JPH06117053A - Covering pipe terminal end treating method for partial unbonded pc steel stranded wire and construction thereof - Google Patents

Abstract

PURPOSE:To surely isolate the inner part from the outer part of a covering pipe by filling water cut-off material around a core wire and between side wires on the side of the terminal end of a covering pipe, and covering the place and the terminal end of the covering pipe with cloth tape and the like. CONSTITUTION:On the side of the terminal end of a covering pipe 14 in which the unbonded part of a partial unbonded PC steel stranded wire 12 is formed, a tool such as a chisel 23 is inserted between side wires 16a adjoiningly stranded so as to forcedly spread. Next, water cut-off material 20 is injected at least around a core wire 16b through the gaps between the side wires 16a and filled therein. Next, the water cut-off material 20 is further spread between the side wires 16a on the surface of the place filled with the water cut-off material 20, and the water cut-off material 20 on the surface is protected by taping. Next, this place and the covering pipe 14 are continuously covered with cloth tape 22 and the like. Hereby, it can be prevented that grease 18 flows out from the covering pipe 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for covering a partially unbonded PC stranded wire covering an unbonded portion which is not fixed or fixed to concrete by partially covering with a covering tube, and a covering tube finishing structure. .

[0002]

2. Description of the Related Art As a high-strength steel wire used in a so-called earth anchor construction method for preventing landslides, for example, several side wires are twisted around a core wire.
PC steel strands (also called strands or cables) are well known. Such PC steel stranded wire is usually formed as a bare wire, and generally, can be fixed and fixed to the cast concrete.

[0003] In addition, a non-fixed type of unbonded PC steel wire, which is not fixed and fixed to concrete and whose expansion and contraction is not suppressed, against such general PC steel wire (fixed type PC steel wire) PC steel stranded wire is also known. In this unbonded PC steel stranded wire, the coated pipe made of plastic such as polyethylene resin covers the PC stranded wire to isolate the PC stranded wire from the concrete, and rust preventive oil such as grease is applied inside the coated pipe. By filling
It prevents the rust of the PC steel wire and reduces the frictional resistance between the cladding tube and the PC steel wire, enabling expansion and contraction of the PC steel wire.

Further, a partially unbonded PC steel stranded wire in which a bare wire portion (bond portion) left as a bare wire and a coating portion (unbonded portion) covered with a coating tube filled with grease or the like are also present, PC used for earth anchor method
Well known as steel stranded wire.

As a method of forming a partially unbonded PC stranded wire, a method by extrusion molding and a method by insertion are generally used.

[0006] For example, in the former molding method by extrusion molding, first, a molten plastic, for example, a polyethylene resin is extruded onto the surface of a PC steel wire, while a semi-fluid-like grease is applied between the PC steel wire and the molten plastic. Partly filled in, the PC stranded wire is covered over the entire length with a covering tube made of polyethylene resin.

[0007] In the portion not filled with grease, the PC steel strand can be easily visually confirmed through the coating pipe, so the coating pipe is cut at both ends of the portion,
Unbonded part of unbonded part by peeling the cladding tube of the part not filled with grease
Wire is formed from PC steel.

Also, in the latter method of inserting, a cladding tube preformed corresponding to the length of the unbonded portion is inserted into the corresponding portion of the PC steel strand while applying grease, A partially unbonded PC steel wire is formed by partially covering a predetermined portion of the PC steel wire.

[0009]

By the way, in the known method as described above, a water-stopping material or the like is applied to the boundary portion between the bond portion and the unbonded portion, that is, each end of the cladding tube, and a vinyl tape or the like is used. By coating, drilling water, inflow of groundwater and slippage of cladding pipe are prevented.

When the unbonded part of the PC steel strand is heated due to the solidification heat of the concrete or the high temperature of the PC steel strand itself, the grease filled between the cladding tube and the PC steel strand becomes liquid. There is a risk that On the surface of the PC steel strand, the waterproof material, vinyl tape, etc. prevent the grease from flowing out from the unbonded portion.

