JPS6157724A - Method of preventing steel structure from corrosion - Google Patents

Abstract

PURPOSE:To apply rapid and reliable corrosion preventing processing on a waterproof sheet irrespective of waves, by a method wherein a flexible rubber magnetic rubber sheet, having an underwater adhesive for corrosion prevention applied on its surface, is developed over the ground surface of an underwater steel structure. CONSTITUTION:Underwater adhesive 2 for corrosion prevention is coated in the air on the one surface of a waterproof sheet 2 made of a flexible magnet rubber sheet. Meanwhile, an underwater steel structure 4, such as steel top plates, pier steel piles, is present in water. A diver carries the waterproof sheet 1 in water, the underwater adhesive 2 for corrosion prevention of the waterproof sheet 1 is brought into contact with and developed over a surface 5 of the ground underwater structure 4, the sheet 1 is forced into press contact with the surface 5 by means of a magnetic force. This enables to perform rapid corrosion preventing processing without influence being exercised on the surface of the underwater steel structure by waves.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to surface corrosion protection of underwater steel structures. Alternatively, maintenance of the splash zone area Long-term corrosion protection is extremely important but very difficult.There are various other materials and construction methods, such as underwater corrosion-resistant paint, underwater bond, or composite corrosion-protection methods using underwater adhesives and various sheets. As a practical matter, when applying adhesives or pressure-bonding coatings on objects that are underwater or on wet surfaces, the initial adhesion is poor due to the influence of water and seawater, causing the adhesive to shift or peel off before it can function properly. However, satisfactory materials and construction methods have not yet been found.

[Problems to be Solved by the Invention] The purpose of the present invention is to quickly and reliably provide anti-corrosion treatment to the surfaces of steel structures located below seawater. The invention involves applying an adhesive to one side of a waterproof sheet in the air, carrying it into the water, contacting the adhesive with the surface of an underwater steel structure or a wet surface above the water level, and spreading the sheet on the same surface. In addition, it is constituted by a method for preventing corrosion of steel structures, which is characterized in that the sheet is attached to the surface by magnetic force.

``Function'' Therefore, when a diver brings the above-mentioned adhesive-coated sheet applied in the air underwater and adheres it to the surface of the above-mentioned structure, the outer surface of the sheet is stretched and spread by hand along the same surface. The seawater between the surface and the adhesive is removed and the adhesive begins its initial adhesive action. In this case, the sheet is completely attracted to the above surface by its magnetic force, or the outward direction is held down by a permanent magnet so that the sheet is firmly attached to the surface by the magnetic force. After the initial adhesive action is completed, the sheet is fixed to the surface by the adhesive.

Embodiment I A flexible magnetic rubber sheet is used as the waterproof sheet 1, and is cut into predetermined dimensions. Then, on one side of the same sheet 1, apply an underwater corrosion-resistant adhesive (epoxy, urethane, etc.) in the air.
Apply polyester-based, acrylic-based, etc.) 2. Then, a diving worker carries this into the seawater 3, and polishes the underwater surface 5 of the marine steel structure 4 such as a steel sheet pile, pier steel pile, etc., which has already been polished by underwater sandblasting, etc., and wet-horizontal polishing table a1 above the water level.
The adhesive 2 is brought into contact with the sheet 15, and the outer surface of the sheet 1 is spread by hand in all directions. In this way, the sheet 1 is pressed against the surface 5 by its magnetic force, and the seawater interposed between the adhesive 2 and the surface 5 is discharged from the four edges of the sheet 1, and the adhesive 2 is applied to the surface 5. The adhesive 2 adheres tightly and hardens, and the coating film of the adhesive 2 covers the surface 5 and protects it from corrosion, and the waterproof sheet 1 protects the adhesive 2.

Table 1 shows comparative examples between a non-magnetic general rubber sheet and the magnetic force of the present invention.

The following is a margin table 1. It is also possible to use a non-magnetic rubber sheet as the waterproof sheet 1 and make permanent magnets adhere to the outer surface of the sheet 1 during the above-mentioned spreading. There is no need to apply or adhere waterproof paint to the surface 5 of the structure 4, and not only can the underwater surface 5 and the adhesive 2 be bonded without intervening seawater, but the adhesive 2 can be spread as described above by magnetic force. This allows the surface 5 to be quickly and reliably anticorrosion-treated without the possibility that the sheet 1 will come off or slip off the surface 5 during initial adhesion and be exposed to waves.

[Brief explanation of the drawing]

The drawing is a longitudinal cross-sectional view showing a state of corrosion protection by the corrosion protection method for steel structures of the present invention. 1. Waterproof sheet, 2. Adhesive, 3. Underwater, 4.
Underwater steel structure, 5... surface.

Claims (1)

[Claims] (1) Apply adhesive to one side of the waterproof sheet in the air, bring it into the water, contact the adhesive on the surface of the underwater steel structure or a wet surface above the water level, and spread the sheet on the same surface. A method for preventing corrosion of steel structures, characterized in that the sheet is attached to the surface by magnetic force.