JPH0872117A - Method for processing coated stranded pc steel wires into unbonded multiple wire - Google Patents

Abstract

PURPOSE: To obtain a method for processing coated stranded PC steel wires into an unbonded multiple wire with the remarkable improvement of not only a rust proof power but also an operability and a workability. CONSTITUTION: A stranded PC steel wire is formed by stranding a plurality of side wires 24 around a core wire 25. After that, the stranded part of the core wire and the side wires is temporarily and successively unstranded through a loosening device, an expansion maintaining device, and the like. The full periphery of each of the core wire and the side wires is coated, heated, cooled, and the like. The full peripheries of the core wire 25 and the side wires 24 are singly coated with a synthetic resin coating layer 26 in the coated stranded PC steel wire. Next, after two or more coated stranded PC steel wires are combined into a circularly bundled shape or a parallel shape, a lubricant 27, such as a grease, is applied to the surface. A synthetic resin coating layer 28 is formed by extrusion on the surface of the coated stranded PC steel wire coated with the lubricant 27. In this manner, an unbonded stranded multiple PC steel wire is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-strand unbonding method for a PC steel stranded wire as a post-tensioning tension material for a prestressed concrete construction method for building structures and civil engineering structures.

[0002]

2. Description of the Related Art Conventionally, as a method of unbonding as a tension material for a post-tensioning system, a grease which also serves as a lubricant and an anticorrosive agent is applied to the surface of PC steel wire, and a synthetic resin coating layer is applied to the surface. Is used for the unbonded sheet.

In the case of the permanent anchor method, the pull-out resistance mechanism is roughly classified into an attachment type and a bearing type.
The former adhesion type is based on adhesion between the surface of the PC steel stranded wire and the grout material, and the latter bearing type is the fixing between the PC steel stranded wire and the grout material, which is performed by a fixing device.

[0004]

However, among the above-mentioned conventional examples, the former PC steel stranded wire has a lubricant on its surface.
With a rust-preventing treatment such as the application of grease that also serves as a rust-preventive agent, even a single-strand unbonded PC steel wire lacks rust-preventing power, let alone a large problem with rust-preventing power as a multi-strand unbonded PC steel wire. However, there are very few examples in which it is used as a multi-strand unbonded PC steel strand.

Therefore, when two or more articles are used in one place regardless of whether it is a building structure or a civil engineering structure, the required number of articles are tied and arranged, and concrete is poured. For example, even when used as a permanent anchor, if the design anchor is 40,000 Kgf, it will be 12.7 m from 7 nominal names.
If the PC stranded wire of m is used, the allowable stress level of 12.7 mm is JIS G3536 tensile load 18,700 k.
gf, the required number of threads is 40,000 kgf / 11,220k
gf = 3.57 Article, 4 Articles must be used.

Therefore, since the required number of lines calculated as described above is cut into a required length one by one at the construction site and used by bundling them, the workability is remarkably poor, In addition, there are various problems with respect to the rust preventive power as described later.

In the latter permanent anchor construction method among the above-mentioned conventional examples, in the case of the adhesive type, the tensile force of the PC steel strand is transmitted within the range of 2 to 3 m above the grout material which is the fixing body. As a result, a large tensile force is exerted on the grout material, which is the fixing body immediately below, causing a ring-shaped crack, and the risk of corrosion of the PC steel wire in that portion is a serious problem.

In addition, in the case of the conventional attachment type permanent anchor method, the rustproofing treatment of the PC steel wire, which is the adhesion portion with the grout material as the fixing body, is used without any rustproofing treatment. is the current situation.

On the other hand, in the case of unbonded PC steel strand,
Whether it is a single-strand unbonded PC stranded wire or a multi-strand unbonded PC stranded wire, the following three elements are listed as those that are particularly required.

(1) The anti-rust coating is not temporary,
High rust prevention and durability. (2) The rust-preventive film must be sufficiently adhered to the surface of the PC steel strand and have ductility that follows the elongation of the PC steel strand due to tension. (3) The unbonded structure including the rust-preventive coating should have low frictional resistance when prestressed is introduced.

In the case of a PC steel strand, another PC
Since the structure is different from that of steel rod or PC steel wire and a plurality of side wires are twisted around the core wire, in the rust prevention treatment only on the surface, the hollow part inside the core wire and the side wire and the side wire Corrosion of the cavity between them is a major problem.

