KR101554864B1 - A preparation method of concrete with a precipitation agent for recovered remocon water and concrete made thereby - Google Patents

Abstract

The present invention relates to a precipitating agent for collected ready-mixed concrete (remicon) water, which comprises 10 to 20 parts by weight of a diluent for a cellulose-based thickening agent and 45 to 46 parts by weight of silicone-based defoaming agent based on a total weight, wherein the precipitating agent increases the precipitation rate of solid content present in collected remicon water and reduces the generation of foam. When a sludge precipitating agent prepared by the method for preparing sludge precipitating agent for collected remicon water according to the present invention is used, the foam generated in the collected remicon water is mixed with sludge to effectively prevent a phenomenon that the foam is not destroyed, rather gets larger and increases; the solid content in the sludge is rapidly aggregated and precipitated to the bottom of a collected water storage tank, thereby increasing real capacity of the collected water storage tank; and introduction of sludge solid content is minimized in using the collected remicon water to increase the durability of concrete, stabilize a product and reduce environmental pollution. In addition, more economically concrete can be produced and an eco-friendly method for producing remicon is provided.

Description

TECHNICAL FIELD The present invention relates to a method of producing a concrete using a sludge settlement accelerator of a ready-mixed concrete recovered water and a concrete produced by such a method. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a sludge settling accelerator for ready-mixed concrete water, a method for preparing the same, and a method for producing concrete using the sludge settling accelerator for ready-mixed concrete water. More specifically, And 45 to 46 parts by weight of a silicone antifoam agent, the bubbles formed in the sludge containing the remicon-recovered water can be quickly removed, so that the solid content in the sludge can be quickly settled, It is possible to make the use of recovered water more easily and to produce high quality concrete.

That is, the sludge settlement promoter of the ready-mixed recovered water provided in the present invention can quickly remove the solid matter contained in the sludge of the ready-mixed recovered water as well as the bubbles inevitably generated in the ready-mixed recovered water, And the amount of the solid content of the sludge contained in the recovered water used in the production of the concrete is remarkably reduced, and the slump, the air amount and the compressive strength of the produced concrete are improved.

Also, the present invention relates to a sludge settlement promoter and a method for manufacturing the sludge settlement enhancer, which are economically advantageous and environmentally friendly in terms of reduction in concrete production cost due to an increase in production efficiency and recycling of ready-mixed concrete water.

The number of recovered concrete is generally the wastewater generated during the concrete manufacturing process. It occurs mainly when concrete is washed so as not to harden during transportation in a concrete conveying vehicle for conveying the concrete used at the construction site. It may occur during the cleaning process of the mixer, and may also occur during the process of cleaning the wheels to prevent the generation of dust in the remicon conveying vehicle.

Conventionally, such wastewater and remicon by-products have been pointed out as a serious environmental pollutant source by entering or discharging into a sewage treatment plant without undergoing a special treatment process, and waste of by-products (for example, sand, gravel, etc.) .

In order to prevent such problems, a wastewater treatment plant was installed and many facilities such as waste remicon aggregate separator were introduced, thereby reducing the primary problem of by-product leakage, thereby improving the recycling rate of resources. Secondly, There have been suggestions for improvement such as preventing the waste of used water by recycling it later.

However, since many kinds of various ingredients and materials are mixed in the ready-mix water, many bubbles are generated due to the water pressure in the washing process. When the ready-mix water containing the washed concrete is put into the aggregate sorting machine, A larger amount of foam is generated by the friction.

These bubbles adhere to the solid content of the sludge (that is, the fine particles contained in the raw material of cement or concrete and the sand, and the fine particles on the gravel), and the viscosity is further raised. As a result, the amount and size of the bubbles become larger and the bubbles continue to accumulate. The accumulation of such bubbles may eventually lead to the inflow of sewage through the storage capacity of the recovered water storage tank, resulting in the occurrence of frequent occurrence of less than 60% of the actual storage capacity of the ready-mixed recovery water storage tank installed in the existing ready- There is still a problem that can be utilized only.

As regulations on environmental pollution are strengthened and expanded, the number of ready-mixed concrete is regulated to be within the range of 3% of sludge solid content in the KS standard. However, since more than 3% of ready-mixed concrete is used, A large amount of laitance of the flying fine particles is generated, and a large problem such as failure to adhere the concrete placed thereon occurs.

Patent No. 0486460 (published on December 03, 2004)

Disclosure of Invention Technical Problem [8] The present invention has been made in view of the above problems, and it is an object of the present invention to provide a sludge settlement promoting agent for a ready- It is possible to effectively prevent the bubbles from becoming larger and larger without being destroyed.

