Manufacturing method for PC components

Abstract

To provide a method for manufacturing PC members capable of manufacturing PC members having various shapes.SOLUTION: A method for manufacturing PC members in which prestressing is applied to concrete members comprises: a tensing step of tensing a tensioning material inserted into insertion holes, through which the tensioning material can be inserted, provided at both ends of the concrete member and a hole or sheath having a curved connecting hole that is connected to the insertion holes at both ends of the PC member; an injection step of injecting grout into the hole or sheath through which the tensioning material tensed by the tensing step has been inserted; a cutting step of cutting the tensioning material inserted into the hole or sheath through which the grout has been injected by the injection step; and a member cutting step of cutting the concrete member through which the tensioning material cut by the cutting step is inserted to manufacture the PC members.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a PC member, which produces a PC member (Prestressed Concrete) in which prestress is applied to a concrete member.

Background Art

[0002] Conventionally, when prestress is applied to a concrete member by, for example, a pretension method, as shown in Fig. 7(a), one end of the tension member 2 is fixed to the fixed object 3, and the tension members 2 are spread out in a fan shape from the fixed object 3 by a fixed spacer 6 according to the interval between the tension members 2 inserted into the concrete member (10) and then inserted therethrough. Then, on the other end side of the tension member 2, prestress is introduced by tensioning with a tension jack (not shown) on the fixed object 6 via the fixed spacer 6 in the same manner. Hereinafter, the concrete member into which prestress is introduced is referred to as a PC (Prestressed Concrete) member 10.

[0003] This PC member 10 is required to have various shapes depending on the application. In order to manufacture PC members 10 of various shapes, for example, a formwork apparatus for manufacturing concrete members as shown in Patent Document 1 is disclosed.

[0004] Patent Document 1 discloses a formwork apparatus for manufacturing concrete members, which includes a base and a bottom frame placed on the base. The bottom frame is separated from each other with gaps of a predetermined width at at least one position of the portion corresponding to the middle part of the concrete member, into a plurality of bottom frame parts continuous in the linear direction of the tension member, and each separated bottom frame part is provided on the base so as to be movable in the elastic deformation direction of the concrete member when prestress is introduced, and an elastic member is embedded in the gap. Thereby, the formwork apparatus for manufacturing concrete members disclosed in Patent Document 1 is capable of ensuring the quality of a concrete member having a concave portion in the middle part of the bottom surface in the linear direction of the tension member and preventing damage to the bottom frame.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-109449 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] On the other hand, actual construction sites require PC members 10 with a greater variety of shapes. However, the technology shown in Patent Document 1 has the problem that it can only manufacture concrete members having a concave portion in the middle of the bottom surface in the linear direction of the tensioning member.

[0007] Therefore, the present invention was devised in view of the aforementioned problems, and its objective is to provide a method for manufacturing PC members that can produce PC members having various shapes. [Means for solving the problem]

[0008] The method for manufacturing a PC member according to claim 1 is a method for manufacturing a PC member in which a prestressed concrete member is applied, characterized in that the PC member is manufactured by: a tensioning step of tensioning a tensioning member inserted into a hole or sheath having through holes provided at both ends of the concrete member through which a tensioning member can be inserted and a curved communication hole communicating with the through holes at both ends of the PC member; an injection step of injecting grout into the hole or sheath through which the tensioning member tensioned in the tensioning step is inserted; a cutting step of cutting the tensioning member inserted into the hole or sheath through which the grout has been injected in the injection step; and a member cutting step of cutting the concrete member through which the tensioning member cut in the cutting step is inserted.

[0009] The method for manufacturing a PC member according to claim 2 is characterized in that, in the method for manufacturing a PC member according to claim 1, the through holes at both ends of the concrete member are provided on a straight line in the direction in which the tensioning member is inserted. [Effects of the Invention]

[0010] According to the inventions of claims 1 and 2, the concrete member through which the tensioning material, which has been cut in the member cutting process, is cut is performed. This makes it possible to manufacture a curved PC member by cutting the curved communication hole into which the grout has been injected. This makes it possible to manufacture PC members of various shapes with sufficient strength.

