JPH09109129A - Perforated concrete product, method and apparatus for manufacturing the product and extracting form for its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the step when a concrete product is coupled by forming the product by using a main form and a perforating extracting form and forming the sectional shapes of all the positions of the formed holes the same. SOLUTION: The perforated concrete product C is formed by using a main form of integral shape as one entirety and extracting forms 2 of the number of holes H in the main form to be inserted, and the holes H of the product C all have the same sectional shape at all the positions. Accordingly, when many cables are inserted, there is no narrow or wide gap at the inner walls of the holes H, and even if the products C are coupled as a common groove, no step is formed between the products C and C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast perforated concrete product used for a common groove for burying a cable underground, a manufacturing method thereof, a manufacturing apparatus therefor, and a punching frame for manufacturing the same. is there.

[0002]

2. Description of the Related Art Conventionally, a perforated concrete product such as a concrete block for underground burying in which a hole for inserting an electric wire cable or the like is formed, a punching formwork is arranged in a main formwork. Concrete is placed by pouring fresh concrete into it, curing it after applying vibrations, etc., and then after curing, pulling out the above-mentioned punching form in the longitudinal direction of the cylinder and removing it from the main formwork. It was common to manufacture products.

However, in the above-mentioned punching mold, when the punching mold is pulled out after hardening of concrete, friction occurs between the surface of the punching mold and the concrete portion. Therefore, in order to reduce the friction between the punching mold and the concrete portion, it is necessary to form the tubular punching mold in a taper shape that tapers toward the tip. However, when the taper angle is increased, the diameter of the hole of the manufactured concrete product is largely different between the one end and the other end of the concrete product, and a step is formed at the joint when the holes are continuously arranged.
When a wire or the like is inserted through a concrete product that has a step at the seam in this way, the wire is caught at the seam, and if you try to force it through, it will damage the wire cable and cause poor conduction. there were.

Further, in the case where a plurality of punching molds are supported by a single supporting mechanism, if the horizontality or parallelism of some of the punching molds is slightly changed during curing of the concrete, the punching molds will be damaged. There is also a problem that it becomes very difficult to pull out, and if it is forcibly pulled out, the end surface of the concrete product is damaged and the product value is reduced.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is that the drawing mold can be easily drawn out. And to provide an ideal perforated concrete product in which the shape of the holes is the same in all cross sections, and in addition, to provide a concrete product with high strength and high toughness,
Another object of the present invention is to provide a manufacturing method and a manufacturing apparatus for manufacturing the concrete product, and a punching mold for manufacturing a perforated concrete product.

[0006]

A perforated concrete product according to a first aspect of the present invention is formed by using one main formwork and a punching formwork for forming a hole, and a total of the formed holes is formed. The cross-sectional shape at all positions is the same. In addition to the above-mentioned means, the perforated concrete product according to the invention of claim 2 has at least one hole having a circular cross section which penetrates from one side wall to the opposite side wall thereof, and the peripheral wall of the hole has a center line of the hole. And are formed parallel to each other in the length direction.

The perforated concrete product according to the third aspect of the present invention comprises, in addition to the above-mentioned means, a blast furnace slag fine powder and fibers as a concrete composition. The perforated concrete product according to the invention of claim 4 is
In addition to the means of claim 3, polyvinyl alcohol fiber is used as the fiber. In the method for manufacturing a perforated concrete product according to the fifth aspect of the present invention, when manufacturing a perforated concrete product, the outer shape of the perforated frame is reduced when the perforated frame is extracted from the concrete product.

In the method for producing a perforated concrete product according to a sixth aspect of the present invention, in the above-mentioned means, a punching mold is provided at a position where a hole for the concrete product is formed in a main formwork for producing the perforated concrete product. A frame is arranged so that the inside of the punching mold can be pressurized with a fluid, a plurality of through holes are formed in the peripheral wall of the punching mold, and the length of the punching mold is provided on the outer periphery of the punching mold. In the state where the elastic tube is arranged along the depth direction and concrete is placed in the main formwork, the outer space of the elastic tube is expanded by pressurizing the space inside the drawing formwork with a fluid, and when the drawing formwork is taken out. Reduce the outer diameter of the elastic tube.