In addition, it is possible to increase the substantial storage capacity of the ready-mixed-water storage tank by rapidly aggregating the solid content in the sludge and precipitating below the collected-water storage tank, and by minimizing the inflow of the solidified sludge when using ready- To stabilize quality and to reduce environmental pollution.

By using such a sludge settling promoter, it is possible to manufacture concrete more economically and to provide an environmentally-friendly concrete production method.

In order to achieve the object of the invention mentioned above, the present invention provides a settlement accelerator for recovered ready-mixed concrete water containing 10 to 20 parts by weight of a diluent of a cellulose-based thickener based on the total weight and 45 to 46 parts by weight of a silicone- The sedimentation promoter of the ready-mixed concrete recovered water is characterized by increasing the settling velocity of the solid content present in the ready-mixed concrete recovered water and simultaneously reducing the occurrence of bubbles.

The cellulose-based thickener used in the present invention preferably has a weight-average molecular weight in the range of 50,000 to 180,000, and may be selected from the group consisting of hydroxypropyl methyl cellulose (HPMC) and / or hydroxyethyl methyl cellulose (HEMC ).

The silicone-based defoaming agent used in the present invention may be selected from the group consisting of a silicone resin, a silicone oil, and a silicone polymer. The diluent of the cellulose-based thickener may be a diluted solution of the cellulose thickener in distilled water at a ratio of 200 times Is preferably used.

Another embodiment of the present invention is a method for producing a sedimentation promoting agent for a ready-mixed recovered water, comprising the steps of: a) mixing hydroxypropyl methyl cellulose (HPMC) and / or hydroxypropyl methyl cellulose (HPMC) having a weight average molecular weight of 50,000 to 180,000 Diluting ethylmethylcellulose (HEMC) with distilled water to a volume ratio of 200 times to prepare a dilution liquid of a cellulose thickener; And b) 10 to 20 parts by weight of a diluent of the cellulose thickener and 45 to 46 parts by weight of a silicone antifoam agent, wherein the silicone antifoam agent is at least one selected from the group consisting of silicone resin, silicone oil and silicone polymer .

Another embodiment of the present invention is a method for producing concrete using a sedimentation accelerator of a ready-mixed recovered water, comprising the steps of: a) hydrolyzing a mixture of hydroxypropyl methyl cellulose (HPMC) having a weight average molecular weight of 50,000 to 180,000 and / Or hydroxyethyl methyl cellulose (HEMC) diluted to a volume ratio of 200 times with distilled water to prepare a dilution liquid of a cellulose thickener; b) 10 to 20 parts by weight of a diluent of the cellulose thickener and 45 to 46 parts by weight of a silicone antifoaming agent to prepare a settlement accelerator of ready-mixed concrete water; c) 10 to 20 parts by weight of a cellulose-based thickener, 32 to 45 parts by weight of water, 20 to 30 parts by weight of a methyl methacrylate-based polymer, 10 to 15 parts by weight of a polycarboxylic acid-based polymer and 0.5 to 3 parts by weight of a silicone- Thereby producing a chemical admixture for concrete; d) Mixing the sedimentation accelerator of the ready-mixed recovered water in an amount of not less than 0.1 parts by weight and not more than 0.5 parts by weight with respect to 100 parts by weight of the ready-mixed recovered water to precipitate sludge solid content to thereby obtain a ready-mixed recovered water having a residual solid content of 3 wt% Producing; e) 70 to 77 parts by weight of a filler, 13 to 19 parts by weight of a cement, 2 to 10 parts by weight of recovered concrete mixed with a sedimentation accelerator, and 5 to 13 parts by weight of a used water are mixed, 1 to 1.5 wt% based on the total weight of the concrete mixture; And f) curing the concrete mixture in a mold.

Wherein the silicone-based defoaming agent is selected from the group consisting of a silicone resin, a silicone oil, and a silicone polymer, wherein the filler comprises a fine aggregate and a coarse aggregate, wherein the cement has a fly ash content of 3-5% And / or an admixture of slag fine powder.

In step c), 10 to 15 parts by weight of sodium gluconate and / or 1 to 2 parts by weight of lauric acid may further be added in the step of preparing the chemical admixture for concrete, and the methyl The methacrylate-based polymer is preferably polymethyl methacrylate (PMMA) and / or polymethacrylate (PMA).

Wherein the polycarboxylic acid polymer is at least one selected from the group consisting of an alcohol polyalkylene glycol mono (meth) acrylic acid ester monomer, a (meth) acrylic acid monomer and a (meth) acrylic acid ester monomer And the like.

As described above, the present invention effectively reduces bubbles formed in the recovered water using the ready-mixed recovery water sludge settlement promoter and quickly sinks the solidified sludge, thereby increasing the substantial storage capacity of the ready-to- .

