JPH1161734A - Anti-corrosion repairing method for cable of suspended structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely maintain anti-corrosion performance over a long period of time by attaching a pipe-shaped detachable cover maintaining a gap through spacers on the surface of an existing cable of suspended structure and by filling up the gap with an anti-corrosion resin and hardening it thereby forming an anti-corrosion layer. SOLUTION: A detachable pipe-shaped cover 12 maintaining a gap 30 is attached through spacers 21, 22 and 23 on the surface of an existing cable 20 for a suspended structure. Then, a side end portion in a circumferential direction and both end portions of the pipe-shaped cover 12 is sealed and the gap 30 is filled up with an anti-corrosion resin and, after hardened, the pipe-shaped cover 12 is removed and a covered layer is formed on the outer periphery of the cable 20. Next, the spacers 21 to 23 are made of a material having anti-corrosion performance and adhesive property with an anti- corrosion resin and thus can be embedded in one united body together with the anti- corrosion resin. In this way, the surface of the cable 20 can be covered with the anti- corrosion resin. This method enables maintenance of the anti-corrosion performance over a longer period of time compared to the conventional repairing method using a repairing cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anticorrosion repair method for a cable having a suspension structure such as a cable-stayed bridge or a suspension roof, which is required to have high corrosion resistance for a long time. The present invention relates to an anticorrosion repair method for repairing a coating material over the entire circumference or locally.

[0002]

2. Description of the Related Art Corrosion protection methods for cables with suspension structures such as cable-stayed bridges include coating the surface of the cable with fiber-reinforced plastic, or covering the cable surface with a polyethylene pipe and then pouring grout into the gap between the cable and cover. Generally, a method of extruding and coating polyethylene on a cable surface at a factory before erection is common.

[0003] In such a cable, degradation of the coating material progresses due to long-term exposure of 10 to 20 years.
In the deteriorated part of the coating layer, the mechanical strength of the coating layer decreases and the anticorrosion performance deteriorates. Indispensable.

As shown in FIG. 9, a conventional cable repair method is to use a stainless steel plate, an aluminum plate, or a painted steel plate 51 formed into a cylindrical shape having a larger inner diameter than the outer diameter of the cable 20 to deteriorate the cable surface. Anticorrosion coating material 11
Can be left as it is or peeled off to remove the cable 20
And the end in the longitudinal direction or the circumferential direction is
And a repair cover method of locking with a sealing material 53 has been common.

[0005]

However, in such a conventional cable repair method, a gap is easily formed due to corrosion of bolts locking the end of the cover, deterioration of the sealing material, and the like in a long-term exposure. However, since corrosive factors such as water, moisture, and corrosive gas enter therefrom, the repair method cannot be said to be a sufficient repair method for preventing corrosion of the cable. In addition, in the repair cover method, there is a problem that the aesthetic appearance of the cable is impaired because projections such as bolts are present.

According to the present invention, by coating the surface of a suspension structure cable such as an existing cable-stayed bridge with an anticorrosive resin such as a polyurethane resin, the anticorrosion performance can be reliably maintained for a longer period of time than the conventional repair method using a repair cover. It is an object of the present invention to provide a method for preventing and repairing a cable having a suspension structure which is excellent in appearance without projections or the like.

[0007]

In order to achieve the above object, the present invention has the following features. That is, as shown in the figure, a detachable tubular cover that holds the gap 30 is attached to the surface of the existing suspension structure cable 20 via the spacers 21, 22, and 23, and the circumferential side end of the tubular cover is attached. A cable having a suspended structure, wherein one end or both ends in the longitudinal direction are hermetically sealed, and the gap 30 is filled with the anticorrosive resin 13 and cured, and then the tubular cover is removed to form an anticorrosive layer. Corrosion prevention repair method. FIG. 2 shows a cross section of the cable during anticorrosion construction.

The tubular cover is provided with a tongue-shaped locking portion 12a along the longitudinal direction at the side end in the circumferential direction so as to be openable, and can be hermetically sealed by a locking jig 12b or divided into two in the circumferential direction. In addition, locking portions 40a and 40b are provided on the circumferential side end and the longitudinal direction end, and are hermetically sealed by a locking jig 40c.

