JP7269769B2 - air tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air tube, and more particularly to an air tube used for forming a concrete placing space and closing gaps in the concrete placing space.

At construction sites, a precast concrete construction method, in which factory-manufactured concrete members are assembled on-site, is sometimes adopted. When joining precast concrete members such as precast concrete columns and precast concrete beams, a wooden formwork is used between adjacent precast concrete members to create a space for placing concrete (hereinafter, sometimes abbreviated as “placement space”). ) is formed, and concrete is placed in the formed casting space.

However, it takes a lot of time and effort to install and dismantle the wooden formwork. In addition, it is not easy to form a casting space using a wooden form in a high place, and depending on the surrounding conditions, it may be difficult to form a casting space using a wooden form.

Therefore, a technology has been developed and put into practical use that uses an air tube instead of a wooden formwork to form a placement space. The air tube has a cylindrical tube body that can be filled with compressed air. One longitudinal end (upper end) of the tube body is provided with an intake/exhaust port, and the other longitudinal end (lower end) of the tube body is closed. When the tube main body is filled with compressed air supplied from an air compressor or the like through the intake/exhaust port, the tube main body is inflated by the pressure of the filled compressed air. By preparing a plurality of such air tubes and arranging them so as to surround the space in which concrete is to be placed, a wall (air fence) dividing the space for placing concrete is formed. It is formed.

JP-A-2000-38839

Concrete placement space may be formed only by air tubes, may be formed by a combination of air tubes and formwork, or may be formed by a combination of air tubes and a part of the concrete structure. There is also Air tubes may also be used to close gaps in the placement space. For example, a gap in the placement space formed between two precast concrete beams may be blocked by an air tube. Specifically, when joining two precast concrete beams, joints may be provided at the joints of the two precast concrete beams. More specifically, a part of the inner surface of the casting space provided between two precast concrete beams is formed by the mutually facing ends of the precast concrete beams, and the remaining part of the inner surface of the casting space is and the bottom is formed by a formwork. In such cases, there is a gap between the ends of the two opposing precast concrete beams to provide a joint. That is, a gap is generated in the placement space. Therefore, in order to block such a gap, an air tube is arranged in the gap. In this case, the bottom of the air tube placed in the gap abuts on the surface of the mold forming the bottom of the placing space.

However, the bottom portion 41 of the conventional air tube 40 has a hemispherical shape as shown in FIG. 10(a) or a chevron shape as shown in FIG. 10(b). That is, the bottom outer surface (bottom surface 42) of the air tube 40 facing the mold surface 50 forming the bottom surface of the placing space is not flat. For this reason, a gap is generated between the bottom surface 42 of the air tube 40 and the bottom surface (form surface 50) of the placing space, and concrete, water, etc. leak through this gap.

Here, the problem of the conventional air tube has been described by taking as an example the case of closing the gap in the placement space formed between two precast concrete beams. However, leakage of concrete, etc. due to the gap between the bottom surface of the air tube and the surface of the formwork or other members is limited to the case of closing the gap in the placement space formed between the two precast concrete beams. It's not a problem that arises.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air tube that can reliably prevent leakage of concrete or the like from a concrete placing space.

One of the air tubes of the present invention is an air tube that forms a concrete placing space or closes a gap in the concrete placing space. The air tube has an elongated tube body having a first end face, a second end face located on the opposite side of the first end face, and an intake/exhaust port, and filled with compressed air. The intake/exhaust port is provided at or near the first end surface of the tube body. Further, the second end face of the tube body includes a curved portion protruding toward the inside of the tube body and a flat portion surrounding the curved portion.

Another air tube of the present invention is an air tube that forms a concrete placing space or closes a gap in a concrete placing space. The air tube has an elongated tube body having a first end face, a second end face located on the opposite side of the first end face, and an intake/exhaust port, and filled with compressed air. The intake/exhaust port is provided at or near the first end face of the tube body, and at least a portion of the second end face of the tube body is flat. The part of the tube main body whose distance from the second end face of the tube main body is within a predetermined range is such that the distance from the second end face is reduced when the inside of the tube main body is filled with compressed air. It expands more than other portions of the tube body that exceed the predetermined range.

