JP6029882B2 - Film curing agent, film curing structure, and concrete manufacturing method - Google Patents

Description

  The present invention relates to a film curing agent, a film curing structure, and a concrete manufacturing method.

Conventionally, since the initial drying of concrete causes cracking, strength and compactness reduction, measures to prevent drying after demolding during construction have been taken. As an initial drying prevention method, moisture retention using a sheet or the like is performed.
In addition, as a curing method that does not use a sheet, after concrete demolding, a water retention curing is applied using a film curing agent to prevent drying and ensure a dense surface layer that is related to the durability of the concrete. (For example, refer to Patent Document 1).

  Patent Document 1 describes a coating curing agent for a cement-based material that is a coating curing agent that is applied or dispersed before the cement-based material is cured, and that includes a polymer emulsion, a lithium salt, and a curing accelerator for cement hydration. Has been.

Japanese Patent No. 4664711

  However, in the curing method using the conventional film curing agent described above, the drying prevention effect is small, and the quality of the surface layer portion may not be sufficiently ensured. For example, if you want to remove the formwork earlier than the standard curing period, such as tunnel lining concrete, or if there are severe drying conditions such as wind and solar radiation, a coating curing agent with higher anti-drying performance is required. There was room for improvement in this regard.

  The present invention has been made in view of the above-mentioned problems, and by obtaining an excellent drying prevention effect at the time of curing, it is possible to improve the quality of concrete and enable early demolding. An object of the present invention is to provide a film curing agent, a film curing structure, and a method for producing concrete.

In order to achieve the above object, the film curing agent according to the present invention is a film curing agent for preventing initial drying during curing of concrete, and is an exposed surface after a predetermined curing period of the placed concrete. The water-dispersed polyester is a self-dispersed water-based polyester prepared by a phase inversion method. The water-dispersed polyester is a water-dispersed polyester having a function of moisturizing and curing the concrete. It is characterized by that.

Further, the film curing structure according to the present invention is a film curing structure for preventing initial drying during the curing of concrete, and is an exposed surface after a predetermined curing period of the placed concrete, and is removed from the mold the surface after the coating curing agent consisting of water dispersible polyester is applied, is moisturizing curing, the water-dispersible polyester has a feature that it is a self-dispersible water-based polyester prepared by phase inversion process.

Further, the concrete manufacturing method according to the present invention is a method for manufacturing concrete cast using a formwork, the step of demolding after a predetermined curing period of the cast concrete, and the exposure of the concrete after demolding on the surface, subjected to moisture curing by applying the coating curing agent consisting of water-dispersed polyester, a step for preventing initial drying, was closed, self-balancing the water dispersion polyester was prepared by a phase inversion process It is characterized by being a water-based polyester .

In the present invention, the exposed surface of the concrete that has been demolded after the predetermined curing period is coated with a film curing agent made of water-dispersed polyester, and the ratio of mass change due to drying in the cured concrete is coated with the conventional film curing agent. Since the air permeability coefficient becomes smaller as compared with the case of the above, the effect of preventing the initial drying can be improved, and excellent moisture retention curing can be performed. In addition, since the drying prevention effect is enhanced, it is possible to remove the mold at an early stage, and it is possible to improve the construction efficiency by expelling the demolding, such as tunnel lining concrete. In addition, there is an advantage that it is a simple operation of simply applying the film curing agent.

  According to the film curing agent, the film curing structure, and the concrete production method of the present invention, it is possible to improve the quality of concrete by obtaining an excellent drying prevention effect during curing, and early demolding is possible. It can be.

It is a figure which shows the manufacturing method of the lining concrete by embodiment of this invention, Comprising: (a) is a figure which shows the state at the time of placement, (b) is a figure which shows the state at the time of curing. It is a figure which shows the test result by a test example, Comprising: It is a figure which shows the mass change by drying in each test body. It is a figure which shows the test result by a test example, Comprising: It is a figure which shows the dense evaluation of the concrete after hardening with an air permeability coefficient.

  Hereinafter, a film curing agent, a film curing structure, and a concrete manufacturing method according to embodiments of the present invention will be described with reference to the drawings.

  The concrete manufacturing method according to the present embodiment shown in FIG. 1 is employed when curing concrete 1 placed using a mold 2. Specifically, as shown in FIG. 1 (a), the first step of demolding the concrete 1 placed as shown in FIG. 1 (a) after a predetermined curing period (for example, age 1 day), and demolding as shown in FIG. 1 (b). A coating curing agent 3 made of a material mainly composed of water-dispersed polyester is applied to the exposed surface 1a of the concrete 1 later, and a second step of preventing initial drying is included.