[0011] In particular, according to the invention of claim 2, the through holes are provided on a straight line in the insertion direction. This makes it possible to tension tensioning materials inserted into through holes of the same height and depth during the tensioning process, thereby enabling safer manufacturing of PC members. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows a PC member according to an embodiment of the present invention. [Figure 2] Figure 2 shows a sheath equipped with a cutting section according to an embodiment of the present invention. [Figure 3] Figure 3 is a schematic diagram showing the tensioning process according to an embodiment of the present invention. [Figure 4] Figure 4 is a schematic diagram showing a cutting process according to an embodiment of the present invention. [Figure 5] Figure 5 is a schematic diagram showing a member cutting process according to an embodiment of the present invention. [Figure 6] Figure 6 is a schematic diagram showing the target member according to an embodiment of the present invention. [Figure 7] Figure 7 is a schematic diagram showing an overview of a conventional PC member manufacturing method, where (a) is before demolding and (b) is the state in which the PC member is suspended during demolding. [Modes for carrying out the invention]

[0013] Hereinafter, one embodiment of the manufacturing method for the PC member 10 according to the present invention will be described in detail with reference to the drawings.

[0014] First, the PC member 10 according to an embodiment of the present invention will be described using Figures 1 to 3. Figure 1 is a diagram showing the PC member 10 according to an embodiment of the present invention. Figure 1 shows a cross-sectional view of the PC member 10. Figure 2 is a diagram showing a sheath equipped with a cut portion according to an embodiment of the present invention. Figure 3 is a schematic diagram showing the tensioning process according to an embodiment of the present invention. The PC member 10 is a concrete member that is tensioned and prestressed by a tensioning material 2, as described later. The PC member 10 is equipped with holes 20 or a sheath 1 having through holes 21 through which the tensioning material 2 provided at both ends can be inserted, and curved communication holes 22 that communicate with the through holes 21 at both ends of the PC member 10. The concrete member equipped with these holes 20 before prestressing may be manufactured, for example, by spraying fiber-reinforced mortar using a 3D printer or the like. The PC member 10 may also be in an arch shape, for example.

[0015] The sheath 1 comprises an insertion section 11 having insertion holes 21 through which tensioning material 2 can be inserted from both ends, and a communication section 13 having curved communication holes 22 that communicate with the insertion sections 11 at both ends. The sheath 1 may be a sheath tube made of any metal, for example. The sheath 1 may be made of any synthetic resin, such as plastic. The sheath 1 may be manufactured using, for example, a 3D printer. Also, as shown in Figure 2, the sheath 1 may have a cut section 12 where the communication section 13 and part of the insertion section 11 are cut. The cut section 12 may be made of concrete, copper, or wood, for example. The cut section 12 may be a pipe joined to the communication section 13 or the insertion section 11. The cut section 12 may be joined to the communication section 13 or the insertion section 11 in a manner that allows it to be detached.

[0016] The through-holes 21 are holes into which the tensioning material 2 or grout 5 is inserted. The through-holes 21 open at both ends of the PC member 10. Furthermore, the through-holes 21 at both ends are located on a straight line in the insertion direction x of the tensioning material 2.

[0017] The communication hole 22 is a curved hole that communicates with the insertion holes 21 at both ends. The communication hole 22 may have a fan shape as shown in Fig. 1, for example, but is not limited thereto, and may have any curved shape such as an S-shape.

[0018] The tension member 2 is a tension member for applying prestress to the PC member 10. As the tension member 2, for example, a PC steel wire which is high-strength steel with a diameter of 8 mm or less, a PC steel bar which is high-strength steel with a diameter of 10 mm or more, a PC steel strand formed by twisting PC steel wires, and continuous fiber reinforcing materials such as carbon fiber, aramid fiber, and glass fiber are used.

[0019] The fixtures 3 are installed on both sides of the PC member 10 when prestress is applied to the PC member 10, and are used to fix the tensioned tension members 2.

[0020] The base 4 is a base for fixing the fixtures 3.