However, in a PC steel stranded wire, since a gap is usually formed between the core wire and the side wire, the liquefied grease flows through the gap to the outside of the unbonded portion, that is, the bonded portion, and concrete, There is a possibility that the fixing strength between the wires will be reduced compared to PC steel.

Further, particularly in the insertion method, since the cladding tube is merely inserted while applying grease to the PC steel wire, the grease is not sufficiently filled, and the cladding tube and the PC steel wire are not filled. A gap is likely to occur between them. For this reason, if the boundary is not sufficiently water-stopped, concrete material or the like may enter the cladding pipe, or drilling water, groundwater, or the like may enter during pressure injection into the anchorage. There is

Intrusion of foreign matter such as concrete material and drilling water into the cladding tube is not preferable because it impedes the expansion and contraction operation of the PC steel strand at the unbonded portion.

It is an object of the present invention to provide a method for treating a partially unbonded PC stranded wire for a cladding tube and a cladding tube termination structure capable of reliably isolating the inside and outside of the cladding tube.

[0015]

In order to achieve this object, according to the cladding tube terminal treatment method for a partially unbonded PC steel wire of the present invention, an external force is applied between adjacent side wires of the cladding tube terminal. And forcibly expand it with a gap between the side wires, at least around the core wire by injecting and filling the waterproofing material, and at the same time with the outer peripheral surface of the relevant part of the PC steel wire filled with the waterproofing material and the cladding tube. And are continuously coated by a coating means.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

As shown in FIG. 1, a partially unbonded PC stranded wire cladding end treatment structure 10 according to the present invention comprises:
Partially unbonded PC The stranded portion of the cladding tube 14 forming the unbonded part of the stranded wire 12 is water-stopped.

As can be seen from FIG. 2 in addition to FIG.
Several wires, for example 6 side wires 16a to 1 core wire
A sheathed pipe made of polyethylene resin that is twisted around 16b to form PC steel strand 16 and is called an unbonded tube.
Partial unbonded by covering a predetermined part of PC steel wire with 14
Wire 12 is formed from PC steel.

In such a partially unbonded PC steel stranded wire 12, for example, a bare wire portion of the PC steel stranded wire 16 can be fixed and fixed to concrete or the like, and a portion covered by the covering pipe 14 It is called the unbonded part, and the PC steel strand of the unbonded part is expandable and contractable with respect to the cladding tube.

In such a structure, the cladding tube is usually used.
14, rust preventive oil 18 such as grease is filled between the PC steel strands 16 and the friction resistance between the cladding pipe and the PC strands is reduced, ensuring smooth expansion and contraction of the PC strands inside the cladding pipe. it can.

As a method of forming a partially unbonded PC steel wire, for example, an extrusion molding method of covering the entire length of the PC steel wire by extrusion molding of a covering tube and peeling off the covering tube of an unnecessary portion later, and A method is generally known in which a PC stranded wire is inserted into a cladding tube that has been cut into a predetermined length in advance, and the stranded wire is partially covered at a predetermined location.

However, the structure and forming method of the partially unbonded PC stranded steel wire 12 are known, and the structure and forming method itself are not the gist of the present invention, and therefore will not be described in detail.

Here, in the partially unbonded PC stranded wire cladding pipe terminal treatment structure 10 of the present invention, a waterproofing material is applied to the lateral sides of the cladding pipe end by the water blocking material 20 and the coating means 22. .

As shown in FIG. 3, in such a structure, for example, the waterproof material 20 is filled and filled around the core wire 16b and between the adjacent side wires 16a without any gap. As the water blocking material 20, for example, a rubber-based water blocking material can be used, and the water blocking material is melted at 170 to 190 ° C. and poured and filled.

Injecting the water blocking material 20 around the core wire 16b,
The filling is performed through the gap between the adjacent side wires 16a which is forcibly expanded.