Thus, conventionally, it has been desired to independently perform rust prevention treatment on the outer peripheral surfaces of the core wire and the side wire, but in the case of PC steel stranded wire, piano wire rod → surface treatment → bottom drawn wire →
Since it is manufactured by the process of patenting → finish wire drawing → stranded wire processing → blueing treatment → completion of PC steel stranded wire, plastic strain caused by cold working (stretching and stranded wire processing) during the manufacturing If the rust-prevention treatment is performed in combination with the removal at a temperature of about 450 ° C., which is the final step of the bluing treatment, a synthetic resin that can withstand a temperature of about 450 ° C. unless after the bluing treatment is obtained. This is because there was no method at all, and there was no suitable rust prevention method in place of the synthetic resin.

As described above, after the bluing process, P
In order to form the synthetic resin coating on the entire peripheral surface of each of the core wire and the side wire of the C steel stranded wire, there is no method other than temporarily loosening the twisted portion, and such a thing is impossible. It has been done.

As a result of earnest research, the present invention has solved the problems of the conventional single-strand unbonded PC steel wire, and maintains excellent rust-preventive power even when the multi-strand unbonded PC steel wire is processed. As possible, we succeeded in forming a synthetic resin coating layer on the entire peripheral surface of each of PC steel strands, core wires, and side wires, and applied a coating of synthetic resin coating layer on the entire peripheral surfaces of each core wire and side wires. This led to the development of various multi-strand unbonded PC stranded wires using PC stranded wires.

In addition, according to the present invention, the twisted portion, which has been impossible with the prior art, is temporarily returned, and in the meantime, the entire circumference of each of the core wire and the side wire is coated, heated and cooled to apply the synthetic resin film. The present invention has developed a method of processing various types of multi-strand unbonded PC steel strands using the formed painted PC strands.

As described above, the present invention has been made in view of such a conventional problem, and it is possible to process a multi-section unbonded PC steel stranded wire having various structures which are not seen in the related art. The purpose of the present invention is to provide a multi-strand unbonding method for coated PC steel strands, which significantly improves workability and workability as well as rust force.

[0017]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems and to achieve the intended purpose, the constitution which is the gist of the present invention is constituted by twisting a plurality of side wires around a core wire. Coated PC stranded wire in which a synthetic resin coating layer is formed on the entire peripheral surface of each of the core wire and the side wire.
A multi-strand unbond of a coated PC stranded wire in which a lubricant is applied to each surface of the steel stranded wire and a synthetic resin coating layer is formed by extrusion on two or more surfaces of the coated PC stranded wire coated with the lubricant. It depends on the processing method.

[0018] Further, the present invention relates to a PC steel stranded wire constituted by twisting a plurality of side wires around a core wire, wherein the synthetic resin coating layer is formed solely on the entire peripheral surface of each of the core wire and the side wire. Single-coating with a lubricant applied to the surface of the wire, and a synthetic resin coating layer provided on the surface by extrusion molding. Coating to further form a synthetic resin coating layer on two or more surfaces of the unbonded PC stranded wire by extrusion molding. It is a multi-strand unbonding method for PC steel strands.

Further, in the case of a PC steel stranded wire composed of a plurality of side wires twisted around a core wire, a coated PC steel wire in which a synthetic resin coating layer is formed solely on the entire peripheral surface of each of the core wire and the side wire. A synthetic resin coating layer is provided on two or more surfaces of the wire by extrusion molding, a lubricant is applied to the surface, and a synthetic resin coating layer is formed on the surface by extrusion molding. It depends on the processing method.

Further, the plurality of coated PC steel strands or the single-coated PC steel strand having a surface provided with a synthetic resin coating layer may be annularly or juxtaposed to further form a synthetic resin coating layer on the surface. good.

Further, after the plurality of coated PC stranded wires are held at predetermined intervals by a spacer, the synthetic resin coating layer may be formed on the surface.

