JP2003225904A - Method for manufacturing concrete product having hollow part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a concrete product having a hollow part capable of reducing costs of a form for manufacturing and saving labors without using a high-priced core member in which an enlarging/ contracting mechanism for forming the hollow part of the concrete product having the hollow part such as a culvert block and the like is provided. <P>SOLUTION: A resin pipe is used as a core member and installed in a form. Concrete is cast therein to be compacted and cured with steam. A product is taken out from a steam curing tank, the manufacturing form is opened and the concrete product is released from the form while the resin pipe is being installed as it is. A temperature of the concrete product is lowered near to ordinary temperature, the resin pipe of which the diameter is shrunk is pulled out and used again as the core member. Thus, the method for manufacturing the concrete product having the hollow part is constituted. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a concrete product having a hollow part such as an underdrain block, a beam, a floor slab block, and a retaining wall block, which is required as a core member for forming a hollow part in a concrete product manufacturing formwork. Attach a shaped resin pipe at a predetermined position, put concrete into it and compact it, then steam-cure at a predetermined temperature for a predetermined time in the steam curing tank, and after a predetermined time, place the concrete product manufacturing form in the steam curing tank. From the mold, the concrete product is removed from the mold while the core member is still attached, and the temperature of the resin pipe drops naturally due to the temperature of the concrete product dropping to near room temperature, or the temperature of the resin pipe that is forcedly cooled by cooling or air cooling. From the hollow part of the concrete block when the resin pipe shrinks to the specified size from A method for.

The present invention also relates to a method for producing a concrete product having a hollow portion, in which the resin pipe used as the core member is used again as the core member.

[0003]

2. Description of the Related Art A conventional method for manufacturing a concrete product having a hollow portion (as an example, an underdrain block) will be described with reference to FIG. A general-purpose form frame KT for manufacturing an underdrain block has front and rear end plates (not shown) pivotally attached to the front and rear of the base 1 and side plates 2 on the left and right. When placing the underdrain block, a wire net is mounted on the base to left and right. Close the side plate 2 and the front and rear wife plates,
A core member N having a peripheral edge capable of expanding and contracting, such as a steel plate having a rotating screw and an expanding / contracting device E provided by a link mechanism, is inserted into the front and rear end plates through a core insertion hole, and the core member N is expanded and widened after insertion. After the concrete is put in and compacted, it is carried into a steam curing tank and cured at a predetermined temperature for a predetermined time, and then taken out of the steam curing tank to carry out the manufacturing mold KT, and the expansion / contraction device E of the core member N is moved. The core member N is extracted from the manufacturing mold KT by operating to reduce the diameter, and the front and rear end plates of the manufacturing mold KT and the left and right side plates 2 are opened to remove the underdrain block from the mold. In the manufacturing method according to this aspect, since the hollow portion H serving as the flowing water channel is formed, the manufacturing form K has a mechanism in which the expansion device E and the like are installed.
Since T is expensive and the core member N, which weighs several hundred kg each time it is driven and demolded, is attached and detached, work efficiency is poor, and the core member N such as a steel plate is repeatedly widened and reduced in diameter every time it is attached and detached. It had many shortcomings such as a short life and a hindrance to production at every repair.

Further, since it is difficult to uniformly reduce the total length of the underdrain block when the core member N has a length of 2 m or more, a product such as a U-shaped groove with a length of 4 m, which is partially used, is used. Could not be made. The Applicant investigated, but the telescopic device E
There was no method for producing a concrete product having a hollow portion by the core member N that does not require the above and can be easily extracted.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention was devised in view of the above circumstances. To eliminate the drawbacks of the prior art, a trial production experiment was repeated to solve the problems of the present invention. Using a resin pipe for the core member of the frame, the core member that molds the hollow part has a predetermined size during driving,
Provided is a method for producing a concrete product having a hollow portion, the diameter of which is smaller than the dimension of the hollow portion when the mold is removed so that the core member can be easily removed.

