JP3240959B2 - Fixing tool for belt-shaped PC tendon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fixing device for fixing an end portion of a belt-shaped PC tendon.

[0002]

2. Description of the Related Art As a tendon for prestressed concrete, a FRP tendon has been developed in place of a steel tendon. This tendon material is lightweight, so workability such as transportation and reinforcement is improved, and it is also excellent in corrosion resistance, so it is suitable for salt damage resistant structure, and because it is a non-magnetic material, it is suitable for non-magnetic structure Therefore, there is a tendency that applications are expanded.

[0003] Carbon fiber applied to this FRP tendon material,
When using high-strength fiber such as aramid fiber solidified with resin, if the fiber bundle has a circular cross section,
There is a possibility that the transmission of the frictional force acting on the fibers on the outer periphery to the fibers at the center may become insufficient, and in order to prevent this, the cross section is used in a flat band shape.

[0004] When this FRP tendon is used for prestressed concrete, a terminal fixing tool for applying a constant tension is required. As a structure of the terminal fixing device, a wedge system applied to a tension member made of a conventional steel wire or a steel stranded wire is employed.

FIGS. 3 and 4 show a conventional fixing device of this wedge type, in which a sleeve 2 having an inner peripheral portion 1 having a tapered cone shape and an outer peripheral portion having a tapered cone shape in accordance with the tapered cone of the inner peripheral portion 1 are shown. FRP which is formed of a pair of split wedges 3 and is inserted through the small diameter side opening of sleeve 2
The tension members 4 are sandwiched between the flat surfaces of the two wedges 3 in a state of being arranged in a flat shape, and the wedges 3 are pushed into the FRP tension members 4.
Is fixed.

When connecting the FRP tendon 4 to the PC steel rod 5, a threaded portion 2a is formed on the outer periphery of the sleeve 2 and the other end of the coupler 6 having the PC steel rod 5 connected to one end. A filler such as an epoxy resin is adhered to the female screw portion 6a formed on the periphery and screwed together, and the connection is completed by curing the filler.

[0007]

However, the fixing device having this structure has the following problems.

First, the fixing member is cylindrical, but the fixing member has a cylindrical shape, but the fixing member is excessively large with respect to the tension member. This type of fixing device is made of steel, etc., but the inner circumference must be tapered and cone-shaped, so a large wall thickness must be ensured. , The handling at the time of work was poor.

Further, it is difficult to align the FRP tendon 4 with the center position of the sleeve 2, the center of the PC steel rod or the like tends to be displaced, and it takes a long time to cure the filler. The effort was not easy either.

[0010] The present invention has been made to solve the above problems, and its object is to reduce the size and ease of handling.
An object of the present invention is to provide a fixing device for a belt-shaped PC tendon material which can improve the bonding property with a PC steel rod.

[0011]

In order to achieve the above object, the present invention according to claim 1 of the present invention has a flat rectangular shape and a tapered shape from one end opening to the other end opening. A rectangular casing having a widened rectangular hole formed therethrough, and a band-shaped PC tendon material inserted into one end of the casing from the other end opening and inserted into the casing from the one end opening. Ri Do from a pair of the wedge,
Box connected to the other end opening of the rectangular casing
Cover the other end opening with a
Between the inside of the box joint and the rear end of each wedge
A spring means for urging the wedge in the forward direction is provided . In the present invention, the fixing device has a PC shape.
Since it has a flat shape corresponding to the shape of the tendon, the whole can be miniaturized. Also, the wedge always holds the PC tendon
Urged to the side.

The invention according to claim 2 of the present invention is characterized in that the surface roughness of the contact surface of each of the wedges with the PC tendon material is equivalent to the sharpening roughness of a rough file. With the above surface roughness, PC
It can be fixed by a sufficient biting effect on the tendon material.

[0013]

The invention according to claim 3 of the present invention is characterized in that the rectangular casing is divided in half in the thickness direction and connected by screws. Therefore, in the present invention, assembly and disassembly are easy.

[0015]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a fixing device according to the present invention, and FIG. 2 is a longitudinal sectional view showing a state in which a PC tendon is incorporated into an identification clothing.

