JPH0655366B2 - PC tank precast panel manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PC tank side wall and roof precast panel. More specifically, it relates to a precast panel manufacturing method capable of improving the workability of side walls and roofs and shortening the construction period.

[0002]

2. Description of the Related Art A generally used construction method for a PC tank is to pour bottom slab concrete, assemble a formwork on the bottom slab and pour concrete on site to construct a side wall, and then a roof part. The method of introducing the pre-stress to the side wall and the roof part is used.

Further, in recent years, in order to shorten the construction period and improve the construction management, the side walls and the roof are made into precast panels and assembled, and the precast panels are assembled on site, and the filling concrete is poured between the precast panels. The method of installing and forming a side wall and a roof part is adopted.

In the production of the precast panel, a production stand having a predetermined curvature is preliminarily produced, and a film as an edge cutting material is laid on the upper surface of the production stand to form a bottom formwork, and the side formwork is assembled. Next, after assembling the reinforcing bar and the PC steel material, concrete is poured. The film is laid on the finished precast panel, and the precast panel is manufactured by sequentially stacking the film.

[0005]

In the prior art of the above-mentioned precast panel, it is attempted to shorten the process and improve the construction management as compared with the method of placing concrete on the side wall and the entire roof at the site. Made possible However, with this technology, it is necessary to assemble the main reinforcing bars and distribution bars for each precast panel, which requires a lot of labor and time for processing and assembling the reinforcing bars, which causes problems such as delay in construction period and complicated workability. There is.

The main purpose of the reinforcing bars incorporated in the precast panel is to withstand bending stress generated when the side wall panel is installed or when the roof panel is installed.
After the construction of the C tank, prestress is introduced into the side wall and the roof, and only the compressive force is generated in the concrete cross section, and no reinforcing bar is required. Moreover, in a normal PC tank, a prestress larger than the stress of the solution is introduced so that a tensile force is not generated in the side wall cross section even when the solution is stored in the tank, and the side wall concrete cross section is always applied. Compressive force is generated.

The present invention has been completed as a result of repeated studies based on the above findings.

[0008]

That is, according to the present invention, a production stand having a predetermined curvature is preliminarily provided for a side wall of a cylindrical prestressed concrete tank composed of a bottom slab, a side wall and a roof, and a roof panel. A film is laid on the upper surface of the production table to form a bottom formwork, a side formwork is provided to pour concrete, the concrete surface is finished to a predetermined curvature, and a film is laid on the concrete surface to form a side mold. In a method of placing a frame and placing concrete, and stacking it in order to produce a precast panel, using a waterproof sheet in which fibers are planted on one surface of the single-sided film surface as the bottom formwork, as precast panel concrete,
Provided is a method for manufacturing a precast panel for a PC tank, which is characterized by using concrete mixed with fibers.

As the waterproof sheet, a publicly known one can be used, but a waterproof sheet in which fibers or the like are planted on one surface of the film is used as a waterproof material because the sheet is integrated with the panel when the precast panel concrete is cured. It is suitable.

As the fibers to be mixed with the precast panel concrete, steel fibers, stainless fibers, glass fibers and the like can be used.

[0011]

[Function] In the precast panel concrete mixed with fibers, the bending strength and the tensile strength are improved by the effect of the fibers. For example, when steel fiber is used, the mixing ratio is 1.5% and the bending strength is about double, 70 kg.
/ Cm ² and tensile strength is about 1.8 times 50 kg
/ Cm ² , the toughness is improved to about 200 times. Therefore, the bending stress generated when the side wall precast panel is built differs depending on the inner diameter of the panel and the wall height.
The stress is 5 kg / cm ² or less, and no precast panel reinforcing bar is required.

Also, the inner surface of each precast panel is
A waterproof sheet in which fibers are transplanted is integrated and protected by the panel concrete, and the fibers mixed near the inner surface of the precast panel concrete do not corrode to the stored solution, etc., steel fiber or stainless fiber. Also made available.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIGS. 1, 2, 3, and 4.

The PC tank of the present invention is composed of a bottom slab C, a side wall A and a roof B as shown in FIG. Roof B
As the shape of, a dome shape is generally adopted as shown in FIG. In this embodiment, the shape of the roof B is a dome structure.

As a method of constructing a PC tank, after the foundation work and the piping work are completed, leveled concrete is poured, and the bottom slab C concrete is poured on the ground by casting. When the bottom slab C is completed, the precast panels that are the side wall A and roof B members are manufactured on the bottom slab C.