[0022]

According to the multi-strand unbonding method of the coated PC steel wire of the present invention having the above-described structure, first, in the PC steel wire formed by twisting a plurality of side wires around the core wire, A lubricant is applied to each surface of the coated PC steel wire in which a synthetic resin coating layer is formed on the entire circumference surface of each of the core wire and the side wire, and two or more surfaces of the coated PC steel wire to which the lubricant is applied are applied. By forming the synthetic resin coating layer by the extrusion molding method, corrosion in all hollow portions such as core wires, hollow portions between side wires, hollow portions between side wires or hollow portions between PC steel strands can be prevented. It becomes possible to prevent it.

[0023] Further, the present invention relates to a PC steel stranded wire composed of a plurality of side wires twisted around a core wire, wherein the synthetic resin coating layer is formed on the entire peripheral surface of each of the core wire and the side wire alone. By applying a lubricant on the surface of the wire and providing a synthetic resin coating layer on the surface by extrusion molding method, by forming an additional synthetic resin coating layer on two or more surfaces of the unbonded PC stranded wire by extrusion molding. , PC
The steel stranded wire is more rich in rust prevention and has excellent durability.

Furthermore, in a PC stranded wire formed by twisting a plurality of side wires around a core wire, a coated PC steel in which a synthetic resin coating layer is formed solely on all the peripheral surfaces of the core wire and the side wires. If a synthetic resin primary coating layer is provided on the surface of two or more lines by an extrusion molding method, a lubricant is applied to the surface, and a synthetic resin secondary coating layer is formed on the surface by an extrusion molding method. By peeling the layer and the secondary coating layer in a state of enclosing the lubricant, the side line having the synthetic resin coating layer serves as a mating attachment portion, and complete rust prevention treatment is performed, so that the fixing member and the grout material are cracked. There is no risk of corrosion if it occurs.

[0025] Further, the plurality of coated PC steel strands or the single-coated PC steel strands having a surface provided with a synthetic resin coating layer are arranged in a ring or in parallel to form a synthetic resin coating layer on the surface, or After holding the plurality of coated PC steel strands at a predetermined interval with a spacer, if the synthetic resin coating layer is formed on the surface, when used in a permanent anchor method or the like, a bending stress is applied to the PC steel strand. It can be fixed without any problem. Hereinafter, the present invention will be described in more detail with reference to Examples.

[0026]

EXAMPLE The multi-strand unbonded PC steel stranded wire according to the present invention can be processed into multi-strand unbonded PC steel stranded wire of various structures depending on the place of use or method of use. There are three types of linear shapes.

Therefore, when rust-preventing force is particularly required such as a permanent anchor method as an example of its use, a multi-section unbonded PC steel strand is used, and a straight type is used for the anchor plate or anchor head fixing hole. As shown in FIG. 13, a multi-section unbonded product is used in a bearing type permanent anchor method, with spacers arranged at appropriate intervals so that an unbonded PC steel strand can be inserted in a shape. For example, fixing can be performed without giving bending stress to PC steel strands, and workability is improved, and quadruple rust prevention (core wire / side wire entire circumference coating + grease + primary coating + secondary coating) is applied. Therefore, it has excellent characteristics in all points such as rust prevention, workability, workability and the like, which have been problems in the past, and an ideal permanent anchor method can be carried out.

First, a first embodiment of the method for unbonding a coated PC stranded wire according to the present invention will be described with reference to FIGS. According to the present invention, a plurality of side wires 24, 24,.
A strand A of C steel is constructed (see FIG. 2 (a)). After that, a synthetic resin coating layer (specifically, a single coating 2) is formed on the entire peripheral surface of each of the core wire 25 and the side wires 24, 24.
6) to form a coated PC steel strand B (see FIG. 2 (b)).

The formation of such a synthetic resin film layer is performed by temporarily returning the twisted portion of the core wire and the side line via a loosening device, an expansion maintaining device and the like, which will be described later, and between the core line and the side line. It is preferable to perform coating, heating, cooling, etc. on the entire circumference.

Next, the second step of the present invention will be described. Pre-processed two or more coated PC steel strands B, B ...
Are combined into an annular collective form (see FIG. 4) or a side-by-side form (see FIG. 5), and then a lubricant 27 is applied to each surface. As the lubricant, it is preferable to use grease, for example, and to apply it evenly by a grease applying device described later.

Also, as shown in FIG. 6, only in the case of a straight multi-strand unbonded PC steel stranded wire, immediately before the covering of a synthetic resin coating layer (primary coating layer) 28 described later, the P of each strip is
A spacer 43 for holding the C steel strands B, B... At appropriate intervals may be interposed.