In the partially unbonded PC stranded wire cladding tube terminating method of the present invention, as shown in FIG. 4, for example, by inserting a sharp wedge-shaped tool into the side wires 16a, the side wires are separated from each other. It is being forcibly expanded. A chisel 23, for example, can be used as a wedge-shaped tool.

Here, during the expansion work between the side wires 16a utilizing the chisel 23, as shown in FIG. 4, the PC steel stranded wire 16 is usually moved by a predetermined jig 24 as shown in FIG. The expanded work between the side wires 16a is carried out under the stable condition of the PC stranded wire supported.

The jig 24 is formed, for example, with a groove 26 having a substantially semicircular cross section corresponding to the outer diameter of the PC steel stranded wire 16. The PC steel stranded wire can be supported by fitting into the groove. ing. Then, the jig 24 is formed with a step portion 28 continuous to the groove 26 in the central portion, and by inserting the chisel 23 between the arbitrary side wires 16a at a position corresponding to the step portion, the core 24 is formed. Wire
Expand between the side wires until the exposed state of 16b.

During the expansion work between the side wires 16a, the chisel 23 is usually driven by a hammer (not shown) or the like until it penetrates the outer diameter of the PC steel wire 16,
As shown in FIG. 5, one side insertion work of the chisel separates the two side wires 16a and expands between the side wires.

Then, the water blocking material 20 is injected and filled in a range of about 5 to 10 cm around the core wire 16b through the gap of the side wire 16a expanded by inserting the chisel 23.

After injecting the waterproofing material 20, attach the chisel 23 to the side wire 16
If the wire is pulled out from between a, the wire 16 of the PC steel returns to the initial state under the restoring force of the side wire, and the water blocking material is enclosed around the core wire 16b.

At this time, in the one-time expansion work of the side wire 16a with the chisel 23, as described above, the separation of about two side wires is the limit, so the insertion angle is usually changed. The chisel is inserted at a plurality of points, and the waterproof material 20 is surely filled and sealed all around the core wire 16b.

Then, the chisel 23 is pulled out and stranded with PC steel.
After returning 16 to the initial state, sufficiently apply the waterproof material between the side wires 16a on the surface of the PC steel strand in which the waterproof material 20 is sealed, and leave a gap between the side wires. And taping is performed, for example, by the tape 30 to be attached so as to cover the water blocking material, as shown in FIG.

As the tape 30 to be attached, for example, a cloth tape can be used, and the cloth tape has a width equivalent to the width (5 to 10 cm) filled with the water blocking material 20 until the outer diameter becomes equal to that of the covering pipe 14. Then, it is wrapped around the PC steel strand 16.

Then, as shown in FIGS. 1 to 3, the covering means 22 continuously covers the covering tube 14 and the tape 30 to be mounted, and the covering tube end is treated under the water-stopping process. It

As the covering means 22, for example, a cloth tape can be used similarly to the tape 30 to be attached, and the cloth tape has a full length.
Wraps in the range of 10 to 15 cm.

In such a configuration, the PC on the side of the cladding tube end
The waterproof material 20 is filled both inside and outside the steel stranded wire, and the covering of the cladding tube end is prevented by continuous coating of the portion and the cladding tube end by taping.

As described above, according to the present invention, the water blocking material 20 is filled around the core wire 16b, and
The 14 terminals and the relevant parts are covered by continuous taping, and the inside and outside of the cladding tube are isolated under the water-stopping process. That is, even if the grease 18 filled in the cladding tube 14 is melted and flows out along the side wires 16a and the core wire 16b under the heating by the solidification heat of concrete or the like, the outflow does not occur. The water stop member 20 reliably blocks the water.

Therefore, the grease 18 does not flow out of the cladding tube 14, and at the bond portion of the partially unbonded PC steel wire 12, the fixation between the concrete and the PC steel wire 16 due to the outflow of grease. Defects can be reliably prevented.

Further, since the foreign matter such as drilling water and groundwater can be surely prevented from entering the inside of the cladding tube 14 by the water blocking material 20, taping, etc., the PC steel in the cladding tube, that is, in the unbonded portion, can be prevented. Sufficient expansion and contraction of the stranded wire 16 can be sufficiently ensured.

