JP2020165136A - Rust preventive repair method for steel material, rust preventive repair method for steel tower, and rust preventive repair steel material - Google Patents

Abstract

To provide a rust preventive repair method for a steel material capable of performing rust preventive repair of the steel material in a short period at a low cost, a rust preventive repair method for a steel tower, and a rust preventive repair steel material.SOLUTION: A rust preventive repair method for a steel material comprises: a substrate adjusting step ST11 of adjusting a substrate of the steel material by subjecting a region to be constructed of the steel material to a scraping treatment; a primer applying step ST12 of applying a primer to a region to be applied in which the substrate is adjusted and providing a base layer; a resin applying step ST13 of applying a resin on the base layer to provide a resin layer for preventing permeation of moisture and oxygen to a surface of the steel material; an adhesive applying step ST14 of applying an adhesive onto a resin layer; and an ultraviolet preventing layer forming step ST15 of providing an ultraviolet preventing layer for preventing transmission of ultraviolet rays to the resin layer on the resin layer via the adhesive.SELECTED DRAWING: Figure 5

Description

The present invention relates to a rust preventive repair method for steel materials, a rust preventive repair method for steel towers, and a rust preventive repair steel material, for example, a rust preventive repair method for steel materials preferably used for zinc plated steel materials having a zinc plating layer, and rust preventive for steel towers. Regarding repair methods and rust preventive repair steel materials.

Conventionally, galvanized steel materials that have been subjected to anticorrosion treatment by galvanizing have been used in steel towers for power transmission and the like. In the galvanized steel material, the galvanized layer wears over time and may be corroded by rust or the like. Therefore, a method for repairing a steel material corroded by rust or the like has been proposed (see, for example, Patent Document 1). In the repair method described in Patent Document 1, a rust treatment agent containing a base resin, acetylacetone, a rust preventive pigment and a curing agent for epoxy resin is applied to a corroded steel material to suppress the spread of rust and galvanize. Suppresses deterioration of steel materials.

Japanese Unexamined Patent Publication No. 2016-56411

Since the strength of steel towers for power transmission decreases when galvanized steel materials corrode, repair treatments such as painting, member replacement, and thermal spraying are carried out. Painting is a commonly used rust preventive repair method. In painting, a keren treatment is performed to remove rust and the like generated on the steel material. However, if the steel material is corroded with almost no galvanization, even if the kelen treatment is performed, corrosion products and salts are corroded. The factor cannot be completely removed. Therefore, even if general coating is performed, moisture and oxygen may permeate through minute defects in the coating film, and corrosion may occur from under the coating film.

In member replacement, it is necessary to remove the load for safe construction, and it is necessary to use a jig that shares the load of the replacement member or to move the electric wire. Therefore, in the replacement of parts, design period and cost such as load examination, manpower, construction cost and material cost incurred due to large-scale construction are incurred. Further, in the member replacement, preparatory work such as installation of jigs used for member replacement and movement of electric wires is required, so that there are restrictions on the workplace such as construction cannot be performed during a period of high power demand due to a long-term power outage.

Plating spraying is a technique that solves the problems of painting and member replacement. Plating spraying is a technique for recovering worn plating by spraying zinc, aluminum, etc. with a spraying gun after performing a type 1 kelen treatment by the blasting method. However, plating spraying requires equipment such as a compressor and power supply equipment used in the blasting method, which involves high mechanical damage and transportation of heavy objects. In particular, plating spraying entails a very high construction cost when helicopter transportation is required in mountainous areas. In addition, in plating spraying, it is necessary to secure a construction site in order to place the above equipment, and a construction preparation period such as negotiations with landowners and felling of trees is required.

The present invention has been made in view of such circumstances, and provides a rust preventive repair method for steel materials, a rust preventive repair method for steel towers, and a rust preventive repair steel material capable of rust preventive repair of steel materials in a short period of time and at low cost. The purpose is to do.

The rust preventive repair method for a steel material according to the present invention includes a base material adjusting step of adjusting the base material of the steel material by cleaning the construction target area of the steel material, and applying a primer on the construction target area adjusted to the base material. A primer coating step of providing a base layer, a resin coating step of applying a resin on the base layer to provide a resin layer for preventing moisture and oxygen from permeating the surface of the steel material, and a resin coating step of applying an adhesive on the resin layer. It is characterized by including an adhesive coating step and a UV protection layer forming step of providing a UV protection layer on the resin layer via the adhesive to prevent the transmission of UV rays to the resin layer.

According to the rust preventive repair method for a steel material according to the present invention, the resin layer can prevent oxygen, moisture and dust in the atmosphere from coming into contact with the surface of the steel material, so that the progress of corrosion due to rust on the steel material can be prevented. .. Then, since the ultraviolet ray preventing layer is provided on the resin layer, the ultraviolet ray preventing layer reflects or absorbs the ultraviolet rays against the resin layer, and it becomes possible to prevent the deterioration of the resin layer due to the ultraviolet rays. As a result, the rust preventive repair effect of the steel material can be obtained by a construction method substantially similar to that of painting, so that the rust preventive repair can be performed in a short period of 2 to 3 days. Further, since the design period associated with the repair work and the labor and material costs that may occur due to the large-scale construction are not required, the rust preventive repair can be performed at low cost. Therefore, as a rust preventive repair method for steel materials, it is possible to realize a rust preventive repair method for steel materials that can inexpensively repair corroded steel materials in a short period of time.

The rust preventive repair method for a steel material according to the present invention preferably further includes a protective layer forming step of providing a protective layer for protecting the ultraviolet protective layer on the ultraviolet protective layer. By this method, since the UV protection layer can be protected by the protective layer, it is possible to prevent the UV protection layer from being damaged due to contact with other substances with the UV protection layer, and it is more reliable than the transmission of UV rays through the resin layer. Can be prevented.

In the rust preventive repair method for steel materials according to the present invention, it is preferable that the resin is a polyurea resin. By this method, the highly elastic polyurea resin adheres well to the steel material, and the film thickness can be secured at 1 mm or more. Therefore, the film thickness can be 10 times or more that of general coating. It is possible to efficiently protect the surface of the steel material.