In addition, it is possible to improve workability, which is a top priority element of concrete quality, to maintain stable concrete production quality because there is no fluctuation of slump and air quantity, and the amount of solid content contained in sludge is reduced, thereby improving the durability and water tightness of concrete have.

By using the sludge settlement promoter produced by the method of manufacturing the sludge settlement promoter of the ready-mixed recovered water proposed in the present invention, it is possible to effectively prevent the phenomenon that the foam and sludge generated in the ready- can do.

In addition, it is possible to increase the substantial storage capacity of the ready-mixed-water storage tank by rapidly aggregating the solid content in the sludge and precipitating below the collected-water storage tank, and by minimizing the inflow of the solidified sludge when using ready- Stabilize quality and reduce environmental pollution.

By using such a sludge settling promoter, concrete can be manufactured more economically, an environmentally friendly concrete production method can be provided, and stable and high quality concrete can be produced. In particular, there is no fluctuation of the initial air amount in the concrete production process, and the change of the physical properties over time can be reduced.

FIG. 1 is a photograph showing the settlement degree of the recovered water according to the comparative example and the embodiment of the present invention.

In order to solve the above-mentioned problems of the prior art and to achieve the above object and effect, the present invention is characterized in that a sludge solid content of the ready-mixed recovered water specified in the KS standard is contained in a range of 3% The present invention provides a sludge settling accelerator for concrete with recovered water having an optimized composition.

According to a preferred embodiment of the present invention, the ready-mixed recovery water sludge settlement promoter used for the ready-mixed recovery water comprises 10 to 20 parts by weight of the diluent of the cellulose-based thickener based on the total weight and 45 to 50 parts by weight of the silicone defoamer, The remainder is composed of water, which has significant implications at ratios that do not counteract the effects of each component but can exert the optimum effect.

The thickener used in the present invention is a silicone thickener which has the advantage of increasing the viscosity of the concrete composition to improve the material separation resistance of concrete to maintain moisture retention and facilitate quality control.

Cellulose thickener can be mixed with Hydroxypropyl Methyl Cellulose (HPMC) and Hydroxypropyl Methyl Cellulose (HEMC), respectively, which can be used to make uniform pore formation in the concrete, Excellent concrete filling ability.

Particularly, a cellulose ion exchanger (also referred to as an ion exchange cellulose) having an ion exchange capacity (also referred to as ion exchange cellulose) can be formed by etherification or esterification of the hydroxy group of the cellulose, and CM- cellulose (carboxymethyl Cellulose), SM-cellulose (sulfomethyl cellulose) and the like, and DEAE-cellulose (diethylaminoethyl cellulose) is an anion exchanger. Since the cellulose ion-exchanger is a polymer having no three-dimensional structure, it is used for separation and purification (purification) of biopolymers such as proteins. Such cellulose ion exchangers are electrostatically charged in the sludge, It has the advantage of maximizing the sinking effect by screening.

In general, HEMCs become viscous and sticky aqueous solutions when dissolved in water. Because of this viscosity, unlike ordinary concrete, it takes time to react to gravity action and shows unusual fluidity which seems to show gentle deformation in slump test. In addition, since HEMC shows water retention when dissolved in water, no bleeding occurs in HEMC-added concrete, and the mixed water in concrete is prevented from being dispersed in water.

Since the concrete should not cause any separation of materials, the thickener should be designed to maintain sufficient moisture retention and insensitivity to temperature by acting with water. The thickener used in the cellulose system may be difficult to mix with water due to the surface tension of the water. Therefore, the surface treatment by the esterification reaction and the combination of three or more different kinds of HPMC having different molecular weights using the HPMC which improves the moisture retention and the temperature dependency .

In the present invention, a cellulose thickener having a molecular weight of 50,000 to 180,000 is dissolved in water having a volume ratio of 200, and 10 to 20 parts by weight of a diluent is used. If the molecular weight of the cellulose thickener is lower than 50,000, lumpiness may be generated due to strong adhesion of sludge to the sludge recovered water. If the molecular weight is more than 180,000, adhesion may be weakened and material separation may occur. If the amount of the diluted cellulose thickener is less than 10 parts by weight, the amount of the filler to be added is too small to increase the viscosity. If the amount is more than 20 parts by weight, the viscosity of the concrete increases.

The antifoaming agent used in the present invention is a silicone-based antifoaming agent and is intended to suppress rapidly generated bubbles when using a remicon-recovered water in the production of a concrete mixture. Such a silicone antifoam agent is a silica silicone antifoam agent prepared by mixing at least one material selected from the group consisting of silicone resin, silicone oil and silicone polymer with silica powder, preferably a silicone silicone antifoam agent containing silica solids in an amount of 25 wt% to be.

