Setting retarder and concrete joint treatment method

Abstract

To provide a setting retarder and a concrete placing joint treatment method which can achieve five-day week system in a construction site.SOLUTION: A setting retarder constructed to a surface of concrete in concrete placing joint treatment has a function of adjusting duration of a setting retardation action when constructed to the surface of the concrete. The setting retarder may be a super retardation type such that the duration of the setting retardation action when constructed to the surface of the concrete lasts for 72 hours at the maximum.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a setting retarder and a method for joint treatment of concrete.

Background Art

[0002] Conventionally, when constructing a concrete structure, joint treatment is carried out (see, for example, Patent Document 1). If the joint treatment is not performed appropriately, it may become a structural weakness and affect the durability. A general joint treatment is performed by spraying a setting retarder on the joint portion where bleeding has converged and performing a retarding treatment the next day.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the above - mentioned conventional general joint treatment, for example, when concrete is placed on Friday, a retarding treatment has to be performed on Saturday the next day, which causes a problem of forced overtime on holidays.

[0005] On the other hand, in the construction industry, ensuring future successors has become a major issue, such as the departure of young engineers and a decreasing number of new recruits every year. Therefore, the "two - day weekend and work - style reform" in the construction industry is being promoted, such as further strengthening the correction of long - working hours and improving the environment to ensure holidays.

[0006] The present invention has been made in view of the above, and an object thereof is to provide a setting retarder and a method for joint treatment of concrete that can achieve a two - day weekend system at the construction site.

Means for Solving the Problems

[0007] In order to solve the above-described problems and achieve the object, the setting retarder according to the present invention is a setting retarder applied to the surface of concrete in the concrete joint treatment, and is characterized by having a function capable of adjusting the duration of the setting retardation effect when applied to the surface of concrete.

[0008] Also, another setting retarder according to the present invention is an ultra-retardation type in which the duration of the setting retardation effect when applied to the surface of concrete lasts up to 72 hours in the above-described invention.

[0009] Also, another setting retarder according to the present invention contains an outer film and a main agent having a setting retardation effect covered by this outer film in the above-described invention, and is characterized by having a release control function in which the release of the main agent is controlled by the outer film reacting with concrete to release the main agent.

[0010] Also, another setting retarder according to the present invention is a thickening setting retarder composed of a compound A having a setting retardation effect and a compound B which is one or more thickeners of an alkali thickening type whose aqueous solution viscosity increases in an alkaline environment in the above-described invention.

[0011] Also, another setting retarder according to the present invention is characterized in that the compound A is composed of one or more of oxycarboxylic acid, lignin sulfonic acid, phosphonic acid, humic acid and / or its salt, or saccharides and polyols in the above-described invention.

[0012] Also, another setting retarder according to the present invention is characterized in that the compound B is an acrylic thickener and is composed of one or more thickeners whose aqueous solution viscosity at 5% active ingredient is 10 mPa·s or less at pH = 5 and 200 mPa·s or more at pH = 12 in the above-described invention.

[0013] Further, another setting retarder according to the present invention is characterized in that, in the above-described invention, the compositions of the compound A and the compound B are in a weight ratio of 10 / 90 to 60 / 40.

[0014] Further, another setting retarder according to the present invention is characterized in that, in the above-described invention, it is used by spraying 150 ml to 1500 ml per 1 m 2 of the surface area of the concrete.

[0015] Further, a method for treating a concrete joint according to the present invention is characterized in that the above-described setting retarder is applied to the surface of the concrete to adjust the setting time of the concrete.

Advantages of the Invention

[0016] According to the setting retarder of the present invention, it is a setting retarder applied to the surface of concrete in the treatment of concrete joints, and has a function of adjusting the duration of the setting retardation effect when applied to the surface of concrete. Therefore, by making the duration of the setting retardation effect longer than usual, for example, the treatment of the concrete joint placed on Friday can be carried out on Monday. For this reason, the effect of realizing a two-day weekend system at the construction site can be achieved.

[0017] Further, according to another setting retarder of the present invention, since it is an ultra-retardation type in which the duration of the setting retardation effect when applied to the surface of concrete lasts up to 72 hours, the effect of being able to make the duration of the setting retardation effect last up to 72 hours (three days) can be achieved.

