JP2016098593A - Tendon coupler and anchorage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable tendon coupler capable of connecting a tendon made from bundled steel wires and an anchorage capable of anchoring the tendon made from bundled steel wires without using a wedge.SOLUTION: A tendon coupler comprises: an anchorage block 11 which has multiple steel wire insertion holes 11a into each of which each steel wire of a tendon made by bundling multiple steel wires 3, and is connected to the steel wire 3 so that a tensioning force can be transmitted to the steel wire 3; an adjustment member 12 which is a bolt-like member with a hollow penetrating hole in an axial direction and is screwed with a male screw formed on an inner peripheral surface of the steel wire insertion hole on the anchorage block 11 so that a screwing length can be adjusted; and a rod 13 which is connected to the anchorage block 11 and transmits the tensioning force to the anchorage bock. A second tendon is connected to the rod through a sleeve 15. Each steel wire 3 is inserted into the steel wire insertion hole of the anchorage block 11 and the hollow penetrating hole of the adjustment member 12. A button head 3a formed by enlarging a diameter of an end of the steel wire is engaged to a head part 12c of the adjustment member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a connecting device that enables two tension members to be connected and to introduce tension force continuously, and a fixing device that is fixed to a structural member in a state in which the tension force is introduced to the tension member.

A tension material for introducing prestress into a concrete member or the like is fixed to a structural member made of concrete or the like in a state where a tension force is introduced. Further, depending on the method for constructing the structure, the scale of the structure, and the like, it may be necessary to connect the tendon in the middle.
When a steel wire or a steel stranded wire is used as the tension member, a fixing member that fixes the end of the tension member with a wedge is generally used. Further, when connecting, a method is adopted in which the ends of the steel strands are gripped by a wedge and the gripped portions are connected to each other.

In a tension material in which a plurality of steel strands are bundled, as described in Patent Document 1, it is fixed using a fixing block having a plurality of through holes. The through holes provided in the fixing block are inserted through the end portions of the respective tension members, and the inner diameter of the through holes is enlarged on the leading end side of the stranded wire. The steel strand is fixed to the fixing block by pushing a wedge between the through hole and the steel strand. A reaction force is applied to the concrete member from the fixing block via a steel plate or the like.
Further, when a plurality of steel strands are bundled and connected, the plurality of steel strands of both of the tension members to be connected are fixed to the fixing block in the same manner as the fixing, and these fixing blocks are connected to each other. In addition, as described in Patent Document 2, each steel strand is gripped by a cylindrical female cone and a wedge, and the steel cones are connected to each other by connecting the female cones to each other. .

  On the other hand, when a plurality of steel wires having a diameter of about 7 mm to 8 mm are bundled to form a tension material, a plurality of steel wires are arranged around one wedge, and the steel wires are sandwiched between a female cone having a hollow portion. What is fixed has been used for a long time. Further, connecting and using a tension material in which a plurality of steel wires are bundled is rarely used because it is inferior in economic efficiency and reliability.

JP-A-8-68158 JP 7-127691 A

  However, in a structure in which a tension member in which a plurality of steel wires are bundled is used, when expansion or expansion is performed, it is necessary to connect the tension member to another tension member to introduce a tension force. For example, in a bridge having a concrete floor slab, a tension material in which a plurality of steel wires are bundled is often used as a tension material arranged in a direction perpendicular to the bridge axis. When widening with such a bridge, it is desirable to connect the above-mentioned tendon disposed on the concrete floor slab. In other words, in order to place new concrete in the part where the bridge is widened and to introduce prestress as an integral part of the already used floor slab concrete, a new tension material is connected to the already placed tension material. It is desirable to introduce tension.

  In addition, in a structure in which a tension member in which a plurality of steel wires are bundled is used, the concrete near the fixing end of the tension member deteriorates and may need to be repaired. At this time, it is necessary to remove the deteriorated concrete, place new concrete, re-tension the tension material, and fix it. At this time, most of the tendon is integrated with the existing concrete structure by grout or the like, and the amount of elongation when re-tensioned becomes extremely small. For this reason, when trying to fix with a wedge, it becomes impossible to introduce tension to the tendon due to the wedge slipping during fixing.

  The present invention has been made in view of the circumstances as described above, and its purpose is to provide a tension member that can connect a tension member bundled with steel wires with high reliability and a tension bundle of steel wires. It is an object of the present invention to provide a fixing tool capable of fixing a material without using a wedge.

  In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a plurality of steel wire insertion holes through which each steel wire of a tension material bundled with a plurality of steel wires is inserted, and transmission of tension force to the steel wire A fixing block to which the fixing block can be coupled, and a bolt-shaped member having a hollow through hole in the axial direction, and adjusting a screwing length to a female screw formed on an inner peripheral surface of a steel wire insertion hole provided in the fixing block Is coupled to the other tension material connected to the tension material, and is coupled to the fixing block and transmits the tension force acting from the other tension material to the fixing block. And the adjustment member includes a button head formed by expanding an end portion of a steel wire inserted through the steel wire insertion hole of the fixing block and the hollow through hole of the adjustment member. Is introduced into each steel wire from the fixing block. It is intended to transmit the tensioning force provided by the tension member the connector.