  Here, as shown in FIG.1 (b), the structure (code | symbol 4 in a figure) in which the film curing agent 3 adhered to the exposed surface 1a of the concrete 1 which has not completed curing is the film curing structure of this invention. It corresponds to.

As described above, the film curing agent 3 is a material having an anti-drying effect mainly composed of a water-dispersed polyester, and is described in, for example, Japanese Patent No. 3162477 (Patent Document 2).
“(A) A diol component represented by the following formula (Chemical Formula 5 in Paragraph 12 shown in Patent Document 2) (wherein R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2-7),
(B) one or more alcohol components selected from the group consisting of aliphatic diols, and (c) trihydric or higher polyhydric alcohols;
(D) one or more selected from the group consisting of a divalent carboxylic acid, its acid anhydride or its lower alkyl ester, and (e) a trivalent or higher polyvalent carboxylic acid, its acid anhydride or its lower alkyl ester A polyester resin having an acid value of 3 to 70 KOHmg / g obtained by co-condensation polymerization with an acid component,
Self-dispersed aqueous solution that is dissolved in a ketone solvent, ionizes the carboxyl group of the polyester resin by adding a neutralizing agent, then adds water, then distills off the ketone solvent and phase-shifts to an aqueous system. Polyester resin composition "
Can be used.

The polyester resin used for the production of this self-dispersing water-based polyester resin composition is produced using an alcohol component and an acidic component such as a carboxylic acid, its acid anhydride or its lower alkyl ester as raw material monomers. Since it is described in paragraphs 11 to 22 of Patent Document 2, description thereof is omitted here.
Examples of the film curing agent 3 include New Track 2011 (NT-2011, manufactured by Kao Corporation, registered trademark). This film curing agent 3 made of water-dispersed polyester as a main component is a polyester dispersed in water, and a polymer that forms an elastic film at a low temperature (for example, 5 to 40 ° C.) by introducing an internal plasticizer. It is a material and has a characteristic value of pH 7 to 9, viscosity 30 to 100 mPa · s (25 ° C. condition), and average particle size 90 to 120 nm.

Moreover, the film curing agent 3 is preferably adhered to the concrete surface at a coating amount of 100 to 250 g / m ² , more preferably 150 to 200 g / m ² . And the film curing agent 3 can be favorably apply | coated with respect to a to-be-adhered surface by using a roller, a hand pump sprayer, etc., for example.

Next, the operation of the above-described film curing agent, film curing structure, and concrete manufacturing method will be described in detail based on the drawings.
As shown in FIG. 1, in the present embodiment, the exposed surface 1a of the concrete 1 after the predetermined curing period after being removed is coated with a film curing agent 3 made of a material mainly composed of water-dispersed polyester, and the curing is performed. The ratio of mass change due to drying in the concrete 1 to be made is smaller than when coated with a conventional film curing agent, and since the air permeability coefficient is small, the effect of preventing the initial drying can be improved, which is excellent Moisturizing and curing can be performed.
In addition, since the drying prevention effect is enhanced, it is possible to remove the mold at an early stage, and it is possible to improve the construction efficiency by expelling the demolding, such as tunnel lining concrete.
In addition, there is an advantage that it is a simple operation of simply applying the film curing agent.

  As described above, in the film curing agent, the film curing structure, and the concrete manufacturing method according to the present embodiment, it is possible to obtain an excellent drying prevention effect at the time of curing, and by enabling early demolding, The quality can be improved.

  Next, test examples for supporting the effects of the film curing agent, the film curing structure, and the concrete manufacturing method according to the above-described embodiment will be described below.

(Test example)
As shown in FIG. 2, this test example is a coating curing agent 3 mainly composed of the water-dispersed polyester according to the above-described embodiment with respect to concrete demolded after a predetermined curing period (see FIG. 1). Comparison of the performance (workability, finish) of the examples using the conventional examples, Comparative Examples 1 and 2 using the conventional film curing agent, and Comparative Example 3 of the uncured, based on the test, the example is effective It was confirmed that.

For the test method, test specimens (length 150 mm × width 150 mm × height 150 mm) were produced for each of Examples and Comparative Examples 1 to 3, and each was demolded on the first day of age. In this case, a coating curing agent is applied to the exposed surface of the concrete, and in the case of Comparative Example 3, it is assumed that no treatment with the coating curing agent is performed. Thereafter, the temperature is 20 ° C. and the relative humidity is 60%. It was cured indoors until the age of 56 days. The coating amount of the coating curing agent is 100 g / m ² which is the optimum amount specified by the manufacturer to be used in Comparative Example 1, and 200 g / m ² which is the optimum amount specified by the manufacturer to be used in Comparative Example 1. Then, it was set to 200 g / m ² .
Table 1 shows the concrete composition of the test specimens used. In Table 1, W is water, C is cement, S is fine aggregate, and G is coarse aggregate.

