JP7200026B2 - Antirust repair method for steel material, antirust repair method for steel tower, and antirust repair steel material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rust preventive repair method for steel, a rust preventive repair method for a steel tower, and a rust preventive repair steel material. The present invention relates to a repair method and a rust-proof repair steel material.

Conventionally, steel towers for power transmission use galvanized steel materials that have been subjected to anti-corrosion treatment by galvanizing. A galvanized steel material wears down the galvanized layer over time and may be corroded by rust or the like. Therefore, a method for repairing a steel material that has corroded due to 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, an antirust pigment, and an epoxy resin curing agent is applied to a corroded steel material to suppress the expansion of rust and prevent galvanization. Suppresses deterioration of steel materials.

JP 2016-56411 A

Corrosion of galvanized steel in steel towers for power transmission causes a decrease in strength, so repairs such as painting, replacement of parts, and thermal spraying of plating are carried out. Painting is a commonly used anticorrosive repair method. In painting, a keren treatment is performed to remove rust from the steel material, but if the corrosion of the steel progresses with almost all the zinc plating gone, corrosion products such as corrosion products and salt will remain even after the keren treatment. Factors cannot be completely removed. Therefore, even if ordinary coating is applied, moisture and oxygen may permeate through minute defects in the coating film, and corrosion may occur from under the coating film.

When replacing a member, 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 move the electric wire. For this reason, member replacement requires a design period and costs such as load consideration, manpower, construction costs, and material costs associated with large-scale construction. In addition, replacement of parts requires preparatory work such as installation of jigs used for replacement of parts and movement of electric wires.

Plating thermal spraying is a technology that solves the problems of painting and component replacement. Plating thermal spraying is a technique to restore worn plating by spraying zinc, aluminum, etc. with a thermal spraying gun after performing a type 1 cleaning treatment by blasting. However, plating thermal spraying requires equipment such as a compressor and power supply equipment used in the blasting method, which entails expensive mechanical damage and transportation of heavy objects. In particular, plating thermal spraying entails extremely high construction costs when transportation by helicopter is required in mountainous areas. In addition, in plating thermal spraying, it is necessary to secure a construction site for 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 that enable rust-preventive repair of steel materials in a short period of time and at low cost. intended to

A steel material rust preventive repair method according to the present invention comprises a surface adjustment step of keren-treating a construction target area of a steel material to adjust the base material of the steel material, and applying a primer onto the construction target area after adjusting the base material. a primer coating step of providing a base layer; a resin coating step of coating a resin on the base layer to form a resin layer that prevents permeation of moisture and oxygen to the surface of the steel material; and applying an adhesive on the resin layer. The method includes an adhesive application step and an ultraviolet prevention layer forming step for providing an ultraviolet prevention layer for preventing transmission of ultraviolet rays to the resin layer on the resin layer via the adhesive.

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

It is preferable that the rust preventive repair method for steel materials according to the present invention further includes a protective layer forming step of forming a protective layer on the ultraviolet preventive layer to protect the ultraviolet preventive layer. By this method, the UV protection layer can be protected by the protective layer, so that the UV protection layer can be prevented from being damaged due to the contact of other substances with the UV protection layer. can be prevented.

In the rust preventive repair method for steel materials according to the present invention, the resin is preferably a polyurea resin. With this method, the highly elastic polyurea resin adheres well to the steel material, and a film thickness of 1 mm or more can be secured. It becomes possible to efficiently protect the surface of the steel material.

In the rust preventive repair method for steel materials according to the present invention, the adhesive is preferably an epoxy-impregnated adhesive. By this method, it becomes possible to efficiently bond the resin layer and the anti-ultraviolet layer.

In the rust preventive repair method for steel materials according to the present invention, it is preferable that the UV protection layer contains a carbon fiber reinforced resin. This method reduces the weight of the UV protective layer and improves the strength, elasticity, corrosion resistance, and wear resistance of the UV protective layer, making it possible to prevent damage to the UV protective layer.

A rust prevention repair method for a steel tower according to the present invention includes a surface adjustment step of adjusting a base material of the steel material by scraping a construction target area of the steel material constituting the steel tower, and a primer on the construction target area after adjusting the base material. a step of applying a primer to provide an underlayer by applying a primer, a step of applying a resin on the underlayer to provide a resin layer that prevents permeation of moisture and oxygen to the surface of the steel material, and a step of bonding on the resin layer and an ultraviolet prevention layer forming step of providing an ultraviolet prevention layer for preventing transmission of ultraviolet rays to the resin layer on the resin layer via the adhesive. .