According to one aspect of the present invention, the second end surface of the tube body includes a curved portion protruding toward the inside of the tube body and a flat portion surrounding the curved portion.

According to another aspect of the present invention, the part of the tube body whose distance from the second end face is within the predetermined range is the tube body whose distance from the second end face exceeds the predetermined range. It is made of a material that is more stretchable than the other portion of the above.

According to another aspect of the present invention, a restraining member is provided on the outer peripheral surface of the tube body to restrict expansion of the tube body. The restraint member includes the part of the tube body whose distance from the second end face is within the predetermined range and the other part of the tube body whose distance from the second end face exceeds the predetermined range. , is placed on the boundary of

According to the present invention, an air tube that can reliably prevent leakage of concrete or the like from a concrete placing space is realized.

1 is a front view of an air tube according to a first embodiment; FIG. (a) is a cross-sectional view schematically showing the lower end of the tube body before being filled with compressed air, and (b) is a cross-sectional view schematically showing the lower end of the tube body after being filled with compressed air. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing an example of a concrete placing space and a gap in the placing space, where (a) is a schematic view of the placing space as seen from above, and (b) is a schematic view of the placing space as seen from the front. is. It is process drawing which shows an example of the concrete placing method using the air tube which concerns on 1st Embodiment. FIG. 4 is an explanatory diagram showing an actual inflated state of the lower end of the tube body; It is a front view of the air tube which concerns on 2nd Embodiment. FIG. 4 is an explanatory view showing the lower end of the tube body after being filled with compressed air; FIG. 11 is a front view of an air tube according to a third embodiment; FIG. 4 is an explanatory view showing the lower end of the tube body after being filled with compressed air; (a) is an explanatory diagram showing an example of the bottom portion of a conventional air tube, and (b) is an explanatory diagram showing another example of the conventional air tube bottom portion.

(First embodiment)
An example of an air tube to which the present invention is applied will be described in detail below with reference to the drawings. Incidentally, the air tube to which the present invention is applied is used for forming a concrete placing space or closing a gap in the concrete placing space. Here, an example of an air tube to which the present invention is applied will be described, taking as an example a case where it is used for closing a gap in a concrete placing space.

As shown in FIG. 1, an air tube 1A according to this embodiment has an elongated tube main body 10 filled with compressed air. The tube body 10 is cylindrical as a whole and has a first end face 11 , a second end face 12 and an intake/exhaust port 13 . The first end face 11 is an end face on one longitudinal end side of the tube body 10 , and the second end face 12 is an end face on the other longitudinal end side of the tube body 10 . In other words, the second end surface 12 is an end surface located on the opposite side of the first end surface 11 in the longitudinal direction of the tube body 10 . In this specification, the side on which the first end surface 11 is located is defined as the "upper side" of the air tube 1A or the tube main body 10, and the side on which the second end surface 12 is located is the air tube 1A or the tube main body 10. Define "lower". Therefore, in the following description, the first end surface 11 may be referred to as the "upper surface 11" of the tube body 10, and the second end surface 12 may be referred to as the "bottom surface 12" of the tube body 10.

There is no particular limit to the length of tube body 10 . However, considering the use of forming a concrete placing space or closing a gap in the concrete placing space, the length of the tube body 10 is preferably about 500 mm to 5000 mm, more preferably about 1500 mm. Similarly, the outer diameter of the tube body 10 is not particularly limited, but considering the above applications, the outer diameter of the tube body 10 is preferably about 10 mm to 100 mm, more preferably about 20 mm to 30 mm.

As shown in FIG. 1 , the intake/exhaust port 13 is provided on the upper surface 11 of the tube body 10 or in the vicinity of the upper surface 11 . Specifically, an opening (not shown) provided in the upper surface 11 of the tube body 10 and the valve unit 20 inserted into the opening constitute the intake/exhaust port 13 . The valve unit 20 communicates with the inside and outside of the tube body 10 through the upper surface 11 of the tube body 10 . A plug 20a to which a socket (not shown) can be connected is provided on the upper portion of the valve unit 20 protruding upward from the upper surface 11 of the tube body 10 . The plug 20a is connected to a socket attached to the end of a pressure-resistant hose extending from a compressed air supply source such as an air compressor. In addition, the valve unit 20 has a built-in check valve, and when compressed air having a predetermined pressure or more is supplied through a pressure-resistant hose, the check valve is opened by the pressure of the compressed air, and Compressed air flows in. That is, the inside of the tube main body 10 is filled with compressed air. A check valve built in the valve unit 20 can be opened by a predetermined operation. Therefore, when the socket is removed from the plug 20a and the check valve is opened, the compressed air filled in the tube main body 10 is discharged.