Further, a polyurethane resin is used as the anticorrosion resin 13 to be filled in the gap 30 between the existing cable surface 20 and the tubular cover. Further, spacers 21, 22, which hold a gap 30 between the existing cable surface 20 and the inner surface of the tubular cover.
23 is preferably made of a material that has anticorrosion properties and can be bonded to the anticorrosion resin, and is embedded as an integral part of the anticorrosion resin.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In the present invention, the anticorrosive resin 13 that covers the surface of the existing cable 20 is a liquid that can be injected into a narrow space before curing, has some flexibility after curing, and has corrosion resistance and weather resistance. You need to choose.
In addition, for example, in the repair work of the cable-stayed bridge cable 2 in the cable-stayed bridge 1 shown in FIG. However, since the coating of the anticorrosive resin is performed several times while moving the repair work position 3 having the tubular cover as a main element, the adhesion of the joint portion of the anticorrosive resin may be good. is necessary.

As the anticorrosive resin satisfying these conditions,
Although a polyurethane resin obtained by mixing a main agent and a curing agent is most preferable, a polyethylene resin, an epoxy resin, or the like may be used.

When the anticorrosive resin 13 is coated, the surface of the cable 20 is covered with spacers 21, 22 and 23.
Attach a removable tubular cover that holds the gap 30,
The circumferential end of the tubular cover 12 and one or both ends in the longitudinal direction are hermetically sealed, and the anticorrosive resin 13 is injected into the gap to cover the outer periphery of the cable with the anticorrosive resin.

FIG. 3 is a conceptual view of the attachment of the tubular cover 12.
As shown in FIG. If the cable is installed vertically or close to this, only the lower end in the longitudinal direction of the tubular cover 12 is hermetically sealed via the spacer 21 as shown in FIG. The anticorrosive resin can be injected from the open portion at the upper end of the tubular cover.
However, when the coating length is long, it is preferable to inject the anticorrosive resin from the injection port 12c below the tubular cover in order to prevent air from being entrained.

When the cable is in a horizontal or inclined state or close to the inclined state, both ends of the tubular cover 12 are hermetically sealed via spacers 21 and 23 as shown in FIG. Inlet 12c and air vent 1
2d is provided and anticorrosive resin is injected.

After the anti-corrosion resin 13 has hardened, the tubular cover 12 is removed, so that the cable 20 has no covering projection or the like, and a covering layer having a constant covering thickness is formed on the entire surface. It is possible to easily and accurately realize a coating excellent in anticorrosion property and aesthetic appearance.

The deteriorated anticorrosion coating material 11 coated on the cable 20 may be repaired from above, or it may be repaired by peeling it off.

As a structure of the tubular cover used in the present invention, as shown in FIG. 5, a tongue-shaped locking portion 12a which can be opened in the circumferential direction and is provided at the side end in the circumferential direction along the longitudinal direction. 6, or a semi-cylindrical cover that is divided into two parts in the circumferential direction, as shown in FIG. 6, and has a tongue-shaped engagement at its circumferential side end and longitudinal end. Any of the tubular cover 40 structures provided with the stopping portions 40a and 40b may be used, and examples thereof include those that lock the locking portions 12a, 40a and 40b. Examples of the method of locking include a U-shaped clamp, bolting, and tape-fixing. In the illustrated example, a locking jig 1 showing a U-shaped clamp as an example
2b and 40c are shown. As the material of the tubular cover, a steel plate, a galvanized steel plate, a stainless steel plate, an aluminum plate, and a fiber reinforced plastic are preferable in terms of processing and strength. When the sheet is formed into a tubular shape, it is desirable to use an elastically deformable material that can be widened to cover the cable.

The tubular cover used in the present invention is required to be easily removable from the surface of the anticorrosion resin 13 after the injected anticorrosion resin 13 has hardened. Therefore, it is preferable to perform an adhesion preventing treatment such as chrome plating, Teflon processing, or application of a release agent on the inner surface of the tubular cover so that the anticorrosive resin does not adhere.

