JP3053046B2 - Surface treatment method for PC products by immediate demolding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for a PC product which is immediately removed from a cast concrete by applying vibration and pressure to the concrete.

[0002]

2. Description of the Related Art Conventionally, when molding a PC (precast concrete) product, for example, a hollow product such as a concrete pipe or a PC column formwork for construction, the PC product has a shape along the inside and outside. Using the inner and outer forms, the inner and outer forms are arranged approximately concentrically, and concrete is poured into the space between the two forms, and then when the concrete solidifies or hardens, It is designed to be removed.

In recent years, in order to improve the manufacturing efficiency of the PC product, Japanese Patent Publication No. Hei 1-15361 (B28B1) has been proposed.
/ 08), the mold is filled with 0 slump of concrete and placed on a shaking table, and the concrete is pressed to apply a pressing force to accelerate the solidification of the concrete, thereby immediately removing the concrete. Proposals have been proposed that allow molds.

[0004]

However, such a conventional PC product which is immediately removed from the mold is removed from the mold before the concrete is completely hardened. The surface of the concrete becomes rough due to loss of the surface. For this reason, immediately after the mold is removed, a cement paste or a thin plaster material is immediately applied to the concrete surface by using a means such as a trowel, a roller, or a spray, and then steam curing is performed. Therefore, since the extra work of finishing the concrete surface with cement paste, plastering material, or the like is required, there has been a problem that labor and time are required.

[0005] In view of the above-mentioned problems, the present invention takes measures to prevent the concrete surface from becoming rough after immediate demolding, thereby eliminating the need for surface treatment after demolding and achieving labor saving. It is an object of the present invention to provide a method for surface treatment of PC products by immediate demolding.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a PC product which enables immediate demolding by applying pressure and vibration to concrete poured into a formwork. Before casting, a bag-shaped sheet is attached to the formwork surface in contact with the concrete, and then the concrete is placed in the bag-like sheet.
And then removing the sheet after removing the concrete from the formwork.

The sheet may have water permeability.
desirable.

[0008] Further, the sheet is formed with an uneven portion.
You can also put it.

[0009]

According to the surface treatment method for PC products by immediate demolding described above, when the concrete is demolded from the formwork, the sheet attached to the formwork surface is demolded while being attached to the concrete surface. . Therefore, since the concrete surface can be protected by the sheet at the time of demolding, the concrete surface can be prevented from being damaged. And
By removing the sheet after demolding, the concrete surface is formed smoothly along the sheet ground, so that post-processing can be omitted or simplified. In addition, the sea
The bottomed sheet is attached to the formwork
By placing concrete in the
When the cleat load acts on the bottomed sheet,
Fix both sides where bottom part of bottomed sheet contacts formwork surface
Can improve the adhesion between the bottomed sheet and the formwork.
You.

[0010] Further, the sheet has water permeability.
More concrete can be drained into the formwork,
It can accelerate the solidification of concrete.

[0011] Further , the sheet may be formed with an uneven portion.
In this way, it is possible to form a PC product on the surface at the same time
Uneven pattern can be provided.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 are cross-sectional views showing one embodiment of a surface treatment method for a PC product by immediate demolding according to the present invention. That is, in this embodiment, the PC product 10 for building materials is used.
The PC product 10 is shown in FIG. 1 and FIG.
The molding is performed using a mold 12 shown in FIG. That is, the outer shape of the PC product 10 is formed by the mold 12.

Then, the PC product 10 is formed by casting concrete 14 inside the formwork 12. In the present embodiment, the inner surface of the formwork 12 is cast before the concrete 14 is cast. (Form surface) A sheet 16 formed of a woven fabric or the like and having water permeability is attached to the mold surface 12a.
This sheet 16 has a bottomed shape by providing a bottom 16a.
The bottomed sheet 16 is attached to the mold surface 12a.
I will keep it. Then, a wire mesh is placed in the bottomed sheet 16.
The concrete 14 is cast with the brush 18 set .

Immediately after the concrete 14 is cast, the vibrating rod 20 is inserted into the center of the formwork 12. By inserting the vibrating rod 20, the concrete 14 is pressurized and vibrated, and the solidification of the concrete 14 is remarkably promoted. When the concrete 14 solidifies within a short time, the concrete 14 has a shape-retaining property, and in this state, the formwork 12 and the vibrating rod 20 are extracted and immediately released. Then, when the concrete 14 is removed, the sheet 16 is attached to the surface of the concrete 14, and after the removal, the sheet 16 is removed as necessary.

As described above, in the surface treatment method of the concrete 14 immediately removed from the mold according to the present embodiment, the concrete 14 is cast with the sheet 16 attached to the form surface 12a.
Since the vibrating rod 20 is inserted into the concrete 14 and pressurized and vibrated, the mold 14 is immediately removed from the concrete.
The sheet 16 attached to a is released from the concrete 14 while being attached to the surface of the concrete 14. Therefore, since the concrete 14 is protected by the sheet 16 at the time of demolding, the surface of the concrete 14 is prevented from directly rubbing on the form surface 12a, and thus the surface of the concrete 14 is prevented from being damaged. it can.

