Resin pipe and manufacturing method of resin pipe

Abstract

To provide a resin pipe in which multiple split resin pipes are connected.SOLUTION: A resin pipe has multiple split resin pipes arranged along its length, and a sheet that covers the outer surfaces of the split resin pipes at the connection parts between adjacent split resin pipes along the length and connects the adjacent split resin pipes along the length.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a resin pipe and a method for manufacturing a resin pipe. [Background technology]

[0002] Patent document 1 discloses a protective structure for a tensioned cable, characterized in that at least a part of a protective tube containing the cable at the fixed portion and / or deflection portion of the tensioned cable is provided with a protective spacer consisting of a cylindrical body containing the cable or a solid body circumscribing the cable, which moves following the cable or reduces frictional resistance when the cable moves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-269023 Summary of the Invention [Problem to be solved by the invention]

[0004] Concrete structures have the characteristic of being weak against tensile forces. Therefore, a tension rod is used to apply a compressive force to the concrete structure in advance, thereby controlling the tensile stress when the concrete structure is subjected to a load. Prestressed concrete, which introduces tension using tension rods, is used in bridges and other structures.

[0005] A tendon is usually installed in an insertion hole of a concrete structure via a plastic pipe (see Patent Document 1, etc.). Therefore, when installing a tendon in a concrete structure, a plastic pipe is first installed in the insertion hole of the concrete structure, and then the tendon is installed in the plastic pipe.

[0006] However, tendons are often installed in large structures such as bridges, and the plastic pipes in which the tendons are placed may also be long in length. In addition, there are cases where a sufficient working area cannot be secured around the end of the insertion hole into which the plastic pipe is inserted, and problems such as reduced workability occur when the plastic pipe is long in length. In addition, when the plastic pipe is long in length, it becomes difficult to transport the plastic pipe to the construction site.

[0007] For this reason, there has been a demand for a plastic pipe that can be manufactured by connecting multiple split plastic pipes at the construction site.

[0008] In view of the above, an object of the present disclosure is to provide a resin pipe in which a plurality of split resin pipes are connected. [Means for solving the problem]

[0009] The resin pipe of the present disclosure includes a plurality of divided resin pipes arranged along a longitudinal direction thereof, At the connection between the split resin pipes adjacent along the length, a sheet is provided which covers the outer surfaces of the split resin pipes and connects the split resin pipes adjacent along the length. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a resin pipe in which a plurality of split resin pipes are connected. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a bridge taken along a plane passing through tendons. [Diagram 2] FIG. 2 is an enlarged view of area A in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line CC in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along a plane passing through the central axis of the resin pipe when the resin pipe is placed in the insertion hole. [Figure 5A] FIG. 5A is an explanatory diagram of one configuration example of a procedure for placing a resin tube in an insertion hole. [Figure 5B]FIG. 5B is an explanatory diagram of one configuration example of a procedure for placing a resin tube in an insertion hole. [Figure 6] FIG. 6 is a cross-sectional view of the resin pipe taken along line DD in FIG. [Figure 7] FIG. 7 is a flow chart of a method for producing a resin pipe according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The embodiments for carrying out the invention are described below.

[0013] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description thereof will not be repeated.

[0014] (1) A resin pipe according to one aspect of the present disclosure includes a plurality of divided resin pipes arranged along a longitudinal direction thereof; At the connection between the split resin pipes adjacent along the length, a sheet is provided which covers the outer surfaces of the split resin pipes and connects the split resin pipes adjacent along the length.

[0015] According to the resin pipe according to one aspect of the present disclosure, a configuration in which a plurality of split resin pipes are connected together can be achieved.

[0016] By configuring the resin pipe to have a plurality of split resin pipes, the longitudinal length of each split resin pipe can be shortened, making it easier to transport them to the construction site.

[0017] Furthermore, by configuring the plastic pipe to have multiple split plastic pipes, even if the working area near the end of the insertion hole where the plastic pipe is to be installed is narrow, the split plastic pipes can be installed within the working area. Then, the split plastic pipes can be inserted into the insertion hole through the working area and adjacent split plastic pipes can be connected along the length to install the plastic pipe in the insertion hole.

[0018] By connecting adjacent split plastic pipes along their length with a sheet, it is possible to easily connect adjacent split plastic pipes along their length without requiring special or large equipment when connecting the split plastic pipes.

[0019] In addition, since the sheet can be shaped to match the outer shape of the split resin pipes, adjacent split resin pipes can be easily connected along their length near the connection portion regardless of the shape of the split resin pipes, even if the split resin pipes have a shape other than a straight pipe, such as a tapered shape. Therefore, the shape along the length of the resin pipe according to one embodiment of the present disclosure is not particularly limited, and the resin pipe can include a curved portion such as a tapered shape.

[0020] (2) In (1), an adhesive may be disposed between the outer surface of the split resin pipe and the sheet.

[0021] The resin pipe has an adhesive disposed between the outer surface of the split resin pipe and the sheet, thereby increasing the bonding strength between the sheet and the split resin pipe, and therefore also increasing the bonding strength between adjacent split resin pipes along the length that are connected by the sheet.

[0022] (3) In (1) or (2), the outer surface of the plastic pipe may include a curved portion in a cross section passing through a central axis of the plastic pipe.

[0023] In the conventional method for joining resin pipes, it was sometimes difficult to join split resin pipes at or near the portion where the outer surface includes a curve in the cross section passing through the central axis of the resin pipe. However, according to the resin pipe according to one aspect of the present disclosure, by using a sheet, split resin pipes can be connected regardless of the outer shape of the resin pipe, and a resin pipe of any shape can be made. Therefore, since the outer surface of the resin pipe includes a curved portion in the cross section passing through the central axis of the resin pipe, a high effect can be achieved compared to the conventional technology.

[0024] (4) In any one of (1) to (3), the plastic pipe may be a pipe that houses a tendon.

[0025] Tendons are often installed in large structures such as bridges, and the plastic pipes in which the tendons are placed may also be long in length. In addition, there are cases where a sufficient working area cannot be secured around the end of the insertion hole into which the plastic pipe is inserted, and problems such as reduced workability occur when the plastic pipe is long in length. In addition, when the plastic pipe is long in length, it becomes difficult to transport the plastic pipe to the construction site.

[0026] Since the resin pipe according to one embodiment of the present disclosure has multiple split resin pipes, even if the overall length of the resin pipe is long, the length of each split resin pipe can be short. Furthermore, the split resin pipes can be easily connected by a sheet regardless of the shape of the split resin pipes.

