JP2024021095A - Corrosion-proof construction methods and structural cables that have been treated with the same corrosion-proof construction methods - Google Patents

Abstract

An object of the present invention is to enable easy visual confirmation of deterioration and other conditions of structural cable components on a regular or irregular basis after the construction of a structural cable corrosion protection method. [Solution] The structural cable corrosion prevention method is a corrosion prevention method for structural cables exposed outdoors that are used in suspended structures including suspension bridges and cable-stayed bridges. The anti-corrosion tape 150, which is an example of a removable resin thin film having a waterproof function, is wrapped and covered together with the moisture detection material 122, and the anti-corrosion tape 150 is replaced regularly or non-regularly to check deterioration over time. etc.) The anticorrosion tape 150 covered by the structural cable is peeled off, and the degree of corrosion protection of the structural cable is confirmed by visually observing deterioration such as discoloration or deterioration (change in shape) of the moisture detection material 122. . [Selection diagram] Figure 2

Description

The present invention is applicable to existing objects exposed outdoors that require anti-corrosion measures or newly installed objects exposed outdoors that require anti-corrosion measures (particularly when the objects are used in suspension structures such as suspension bridges and cable-stayed bridges). , existing structural cables exposed outdoors or newly installed structural cables exposed outdoors), particularly when preventing corrosion of such structural cables, which are an example of objects, or Anti-corrosion methods and anti-corrosion methods for prolonging the life of structural cables, which are an example of target objects, when structural cables are corroded (rather than replacing the structural cables, especially when the corrosion is mild and difficult to replace) This invention relates to structural cables that have been subjected to The objects to which the anti-corrosion method of the present invention is suitably applied are not limited to such structural cables, but also existing objects exposed outdoors that require anti-corrosion measures or new structures exposed outdoors. For example, a metal pipe or the like may be used as long as it requires anti-corrosion measures.

Structural cables used in suspension bridges and cable-stayed bridges, which are examples of objects to which anti-corrosion methods can be applied, are exposed to harsh outdoor climatic conditions, so they require painting to prevent deterioration such as rust. becomes. Traditionally, structural cables have been painted with weather-resistant paints, but periodic repainting may be required due to the harsh weather conditions to which painted structural cables are exposed. However, due to the poor accessibility of such structural cables due to the fact that they are installed on high towers such as suspension bridges and cable-stayed bridges, this repainting requires considerable effort. A large amount of money was required. Additionally, in order to repaint properly, the existing paint would have to be removed before repainting, further increasing costs.

Recently, for such repairs by repainting, covering materials made of polychloroprene such as neoprene (the shape of this covering material is, for example, a tape shape that is easy to wrap around in a spiral shape) are being used for hanging structures. It has been found that structural cables can be more permanently protected from outdoor exposure by wrapping them in a helical pattern with varying lengths. However, this type of neoprene cladding matches the appearance of other elements (girders, towers, hangers, etc.) other than structural cables in the suspended structures (suspension bridges, cable-stayed bridges, etc.) in which it is used. It is usually not possible to properly color the product before installation. Therefore, by wrapping bridge structural cables in a spiral with neoprene sheathing and then painting the outer surface of the sheathing, it is possible to achieve appropriate color matching between the structural cables and other bridge elements. However, such a painting process is very time-consuming and therefore very expensive.

In addition, when wrapping suspension bridge structural cables in a helical pattern with neoprene sheathing (tape), each turn of sheathing (tape) must be firmly adhered to the preceding turn to ensure proper seams between them. It is important to seal and thereby prevent moisture and dust from entering the interface between the cover and the structural cable. When using this type of neoprene sheathing (the tape-like sheathing is wrapped helically around the structural cable), there should be significant overlap between successive turns of the sheathing (tape) and the solvent It has been known that a reliable and sufficient seal can be achieved by adhering overlapping layers together using . However, the application of solvents is laborious and expensive, and many solvents have environmental, health, and safety concerns that require great care when handling and disposing of them.

In view of these various problems, U.S. Pat. A corrosion protection method is disclosed that can advantageously protect structural cables from exposure to harsh climatic conditions by helically wrapping structural cables with rubber chlorosulfonated polystyrene materials. The anti-corrosion method disclosed in Patent Document 1 is a method for preventing corrosion by spirally wrapping flexible synthetic rubber tape (chlorosulfonated polyethylene) around structural cables used in suspension bridges or cable-stayed bridges. The method of wrapping is to overlap the tape in half and wrap it in a half-wrap manner to form a double layer of uniform thickness, and then heat the tape to heat-seal the overlapping layers to each other. This seals the seam and also shrinks the tape, allowing the synthetic rubber tape (chlorosulfonated polyethylene) to fit (integrate) the structural cable securely and with sufficient flexibility. According to this anti-corrosion construction method, by wrapping a synthetic rubber tape (chlorosulfonated polyethylene) around a corroded structural cable, it is possible to suppress the infiltration of air and moisture and delay the progress of corrosion. In addition, such flexible synthetic rubber tapes can be colored before performing anti-corrosion methods, so that the flexible synthetic rubber tapes can be colored the same color as the structural cables were originally colored. This allows for proper color matching between structural cables and other elements.