According to the rust preventive repair method for a steel tower according to the present invention, the resin layer can prevent oxygen, moisture, and atmospheric dust from coming into contact with the surface of the steel material. . Further, since the UV protection layer is provided on the resin layer, the UV protection layer reflects or absorbs the UV rays directed to the resin layer, making it possible to prevent deterioration of the resin layer due to the UV rays. As a result, the anti-corrosion repair effect of the steel material can be obtained by a construction method substantially similar to that of painting, so that the anti-corrosion repair can be performed in a short period of 2 to 3 days. Furthermore, since the design period associated with the repair work and the cost of manpower and materials that may be incurred in large-scale construction work are not required, the rust preventive repair can be performed at a low cost. Therefore, the rust preventive repair method for iron and steel makes it possible to realize a rust preventive repair method for steel capable of performing rust preventive repair on corroded steel materials in a short period of time and at low cost.

The rust preventive repair steel material for a steel tower according to the present invention comprises a steel material body, a base layer provided in a region including a corroded portion on the steel body, and a base layer provided on the base layer to prevent moisture and oxygen on the surface of the steel material. and an ultraviolet prevention layer provided on the resin layer to prevent transmission of ultraviolet rays to the resin layer.

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

ADVANTAGE OF THE INVENTION According to this invention, the rust-preventive repair method of the steel material which can carry out the rust-preventive repair of the steel material in a short period of time at low cost, the rust-preventive repair method of a steel tower, and the rust-preventive repair steel material are realizable.

FIG. 1 is a schematic diagram of an angle-shaped steel tower to which the method for rust-preventive repair of steel materials according to the present embodiment is applied. 2 is a schematic enlarged view of the lower portion of the angle steel tower shown in FIG. 1. FIG. FIG. 3 is a diagram showing an example of a main pillar material to which the method for rust-preventive repair of steel materials 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 method for rust prevention repair of steel materials according to an embodiment of the present invention. FIG. 6A is an explanatory diagram of the rust preventive repair method according to the embodiment of the present invention. FIG. 6B is an explanatory diagram of the rust preventive repair method according to the embodiment of the present invention. FIG. 6C is an explanatory diagram of the rust prevention repair method according to the embodiment of the present invention. FIG. 6D is an explanatory diagram of the rust prevention repair method according to the embodiment of the present invention. FIG. 6E is an explanatory diagram of the rust prevention repair method according to the embodiment of the present invention. FIG. 6F is an explanatory diagram of the rust prevention repair method according to the 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 the 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 the 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 shows an example of construction in the step of forming an anti-ultraviolet layer according to the embodiment of the present invention. FIG. 10A is a diagram showing a rust preventive repair steel material according to an example of the present invention. FIG. 10B is a diagram showing a rust preventive repair steel material according to an example of the present invention. FIG. 10C is a diagram showing a rust preventive repair steel material according to an example of the present invention. FIG. 11A is a photograph showing a steel product of member deterioration level A of an equilateral angle steel according to an example of the present invention. FIG. 11B is a photograph showing a steel product of member deterioration level B of the equilateral angle steel according to the example of the present invention. FIG. 11C is a photograph showing a steel product of member deterioration level C of the equilateral angle steel according to the example of the present invention. FIG. 12A is a photograph showing two types of scraping treatment of an equilateral angle steel according to an example of the present invention. FIG. 12B is a photograph showing the second kind of light chalking treatment of the equilateral angle steel according to the example of the present invention. FIG. 12C is a photograph showing the three types of scraping treatment of the equilateral angle steel according to the example of the present invention.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is by no means limited by the following embodiments.

In the following embodiment, 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 diagram of an angle steel tower to which the steel material rust preventive repair method according to the present embodiment is applied, and FIG. 2 is a schematic enlarged view of the lower part of the angle steel tower shown in FIG. . As shown in FIGS. 1 and 2 , the angle steel tower 100 includes a tower body 101 erected along the height direction from the ground, and arm members 102 horizontally protruding from the tower body 101 . The steel tower body 101 has four main pillars 111 arranged along the height direction from the ground surface to the upper end of the pylon body 101, and a plurality of horizontal members 112 arranged horizontally and connecting the main pillars 111 to each other. Prepare. The main pillars 111 are connected to each other and the main pillars 111 and the horizontal members 112 are connected by a plurality of diagonal members 113 arranged to be inclined with respect to the main pillars 111 and the horizontal members 112 .

The main pillars 111 are formed by overlapping joint portions 114 provided at the ends of a plurality of angle irons arranged at a predetermined angle with respect to the ground and joining them with bolts and nuts. The lowermost main pillar member 111 has a joint portion 114 at one end projecting upward, and the other end portion is embedded and fixed in a concrete foundation (not shown).

The cross arm members 102 are composed of a pair of left and right cross arm main members 121 projecting in the horizontal direction from the steel tower body 101, and a pair of left and right cross arm suspensions arranged obliquely between the steel tower body 101 and the tip of the cross arm main member 121. material 122; The cross arm suspension member 122 connects the tower main body 101 and the tip of each cross arm main member 121 .