In the present invention, 45 to 46 parts by weight of a silicone antifoaming agent is used. If the amount is less than 45 parts by weight, bubbles can not be properly removed from the returned water due to bubbling, and the strength of the concrete is lowered and fluidity is insufficient by generating air bubbles on the surface of the AE agent. When the amount exceeds 46 parts by weight, However, there is a concern that the fluidity of the concrete is lowered and the durability is lowered due to freezing and thawing due to insufficient air volume.

A method for producing the settlement accelerator of the ready-mixed recovered water of the present invention is as follows.

First, hydroxyethyl methyl cellulose (HEMC) or hydroxypropyl methyl cellulose (HPMC) powders having a weight average molecular weight ranging from 50,000 to 180,000 were mixed in water at a volume ratio of 200 times, A dilute solution of a cellulose thickener is prepared.

10 to 20 parts by weight of the diluted solution of the cellulose thickener thus prepared and 45 parts by weight of the silicone antifoaming agent were mixed and stirred at a speed of about 5000 rpm for 30 minutes and then 30 to 45 parts by weight of water were added thereto and stirred at about 3000 rpm for about 20 minutes, Lt; / RTI >

The sludge settling promoter of the manufactured ready-mixed recovered water is added in a range of 0.1 part by weight to 0.5 part by weight relative to the ready-mixed recovered water, and stirred at a speed of about 3000 rpm for 20 minutes to prepare a ready-mixed recovered water.

When the bubble formation state and the sludge settlement state of the ready-mixed recovered water of the present invention manufactured by the above-described method were visually directly checked, it was confirmed that most of the sludge solids in the ready- And the residual solid content in the recovered water was less than 3%.

Concrete was prepared using the above-mentioned remicon recovery water in order to confirm the changes in the air amount and the compressive strength of the recovered water using the sludge settlement accelerator of the ready-mixed concrete water recovered in the present invention.

 The sedimentation accelerator of the ready-mixed recovered water is mixed in an amount of 0.1 to 0.5 parts by weight with respect to 100 parts by weight of the ready-mixed recovered water having a solid content of 3 wt% or less, 70 to 77 parts by weight of the filler, 2 to 10 parts by weight of the remicon recovery water mixed with the sedimentation accelerator and 5 to 13 parts by weight of the use water are further mixed and the chemical admixture for concrete is mixed with 1 to 1.5 wt% . The concrete mixture thus prepared was cured by putting it in a mold.

It is preferable to use the chemical admixture shown in Patent Application No. 2014-0099220, which is a prior patent of the present inventor, as a method of producing concrete using the ready-mixed recovery water to which the ready-mixed recovery water subsidence promoter of the present invention is applied.

That is, it is preferable to produce concrete using a chemical admixture for concrete containing a methyl methacrylate-based polymer and a polycarboxylic acid-based polymer, a cellulosic thickener, and a silicone-based defoaming agent, and the above-mentioned ready-mixed recovered water of the present invention.

The chemical admixture for concrete comprises 32 to 45 parts by weight of water, 20 to 30 parts by weight of a methyl methacrylate polymer, 10 to 15 parts by weight of a polycarboxylic acid polymer, 10 to 20 parts by weight of a cellulose type thickener, 3 parts by weight.

The dispersant is preferably a methyl methacrylate polymer. The dispersant is a surfactant component serving as a principle for dispersing cement particles by electrostatically acting on molecules adsorbed on the cement particles. The surfactant component can be wetted, emulsified and solubilized , It plays a role to improve cement particle dispersion, fluidity, uniform cement hydration reaction and workability of concrete in concrete.

The dispersing agent may be selected from known dispersing agents, but is preferably at least one selected from the group consisting of oxycarboxylates, polyoxyethylene alkylaryl ether derivatives, alkylallylsulfonates, polyamine condensates and polycarboxylic acid-based polymer compounds desirable.

Particularly, a polymethacrylate system having a hydrophilic group such as a sulfonic acid group (-SO ₃ ), a carboxyl group (-COO), and a hydroxyl group (-OH) at the end group can be exemplified. Polymethyl methacrylate Methacrylate, PMMA) and / or polymethacrylate (PMA). When such a dispersant is used, the water content of the concrete can be reduced by 20 to 30% as compared with that of the conventional concrete, and the concrete efficiency can be improved by increasing the fluidity of the concrete, and the strength of the cured concrete And can be suitably used for special structures requiring high strength such as high-rise buildings, roads, bridges or bridge piers.

The composition ratio of the methyl methacrylate polymer is preferably 20 to 30 parts by weight. When the methyl methacrylate polymer is added in an amount of less than 20 parts by weight, bleeding occurs due to an increase in the amount of water used in the production of concrete If the amount is more than 30 parts by weight, there arises a problem such as separation of concrete, deterioration of durability due to poor curing, and reduction of working efficiency.