In this tension member connecting device, the tension force transmitted from the other tension members is transmitted from the rod to each steel wire of the tension member via the fixing block and the adjusting member, and the tension force is surely introduced into the tension member. . Therefore, it can be set as a reliable connection tool.
In addition, the button heads at the ends of the steel wires are difficult to be provided at accurate positions. It can be made to contact. Therefore, when tension force is transmitted between other tension members, it is possible to suppress the tension force introduced to each steel wire constituting the tension member from causing a large difference between the steel wires.

  According to a second aspect of the present invention, there is provided the tension member connecting device according to the first aspect, further comprising a pressing member coupled to the fixing block and abutting against the button head to press the button head toward the fixing block. And

  In this tendon connection tool, the relative position between the fixing block and the steel wire button head is fixed by the pressing member. Therefore, the state in which the adjusting member is in contact with the button head of the steel wire can be maintained even before the tension material is introduced into the tension material and the other tension materials.

  According to a third aspect of the present invention, in the tension member connecting device according to the first or second aspect, the other tension member coupled to the rod is predetermined from one end of the cylindrical sleeve. It is fixed to the range via a wedge, and an internal thread is formed on the inner peripheral surface of the other end of the sleeve, and an external thread formed on the rod is screwed.

  In this tendon connecting tool, it is possible to transmit the tension force from other tendon materials to the rod and the fixing block via the sleeve, and reliably transmit the tension force to each steel wire via the adjusting member.

  The invention according to claim 4 is the connecting member of the tendon according to claim 1 or 2, wherein the other tendon coupled to the rod is made of a single steel strand, The steel stranded wire is coupled to the rod through a coupling member, and is provided between the structural member around the connecting member of the tendon and the coupling member or the fixing block, and the coupling member or the It is assumed that the fixing block has a rotation restraining means for restraining the fixing block from rotating about the axis of the tendon.

When a tension force is introduced into the steel strand, which is another tension material, a rotational force around the axis is generated in a direction in which the strand of the steel strand is to be returned. In the connecting member for the tendon according to the fourth aspect, the rotation restraining means suppresses the fixing block from being rotated by such a rotational force and causing the twisting of the steel wire bundled to be twisted. That is, the rotation restraining means applies a reaction force to the structural member to restrain the rotation of the fixing block or the coupling member, thereby suppressing the twisting of the tension material.
The structural member may be a concrete member in which the above-described tendon and other tendons connected to the tendon are embedded and prestress is introduced thereby. Moreover, the structural member etc. which were near the tendon and were fixedly supported separately from the tendon may be used.

  The invention according to claim 5 is provided with a fixing block that includes a plurality of steel wire insertion holes through which the steel wires of the tension members obtained by bundling a plurality of steel wires are inserted, and is coupled to the steel wires so that transmission of the tension force is possible. And a bolt-shaped member having a hollow through-hole in the axial direction, wherein the adjustment member is screwed to the female screw formed on the inner peripheral surface of the steel wire insertion hole provided in the fixing block so that the screwing length can be adjusted. A rod that is coupled to the fixing block and transmits a tension force to the fixing block; a nut that is screwed into a male screw portion included in the rod; and a hole that passes through the rod, and the nut is provided in the hole. A fixing plate that is locked to the periphery and applies a reaction force of the tension force introduced to the tension member to the concrete member, and the adjustment member includes the steel wire insertion hole of the fixing block and the adjustment member. Steel inserted through a hollow through hole Of the button head formed by the enlarged diameter end portion is engaged, said from the fixing block is intended to provide a fixing device of the tendon is to transmit the tensioning force to be introduced into each steel wire.

  In this tension material fixing tool, the rod is connected to a jack to perform tension, and tension force can be introduced from the rod to each steel wire constituting the tension material via the fixing block and the adjusting member. Even if the button head at the end of the steel wire is not formed at an accurate position, the length of the adjustment member protruding from the fixing block is adjusted so that the adjustment member contacts each of the button heads of all the steel wires. be able to. Therefore, tension can be introduced into each steel wire constituting the tension material without causing a large difference between them. And, when a wedge is used, the tension does not decrease at the time of fixing, and a predetermined tension can be accurately introduced.

  The invention according to claim 6 is the tensioner fixing device according to claim 5, further comprising a pressing member connected to the fixing block and abutting against the button head to press the button head toward the fixing block. And

  In this tensioner fixing device, the relative position between the fixing block and the steel wire button head is fixed by the presser member, and the adjustment member abuts against the steel wire button head even before the tension force is introduced. Can be maintained. Therefore, the fixing tool is held at a predetermined position.

