal base, a divalent metal base, an amine compound and ammonia water (S240).

Examples of the solvent include water; Alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; Aromatic or aliphatic hydrocarbons such as toluene, xylene, cyclohexane, and n-hexane; Ester compounds such as ethyl acetate; Ketone compounds such as acetone and methyl ethyl ketone; Cyclic ether compounds such as tetrahydrofuran and dioxane; Etc., and one or more selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms can be used in consideration of the solubility of the starting monomer and the copolymer obtained. According to one embodiment, the deprotection step can be omitted if water is used as the solvent.

The chain transfer agent and the polymerization initiator can be referred to those described in the present specification.

The polymerization time is preferably 0.01 to 10 parts by weight per 100 parts by weight of the mixture,

1.0 part by weight, and reacted for 1 to 10 hours. More preferably 5 to 8 hours. If the reaction time is less than 1 hour, the production efficiency of the copolymer may deteriorate. If the reaction time exceeds 10 hours, the time is too long, which is not economically efficient.

The pH of the thus obtained copolymer is preferably adjusted to 3 to 8, more preferably 5 to 6. The pH adjustment can be adjusted to at least one selected from a monovalent metal base, a divalent metal base, an amine-based compound, and ammonia water.

The admixture according to one embodiment may have a solids content of 30 to 60%.

The admixture according to one embodiment can be used for cement, mortar, concrete, etc. Especially, when used as a dispersant for concrete used in a standing environment, including a polymer containing a first repeating unit containing a phosphate group, The holding performance can be increased, and the initial dispersing ability can be prevented from being lowered. In addition, the phosphate group introduced into the PCE molecular structure has the effect of preventing the slump loss of concrete by slowly hydrolyzing in concrete having a strong base condition (pH > 12).

[additive]

The composition for forming a concrete may further contain an additive within a range that does not impair the effect of the present invention.

The additive may be selected from the group consisting of a cement dispersant, a defoamer, a water soluble polymer, an air entraining agent, a cement wetting agent, a swelling agent, a water repellent, a retarding agent, a fast cure accelerator, a water soluble polymeric material, a thickener, Or any combination thereof.

The amount of the additive may be 0.1 part by weight to 10 parts by weight based on 100 parts by weight of the total amount of the composition for forming a concrete.

 [concrete]

The concrete can be produced from the above-described composition for forming a concrete. A description of the composition for forming concrete is given in this specification.

The concrete may contain a polycarboxylate ether compound containing a repeating unit derived from the compound represented by the formula (1) and a polyalkyl ether compound having a hydrophilic lipophile balance (HLB) of 10 to 13 at the same time It is possible to provide an architectural structure having excellent durability and high durability.

The method of manufacturing the concrete can be easily manufactured by a person skilled in the art with reference to the following embodiments.

Hereinafter, the composition for forming concrete according to one embodiment of the present invention will be described in more detail with reference to Preparation Examples and Examples. In the following Production Examples and Examples, the molar equivalent of A and the molar equivalent of B are the same among the expressions " B was used instead of A ".

[Example]

Example 1

80 parts by weight of unsaturated polyethylene glycol ether monomer (CH ₂ ═C (CH ₃ ) -CH ₂ -O- (CH ₂ CH ₂ O) ₅₃ -H, weight average molecular weight: 2,400) parts of phosphate-based monomer (chemical formula: CH2 = CH-C = O- (O-CH 2 CH 2) 3 -OP = O (OH) 2 molecular weight: 284.2) 12 parts by weight, 2-ethyl hydroxy acrylate, 6.6 wt. Mercaptoethanol as a chain transfer agent in an amount of 0.2 part by weight, and the remainder as a solvent, and 1.2 parts by weight of t-amylperoxy-2-ethylhexanoate as a polymerization initiator was gradually added dropwise and stirred at 85 캜 for 6 hours. After the completion of the reaction, the temperature was cooled to 60 DEG C and caustic soda was then added in the atmosphere to adjust the pH to 6.0 to obtain 1,866 g of a polycarboxylate ether compound, 50% solid content (yield: 88%, weight average molecular weight ): 60,000, viscosity: 500 ± 50 cps).

Example 2

(Yield: 84%, weight-average molecular weight (MW): 58,000, weight-average molecular weight (MW): 58,000) was obtained in the same manner as in Example 1 except that the polyester- Viscosity: 500 ± 50 cps).

