Concrete curing sheet with variable heat retention performance

Abstract

To provide a concrete curing sheet with variable heat retention performance that can appropriately cure poured concrete in a manner according to the environment.SOLUTION: Provided is a concrete curing sheet 10 to be laid in two or more layers on a concrete surface 1S to cure poured concrete 1. The sheet includes an air bubble sheet 20 having a cap film 21 and a back film 22, and an adhesive layer 11 that adheres between the two or more layers of the curing sheet 10, thereby maintaining the overlapping state of the curing sheets 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a concrete curing sheet with variable heat retention properties that is laid on the surface of concrete to cure the poured concrete. [Background technology]

[0002] Conventionally, when concrete is poured to construct concrete structures at construction sites such as civil engineering structures and architectural structures, curing sheets have been used to cure the poured concrete so that the hydration reaction of cement, the main material of concrete, can be fully exerted (for example, Patent Document 1). For example, when controlling the quality of concrete, if a test specimen is prepared and subjected to a strength test, it is known that if the specimen is cured underwater, the strength will be 15 to 30 percent higher than if the specimen is left in the air. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-157507 Summary of the Invention [Problem to be solved by the invention]

[0004] For this reason, for example, when the formwork is removed from the concrete, a curing sheet is laid on the surface of the concrete to prevent moisture from escaping. Furthermore, since it is also necessary to prevent heat from escaping from the concrete, the curing sheet must also have heat-retaining properties.

[0005] However, the surface of the concrete immediately after demolding is still wet with the moisture contained in the concrete. As the concrete surface dries, it loses its moisture and heat, making it more susceptible to cracks. For this reason, materials for concrete curing sheets must be impermeable and have insulating properties, and a variety of materials and technologies are becoming increasingly popular. However, because the temperature, humidity, and other environmental factors vary from site to site, a curing sheet that performs adequately at one site may perform excessively well at another site. As a result, using a curing sheet with the same performance at sites with different environments can result in increased costs.

[0006] An object of the present invention is to provide a concrete curing sheet with variable heat retention performance that can appropriately cure poured concrete in a manner suited to the environment. [Means for solving the problem]

[0007] One form of the present invention is a concrete curing sheet with variable thermal insulation performance that is used, for example, by laying two or more sheets on top of each other on a concrete pour surface to cure poured concrete, and is characterized by having a holding section that keeps multiple curing sheets stacked together. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view illustrating a protective sheet 10 according to a first embodiment. [Figure 2] FIG. 1 is a perspective view illustrating an air bubble sheet 20 of a first embodiment. [Figure 3] FIG. 10 is a perspective view of a protective sheet 210A according to a second embodiment. [Figure 4] FIG. 10 is a perspective view of a protective sheet 210B according to a third embodiment. [Figure 5] FIG. 11 is a vertical cross-sectional view of a protective sheet 210C according to a fifth embodiment. [Figure 6] FIG. 10 is a diagram illustrating an air bubble sheet 320 used in the protective sheet of the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (First embodiment) FIG. 1 is a cross-sectional view illustrating a curing sheet 10 according to a first embodiment. FIG. 1(A) is a diagram illustrating how three curing sheets 10 are laid on concrete 1 while the release paper 12 is being peeled off. FIG. 1(B) is a diagram illustrating a state in which three curing sheets 10 are stacked and laid on concrete 1. FIG. 2 is a perspective view illustrating the air bubble sheet 20 of the first embodiment. In each drawing, the thickness of each component is exaggerated as appropriate.

[0010] As shown in FIG. 1, a curing sheet 10 is used by being laid on a concrete surface 1S in order to seal and cure poured concrete 1. A plurality of layers of curing sheets 10 are laid on the concrete surface 1S. The method of layering a plurality of curing sheets 10 may involve, for example, laying multiple layers of curing sheets 10 on the concrete surface 1S, or laying the curing sheets 10 one by one on the concrete surface 1S. The worker may select an appropriate layering method from these methods depending on the conditions at the concrete pouring site, etc. The example in Figure 1 shows three curing sheets 10 stacked on top of each other, but workers may use two or more curing sheets 10 stacked on top of each other depending on the temperature and humidity of the construction site environment, the condition of the concrete surface 1S immediately after removal from the form, etc.

[0011] One protective sheet 10 is made by laminating an adhesive layer 11 and a release paper 12 on a bubble sheet 20. When using the curing sheet 10, the worker simply covers the concrete 1 with the side without the adhesive layer 11 facing the concrete surface 1S. When stacking multiple curing sheets 10, the worker simply peels off the release paper 12 to bond the layers together. In this case, the release paper 12 of the uppermost curing sheet 10 does not need to be peeled off.

[0012] The sheet material constituting the curing sheet 10 may be, for example, a resin material that can be molded to be impermeable and that can prevent the dissipation of moisture from the concrete 1 .

[0013] This sheet material can be made of a thermoplastic resin, such as a polyolefin resin such as polypropylene, polyethylene, or polystyrene, or a polyester resin such as polyethylene terephthalate, either alone or in a suitable combination of two or more kinds.