  As described above, in the tension member connecting device of the present invention, it is possible to transmit a tension force almost evenly to each steel wire by connecting a tension material in which a plurality of steel wires are bundled with other tension materials. It becomes. Further, in the tension member fixing device of the present invention, even if the tension force is introduced into the tension material bundled with a plurality of steel wires and fixed without causing a decrease in the tension force, the range in which the tension force is introduced is short. Tension can be introduced accurately.

It is a schematic sectional drawing which shows the connecting tool of the tendon which is one Embodiment of this invention. It is the side view and front view of a fixing block which are used with the connecting device of the tendon shown in FIG. It is the schematic which shows the front view and side view of the adjustment member which are used with the connecting tool of the tendon shown in FIG. 1, and the state which attached the adjustment member to the fixing block. FIG. 2 is a side view and a front view of a rod used in the tendon connecting member shown in FIG. 1 and a side view of a pressing member that can be attached to the rod. It is a schematic sectional drawing which shows the process of widening a concrete floor slab using the connecting tool of the tendon shown in FIG. It is a schematic sectional drawing which shows the process of widening a concrete floor slab using the connecting tool of the tendon shown in FIG. It is a schematic sectional drawing which shows the process of widening a concrete floor slab using the connecting tool of the tendon shown in FIG. It is a schematic sectional drawing which shows the process of widening a concrete floor slab using the connecting tool of the tendon shown in FIG. It is a schematic sectional drawing which shows the process of widening a concrete floor slab using the connecting tool of the tendon shown in FIG. It is a schematic sectional drawing which shows the process of widening a concrete floor slab using the connecting tool of the tendon shown in FIG. FIG. 10 is a schematic cross-sectional view showing a tension member connecting device including rotation restraining means for restraining the fixing block from rotating about an axis, which is another embodiment of the present invention. It is a schematic sectional drawing which shows the fixing tool of the tendon material which is one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing a tendon connection tool according to an embodiment of the present invention.
This tendon connecting tool includes a first tendon 1 in which 12 steel wires 3 are bundled and a second tendon 2 in which 19 steel wires are twisted to form a single strand 4 of steel. To connect. The twelve steel wires 3 constituting the first tendon 1 all have a diameter of 8 mm. Moreover, the steel strand 4 which is the 2nd tension material 2 twists 19 steel wires, and makes diameter 28.6 mm.

  The connecting member for the tendon is attached to each of the fixing block 11 to which each of the steel wires 3 constituting the first tendon is locked, and each of the twelve steel wire insertion holes 11a provided in the fixing block 11. Adjustment member 12, a rod 13 connected to the fixing block 11, a pressing member 14 attached to the rod 13 and pressing the button head 3 a formed at the tip of the steel wire, and the rod 13. The main part is composed of a cylindrical sleeve 15 and a wedge 16 for fixing the second tendon 2 inserted inside the substantially cylindrical shape of the sleeve 15 to the sleeve 15. Yes. In addition, the said button head 3a enlarges the diameter of the front-end | tip part of the side to connect about each of the steel wire 3 which comprises a 1st tension material, and makes it button shape.

As shown in FIG. 2, the fixing block 11 has a front surface and a rear surface that are flat and parallel to each other, and a side surface that forms a cylindrical curved surface. A central hole 11b is formed along the center line of the cylindrical curved surface from the center of the front surface, and twelve steel wire insertion holes 11a penetrating the rear surface at equal intervals in the circumferential direction are formed around the central hole 11b.
The center hole 11b has a female screw cut on the inner peripheral surface, and the depth thereof is set so that the screw-in length of the rod 13 to be screwed with the female screw becomes a sufficient length. The central hole 11b may penetrate the rear surface.
The steel wire insertion hole 11a is provided to be inclined so as to approach the center side from the front side toward the rear side. The inner diameter of the steel wire insertion hole 11a is such that the steel wire 3 can be freely inserted near the rear surface, and the inner diameter is enlarged on the front surface side. A female screw is cut on the inner peripheral surface of the inner diameter enlarged portion 11c, and the adjusting member 12 can be screwed into the inner diameter enlarged portion 11c from the front side.

  As shown in FIG. 3, the adjusting member 12 is a bolt-shaped member having a hollow through hole 12a formed in the axial direction, and includes a screwed portion 12b having a male screw formed on the outer peripheral surface and a screwed portion 12b at the end. And a head portion 12c provided so as to protrude from the outer peripheral surface. The hollow through hole 12a has a size that allows the steel wire 3 constituting the first tendon 1 to be freely inserted. The screwed portion 12 b is screwed into the inner diameter enlarged portion 11 c of the steel wire insertion hole 11 a formed in the fixing block 11. The head 12c has a hexagonal peripheral surface, and can be easily rotated around the axis when screwing or adjusting the screwing amount. Further, a button head 3 a formed at the tip of the steel wire 3 is locked to the head portion 12 c.

