JPH0655523A - Form for concrete product - Google Patents

Abstract

PURPOSE:To make the mold-releasing of a hollow concrete product possible especially just after steam curing by a method wherein the side frame of a form consists of a support main body and a releasing member made of material, which does not deform at the concrete curing temperature and can be collapsed under chemicals, heat, vibration and in their combination. CONSTITUTION:In the form for molding a square hollow body consisting of an outer frame 11 and an inner frame 23, the inner frame 23 consists of a support main body 25 and a releasing member 267. As the releasing member 27, foamed polystyrene, molding sand or the like is used. Concrete is placed in a tubular space 14, which is formed between the outer frame 11 and the inner frame 23, and, after being steam-cured, the outer frame 11 is separated. Next, when the releasing member 27 is made of foamed polystyrene plate, methylene chloride is used for collapsing and when the member 27 is made of molding sand, KOH water solution is used for collapsing. After that, mold releasing is carried out by lifting a concrete product. Further, the foamed polystyrene plate is preferably covered with heat-resistant and chemicals-resistant film excluding its upper end part. When the molding sand is used, filling up is preferably applied to the releasing surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formwork used when a hollow or solid concrete product is factory or field produced. In particular, the present invention is suitable for forming hollow concrete products. Here, the hollow body is a concept including a tubular body (square cylinder / round cylinder) and a box body, and the solid body includes a columnar body (square pillar / round pillar / pyramid, etc.), a stepped body, and a channel. It is a concept that includes variants such as shapes and tyco shapes.

[0002]

2. Description of the Related Art For example, when molding a large square tubular concrete product (box culvert), a mold as shown in FIGS.

The base 9 comprises an outer frame 11 and an inner frame 13 placed on the base 9. The outer frame 11 and the inner frame 13 are
It is vertically divided into a plurality of parts (the outer frame 11 is divided into two and the inner frame 13 is divided into three in the illustrated example), and both the outer frame 11 and the inner frame 13 are screwed (bolted) via the brackets 15 and 15. It is clamped. Further, the lower end portion of the inner frame 11 is also bolted or clamped to the base 9 like the outer frame 11.

Then, the base 9, the outer frame 11 and the inner frame 1
Concrete material is poured into the cylindrical space 14 formed in 3. Demolding is steam curing (60-80 ° C x 4-5 hours)
After that, stop heating and slowly cool, and after 24 hours,
It may be performed immediately after steam curing. This demolding work was performed by removing the bolts 17 and the clamps and lifting each divided body of the outer frame 11 and the inner frame 13 with a crane or the like.

[0005]

However, in the above case, when the mold is removed immediately after steam curing, the inside of the inner frame 13 is considerably high in temperature, and a person inserts it to remove the bolt until it cools down. The productivity of the demolding work was not good.

Further, in the case of the mold having the above-mentioned structure, there are many connecting bolts or clamps for both the outer frame 11 and the inner frame 13 at the time of demolding / assembling the mold, which requires a lot of man-hours.

In view of the above, it is an object of the present invention to provide a concrete product formwork capable of demolding a hollow concrete product after curing, immediately after completion of steam curing.

Another object of the present invention is to provide a concrete product formwork capable of reducing the number of demolding / formwork assembly steps.

[0009]

The formwork for concrete products according to the present invention solves the above problems by the following constitution.

In a mold used for producing a hollow or solid concrete product, at least the side mold comprises a support body and a mold release member forming a mold release surface. It is characterized in that it is not deformed at a temperature during concrete curing, and is made of a material which can be collapsed by any one of chemicals, heating, and vibration or a combination of them in combination after the concrete is cured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. However, the technical scope of the present invention is not limited to these, and covers various aspects within the scope of the claims. The same parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted in whole or in part.

A. The present embodiment shown in FIGS. 1 and 2 is similar to the conventional one shown in the related art (FIGS. 3 and 4) in the outer frame 11 and the inner frame 23.
In the rectangular hollow body forming mold consisting of and, the inner frame 23 has the following structure.

The inner frame (form) 23 comprises a support body 25 and a release member 27 forming a release surface. The release member 27 is formed of a material that does not deform at the temperature during curing of the concrete and that can be collapsed by any one of chemicals, heating, and vibration or a combination of them in combination after the completion of curing of the concrete. There is.

Here, examples of the releasing member include styrofoam and foundry sand.

