JP6967990B2 - Lining sheet for concrete formwork - Google Patents

Description

The present invention relates to a lining sheet for a concrete formwork, which is used by being attached to a formwork panel for dehydration and deaeration at the time of placing concrete.

In general, for concrete structures, a concrete formwork is formed by framing a formwork panel made of wood or metal, and concrete is poured into the formwork to compact it, and then it is cured and hardened. , Constructed by removing the formwork panel.

At this time, the quality of concrete can be improved by reducing the amount of water used for cement. However, if the amount of water used is reduced, the workability when pouring concrete deteriorates, so in reality, excess water is used to ensure workability.

It is desirable that the water added in excess in this way is discharged to the outside during curing. In addition, air is mixed in the concrete and bubbles are also generated, and it is desirable that the mixed air is also discharged to the outside during curing.

For this reason, conventionally, a porous sheet having breathability and water permeability is attached to the inner surface of the formwork panel in contact with concrete without allowing concrete particles such as aggregates and cement particles to pass through, and the concrete is passed through the porous sheet. It has been proposed to perform dehydration and degassing (defoaming).

For example, Patent Documents 1 to 4 below disclose that a porous synthetic resin sheet that allows the passage of water and air while blocking the passage of concrete particles is used as the lining sheet of the concrete formwork. By using such a lining sheet, it is possible to satisfactorily dehydrate excess water and degas mixed air during curing of concrete.

Japanese Unexamined Patent Publication No. 2013-100688 Japanese Unexamined Patent Publication No. 2008-75252 Japanese Patent No. 4443909 Japanese Unexamined Patent Publication No. 2016-211303

By the way, when the formwork panel to which the lining sheet is attached is used, concrete particles adhere to the lining sheet in contact with the concrete and the pores are closed. Therefore, in order to use the lining sheet repeatedly, the lining is used. It is necessary to wash away the concrete particles adhering to the surface of the sheet. However, it is often difficult to remove the concrete particles that have dried and hardened and are bound to the lining sheet.

Further, as the lining sheet, a relatively expensive sheet having a multi-layer structure is used, and if it is made disposable, the installation cost of the concrete formwork is too high.

The present invention has been made in view of such problems, and it is intended to provide a lining sheet for a concrete formwork which can be used at low cost and can be satisfactorily dehydrated and degassed. The purpose.

In order to solve the above problems, the concrete formwork lining sheet according to the present invention is a concrete formwork lining sheet used by being attached to the surface of a formwork panel, and has breathability and water permeability. A porous dehydration / degassing sheet that does not allow concrete particles to pass through, a base sheet, and an elastic foamed resin layer applied to one surface of the base sheet, and the opening is exposed only on the surface side. A foamed resin layer having a large number of non-penetrating holes and having a surface side functioning as a suction cup, and a suction sheet having breathability and water permeability composed of the foamed resin layer, and the dehydration / degassing sheet of the foamed resin layer. It is characterized in that the dehydration / degassing sheet and the suction sheet are overlapped with each other in close contact with the surface side.

Further, the method for installing the concrete formwork according to the present invention is a base sheet and an elastic foamed resin layer applied to one surface of the base sheet, and the opening is exposed only on the surface side. A breathable and water-permeable adsorption sheet composed of a foamed resin layer whose surface side functions as a sucker by having a large number of through holes is attached to the surface of the formwork panel in close contact with the base sheet. The process of attaching the adsorption sheet and the porous dehydration / degassing sheet that has air permeability and water permeability but does not allow concrete particles to pass through are covered with the adsorption sheet and brought into close contact with the foamed resin layer, and the surface of the formwork panel is attached. The process of attaching the dehydration / degassing sheet to be attached to the side, the formwork panel installation process of installing the formwork panel in which the suction sheet and the dehydration / degassing sheet are overlapped and attached at a concrete placing place, It is characterized by having.

According to the concrete formwork lining sheet according to the present invention, it is possible to repeatedly use the sheet while dewatering and degassing by simply replacing the dewatering / degassing sheet after use.