[0006]

In the present invention created to solve the above-mentioned problems, as a result of a trial experiment, preferably polyethylene, polypropylene or the like is preferably used as a material of the resin pipe as appropriate. Then, in the method for producing a concrete product having a hollow part such as an underdrain block, a beam, a floor slab block, a retaining wall block, the first step is a concrete product having a hollow part such as an underdrain block, a beam, a floor slab block, a retaining wall block. In the manufacturing form, a resin pipe having a predetermined shape is attached as a core member forming a hollow portion having a predetermined shape at a predetermined position to close the concrete product manufacturing form. In the second step, concrete is added. The third step of compaction is steam curing at a predetermined temperature in the steam curing tank for a predetermined time, and the fourth step is a concrete product manufacturing mold after a predetermined time. Open concrete products manufacturing formwork removed from steam curing tank, demolded concrete products while the resin pipe is mounted a core member, a fifth
In the process, the resin pipe is cooled by naturally cooling the temperature of the concrete product to near normal temperature, or the resin pipe is forcibly cooled by water cooling or air cooling, and the resin pipe whose diameter has been reduced due to temperature drop is molded into a predetermined shape dimension. The method for producing a concrete product having a hollow portion is characterized in that the concrete product is removed from the hollow portion and used again as a core member.

Further, according to claim 2 of the present invention created to solve the above problems, when a resin pipe to be a core member is attached to a mold for producing concrete products, the end of the resin pipe is placed inside or A method for producing a concrete product having a hollow portion according to claim 1, wherein the method is constrained and supported from the outer side or the inner side and the outer side.

Further, in claim 3 of the present invention created to solve the above problems, in the first step, the entire length of the resin pipe is restrained at a predetermined position of the manufacturing mold without sealing both ends thereof. The method for producing a concrete product having a hollow portion according to claim 1 or 2, wherein the concrete product is attached.

Further, in claim 4 of the present invention created to solve the above-mentioned problems, an unused or used resin pipe is carried into a steam curing tank for a predetermined time, cured at a high temperature, and then taken out to a temperature close to room temperature. The hollow portion according to any one of claims 1 to 3, which is used in the first step according to claim 1 after the temperature is lowered to reduce the diameter of the resin pipe to a predetermined dimension. Configure a method for manufacturing a concrete product.

Further, in claim 5 of the present invention created to solve the above-mentioned problems, the unused or used resin pipe is steamed for a predetermined time by restraining the entire length or the entire length and a part or the entire outer peripheral surface. The method of claim 1, wherein the resin pipe is used in the first step after being brought into a curing tank, cured at high temperature, taken out, and then cooled to near room temperature to reduce the diameter of the resin pipe to a predetermined size. A method for manufacturing a concrete product having a hollow portion according to any one of 1 to 3 is constituted.

Further, in claim 6 of the present invention created to solve the above problems, the total length of the resin pipe used as the core member is an arbitrary length within 0.1 m to 5 m.
A method for manufacturing a concrete product having a hollow portion according to any one of claims 1 to 5 is characterized.

Further, in claim 7 of the present invention created to solve the above-mentioned problems, the resin pipe used again as the core member loses the resilience of contraction and expansion after several orders of use (within the tolerance range). If it deviates significantly, it cannot be removed from the demolded concrete product) and when the surface of the resin pipe is damaged (aesthetics of the inner surface of the waterway are damaged and the roughness coefficient increases), and a newly manufactured resin pipe is collected. A method for producing a concrete product having a hollow portion according to any one of claims 1 to 6, wherein the concrete product is regenerated as a part of a raw material and reused.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment] FIG. 1 is an explanatory view showing the outline of first to third steps of an embodiment according to claim 1 of the present invention, and FIG. It is explanatory drawing which shows the outline of the 4th, 5th process of the Example which concerns. An embodiment of the present invention will be described below with reference to both drawings.

