JP2568402Y2 - Unbonded PC stranded wire termination structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an unbonded PC stranded wire end structure in which a stranded PC steel wire is covered with an unbonded tube (cladding tube).

[0002]

2. Description of the Related Art For example, an unbonded tube (coated tube) made of a polyethylene pipe is used for the entire length or a predetermined portion of a PC steel stranded wire (also referred to as a strand or simply a cable).
A so-called non-fixed type PC steel stranded wire (unbonded PC steel stranded wire) coated with is provided as an anchor tensile material used for ground anchor construction and the like.

[0003] In the unbonded PC steel stranded wire, a rust-preventive oil such as grease is filled in the unbonded tube to secure expansion and contraction of the PC steel stranded wire with respect to the unbonded tube, and to allow the PC steel stranded wire in the unbonded tube to be expanded. Rust, corrosion, etc. are prevented.

[0004]

[Problem to be solved by the invention] Here, unbonded PC
As a steel stranded wire terminal structure, for example, a configuration having a crimp grip is known. In such a terminal structure, usually, the unbonded tube is cut and peeled in a predetermined range from the terminal to form a bare portion of the PC stranded wire, and the crimping grip is formed by crimping using a crimping jack or the like. It is fixed to the bare part of the steel strand.

[0005] Incidentally, since the unbonded tube is usually free with respect to the PC steel strand, it can be moved with respect to the fixed crimping grip. That is,
When the unbonded tube moves relative to the PC steel strand in the direction away from the crimping grip, a gap is created between the crimping grip and the unbonded tube.

In the gap between the crimping grip and the unbond tube, the rust-preventing effect of grease or the like is not sufficiently obtained. May occur on the exposed PC steel strand.

An object of the present invention is to provide an end structure of an unbonded PC stranded wire that prevents exposure of the PC stranded wire between an unbonded tube and a crimping grip.

[0008]

According to the present invention, a step having a specific height is formed at a predetermined position on an end of an unbonded tube by winding a tape having a predetermined width. Have been. The tape and the crimping grip are connected to each other by covering with a covering means that continuously covers the outer ends of the tape and the crimping grip.

[0009]

According to the present invention, detachment of the unbonded tube from the coating means is reliably prevented under the engagement of the tape with the step of the unbonded tube and the coating means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, in an unbonded PC stranded wire end structure 10 according to the present invention, a crimping grip is used.
12 is fixed to the bare wire end of the unbonded PC steel strand 14.

[0012] The unbonded PC steel strand 14 is formed, for example, by covering an entire or predetermined part of a PC steel strand 16 formed by twisting a plurality of wires with an unbonded tube (coated tube) 18 made of polyethylene pipe. Are formed by filling an unbonded tube with a rust-preventive oil (not shown) such as grease.

[0013] In the unbonded PC steel strand 14, the frictional resistance is reduced by grease or the like, so that the smooth movement of the PC steel strand 16 with respect to the unbonded tube 18 is ensured, and drilling water, groundwater Rust, corrosion, etc., resulting from the intrusion of water, etc., are prevented.

Incidentally, such an unbonded PC steel strand 14
Is publicly known, and the basic configuration itself is not the purpose of the present invention, and thus will not be described in detail here.

The terminal treatment of the unbonded PC stranded wire 14 for fixing the crimping grip 12 to the terminal is usually performed as follows.

As shown in FIGS. 2 and 3, at the end (cut end) of the unbonded PC steel strand 14, only the unbonded tube 18 is cut and peeled off within a predetermined range from the cut end. A bare wire portion of the stranded wire 16 is formed. Then, as shown in FIG. 3, a crimping grip 12 having a corresponding inner diameter is inserted into the bare wire portion of the PC steel stranded wire 16 and crimped. The fixation of the crimping grip 12 is usually performed by a dedicated crimping jack (not shown).

Note that a general jack can be used as the crimping jack, and the configuration itself is not the purpose of the present invention, and therefore will not be described in detail here.

Here, as can be seen from FIG. 4 in addition to FIG. 1, in the present invention, a tape 20 having a predetermined width is provided at an end of the unbond tube 18 at a specific height, that is, a specific thickness. It is wound up to form a step. Then, the unbonding is performed by continuous coating of the step portion of the unbonded tube 18 and the crimping grip 12 by the coating means 22.
The connection between the unbond tube 18 and the crimping grip at the end of the PC steel strand 14 and the rustproofing between them are simultaneously performed.

As the covering means 22, for example, a heat-shrinkable tube which is brought into close contact with the inner member by shrinkage due to heating can be used. As the heat-shrinkable tube (coating means) 22, a general commercial product or the like can be sufficiently used, and as shown in FIG.
The tape 20 is cut in advance to a length that completely covers the tape 20 and the pressure grip 12 before use.

