JP2001081800A - Corrosioin-resistant structure by sticking corrosion resisting metal thin-plane and corrosion-proofing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide corrosion-resistant structure of a steel structure capable of being easily executed at a low cost while maintaining corrosion resistance for a very long period of time and a corrosion-resistant method in a corrosion- resistant technoloy of the steel structure. SOLUTION: In corrosion-resistant structure coating the surface of steel materials of a steel structure with a corrosion resisting metal thin plate, water- proofing cohesive tapes 6 are provided to the end of the metal thin plate 7 and the lower part of a joint. In the corrosion-resistant structure of the steel structure, an adhesive 2 is applied on part other than part having the water- proofing cohesive tapes 6 between the surface of steel materials and a metal thin plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general anticorrosion treatment technology for steel structures such as bridges, steel towers, elevated water tanks, tanks, and marine structures, and more particularly to a steel structure having a corrosion-resistant metal sheet on a steel material surface. The present invention relates to an anticorrosion structure having improved long-term durability and a method thereof.

[0002]

2. Description of the Related Art Steel structures such as bridges, steel towers, elevated water tanks, tanks, and offshore structures cause red rust, yellow-brown floating rust, and flow rust due to corrosion. As a result, the strength of the structure is reduced due to the decrease in wall thickness, and some anticorrosion measures are required. Conventionally, as a method of preventing corrosion of these structures, a painting method is generally used, and a heavy-duty anticorrosive coating with improved long-term durability is known, but the coating cost is high and the service life is limited. In addition, there is a problem that maintenance cost is high since regular repainting is necessary.

On the other hand, by adding a small amount of elements such as P, Cu, Cr and Ni to steel materials, dense rust (stable rust) having protection against corrosion is formed in the air in several years. Weather resistant steel is known as a steel material having a very low corrosion rate. Since weather-resistant steel is a so-called maintenance-free steel that has a permanent anticorrosive effect without being painted after stable rust is formed, its use in structures such as bridges and steel towers has been increasing in recent years.

However, in places where stable rust is unlikely to be formed, for example, at the end of a bridge girder or under a flange, or in a sea salt particle flying environment or a snowmelt salt spraying area on the coast, unstable rust is generated, so that corrosion prevention is required. It is not preferable because the effect does not appear. Furthermore, there is a problem in that floating rust such as red rust and yellow rust and flowing rust are generated, which causes a problem in appearance and also causes environmental pollution in the surroundings, thereby limiting the usable area.

[0005] Furthermore, since the weather-resistant steel material improves the weather resistance by forming stable rust on the surface, there is also a problem that it is refrained from urban structures that require an aesthetic appearance. Was.

[0006] In order to solve these problems, there is known a method of preventing corrosion of a steel structure by coating a corrosion-resistant surface of the steel structure with a thin plate of titanium having corrosion resistance. Titanium has high corrosion resistance, and covering the anticorrosion target surface with titanium theoretically enables semi-permanent anticorrosion. As a method of coating titanium on the surface to be protected, a method of directly welding a titanium sheet to the surface of a steel material, a method of attaching a titanium sheet with an adhesive, and a method of interposing a titanium clad material between the titanium sheet and the metal body to be protected. (Japanese Unexamined Patent Publication No. 7-279191), a method of using titanium clad steel over the entire anticorrosion structure instead of a structure in which a titanium thin plate is attached (“Journal of the Japan Welding Society” published in 1991) 60, No. 8, p. 38) are known.

[0007]

However, it is not easy to completely cover the surface of a steel structure with titanium. For example, when a titanium thin plate is directly welded to the surface of a steel material, the welded portion becomes an alloy of titanium and iron, which impairs strength and corrosion resistance. In the method of attaching a titanium sheet with an adhesive, water and corrosive substances entering from the seam or the end of the titanium sheet deteriorate the adhesive, reduce the adhesive strength, cause the titanium thin film to peel off, and cause long-term use. Not suitable. Also, JP-A-7-27
In the method of coating a titanium thin plate via a titanium clad material disclosed in 9191 publication, welding work is required for each of the metal body to be protected and the clad material, and each of the clad material and the titanium thin plate, and further, the construction cost for inspection of the welded portion and the like Is high. Further, JP-A-7-279
In the invention of the 191 publication, in order to prevent the deformation of the titanium sheet, it is necessary to inject a filler into a gap formed between the titanium sheet and the metal body to be protected, which increases the cost and takes time for construction. Further, if titanium clad steel is used for the entire anticorrosion structure, there is a problem that the price becomes very high.

