Joint structure and joining method of concrete member

Abstract

To be able to maintain a state in which the opening of a connecting hole is sealed with a plate in a joint structure in which adjacent concrete members are joined.SOLUTION: A first concrete member A1 is provided with a box-shaped recess part 11 opening onto a joint surface 10 and a connecting hole 12 that opens on the bottom part of the box-shaped recess part 11 and goes through the first concrete member A1, a first PC steel rod B1 is inserted into the connecting hole 12, an end part B1' of the first PC steel rod B1 protruding into the box-shaped recess part 11 is fitted with a plate 15 that seals the opening of the connecting hole 12, an elastic member 16 and a fixing member 17, an end part B2" of a second PC steel rod B2 protruding from the joint surface 10 of a second concrete member A2 is connected to the end part B1' of the first PC steel rod B1 within the box-shaped recess part 11, and tension is applied to the first PC steel rod B1 and the second PC steel rod B2, and thus the first concrete member A1 and the second concrete member A2 are joined.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a joining structure and a joining method for concrete members.

Background Art

[0002] Conventionally, as shown in FIG. 7, a plurality of concrete members 100 such as box culverts are arranged side by side, and a plurality of concrete members 100 are connected by PC steel bars 101 passed through each concrete member 100 to construct a structure 102 such as a tunnel, a water pipe, or a ditch. The concrete members 100 are manufactured by various methods, for example, precast concrete or a combination of precast concrete and cast-in-place concrete.

[0003] For example, in Patent Document 1, as shown in FIG. 8, PC steel bars 101 are respectively passed through connecting holes 105 penetrating each concrete member 100, and inside a box-shaped recess 106 opened on one side surface of each concrete member 100, the ends of the PC steel bars 101 passed through each concrete member 100 are connected to each other using a coupler 107. In this way, in a state where the PC steel bars 101 arranged so as to penetrate each concrete member 100 are connected, when tension is applied to the PC steel bars 101, the adjacent concrete members 100 can be joined in close contact with each other.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in the joining structure shown in Patent Document 1, after the concrete members 100 are brought into close contact with each other, it is common for a time-dependent hardening material such as grout to be filled into the connecting holes 105 via the inside of the box-shaped recess 106. Therefore, when the plate 108 is disposed at the opening of the connecting hole 105 that appears at the bottom of the box-shaped recess 106, a notch is provided in the plate 108 so that the time-dependent hardening agent filled in the box-shaped recess 106 is then filled into the connecting hole 105.

[0006] In recent years, the management of the filling state of the time-dependent hardening agent has become more stringent. Injection holes are provided in the box-shaped recess 106 and the connecting holes 105 respectively to inject the time-dependent hardening material, and they are sealed from each other to manage the filling state of the time-dependent hardening agent individually. However, in the conventional joining structure, as shown in FIG. 9, when tension is applied to the PC steel bars 101 to join the concrete members 100, the PC steel bars 101 may elongate, causing the plate 108 to move inward of the box-shaped recess 106. When the time-dependent hardening material is injected into the box-shaped recess 106 and the connecting holes 105 with the plate 108 separated from the opening of the connecting hole 105 in this way, the filled time-dependent hardening material may leak between the connecting hole 105 and the box-shaped recess 106, and there may be a shortage of filling of the time-dependent hardening material inside the box-shaped recess 106 or the connecting hole 105.

[0007] On the other hand, as shown in FIG. 10, a structure in which the positions of the PC steel bars 101 are changed for each concrete member 100 and no tension is applied to the PC steel bars 101 between adjacent PC steel bars 101 is also conceivable. However, in order to change the position of the PC steel bar 101 for each concrete member 100 as shown in FIG. 10, a plurality of types of concrete members 100 with different positions of the PC steel bar 101 must be prepared, resulting in high costs. Also, the order and arrangement of arranging the plurality of concrete members 100 must be considered, which is complicated.

[0008] In view of the above circumstances, an object of the present invention is to provide a means capable of maintaining a state in which an opening of a connection hole is sealed with a plate in a joining structure in which adjacent concrete members are joined.