As can be understood from the partially enlarged cross-sectional view shown in the lower right part of the paper surface of FIG. and a portion 12b. The flat portion 12b in this embodiment is formed in an annular shape surrounding the entire circumference of the curved portion 12a. In other words, the curved portion 12a that is the central portion of the bottom surface 12 is curved, and the flat portion 12b that is the peripheral portion of the bottom surface 12 is flat.

2A and 2B are schematic cross-sectional views of the lower end portion of the tube body 10. FIG. When the internal pressure of the tube body 10 reaches or exceeds a predetermined pressure, the lower end of the tube body 10 including the bottom surface 12 changes (expands) from the state shown in FIG. 2(a) to the state shown in FIG. 2(b). However, FIG. 2B schematically shows the expanded state of the lower end of the tube body 10 when the expansion of the tube body 10 is not regulated at all.

When the air tube 1A is used to close the gap in the concrete placing space, the air tube 1A (tube body 10) is arranged (inserted) in the gap in the placing space. Then, when the tube main body 10 arranged in the gap of the placing space is filled with compressed air, the expansion of the tube main body 10 is restricted by the inner surface of the gap. That is, the actual tube body 10 cannot expand freely, and at least the lower end of the tube body 10 does not expand to exactly the same state as shown in FIG. 2(b).

Therefore, by explaining an example of the concrete placing method using the air tube 1A according to the present embodiment, the actual expanded state of the air tube 1A (tube body 10) arranged in the gap of the concrete placing space will be clarified. to

Please refer to FIG. A gap 100 shown in FIGS. 3(a) and 3(b) is a gap in a placement space S provided between two precast concrete beams 101 and 102. FIG. The placement space S is formed by a combination of a part of the precast concrete beams 101 and 102 and a formwork. More specifically, as shown in FIG. 3A, the inner surfaces s1 and s2 of the placing space S are formed by the end surfaces of one precast concrete beam 101, and the inner surface of the placing space S s3 is formed by the end surface of the other precast concrete beam 102; In addition, the inner surface s4 of the placing space S is formed by the surface of the mold 104. As shown in FIG. As shown in FIG. 3(b), the bottom surface s5 of the placing space S is formed by the surface of another mold 105. As shown in FIG.

As shown in FIG. 4, the concrete placing method in this embodiment includes at least a gap closing step (Step 1) and a concrete filling step (Step 2). Furthermore, the gap closing step (Step 1) includes at least a preparation step (Step 1-1), an installation step (Step 1-2), and an air filling step (Step 1-3).

In the preparation step (Step 1-1), the air tube 1A shown in FIG. 1 described above is prepared. That is, the top surface 11 as a first end surface and the bottom surface as a second end surface including a curved portion 12a located on the opposite side of the top surface 11 and protruding inward and an annular flat portion 12b surrounding the curved portion 12a. 12 and an air tube 1A is prepared.

In the installation step (Step 1-2) shown in FIG. 4, the prepared air tube 1A is arranged in the gap 100 of the placing space S shown in FIGS. 3(a) and 3(b). At this time, as shown in FIG. 5, the lower end of the tube body 10 is inserted into the bottom of the gap 100, and the bottom surface 12 of the tube body 10 is brought into contact with the surface of the mold 105 (the bottom surface s5 of the placing space S). . More specifically, the flat portion 12b, which is part of the bottom surface 12 of the tube body 10, is brought into contact with the surface of the mold 105 (the bottom surface s5 of the placing space S).

When the tube body 10 is placed in the gap 100 as described above, most of the tube body 10 including the lower end is sandwiched between the opposing inner surfaces 100a and 100b of the gap 100. As shown in FIG. It is clear from FIG. 3(a) that the inner surfaces 100a and 100b of the gap 100 are part of the end surfaces of the precast concrete beams 101 and 102. FIG. Also, it is clear from FIG.

