JP2617741B2 - Method of manufacturing concrete PC shell - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a concrete PC shell used for building construction and the like.

2. Description of the Related Art Conventionally, a method of manufacturing a PC shell of this type is generally performed as shown in FIG.

In the figure, a is an inner form made of iron plate or plywood and formed in a substantially square cross section, and both ends thereof are supported by pedestals b. (The other end is not shown.) Reinforcing bars c are arranged outside the inner mold a with a space. d is the main rebar, e is the outer formwork, and f is the Tokiwa.
Concrete g is poured into the formwork thus formed. After hardening the concrete g, the outer mold e is removed, and the hardened product h is removed from the inner mold a. The product thus formed as shown in Fig. 10 is a PC
It is carried to the construction site as a shell and used as it is as a floor slab, or concrete is poured into the central space i to form a composite column as an example.

Problems to be Solved by the Invention However, the above-mentioned conventional method has the following disadvantages. That is, it is difficult to remove the product h from the inner mold a after molding the product h. In the case of this removal, the product h is adhered to the inner mold a by the concrete g, and the concrete g is hardened, and the adhered area extends over the outer front body of the inner mold a, so that the peeling It is difficult to remove the mold, and it takes time and labor.

The present invention has been made to solve the above problems, and its object is to separate the shell from the inner mold after molding the shell, as in the conventional method described above. It is an object of the present invention to provide a method for producing a concrete PC shell that is not difficult as in the conventional method, can be demolded extremely easily, and can reduce the labor significantly.

Means and Actions for Solving the Problems To describe the present invention which achieves the above-mentioned object, it comprises two reaction force supporting bases which are spaced apart and parallel to each other, and at least four tensions are provided. The steel material provided with is provided in a relaxable manner, and the steel material is covered with a flexible sheet from the outside across all the steel materials to form an inner mold, and a frame-shaped reinforcing bar is provided outside the inner mold. Fit, place at intervals,
An outer mold is disposed outside the inner mold, concrete is cast inside the outer mold, and after the product is molded by curing of the concrete, the outer mold is removed, and the inner mold is removed. Concrete PC characterized by being deformed inside and demolding
This is a method for manufacturing a shell.

EXAMPLE In FIG. 1, reference numerals 1 and 1 denote reaction force supports respectively, 2 denotes a tensioned steel material, 3 denotes a flexible sheet, 4 denotes an inner frame formed in this way, and 5 denotes a reinforcing bar. . 6 is an outer form, 7 is concrete, 8 is a normal board, and 9 is a PC steel material.
Although six steel materials 2 are shown, it is sufficient that the number is at least four, and any other number may be used. As the steel material 2, a twisted piano wire, a piano wire, a wire rope, or the like may be arbitrarily used. And, it is provided on the reaction force support base 1 which exerts a reaction force on the pulling force so as to be freely tensioned, relaxed, attached and detachable. The drawing shows the case where tension is applied. Means such as devices, tools, and the like for the above-described tension, relaxation, detachment, and attachment are omitted in detail.

Next, the flexible sheet 3 is shown in FIGS.
Various types having projections 10 on the surface as shown in the figure may be appropriately used. The flexible sheet 3 is a sheet made of rubber, synthetic resin, or the like.
Is 4 mm in height. This projection 10 forms a concave portion inside the PC shell to be formed, and improves the adhesion when a concrete column is formed by casting concrete inside the PC shell. Also, as shown in FIG. 1, before the concrete 7 is cast, a PC steel material 9 made of a piano wire or the like is pre-tensioned, and the concrete 7 is cast in such a manner as to be built therein. After the concrete 7 hardens, its tension is relaxed and prestressed. In this case, the reaction force support base 1 is used.

As described above, the concrete 7 is cast inside the outer mold 6 and outside the inner mold 4. After hardening the concrete 7, the outer mold 6 is removed, and then the inner mold 4 is deformed inward.

FIG. 5 and FIG. 6 show this state. That is, the steel material 2 which has been tensioned in FIG. 5 is loosened as shown in FIG.
Is constrained to the center by Then, the flexible sheet 3 is deformed inward and peeled off. The order of removing the inner mold frame 4 and the outer mold frame 6 does not matter.

In this manner, for example, the well 12 formed as shown in FIG. 7 is carried to a construction site and used as it is as a floor slab, or a main reinforcing bar 13 is provided as shown in FIG. Pour concrete 14 to form composite columns 15. In addition to the shell composite column or the like according to the present invention, a composite beam or the like can be formed although not shown.

EFFECTS OF THE INVENTION The present invention is configured as described above and includes at least four
A steel material that is given tension is provided so that it can be relaxed, a flexible sheet is placed on it to form an inner formwork, and an outer formwork is provided outside the inner formwork. When the mold is removed and the mold is removed, the outer mold is removed, the steel material of the inner mold is loosened, the flexible sheet is deformed inward, and the flexible sheet can be peeled inward from concrete. It is much easier to demold than the method described in the examples. Therefore, the trouble can be greatly reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and schematically shows a method of manufacturing a concrete PC shell. FIGS. 2 to 4 are perspective views of various flexible sheets having projections on the surface used in the present invention. FIGS. 5, 5 and 6 are views showing a demolding method when manufacturing the same PC shell, FIG. 7 is a sectional view of a PC shell made according to the present invention, and FIG. FIG. 9 is a schematic view of a conventional manufacturing method of the same type, and FIG. 10 is a cross-sectional view of a PC shell manufactured by the same method. DESCRIPTION OF SYMBOLS 1 ... Reaction force support stand 2 ... Steel 3 ... Flexible sheet 4 ... Inner form 5 ... Reinforcing bar 6 ... Outer form 7 ... Concrete

Claims (1)

(57) [Claims] (1) Two reaction force supports provided at an interval,
At intervals and in parallel, at least four tensile steel members are provided so as to be able to relax, and from the outside of the steel members, a flexible sheet is covered over all the steel members to form an inner formwork, A frame-shaped reinforcing bar is fitted and arranged outside the inner mold at an interval, an outer mold is arranged outside the inner mold, and concrete is cast inside the outer mold. Then, after the product is molded by hardening the concrete, the outer mold is removed, the inner mold is deformed inward, and the mold is removed from the mold, thereby producing a concrete PC shell.