Example 3

(Yield: 84%, weight average molecular weight (MW): 58,000, weight-average molecular weight (MW): 58,000) was obtained in the same manner as in Example 1, except that 5 parts by weight of a phosphate- Viscosity: 500 ± 50 cps).

Example 4

Except that 40 parts by weight of a phosphate-based monomer was used.

(Yield: 85%, weight average molecular weight (MW): 58,000, viscosity: 500 ± 50 cps) was obtained in the same manner as in Example 1, except that the polycarboxylate compound

Example 5

(Yield: 84%, weight-average molecular weight (MW): 58,000, weight-average molecular weight (MW): 58,000) was obtained in the same manner as in Example 1, except that the polyester- Viscosity: 500 ± 50 cps).

Example 6

(Yield: 85%, weight-average molecular weight (MW): 58,000, weight-average molecular weight (MW): 58,000) was obtained in the same manner as in Example 1, except that the polyester- Viscosity: 500 ± 50 cps).

Comparative Example 1

Except that 3.3 parts by weight of acrylic acid (chemical formula: CH ₂ = CH-COOH, molecular weight: 72) was used in place of the phosphate monomer, to obtain 1,700 g of polycarboxylate ether compound, 50% solid (yield: 89%, weight average molecular weight (MW): 62,000, viscosity: 500 ± 50 cps).

Comparative Example 2

1,600 g of a polycarboxylate ether compound and 50% of a polycarboxylate compound were prepared in the same manner as in Example 1, except that 8.2% by weight of acrylic acid (chemical formula: CH ₂ = CH-COOH, solid content (yield: 89%, weight average molecular weight (MW): 62,000, viscosity: 500 ± 50 cps) was obtained.

Comparative Example 3

1,700 g of a polycarboxylate ether compound and 50% of a polycarboxylate compound were prepared in the same manner as in Example 1, except that 12.1% by weight of acrylic acid (chemical formula: CH ₂ = CH-COOH, solid content (yield: 89%, weight average molecular weight (MW): 62,000, viscosity: 500 ± 50 cps) was obtained.

&Lt; Method for measuring weight average molecular weight of copolymer >

1) Species: Waters LCM1

2) Detector: Differential refractometer (RI) detector (Waters 410)

3) Eluent: Type Acetonitrile / 0.05M sodium acetate ion exchange solution = 40/60 (vol%), adjusted to pH 6.0 in acetic acid

4) Eluent flow rate: 0.6 ml / min

5) Column: Type TSK-GEL G4000SWXL + G3000SWXL

"G2000SWXL" + "GUARD COLUMN" Each 7.8 x 300 mm, 6.0 x 40 mm

6) Column temperature: 40 DEG C

7) Calibration curve: based on polyethylene glycol

Experimental Example

The test was carried out in accordance with KSF 2402, and the admixture prepared according to Examples 1 to 6 and Comparative Examples 1 to 3 was used as a concrete composition as shown in Table 1, using a solid content of 20% and a cement content of 0.8%. The stirring time was 2 minutes, and the concrete temperature was 30 ° C.

W / B
(%) S / a
(%) water
(kg / m ³ ) bookbinder Aggregate (kg / m ³ ) AD
(%) Cement (kg / m ³ ) Fine aggregate Coarse aggregate 51.4 48 180 350 835 915 0.8

※ W / B: (total weight of water / total weight of binder) × 100

※ S / a: (total volume of fine aggregate / total volume of coarse aggregate) × 100

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

※ Cement: Cheonmam Table Cement (Sungshin Cement Co.)

The slump test results of the concrete with time are shown in Figs. 1 and 2. The slump test was performed two or more times for each sample, and the average value was shown.

division Slump value (nm) 0 minutes 60 minutes 120 minutes 180 minutes Example 1 190 220 220 200 Example 2 170 200 195 170 Example 3 160 190 185 160 Example 4 200 225 225 205 Example 5 160 180 165 145 Example 6 200 225 215 195 Comparative Example 1 150 185 150 110 Comparative Example 2 160 195 160 120 Comparative Example 3 165 200 160 125

Referring to FIGS. 1 and 2, Examples 1 to 6 according to the present invention confirmed that the fluidity of concrete was maintained stably over time, as compared with Comparative Examples 1 to 3. Particularly, in Examples 1 to 4, the slump degradation was low even after 3 hours, whereas in Comparative Examples 1 to 3, it was experimentally confirmed that after 3 hours, the slump decreased compared to the initial time, It can be seen that when the concrete is formed using the composition for forming concrete containing a polymer containing repeating units as an admixture, the effect of preventing the slump loss while stably enhancing the fluidity maintenance performance of the concrete can be obtained.