The polycarboxylic acid polymer used as the preservative in the chemical admixture for concrete is used only for the effect of maintaining the fluidity or viscosity, so that it is preferable to control the fluidity or viscosity of the concrete in the early stage. When the main chain of the carboxyl group (COO-) of the polycarboxylic polymer having a long side chain is embedded in the product of the hydrate of the cement, the above-mentioned polycarboxylate-based sustaining agent has a secondary dispersing ability of the side chain, maintain. In this case, the polycarboxylic acid-based sustaining agent is preferably used in a range of 10 to 15 parts by weight, and when the polycarboxylic-based oil-retaining agent is less than 10 parts by weight, In the case of a weight part, durability may be lowered due to poor curing.

The polycarboxylic acid-based polymer is at least one member selected from the group consisting of an alcohol-polyalkylene glycol mono (meth) acrylic acid ester monomer, a (meth) acrylic acid-based monomer and a (meth) (Meth) acrylic acid monomers and (meth) acrylic acid monomers in combination with a macromonomer of an alkoxypolyalkylene glycol mono (meth) acrylate ester and a functional acrylic ester monomer in combination with a polycarboxylic acid monomer It is possible to increase the flowability of the concrete composition in a region of a high water reducing rate and dramatically prevent deterioration over time of the obtained fluidity over a long period of time, To run continuously Good workability can be imparted.

The polyoxyalkylene alkenyl ether sulfide salt is a reactive surfactant contained in the carboxylic acid copolymer as a unit monomer and has both a hydrophobic group and a hydrophilic group so that the water solubility of the polymer is enhanced and the polymer can be physically adsorbed on the cement particles By increasing the properties of the cement particles, it helps to maintain the dispersibility of the cement particles.

In addition, the polyoxyalkylene alkenyl ether sulfide salt has a double bond capable of participating in a radical reaction, and thus acts as a polymer surfactant by copolymerizing with monomers. The hydrophobic portion of the surfactant helps adsorb to the cement particles, and the ionic portion forms an electric double layer to increase the zeta potential and increase the electrostatic repulsion and stability between the dispersed particles. Accordingly, the polyalkylene glycol chain has both hydrophilic property and cement dispersing effect due to steric repulsion, as well as electrostatic repulsion by the sulfonic acid at the end of the surfactant, thereby improving dispersibility and air stability.

The alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer and the polyoxyalkylenealkenyl ether sulfide salt have a double bond capable of participating in a radical reaction, so that they are copolymerized with the monomers to form an electrostatic repulsion force between the dispersed particles and Stability can be induced, thereby maintaining the fluidity for a long period of time, thereby minimizing a change in the concrete composition over time.

The polycarboxylic acid copolymer may be prepared through a copolymer using the polymerization initiator using a polymerization initiator and the copolymer method may be carried out by solution polymerization or bulk polymerization. But is not limited thereto.

In addition, a silicone thickener can be used as the thickener, which increases the viscosity of the concrete composition to improve the resistance to separation of the concrete material, thereby maintaining moisture retention and facilitating quality control.

Cellulose thickener can be mixed with Hydroxypropyl Methyl Cellulose (HPMC) and Hydroxypropyl Methyl Cellulose (HEMC), respectively, which can be used to make uniform pore formation in the concrete, Excellent concrete filling ability.

When HEMC is dissolved in water, it becomes a viscous and sticky aqueous solution. Because of this viscosity, it takes time to react to gravity action unlike ordinary concrete, and it exhibits unusual fluidity which seems to show gentle deformation in the slump test. In addition, since HEMC shows water retention when dissolved in water, no bleeding occurs in HEMC-added concrete, and the mixed water in concrete is prevented from being dispersed in water.

Since the concrete should not cause any separation of materials, the thickener should be designed to maintain sufficient moisture retention and insensitivity to temperature by acting with water. The thickener used in the cellulose system may be difficult to mix with water due to the surface tension of the water. Therefore, the surface treatment by the esterification reaction and the combination of three or more different kinds of HPMC having different molecular weights using the HPMC which improves the moisture retention and the temperature dependency .

A cellulose thickener having a molecular weight of 50,000 to 180,000 is dissolved in 200-fold volume of water, and 10 to 20 parts by weight of a diluent is used. If the molecular weight of the cellulose thickener is lower than 50,000, lumpiness may be generated due to strong adhesion of sludge to the sludge recovered water. If the molecular weight is more than 180,000, adhesion may be weakened and material separation may occur. If the amount of the cellulose thickener is less than 10 parts by weight, the amount of the filler is too small to increase the viscosity. If the amount of the cellulose thickener is more than 20 parts by weight, the viscosity of the concrete increases.