Accordingly, the present invention provides an anticorrosion structure and an anticorrosion method for a steel structure, characterized in that it is easy and inexpensive to construct while maintaining an extremely long-term corrosion resistance in a technique for anticorrosion of a steel structure. Aim.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have studied an anticorrosion structure of a steel structure which can be easily constructed at a lower cost while maintaining an extremely long-term corrosion resistance. Was done.

[0010] As a result, the above problem can be solved by providing a corrosion-resistant structure in which the surface of a steel material of a steel structure is covered with a corrosion-resistant metal sheet and having a waterproof adhesive tape at the end of the metal sheet and below the seam. I found something to be done.

Further, by adopting a structure in which an adhesive is applied to a portion other than the waterproof adhesive tape between the surface of the steel material and the metal sheet, the adhesive strength of the metal sheet is increased, and deformation of the metal sheet is prevented. It has been found to have super long-term durability.

The present invention has been made based on such findings, and is a corrosion protection structure and a corrosion protection method for a steel structure having the following features.

[1] An anticorrosion structure in which a steel material surface of a steel structure is covered with a corrosion-resistant metal sheet, wherein a water-resistant adhesive tape is provided at an end of the metal sheet and below a seam. Construction.

[2] In the anticorrosion structure for a steel structure according to the above [1], an adhesive is applied to a portion between the surface of the steel material and the thin metal plate other than having the waterproof adhesive tape. An anticorrosion structure for steel structures characterized by the following.

[3] An anticorrosion method for coating the surface of a steel material of a steel structure with a corrosion-resistant metal sheet, wherein a waterproof adhesive tape is provided at an end of the metal sheet and below a seam. Method.

[4] In the method for preventing corrosion of a steel structure according to the above [3], an adhesive is applied to a portion between the surface of the steel material and the thin metal plate other than having the waterproof adhesive tape. Corrosion protection method for steel structures characterized by the following.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below.

According to the present invention, in a structure in which a corrosion-resistant metal sheet is coated on a steel material surface of a steel structure to prevent corrosion, a waterproof pressure-sensitive adhesive tape is provided at an end portion of the metal sheet and a lower portion of a seam.

By providing a waterproof adhesive tape at the end of the metal sheet coated on the steel surface and under the seam, water and corrosive substances reaching the steel surface from the seam and the end are prevented. is there. By preventing water and corrosive substances from entering, corrosion of the steel material surface is prevented. In addition, since the metal sheet blocks not only water and corrosive substances but also ultraviolet rays, deterioration of the waterproof pressure-sensitive adhesive tape over time is suppressed, and ultra-long-term durability of the steel structure is secured.

Further, the waterproof pressure-sensitive adhesive tape reduces the stress caused by the difference in the thermal expansion coefficient between the steel material generated due to the temperature difference between the temperature and the metal sheet attached thereon, and has the effect of preventing the metal sheet from peeling off. Have. In addition, it has the effect of buffering irregularities on the surface of steel materials such as weld beads of steel structures and steps due to differences in sheet thickness, preventing a decrease in the adhesive force of the metal sheet to be stuck thereon, and improving the appearance. It has the effect of improving.

Further, in the method for preventing corrosion of a steel structure according to the present invention, it is preferable to apply an adhesive to portions other than those having a waterproof pressure-sensitive adhesive tape. Due to the effect of the adhesive, the adhesive strength between the steel material surface and the metal sheet is increased, and at the same time, the deformation of the metal sheet is prevented, and the anticorrosion effect is further enhanced. Also,
Waterproof adhesive tape at the seams and ends prevents water and corrosive substances from entering from the seams and ends, and furthermore, the ultraviolet rays blocking effect of the metal sheet prevents the adhesive from deteriorating, and the metal sheet can be used for a long time. Can be maintained, so that it is effective for an extremely long-term use.

In addition, there is no work requiring a particularly high level of skill in the work of attaching a metal sheet, so that the work is easy and the work can be performed at low cost.