The rod 13 is a rod-shaped member as shown in FIG. 4, and a first male screw portion 13b is formed in a predetermined range from a first end 13a which is an end screwed into the fixing block 11, and the other A second male screw portion 13d is formed in a predetermined range from the second end 13c, which is the end of the second end. Between the first male screw portion 13b and the second male screw portion 13d, there is formed a tool locking portion 13e having a flat side surface without forming a male screw, and this rod 13 is rotated around the axis. Therefore, a tool such as a wrench can be fitted. One of the first male screw portion 13b and the second male screw portion 13d is a so-called reverse screw, and the spiral inclination direction is provided in the reverse direction. Therefore, the internal thread of the center hole 11b of the fixing block 11 to be screwed with the external thread portion which is the reverse thread, or the internal thread of the sleeve 15 (which will be described in detail later) is also a reverse thread. Further, the first male screw portion 13b and the second male screw portion 13d have different screw pitches. In the present embodiment, the screw pitch of the first male screw portion 13b is the second screw screw pitch. It is smaller than the thread-like pitch of the male screw portion 13d. Therefore, the length in the axial direction in which the first male screw portion 13b is screwed into the female screw with the same rotation amount is smaller than the length in which the second male screw portion 13d is screwed.
The second end of the rod 13 is formed with a hole 13f in the axial direction from the center of the end face to avoid interference with the end of the second tension member 4.

  The pressing member 14 is a disk-shaped member having an opening 14 a in the center, and a female screw is cut on the inner peripheral surface of the opening and is screwed into the first male screw portion 13 b of the rod 13. . Therefore, it can be moved in the axial direction of the rod 13 by rotating, and can be pressed against the fixing block 11 by contacting the button head 3a formed on the steel wire 3 as shown in FIG. It has become.

The sleeve 15 has a cylindrical side surface, and a hollow hole 15a is formed in the axial direction. The hollow hole 15a has an inner diameter that changes in the axial direction. The inner diameter is the largest in a predetermined range from the first end 15b, which is one end in the axial direction, and the second male screw portion 13d of the rod 13 is provided. The internal thread portion 15c can be screwed. On the other end side from the female screw portion 15c, that is, the second end 15d side, the inner diameter of the hollow hole 15a is gradually reduced so that the second tendon 2 can be freely inserted through the second end 15d. ing.
Further, a wedge inspection hole 15e penetrating from the hollow hole 15a to the outer peripheral surface is formed between the female screw portion 15c of the sleeve 15 and the portion whose inner diameter is reduced. The wedge inspection hole 15e enables the state of the wedge 16 to be confirmed after the wedge 16 is pushed in and the sleeve 15 is fixed to the steel strand 4.

  The wedge 16 is obtained by dividing an axially symmetric member whose outer peripheral surface is a conical curved surface and whose inner peripheral surface is a cylindrical curved surface into a plurality of members in the circumferential direction. As shown in FIG. 1, the sleeve 15 is interposed between the second tension member 2 inserted into the hollow hole 15 a from the second end 15 d side of the sleeve 15 and the inner peripheral surface of the sleeve 15 that is gradually reduced. 15 is pushed from the first end 15b side. Accordingly, the outer peripheral surface which is a conical curved surface is pressed against the inner peripheral surface of the sleeve 15 whose diameter is gradually reduced, and the inner peripheral surface which is a cylindrical curved surface is pressed against the peripheral surface of the second tension member 2. Thus, when the sleeve 15 and the second tendon 2 are pushed in, the circumferential dimension of each divided wedge is set so that a gap is generated between the plurality of wedges. Has been. In addition, the surface of the wedge 16 that is pressed against the second tendon 2 is provided with a measure to increase friction so that no slip occurs between the second tendon 2.

Next, a description will be given of a process of introducing prestress so that the concrete floor slab of the bridge is widened and connected to the existing portion of the concrete and the widened portion of the concrete by using the above-mentioned tendon connecting member.
As shown in FIG. 5A, a tension material is disposed on the concrete slab 21 in a direction perpendicular to the axis of the bridge, and prestress has already been introduced. This tendon is a first tendon 1 in which 12 steel wires having a diameter of 8 mm are bundled. On the widening side of the concrete floor slab 21, the concrete of the fixing portion 21a of the first tendon 1 is suspended as shown in FIG. 5 (b) to expose the respective steel wires 3 of the first tendon 1. And these steel wires 3 are cut | disconnected so that protrusion length may become substantially the same.

  As shown in FIG. 6A, the steel wire 3 is inserted into a sheath 22 and a part of a coupler sheath 23 to be attached to a connection portion, and the tension material and its connecting portion are covered with the sheath after the tension material is connected. Keep it available. Then, one steel wire 3 is inserted into each of the 12 steel wire insertion holes 11 a from the rear surface side of the fixing block 11. At this time, the adjustment member 12 is screwed into the steel wire insertion hole 11 a formed in the fixing block 11 from the front side, and the steel wire 3 is formed in the adjustment member 12 from the steel wire insertion hole 11 a of the fixing block 11. It is inserted through the hollow through-hole 12 a and penetrated to the front side of the fixing block 11.

