JPH0358408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for protecting steel sections used in corrosive environments. More specifically, the present invention relates to a corrosion protection method for underwater parts, tidal zones, and splash zones of steel sheet piles or steel pipe sheet piles, which are mainly driven into the sea and used as the foundations of seawalls and quays.

Conventional technology 1 Generally, steel materials used in the marine environment are not only immersed in seawater containing a large amount of salt and washed by waves and currents, but also exposed to spray or the ocean atmosphere containing sea salt particles. Corrosion and wear occur, leading to perforation and destruction during long-term use.

In the past, various methods have been proposed to prevent this kind of corrosion, one of which is to coat the severely corroded areas with a corrosion-resistant coating such as petrolatum, and then cover the outside with a hard protective layer made of fiber-reinforced plastic. Methods of applying covers are known. The above-mentioned protective cover prevents peeling and damage of the anti-corrosion layer when subjected to external impact or pressure such as wave force or collision with floating objects, and prevents seawater from penetrating into the anti-corrosion layer and preventing corrosion of the anti-corrosion layer from occurring in seawater. This is to prevent elution to.

Problems to be Solved by the Invention 1 However, although the above-mentioned protective cover was effective in protecting the anti-corrosion layer from external impact and pressure, it did not prevent seawater from penetrating into the anti-corrosion layer or seawater from the anti-corrosion layer. It was not possible to prevent the elution into the inside.
In other words, the above-mentioned protective cover is usually formed by laminating fibers such as glass or polyester and liquid hardened resin on the inner or outer surface of a mold that is manufactured to match the shape of the steel section to be protected against corrosion. However, slight differences in shape between the above-mentioned mold and the shaped steel are unavoidable, and there are manufacturing errors in the shaped steel itself, as well as shrinkage during curing of the liquid hardening resin impregnated into the fibers. Not only is it extremely difficult to manufacture a protective cover that matches the shape of the shaped steel, but it is also inevitable that unevenness will occur in the anticorrosive layer that coats the surface of the shaped steel. A gap may be created between the corrosion protection layer and the protective cover, causing seawater to enter the corrosion protection layer and deteriorating its performance, or seawater may also seep into the surface of the shaped steel inside the corrosion protection layer, resulting in long-term damage. There was a problem that corrosion protection could not be achieved.

Prior Art 2 In order to solve the above-mentioned problems with the protective cover, the applicant has developed an anti-corrosion covering (actual) using a protective cover in which a cushioning material such as plastic foam is attached to the inside of a fiber-reinforced plastic board. Kosho 56-
No. 9703) and has been put into practical use as a corrosion-protective coating for steel materials of various shapes.

Problem to be Solved by the Invention 2 However, the protective cover with the above-mentioned buffer material adheres completely to the anti-corrosion layer coated on a single section steel or steel pipe, preventing seawater from penetrating into the anti-corrosion layer. Although it can prevent food materials from leaching into seawater, it cannot completely protect against the corrosion-protective layer coated on the shaped steel of steel sheet pile quays and steel pipe sheet pile quays, which are constructed by connecting individual steel materials at joints. It is difficult to cover tightly,
There are still problems such as gaps forming between the anti-corrosion layer and the protective cover and seawater infiltrating into the anti-corrosion layer as described above, or the anti-corrosion material leaching into the seawater, making long-term corrosion protection impossible. It remained. This is due to the fact that steel sheet pile quays and steel pipe sheet pile quays are not constructed from a single steel section, but rather are constructed by connecting multiple sections of steel and driving them into the soil. In other words, it is difficult to drive each section of steel into the soil in a straight line due to differences in sea conditions such as waves and currents, and physical conditions such as the hardness and softness of the ground. This is because the orientation of each steel section differs slightly at the connecting portion, so the cross section of the entire wall body in which the section steels are connected exhibits an irregular shape everywhere.

Structure of the Invention The present invention improves the above-mentioned problems that occur when applying corrosion protection, and can adhere not only to a single section steel but also to an irregularly shaped wall made of a plurality of section steels connected without any gaps. This was done with the purpose of forming a coating layer with excellent corrosion resistance, strength, and durability.The gist of this method is to implant a threaded body into a shaped steel, and then to remove the threaded body from the shaped steel. After applying or pasting an anti-corrosion coating on the surface, a protective sheet made by airtightly surrounding cloth or pine impregnated with a liquid cured resin with an impermeable film is tightly attached to the anti-corrosion coating before the liquid cured resin hardens. This anti-corrosion method is characterized in that the coating layer is formed by applying a coating and fixing it using a caul plate and a tightening member.