Here, an example of the procedure of the anticorrosion method according to the present invention will be described below. The procedure is a base treatment step of performing a base treatment of a steel material surface of a steel structure to be subjected to corrosion prevention, a waterproof adhesive tape attaching step of attaching a waterproof adhesive tape, and a metal sheet attaching step of attaching a corrosion-resistant metal sheet thereon,
Can be divided into Hereinafter, details of each step will be described.

Base Treatment Step Before applying the waterproof adhesive tape, a base treatment of the steel material surface of the steel structure is performed. As the base treatment, the following treatment is performed on a new steel structure or an existing steel structure.

[In the case of a new steel structure] A blasting treatment (ISO Sa2.5) with black scale (steel plate with mill scale) as it is
Or equivalent to ISO Sa3), polishing (smooth surface) treatment,
Primer coating (primer such as inorganic zinc-rich primer) and coating (including rust prevention coating).

It should be noted that these processing methods may be performed alone or in combination of two or more.

[In the case of an existing steel structure] Blasting treatment (I
SO Sa2.5 or ISO Sa3), 2 types of Keren (equivalent to ISO St3) treatment, 2 types of Keren (IS
O St3 equivalent) + Coating (including rust prevention coating) treatment.

It should be noted that these processing methods may be performed alone or in combination of two or more.

Waterproof pressure-sensitive adhesive tape sticking step A waterproof pressure-sensitive adhesive tape is stuck to the surface of the steel material subjected to the base treatment. At this time, the waterproof adhesive tape is attached so as to be located at the joint and the end of the thin metal plate.

By providing a waterproof pressure-sensitive adhesive tape at the end of the metal sheet coated on the steel surface and below the seam, water and corrosive substances reaching the steel surface from the seam and the end can be prevented. By preventing intrusion of water and corrosive substances, corrosion of the steel material surface is prevented, and ultra-long-term durability of the steel structure is ensured.

The waterproof pressure-sensitive adhesive tape reduces the stress caused by the difference in the coefficient of thermal expansion between the steel material generated due to the difference in temperature and the temperature of the metal sheet and the metal sheet to be adhered thereon, thereby preventing the metal sheet from peeling off. Have. In addition, it has the effect of buffering irregularities on the surface of steel materials such as weld beads of steel structures and steps due to differences in sheet thickness, preventing a decrease in the adhesive force of the metal sheet to be stuck thereon, and improving the appearance. It has the effect of improving.

Here, the waterproof pressure-sensitive adhesive tape is one obtained by applying a pressure-sensitive adhesive to the surface of a tape base material or formed integrally, and has a high adhesive strength to a steel material surface and a thin metal plate, and has a high water permeability. Are preferred. For example, as a base material of the waterproof adhesive tape, a rubber material such as butyl rubber, a resin material such as acrylic, silicon, polyethylene, epoxy, urethane, or a combination thereof can be used as a material. A material mainly composed of natural rubber, styrene-butadiene rubber, butyl rubber, acrylic or the like can be used. Also,
The waterproof adhesive tape preferably has a thickness of 0.1 to 2.0 mm, an adhesive strength of 1 kg / cm or more, and a water absorption of 1.0% or less.

The waterproof pressure-sensitive adhesive tape is not limited to the joints and ends of the metal sheet, but may be a structure having the entire lower surface of the metal sheet.

Further, in the anticorrosion structure of a steel structure according to the present invention, it is preferable to apply an adhesive to portions other than having a waterproof adhesive tape between the surface of the steel material and the thin metal plate. The effect of the adhesive further increases the adhesive strength between the steel material surface and the metal sheet, and also has an effect of preventing deformation of the metal sheet, thereby ensuring ultra-long-term corrosion resistance.

When an ordinary adhesive is used, the adhesive may deteriorate over time due to the penetration of water or corrosive substances or the irradiation of ultraviolet rays, and the adhesive strength may be reduced. However, in the present invention, since the waterproof adhesive tape is provided at the joints and ends of the sheet metal, it prevents water and corrosive substances from entering therefrom, and the sheet metal also blocks ultraviolet rays, thereby bonding the sheet. Peeling of the metal sheet due to a decrease in adhesive strength due to deterioration of the agent is prevented, and the anticorrosion effect is maintained even when used for an extremely long time.

The adhesive does not need to be provided on the entire surface of the gap between the adhesives, and may be used partially.