US Patent No. 5,390,386

However, in the anti-corrosion construction method disclosed in Patent Document 1, a structural cable wrapped with a tape (or sheet) used for corrosion prevention as a sheathing material cannot be seen after construction because the cable itself cannot be seen due to the sheathing material. , the status of deterioration of structural cable components (presence and progress of rust on the structural cable (steel material) itself, rust prevention in the structural cable (steel material) such as galvanization, wax, and anti-rust paint) It is not possible to visually confirm the presence or absence of rust on the layer, the progress of rust, the deterioration state of the outer tube such as PE pipe (polyethylene pipe), etc. Therefore, currently, in order to check the status of deterioration, etc. of the structural cable components, it is necessary to remove the covering material formed by the tape (or sheet) used for corrosion protection, which is a problem in that workability is extremely poor. There is.

Furthermore, when removing the covering material formed by the tape (or sheet) used for corrosion protection in order to check the status of deterioration of structural cable components, it is necessary to It is very important to check that the cables used are protected from moisture. However, in the anti-corrosion construction method disclosed in Patent Document 1, it is not possible to easily confirm whether or not the structural cable is reliably blocked from moisture by removing and checking the covering material.

The present invention was developed in view of the above-mentioned problems of the prior art, and its purpose is to improve existing structures that are used in suspension structures such as suspension bridges and cable-stayed bridges and are exposed outdoors. This is a corrosion protection method for objects that require anti-corrosion measures, such as cables or newly installed structural cables exposed outdoors, and is used to prevent corrosion of such structural cables, etc. (rather than replacing the structural cables, etc., especially when corrosion is mild and difficult to replace) It is an object of the present invention to provide a structural cable in which the state of deterioration and the like of a component such as a cable can be easily visually confirmed and to which a corrosion-proof construction method has been applied.

In order to achieve the above object, the anti-corrosion construction method according to the present invention and the structural cable to which the anti-corrosion construction method has been applied include the following technical means.

That is, a corrosion protection method according to an aspect of the present invention is a corrosion protection method for an existing object that is exposed outdoors that requires corrosion protection measures or a newly installed object that is exposed outdoors that requires corrosion protection measures, and the method includes: has a shape that is longer in one direction, that is, the longitudinal direction, than the other direction, and the object is wrapped together with a moisture detection material in a peelable resin thin film that is adhesive to each other and has a waterproof function. The method is characterized in that the degree of corrosion protection of the object is confirmed by peeling off the thin resin film covering the object to check for deterioration over time.

Further, a corrosion prevention method according to another aspect of the present invention is used for suspension structures including suspension bridges and cable-stayed bridges, and is a corrosion prevention method for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors. The structural cable is wrapped and covered together with a moisture detection material using a peelable resin thin film that is adhesive to each other and has a waterproof function, and is covered with the structural cable to confirm deterioration over time. The method is characterized in that the resin thin film is peeled off to check the degree of corrosion protection of the structural cable.

Preferably, the moisture detection material can be configured to be provided together with a filler that is filled between the object or the structural cable and the resin thin film.

More preferably, the moisture detection material may be provided in a portion covered with the resin thin film along the longitudinal direction of the object or the structural cable.

More preferably, the moisture detection material is provided in a part of a portion covered with the resin thin film along the longitudinal direction of the object or the structural cable, and A water-conducting member may be further provided along the portion covered with the resin thin film so as to contact the moisture detection material.

More preferably, the resin thin film is tape-shaped, and the tape-shaped resin thin film is spirally wound around the object or the structural cable with at least a part of the tape width overlapping the object or the structural cable. Alternatively, the structural cable may be wrapped and covered by the tape-shaped thin resin film.

Further, a corrosion prevention method according to another aspect of the present invention is used for suspension structures including suspension bridges and cable-stayed bridges, and is a corrosion prevention method for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors. The structural cable is wrapped and covered together with a moisture detection material and a sensor for detecting deterioration of the moisture detection material by a resin thin film that can be bonded to each other and has a waterproof function, and the sensor detects deterioration of the structure over time to confirm deterioration over time. It is characterized by checking the degree of corrosion protection of the cable for use.