FIG. 1 is a cross-sectional view of a lining sheet according to an embodiment of the present invention. FIG. 2 is an enlarged view showing the surface of the foamed resin layer according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a usage state of the lining sheet according to the embodiment of the present invention. FIG. 4 is a flowchart showing a method of installing a concrete formwork according to an embodiment of the present invention. FIG. 5 is a diagram for explaining a method of attaching the lining sheet to the formwork panel according to the embodiment of the present invention. FIG. 6 is a perspective view showing an installed state of the concrete formwork according to the embodiment of the present invention. FIG. 7 is a diagram showing a state in which wrinkles according to an embodiment of the present invention are transferred to concrete.

Hereinafter, the method of installing the lining sheet and the concrete formwork for the concrete formwork according to the present embodiment will be described. FIG. 1 is a cross-sectional view of a lining sheet according to the present embodiment. FIG. 2 is an enlarged view showing the surface of the foamed resin layer according to the present embodiment. FIG. 3 is a cross-sectional view showing a usage state of the lining sheet according to the present embodiment.

The lining sheet 15 is used by being attached to the inner surface of the formwork panel 11 of the concrete formwork 10, has breathability and water permeability without passing concrete particles such as aggregates and cement particles, and is cast. Dehydrate and degas (defoam) concrete.

The lining sheet 15 is configured by superimposing a non-woven fabric sheet 20 that functions as a dehydration / degassing sheet and a suction sheet 30 that is in close contact with the non-woven fabric sheet 20. This superposition can be performed at the storage place of the formwork panel 11 or at the construction site where concrete is placed. The non-woven fabric sheet 20 is a non-woven fabric sheet made of PEs (polyester), and is manufactured by making PEs fibers by a wet method.

The nonwoven fabric sheet 20 manufactured by the wet method is a porous sheet in which voids, which are fine gaps between fibers, are formed throughout. The voids are configured to allow water or air to pass through but not to allow concrete particles to pass through, and the nonwoven fabric sheet 20 has air permeability and water permeability but does not allow concrete particles to pass through.

The adsorption sheet 30 has a two-layer structure and is composed of a foamed resin layer 31 and a raised nonwoven fabric base sheet 35. The foamed resin layer 31 is a layer of elastic soft foamed acrylic resin. The foamed resin layer 31 is porous, and a large number of micropores 32, 33 are formed inside and on the surface.

The micropores 32 and 33 are non-penetrating micropores 32 that are openly exposed only on one surface side (the surface opposite to the raised nonwoven fabric base sheet 35) and from the surface side to the surface on the raised nonwoven fabric base sheet 35 side. It is provided with through micropores 33 penetrating the foamed resin layer 31 (see FIG. 2). The foamed resin layer 31 on which the through micropores 33 are formed allows water and air to pass through, and has air permeability and water permeability.

Since the non-penetrating micropores 32 are openly exposed only on the surface side opposite to the raised non-woven fabric base sheet 35, when the surface of the elastic foamed resin layer 31 comes into close contact with a smooth surface such as a sheet having smoothness, Due to the pressure difference between the inside and the outside of the sealed non-penetrating micropores 32, the surface (adsorption surface) of the foamed resin layer 31 functions as a suction cup that adsorbs to the smooth surface.

The brushed nonwoven fabric base sheet 31 is a brushed nonwoven fabric sheet with a brushed surface, which is formed of polyester (PEs) fibers. The raised nonwoven fabric base sheet 31 can be manufactured, for example, by a needle punching method, which is a dry method. The brushed nonwoven fabric base sheet 31 has gaps between fibers formed throughout, and is not only breathable and water permeable, but also allows concrete particles and the like to pass through.

The adsorption sheet 30 is manufactured by applying the foamed resin layer 31 to one surface of the raised nonwoven fabric base sheet 31. The lining sheet 15 is formed by superimposing the non-woven fabric sheet 20, which is a dehydration / degassing sheet, and the adsorption surface (foamed resin layer 31) of the adsorption sheet 30 in close contact with each other.

Subsequently, a procedure for installing the concrete formwork 10 using the lining sheet 15 will be described. FIG. 4 is a flowchart showing a method of installing a concrete formwork according to the present embodiment. FIG. 5 is a diagram for explaining a method of attaching the lining sheet to the formwork panel according to the present embodiment. FIG. 6 is a perspective view showing an installed state of the concrete formwork according to the present embodiment.