  The steel wire 3 inserted through the steel wire insertion hole 11a of the fixing block 11 and the hollow through hole 12a of the adjusting member 12 is attached with a jack head forming jack 24 as shown in FIG. The button head 3a is formed. The button head 3a is obtained by strongly compressing the tip end portion of the steel wire 3 in the axial direction by the jack 24 and causing plastic deformation to expand the diameter. The formed button head 3a is locked to the head portion 12c of the adjustment member 12, and has a sufficient outer diameter so as not to come off from the adjustment member 12 and the fixing block 11 in a state where tension is introduced into the steel wire 3. Shall have. Thus, the process of forming the button head 3a at the end of the steel wire is repeated, and the button head 3a is formed on all the twelve steel wires 3 as shown in FIG.

  When the button head 3a is formed on the steel wire, the fixing block 11 on which the adjustment member 12 is attached is drawn toward the distal end side of the steel wire 3, and the head 12c of the adjustment member 12 is abutted against the button head 3a. At this time, the position where the button head 3a is formed is slightly shifted in the axial direction for each steel wire 3, but by adjusting the screwing length of the adjusting member 12 screwed into the fixing block 11, With the central axis of the first tendon 1 and the central axis of the fixing block 11 coinciding with each other, the head 12c of the adjustment member can be brought into contact with the button head 3a for all the steel wires 3.

  On the other hand, the second tendon 2 connected to the first tendon 1 is composed of a single steel strand 4, and a sheath 25 is mounted around the steel strand 4, and FIG. As shown in a), the coupler sheath 26 of the connecting portion is attached. The coupler sheath 26 can be connected to the coupler sheath 23 attached to the first tendon 1 side so as to cover the connection portion. A sleeve 15 is fixed to the tip of the steel strand 4 using a wedge 16. As shown in FIG. 8A, a steel strand 4 is inserted into the sleeve 15 from the side where the inner diameter of the hollow hole 15a is reduced, that is, from the second end 15d side. Then, the wedge 16 is pushed between the inclined inner peripheral surface of the sleeve 15 and the steel strand 4 from the opposite side, that is, the first end 15b side. The wedge 16 is pressed against the inclined inner peripheral surface of the steel strand 4 and the sleeve 15 by pushing the wedge 16 strongly or pulling the sleeve 15 and the steel strand 4 away from each other, as shown in FIG. ), The sleeve 15 is fixed to the steel strand 4.

  As shown in FIG. 9 (a), the first male thread portion 13b of the rod 13 is screwed into the center hole 11b of the fixing block 11 attached to the steel wire 3 as the first tension material by a predetermined length. Let Then, the end portion of the steel strand 4 to which the sleeve 15 is fixed is abutted against the end surface on the opposite side of the rod 13, that is, the side where the second male screw portion 13d is formed. A tool such as a wrench is locked to the tool locking portion 13e of the rod 13 to rotate the rod 13 around the axis. At this time, since one of the first male screw portion 13b and the second male screw portion 13d formed on the rod 13 is a reverse screw, the first male screw portion 13b is rotated by rotating the first male screw portion 13b. And the second male screw portion 13 d can be screwed into the female screw portion 15 c formed in the sleeve 15. Also, the first male screw portion 13b and the second male screw portion 13d have different screw pitches, and the speed at which the first male screw portion 13b is screwed into the center hole 11b of the fixing block when the rod 13 is rotated is as follows. The second male screw portion 13d is smaller than the speed at which the second male screw portion 13d is screwed into the sleeve 15. However, the first male screw portion 13b is screwed into the fixing block 11 before the second male screw portion 13d is screwed into the sleeve 15, and the second male screw portion 13b as shown in FIG. 9B. When a sufficient length of 13d is screwed into the female screw portion 15c of the sleeve, the first male screw portion 13b is also screwed into the center hole 11b of the fixing block. Here, the sufficient length is a screw-in length sufficient to transmit a tension force from the fixing block 11 to the rod 13 or from the rod 3 to the sleeve 15.

  When the screwing of the rod 13 is completed, the presser member 14 screwed into the first male screw portion 13b of the rod 13 is rotated and brought into contact with the button head 3a. As a result, the button head 3 a is sandwiched between the adjustment member 12 and the pressing member 14, and the fixing block 11 is fixed to the steel wire 3.

  When the steel wire 3 as the first tendon and the steel strand 4 as the second tendon are connected as described above, the coupler sheaths 23 and 26 of the connecting portion are connected to connect the steel wire 3 and the steel. Cover the stranded wire 4 and the connection. As shown in FIG. 10A, a fixing plate 27 is attached to the other end of the steel strand 4, and a formwork 28 for assembling the concrete of the floor slab widening portion is assembled. And concrete is laid in a formwork.