Further, a corrosion prevention method according to another aspect of the present invention is used for suspension structures including suspension bridges and cable-stayed bridges, and is a corrosion prevention method for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors. The structural cable is wrapped and covered with a sensor for detecting moisture by a resin thin film that can be bonded to each other and has a waterproof function, and the sensor is installed by peeling off the resin thin film or removing the resin thin film. It is characterized in that it can be connected to a measuring device without peeling, and the degree of corrosion protection of the structural cable is checked using the sensor and the measuring device to check deterioration over time.

Further, a structural cable subjected to the anti-corrosion method according to another aspect of the present invention is used in a suspension structure including a suspension bridge and a cable-stayed bridge, which is subjected to the anti-corrosion method described above. It is characterized by being a structural cable exposed outdoors.

According to the anti-corrosion construction method and the structural cable applied with the anti-corrosion construction method of the present invention, it is used in suspension structures such as suspension bridges and cable-stayed bridges, and is used for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors. This is a corrosion protection method for objects that require anti-corrosion measures such as structural cables, and is used to prevent corrosion of such structural cables, etc., or when structural cables, etc. are corroded (even if the corrosion is mild). Deterioration of structural cables and other component parts periodically or irregularly after the construction of anti-corrosion methods to prolong the life of structural cables, etc. It is possible to easily visually check and confirm such conditions, and it is also possible to provide a structural cable to which the corrosion prevention method has been applied.

In the anti-corrosion method for structural cables according to the embodiment of the present invention, the anti-corrosion tape wraps and covers the structural cable, in which (A) it is wrapped in a spiral shape with less than half a wrap, and (B) a half wrap. It is a figure for explaining the state in which it is wound spirally. FIG. 2 is a diagram (part 1) for explaining a state in which a structural cable is wrapped and covered with an anticorrosive tape in the anticorrosion construction method for a structural cable according to an embodiment of the present invention. FIG. 2 is a diagram (Part 2) for explaining a state in which a structural cable is wrapped and covered with an anticorrosive tape in the anticorrosion construction method for a structural cable according to an embodiment of the present invention. FIG. 7 is a diagram for explaining a state in which a structural cable is wrapped and covered with an anticorrosive tape in a method for preventing corrosion of a structural cable according to a second modification of the embodiment of the present invention. FIG. 5 is a diagram (part 1) for explaining a state in which water immersion is confirmed in the structural cable corrosion prevention method shown in FIG. 4; FIG. 5 is a diagram (part 2) for explaining a state in which moisture immersion is confirmed in the corrosion prevention method for structural cables shown in FIG. 4;

EMBODIMENT OF THE INVENTION Below, the corrosion prevention construction method of the structural cable based on embodiment of this invention, and the structural cable to which the corrosion prevention construction method was performed are demonstrated in detail with reference to drawings. Note that the structural cable constructed according to the corrosion prevention method (corrosion prevention construction method) for a structural cable according to the present embodiment as explained below is the structural cable according to the embodiment of the present invention (corrosion prevention construction method applied). It is a structural cable. In addition, in the following explanation, it is a corrosion prevention method for existing structural cables that are used in suspension structures such as suspension bridges and cable-stayed bridges and is exposed outdoors. We will explain a corrosion prevention method to prolong the life of structural cables (instead of replacing the structural cables when it is difficult to replace them). The method is not limited to construction, and may be performed as a corrosion prevention method to prevent corrosion of newly installed structural cables exposed outdoors. In addition, structural cables that are subject to corrosion protection include cable wires and a mantle tube (FRP (reinforced plastic) pipe, PE (polyethylene) pipe, etc. for corrosion prevention purposes) that covers the outer circumference of the cable wire. However, it does not matter whether the cable has an anti-corrosive paint applied directly to the cable without a jacket tube for corrosion prevention purposes, or has any other structure. .

Here, objects to which the anti-corrosion method according to the present invention is suitably applied are not limited to such structural cables, but existing objects that are exposed outdoors and require anti-corrosion measures, or objects that are exposed outdoors. As long as it is a newly installed item that requires anti-corrosion measures, it may be an existing metal pipe exposed outdoors or a newly installed metal pipe exposed outdoors that requires anti-corrosion measures. In the following description, the object to which the anticorrosion method according to the present invention is suitably applied is an existing structural cable exposed outdoors or a newly installed structural cable exposed outdoors. Furthermore, when applying the anti-corrosion method, when wrapping and covering the structural cable with a peelable resin thin film that can be bonded to each other and has a waterproof function, if the structural cable has a step etc. A filler is sometimes filled between the structural cable and the resin thin film in order to alleviate differences in level and the like.