Means for Solving the Problems

[0009] In order to solve such problems, according to the present invention, there is provided a joining structure in which a first concrete member and a second concrete member adjacent to each other are joined via a joining surface, wherein the first concrete member includes a box-shaped recess opening to the joining surface and a connection hole opening to the bottom of the box-shaped recess and penetrating the first concrete member. A first PC steel bar is inserted into the connection hole of the first concrete member, and a plate for sealing the opening of the connection hole, an elastic member for urging the plate toward the connection hole, and a fixing member for supporting the elastic member are attached to an end portion of the first PC steel bar protruding into the box-shaped recess. An end portion of the second PC steel bar protruding from the joining surface of the second concrete member is connected to the end portion of the first PC steel bar in the box-shaped recess, and by applying tension to the first PC steel bar and the second PC steel bar, the first concrete member and the second concrete member are joined. A joining structure is provided.

[0010] In this joining structure, the box-shaped recess and the connection hole of the first concrete member may be filled with a time-hardening material. Further, a sealing material covering the opening of the box-shaped recess of the one concrete member may be disposed on the joining surface of the second concrete member.

[0011] According to the present invention, there is also provided a method for joining the first concrete member and the second concrete member by the joining structure described above, wherein the method includes inserting into a connecting hole of the first concrete member and projecting into a box-shaped recess of the first concrete member an end portion of a first PC steel bar, mounting a plate for sealing an opening of the connecting hole of the first concrete member, an elastic member for biasing the plate toward the connecting hole, and a fixing member for supporting the elastic member, connecting an end portion of a second PC steel bar projecting from a joint surface of the second concrete member adjacent to the first concrete member to the end portion of the first PC steel bar, and applying tension to the first PC steel bar and the second PC steel bar to join the first concrete member and the second concrete member.

[0012] In this joining method, the box-shaped recess and the connecting hole of the first concrete member may be filled with a time-lapse hardening material. Further, such a joining method may be repeated.

Advantages of the Invention

[0013] According to the present invention, in a joining structure in which adjacent concrete members are joined, by biasing the plate toward the connecting hole with an elastic member, it becomes possible to maintain a state in which the opening of the connecting hole is sealed with the plate. As a result, it is possible to prevent the time-lapse hardening material filled in the connecting hole from leaking into the box-shaped recess, and to avoid insufficient filling of the time-lapse hardening material inside the connecting hole.

[0014] Note that the above effects are not necessarily limited, and any of the effects shown in this specification, or other effects that can be grasped from this specification, may be achieved together with, or instead of, the above effects.

Brief Description of the Drawings

[0015]

Figure 1

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Figure 10

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration may be denoted by the same reference numerals, and redundant description may be omitted.

[0017] FIG. 1 shows an example of a joint structure 1 of a concrete member according to an embodiment of the present invention. In this joint structure 1, it has a structure in which a first concrete member A1 on the right and a second concrete member A2 on the left adjacent to each other are joined via a joint surface 10.

[0018] The first concrete member A1 includes a box-shaped recess 11 that opens to the joint surface 10 and a connecting hole 12 that opens at the bottom of the box-shaped recess 11 and penetrates the first concrete member A1. In the first concrete member A1, one end of the connecting hole 12 (the left end of the connecting hole 12 in the illustrated example) opens at the bottom of the box-shaped recess 11, and the other end of the connecting hole 12 (the right end of the connecting hole 12 in the illustrated example) opens on the right side surface of the first concrete member A1 (the surface opposite to the joint surface 10). Note that the second concrete member A2 also basically has the same configuration. That is, the second concrete member A2 also has a box-shaped recess 11 that opens to the joint surface between the second concrete member A2 and the next concrete member (not shown), and a connecting hole 12 that opens at the bottom of the box-shaped recess 11 and penetrates the second concrete member A2.