[0018] Further, according to another setting retarder of the present invention, it contains an outer film and a main agent having a setting retardation effect covered by this outer film, and since the outer film has a release control function in which the release of the main agent is controlled by reacting with the concrete to release the main agent, the effect of being able to easily adjust the duration of the setting retardation effect can be achieved.

[0019] Moreover, according to another setting retarder of the present invention, since it is a thickening setting retarder composed of compound A having a setting retardation effect and one or more kinds of compound B which is a thickener of an alkali thickening type whose aqueous solution viscosity increases in an alkaline environment, there is an effect that the duration of the setting retardation effect can be easily adjusted.

[0020] Moreover, according to another setting retarder of the present invention, since the compound A is composed of one or more kinds of oxycarboxylic acid, lignin sulfonic acid, phosphonic acid, humic acid and / or its salt, or saccharides, polyols, there is an effect that the duration of the setting retardation effect can be easily adjusted.

[0021] Moreover, according to another setting retarder of the present invention, since the compound B is an acrylic thickener and is composed of one or more kinds of thickeners whose aqueous solution viscosity at 5% active ingredient is 10 mPa·s or less at pH = 5 and 200 mPa·s or more at pH = 12, there is an effect that the duration of the setting retardation effect can be easily adjusted.

[0022] Moreover, according to another setting retarder of the present invention, since the composition of the compound A and the compound B is 10 / 90 to 60 / 40 by weight ratio, there is an effect that the duration of the setting retardation effect can be easily adjusted.

[0023] Moreover, according to another setting retarder of the present invention, since it is sprayed and used at 150 ml to 1500 ml per 1 m 2 of the concrete surface area, there is an effect that the duration of the setting retardation effect can be easily adjusted.

[0024] Moreover, according to the concrete joint treatment method of the present invention, since the above-described setting retarder is applied to the surface of the concrete to adjust the setting time of the concrete, there is an effect that a two-day weekend system at the construction site can be realized.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments of a setting retarder and a method for joining concrete according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by this embodiment.

[0027] (Setting Retarder) First, an embodiment of the setting retarder according to the present invention will be described. The setting retarder according to this embodiment is applied to the surface of concrete in the process of joining concrete, and has a function of adjusting the duration of the setting retardation effect after being applied to the surface of concrete. The duration of the setting retardation effect may be longer than that of a normal setting retarder, but it is preferably of an ultra-long retardation type that lasts for up to 72 hours (3 days).

[0028] The setting retarder may contain an outer film and a main agent having a setting retardation effect covered by this outer film, and has a release control function in which the release of the main agent is controlled by the reaction of the outer film with concrete to release the main agent. By this release control function, the duration of the setting retardation effect can be easily adjusted. As a setting retarder embodying this, for example, a liquid agent containing a plurality of small capsules can be mentioned. The outer film of the capsule reacts with the alkaline components and moisture in the concrete and gradually dissolves to release the main agent. By appropriately setting the thickness and material of the outer film of the capsule used, the size of the capsule, etc., it can be easily adjusted to a desired duration. Note that the release control function of the present invention is not limited to this, and other release control functions may be used.

[0029] According to this embodiment, by making the duration of the setting retardation action longer than usual, for example, the joint treatment of the concrete placed on Friday can be carried out on Monday. Therefore, a two-day weekend system at the construction site can be realized.

[0030] In the above embodiment, a thickening setting retarder composed of compound A having a setting retardation action and one or more compound Bs which are thickeners of the alkali thickening type whose aqueous solution viscosity increases in an alkaline environment may be used. Even in this case, the duration of the setting retardation action can be easily adjusted.

[0031] Compound A may be composed of one or more of oxycarboxylic acid, lignin sulfonic acid, phosphonic acid, humic acid and / or its salts, or saccharides, polyols. Compound B is an acrylic thickener, and may be composed of one or more thickeners having an aqueous solution viscosity of 10 mPa·s or less at pH = 5 and 200 mPa·s or more at pH = 12 in 5% by weight of the active ingredient. The composition of compound A and compound B may be, for example, 10 / 90 to 60 / 40 by weight ratio. The setting retarder may be used, for example, by spraying 150 ml to 1500 ml per 1 m 2 of the surface area of the concrete.