Here, the figures referred to in the following explanation are basically schematic diagrams omitting detailed structures for easy understanding of the present invention, and the parts should be expressed by the external shape rather than the internal part. In some cases, the interior is expressed as if seen through, or in some cases, parts that should be expressed as a cross section rather than an outer shape are expressed as an external shape, or that parts that should be expressed as an external shape instead of a cross section are expressed as a cross section. Sometimes it is expressed.

A corrosion protection method for structural cables according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. Note that FIG. 1 shows an example in which anticorrosive tape is used as a weldable resin thin film in the structural cable corrosion prevention method according to the present embodiment, and FIGS. 2 and 3 illustrate the structural cable corrosion prevention method according to this embodiment. FIG. 2 is a diagram for explaining a state in which a structural cable is wrapped and covered with an anticorrosion tape in a cable anticorrosion construction method. In addition, in any case shown in the figure, a peelable resin thin film tape (sometimes referred to as anticorrosion tape in the above explanation) is a resin thin film that can be bonded to each other and has a waterproof function in the corrosion prevention method for structural cables. (In the following explanation, it may be referred to as anti-corrosion tape), but the resin thin film is sheet-shaped, and the structural cable is covered with the sheet-shaped resin thin film. The structural cable may be wrapped and covered by bonding both ends of the cable in a direction perpendicular to the longitudinal direction to each other.

As shown in FIGS. 1 to 3, the structural cable corrosion prevention method according to the present embodiment has the following features.

The corrosion protection method according to the present embodiment is a corrosion protection method for existing objects that are exposed outdoors that require corrosion protection measures or for newly installed objects that are exposed outdoors and that require corrosion protection measures. It has a shape that is longer in one longitudinal direction than in another direction. As mentioned above, the targets of the anti-corrosion method according to the present invention are, but are not limited to, existing structures that are used for suspended structures including suspension bridges and cable-stayed bridges, and that require anti-corrosion measures that are exposed outdoors. This will be explained as a structural cable that will be exposed outdoors or will be newly installed and requires anti-corrosion measures. The anticorrosion method according to the present embodiment is based on the premise that such structural cables are wrapped and covered with a moisture detection material using a peelable resin thin film that can be bonded to each other and has a waterproof function. . Then, as a check for aging deterioration (when replacing the resin thin film on a regular or non-regular basis), the resin thin film covering the structural cable is peeled off, and the degree of corrosion protection of the structural cable is measured by discoloration of the moisture detection material. It is characterized by confirming deterioration such as deterioration or deterioration (an example of deterioration is shape change) by visual recognition or the like.

Here, as an example of a peelable resin thin film that is adhesive to each other and has a waterproof function, an anticorrosion tape used in the Anti-Mec (registered trademark) method manufactured and sold by the applicant of the present application is used. Can be done. This anti-corrosion tape is made by impregnating a plastic cloth (this cloth can be said to correspond to the resin thin film itself) with a compound mainly composed of a specially formulated drying oil, and is suitable for corrosion protection of structural cables. It is. This anti-corrosion tape is an oxidative polymerization type tape that absorbs sunlight, heat and oxygen to harden the surface through oxidative polymerization to form a cured film, and has corrosion resistance, weather resistance, heat resistance, flexibility, and displacement tracking. Excellent in sex. This anti-corrosion tape is not a welding method in which parts of the anti-corrosion tape are melted by heat and adhered to each other, which cannot be removed or is difficult to remove after installation. Thin resin films are bonded to each other by having adhesive properties that allow them to be integrated, or by applying an adhesive with such properties to the resin thin film (in this case, anticorrosion tape), and are not peeled off after installation. Is possible.

This type of anti-corrosion tape is used to wrap structural cables in a spiral to cover them, but in order to improve the adhesion of the anti-corrosion tape, a primer material with rust prevention effect is applied to the structural cables. The anti-corrosion properties of the anti-corrosion tape are improved by forming steps such as bands or cable bundles and using fillers to make the wrapping of the anti-corrosion tape smooth, and by forming a coating film in a short time to prevent the adhesion of dust, etc.・A top coat may be applied to the surface of anti-corrosion tape to improve weather resistance. In this way, the installation of anticorrosion tape involves the following steps: (1) preparation of the substrate, (2) application of undercoat, (3) filling with filler (forming of stepped parts), (4) winding of anticorrosion tape, and (5) application of topcoat. Each process is a main process.

Here, referring to FIG. 1, by spirally wrapping a removable tape-shaped resin thin film (anticorrosion tape), which is a resin thin film that can be bonded to each other and has a waterproof function, around the structural cable. An embodiment of wrapping and covering with such a tape-shaped resin thin film (anticorrosion tape) will be described.

Figure 1 (A) shows a state in which the anticorrosive tape 150 is spirally wound with less than half a wrap (approximately 1/4 of the tape width overlapped), and Figure 1 (B) shows a state in which the anticorrosion tape 150 is spirally wound in a half wrap. Each state is shown below. Note that here, it is assumed that an anticorrosive paint is directly applied to the cable wire 110 without providing a mantle for corrosion prevention purposes.