  After the cast concrete 21a has hardened, the formwork 28 is removed, and a fixing tool 29 is attached to the tension end of the steel strand 4 as shown in FIG. 10B, and a tension jack 30 is attached. And tension | tensile_strength is introduce | transduced into the steel strand 3 which is the 1st tension material connected with the steel strand 4 which is the 2nd tension material. The tension is transmitted from the steel strand 4 to the fixing block 11 via the sleeve 15 and the rod 13, and the fixing block 11 is drawn to the tension side. The head 12c of the adjustment member 12 screwed into the steel wire insertion hole 11a of the fixing block 11 is engaged with the button head 3a formed at the end of the steel wire 3, so that the fixing block 11 is on the tension side. As it is drawn, tension is introduced into the steel wire 3. At this time, each adjusting member 12 is brought into contact with all the steel wires 3 from before the tension, and the tension force is introduced into each of the steel wires 3 in a state of being almost nearly equal.

In addition, when the 2nd tension | tensile_strength connected to the steel wire 3 which is a 1st tension | tensile_strength is the single steel strand 4, the sleeve 15 or the fixing block 11 which couple | bonds the strand 4 and the rod 13 is provided. There may be a need for a rotation restraining means for restraining the steel strand 4 from rotating about the axis.
When a tension force is introduced into one steel strand 4, a rotational force around the axis is generated in a direction to return the twist of the strand 4 from the steel. The sleeve 15 is rotated by this rotational force, and the rotational force is transmitted to the fixing block 11 through the rod 13. Accordingly, when the fixing block 11 rotates, the plurality of steel wires 3 coupled to the fixing block 11 are twisted so as to be entangled with each other. As shown in FIG. 5 to FIG. 10, when the steel wire 3 is embedded in an existing concrete member and a part of what is fixed to the concrete member by grout is suspended, a plurality of steel wires 3 are shortly covered. Are twisted to each other, and bending deformation occurs locally with a large curvature. If tension is introduced in this state, the steel wire 3 may be broken. For this reason, the rotation restricting means prevents the sleeve 15 or the fixing block 11 from rotating about the axis, and prevents the steel wire 3 from being twisted.
As the rotation restraining means for suppressing the rotation of the sleeve 15 or the fixing block 11, for example, the one shown in FIG. 11 can be adopted.

In the connection tool including the rotation restraining means, the steel plate 17 is provided between the sheath 25 through which the single strand 4 is inserted and the coupler sheath 26. The steel plate 17 has a circular outer peripheral edge and is provided with a circular hole in the center. And the sheath 25 is connected so that the circular hole of a center part may be followed, and the wire 4 is penetrated. A coupler sheath 26 is connected to the outer peripheral portion of the opposite surface of the steel plate 17. A bolt hole penetrating the steel plate 17 is formed between the circular hole and the outer peripheral edge of the steel plate 17, and a bolt 18 is inserted into the bolt hole and fixed. On the other hand, the end face of the sleeve 15 facing the steel plate 17 is provided with an axial hole 15 f at a position corresponding to the bolt 18. The tip of the bolt 18 is inserted into the hole 15f, and the bolt 18 is allowed to move in the axial direction within the hole 15f.
A plurality of such bolts 18 and sleeve holes 15f may be provided in the circumferential direction.

  Since the bolt 18 is inserted into the hole 15f provided in the sleeve 15 in this way, even if the steel strand 4 is tensioned and the sleeve 15 moves in the axial direction, the sleeve 15 is not restrained. Tension is introduced into the stranded wire 4 and the steel wire 3. Further, even if a tension force is introduced into the steel strand 4 and a force to rotate the sleeve in a direction to return the twist of the steel strand 4 is generated, the steel wire 17 is fixed to the steel plate 17 and the tip of the hole is formed in the sleeve 15. The bolts 18 inserted into 15 f restrain the rotation of the sleeve 15, and the rotation of the fixing block 11 and the twist of the steel wire 3 can be suppressed.

  The rotation restraining means is not limited to the one shown in FIG. 11, but includes a protrusion provided on the inner peripheral surface of the coupler sheath and an axial groove provided on the outer peripheral surface of the sleeve. It may be inserted into the groove so as to restrain the rotation of the sleeve and enable relative movement in the axial direction. Further, a protrusion protruding from the outer peripheral surface of the sleeve may be engaged with an axial groove or protrusion provided in the coupler sheath. Further, it is possible to employ a structure that restricts the rotation of the fixing block with the same structure.