FIG. 3 is a diagram showing an example of the main pillar material 111 to which the steel material rust preventive repair method according to the present embodiment is applied. In the example shown in FIG. 3, a part of the main column material 111 has the rust preventive repair steel material 1 which is subjected to the rust preventive repair method according to the present embodiment. This rust preventive repair steel material 1 is provided across two main pole members 111a and 111b via a joint portion 114. As shown in FIG. The antirust 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 this embodiment. As shown in FIG. 1 , the rust preventive repair steel material 1 includes a steel material body 11 to be subjected to rust preventive treatment, and a rust preventive repair portion 12 provided on the steel material body 11 . The rust prevention 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. 15 and a protective layer 16 provided thereon. In addition, in the rust-proof repair steel material 1, the protective layer 16 does not necessarily need to be provided, and can be omitted as necessary.

As the steel main body 11, a material that causes corrosion such as rust due to wind and rain is used. As the steel material main 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. Steel materials made of various metals such as iron and steel are used as the steel material main body 11 . Further, as the steel material main body 11, a plated steel material having a plating layer provided on the surface thereof by plating may be used, or an untreated steel material may be used. Among these, as the steel material body 11, a galvanized steel material having a galvanized layer, which is used for a steel tower or the like, is preferably used. In this case, the galvanized steel material may have a galvanized layer, or may have a galvanized layer that has disappeared due to corrosion due to rust, etc., and has rust on the surface. The steel material body 11 may be an existing steel material used for a structure such as a steel tower, or may be a single steel material body 11 before being used for a structure. As the steel main body 11, one used in a structure such as a steel tower for power transmission and having a surface already corroded by rust or the like may be used, or an unused one without corrosion may be used. When using a steel material with rust on the surface as the steel material main body 11, the surface rust and coating are removed by keren treatment or the like before use.

The base layer 13 is applied to the surface of the steel body 11 to smoothen the surface of the steel body 11 to which the steel repair portion 12 is applied, thereby improving the adhesiveness between the steel body 11 and the resin layer 14. do. The base layer 13 is provided by applying a primer containing a base agent and a curing agent in a predetermined ratio to the surface of the steel body 11 and curing the primer. As the primer for the base layer 13, for example, an epoxy-modified urethane resin (for example, product name: "FP-UL1", manufactured by Nippon Steel Chemical & Materials Co., Ltd.) is used. The thickness of the underlying 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 to water, salt, and oxygen with respect to the surface of the steel body 11, and prevents contact between the surface of the steel body 11 and water, salt, and oxygen. In addition, the resin layer 14 has impact resistance and abrasion resistance, and protects the steel body 11 from impact and abrasion. Furthermore, the resin layer 14 smoothes the uneven surface of the steel main body 11 to be applied, if the joint portion 114 or the like has a uneven surface. The resin layer 14 contains resin such as polyurea resin, polyurethane resin, silicone resin, for example. 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 should be 0.1 mm or more and less than 5 mm from the viewpoint of reducing the permeability of the surface of the steel body 11 to water, salt, and oxygen, and from the viewpoint of impact resistance and abrasion resistance of the steel body 11. , more preferably 0.5 mm or more and less than 1.2 mm, and even more preferably 0.8 mm or more and less than 0.9 mm.

The anti-ultraviolet layer 15 absorbs or reflects ultraviolet rays or the like with respect to the resin layer 14 and protects the resin layer 14 from deterioration due to ultraviolet rays. The UV protection layer 15 is not particularly limited as long as it can absorb or reflect UV rays to the resin layer 14 . As the ultraviolet protection layer 15, for example, a fiber-reinforced resin sheet obtained by reinforcing a base material resin with fibers or a fiber-reinforced sheet before being impregnated with resin is used. By using a fiber-reinforced resin sheet (including a fiber-reinforced sheet impregnated with a resin) as the UV-blocking layer 15 , the UV-blocking layer 15 is adhered onto the resin layer 14 via an adhesive. can be provided. Note that the fiber-reinforced sheet becomes a fiber-reinforced resin by impregnating it with an adhesive. In addition, the anti-ultraviolet layer 15 is made of a member having abrasion resistance and impact resistance, and thus plays a role of protecting the resin layer 14 when cleaning is performed during repainting.

The fiber-reinforced resin is not particularly limited as long as it can absorb or reflect ultraviolet rays to the resin layer 14. Examples include glass-fiber-reinforced plastics (GFRP) and carbon fiber-reinforced resin (CFRP). -Fiber-Reinforced Plastics), boron fiber-reinforced plastics (BFRP), aramid fiber-reinforced plastics (AFRP), and polymer fiber-reinforced resins. Among these, carbon fiber reinforced resins are preferable from the viewpoint of light weight, high strength, high elasticity, high corrosion resistance, insulating properties, high abrasion 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, the PAN-based carbon fiber reinforced resin and the pitch-based carbon fiber reinforced resin are preferred, and the pitch-based carbon fiber reinforced resin is more preferred, from the viewpoint of superior wear resistance. In addition, as the carbon fiber reinforced resin, a carbon fiber reinforced resin sheet (including a carbon fiber reinforced sheet impregnated with a resin) is used from the viewpoint that the ultraviolet protection layer 15 can be provided on the resin layer 14 by adhesion. preferable. As the carbon fiber reinforced resin, for example, trade name: "Tow Sheet" manufactured by Nippon Steel Chemical & Materials Co., Ltd. is used.