[0032] (Setting retarder composition) Next, an embodiment of the setting retarder composition will be described. As a first embodiment, the present invention provides a setting retarder composition for cement-based building materials, and in each case, based on the total weight of the composition, a) at least one setting retarder selected from the group consisting of 3 to 13 wt% of sugar acid, sugar, sugar alcohol, hydroxycarboxylic acid, lignin sulfonic acid, phosphoric acid, phosphonic acid, boric acid, and their salts, b) at least one thickener selected from 10 to 20 wt% of an alkali-swellable polymer, and c) the balance being water.

[0033] The setting retarder related to the present invention is a chemical substance or a mixture of chemical substances that delays the hydration reaction of cement-based building materials after adding mixing water, as compared with the case where such a setting retarder is not added. In particular, the setting retarder affects the hydration reaction in the early age and reduces the increase in compressive strength.

[0034] At least one setting retarder is composed in the composition of the present invention at 3 to 13 wt%, preferably 5 to 10 wt%, particularly preferably 8 wt% based on the total weight of the composition. According to an embodiment, at least one setting retarder is selected from the group consisting of sugar acids, sugars, sugar alcohols, hydroxycarboxylic acids, lignin sulfonic acids, phosphoric acids, phosphonic acids, boric acids, and their salts.

[0035] The sugar acid in the present invention is a monosaccharide having a carboxyl group, such as aldonic acid, uronic acid, urosonic acid, or alduronic acid. The preferred sugar acid is aldonic acid. Examples of sugar acids useful in the present invention include, but are not limited to, glyceric acid, xylonic acid, gluconic acid, ascorbic acid, neuraminic acid, glucuronic acid, galacturonic acid, iduronic acid, tartaric acid, mucic acid, and saccharic acid. The sugar acid exists as a free acid or as a salt. As an embodiment, the salt of the sugar acid is a salt with metals in Groups IIa, IIa, IIb, IIb, IVb, and VIIIb of the periodic table of elements. Preferred salts of the sugar acid are salts of alkali and alkaline earth metals, iron, cobalt, copper, or zinc. Particularly preferred are salts of monovalent metals such as lithium, sodium, and potassium.

[0036] The sugars in the present invention are carbohydrates having an aldehyde group. In a particularly preferred embodiment, the sugars belong to the group of monosaccharides or disaccharides. Examples of saccharides include, but are not limited to, glyceraldehyde, threose, erythrose, xylose, lyxose, arabinose, ribose, allose, altrose, glucose, mannose, gulose, idose, galactose, talose, fructose, sorbose, lactose, maltose, sucrose, lactulose, trehalose, cellobiose, chitobiose, isomaltose, palatinose, mannobios, raffinose and xylobiose.

[0037] The sugar alcohols in the present invention are polyhydric alcohols derivable from sugars by an oxidation-reduction reaction. Thus, sugar alcohols belong to the class of alditols. Examples of sugar alcohols include, but are not limited to, ethylene glycol, glycerol, diglycerol, threitol, erythritol, pentaerythritol, dipentaerythritol, xylitol, ribitol, arabitol, sorbitol, sorbitan, isosorbide, mannitol, dulcitol, fucitol, iditol, inositol, volemitol, lactitol, maltitol, isomalt, maltotriitol, maltotetraitol, and polyglycitols.

[0038] The hydroxycarboxylic acids in the present invention are carboxylic acids containing an OH- moiety within the same molecule. Examples of hydroxycarboxylic acids include, but are not limited to, malic acid, citric acid, isocitric acid, tartaric acid, tartronic acid, mandelic acid, salicylic acid, lactic acid, tannic acid and humic acid. Preferred hydroxycarboxylic acids are citric acid, tartaric acid, and lactic acid. Hydroxycarboxylic acids exist as free acids or salts. According to an embodiment, the salts of hydroxycarboxylic acids are salts with ammonium or metals of groups IIa, IIa, IIb, IIb, IVb, VIIIb of the periodic table of the elements. Preferred salts of hydroxycarboxylic acids are alkali metal salts, alkaline earth metal salts or ammonium salts.