The fixing device 10 shown in the figure is divided into two parts in the thickness direction and connected to each other via a plurality of bolts and nuts 12 and 14. A flat rectangular casing 16 is inserted into the casing 16 through one end opening thereof. A pair of wedges 18 for holding and fixing the PC tendon 4 to be fixed thereto, and a rectangular joint connected to the rear end of the casing 16 via a plurality of bolts 12 and fixing the end of the PC steel bar 5 at the center of the rear surface. It comprises a box 20 and a pair of compression coil springs 22 interposed between the inner wall of the joint box 20 and the rear end of the wedge 18 to constantly urge each wedge 18 forward.

The assembled casing 16 has an inclined surface 16 whose one end opening and the other end opening have the same width and whose height is tapered from the one end opening to the other end opening.
a.

Each of the wedges 18 has the same width and is formed in a tapered shape in the front-rear direction according to the inclination of the inclined surface 16a. Then, on the contact surface of each wedge 18 with the PC tendon 4, irregularities 18 a having a surface roughness corresponding to the sharpening shape of the rough file are formed, and the state in which the PC tendon 4 is sandwiched is enlarged to a part of FIG. PC as shown
It bites into the fiber bundle of the tendon 4 and firmly clamps it.

In addition, a pair of half-shaped bosses 18b project from the rear ends of the two wedges 18 so as to receive and guide the spring 22 in a state where both are combined. The two wedges 18 are urged in the forward direction by the spring pressure of the spring 22, and the gap between them is reduced by the inclined surface 16a. Therefore, the holding force against the PC tendon 4 is firmly and constantly maintained. I can do it.

It should be noted that in FIG.
Although the shallow groove for positioning with respect to the PC tendon 4 is not formed on the holding surface of the PC, the center in the width direction of the PC tendon 4 is positioned and fixed at the center of the casing by forming this shallow groove. Then, it can be easily fixed in alignment with the axis of the PC steel bar 5 attached to the joint box 20 to be assembled thereafter.

[0022]

As is apparent from the above description, the fixing device for a PC tendon according to the present invention has the following effects.

Since the casing has a flat rectangular shape according to the shape of the belt-shaped PC tendon, it can be made smaller than before, and is highly portable and easy to handle during operation.

By making the wedge holding surface rough and rough like a file, the biting effect on the PC tendon is large.

By biasing the wedge in the forward direction by the spring, the holding force against the PC tendon can be increased and stably maintained.

By dividing the casing into halves, the assembling and disassembling properties are rich and the adjustment can be easily performed according to the thickness of the PC tendon.

By joining to a joint box or the like via a bolt, a simple and quick joining can be performed without the need for a filler, as compared with the conventional screwing method. It is also easy to align the axis with the PC steel rod to be joined through.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a fixing device according to the present invention.

FIG. 2 is a longitudinal sectional view showing an assembled state of the identification clothing.

FIG. 3 is an exploded perspective view of a conventional fixing device.

FIG. 4 is a longitudinal sectional view showing an assembled state of the identification clothing.

[Explanation of symbols]

 4 PC Tensioning Material 10 Fixing Tool 16 Flat Rectangular Casing 16a Inclined Surface 18 Wedge 18a Unevenness 22 Compression Coil Spring

Claims (3)

(57) [Claims] 1. A rectangular casing having a flat rectangular shape and having a rectangular hole penetrating and widening in a tapered shape from one end opening to the other end opening, and inserted into one end side from the other end opening. It is and Ri from the one open end Do a pair of wedge insertion are strip-shaped PC tendon to sandwich fixed toward in the casing, is connected to the other end opening of the rectangular casing box
Cover the other end opening with a
Between the inside of the box joint and the rear end of each wedge
A fastener for a PC tendon, comprising spring means for urging the wedge in the forward direction . 2. The fixing device for a PC tendon according to claim 1, wherein the surface roughness of the contact surface of each wedge with the PC tendon corresponds to the sharpening roughness of a rough file. Wherein the rectangular casing thereof in the thickness direction is half-divided, and PC according to claim 1 or 2, characterized in that coupled with screws
Tendon fasteners.