The state shown in FIG. 1A shows a structural cable 100 that is undergoing corrosion protection construction, and the cable wire 110 is covered with a filler 120 at a stepped portion (not shown in a cable band or cable This is a state in which the structural cable is wrapped in the anticorrosive tape 150 by forming a stepped portion (stepped portion by a bundle, etc.), and further by wrapping the anticorrosive tape 150 in a spiral shape with less than half a wrap.

The state shown in FIG. 1(B) shows the structural cable 102 in the process of being applied with the anti-corrosion method. A stepped portion formed by a bundle or the like is formed, and the anti-corrosion tape 150 is spirally wound in a half-wrap manner, so that the structural cable is wrapped in the anti-corrosion tape 150.

In either case of FIG. 1(A) or FIG. 1(B), the overlapping portion (approximately 1/4 of the tape width) of the anticorrosive tapes 150 spirally wound around the cable wire 110 and the filler 120 Alternatively, in the overlapping portion (approximately 1/2 of the tape width) of the anti-corrosion tapes 152, when the anti-corrosion tapes 150 (anti-corrosion tapes 152) are joined to each other (without being thermally welded by heating, for example) ) The anti-corrosion tapes 150 (anti-corrosion tapes 152) are bonded to each other by having adhesive properties that allow them to be integrated, or by applying an adhesive with adhesive properties to the anti-corrosion tapes 150 (anti-corrosion tapes 152). Therefore, it is possible to peel it off after construction. The anticorrosion tapes 150 (anticorrosion tapes 152) bonded to each other in this manner can prevent air and moisture from entering from the overlapping portions, thereby delaying the progress of corrosion. In addition, by making it peelable, it is possible to replace the anti-corrosion tape 150 (anti-corrosion tape 152) periodically or non-regularly as a check for aging deterioration after the construction of covering the structural cable with the anti-corrosion tape 150 (anti-corrosion tape 152). The degree of corrosion protection of the structural cable can be easily confirmed by peeling off the anticorrosion tape 150 (anticorrosion tape 152) covered by the structural cable and visually checking the deterioration of the moisture detection material. This is preferable because it can be done. From now on, the anticorrosion tape 150 and the anticorrosion tape 152 will be explained using the anticorrosion tape 150 as a representative.

Here, as shown in FIGS. 1 to 3, the moisture detection material 122 is provided together with a filler 120 that is filled between the structural cable (more specifically, the cable wire 110) and the anticorrosion tape 150. . Here, the moisture detection material 122 provided together with the filler 120 will be specifically explained.

The presence or absence of water or moisture is largely related to the corrosion of structural cables such as suspension bridges or cable-stayed bridges, which are the object of the anticorrosion method according to the present invention. Therefore, visualization of moisture or moisture infiltration is important in determining the progress of corrosion. Therefore, in this embodiment, a substance (moisture detection material 122) that discolors or changes in quality due to moisture or moisture is disposed to prevent moisture or moisture from entering. Specific examples include the following substances.
(1) Water-soluble microcapsules containing dye (dye-encapsulating microcapsules)
It is detected by the microcapsules being destroyed and the dye being eluted in response to moisture infiltration.
(2) Silica gel used for dehumidification, etc. Silica gel is detected by the discoloration of silica gel due to moisture or moisture. Note that this method can be expected to have a corrosion-preventing effect on structural cables (steel materials) during the period when silica gel absorbs water or moisture.
(3) Powder or solution of cobalt chloride hexahydrate This is detected by discoloration due to water or moisture.
(4) Water-absorbing sheet Since its volume expands by absorbing moisture, the change in volume is visually detected.
(5) Water-soluble sheet Because water is eluted by absorbing water, for example, characters are printed on the sheet using ink, and melting of the ink can be visually detected.

Note that such moisture detection materials (1) to (3), such as powder, may be kneaded into the filler 120 and mixed, and provided together with the filler 120 between the anticorrosion tape 150 and the cable wire 110. As for sheet-like (4) to (5), one example is that they are sandwiched between the filler 120 and the anticorrosive tape 150.

