JP3271041B2 - FRP cable fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for an FRP rod in prestressed concrete or an underground anchor.

[0002]

2. Description of the Related Art Hitherto, application of FRP rods as a tendon for prestressed concrete structures and the like has been studied.

[0003]

Conventionally, in the FRP rod fixing technique, there is a problem that the destructive nature of the FRP is weak and the toughness required under the action of an impact load and an earthquake load is poor. That is, if the tension applied to the rod is increased while fixing both ends of the FRP rod, the FRP rod will be tensilely broken by brittle rupture while maintaining elastic properties. For this reason, when an unexpectedly large load is applied to the structure using the FRP rod, the strength of the member is instantaneously exceeded. It takes a very dangerous form of destruction, such as

[0004]

[Object of the present invention]

<A> The present invention solves the above-mentioned problems, and an object of the present invention is to provide a fixing device having high reliability in designing a structure. <B> The present invention solves the above-mentioned problems, and the FRP
An object of the present invention is to provide a fixing device having good slidability even when an eccentric load acts on a rod.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a fixing device for an FRP rod, which comprises a cylindrical member for holding the FRP rod, and an outer cylinder for accommodating the cylindrical member. A sliding groove is provided on the inner periphery of the outer cylinder, and the protrusion slides in the sliding groove according to the tension acting on the FRP rod. FRP rod fixing device characterized by moving

[0006]

Embodiments of the present invention will be described below with reference to the drawings. Although the embodiment is a fixing device for fixing the FRP rod 13 in a structure, the present invention is also applicable to a case where the FRP rod 13 is fixed in the ground or the like.

<A> Fixing Device (FIGS. 1 and 5) The fixing device is a cylindrical member 10 for holding an FRP rod 13.
And an outer cylinder 20 which is slidably (slidably) accommodated with the cylinder member 10. Connect the FRP rod 13 to the cylindrical member 1
For example, in addition to using the wedge 12 as shown in FIG. 1, the FRP rod 13 is fixed to a bolt 15 with an epoxy resin 14 or the like as shown in FIG.
A nut 16 may be attached to the cylindrical member 10 via the bolt 15 and the nut 16. FRP rod 13
Is made of, for example, a new material fiber, carbon, glass, aramid, or the like.

<B> Cylindrical Member (FIGS. 1 and 4) The cylindrical member 10 is a cylindrical body for holding the FRP rod 13 therein, and has a sliding groove 11 formed in the outer periphery along the axial direction. I have. The sliding groove 11 provides resistance such as friction when sliding with the outer cylinder 20. In order to gradually increase the sliding friction resistance with the outer cylinder 20, FIG.
The sliding groove 11 is formed in a tapered shape as shown in FIG.

<C> Outer cylinder (FIG. 1) The outer cylinder 20 slidably holds the cylinder member 10 inside, and has a projection 21 formed on the inner periphery. Protrusion 21
Slides in the sliding groove 11 of the cylindrical member 10, and the sliding resistance is determined by the diameter difference between the maximum lateral width (diameter) of the projection 21 and the width (diameter) of the sliding groove 11. That is, the used FRP rod 13
The projection 21 presses into the sliding groove 11 and slides before the breaking tension is applied, and a sliding resistance is generated due to a difference in diameter between the sliding groove 11 and the projection 21. Also, the sliding resistance can be adjusted by the number of the projections 21. in this way,
By forming the sliding groove 11 on the outer periphery of the cylindrical member 10 and forming the projection 21 on the inner periphery of the outer cylinder 20, the FRP rod 1
3, even if the eccentric load acts on the cylindrical member 10 and the outer cylinder 20 eccentrically, the protrusion 21 smoothly press-fits into the sliding groove 11,
Sliding resistance can be obtained.

The length L in the axial direction of the cylindrical member 10 is made substantially equal to the length L from the end of the outer cylinder on the side where the cylindrical member 10 is inserted to the protrusion 21. With such a configuration, the eccentricity between the cylindrical member 10 and the projection 21 can be suppressed, and the projection 21 and the sliding groove 11 can be smoothly pressed.

As shown in FIG. 1, the cross section of the projection 21 in the protruding direction may be a shape in which the side parallel to the central axis of the rectangle is bulged, an arc shape such as a circle or an ellipse, or another shape. When the sliding groove 11 of the projection 21 is formed in a tapered shape as shown in FIG. 4, the width of the passage sliding groove 11 of the projection 21 gradually decreases, and the sliding resistance increases.

As the material of the tube member 10 and the outer tube 20, for example, a metal, aluminum or stainless steel having high corrosion resistance can be used, both of which are made of stainless steel, or the tube member 10 is made of aluminum and the outer tube 20 is made of aluminum. A combination of stainless steel can also be used.