[0021] The grout 5 is a grout material to be injected into the sheath 1. Any grout material may be used.

[0022] Next, a method for manufacturing a PC member according to an embodiment of the present invention will be described with reference to Figs. 3 to 6. Fig. 3 is a schematic diagram showing the tensioning step according to the embodiment of the present invention. Fig. 4 is a schematic diagram showing the cutting step according to the embodiment of the present invention. Fig. 5 is a schematic diagram showing the member cutting step according to the embodiment of the present invention.

[0023] First, as shown in Fig. 2, after the concrete strength of the PC member 10 has developed, a tensioning step of tensioning the tension member 2 inserted through the hole 20 or the sheath 1 is performed in the tensioning step. In such a case, in the tensioning step, both ends of the tension member 2 inserted through the insertion holes 21 are fixed with the fixtures 3, and the tension member 2 is tensioned using a tension jack (not shown) or the like. At this time, since the insertion holes 21 at both ends are provided on the straight line in the insertion direction x of the tension member 2, it is possible to tension the tension member 2 inserted into the insertion holes at the same height and in the same depth direction in the tensioning step, and the PC member 10 can be manufactured more safely.

[0024] Next, in the injection process, grout 5 is injected into the hole 20 or sheath 1 through which the tensioning material 2, which was tensioned in the tensioning process, is inserted. After the injected grout 5 hardens in the injection process, the process proceeds to the next cutting process. Also, in the injection process, if the sheath 1 has a cut section 12, it is not necessary to inject grout 5 into the inside of the cut section 12. This makes it possible to manufacture the PC member 10 at a low cost.

[0025] Next, as shown in Figure 3, in the cutting process, the tensioning member 2 inserted through the hole 20 into which the grout 5 was injected in the injection process or through the sheath 1 is cut. This makes it possible to apply prestress to the PC member 10.

[0026] Next, as shown in Figure 4, in the member cutting process, the PC member 10 through which the tensioning material 2, which was cut in the cutting process, is inserted is cut. In the member cutting process, for example, a curved PC member 10 can be manufactured by cutting a curved communication hole 22 into which grout 5 has been injected.

[0027] Furthermore, as shown in Figure 6, in the member cutting process, for example, the through hole 21 into which the grout 5 has been injected may be cut, and the cut through hole 21 into which the grout 5 has been injected may be used as the target member 7 for the purpose of manufacturing. This makes it possible to manufacture PC members 10 of various shapes with sufficient strength. In addition, by cutting or separating the cut portion 12 of the sheath 1 in the cutting process, it becomes possible to manufacture PC members 10 of various shapes more easily.

[0028] The method for manufacturing the PC member 10 according to the embodiment of the present invention has been described in detail above. However, the embodiments described above or illustrated are merely examples of embodiments that have been materialized in carrying out the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these embodiments. [Explanation of Symbols]

[0029] 1: Sheath 2: Tensile material 3: Fixed object 4: Base 5: Grout 6: Spacing retainer 7: Target Member 10: PC components 11: Insertion part 12: Cutting section 13:Communication part 20: Hole 21: Through hole 22:Communication hole

Claims

1. A method for manufacturing a prestressed concrete (PC) member, wherein the PC member is a concrete member to which prestress has been applied, A tensioning step of tensioning a tensioning member inserted into a hole or sheath having through holes provided at both ends of the concrete member through which a tensioning member can be inserted, and a curved communication hole that communicates with the through holes at both ends of the PC member, An injection step in which grout is injected into the hole or sheath through which the tensioning material, which has been tensioned by the tensioning step, is inserted. A cutting step of cutting the tensioning material inserted through the hole or sheath into which the grout has been injected in the injection step, The precast concrete (PC) member is manufactured by a member cutting step, which involves cutting the concrete member through which the tensioning material cut in the cutting step is inserted. A method for manufacturing PC components characterized by the following.

2. The insertion holes at both ends of the concrete member are provided on a straight line in the direction in which the tensioning member is inserted. A method for manufacturing a PC member according to claim 1, characterized by the above.

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