The spacers 21, 22, and 23 that hold the gap between the surface of the existing cable and the inner surface of the tubular cover are made of a material that has anticorrosion properties and can be adhered to the anticorrosion resin, so that the spacers are integrated with the anticorrosion resin 13. Can be embedded. When a polyurethane resin is selected as the anticorrosive resin 13, a polyurethane resin piece that has been cured and manufactured in advance can be used for the spacer.

The spacers are preferably arranged at appropriate intervals so that a uniform gap is formed between the cable surface and the inner surface of the tubular cover.

[0021]

【Example】

[Embodiment 1] As an embodiment of the present invention, an example in which an existing cable stayed bridge cable is coated with a two-component curing type polyurethane resin will be described.

As shown in FIG. 4, a tubular cover 12 was attached to a fiber-reinforced plastic-coated cable having an outer diameter of 250 mm via spacers 21, 22, and 23 having a thickness of 7 mm. The spacers 21 and 23 installed at both ends of the tubular cover 12 are made of a rubber material, and the spacer 22 installed at the center in the longitudinal direction of the cover is made of a polyurethane resin to be filled in advance, and the polyurethane resin to be filled in the gap 30 is used. It was embedded as one.

The tubular cover 12 is a galvanized plate having a thickness of 1 mm, an inner diameter of 264 mm and a length of 2 m, and is provided with a locking portion 12a along the longitudinal direction at the circumferential end as shown in FIG. The shape could be opened in the direction. The gap 30 with the surface of the cable 20 after closing the opening of the locking portion 12a, that is, the coating thickness of the anticorrosive resin 13 to be filled was 7 mm.

A release agent was applied to the inner surface of the tubular cover 12. Engagement part 12a at the circumferential end of tubular cover 12
Was hermetically sealed using a U-shaped clamp 12b. Both ends in the longitudinal direction of the tubular cover were hermetically sealed with tape and a steel band stopper.

A polyurethane inlet 12c having a diameter of 10 mm was provided below the tubular cover, and an air vent 12d was provided above the tubular cover.

After preparing as described above, the injection port 12c
Inject a two-part curing type urethane resin coating agent,
It was confirmed that the resin was filled from the air vent at the top of the cable, and the injection was completed. After curing and curing for 24 hours, the tubular cover was removed.

As a result, the coating appearance of the cable was good, and no defects that impaired the film properties were observed at all. Clearance 30 between cable surface 20 and inner surface of tubular cover 12
Was also embedded in the anticorrosive resin as one piece, and the adhesion was good.

With respect to the coating layer, the film thickness distribution and the inspection and evaluation by a pinhole test were also performed. As a result, the film thickness was 6 to 8 mm, and there was no problem. No pinhole was detected in the 10 kV pinhole test, and a good coating layer was formed.

Embodiment 2 As an embodiment of the present invention, an example in which an existing cable stayed bridge cable is coated with an anticorrosive resin over a long span will be described.

As shown in FIG. 6, five sets of substantially semi-cylindrical 2 m-long covers, each of which is divided into two parts in the circumferential direction by a fiber-reinforced plastic-coated cable having an outer diameter of 250 mm via a 7 mm-thick spacer. Length 10 in which circumferential end 40a and longitudinal end 40b are locked by U-shaped clamp 40c
m of the tubular cover 40 was attached.

The spacer provided at the end of the tubular cover 40 is made of a rubber material, and the spacer provided every 1 m in the longitudinal direction of the cover is made of a polyurethane resin to be filled which has been cured in advance. As embedded.

The tubular cover 40 is obtained by dividing a 3 mm-thick galvanized plate into two parts in the circumferential direction, and is provided with locking portions 40a and 40b at a circumferential end and a longitudinal end. The inner diameter of the stop after closing was 264 mm. A release agent was previously applied to the inner surface of the tubular cover. The tubular cover was provided with a 10 mm diameter polyurethane resin paint inlet 40d and an air vent 40e.

A two-component curing type polyurethane resin is injected from the injection port 40d, and the resin is filled through the air vent 40e at the upper part of the cable. The injection is completed. After curing and curing for 24 hours, Then, the entire tubular cover 40 was removed.

As a result, as in the case of Example 1, the appearance of the obtained cable was good, and no defects that impaired the film characteristics were observed. The spacer for maintaining the gap between the cable surface and the inner surface of the tubular cover was also embedded in the anticorrosive resin as one piece, and the adhesion was good.