[0027] Therefore, by using the plastic pipe according to one embodiment of the present disclosure as a pipe to house the tensioning material, the plastic pipe can be transported more easily than in the case of using a conventional plastic pipe that cannot be divided, and workability can be improved when installing the plastic pipe into the insertion hole.

[0028] (5) A method for manufacturing a resin pipe according to one aspect of the present disclosure includes a step of installing a plurality of split resin pipes along a longitudinal direction of the split resin pipes, The method includes a connecting step of installing a sheet to cover the outer surfaces of the split resin pipes at the connections between the split resin pipes adjacent along the length, and connecting the split resin pipes adjacent along the length.

[0029] According to the method for manufacturing a plastic pipe according to an embodiment of the present disclosure, since the plastic pipe has a plurality of split plastic pipes, the length of each split plastic pipe along the longitudinal direction can be shortened, and the split plastic pipes can be easily transported to the construction site. In addition, even if the working area near the end of the insertion hole in which the plastic pipe is to be installed is narrow, the split plastic pipes can be installed within the working area. Then, the split plastic pipes can be inserted into the insertion hole through the working area, and adjacent split plastic pipes can be connected along the longitudinal direction to manufacture the plastic pipe within the insertion hole.

[0030] According to the method for manufacturing a resin pipe according to one aspect of the present disclosure, adjacent split resin pipes can be connected along the length by a sheet, so that adjacent split resin pipes along the length can be easily connected without requiring a special device or a large device for connecting the split resin pipes.

[0031] Furthermore, since the sheet can be processed into a shape that matches the outer shape of the split resin pipe, even if the split resin pipe has a shape other than a straight pipe, such as a tapered shape, adjacent split resin pipes can be easily connected along their length near the connection portion regardless of the shape. Thus, according to the method for manufacturing a resin pipe according to one aspect of the present disclosure, the shape along the length is not particularly limited, and a resin pipe including a curved portion such as a tapered shape can be manufactured.

[0032] (6) In (5), in the installing step, the split resin pipes may be installed in insertion holes provided in a concrete structure of a bridge.

[0033] In many cases, a sufficient working area cannot be secured near the end of an insertion hole provided in a concrete structure of a bridge, which has traditionally made it difficult to place a plastic pipe in the insertion hole provided in the concrete structure of a bridge.

[0034] In contrast, according to a method for manufacturing a plastic pipe according to one aspect of the present disclosure, the plastic pipe can be easily installed in the insertion hole regardless of the size of the working area at the end of the insertion hole.

[0035] [Details of the embodiment of the present disclosure] A specific example of a resin pipe and a method for manufacturing a resin pipe according to an embodiment of the present disclosure (hereinafter referred to as the present embodiment) will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0036] In this specification, there are cases where the names of components are described with '1', '2', etc. added to them, such as 'first end', 'second end', 'first metal pipe end', and 'second metal pipe end'. '1', '2', etc. are written merely to distinguish between the components and to prevent confusion during description, and do not represent placement, priority, etc. For this reason, when there is no particular risk of confusion, they can be simply written as 'end', 'metal pipe end', etc. [Resin pipe] An example of the configuration of the resin pipe of this embodiment will be described.

[0037] First, a cable structure, which is an application example of the resin pipe of this embodiment, will be described with reference to Figs. 1, 2 and 3. Figs. (1) Cable structure FIG. 1 is a cross-sectional view of a bridge 10 including a plastic pipe according to this embodiment, taken along a plane passing through a tendon 11. As shown in FIG.

[0038] Fig. 2 shows an enlarged view of region A in Fig. 1. In the following description, the cable structure including the resin pipe of this embodiment will be described using region A, but other concrete structures 12 in region B and the like can have the same structure.

[0039] FIG. 3 shows a cross-sectional view taken along line CC in FIG.

[0040] 1, 2, and 3, the X-axis is the axis along the bridge axis, and is the axis along the length of the bridge 10. The Y-axis is the axis perpendicular to the bridge axis, and is the axis along the width of the bridge 10. The Z-axis is the axis along the height.

[0041] The cable structure 20 shown in Figures 2 and 3 has a structure in which the tendons 11 are inserted and fixed via resin pipes 23 into insertion holes 21 provided in concrete structures such as cross beams, bulkheads, and column capitals of a prestressed concrete bridge, which is the bridge 10 (see Figure 1). For this reason, the cable structure 20 can also be referred to as a cable anchoring structure or the like.

[0042] In the cable structure 20, the tendons 11 may be entirely disposed within the concrete structure except for their ends. The cable structure 20 may also have an external cable structure in which at least a portion of the tendons 11 is disposed outside the concrete structure.

[0043] In the bridge 10 shown in Fig. 1, the tendons 11 are arranged along the bridge axis. However, the tendons 11 can be arranged according to the direction of the compressive force applied to the concrete structure, and are not limited to this form.

[0044] As shown in FIG. 1, the tendon 11 passes through a deflection section 13 provided, for example, in a lower deck slab 15, and both ends are inserted into insertion holes provided in a cross beam, which is a concrete structure 12, and can be fixed with fasteners.

[0045] In the bridge 10 shown in FIG. 1, the tendons 11 can be disposed in a space 16 located between an upper deck 14 and a lower deck 15, that is, inside the bridge 10.

[0046] In FIG. 1, the bridge piers 17 and other parts are partially omitted.

[0047] A cable structure 20 including a plastic pipe 23 of this embodiment shown in Figures 2 and 3 has a metal pipe 22 arranged in an insertion hole 21 of a concrete structure 12 such as a cross beam of a bridge 10, a plastic pipe 23 arranged in the metal pipe 22, and a tension member 11 arranged in the plastic pipe 23.

[0048] Each member of the cable structure 20 will be described below. (Insertion hole) The insertion hole 21 is provided in the concrete structure 12. In Fig. 2, the insertion hole 21 is arranged along the X-axis which is the bridge axis, but is not limited to such a form. The insertion hole 21 can be arranged according to the tendon 11 to be arranged in the insertion hole 21.

[0049] The insertion hole 21 is a through hole provided in the concrete structure 12, and is a hole into which the tendon 11 and the resin pipe 23 are inserted.

[0050] The insertion hole 21 is a through hole provided in the concrete structure 12, and has a first end 21A that corresponds to an opening exposed from the concrete structure 12, and a second end 21B.