In addition to the above-mentioned means, in the method for producing a perforated concrete product according to a seventh aspect of the present invention, the outer diameter of the elastic tube is reduced when the punching frame is withdrawn, and then increased, and at least this operation is performed. Is performed once or more. In the method for producing a perforated concrete product according to the invention described in claim 8, in the invention described in claim 6 or 7, the fluid is air.

According to a ninth aspect of the present invention, there is provided an apparatus for producing a perforated concrete product, which is arranged at a position for forming a main formwork for producing a perforated concrete product and a hole for the concrete product in the main formwork. A punching mold having a peripheral wall provided with a through hole for fluid circulation, a fluid supply device for adjusting the fluid pressure in the punching mold, and an outer periphery of the punching mold in the length direction of the punching mold. When the concrete is placed in the formwork, the outer diameter of the elastic tube is expanded by pressurizing the space inside the formwork with a fluid. Release pressurized fluid.

In addition to the above-mentioned means, the manufacturing apparatus for perforated concrete products according to the tenth aspect of the present invention discharges the pressurized fluid and puts it in a depressurized state when the punching frame is withdrawn. The punching mold for producing a perforated concrete product according to the invention of claim 11, wherein the punching mold is formed into a tubular shape,
The peripheral wall is provided with a through hole that communicates with the inside and outside of the cylinder, and a cylindrical elastic tube is arranged in an airtight state along the length direction of the extraction mold on the outer periphery of the cylindrical part, and the extraction mold is filled with fluid. Provide a supply port.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Regarding the Shape of Concrete Product C) As shown in FIG. 3, a perforated concrete product C according to the present invention includes one main formwork 1 as a whole shown in FIG.
Punching formwork 2 that is inserted into the main formwork 1 by the number of holes H ...
The holes H ... of the concrete product C formed by using the are the same in sectional shape at all positions.

That is, in the case of the embodiment shown in FIG. 3, four holes H ... With a circular cross section are formed to penetrate from one side wall 5 of the concrete product C to the opposite side wall 6, and the holes H ...
The inner peripheral wall 7 is formed so as to be parallel to the center line of the hole H in its length direction. A vertical fastening hole 10 is provided at the center of the concrete product C. Therefore, when a large number of cables are inserted, the inner wall of the hole H ... Does not have a narrow space, and as shown in FIG.
Even when C is connected as a common groove, there is no step between the concrete products C, so that the cable is not damaged. Further, as a matter of course, even when the cable is inserted into the communicating hole, it is easy because it does not hit the step.

(Composition of concrete product C) As a general basic composition of concrete products, cement, sand as fine aggregate, gravel as coarse aggregate, water, etc. are used. Gravel as coarse aggregate is not used, and a certain proportion of cement is replaced with fine powder of blast furnace slag. Fine powder itself of blast furnace slag for concrete is well known, and JIS standard (JIS A 6206-1995) is used as a mortar mixed material.
When a high-quality concrete product C is required, the fine powder of blast furnace slag is used in an amount of less than 50% (weight ratio) with respect to the cement, but the cement is used in consideration of cost, toughness, load-bearing stress, etc. 10% (weight ratio)
It may be the following, and may be appropriately set depending on the required physical properties, the proportion of other compositions, and the like.

By the way, the composition of the concrete product C of this embodiment should be accurately expressed as a mortar product because cement, sand, water, etc. are used as described above but gravel is not mixed. The meaning of the term concrete product is a term of a concept including a mortar product, and since the technical idea of the present invention is applicable not only to mortar products but to concrete products in general, it is expressed as a concrete product throughout the specification. To do.

The concrete product of this example further comprises a fiber, in particular a plastic fiber, as one of its compositions. As the fiber, polyvinyl alcohol (trade name: vinylon) fiber (hereinafter referred to as vinylon fiber) is suitable. Vinylon fiber was developed 50 years ago in Japan, and since then, it has been used in various fields and its applications have been developed. Recently, its excellent physical properties, adhesion to various matrices (matrix), chemical resistance, weather resistance, etc. have been evaluated, and it is mainly used in industrial and industrial fields such as cement reinforcement field (slate) as a substitute for asbestos. It has come to be widely used as an application.