In the rust preventive repair method for steel materials according to the present invention, it is preferable that the adhesive is an epoxy-impregnated adhesive. By this method, the resin layer and the ultraviolet protection layer can be efficiently adhered to each other.

In the rust preventive repair method for steel materials according to the present invention, it is preferable that the ultraviolet ray preventive layer contains a carbon fiber reinforced resin. By this method, the UV protection layer is made lighter, and the strength, elasticity, corrosion resistance and wear resistance are improved, so that it is possible to prevent the UV protection layer from being damaged.

The rust preventive repair method for the steel tower according to the present invention includes a base material adjusting step of adjusting the base material of the steel material by cleaning the construction target area of the steel material constituting the steel material, and a primer on the construction target area where the base material is adjusted. And a primer coating step of applying resin to provide a base layer, a resin coating step of coating resin on the base layer to provide a resin layer for preventing moisture and oxygen from permeating the surface of the steel material, and adhesion on the resin layer. It is characterized by including an adhesive application step of applying an agent, and an ultraviolet ray prevention layer forming step of providing an ultraviolet ray prevention layer on the resin layer via the adhesive to prevent ultraviolet rays from being transmitted to the resin layer. ..

According to the rust preventive repair method for a steel tower according to the present invention, the resin layer can prevent oxygen, moisture and dust from coming into contact with the surface of the steel material, so that the progress of corrosion due to rust on the steel material can be prevented. .. Then, since the ultraviolet ray preventing layer is provided on the resin layer, the ultraviolet ray preventing layer reflects or absorbs the ultraviolet rays against the resin layer, and it becomes possible to prevent the deterioration of the resin layer due to the ultraviolet rays. As a result, the rust preventive repair effect of the steel material can be obtained by a construction method substantially similar to that of painting, so that the rust preventive repair can be performed in a short period of 2 to 3 days. Further, since the design period associated with the repair work and the labor and material costs that may occur due to the large-scale construction are not required, the rust preventive repair can be performed at low cost. Therefore, as a rust preventive repair method for steel, it is possible to realize a rust preventive repair method for steel that can inexpensively repair corroded steel materials in a short period of time.

The rust-preventive repair steel material for the steel tower according to the present invention is provided on the steel material main body, the base layer provided in the region including the corroded portion on the steel material main body, and the water and oxygen on the steel material surface. It is characterized in that it is provided with a resin layer for preventing the transmission of the steel and an ultraviolet ray preventing layer provided on the resin layer for preventing the transmission of ultraviolet rays to the resin layer.

According to the rust-preventive repair steel material according to the present invention, since the resin layer can prevent oxygen, moisture and dust in the atmosphere from coming into contact with the surface of the steel material body, it is possible to prevent the progress of corrosion due to rust on the steel material body. .. Since the UV protection layer is provided on the resin layer, the UV protection layer can prevent or absorb the irradiation of UV rays on the resin layer. As a result, a rust preventive effect substantially similar to that of painting can be obtained, so that the corroded portion can be repaired in a short period of 2 to 3 days. Further, since the design period associated with the repair and the labor and material costs associated with the large-scale construction are not required, rust prevention can be performed at low cost. Therefore, the rust-preventive repair steel material can repair the corroded steel material at low cost in a short period of time.

According to the present invention, it is possible to realize a rust preventive repair method for a steel material, a rust preventive repair method for a steel tower, and a rust preventive repair steel material that can inexpensively repair a steel material in a short period of time.

FIG. 1 is a schematic view of a chevron steel tower to which the rust preventive repair method for steel materials according to the present embodiment is applied. FIG. 2 is a schematic enlarged view of the lower part of the chevron steel tower shown in FIG. FIG. 3 is a diagram showing an example of a main pillar material to which the rust preventive repair method for a steel material according to the present embodiment is applied. FIG. 4 is a schematic cross-sectional view of the rust preventive repair steel material according to the present embodiment. FIG. 5 is a flow chart showing an outline of a rust preventive repair method for a steel material according to an embodiment of the present invention. FIG. 6A is an explanatory diagram of a rust preventive repair method according to an embodiment of the present invention. FIG. 6B is an explanatory diagram of a rust preventive repair method according to an embodiment of the present invention. FIG. 6C is an explanatory diagram of a rust preventive repair method according to an embodiment of the present invention. FIG. 6D is an explanatory diagram of a rust preventive repair method according to an embodiment of the present invention. FIG. 6E is an explanatory diagram of a rust preventive repair method according to an embodiment of the present invention. FIG. 6F is an explanatory diagram of a rust preventive repair method according to an embodiment of the present invention. FIG. 7A is a diagram showing an example of construction of a rust preventive repair portion in the rust preventive repair steel material according to the embodiment of the present invention. FIG. 7B is a diagram showing an example of construction of a rust preventive repair portion in the rust preventive repair steel material according to the embodiment of the present invention. FIG. 7C is a diagram showing an example of construction of a rust preventive repair portion in the rust preventive repair steel material according to the embodiment of the present invention. FIG. 8 is a diagram showing another example of construction of the rust preventive repair portion in the rust preventive repair steel material according to the embodiment of the present invention. FIG. 9 is an example showing a construction example in the UV protection layer forming step according to the embodiment of the present invention. FIG. 10A is a diagram showing a rust preventive repair steel material according to an embodiment of the present invention. FIG. 10B is a diagram showing a rust preventive repair steel material according to an embodiment of the present invention. FIG. 10C is a diagram showing a rust preventive repair steel material according to an embodiment of the present invention. FIG. 11A is a photograph showing a steel material having a member deterioration level A of equilateral angle steel according to an embodiment of the present invention. FIG. 11B is a photograph showing a steel material having a member deterioration level B of equilateral angle steel according to an embodiment of the present invention. FIG. 11C is a photograph showing a steel material having a member deterioration level C of equilateral angle steel according to an embodiment of the present invention. FIG. 12A is a photograph showing a type 2 kelen treatment of equilateral angle steel according to an embodiment of the present invention. FIG. 12B is a photograph showing a type 2 light and slight kelen treatment of equilateral angle steel according to an embodiment of the present invention. FIG. 12C is a photograph showing a type 3 kelen treatment of equilateral angle steel according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments.