Since the portion where the water blocking material 20 is filled and applied is protected by taping with the tape 30 to be mounted, the next work process can be started without waiting for the hardening of the water blocking material. Therefore, interruption of work can be avoided and workability can be improved.

Here, a sharp tool is used.
Although 23 is exemplified, the present invention is not limited to this, and a minus driver or the like may be used.

Here, in the method of the embodiment, chisel
Although the space between the adjacent side wires 16a is expanded by inserting 23, the gap is not limited to this because it is sufficient to form a gap into which the water blocking material 20 can be injected.

For example, as shown in FIG. 6, a fixed gripping tool (fixing tool) 34 provided on the jig 32, and a movable gripping tool (movable support tool) arranged so as to be separated from the fixing tool by a predetermined distance. ) 36
Using and, by the rotation of the movable support with respect to the fixture,
A method of expanding between the side wires 16a of the adjacent PC steel strands may be used.

The fixture (grip) 34 of the jig is, for example,
With a rotation operation of the operation handle 38, the lead screw 40 is screwed in and out of a nut (not shown), and is configured in a vise to raise and lower the gripping piece 42.
Between it and 44, the PC steel strand 16 can be gripped and fixed.

The jig 32 is formed with a pair of support pieces 46 and 47 capable of supporting the partially unbonded PC stranded wire 12 so that the partially unbonded PC stranded wire can be placed in a stable state. It is possible.

As can be seen from FIG. 6, for example, a hand-type pipe wrench can be used as the movable support tool (grasping tool) 36, and a PC steel stranded wire can be used at a position about 30 cm away from the fixing tool 34. 16 is gripped by a pipe wrench.

In such a method, when the pipe wrench (grasping tool) 36 is rotated with respect to the fixing tool 34 in the direction opposite to the twisting direction of the side wire 16a, as shown in FIG. The twists are partially relaxed, expanding between adjacent side wires. Then, the water blocking material 20 is injected and filled around the core wire 16b through the gap formed between the side wires 16a, and after the water blocking material is filled, the turning operation force of the pipe wrench 36 is released. For example, under the restoring force of the side wire, the PC stranded wire 16 returns to the initial state, and the water blocking material is enclosed around the core wire.

Thereafter, as in the above-described embodiment, if the tape 30 for mounting is used for taping at the location and continuous taping is performed between the location and the ends of the covering pipe 14, the water blocking process is performed. The unwrapped PC steel stranded wire cladding end structure 10 of the present invention shown in FIG. 1 is sufficiently obtained.

In this method, since the twist of the side wire 16a of the PC steel strand is loosened, a gap is formed between the side wires on the entire circumference. Therefore, the water-sealing material 20 can be filled into the entire circumference of the core wire 16b under one expansion work, and the workability is improved.

Although a pipe wrench is used as the movable support 36 here, the tool is not limited to this, as long as the tool can be rotated with respect to the fixture 34.

Here, in the embodiment, the rubber-based water blocking material is exemplified as the water blocking material 20, but it is sufficient if it is possible to prevent the outflow of the melted grease, the inflow of drilling water, etc. The present invention is not limited to this, and for example, a resin adhesive or the like may be used.

A cloth tape is used as the applied tape 30 and the covering means 22, but the present invention is not limited to this.
For example, vinyl tape or the like may be used. However, since the cloth tape is superior in stability to the rubber-based waterproof material as compared with the vinyl tape, by using the cloth tape for the wearing tape 30 and the covering means 22, the workability and the stop after the work are improved. The certainty of the water effect is improved.

Furthermore, the covering means 22 is not limited to taping because it is sufficient if the filling portion of the water blocking material 20 and the end of the covering pipe 14 can be continuously covered, and for example, the heat shrinkable tube 50 is covered. You may use it as a means.

