JPH11117456A - Fixed section structure for pc steel stranded wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wires from being untwisted by inserting a bundle portion near the terminal of the bulb section of multiple wires constituting each PC steel stranded wire into a circular constraining material, and constraining all wires from the outer periphery with the constraining material. SOLUTION: The zone protruded from the sheath of a PC cable constituted of multiple PC steel stranded wires 2 is dispersed into the PC steel stranded wires Z. A bulb section 4 is formed near the terminals of all wires 3 constituting each PC steel stranded wire 2, and the terminal side of the wires 3 are constrained by a circular constraining material 5 having an insertion hole 51 with the size capable of holding all wires 3 in the bundled state. The bundled portion of all wires 3 is inserted into the insertion hole 51 of the constraining material 5 to constrain the wires 3 from the outer periphery, and the bundled state is maintained after the bulb section 4 is formed until it is fixed in concrete, thereby the deformation of the bulb section 4 is prevented, and the shapes of all bulb sections 4 can be kept uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a PC steel stranded wire in which ends of a PC cable composed of a plurality of PC steel stranded wires are dispersed and fixed for each PC steel stranded wire.

[0002]

2. Description of the Related Art As shown in FIG. 3, sections of a PC cable composed of a plurality of PC steel strands, which protrude from a sheath, are dispersed for each PC steel strand. In the method of fixing the strands with a sufficient distance between the strands to obtain an adhesive force with the concrete, the PC strands are formed in order to increase the adhesive strength particularly at the end of each strand. From multiple wires,
There is a method of forming a bulb portion by bending a part thereof.

[0003] The bulb portion is formed by applying a compressive force in the axial direction to a PC stranded wire in a state where a portion closer to the sheath is gripped by a chuck and a portion closer to the end is gripped by a plunger. In the formed state, the sheath side of the bulb remains stranded and each wire is in a constrained state, whereas the distal side is simply a bundle and it is not particularly constrained Each wire can be deformed by receiving a force from the distal end.

For this reason, when the PC cable is installed at the construction position of the structure and the bulb portion is arranged at a predetermined position, the wires may be loosened due to contact or collision with the existing rebar or the like. There is a problem that the shape becomes uneven.

[0005] The bulb portion serves to increase the surface area of the PC stranded wire by separating each wire and increase the adhesion to concrete, but if the shape of each bulb portion becomes uneven, each PC steel will A difference occurs in the adhesion strength of each stranded wire, so that all the PC stranded wires cannot exhibit a uniform resistance, so that there is an inconvenience that the predetermined proof strength as a PC cable cannot be expected.

In view of the above background, the present invention proposes a fixing unit structure for preventing loosening of a wire constituting a bulb portion.

[0007]

According to the present invention, a portion of a plurality of wires constituting each PC steel stranded wire which is bundled near the end of a bulb portion is placed in an annular restraining member through which all the wires can be inserted. Inserting, restraining all the wires from the outer circumference with the restraining material,
By maintaining the state of the bundle, the portion to be bundled is loosened by contact or collision with a reinforcing bar or the like, and the bulb portion is prevented from being deformed, and the shape of the entire bulb portion is uniformly maintained.

[0008] If the shape of all the bulb portions is kept uniform, the adhesion strength at the bulb portion of all the PC steel strands becomes the same, and there is no difference in the adhesion strength between the individual PC steel wires. The stranded wire of PC steel can exert resistance uniformly, and a predetermined strength as a PC cable can be expected.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 3, the present invention disperses a section of a PC cable 1 composed of a plurality of PC steel strands 2 protruding from a sheath 6 for each PC steel strand 2. 1, a bulb portion 4 is formed near the end of each PC stranded wire 2 in a state where the ends of all the wires 3 constituting the PC stranded wire 2 are constrained by a restricting material 5 as shown in FIG.
This is a fixing unit structure for fixing the C steel strand 2 in the concrete 7.

The bulb portion 4 uses a valve machine 8 as shown in FIG. 4, and a portion closer to the sheath 6 than a portion where the bulb portion 4 of the PC steel stranded wire 2 is to be formed is chucked 9 and a portion closer to the end is planned. The plunger 10 is moved toward the chuck 9 while being gripped by the jars 10, and a compressive force is applied to the PC stranded wire 2 in the axial direction thereof, and a portion of the plurality of wires 3 between the chuck 9 and the plunger 10 is formed. In the radial direction with respect to the axis of the PC steel strand 2.

The entire wire 3 is inserted into the restraining member 5 before being gripped by the plunger 10, and in this state, a compressive force is applied to the PC steel stranded wire 2. As shown in FIG.
At the time of formation, all the wires 3 are bundled near the bulb portion 4 from the end, and the restraining material 5 is arranged at the portion where the bundle is formed.

A portion where all the wires 3 are bundled is restrained from the outer periphery by being inserted into the insertion hole 51 of the restraining member 5, and remains in a bundle from the formation of the bulb portion 4 to the fixation in the concrete 7. I do.

The constraining member 5 is an annular member having an insertion hole 51 large enough to allow all the wires 3 to pass therethrough and to maintain a state in which all the wires 3 are bundled. As long as the loosening can be restrained, the size, shape, or thickness of the restraining material 5 itself is not limited at all, and a ready-made washer can be used as the restraining material 5.

[0014]

According to the present invention, the bundles of the plurality of wires constituting each PC steel strand, which are bundled near the end of the bulb portion, are inserted into an annular restraint through which all the wires can be inserted, and all the wires are inserted by the restraint. Since the bundle is held by constraining the wire from the outer periphery, the bulb portion due to loosening of the bundle portion can be prevented from being deformed, and the shape of all the bulb portions can be uniformly maintained.

Since the shape of all the bulb portions is kept uniform, the adhesion strength at the bulb portion of all the PC steel strands becomes equal, and the difference in the adhesion strength between the individual PC steel wires is eliminated. A predetermined strength as a PC cable can be expected.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a plurality of wires of a PC steel strand are inserted through a restraining member.

FIG. 2 is a sectional view showing a state in which a bulb portion is fixed in concrete.

FIG. 3 is a perspective view showing an end of a PC cable.

FIG. 4 is an elevation view showing a valve machine for forming a bulb portion.

[Explanation of symbols]

1 ... PC cable, 2 ... PC steel strand, 3 ... wire, 4 ... bulb, 5 ... restraining material, 51 ... insertion hole, 6 ...
... sheath, 7 ... concrete, 8 ... valve machine,
9 ... Chuck, 10 ... Plunger.

Claims (1)

[Claims] 1. A section of a PC cable composed of a plurality of PC steel strands, the section protruding from a sheath being dispersed for each PC steel strand, and a PC steel strand being formed near the end of each PC steel strand. Is a fixing part structure in which a PC steel stranded wire is fixed in concrete in a state in which a part thereof is bent from a plurality of wires to form a bulb portion, and a plurality of wires constituting each PC steel stranded wire are fixed. The portion that becomes a bundle near the end of the bulb portion is inserted into an annular restraining member through which all the wires can be inserted, and the fixing portion of the PC steel strand is restrained from the outer periphery.