A commercially available cloth tape, vinyl tape, or the like can be used as the tape 20, and the cloth tape or the like is wound around the surface of the unbond tube 18 to the extent that the step can be recognized, for example, about two layers.

As can be seen from FIG. 1, in such a configuration, the heat-shrinkable tube 22 wraps the tape 20 and the crimping grip 12 by heat shrinkage so that the PC steel stranded wire 1
6. The heat-shrinkable tube is engaged with the outer ends of both the stepped portion of the tape and the crimping grip, since it is substantially adhered to the surface of each member including the unbonded tube 18. In other words, according to the present invention, the continuous covering of the step portion of the tape 20 and the crimping grip 12 by the heat-shrinkable tube 22, the engagement with the outer end by wrapping,
The movement and detachment of the unbonded tube 18 and the crimping grip in the axial direction of the PC steel strand 16 with respect to the heat-shrinkable tube are reliably prevented.

Therefore, even if a gap is formed between the unbond tube 18 and the crimping grip 12, the gap is not exposed, and is isolated from foreign matters such as drilling water and groundwater.
PC steel strand 14 is reliably protected.

Since the intrusion of foreign matters such as drilling water and groundwater from the end of the unbond tube 18 can be reliably prevented, the smooth expansion and contraction of the PC stranded wire in the unbond portion is sufficiently ensured.

Here, in the embodiment, a heat-shrinkable tube is exemplified as the covering means 22. However, it is sufficient if the tape 20 and the pressure grip 12 can be continuously mounted. The present invention is not limited to this. For example, a configuration may be adopted in which a cloth tape, a vinyl tape, or the like is used as the covering means, and the tape and the pressure grip are continuously covered by taping with these.

However, the heat-shrinkable tube is not covered by the coating means.
If it is set to 22, it is sufficient to continuously cover the tape 20 and the crimping grip 12 with the heat-shrinkable tube previously cut to the corresponding length and heat it, so that the work is not complicated, the workability and the workability are improved. Certainty is reliably improved.

The embodiment described above is for explaining the present invention, and does not limit the present invention in any way.
It goes without saying that all modifications and alterations within the technical scope of the present invention are included in the present invention.

[0027]

[Effect of the Invention] As described above, according to the unbonded PC stranded wire end structure according to the invention, a tape is wound around an unbonded tube to form a step, and the tape and the pressure grip are continuously connected by a covering means. By moving the unbonded tube and the crimping grip in the axial direction with respect to the covering means, the movement and detachment can be reliably prevented. for that reason,
Between the unbond tube and the crimping grip, the PC strand is not exposed, and it is reliably isolated and protected from foreign substances such as drilling water and groundwater.

Since the intrusion of foreign matters such as drilling water and groundwater from the end of the unbonded tube can be reliably prevented, the smooth expansion and contraction of the PC steel strand in the unbonded portion is sufficiently ensured.

Further, if the heat-shrinkable tube is used as the covering means, it is sufficient if the heat-shrinkable tube cut in advance to the corresponding length is continuously coated on the tape and the pressure-fitting grip and heated, which complicates the operation. Therefore, workability and work reliability are surely improved.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an end structure of an unbonded PC stranded wire according to the present invention, showing a heat-shrinkable tube (coating means) in a longitudinal sectional view.

FIG. 2 is a partial perspective view of an unbonded PC steel strand showing an initial state of the terminal.

FIG. 3 is an exploded perspective view of an unbonded PC steel stranded wire and a pressure grip.

FIG. 4 is an exploded perspective view of the unbonded PC stranded wire and the heat-shrinkable tube after the crimping grip is fixed.

[Explanation of symbols]

 10 End structure of unbonded PC stranded wire 12 Crimping grip 14 Unbonded PC stranded wire 16 PC stranded wire 18 Unbonded tube (cladding tube) 20 Tape 22 Coating means (heat shrinkable tube)

Claims (2)

(57) [Scope of request for utility model registration] 1. An unbonded PC stranded wire end structure in which a crimping grip is fixed to a bare portion of a PC steel stranded wire formed by cutting and peeling an unbonded tube over a predetermined range from a terminal. By winding, a step of a specific height is formed at a predetermined position at the end of the unbonded tube, at least the tape, by covering with a covering means that continuously covers the mutual outer ends of the crimp grip, the tape, End structure of unbonded PC steel strand, characterized in that the crimp grips are connected to each other. 2. The unbonded PC stranded wire end structure according to claim 1, wherein the covering means is a heat-shrinkable tube having a length capable of integrally covering the outer ends of the tape and the crimping grip.