JP2000220254A - Tension anchoring structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the diversion of a precision-machined member to reduce cost for prestressing a concrete member or the like in tension anchoring structure for anchoring by tensioning a tension member with nonmetallic continuous fiber as main material. SOLUTION: A cylindrical member is inserted to the outside of the end of a tension member, and synthetic resin or mortar is filled to integrate the cylindrical member with the tension member 1 to form a stuck anchor body 2. The tension member 1 is inserted in a tension anchor jig 3 with an external thread cut on the outer peripheral surface, and the stuck anchor body 2 is locked to the tension anchor jig 3. A nut 4 is screwed in the tension anchor jig 3 to anchor the tension member 1 to a concrete member 10 or the like through an anchor plate 5. Tension is introduced in by screwing a tension pipe 6 to the outside of the tension anchor jig 3 and locking the other end of the tension pipe 6 to a jack 7. The tension anchor jig 3 can be a cylindrical member or a member split by an axial cutting face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension-fixing structure of a tension material used for a prestressed concrete member or the like, and more particularly, to a non-metal continuous fiber such as carbon fiber, aramid fiber, glass fiber or the like as a tension material. The present invention relates to a tension fixing structure when using an FRP tendon material formed by bundling fibers into a rod shape or a strand shape with a synthetic resin.

[0002]

2. Description of the Related Art Conventionally, as a tension member for introducing prestress into concrete, a PC steel rod, a PC steel wire or a PC steel wire has been widely used. The anchoring of these tendons generally forms threads at the ends of PC steel rods,
A nut is screwed into this and fixed via an anchor plate. In the case of the PC steel wire or the PC steel wire, the end portion is gripped using a wedge, and the introduction and fixing of the tension are performed.

On the other hand, in the case of a non-metal continuous fiber or a FRP tendon formed by forming a continuous fiber into a rod shape with a synthetic resin, which has been used as a tendon for prestressed concrete in recent years, such a conventional strain as described above is used. It is difficult to apply the fixing structure as it is. In other words, it is not possible to provide a thread directly on the FRP tendon like a PC steel bar,
When the continuous fiber or the FRP tendon is strongly gripped by using a wedge, the continuous fiber has a significantly lower shear strength than the tensile strength, and thus tends to break at the fixing portion. For this reason,
For fixing the continuous fiber or the FRP tendon material, a method utilizing the adhesive force of a synthetic resin or mortar has been proposed. For example, there is a structure as shown in FIG.

In this tension fixing structure, the FRP tendon 10
One end is inserted into a steel tubular member 102, and a non-shrink mortar or a synthetic fiber or the like is filled between them and hardened and integrated. The outer peripheral surface of the steel tubular member 102 is shown in FIG.
As shown in (a), a thread is formed, a nut 103 is screwed into the thread, and the thread is fixed to a concrete member or the like via an anchor plate 104. FIG. 4 (b)
As shown in FIG. 7, a female screw is formed inside the distal end of the tubular member 102, and the tension rod 105 is inserted and inserted.
The jack 10 is screwed into the jack 10 through the tension rod 105.
6 introduces tension. Note that a cylindrical tensioning member may be screwed to the outside of the cylindrical member, and tension may be applied through this.

[0005]

However, the above-mentioned conventional tension fixing structure has the following problems. The tension fixing structure provided at the end of the tension member is removed by the time the structure is completed, and may not be used as a permanent structure. In particular, since the FRP tendon is easy to provide irregularities on the peripheral surface and can increase the adhesive force with concrete or grout, the so-called post-tension method also introduces tension to the tendon, and then grouts the concrete structure. It is integrated with the body and the tension anchor is removed. That is, tension is introduced into the tendon material inserted into the sheath, and once fixed to the concrete member by the fixing device, grout is filled, and after fixing, the fixing device is removed. Then, the tension of the tendon is transmitted to the concrete by the adhesive force between the tendon and the grout, and prestress is introduced into the concrete by the same mechanism as that of the member to which the prestress was introduced by the pretensioning method.

[0006] When the prestress is introduced in this way, the portion of the tendon projecting outside the concrete member is cut off. In the conventional fixing structure shown in FIG. 4, the steel tubular member 102 fixed to the tension member 101 for tensioning and fixing is not required. Such a cylindrical member 102
Is precisely threaded on the outer peripheral surface and requires high production costs.However, it is tightly integrated with the tendon using synthetic resin or mortar, etc. It is difficult to use. For this reason, the expensive cylindrical member 10
2 is discarded only once, and there is a problem that the cost for introducing prestress increases. Similarly, when a tendon is used as a temporary material, the tendon itself is removed, and the tubular member cannot be diverted and is often discarded.

On the other hand, when prestress is introduced into concrete by the pretension method, a tension is introduced into the tendon by receiving a reaction force from an anchor block for tensioning a cable provided in a yard for producing prestressed concrete members. Then, fixing is performed. However, after the concrete poured so as to embed the tendon hardens, the tension is released at the fixing end, and the tendon is cut at the end of the concrete member. Therefore, there is a problem that the cut-out tendon and the tubular member fixed to this end are discarded, and a member subjected to precise screw processing cannot be diverted as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a tension fixing structure for introducing tension to a tension member and performing fixing, in which precise processing is performed. To reduce the cost for introducing prestress.

[0009]

In order to solve the above-mentioned problem, the invention according to claim 1 is a method of extrapolating a tubular member to an end of a tension member mainly composed of non-metal continuous fibers, and synthesizing the same. An adhesive fixing body formed integrally with the tendon material with resin or mortar; provided so as to surround the tendon material; the attached fixation body is locked so that the tendon material does not come off; A mountain-cut tension fixing jig, a fixing nut screwed to the tension fixing jig and transmitting tension to a structure around the tension member, and the adhesion fixing member is inserted inside, One end is screwed to the tension fixing jig, and the other end is provided with a tension tube engaged with a jack for introducing tension to the tension member.

In such a tension fixing structure, an adhesion fixing member is formed at an end of the tension member, which is locked by the tension fixing jig so that the tension member does not fall out of the tension fixing jig. Then, the tension of the tension member is transmitted to a structure such as a concrete member via a nut screwed into a thread on the outer peripheral surface of the tension fixing jig.

Further, when introducing tension into the tendon,
A tension tube having an inner diameter larger than the outer diameter of the adhesion fixing body is mounted on the outside of the adhesion fixing body, and one end is screwed to a tension fixing jig. The other end is engaged with a jack, and by operating the jack, the tension member is pulled through the tension tube and the tension fixing jig. As a result, tension is introduced into the tendon, and elongation occurs, and the tendon gradually comes out of the surrounding structure. Accordingly, a gap is formed between the nut and the structure, and the nut is rotated to tighten the nut. In this way, tension is introduced into the tendon, and the operation of the jack is stopped, whereby the nut is locked to the structure and the end of the tendon is fixed.

The fixing device is removed when it is no longer necessary to fix the tendon such that the tendon is integrated with the structure by an adhesive force or the tension is not required.
At this time, the tubular member forming the adhesion fixing body is integrated with the tension member with synthetic resin or mortar, and it is difficult to separate the tension member. Just being locked, it can be easily removed and reused.

According to a second aspect of the present invention, in the tension fixing structure according to the first aspect, the tension fixing jig has a minimum inner diameter larger than a maximum dimension in a direction perpendicular to an axis of the adhesion fixing member. It is provided with a fitting which is attached from the periphery of the tension member and locks the adhered fixing body to the tension fixing jig.

In order for the tension fixing jig provided to surround the tension member to be directly engaged with the adhesion fixing member, the maximum dimension in the direction perpendicular to the axis of the adhesion fixing member is larger than the inner diameter of the tension fixing jig. Needs to be larger. When the size of the adhered fixing body is larger than the inner diameter of the tension fixing jig,
The tension fixing jig cannot be attached after the adhesion fixing member is formed at the end of the tension member, and must be attached to the tension member before forming the adhesion fixing member.

However, in the tension fixing structure according to the second aspect, since the minimum inner diameter of the tension fixing jig is larger than the maximum dimension in the direction perpendicular to the axis of the adhesion fixing member, the adhesion fixing member is connected to the end of the tension member. After the formation of the tension fixing jig, the attached fixing body can be inserted inside the tension fixing jig, and the tension fixing jig can be mounted. Then, by inserting a locking metal between the tension fixing jig and the adhesion fixing body and locking them, the introduction and fixing of the tension of the tension member can be performed similarly to the tension fixing structure according to claim 1. It can be carried out.

According to the third aspect of the present invention, the locking member may be formed by dividing a ring-shaped or cylindrical member into a plurality of sections along a cutting surface in the axial direction.

Since such a locking member is divided into a plurality of parts, after the end portions of the adhesive fixing member and the tension member are inserted into the tension fixing jig, they are combined around the tension member to form a tension with the adhesion fixing member. It can be inserted between the fixing jigs. Then, the attached fixing body is locked by the locking fixture, and since the outer diameter of the locking fixture is larger than the minimum inner diameter of the tension fixing jig, it is locked by the tension fixing jig. Therefore, the attached fixing body is locked so as not to come out of the tension fixing jig.

Further, the locking metal member is a wedge-shaped member obtained by dividing a cylindrical body having a variable outer diameter into a plurality of parts by a cutting surface in an axial direction, and is provided inside the tension fixing jig. It can be penetrated and locked.

Even with such a locking member, a plurality of divided members can be combined around the tension member and inserted between the adhesion fixing member and the tension fixing jig to lock these members.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a tension fixing structure according to an embodiment of the present invention. This tension fixing structure introduces prestress into the concrete member 10 using the FRP tendon 1, and as shown in FIG. 1 (a), a cylindrical member extrapolated to the end of the FRP tendon 1 And a tension fixing jig 3 composed of a cylindrical tube into which the FRP tendon 1 is inserted, and the end of which the fixation and fixing body 2 is locked. It has. This tension fixing jig 3
Has an inner diameter smaller than the outer diameter of the adhered fixing body 2,
The attached fixing body 2 is locked at the end so that the FRP tendon 1 does not come off. A thread is cut on the outer peripheral surface of the tension fixing jig 3, and a fixing nut 4 is screwed into the thread. The fixing nut 4 has a bearing surface abutting on the fixing plate 5, and transmits the tension of the FRP tendon 1 to the concrete member 10 via the bearing block 9.

The FRP tendon 1 is formed by bundling non-metal continuous fibers such as carbon fiber, aramid fiber, glass fiber and the like, and forming it into a strand or a rod with a synthetic resin. And by providing the knot-like convex part on the peripheral surface,
The adhesive force with the grout is increased. The FRP tendon 1 is arranged in a duct formed by embedding a tubular sheath in a concrete member, and an end for tensioning and fixing projects outside the concrete member. The FRP tendon 1 as described above is
It is advantageous in that it is lighter than metal materials such as C steel wire and has excellent corrosion resistance and the like. It can also be used for structures that are non-magnetic and need to control the magnetic field.

The fixing and fixing member 2 is made of metal or FR.
A tubular member made of P is extrapolated to the end of the FRP tendon 1 and filled with mortar or synthetic resin between them.
FRP with cylindrical member due to adhesive force of hardened mortar etc.
The tendon 1 is firmly integrated with the tendon 1 so that the tubular member does not fall out of the FRP tendon 1 even when a large tension acts. The cylindrical member of the fixing member 2 is not threaded.

The tension fixing jig 3 is a metal cylindrical tube that has been subjected to precise screw processing. The tension member 1 is inserted into the inside without being integrated with the FRP tension member 1, and is adhered and fixed. Body 2
Is locked so as not to come off. At this time, the contact portion between the two has a size enough to withstand the bearing pressure. There are two types of tension fixing jigs: pre-installed type and post-installed type.
The tension fixing jig 3 is a pre-attached type, and is attached to the FRP tension member 1 in advance when attaching the adhesion fixing member 2. Therefore, this type of tension fixing jig is effective when the work of attaching the adhered fixing body 2 to the FRP tension member 1 is sequentially performed on site.

The bearing block 9 is a reinforcing steel member. The bearing block 9 is interposed between the fixing plate 5 and the concrete member 10 to introduce tension into the FRP tendon 1. .

Next, FRP is performed using the tension fixing jig 3.
A method for tensioning and fixing the tension member 1 will be described.
As shown in FIG. 1A, the F on which the adhered fixing body 2 is formed
After the supporting block 9, the fixing plate 5, the nut 4, and the tension fixing jig 3 are attached to the end of the RP tension member 1, the tension pipe 6 is attached to the tip side of the tension fixing jig 3 from outside the adhered fixing body 2. To join. The tension tube 6 has a female screw formed therein to be screwed with the tension fixing jig 3, and can be easily joined by screwing the tension tube 6 outside the distal end portion of the tension fixing jig 3. Further, the tension tube 6 is also threaded on the outer peripheral surface.

A center hole jack 7 is mounted around the tension tube 6, and a tip end of the center hole jack 7 is abutted against the fixing plate 5, and a nut 8 is screwed to a rear outer side of the tension tube 6 so that the tension tube 6 is centered. It is locked to the hole jack 7. Thereafter, the center hole jack 7 is operated by hydraulic pressure or the like, and the attached fixing body 2 is pulled through the tension pipe 6 and the tension fixing jig 3. As a result, tension is introduced into the FRP tendon 1 and elongation occurs, so that the FRP tendon 1 gradually comes out of the concrete member 10. Accordingly, a gap is formed on the concrete member side of the fixing nut 4, and the fixing nut 4 is tightened so as to be in close contact with the fixing plate 5.
Thus, tension is introduced into the FRP tendon material 1,
Even when the tensile force by the center hole jack is loosened, the fixing nut 4 is locked to the concrete member 10 via the fixing plate 5 and the support block 9, and the end of the FRP tendon 1 is fixed.

After the tension and fixation are completed, the duct entrance of the concrete member 10 is closed with a filler such as clay, a tube is inserted into the duct, grout is injected, and
The RP tendon 1 and the concrete member 10 are integrated.
After the grout hardens, a saw or the like is inserted into the portion where the FRP tendon 1 is exposed between the support blocks 9 to cut the FRP tendon 1, and the fixing plate 5, the fixing nut 4, the tension fixing jig Remove 3 mag. At this time, the cylindrical member of the adhesion fixing body 2 is integrated with the FRP tendon 1 by mortar or the like, and it is difficult to separate the FRP tendon. 2, it can be easily removed. Therefore, the tension fixing jig 3 can be reused.

When prestress is introduced into a concrete member by the pretensioning method using the tension fixing structure, a reaction force is applied to an anchor block fixedly provided in a production yard, and the tension tube 6 and The FRP tension member is stretched and fixed via the tension fixing jig 3. Thereafter, the formwork is assembled so as to surround the stretched tendon, and concrete is poured into the formwork to integrate the FRP tendon and the frame. After the concrete hardens, the tension is released at the anchoring end of the tendon, and the FRP tendon is cut to fit the end surface of the concrete member. Even when the prestressed is introduced in this way, the end of the FRP tendon which is not embedded in the concrete member and the adhered fixing body fixed thereto are discarded, but the tension fixing jig is reused. can do.

When the FRP tendon is used as a temporary material, the FRP tendon and its fixing device are removed after the tendon becomes unnecessary. In this case, the FRP tendon can be reused in some cases, but generally the length must be adjusted and the attached fixing member must be replaced with a new one. At this time, the tension fixing jig can be reused.

