JPH06143233A - Manufacture of pc panel - Google Patents

Abstract

PURPOSE:To improve placing and finishing surfaces of concrete, and to labor- save and simplify manufacturing steps by placing a drop-in foam corresponding to an inner surface of a PC (prestressed concrete) panel having a reinforcing rib on an outer periphery on concrete supplied to a bed and vibrating it when the panel and manufactured. CONSTITUTION:A peripheral form S is placed on a bed B for manufacturing a PC panel, and bars assembled with rib reinforcing bars H and mesh bars M are placed. Then, concrete or fiber-reinforced concrete 1 is supplied to a thin plate (a). Thereafter, a vibrator 4 is mounted in a drop-in form 3 corresponding to an inner surface of the panel, placed on the concrete 1, and the vibrator 4 is operated. The form 3 is moved down. When leg F so previously set as to become a thickness (d) of the plate (a) of a product panel reaches the bed B, it is clamped with a bolt N, etc. Thereafter, an upper surface of the rib part is leveled by a trowel, etc. Incidentally, tiles, stone material, etc., may be previously placed on the bed B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a PC (precast concrete) panel.

[0002]

2. Description of the Related Art Conventionally, in the case of manufacturing a PC panel having ribs on the outer peripheral portion as shown in FIG. 1, a peripheral form having a size of the panel on a bed B as shown in FIG. 2 (A). 2 (B) after attaching S, arranging the mesh reinforcement M on the bed B in the peripheral form S and reinforcing reinforcements H on the ribs, and further attaching the form W for ribs. Then, concrete 1 was placed. When pouring concrete, it was necessary to hang a rod-shaped vibrator and a box-shaped vibrator as shown in FIG. 3 on the entire surface of the thin plate portion a and the rib portion b of the PC panel. Further, after the concrete filling work using the vibrator, a step of leveling with a trowel or the like is necessary so that the thin plate portion a in FIG. 1 has a uniform thickness.

[0003]

However, the conventional technique has a problem that the work is complicated in addition to the filling work of the vibrator. In recent years, fiber-reinforced concrete having high strength, light weight and durability has been often used for manufacturing the PC panel. However, since the fiber-reinforced concrete has high viscosity, the fluidity of the fiber-reinforced concrete is poor, and it is necessary to carefully hang the rod-shaped vibrator and the box-shaped vibrator over the entire thin plate portion a and rib portion b of the PC panel. However, there is a problem in that much labor is required. Therefore, in the work of applying the rod-shaped vibrator and the box-shaped vibrator to the entire surface of the PC panel, insufficient filling of the fiber reinforced concrete such as forgetting to apply is scattered, and the surface of the finished surface of the PC panel is repaired. There was a problem that I had to do it.

In addition, when the PC panel is manufactured by attaching tiles, in the work of hanging the rod-shaped and box-shaped vibrators on the entire surface of the PC panel, there are spots of insufficient filling such as forgetting to hang the tiles, and There is a possibility that bad adhesion may occur, and the problem that the rod-shaped vibrator hits the tile and the tile breaks, and that the viscosity of the fiber reinforced concrete is difficult and it takes time to work smoothly, and the entire formwork When vibrating, there was a problem that the tiles dance and the smooth design of the surface is lost. In addition, in the conventional construction method, a step of leveling with a trowel or the like is required after the filling work of the fiber reinforced concrete using the vibrator so that the thin plate portion of FIG. There is a problem that the work becomes complicated.

[0005]

The inventors of the present invention have made extensive studies to solve the above-mentioned problems, and as a result, have found that the problems can be solved by using a newly developed formwork and have reached the present invention. did. That is, the object of the present invention is to
It is an object of the present invention to provide a PC panel manufacturing method capable of manufacturing a PC panel which is well filled with concrete and has an excellent finished surface, and which can save labor and simplify the manufacturing process. And, in order to manufacture a PC panel having a reinforcing rib portion on the outer peripheral portion, such an object is to supply concrete onto a bed for manufacturing a PC panel, and then to supply the concrete onto the bed.
This can be easily achieved by a method of manufacturing a PC panel, which is characterized in that a drop inner mold corresponding to the inner surface of the panel is placed and the drop mold is vibrated.