[0051] The shape of the insertion hole 21 is not particularly limited, and may be, for example, bent at one or more points along the longitudinal direction. The cross-sectional shape of the insertion hole 21 in a plane perpendicular to the longitudinal direction is also not particularly limited, and may be, for example, circular. The circular shape includes a perfect circle and an ellipse. The cross-sectional shape of the insertion hole 21 in a plane perpendicular to the longitudinal direction does not need to be constant, and the shape and size may differ depending on the position along the longitudinal direction of the insertion hole 21. (metal tube) The metal pipe 22 is a pipe provided to protect the insertion hole 21, which is a through hole provided in the concrete structure 12, and is provided along the inner surface 211 (see FIG. 3) of the insertion hole 21. The inner surface 211 of the insertion hole 21 and the outer surface 221 of the metal pipe 22 can be configured to be in direct contact with each other.

[0052] The metal pipe 22 is a pipe made of metal, and the material is not particularly limited, but may be made of steel, for example, in consideration of costs, etc. Therefore, the metal pipe 22 may be, for example, a steel pipe. The surface of the metal pipe 22 may be plated, painted with resin, or the like.

[0053] The inner diameter D22 (see FIG. 3) of the metal tube 22 is not particularly limited, but may be, for example, 80 mm or more and 200 mm or less. The inner diameter D22 of the metal tube 22 can be evaluated at any cross section perpendicular to the longitudinal direction of the metal tube 22, and when the cross section is elliptical, the inner diameter D22 of the metal tube 22 can be the average value of the lengths of the major axis and the minor axis.

[0054] The insertion hole 21 and the metal pipe 22 may have the same length, but the metal pipe 22 may be exposed from the insertion hole 21 at the second end 21B of the insertion hole 21. In other words, the metal pipe 22 may be longer than the insertion hole 21 at the second end 21B of the insertion hole 21, and the second metal pipe end 22B of the metal pipe 22 may protrude from the concrete structure 12.

[0055] The metal tube 22 has two ends along its length, a first metal tube end 22A and a second metal tube end 22B, and the fixing device 24 of the tension member 11 is provided at the first metal tube end 22A via a support member 25. The support member 25 and the first metal tube end 22A are not limited to a direct contact as shown in FIG. 2, and other members may be disposed between the support member 25 and the first metal tube end 22A. FIG. 2 shows only one configuration example of the cable structure 20, and therefore the connection between the support member 25 and the metal tube 22 and between the other members is not limited to the connection shown in FIG. 2, and any other members may be disposed as necessary. The second metal tube end 22B is the end of the metal tube 22 that is located opposite to the end where the fixing device 24 of the tension member 11 is disposed. (Resin pipe) The plastic pipe 23 is a pipe that can be arranged on the outer periphery of the tendon 11 in order to protect the tendon 11 when the tendon 11 is inserted into the insertion hole 21. By arranging the plastic pipe 23 between the insertion hole 21 and the outer periphery of the tendon 11, the tendon 11 can be easily removed from the insertion hole 21, and the tendon 11 can be easily replaced. The outer diameter D23 (see FIG. 3) of the plastic pipe 23 may be smaller than the inner diameter D22 of the metal pipe 22, and is not particularly limited, but can be, for example, 70 mm or more and 180 mm or less. The outer diameter D23 of the plastic pipe 23 can be evaluated at any cross section perpendicular to the longitudinal direction of the plastic pipe 23, and when the cross section is elliptical, the average value of the lengths of the major axis and the minor axis can be set to the outer diameter D23 of the plastic pipe 23.

[0056] The details of the resin pipe 23 will be described in "(2) Resin Pipe". (Tension material) The tendon 11 is disposed within the plastic pipe 23 .

[0057] There are no particular limitations on the type of tendon 11, and any tendon capable of introducing tension into a concrete structure such as a main girder can be used. As the tendon 11, for example, one or more types selected from PC steel strands, PC steel rods, carbon fiber composite cables, etc., can be used. Note that the "PC" in PC steel strands, etc., is an abbreviation for "prestressed concrete."

[0058] The number of tendons 11 in the cable structure 20 is not particularly limited, and may be one or may be multiple as shown in Figs.

[0059] The tendons 11 may also have an anti-corrosion coating on their surfaces.

[0060] The material of the anticorrosive coating is not particularly limited, and may be, for example, one or more selected from zinc plating, resin, etc. The anticorrosive coating may be composed of multiple layers, such as zinc plating and a resin coating.

[0061] The resin may be, for example, a thermosetting resin, and is preferably one or more types selected from epoxy resin, polyethylene resin, and the like.

[0062] By providing the anticorrosive coating on the surface of the tendon 11, the installed tendon 11 can be prevented from corroding and the like, and its durability can be increased.

[0063] At the first end 21A of the insertion hole 21, the first tendon end 11A of the tendon 11 is gripped and fixed by a fixing device 24. The tendon 11 is also gripped by a fixing device (not shown) at the end located opposite the first tendon end 11A along the longitudinal direction, so that tension can be introduced to the main girder, etc.

[0064] The cable structure 20 may also include further optional components. (fixing devices, support members) The cable structure 20 may have an anchorage 24 that grips the first tendon end 11A of the tendon 11.

[0065] The configuration of the fixing device 24 is not particularly limited, and various fixing devices can be used depending on the type of the tension member 11, etc. For example, when the cable structure 20 has a plurality of tension members 11, a fixing device 24 capable of collectively holding the plurality of tension members 11 can be used as shown in Fig. 2, or a fixing device can be provided for each tension member 11.

[0066] The cable structure 20 may also have a support member 25 for supporting a load applied to the fixing device 24. Note that the support member 25 is not limited to the shape and installation form shown in FIG. 2 as long as it can support the load applied to the fixing device 24. (Grout cap) In the cable structure 20, in order to protect the first tendon end 11A of the tendon 11, a filler 27 can also be arranged around the first tendon end 11A of the tendon 11. For this reason, the cable structure 20 can also have a grout cap 26 that has a function as a formwork for filling the filler 27 and can protect the first tendon end 11A and the filler 27.

[0067] The grout cap 26 may also have a supply port or the like for supplying a filler 27 into the grout cap 26 or between the tendon 11 and the resin pipe 23 . (Filler) The cable structure 20 may further include a filler 27 disposed between the tendons 11 and the resin tubes 23 .

[0068] By further including the filler 27 disposed between the tendon 11 and the plastic pipe 23, it is possible to suppress vibration and displacement of the tendon 11 within the plastic pipe 23 even when an external force is applied to the tendon 11. This makes it possible to prevent the tendons 11 from rubbing against each other and causing damage to the tendons 11, and to prevent corrosion of components such as the tendons 11 and the fixing devices 24.

[0069] The material of the filler 27 is not particularly limited, and may be any material that can be filled between the tendon 11 and the resin pipe 23 .