Next, the third step of the present invention will be described. By forming a synthetic resin coating layer (specifically, the primary coating layer 28) on the surface of the coated PC steel wire B coated with the lubricant 27 obtained in the previous step by the extrusion molding method, The line is what you get.

On the other hand, a system for manufacturing a single unbonded PC steel strand as a basis of the method of the present invention will be described with reference to FIGS. FIG. 1 shows a core wire of a PC stranded wire,
A coated PC stranded wire formed by forming a synthetic resin coating layer on the entire peripheral surface of each side wire alone, and an unbonded PC stranded wire
FIG. 1 is a block diagram showing a most suitable processing line or a manufacturing apparatus therefor (hereinafter, simply referred to as a system apparatus) for carrying out a method for forming a steel strand, in which 1 is a PC steel strand to be processed. .

The PC steel strand 1 has the cross-sectional structure shown in FIG. 2 (a). That is, the PC steel strand 1 is
There is a core wire 25 in the center portion, and a structure in which six side wires 24, 24,... Arranged around the core wire 25 in a joined state are spirally combined.

In this system device, after setting the coiled PC steel stranded wire 1 in the uncoiler device 2, the free end side of the PC steel stranded wire 1 is the next process device. Pull-out roll 3, polishing device 4, loosening device 5, expansion maintaining device 6a, core wire adjusting device 7, expansion maintaining device 6b, electrostatic powder coating device 8, high frequency induction heating device 9, cooling device 1
0, the expansion maintaining device 6c, and the gradual closing device 11 are fed in this order to perform the plating.

Then, a strip of unbonded PC steel strand C
In the case of processing into (see FIG. 2 (c)), processing is performed in the order of the grease applying device 12, the primary coating forming and extruding device 13a, and the cooling device 14a. When processing into a wire B with a coated PC steel on which a synthetic resin film 26 of
2. The primary coating forming and extruding device 13a is opened, and the subsequent steps are the same as the above-described processing of the coated PC steel strand B, the outer diameter measuring device 15a, the pinhole detecting device 16a, the take-off device 17
After a, by fixing the free end side of the slated PC steel wire to the wooden drum equipped in the winding device 19a, the preparation for manufacturing is completed, and then the system device is connected in series. When it is operated, it is automatically wound up on a wooden drum at a rate of 2000 kg.

The PC steel strand 1 drawn out from the uncoiler device 2 is completely removed of rust, oils and fats, dusts and the like adhering to the surface thereof by the steel brush or buff of the polishing device 4. Because

Then, the polished PC steel strand 1 is supplied to the relaxation device 5, and the side wire 24 spirally fitted to the core wire 25 of the PC steel strand 1 by the relaxation device 5 is sequentially formed. Then, the side line 24 is returned temporarily and temporarily, and the returned side line 24 is maintained at a fixed interval by the spread maintaining devices 6a, 6b, 6c.

Next, the expansion maintaining devices 6a, 6b,
While the side wire 24 is maintained at a constant interval by 6c, an adhesion film layer of powder coating is formed on each of the entire peripheral surfaces of the core wire 25 and the side wire 24 by the electrostatic powder coating method, and this is applied to a high frequency wave. After heating and welding with the induction heating device 9,
The coating is cooled to room temperature by the cooling device 10, and thereafter,
The core wire 2 is adjusted to the original state by the loose closing device 11.
5. The formation of the entire peripheral surface sole coating 26 of each side wire 24 is completed, and the processing of the coated PC steel wire 20a is completed.

Therefore, in the case of processing into a single-strand unbond, a lubricant 27 such as grease is uniformly applied to the surface of the coated PC steel wire 20a by the grease coating device 12, and the surface thereof is further coated with the synthetic resin by the molding extrusion device 13a. After forming the coating layer 29, it is cooled to room temperature by the cooling device 14a to obtain the single-strand unbonded PC steel wire C shown in FIG. 2 (C).

Further, in the subsequent manufacturing steps, the processing of the coated PC steel twisted wire B and the processing of the single unbonded PC steel twisted wire C are similar, and the outer diameter is continuously measured and recorded by the outer diameter measuring device 15a. The pinhole detecting device 16a continuously detects and records the pinholes, and the take-up device 17 takes up the pinholes at a constant speed and winds 2000 kg each by the wooden drum inserted in the winder 19a.