Next, the effect (discoloration or deterioration due to moisture or moisture) of such moisture detection material 122 was confirmed as described below.
(A) A simple test specimen was prepared by placing a filler and dye-containing microcapsules on an iron plate simulating a structural cable, and wrapping the same with anticorrosive tape. A notch was made on the anticorrosion tape of the simple test specimen to reach the filler, and the specimen was immersed in water for several days and then taken out. When the simple test specimen was taken out and disassembled, it was confirmed that the microcapsules and filler were discolored only in the area where water had entered, making it possible to visually determine that water had entered.
(B) A filler kneaded with cobalt chloride hexahydrate was prepared as a simple test specimen. It was confirmed that when water was intentionally applied to this simple test specimen to simulate water infiltration, it turned into a red solution, making it possible to visually determine that water had infiltrated.
(C) A simple test specimen was prepared by placing a filler on an iron plate imitating a structural cable and wrapping the filler with a polyvinyl alcohol sheet (water-soluble sheet) printed with black ink. When water was sprayed onto the simple test specimen to simulate water intrusion, the polyvinyl alcohol sheet eluted and the ink appeared to be dissolved, confirming that it was possible to visually determine that water had infiltrated.

Next, the arrangement of such moisture detection material 122 will be explained with reference to FIGS. 2 and 3.

Here, such a moisture detection material is covered with an anti-corrosion tape 150, which is a thin resin film, along the longitudinal direction of the structural cable 100 (in FIG. 2, the cable wire 110 is shown), as shown in FIG. It is preferable that it be provided in a portion. Further, as shown in FIG. 3, such a moisture detection material is used in a portion covered with an anti-corrosion tape 150, which is a thin resin film, along the longitudinal direction of the structural cable 100 (in FIG. 3, the cable wire 110 is shown). The moisture detection material 122 comes into contact with a portion of the structural cable (in FIG. 3, the cable wire 110 is shown) that is covered with an anticorrosion tape 150 that is a thin resin film along the longitudinal direction. It is also preferable that a water-conducting member 130 is further provided. Here, an example of the water-conducting member 130 is a sheet that easily transmits moisture.

In FIGS. 2 and 3, the moisture detection material (1) to (3), such as powder, is kneaded into the filler 120 and mixed together with the filler 120, the anticorrosion tape 150, and the cable wire 110. I'm trying to set it up in between. For this reason, the moisture detection material 122 is shown in parentheses on the filler 120.

As described above, in the anti-corrosion method according to the present embodiment, between the structural cable 100 or the structural cable 102 including the plurality of cable wires 110 and the resin thin film (corrosion-proof tape 150), A moisture detection material 122 such as powder, paint, sheet, etc. that changes color or quality due to moisture or moisture is installed. This makes it possible to visually recognize the infiltration of moisture, which is a cause of corrosion, to assist in determining the progress of corrosion of steel materials. As described above, materials that change color due to moisture or moisture, such as microcapsules, silica gel, and cobalt chloride hexahydrate, which can be suitably employed as the moisture detection material 122, include materials that change color due to moisture or moisture, such as microcapsules, silica gel, and cobalt chloride hexahydrate, and materials that change color due to moisture absorption. It is conceivable that sheets, water-soluble sheets, etc. may deteriorate (change in shape) due to moisture or humidity. As described above, it is clearly stated that the term "modification (change in properties)" in the present invention includes discoloration in which the color changes and modification in which the shape changes, although this is just one example.

Then, as a check for aging deterioration (when replacing the anti-corrosion tape 150, which is a thin resin film, periodically or non-regularly), the anti-corrosion tape 150, which is a thin resin film covered with the structural cable, is peeled off. This is preferable in that the degree of corrosion protection of the cable can be easily confirmed by visually checking the deterioration of the moisture detection material. In particular, the anticorrosion tape 150, which is a thin resin film, often needs to be replaced regularly or irregularly as maintenance after construction. Therefore, there is no need to make the anti-corrosion tape and filler transparent, and when replacing the anti-corrosion tape for maintenance, it is possible to visually check for deterioration (discoloration, change in quality (shape change), etc.) of the moisture detection material, making it easier to prevent moisture intrusion. It can be confirmed.
<First modification example>
By the way, visual recognition of such discoloration or deterioration of the moisture detection material may be influenced by the subjectivity of the operator, and it is also possible that discoloration or deterioration of the moisture detection material cannot be visually recognized except during maintenance. This could be a problem. The following measures can be taken to address these problems.

The anti-corrosion construction method according to this modification is based on the premise that the structural cables are wrapped and covered together with the moisture detection material 122 by a thin resin film (anti-corrosion tape 150) that can be bonded to each other and has a waterproof function. It is characterized by being wrapped and covered together with a sensor that detects degeneration of the moisture detection material 122. Then, as a check for aging deterioration, the degree of corrosion protection of the structural cable is checked using the sensor.