FIG. 2A is a schematic sectional view showing a tension fixing structure according to an embodiment of the present invention. This tension fixing structure is different from the tension fixing jig 3 used in the tension fixing structure shown in FIG. 1 in that a tension fixing jig 13 formed so that the minimum inner diameter is larger than the outer diameter of the adhesion fixing body 12. And a fitting 17 which is fitted inside the tension fixing jig 13 and locks the attached fixing body 12 to the tension fixing jig 13.

As shown in FIG. 2 (b), the tension fixing jig 13 has a reduced diameter portion 13a whose inner diameter is reduced by projecting inward near the rear end. The metal fitting 17 inserted therein is locked by the reduced diameter portion 13a. The inner and outer peripheral surfaces of the tension fixing jig 13 are threaded. The locking member 17 is obtained by dividing a ring-shaped member having a part with a large inner diameter and a part with a small inner diameter into two parts by a cut surface in the axial direction. The end face of the adhesive fixing body 12 on the side joined to the tension member abuts on the portion 17b having a small inner diameter and is locked.

The tension fixing jig 13 is of a retrofit type, and has an inner diameter larger than the outer diameter of the adhesion fixing body 12, so that it can be inserted even after the adhesion fixing body 12 is attached to the FRP tension member 11. . For this reason, the adhesion fixing body 12
Are manufactured in a lump at a factory, etc.
This is effective when attaching.

Next, a process of tensioning and fixing the FRP tensioning member 11 using the tension fixing jig 13 and the locking metal 17 will be described. The attached fixing body 12 is attached to the FRP tendon 11 in advance at a factory or the like. At the construction site, the adhesion fixing body 12 and the FRP
The tension member 11 is inserted from behind the tension fixing jig 13.
Then, the locking metal member 17 divided into two is attached to the fixing body 1.
At the back of 2, the FRP tensioning member 11 is assembled around, and inserted between the adhesion fixing body 12 and the tension fixing jig 13. As a result, the adhesion fixing body 12 is locked to the tension fixing jig 13 via the locking metal 17.

A fixing nut 14 is screwed onto the outer peripheral surface of the tension fixing jig 13, and a bearing surface of the fixing nut 14 is abutted against a fixing plate 15. A bearing block 19 is interposed between the fixing plate 15 and the concrete member 20. A tension tube 16 whose outer peripheral surface is threaded is screwed into the rear inner side of the tension fixing jig 13 for connection. The tension tube 16 is engaged with a center hole jack (not shown) in the same manner as the embodiment shown in FIG. 1, and the attached fixing body 12 is pulled through the tension tube 16 and the tension fixing jig 13. Then, the fixing nut 14 is tightened to the fixing plate 15 side to fix.

After the tension and fixation are completed, grout is injected into the sheath through which the tension material has been inserted, and the FRP tension material 11
After the grout hardens, the FRP tendon 11 is cut off and the fixing device is removed. Even in such a tension fixing structure, the tension fixing jig 13 can be reused.

FIG. 3A is a schematic sectional view showing a tension fixing structure according to an embodiment of the present invention. This tension fixing structure is different from the tension fixing jig 3 used in the tension fixing structure shown in FIG. 1 in that the minimum inner diameter is larger than the outer diameter of the adhesion fixing body 22 and the inner diameter is increased toward the concrete member 30. A tension fixing jig 23 having a portion to be reduced, and a locking metal fitting 27 which is a wedge-shaped member obtained by dividing a cylindrical body having a variable outer diameter into two parts and is fitted inside the tension fixing jig 23. And As shown in FIG. 3B, the tension fixing jig 23 has a portion 23a whose inner diameter is gradually reduced and a portion 23a whose inner diameter does not change.
b and a portion 23a whose inner diameter is reduced
A lock fitting 27 shown in (c) is fitted and locked by a wedge action. The outer peripheral surface of the tension fixing jig 23 and the portion where the diameter of the inner peripheral surface does not change are subjected to threading, and the tension tube 26 is screwed to the portion of the inner peripheral surface where the female screw is provided. . A fixing nut 24 is screwed to the outside of the tension fixing jig 23, and is locked to the fixing plate 25.