[0070] However, as shown in Figures 2 and 3, multiple tendons can be used as the tendon 11. Also, the plastic pipe 23 can have a tapered shape in which the outer diameter gradually increases near the first end 21A of the insertion hole 21, as shown in Figure 2, for example, or can have a shape that is bent at multiple points along the length. For this reason, the space between the tendon 11 and the plastic pipe 23 is likely to have a complex shape.

[0071] Therefore, it is preferable that the filler 27 is a material that has fluidity, i.e., is a liquid material, when filled, and becomes solid after filling. By using a material that is a liquid material when filled and becomes solid after filling as the filler 27, the filler 27 can be easily filled regardless of the shape of the space between the tendon 11 and the plastic pipe 23.

[0072] The material of the filler 27 is not particularly limited, but is preferably a non-shrink grout agent, and for example, one or more types selected from cement mortar, epoxy resin mortar, water glass grout, and the like can be used.

[0073] It is preferable that the filler 27 is filled in the entire gap between the tendon 11 and the plastic pipe 23 . (2) Plastic pipe The components of the resin pipe 23 of this embodiment will be described with reference to FIGS. 4, 5A, 5B, and 6. FIG.

[0074] Fig. 4 is a cross-sectional view of the cable structure 20 described with reference to Fig. 2, taken along a plane passing through the central axis of the resin pipe 23 when the resin pipe 23 is disposed in the insertion hole 21. Fig. 4 is a view showing a state in which the tendons 11, the fixing devices 24, the filler, etc. have not yet been disposed.

[0075] 5A and 5B are explanatory diagrams of one configuration example of a procedure for installing the resin tube 23 in the insertion hole 21. FIG.

[0076] FIG. 6 is a cross-sectional view of the resin pipe 23 taken along line DD in FIG.

[0077] As shown in FIG. 4, the resin pipe 23 of this embodiment can have a plurality of divided resin pipes 231 arranged along the longitudinal direction.

[0078] In addition, the resin pipe 23 of this embodiment can have a sheet 41 at the connection portion 42 between adjacent split resin pipes 231 along the longitudinal direction that covers the outer surface 23A of the split resin pipe 231 and connects adjacent split resin pipes 231 along the longitudinal direction. (split resin tube) 1, 2, and 3, the resin pipe 23 can be placed in an insertion hole 21 provided in a concrete structure 12 such as a cross beam of a bridge 10. However, the length along the longitudinal direction of the insertion hole 21 is usually about several meters, and the length along the longitudinal direction of the resin pipe 23 is equal to or longer than the length along the longitudinal direction of the insertion hole 21. Therefore, the length L23 along the longitudinal direction of the resin pipe 23 (see FIG. 4) is also about several meters.

[0079] For this reason, if a sufficient size of working area cannot be secured near the end of the insertion hole 21 into which the resin pipe 23 is inserted, there is a problem that the workability decreases when installing the resin pipe 23 in the insertion hole 21. In addition, if the length of the resin pipe 23 along the longitudinal direction becomes long, it becomes difficult to transport the resin pipe 23 to the construction site.

[0080] Furthermore, the plastic pipe 23 may be tapered at the first tendon end 11A where the fixing device 24 of the tendon 11 is disposed. This is because, by tapering the plastic pipe 23 so that the diameter of the plastic pipe 23 increases at the first tendon end 11A, the adhesive force of the filler 27 (see FIG. 2) filled in the plastic pipe 23 to the tendon 11 is improved, and the fatigue resistance of the tendon 11 is improved.

[0081] When the resin pipe 23 has a tapered shape, depending on the size of the tapered portion, it may be necessary to insert the resin pipe 23 from the first end 21A of the insertion hole 21. However, as shown in Figures 5A and 5B, when another structure 51 or the like is disposed near the first end 21A of the insertion hole 21, there are cases where the width L52 of the working area 52 near the first end 21A cannot be sufficiently secured.

[0082] According to the resin pipe 23 of the present embodiment, it is possible to configure the resin pipe 23 by connecting a plurality of split resin pipes 231. By configuring the resin pipe 23 to have a plurality of split resin pipes 231, it is possible to shorten the length along the longitudinal direction of each split resin pipe 231, and the resin pipes 231 can be easily transported to the construction site.

[0083] Furthermore, by configuring the resin pipe 23 to have a plurality of split resin pipes 231, even if the working area 52 near the end of the insertion hole 21 in which the resin pipe 23 is to be placed is narrow, the split resin pipe 231 can be placed within the working area 52. That is, for example, as shown in Fig. 5A, the length along the longitudinal direction of the split resin pipe 231A is made shorter than the width L52 of the working area 52, and the split resin pipe 231A can be easily moved within the working area 52 and placed in the insertion hole 21, as shown by the block arrow E.

[0084] Then, the split resin pipes 231 are inserted into the insertion hole 21 through the working area 52 and adjacent split resin pipes 231 are connected along the longitudinal direction, thereby manufacturing the resin pipe 23 in the insertion hole 21.

[0085] The material of the split resin pipe 231 is not particularly limited, but is preferably made of polyolefin resin, and more preferably made of polyethylene, in consideration of costs, flexibility when inserted into the insertion hole 21, etc. The resin pipe 23 can contain additives, etc., as necessary, in addition to resins such as polyolefin.

[0086] 4, 5A, and 5B, an example is given in which the resin pipe 23 has a split resin pipe 231A and a split resin pipe 231B as the split resin pipes 231, but the present invention is not limited to such an embodiment. The number of split resin pipes 231 included in the resin pipe 23 can be selected so that the length along the longitudinal direction of each split resin pipe 231 is a desired length.

[0087] Furthermore, the length along the longitudinal direction of the split resin pipe 231 is not particularly limited and can be selected according to the size of the working area 52 near the end of the insertion hole 21 into which the split resin pipe 231 is inserted. For example, as shown in Fig. 5A, the length along the longitudinal direction of the split resin pipe 231A inserted from the first end 21A of the insertion hole 21 can be shorter than the width L52 of the working area 52 between the first end 21A and the structure 51.

[0088] The lengths along the longitudinal direction of the split resin pipes 231 of the resin pipe 23 may be the same or different. (Sheet) Conventionally, methods known as butt welding and EF (Electro Fusion) welding have been used to connect resin pipes.

[0089] In the case of butt welding, it is necessary to clean the end faces of the resin pipes to be connected and to make the end faces of the resin pipes perpendicular to the longitudinal direction of the pipes. Also, a large welding device is required to perform butt welding.

[0090] EF fusion requires that the plastic pipes to be connected be parallel to each other, which makes it difficult to connect pipes that include tapered or bent sections.

