JP2001152475A - Covering corrosion-proof transparent cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a covering corrosion-proof cover for an offshore steel structure whose condition of the substrates and the steel structure as a core member can be observed from the outside by using plastic protection members having transparency. SOLUTION: The plastic protection member 4 covering a petrolatum-based corrosion-proof layer 3 formed in a tidal range of a steel pipe pile 1 or a steel pipe sheet pile 2 or in a scattering zone of splashes is made of a polycarbonate resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover for corrosion protection of a splash zone and a tidal zone in a marine steel structure.

[0002]

2. Description of the Related Art Steel pipe piles, steel sheet piles, steel pipe sheet piles and the like are used for foundation piles, floating piers, seawalls, etc. of offshore platforms. Electrostatic protection is applied to parts that are constantly submerged in the sea, but in areas where the tide is tidal or splashing,
Corrosion conditions are extremely severe, and it is usual to form an anticorrosion layer such as a petrolatum-based layer and then form a plastic-based protective layer.

Conventionally, as this plastic protective layer,
Glass fiber reinforced types of unsaturated polyester resin, vinyl chloride resin, polypropylene resin, epoxy resin, polyethylene resin, and acryl-modified vinyl chloride resin have been used. However, these are all opaque, and after applying the plastic protective layer, it is not possible to externally confirm the construction state of the underlying anticorrosion layer or the deterioration state of the anticorrosion performance over time. However, when these inspections and inspections were necessary, the plastic protective layer had to be removed.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention uses a transparent plastic protective member to externally observe the state of a steel structure as a base material and, as a result, a core material. It is an object of the present invention to provide a possible corrosion protection cover for marine steel structures.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a plastic protective member for covering a petrolatum-based anticorrosion layer provided in a tide zone or a splash zone of a steel pipe pile or a steel sheet pile. In addition, a plastic protective member is made of a polycarbonate resin to provide a transparent cover for corrosion protection.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is based on the fact that a polycarbonate resin, which is a transparent plastic and has excellent durability and impact resistance, is used as an anticorrosion cover. The present invention will be described in detail with reference to the drawings. FIG. 1 is an embodiment in which the transparent anticorrosive cover of the present invention is applied to a steel pipe pile, and FIG. 2 is an enlarged explanatory view of a portion A in FIG.
FIG. 3 is another embodiment in which the transparent coated anticorrosion cover of the present invention is applied to a steel pipe sheet pile, and FIG.
5 is an enlarged explanatory view of a part B of FIG. 3, and FIG. 5 is an enlarged explanatory view of a part C of FIG.

A steel pipe pile 1 and a steel pipe sheet pile 2 are provided with
First, use a tape impregnated with petrolatum, and use the anticorrosion layer 3
To form A plastic protective member 4 made of polycarbonate resin is attached to the outer layer. As shown in FIG. 1, in the case of the steel pipe pile 1, the plastic protection member 4 is a cutout cylindrical shape that covers about 95% or more of the circumference of the steel pipe pile 1, and is attached to both ends thereof for mounting. A flange 5 is provided. A polycarbonate backing plate 6 is installed on the anticorrosion layer 3 formed on the steel pipe pile 1 and attached so that the cutout portion of the plastic protection member 4 comes within the range of the backing plate 6. The flange 5 is provided with a mounting hole 8 for a bolt 7, and is fastened using a mounting bracket 9. The bolt 7 and the nut are preferably made of corrosion-resistant metal such as stainless steel or brass,
Usually, carbon steel bolts can also be used. If it is necessary to perform anticorrosion treatment, bolts and nuts should be plated with zinc, etc.
Alternatively, an appropriate anticorrosion treatment such as embedding bolts and nuts with resin can be performed.

The polycarbonate used as the plastic protective member 4 is preferably a resin excellent in mechanical properties such as impact resistance and having a viscosity average molecular weight of about 20,000 to 40,000. In addition, in order to improve weather resistance, at least the surface on the outside at the time of construction is coated with an acrylic resin, a fluororesin such as vinylidene fluoride, or a silicone resin to which an appropriate amount of an ultraviolet absorber is added. Is desirable. The plastic protective member 4 may be configured so as to surround the circumference by one piece, or may be divided into two parts, such as two equal parts or four equal parts. In the embodiment of the steel pipe sheet pile 2 shown in FIGS.
The anticorrosion layer 3 is formed, and the plastic protection member 4 having a substantially quadrant shape is attached using the sheet pile joint 10. In the part where the sheet pile joint 10 is used, the plastic protective members 4 are attached so as to overlap each other.
At the part of the protection member 4 at the center of the steel pipe part, the same as in the case of the steel pipe pile, it is attached.

In FIG. 5, two plastic protective members 4 for covering the surfaces of the left and right steel pipe sheet piles 2 are tightened by using stud bolts 11 provided on a sheet pile joint 10. By overlapping the flanges 5 of the two plastic protective members 4 applied to the left and right steel pipe sheet piles 2,
The exposure of the anticorrosion layer can be blocked. In this case, using the backing plate at the joint of the plastic protective member 4
It is not necessary. The use of an anti-corrosion material or an anti-corrosion treatment for the stud bolt 11 and the nut is the same as in the case of the steel pipe pile. FIG. 5 shows an example of embedding with a water-curable epoxy resin 12 and using a bolt cap 13 made of polyacetal. The thickness and the overall size of the polycarbonate plastic protective member 4 need to be adjusted to the size of the steel pipe piles and steel sheet piles to be used. It is preferable to have a divided shape and size.

[0010]

[Example] A steel pipe pile with a diameter of 1,000 mm and a thickness of 2 mm
The test was performed using a cover made of a polycarbonate resin (viscosity average molecular weight 25,000, surface coated with an acrylic film (40 μm)) having a thickness of 3 mm and a length of 2,000 mm on a steel pipe sheet pile having a diameter of 800 mm. Defects of the petrolatum layer were intentionally provided in advance on the steel pipe piles and steel sheet piles, but the rust generated on the steel pipe piles and steel sheet piles was easily observed from the outside due to the difference in color. It was discovered, and corrosion of steel pipe piles and steel sheet piles was discovered early.

[0011]

According to the present invention, since the transparent polycarbonate resin is used for the plastic protective member, it is easy to observe and inspect the construction state of the petrolatum-based anticorrosion layer applied to the steel pipe pile in seawater through the plastic protective member. Was.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment in which a coated anticorrosion cover having transparency of the present invention is applied to a steel pipe pile.

FIG. 2 is an enlarged explanatory view of a portion A in FIG. 1;

FIG. 3 is a plan view showing another embodiment in which the coated anticorrosive cover having transparency of the present invention is applied to a steel pipe sheet pile.

FIG. 4 is an enlarged explanatory view of a portion B in FIG. 3;

FIG. 5 is an enlarged explanatory view of a portion C in FIG. 3;

[Explanation of symbols]

 1: Steel pipe pile 2: Steel pipe sheet pile 3: Corrosion protection layer 4: Plastic protection member 5: Flange 6: Patch plate 7: Bolt 8: Mounting hole 9: Mounting bracket 10: Sheet pile joint 11: Stud bolt 12: Underwater curing epoxy resin 13: bolt cap

Claims (1)

[Claims] 1. A plastic protective member for covering a petrolatum-based anticorrosion layer provided in a tide zone or a splash zone of a steel pipe pile or a steel sheet pile, wherein the plastic protective member is made of a polycarbonate resin. Transparent coated anticorrosion cover.