[0039] The phosphoric acid of the present invention is a derivative of phosphoric acid. The phosphoric acid is free phosphoric acid, an oligomer of phosphoric acid, and / or a polymer of phosphoric acid such as diphosphoric acid, triphosphoric acid, and tetraphosphoric acid. The phosphoric acid can exist in a protonated, partially deprotonated, or fully deprotonated state. Fluorinated phosphoric acid is also possible. Examples of suitable phosphoric acids are trisodium orthophosphate, and tetrasodium pyrophosphate, sodium hexametaphosphate, and disodium fluorophosphate. The phosphoric acid can refer to one ester of an ester of phosphoric acid or an oligomer thereof. Examples of esters of phosphoric acid include mixed esters with the above hydroxycarboxylic acids and / or sugar acids, mixed esters with carboxylic acids, particularly mixed esters with fatty acids, alkyl esters, aryl esters, and esters with polyalkylene glycols, but are not limited thereto.

[0040] Similarly, there are mono-, di-, tri-, tetra-, penta- or hexa-phosphonic acids, and their oligomers and / or esters. Preferably, the phosphonic acid has an organic functional moiety. The phosphonate exists in a protonated, partially deprotonated, or fully deprotonated state. Examples of suitable phosphonic acids are 1-hydroxyethylidene-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 3-aminopropylphosphonic acid, aminotris(methylenephosphonic acid), and diethylenetriaminepenta(methylenephosphonic acid).

[0041] Preferred borates in the present invention are salts of boric acid, boric acid or borax.

[0042] Sodium gluconate is a particularly preferred embodiment as at least one setting retarder.

[0043] At least one thickener is selected from alkali-swellable polymers.

[0044] Mixtures of different alkali-swellable polymers can also be used. At least one thickener is present in the composition according to the invention in an amount of 10 to 20 wt%, preferably 12 to 17 wt%, based on the total weight of the composition.

[0045] According to a preferred embodiment, at least one thickener is an alkali-swellable polymer, preferably an alkali-swellable polymer emulsion. The alkali-swellable polymer is a carboxylic acid-functional copolymer that can be produced by free radical emulsion polymerization of ethylenically unsaturated monomers. The alkali-swellable polymer is a preferential copolymer of (meth)acrylic acid and an ester of (meth)acrylic acid. The copolymer of (meth)acrylic acid and an ester of (meth)acrylic acid may have a content of further monomer units such as esters of vinyl alcohols such as propylene, butadiene, styrene, vinyl chloride, vinyl alcohol and / or vinyl acetate. The most preferred copolymer in the present invention is a copolymer of methacrylic acid and an acrylic acid ester, especially a copolymer of methacrylic acid and ethyl acrylate with a molar ratio of about 1:1. The copolymer is a polymer with an anionic charge. Usually, the alkali-swellable polymer has a high molecular weight with a number average molecular weight Mn of 10,000 to 10,000,000 g / mol, preferably 10,000 to 1,000,000 g / mol, especially 30,000 to 500,000.

[0046] The glass transition temperature (Tg) of the alkali-swellable polymer is not particularly limited and can vary widely. The Tg of the alkali-swellable polymer measured according to ASTM D3418 is in the range of -20°C to +90°C. The alkali-swellable polymer thickens by water absorption and swelling and causes such thickening depending on the change from low pH to high pH. At low pH, the copolymer is insoluble in water but becomes soluble and thickens at high pH after being neutralized. Mixtures of two or more alkali-swellable polymers are also possible.

[0047] As such an alkali-swellable polymer, an aqueous emulsion, also called ASE (alkali-soluble / swellable polymer emulsion), is particularly preferred. Preferred ASEs have a solids content of 10 to 40 wt%, particularly 25 to 35 wt%. The alkali-swellable polymer emulsion of the present invention exhibits effective thickening at pH > 5, more preferably at pH > 7, and particularly at pH > 8.