In the following embodiments, an example in which the rust preventive repair method according to the present embodiment is applied to a steel tower will be described. FIG. 1 is a schematic view of a chevron steel tower to which the rust preventive repair method for steel materials according to the present embodiment is applied, and FIG. 2 is a schematic enlarged view of the lower part of the chevron steel tower shown in FIG. .. As shown in FIGS. 1 and 2, the angle steel tower 100 includes a steel tower main body 101 that is erected along the height direction from the ground, and an arm metal material 102 that projects horizontally from the steel tower main body 101. The tower main body 101 includes four main pillar members 111 arranged along the height direction from the ground surface to the upper end of the steel tower main body 101, and a plurality of horizontal members 112 arranged in the horizontal direction and connecting the main pillar members 111 to each other. To be equipped. The main pillar members 111 to each other and the main pillar member 111 and the horizontal member 112 are connected by a plurality of diagonal members 113 arranged so as to be inclined with respect to the main pillar member 111 and the horizontal member 112.

The main column member 111 is formed by overlapping a plurality of angle steels arranged at an inclination with respect to the ground at a predetermined angle, overlapping joint portions 114 provided at the end portions, and joining them with bolts and nuts. Further, the lowermost main pillar member 111 has a multi-end portion embedded in a concrete foundation (not shown) and fixed in a state where the joint portion 114 at one end is projected upward.

The arm metal material 102 is a pair of left and right arm metal main members 121 protruding from the tower main body 101 in the horizontal direction, and a pair of left and right arm metal suspensions arranged at an angle between the steel tower main body 101 and the tip of the arm metal main material 121. A material 122 is provided. The arm suspension member 122 connects the tower main body 101 and the tip of each arm metal main material 121.

FIG. 3 is a diagram showing an example of a main pillar member 111 to which the rust preventive repair method for a steel material according to the present embodiment is applied. In the example shown in FIG. 3, a part of the main pillar member 111 has a rust-preventive repair steel material 1 to which the rust-preventive repair method according to the present embodiment is applied. The rust preventive repair steel material 1 is provided between the two main pillar materials 111a and the main pillar material 111b via the joint portion 114. The rust-preventive repair steel material 1 prevents corrosion of the main pillar material 111 due to rust or the like.

FIG. 4 is a schematic cross-sectional view of the rust preventive repair steel material 1 according to the present embodiment. As shown in FIG. 1, the rust preventive repair steel material 1 includes a steel material main body 11 to be subjected to the rust preventive treatment, and a rust preventive repair portion 12 provided on the steel material main body 11. The rust preventive repair portion 12 includes a base layer 13 provided on the steel body 11, a resin layer 14 provided on the base layer 13, an ultraviolet protection layer 15 provided on the resin layer 14, and an ultraviolet protection layer. A protective layer 16 provided on the 15 is provided. In the rust preventive repair steel material 1, the protective layer 16 does not necessarily have to be provided and can be omitted if necessary.

As the steel body 11, a steel body that is corroded by rust or the like due to wind or rain is used. As the steel body 11, one that has already been corroded such as rust may be used, or one that has not yet been corroded such as rust may be used. As the steel material main body 11, steel materials made of various metals such as iron and steel are used. Further, as the steel material main body 11, a plated steel material having a plating layer provided on the surface by a plating treatment may be used, or an untreated steel material may be used. Among these, as the steel material main body 11, a galvanized steel material having a zinc-plated layer used for a steel tower or the like is preferably used. In this case, as the galvanized steel material, one having a galvanized layer may be used, or one in which the galvanized layer disappears and rust or the like is generated on the surface due to corrosion due to rust or the like may be used. The steel body 11 may be an existing steel material used for a structure such as a steel tower, or may be a single steel body 11 before being used for a structure. Further, as the steel body 11, a steel body 11 used in a structure such as a steel tower for power transmission and whose surface has already been corroded by rust or the like may be used, or an unused steel body 11 which is not corroded may be used. When a steel material having rust on the surface is used as the steel material main body 11, rust and coating on the surface are removed by a cleaning treatment or the like before use.

By applying the base layer 13 to the surface of the steel material main body 11, the surface of the steel material main body 11 to be constructed by the steel material repair portion 12 is smoothed, and the adhesiveness between the steel material main body 11 and the resin layer 14 is improved. To do. The base layer 13 is provided by applying a primer containing a main agent and a curing agent in a predetermined ratio to the surface of the steel material main body 11 and curing the base layer 13. As the primer of the base layer 13, for example, an epoxy-modified urethane resin (for example, trade name: "FP-UL1", manufactured by Nippon Steel Chemical & Materials Co., Ltd.) is used. The thickness of the base layer 13 is, for example, 50 μm or more and 500 μm or less. The primer of the base layer 13 is not limited to the epoxy-modified urethane resin, and can be appropriately selected according to the materials of the steel body 11 and the resin layer 14.

The resin layer 14 has low permeability of water, salt, oxygen, etc. to the surface of the steel body 11, and prevents contact between the surface of the steel body 11 with water, salt, and oxygen. Further, the resin layer 14 has impact resistance and abrasion resistance, and protects the steel body 11 from impact and abrasion. Further, when the resin layer 14 has a step such as a joint portion 114 on the surface of the steel material main body 11 to be constructed, the step is smoothed. The resin layer 14 contains, for example, a resin such as a polyurea resin, a polyurethane resin, or a silicone resin. As the polyurea resin, for example, trade name: "FU-Z", manufactured by Nippon Steel Chemical & Materials Co., Ltd. is used. The thickness of the resin layer 14 shall be 0.1 mm or more and less than 5 mm from the viewpoint of reducing the permeability of water, salt and oxygen to the surface of the steel material body 11 and from the viewpoint of impact resistance and abrasion resistance to the steel material body 11. Is more preferable, 0.5 mm or more and less than 1.2 mm is more preferable, and 0.8 mm or more and less than 0.9 mm is further preferable.