The present invention will be described in detail below. Figure 1
A method of manufacturing a PC panel having a reinforcing rib on the outer peripheral portion as shown in will be described. As shown in FIG. 4 (A),
First, the peripheral form S is assembled on the bed B, and the bar arrangement 2 in which the rib reinforcements H and the mesh lines M are connected and assembled in advance is placed inside the peripheral form S. In addition, tiled P
When manufacturing a C panel, tiles may be laid on the bed B before placing the reinforcing bar 2. In this case, the tile is, for example, 45 mm square or 45 × 95 mm square, and may be a tile used for a general PC panel. Similarly, when manufacturing a stone-clad panel, it is sufficient to spread stone materials before placing the bar arrangement 2. On this occasion,
In order to secure the adhesion between the stone and the concrete, the stone may be attached with a metal fitting such as a shear connector and the back surface of the stone may be treated by applying a resin or the like.

Next, concrete 1 is supplied to the thin plate portion a as shown in FIG. 4 (B). After the supply, it is preferable to spread the concrete with a scoop, a trowel, etc. so that the thickness becomes almost constant. At this time, the thickness t is the product PC panel thickness d
It is necessary to make it larger, but the thickness t is at least P
It is sufficient that the thickness is larger than the C panel thickness d, and it is not necessary to strictly keep the thickness constant.

Next, as shown in FIG. 5, a vibrator 4 is attached to a dropping inner mold 3 corresponding to the inner side surface of the PC panel, and as shown in FIG.
As shown in (C), it is placed on the concrete 1 that has been spread to a substantially constant thickness t. In addition, the construction of the dropping inner formwork 3 is such that the bottom part a corresponding to the entire area of the thin plate part a of the PC panel, the PC
It is composed of b corresponding to the total area of the rib portion b of the panel and the taper portion of the thin plate portion a, the foot portion F of the dropping inner formwork, and the mounting location c of the vibrator 4. Although there is no opening in the bottom portion a, holes may be appropriately formed in the bottom portion a, or a cloth or the like may be attached in order to release air at the time of driving. Further, the place of attachment of the vibrator 4 is not limited to c and is not particularly limited as long as it can vibrate the drop-in mold 3 and may be the foot F, for example.

Since the drop inner mold has a size corresponding to the inner surface of the product PC panel, its size depends on the size of the product PC panel, and there is no limitation as long as it is not larger than the product PC panel. No, but the bottom a is at least 0.25 m ²
It is preferable to have the above area (0.5 m square or more). The drop inner mold may be made of wood, plastic, or the like, as long as it is within a range in which impact due to vibration of the attached vibrator and deformation of the bottom a of the inner mold due to its own weight do not occur.
Preferably, a material having high rigidity (for example, iron) is desirable.

After placing the drop inner mold 3, the vibrator 4
Is activated to flow the concrete, and the filling on the bed B and the peripheral formwork S is started. The dropping inner formwork descends due to the flow and filling of the concrete. Product PC in advance
The vibrating and filling work is continued until the foot portion F of the dropping inner formwork 3 set to have the thickness d of the thin plate portion a of the panel reaches the bed B. As the dropping inner formwork 3 descends, the concrete 1 moves to the bed B through the mesh streaks M of the thin plate portion a.
The mesh line M flows from the bed B to the rib portion B formed by the b portion of the inner mold 3 and the peripheral mold S that flow upward.
Through the ribs, the concrete flows and fills the rib portion H sequentially from the bottom to the top. At this time, bubbles such as air contained in the concrete or air caught from the surroundings during pouring are rapidly pushed upward from below, so that dense packing without bubble accumulation is performed.