The protective layer 16 prevents the UV protection layer 15 from permeating moisture and oxygen and protects it from UV rays. As the protective layer 16, for example, a fluorine-based paint (trade name: “Bonflon Steel Tower Top Coat #2200”, manufactured by AGC Coatec Co., Ltd.) is used. The thickness of the protective layer 16 is, for example, 40 μm or more from the viewpoint of protecting the UV protection layer 15 from moisture, oxygen, and UV rays. The rust preventive repair method according to the present embodiment will be described in detail below.

FIG. 5 is a flow chart showing an outline of a method for rust prevention repair of steel materials according to an embodiment of the present invention. As shown in FIG. 5, the method of repairing rust for a steel material according to the present embodiment, for example, when corrosion such as rust occurs in a galvanized steel material that has been subjected to galvanizing treatment, such as a steel tower for power transmission, By applying it to the area including the corroded part where rust etc. have occurred, further progress of rust in the corroded part is prevented. The steel material rust preventive repair method according to the present embodiment includes a surface preparation step ST11 in which the surface of the steel main body 11 to be constructed is adjusted by scraping, and a primer is applied on the steel main body 11 whose surface has been adjusted. A primer coating step ST12 for providing a base layer 13, a resin coating step ST13 for coating a resin on the base layer 13 to form a resin layer 14, an adhesive coating step ST14 for coating an adhesive on the resin layer 14, and an adhesive. and an ultraviolet prevention layer forming step ST15 for providing an ultraviolet prevention layer 15 on the resin through the . Each step will be described in detail below.

6A to 6F are explanatory diagrams of the rust preventive repair method according to the present embodiment. As shown in FIG. 6A, the steel main body 11 to be subjected to construction has a corroded area A1 corresponding to a corroded portion 11A in which corrosion such as rust occurs on the surface. As shown in FIG. 6B, in the substrate adjustment step ST11, the substrate of the construction target area A2 on the surface of the steel body 11 is adjusted. The construction target area A2 is preferably set to a range wider than the corroded area A1 of the corroded portion 11A including rust and the like occurring in the steel material body 11 . As a result, lifting of the ends of the steel material repaired portion 12 after the UV protection layer 15 is provided can be prevented, and the steel material repaired portion 12 and the steel material main body 11 can be brought into close contact with each other more reliably. Further, in the step of attaching the UV protection layer 15, which will be described later, for example, even when the UV protection sheet is folded back at the end of the steel material body 11 to provide the UV protection layer 15, the UV protection sheet of the UV protection layer 15 It is possible to prevent the anti-ultraviolet layer 15 from floating due to its elasticity. From the viewpoint of further improving the effect described above, the construction target area A2 preferably includes an area A3 that is 10 mm or more wider than the end of the corroded portion 11A in addition to the corroded area A1, and may include an area A3 that is 20 mm or more wider than the end of the corroded portion 11A. More preferably, it includes a range A3 that is 30 mm or more wide, and from the viewpoint of shortening the construction time, preferably includes a range A3 that is 60 mm or less from the end of the corroded portion 11A, and includes a range A3 that is 50 mm or less. is more preferable, and it is even more preferable to include a range A3 of 40 mm or less.

In the substrate adjustment step ST11, the substrate is adjusted by, for example, keren treatment. In the keren treatment, rust, dust, and dirt are removed with electric tools or hand tools. The cleaning treatment may be any one of 1st cleaning treatment, 2nd cleaning treatment, 2nd mild cleaning treatment and 3rd cleaning treatment. In the present embodiment, the first cleaning treatment is a cleaning treatment that completely removes rust and paint using a blasting method, acid cleaning, and a stripping agent, and the second cleaning treatment is an electric cleaning such as a disk sander. It is a scraping treatment that completely removes rust using a tool, the second kind of light scraping treatment is a scraping treatment that removes only fragile rust with an electric tool such as a wire cup, and the third scraping is a scraping treatment that removes rust and floats. It is a scraping treatment that removes rust from the paint film using hand tools such as wire brushes, scrapers, scraping sticks, and sandpaper. According to the present embodiment, there is no need to perform the first-class cleaning treatment, which is expensive in construction cost, and the rust prevention treatment of steel materials is realized even with the second-class cleaning treatment, the second-class light cleaning treatment, and the third-class cleaning treatment, which are inexpensive in construction cost. can do.