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 The embodiments shown in FIGS. 1 and 2 are examples of the present invention for a steel sheet pile quay. FIG. 1 is a cross-sectional view of the main part when the present invention is applied to a steel sheet pile. FIG. 2 is a perspective view of the present invention applied to a steel sheet pile. Further, FIGS. 3 and 4 relate to the protective sheet used in the present invention, with FIG. 3 being a sectional view and FIG. 4 being a schematic explanatory view.

In Figs. 1 to 4, first, a screw body 2 for fixing and holding a covering material for corrosion-proofing the steel sheet pile is implanted in a recessed portion of a steel sheet pile 1, which is an object to be protected from corrosion. As a method of implanting the screw body 2 into the steel sheet pile 1, a method using electric welding and a method of drilling a hole in the steel sheet pile and then cutting a tap screw and screwing the screw body are used. A bolt made of mild steel or a stainless steel bolt is used as the screw body implanted by electric welding.

A mild steel bolt, a stainless steel bolt, a brass bolt, or a titanium bolt is used as the threaded body that is screwed onto the tap screw and implanted.

Preferably, mild steel bolts or stainless steel bolts are used and are implanted into the steel sheet pile 1 by electric welding.

Next, the corrosion-protective surface of the steel sheet pile 1 is coated with or affixed with the corrosion-proofing material 3. The anti-corrosion material 3 is to have anti-corrosion properties such as adhesiveness, impermeability, electrical insulation, underwater adhesion, etc., and is usually applied by applying a petrolatum-based anti-corrosion paste or impregnating cloth with a petrolatum-based anti-corrosion material. It is used by pasting a petrolatum-based anticorrosive tape in the form of a tape or a petrolatum-based anticorrosive sheet made by mixing petrolatum with rubber. Preferably, a method is used in which the petrolatum anticorrosion tape or the petrolatum anticorrosion sheet is attached to the outside coated with the paste petrolatum anticorrosion tape.

In addition to the above, a rubber-based adhesive or an epoxy-based corrosion-proofing material can also be used as the corrosion-proofing material in step 3.

After coating the corrosion-protected surface of the steel sheet pile 1 with the corrosion-proofing material 3 as described above, a protective sheet 4 is placed on the outside of the corrosion-proofing material.
Cover. The protective sheet 4 is made by impregnating a cloth or mat 4a with liquid cured resin, airtightly surrounding the cloth or mat with a water-impermeable film 4b, and then passing the screw body 2 installed in the steel sheet pile 1 through the protective sheet 4. It is provided in the through hole 4c. As the cloth 4a used for the protective sheet 4, glass cloth is usually used. Further, a glass chopped strand mat or a polyester nonwoven fabric is used for the mat 4a. Preferably, glass chopped strand mats or glass chopped strand mats and glass cloth are laminated alternately. The liquid cured resin with which the cloth or mat 4a is impregnated is desirably a solvent-free resin, and epoxy resin and its curing agent are usually used. A synthetic resin film such as a vinyl chloride film or a polyethylene film is used as the water-impermeable film 4b, which is coated on a cloth impregnated with a liquid cured resin or on the mat 4a to airtightly surround it. The protective sheet 4 configured as described above is provided with a through hole 4c for passing through the screw body 2 implanted in the steel sheet pile 1, and the area around the through hole 4c is provided to maintain airtightness. Attach adhesive tape 4d. Another method for keeping the area around the hole 4c airtight is to pre-impregnate the area around the hole 4c or an appropriate area with a liquid cured resin and harden it, and then drill the hole. You can also do it.

The protective sheet 4 is made of steel sheet piles in such a way that the threaded bodies 2 pass through holes 4c formed in the protective sheet 4 before the liquid hardening resin impregnated into the cloth or mat 4a starts a hardening reaction. The anticorrosive material 3 covered with the anti-corrosion material 3 is closely coated on the outside thereof.

Next, a patch plate 5 that is formed so as to overlap the shape of the steel sheet pile 1 in the vicinity of where the screw body 2 is installed and has a through hole for penetrating the screw body 2 is attached to the screw body 2.
The screws 6 and 7 are screwed onto the threaded bodies 2 and fixed by tightening. A synthetic resin cap 8 is screwed onto the screw body 2 to prevent corrosion.