[0091] In some cases, a sufficient size of working area cannot be secured near the end of the insertion hole 21 where the resin pipe 23 of this embodiment is to be installed, and therefore butt fusion, which requires a large fusion device, cannot be applied. In addition, since the resin pipe 23 may include a tapered portion, EF fusion cannot be applied either. In other words, it is difficult to connect the split resin pipes 231 to form the resin pipe 23 by butt fusion or EF fusion, which have been conventionally used to join resin pipes.

[0092] Therefore, the resin pipe 23 of this embodiment can have a sheet 41 that connects the multiple split resin pipes 231 adjacent to each other along the longitudinal direction.

[0093] 4, the sheet 41 can be arranged so as to cover the outer surface 23A of the split resin pipe 231 at the connection portion 42 between longitudinally adjacent split resin pipes 231. More specifically, the sheet 41 can be arranged so as to cover the area including the connection portion 42 of two longitudinally adjacent split resin pipes 231.

[0094] By connecting adjacent split resin pipes 231 along the longitudinal direction with sheet 41, the split resin pipes 231 can be easily connected along the longitudinal direction without requiring special or large equipment when connecting the split resin pipes 231.

[0095] Furthermore, since the sheet 41 can be shaped to match the outer shape of the split resin pipes 231, even if the split resin pipes 231 have a shape other than a straight pipe, such as a tapered shape, adjacent split resin pipes 231 can be easily connected along their length near the connection portion 42 regardless of the shape. Therefore, the shape along the length of the resin pipe 23 in this embodiment is not particularly limited, and it can also include a curved portion such as a tapered shape.

[0096] The connection portion 42 refers to a portion where the opposing faces of adjacent split resin pipes 231 along the longitudinal direction come into contact with each other.

[0097] The sheet 41 is not particularly limited, and may be any sheet capable of connecting adjacent split resin pipes 231 by being placed so as to include the connection parts 42 of adjacent split resin pipes 231. As the sheet 41, for example, a sheet capable of adhering to the outer surface 23A of the split resin pipe 231, i.e., an adhesive sheet, can be suitably used, and for example, one or more types selected from a heat shrink sheet, an adhesive sheet, a self-adhesive sheet, etc. can be used. Note that the sheet 41 can have a tube shape, a tape shape, etc., and therefore may be expressed as a heat shrink tube, a heat shrink tape, an adhesive tape, a self-adhesive tape, etc. according to the shape.

[0098] The adhesive sheet means a sheet that, when placed on the outer surface 23A of the split resin pipe 231, can exert an adhesive force between the split resin pipe 231 and the sheet. The adhesive force here means the force that adheres to the outer surface 23A of the split resin pipe 231 without peeling off naturally, and is not limited to adhesion by adhesive or the like.

[0099] When there are multiple connection parts 42 along the length of the resin pipe 23, a sheet can be selected according to the shape and material of the split resin pipes around the connection parts 42, and a different type of sheet 41 may be used for each connection part 42.

[0100] The heat shrinkable sheet is a sheet that shrinks when heat is applied. Therefore, it can be applied using small equipment such as a dryer or a gas burner, and does not require special equipment or large equipment to connect the split resin pipes 231. Therefore, by using a heat shrinkable sheet as the sheet 41, adjacent split resin pipes 231 can be easily connected along the longitudinal direction.

[0101] Furthermore, since the heat-shrinkable sheet is a sheet that shrinks when heated, when heated it can be deformed into a shape that matches the outer shape of the split resin pipe 231. Therefore, even if the split resin pipe 231 has a shape other than a straight pipe, such as a tapered shape, the heat-shrinkable sheet can adhere to the adjacent split resin pipe 231 along the length near the connection portion 42 regardless of the shape, and can easily be connected.

[0102] The material of the heat shrinkable sheet is not particularly limited, and any material that can shrink when heat is applied and can be deformed to match the outer shape of the split resin pipe 231 can be used.

[0103] The material of the heat shrinkable sheet may be one or more selected from the group consisting of ethylene propylene rubber, cross-linked polyethylene, and polyolefin elastomers.

[0104] The adhesive sheet is a sheet in which an adhesive is disposed on the surface of a base material. Therefore, when the sheet is disposed on the split resin pipes 231, no special equipment is required for application, and adjacent split resin pipes 231 can be easily connected along the longitudinal direction.

[0105] Furthermore, the adhesive sheet can be cut as necessary to a shape that matches the outer shape of the split resin pipe 231. Therefore, even if the split resin pipe 231 has a shape other than a straight pipe, such as a tapered shape, the adhesive sheet can be adhered to adjacent split resin pipes 231 along the length near the connection portion 42 regardless of the shape, and can easily be connected.

[0106] Although there are no particular limitations on the materials of the adhesive sheet substrate and the adhesive, it is preferable that the substrate material be one or more types selected from resin and metal from the viewpoint of increasing the bonding strength between the split resin pipes 231. The adhesive can be selected depending on the material of the split resin pipes 231, etc.

[0107] The self-adhesive sheet is a sheet that adheres closely to itself when it is stretched and wrapped around the sheet. Therefore, when it is placed on the split resin pipe 231, it can be installed without requiring special equipment, and adjacent split resin pipes 231 can be easily connected along the length.

[0108] The self-adhesive sheet can be installed by wrapping it around the outer surface of the split resin pipe 231 while stretching it, so it can be shaped to match the outer shape of the split resin pipe 231. Therefore, even if the split resin pipe 231 has a shape other than a straight pipe, such as a tapered shape, the self-adhesive sheet can be adhered to adjacent split resin pipes 231 along the length near the connection portion 42 regardless of the shape, and can be easily connected.

[0109] The self-adhesive sheet can include, for example, butyl rubber.

[0110] The sheet 41 may have, for example, a tube shape, and may be inserted along the length of the split resin pipe 231 and disposed on the outer surface of the split resin pipe 231. The sheet 41 may also have a sheet or tape shape, and may be disposed on the outer surface of the split resin pipe 231 by wrapping it around the split resin pipe 231 in a spiral or annular shape.

[0111] The thickness T41 of the sheet 41 (see FIG. 6) is not particularly limited either, but is preferably, for example, 0.5 mm or more and 5 mm or less, and more preferably 1 mm or more and 3 mm or less. The thickness T41 of the sheet 41 here is the thickness after the sheet 41 is placed on the outer surface 23A of the split resin pipe 231. For this reason, for example, when the sheet 41 is a heat-shrinkable sheet, the thickness of the heat-shrinkable sheet before heating can be selected so as to be within the above range after heating.