The method of manufacturing the side wall A and the roof B member will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, prior to the manufacture of the side wall precast panel A, first, the manufacturing table 7 is used.
Is temporarily made of concrete or the like, and the surface of the production table 7 is finished to have the same curvature as the inner diameter of the side wall A.
The increase or decrease in the number of the production tables 7 produced is determined by the inner diameter of the PC tank or the like. Next, the waterproof sheet 4 which also serves as a bottom frame is laid on the surface of the production table 7. When the laying of the bottom formwork 4 is completed, the side formwork 3 is assembled according to a predetermined size of the side wall precast panel A. Next, in the side mold part 3 in the circumferential direction, a connecting bar 6 is provided penetrating the side mold frame 3 for tightly connecting with the adjacent precast panel A at the time of building. Also,
In the circumferential direction of the precast panel A, a predetermined PC steel material 5 is arranged according to the volume of the solution stored in the PC tank. When the arrangement of the connecting bar 6 and the PC steel material 5 is completed, the concrete 2 mixed with the fiber 1 is poured. The surface of the concrete 2 is molded so as to have a predetermined curvature like the production table 7. When the hardening of concrete 2 is over,
Again, the waterproof sheet 4 which also serves as a bottom formwork is laid on the surface of the concrete 2, the side formwork 3 is assembled, the connecting bar 6 and the PC.
The steel material 5 is arranged, the concrete 2 is poured, and the precast panels A are sequentially stacked and manufactured.

The roof precast panel B is manufactured in the same manner as the side wall precast panel A. First, a manufacturing table (not shown) is manufactured so that the surface has a predetermined dome curvature, and then a bottom frame is formed on the surface of the manufacturing table. The waterproof sheet 4 which also serves as the above is laid, and the side formwork 9 is assembled according to the size of the roof precast panel B. Next, as shown in FIG. 3, a connecting bar 8 for tightly connecting with the adjacent roof precast panel B is arranged so as to penetrate through the side form 9, and concrete 2 mixed with fibers 1 is poured. Hereinafter, like the side wall precast panel A, they are sequentially stacked and manufactured. The side wall precast panel A and the roof precast panel B are manufactured by several parallel operations.

When the production of the side wall precast panel A and the roof precast panel B is completed, the side wall precast panel A is first built in and arranged at a predetermined position, and the side wall precast panel A is packed with concrete (not shown).
To build a side wall. Next, roof precast panels B are sequentially installed, and a filling concrete (not shown) is placed on each panel B and the central portion to construct a roof.

When the construction of the side wall and the roof is completed, prestress is introduced by the PC steel material 5, and each precast panel and the filling concrete are integrated.

As the fiber 1, glass fiber or the like that does not corrode is effective, but it is also possible to use steel fiber or stainless fiber due to the anticorrosion effect of the waterproof sheet 4 that is adhered to the inner surface of the precast panel. In the case of steel fiber, the mixing ratio of the fiber 1 is usually about 1 to 2% by volume, which is added to concrete.

[0021]

The precast panel manufacturing method of the present invention makes it possible to manufacture a precast panel that does not require a reinforcing bar by using a waterproof sheet and a fiber concrete on the inner surface of the panel, and processing and assembling the reinforcing bar at the time of manufacturing the panel. There is no complicated work, etc., shortening the construction period and facilitating construction management. Further, the reinforcing bars in the precast panel are eliminated, and the PC steel material can be easily arranged.

[0022]

[Brief description of drawings]

FIG. 1 is a plan view of a side wall precast panel in a manufactured state showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a side wall precast panel manufacturing state of the present invention.

FIG. 3 is a plan view of a roof precast panel manufactured in an example of the present invention.

FIG. 4 is a sectional view illustrating a built-in state of the precast panel of the present invention.

[Explanation of symbols]

 1 Fiber 2 Concrete 3 Sidewall Form 4 Tarpaulin 5 PC Steel 6 Sidewall Precast Panel Connecting Bar 7 Sidewall Precast Panel Making Table 8 Roof Precast Panel Connecting Bar 9 Roof Side Form A Sidewall Precast Panel B Roof Precast Panel C Bottom Plate

Claims (1)

[Claims] 1. A side wall of a cylindrical prestressed concrete tank composed of a bottom slab, a side wall, and a roof, and a roof panel are preliminarily prepared on a production table having a predetermined curvature, and a film is laid on the upper surface of the production table. Bottom formwork, side formwork is provided and the concrete is cast, the concrete surface is finished to have a predetermined curvature, and a film is laid on the concrete surface, and the side formwork is assembled into concrete. In the method of casting and sequentially stacking to produce a precast panel, a waterproof sheet with fibers on one side of the film on one side is used as the bottom formwork, and fiber-mixed concrete is used as the precast panel concrete. PC tank precast panel manufacturing method.