The adhesive is not particularly limited, but may be vinyl acetate, acrylic, ethylene, polyamide, polyimide, polyvinyl alcohol, polyester, polyurethane, urea, melanin, phenol, resorcinol,
Epoxy, polyimide, natural rubber, chloroprene rubber,
Resin such as nitrile rubber, urethane rubber, styrene-butadiene rubber, butyl rubber, α-olefin, cyanoacrylate, modified acrylic, or a combination thereof, as the main material, solvent drying type, two-component mixing reaction type, catalyst addition type It is preferable to use one that is cured by a curing method such as a moisture curing type, an anaerobic curing type, a thermosetting type, a hot melt type, a pressure sensitive type, and a rewetting type.

The adhesive is preferably made of a polyamide, polyimide, epoxy or cyanoacrylate resin as a main material from the viewpoint of adhesiveness to metal.

The thickness of the adhesive is not particularly limited, but is preferably 0.05 to 1.0 mm in order to avoid poor adhesion due to a thin film, increase in internal stress due to a thick film, and increase in factors of peeling.

Further, a waterproof sheet may be attached to the surface of the steel material. It is preferable that the surface of the steel material is covered with the waterproof sheet, because intrusion of water or the like into the steel material can be prevented, and the durability is further improved. The waterproof sheet prevents water and corrosive substances from penetrating into the steel material surface due to its waterproofness, and directly prevents corrosion of the steel material surface. The main material of the waterproof sheet is a rubber material such as unvulcanized or vulcanized butyl rubber, or a resin material such as acrylic, epoxy, Teflon, silicone, olefin, α-olefin, urethane, or a combination thereof. Is preferred. Particularly preferred is unvulcanized butyl rubber in view of its price, water tightness, stress relaxation effect and the like. The waterproof sheet preferably has a water absorption of 1.0% or less and a volume resistivity of 10 ⁶ Ω · cm or more as electrical insulation.

The form of the waterproof sheet may be a rubber material or a resin material alone, but may be a foamed sheet having closed cells or a multi-layer formed by combining a cushioning layer such as a nonwoven fabric or a mesh. It can also be a sheet. By using a multilayer sheet, the effect of buffering steps on the surface of the steel material is improved.

The thickness of the waterproof sheet is preferably from 0.1 to 5 mm. If it is less than 0.1 mm, it is easily broken and there is a problem in waterproofness and workability. If it is more than 5 mm, it becomes too heavy to handle. Particularly preferred one is 0.5 to 2 mm. As a method of attaching a waterproof sheet, a method using an adhesive, a method using an adhesive, a method using a combination of an adhesive and an adhesive, an adhesive sheet or an adhesive tape in which a substrate is impregnated or coated with an adhesive There is a way to use Further, a waterproof sheet having an adhesive surface may be used.

Further, a waterproof adhesive tape may be used instead of the waterproof adhesive tape. Adhesive tape is acrylic,
Acrylic on a tape base made of resin material such as urethane,
It is preferable to use one coated with an adhesive such as epoxy, butyl, polyethylene, or vinyl.

Metal Sheet Attaching Step A corrosion-resistant metal sheet is attached on a waterproof adhesive tape.
It is preferable that parts other than the waterproof pressure-sensitive adhesive tape are adhered by an adhesive. As the adhesive, the above-mentioned adhesive can be used.

As the corrosion-resistant metal sheet, for example, titanium,
Titanium alloy, stainless steel, aluminum, aluminum alloy, hot-dip galvanized steel sheet, hot-dip aluminum coated steel sheet, zinc-aluminum-coated steel sheet and enameled steel sheet are preferred, but are not particularly limited as long as they are corrosion-resistant thin metal sheets.

The thickness of the metal sheet is preferably about 10 μm to 1 mm. When the thickness is less than 10 μm, the thin plate is easily damaged during construction. If the thickness is more than 1 mm, not only the weight of the thin plate itself is increased and the reliability of the adhesive durability may be lowered, but also the workability is deteriorated and the cost is increased. Particularly preferred is 50 μm
It is about 300 μm.

FIG. 1 shows an example of a method of attaching a seam of a thin metal plate.
And will be described below. The method of attaching the metal sheet to the seam is not limited to the following method as long as it can prevent water and corrosive substances from entering. Here, 1 in the figure indicates a steel material, and 2 indicates an adhesive. The illustration of the following (h) is omitted.