The antifoaming agent used in the present invention is a silicone-based antifoaming agent and is intended to suppress rapidly generated bubbles when using a remicon-recovered water in the production of a concrete mixture. Such a silicone antifoam agent is a silica silicone antifoam agent prepared by mixing at least one material selected from the group consisting of silicone resin, silicone oil and silicone polymer with silica powder, preferably a silicone silicone antifoam agent containing silica solids in an amount of 25 wt% to be.

In the present invention, the silicone antifoaming agent is used in an amount of 0.5 to 3 parts by weight. If the amount is less than 0.5 parts by weight, the bubbles in the recovered concrete can not be properly removed due to the formation of bubbles, and the bubbles are generated on the surface of the AE agent to lower the strength of the concrete and insufficient fluidity. However, there is a concern that the fluidity of the concrete is lowered and the durability is lowered due to freezing and thawing due to insufficient air volume.

The gluconic acid based compound, preferably sodium gluconate, which can be used in addition to the chemical admixture for concrete of the present invention, serves to retard the rate at which the cement composition is agglomerated. Specifically, the gluconic acid-based compound prevents the concrete composition from prematurely agglomerating at a predetermined coagulation rate or higher, thereby preventing the deterioration of the workability and durability of the concrete composition.

In the present invention, sodium gluconate is preferably used in an amount of 10 to 15 parts by weight. When sodium gluconate is used in an amount of less than 10 parts by weight, the concrete composition may rapidly aggregate to deteriorate workability and durability. When the amount exceeds 15 parts by weight, So that the workability and durability are deteriorated.

Lauric acid, which can be used in addition to the above-mentioned gluconate-based compound, can be selected from among fatty acid metal salts and fatty acid esters. However, in the case of fatty acid esters, It is more preferable to use a fatty acid metal salt because it may cause a trouble to the reaction or cause a deterioration in the adhesive strength.

As the fatty acid metal salt, zinc laurate, calcium laurate and aluminum laurate are preferable, and it is preferably used in the range of 1 to 2 parts by weight. If the content of the lauric acid is less than 1 part by weight, And when the amount of the used amount is more than 2 parts by weight, the air bubble stability of the concrete is deteriorated and the strength of the concrete can be weakened.

In addition, the lauric acid increases the resistance to the electrical influence of Ca ^{2 +} ions discharged through the cement hydration reaction, thereby preventing adsorption to the cement. Therefore, it is possible to obtain the desired initial air amount in the non-hardened concrete and to reduce the air amount loss after the aging. Further, in the case of the fatty acid metal salt, it is preferable to select a powder type having a particle diameter of 5 mu m or less because the smaller the particle size is, the greater the effect to be exhibited.

As a method of administering the metal salt of lauric acid or the ester of lauric acid into the concrete, there is a method of being directly applied to the concrete to keep it in the pore, and a method of mixing it with the admixture to put it into concrete. In the present invention, To 1 to 2 parts by weight of lauric acid.

The method for producing concrete containing added remnant recovered water using the sludge settlement accelerator of the present invention is to produce concrete by adding the chemical admixture for concrete to the process of producing concrete mixture using the remicon recovered water.

More specifically, 10 to 20 parts by weight of a cellulose-based thickener, 32 to 45 parts by weight of water, 20 to 30 parts by weight of a methyl methacrylate-based polymer, 10 to 15 parts by weight of a polycarboxylic acid- To prepare a chemical admixture for concrete; A mixture of 70 to 77 parts by weight of a filler, 13 to 19 parts by weight of a cement, 2 to 10 parts by weight of a remicon recovery water and 5 to 13 parts by weight of water for use is mixed with 1 to 1.5 wt% of the chemical admixture for concrete A step of mixing the concrete mixture into a range; And curing the concrete mixture after putting it in a mold.

In preparing the chemical admixture for concrete, it is preferable to stir the water at a temperature of 15 to 25 ° C. If the temperature of the water is lower than 15 ° C, the viscosity of the raw materials may increase, resulting in a long mixing time or difficulty in mixing. When the temperature exceeds 25 ° C, the viscosity control effect hardly appears.

The filler used in the concrete compounding step includes fine aggregate and coarse aggregate. The filler includes fine aggregate and coarse aggregate. The cement contains fly ash and / or slag fine powder in a range of 3 to 5% It is preferable that the chemical admixture for concrete is selected from the group consisting of oxycarboxylates, polyoxyethylene alkylaryl ether derivatives, alkylallylsulfonates and polyamine condensates in the preparation of the chemical admixture for concrete Or a compound containing at least one or more amino acids.

