JPS6026682B2 - Manufacturing method for hollow concrete molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a concrete molded product, particularly a hollow concrete molded product having hollow portions such as holes and depressions.

In order to remove the inner formwork corresponding to the hollow part after the concrete has hardened in the production of concrete molded products with hollow parts, there is a method of destroying and removing the inner formwork or a method of disassembling the prefabricated inner formwork. However, if the inner formwork is made strong, it takes time to break it, and if it is made easy to break, it is easily deformed when filling with concrete, so it is difficult to make the inner formwork and fill it with concrete. Not only is it difficult to work with, but it is also uneconomical because it is disposable.
In addition, the latter method has disadvantages in that it takes time and effort to assemble and disassemble the inner formwork, resulting in poor workability, and the structure of the inner formwork is complicated and expensive. In the present invention, a flexible sheet is wrapped around the outer surface of the inner form in advance, and after the concrete has hardened, the inner form is removed together with the Shigeru mold sheet, or the inner form is pulled out and then the machine mold sheet is removed. This makes it possible to easily and inexpensively manufacture hollow concrete molded products without requiring the complicated and uneconomical work of destroying or assembling and disassembling the inner formwork.
EXAMPLES Below, examples will be described with reference to the drawings, first a hollow concrete molded product, and then a manufacturing method of the present invention. 1st,
The pillar section 1, which is a hollow concrete molded product shown in Fig. 2, has a square tube shape with closed upper and lower ends, and a large number of square frame-shaped horizontal reinforcing bars 2 are arranged at a predetermined distance from each other along the wall thickness. They are buried in rows, and a large number of approximately hemispherical small holes 3 are provided in rows on the inner circumferential surface to create an uneven surface that allows post-cast concrete to bite easily.

The beam member 4, which is a concrete molded product shown in FIG.
The upper surface, front and rear ends are open, and the longitudinal section is in the shape of a square gutter with a substantially U-shape, and a square frame-shaped rattan reinforcing bar 5 is installed along the inner circumferential surface within the wall thickness.
A large number of them are lined up at a predetermined interval from each other, and their left and right side parts and bottom parts are buried within the wall thickness, and a large number of approximately hemispherical small holes 6 are provided in a row on the inner circumferential surface to allow the post-cast concrete to be placed in a row. It has an uneven surface with good bite.

The pillar member 1 and beam member 4 are used as shown in FIGS. 5-7.

That is, a plurality of column members 1 are held upright by being held upright by a plurality of main reinforcing bars 6 that have been erected on a slab in advance, and the beam members 4 are placed across the upper end edge of the column members 1, 1 facing each other at a required distance. The tip of the main reinforcing bar 6' inserted into the beam member 4 is inserted into the column members 1, 1 from the upper end opening, and a ready-made steel bar is inserted between the mutually opposing beam sections 4 (only one shown). The floor template 7 is constructed, the required reinforcing bars are provided, and ready-mixed concrete is placed on the floor template 7 and inside the column members 1 and beam members 4. Next, to explain the manufacturing method of the column member 1, as shown in FIG. An inner formwork 9 in the form of a hollow rectangle corresponding to the size of is prepared. Then, around the outer periphery of the inner formwork 9, a neighboring sheet 10, in which two synthetic resin films are polymerized and bonded and a number of approximately hemispherical air sacs are arranged in the middle, is wrapped, and on the outside thereof, the horizontal reinforcement 2 are placed next to each other at a required interval, and the inner formwork 9 is installed within the outer formwork 8, and the inner and outer formworks 9,
8 is filled with concrete 11, and after it hardens, the outer formwork 8 is removed and the inner formwork 9 is pulled out from the entrance of the hollow part, and then the mold release sheet 10 is removed. is obtained.

In this case, the concrete 11 adheres to the koji mold sheet 10 and does not adhere to the inner formwork 9, and furthermore, the release sheet 1 is flexible and deforms, easily creating a gap between it and the inner formwork 9 and slipping. Since the inner formwork 9 can be easily pulled out in the longitudinal direction from the closed end of the hollow part, the machine form sheet 10 can also be easily removed from the concrete 11, and each of its air pockets can be easily removed. Accordingly, the small holes 3 are arranged in a row on the inner peripheral surface of the column member 1.

In addition, the method for manufacturing the beam member 4 is different from the method for manufacturing the column member I by using molds of the same shape as the inner and outer molds 9 and 8 (not shown). The difference is that concrete is filled up to the U-shaped section and the upper part 5' of each bar 5 is left exposed from the concrete, but the other methods are the same.

As is clear from the above description, according to the present invention,
A flexible rock-shaped sheet made of polymerized synthetic resin film and many air sacs arranged in the middle is wrapped in advance around the outer surface of the inner form, and this inner form is installed inside the outer form. Since concrete was filled between both formworks, after curing, the concrete adhered to the Shigeru type sheet and not to the inner formwork, and the adjacent type sheet had many air sacs installed in rows. Because it is flexible, pushing or pulling the inner formwork deforms it and creates a gap between it, so it can be easily removed from the entrance of the hollow part without disassembling or destroying the inner formwork, and the template sheet can also be easily removed. Since it can be removed, it is easy to work with and is economical. In addition, the inner surface of the hollow part of the formed hollow concrete molded product has a large number of small holes that correspond to the air sacs of the adjacent sheet, and these many small holes allow the post-cast concrete in the hollow part to be absorbed. In addition to improving adhesion, since the adjacent sheet also serves as a mold for the small holes, there is no need to separately prepare a mold for the small holes, which is economical.

[Brief explanation of the drawing]

Figures 1 and 2 are a perspective view and a partially omitted vertical sectional view of a column member manufactured by the manufacturing method of the present invention, and Figure 3 is a perspective view of a beam member manufactured by the manufacturing method of the present invention. Fig. 4 is a vertical sectional view showing an embodiment of the present invention for manufacturing the column members shown in Figs. 1 and 2 above, and Figs. 5 to 7 show how the column members and beam members shown in Figs. 1 to 3 are used. It is a front view. 10... Template sheet, 9... Inner formwork,
8...Outer formwork, 11...Concrete. Ice, illustration 2 illustrations, 3 illustrations, 5 illustrations, 6 illustrations, 7 illustrations.

Claims (1)

[Claims] 1. Wrap a mold release sheet with a synthetic resin film polymerized and bonded and a number of air sacs arranged in the middle around the outer surface of the inner formwork corresponding to the hollow part of the hollow concrete molded product to be manufactured, and A formwork is installed in the outer formwork, concrete is filled between the inner and outer formworks, and after the concrete hardens, the inner formwork and release sheet are taken out from the opening of the hollow part of the hollow concrete molded product. A method for manufacturing hollow concrete molded products characterized by: