JPH06116948A - Tensionning and anchoring method of frp tendon - Google Patents

Abstract

PURPOSE:To prevent a tendon from cutting by placing the end of the tendon into the center hole of a wedge after an adhesive is applied between surfaces opposite to each other of the wedge consisting of two vertically split divided bodies. CONSTITUTION:An adhesive 30 of natural rubber, etc., is applied to surfaces 3c opposite to each other of two vertically split divided bodies 3' forming a wedge 3 having the peripheral surface 3b in the shape of a cone. After that, the end of an FRP tendon 2 is inserted into the center hole 3a of the wedge 3. Then, the wedge 3 is inserted into a through-hole 1a of an anchor head 1. In addition, the end of the tendon 2 is tensioned by a center hole jack and is anchored to a concrete construction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension fixing method for an FRP tension member, and more specifically, an FRP tension member used as a tension member for prestressed concrete structures or a tension member for joining marine structures. The present invention relates to a tension fixing method for tension materials.

[0002]

2. Description of the Related Art FIG. 3 is a principle explanatory view of a tension fixing method for an FRP tension member. The tension fixation of the FRP tension material is
A central hole 3a which is composed of two longitudinally divided bodies and whose outer peripheral surface 3b has a conical shape as a whole and through which the FRP tension member is inserted.
And each mutual facing surface 3c located on the left and right of the center hole.
Are wedges 3 each having a shape uniformly removed by an appropriate thickness, and a tapered through hole 1 into which the wedges are inserted.
with the anchor head 1 having a, the central hole 3 of the wedge
The end of the FRP tension member 2 is arranged in a and the wedge 3 is arranged in the through hole 1a of the anchor head.
It is carried out by a method utilizing a wedge action generated by pulling.

The mutually opposing surfaces 3c of the wedges approach each other at the time of tension fixing, and the two vertically divided divided members press and fix the FRP tension member 2 arranged in the central hole 3a. And, the gap between the mutually opposing surfaces 3c of the wedge is usually 1 to 5 mm.
It is considered as a degree.

[0004]

The central hole 3a of the wedge 3 has an F
When the end of the RP tension member 2 is arranged and the wedge 3 is arranged in the through hole 1a of the anchor head 1, sometimes, as shown in FIG. 4, one of the two vertically divided split bodies is displaced in the axial direction. Further, as shown in FIG. 5, the gap between the mutually facing surfaces 3c of the wedge becomes unbalanced, and as a result, the tension member 2 made of FRP is broken during tension fixing, and tension fixing becomes insufficient. The present invention has been made in view of the above circumstances, and an object thereof is to improve the tension of a FRP tension member, which is improved so as to prevent the tension member from being cut during tension fixing and to perform reliable tension fixing. It is to provide a fixing method.

[0005]

That is, the gist of the present invention consists of two longitudinally divided bodies, the outer peripheral surface of which has a conical shape as a whole, and a central hole through which a FRP tension member is inserted. Each of the mutually facing surfaces located on the left and right of the central hole uses a wedge having a shape uniformly removed by an appropriate thickness, and an anchor head having a tapered through hole into which the wedge is inserted. , Arranging the end of the FRP tension material in the center hole of the wedge and disposing the wedge in the through hole of the anchor head,
In the tension fixing method of the FRP tension member using the wedge action generated by pulling the anchor head, when disposing the end of the FRP tension member in the center hole of the wedge,
A method of tension-fixing a tension member made of FRP is characterized in that an adhesive agent is applied between the mutually facing surfaces of the wedge with a substantially constant thickness.

[0006]

The pressure-sensitive adhesive applied with a substantially constant thickness between the mutually facing surfaces of the wedge prevents one of the two vertical divisions from being displaced in the axial direction, and at the same time, the mutually facing surfaces of the wedge. To prevent the gap between the mutually facing surfaces from being unbalanced.

[0007]

EXAMPLES One example of the present invention will be described below in which an FRP tension material (hereinafter, simply referred to as a tension material) is used as a PC tension material and a plurality of tension materials are simultaneously pulled and tension-fixed. A description will be given with reference to the drawings. In the present invention, as a basic method of tension fixing, in particular, the tension fixing method described in Japanese Patent Publication No. 3-25666, that is, it is composed of two vertically divided divided bodies, and the outer peripheral surface has a conical shape as a whole. , A wedge having a smooth central hole through which the tension member is inserted, and the mutually opposing surfaces located on the left and right of the central hole are formed by uniformly removing the appropriate thickness, and the wedge is inserted. An anchor head having a tapered through hole is used, and an engaging member which is close to the wedge and engages with the outer peripheral surface of the tension member is fixed at a predetermined position of the tension member.
It is preferable to employ a method in which the tension member is pressed against the end surface of the wedge by the engaging member to push the wedge into the through hole of the anchor head to pull the tension member and fix the tension.

First, the tension fixing method described in Japanese Patent Publication No. 3-25666 will be described with reference to FIGS. FIG. 6 is a vertical cross-sectional view showing a main part of a method for tension-fixing a tension member made of FRP. In FIG. 6, the tension member 2 is inserted into the tapered through hole 1a of the anchor head 1 and
The tension member 2 is located in a smooth central hole of the wedge 3 which is composed of two vertically divided divided bodies and whose outer peripheral surface has a conical shape as a whole.
Is inserted between the tension member 2 and the inner circumference of the through hole 1a, and a predetermined position of the tension member 2 is clamped by an engaging member 4 which is close to the wedge 3 and engages with the outer peripheral surface of the tension member 2. The engagement member 4 is fixed at a position, a temporary tension force is applied to the tension member 2 via the anchor head 1, and the end face of the wedge 3 is pressed by the side surface of the engagement member 4 by utilizing the temporary tension force. 3 is a through hole 1a of the anchor head 1.
Push into.

As described above, the anchor heads 1 are fixed to the tension members 2 at two positions with a predetermined interval corresponding to the distance between both ends of the concrete structure 6 as the target structure. After that, the main tension force for prestressing the tension member 2 is applied through the anchor head 1, the tension member 2 is extended, and the fixing nut 19 is rotated to abut against the bearing plate 5, so that the concrete structure 6 is predetermined. It is a way to stabilize and fix the tension in the place.

FIG. 7 is a front view showing the anchor head, and FIG.
FIG. 8 is a sectional view taken along line AA of FIG. 7. The anchor head 1 has a short cylindrical shape made of a corrosion-resistant material such as ceramics or metal, and has a center hole jack 13 (FIG.
Female thread 1b into which a tension rod 11 for pulling operation according to (1) is engraved, and a plurality of through holes 1a into which wedges 3 are inserted at predetermined intervals are formed around the female thread 1b. The inner peripheral surface 1c of 1a is tapered corresponding to the outer peripheral surface of the wedge 3, small female screws 1d are engraved at equal positions at three positions between the through holes 1a, and also on the outer periphery. A female screw 1e that is screwed with a fixing nut 19 described later is provided.

The FRP tension member 2 is formed by aligning a plurality of wire rods composed of a matrix resin and a plurality of single fibers. Specifically, the plurality of wire rods are obtained by impregnating long fibers with a resin, passing them through a molding die while aligning them in the longitudinal direction, drawing them out, and curing them. And
The plurality of wire rods may be twisted together and may be covered with a covering material if necessary. As the single fiber, inorganic glass fiber, carbon fiber, or the like, organic aromatic polyamide fiber or the like is suitable, as the matrix resin, epoxy resin containing a curing agent, unsaturated polyester resin, heat such as diallyl phthalate resin A curable resin is suitable.

9 and 10 are a side view and a front view showing the wedge, respectively. The wedge 3 is composed of two vertical divisions of a corrosion resistant material such as ceramics or metal, has an outer peripheral surface 3b having a conical shape as a whole, and has a central hole 3a through which the tension member 2 is inserted. The diameter of both ends of 3a is slightly larger than the diameter of the tension member 2 itself and spreads out so that unnecessary external force is not applied to the tension member 2. Each has a shape uniformly removed by an appropriate thickness, and a stepped groove 3e is provided along the outer periphery in the vicinity of the end on the large diameter side. Also, wedge 3
The inner peripheral surface 3d is finished in a smooth state without unevenness, and is inserted into the through hole 1a of the anchor head 1.

FIG. 11 is a perspective view showing the engaging member.
The engaging member 4 has a pair of sandwiching pieces 4a, 4a, and the sandwiching pieces 4a, 4a are provided with irregularities on the engaging surfaces 4b, 4b at the tips for engaging the outer periphery of the tension member 2, Parts 4c, 4c
The front end can be opened / closed by the opening / closing operation of, and the side surface is placed in contact with the end surface of the retaining plate 7 interposed between the side surface and the wedge 3. Then, the engaging member 4 sandwiches the outer peripheral surface of the tension member 2 with the engagement surfaces 4b and 4b, holds the hand-holding portions 4c and 4c to perform a gripping operation, and presses from the outer periphery to clamp the tension member 2. When the claw is not applied, it is held in that state and fixed at a predetermined position, and when the claw is removed, the holding is released.

The retaining plate 7 is in the form of a disk having a diameter slightly smaller than that of the anchor head 1, and has through holes 7a and 7b through which the tension rod 11 and the tension member 2 are inserted and a small female screw 1d of the anchor head 1. Has a through hole (not shown) corresponding thereto, and a bolt (not shown) inserted through the through hole is screwed into the small female screw 1d so as to be attached to the anchor head 1 so that the wedge 3 can be displaced. is there.

FIG. 12 is a longitudinal sectional view showing an example in which another engaging member is used. In this case, the engaging member 8 includes cylindrical sockets 9 and 9 and concave and convex wedges 1 and 9 which are arranged close to the wedge 3 corresponding to each tension member with the retaining plate 7 interposed.
It consists of 0 and 10. The socket 9 has an uneven wedge 10.
Has a tapered through hole 9a into which
In the same manner as in each of the above cases, unevenness is formed on the contact surface with the tension member 2, and the tension member 2 is fixed to a predetermined position of the tension member 2 by the wedge action.

The bearing plate 5 has a square plate shape which is sufficiently larger than the outer shape of the fixing nut 19 and the like, and as shown in FIGS. 6, 13 and 14, a plurality of tension members are collectively inserted and the anchor head. 1 has a center hole 5a through which it can go in and out, and is fitted and fixed in a recess formed in the end of the concrete structure 6. As shown in FIGS. 13 and 14, the center hole jack 13 for pulling the tension member 2 includes a ram chair 14 whose tip end surface abuts on a bearing plate 5 provided on the end surface of the concrete structure 6, and a tension rod. A tension member 2 is provided with a cylinder 15 having a central hole 12 through which 11 is inserted, a ram (not shown), and the like, and by the movement of the ram, the anchor head 1, the tension rod 11, and a tightening nut 18 screwed to the tip of the tension member 2. It gives a tension to.

The fixing nut 19 is screwed into the male screw 1e on the outer circumference of the anchor head 1 and has a plurality of holes 19a on the outer circumference.
And a hook spanner (not shown) is hooked in the hole 19a and rotated. Then, when the tension member 2 is stretched by being given a tension force, the fixing nut 19 is rotated to approach the pressure bearing plate 5 by an amount commensurate with the tension, and is brought into contact with the outer surface of the pressure bearing plate 5. And has a function of transmitting the tension force of the tension member 2 to the bearing plate 5.

13 and 14 are partially longitudinal side views showing a method of fixing a FRP tension member as a PC tension member. In FIG. 13, one tension member 2 is provided in each through hole 1a.
One of the two anchor heads 1 (1) (left end) inserted through is attached to the outside of the bearing plate 5, and the other (right end) is oriented in the opposite direction to the one described above in consideration of the elongation of the tension member 2 during tension. The sheath 16 with the outer end facing the center hole 5a of the pressure support plate 5 at predetermined positions, the wedge 3 is inserted into each through hole 1a, and then the retaining plate 7 is attached to the left end of the tension member 2. In the part, on the outside of the anchor head 1, FIG.
1 is fixed to a predetermined position of each tendon 2, and the right end portion of the tendon 2 is provided outside the anchor head 1.
The engagement member 8 shown in 2 is fixed to a predetermined position of each tendon 2. Then, in FIG. 13, the anchor head 1 at the right end
Female screw 1b, through hole 7a of retaining plate 7
The tip of the tension rod 11 penetrating through is screwed as shown in FIG. 8 to attach the tension rod 11 to the anchor head 1.

Next, the tension rod 11 is inserted into the center hole 12 of the center hole jack 13 supported by the ram chair 14 which is brought into contact with the pressure support plate 5, and the center hole jack 13 is set, and the center hole jack 13 is projected from the end thereof. A fixing nut 19 screwed onto the tip of the tension rod 11 and screwed onto the outer circumference of the anchor head 1 at the left end.
When the center hole jack 13 is extended with the pressure contact plate 5 in contact with the support plate 5, a temporary tension force is applied to the tension member 2 via both anchor heads 1 and 1 to extend the tension member 2.

When the above operation is performed, at the beginning of provisional tensioning force, there is almost no wedge action of the wedges 3 and 3, and the tension member 2 is against the smooth inner peripheral surface 3d of the center hole 3a of the wedges 3 and 3. Although it is in a slipping state, the wedges 3 and 3 at both left and right ends are pressed by the respective engaging members 4 and 8 by using the temporary tension force of the tension member 2 and pushed into the through hole 1a, and the anchor head 1 is used. When the tension member 2 is pulled, the wedge 3 is sufficiently pushed into the through hole 1a, and the anchor heads 1, 1 are set at two positions of the tension member 2 with a predetermined interval corresponding to the distance between both ends of the concrete structure 6. Is firmly fixed. In this state, until the right anchor head 1 reaches the outside of the bearing plate 5,
This tension for pre-stress is the center hole jack 1
The tension member 2 is applied by 3 and the tension member 2 is elongated.

The fixing nut 19 on the right end side is separated from the pressure bearing plate 5. In this state, since the wedge 3 is sufficiently pushed into the through hole 1a and the anchor heads 1 and 1 are fixed to the tension member 2, the engaging members 4 and 8 are unnecessary, and therefore the engaging members 4 and 8 are not necessary. And the engaging members 4 and 8 are removed, and the engaging members 4 and 8 are removed, and the unnecessary portion of the tension member 2 including the damaged portion on the outer periphery is cut and removed. As shown in FIG. The fixing nut 19 that is screwed onto the outer circumference of the fixing nut 19 is rotated by a hooking wrench (not shown) attached to a plurality of holes 19a on the outer periphery of the fixing nut 19 to bring them into contact with the pressure bearing plate 5 to apply the required main tension force to each tension member 2 and the tension member. Both ends of 2 are fixed to the concrete structure 6.

In the operation of applying the main tension force to the tension member 2,
When a large compressive force is applied to the tension member 2 from the outer circumference when the tension member 2 has a large tensile stress, the tension member 2 is made of FRP, so that the tension member 2 is usually broken even at a tensile strength or less, but the inner peripheral surface 3d of the wedge 3 is smoothed. Therefore, the stress concentration of the tension member 2 received from the inner peripheral surface 3d can be prevented, and this stress can be averaged along the length direction of the wedge 3, so that the tension member 2 can be prevented from breaking. Further, when the tensile stress of the tension member 2 is small, the compressive force acting on the tension member 2 from the wedge 3 is also small, and in addition, since the surface of the tension member 2 is slippery, the frictional force resisting the tension force acts on the wedge 3. It is unlikely to occur between the tension member 2 and as a result, relative movement occurs between the wedge 3 and the tension member 2 and slips through,
The wedge 3 itself does not function as a fixing tool.

However, the engaging member 4 can prevent the tendon 2 from slipping out. That is, the engaging members 4 and 8 bite into the tension member 2 due to the unevenness of the contact surface from the outer periphery by a predetermined load and are integrated with the tension member 2, and the temporary tension force of the tension member 2 is used to make the wedge 3. Can be pushed into the through hole 1a of the anchor head 1 to fully exert the wedge action, and the slipping-out of the tension member 2 can be reliably prevented.

Next, when the main tension force is applied from the above state, the tension member 2 does not slip out, so that the wedge action of the wedge 3 becomes strong, and all the tension force of the tension member 2 is rubbed by the wedge 3. You will be able to take charge by force. Therefore, regardless of the magnitude of the tension force, the tensile force acting on the tension member 2 at the portion of the engaging member 4 is very small, and the tension member 2 does not break even if the compression force from the outer periphery is large.

As the engaging member, one shown in FIG. 15 may be used. In this case, the engagement member is composed of a cylindrical adhesive sleeve 20 arranged in proximity to the wedge 3 via the retaining plate 7, and an adhesive 21 filled in the adhesive sleeve 20. Adhesive sleeve 20
Is a through hole 20 through which the tension member 2 is inserted at the center of both end plates.
It has a and is fixed at a predetermined position of the tension member 2 by the adhesive 21 filled inside. Further, it is possible to use a vise as the engaging member instead of the engaging member shown in FIG.

Next, the tension fixing method of the present invention will be described. 2A to 2C, the wedge 3 is formed by applying an adhesive 30 with a substantially constant thickness between the mutually facing surfaces 3c, 3c of the wedge 3 composed of two vertically divided divided bodies 3 ', 3'. It is a front view which shows the process of assembling, and illustration of the tension member 2 is abbreviate | omitted. Further, FIG. 1 is a side view showing an essential part of the tension fixing method of the present invention.

The tension fixing method of the present invention uses the central hole 3 of the wedge 3.
When arranging the end of the tension member 2 on a, it is characterized in that the adhesive 30 is applied between the mutually facing surfaces 3c, 3c of the wedge 3 with a substantially constant thickness. Adhesives generally have the property of producing a measurable or perceptible binding capacity when separated by momentary contact under weak pressure and are also called pressure sensitive adhesives. In the present invention, the pressure-sensitive adhesive 30 is not particularly limited, and various known pressure-sensitive adhesives can be used.
For example, a rubber-based pressure-sensitive adhesive obtained by blending an elastomer such as natural rubber, SBR, SIS, polyisobutylene, and butyl rubber with a tackifier, a softening agent, an antiaging agent, a copolymer of an acrylic ester and a functional group-containing monomer. It is possible to use a contained pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive containing a silicone comb and a silicone resin, and the like.
In addition to solvent-type pressure-sensitive adhesives dissolved in solvents such as toluene, solvent-based pressure-sensitive adhesives such as water-based emulsion type and hot-melt type can also be used.

The adhesive 30 is composed of two vertically divided division bodies 3 ',
It suffices to apply it to either one of the mutually opposing surfaces 3c, 3c of 3 ', and usually it is applied with a jig such as a spatula before setting the tendon 2. With respect to the mutual facing surfaces 3c, 3c, that is, the mutual facing surfaces 3c, 3 located on the left and right of the center hole 3a.
It is applied to c so as to have a substantially constant thickness. The thickness of the adhesive 30 does not need to be thicker than necessary, and is usually 500.
The thickness is not more than 100 μm, preferably not more than 100 μm.

The adhesive 30 applied as described above is crushed into a thin film by the mutual facing surfaces 3c, 3c of the wedge 3 during tension fixing, and the mutual facing surfaces 3c, 3c are prevented from approaching each other. It does not hinder. And two vertically divided divisions 3 ',
One side 3'is prevented from shifting in the axial direction, and the movement of each of the mutually opposed surfaces 3c, 3c of the wedge is restricted to prevent the gap between the mutually opposed surfaces 3c, 3c from being unbalanced.
As a result, the tension member 2 is prevented from being cut when the tension is fixed,
In addition, the tension is firmly established.

In the tension fixing method of the present invention, as a basic method of tension fixing, it is preferable to adopt the method described in Japanese Patent Publication No. 3-25666, as described above, but as another method, the anchor head 1 is used. The inner peripheral surface 3d of the wedge 3 to be inserted into the through hole 1a is made uneven, and the outer periphery of the end of the tension member 2 is brought into contact with this inner peripheral surface, and the end of the tension member 2 is clamped by the wedge action. It is also possible to adopt a method in which the anchor head 1 is pulled by using a jack (not shown) and the tension member 2 is tension-fixed.

The tension fixing method for the FRP tension member according to the present invention is applied to the tension member for joining the structure near the coast, the terminal processing of the communication cable which is lightweight and requires high tensile strength and electrical insulation, and the extension for suspension bridge. F as an industrial reinforcing material such as tension material
It can also be applied to the end of the RP tension material, and the FRP tension material may be of any type such as spiral type, strand type or the like.

[0032]

According to the present invention described above, there is provided a tension fixing method for a tension member made of FRP, which is improved so as to prevent the tension member from being cut during tension fixing and perform reliable tension fixing. To be done.

[Brief description of drawings]

FIG. 1 is a side view showing a main part of a tension fixing method of the present invention.

2A to 2C are front views showing a step of assembling a wedge by applying an adhesive with a substantially constant thickness between respective mutually facing surfaces of the wedge composed of two vertically divided divided bodies. The illustration of the tendons is omitted.

FIG. 3 is a principle explanatory diagram of a tension fixing method for an FRP tension member.

FIG. 4 is an explanatory diagram of a state in which one of the two vertically divided divided bodies is axially displaced.

FIG. 5 is an explanatory diagram showing a state in which the gap between the mutually opposing surfaces 3c of the wedge is unbalanced.

FIG. 6 is a vertical cross-sectional view showing a main part of a method for tension-fixing a tension member made of FRP.

FIG. 7 is a front view showing an anchor head.

8 is a cross-sectional view taken along the line AA of FIG.

FIG. 9 is a side view showing a wedge.

FIG. 10 is a front view showing a wedge.

FIG. 11 is a perspective view showing an engagement member.

FIG. 12 is a vertical cross-sectional view showing another example of the engaging member.

FIG. 13 is a partial vertical cross-sectional view showing a method of fixing a FRP tension member as a PC tension member.

FIG. 14 is a partial vertical cross-sectional view showing a method for fixing a FRP tension member as a PC tension member.

FIG. 15 is a vertical cross-sectional view showing an example of an engagement member different from the case described above.

[Explanation of symbols]

 1: Anchor head 1a: Through hole 2: Tension material 3: Wedge 3a: Center hole 3b: Outer peripheral surface 3d: Inner peripheral surface 4, 8: Engaging member 30: Adhesive

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[Procedure amendment]

[Submission date] March 16, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Detailed explanation of the invention

[Correction method] Change

[Correction content]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension fixing method for an FRP tension member, and more specifically, an FRP tension member used as a tension member for prestressed concrete structures or a tension member for joining marine structures. The present invention relates to a tension fixing method for tension materials.

[0002]

2. Description of the Related Art FIG. 3 is a principle explanatory view of a tension fixing method for an FRP tension member. The tension fixation of the FRP tension material is
A central hole 3a which is composed of two longitudinally divided bodies and whose outer peripheral surface 3b has a conical shape as a whole and through which the FRP tension member is inserted.
And each mutual facing surface 3c located on the left and right of the center hole.
Are wedges 3 each having a shape uniformly removed by an appropriate thickness, and a tapered through hole 1 into which the wedges are inserted.
with the anchor head 1 having a, the central hole 3 of the wedge
The end of the FRP tension member 2 is arranged in a and the wedge 3 is arranged in the through hole 1a of the anchor head.
It is carried out by a method utilizing a wedge action generated by pulling.

The mutually opposing surfaces 3c of the wedges approach each other at the time of tension fixing, and the two vertically divided divided members press and fix the FRP tension member 2 arranged in the central hole 3a. And, the gap between the mutually opposing surfaces 3c of the wedge is usually 1 to 5 mm.
It is considered as a degree.

[0004]

The central hole 3a of the wedge 3 has an F
When the end of the RP tension member 2 is arranged and the wedge 3 is arranged in the through hole 1a of the anchor head 1, sometimes, as shown in FIG. 4, one of the two vertically divided split bodies is displaced in the axial direction. Further, as shown in FIG. 5, the gap between the mutually facing surfaces 3c of the wedge becomes unbalanced, and as a result, the tension member 2 made of FRP is broken during tension fixing, and tension fixing becomes insufficient. The present invention has been made in view of the above circumstances, and an object thereof is to improve the tension of a FRP tension member, which is improved so as to prevent the tension member from being cut during tension fixing and to perform reliable tension fixing. It is to provide a fixing method.

[0005]

That is, the gist of the present invention consists of two longitudinally divided bodies, the outer peripheral surface of which has a conical shape as a whole, and a central hole through which a FRP tension member is inserted. Each of the mutually facing surfaces located on the left and right of the central hole uses a wedge having a shape uniformly removed by an appropriate thickness, and an anchor head having a tapered through hole into which the wedge is inserted. , Arranging the end of the FRP tension material in the center hole of the wedge and disposing the wedge in the through hole of the anchor head,
In the tension fixing method of the FRP tension member using the wedge action generated by pulling the anchor head, when disposing the end of the FRP tension member in the center hole of the wedge,
A method of tension-fixing a tension member made of FRP is characterized in that an adhesive agent is applied between the mutually facing surfaces of the wedge with a substantially constant thickness.

[0006]

The pressure-sensitive adhesive applied with a substantially constant thickness between the mutually facing surfaces of the wedge prevents one of the two vertical divisions from being displaced in the axial direction, and at the same time, the mutually facing surfaces of the wedge. To prevent the gap between the mutually facing surfaces from being unbalanced.

[0007]

EXAMPLES One example of the present invention will be described below in which an FRP tension material (hereinafter, simply referred to as a tension material) is used as a PC tension material and a plurality of tension materials are simultaneously pulled and tension-fixed. A description will be given with reference to the drawings. In the present invention, as a basic method of tension fixing, in particular, the tension fixing method described in Japanese Patent Publication No. 3-25666, that is, it is composed of two vertically divided divided bodies, and the outer peripheral surface has a conical shape as a whole. , A wedge having a smooth central hole through which the tension member is inserted, and the mutually opposing surfaces located on the left and right of the central hole are formed by uniformly removing the appropriate thickness, and the wedge is inserted. An anchor head having a tapered through hole is used, and an engaging member which is close to the wedge and engages with the outer peripheral surface of the tension member is fixed at a predetermined position of the tension member.
It is preferable to employ a method in which the tension member is pressed against the end surface of the wedge by the engaging member to push the wedge into the through hole of the anchor head to pull the tension member and fix the tension.

First, the tension fixing method described in Japanese Patent Publication No. 3-25666 will be described with reference to FIGS. FIG. 6 is a vertical cross-sectional view showing a main part of a method for tension-fixing a tension member made of FRP. In FIG. 6, the tension member 2 is inserted into the tapered through hole 1a of the anchor head 1 and
The tension member 2 is located in a smooth central hole of the wedge 3 which is composed of two vertically divided divided bodies and whose outer peripheral surface has a conical shape as a whole.
Is inserted between the tension member 2 and the inner circumference of the through hole 1a, and a predetermined position of the tension member 2 is clamped by an engaging member 4 which is close to the wedge 3 and engages with the outer peripheral surface of the tension member 2. The engagement member 4 is fixed at a position, a temporary tension force is applied to the tension member 2 via the anchor head 1, and the end face of the wedge 3 is pressed by the side surface of the engagement member 4 by utilizing the temporary tension force. 3 is a through hole 1a of the anchor head 1.
Push into.

As described above, the anchor heads 1 are fixed to the tension members 2 at two positions with a predetermined interval corresponding to the distance between both ends of the concrete structure 6 as the target structure. After that, the main tension force for prestressing the tension member 2 is applied through the anchor head 1, the tension member 2 is extended, and the fixing nut 19 is rotated to abut against the bearing plate 5, so that the concrete structure 6 is predetermined. It is a way to stabilize and fix the tension in the place.

FIG. 7 is a front view showing the anchor head, and FIG.
FIG. 8 is a sectional view taken along line AA of FIG. 7. The anchor head 1 has a short cylindrical shape made of a corrosion-resistant material such as ceramics or metal, and has a center hole jack 13 (FIG.
Female thread 1b into which a tension rod 11 for pulling operation according to (1) is engraved, and a plurality of through holes 1a into which wedges 3 are inserted at predetermined intervals are formed around the female thread 1b. The inner peripheral surface 1c of 1a is tapered corresponding to the outer peripheral surface of the wedge 3, small female screws 1d are engraved at equal positions at three positions between the through holes 1a, and also on the outer periphery. A female screw 1e that is screwed with a fixing nut 19 described later is provided.

The FRP tension member 2 is formed by aligning a plurality of wire rods composed of a matrix resin and a plurality of single fibers. Specifically, the plurality of wire rods are obtained by impregnating long fibers with a resin, passing them through a molding die while aligning them in the longitudinal direction, drawing them out, and curing them. And
The plurality of wire rods may be twisted together and may be covered with a covering material if necessary. As the single fiber, inorganic glass fiber, carbon fiber, or the like, organic aromatic polyamide fiber or the like is suitable, as the matrix resin, epoxy resin containing a curing agent, unsaturated polyester resin, heat such as diallyl phthalate resin A curable resin is suitable.

9 and 10 are a side view and a front view showing the wedge, respectively. The wedge 3 is composed of two vertical divisions of a corrosion resistant material such as ceramics or metal, has an outer peripheral surface 3b having a conical shape as a whole, and has a central hole 3a through which the tension member 2 is inserted. The diameter of both ends of 3a is slightly larger than the diameter of the tension member 2 itself and spreads out so that unnecessary external force is not applied to the tension member 2. Each has a shape uniformly removed by an appropriate thickness, and a stepped groove 3e is provided along the outer periphery in the vicinity of the end on the large diameter side. Also, wedge 3
The inner peripheral surface 3d is finished in a smooth state without unevenness, and is inserted into the through hole 1a of the anchor head 1.

FIG. 11 is a perspective view showing the engaging member.
The engaging member 4 has a pair of sandwiching pieces 4a, 4a, and the sandwiching pieces 4a, 4a are provided with irregularities on the engaging surfaces 4b, 4b at the tips for engaging the outer periphery of the tension member 2, Parts 4c, 4c
The front end can be opened / closed by the opening / closing operation of, and the side surface is placed in contact with the end surface of the retaining plate 7 interposed between the side surface and the wedge 3. Then, the engaging member 4 sandwiches the outer peripheral surface of the tension member 2 with the engagement surfaces 4b and 4b, holds the hand-holding portions 4c and 4c to perform a gripping operation, and presses from the outer periphery to clamp the tension member 2. When the claw is not applied, it is held in that state and fixed at a predetermined position, and when the claw is removed, the holding is released.

The retaining plate 7 is in the form of a disk having a diameter slightly smaller than that of the anchor head 1, and has through holes 7a and 7b through which the tension rod 11 and the tension member 2 are inserted and a small female screw 1d of the anchor head 1. Has a through hole (not shown) corresponding thereto, and a bolt (not shown) inserted through the through hole is screwed into the small female screw 1d so as to be attached to the anchor head 1 so that the wedge 3 can be displaced. is there.

FIG. 12 is a longitudinal sectional view showing an example in which another engaging member is used. In this case, the engaging member 8 includes cylindrical sockets 9 and 9 and concave and convex wedges 1 and 9 which are arranged close to the wedge 3 corresponding to each tension member with the retaining plate 7 interposed.
It consists of 0 and 10. The socket 9 has an uneven wedge 10.
Has a tapered through hole 9a into which
In the same manner as in each of the above cases, unevenness is formed on the contact surface with the tension member 2, and the tension member 2 is fixed to a predetermined position of the tension member 2 by the wedge action.

The bearing plate 5 has a square plate shape which is sufficiently larger than the outer shape of the fixing nut 19 and the like, and as shown in FIGS. 6, 13 and 14, a plurality of tension members are collectively inserted and the anchor head. 1 has a center hole 5a through which it can go in and out, and is fitted and fixed in a recess formed in the end of the concrete structure 6. As shown in FIGS. 13 and 14, the center hole jack 13 for pulling the tension member 2 includes a ram chair 14 whose tip end surface abuts on a bearing plate 5 provided on the end surface of the concrete structure 6, and a tension rod. A tension member 2 is provided with a cylinder 15 having a central hole 12 through which 11 is inserted, a ram (not shown), and the like, and by the movement of the ram, the anchor head 1, the tension rod 11, and a tightening nut 18 screwed to the tip of the tension member 2. It gives a tension to.

The fixing nut 19 is screwed into the male screw 1e on the outer circumference of the anchor head 1 and has a plurality of holes 19a on the outer circumference.
And a hook spanner (not shown) is hooked in the hole 19a and rotated. Then, when the tension member 2 is stretched by being given a tension force, the fixing nut 19 is rotated to approach the pressure bearing plate 5 by an amount commensurate with the tension, and is brought into contact with the outer surface of the pressure bearing plate 5. And has a function of transmitting the tension force of the tension member 2 to the bearing plate 5.

13 and 14 are partially longitudinal side views showing a method of fixing a FRP tension member as a PC tension member. In FIG. 13, one tension member 2 is provided in each through hole 1a.
One of the two anchor heads 1 (1) (left end) inserted through is attached to the outside of the bearing plate 5, and the other (right end) is oriented in the opposite direction to the one described above in consideration of the elongation of the tension member 2 during tension. The sheath 16 with the outer end facing the center hole 5a of the pressure support plate 5 at predetermined positions, the wedge 3 is inserted into each through hole 1a, and then the retaining plate 7 is attached to the left end of the tension member 2. In the part, on the outside of the anchor head 1, FIG.
1 is fixed to a predetermined position of each tendon 2, and the right end portion of the tendon 2 is provided outside the anchor head 1.
The engagement member 8 shown in 2 is fixed to a predetermined position of each tendon 2. Then, in FIG. 13, the anchor head 1 at the right end
Female screw 1b, through hole 7a of retaining plate 7
The tip of the tension rod 11 penetrating through is screwed as shown in FIG. 8 to attach the tension rod 11 to the anchor head 1.

Next, the tension rod 11 is inserted into the center hole 12 of the center hole jack 13 supported by the ram chair 14 which is brought into contact with the pressure support plate 5, and the center hole jack 13 is set, and the center hole jack 13 is projected from the end thereof. A fixing nut 19 screwed onto the tip of the tension rod 11 and screwed onto the outer circumference of the anchor head 1 at the left end.
When the center hole jack 13 is extended with the pressure contact plate 5 in contact with the support plate 5, a temporary tension force is applied to the tension member 2 via both anchor heads 1 and 1 to extend the tension member 2.

When the above operation is performed, at the beginning of provisional tensioning force, there is almost no wedge action of the wedges 3 and 3, and the tension member 2 is against the smooth inner peripheral surface 3d of the center hole 3a of the wedges 3 and 3. Although it is in a slipping state, the wedges 3 and 3 at both left and right ends are pressed by the respective engaging members 4 and 8 by using the temporary tension force of the tension member 2 and pushed into the through hole 1a, and the anchor head 1 is used. When the tension member 2 is pulled, the wedge 3 is sufficiently pushed into the through hole 1a, and the anchor heads 1, 1 are set at two positions of the tension member 2 with a predetermined interval corresponding to the distance between both ends of the concrete structure 6. Is firmly fixed. In this state, until the right anchor head 1 reaches the outside of the bearing plate 5,
This tension for pre-stress is the center hole jack 1
The tension member 2 is applied by 3 and the tension member 2 is elongated.

The fixing nut 19 on the right end side is separated from the pressure bearing plate 5. In this state, since the wedge 3 is sufficiently pushed into the through hole 1a and the anchor heads 1 and 1 are fixed to the tension member 2, the engaging members 4 and 8 are unnecessary, and therefore the engaging members 4 and 8 are not necessary. And the engaging members 4 and 8 are removed, and the engaging members 4 and 8 are removed, and the unnecessary portion of the tension member 2 including the damaged portion on the outer periphery is cut and removed. As shown in FIG. The fixing nut 19 that is screwed onto the outer circumference of the fixing nut 19 is rotated by a hooking wrench (not shown) attached to a plurality of holes 19a on the outer periphery of the fixing nut 19 to bring them into contact with the pressure bearing plate 5 to apply the required main tension force to each tension member 2 and the tension member. Both ends of 2 are fixed to the concrete structure 6.

In the operation of applying the main tension force to the tension member 2,
When a large compressive force is applied to the tension member 2 from the outer circumference when the tension member 2 has a large tensile stress, the tension member 2 is made of FRP, so that the tension member 2 is usually broken even at a tensile strength or less, but the inner peripheral surface 3d of the wedge 3 is smoothed. Therefore, the stress concentration of the tension member 2 received from the inner peripheral surface 3d can be prevented, and this stress can be averaged along the length direction of the wedge 3, so that the tension member 2 can be prevented from breaking. Further, when the tensile stress of the tension member 2 is small, the compressive force acting on the tension member 2 from the wedge 3 is also small, and in addition, since the surface of the tension member 2 is slippery, the frictional force resisting the tension force acts on the wedge 3. It is unlikely to occur between the tension member 2 and as a result, relative movement occurs between the wedge 3 and the tension member 2 and slips through,
The wedge 3 itself does not function as a fixing tool.

However, the engaging member 4 can prevent the tendon 2 from slipping out. That is, the engaging members 4 and 8 bite into the tension member 2 due to the unevenness of the contact surface from the outer periphery by a predetermined load and are integrated with the tension member 2, and the temporary tension force of the tension member 2 is used to make the wedge 3. Can be pushed into the through hole 1a of the anchor head 1 to fully exert the wedge action, and the slipping-out of the tension member 2 can be reliably prevented.

Next, when the main tension force is applied from the above state, the tension member 2 does not slip out, so that the wedge action of the wedge 3 becomes strong, and all the tension force of the tension member 2 is rubbed by the wedge 3. You will be able to take charge by force. Therefore, regardless of the magnitude of the tension force, the tensile force acting on the tension member 2 at the portion of the engaging member 4 is very small, and the tension member 2 does not break even if the compression force from the outer periphery is large.

As the engaging member, one shown in FIG. 15 may be used. In this case, the engagement member is composed of a cylindrical adhesive sleeve 20 arranged in proximity to the wedge 3 via the retaining plate 7, and an adhesive 21 filled in the adhesive sleeve 20. Adhesive sleeve 20
Is a through hole 20 through which the tension member 2 is inserted at the center of both end plates.
It has a and is fixed at a predetermined position of the tension member 2 by the adhesive 21 filled inside. Further, it is possible to use a vise as the engaging member instead of the engaging member shown in FIG.

Next, the tension fixing method of the present invention will be described. 2A to 2C, the wedge 3 is formed by applying an adhesive 30 with a substantially constant thickness between the mutually facing surfaces 3c, 3c of the wedge 3 composed of two vertically divided divided bodies 3 ', 3'. It is a front view which shows the process of assembling, and illustration of the tension member 2 is abbreviate | omitted. Further, FIG. 1 is a side view showing an essential part of the tension fixing method of the present invention.

The tension fixing method of the present invention uses the central hole 3 of the wedge 3.
When arranging the end of the tension member 2 on a, it is characterized in that the adhesive 30 is applied between the mutually facing surfaces 3c, 3c of the wedge 3 with a substantially constant thickness. Adhesives generally have the property of producing a measurable or perceptible binding capacity when separated by momentary contact under weak pressure and are also called pressure sensitive adhesives. In the present invention, the pressure-sensitive adhesive 30 is not particularly limited, and various known pressure-sensitive adhesives can be used.
For example, a rubber-based pressure-sensitive adhesive obtained by blending an elastomer such as natural rubber, SBR, SIS, polyisobutylene, and butyl rubber with a tackifier, a softening agent, an antiaging agent, a copolymer of an acrylic ester and a functional group-containing monomer. It is possible to use a contained pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive containing a silicone comb and a silicone resin, and the like.
In addition to solvent-type pressure-sensitive adhesives dissolved in solvents such as toluene, solvent-based pressure-sensitive adhesives such as water-based emulsion type and hot-melt type can also be used.

The adhesive 30 is composed of two vertically divided division bodies 3 ',
It suffices to apply it to either one of the mutually opposing surfaces 3c, 3c of 3 ', and usually it is applied with a jig such as a spatula before setting the tendon 2. With respect to the mutual facing surfaces 3c, 3c, that is, the mutual facing surfaces 3c, 3 located on the left and right of the center hole 3a.
It is applied to c so as to have a substantially constant thickness. The thickness of the adhesive 30 does not need to be thicker than necessary, and is usually 500.
The thickness is not more than 100 μm, preferably not more than 100 μm.

The adhesive 30 applied as described above is crushed into a thin film by the mutual facing surfaces 3c, 3c of the wedge 3 during tension fixing, and the mutual facing surfaces 3c, 3c are prevented from approaching each other. It does not hinder. And two vertically divided divisions 3 ',
One side 3'is prevented from shifting in the axial direction, and the movement of each of the mutually opposed surfaces 3c, 3c of the wedge is restricted to prevent the gap between the mutually opposed surfaces 3c, 3c from being unbalanced.
As a result, the tension member 2 is prevented from being cut when the tension is fixed,
In addition, the tension is firmly established.

In the tension fixing method of the present invention, as a basic method of tension fixing, it is preferable to adopt the method described in Japanese Patent Publication No. 3-25666, as described above, but as another method, the anchor head 1 is used. The inner peripheral surface 3d of the wedge 3 to be inserted into the through hole 1a is made uneven, and the outer periphery of the end of the tension member 2 is brought into contact with this inner peripheral surface, and the end of the tension member 2 is clamped by the wedge action. It is also possible to adopt a method in which the anchor head 1 is pulled by using a jack (not shown) and the tension member 2 is tension-fixed.

The tension fixing method for the FRP tension member according to the present invention is applied to the tension member for joining the structure near the coast, the terminal processing of the communication cable which is lightweight and requires high tensile strength and electrical insulation, and the extension for suspension bridge. F as an industrial reinforcing material such as tension material
It can also be applied to the end of the RP tension material, and the FRP tension material may be of any type such as spiral type, strand type or the like.

[0032]

According to the present invention described above, there is provided a tension fixing method for a tension member made of FRP, which is improved so as to prevent the tension member from being cut during tension fixing and perform reliable tension fixing. To be done.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuji Shimamoto 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd.

Claims (1)

[Claims] 1. A vertical split member, which has a conical outer peripheral surface as a whole, has a central hole through which an FRP tension member is inserted, and the mutually opposing surfaces located on the left and right of the central hole. Using wedges each having a shape uniformly removed by an appropriate thickness and an anchor head having a tapered through hole into which the wedge is inserted, a terminal of a FRP tension material is provided in the center hole of the wedge. And the wedge is arranged in the through hole of the anchor head, and the tension fixing method of the FRP tension member using the wedge action generated by pulling the anchor head is used. A method for tension-fixing a tension member made of FRP, characterized in that an adhesive is applied between the mutually facing surfaces of the wedge so as to have a substantially constant thickness when the terminals are arranged.