Accordingly, by removing the sheet 16 from the concrete 14 after demolding, the concrete 14
The surface is formed smoothly along the sheet material. Therefore,
Post-treatment of the surface of the concrete 14 after demolding can be omitted or simplified, and significant labor saving and improvement in production efficiency can be achieved.

In the present embodiment, since the sheet 16 is formed of a woven cloth or the like and has water permeability, the form 1
The moisture of the concrete 14 poured into the
, The solidification of the concrete 14 can be further accelerated.

[0018]

Further, when the load of the cast concrete 14 acts on the bottomed sheet 16, the bottom portion 16a of the bottomed sheet 16 is brought into contact with the form surface.
6b and 16b can be fixed, so that the adhesion between the bottomed sheet 16 and the formwork 12 can be improved.

FIG. 3 shows another embodiment along the operation steps, and the same components as those of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In the present embodiment, a film-like sheet 22 having an uneven portion 22a formed by applying a tile pattern or a stone-patterned pattern is used. The surface treatment method itself is the same as in the above embodiment.
As shown in (a), the sheet 22 is attached to the inner surface 12a of the mold 12. Next, concrete 14 is cast, and then the vibrating rod 20 is inserted into the formwork 12, and the concrete 14 is pressed by the vibrating rod 20,
Excite. Thereafter, as shown in FIG.
Is immediately removed from the concrete 14. After demolding, Figure 3
As shown in (c), the sheet 22 is peeled from the concrete 14, but this operation may be performed immediately after the mold 12 is removed, or in some cases, after the concrete 14 is hardened. May be. In the present embodiment, while the same operation and effect as those of the above embodiment can be secured, the desired uneven pattern 26
There is an advantage that can be attached.

In this embodiment, the PC product 10 has been described as an example. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to other hollow column members that can be immediately removed.

[0022]

As described above, according to the first aspect of the present invention,
In the surface treatment method for PC products by immediate demolding shown in (1), before casting the concrete, a sheet was previously attached to the formwork surface in contact with this concrete, so when removing the concrete from the formwork, Since the mold is removed in a state where the sheet is adhered to the surface of the concrete, the surface of the concrete can be protected by this sheet and the surface can be prevented from being damaged. Then, by removing the sheet after demolding,
Since the concrete surface is formed smoothly along the sheet material, post-treatment of the concrete surface can be omitted or simplified, and labor saving and improvement in PC product production efficiency can be achieved. Also, the sheet is shaped like a bottom.
And attach it to the formwork surface.
The concrete that was cast
When a load acts on the bottomed sheet,
Can fix both sides where the bottom part of the
Therefore, the adhesion between the bottomed sheet and the mold can be improved.

Further, in the second aspect of the present invention, the
Since the sheet has water permeability,
The concrete can be drained and the concrete solidifies quickly.
And various other excellent effects.

Furthermore, in the third aspect of the present invention, the
By forming uneven parts on the sheet, PC products
The desired uneven pattern on the surface at the same time as molding
Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view at the time of concrete casting showing an embodiment of a surface treatment method for a PC product by immediate demolding according to the present invention.

FIG. 2 shows the surface of a PC product obtained by immediate demolding according to the present invention.
It is sectional drawing at the time of pressurization and vibration which shows one Example of a processing method .

FIG. 3 is a process chart showing the steps of another embodiment of the surface treatment method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 PC product 12 Formwork 14 Concrete 16,22 Sheet 16a Bottom part 16b Both side parts 20 Vibration bar

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Miki Aoyama 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd. Inside Obayashi Corporation Technical Research Institute (72) Inventor Yoshimasa Hayashi 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd. Obayashi Technical Research Institute (72) Inventor Haruka Ogawa 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd.Obayashi Technical Research Institute (72) Inventor Tatsuya Wakisaka 4-640 Shimoseito, Kiyose-shi, Tokyo Japan Obayashi Technical Research Co., Ltd. In-house (72) Inventor Noriyuki Furuya 4-640 Shimoseito, Kiyose-shi, Tokyo In-house Obayashi Technical Research Institute (72) Inventor Koji Hamada 4-640 Shimoseito, Kiyose-shi, Tokyo In-house Obayashi Technical Research (72) Inventor Takayuki Sone 2-3-3 Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office (56) Literature Patent Akira 63-306004 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) B28B 1/00 - 1/54 B28B 3/00 - 5/12 B28B 7/00 - 7 / 46

Claims (3)

(57) [Claims] 1. A PC product capable of instantaneous demolding by applying pressure and vibration to concrete cast on a formwork, wherein the concrete surface is in contact with the concrete before the concrete is cast. to attach a sheet formed into a bag shape to
After that, concrete is poured into this bag-like sheet,
Then the surface treatment method of the PC product by immediate demolding, characterized in that removing the sheet concrete from the mold after demolding. Wherein said sheet has a surface treatment method of the PC product by immediate demolding of claim 1, characterized in that it comprises a water-permeable. 3. An uneven portion is formed on the sheet.
The immediate demolding according to claim 1 or 2,
Surface treatment method for PC products.