[0019] A first PC steel bar B1 is inserted into the connecting hole 12 of the first concrete member A1. One end portion of the first PC steel bar B1 (the left end portion of the first PC steel bar B1 in the illustrated example) B1' protrudes into the box-shaped recess 11 provided in the first concrete member A1, and the other end portion of the first PC steel bar B1 (the right end portion of the first PC steel bar B1 in the illustrated example) B1" protrudes from the right side surface of the first concrete member A1 (the surface opposite to the joint surface 10). A sealing plate 5 and a fixing member 6 such as a nut for supporting the sealing plate 5 are attached to the protruding other end portion B1" of the first PC steel bar B1. Note that the second concrete member A2 also basically has the same configuration. That is, a second PC steel bar B2 is inserted into the connecting hole 12 of the second concrete member A2. One end portion of the second PC steel bar B2 (the left end portion of the second PC steel bar B2 in the illustrated example) B2' protrudes into the box-shaped recess 11 provided in the second concrete member A2, and the other end portion of the second PC steel bar B2 (the right end portion of the second PC steel bar B2 in the illustrated example) B2" protrudes from the joint surface 10 between the first concrete member A1 and the second concrete member A2 into the box-shaped recess 11 of the first concrete member A1.

[0020] The first concrete member A1 is provided with an injection hole 7 communicating with the box-shaped recess 11 and an injection hole 8 communicating with the connection hole 12. Similarly, the second concrete member A2 is also provided with an injection hole 7 communicating with the box-shaped recess 11 and an injection hole 8 communicating with the connection hole 12.

[0021] One end B1' of the first PC steel bar B1 and the other end B2" of the second PC steel bar B2 are connected by a connecting member 13 such as a coupler within the box-shaped recess 11 of the first concrete member A1. Thus, tension is transmitted from the second PC steel bar B2 to the first PC steel bar B1.

[0022] In the first concrete member A1, a plate 15 for sealing the opening of the connection hole 12, an elastic member 16 for biasing the plate 15 toward the connection hole 12, and a fixing member 17 for supporting the elastic member 16 are attached to the end B1' of the first PC steel bar B1 protruding into the box-shaped recess 11.

[0023] As enlarged and shown in FIG. 2, in the first concrete member A1, the plate 15 is disposed in close contact with the bottom of the box-shaped recess 11 so as to seal the opening of the connection hole 12. On the back surface of the plate 15 (the inner side of the box-shaped recess 11, the left side surface of the plate 15 in the illustrated example), an elastic member 16 such as a disc spring is disposed. Further, on the back surface of the elastic member 16 (the inner side of the box-shaped recess 11, the left side surface of the elastic member 16 in the illustrated example), a fixing member 17 such as a nut is attached. The first PC steel bar B1 passes through these plate 15, elastic member 16, and fixing member 17. The plate 15 and the elastic member 16 are movable with respect to the first PC steel bar B1, but the attachment position of the fixing member 17 with respect to the first PC steel bar B1 is fixed. And thus, with the elastic member 16 disposed on the back surface of the plate 15, by moving the attachment position of the fixing member 17 with respect to the first PC steel bar B1 closer to the plate 15, a compressive force is applied to the elastic member 16, and the plate 15 is biased toward the connection hole 12 by the repulsive force thereof, so that the plate 15 is always brought into close contact with the bottom of the box-shaped recess 11.

[0024] Note that the second concrete member A2 also basically has the same configuration. That is, also in the second concrete member A2, at the end B2' of the second PC steel bar B2 protruding into the box-shaped recess 11, a plate 15 for sealing the opening of the connecting hole 12, an elastic member 16 for biasing the plate 15 toward the connecting hole 12 side, and a fixing member 17 for supporting the elastic member 16 are mounted. And similarly in the second concrete member A2, a compressive force is applied to the elastic member 16, and the plate 15 is biased toward the connecting hole 12 by the repulsive force thereof, so that the plate 15 is always brought into close contact with the bottom of the box-shaped recess 11.

[0025] Next, an example of the joining method of the joining structure 1 of the concrete member according to the embodiment of the present invention configured as described above will be described.