[0048] The alkali-swellable polymer can also be hydrophobically modified. This is typically done by incorporating a small number of hydrophobic macromonomers into the polymer. Such macromonomers are esters of (meth)acrylic acid and hydrophobic alcohols, derivatives of styrene, or nonionic surfactants. The molecular weight of the hydrophobically modified alkali-swellable polymer is typically lower than that of the above-described ASE polymers. The hydrophobically modified alkali-swellable polymer is preferentially used as an aqueous emulsion, also called HASE (hydrophobically modified alkali-soluble polymer emulsion).

[0049] Suitable ASEs and HASEs are available under the brand names Acrysol from Dow Chemical, Acryset from Nippon Shokubai, or Rheovis from BASF.

[0050] Pigments can be used to add colorants to the set retarder composition of the present invention. This is useful for identifying the location where it has already been applied during the application of the set retarder composition. Suitable pigments are organic pigments or inorganic pigments. The use of organic dyes is also possible. Suitable pigments are known to those skilled in the art. According to an aspect, titanium dioxide (TiO2) is used as the pigment. According to other embodiments, azo pigments are used as the pigment. According to still other embodiments, fluorescein, rhodamine or its derivatives are used as the pigment. The pigment can be used in the set retarder formulation of the present invention in an amount of 1 wt% or less based on the total weight of the set retarder composition.

[0051] As a second embodiment, the present invention relates to a setting retarder composition for cement-based building materials, and the composition includes the following a) At least 3 to 13 wt% for cement hydration selected from the group consisting of sugar acids, sugars, sugar alcohols, hydroxycarboxylic acids, lignin sulfonic acids, phosphates, phosphonic acids, borates and salts thereof, b) At least one thickener selected from the group consisting of alkali-swellable polymers, 10 to 20 wt%, c) Optionally 20 to 90 wt%, preferably 50 to 90 wt%, particularly 67 to 87 wt% of at least one filler, d) 0 to 1 wt% of a pigment, e) 0 to 1 wt% of a preservative, and the balance is composed of water.

[0052] As a third embodiment, the present invention is a method for manufacturing laitance-finished concrete, comprising: a) a step of bringing the setting retarder composition as described above into contact with the surface of the uncured cement-based building material; b) a step of curing the cement-based building material while the surface is in contact with the setting retarder composition; and c) a step of removing the setting retarder composition and residual materials from the concrete surface.

[0053] (Method for treating concrete joints) Next, an embodiment of the method for treating concrete joints according to the present invention will be described. The method for treating concrete joints according to this embodiment is to apply the above-described setting retarder to the surface of the concrete to adjust the setting time of the concrete. Specifically, as shown in FIG. 1, first, a setting retarder whose duration of the setting retardation action has been adjusted to a predetermined time (for example, 3 days) in advance is prepared (step S1). Next, for example, the concrete placement is completed on Friday evening (step S2). After waiting for a predetermined time (for example, 1 to 3 hours) until bleeding subsides after the placement is completed, the setting retarder is sprayed on the concrete surface (step S3). An example of the spraying situation is shown in FIG. 2(1).

[0054] Since the setting retardation effect of this setting retarder lasts for three days, work can be suspended on the following Saturday and Sunday (step S4). Next, on Monday, a joint treatment such as a water jet is performed (step S5). An example of the completion of the joint treatment is shown in Fig. 2(2).

[0055] Thus, according to this embodiment, since the joint treatment of the concrete placed on Friday can be carried out on Monday, Saturday and Sunday during that period can be set as holidays. Therefore, a two-day weekend system at the construction site can be realized. For this reason, it is possible to get rid of the so-called 3K (dirty, dangerous, and strenuous) in the construction industry and realize the new 3K (salary, holidays, and hopes). It is expected that the salary will increase due to improved productivity, a two-day weekend can be ensured, and the workplace will become a place where people can have hopes.

[0056] The present invention is in line with the promotion of work-style reform. Considering the labor costs that have been paid for joint treatment, even if the material cost of the setting retarder is high, its value of use is considered to be high.

[0057] As described above, according to the setting retarder according to the present invention, it is a setting retarder applied to the surface of concrete in the joint treatment of concrete, and has a function of adjusting the duration of the setting retardation effect when applied to the surface of concrete. By making the duration of the setting retardation effect longer than usual, for example, the joint treatment of the concrete placed on Friday can be carried out on Monday. For this reason, a two-day weekend system at the construction site can be realized.