[0112] By setting the thickness T41 of the sheet 41 to 0.5 mm or more, the strength of the sheet 41 can be increased, and the occurrence of breakage or the like at the connection portion 42 of the split resin pipe 231 in the resin pipe 23 can be prevented.

[0113] By setting the thickness T41 of the sheet 41 to 5 mm or less, the portion of the surface of the resin pipe 23 where the sheet 41 is provided can be prevented from rising up compared to other portions and made smooth. Therefore, when the split resin pipes 231 are sequentially inserted into the insertion hole 21, the portion where the sheet 41 is provided can be prevented from coming into contact with the metal pipe 22, etc., and being damaged, etc.

[0114] There is no particular limit to the extent or length of the sheet 41 covering adjacent split resin pipes 231 along their length, including the connection portions 42. The sheet 41 can cover the entire outer surface along the length of the resin pipe 23, for example, but from the standpoint of reducing costs, workload, and the like, it is preferable to place the sheet 41 only in the vicinity of the connection portions 42 of the split resin pipes 231. The extent to which the sheet 41 covers the outer surface of the split resin pipes 231 can be selected depending on the joining strength, etc., required for the resin pipe 23.

[0115] The resin pipe 23 of the present embodiment may have a tapered shape or a shape bent along the longitudinal direction. That is, in a cross section passing through the central axis of the resin pipe 23, the outer surface of the resin pipe 23 may include a curved portion.

[0116] In the resin pipe 23 of this embodiment, it is preferable that the outer surface of the resin pipe 23 includes a curved portion 43 in a cross section passing through the central axis of the resin pipe 23 .

[0117] In conventional methods for joining resin pipes, it was difficult to connect split resin pipes 231 at or near a portion where the outer surface includes a curve in a cross section passing through the central axis of the resin pipe 23. However, according to the resin pipe 23 of this embodiment, by using the sheet 41, it is possible to connect split resin pipes 231 regardless of the outer shape of the resin pipe 23, and the resin pipe 23 can be made into any shape. Therefore, since the outer surface of the resin pipe 23 includes the curved portion 43 in a cross section passing through the central axis of the resin pipe 23, a high effect can be achieved compared to the conventional technology.

[0118] In the resin pipe 23 of this embodiment, the outer shape of the resin pipe 23 at the connection portion 42 of the divided resin pipes 231 adjacent along the longitudinal direction is not particularly limited. Therefore, the position of the connection portion 42 along the longitudinal direction of the resin pipe 23 can be arbitrarily selected. For example, in a cross section passing through the central axis of the resin pipe 23, the connection portion 42 may intersect with the curved portion 43. (glue) As shown in Fig. 6, the resin pipe 23 of this embodiment may have an adhesive 61 disposed between the outer surface 23A of the split resin pipe 231 and the sheet 41. Fig. 6 is a cross-sectional view of the resin pipe 23 taken along line DD in Fig. 4 when the resin pipe 23 has the adhesive 61.

[0119] The resin pipe 23 has the adhesive 61 disposed between the outer surface 23A of the split resin pipe 231 and the sheet 41, thereby increasing the bonding strength between the sheet 41 and the split resin pipe 231. This increases the bonding strength between the split resin pipes 231 adjacent along the longitudinal direction that are connected by the sheet 41.

[0120] The type of adhesive 61 is not particularly limited and can be selected depending on the type of sheet 41. It is preferable to use adhesive 61 when sheet 41 is, for example, a heat shrinkable sheet or a self-adhesive sheet. In consideration of workability, it is preferable that adhesive 61 is a material that melts and exhibits fluidity when heat is applied to sheet 41 or adhesive 61, and resolidifies after cooling.

[0121] The melting point of the adhesive 61 is not particularly limited, but it is preferable that the adhesive 61 does not melt when it is used after the resin pipe 23 is installed. Therefore, the melting point of the adhesive 61 is preferably 60° C. or higher, and more preferably 65° C. or higher. However, if the melting point of the adhesive 61 is too high, it becomes difficult to melt it during bonding, so the melting point of the adhesive 61 is preferably 250° C. or lower, and more preferably 200° C. or lower.

[0122] The thickness T61 of the adhesive 61 is not particularly limited, and can be, for example, 0.1 mm or more and 1 mm or less after adhesion, i.e., after solidification, for example. By making the thickness T61 of the adhesive 61 0.1 mm or more, the bonding strength with the split resin pipe 231 can be sufficiently increased. Furthermore, by making the thickness T61 of the adhesive 61 1 mm or less, the portion of the surface of the resin pipe 23 where the sheet 41 is provided can be prevented from rising compared to other portions and can be made smooth. Therefore, when the split resin pipe 231 is inserted into the insertion hole 21, the portion where the sheet 41 is provided can be prevented from coming into contact with the metal pipe 22 or the like and being damaged.

[0123] The thickness T61 of the adhesive 61 can be evaluated in a cross section perpendicular to the longitudinal direction of the resin pipe 23, and it is preferable that the thickness T61 falls within the above range no matter where it is measured.

[0124] The location where the resin pipe 23 of this embodiment described above is applied and installed is not particularly limited, and for example, as long as it is a location that houses the tendon 11 in a concrete structure, it can be suitably applied to any location and concrete structure. The resin pipe 23 of this embodiment can be applied to a bridge 10, for example, as described in "(1) Cable structure", and is preferably disposed in an insertion hole 21 provided in a concrete structure 12 of the bridge 10, for example.

[0125] 5A and 5B, in the vicinity of the first end 21A and the second end 21B, which are the ends of the insertion hole 21 provided in the concrete structure 12 of the bridge 10, it is often difficult to ensure a sufficient working area 52. For this reason, it has sometimes been difficult to place a resin pipe in the insertion hole 21 provided in the concrete structure 12 of the bridge 10.

[0126] In contrast, according to the resin pipe 23 of this embodiment, in which multiple split resin pipes 231 are connected by a sheet 41, the resin pipe 23 can be easily installed in the insertion hole 21 regardless of the size of the working area 52 at the end of the insertion hole 21.

[0127] The bridge 10 has already been explained, so its explanation will be omitted.

[0128] The resin pipe 23 of this embodiment can be suitably used as a pipe for accommodating the tendon 11, as described in "(1) Cable structure".

[0129] The tendons 11 are often installed in large structures such as bridges, and the plastic pipes 23 in which the tendons 11 are arranged may also become long along their length. In addition, there are cases where a sufficient working area cannot be secured around the end of the insertion hole 21 into which the plastic pipes 23 are inserted, and problems such as reduced workability arise when the length of the plastic pipes 23 along their length becomes long. In addition, when the length of the plastic pipes 23 along their length becomes long, it becomes difficult to transport the plastic pipes to the construction site.