As shown in FIG. 4 (D), when the foot portion F of the dropped inner mold 3 reaches and contacts the bed B, the foot portion F is fixed by a knock pin or bolt N. Even when the foot portion F of the drop-in mold 3 reaches and contacts the bed B, the filling of the concrete 1 is sufficient, and the operation of the vibrator 4 may be terminated. After fixing, the vibrator 4 may be continuously operated and further compacted. After that, the upper surface of the rib portion L is leveled with a trowel or the like, and the driving is finished. If a plurality of the drop molds of the present invention are used in parallel, a large PC panel can be easily placed.

Next, after hardening of the concrete, the peripheral form S
And the drop inner formwork 3 is removed to obtain a product PC panel. The vibrator 4 used in the present invention may be any one that can be attached to a mold or the like, but it is preferable to use a vibrator having a high-frequency vibration motor with excellent vibration efficiency.

As the concrete 1, glass fiber reinforced concrete (GRC), synthetic fiber reinforced concrete (PFRC), carbon fiber reinforced concrete (CFR)
C) and steel fiber reinforced concrete (SFRC)
Such as fiber reinforced concrete is included. The fiber-reinforced concrete also includes fiber-reinforced cement excluding coarse aggregate.

Hereinafter, the present invention will be described in detail by taking as an example a manufacturing process of a tiled PC panel using a fiber reinforced concrete (hereinafter abbreviated as CFRC) having high viscosity and difficult to handle. The preparation of CFRC is described in JP-A 63-16255.
It was carried out according to the method described in Japanese Patent Publication No. The mixer is a high-speed mortar mixer (kneading capacity: 750, rotation speed: revolution blade 31 rpm, rotation blade 40 to 120 rp).
m) was used.

The present invention will be described below with reference to examples, but the present invention is not limited to the examples as long as the gist thereof is not exceeded.

[0016]

[Examples] High-accuracy cement (100 parts by weight) manufactured by Chichibu Cement Co., lightweight aggregate (25 parts), pitch-based high-strength, high-elasticity carbon fiber bundle of short fibers (Carbon Fiber registered trademark DIAREAD of Mitsubishi Kasei) (3 parts by weight), a thickener and an antifoaming agent (0.25 parts by weight in total) were charged into a mixer, and 1
Kneaded for minutes. Next, water in which sodium citrate (0.5 parts by weight) was dissolved as a setting retarder and a water reducing agent (48 parts in total) were added, and the mixture was kneaded for 1 minute. The kneading amount was 0.3 m3. After kneading, tiles of 45 mm square and reinforcing bars (mesh bar: diameter 4 mm, width 150 mm, rib cage basket rebar: main bar; 10 mm in diameter for the cross section of the rib section, rib section reinforcing bar: diameter 4 mm, 100 mm
Form frame (width: 2245 mm x 119)
The CFRC slurry kneaded to a thickness of 5 mm and a thickness of 150 mm) was spread with a scoop, a trowel or the like so that the thickness was about 10 cm or more. On top of that, the product PC panel (the rib portion has a thickness of 150 mm, the upper end portion of the rib portion has a width of 150 mm, the lower portion of the rib portion and the thin plate portion have a width of 200 mm, and the thin plate portion has an a portion of 1845 m.
A drop inner formwork corresponding to the inner side surface of m × 795 mm in width and 50 mm in thickness was placed. A variable high-frequency vibrator (vibrator manufactured by Tokuden Denki Kogyo; model HV
750B, frequency 6000-7200VPM, output 0.
75 KW) and attached and operated for 2.5 minutes. The foot portion F of the drop-in mold reached the bed B 0.5 minutes after the operation of the vibrator. Immediately after reaching, it was fixed with bolts and further compacted for 2 minutes. After that, the upper ends of the ribs were flattened with a trowel to finish.
The working time was 12.5 minutes from the end of kneading. After that, a sheet was put on and cured, and the mold was removed the next day. After demolding, the panel was turned over, the number of bubbles (3 mm or more) in the tile joint portion was observed, and the total number of bubbles was converted per 1 m of joint to obtain a concrete filling index. The results are shown in Table 1.