It is preferable that the chemical admixture for concrete is used in an amount of 1 to 1.5 wt% with respect to the weight of the cement contained in the concrete mixture. This is because when the hydration reaction of water and cement is combined, the pozzolanic reaction occurs and the strength is increased. When the amount of the chemical admixture for concrete is less than 1 part by weight, the strength and sinking crack may be caused. In addition, depending on the concrete structure, the chemical admixture for concrete may be used in excess of 1.5 wt%, but when used in excess of 1.5 wt% in general, problems such as durability deterioration and work efficiency decrease occur due to material separation and curing failure .

As mentioned above, when concrete is prepared by adding ready-mixed concrete water, the ratio of the solid content of the sludge to the amount of cement in the concrete mixture (sludge obtained by drying at 105 to 110 ° C) It is necessary to use the remicon recovery water which satisfies the quality standard of the concrete within 3 wt%. When the quality of the sludge does not reach the standard level, the concrete condensation time is shortened and the slump change is accelerated by about 20 to 30 minutes, the compressive strength is decreased by 15 to 20%, and the air amount is increased by 1 wt% I have an adverse effect on concrete quality such as 8 ~ 10% increase.

Hereinafter, preferred embodiments of the present invention will be described in detail. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein, but all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. And such modifications are within the scope of protection of the present invention.

[ Experimental Example  One]

Manufacture of ready-mixed precipitant accelerator and ready-mixed concrete recovered water

Hydroxypropyl methylcellulose powder having a weight average molecular weight of 100,000 as a cellulose thickener was mixed with water at a volume ratio of 200 times to prepare a diluent for a thickener.

45 parts by weight of a silicone antifoaming agent was added to 15 parts by weight of a cellulose-based thickener diluent, stirred at a speed of 5000 rpm for 30 minutes, and then added with 40 parts by weight of water, followed by stirring at 3000 rpm for about 20 minutes to prepare a sedimentation accelerator.

The sludge settling promoter of the prepared remicon water was prepared by adding 0.4% by weight of the sludge settling promoter to the ready mixed concrete, and the mixture was stirred at a speed of 3000 rpm for 20 minutes to prepare a ready mixed concrete. To produce concrete.

At this time, it is preferable that the concrete is formulated as described above, and that 1.0-3.5 parts by weight of a chemical admixture for non-toxic concrete using a remicon recovery water is used for the total weight of cement when producing concrete, In the case where the amount of the admixture is less than 0.5 part by weight in the process of increasing the strength due to the occurrence of the pozzolanic reaction, strength is lowered and sinking crack is generated due to addition of water.

( Comparative Example  One)

Concrete was blended with ordinary concrete mixture using remicon recovery water without sedimentation accelerator.

(Comparative Example 2)

The same composition as in Comparative Example 1 was always used, and the concrete was formulated using 0.1% of the sedimentation accelerator as the recovered water.

( Example  One)

Conducted in the same manner as in Comparative Example 1 at all times, the concrete was mixed using 0.3% of the sedimentation accelerator as the recovered water.

( Example  2)

Conducted in the same manner as in Comparative Example 1 at all times, concrete was formulated by using a sedimentation accelerator at 0.5% of the recovered water.

[ Experimental Example  2]

1.76 kg of water, 1.76 kg of recovered water, 5.28 kg of cement, 0.66 kg of slag fine powder, 0.66 kg of fly ash, 16.94 kg of fine aggregate, and a coarse aggregate of the aggregate promoter prepared in Comparative Examples 1 and 2 and Examples 1 and 2, The physical properties of the concrete prepared by blending 1% (0.66 kg) parts by weight of the chemical admixture for concrete in the total weight of the powder in the concrete composition comprising 16.94 kg are shown in Tables 1 and 2 below.

   division Early 30 min 60min slump air slump air slump air Comparative Example 1 190 5.2 175 4.9 155 4.2 Comparative Example 2 195 5.3 180 5.1 165 4.6 Example 1 200 5.1 190 5.0 180 4.8 Example 2 200 5.0 190 5.0 180 4.9

Table 1 shows the results of the measurement of the slump and the air amount of the unhardened concrete. In the case of Comparative Examples 1 and 2, since the air amount of the concrete is largely reduced, the workability is lowered in putting on the spot, However, in the case of Examples 1 and 2 in which an appropriate amount of the sludge settling agent of the present invention was used, this problem did not occur, and it was confirmed that the variation width of the slump and the air amount with the passage of time decreased without fluctuation of the air amount.