FIG. 1 is an explanatory view showing the outline of the first to third steps of the embodiment according to claim 1 of the present invention. FIG. 1 (a) shows an example of a concrete product having a hollow portion. FIG. 3 is a diagram showing a first step of a method for manufacturing an underdrain block, in which a required shape is obtained as a core member for inserting a required reinforcing bar M into a form K for manufacturing an underdrain block B (the right side plate 30 is omitted) to form a flowing water channel. The resin pipe 20 of the front and rear gable plate 4 of the manufacturing form K
0, 40 (has the function of scooping the upper inner surface of the end portion of the resin pipe 20 into a predetermined position on the inner surfaces of the front and rear girder plates described later with reference to FIG. 3), when closing the resin pipe 20, the inner surface of the end portion or the outer surface or the end portion Hold it from the inner surface and the outer surface, and as shown in the lower view of the arrow cl, the left and right side plates 30 and the front and rear end plates 40
Close. The resin pipe 20 may be put in the reinforcing bar M in advance and inserted into the manufacturing form K at the same time.

FIG. 1 (b) is a view showing the second step, in which concrete C is put into the manufacturing form K and the manufacturing form K is vibrated or V is added to the manufacturing form K to compact the concrete C. (C) of the lower diagram is a diagram showing the third step, in which the manufacturing mold K, which has been compacted, is heated to a predetermined temperature (40 ° C).
It is conveyed into the steam curing tank SR (in the range of up to 65 ° C) and steam cured for a predetermined time (5 to 7 hours).

FIG. 2 is an explanatory view showing the outline of the fourth and fifth steps of the embodiment according to claim 1 of the present invention, and FIG. 2 (d) is a view showing the fourth step, which is manufactured after a predetermined time. The mold K for use is carried out from the steam curing tank SR, the front and rear gable plates 40, 40 and the left and right side plates 30, 30 of the manufacturing form K are opened as shown in the lower diagram, and the underdrain block B with the resin pipe 20 still attached. Demold.

FIG. 2 (e) is a view showing a fifth step, in which the underdrain block B is naturally cooled to near room temperature to cool the resin pipe, or the resin pipe is forcibly cooled by water cooling or air cooling to obtain a predetermined shape. Since a void portion is formed between the inner surface of the hollow portion H formed to have a dimension and the resin pipe 20 having a reduced diameter, the manufacturing method is configured so that the end portion of the resin pipe 20 can be gripped and easily removed from the hollow portion H.

In the manufacturing method described above, the expensive core member of the prior art is not required, the cost of the manufacturing mold is reduced, and the maintenance of the core member of the manufacturing frame is also unnecessary. Unlike this, the removal of the resin pipe is light in weight, so the work is easy and the production efficiency is improved, and the cost of the underdrain block can be reduced by the repeated use of the resin pipe.

FIG. 3 shows the method of supporting the ends of the resin pipe 20 provided on the inner surfaces of the front and rear girder plates 40, 40 in the embodiment according to claims 2 and 3, and the resin pipe inserted into the manufacturing form K. 20 is guided by a support member 44 having an inclined surface so that the inner surface of the end is scooped up by closing the front and rear end plates 40, 40, or from the outer surface of the end of the resin pipe in addition to the support from the inner surface of the end. Also, the ring-shaped support member 46 restrains and supports it, and at the same time, the joint member is formed in the hollow portion H inlet by the support member 46 so that the hollow portion H of the underdrain block B can be molded at a predetermined position with an allowable size.

Further, the opening 42 shown in FIG.
In the first step, the openings 42 are bored in the front and rear girder plates 40, 40 to open both ends of the resin pipe 20 without hermetically closing the resin pipe 20 due to a temperature rise during steam curing. It is possible to avoid an increase in internal pressure due to air expansion applied and to maintain a predetermined hollow portion molding size by restraining the entire length of the manufacturing mold at a predetermined position.