[0014] Furthermore, when forming the curing sheet 10, a pigment or dye can be added to the resin material in order to color the curing sheet 10. For example, coloring the curing sheet 10 in a color such as white, which does not easily absorb heat, can prevent undesirable increases in the surface temperature of the concrete 1 due to sunlight, particularly in the summer. On the other hand, in the winter, coloring the curing sheet 10 in a color such as black, which easily absorbs heat, can improve heat retention during curing and prevent cracks and other problems caused by temperature differences with the interior of the concrete 1. The air bubble sheet 20 is made up of at least one layer, and the specific form thereof is not particularly limited as long as the layer laid facing the concrete surface 1S is formed using the above-mentioned resin material.

[0015] 2, bubble sheet 20 may have a three-layer structure including cap film 21 having numerous hollow protrusions 21a (hollow projections), back film 22 for enclosing air within caps 21a, and liner film 23 laminated on the top surface of caps 21a formed on cap film 21. Adhesive layer 11 and release paper 12 may be laminated on one side of bubble sheet 20. When a three-layered air bubble sheet 20 is used as the curing sheet 10, either the back film 22 or the liner film 23 may be laid directly on the concrete surface 1S.

[0016] Although not shown, the bubble sheet 20 may have a two-layer structure in which a cap film 21 and a backing film 22 are laminated (i.e., a structure without a liner film 23). In this case, it is preferable that the adhesive layer 11 and the release paper 12 are laminated on the surface of the backing film 22. This is because the surface of the backing film 22 is flat. In this embodiment, it is preferable to lay the cap film 21 directly above the concrete surface 1S. Furthermore, only the protective sheet laminated on the bottom layer may be an air bubble sheet without the adhesive layer 11 and release paper 12. In this case, the cap film 21 side may be laid directly above the concrete surface 1S.

[0017] Such air bubble sheet 20 has high heat insulating properties, so that the protective sheet 10 can improve the heat retention during protective use. Furthermore, as described above, when coloring the protective sheet 10, it is sufficient that at least one of the cap film 21, the back film 22, the liner film 23, and the adhesive layer 11 is colored.

[0018] As described above, the curing sheet 10 of this embodiment has heat insulating and moisture-retaining properties. Therefore, by laying the curing sheet 10 on the concrete surface 1S immediately after demolding, the concrete 1S in a wet state can be adequately kept moist and warm, and the occurrence of cracks can be suppressed.

[0019] Furthermore, the number of curing sheets 10 can be adjusted depending on the on-site environment (temperature, humidity, etc.) and the condition of the concrete surface 1S immediately after demolding. This allows the curing sheets 10 to cure the concrete 1 at low cost. On the other hand, it is possible to prepare a sheet with sufficient heat insulation and moisture retention properties and use a single sheet for curing at multiple sites regardless of the conditions. However, when using a single sheet for curing, the heat insulation and moisture retention properties of the sheet cannot be adjusted, so even if the performance is appropriate for one site, it may be excessive for another site. This results in high costs.

[0020] Furthermore, in this embodiment, multiple layers of the curing sheets 10 can be stuck together by the adhesive layers 11, so they can maintain close contact with each other. Therefore, the curing sheets 10 can uniformly insulate and moisturize the concrete surface 1S.

[0021] (Second embodiment) A second embodiment of the present invention will now be described. In the following explanations and drawings, parts that perform similar functions in each embodiment and in other embodiments are appropriately given similar names, and the same reference numerals or the same reference numerals at the end (last two digits, etc.) are appropriately given, and duplicate explanations are appropriately omitted. In the second embodiment, and in the third and fourth embodiments described below, three types of protective sheets 210A, 210B, and 210C having different configurations of the holding parts from those in the first embodiment will be described. Although the protective sheet in the second to fourth embodiments is an example of a three-layer air bubble sheet, as described above, it may also be a two-layer air bubble sheet.

[0022] FIG. 3 is a perspective view of a protective sheet 210A according to the second embodiment. As shown in FIG. 3(A), each protective sheet 210A has eyelets 205 (retaining portions) provided at a predetermined pitch. The stacked protective sheets 210A are held in a stacked state by passing strings 205a through the eyelets 205 and tying them together.

[0023] (Third embodiment) FIG. 4 is a perspective view of a protective sheet 210B according to the third embodiment. As shown in FIG. 4(B), each protective sheet 210B is provided with strip-shaped hook and loop fasteners 206a and 206b, with one surface being the hook side and the other surface being the loop side. As a result, the stacked protective sheets 210B are detachably joined to each other by the hook-and-loop fasteners 206a and 206b. 3(B), when viewed normal to the sheet surface, the hook and loop side hook and loop fasteners 206a, 206b are arranged so that they intersect vertically and horizontally, but they may also be arranged parallel to each other at equal intervals. In this case, the joining area of ​​the hook and loop side hook and loop fasteners 206a, 206b can be increased, thereby more reliably joining the stacked protective sheets 210B. Alternatively, a hook-and-loop fastener may be laminated over the entire surface of the sheet.