Next, a system device for carrying out the multi-strand unbonding method according to the present invention will be described with reference to FIG. For easy understanding, the same parts as those of the above-described one unbonded PC steel stranded system device are denoted by the same reference numerals, and only the parts having different configurations are described with new numbers.

FIG. 3 shows an optimum system apparatus for manufacturing and processing a multi-strand unbonded PC stranded wire using the coated PC stranded wire B and the single-strand unbonded PC stranded wire C having the cross-sectional structure shown in FIG. It is a block diagram, and in FIG.
0a is a coated PC steel strand to be processed into a multi-section unbonded PC steel strand.

This system unit consists of a coated PC stranded wire 2
1a unbonded PC using 0a or painted PC steel strand
The steel stranded wire 20b wound on the wooden drum is set in the uncoiler device 2a, and the free end side thereof is sequentially pulled out of the next step with the drawing device 17b and the grease coating device 12 in the next step.
a, primary coating molding extrusion device 13a, cooling device 14b, grease applying device 12b, secondary coating molding extrusion device 13b,
Slats are performed in the order of the cooling device 14c.

However, the grease applying device 12a,
The primary coating forming and extruding device 13b and the cooling device 14b are opened, and the grease applying device 12b and the secondary coating forming and extruding device 1 are opened.
3c and the cooling device 14c in this order, and the subsequent steps are performed through the outer diameter measuring device 15b, the pinhole detecting device 16b, the take-off device 17c, and the winding device 1 as in the single-row unbonding process.
Fixing the free end side of the coated PC stranded wire 20a or the single-strand unbonded PC stranded wire 20b which has been slatted to the wooden drum mounted on the 9b, the production preparation is completed,
By operating such a system unit in series, the wooden drum is wound up by 2000 kg at a time.

Further, the required number of uncoiler devices 2a are arranged by the multi-section unbonded PC steel stranded wire to be manufactured, and the coated PC stranded wire wound around a wooden drum is used.
The wire 20b is set with a 0a or single-strand unbonded PC steel wire, and its free ends are supplied to the drawing device 17b in the next step, and are sequentially fed to the subsequent drawing device 17c.

Only in the case of the multi-strand unbonded PC steel strand shown in FIG. 4, grease 27 is applied to each surface of the coated PC strand 20a by the grease applying device 12a, and as shown in FIG. Tajo Unbond PC
In the case of a steel stranded wire, the synthetic resin coating layer (primary coating layer) 28 is formed by the primary coating forming and extruding device 13b without opening the grease applying device 12a and applying the lubricant 27 such as grease.

Further, only in the case of the linear multi-strand unbonded PC stranded wire shown in FIGS. 6, 9 and 12, the spacer 43 is inserted immediately before the primary coating molding extrusion device 13b while inserting the spacers 43 at appropriate intervals. The resin coating layer 29 is formed.

Next, each of the multi-section unbonded PC steel strands on which the synthetic resin coating layer 28 has been formed is connected to the cooling device 1.
4b, the synthetic resin coating layer (primary coating layer) 28 is cooled by the grease coating device 12b in the next step.
A lubricant 27 such as grease is applied to the surface of the, and a synthetic resin coating layer (secondary coating layer) 30 is formed on the surface thereof by the secondary coating molding extrusion device 13c, and is cooled to room temperature by the cooling device 14c. is there.

Accordingly, the grease applying device 12b, the secondary coating forming and extruding device 13c, and the cooling device 14c are opened, and the subsequent steps are the same as in the previous example.

In the preceding step, the formation of the coating layer is completed, and the cooled multi-strand unbonded PC strand is continuously measured and recorded by the outer diameter measuring device 15b and continuously by the pinhole detecting device 16b. To detect and record
2000 kg on the wooden drum inserted in the winder 19b while being taken up at a constant speed by the take-up device 17c.
It is rolled up one by one.

Next, a second embodiment of the multi-row unbonding method according to the present invention will be described with reference to FIGS. To facilitate understanding, the same parts as those in the first embodiment described above are designated by the same reference numerals, and only different parts will be described with new numbers.