More specifically, for example, an optical fiber is provided as a sensor along the longitudinal direction of the structural cable so as to be able to detect discoloration or deterioration (discoloration is preferred here) of the moisture detection material 122. That is, the structural cable is provided so as to be wrapped and covered with the anticorrosion tape 150 together with the moisture detection material 122 and the sensor. The degree of corrosion protection (degree of moisture intrusion) of the structural cable is then confirmed using the optical fiber to confirm deterioration over time. In this case, by converting the color of the moisture detection material 122 into data and comparing the color data with the previous detection, it is possible to accurately detect discoloration or deterioration (in this case, discoloration) of the moisture detection material 122. can. This makes it possible to accurately and easily check for discoloration or deterioration (in this case, discoloration) of the moisture detection material, without being influenced by the operator's subjectivity through visual inspection, etc., and even outside of maintenance. be able to.
<Second modification example>
To address the problems in the first modification described above, the following measures can be taken as a second modification. Note that this modification will be explained in detail below with reference to FIGS. 4 to 6, but structures that are the same as those in FIGS. do not have.

FIG. 4 is a diagram corresponding to FIGS. 2 and 3, and is a diagram for explaining a state in which a structural cable is wrapped and covered with an anticorrosive tape in the anticorrosion construction method for a structural cable according to this modification. In FIG. 4, the moisture detection material 122 is not used (the moisture detection material 122 is not kneaded into the filler 120 and mixed), and instead of the moisture detection material 122 described above, the filler 120 and anticorrosive tape are used. 150, one or more conducting wires 230 are provided as a sensor for detecting moisture (in this specification, the same meaning as detection) (including the case where one conducting wire 230 is provided in a pair). In FIG. 4, two conductive wires 230 are provided between the filler 120 and the anticorrosive tape 150. That is, in the structural cable according to this modification, the cable wire 110 and the filler 120 are bonded together with the conductive wire 230, which is a sensor for detecting moisture, by the anticorrosive tape 150, which is a thin resin film that can be bonded to each other and has a waterproof function. It envelops and covers. That is, as shown in FIG. 4, after filling the unevenness of the cable wire 110 with the filler 120, one or more conductors 230 (here, two) are arranged on the surface of the filler 120, and the upper layer is coated with anti-corrosion. A tape 150 is wrapped around it.

Note that the provision of two or more conductors 230 is for the purpose of improving reliability; if only one conductor is provided, the anticorrosion tape 150 may be damaged in the downward direction of the structural cable where gravity acts, and moisture may leak only downward. The reason for this is to avoid the fact that if the wire is immersed in water, the water immersion cannot be detected if the conductor exists only above. Moreover, the sensor that detects moisture is not particularly limited as long as it is a sensor that electrically detects moisture. Here, time domain reflectometry (TDR) using a conductive wire 230 is adopted, but this type of electrical method is not used (it does not need to be a conductive wire), but a method for detecting moisture. Optical Time Domain Reflectometry (OTDR) using an optical fiber as a sensor may be employed (it does not need to be an optical fiber).

The conductive wire 230 is configured to be connectable to a measuring device 240 provided outside the structural cable without peeling off the anticorrosion tape 150, which is a resin thin film, or without peeling off the anticorrosion tape 150. That is, when checking for moisture intrusion into the structural cable (same meaning as moisture immersion in this specification), it is necessary to electrically connect the end of the conducting wire 230, which is a sensor that detects moisture, and the measuring device 240. Then, the presence or absence of moisture (occurrence or absence of moisture immersion) is confirmed by a change in an electrical signal (what is called characteristic impedance in TDR). Note that if the end of the conductor wire 230 is brought out from the gap between the anticorrosion tape 150 in advance, it is advantageous in that there is no need to peel off the anticorrosion tape 150 when checking for moisture intrusion (which may cause moisture intrusion). Therefore, the end of the conducting wire 230 may be wrapped in anticorrosive tape 150, and the anticorrosive tape 150 wrapped around the end of the conducting wire 230 may be peeled off when checking for moisture infiltration.

It has been confirmed, as shown in FIGS. 5 and 6, that moisture intrusion can actually be detected in this modified example configured as shown in FIG. 4.

FIG. 5(A) is a sectional view along the longitudinal direction of the structural cable, and FIG. 5(B) is a sectional view taken along line 5B-5B shown in FIG. 5(A).

Here, as shown in FIG. 5, a damaged part was artificially provided in the anticorrosive tape 150, and the damaged part was immersed in water to check the signal change. Note that the triangular marks (both white and black) in FIG. 5A correspond to the triangular marks in FIG. 6.