The heat-shrinkable tube 50 is formed to have a length capable of continuously covering the filling portion of the waterproof material 20, that is, the winding portion of the tape 30 to be covered and the end of the covering tube 14, for example, about 20 cm. Then, as shown in FIG. 8, the cladding tube is loosely inserted in advance. Then, after taping the portion with the mounting tape 30, the heat-shrinkable tube 50 is shifted to be installed on the ends of the mounting tape 30 and the covering tube 14, and the heat-shrinkable tube is shrunk under heating, so that As described above, the tape to be mounted and the ends of the cladding tube are continuously coated.

Even in the structure using the heat-shrinkable tube 50, as shown in FIG. 9, since the end of the covering tube 14 and the tape 30 to be mounted are continuously covered, the covering by taping is performed. The same effect as that of the embodiment is surely obtained.

Since it suffices to heat the heat-shrinkable tube 50, workability during the covering work is further improved.

The above-mentioned embodiments are for explaining the present invention and do not limit the present invention in any way.
It goes without saying that the present invention includes all those which are modified or modified within the technical scope of the present invention.

[0059]

As described above, according to the method for treating a partially unbonded PC stranded wire cladding tube according to the present invention, the inside and outside of the cladding tube can be reliably treated by the waterproofing material and the waterproofing process by the coating means. Is isolated in. Therefore, the grease does not flow out of the cladding tube, and it is possible to reliably prevent defective fixing between the concrete and the PC steel wire at the bonded portion of the partially unbonded PC steel wire.

Further, since the foreign material such as the concrete material and the drilling water can be surely prevented from entering the cladding tube by the water blocking material and the covering means, the PC steel stranded wire in the cladding tube, that is, in the unbonded portion can be surely prevented. Sufficient expansion and contraction can be secured.

In both the method of using a tool such as a chisel and the method of loosening the twist of the side wires with a pair of holding tools, since the side wires can be sufficiently widened, a gap between the side wires is provided. Reliable and easy filling and filling of the waterproofing material.

Here, according to the method of loosening the twist of the side wire with the pair of gripping tools, the side wire on the entire circumference is expanded in a single expansion work, so that the waterproofing material is used. The workability is improved without the need for multiple filling operations.

Further, by supporting and fixing the partially unbonded PC stranded wire with a jig corresponding to each method, work in a stable state can be surely obtained, and workability is surely improved.

If a water blocking material is further applied between the side wires on the surface of the portion filled with the water blocking material and protected by taping, the gap on the surface of the side wire is surely filled. Also, the inflow of drilling water can be sufficiently prevented.

Further, since the water blocking material on the surface is protected by taping, it is possible to shift to the next working step without waiting for the hardening of the water blocking material, so that interruption of the work can be avoided and workability is improved. Get rid of.

Further, when the cloth tape is used as the covering means, the cloth tape is excellent in the stability of the water blocking material, so that the workability and the certainty of the water blocking effect after the work are improved.

When the heat-shrinkable tube is used as the coating means, the workability can be further improved because the heat-shrinkable tube can be continuously covered by the heating work of the heat-shrinkable tube and between the ends of the coating tube.

[Brief description of drawings]

FIG. 1 is a schematic front view of a partially unbonded PC stranded wire cladding tube terminating structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a schematic perspective view of a partially unbonded PC stranded wire placed on a jig in an example of a method for covering a partially unbonded PC stranded wire cladding tube according to the present invention.

FIG. 5 is a vertical cross-sectional view of a PC stranded wire showing an expanded state of a side wire in an example of a method for treating a cladding tube of a partially unbonded PC stranded wire of the present invention.

FIG. 6 is a schematic perspective view of a partially unbonded PC steel strand fixed to a jig in another method.

FIG. 7 is a schematic front view of a PC stranded wire showing an expanded state of a side wire in another method.

FIG. 8 is a schematic perspective view of a partially unbonded PC stranded wire before being covered with a covering means according to another embodiment.

FIG. 9 is a schematic front view of a partially unbonded PC stranded wire cladding tube terminating structure after coating with coating means according to another embodiment.