The vinylon fiber, which is a fiber for substituting asbestos, generally has a diameter of several tens of μm, while in the present embodiment, what is mixed in the cement has a kneading property and dispersibility in concrete. 200-60 from the viewpoint of improvement
The diameter is preferably as thick as 0 μm. In order to reinforce concrete, the vinylon fibers to be kneaded in concrete are required to have not only a large diameter but also excellent durability. Cement is a strong basic substance and hardens in the presence of water. Cement products are building materials
Since it is used as earth and wood under natural conditions for many years, its reinforcing fiber is also strictly required to have long-term durability. The required performance varies depending on the characteristics of the cement, the usage of the cement product, etc., but the alkali resistance, rust resistance, and
UV resistance is required.

One of those that meets such requirements is Cratec (trade name: Kuraray Co., Ltd.). Various products are possible in the product group, but among them, RF350 (diameter 0.20 mm, standard length 12 m
m, specific gravity 1.3, tensile strength 90 kg / square mm, Young's modulus 2900 kg / square mm), RF4000
(Diameter 0.66 mm, standard length 30 mm, specific gravity 1.3, tensile strength 90 kg / square mm, Young's modulus 2900 kg / square mm) is also suitable. The vinylon fiber is mixed in an amount of about 0.5 to 1.0 percent (weight ratio) with respect to cement, with a limit of 2 percent (weight ratio) to cement.

In the above examples, the case of vinylon fiber was shown as the most suitable example, but it is known that concrete is reinforced with fiber, and glass fiber, steel fiber, carbon fiber, polypropylene fiber, ultra high strength polyethylene. Various fibers such as fiber and aramid fiber are possible,
Other materials may be selected in consideration of cost and the like. When the concrete product C of this embodiment is used as a joint groove, the connecting steel bar is used but no reinforcing material is required.

(Regarding Method for Producing Concrete Product C) Conventionally, such a method for producing a perforated concrete product C was possible by dividing the main formwork 1 into two or more, but one It could not be realized with only the main formwork 1. The manufacturing method according to the present invention has made this possible. In this manufacturing method, when the perforated concrete product C is manufactured, the punching frame 2 for forming the holes H ...
The feature is that the outer shape is reduced when it is extracted from.

That is, in the main formwork 1 for producing a perforated concrete product C as shown in FIG. 4, the width of the main formwork C is set at a position where the holes H ... of the concrete product C are formed. It is configured such that four slightly elongated drawing frames 2 ... Are arranged so as to be able to be drawn out, and the inside of the drawing frames 2 can be pressurized with a fluid, for example, air. As shown in FIGS. 1 and 5, a plurality of through holes 2a for air circulation are formed in the peripheral wall of the punching mold 2 ... Excellent durability along the length direction of the form 2,
Airtight elastic tubes 8 are arranged, and both ends of the elastic tubes 8 are fastened with belts so that air does not leak from between the outer circumference of the drawing frame 2 and the elastic tubes 8.

Then, in a state where concrete is poured into the main formwork 1, the inner space of the punching formwork 2 is pressurized with air so that the outer diameter of the elastic tube 8 is uniformly expanded while it remains a tubular body. In this state, fresh concrete kneaded with the above composition is poured, and after curing for about 1 day, air is released to reduce the outer diameter of the elastic tube 8 and promote separation of the inner wall of the hole and the elastic tube 8. . In this state, the punching molds 2 ... Are pulled out from the holes H ... of the cleat product C in the main mold 1.

In the above-mentioned structure, it is possible to reduce the outer diameter of the elastic tube 8 in a state where the punching mold 2 is pulled out, and to pull out the punching mold 2 as it is, but thereafter, the outer diameter of the elastic tube 8 is increased again. Further, by adopting a means for reducing the outer diameter and performing this operation at least once, the separation between the inner wall of the hole H and the elastic tube 8 is further promoted, and the removal of the punching mold 2 is facilitated.

In particular, in the above structure, by using air as the fluid, the operation of the manufacturing apparatus and fluid management can be further facilitated. The fluid may be water, oil, or the like, in addition to air, but when the concrete product C is manufactured, the fluid is repeatedly supplied and discharged, so that the fluid corrodes the extraction mold 2 and the elastic tube 8. Must not be a thing. Further, in order to stabilize the shape of the elastic tube 8 when pouring fresh concrete, the temperature of the fluid is adjusted (lowered), or in addition to this, the pressure is adjusted,
The phase may be once changed to a solid. For example, the fluid may be water and may be solidified as ice only when pouring concrete.

