JPH1061184A - Method for curing concrete body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete body curing method having a high degree of freedom, which can maintain a wet condition for a long time, and which can be applied for a vertical wall surface. SOLUTION: In a concrete body curing method, when the strength of a concrete body 10 formed by being placed, reaches a predetermined value, a form is removed, and a sheet 12 is stuck. The sheet 12 is composed of a water impermeable synthetic resin film 12 having a predetermined thickness and an adhesive 12b applied over the whole surface of the film 12a. The sheet 12 can be stuck all over the surface of the concrete body 10 by means of the adhesive 12b. After the sheet 12 is stuck on the concrete body 10, moisture to be evaporated and scattered from the concrete body 10, is blocked by the water impermeable synthetic film 12a, thereby it is possible to hold the concrete body 10 in a wet condition for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for curing a concrete body, and more particularly, to a technique for improving wet curing.

[0002]

2. Description of the Related Art Concrete structures are required to exhibit predetermined strength and durability after concrete is poured and hardened. Concrete undergoes detrimental effects such as low temperature, drying and rapid temperature change during hardening, so that the strength and durability are reduced. For this reason, it is necessary to cure the concrete surface so as to protect it and sufficiently exhibit strength and durability.

In this type of concrete curing method, it is desirable to keep the concrete surface in an appropriate wet state. Conventional curing methods include a method in which a weir is kept for a long time and a method in which concrete has a predetermined strength. At that point, it is roughly divided into a method of curing after removing the crest plate.

[0004] The latter curing method includes a flooding curing method in which water is accumulated on the concrete surface, an underwater curing method in which a concrete body is immersed in water, and a sheet covered with a sheet in order to prevent the surface from drying due to direct sunlight or wind. There are a curing method and a water curing method for preventing water from escaping from the concrete surface by spraying water, and a film curing method for forming a film on the concrete surface with paraffin or the like to prevent water evaporation.

[0005] In recent years, with the increase in the size of concrete structures, low heat type cements such as moderate heat cement and high belite cement have been used in many cases. When such a cement is used, curing is required for a longer time than usual in the characteristics of the cement. However, the conventional curing methods described above have technical problems as described below. was there.

[0006]

That is, in a curing method in which a weir is kept for a long period of time, the conversion of a mold is restricted, so that the workability is poor, and it is not generally adopted. On the other hand, the method of flooding and curing underwater is not general because there are limitations on applicable concrete bodies. Further, in the curing method of covering with a sheet, although drying by direct sunlight or wind can be prevented, it is not possible to prevent moisture from escaping, and it is not possible to keep a wet state for a long time.

Further, in the curing method of watering, if watering is performed properly, the wet state can be maintained for a long period of time. However, repetition of dry and wet may cause cracks on the surface, resulting in cracks on the surface. Due to the difference in the state of water absorption, the finished surface becomes uneven, which is not preferable from an aesthetic point of view.

Further, in the film curing method, since a film is formed on the surface of the concrete body, if it is used for a vertical wall-shaped concrete body, there is a problem that the film forming agent drips and a uniform film is formed. And it was difficult to maintain a constant wet state for a long period of time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to keep a wet state for a long period of time and to apply the present invention to a vertical wall or the like. It is an object of the present invention to provide a method of curing a concrete body having a high degree of freedom.

[0010]

To achieve the above object, the present invention relates to a method for curing a cast concrete body, the method comprising: removing the form for forming the concrete body; A sheet made of an adhesive and a moisture-impermeable synthetic resin film was adhered to the surface. According to the concrete body curing method configured as described above, after removing the form, a sheet made of an adhesive and a moisture-impermeable synthetic resin film is attached to the surface of the concrete body, so that the concrete body is evaporated from the concrete body. Moisture that is about to escape is blocked by the film and the concrete body can be kept moist for a long time. in this case,
The sheet consisting of the adhesive and the synthetic resin film can be manufactured in a factory, and the synthetic resin film can be easily formed to a uniform thickness. The effect of preventing evaporation and escape is obtained. In addition, by appropriately selecting the material and thickness of the adhesive,
If the adhesive strength is reduced about several months after the sheet is attached, the sheet can be naturally peeled off. The synthetic resin film can be selected from a photodegradable synthetic resin film and an alkali-degradable synthetic resin film. When such a film is adopted,
When sunlight is applied to the film attached to the concrete body, the film is gradually decomposed, or the film gradually deteriorates due to the alkali component diffusing from the concrete body side, so that the sheet can be peeled off naturally. Will be possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 shows an embodiment of a method for curing a concrete body according to the present invention. The curing method shown in the figure shows a case where the present invention is applied to a concrete body 10 having a vertical wall surface. The concrete body 10 is formed by placing a formwork (not shown) and pouring concrete into the formwork.