Comparative Example A tiled PC panel having the same shape as that of the CFRC slurry prepared by kneading under the same procedure and under the same conditions as in the example was manufactured using a rod-shaped vibrator and a box-shaped vibrator. The casting was performed in order from the rib portion to the thin plate portion. The rib portion was sequentially applied with a bar-shaped vibrator while pouring the CFRC slurry. Box-shaped vibrators were sequentially applied to the entire thin plate. The vibrator was operated in the same place for at least 5 seconds while stationary. After that, the work of adjusting the thickness of the thin plate and the work of finishing the entire surface were performed using a trowel or the like. The working time was 20 minutes for the vibrator work, 15 minutes for the thickness adjustment, and 10 minutes for the finish, for a total of 45 minutes.
After that, the sheet was hung and cured, and the mold was removed the next day. After demolding, the panel was turned over, the number of bubbles (3 mm or more) in the tile joint portion was observed, and the total number of bubbles was converted per 1 m of joint to obtain a concrete filling index. The results are shown in Table 1.

[0018]

[Table 1]

[0019]

EFFECTS OF THE INVENTION By using the manufacturing method of the present invention, it is possible to (1) manufacture a PC panel that is well filled with the concrete and has few bubbles, and (2) omit the work of adjusting the thickness of the thin plate portion (a) of the product PC panel. The work process can be simplified and the time can be shortened. (3) The filling work using the conventional box-shaped or rod-shaped vibrator can be omitted, and the work process can be simplified. Especially when manufacturing tiled PC panels, (4) the vibrating machine does not directly hit the tiles, so the tiles do not break, and (5) the vibration from the top surface of the formwork prevents the tiles from dancing. When the fiber reinforced concrete is placed, (6) C is generated by the vibration of the drop form.
It is possible to manufacture a high-strength PC panel in which F is oriented and the strength distribution is uniform.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a structure of a PC panel.

FIG. 2 is an explanatory diagram of a method for manufacturing a PC panel.

FIG. 3 is an illustration of the shape of a typical vibrator that is commonly used.

FIG. 4 is an explanatory view of a method for manufacturing a PC panel of the present invention.

FIG. 5 is an explanatory view of the structure of the drop inner formwork of the present invention.

[Explanation of symbols]

1 Concrete 2 Reinforcement 3 Dropped inner formwork 4 Vibrator a PC panel thin plate b PC panel rib part a Dropped inner formwork PC panel thin plate part equivalent to the total area of thin plate b Dropped inner formwork PC The part corresponding to the total area of the taper part of the rib part and the thin plate part of the panel c The place where the vibrator of the drop inner form is attached d The thickness of the PC panel thin part t The initial thickness of the supplied concrete B Bed F The drop inner form Foot part H Reinforcing bar M Mesh bar N Knock pin or bolt S Peripheral form W W Form for rib

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Shiraki Akira Shiraki 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryoh Kasei Co., Ltd. (72) Inventor Taiichi Otani 2-5-2 Marunouchi, Chiyoda-ku, Tokyo No. Sanryo Kasei Co., Ltd. (72) Inventor Hirofumi Otakuro 1-1 Kurosaki Shiroishi, Hachimansai-ku, Kitakyushu City, Fukuoka Prefecture Mitsubishi Kasei Co., Ltd. Kurosaki Plant (72) Inventor Yoshihiro Honda 1-21- Tsukushino, Machida, Tokyo 67

Claims (4)

[Claims] 1. When manufacturing a PC panel having reinforcing ribs on the outer periphery, concrete is supplied onto a bed for manufacturing the PC panel, and a drop inner formwork corresponding to the inner side surface of the PC panel is placed on the concrete. Then, the method for manufacturing a PC panel is characterized in that the dropping inner mold is vibrated. 2. The method for producing a PC panel according to claim 1, wherein the concrete is fiber reinforced concrete. 3. The method of manufacturing a PC panel according to claim 1, wherein the tile is previously placed on the bed for manufacturing the PC panel, and then the concrete is supplied. 4. The method of manufacturing a PC panel according to claim 1, wherein the stone material is placed in advance on the bed for manufacturing the PC panel, and then the concrete is supplied.