On the contrary, the elastic tube 8 is used without expanding means.
May be made of a foam material such as a styrene-based plastic having communicating foaming holes, and may be contracted only when the extraction frame 2 is extracted. As the contracting means in this case, it is desirable to suck air, and the foaming hole may be separately filled with a liquid, for example, water, and the water may be contracted by sucking the water only when the extraction frame 2 is extracted. In addition, in order to further facilitate the extraction of the punching mold 2, a separating agent may be applied to the outer circumference of the elastic tube 8 to facilitate the separation from the inner wall of the hole.

(Regarding Manufacturing Apparatus) Next, a manufacturing apparatus for the perforated concrete product C according to the present invention will be specifically described. The device of the present invention prepares the main formwork 1 for manufacturing the perforated concrete product C, as in the conventional device. In the case of the main formwork 1 of the embodiment shown in FIG.
This is the case where a book is provided. First, the structure itself of the main formwork 1 is the same as that of the prior art. From the side of the main formwork 1, the punching formwork 2 ... Is arranged at a position where the holes H ... of the concrete product C are formed.

The cutting mold 2 used in the above apparatus is shown in FIG.
Further, as shown in FIG. 5, each of them is formed into a cylindrical body having a constant thickness longer than the length of the main form 1, and a proper number of through holes 2a ... It should be noted that although a plurality of punching molds 2 ... May be individually inserted into the main molds 1 ..., all of the punching molds 1 ... It may be mounted on a plate (not shown) and the punching molds 2 ...

A cylindrical elastic tube 8 is arranged on the outer periphery of the cylindrical body of the punching mold 2 ... In the lengthwise direction of the cylindrical body, and both ends are tightened by tightening belts 9 and 9 so as to be mounted in an airtight state. To do. Further, the punching mold 2 is provided with an air supply port 3 on one side thereof, and a pressurized air supply device 4 capable of adjusting the air pressure for adjusting the air pressure in the punching mold 2 is connected to the supply port 3. To do. Although various configurations of the elastic tube 8 are conceivable, from the viewpoint of durability, wear resistance is taken into consideration and repeated expansion and contraction (expansion rate is the distance from the surface of the punching frame 2 to the surface of the elastic tube 8 (elasticity). Taking into consideration that the thickness (the thickness of the tube 8) is increased by about 1% due to expansion, the tube 8 is composed of four layers as shown in FIG. 6, for example.

That is, from the outer layer to the polyethylene cover layer 8
a, the cover rubber layer 8b, the reinforcing layer 8c, and the inner rubber layer 8
d. The polyethylene cover layer 8a is made of ultra-high molecular weight polyethylene, which is abrasion resistant, has a low coefficient of friction and is non-adhesive, and has excellent chemical resistance in consideration of friction and ease of slipping when sliding on concrete. To the outer surface. Cover rubber layer 8b and inner rubber layer 8
For d, natural rubber that is excellent in elongation and tensile strength and rich in airtightness is used. As the reinforcing layer 8c, a polyester cord which is often used in tires and hoses and has excellent durability is used.

The degree of expansion of the elastic tube 8 is appropriately selected depending on the shape and size of the perforated concrete product C, the material of the elastic tube 8 or the laminated structure thereof. In order to keep it in a stable state, it is not desirable to set it to 10% or more. In the above configuration, in the state where concrete is poured into the main formwork 1, the inner space of the punching formwork 2 is pressurized with air to evenly expand the outer diameter of the elastic tube 8, and
The pressurized fluid is discharged when the extraction frame 2 is in the extracted state.

As a modification of the above-described embodiment, the elastic tube 8 can be separated well by releasing the pressurized fluid in the extracted state of the extraction mold 2 and further reducing the pressure. Although the holes have a circular cross section in the above embodiments, they may have other shapes such as an elliptical cross section. Further, although the case where the number of holes is four has been described, the number of holes may be four or more or less. Further, the case of the method and apparatus for manufacturing a concrete product in which the holes have a uniform cross-section has been described, but the manufacturing method and apparatus can be applied even if the holes have a non-uniform cross-section.