FIG. 4 shows an embodiment according to claim 4, and FIG.
After the unused or after-use resin pipe 20 of (a) is supported at multiple points in the longitudinal direction to prevent bending of the resin pipe and is carried into the steam curing tank SR at a predetermined temperature for a predetermined time and subjected to high temperature curing. As shown in FIG. 1 (b), the resin pipe 20 having the temperature reduced to near room temperature in the state shown in FIG. A method of manufacturing a concrete product having a hollow portion, which is inserted into a mold K together with a wire mesh M and used in the first step described in claim 1, is constituted. Note that FIG. 4A and FIG.
It is also possible to carry out high temperature curing in a warm water tank instead of the steam curing tank as indicated by the one-dot chain line in (b).

FIG. 5 shows an embodiment according to claim 5, in which the unused or used resin pipe 20 is unrestrained,
In both cases, as shown in FIG. 5, the plate-like restraint member 50 or the restraint band 55 provided with the openings 52 is restrained, and in either case, the diameter of the molded concrete block decreases due to the temperature drop to near room temperature. Although it was able to be removed from the hollow part, the total shrinkage of the resin pipe shrank by about 5 mm when unrestrained, whereas it can be shrunk by about 13 mm when constrained as shown in FIG. Therefore, the resin pipe can be removed more easily by restraining the resin pipe.

In claim 6 (not shown), the total length of the resin pipe 20 used as the core member is an arbitrary length within 0.1 m to 5 m, and it is difficult to manufacture the core member with the conventional core member. A method of manufacturing a concrete product having a hollow portion, which makes it possible to easily manufacture an underdrain block B that requires a core having a length of 2 m or more, such as 4 m or 5 m, is configured.

In the embodiment according to claim 7 (not shown), the resin pipe 20 used as the core member again is damaged by steaming after several times of use and the surface is damaged at the time of removal, and the restoring property of contraction and expansion is lost, and steam curing is performed. A hollow part that is recovered when it is expected that it will be difficult to remove the resin pipe 20 at the time of the next casting, such as when the difference in shrinkage between the former and the former is small, and that the resin pipe 20 is regenerated as a part of a newly manufactured resin pipe raw material and reused. A method of manufacturing a concrete product having

FIG. 6 shows various concrete products which can be manufactured according to the present invention, wherein (a) to (f) show concrete product having a hollow portion, that is, an embodiment of an underdrain block, and a symbol H is a running water channel or another. Hollow part for the purpose,
The side groove with the slit SG shown in (b), the underdrain block with the grating shown in (d), etc. can be easily manufactured by attaching a mold corresponding to the bottom surface of the manufacturing mold and applying a resin pipe. , (G) to (j), a concrete product having a hollow portion H2 can be produced without departing from the present invention. The product (j) is a bottomed block manufactured by cantilever supporting a resin pipe whose upper part is closed at the bottom of the manufacturing mold.

[0026]

When the present invention according to claim 1 is applied, the core member having the expansion device E for forming the hollow portion H therein and the like is not required, and the manufacturing cost of the manufacturing form and the work are reduced. The labor and time are halved, and the production is not hindered by the repair of the core member, and the working efficiency is improved and the product price is reduced.

Further, according to the present invention as set forth in claims 2 to 5, the resin pipe as the core member stores a shrinkage difference due to a temperature difference between a high temperature and a falling temperature, and is hollow formed by casting. There is an economic effect that it can be used many times because it shrinks so that it can be easily removed from the size of the part.

Further, the product of the underdrain block having a length of 4 m can be manufactured, and there is an effect that the production efficiency can be improved and the laying work can be saved.

Further, the resin pipe used as the core member again is recovered at the time when the resilience of shrinkage and expansion is lost after several times of use and the surface of the resin pipe is damaged, and the resin pipe raw material newly manufactured. There is also an effect that it can be recycled as a part of.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of first to third steps of an embodiment according to claim 1 of the present invention.

FIG. 2 is an explanatory view showing the outline of fourth and fifth steps of the embodiment according to claim 1 of the present invention.

FIG. 3 is an explanatory view showing an outline of an embodiment according to claims 2 and 3 of the present invention.

FIG. 4 is an explanatory view showing an outline of an embodiment according to claim 4 of the present invention.

FIG. 5 is an explanatory view showing an outline of an embodiment according to claim 5 of the present invention.