In the air filling step (Step 1-3) shown in FIG. 4, the air tube 1A (tube body 10) is filled with compressed air through the intake/exhaust port 13 (FIG. 1) to inflate the tube body 10. As shown in FIG. When the tube body 10 is filled with compressed air, the inner surfaces 100a and 100b of the gap 100 restrict radial expansion of the lower end portion of the tube body 10 shown in FIG. As a result, the outer peripheral surface of the lower end of the tube body 10 does not protrude as shown in FIG. 100b. Also, the bottom surface 12 (flat portion 12b) of the tube body 10 is in close contact with the bottom surface of the gap 100 (the surface of the mold 105). It goes without saying that the portions of the tube body 10 other than the lower end portion are also in close contact with the inner surfaces 100a and 100b of the gap 100. As shown in FIG.

As described above, by executing the gap closing step (Step 1) shown in FIG. 4, the gap 100 in the placing space S shown in FIGS. completely occlude. Here, since the bottom surface of the air tube 1A (the bottom surface 12 of the tube body 10) includes the flat portion 12b, no gap is formed between the bottom surface of the air tube 1A and the bottom surface of the gap 100.

After that, the concrete filling step (Step 2) shown in FIG. 4 is executed. That is, concrete is filled in the placement space S (FIG. 3) in which the gap 100 is blocked by the air tube 1A. At this time, since the gap 100 of the placing space S shown in FIG. 3 is completely blocked by the air tube 1A, concrete, water, etc. leak from the gap 100 (especially the lower part of the gap 100). never do.

After that, the air tube 1A and the molds 104 and 105 are removed after a necessary curing period has elapsed. When removing the air tube 1A, the check valve of the valve unit 20 (FIG. 1) is operated to release the compressed air from the tube main body 10. FIG.

Incidentally, in the installation step (Step 1-2) shown in FIG. 4, the tube main body 10 may be slightly filled with compressed air before the air tube 1A is arranged in the gap 100. FIG. Thereby, the shape of the tube main body 10 is maintained, and the tube main body 10 can be easily inserted into the gap 100 .

As described above, even when a plurality of air tubes 1A are arranged to form an air fence that partitions the placement space, leakage of concrete, water, etc. from the lower ends of the respective air tubes 1A and the vicinity thereof is prevented. should be understood. That is, the flat portion 12b included in the bottom surface 12 of each air tube 1A forming the air fence is brought into close contact with the surface of the formwork and other members forming the bottom surface of the placing space. At the same time, the lower ends of the adjacent air tubes 1A are brought into close contact with each other.

Examples of materials for the tube body 10 include strong woven fabric such as canvas, synthetic resin such as polyvinyl chloride, natural resin, and rubber. Moreover, the surface of the tube body 10 can be coated as necessary. For example, the inner surface of the tube body 10 may be coated for the purpose of improving durability and airtightness, and the outer surface of the tube body 10 may be coated for the purpose of improving durability and preventing sticking of concrete. can be done. However, the same coating may be applied to the inner and outer surfaces of the tube body 10 .

(Second embodiment)
Another example of an air tube to which the present invention is applied will be described in detail below with reference to the drawings. The air tube according to this embodiment has the same basic structure as the air tube 1A (FIG. 1) according to the first embodiment, and is used for the same applications as the air tube 1A according to the first embodiment. Therefore, only differences from the air tube 1A according to the first embodiment will be described, and duplicate descriptions will be omitted as appropriate. Moreover, the same reference numerals are used for the same or substantially the same configuration as the configuration already described.

As shown in FIG. 6, the tube main body 10 of the air tube 1B according to this embodiment is made of at least two kinds of materials with different stretchability. Specifically, a portion of the tube body 10 whose distance from the bottom surface 12 is within a predetermined range is made of a material that is more elastic than other portions of the tube body 10 whose distance from the bottom surface 12 exceeds the predetermined range. formed. Here, the distance from the bottom surface 12 is the linear distance from the bottom surface 12 along the axis of the tube body 10 . Further, the bottom surface 12 of the tube main body 10 in this embodiment is entirely flat.