[0032]

The present invention has the following effects due to the above configuration. 1. According to the invention described in claim 1 or 2, the concrete product is formed by using one main formwork and a punching formwork for forming holes, and the sectional shapes at all positions of the formed holes are Since the concrete products have the same surface, the holes of the concrete products have the same shape at all positions, so there is no step when connecting the concrete products. When is used as a common groove, it is easy to lay a fiber cable or the like, and the fiber cable or the like is not damaged at the corners of the holes.

2. According to the invention of claim 3, since the blast furnace slag fine powder and the fiber are contained as the concrete composition, in addition to the effect of the invention of claim 1 or 2, a perforated concrete product is obtained. It has the characteristics of high strength and high toughness, which allows the product to be made even thinner, expands the cross-sectional area of the hole, and allows more cables to be laid. Also, due to the characteristics of high strength and high toughness,
The damage caused by pulling out the punching form during manufacturing can be reduced.

3. According to the invention described in claim 4, by using polyvinyl alcohol fiber as the fiber, in addition to the effect of the invention described in claim 3, durability at low cost such as alkali resistance, rust resistance, and ultraviolet resistance is provided. It is possible to obtain a perforated concrete product having excellent properties.

4. According to the invention described in claim 5, when manufacturing the perforated concrete product, when the member for forming a hole is extracted from the concrete product, a means for reducing the outer shape thereof is adopted, and therefore, the extraction of the extraction form Facilitates the production of concrete products. In addition, since the inner wall of the hole is less likely to be damaged during extraction, a high-quality concrete product can be manufactured.

5. According to the invention as set forth in claim 6, in addition to the effect of the invention as set forth in claim 5, in the state where concrete is placed in the formwork, the space inside the punching formwork is pressurized with a fluid to remove the elastic tube outside. By expanding the diameter and adopting a means to reduce the outer diameter of the elastic tube when the drawing frame is pulled out, simply by putting in and out the fluid,
Since it is easy to put in and take out the punching frame, the perforated concrete product can be efficiently manufactured even though the manufacturing apparatus itself has a simple structure.

6. According to the invention described in claim 7, in addition to the effect of the invention described in claim 6, the outer diameter of the elastic tube is reduced in the state in which the punching frame is taken out, and then increased, and at least this operation is performed. By adopting the means for performing the operation once or more, the work of extracting the punching form after the curing of the concrete is further facilitated.

7. According to the invention of claim 8, in addition to the effect of the invention of claim 6 or 7,
By using air as the fluid, there is no need to prepare a special pressurized fluid, and fluid management is easy and safety is high. 8. According to the invention as set forth in claim 9, in a state where concrete is placed in the main formwork, the space inside the drawing formwork is pressurized with a fluid to increase the outer diameter of the elastic tube, and at the same time the drawing formwork is pulled out. Then, by discharging the pressurized fluid, it is possible to obtain a perforated concrete product having holes of uniform cross section with a simple structure.

9. According to the invention described in claim 10, in addition to the effect that the invention described in claim 9 has, the pressurized fluid is discharged to bring the pressure into a depressurized state in the extraction state of the extraction mold, thereby further reducing Easy to pull out. 10. According to the invention of claim 11, the punching form is formed in a tubular shape, the peripheral wall is provided with a through hole communicating with the inside and outside of the cylinder, and the outer periphery of the tubular part is provided along the length direction of the punching form. By arranging the cylindrical elastic tube in an airtight state and providing the fluid supply port in the punching mold, it contributes to the realization of a perforated concrete product having a uniform cross-section.

[Brief description of the drawings]

FIG. 1 is a perspective view of a partial cross section according to an embodiment of the present invention.

FIG. 2 is a front view showing a connected state of concrete products C according to an embodiment of the present invention.

FIG. 3 is a perspective view of a concrete product C according to an embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view of a main formwork according to an embodiment of the present invention.

FIG. 5 is a front view of a partial cross section of a punching mold according to an embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of an elastic tube according to an embodiment of the present invention.