Examples 5 and 6 also show that the concrete fluidity is maintained stably for 3 hours as compared with Comparative Examples 1 to 3, but the concrete fluidity is maintained within the phosphate-based monomer containing range (5-40 parts by weight based on 100 parts by weight) It was confirmed that the maintenance effect was lowered as in Example 5 when the temperature was outside the predetermined range as compared with Examples 1 to 4, or the efficiency was not increased even when the concentration was increased as in Example 6, and the efficiency was lowered economically.

As a result, the composition for concrete formation containing a polymer containing a first recurring unit derived from a phosphate monomer (I) as an admixture maximizes the retention performance, And it was confirmed that the use of the retarder in the past has the effect of minimizing the delay in the condensation, which is a problem that has occurred, and preventing the decrease in strength.

In addition, the phosphate in the first repeating unit is hydrolyzed slowly in concrete having a strong base condition, thereby preventing the slump loss of the concrete.

In addition, since the strong negative charge of the phosphate group in the first repeating unit can significantly increase the adsorption performance, if the ratio of the side chain monomer is increased in the prior art, the ratio of the acid monomer having the adsorption function with the cement decreases, And the problem of causing initial dispersion force loss can be solved.

As described above, the admixture of the above-mentioned examples contains a polymer containing phosphate in the PCE molecular structure, so that the slump retention performance of about 3 hours can be stably ensured and the initial dispersibility is prevented from lowering, And the like.

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 (11)

Aggregates, binders, admixtures and water,
The admixture
A first repeating unit derived from a phosphate-based monomer (I) represented by the following formula (1);
A second repeating unit derived from an unsaturated (poly) alkylene glycol ether monomer (II) represented by the following formula (2); And
A third recurring unit derived from an unsaturated carboxylate. A composition for forming a concrete, comprising:
&Lt; Formula 1 >

In Formula 1,
R ₁ , R ₂ and R ₃ each independently represent hydrogen or a methyl group,
n is an average addition number of moles of oxyalkylene groups and is an integer of 1 to 20,
(2)

In Formula 2,
R ₄ , R ₅ and R ₆ each independently represent hydrogen or a methyl group,
X represents an alkylene group or an oxyethylene group having 1 to 4 carbon atoms,
R ^a O is one or a mixture of two or more oxyalkylene groups having 2 to 20 carbon atoms,
n is an average addition mole number of the oxyalkylene group, and is an integer of 10 to 120; delete The method according to claim 1,
Wherein the content of the first repeating unit derived from the phosphate monomer (I) is 5 to 40 parts by weight per 100 parts by weight of the polymer. The method according to claim 1,
Wherein the content of the second repeating unit derived from the unsaturated (poly) alkylene glycol ether monomer (II) is 30 to 95 parts by weight per 100 parts by weight of the polymer. The method according to claim 1,
Wherein the content of the third repeating unit derived from the unsaturated carboxylate per 100 parts by weight of the polymer is 1 to 40 parts by weight. The method according to claim 1,
Wherein said unsaturated carboxylate comprises methyl methacrylate, methyl acrylate, ethyl 2-hydroxyacrylate, vinyl acetate, or a combination thereof. The method according to claim 1,
Wherein the weight average molecular weight (Mw) of the polymer is 5,000 to 100,000. The method according to claim 1,
Wherein the admixture further comprises an additive comprising urea, diethanolamine, triethanolamine or a combination thereof. The method according to claim 1,
Wherein the amount of the admixture is 0.01 to 2 parts by weight per 100 parts by weight of the composition for forming a concrete. The method according to claim 1,
The binder is selected from the group consisting of concrete, including Portland cement, crude steel Portland cement, lime cement, slag cement, blast furnace slag cement, Portland pozzolan cement, fly ash, bottom ash, gypsum cement, lime cement, silica fume, / RTI &gt; A concrete produced from the composition for forming a concrete according to any one of claims 1 to 10.

Images