Here, Table 2 shows the film curing agent used for each specimen.
The embodiment uses the embodiment described above.
Comparative Example 1 is a film curing agent (commercial product) using aqueous paraffin as a main component.
Comparative Example 2 is a film curing agent (commercial product) using a surfactant and glycol as main components.

The evaluation method by this test example performed the mass change test and the surface air permeability test, and compared in each test body (Example, Comparative Examples 1-3).
In the mass change test, as shown in FIG. 2, the mass change due to moisture dissipation from the surface of each test specimen is a ratio (%) to the total mass at the start of drying, that is, the mass change due to drying after the start of curing of concrete ( %).

  As a result, it can be confirmed that the change in mass of the film curing agent of the example is the smallest and the concrete drying prevention effect is the highest. On the other hand, in the case of the conventional film curing agent of Comparative Examples 1 and 2, it can be seen that the effect of suppressing drying is seen, but the effect is small as compared with the Examples.

Next, in the surface air permeability test, as shown in FIG. 3, the compactness after curing of the concrete is evaluated. The surface air permeability test is performed using the torrent method (“Strong effect of curing condition on air permeability of surface”). Concrete, Concrete Plant International ”pp 72-76, Phan HDQuoc, T. Kishi, April 2009).
In addition, in this test, in addition to the above Examples and Comparative Examples 1 to 3, Comparative Example 4 in which the moisture age was cured by wrapping until the age of 3 days, and then in the air until the age of 56 days, and the age of the material Comparison of Comparative Example 5 that was moisturized by lapping up to 7 days and then cured in air until the age of 56 days, and that that was moisturized and cured by wrapping up to the age of 28 days, and then cured in air until the age of 56 days Example 6 was performed together.

As a result, in the case of the example, the air permeability coefficient was approximately 0.8 × 10 ⁻¹⁶ m ² , and an effect substantially equivalent to that of Comparative Example 5 (normal 7-day moisturizing curing) could be obtained. Moreover, since the comparative example 1 is 2.8 * 10 <^-16> m < ^{2 >} and the comparative example 2 is 2.3 * 10 <^-16> m < ² >, the effect by the film curing agent of an Example is the effect by the conventional film curing agent. The air permeability, that is, the denseness was higher than that of the concrete, and the quality of the concrete was confirmed to be improved.

From the above, it can be confirmed that the film curing agent according to the present example has a higher drying prevention effect than the conventional film curing agents according to Comparative Examples 1 and 2.
Separately from the above test, a comparative test was performed with respect to the coating amount of the coating curing agent, and a reasonable coating amount of the coating curing agent capable of obtaining the effect by the above test was selected as 100 to 250 g / m ² .

As described above, the embodiments of the film curing agent, the film curing structure, and the concrete manufacturing method according to the present invention have been described. However, the present invention is not limited to the above-described embodiments, and is appropriately within the scope of the present invention. It can be changed.
For example, as concrete using the film curing agent of the present invention, tunnel lining concrete is one example, and general concrete is widely used.
Further, the mixing of concrete, the time until demolding, the timing of applying the coating curing agent 3, the coating amount, and the like can be appropriately changed according to the construction conditions.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

1 Concrete 1a Exposed surface 2 Formwork 3 Coating curing agent 4 Coating curing structure

Claims (3)

A coating curing agent for preventing initial drying during curing of concrete,
It is an exposed surface after a predetermined curing period of the placed concrete, and is made of a water-dispersed polyester having a function of moisturizing and curing the concrete , which is applied to the surface after mold release .
A film curing agent , wherein the water-dispersed polyester is a self-dispersing water-based polyester prepared by a phase inversion method . A film curing structure for preventing initial drying during curing of concrete,
A exposed surface after a predetermined curing period pouring concrete, the surface after mold demolding, coating curing agent is applied consisting of an aqueous dispersion polyester, is moisturizing cured,
A film curing structure, wherein the water-dispersed polyester is a self-dispersing water-based polyester prepared by a phase inversion method . A method for producing concrete placed using a formwork,
A step of demolding after a predetermined curing period of the cast concrete;
A step of performing moisture retention by applying a film curing agent made of water-dispersed polyester to the exposed surface of the concrete after demolding, and preventing initial drying;
I have a,
A concrete production method, wherein the water-dispersed polyester is a self-dispersing water-based polyester prepared by a phase inversion method.

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