[0058] Also, according to another setting retarder according to the present invention, since the duration of the setting retardation effect when applied to the surface of concrete is an ultra-long retardation type that lasts for up to 72 hours, the duration of the setting retardation effect can be made to last for up to 72 hours (three days).

[0059] Moreover, according to another setting retarder of the present invention, it contains an outer film and a main agent having a setting retardation effect covered by this outer film, and since the outer film reacts with concrete to release the main agent, it has a release control function for controlling the release of the main agent, so the duration of the setting retardation effect can be easily adjusted.

[0060] Moreover, according to another setting retarder of the present invention, it is a thickening setting retarder composed of a compound A having a setting retardation effect and a compound B which is one or more kinds of thickeners of an alkali thickening type whose aqueous solution viscosity increases in an alkaline environment, so the duration of the setting retardation effect can be easily adjusted.

[0061] Moreover, according to another setting retarder of the present invention, since the compound A is composed of one or more of oxycarboxylic acid, lignin sulfonic acid, phosphonic acid, humic acid and / or its salt, or saccharides and polyols, the duration of the setting retardation effect can be easily adjusted.

[0062] Moreover, according to another setting retarder of the present invention, the compound B is an acrylic thickener, and is composed of one or more thickeners whose aqueous solution viscosity at 5% active ingredient is 10 mPa·s or less at pH = 5 and 200 mPa·s or more at pH = 12, so the duration of the setting retardation effect can be easily adjusted.

[0063] Moreover, according to another setting retarder of the present invention, since the composition of the compound A and the compound B is 10 / 90 to 60 / 40 by weight ratio, the duration of the setting retardation effect can be easily adjusted.

[0064] Moreover, according to another setting retarder of the present invention, 2 it is used by spraying 150 ml to 1500 ml per 1 m

[0065] Further, according to the concrete joint treatment method of the present invention, the above-mentioned setting retarder is applied to the surface of the concrete to adjust the setting time of the concrete, so that a two-day weekend system at the construction site can be realized.

Industrial Applicability

[0066] As described above, the setting retarder and the concrete joint treatment method according to the present invention are useful for the concrete joint treatment, and in particular, are suitable for realizing a two-day weekend system at the construction site.

Claims

1. A setting retarder applied to the surface of concrete in the concrete joint treatment, having a function capable of adjusting the duration of the setting retardation effect when applied to the surface of concrete, which is a thickening setting retarder composed of a compound A having a setting retardation effect and one or more thickeners B of an alkali thickening type whose aqueous solution viscosity increases in an alkaline environment, wherein the compound B is an acrylic thickener, and is composed of one or more thickeners having an aqueous solution viscosity of 10 mPa·s or less at pH = 5 and 200 mPa·s or more at pH = 12 in 5% by weight of the active ingredient. The setting retarder is characterized by this.

2. The setting retarder according to claim 1, characterized in that it is an ultra-retardation type in which the duration of the setting retardation effect when applied to the surface of concrete lasts up to 72 hours.

3. Containing an outer film and a main agent having a setting retardation effect covered by this outer film, and having a release control function in which the release of the main agent is controlled by the outer film reacting with concrete to release the main agent. The setting retarder according to claim 1 or 2 is characterized by this.

4. The compound A is composed of one or more of oxycarboxylic acid, lignin sulfonic acid, phosphonic acid, humic acid and / or its salts, or saccharides, polyols. The setting retarder according to any one of claims 1 to 3 is characterized by this.

5. The setting retarder according to any one of claims 1 to 4, characterized in that the composition of the compound A and the compound B is 10 / 90 to 60 / 40 by weight ratio.

6. The surface area of the concrete is 1 m ２ The setting retarder according to any one of claims 1 to 5, characterized in that it is used by spraying 150 ml to 1500 ml per square meter of the surface area of the concrete.

7. A concrete joint treatment method characterized by applying the setting retarder according to any one of claims 1 to 6 to the surface of concrete to adjust the setting time of the concrete.

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