The concrete formwork 10 includes a formwork panel 11, a separator 13, and a lining sheet 15. In installing the concrete formwork 10, first, in S1, the suction sheet 30 is attached to the surface of the formwork panel 11.

At this time, the raised non-woven fabric base sheet 35 of the suction sheet 30 is attached so as to be in close contact with the surface of the formwork panel 11 so that the suction surface of the suction sheet 30 is exposed on the surface. Since the suction sheet 30 is usually provided in a rolled state, it is cut in advance to the same size as the sticking surface of the formwork panel 11.

After sticking, the suction sheet 30 is fixed to the form panel 11 with a tacker or double-sided tape so that the suction sheet 30 does not shift with respect to the form panel 11.

Subsequently, in S2, a non-woven fabric sheet 20 which is a dehydration / degassing sheet is attached to the surface side of the mold panel 11 so as to cover the adsorption sheet 30. Since the non-woven fabric sheet 20 is provided in a rolled state like the suction sheet, it is cut in advance slightly larger (about 5 to 10 cm) than the sticking surface of the formwork panel 11.

When the non-woven fabric sheet 20 is installed so as to cover the suction sheet 30, the suction surface of the foamed resin layer 31 of the suction sheet 30 and one surface of the non-woven fabric sheet 20 are in close contact with each other and overlapped with each other. At this time, since the foamed resin layer 31 is formed of an elastic soft foamed resin (acrylic resin) and has a high frictional force on the surface, the non-woven fabric sheet 20 and the adsorption sheet 30 in close contact with each other are relatively hard to slip.

Then, the non-woven fabric sheet 20 is stretched without wrinkles by fastening the end portion of the non-woven fabric sheet 20 that covers and affixes the front surface of the formwork panel 11 to the side surface or the back surface of the formwork panel 11 with a tacker, a gum tape 25, or the like. It can be pasted in a state of being.

Next, in S3, the formwork panel 11 to which the lining sheet 15 is attached is installed at the concrete placing place. When installing the formwork panels 11, a pair of formwork panels 11 are installed so that the surfaces to which the lining sheets 15 are attached face each other at predetermined intervals, and the pair of formwork panels 11 are connected by a separator 13. NS.

Installation of the concrete formwork 10 is completed by S1 to S3 (see FIG. 6), and subsequently, in S4, the concrete 5 is poured into the space surrounded by the formwork panel 11 and placed. The poured concrete 5 comes into contact with the non-woven fabric sheet 20 located on the outermost surface side of the formwork panel 11.

The non-woven fabric sheet 20 has breathability and water permeability, but has the property of not allowing concrete particles such as aggregates and cement particles to pass through, and is mixed with excess water in the concrete 5 when the poured concrete 5 is cured. Only air is discharged to the outside of the concrete 5 through the non-woven fabric sheet 20, and dehydration and degassing (defoaming) can be performed satisfactorily.

At this time, the excess water and the mixed air that have passed through the nonwoven fabric sheet 20 pass through the foamed resin layer 31 of the adsorption sheet 30 that is in close contact with the nonwoven fabric sheet 20, which is the next layer. The foamed resin layer 31 has air permeability and water permeability, and excess water and mixed air can pass through the foamed resin layer 31 from the concrete 5 side to the formwork panel 11 side.

Excess water and mixed air that have passed through the foamed resin layer 31 enter the raised nonwoven fabric base sheet 35. As described above, the brushed nonwoven fabric base sheet 35 has a large number of voids formed therein, and excess water and mixed air pass through the brushed nonwoven fabric base sheet 35 and are discharged to the outside of the lining sheet 15. ..

In the present embodiment, by using the raised type raised non-woven fabric base sheet 35 manufactured by the needle punch method as the base sheet of the adsorption sheet 30, excess water and mixing that have passed through the non-woven fabric sheet 20 and the foamed resin layer 31 are used. Since air is easily discharged to the outside through the raised nonwoven fabric base sheet 35 in which a large number of voids are formed, good dehydration and defoaming are possible.

