JP3928712B2 - Anticorrosion structure and anticorrosion method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anticorrosion structure and an anticorrosion method for marine structures such as concrete structures and steel structures .
[0002]
[Prior art]
In the marine environment, particularly in the splash zone, chloride ions and oxygen enter the concrete, causing a phenomenon that corrodes the internal rebar.
For this reason, reinforced concrete structures, prestressed concrete structures, steel structures and the like in the marine environment have been conventionally subjected to anticorrosion treatment.
The first type of anti-corrosion method is that the concrete is densified with the material and composition of the concrete to suppress the invasion and movement of the corrosion factor of the steel material, or the corrosion factor reaches the steel material by increasing the cover of the reinforcing bar. There is a way to delay the time.
In addition, as the second type of anticorrosion method, the surface of the concrete is covered with a surface coating material to suppress the invasion of corrosion factors of the steel material, and the corrosion progresses by using an anticorrosive steel material such as an epoxy resin coated reinforcing bar. There are a method for suppressing the corrosion and an electrochemical method such as an anti-corrosion.
[0003]
[Problems to be solved by the invention]
The above-described conventional anticorrosion structure and anticorrosion method have the following problems.
<I> The surface coating material is generally an organic substance and contains a substance that may adversely affect the environment and the human body.
<B> Since organic surface coating materials deteriorate over time, it is necessary to perform maintenance periodically.
<C> Generally, the service life of a resin-based surface coating material is about 10 years, and it is necessary to remove it at the time of repainting the surface coating material and dispose it. Since the peeled surface coating material becomes industrial waste, it takes a lot of costs for disposal, and there are many adverse effects on the global environment.
[0004]
OBJECT OF THE INVENTION
The present invention has been made to solve the above-described conventional problems, and an object thereof is to provide a corrosion prevention structure and a corrosion prevention method that are safe materials and have a high corrosion prevention effect.
Moreover, it aims at providing the anti-corrosion structure and anti-corrosion method with a long durable life.
Furthermore, it aims at providing the anti-corrosion structure and the anti-corrosion method which can be easily disposed of even after the period of use.
The present invention achieves at least one of these objects.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, as a first invention of the present invention, an anticorrosion structure for a marine structure composed of a main body provided with a steel material, wherein a surface layer material is arranged on a part or all of the surface of the main body. the surface layer material comprises a plate or sheet material, and a protective layer formed in advance on the ocean-side surface of the plate material or a sheet material, more configuration, the protective layer, marine organisms to produce the protein and calcium carbonate was formed by depositing by use of the protein, adhesion area ratio of the marine organisms is approximately 70% or more, the corrosion protection structure the thickness of the protective layer is characterized by a 50~100μm It is to provide.
Further, as a second invention of the present invention, the anticorrosion structure of an oceanic structure comprising a surface layer material and a concrete structure constructed using the surface layer material as an embedded formwork, wherein the surface layer material is a plate material or a sheet. and wood, and a protective layer formed in advance on the ocean-side surface of the plate material or a sheet material, more structure, the protective layer may cause adhesion of marine organisms to produce the protein and calcium carbonate by use of the protein formed by adhesion area ratio of the marine organisms is approximately 70% or more, the thickness of the protective layer provides corrosion protection structure, which is a 50 to 100 [mu] m.
[0006]
And the anticorrosion method of this invention is a marine equipped with steel material which manufactured the surface layer material as 3rd invention, arrange | positioned the said surface layer material as an embedded formwork, and cast concrete inside the said embedded formwork. a corrosion process of the structure, the surface layer material comprises a plate or sheet material, and a protective layer formed in advance on the ocean-side surface of the plate material or a sheet material, more constructed, the protective layer, and protein the marine organisms to form calcium carbonate is formed by adhering by using the protein, adhesion area ratio of the marine organisms is approximately 70% or more, the thickness of the protective layer is 50~100μm An anticorrosion method is provided.