The ultraviolet protection layer 15 absorbs or reflects ultraviolet rays and the like on the resin layer 14 and protects the resin layer 14 from deterioration due to ultraviolet rays. The ultraviolet protection layer 15 is not limited as long as it can prevent the ultraviolet rays from the resin layer 14 by absorption or reflection. As the UV protection layer 15, for example, a fiber-reinforced resin sheet in which the resin of the base material is reinforced with fibers or a fiber-reinforced sheet before impregnation with the resin is used. By using a fiber-reinforced resin sheet (including a fiber-reinforced sheet impregnated with resin) as the ultraviolet-preventing layer 15, the ultraviolet-preventing layer 15 is attached onto the resin layer 14 via an adhesive. Can be provided. The fiber reinforced sheet becomes a fiber reinforced resin by impregnating it with an adhesive. Further, the ultraviolet protection layer 15 plays a role of protecting the resin layer 14 when cleaning is performed at the time of repainting by using a member having wear resistance and impact resistance.

The fiber reinforced resin is not particularly limited as long as it can absorb or reflect ultraviolet rays to the resin layer 14. For example, glass fiber reinforced plastic (GFRP: Glass-Fiber-Reinforced Plastics), carbon fiber reinforced resin (CFRP: Carbon). -Fiber-Reinforced Plastics), Boron Fiber Reinforced Resin (BFRP: Boron Fiber-Reinforced Plastics), Aramid Fiber Reinforced Resin (AFRP: Aramid-Fiber-Reinforced Plastics), Polymer Fiber Reinforced Resin and the like. Among these, carbon fiber reinforced resin is preferable from the viewpoints of light weight, high strength / high elasticity, high corrosion resistance, insulating property, high wear resistance and the like. As the carbon fiber reinforced resin, various carbon fiber reinforced resins such as PAN-based carbon fiber reinforced resin and pitch-based carbon fiber reinforced resin can be used. Among these, PAN-based carbon fiber reinforced resin and pitch-based carbon fiber reinforced resin are preferable, and pitch-based carbon fiber reinforced resin is more preferable, from the viewpoint of being more excellent in abrasion resistance. Further, as the carbon fiber reinforced resin, a carbon fiber reinforced resin sheet (including a carbon fiber reinforced sheet impregnated with resin) is used from the viewpoint that the ultraviolet ray prevention layer 15 can be provided on the resin layer 14 by sticking. preferable. As the carbon fiber reinforced resin, for example, trade name: "Toe Sheet", manufactured by Nippon Steel Chemical & Materials Co., Ltd. is used.

The protective layer 16 prevents the permeation of moisture and oxygen and protects the ultraviolet protection layer 15 from ultraviolet rays. As the protective layer 16, for example, a fluorine-based paint (trade name: “Bonflon steel tower topcoat # 2200”, manufactured by AGC Cortec Co., Ltd.) or the like is used. The thickness of the protective layer 16 is, for example, 40 μm or more from the viewpoint of protecting the ultraviolet protection layer 15 from moisture, oxygen, and ultraviolet rays. Hereinafter, the rust preventive repair method according to the present embodiment will be described in detail.

FIG. 5 is a flow chart showing an outline of a rust preventive repair method for a steel material according to an embodiment of the present invention. As shown in FIG. 5, the rust preventive repair method for a steel material according to the present embodiment is, for example, when corrosion such as rust occurs on a galvanized steel material that has been galvanized, such as a steel tower for power transmission. By constructing in the area including the corroded part where rust is generated, further progress of rust in the corroded part is prevented. The rust preventive repair method for the steel material according to the present embodiment includes a base material adjusting step ST11 for adjusting the base material of the steel material main body 11 to be constructed by a cleaning treatment, and a primer applied on the steel material main body 11 for which the base material has been adjusted. A primer coating step ST12 for providing the ground layer 13, a resin coating step ST13 for coating a resin on the base layer 13 to provide a resin layer 14, an adhesive coating step ST14 for applying an adhesive on the resin layer 14, and an adhesive. Includes the UV protection layer forming step ST15 in which the UV protection layer 15 is provided on the resin via the above. Hereinafter, each step will be described in detail.

6A to 6F are explanatory views of a rust preventive repair method according to the present embodiment. As shown in FIG. 6A, the steel body 11 to be constructed has a corroded region A1 corresponding to a corroded portion 11A in which corrosion such as rust has occurred on the surface. As shown in FIG. 6B, in the base material adjusting step ST11, the base material of the construction target area A2 on the surface of the steel material main body 11 is adjusted. The construction target area A2 is preferably set to a wider range than the corroded area A1 of the corroded portion 11A including rust generated on the steel body 11. As a result, it is possible to prevent the end portion of the steel material repair portion 12 from floating after the ultraviolet ray prevention layer 15 is provided, and to make the steel material repair portion 12 and the steel material main body 11 more reliably adhere to each other. Further, in the step of attaching the UV protection layer 15 described later, for example, even when the UV protection sheet is folded back at the end of the steel body 11 to provide the UV protection layer 15, the UV protection sheet of the UV protection layer 15 is provided. It is possible to prevent the UV protection layer 15 from floating due to its elasticity. From the viewpoint of further improving the above-mentioned effect, the construction target area A2 preferably includes a range A3 wider than the end portion of the corroded portion 11A by 10 mm or more, and may include a wide range A3 of 20 mm or more in addition to the corroded region A1. It is more preferable to include a range A3 wider than 30 mm, and from the viewpoint of shortening the construction time, it is preferable to include a range A3 60 mm or less from the end of the corroded portion 11A, and a range A3 of 50 mm or less is included. Is more preferable, and it is further preferable to include a range A3 of 40 mm or less.