(A) Butting method A method of butting a thin metal plate 7 on the waterproof adhesive tape 6 so that no gap is formed.

(B) Butt + cover method A strip-shaped metal sheet 8 is attached with an adhesive or a waterproof adhesive tape 6 so as to bridge the seam of the metal sheet 7 abutted and attached on the waterproof adhesive tape 6. Method.

(C) Laminating method The metal thin plates 7 on the waterproof adhesive tape 6 are
mm, adhesive or waterproof adhesive tape 6
A method of bonding using

(D) Method of joining seams A method in which the end of a thin metal plate is bent outward, and the joint is affixed with a waterproof adhesive tape 6.

(E) Goby Folding Method The end of the thin metal plate 7 is goby-folded on the waterproof adhesive tape 6 and caulked. After crimping, the folded portion may be folded down.

(F) Cap method The end of the thin plate is bent over the waterproof adhesive tape 6 to form a seam joint, and the seam is covered with a gutter-shaped cap 9 and swaged.

(G1) to (g4) Welding method The thin plate ends are joined to each other on the waterproof adhesive tape 6 by resistance seam welding or spot welding. In FIG. 1, reference numeral 10 denotes a welded portion. The shape of the joint portion is a shape in which the end is bent and joined (g1), and a shape in which the end is goby-folded (g)
2) There are a shape (g3) in which the end is bent and the seam is covered with a gutter-like cap 9 (g3), and a shape in which the seam is overlapped (g4). In the case of g4, it is convenient to use an integrated metal sheet in which the overlapped portion is welded in advance and integrated.

Here, in the case of spot welding, it is also possible to perform welding after bonding the joints with an adhesive in advance.

(H) Brazing Method The ends of the thin plates are joined to each other on the waterproof adhesive tape 6 by a brazing method. In the brazing method, a metal / alloy (wax) 11 having a melting point lower than that of the base material is added from the outside of the joint to the joint of the metal sheets 7, and the metal sheet and the metal plate 7 are caused to penetrate into the gap of the joint by wetting and capillary phenomenon. Examples of brazing materials include copper brazing, brass brazing, silver brazing, phosphor brass brazing, gold brazing, palladium brazing, nickel brazing, aluminum brazing, and titanium brazing. Among them, the type of the brazing material for titanium brazing is silver brazing (Ag-Cu-based, Ag-Cu-Ni-based,
g-Al type), aluminum braze (pure Al, Al-
Mn type), titanium brazing (Ti-Ni-Cu type, Ti
-Zr-Ni-Cu type), zirconium brazing (Z
(r-Cu type, etc.) are preferable.

One example of the processing method at the end of the metal sheet is illustrated in FIG. 2 and described below.

(A) Method of Having Waterproof Adhesive Tape at the End of Thin Metal Sheet The waterproof adhesive tape 6 prevents water and corrosive substances from entering the end of the thin metal sheet.

(B) Method Using Waterproof Adhesive Tape and Sealing Material The above (a) is further sealed so that the end is covered with a sealing material 12. This prevents intrusion of water and corrosive substances from the ends. Silicone, modified silicon, silicon mastic, sulfide, modified sulfide, urethane, acrylic urethane,
A resin mainly composed of resin such as acryl, styrene-butadiene rubber and butyl rubber is preferable.

(C) Method Using Waterproof Adhesive Tape + Cover In addition to the above (a), the steel structure 1 is further covered with a stainless steel or weather-resistant steel cover 13 so as to cover the end of the metal sheet 7.
And the gap between the metal sheet 7 and the metal sheet 7 is sealed with a sealing material 12. As the sealing material, the same as described above can be used. Further, a waterproof adhesive tape may be used between the cover 13 and the metal sheet 7. As a welding method, an ordinary method may be used, and examples thereof include arc welding, laser welding, and resistance welding. In FIG. 2, reference numeral 14 denotes a welded portion.

(D) Stainless steel or titanium clad steel 15 is welded to the surface of the steel structure corresponding to the end of the thin metal plate 7, and the thin metal plate 7 is adhered thereon via a waterproof adhesive tape 6. Since the waterproof adhesive tape 6 adheres to the smooth metal surface of the stainless steel or titanium clad steel 15, there is an effect that the adhesion of the waterproof adhesive tape becomes strong.

