JPH0324355Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is applicable to steel pipe piles, steel sheet piles, and various shaped steel used in marine, port, and river structures such as piers, seawalls, and bridges that are exposed to waves and water currents. This article relates to anti-corrosion coating structures for steel materials such as steel materials.

(Prior art) Conventionally, steel materials used for this type of application are subject to severe corrosion, especially in the tidal zone and splash zone, which are constantly exposed to seawater and air, so it has been difficult to apply anti-corrosion coating to these areas after repair. For example, Jikko 56-
As seen in Publication No. 9703, anti-corrosion tape coated with anti-corrosion coating is wrapped with a synthetic resin plate, and the anti-corrosion coating is applied to the corroded areas to improve its adhesion and to reduce external impact. A method has been adopted in which a buffer layer made of a foamed resin material is provided inside the synthetic resin plate.

However, foamed resins such as foamed polyethylene and foamed polyurethane used as the above-mentioned cushioning materials,
So-called closed-cell foamed resins, in which each cell is independent, have been used. this is,
This is because it was designed to block water from the outside and provide a buffering effect.

(Problem that the invention aims to solve) However, when this closed-cell cushioning material is used, it is difficult to accurately follow the surface shape when the surface of the steel material is uneven due to corrosion, pitting, etc. Furthermore, due to external shocks, water pressure, etc., this cushioning material becomes distorted (so-called "permanent strain") and does not return to its original state, creating a space between it and the steel material. It is becoming. Therefore, contrary to the intention of using a buffer material, the adhesion of the anticorrosive material to the steel material deteriorates, and seawater or the like enters the surface of the steel material, accelerating the rate of corrosion.

(Means for solving the problem) In view of these conventional problems, the present invention was developed by using a water-permeable open-cell foam resin instead of the closed-cell foam resin as a cushioning material. However, even if seawater or the like passes through this open foam, it does not affect the corrosion protection that comes into contact with the steel material.Moreover, this foam has good ability to follow the uneven shape of the steel material surface, and has good stability even when subjected to impact. It was found that the adhesion of the anticorrosive material to the steel material and the adhesion to the protective cover on the outside of the cushioning material were better than those of the closed foam type.

Therefore, the present invention is characterized in that this open-cell foam resin is used as a cushioning material.

That is, the present invention consists of an anticorrosive layer made of a highly anticorrosive material such as petrolatum paste that is in contact with steel, a buffer layer formed on the outside of the anticorrosive layer, and a protective cover such as fiber-reinforced plastic that covers the buffer layer.
The present invention proposes an anticorrosive coating structure characterized by using an open-cell foamed resin for the buffer layer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Example) In Fig. 1, 1 is a steel material such as a steel pipe used as a support pile for a pier, etc., 2 is a paste-like anti-corrosion layer mainly composed of petrolatum, and 3 is an open-cell foamed polyurethane foam. Buffer layer made of polyethylene etc. 4 is fiber reinforced plastic (FRP),
A protective cover made of synthetic rubber or corrosion-resistant metal.

However, since coating the corroded portions of steel materials such as the steel pipe 1 requires work underwater or above water, the three-layered coating is preformed integrally in a factory. Then, to cover the steel pipe 1, the above-mentioned covering body is manufactured by vertically dividing a cylinder having an inner diameter that matches the outer circumferential surface of the steel pipe 1 into two parts, and the abutting edges of both protective covers 4 of the outermost layer of the covering body are The outward flange is formed integrally.

Therefore, first, we used a scraper to remove various organisms such as shellfish and floating rust that adhered to the repaired coating area on the surface of the steel pipe 1.
After removing it with a tool such as an air sander, and if there are significant depressions due to pitting corrosion etc., fill them with anti-corrosion paste to smooth them out, then abut the two halves of the covering at the outer periphery of the steel pipe 1 and tighten bolts with the flanges,
It is brought into close contact with the surface of the steel pipe 1 with an appropriate surface pressure.

In addition, as mentioned above, the present invention does not affect the anticorrosion effect even if water permeable open foam resin is used.
There is a risk that seawater or the like may enter the surface of the steel pipe 1 from the flange portion or the sealing portion at the lower end of the sheathing, or if a large impact is applied after construction and the thickness of a portion of the anticorrosion layer 2 becomes extremely thin.

Therefore, as shown in FIG. 2, if a flexible water-stop sheet 5 made of synthetic resin such as vinyl chloride, polyethylene, nylon, or polyester or a corrosion-resistant metal is interposed between the anticorrosion layer 2 and the buffer layer 3, the above Problems such as this can also be solved.

(Effects of the invention) The present invention is constructed as described above, and unlike conventional methods, open-cell foamed resin is used as the cushioning material constituting the anti-corrosion coating, so it follows the surface shape of the steel material after repair. It has excellent corrosion resistance, has a restoring force against external impact, and the entire coating always adheres to the steel material, exhibiting a higher corrosion protection effect than conventional ones, and its industrial effects are extremely significant.

[Brief explanation of the drawing]

FIG. 1 shows an example of an anticorrosive coating structure according to the present invention, and FIG. 2 shows another example. 1... Steel materials such as steel pipes, 2... Corrosion protection layer, 3... Buffer layer, 4... Protective cover, 5... Water stop sheet.

Claims (1)

[Claims for Utility Model Registration] (1) Comprised of an anti-corrosion layer 2 in contact with the steel material 1, a buffer layer 3 formed on the outside thereof, and a protective cover 4 made of fiber-reinforced plastic or the like covering the buffer layer 3; 3 has an anti-corrosion coating structure characterized by using open-cell foamed resin. (2) Vinyl chloride between the anti-corrosion layer 2 and the buffer layer 3,
The anti-corrosion coating structure for steel material according to claim 1, which is a utility model registration, and comprises a water-stop sheet 5 made of a synthetic resin such as polyethylene, nylon, or polyester or a corrosion-resistant metal.