With respect to the coating layer, the film thickness distribution and inspection evaluation by a pinhole test were also performed. As a result, the film thickness was 6 to 8 mm, and there was no problem. No pinhole was detected in the 10 kV pinhole test, and a good coating layer was formed.

[0036]

As described above, according to the method of the present invention for preventing and repairing an existing suspension structure cable, the spacers 21, 22, 2, and 2 are provided on the surface of the suspension structure cable 20 such as an existing cable-stayed bridge.
3, a detachable tubular cover that holds the gap 30 is attached, and a circumferential end of the tubular cover is provided;
One end or both ends in the longitudinal direction are hermetically sealed, the gap is filled with the anticorrosive resin 13 and cured, and then the tubular cover is removed to form an anticorrosive layer. Thus, it is possible to provide a coating excellent in aesthetic appearance that does not have protrusions and the like while reliably maintaining the anticorrosion performance over a long period of time.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a cable stayed bridge cable to which the present invention is applied.

FIG. 2 is a cross-sectional view of a cable during anticorrosion repair work of the present invention.

FIG. 3 is a partially cutaway side view conceptual diagram showing a state where the tubular cover of the present invention is mounted on a vertical cable.

FIG. 4 is a partially cutaway side view conceptual diagram showing a state where the tubular cover of the present invention is mounted on a horizontal or inclined cable.

FIG. 5 is a perspective view of an example of a circumferentially openable tubular cover of the present invention.

FIG. 6 is a perspective view of another example of the tubular cover of the present invention, which is divided into two in the circumferential direction and can be locked at the circumferential side end and the longitudinal end.

FIG. 7 is a longitudinal sectional view of FIG.

8 is a cutaway side view showing an example of a structure in which a suspension structure cable is covered with the tubular cover of FIG. 6;

FIG. 9 is a perspective view showing an example of a conventional cable anticorrosion coating structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cable-stayed bridge 2 Cable-stayed bridge cable 3 Repair work position 10 Cable strand 11 Existing anticorrosion coating 12 Tubular cover 12a Side end locking part 12b Side end locking jig 12c Inlet 12d Air vent 13 Anticorrosive resin 20 Existing Cable (including anticorrosion layer) 21, 22, 23 Spacer 30 Gap 40 Two-part tubular cover 40a Locking portion at side end 40b Locking portion at longitudinal end 40c Locking jig 40d Inlet 40e Air vent 51 Repair Cover 52 Bolt 53 Sealing material

[Procedure amendment]

[Submission date] September 12, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 7

[Correction method] Change

[Correction contents]

FIG. 7

Claims (6)

[Claims] 1. A detachable tubular cover for holding a gap 30 is attached to the surface of an existing suspension structure cable 20 via spacers 21, 22, 23, and a circumferential end of the tubular cover and a longitudinal end thereof. A method for preventing and repairing a suspended structure cable, comprising sealing and sealing one end or both ends in the direction, filling the gap with an anticorrosive resin, curing the resin, and removing the tubular cover to form an anticorrosive layer. 2. The tubular cover 12 is provided with a locking portion 12a along the longitudinal direction at a circumferential side end thereof, and can be opened, and the opening is hermetically sealed by a locking jig 12b. Item 7. The method for anticorrosion repair of a suspended structure cable according to Item 1. 3. The tubular cover 40 is divided into two parts in the circumferential direction, and has a locking part 40a, a circumferential side end and a longitudinal end.
The method according to claim 1, further comprising a sealing jig (40b) and a sealing jig (40c). 4. The method according to claim 1, wherein an inner surface of the tubular cover is treated to prevent adhesion. 5. The method according to claim 1, wherein the corrosion-resistant resin filling the gap 30 between the surface of the existing cable 20 and the tubular cover is a polyurethane resin. . 6. The spacers 21, 22, 23 for holding a gap 30 between the surface of the existing cable 20 and the inner surface of the tubular cover,
Using a material that has anticorrosion properties and can be bonded to anticorrosion resin,
6. The method according to claim 1, wherein the cable is embedded as an anticorrosive resin.