[0026] First, as shown in FIG. 3, the plate 15, the elastic member 16, and the fixing member 17 are sequentially mounted on one end B1' of the first PC steel bar B1 inserted into the connecting hole 12 of the first concrete member A1 and protruding into the box-shaped recess 11 of the first concrete member A1. Note that the other end B1" of the first PC steel bar B1 inserted into the connecting hole 12 of the first concrete member A1 is fixed by a fixing member 6 in a state where the connecting hole 12 is closed by a sealing plate 5 on the right side surface (the side surface opposite to the joining surface 10) of the first concrete member A1.

[0027] Then, with the other end B1" of the first PC steel bar B1 fixed in this way, the mounting position of the fixing member 17 with respect to the first PC steel bar B1 is moved closer to the plate 15, thereby applying a compressive force to the elastic member 16, and the plate 15 is biased toward the connecting hole 12 by the repulsive force thereof, and the plate 15 is brought into close contact with the bottom of the box-shaped recess 11.

[0028] Also, a connecting member 13 such as a coupler is mounted on the tip of one end B1' of the first PC steel bar B1.

[0029] Next, as shown in FIG. 4, the first concrete member A1 and the second concrete member A2 are arranged adjacent to each other via the joint surface 10. In this case, as shown in FIG. 3, it is desirable to previously arrange the sealing material 20 so as to cover the opening of the box-shaped recess 11 of the first concrete member A1. By covering the opening of the box-shaped recess 11 with the sealing material 20 in this way, as shown in FIG. 4, when the first concrete member A1 and the second concrete member A2 are arranged adjacent to each other, at the joint surface 10, the opening of the connecting hole 12 of the second concrete member A2 can be blocked with the sealing material 20.

[0030] Next, as shown in FIG. 5, from the side surface opposite to the joint surface 10, the second PC steel bar B2 is inserted into the connecting hole 12 of the second concrete member A2, and the other end B2" of the second PC steel bar B2 is connected to one end B1' of the first PC steel bar B1 with the connecting member 13 inside the box-shaped recess 11 of the first concrete member A1. Then, the plate 15, the elastic member 16, and the fixing member 17 are sequentially attached to one end B2' of the second PC steel bar B2 protruding into the box-shaped recess 11 of the second concrete member A2.

[0031] Then, with the other end B2" of the second PC steel bar B2 connected to one end B1' of the first PC steel bar B1 in this way, the attachment position of the fixing member 17 with respect to the second PC steel bar B2 is moved closer to the plate 15, thereby applying a compressive force to the elastic member 16. With the repulsive force of the elastic member 16, the plate 15 is biased toward the connecting hole 12 side, and the plate 15 is brought into close contact with the bottom of the box-shaped recess 11. Note that when a compressive force is applied to the elastic member 16 in this way and the plate 15 is brought into close contact with the bottom of the box-shaped recess 11, a tension is generated between the second PC steel bar B2 and the first PC steel bar B1, and at the joint surface 10, the first concrete member A1 and the second concrete member A2 can be joined in close contact. At this time, an elongation strain ΔL is generated in the PC steel bar B1 due to the tension, and the position of the fixing member 17 attached to the PC steel bar B1 shifts by ΔL toward the concrete member A2 side. As a result, the elastic member 16 extends, and its compressive force is relaxed, but the state in which the plate 15 is kept in close contact with the bottom of the box-shaped recess can be maintained by the remaining compressive force.

[0032] Also, a connecting member 13 such as a coupler is attached to the tip of one end B2' of the second PC steel bar B2.

[0033] In this way, after the first concrete member A1 and the second concrete member A2 are joined in close contact via the joint surface 10, a time-dependent hardening material 21 such as grout or cement milk is filled into the connecting hole 12 of the first concrete member A1 through the injection hole 8. Similarly, the box-shaped recess 11 of the first concrete member A1 may be filled with a time-dependent hardening material 21 such as grout or cement milk through the injection hole 7. Further, the connecting hole 12 of the second concrete member A2 may be filled with a time-dependent hardening material 21 such as grout or cement milk through the injection hole 8. Note that the time-dependent hardening material 21 filled in each of the connecting hole 12 of the first concrete member A1, the box-shaped recess 11 of the first concrete member A1, and the connecting hole 12 of the second concrete member A2, and the injection holes 7 and 8 are shown in FIG. 1.