In the primer application step ST12, as shown in FIG. 6C, a base layer 13 is provided by applying a primer onto the construction target area A2 on the steel material body 11 whose substrate has been adjusted in the substrate adjustment step ST11. In the primer application step ST12, rust and dust on the application 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, the base layer 13 is provided by uniformly applying a primer prepared by mixing a main agent and a hardening agent in a predetermined mixing ratio in advance on the steel material body 11 whose base material has been adjusted, and then drying the primer for a predetermined time. Here, the underlying layer 13 after drying may be smoothed with sandpaper or the like, if necessary.

In the resin application step ST13, as shown in FIG. 6D, a resin layer 14 is provided by applying resin onto the base layer 13. As shown in FIG. Thereby, the resin layer 14 as a highly elastic layer can be provided on the construction target area A<b>2 of the steel material body 11 . In the resin coating step ST13, a curable resin obtained by mixing a main agent and a curing agent in a predetermined mixing ratio in advance is uniformly coated on the base layer 13 . Here, it is preferable that the level difference of the resin after coating is within 1 mm.

In addition, 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 area A2 of the steel main body 11 that is the construction target. As a result, it is possible to prevent contact between the anti-ultraviolet layer 15 of the rust prevention repair portion 1 and 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 anti-ultraviolet layer 15 It is possible to prevent corrosion based on the potential difference due to the electrical connection between and other conductive members. The predetermined range is preferably, for example, 10 mm or more and 100 mm or less from the end 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 coated and before the resin is cured. Here, for example, at the stepped portion 114A (see FIG. 3) generated at the joint portion 114 of the steel material body 11, it is preferable to apply thick resin to eliminate the step between the stepped portions 114A. As a result, since the rust prevention repair portion 11 can be provided across the plurality of steel bodies 11 via the joint portion 114, the space between the plurality of steel bodies 11 can be continuously repaired.

In the resin coating step ST13, a drying process is performed for a predetermined time after coating the resin. 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 UV protection layer 15 is provided, bending of the UV protection layer 15 can be prevented and the UV protection layer 15 can be adhered to the resin layer 14 without gaps. In particular, when angle iron is used as the steel main body 11, the corners 120 become excess when the resin layer 14 is applied, so it is preferable to shape the surface of the resin layer 14.

An adhesive is applied onto the resin layer 14 in the adhesive application step ST14. In the adhesive application step ST14, an epoxy-impregnated resin mixed with the dried resin layer 14 at a predetermined ratio is applied onto the resin layer 14. As shown in FIG. Here, it is preferable to apply the epoxy-impregnated adhesive over a wider area than the surface on which the UV protection layer 15 is formed. Further, by increasing the coating amount of the epoxy-impregnated adhesive on the resin layer 14, it is possible to facilitate degassing after the UV-blocking layer 15 is provided. In particular, when angle iron is used as the steel body 11, the epoxy-impregnated adhesive can prevent air bubbles from remaining on the corners 120 by increasing the coating amount on the corners 120 from that on the flat surfaces.

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 anti-corrosion repair steel material 1 can block ultraviolet rays in light rays reaching the surface of the resin layer 14 by the ultraviolet prevention layer 15, so deterioration of the resin layer 14 can be suppressed. The UV protection layer 15 is not particularly limited as long as it can block UV rays, and various fiber reinforced resins, carbon fiber reinforced resins, and the like described above can be used. Moreover, as the ultraviolet protection layer 15, not only a sheet made of fiber-reinforced resin but also a fiber-reinforced sheet before being impregnated with resin can be used. Among these, by using a carbon fiber reinforced resin, the strength of the steel main body 11 that has been reduced in thickness by corrosion can be recovered.

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

In the cutting process of the sheet, the upper and lower ends of the UV protection layer 15 are fixed to a fixing member such as a plywood board with a 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 can be prevented by fixing the UV protection layer 15 to the fixing member with masking tape. be able to.

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

In the UV protection layer forming step ST15, for example, at the joint 114 to which the steel body 11 is connected, it is preferable to overlap the ends of the UV protection layers 15 with each other.

Next, in the UV protection layer forming step ST15, the UV protection layer 15 having the UV protection sheet stuck on the resin layer 14 is pressed with a roller or the like to remove air bubbles interposed between the UV protection layer 15 and the resin layer 14. is extruded to defoam. Thereby, the UV protection layer 15 and the resin layer 14 can be brought into close contact with each other.

Next, a protective layer 16 is formed on the UV protection layer 15 by applying a resin such as an epoxy-impregnated adhesive onto the UV protection layer 15 . Here, defoaming treatment may be performed by pressing the protective layer 16 with a roller or the like, if necessary. As a result, the protective layer 16 can be further provided on the UV blocking layer 15, so that the UV blocking layer 15 can be protected from permeation of moisture and oxygen, and the resin layer 14 can be protected from UV rays. Note that the protective layer 16 does not necessarily have to be provided.