Jaeil Comparative Example 1 Comparative Example 2 Example 1 Example 2 3 days 16.2 18.3 19.5 19.7 7 days a year 26.1 28.1 29.6 29.8 28 days old 34.2 37.2 38.1 38.5

* Unit MPa

Table 2 shows the results of the compressive strength tests of the cured concrete according to the ages. Compared with the comparative examples 1 and 2, it was found that the compression strength was higher when the sludge settlement accelerator of the ready mixed concrete of the present invention was used. In particular, it was confirmed that the difference between Example 1 and Example 2 was not large, and it was confirmed that it was preferable to determine the amount of use in the range of Examples 1 and 2. [

[ Experimental Example  3]

In Comparative Examples 1 and 2 and Examples 1 and 2, a visual observation experiment was carried out to directly confirm the removal effect of the bubbles and the settling effect of the solid content of the sludge, and the results are shown in FIG. As can be seen from FIG. 1, the results of Comparative Example 1, Comparative Example 2, Example 1 and Example 2 are shown from the left. After administration of the sludge settling accelerator of the ready-mixed concrete water of the present invention (except Comparative Example 1) Stirring the mixture at 3000 rpm for 20 minutes, leaving the mixture for 30 minutes, and observing the result.

In the case of Comparative Example 1, it was confirmed that the bubble was not stable, the turbidity of the recovered water was high, and the sludge did not sink. In the case of Comparative Example 2, it was found that the sludge settling promoter of the ready-mixed recovery water was injected 0.1% of the total recovered water amount to the general ready-mixed concrete withdrawn water. It was found that the turbidity became thin and the sludge was slightly settled, .

In the case of Example 1, 0.3% of the total amount of the recovered water was added to the general ready-mixed recovery water, and the turbidity was much weaker than that of Example 1, and the sludge was found to settle.

In the case of Example 4, 0.5% of the total amount of the recovered water was added to the general ready-mixed recovery water, and the turbidity was much reduced and the sludge was settled similarly to the case of Example 3. FIG.

Claims (12)

delete delete delete delete delete In a method for producing concrete,
a) Hydroxypropyl Methyl Cellulose (HPMC) and / or Hydroxyethyl Methyl Cellulose (HEMC) having a weight average molecular weight of 50,000 to 180,000 are diluted with distilled water to a volume ratio of 200 times to prepare a cellulose thickener ≪ / RTI >
b) 10 to 20 parts by weight of a diluent of the cellulose thickener and 45 to 46 parts by weight of a silicone antifoaming agent to prepare a settlement accelerator of ready-mixed concrete water;
c) 10 to 20 parts by weight of a cellulose-based thickener, 32 to 45 parts by weight of water, 20 to 30 parts by weight of a methyl methacrylate-based polymer, 10 to 15 parts by weight of a polycarboxylic acid-based polymer and 0.5 to 3 parts by weight of a silicone- Thereby producing a chemical admixture for concrete;
d) Mixing the sedimentation accelerator of the ready-mixed recovered water in an amount of not less than 0.1 parts by weight and not more than 0.5 parts by weight with respect to 100 parts by weight of the ready-mixed recovered water to precipitate sludge solid content to thereby obtain a ready-mixed recovered water having a residual solid content of 3 wt% Producing;
e) 70 to 77 parts by weight of a filler, 13 to 19 parts by weight of cement, 2 to 10 parts by weight of recovered water having a residual solid content of 3 wt% or less and 5 to 13 parts by weight of a used water, 1 to 1.5 wt% based on the weight of the cement; And
and f) curing the concrete mixture by placing the concrete mixture in a mold to produce concrete using the remicon recovered water and the settlement promoter. The method according to claim 6,
Wherein the silicone-based defoaming agent is at least one selected from the group consisting of silicone resin, silicone oil, and silicone polymer. The method according to claim 6,
Wherein the filler comprises a fine aggregate and a coarse aggregate,
Characterized in that the cement comprises an admixture of fly ash and / or slag fine powder of 3 to 5% of the total weight of the filler. The method according to claim 6,
In the step of producing the chemical admixture for concrete of the step c), a mixture of 10 to 15 parts by weight of sodium gluconate and / or 1 to 2 parts by weight of lauric acid is further added, And a method of producing concrete using a sedimentation promoting agent. The method according to claim 6,
Wherein the methyl methacrylate-based polymer is polymethyl methacrylate (PMMA) and / or polymethacrylate (PMA). The concrete is manufactured using the remicon recovered water and the sedimentation accelerator How to. The method according to claim 6,
Wherein the polycarboxylic acid polymer is at least one member selected from the group consisting of alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomers, (meth) acrylic acid monomers and (meth) acrylic acid ester monomers A method for producing concrete using remicon recovery water and a sedimentation promoter, comprising a copolymer of the selected compound. A concrete produced by a method for producing concrete using the remicon recovered water and the settlement accelerator according to any one of claims 6 to 11.

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