[Explanation of symbols]

 10 Partial unbonded PC steel stranded wire sheathing structure 12 Partial unbonded PC steel stranded wire 14 Cladding pipe 16 PC steel stranded wire 16a side wire 16b Core wire 18 Grease (rust preventive oil) 20 Water blocking material 22 Coating means (cloth) Tape) 23 chisel (tool) 24 jig 26 groove 28 step 30 tape to be mounted (cloth tape) 32 jig 34 gripping tool (fixing tool) 36 gripping tool (movable support tool) 50 heat shrink tube (covering means) )

Claims (10)

[Claims] 1. A partially unbonded PC steel strand, on the side of a cladding tube end forming an unbonded portion of the wire, forcibly expands between adjacent side wires under an external force, and from a gap between the side wires, Inject a water blocking material around at least the core wire,
Partial unbonded PC steel wire coating that fills the end of the coating tube by continuously covering the outer peripheral surface of the location where the water blocking material of the PC steel wire is filled and the coating tube with a coating means Pipe terminal processing method. 2. A waterproofing material is injected and filled around the core wire through a gap between the side wires by inserting a tool between the side wires that are twisted adjacent to each other to expand the space between the side wires. 1
Described is a method for treating the end of a partially unbonded PC steel stranded wire cladding. 3. A PC steel wire is fitted and supported in a groove of a jig having a substantially semicircular cross section corresponding to the outer diameter of the PC steel wire, and at a position corresponding to the step portion of the jig continuous with the groove. 3. The method for treating a partially unbonded PC steel stranded wire cladding tube according to claim 2, wherein the side wires adjacent to each other are widened by penetrating the tool through the side wires. 4. A PC steel stranded wire of a cladding tube terminal is erected and fixed between a pair of gripping tools arranged so as to be separated from each other by a predetermined distance, and at least one of the pair of gripping tools is a side wire of the PC steel stranded wire. By rotating in a direction opposite to the twisting direction of the side wires to partially loosen the twisting of the side wires to expand between the side wires, and to inject and fill the waterproof material around the core wire from the gap between the side wires. 1. The method for terminal treatment of partially unbonded PC stranded wire cladding. 5. A vise-shaped fixture provided on a jig is used as one gripper, and a movable support for the fixture is used as the other grip, and the movable support is rotated with respect to the fixture. The method for treating a partially unbonded PC steel stranded wire cladding tube according to claim 4, wherein the twist of the side wire is partially relaxed. 6. A water blocking material is further applied between the side wires on the surface of the portion filled with the water blocking material to protect the water blocking material on the surface by taping, and at the same time, the location and the cladding tube end are connected. The method for treating a partially unbonded PC stranded wire covering tube end according to any one of claims 1 to 5, wherein the covering is continuously carried out by a covering means. 7. A cladding tube terminal structure for partially unbonded PC steel wire, in which a PC steel wire formed by twisting several side wires around a core wire is partially covered with a cladding tube of a predetermined length. The side of the cladding tube is filled with at least a waterproof material around the core wire of the PC steel wire, and the outer peripheral surface of the PC steel wire and the cladding tube corresponding to the filling location of the waterproof material are covered. A cladding tube terminal treatment structure for partially unbonded PC steel wires, characterized in that it is continuously coated by means and subjected to a water stop treatment. 8. The partially unbonded PC steel stranded wire according to claim 7, wherein the waterproof material is further applied between the side wires on the surface of the portion filled with the waterproof material, and the waterproof material is protected by taping. Cladding tube end treatment structure. 9. The covering means is a cloth tape,
The cladding end treatment structure for partially unbonded PC stranded wire according to claim 7 or 8, wherein the cladding ends are covered by continuous taping. 10. The cladding tube end of a partially unbonded PC stranded steel wire according to claim 7 or 8, wherein the coating means is a heat-shrinkable tube which is disposed and thermally contracted in a state of being bridged between the location and the cladding tube end. Processing structure.