Next, a method of fixing the FRP rod will be described. <A> Setting of fixing device (FIG. 2) The fixing device is attached to one end of the FRP rod 13 extending from the structure. That is, the FRP rod 13 is passed through the support plate 30 installed on the structure, the inner hole of the outer cylinder 20 is fixed to the cylindrical member 10, and the FRP rod 13 is installed on the support plate 30. F not shown
An initial tension is applied to the other end of the RP rod 13 so that the FRP
The rod 13 is fixed. At the time of fixing, the projection 21 of the outer cylinder 20 is supported at the end of the sliding groove 11. As for the outer cylinder 20 and the support plate 30, the outer cylinder 20 and the support plate 30 may be formed integrally, or the outer cylinder 20 may be set to a predetermined size so as to serve as the support plate 30.

<B> At the time of increase in tension (FIG. 3) When an excessive load is applied to a structure due to an earthquake or the like, a tensile force higher than the breaking tension may be applied to the FRP rod 13 in some cases.
In this case, before the tension acting on the FRP rod 13 reaches the breaking tension, the outer cylinder 2 is inserted into the sliding groove 11 of the cylinder member 10.
The zero projection 21 is retracted. As a result, the fixing end of the FRP rod 13 moves in the tension direction,
The tension acting on the rod 13 decreases. Therefore, FR
Even if a tensile force higher than the breaking tension is applied to the P rod 13,
The FRP rod 13 can be fixed without being broken by the sliding mechanism.

[0015]

According to the present invention, the following effects can be obtained. <A> By sliding the FRP rod fixing portion with a predetermined tension, a tension characteristic equivalent to that of a PC steel material having a yielding capability can be imparted to the FRP rod. Therefore, even if a tensile force higher than the breaking tension is applied to the FRP rod having no yielding capability, the FRP rod can be fixed without breaking.

<B> By providing a sliding groove in the cylinder member and providing a projection on the outer cylinder, even if eccentricity occurs between the cylinder member and the outer cylinder, the fixing device is expected to introduce a tension acting on the rod. It can be slid smoothly and fixed until tension is reached.

<C> The eccentricity of the cylindrical member and the projection is suppressed by making the axial length of the cylindrical member substantially equal to the length from the end of the outer cylinder into which the cylindrical member is inserted to the projection. Can,
Smooth press-fit sliding between the protrusion and the sliding groove is enabled.

[Brief description of the drawings]

FIG. 1 is a perspective view of a fixing device.

FIG. 2 is a side sectional view of a fixing device.

FIG. 3 is an explanatory diagram of a fixing method.

FIG. 4 is an arrangement diagram of a projection of an outer cylinder and a tapered groove of a cylinder member.

FIG. 5 is a diagram of holding an FRP rod with an epoxy resin.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-268862 (JP, A) JP-A-4-203068 (JP, A) JP-A-6-128886 (JP, A) JP-A-6-128886 287949 (JP, A) Shokai Sho 61-161327 (JP, U) Shokai Hei 1-167431 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E04C 5/08

Claims (5)

(57) [Claims] 1. A fixing device for an FRP rod, comprising: a cylindrical member for holding the FRP rod; and an outer cylinder for accommodating the cylindrical member, wherein a sliding groove is provided in an axial direction on an outer periphery of the cylindrical member. A protrusion that fits in a sliding groove of the member is provided on the inner periphery of the outer cylinder, and the protrusion slides in the sliding groove according to a tension acting on an FRP rod; Rod fixing device. 2. A fixing device for an FRP rod, comprising: a cylindrical member for holding the FRP rod; and an outer cylinder for accommodating the cylindrical member, and a plurality of sliding members along an axial direction at equal intervals around an outer periphery of the cylindrical member. A plurality of projections are provided at regular intervals along the inner circumference of the outer cylinder, the projections are fitted in the sliding grooves, and the projections are formed in accordance with the tension acting on the FRP rod. The FRP rod fixing device slides in the sliding groove. 3. The FRP according to claim 1, wherein
An FRP rod, wherein an axial length of the cylindrical member is substantially equal to a length from an end of the outer cylinder on a side where the cylindrical member is inserted to the protrusion. Fixing device. 4. The FRP according to claim 1, wherein
A fixing device for an FRP rod, wherein the protrusion contacting a wall surface of the sliding groove has an arc shape. 5. The FRP according to claim 1, wherein
A fixing device for an FRP rod, wherein the sliding groove is formed in a tapered shape, and the sliding resistance increases as the protrusion slides in the sliding groove.