(E) A coating 16 is applied to the surface of the steel structure corresponding to the end of the thin metal plate 7, and the waterproof adhesive tape 6
The metal thin plate 7 is stuck through. Waterproof adhesive tape 6
Is adhered to the smooth surface on which the coating 16 is applied, so that there is an effect that the adhesion of the waterproof adhesive tape 6 becomes strong. The paint to be applied is not particularly limited, but a paint that forms a smooth coating film is preferable.

As described above, there is provided an anticorrosion structure for a steel structure which can be easily and inexpensively constructed while maintaining an extremely long-term corrosion resistance. Further, an anticorrosion method according to the present invention is provided.

The present invention may be applied to the construction of a new steel structure or to the repair of an existing steel structure.

[0065]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

As an example of the present invention, a test material provided with a seam of a thin metal plate was prepared. Table 1 shows Examples 1 to 3 of the present invention.
6 and processing methods according to Comparative Examples 1 and 2.

[0067]

[Table 1]

As the test steel material, a weather-resistant steel (200 mm
× 200 mm × 6 mm).

As the waterproof adhesive tape, a VHB tape manufactured by Sumitomo 3M Limited and having a thickness of 1.0 mm was used.

The test pieces of Examples 1 to 6 and Comparative Examples 1 and 2 obtained as described above were subjected to a test for verifying long-term durability.

In the test, a test piece was repeatedly irradiated with ultraviolet light, rainfall, and salt fly using a combined cycle accelerated weathering tester.

After a period corresponding to 20 years of exposure in an environment near the shore, the test specimens were evaluated. The evaluation method is: appearance survey, presence or absence of peeling of the metal sheet, adhesion state of the metal sheet, forcibly peeling the metal sheet and examining the appearance of the waterproof adhesive tape under it, and further forcibly peeling the waterproof adhesive tape, and the steel material surface Was surveyed.

Table 2 shows the results of the test.

[0074]

[Table 2]

As shown in Table 2, none of the test pieces of the present invention (Examples 1 to 6) showed peeling of the metal sheet.
The thin metal plate was firmly adhered, and the waterproof adhesive tape was firmly adhered without any abnormality such as swelling, floating, discoloration, etc., and no corrosion was observed on the steel material surface.

On the other hand, in Comparative Examples 1 and 2, the thin plate peeled off, floated, and swollen from the end of the thin plate, and rust was observed on the surface of the steel material around the end of the thin metal plate.

[0077]

As described above, according to the present invention, there is provided an anticorrosion structure and an anticorrosion method for a steel structure which can be easily and inexpensively constructed while maintaining ultra-long-term corrosion resistance by minimum maintenance.

The present invention may be applied to the construction of a new steel structure, or may be applied to the repair of an existing steel structure.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a method of attaching a seam of a metal thin plate.

FIG. 2 is a diagram illustrating an example of a processing method at an end of a thin metal plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel material 2 Adhesive 6 Waterproof adhesive tape 7 Metal sheet 8 Strip-shaped metal sheet 9 Trough-shaped cap 10 Welding part 11 Wax 12 Sealing material 13 Cover 14 Welding part 15 Titanium clad steel 16 Painting

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masaharu Honda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. F-term (reference) 2D018 BA00 2D059 AA05 GG21 4K062 AA10 EA01 EA20 FA01 GA10

Claims (4)

[Claims] 1. An anticorrosion structure for a steel structure, wherein a steel material surface of the steel structure is covered with a corrosion-resistant metal sheet, wherein a waterproof adhesive tape is provided at an end of the metal sheet and below a seam. . 2. The steel structure according to claim 1, wherein a portion between the surface of the steel material and the thin metal plate other than the portion having the waterproof adhesive tape is coated with an adhesive. Anticorrosion structure. 3. An anticorrosion method for covering a steel material surface of a steel structure with a corrosion-resistant metal sheet, comprising a waterproof pressure-sensitive adhesive tape at an end of the metal sheet and below a seam. . 4. The steel structure according to claim 3, wherein an adhesive is applied to a portion between the surface of the steel material and the thin metal plate other than having the waterproof adhesive tape. Anticorrosion method.