When the strength of the concrete body 10 reaches a predetermined value, the form is removed and the sheet 12 is attached. FIG. 1 is a cross-sectional view after the attachment. The sheet 12 shown in FIG. 1 includes a moisture-impermeable synthetic resin film 12a having a predetermined thickness, and an adhesive 12b adhered to one surface of the synthetic resin film 12a.

The synthetic resin film 12a may be, for example, a high-density or low-density polyethylene, but may be, for example, a photodegradable polyethylene film or an alkali-degradable synthetic resin film.

When a photodegradable polyethylene film is used, the film 12a gradually decomposes when the film 12a adhered to the concrete body 10 is exposed to sunlight, so that the film 12a naturally degrades near the end of the curing period. Sheet 1
2 can be peeled off.

Examples of the alkali-degradable synthetic resin film include, for example, films made of polycarbonate which is hydrolyzed to alkali, polybutylene terephthalate, polyimide which is degraded by alkali, etc. When used, the film 12a gradually deteriorates due to the alkali component diffused from the concrete body 10 side, and similarly, it becomes possible to peel off the sheet naturally.

When the sheet 12 is adhered to the concrete body 10, the sheet 12 is adhered with the adhesive 12b so as to cover the entire surface of the concrete body 10. When the sheet 12 is adhered, moisture that is going to evaporate and escape from the concrete body 10 is blocked by the moisture-impermeable synthetic resin film 12a, and the concrete body 10 can be kept in a wet state for a long time.

In this case, the sheet 12 composed of the adhesive 12b and the synthetic resin film 12a can be manufactured at a factory, and the synthetic resin film 12a can be easily formed to a uniform thickness. A uniform evaporation and loss prevention effect can be obtained in the entire area where 12 is adhered.

Also, by appropriately selecting the material and thickness of the adhesive 12b so that the adhesive strength is reduced about several months after the sheet 12 is adhered, the sheet
2 can be peeled off.

FIG. 2 shows a curing method (sheet curing) according to the present invention, a conventional curing method, standard curing (curing in water at 20 ° C.), air curing (curing at room temperature at 20 ° C.), and film curing (film formation). The test results of the uniaxial compressive strength when each concrete body was cured with the agent paraffin). In this test, the following concrete materials were used, and the following concrete formulations were used.

[0020]

[Table 1]

[0021]

[Table 2] The sheet 12 used for the sheet curing of the present invention is a synthetic resin film 12a made of polypropylene, and has a thickness of 0.065 mm and a tensile strength of 5.3 kg / 25 m.
m, elongation at break was 600%. Also, adhesive 1
2b has a peel adhesion at 180 ° C. of 430 gf / 25.
mm acrylic adhesive was used.

As is clear from the test results shown in FIG. 2, according to the curing method of the present invention, the compressive strength at the age of 28 days is about 10% larger than that of the air curing and the film curing. At 91 days of age, the compressive strength was about 3
It was confirmed that the size increased by about 30%.

In the above embodiment, the case where the present invention is applied to the concrete body 10 having a vertical wall surface is illustrated, but the present invention is not limited to this.
For example, the present invention can be applied to a column having a square cross section.

[0024]

As described above in detail in the embodiments,
According to the method for curing a concrete body according to the present invention, since the surface of the concrete body can be cured for a long period of time while keeping the surface of the concrete body wet, high-quality concrete excellent in strength and durability can be obtained, and the sheet Since the sticking operation can be easily performed, the construction efficiency is also improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment showing a concrete body curing method according to an embodiment of the present invention.

FIG. 2 is a graph showing measurement results of compressive strength in the curing method of the present invention and a conventional curing method.

[Explanation of symbols]

 10, 10a Concrete body 12 Sheet 12a Synthetic resin film 12b Adhesive

Claims (2)

[Claims] 1. A method for curing a cast concrete body, comprising: removing the formwork for forming the concrete body; and forming an adhesive and a moisture-impermeable synthetic resin film on the surface of the concrete body. A method for curing a concrete body, comprising attaching a sheet. 2. The method for curing a concrete body according to claim 1, wherein the synthetic resin film is selected from a photodegradable synthetic resin film and an alkali-degradable synthetic resin film.