[0130] Since the resin pipe 23 of this embodiment has a plurality of split resin pipes 231, even if the overall longitudinal length of the resin pipe 23 is long, the longitudinal length of each split resin pipe 231 can be short. Furthermore, the split resin pipes 231 can be easily connected by the sheet 41 regardless of the shape of the split resin pipes 231.

[0131] Therefore, by using the plastic pipe 23 of this embodiment as a pipe that houses the tension member 11, the plastic pipe 23 can be transported more easily than in the case of using a conventional plastic pipe that cannot be divided, and the workability when installing the plastic pipe 23 into the insertion hole can be improved. [Manufacturing method of resin pipes] Next, a method for manufacturing a resin pipe according to the present embodiment will be described. According to the method for manufacturing a resin pipe according to the present embodiment, the above-mentioned resin pipe can be manufactured. Therefore, the description of the matters already described will be omitted.

[0132] The method for producing a resin pipe of this embodiment relates to a method for producing a resin pipe 23 including a plurality of divided resin pipes. The method for producing a resin pipe of this embodiment can be carried out according to a flow 70 shown in Fig. 7, and can include the following installation step (S1) and connection step (S2).

[0133] Each step will be described below. (1) Installation process (S1) In the installation step (S1), the multiple split resin pipes 231 can be installed along the longitudinal direction of the split resin pipes 231. For example, as shown in FIG. 5A, the split resin pipes 231B can be inserted from the second end 21B of the insertion hole 21 along the block arrow F.

[0134] 5A and 5B, since the split resin pipe 231A has a tapered shape, for example, in the working area 52, the split resin pipe 231A can be moved along the block arrow E in FIG. 5A and inserted from the first end 21A of the insertion hole 21.

[0135] Then, as shown in Fig. 5B, split resin pipe 231A and split resin pipe 231B can be arranged in a row along the longitudinal direction. At this time, connection portion 42 between split resin pipe 231A and split resin pipe 231B, which is connected by sheet 41 in the connection step (S2), is disposed outside insertion hole 21, as shown in Fig. 5B.

[0136] In the installation step (S1), the location where the split resin pipe 231 is installed is not particularly limited, and the split resin pipe 231 can be installed in any location where installation of the resin pipe 23 is required.

[0137] The resin pipe manufactured by the resin pipe manufacturing method of this embodiment can be used as a pipe for accommodating a tendon, for example. Therefore, the split resin pipe 231 can be installed in any location or structure for accommodating the tendon 11 of the concrete structure 12, for example. The resin pipe 23 manufactured by the resin pipe manufacturing method of this embodiment can be placed in the insertion hole 21 provided in the concrete structure 12 of the bridge 10, for example, as described in "(1) Cable structure". Therefore, for example, in the installation step (S1), the multiple split resin pipes 231 can be installed in the insertion hole 21 provided in the concrete structure 12 of the bridge 10.

[0138] In many cases, a sufficient size of work area cannot be secured near the first end 21A or the second end 21B, which are the ends of the insertion hole 21 provided in the concrete structure 12 of the bridge 10. For this reason, it has been difficult to install the resin pipe 23 in the insertion hole 21 provided in the concrete structure 12 of the bridge 10 in the past.

[0139] In contrast, according to the resin pipe manufacturing method of this embodiment, in which multiple split resin pipes 231 are connected by sheet 41, the resin pipe 23 can be easily installed in the insertion hole 21 regardless of the size of the working area at the end of the insertion hole 21.

[0140] In the installation step (S1), if necessary, an adhesive 61 can be placed between the sheet 41 and the outer surface 23A of the split resin pipe 231. The adhesive 61 may be placed in advance on the surface of the sheet 41 that faces the outer surface 23A of the split resin pipe 231, or may be placed on the outer surface 23A of the split resin pipe 231 during construction.

[0141] (2) Connection process (S2) In the connecting step (S2), a sheet 41 is placed at a connection 42 between longitudinally adjacent split resin pipes 231 so as to cover outer surfaces 23A of the split resin pipes 231, thereby connecting the longitudinally adjacent split resin pipes 231.

[0142] The method for installing the sheet 41 in the connecting step (S2) is not particularly limited, and can be selected depending on the type of the sheet 41, etc.

[0143] When the sheet 41 is a heat-shrinkable sheet, in the connection step (S2), first, a heat-shrinkable sheet can be arranged so as to cover the outer surface 23A of the split resin pipe 231 at the connection portion 42 between adjacent split resin pipes 231 along the longitudinal direction. Next, the arranged heat-shrinkable sheet can be heated. This causes the heat-shrinkable sheet to shrink and deform, and can be closely attached to the split resin pipe 231. By heating the heat-shrinkable sheet to closely attach it to the split resin pipe 231, the heat-shrinkable sheet can connect adjacent split resin pipes 231 along the longitudinal direction.

[0144] When the sheet 41 is an adhesive sheet, in the connecting step (S2), after removing the release sheet on the surface of the adhesive sheet on which the adhesive is disposed, the adhesive sheet can be disposed so as to cover the outer surface 23A of the split resin pipe 231 at the connecting portion 42 between adjacent split resin pipes 231 along the longitudinal direction. By disposing the adhesive sheet so as to cover the outer surface 23A of the split resin pipe 231 at the connecting portion 42, the adhesive sheet can be bonded to the split resin pipe 231 by the adhesive. Therefore, the adhesive sheet can connect adjacent split resin pipes 231 along the longitudinal direction.

[0145] When the sheet 41 is a self-adhesive sheet, in the connection step (S2), the self-adhesive sheet can be stretched and wrapped around the connection parts 42 between adjacent split resin pipes 231 along the length so that parts of the self-adhesive sheet are in contact with each other. This allows the self-adhesive sheet to be tightly attached to the split resin pipes 231. Therefore, the self-adhesive sheet can connect adjacent split resin pipes 231 along the length.

[0146] When the connecting step (S2) is completed, as shown in Fig. 5B, the portion joined by the sheet 41 is located outside the insertion hole 21. Therefore, if necessary, the portion of the split resin pipe 231A, including the tapered portion, can also be positioned inside the insertion hole 21 by moving the connected resin pipe 23 to the right in Fig. 5B along the block arrow G.

[0147] The installation step (S1) and the connection step (S2) can be repeatedly performed according to the number of split resin pipes 231 to be connected.