7A to 7C are diagrams showing an example of construction of the rust preventive repair steel material 1 according to the present embodiment. In the example shown in FIGS. 7A to 7C, the rust-preventive repair steel material 1 is provided with the rust-preventive repair portions 12 folded back at both end portions of a pair of flat portions 111 of the steel material 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 portions 110 of the steel body 11 of the angle iron is set as an ultraviolet prevention layer forming area A4, and the set ultraviolet prevention layer formation is performed. A construction target area A2 is set in a range wider than the area A4, and the base layer 13 is provided after surface adjustment. Next, as shown in FIG. 7B, a resin layer 14 is provided on the underlying layer 13 . Next, as shown in FIG. 7C, after applying an epoxy-impregnated adhesive to the resin layer 14, a pair of UV protection sheets constituting the UV protection layer 15 are applied from the front side 11a to the back side 11b of the pair of flat portions 110. Then, as shown in FIG. Both ends of the plane portion 110 are folded back from the front surface 11a side to the back surface 11b side and adhered to the steel material main body 11 . As a result, the rust prevention repair portion 12 is provided on the surface 11a side of the steel main body 11 of the angle steel from the end of one flat portion 110 to the end of the other flat portion 110 via the corner 120, It has a folded portion 12A at the end 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 prevention repair portion 12 of the rust prevention repair steel material 1 may be provided on the back surface 11b side of the steel material 11 of the angle iron. In this case, the anti-ultraviolet sheet constituting the anti-ultraviolet layer 15 is attached to the steel main body 11 by folding back from the back surface 11b side to the front surface 11a side at both ends of the pair of flat portions 110 . As a result, the rust prevention repair portion 12 is provided on the back surface 11b side of the steel main body 11 of the angle steel from the end of one flat portion 110 to the end of the other flat portion 110 via the corner 120, It has a folded portion (not shown) at the end on the surface 11a side. Even in the case of construction in this way, it is possible to prevent moisture and air from contacting the surface of the steel body 11 from the rear surface 11b side of the steel body 11, so 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 UV layer forming step ST15, the resin layer 14 is coated with the epoxy-impregnated adhesive, and then the UV protection layer 15 is adhered onto the resin layer 14 . Here, the epoxy resin or the like used as the adhesive may slow down the curing reaction rate at low temperatures (for example, 5° C. or lower), making it difficult to attach the UV-blocking sheet of the UV-blocking layer 15 . . In this case, as shown in FIG. 9, after covering the target area of the steel body 11 with a bubble cushioning material 200, heating elements 201A, 201B and 201C are fixed near the target area of the steel body 11. FIG. Examples of the heating elements 201A, 201B and 201C include disposable body warmers. As a result, for example, even when the rust preventive repair portion 11A is applied to the steel body 11 placed outdoors in winter, the area to be repaired of the steel body 11 can be maintained at a desired temperature or higher, so that the temperature can be efficiently maintained. An anti-ultraviolet layer 15 can be applied. The surface temperature of the steel main body 11 can be appropriately adjusted by adjusting the intervals among the heating elements 201A, 201B and 201C.

As described above, according to the above-described embodiment, the resin layer 14 can prevent the surface of the steel body 11 from coming into contact with oxygen, moisture, and dust in the atmosphere. can be prevented. Since the UV protection layer 15 is provided on the resin layer 14, the UV protection layer 15 can reflect or absorb the irradiation of UV rays to the resin layer 14 to prevent it. As a result, the rust prevention repair effect of the steel material body 11 can be obtained by a construction method substantially similar to that of painting, so that the rust prevention repair can be performed in a short period of 2 to 3 days. Furthermore, since the design period associated with the repair work and the manpower and material costs associated with the large-scale construction are not required, the rust preventive repair can be performed at a low cost. Therefore, the rust preventive repair method for steel materials can 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-described embodiment, the resin layer 14 is in close contact with the steel 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 effectively blocked from the surface. Further, since it is not necessary to replace the corroded steel main body 11, labor and material costs associated with high-level design and large-scale construction associated with the replacement of members are not required. In addition, construction can be completed within a power outage period of 2 to 3 days, so work can be completed in a short period of time. Furthermore, since construction can be done using materials and equipment that can be manually transported, even when construction is performed on existing steel materials, expensive construction costs such as helicopter transport are not incurred, and compressors and generators are not required. No need for large equipment. In addition, there is no need to prepare for construction, such as securing the construction site necessary for construction, negotiating with landowners to secure the construction site, and cutting down trees. .