FIG. 7 is a cross-sectional view of a multi-strand unbonded PC steel stranded wire formed in an annular collective shape. This multi-strand unbonded PC stranded wire is formed around a core wire 25 similarly to the first embodiment. A single PC by twisting multiple side lines 24, 24 ...
A steel strand is formed, and then a synthetic resin coating layer 26 is individually applied to the entire peripheral surface of the steel strand to form a coated PC steel strand.

Incidentally, the formation of the synthetic resin coating layer 26 is carried out in the same manner as in the first embodiment, that is, the relieving device 5 and the expansion maintaining device 6.
The core wire 25 and the side wires 24, 24 via a, 6b, 6c, etc.
It is preferable to temporarily return the twisted portions of the core wires 25 in sequence, and to perform coating, heating, cooling, etc. on the entire circumference of each of the core wire 25 and the side wires 24, 24.

Then, a lubricant 27 such as grease is applied to this surface.
Is evenly applied through a coating device, and a synthetic resin coating layer 29 is further coated on this surface by an extrusion molding method, so that a single unbonded PC steel strand C (see FIG. 2C) is obtained. can get.

Then, as shown in FIG. 7, the unbonded PC steel strand C of the single strip is combined in an annular shape, and then the synthetic resin coating layer 28 is formed on these surfaces by an extrusion molding method.
To form a collective multi-section unbond P
A wire is obtained from C steel.

As shown in FIG. 8, the single-strand PC steel strands are arranged side by side, and a synthetic resin coating layer 28 is coated on the surface by extrusion molding to form a parallel type. May be formed.

FIG. 9 is a cross-sectional view of the multi-strand unbonded PC steel wire in which the single-strand coated PC steel wire is assembled in a straight line shape. Spacers 43 for holding the wires between the unbonded PC steel wires at appropriate intervals are shown. It is a multi-strand unbonded PC steel stranded wire that is interposed.

Next, a third embodiment of the multi-strand unbonding processing method according to the present invention will be described with reference to FIGS. In addition, in order to facilitate understanding, the above-mentioned first and second
The same parts as those of the embodiment are denoted by the same reference numerals, and only the parts having different configurations will be described with new numbers.

FIG. 10 is a cross-sectional view of a multi-strand unbonded PC steel stranded wire formed in a ring-shaped aggregate. The multi-strand unbonded PC steel stranded wire has a core wire 25 and an outer periphery of the core wire 25 in an annular shape. Are made of painted PC steel wires in which synthetic resin coating layers 26, 26... Are formed on the entire peripheral surface of each of the six side wires 24, 24.

In other words, the other 6 strands of such coated PC steel are assembled into a ring so that one of them is a core wire, and then,
A synthetic resin coating layer 29 is applied to this surface by an extrusion molding method.

Then, a lubricant 27 such as grease is applied to the surface of the synthetic resin coating layer 29, and a synthetic resin coating layer (secondary coating layer) 30 is formed on the surface of the synthetic resin coating layer 29 by an extrusion molding method to form an assembly. It is possible to obtain a wire from a multi-section unbonded PC steel having a shape.

Further, as described above, the seven coated PC steel strands are gathered in an annular shape, or they are arranged in parallel as shown in FIGS. 11 to 12, and the plurality of coated PC steel strands are provided with spacers 43. If the synthetic resin coating layer 30 is formed on the surface after being held at a predetermined interval with, when used in a permanent anchor construction method, etc., it can be fixed without giving bending stress to the PC steel wire, improving workability. In addition, since it has a quadruple rust prevention (core wire / side wire all around coating + grease + primary coating + secondary coating), all of the rust prevention power, workability, workability etc. In that respect, it has excellent characteristics and an ideal permanent anchor construction method can be constructed.

The method of the present invention for applying a multi-strand unbonding process to a coated PC strand is not limited to these examples, but can be freely changed within the scope of the present invention. The invention embraces all of them.

[0065]

The multi-strand unbonding method of the coated PC steel wire of the present invention is a PC steel wire formed by twisting a plurality of side wires around the core wire. A lubricant is applied to each surface of the coated PC steel wire on which a synthetic resin coating layer is formed on the entire circumference alone, and synthetic resin is applied to two or more surfaces of the coated PC steel wire coated with the lubricant by extrusion molding. By forming the coating layer, it is possible to prevent corrosion in any hollow portion such as the core wire, the hollow portion inside the side wires or the hollow portion between the side wires or the hollow portion between the PC steel strands, and the like,
In particular, salt spray test (200
No rust or swelling was observed even after 0 hour),
It has the effect of excellent rust prevention and durability.