In the base material adjustment step ST11, for example, the base material is adjusted by a kelen treatment. In the cleaning treatment, rust, dust, and dirt are removed with an electric tool or a hand tool. The cleaning treatment may be any one of 1 type kelen treatment, 2 type keren treatment, 2 type light kelen treatment and 3 type keren treatment. In the present embodiment, the type 1 cleaning treatment is a cleaning treatment that completely removes rust and coating by using a blast method, acid cleaning, and a release agent, and the type 2 cleaning treatment is an electric operation such as a disc sander. It is a cleaning treatment that completely removes rust using a tool, and the type 2 light cleaning treatment is a cleaning treatment that removes only fragile rust with an electric tool such as a wire cup, and the type 3 cleaning is rust and floating. This is a rust treatment that removes rust from the paint film using hand tools such as wire brushes, scrapers, scrapers, and sandpaper. According to this embodiment, it is not necessary to perform the first-class kelen treatment, which is expensive in construction cost, and the rust-preventive treatment of the steel material is realized even in the second-class kelen treatment, the second-class light kelen treatment, and the third-class kelen treatment, which are inexpensive in construction cost. can do.

In the primer coating step ST12, as shown in FIG. 6C, the primer is applied onto the construction target area A2 on the steel body 11 whose substrate has been adjusted in the substrate adjusting step ST11 to provide the base layer 13. In the primer coating step ST12, rust and dust in the construction target area A1 are removed with a blower and a waste cloth, and then dirt such as oil is wiped off with an organic solvent such as acetone. Then, a primer in which the main agent and the curing agent are mixed in advance at a predetermined blending ratio is uniformly applied onto the steel body 11 whose base material has been adjusted, and then dried for a predetermined time to provide the base layer 13. Here, if necessary, the dried base layer 13 may be smoothed with sandpaper or the like.

In the resin coating step ST13, as shown in FIG. 6D, a resin is applied onto the base layer 13 to provide the resin layer 14. As a result, the resin layer 14 as a highly elastic layer can be provided on the construction target area A2 of the steel material main body 11. In the resin coating step ST13, a curable resin in which a main agent and a curing agent are mixed in advance in a predetermined blending ratio is uniformly applied onto the base layer 13. Here, it is preferable that the step of the resin after coating is within 1 mm.

Further, in the resin coating step ST13, it is preferable to apply the resin to other conductive members within a predetermined range from the end of the construction target region A2 of the steel material main body 11 to be constructed. As a result, it is possible to prevent the UV protection layer 15 of the rust preventive repair portion 1 from coming into contact with other conductive members in a predetermined range from the end of the construction target area A2 of the steel body 11 after construction, so that the UV protection layer 15 It is possible to prevent corrosion due to a potential difference due to conduction between the and other conductive members. The predetermined range is preferably, for example, 10 mm or more and 100 mm or less from the end portion of the construction target area A2.

Further, in the resin coating step ST13, the surface of the resin layer 12 is shaped so as to be smooth after the resin is applied and before the resin is cured. Here, for example, in the step portion 114A (see FIG. 3) generated at the joint portion 114 of the steel material main body 11, it is preferable to thickly coat the resin to eliminate the step between the step portions 114A. As a result, the rust preventive repair portion 11 can be provided between the plurality of steel material main bodies 11 via the joint portion 114, so that the plurality of steel material main bodies 11 can be continuously repaired.

In the resin coating step ST13, the resin is coated and then dried for a predetermined time. The drying time is, for example, 3 hours or more and 24 hours or less. In the resin coating step ST13, after the resin layer 14 is cured, the surface of the resin layer 14 is shaped using a cutter, sandpaper, or the like. As a result, when the ultraviolet protection layer 15 is provided, the ultraviolet protection layer 15 can be prevented from bending and adhered to the resin layer 14 without gaps. In particular, when angle steel is used as the steel body 11, the corners 120 become extra when the resin layer 14 is applied, so it is preferable to shape the surface of the resin layer 14.

In the adhesive application step ST14, an adhesive is applied onto the resin layer 14. In the adhesive application step ST14, an epoxy-impregnated resin mixed in a predetermined ratio on the dried resin layer 14 is applied onto the resin layer 14. Here, the epoxy-impregnated adhesive is preferably applied over a wider area than the surface on which the UV protection layer 15 is formed. Further, the epoxy-impregnated adhesive can facilitate defoaming after the ultraviolet protection layer 15 is provided by increasing the coating amount on the resin layer 14. In particular, when the epoxy-impregnated adhesive uses angle steel as the steel body 11, the residual air bubbles can be prevented from remaining in the corners 120 by increasing the coating amount of the corners 120 from the flat surface.

In the UV protection layer forming step ST15, the UV protection layer 15 is provided on the resin layer 14 via an adhesive. Here, for example, an ultraviolet protection sheet is attached on the resin layer 14. As a result, the rust preventive repair steel material 1 can block the ultraviolet rays in the light rays reaching the surface of the resin layer 14 by the ultraviolet ray prevention layer 15, so that the deterioration of the resin layer 14 can be suppressed. The ultraviolet ray preventing layer 15 is not particularly limited as long as it can prevent ultraviolet rays, and the above-mentioned various fiber reinforced resins, carbon fiber reinforced resins and the like can be used. Further, as the ultraviolet ray prevention layer 15, not only a sheet made of fiber reinforced resin but also a fiber reinforced sheet before impregnation with the resin can be used. Among these, by using the carbon fiber reinforced resin, the strength of the corroded and thinned steel body 11 can be restored.

In the UV protection layer forming step ST15, first, a member sketch of the steel material 11 to be attached to the UV protection layer 15 is performed. In the member sketch, the ultraviolet protection layer 15 is cut out according to the shape of the portion where the members of the steel body 11 overlap and the shape of the joint portion 114 fixed by bolting. Here, it is preferable to use a sketch diagram prepared in advance. As a result, for example, when the work is performed on the steel body 11 of the steel tower, each dimension of the sketch drawing created in advance can be communicated from the worker at the upper part of the steel tower to the lower worker, so that the member sketch can be performed quickly. ..

In the sheet cutting process, the upper and lower ends of the UV protection layer 15 are fixed to a fixing member such as plywood with masking tape or the like. As a result, even when a soft and easily damaged carbon fiber reinforced resin is used as the UV protection layer 15, damage to the UV protection layer 15 is prevented by fixing the UV protection layer 15 to the fixing member with masking tape. be able to.