FIG. 6 is a schematic view of various concrete products that can be produced by the present invention.

FIG. 7 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

B- Underdrain block C- Concrete H- Hollow part of the underdrain block (flow channel) K- Formwork for underdrain block N- Prior art core member M- Wire mesh V- Compaction device SR for vibration or forward / backward movement -Steam curing tank 20-Resin pipe 30-Left and right side plates 40 of the formwork for producing the underdrain block-Front and rear gable plates 42 of the formwork for producing the underdrain block-Opening 44 of the front and rear gable plates-Bearing members 46 provided on the inner surface of the front and rear gable plates A ring-shaped member that supports the outer peripheral surface of the resin pipe provided on the inner surface of the end plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Miyai             Gunma Prefecture Maebashi City Jotomachi 5-14-3 (72) Inventor Takashi Iwasa             22 Amakawaramachi, Maebashi City, Gunma Prefecture F term (reference) 4G053 AA07 BE04 CA10 CA21 EA03                       EA13 EB03 EB06                 4G055 AA01 AC08 BA04 CB01                 4G058 AA01 AC07 AF02 AF05 AF06                       FA20 FA53

Claims (7)

[Claims] 1. A method for producing a concrete product having a hollow part such as an underdrain block, a beam, a floor slab block, and a retaining wall block, wherein the first step is to form the hollow part such as an underdrain block, a beam, a floor slab block, a retaining wall block. The concrete product manufacturing formwork has a resin pipe having a predetermined shape and size as a core member that forms a hollow part having a predetermined shape and size, and the concrete product manufacturing formwork is closed. The second step is concrete. The third step is steam curing at a predetermined temperature in the steam curing tank for a predetermined time. The fourth step is to remove the concrete product manufacturing formwork from the steam curing tank after a predetermined time. Open the concrete product manufacturing form and remove the concrete product with the resin pipe that is the core member still attached. The fifth step is to keep the temperature of the concrete product near room temperature. To cool the resin pipe by natural cooling, or forcibly cool the resin pipe by water cooling, air cooling, etc., and pull out the resin pipe whose diameter has been reduced due to the temperature drop from the hollow part molded to the specified shape and re-core. A method for producing a concrete product having a hollow portion, which is used as a member. 2. When mounting a resin pipe as a core member to a concrete product manufacturing formwork, the end portion of the resin pipe is supported by being restrained from the inside or the outside or the inside and the outside. A method for producing a concrete product having a hollow portion according to claim 1. 3. The method according to claim 1, wherein, in the first step, the resin pipe is attached to a predetermined position of the manufacturing form frame while the both ends of the resin pipe are not closed and are closed. A method for producing a concrete product having a hollow portion according to item 1. 4. Unused or used resin pipes are carried into a steam curing tank for a predetermined time, cured at high temperature, and then taken out.
The hollow according to any one of claims 1 to 3, which is used in the first step according to claim 1 after the temperature of the resin pipe is reduced to near room temperature to reduce the diameter of the resin pipe to a predetermined size. Method for producing a concrete product having parts. 5. The unused or used resin pipe is carried into the steam curing tank for a predetermined time while restraining the entire length or the entire length and a part or the whole of the outer peripheral surface, is aged at a high temperature, is taken out, and the temperature is lowered to around room temperature. The concrete product having a hollow portion according to any one of claims 1 to 3, which is used in the first step according to claim 1 after the diameter of the resin pipe is reduced to a predetermined size. Manufacturing method. 6. The hollow part according to claim 1, wherein the total length of the resin pipe used as the core member is an arbitrary length within 0.1 m to 5 m. A method for manufacturing a concrete product having the following. 7. The resin pipe material used as the core member again is recovered at the time when the resilience of shrinkage and expansion is lost after several uses and when the surface of the resin pipe is damaged, and the resin pipe raw material is newly manufactured. The method for producing a concrete product having a hollow portion according to any one of claims 1 to 6, wherein the concrete product having a hollow portion is reclaimed and reused.