JP2005231375A - Method of aging concrete object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain a surface of concrete object in a constant moist state. <P>SOLUTION: A sheet 12 is pasted after the removal of a mold on a poured and formed concrete object 10 when its strength reaches a predetermined value. The sheet 12 has a moisture-impermeable synthetic resin film 12a of a predetermined thickness and an adhesive 12b applied on one face of the synthetic resin film 12a. On pasting the sheet 12 on the concrete object 10, the sheet 12 is pasted on the surface of concrete object 10 with the adhesive 12b. An acrylic adhesive is used in the adhesive 12b. When the sheet 12 is pasted, moisture is prevented from evaporating off the concrete object 10 by the moisture-impermeable synthetic resin film 12a, and the concrete object 10 is maintained in the moist state for a long period of time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for curing a concrete body, and more particularly to a technique for improving wet curing.

  Concrete structures are required to exhibit a predetermined strength and durability after the concrete is placed and cured. When concrete is affected by harmful effects such as low temperature, drying, and sudden temperature changes during curing, the strength and durability of the concrete decrease. For this reason, it is necessary to perform curing in order to protect the concrete surface and to fully exhibit strength and durability.

  In this type of concrete curing method, it is desirable to keep the concrete surface in a moderately moist state. Conventional curing methods include a method in which the slats are left for a long time and the concrete has a predetermined strength. At the time, it is roughly divided into a method of curing after removing the board.

  The latter curing method includes (1) a submerged curing method for storing water on the concrete surface, (2) an underwater curing method for immersing the concrete body in water, and (3) preventing the surface from being dried by direct sunlight or wind. (4) Curing method to prevent the escape of moisture from the concrete surface by spraying water, (5) Forming a film with paraffin on the concrete surface to prevent water evaporation There is a curing method.

  By the way, in recent years, with the increase in the size of concrete structures, low heat generation type cements such as medium heat cement and high belite cement are often used. When such a cement is used, curing is required for a longer period of time than usual due to the characteristics of the cement. However, the conventional curing methods described above are technical problems as described below. was there.

  That is, in the curing method in which the siding plate is left for a long period of time, the diversion of the formwork is limited, so that the workability is inferior and is generally not so often employed. On the other hand, the flooded water of (1) and the underwater curing method of (2) are not general because there are limitations on the applicable concrete body. Further, (3) 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 cannot be kept wet for a long time.

  Furthermore, (4) In the curing method of watering, if watering is performed properly, it can be kept in a wet state for a long period of time, but turtle-shaped cracks may occur on the surface due to repeated drying and wetting. Due to the difference in the water absorption state, the finished surface becomes uneven, which is not preferable in view of beauty.

  Further, (5) in the film curing method, a film is formed on the surface of the concrete body. Therefore, when the film curing method is applied to a vertical wall-shaped concrete body, there is a problem that the film forming agent hangs down and a uniform film is formed. It was difficult to maintain a constant moist state for a long time.

  The present invention has been made in view of such conventional problems. The object of the present invention is to maintain a moist state for a long period of time and to a degree of freedom applicable to vertical wall surfaces and the like. It is in providing the curing method of a concrete body with.

  In order to achieve the above object, the present invention provides an adhesive and a moisture-impermeable synthetic resin film on the surface of a concrete body formed by placing concrete in a mold and removing the mold. In the curing method of the concrete body to which the sheet is attached, the adhesive is an acrylic adhesive.

  According to the curing method for a concrete body configured in this way, a sheet made of an adhesive and a water-impermeable synthetic resin film is stuck on the surface of the concrete body after the formwork is removed. Moisture that tends to escape is blocked by the film, and the concrete body can be kept moist for a long time.

  In this case, the sheet made of the adhesive and the synthetic resin film can be produced at the factory, and the synthetic resin film can be easily formed to have a uniform thickness. A uniform evaporation dissipation prevention effect can be obtained.

  In addition, by appropriately selecting the material and thickness of the adhesive, the sheet can be peeled off naturally if the adhesive force is reduced within a few months after the sheet is attached.

  The acrylic adhesive used in the present invention can be bonded even with strong alkali concrete, and can be bonded even when the surface of the concrete body is wet, and it has a low strength against peeling, so it is easy. Can be peeled off.

  As described above in detail in the examples, according to the method for curing a concrete body according to the present invention, the surface of the concrete body can be cured for a long time while being kept in a moist state, and thus excellent in strength and durability. High-quality concrete can be obtained, and acrylic adhesives can be bonded even in a strong alkali or in a wet state, and the peel strength is small, so the sheet can be easily attached and removed, Construction efficiency is also improved.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a concrete body curing method 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 installing a mold (not shown) and placing concrete in the mold.

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

  The synthetic resin film 12a may be, for example, high density or low density polyethylene.

  When sticking the sheet 12 to the concrete body 10, the sheet 12 is stuck by the adhesive 12 b so as to cover the entire surface of the concrete body 10. An acrylic adhesive is used for the adhesive 12b. In this case, the adhesive 12b may be provided on the entire surface of the sheet 12, or may be provided partially. When the sheet 12 is pasted, the moisture that evaporates away from the concrete body 10 is blocked by the moisture-impermeable synthetic resin film 12a, and the concrete body 10 can be kept wet for a long period of time.

  In this case, the sheet 12 composed of the adhesive 12b and the synthetic resin film 12a can be manufactured at the factory, and the synthetic resin film 12a can be easily formed to have a uniform thickness. A uniform evaporation-dissipation prevention effect can be obtained over the entire wearing area.

  In addition, if the adhesive force is reduced within a few months after the sheet 12 is adhered by appropriately selecting the material and thickness of the adhesive 12b, the sheet 12 can be peeled naturally.

  FIG. 2 shows a curing method (sheet curing) according to the present invention, a conventional curing method, a standard curing (20 ° C. underwater curing), an air curing (20 ° C. room temperature curing), and a film curing (film forming agent paraffin). And it is a test result of uniaxial compressive strength when each concrete body is cured. In this test, the following concrete materials were used, and the concrete composition shown below was used.

  The sheet 12 used for sheet curing of the present invention was a synthetic resin film 12a made of polypropylene as a raw material, had a thickness of 0.065 mm, a tensile strength of 5.3 kg / 25 mm, and an elongation at break of 600%. . As the adhesive 12b, an acrylic adhesive having a peel adhesive force of 180 ° C. of 430 gf / 25 mm was used.

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

  In addition, although the case where this invention was applied to the concrete body 10 which has a vertical wall surface was illustrated in the said Example, implementation of this invention is not limited to this, For example, a pillar of a square cross section etc. It can also be applied to.

It is sectional drawing of the construction state which shows one Example of the curing method of the concrete body concerning this invention. It is a graph which shows the measurement result of the compressive strength in the curing method of this invention, and the conventional curing method.

Explanation of symbols

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

Claims (2)

In a concrete body curing method in which concrete is placed in a formwork, and a sheet made of an adhesive and a moisture-impermeable synthetic resin film is adhered to the surface of the concrete body formed by removing the formwork. ,
A method for curing a concrete body, wherein the adhesive is an acrylic adhesive. The method for curing a concrete body according to claim 1, wherein the acrylic adhesive has a peel adhesive strength at 180 ° C of 430 gf / 25 mm.

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