Next, in the ultraviolet protection layer forming step ST15, as shown in FIG. 6E, the ultraviolet protection layer 15 is provided on the resin layer 14. Here, it is preferable that the UV protection layer 15 is provided in the UV protection layer forming region A4, which is narrower than the resin layer 14 provided in the construction target region A2. As a result, even when a conductive carbon fiber reinforced resin is used as the UV protection layer 15, contact between the UV protection layer 15 and the steel body 11 can be prevented, so that potential difference corrosion can be prevented. .. From the viewpoint of further improving the above-mentioned effect, the construction target area A2 is preferably a range wider than the end of the ultraviolet protection layer forming region A4 by 10 mm or more, more preferably 20 mm or more, and wider than 30 mm. The range is more preferably 60 mm or less, more preferably 50 mm or less, and 40 mm or less from the end of the UV protection layer forming region A4 from the viewpoint of shortening the construction time. It is more preferable to set it in the range of.

In the UV protection layer forming step ST15, for example, in the joint portion 114 to which the steel body 11 is connected, it is preferable that the ends of the UV protection layer 15 are overlapped with each other.

Next, in the UV protection layer forming step ST15, air bubbles intervening between the UV protection layer 15 and the resin layer 14 are pressed by a roller or the like from above the UV protection layer 15 on which the UV protection sheet is attached. Extrude and defoam. As a result, the ultraviolet protection layer 15 and the resin layer 14 can be brought into close contact with each other.

Next, a resin such as an epoxy-impregnated adhesive is applied onto the ultraviolet protection layer 15 to form a protective layer 16 on the ultraviolet protection layer 15. Here, if necessary, the protective layer 16 may be pressed with a roller or the like to perform defoaming treatment. As a result, the protective layer 16 can be further provided on the ultraviolet protection layer 15, so that the ultraviolet protection layer 15 can be protected from the permeation of moisture and oxygen and protected from the ultraviolet rays to the resin layer 14. The protective layer 16 does not necessarily have to be provided.

7A to 7C are views showing an example of a construction example of the rust preventive repair steel material 1 according to the present embodiment. In the examples shown in FIGS. 7A to 7C, the rust preventive repair steel material 1 is provided with the rust preventive repair portion 12 folded back at both ends of a pair of flat surface portions 111 of the steel material main body 11 of angle steel. In this case, as shown in FIG. 7A, a predetermined range from the front surface 11a side to the back surface 11b side of the pair of flat surfaces 110 of the steel body 11 of the angle steel is set as the ultraviolet protection layer forming region A4, and the set ultraviolet protection layer is formed. The construction target area A2 is set in a range wider than the area A4, and the surface is adjusted to provide the base layer 13. Next, as shown in FIG. 7B, the resin layer 14 is provided on the base layer 13. Next, as shown in FIG. 7C, after applying the epoxy impregnated adhesive to the resin layer 14, a pair of UV protection sheets forming the UV protection layer 15 are formed from the front surface side 11a to the back surface side 11b of the pair of flat surface portions 110. It is folded back from the front surface 11a side to the back surface 11b side at both ends of the flat surface portion 110 and attached to the steel material main body 11. As a result, the rust preventive repair portion 12 is provided on the surface 11a side of the steel body 11 of the angle steel from the end portion of one flat surface portion 110 to the end portion of the other flat surface portion 110 via the corner portion 120. The folded-back portion 12A is provided at the end portion on the back surface 11b side.

FIG. 8 is a diagram showing another example of construction of the rust preventive repair steel material 1 according to the present embodiment. As shown in FIG. 8, the rust preventive repair portion 12 of the rust preventive repair steel material 1 may be provided on the back surface 11b side of the steel material 11 of the angle steel. In this case, the UV protection sheet constituting the UV protection layer 15 is folded back from the back surface 11b side to the front surface 11a side at both ends of the pair of flat surface portions 110 and attached to the steel material main body 11. As a result, the rust preventive repair portion 12 is provided on the back surface 11b side of the steel body 11 of the angle steel from the end portion of one flat surface portion 110 to the end portion of the other flat surface portion 110 via the corner portion 120. It has a folded portion (not shown) at the end on the surface 11a side. Even when the construction is performed in this way, it is possible to prevent moisture and air from coming into contact with the surface of the steel body 11 from the back surface 11b side of the steel body 11, so that further corrosion of the steel body 11 can be prevented. ..

FIG. 9 is an example showing a construction example in the UV protection layer forming step ST15. As described above, in the ultraviolet layer forming step ST15, the epoxy impregnated adhesive applied on the resin layer 14 is applied, and then the ultraviolet protection layer 15 is attached onto the resin layer 14. Here, the epoxy resin or the like used as an adhesive may have a low curing reaction rate at a low temperature (for example, 5 ° C. or lower), making it difficult to attach the UV protection sheet or the like of the UV protection layer 15. .. In this case, as shown in FIG. 9, after covering the construction target area of the steel body 11 with the bubble wrap 200, the heating elements 201A, 201B and 201C are fixed in the vicinity of the construction target area of the steel body 11. Examples of the heating elements 201A, 201B and 201C include disposable body warmers and the like. As a result, for example, even when the rust preventive repair portion 11A is applied to the steel body 11 arranged outdoors in winter, the construction target area of the steel body 11 can be kept above a desired temperature, which is efficient. The UV protection layer 15 can be attached. The surface temperature of the steel body 11 can be appropriately adjusted by adjusting the intervals between the heating elements 201A, 201B and 201C.

As described above, according to the above embodiment, the resin layer 14 can prevent oxygen, moisture, and dust in the atmosphere from coming into contact with the surface of the steel body 11, and thus the progress of corrosion of the steel body 11 due to rust. Can be prevented. Since the ultraviolet protection layer 15 is provided on the resin layer 14, the ultraviolet protection layer 15 can prevent the resin layer 14 from being irradiated with ultraviolet rays by reflecting or absorbing it. As a result, the rust preventive repair effect of the steel body 11 can be obtained by a construction method substantially similar to that of painting, so that the rust preventive repair can be performed in a short period of 2 to 3 days. Further, since the design period associated with the repair work and the labor and material costs associated with the large-scale construction are not required, the rust preventive repair can be performed at low cost. Therefore, as a rust preventive repair method for steel materials, it is possible to realize a rust preventive repair method for steel materials that can inexpensively repair corroded steel materials in a short period of time.