In addition, according to the above-described embodiment, the corrosion resistance and wear resistance of the rust preventive repair portion 11 can be extremely high, so that defects due to scratches etc. are unlikely to cause corrosion, and repainting work can be performed again. It doesn't take much time to do it. In addition, the work can be performed even when rust remains, and since the adhesion between the rust preventive repair portion 11 and the steel material body 11 is high, corrosive factors such as water and oxygen are not supplied to the surface of the steel material body 11, preventing rust from forming. The occurrence and development are suppressed, and construction is possible even in a state where rust remains.

EXAMPLES Examples carried out to clarify the effects of the present invention will be described below. In addition, the present invention is not limited at all by the following examples and comparative examples.

The present inventors prepared rust-preventive treated steel materials subjected to the rust-preventive repair method for steel materials according to the above-described embodiments, and conducted corrosion acceleration tests to evaluate the rust-preventive effect. In the following examples, the rust-preventive treated steel material is a rust-preventive treated steel material in which the entire surface of one flat portion 110A is subjected to anti-rust treatment, and the other flat portion 110B is partially subjected to anti-rust treatment. A (see FIG. 10A), antirust treated steel material B (see FIG. 10B) in which antirust treatment is applied to the entire surfaces of one flat portion 110A and the other flat portion 110B, one flat portion 110A, and the other flat portion 110B and antirust-treated steel material C (see FIG. 10C) in which the entire surface of the corner portion 120 is subjected to antirust treatment and the end of the flat portion of the carbon fiber reinforced resin is folded back.

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

(Surface condition observation)
The steel materials before and after the accelerated corrosion test were observed with a loupe, and deformation and abnormal swelling were evaluated according to the following criteria.
○: No deformation or abnormal swelling ×: Deformation or abnormal swelling

(Cross-section observation)
The cross section of the steel material before and after the accelerated corrosion test was observed with a microscope to confirm the state of internal corrosion, and the results were evaluated according to the following criteria.
○: No progress of rust and no blistering ×: Progress of rust or blistering

(Paint film adhesion)
The adhesion of the steel before and after the accelerated corrosion test was measured with an adhesion tester (model number: "KH-AT-A AT11163", manufactured by DeFelsko) to confirm the adhesion between the steel and the carbon fiber reinforced resin. evaluated according to the standard.
○: No decrease in adhesion △: Decrease in adhesion

(Observation of surface peeling)
Carbon fiber reinforced resin and polyurea resin were removed from the steel material after the accelerated corrosion 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 state observation, cross-sectional state observation, paint film adhesion and surface peeling observation were evaluated according to the following criteria.
◎: All evaluations are good ○: Evaluations other than adhesion are good ×: Evaluation of surface condition is poor

(Example 1)
Equal angle steel (member deterioration level A (see Fig. 11A): total surface corrosion) was subjected to two types of keren treatment (see Fig. 12A), and then primer (product name: “FP-UL1”, Nippon Steel Chemical & Material Co., Ltd.) was applied and dried at 23° C. for 3 hours to form a primer layer. Next, after applying polyurea resin (product name: "FU-Z", manufactured by Nippon Steel Chemical & Materials Co., Ltd.), it is cured at 23°C for 12 hours to form a resin layer. name: "FR-E9P", manufactured by Nippon Steel Chemical & Material Co., Ltd.) is applied on the resin layer, and a carbon fiber sheet (product name: "FTS-C8-30", manufactured by Nippon Steel Chemical & Material Co., Ltd.) is applied. Impregnated and adhered. After that, after defoaming the carbon fiber sheet, a fluorine-based paint (trade name: “Bonflon tower topcoat #2200” manufactured by AGC Cortec Co., Ltd.) is applied on the resin layer to form a topcoat layer to prevent rust. Treated steel was created. The evaluation results are shown in Table 1 below.

(Example 2)
The same as in Example 1 except that the steel material of the equal-angle steel (deterioration level B of the member (see FIG. 11B): slight corrosion under the coating film) was used instead of the steel material of the equal-angle steel (deterioration level A of the member). A rust-proof treated steel material was created by The evaluation results are shown in Table 1 below.

(Example 3)
The procedure was the same as in Example 1, except that instead of the equal-legged angle steel (member deterioration level B), the equal-legged angle steel (member deterioration level C (see FIG. 11C): slight corrosion under the coating film) was used. A rust-proof treated steel material was created by The evaluation results are shown in Table 1 below.

(Example 4)
A rust-proof treated steel material was produced in the same manner as in Example 1, except that the cleaning treatment was changed to the second kind of light cleaning treatment (see FIG. 12B). The evaluation results are shown in Table 1 below.

(Example 5)
A rust-proof treated steel material was produced in the same manner as in Example 2, except that the cleaning treatment was changed to a class 2 light cleaning treatment. The evaluation results are shown in Table 1 below.

(Example 6)
A rust-proof treated steel material was produced in the same manner as in Example 3, except that the cleaning treatment was changed to the second kind of light cleaning treatment. The evaluation results are shown in Table 1 below.