Further, in the case of a PC steel stranded wire constituted by twisting a plurality of side wires around a core wire, a coated PC steel wire in which a synthetic resin coating layer is formed on the entire peripheral surface of each of the core wire and the side wire alone. By applying a lubricant on the surface of the wire and providing a synthetic resin coating layer on the surface by extrusion molding method, by forming an additional synthetic resin coating layer on two or more surfaces of the unbonded PC stranded wire by extrusion molding. In addition, it has the effect of being excellent in rust prevention and durability.

Furthermore, in a PC stranded wire formed by twisting a plurality of side wires around a core wire, a coated PC steel in which a synthetic resin coating layer is formed on all the peripheral surfaces of each of the core wire and the side wires. If a synthetic resin primary coating layer is provided on the surface of two or more lines by an extrusion molding method, a lubricant is applied to the surface, and a synthetic resin secondary coating layer is formed on the surface by an extrusion molding method. By peeling the layer and the secondary coating layer in a state of enclosing the lubricant, a side line having a synthetic resin coating layer becomes a mating attachment portion, and complete rust prevention treatment is performed, so that a provisional instruction, a fixing body, and a grout material are provided. Even if a crack occurs, it has an excellent effect that there is no risk of corrosion.

Further, the plurality of coated PC steel strands or the single-coated PC steel strand having a surface provided with a synthetic resin coating layer are arranged in a ring or in parallel to form a synthetic resin coating layer on the surface, or After holding the plurality of coated PC steel strands at a predetermined interval with a spacer, if the synthetic resin coating layer is formed on the surface, when used in a permanent anchor method or the like, a bending stress is applied to the PC steel strand. Because it can be fixed without any problems, the workability is improved, and triple or quadruple rust prevention (core wire / side wire whole circumference coating + grease + primary coating + secondary coating) has been applied, which has been a conventional problem of prevention It has excellent characteristics in all aspects such as rust, workability, workability, etc., and has an excellent effect that an ideal permanent anchor construction method can be carried out.

As described above, according to the present invention, the twisted portions, which have been impossible in the prior art, are temporarily returned sequentially,
In the meantime, the entire circumference of the core wire and side wire can be coated, heated, and cooled to form a synthetic resin film. This makes it possible to process multi-strand unbonded PC steel wires with a variety of unprecedented structures. In addition, workability and workability can be significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an entire system device used in a method for processing a coated PC steel strand and a single-strand unbonded PC steel strand according to the present invention.

FIG. 2A is a cross-sectional view of a PC steel stranded wire used in the present embodiment, FIG. 2B is a cross-sectional view of a coated PC stranded wire, and FIG. 3C is a single unbonded PC steel. It is sectional drawing of a stranded line.

FIG. 3 is a schematic view showing an entire system apparatus used in the method for processing a multi-section unbonded PC steel strand according to the present invention.

FIG. 4 is a cross-sectional view showing a first embodiment of a collective multi-section unbonded PC steel strand.

FIG. 5 is a cross-sectional view showing a first embodiment of a parallel-type multi-section unbonded PC steel strand.

FIG. 6 is a cross-sectional view showing a first embodiment of a linear multi-section unbonded PC steel strand.

FIG. 7 is a cross-sectional view showing a second embodiment of a collective-type multi-strand unbonded PC steel stranded wire.

FIG. 8 is a cross-sectional view showing a second embodiment of a parallel-type multi-section unbonded PC steel strand.

FIG. 9 is a cross-sectional view showing a second embodiment of a straight multi-section unbonded PC steel strand.

FIG. 10 is a third view of a collective multi-strand unbonded PC steel strand.
It is sectional drawing which shows an Example.

FIG. 11 is a side view of a third type of multi-strand unbonded PC steel stranded wire.
It is sectional drawing which shows an Example.

FIG. 12 is a third view of a straight multi-section unbonded PC steel strand.
It is sectional drawing which shows an Example.