Further, according to the above embodiment, the resin layer 14 is in close contact with the steel material body 11, and the film thickness of the resin layer 14 can be increased as compared with general coating. Oxygen, moisture and dust in the atmosphere can be efficiently blocked from the surface. Since it is not necessary to replace the members of the corroded steel body 11, the labor and material costs associated with the advanced design and large-scale construction associated with the replacement of the members are not required. Moreover, since the construction can be completed within a power outage period of 2 to 3 days, the work can be performed in a short period of time. Furthermore, since construction can be carried out using materials and equipment that can be transported manually, even when construction is performed on existing steel materials, high construction costs such as helicopter transportation are not incurred, and compressors, generators, etc. No large equipment is required. In addition, there is no need for a construction preparation period such as securing the construction site required for construction, negotiations with landowners to secure the construction site, and cutting down trees, and repairs can be made inexpensively in a short time after the discovery of the repair target site. ..

Further, according to the above embodiment, since the corrosion resistance and the wear resistance of the rust preventive repair portion 11 can be made extremely high, defects due to scratches and the like are less likely to cause corrosion, and repainting is also performed again for cleaning work. It doesn't take time to do it. In addition, it can be installed even when rust remains, and since the rust preventive repair portion 11 and the steel body 11 have high adhesion, corrosion factors such as water and oxygen are not supplied to the surface of the steel body 11 and rust is prevented. Occurrence and development are suppressed, and construction is possible even when rust remains.

Hereinafter, examples carried out for clarifying the effects of the present invention will be described. The present invention is not limited to the following examples and comparative examples.

The present inventors prepared a rust-preventive treated steel material to which the rust-preventive repair method for the steel material according to the above-described embodiment was applied, and carried out a corrosion acceleration test to evaluate the rust-preventive effect. In the following examples, the rust-preventive steel material is a rust-preventive steel material in which the entire surface of one flat surface portion 110A is subjected to rust-preventive treatment and a part of the surface of the other flat surface portion 110B is subjected to rust-preventive treatment. A (see FIG. 10A), rust-preventive steel material B (see FIG. 10B) in which the entire surfaces of one flat surface portion 110A and the other flat surface portion 110B are subjected to rust-preventive treatment, one flat surface portion 110A, and the other flat surface portion 110B. A rust-preventive steel material C (see FIG. 10C) was prepared by subjecting all surfaces of the corner 120 to a rust-preventive treatment and folding the end portion of the flat surface portion of the carbon fiber reinforced resin back.

<Corrosion acceleration test>
Corrosion acceleration tester (model number: "BQD-2 type", manufactured by Itabashi Rika Kogyo Co., Ltd.) Corrosion acceleration test was conducted in accordance with JASO M 609-91. A 35% sodium chloride aqueous solution is sprayed at a temperature of 35 ° C. ± 1 ° C. for 2 hours, dried at a temperature of 60 ° C. ± 1 ° C. and a humidity of 30% RH for 4 hours, and then dried at a temperature of 50 ° C. ± 2 ° C. and a humidity of 95 RH%. It was moistened under the above conditions. One cycle consisting of the above three steps was carried out for 360 cycles (corresponding to 22 years in the Tokyo area), and the following evaluations were carried out.

(Observation of surface condition)
The steel materials before and after the corrosion acceleration test were observed with a magnifying glass, and deformation and abnormal swelling were evaluated according to the following criteria.
◯: No deformation or abnormal swelling ×: Deformation or abnormal swelling

(Observation of cross-sectional condition)
The cross section of the steel material before and after the corrosion acceleration test was observed with a microscope to confirm the state of internal corrosion, and evaluated according to the following criteria.
◯: Rust progress and no swelling ×: Rust progress or swelling

(Coating film adhesion)
The adhesive strength of the steel material before and after the corrosion acceleration test was measured with an adhesion tester (model number: "KH-AT-A AT11163", manufactured by DeFelsko) to confirm the adhesion between the steel material and the carbon fiber reinforced resin, and the following Evaluated by criteria.
◯: No decrease in adhesive force △: There is a decrease in adhesive force

(Observation of surface peeling)
The carbon fiber reinforced resin and the polyurea resin were removed from the steel material after the corrosion acceleration test, and the surface of the steel material was observed with a microscope.
○: No progress of rust ×: Progress of rust

(Comprehensive evaluation)
The results of surface condition observation, cross-sectional condition observation, coating film adhesion and surface peeling observation were evaluated according to the following criteria.
⊚: All evaluations are good ○: Evaluations other than adhesive strength are good ×: Surface condition evaluation is poor

(Example 1)
After applying 2 types of kelen treatment (see Fig. 12A) to the steel material of equilateral angle steel (member deterioration level A (see Fig. 11A): total surface corrosion), a primer (trade name: "FP-UL1", Nittetsu Chemical & Co., Ltd. (Manufactured by Material Co., Ltd.) was applied and dried at 23 ° C. for 3 hours to provide a primer layer. Next, after applying a polyurea resin (trade name: "FU-Z", manufactured by Nittetsu Chemical & Materials Co., Ltd.), it was cured at 23 ° C. for 12 hours to provide a resin layer, and then an epoxy-impregnated adhesive (commodity). Name: "FR-E9P", manufactured by Nittetsu Chemical & Material Co., Ltd.) is applied on the resin layer to form a carbon fiber sheet (trade name: "FTS-C8-30", manufactured by Nittetsu Chemical & Material Co., Ltd.). Impregnated and adhered. After that, after defoaming the carbon fiber sheet, a fluorine-based paint (trade name: "Bonflon steel tower topcoat # 2200", manufactured by AGC Cortec Co., Ltd.) is applied on the resin layer to provide a topcoat layer to prevent rust. A treated steel material was prepared. The evaluation results are shown in Table 1 below.