However, the bottom surface 12 of the tube body 10 may be at least partially flat, and it is not essential that the entire surface be flat. For example, the bottom surface 12 of the tube body 10 in this embodiment has curved portions and flat portions that are the same as or substantially the same as the curved portions 12a and flat portions 12b provided on the bottom surface 12 of the tube body 10 in the first embodiment. may be provided.

The predetermined range in this embodiment is 100 mm. That is, the portion of the tube body 10 within 100 mm from the bottom surface 12 is made of a material that is more stretchable than the other portions that are more than 100 mm from the bottom surface 12 . In the following description, the portion within 100 mm distance from the bottom surface 12 is called "lower end portion 10a", and the other portion over 100 mm distance from bottom surface 12 is called "main portion 10b". Here, the total length of the tube main body 10 in this embodiment is 1500 mm. In other words, the lower end portion 10a of the tube body 10 is made of a material that is more elastic than the majority of the tube body 10 (main portion 10b) excluding the lower end portion 10a.

As shown in FIG. 7, the lower end portion 10a of the tube body 10, which is made of a material that is more elastic than the main portion 10b, is stretched more than the main portion 10b when the tube main body 10 is filled with compressed air. inflate greatly. However, FIG. 7 schematically shows the inflated state of the lower end portion 10a of the tube main body 10 when the expansion of the tube main body 10 is not regulated at all, as in FIG. 2(b).

When the air tube 1B (tube main body 10) actually arranged in the gap of the concrete placing space is filled with compressed air, the lower end portion 10a of the tube main body 10 is displaced due to the reasons already explained mainly with reference to FIG. The outer peripheral surface of the is in close contact with the opposing inner surface of the gap. Also, the flat bottom surface 12 of the tube body 10 remains in close contact with the bottom surface of the gap (for example, the surface of the mold) before and after filling with compressed air. Therefore, if the air tube 1B according to the present embodiment is used to close the gap in the placement space or form an air fence that partitions the placement space, the concrete from the lower end portion of the air tube 1B or the vicinity thereof Leakage of water, etc. is reliably prevented.

Incidentally, the predetermined range can be changed arbitrarily. In other words, the length of the lower end portion 10a, which is made of a material that is more elastic than the other portions, can be set to a desired length. However, the length of the lower end portion 10a is preferably about 50 mm to 200 mm.

(Third Embodiment)
Another example of an air tube to which the present invention is applied will be described in detail below with reference to the drawings. The air tube according to this embodiment has the same basic structure as the air tube 1A (FIG. 1) according to the first embodiment, and is used for the same applications as the air tube 1A according to the first embodiment. Therefore, only differences from the air tube 1A according to the first embodiment will be described, and duplicate descriptions will be omitted as appropriate. Moreover, the same reference numerals are used for the same or substantially the same configuration as the configuration already described.

As shown in FIG. 8, on the outer peripheral surface of the tube body 10 of the air tube 1C according to this embodiment, a restraining member 30 is provided to restrict the expansion of the tube body 10. As shown in FIG. The restraining member 30 is provided at the boundary between a portion of the tube body 10 whose distance from the bottom surface 12 is within a predetermined range and another portion of the tube body 10 whose distance from the bottom surface 12 exceeds the predetermined range. there is The illustrated restraining member 30 is a wire wound on the outer peripheral surface of the tube body 10 along the circumferential direction of the tube body 10 and mainly restricts the expansion of the tube body 10 in the radial direction. The bottom surface 12 of the tube body 10 is entirely flat.

However, the bottom surface 12 of the tube body 10 may be at least partially flat, and it is not essential that the entire surface be flat. For example, the bottom surface 12 of the tube body 10 in this embodiment has curved portions and flat portions that are the same as or substantially the same as the curved portions 12a and flat portions 12b provided on the bottom surface 12 of the tube body 10 in the first embodiment. may be provided.

The predetermined range in this embodiment is 50 mm. That is, the restraining member 30 is wound on the outer peripheral surface of the tube body 10 at a distance of 50 mm from the bottom surface 12 . In the following description, the portion of the tube body 10 below the wire 30 will be referred to as the "lower end portion 10a", and the other portion of the tube body 10 above the wire 30 will be referred to as the "main portion 10b". Here, the total length of the tube main body 10 in this embodiment is 1500 mm. That is, the length of the lower end portion 10a is 50 mm, and the length of the main portion 10b is 1450 mm.