[0148] According to the manufacturing method of the resin pipe of this embodiment, since the resin pipe 23 has a plurality of split resin pipes 231, the length along the longitudinal direction of each split resin pipe 231 can be shortened, and the split resin pipes 231 can be easily transported to the construction site. Even if the working area 52 near the end of the insertion hole 21 where the resin pipe 23 is to be installed is narrow, the split resin pipes 231 can be installed within the working area 52. Then, the split resin pipes 231 are inserted into the insertion hole 21 through the working area 52, and adjacent split resin pipes are connected along the longitudinal direction, whereby the resin pipe 23 can be manufactured within the insertion hole 21.

[0149] According to the manufacturing method of the resin pipe of this embodiment, adjacent split resin pipes 231 along the longitudinal direction can be connected by the sheet 41. Therefore, there is no need for a special device or a large device for connecting the split resin pipes 231, and adjacent split resin pipes 231 along the longitudinal direction can be easily connected.

[0150] Furthermore, since the sheet 41 can be processed into a shape that matches the outer shape of the split resin pipes 231, even if the split resin pipes 231 have a shape other than a straight pipe, such as a tapered shape, adjacent split resin pipes 231 can be easily connected along their length near the connection parts 42 regardless of the shape. Therefore, according to the manufacturing method for a resin pipe of this embodiment, the shape along the length is not particularly limited, and a resin pipe including a curved portion such as a tapered shape can be manufactured. [Method of manufacturing cable structure] Next, a method for manufacturing a cable structure including a resin pipe according to an embodiment of the present disclosure will be described. According to the method for manufacturing a cable structure, the cable structure 20 according to an embodiment of the present disclosure can be manufactured. Therefore, the description of the matters already described will be omitted.

[0151] The method for manufacturing a cable structure according to the present embodiment may include a resin pipe manufacturing step, a tendon arrangement step, and a tensioning step. The method for manufacturing a cable structure according to the present embodiment may also include a filler filling step, etc., as necessary.

[0152] Each step will be described below. (1) Resin pipe manufacturing process In the resin pipe manufacturing process, a resin pipe disposed in an insertion hole provided in a concrete structure can be manufactured. The resin pipe 23 can be disposed in an insertion hole 21 provided in a concrete structure 12 of a bridge 10, for example. Therefore, in the resin pipe manufacturing process, a resin pipe 23 disposed in an insertion hole 21 provided in a concrete structure 12 of a bridge 10, for example, can be manufactured.

[0153] In the resin pipe manufacturing process, the resin pipe 23 can be manufactured in the insertion hole 21 by the resin pipe manufacturing method according to one embodiment of the present disclosure. Therefore, the resin pipe manufacturing process can have an installation process and a connection process. The installation process and the connection process have already been described, so the description will be omitted. (2) Tensile arrangement process In the tendon placement process, the tendon 11 can be placed inside the plastic pipe 23. (3) Tension process In the tensioning process, tension can be introduced to the tendons 11. There is no particular limitation on the method of introducing tension to the tendons 11, and tension can be introduced by connecting a jack to the tendons 11 and using the jack.

[0154] In the tensioning process, it is preferable to introduce tension into the tendons 11 while measuring the tension introduced into the tendons 11 and the amount of displacement of the tendons 11 and creating a tension control chart.

[0155] After the tensioning process is completed, the longitudinal ends of the tendons can be gripped and secured by fasteners.

[0156] By carrying out the tension member placement step and tensioning step, a cable structure 20 can be obtained in which tension members 11 with tension introduced therein are placed within the resin tube 23. (4) Filling process In the filler filling step, first, for example, a grout cap 26 may be installed so as to cover the first tendon end 11A of the tendon 11 (grout cap installation step).

[0157] Then, a filler 27 can be filled between the tendon 11 and the resin pipe 23 and in the grout cap 26 .

[0158] In the filler filling step, the filler 27 can be filled from a supply port connected to the inside of the grout cap 26 or the gap between the tendon 11 and the resin pipe 23. At this time, gas in the gap between the tendon 11 and the resin pipe 23 can be exhausted from an exhaust port provided separately from the supply port, which is connected to the inside of the grout cap 26 or the gap between the tendon 11 and the resin pipe 23. From the viewpoint of filling the gap between the tendon 11 and the resin pipe 23 with the filler 27 without leaving any gaps, it is preferable that the exhaust port is provided at a higher position than the supply port.

[0159] By further including the filler 27 disposed between the tendon 11 and the plastic pipe 23, it is possible to suppress vibration and displacement of the tendon 11 within the plastic pipe 23 even when an external force is applied to the tendon 11. This makes it possible to prevent the tendons 11 from rubbing against each other and causing damage to the tendons 11, and to prevent corrosion of components such as the tendons 11 and the fixing devices 24. [Explanation of symbols]

[0160] 10 Bridges 11 Tensor material 11A 1st tendon end 12 Concrete Structures 13 Deflection section 14 Upper floor plate 15 Lower floor version 16 Space 17 Pier Area A B area XX axis (bridge axis) YY axis ZZ axis 20 Cable structure 21 Insertion hole 211 Inner surface 21A 1st end 21B 2nd end 22 Metal tube D22 Inner diameter 22A 1st metal tube end 22B 2nd metal tube end 221 External surface 23 Plastic pipe D23 Outer diameter 23A outer surface 231 Split resin pipe 231A Split resin pipe 231B Split resin pipe 24 Fixture 25 Supporting member 26 Grout Cap 27 Fillers 41 sheets T41 Thickness 42 Connection 43 Curved section 51 Structures 52 Work area L52 width E Block Arrow F Block Arrow G Block Arrow 61 Adhesive T61 Thickness 70 Flow S1 Installation process S2 connection process

Claims

1. A plurality of split resin pipes arranged along a longitudinal direction; a sheet covering an outer surface of the split resin pipe at a connection between adjacent split resin pipes along the length and connecting the adjacent split resin pipes along the length.

2. The plastic pipe of claim 1 , further comprising an adhesive disposed between an outer surface of the split plastic pipe and the sheet.

3. The plastic pipe according to claim 1 or 2, wherein an outer surface of the plastic pipe includes a curved portion in a cross section passing through a central axis of the plastic pipe.

4. The plastic pipe according to claim 1 or 2, wherein the plastic pipe is a pipe for accommodating a tendon.

5. an installation step of installing a plurality of split resin pipes along a longitudinal direction of the split resin pipes; a connecting step of placing a sheet to cover the outer surface of the split resin pipe at the connection between the split resin pipes adjacent along the length, and connecting the split resin pipes adjacent along the length.

6. The method for manufacturing a resin pipe according to claim 5 , wherein in the installing step, a plurality of the split resin pipes are installed in insertion holes provided in a concrete structure of a bridge.

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