[0034] In the joining structure 1 of the concrete member according to the embodiment of the present invention joined in this way, a tension is applied between the second PC steel bar B2 and the first PC steel bar B1. When the first concrete member A1 and the second concrete member A2 are closely joined at the joining surface 10, in the box-shaped recess 11 of the first concrete member A1, the plate 15 is biased toward the connecting hole 12 by the elastic member 16. Therefore, the state in which the opening of the connecting hole 12 is sealed by the plate 15 can be maintained. As a result, it is possible to prevent the time-dependent hardening material 21 filled in the connecting hole 12 and the box-shaped recess 11 of the first concrete member A1 from leaking out from each other, and it is possible to avoid insufficient filling of the time-dependent hardening material 21 inside the connecting hole 12 or inside the box-shaped recess 11. By filling the connecting hole 12 and the box-shaped recess 11 of the first concrete member A1 with the time-dependent hardening material 21 without gaps, the rust prevention effect of the first PC steel bar B1 inserted into the connecting hole 12 and the box-shaped recess 11 can be maintained, and the strength can be improved by the integral structure. By filling the connecting hole 12 with the time-dependent hardening material 21 through the injection hole 8 and filling the box-shaped recess 11 with the time-dependent hardening material 21 through the injection hole 7, the spaces inside the connecting hole 12 and the box-shaped recess 11 can be insulated and sealed separately, and the filling amount of the time-dependent hardening material such as grout injected from the injection holes 7 and 8 can be managed individually. As a result, insufficient filling of the time-dependent hardening material can be prevented.

[0035] As described above, an example of the embodiment of the present invention has been described, but the present invention is not limited to the illustrated form. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the idea described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.

[0036] An example of closely adhering and joining the first concrete member A1 and the second concrete member A2 has been described. After closely adhering and joining the first concrete member A1 and the second concrete member A2, next, through a similar process, the second concrete member A2 and the next third concrete member A3 (not shown) can also be closely adhered and joined. Further, by repeating the same joining method as described below, a plurality of concrete members can be joined together.

[0037] After the first concrete member A1 and the second concrete member A2 are closely adhered and joined, an example of filling the connection hole 12 and the box-shaped recess 11 of the first concrete member A1 with the time-lapse hardening material 21 has been described. After the first concrete member A1 and the second concrete member A2 are closely adhered and joined, next, similarly, the second concrete member A2 and the next third concrete member A3 (not shown) are closely adhered and joined. Then, the connection hole 12 and the box-shaped recess 11 of the first concrete member A1 and the connection hole 12 and the box-shaped recess 11 of the second concrete member A2 may be filled with the time-lapse hardening material 21 together. Further, the filling of the time-lapse hardening material 21 into the connection holes of each concrete member can be performed at any timing as long as the opening of the connection hole 12 is sealed by the plate 15. Similarly, the filling of the time-lapse hardening material 21 into the box-shaped recess 11 of each concrete member can be performed at any timing as long as the box-shaped recess is sealed by the sealing material 20 (and the adjacent concrete member).

[0038] Also, the effects described in this specification are merely illustrative or exemplary and not limiting. That is, the technology according to the present disclosure can exhibit other effects that are obvious to those skilled in the art from the description of this specification, together with or instead of the above effects.

Example

[0039] As shown in Fig. 6, a test piece 2 simulating the joint structure 1 of the concrete member according to the embodiment of the present invention was constructed, and the filling performance of the time-dependent hardening material 21 was tested. As shown in Fig. 6, in the test piece 2, a space 31 assuming the connecting hole 12 was formed inside the casing 30, and the first PC steel bar B1 was inserted through the space 31. The end B1' of the first PC steel bar B1 was projected from the left side surface of the casing 30, and a plate 15 for sealing the opening 31' of the space 31, an elastic member 16 for urging the plate 15 toward the casing 30 side, and a fixing member 17 for supporting the elastic member 16 were attached to the end B1'. Further, the end B1" of the first PC steel bar B1 was projected from the right side surface of the casing 30, and a plate 15 for sealing the opening 31" of the space 31 and a fixing member 17 for pressing the plate 15 toward the casing 30 side were attached to the end B1". Then, at the end B1' of the first PC steel bar B1, by moving the attachment position of the fixing member 17 with respect to the first PC steel bar B1 closer to the plate 15, a compressive force was applied to the elastic member 16, and the plate 15 was urged toward the connecting hole 12 side by the repulsive force thereof, so that the plate 15 was always in close contact with the bottom of the box-shaped recess 11.