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

(Example 8)
A rust-proof treated steel material was produced in the same manner as in Example 2, except that the cleaning treatment was changed to the 3-kind cleaning treatment. The evaluation results are shown in Table 1 below.

(Example 9)
A rust-proof treated steel material was produced in the same manner as in Example 3, except that the cleaning treatment was changed to a three-kind cleaning treatment. The evaluation results are shown in Table 1 below.

(Comparative example 1)
An accelerated corrosion test was performed without antirust treatment and evaluated. 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, which were subjected to the rust-preventive repair method for steel materials according to the above-described embodiment, by performing two or more light cleaning treatments, the surface condition observation, It can be seen that good results are obtained in all of the cross-sectional state observation, adhesion measurement, and surface peeling observation (Examples 1 to 9). In particular, observation of the surface state did not reveal any floating, peeling, or rusting. Although the rust remaining on the surface of the old paint film and the old paint film were not completely removed by the second kind of light cleaning, blistering due to progress of rust was not observed even after the accelerated test. It can be seen that the penetration of water and oxygen can be prevented by the resin layer and the carbon fiber reinforced resin layer, which are extremely strong and thick compared to the coating film. In addition, it can be seen that good results can be obtained except for adhesion measurement even if three kinds of cleaning treatments are performed. From these results, it can be seen that, according to the above-described embodiment, the penetration of water and oxygen can be prevented by the resin layer and the carbon fiber reinforced resin layer, which are extremely strong and thick compared to the coating film. On the other hand, it can be seen that in the case of the steel material that was not subjected to the antirust treatment, the corrosion of the surface of the steel material could not be prevented, and the surface condition was remarkably deteriorated (Comparative Example 1).

INDUSTRIAL APPLICABILITY The present invention has the effect of realizing a rust-preventive repair method for steel materials and a method for rust-preventive repair of steel towers that enable rust-proof repair of corroded steel materials in a short period of time and at low cost. It can be suitably used as a rust-proof repair method for steel materials used.

Reference Signs List 1 anticorrosive repair steel material 11 steel material body 12 anticorrosive repair portion 13 base layer 14 resin layer 15 ultraviolet prevention layer 16 protective layer 100 angle steel tower 101 tower body 102 arm metal material 111 main pillar material 112 horizontal material 113 diagonal material 114 joint part 121 cross arm main material 122 cross arm hanging material 200 bubble cushioning material 201 heating element

Claims (7)

A surface adjustment step of adjusting the surface of the steel material by scraping the construction target area of the steel material;
A primer application step of applying a primer onto the construction target area in which the base material has been adjusted to form a base layer;
a resin coating step of coating a resin on the base layer to form a resin layer that prevents permeation of moisture and oxygen to the surface of the steel material;
an adhesive application step of applying an adhesive onto the resin layer;
An ultraviolet prevention layer forming step of providing an ultraviolet prevention layer for preventing transmission of ultraviolet rays to the resin layer on the resin layer via the adhesive;
including
A rust preventive repair method for a steel material, characterized in that , in the UV preventive layer forming step, the UV preventive layer is provided in a region narrower than the resin layer . 2. The rust preventive repair method for steel material according to claim 1, further comprising a protective layer forming step of providing a protective layer for protecting said ultraviolet preventive layer on said ultraviolet preventive layer. The rust preventive repair method for steel materials according to claim 1 or 2, wherein the resin is a polyurea resin. The rust prevention repair method for steel materials according to any one of claims 1 to 3, wherein the adhesive is an epoxy-impregnated adhesive. The rust prevention repair method for steel materials according to any one of claims 1 to 4, wherein the ultraviolet protection layer contains a carbon fiber reinforced resin. A surface adjustment step of adjusting the surface of the steel material by scraping the construction target area of the steel material constituting the steel tower;
A primer application step of applying a primer onto the construction target area in which the base material has been adjusted to form a base layer;
a resin coating step of coating a resin on the base layer to form a resin layer that prevents permeation of moisture and oxygen to the surface of the steel material;
an adhesive application step of applying an adhesive onto the resin layer;
An ultraviolet prevention layer forming step of providing an ultraviolet prevention layer for preventing transmission of ultraviolet rays to the resin layer on the resin layer via the adhesive;
including
A rust preventive repair method for a steel tower , wherein in the UV preventive layer forming step, the UV preventive layer is provided in a region narrower than the resin layer . a steel body;
a base layer provided in a region including a corroded portion on the steel body;
a resin layer provided on the base layer to prevent permeation of moisture and oxygen to the surface of the steel material;
an ultraviolet prevention layer provided on the resin layer to prevent transmission of ultraviolet rays to the resin layer;
with
A rust-preventive repair steel material, wherein the ultraviolet protection layer is provided in a region narrower than the resin layer .

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