  In embodiment described above, the 2nd tension material connected to the steel wire 3 which is a 1st tension material is the wire 4 from one steel, However, it replaces with the wire 4 from steel, and is steel. A rod can also be used. It is also possible to use a tension material in which carbon fibers or aramid fibers or the like are bundled and having a fixing end member having a male screw formed on the outer peripheral surface thereof. When using a tension material that can be provided with an external thread portion at the end as the second tension material, such as these tension materials, instead of the sleeve 15, the first end joined to the rod is directed toward the center portion. Thus, it is possible to use a sleeve in which the first female screw portion is formed and the second female screw portion is provided from the second end toward the central portion. The second thread can be connected to the first tension member via the sleeve, the rod, and the fixing block by screwing the male thread portion of the tension member into the second female thread portion of the sleeve.

Next, an embodiment of a tension member fixing device according to the present invention will be described with reference to FIG.
This tension material fixing tool fixes the tension material in which twelve steel wires 31 are bundled to the concrete member 32 in a state where the tension force is introduced.
This tension member fixing tool is installed in a fixing block 41 to which each of the steel wires 31 constituting the tension member is locked, and in each of the twelve steel wire insertion holes 41a provided in the fixing block 41. A member 42, a rod 43 connected to the fixing block 41, a pressing member 44 that is attached to the rod 43 and presses the button head 31 a provided at the end of the steel wire, and is connected to the fixing block 41. Further, a nut 45 that is screwed to the rod 43 and a fixing plate 46 that applies a reaction force of tension to the concrete member 32 from the nut 45 are provided.

As the fixing block 41, the adjusting member 42, and the pressing member 44 of the button head, the same ones used in the tension member connecting device shown in FIG. 1 can be adopted.
The rod 43 is a rod-shaped member, and a first male screw portion 43b is formed in a predetermined range from a first end 43a which is an end screwed into the fixing block 41, and a second end which is the other end. A second male screw portion 43d is formed in a predetermined range from 43c. Unlike the rod 13 used in the tension member connecting tool shown in FIG. 1, in the rod 43 used in the fixing tool, the first male screw portion 43b and the second male screw portion 43d are screwed in a normal direction. It is a so-called pure screw provided. The screw pitch may be the same or different.
The nut 45 is screwed into the second male screw portion 43 d of the rod 43.
The fixing plate 46 is made of a steel plate material such as a rectangle or a circle, and is provided with a through hole into which the rod 43 can be inserted in the center. A nut 45 is screwed into the rod 43 inserted into the through hole from the second end 43c side, and the nut 45 is brought into contact with the periphery of the through hole. Further, as shown in FIG. 11, the fixing plate 46 is used in a state where the back side is in close contact with the concrete member 32, and receives a reaction force when a tension force is introduced into the steel wire 31.

Such a tendon fixing device can be used in the following situations, for example.
If the vicinity of the anchorage of a concrete member that has been prestressed using a tension member bundled with steel wires has deteriorated over time and needs to be repaired, hold the concrete near the anchor of the tension member. It can be used when new concrete is placed and tension is again introduced into the tendon and fixed.

The process of repairing concrete deteriorated as described above and introducing prestress again can be performed as follows.
Fixing concrete near the fixing portion to expose the steel wire 31, attaching the fixing block 41 into which the adjusting member 42 is screwed to the steel wire 31, forming the button head 31a at the tip of the steel wire 31, fixing The process of drawing the block 41 toward the tip end side of the steel wire 31 and adjusting the screwing length of the adjustment member 42 so that the head 42a of the adjustment member 42 is brought into contact with the button head 31a for all the steel wires 31 from FIG. This can be performed in the same manner as in the case of using the tendon connection tool shown in FIG.
After the adjustment member 42 is brought into contact with the button head 31a for all the steel wires 31, the presser member 44 screwed into the rod 43 is rotated so as to press the button head 31a. Thereby, the fixing block 41 and the rod 43 are fixed to the steel wire 31.

  The rear end, that is, the second end 43 c of the rod 43 screwed into the fixing block 41 is inserted into the through hole of the fixing plate 46 and the nut 45 is screwed. Then, a sheath is attached so as to cover the steel wire 31, the fixing block 41, and the rod 42, which are tendons, and fixed to a formwork for placing new concrete. Concrete is placed in the mold, and after hardening, the tip end side is gripped from the nut 45 of the rod 43 and the rod 43 is pulled by a tensioning jack. As a result, the fixing block 41 is drawn, and a tension force is introduced into the steel wire 31 from the button head 31 a that is in contact with the head portion 42 a of the adjustment member 42. At this time, by adjusting the screwing length of the adjusting member 42, the adjusting member 42 is in contact with the button head 31a for all the steel wires, so that the tension force is introduced to the steel wire 31 almost evenly.

  When a predetermined tension force is introduced by the tensioning jack, the nut 45 is tightened in this state and strongly pressed against the fixing plate 46. When the tension of the jack is released, the tension is transmitted from the nut 45 to the concrete member 32 via the fixing plate 46, and the end of the tension material is fixed to the concrete member 32. When the tension force of the jack is released, the rod 43 is fixed through the nut 45, so that no axial slip occurs, and a predetermined tension force can be introduced into the tension material without reducing the tension force. .