[0040] In this way, with the plate 15 in close contact with the bottom of the box-shaped recess 11, a tensile force F was applied to the first PC steel bar B1 by a cylinder device 35 attached to the end B1' of the first PC steel bar B1. The tensile force F was set to a load equivalent to the tensile force on the first PC steel bar B1 when the first concrete member A1 and the second concrete member A2 were closely joined. Then, with the tensile force F applied to the first PC steel bar B1, the time-dependent hardening material 21 was filled into the space 31 through the inlet 36. At that time, the air in the space 31 was extracted through the air hole 37.

[0041] As a result, even when the time-dependent hardening material 21 was filled into the space 31 with the tensile force F applied to the first PC steel bar B1, the state where the plate 15 was in close contact with the bottom of the box-shaped recess 11 was maintained, and thus no leakage of the time-dependent hardening material 21 occurred.

Industrial Applicability

[0042] The present invention can be applied to a joining structure and a joining method of concrete members.

Explanation of Signs

[0043] A1 First concrete member A2 Second concrete member B1 First PC steel bar B2 Second PC steel bar 1 Joining structure of concrete members 2 Specimen 5 Sealing plate 6 Fixing member 7, 8 Injection holes 10 Joining surface 11 Box-shaped recess 12 Connecting hole 13 Connecting member 15 Plate 16 Elastic member 17 Fixing member 20 Sealing material 21 Time-dependent hardening material 30 Casing 31 Space 35 Cylinder device 36 Entrance 37 Air hole 100 Concrete member 101 PC steel bar 102 Structure 105 Connecting hole 106 Box-shaped recess 107 Coupler 108 Plate

Claims

1. A joining structure in which a first concrete member and a second concrete member adjacent to each other are joined via a joining surface, wherein the first concrete member includes a box-shaped recess opening to the joining surface and a connecting hole opening to the bottom of the box-shaped recess and penetrating the first concrete member, a first PC steel bar is inserted into the connecting hole of the first concrete member, and a plate for sealing the opening of the connecting hole, an elastic member for urging the plate toward the connecting hole, and a fixing member for supporting the elastic member are attached to an end of the first PC steel bar protruding into the box-shaped recess, an end of a second PC steel bar protruding from the joining surface of the second concrete member is connected to an end of the first PC steel bar in the box-shaped recess, and the first concrete member and the second concrete member are joined by applying tension to the first PC steel bar and the second PC steel bar. A joining structure characterized by this.

2. The joining structure according to claim 1, characterized in that a time-dependent hardening material is filled in the box-shaped recess and the connecting hole of the first concrete member.

3. The joining structure according to claim 2, characterized in that a sealing material covering the opening of the box-shaped recess of the first concrete member is arranged.

4. A method of joining the first concrete member and the second concrete member by the joining structure according to claim 1, wherein a plate for sealing the opening of the connecting hole of the first concrete member, an elastic member for urging the plate toward the connecting hole, and a fixing member for supporting the elastic member are attached to an end of the first PC steel bar inserted into the connecting hole of the first concrete member and protruding into the box-shaped recess of the first concrete member, an end of a second PC steel bar protruding from the joining surface is connected to an end of the first PC steel bar, and the first concrete member and the second concrete member are joined by applying tension to the first PC steel bar and the second PC steel bar. A joining method characterized by this.

5. The joining method according to claim 4, characterized in that a time-dependent hardening material is filled in the box-shaped recess and the connecting hole of the first concrete member.

6. A joining method, characterized in that a concrete member is further added to the second concrete member, and the joining method according to claim 4 or 5 is repeatedly performed.

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