[0024] (Fourth embodiment) A fourth embodiment of the present invention will now be described. FIG. 5 is a vertical cross-sectional view of a protective sheet 210C according to the fourth embodiment. As shown in Figures 5(A) and 5(B), the overlapping protective sheets 210C can be joined with hooks. That is, one protective sheet 210C is provided with a male hook member 207a, and the other protective sheet 210C is provided with a female hook member 207b.

[0025] As explained above, the protective sheets 210A, 210B, 210C of the second to fourth embodiments are provided with hook-and-loop fasteners, hooks, eyelets, etc. to maintain the stacked state. This is convenient because no waste such as release paper is generated at the construction site.

[0026] (Fifth embodiment) Five embodiments of the present invention will be described. FIG. 6 is a diagram illustrating an air bubble sheet 320 used in the protective sheet of the fifth embodiment. FIG. 6(A) is a view of the air bubble sheet 320 as seen from the normal direction of the sheet surface. FIG. 6(B) is an enlarged view of the vertical cross section of the air bubble sheet 320. The protective sheet of the fifth embodiment is obtained by providing the holding portion (adhesive tape or the like) of the above-described embodiment to the air bubble sheet 320 shown in Fig. 6. Explanation of the configuration of the holding portion will be omitted. The bubble sheet 320 has linear welds 325 . As shown in FIG. 6(A), a plurality of linear welds 325 are provided lengthwise and widthwise on air bubble sheet 320 in a linear pattern at predetermined intervals. 6(B), in the area where the linear welded portion 325 is provided, the liner film 23 and the cap film 21 are joined by thermal welding (see arrow A). In addition, in the area where the linear welded portion 325 is provided, in the area where the linear welded portion 325 and the cap 21a intersect, the cap film 21, the liner film 23, and the cap film 21 are joined together (see arrow B).

[0027] Therefore, within the rectangular area surrounded by the linear weld 325, not only is the cap 21a sealed by the back film 22, but the space 325a outside the cap 21a is also sealed by the linear weld 325. As a result, by using the air bubble sheet 320 as a concrete curing sheet, the heat insulating properties can be improved.

[0028] The curing sheets of the second to fifth embodiments allow multiple sheets to be detachably stacked, so that even after being stacked once, they can be easily separated and stacked again. Therefore, the curing sheets of the second to fifth embodiments are more convenient than the curing sheet of the first embodiment when sheets used at one construction site are reused at a next construction site, etc.

[0029] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and variations, such as the modified embodiments described below, are possible, and these are also within the technical scope of the present invention. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments. Note that the configurations of the above-described embodiments and the modified embodiments described below can be used only in part, or in appropriate combination, and detailed description thereof will be omitted.

[0030] (Variations) (1) In the embodiment, an example in which multiple protective sheets of the same shape are stacked is shown, but this is not limiting. For example, in a configuration in which layers are bonded together using an adhesive layer and release paper, the protective sheet stacked on the top layer does not need to have an adhesive layer or release paper.

[0031] (2) In the embodiment, the protective sheet is an air bubble sheet with a cap film, but is not limited to this. The protective sheet may be any type as long as it has a structure for bonding layers together, and the type of sheet material is not limited as long as it has appropriate heat retention and moisture retention properties.

[0032] (3) In the embodiment, the protective sheet includes a bubble sheet, but is not limited thereto. The protective sheet may include a foam sheet instead of or in addition to the bubble sheet. The material of the foam sheet is not limited, and may be, for example, a foamed polyethylene sheet.

[0033] (4) In an embodiment, the curing sheet may have a nonwoven fabric, woven fabric, or knitted fabric laminated on the surface facing the poured concrete. In this case, when the curing sheet is laminated on the wet poured concrete surface, the nonwoven fabric or the like will contain an appropriate amount of moisture, thereby preventing the poured concrete surface from drying out too quickly. [Explanation of symbols]

[0034] 1: Concrete 1S: Concrete surface 10, 210A, 210B, 210C: Curing sheet 11: Adhesive layer 12: Release paper 20,320: Bubble sheet 205: Eyelet 206a, 206b: hook and loop fastener 207a: Male member (hook) 207b: Female parts (hooks)

Claims

1. A concrete curing sheet with variable thermal insulation performance that is used by laying two or more sheets on a concrete pouring surface in order to cure poured concrete, Equipped with a holding section that holds multiple protective sheets in a stacked state A concrete curing sheet with variable heat retention performance.

2. The holding portion is at least one of an adhesive, a hook and loop fastener, a hook, and an eyelet provided on the surface of the sheet.

2. The concrete curing sheet with variable thermal insulation performance according to claim 1.

3. This concrete curing sheet with variable thermal insulation performance is a laminate of multiple sheets, At least one of the plurality of sheets is a bubble wrap.

2. The concrete curing sheet with variable thermal insulation performance according to claim 1.

4. This concrete curing sheet with variable thermal insulation performance is a laminate of multiple sheets, At least one of the plurality of sheets is a foam sheet.

4. A concrete curing sheet with variable heat retention properties according to claim 1.

5. The seat body is colored 4. A concrete curing sheet with variable heat retention properties according to claim 1.

6. Equipped with nonwoven, woven or knitted fabric laminated on the concrete pouring surface side 4. A concrete curing sheet with variable heat retention properties according to claim 1.

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