As shown in FIG. 9, when tube body 10 is filled with compressed air, expansion of tube body 10 is restricted at the boundary between lower end portion 10a and main portion 10b. As a result, the lower end portion 10a, which has a smaller volume than the main portion 10b, expands more than the main portion 10b. However, FIG. 9 schematically shows the expanded state of the lower end portion 10a of the tube main body 10 when the expansion of the tube main body 10 is not restricted at all, as in FIG. 2(b).

When the air tube 1C (tube main body 10) actually arranged in the gap of the concrete placing space is filled with compressed air, the lower end portion 10a of the tube main body 10 is displaced due to the reason already explained mainly with reference to FIG. The outer peripheral surface of the is in close contact with the opposing inner surface of the gap. Also, the flat bottom surface 12 of the tube body 10 remains in close contact with the bottom surface of the gap (for example, the surface of the mold) before and after filling with compressed air. Therefore, if the air tube 1C according to the present embodiment is used to block the gap in the placement space or form an air fence that partitions the placement space, the concrete from the lower end portion of the air tube 1C or the vicinity thereof Leakage of water, etc. is reliably prevented.

Incidentally, the predetermined range can be changed arbitrarily. That is, the length of the lower end portion 10a, which expands relatively greatly when compressed air is filled, can be set to a desired length. However, the length of the lower end portion 10a is preferably about 50 mm to 200 mm. Also, the restraint member 30 is not limited to a wire, and may be, for example, a string, a ring made of synthetic resin, or a metal. Furthermore, a plurality of restraining members 30 may be spaced apart along the length of the tube body 10 . In this case, the predetermined range is the distance between the bottom surface 12 and the restraining member 30 farthest from the bottom surface 12 .

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

1A, 1B, 1C, 40 air tube 10 tube main body 10a lower end portion 10b main portion 11 first end surface (upper surface)
12 Second end face (bottom face)
12a curved portion 12b flat portion 13 intake/exhaust port 20 valve unit 20a plug 30 restraint member (wire)
41 Bottom 42 Bottom 50 Formwork surface 100 Gap 100a, 100b (Gap) Inner surfaces 101, 102 Precast concrete beams 104, 105 Formwork S Placement space s1, s2, s3 (Placement space) Inner surface s5 (Placement space ) bottom of

Claims (5)

An air tube that forms a concrete placing space or closes a gap in the concrete placing space,
having an elongated tube body having a first end face, a second end face located on the opposite side of the first end face, and an intake/exhaust port, the inside of which is filled with compressed air;
The intake/exhaust port is provided at or near the first end face of the tube body,
the second end surface of the tube body includes a curved portion protruding toward the inside of the tube body and a flat portion surrounding the curved portion ;
The second end surface including the curved portion and the flat portion is integrally molded with the tube body,
air tube. An air tube that closes a gap in a concrete placing space,
having an elongated tube body having a first end face, a second end face located on the opposite side of the first end face, and an intake/exhaust port, the inside of which is filled with compressed air;
The intake/exhaust port is provided at or near the first end face of the tube body,
At least part of the second end face of the tube body is flat,
The lower end portion of the tube body, the distance from the second end face of which is within the predetermined range, is such that when the inside of the tube body is filled with compressed air, the distance from the second end face is the predetermined range. expands more than the main portion of the tube body exceeding the range,
The lower end portion of the tube body and at least part of the main portion are arranged inside the gap of the concrete placing space.
air tube. In the air tube according to claim 2,
The second end face of the tube body includes a curved portion protruding toward the inside of the tube body and a flat portion surrounding the curved portion.
air tube. In the air tube according to claim 2 or 3,
The lower end portion of the tube body is made of a material that is more stretchable than the main portion of the tube body,
air tube. In the air tube according to claim 2 or 3,
a restraining member provided on the outer peripheral surface of the tube body for restricting expansion of the tube body;
The restraining member is arranged at a boundary between the lower end portion of the tube body and the main portion of the tube body,
air tube.

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