[Explanation of symbols]

 C ... Perforated concrete product H ... Hole 1 ... Main formwork 2 ... Punching formwork 2a ... Through hole 3 ... Fluid (air) supply port 4 ... Fluid ( Air supply device 5 ... One side wall 6 ... Opposite side wall 7 ... Inner peripheral wall 8 ... Elastic tube 8a ... Polyethylene cover 8b ... Cover rubber 8c ... Reinforcing layer 8d ... Inner rubber 9 ... Tightening belt 10 ... Vertical tightening hole

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[Procedure amendment]

[Submission date] August 20, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is that the drawing mold can be easily drawn out. and the shape of the hole provides an ideal perforated concrete products that the same in every section, to provide high toughness of the concrete product with high strength, in addition,
Another object of the present invention is to provide a manufacturing method and a manufacturing apparatus for manufacturing the concrete product, and a punching mold for manufacturing a perforated concrete product.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

Then, in a state where concrete is poured into the main formwork 1, the inner space of the punching formwork 2 is pressurized with air so that the outer diameter of the elastic tube 8 is uniformly expanded while it remains a tubular body. In this state, fresh concrete kneaded with the above composition is poured, and after curing for about 1 day, air is released to reduce the outer diameter of the elastic tube 8 and promote the separation of the inner wall of the hole and the elastic tube 8. . In this state, the U-primary mold 1
Pull out the punching mold 2 ... from inside the hole H ... of the product N.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

The cutting mold 2 used in the above apparatus is shown in FIG.
Further, as shown in FIG. 5, each of them is formed into a cylindrical body having a constant thickness longer than the length of the main form 1, and a proper number of through holes 2a ... Although a plurality of punching molds 2 ... May be individually inserted into the main molds 1 ..., all of the punching molds 2 ... It may be mounted on a plate (not shown) and the punching molds 2 ...

Claims (11)

[Claims] 1. A perforated concrete product which is formed by using one main formwork and a punching formwork for forming holes, and has the same sectional shape at all positions of the formed holes. 2. At least one hole having a circular cross section that penetrates from one side wall to the opposite side wall is formed, and the peripheral wall of the hole is parallel to the center line of the hole in its length direction. The perforated concrete product according to 1. 3. The perforated concrete product according to claim 1, wherein the concrete composition contains fine powder of blast furnace slag and fibers. 4. The perforated concrete product according to claim 3, wherein polyvinyl alcohol fibers are used as the fibers. 5. When manufacturing a perforated concrete product,
A method for producing a perforated concrete product, which comprises reducing the outer shape of a punching mold for forming a hole from a concrete product. 6. A main formwork for producing a perforated concrete product, wherein a punching formwork is arranged at a position where a hole of the concrete product is formed, and the inside of the punching formwork can be pressurized with a fluid. At the same time, a plurality of through holes are formed in the peripheral wall of the punching mold, elastic tubes are arranged along the length of the punching mold on the outer periphery of the punching mold, and concrete is poured into the main mold. In the state, the inner space of the punching mold is pressurized with a fluid, and the outer diameter of the elastic tube is enlarged by the pressurized fluid through the through hole, and the outer diameter of the elastic tube is reduced when the punching frame is pulled out. The method for producing a perforated concrete product according to claim 5. 7. The method for producing a perforated concrete product according to claim 6, wherein the outer diameter of the elastic tube is made smaller and then made larger in a state where the die is pulled out, and this operation is performed at least once. . 8. The method for manufacturing a perforated concrete product according to claim 6, wherein the fluid is air. 9. A main formwork for producing a perforated concrete product, and a die formwork which is arranged at a position for forming a hole in the concrete product of the main formwork and has through holes for fluid circulation formed in a peripheral wall. ,
A fluid supply device that adjustably supplies the fluid pressure in the punching mold, and an elastic tube arranged along the length direction of the punching mold on the outer periphery of the punching mold, and concrete is placed in the mold. An apparatus for manufacturing a perforated concrete product characterized by pressurizing the inner space of the punching mold with a fluid to expand the outer diameter of the elastic tube in the pouring state and discharging the pressurized fluid when the punching mold is pulled out. . 10. An apparatus for producing a perforated concrete product according to claim 9, wherein the pressurized fluid is discharged and the fluid is depressurized when the punching mold is withdrawn. 11. A cylindrical elastic tube is formed by forming a punching mold into a tubular shape, forming a through hole in the peripheral wall so as to communicate with the inside and outside of the cylinder, and having a tubular shape along the lengthwise direction of the punching mold on the outer circumference of the tubular part. Is a hermetically-sealed state, and the punching formwork is provided with a fluid supply port. A punching formwork for producing a perforated concrete product.