As mentioned above, the screw body 2 is attached to the corrosion-protected side of the steel sheet pile 1.
After planting, the anticorrosive material 3 is covered, and the surface of the steel sheet pile 1 is coated with a protective sheet 4 while the liquid hardening resin impregnated into the cloth or mat 4a, which is the base material of the protective sheet 4, is not hardened. Since the steel sheet pile 1, the corrosion-proofing material 3, and the protective sheet 4 are coated in close contact with the outside of the corrosion-proofing material 3, the steel sheet pile 1, the corrosion-proofing material 3, and the protective sheet 4 can be integrally coated without creating any gaps. Also protective sheet 4
is not only tightened and fixed by the tightening members 6 and 7 via the patch plate 5 formed so as to overlap with the shape of the steel sheet pile near the screw body 2, but also impregnated into the cloth or mat 4a of the protective sheet 4. The corrosion-proofing material 3 is strongly pressed against the surface of the steel sheet pile 1 due to the shrinkage of the resin that occurs during the process of hardening the liquid cured resin after a certain period of time has elapsed. Backing plate 5
Although the protective sheet 4 may be attached as is, it may be removed after the protective sheet 4 has hardened. When removing the backing plate 5, remove the screw body 2 protruding from the hardened protective sheet 4.
The fastening members 6 and 7 are screwed onto and tightened and fixed.

The corrosion-proofing material 3 may be directly coated on the surface of the steel sheet pile 1, but it is also possible to apply or adhere it to one side of the protective sheet 4 so that the surface of the steel sheet pile 1 is coated with the protective sheet.

Embodiment 2 FIGS. 5 and 6 show an example in which the present invention is applied to a wall made of steel pipe sheet piles 9. FIG. 5 is a sectional view, and FIG. 6 is a front view. The wall body made of steel pipe sheet pile 9 is a joint part 10 provided on the steel pipe.
It is desirable to protect the entire outer periphery of the wall from corrosion. The method for preventing corrosion of a wall constructed of such steel pipe sheet piles is the same as that for the steel sheet piles described above, and the same parts as in FIGS. 1 and 2 are given the same numbers.

Example 3 FIGS. 7 and 8 show an example in which the present invention is applied to an H-section steel 11. Figure 7 is a cross-sectional view;
FIG. 8 is a perspective view. It is desirable to protect the entire outer periphery of H-beam steel, and the corrosion protection method is the same as that for the steel sheet piles, and the same parts as in FIGS. 1 and 2 are given the same numbers.

Effects of the Invention As detailed above, according to the present invention, a soft protective sheet is coated on the outside of the coated or pasted anti-corrosion sheet during anti-corrosion construction, so that it can be coated in close contact with the shaped steel. Furthermore, it is possible to cover irregularly shaped portions such as those where a plurality of connected steel sections are oriented in different directions with sufficient adhesion. Furthermore, since the protective sheet hardens and increases its strength after a certain period of time has elapsed, it has sufficient strength as a protective material and can strongly protect the anti-corrosion material. Furthermore, the corrosion protection sheet and the protective sheet are tightened and fixed by a screw body embedded in the shaped steel and a tightening member screwed onto the screw body, so they will not fall off and can provide long-term corrosion protection. becomes. Furthermore, since the corrosion-proofing material can be applied or attached underwater, and the protective sheet is watertightly surrounded by an impermeable film, the present invention can be applied to shaped steel sections in water very easily. It is something.

As described above, the present invention greatly contributes to the corrosion protection of section steel.

[Brief explanation of drawings]

Figures 1 and 2 are examples of the present invention for steel sheet piles, Figures 3 and 4 are cross-sectional views and schematic illustrations of protective sheets used in the present invention, and Figures 5 and 6 are steel pipe sheet piles. FIG. 7 is an embodiment of the present invention for
FIG. 8 shows an embodiment of the present invention for H-beam steel. 1...Steel sheet pile, 2...Screw body, 3...Anti-corrosion,
4...protective sheet, 4a...cloth or matte, 4
b...Water-impermeable film, 4c...Through hole, 4d...
...Adhesive tape, 5...Packing plate, 9...Steel pipe sheet pile,
10...Joint part of steel pipe sheet pile, 11...H section steel.

Claims (1)

[Claims] 1. The surface of the shaped steel in which the threaded body is implanted is coated with corrosion protection, and the outside of the corrosion protection is airtightly surrounded with a cloth or mat impregnated with liquid hardened resin with an impermeable film, and the screw body is After applying a protective sheet with through-holes for the body so that the threaded body passes through the through-hole before the liquid hardening resin hardens, the section steel in the vicinity of where the threaded body is implanted is attached. A hard backing plate that is molded to overlap the shape and has a through hole for the screw body is pressed against the outside of the protective sheet so that the screw body penetrates the through hole, and the hard plate protrudes outward from the plate. A method for preventing corrosion of shaped steel, characterized by tightening and fixing using a screw body and a tightening member screwed onto the screw body.