When the curing of the cast concrete 5 is completed and the concrete 5 is hardened, the forming work of the concrete structure is completed by removing the formwork panel in S5. According to the present embodiment, since the lining sheet 15 is satisfactorily dehydrated and defoamed, it is possible to form a sturdy concrete structure having a smooth surface and almost no voids.

Further, in the present embodiment, when the concrete 5 is poured, the voids of the nonwoven fabric sheet 20 are closed by the excess water, and the air permeability of the nonwoven fabric sheet 20 is lowered. Therefore, after the concrete 5 is poured, the adsorption surface of the foamed resin layer 31 is adsorbed on the smooth surface of the non-woven fabric sheet 20 and functions as a suction cup. As a result, the non-woven fabric sheet 20 and the suction sheet 30 are firmly adhered to each other, and even if a force in the sliding direction acts on the non-woven fabric sheet 20 due to the weight of the concrete 5, the non-woven fabric sheet 20 does not slip and move, but slips onto the non-woven fabric sheet 20. The occurrence of wrinkles can be prevented.

If the non-woven fabric sheet 20 is not slip-prevented, a part of the non-woven fabric sheet 20 that comes into contact with the concrete 5 may be displaced after the concrete 5 is poured, and wrinkles may be formed on the non-woven fabric sheet 20. be. When wrinkles are formed on the non-woven fabric sheet 20, the wrinkles are transferred to the surface of the concrete structure, and the smoothness of the surface is impaired (FIG. 7).

On the other hand, when the concrete 5 is poured, it is adsorbed by the suction sheet 30 to prevent the non-woven fabric sheet 20 from slipping. In the present embodiment, the non-woven fabric sheet 20 is prevented from wrinkling and the surface is clean. Concrete structures can be formed.

Further, in the present embodiment, after the formwork panel 11 to which the lining sheet 15 is attached is used, the concrete particles cannot pass through the non-woven fabric sheet 20 on the surface reconstruction side, so that they are attached only to the non-woven fabric sheet 20. Therefore, if the suction sheet 30 firmly attached to the surface of the formwork panel 11 is left as it is and only the non-woven fabric sheet 20 is replaced, the formwork panel 11 with the lining sheet 15 exhibiting the same function is used again. be able to.

Normally, once the formwork panel 11 is used, dried and hardened concrete particles are attached to the surface thereof, and the formwork panel 11 is repeatedly used after being washed away. On the other hand, in the present embodiment, the nonwoven fabric sheet 20 is peeled off after use, and the nonwoven fabric sheet 20 of the same size is attached again in the same manner, and there is no need to wash the mold panel 11 and the suction sheet 30. Can be reused.

Further, the adsorption sheet 30 composed of the foamed resin layer 31 and the raised nonwoven fabric base sheet 35 is usually expensive, whereas the nonwoven fabric sheet 20 is relatively inexpensive. Therefore, according to the present embodiment in which the formwork panel 11 and the suction sheet 30 can be used repeatedly by replacing only the non-woven fabric sheet 20, the appearance is beautiful while significantly reducing the installation cost of the concrete formwork 10. It is possible to form a strong concrete structure.

Further, when the used nonwoven fabric sheet 20 is peeled off, there is a portion where the nonwoven fabric sheet 20 is adsorbed on the foamed resin layer 31 of the adsorption sheet 30, so that the foamed resin layer 31 is peeled off from the brushed nonwoven fabric base sheet 35. There is also a risk that it will end up. On the other hand, in the present embodiment, the raised type raised non-woven fabric base sheet 35 is used as the base sheet to which the foamed resin layer 31 is applied, and the foamed resin and the raised non-woven fabric are entangled with each other to form a foamed resin. The layer 31 and the raised non-woven fabric base sheet 35 are strongly bonded to each other, and both can be prevented from peeling off.

The non-woven fabric sheet 20 may be replaced at a warehouse where the used formwork panel 11 is stored or at the next concrete placing site. At this time, the used non-woven fabric sheet 20 is left affixed until the formwork panel 11 or the like is reused, and when the used non-woven fabric sheet 20 is reused, the used non-woven fabric sheet 20 is peeled off and a new non-woven fabric sheet 20 is attached. Is desirable.