(Example 2)
Same as in Example 1 except that the steel material of equilateral angle steel (member deterioration level B (see FIG. 11B): slight corrosion under coating) was used instead of the steel material of equilateral angle steel (member deterioration level A). Made a rust-preventive treated steel material. The evaluation results are shown in Table 1 below.

(Example 3)
Same as in Example 1 except that the steel material of equilateral angle steel (member deterioration level C (see FIG. 11C): slight corrosion under the coating film) was used instead of the steel material of equilateral angle steel (member deterioration level B). Made a rust-preventive treated steel material. The evaluation results are shown in Table 1 below.

(Example 4)
A rust-preventive treated steel material was prepared in the same manner as in Example 1 except that the keren treatment was changed to a type 2 light keren treatment (see FIG. 12B). The evaluation results are shown in Table 1 below.

(Example 5)
A rust-preventive treated steel material was prepared in the same manner as in Example 2 except that the keren treatment was changed to the type 2 light keren treatment. The evaluation results are shown in Table 1 below.

(Example 6)
A rust-preventive treated steel material was prepared in the same manner as in Example 3 except that the keren treatment was changed to the type 2 light keren treatment. The evaluation results are shown in Table 1 below.

(Example 7)
A rust-preventive treated steel material was prepared in the same manner as in Example 1 except that the keren treatment was changed to the type 3 keren treatment (see FIG. 12C). The evaluation results are shown in Table 1 below.

(Example 8)
A rust-preventive treated steel material was prepared in the same manner as in Example 2 except that the keren treatment was changed to the type 3 keren treatment. The evaluation results are shown in Table 1 below.

(Example 9)
A rust-preventive treated steel material was prepared in the same manner as in Example 3 except that the keren treatment was changed to the type 3 keren treatment. The evaluation results are shown in Table 1 below.

(Comparative Example 1)
It was evaluated by conducting a corrosion acceleration test without rust prevention treatment. The evaluation results are shown in Table 1 below.

As can be seen from Table 1, in the rust-preventive treated steel materials A, B, and C to which the rust-preventive repair method for the steel material according to the above embodiment has been applied, the surface condition can be observed by performing two or more types of slight or more cleansing treatment. It can be seen that good results can be obtained in all of the cross-sectional state observation, the adhesive force measurement and the surface peeling observation (Examples 1 to 9). In particular, when observing the surface condition, no floating, peeling, or rust was observed. Although the rust remaining on the old coating film surface and the old coating film were not completely removed by the type 2 light keren, no swelling due to the progress of rust was observed even after the accelerated test. It can be seen that the resin layer and the carbon fiber reinforced resin layer, which are overwhelmingly stronger and thicker than the coating film, can prevent the ingress of water and oxygen. Further, it can be seen that even if the three types of kelen treatment are applied, good results can be obtained except for the adhesion measurement. From these results, it can be seen that according to the above embodiment, the infiltration of water and oxygen can be prevented by the resin layer and the carbon fiber reinforced resin layer, which are overwhelmingly stronger and thicker than the coating film. On the other hand, it can be seen that the steel material not subjected to the rust preventive treatment cannot prevent the corrosion of the steel material surface and the surface condition is remarkably deteriorated (Comparative Example 1).

The present invention has the effect of realizing a rust preventive repair method for steel materials and a rust preventive repair method for steel towers that can inexpensively repair corroded steel materials in a short period of time, and is particularly applicable to various steel towers such as angle steel towers. It can be suitably used as a rust preventive repair method for the steel material used.

1 Anti-corrosion repair steel 11 Steel body 12 Anti-corrosion repair part 13 Base layer 14 Resin layer 15 UV protection layer 16 Protective layer 100 Yamagata steel tower 101 Steel tower body 102 Arm metal material 111 Main pillar material 112 Horizontal material 113 Diagonal material 114 Joint part 121 Arm metal main material 122 Arm metal suspension material 200 Bubble buffer 201 Heat generator

Claims (7)

A base material adjustment process that adjusts the base material of the steel material by cleaning the construction target area of the steel material, and
A primer application step of applying a primer on the construction target area in which the substrate is adjusted to provide a base layer, and
A resin coating step of applying a resin on the base layer to provide a resin layer for preventing the permeation of moisture and oxygen to the surface of the steel material, and a resin coating step.
An adhesive application step of applying an adhesive on the resin layer and
An ultraviolet protection layer forming step of providing an ultraviolet protection layer on the resin layer via the adhesive to prevent the transmission of ultraviolet rays to the resin layer.
A rust preventive repair method for steel materials, which comprises. The rust preventive repair method for a steel material according to claim 1, further comprising a protective layer forming step of providing a protective layer for protecting the ultraviolet protection layer on the ultraviolet protection layer. The rust preventive repair method for a steel material according to claim 1 or 2, wherein the resin is a polyurea resin. The rust preventive repair method for a steel material according to any one of claims 1 to 3, wherein the adhesive is an epoxy-impregnated adhesive. The rust preventive repair method for a steel material according to any one of claims 1 to 4, wherein the ultraviolet protection layer contains a carbon fiber reinforced resin. A base material adjustment process that adjusts the base material of the steel material by cleaning the construction target area of the steel material that constitutes the steel tower, and
A primer application step of applying a primer on the construction target area in which the substrate is adjusted to provide a base layer, and
A resin coating step of applying a resin on the base layer to provide a resin layer for preventing the permeation of moisture and oxygen to the surface of the steel material, and a resin coating step.
An adhesive application step of applying an adhesive on the resin layer and
An ultraviolet protection layer forming step of providing an ultraviolet protection layer on the resin layer via the adhesive to prevent the transmission of ultraviolet rays to the resin layer.
A rust preventive repair method for steel towers, which is characterized by including. Steel body and
The base layer provided in the area including the corroded part on the steel body and
A resin layer provided on the base layer to prevent moisture and oxygen from permeating the surface of the steel material,
An ultraviolet protection layer provided on the resin layer to prevent the transmission of ultraviolet rays to the resin layer,
A rust-preventive repair steel material that is characterized by being equipped with.