  The present invention is not limited to the embodiment described above, and can be carried out by appropriately changing the shape, dimensions, etc. within the scope of the present invention. For example, in the above embodiment, the steel wire having a diameter of 8 mm is used, but it may be 7 mm, and each member to be used can be changed in size or the like correspondingly. Further, the holding members 14 and 44 are screwed into the first male screw portions of the rods 13 and 43, but are not limited to such a form, and are separately bolted to the fixing block. It is also possible to employ one that is connected to the button head and is pressed against the button head by tightening these bolts.

1: first tension material, 2: second tension material, 3: steel wire constituting the first tension material, 3a: button head formed at the tip of the steel wire, 4: second tension material Constituting steel strands,
11: fixing block, 11a: steel wire insertion hole provided in the fixing block, 11b: center hole, 11c: inner diameter enlarged portion of the steel wire insertion hole, 12: adjustment member, 12a: hollow through hole, 12b: screwed portion, 12c: head, 13: rod, 13a: first end in the axial direction of the rod, 13b: first male screw portion, 13c: second end in the axial direction of the rod, 13d: second male screw portion, 13e: tool 14a: Opening in the center, 15: Sleeve, 15a: Hollow hole, 15b: First end in the axial direction of the sleeve, 15c: Female thread portion in the sleeve, 15d: In the axial direction of the sleeve Second end, 15e: Wedge inspection hole, 15f: Hole provided in the sleeve, 16: Wedge, 17: Steel plate, 18: Bolt,
21: Concrete slab, 21a: Fixing part of tension material already arranged on the concrete slab, 22: Sheath, 23: Coupler sheath, 24: Jack for forming the button head, 25: Sheath, 26: Coupler sheath, 27: Fixing plate, 28: Formwork, 29: Fixing tool, 30: Jack for tension,
31: Steel wire, 31a: Button head formed at the tip of the steel wire, 32: Concrete member,
41: fixing block, 42: adjustment member, 42a: head of adjustment member, 43: rod, 43a: first end in the axial direction of the rod, 43b: first male screw portion, 43c: second in the axial direction of the rod End, 43d: second male threaded portion, 44: holding member, 45: nut, 46: fixing plate

Claims (6)

A fixing block having a plurality of steel wire insertion holes through which the steel wires of the tension members bundled with a plurality of steel wires are inserted, and coupled to the steel wires so as to be able to transmit a tension force;
A bolt-shaped member having a hollow through hole in the axial direction, and an adjustment member screwed to the female screw formed on the inner peripheral surface of the steel wire insertion hole provided in the fixing block so that the screwing length can be adjusted;
A rod that is coupled to another tendon connected to the tendon and is coupled to the fixing block and transmits a tension force acting from the other tendon to the fixing block;
The adjustment member is engaged with a steel wire insertion hole of the fixing block and a button head formed by expanding an end of a steel wire inserted through the hollow through hole of the adjustment member, A tension member connector characterized by transmitting a tension force to be introduced into each steel wire.   The tension member connecting device according to claim 1, further comprising a pressing member that is connected to the fixing block and presses the button head against the fixing block while being in contact with the button head.   The other tendon connected to the rod is fixed to a predetermined range from one end of the cylindrical sleeve via a wedge, and an internal thread is formed on the inner peripheral surface of the other end of the sleeve. 3. The tension member connecting device according to claim 1, wherein a male screw portion formed on the rod is screwed together. 4. The other tendon connected to the rod consists of a single strand of steel,
The steel strand is coupled to the rod via a coupling member,
Rotation restraint provided between the structural member around the connecting member of the tendon and the coupling member or the fixing block, and restrains the coupling member or the fixing block from rotating around the axis of the tendon. The tension member connecting device according to claim 1 or 2, further comprising means. A fixing block having a plurality of steel wire insertion holes through which the steel wires of the tension members bundled with a plurality of steel wires are inserted, and coupled to the steel wires so as to be able to transmit a tension force;
A bolt-shaped member having a hollow through hole in the axial direction, and an adjustment member screwed to the female screw formed on the inner peripheral surface of the steel wire insertion hole provided in the fixing block so that the screwing length can be adjusted;
A rod coupled to the fixing block and transmitting tension to the fixing block;
A nut to be screwed into the male screw part included in the rod;
A fixing plate that includes a hole through which the rod passes, the nut being locked around the hole, and a reaction force of a tension force introduced into the tension material acting on the concrete member;
The adjustment member is engaged with a steel wire insertion hole of the fixing block and a button head formed by expanding an end of a steel wire inserted through the hollow through hole of the adjustment member, A tension material fixing tool characterized by transmitting a tension force to be introduced into each steel wire.   6. The tensioner fixing device according to claim 5, further comprising a pressing member connected to the fixing block and abutting against the button head to press the button head toward the fixing block.

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