When the used non-woven fabric sheet 20 is peeled off and the suction surface of the suction sheet 30 attached to the mold panel 11 is stored in an exposed state, dust, dust, etc. adhere to the suction surface, and the foamed resin layer 31 This is because the suction cup function may be deteriorated.

Further, in the installation of the concrete formwork 10, when the formwork panels 11 are connected by the separator 13, a separator hole for passing the separator 13 is formed in the lining sheet 15, but this embodiment In the case, since the non-woven fabric sheet 20 located on the surface reconstruction side is replaced with a new one every time the formwork panel 11 is installed, there is a possibility that the concrete 5 may leak from the separator hole formed in the past use. No.

Further, according to the present embodiment, when the concrete 5 is cured, a part of the excess water stays in the voids of the nonwoven fabric sheet 20 to retain water, and the excess water cures the concrete 7 in an appropriate wet state. Can also be done.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.
For example, the shape and material of the nonwoven fabric sheet (dehydrating / degassing sheet), the foamed resin layer, and the brushed nonwoven fabric base sheet constituting the lining sheet can be appropriately changed.

As a material for the dehydrated / degassed sheet and the raised non-woven fabric base sheet, for example, a synthetic resin such as polyethylene or PET (polyethylene terephthalate) can be used. Further, as the material of the foamed resin layer, a soft resin having elasticity such as silicon can be used.

Further, in the above embodiment, a brushed type dry brushed non-woven fabric is used as the base sheet of the foamed resin layer, but a non-woven fabric sheet that is not a brushed type, for example, a wet non-woven fabric made by a wet method or a cloth of a woven fabric other than the non-woven fabric. A sheet may be used. However, in order to satisfactorily discharge excess water and mixed air to the outside of the lining sheet, it is desirable to use a sheet having high water permeability and breathability.

Further, in the above embodiment, a wet non-woven fabric sheet is used as the dehydration / degassing sheet, but any cloth having water permeability and breathability and not allowing concrete particles to pass through, such as a dry non-woven fabric or a woven cloth, is used. , Other cloths can be used as appropriate.

5 Concrete 10 Concrete formwork 11 Formwork panel 13 Separator 15 Lined sheet 20 Non-woven fabric sheet (dehydration / degassing sheet)
30 Adsorption sheet 31 Foamed resin layer 32 Non-penetrating micropores 33 Penetrating micropores 35 Brushed non-woven fabric base sheet

Claims (4)

In the concrete formwork lining sheet used by pasting on the surface of the formwork panel
A porous dewatering / degassing sheet that is breathable and water permeable but does not allow concrete particles to pass through.
A foamed resin layer having elasticity applied to one surface of the substrate sheet and the substrate sheet, and having a large number of non-penetrating holes exposed only on the surface side, the surface side functions as a suction cup. A suction sheet composed of a resin layer and having breathability and water permeability,
For a concrete formwork, the dehydrated / degassed sheet is brought into close contact with the surface side of the foamed resin layer, and the dehydrated / degassed sheet and the adsorption sheet are overlapped with each other. Lined sheet. The lining sheet for a concrete formwork according to claim 1, wherein the base material sheet is a brushed non-woven fabric sheet. The lining sheet for a concrete formwork according to claim 1 or 2, wherein the dehydration / degassing sheet is a wet non-woven fabric sheet. In the installation method of concrete formwork
A foamed resin layer having elasticity applied to one surface of the substrate sheet and the substrate sheet, and having a large number of non-penetrating holes exposed only on the surface side, the surface side functions as a suction cup. A suction sheet sticking step of sticking the base sheet in close contact with the surface of the formwork panel, which is composed of a resin layer and has breathability and water permeability.
A porous dewatering / degassing sheet that is breathable and water permeable but does not allow concrete particles to pass through is placed on the surface side of the formwork panel by covering the adsorption sheet and adhering it to the foamed resin layer. Ki sheet pasting process and
The formwork panel installation process of installing the formwork panel in which the adsorption sheet and the dehydration / degassing sheet are superposed and attached at a concrete placing place, and
A method of installing a concrete formwork, which is characterized by being provided with.

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