Such a tension fixing jig 23 is also of a retrofit type, and can be attached even after the adhesion fixing body 22 is attached to the FRP tension member 21 similarly to the tension fixing jig shown in FIG. And the locking metal fitting 27 divided into two
Is attached to the periphery of the FRP tendon material 21, and the adhered fixing body 2
2 and the tension fixing jig 23, the attached fixing body 22 is locked to the tension fixing jig 23, and tension can be introduced and fixed to the tension member. When the tension fixing structure becomes unnecessary, the tension fixing jig 23 can be reused.

[0038]

As described above, in the tension fixing structure according to the present invention, after the prestress is introduced into the structure, or after the tension member is used as a temporary material, the tension fixing structure at the fixing end is reduced. When it becomes unnecessary, it is possible to collect and reuse the tension fixing jig subjected to precise screw processing, and it is possible to reduce the cost for introducing prestress. In addition, by using a locking member between the adhesion fixing body and the tension fixing jig, the tension fixing jig can be attached even after the adhesion fixing body is attached to the FRP tendon material, and construction work and management can be performed. It will be easier.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a tension fixing structure according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a tension fixing structure according to an embodiment of the present invention, and a side view showing a tension fixing jig and a locking metal used in the tension fixing structure. FIG.

FIG. 3 is a schematic cross-sectional view showing a tension fixing structure according to an embodiment of the present invention, and a side view showing a tension fixing jig and a locking metal used in the tension fixing structure. FIG.

FIG. 4 is a schematic sectional view showing a conventional tension fixing structure, and a diagram showing a state in which a tension member is tensioned.

[Explanation of symbols]

 1, 11, 21 FRP tendon 2, 12, 22 Adhesive fixing body 3, 13 23 Tension fixing jig 4, 14, 24 Fixing nut 5, 15, 25 Fixing plate 6, 16, 26 Tension pipe 7 Center hole jack 8 Nut 9, 19, 29 Bearing block 10, 20, 30 Concrete member 17, 27 Locking bracket

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kahori Matsumoto 1726 Niragawa, Minamikawachi-cho, Kawachi-gun, Tochigi Prefecture Within Sumitomo Construction Co., Ltd. (72) Inventor Teiji Kumaoka 13th Arakicho, Shinjuku-ku, Tokyo F term (reference) 2E164 AA05 BA06 BA12 DA14 DA25 4G058 GA01 GB04 GF12 GF17 GF26 GF30

Claims (4)

[Claims] 1. An adhesive fixing member formed by extrapolating a tubular member at an end of a tension member mainly composed of non-metal continuous fibers and integrating the tension member with a synthetic resin or mortar; A tension fixing jig provided around the material, locked with the adhesion fixing body so that the tension member does not come off, and threaded on the outer peripheral surface; and screwed to the tension fixing jig, A fixing nut for transmitting a tension to a structure around the tension member; and the adhesion fixing member is inserted inside, and one end is screwed to the tension fixing jig and the other end is And a tension tube engaged with a jack for introducing a tension into the tension member. 2. The tension fixing jig has a minimum inner diameter larger than a maximum dimension in a direction perpendicular to an axis of the adhesion fixing member, and is mounted from around the tension member to fix the adhesion fixing member. The tension fixing structure according to claim 1, further comprising a locking member that locks the jig. 3. The locking member is obtained by dividing a ring-shaped or cylindrical member into a plurality of sections along a cutting surface in an axial direction.
The inner diameter of the ring-shaped or cylindrical member is set to a size in which the tension member is inserted and the attached fixing member is locked, and the outer diameter is set to be larger than the minimum inner diameter of the tension fixing jig. The tension fixing structure according to claim 2, wherein the tension fixing structure is formed. 4. The locking member is a wedge-shaped member obtained by dividing a cylindrical body having a variable outer diameter into a plurality of sections by a cut surface in an axial direction, and penetrates and locks the inside of the tension fixing jig. The tension fixing structure according to claim 2, wherein the tension fixing structure is provided.