FIG. 13 is an explanatory view showing a bearing-type permanent anchor.

[Explanation of symbols]

 1 PC stranded wire 2 Uncoiler 2a Uncoiler 3 Drawer roll 4 Polishing device 5 Releasing device 6a Expansion maintenance device 6b Expansion maintenance device 6c Expansion maintenance device 7 Core wire adjusting device 8 Coating device 9 High frequency induction heating device 10 Cooling device 11 Loosening Closing device 12 Grease applying device 12a Grease applying device 12b Grease applying device 13a Coating molding extruding device 13b Coating molding extruding device 13c Coating molding extruding device 14a Cooling device 14b Cooling device 14c Cooling device 15a Outer diameter measuring device 15b Outer diameter measuring device 16a Pin Hall detection device 16b Pinhole detection device 17a Take-up device 17b Take-up device 17c Take-up device 19a Winder 19b Winder 20a Painted PC steel stranded wire 20b Single-strand unbonded PC steel stranded wire 21 Multi-strand unbonded PC steel stranded wire 22 Multi-strand unbonded P Steel strand 23 Multi-section unbonded PC steel strand 24 Side wire 25 Core wire 26 Single coating 27 Lubricant 28 Synthetic resin coating layer (primary coating layer) 29 Synthetic resin coating layer 30 Synthetic resin coating layer (secondary coating layer) 31 Upper cap 32 Anchor plate 33 Head cap 34 Filling with rust preventive agent 35 Anchor head 36 Straight linear multi-section unbonded PC stranded wire 37 Fixing tool deformed pipe upper cap 38 Fixing tool pipe 39 Lower anchor plate 40 Crimping grip 41 Rust preventive filling cap 42 Prevention Rusting agent 43 Tuning spacer for linear anchor plate hole

Claims (9)

[Claims] 1. A coating P comprising a PC steel stranded wire composed of a plurality of side wires twisted around a core wire, wherein a synthetic resin coating layer is formed solely on the entire peripheral surface of each of the core wire and the side wire.
A coated PC steel, characterized in that a lubricant is applied to each surface of a C steel strand and a synthetic resin coating layer is formed on two or more surfaces of the coated PC strand coated with the lubricant by an extrusion method. Multi-strand unbonding method for strands. 2. The multi-section unbonding method according to claim 1, wherein said synthetic resin coating layer is formed on a surface of said plurality of coated PC steel strands in an annular or parallel arrangement. 3. The method according to claim 1, wherein the synthetic resin coating layer is formed on the surface after holding the plurality of coated PC steel wires at a predetermined interval by a spacer. . 4. A PC stranded wire formed by twisting a plurality of side wires around a core wire, wherein a coating P in which a synthetic resin coating layer is formed solely on all the peripheral surfaces of the core wire and the side wires.
C-strand wire is coated with a lubricant, and a synthetic resin coating layer is formed on the surface by extrusion molding. Single-strand coating PC steel strand is formed with a synthetic resin coating layer on two or more surfaces by extrusion molding. A multi-strand unbonding method for coated PC steel strands, characterized by: 5. The multi-section unbonding method according to claim 4, wherein the plurality of single-coated PC steel strands are arranged in a ring or in parallel to form a synthetic resin film layer on the surface. 6. The multi-strand unbonding process according to claim 4, wherein the plurality of single-strand coated PC steel strands are held at predetermined intervals by spacers, and then the synthetic resin coating layer is formed on the surface. Method. 7. A PC stranded wire formed by twisting a plurality of side wires around a core wire, wherein a coating P in which a synthetic resin coating layer is formed solely on the entire peripheral surface of each of the core wire and the side wires.
A coating characterized in that a synthetic resin coating layer is provided on two or more surfaces of a C steel stranded wire by an extrusion molding method, a lubricant is applied to the surface, and then a synthetic resin coating layer is formed on the surface by an extrusion molding method. Multi-strand unbonding method for PC stranded wire. 8. The multi-strand unbonding method according to claim 7, wherein the plurality of coated PC steel wires are arranged annularly or in parallel and the synthetic resin coating layer is formed on the surface. 9. The multi-section unbonding method according to claim 7, wherein said synthetic resin coating layer is formed on the surface after holding said plurality of coated PC strands at predetermined intervals by spacers. .