As shown in FIG. 6, before the damaged part was immersed in water, the waveform had a chevron-shaped peak on the outside of the structural cable (i.e., the part where the conductor 230 is exposed to the atmosphere); After immersing moisture in two places of the conductor 230 of the conductor 230 and the external conductor 230 itself of the structural cable for comparison, in addition to the waveform having such chevron-shaped peaks in two places, the moisture immersion A waveform with a valley-shaped peak similar to the waveform in the external conductor 230 itself of the structural cable was confirmed in the damaged part of the anticorrosion tape 150 soaked in water using the measuring instrument 240. This makes it possible to confirm moisture immersion in the damaged part of the anticorrosion tape 150 inside the structural cable, in the same way as in the conductor 230 itself outside the structural cable, thereby eliminating the possibility of being influenced by the operator's subjectivity through visual inspection, etc. Even when there is no maintenance, and even when it is not during maintenance, the sensor that detects moisture (here, the conductor 230 because the TDR method is used) is electrically connected to the measuring device 240 and the waveform (change in characteristic impedance) is checked. This makes it possible to accurately and easily confirm moisture intrusion into the interior of the structural cable due to damage to the anticorrosion tape 150 or the like.

As described above, according to the anti-corrosion construction method according to the present embodiment and the structural cable etc. applied with the anti-corrosion construction method, it is possible to use This is a corrosion prevention method for cables, etc., which is a method to prolong the life of structural cables, etc., rather than replacing them when they become corroded (especially when the corrosion is mild and replacement is difficult). After the construction of the anti-corrosion method, it is possible to regularly or irregularly check the status of deterioration of structural cables and other structural parts. Cables etc. can be provided.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

The present invention relates to a corrosion protection technology for structural cables, etc. that are exposed outdoors and used in suspension structures such as suspension bridges and cable-stayed bridges. This method is particularly suitable for anti-corrosion methods that extend the life of structural cables, etc. rather than replacing them (especially when it is difficult to do so).

100, 102 Structural cable undergoing anti-corrosion construction method 110 Cable wire 120 Filler 122 Moisture detection material 130 Water conductive member 230 Conductive wire (as a sensor for detecting moisture) 240 Measuring device

Claims (9)

A corrosion protection construction method for an existing object exposed outdoors that requires anti-corrosion measures or a newly installed object exposed outdoors that requires anti-corrosion measures, wherein the object has one longitudinal direction compared to the other direction. It has a long shape,
Wrapping and covering the object together with a moisture detection material using a peelable resin thin film that is adhesive to each other and has a waterproof function;
A method for preventing corrosion of an object requiring anti-corrosion measures, characterized in that the degree of corrosion protection of the object is confirmed by peeling off a thin resin film covered with the object as a check for deterioration over time. A corrosion protection method for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors, used in suspension structures including suspension bridges and cable-stayed bridges,
Wrapping and covering the structural cable together with a moisture detection material using a peelable resin thin film that is adhesive to each other and has a waterproof function;
A corrosion protection construction method characterized by peeling off a resin thin film covered with the structural cable to check the degree of corrosion protection of the structural cable as a check for aging deterioration. 3. The anticorrosion construction method according to claim 1, wherein the moisture detection material is provided together with a filler that is filled between the object or the structural cable and the resin thin film. 3. The anticorrosion construction method according to claim 1, wherein the moisture detection material is provided in a portion covered with the resin thin film along the longitudinal direction of the object or the structural cable. The moisture detection material is provided in a part of a portion covered with the resin thin film along the longitudinal direction of the object or the structural cable,
Claim 1 or 2, characterized in that a water conductive member is further provided in a portion covered with the resin thin film along the longitudinal direction of the object or the structural cable so as to contact the moisture detection material. The anticorrosion method according to claim 2. The resin thin film is in the form of a tape, and by overlapping at least a portion of the tape width and spirally wrapping the tape-shaped resin thin film around the object or the structural cable, 3. The anticorrosion construction method according to claim 1, wherein the cable is wrapped and covered with the tape-shaped thin resin film. A corrosion protection method for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors, used in suspension structures including suspension bridges and cable-stayed bridges,
Wrapping and covering the structural cable together with a moisture detection material and a sensor for detecting denaturation of the moisture detection material with a resin thin film that can be bonded to each other and has a waterproof function;
A corrosion protection construction method, characterized in that the degree of corrosion protection of the structural cable is confirmed by the sensor as a check for aging deterioration. A corrosion protection method for existing structural cables exposed outdoors or newly installed structural cables exposed outdoors, used in suspension structures including suspension bridges and cable-stayed bridges,
Wrapping and covering the structural cable together with a sensor for detecting moisture using a resin thin film that can be bonded to each other and has a waterproof function;
The sensor can be connected to a measuring device by peeling off the resin thin film or without peeling off the resin thin film,
A corrosion protection construction method, characterized in that the degree of corrosion protection of the structural cable is confirmed by the sensor and the measuring device as a check for aging deterioration. A structural cable exposed outdoors and used in suspension structures including suspension bridges and cable-stayed bridges, which is subjected to the anticorrosion method according to any one of claims 2, 7, and 8.

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