(I) The method of forming styrofoam is as follows:
The release surface side using an adhesive that can peel off with the solvent described below,
That is, the styrofoam plate is attached to the outer peripheral surface of the inner frame 23. At this time, the styrofoam plate is preferably wrapped with a heat-resistant / chemical-resistant film (for example, a paper film in the case of methylene chloride as a chemical) that does not collapse by the disintegrating means, except for the upper end portion. By doing so, the expanded polystyrene can be easily removed from the mold and concrete after the collapse. The thickness of the styrofoam is
Although it depends on the size of the mold, it is 0.5 to 5 cm.

(Ii) The method for forming the casting sand is, for example, as follows:
Using 100 parts of silica sand to which 1 part of sodium silicate is added, the product is tamped and then blown with carbon dioxide gas to be hardened and formed. At this time, in order to smooth the finished surface of the concrete product, resin, impermeable paper, wax, or the like is applied to the release surface of the release member 35 (the surface in contact with the concrete) to stop it. Is desirable. The thickness of the foundry sand varies depending on the size of the mold, but is 1 to 10 cm.

B. The mode of use of the above embodiment is as follows.

Concrete is poured into the annular space of the mold having the above construction, and after steam curing or cooling, the mold is removed. For the outer frame 11, bolts are removed as in the conventional case. On the other hand, if the inner frame 23 appropriately collapses the release member 27 by the above-described collapsing means (medicine / heating / vibration), the concrete product can be craned without removing the support body 25 of the inner frame 23. The concrete product can be removed from the mold.

Here, if the drug as the disintegrating means can disintegrate (including dissolve) the release member,
There is no particular limitation, and any organic solvent, alkali, acid, etc. may be used.

[0020]

[Test Example] Next, a test conducted by the present inventors will be described.

Inside the experimental mold (inner diameter: 94 mmφ, height 100 mm) 31 formed on the base plate 29 shown in FIGS. 3 to 4, a mold releasing member (thickness: 10 mm, thickness: 1 cm of Styrofoam or molding sand) was used. ) 33 was formed according to the method described above. Then, the concrete of the formulation shown in Table 1 (about 700
Pour g) and fix it on the table type bi-plater 5
Vibration was applied for a second to perform compaction.

Then, cover the concrete part with a rubber,
A 2 kg iron weight is placed, steam curing is performed at 50-60 ° C for 4 hours, and 24 hours later, methylene chloride or 20% KOH is applied to each release member (styrofoam or casting sand).
The solution was sprinkled with water.

In the case of a polystyrene foam plate, 16 ml of methylene chloride was used to melt and disintegrate in 30 seconds. Also, in the case of casting sand, it was disintegrated in about 7 minutes using 120 g of KOH aqueous solution.

[0024]

In the concrete product formwork according to the present invention, the side formwork is composed of the support body and the mold release member forming the mold release surface, and the mold release member is set to the temperature during concrete curing. Does not deform, and after curing the concrete
The following operational effects can be obtained by the configuration formed of a material that can be disintegrated by any one of heating and vibration or a disintegrating means combining them.

Further, when the present invention is applied to the inner frame when molding a hollow concrete product, it is necessary for a person to enter the inner frame for removing the bolts or the like for the same reason as above when demolding. Absent. Therefore, the demolding of the hollow concrete product after curing can be performed immediately after the steam curing is completed.

Since the mold is divided into the support main body and the mold releasing member and the mold releasing member can be collapsed by chemicals or the like after the concrete is cured, it is not necessary to divide the mold frame into vertically divided parts. Therefore, a connecting means such as a bolt or a clamp for connecting the divided bodies is not required, and the man-hours for demolding / formwork assembling can be reduced.

[0027]

[Table 1]

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a concrete product formwork of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a cross-sectional view showing an experimental concrete product formwork used in the test.

FIG. 4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a sectional view showing an example of a conventional formwork for concrete products.

6 is a sectional view taken along line 6-6 of FIG.

[Explanation of symbols]

 11 Outer Frame 14 Cylindrical Space 13, 23 Inner Frame 25, 33 Support Main Body 27, 35 Release Member 31 Form 37 Concrete Product

Claims (1)

[Claims] 1. A mold used for producing a hollow or solid concrete product, wherein at least the side mold comprises a support body and a mold release member forming a mold release surface. The member does not deform at the temperature during concrete curing,
A concrete product formwork characterized by being formed of a material that can be disintegrated by any one of chemicals, heating, vibration, or a combination of them in combination after curing the concrete.