Moreover, as a fourth invention, a surface layer material is manufactured, and the surface layer material is attached to a surface of an offshore structure including an existing steel material. The surface layer material includes a plate material or a sheet material, and the plate material or a protective layer formed in advance on the ocean-side surface of the sheet material, more configuration, the protective layer, a marine organism that produces the protein and calcium carbonate was formed by depositing by use of the protein, the A marine organism adhesion area ratio is 70% or more, and the thickness of the protective layer is 50 to 100 μm.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0008]
<I> Application conditions The present invention can be applied to any structure that requires anticorrosion treatment. In particular, it is effective to apply to a reinforced concrete structure, a prestressed concrete structure, a steel structure, etc. existing in a marine environment such as a waterside or near the sea, the sea, or a splash zone.
[0009]
<B> Surface material The surface material 1 is produced by attaching marine organisms.
In the tidal zone, marine organisms are most common in barnacles and oysters, including limpets, mussels, snails, snails, etc., and in the middle of the sea, there are sandworms, bryozoans, and sea squirts. Among them, the species of marine organisms that form a dense bottom shell are barnacles and oysters.
The surface layer material 1 is manufactured by attaching marine organisms to a concrete plate material, for example. By attaching marine organisms, a layer composed of the bottom shell of marine organisms is formed on the surface of the surface material 1.
Thin and easy-to-handle plate or sheet materials can be easily placed in the sea or in the tidal zone where marine organisms are likely to attach, so marine organisms can be attached efficiently and the amount of attachment can be controlled. It is suitable for.
Moreover, the surface layer material 1 can also be manufactured by cutting out adhering marine organisms in plate shape.
[0010]
<C> Anti-corrosion structure The protective layer formed by marine organisms is composed of proteins produced by marine organisms (substances used when adhering to concrete surfaces) and calcium carbonate. The main component of the marine organism adhesion layer is calcium carbonate.
The structure of the marine organism adhesion layer is a layer having a denser structure than the cement paste and a thickness of about 50 to 100 μm (see FIG. 2).
[0011]
<D> Construction method of anticorrosion structure An embodiment in which the surface material 1 is arranged on the surface of a concrete structure will be described.
FIG. 1 shows an embodiment of the anticorrosion method in the pier superstructure. From the sea surface 4 of FIG. 1 to the bottom surface of the main body 2, it corresponds to a splash zone. This splash zone is a place where severe deterioration of conditions is particularly likely to proceed for the structure, but it is also a place where marine organisms cannot be expected to adhere naturally.
Therefore, the surface material 1 to which marine organisms are attached in advance is disposed on the surface of the main body 2 as an embedded formwork. A well-known stud, an anchor, etc. are attached to the inner surface of the surface layer material 1, and are integrated with the concrete to be placed inside the surface layer material 1 later. In addition, the joint portion between the surface layer materials 1 can be joined by being filled with a known resin filler such as epoxy resin or silicon resin.
Moreover, when the main-body part 2 is an existing concrete structure, the surface layer material 1 can be attached to the surface of the main-body part 2 as a surface panel. In this case, the surface layer material 1 is fixed to the surface of the main body 2 with a known adhesive or bolt.
[0012]
<E> Reduction effect of diffusion coefficient of chloride ion and oxygen (Fig. 3)
FIG. 3A shows the relationship between the chloride ion diffusion coefficient and the biofouling area ratio. Here, the biological adhesion area ratio refers to the ratio of marine organisms attached to the surface.
As the biological adhesion area ratio increases, the chloride ion diffusion coefficient tends to decrease, and it is considered that the penetration of chloride ions is suppressed by the adhesion layer. In particular, up to about 30% of the biofouling area ratio, a value similar to the diffusion coefficient when there is no adhesion is measured, and the effect of reducing the diffusion coefficient due to biofouling is not clear, but the biofouling area ratio is 70 If it exceeds%, the reduction effect appears remarkably.
[0013]
FIG. 3B shows the relationship between the oxygen diffusion coefficient and the amount of biofouling.
The oxygen diffusion coefficient tends to decrease as the amount of biofouling increases, and it can be said that biofouling also has an effect of suppressing oxygen diffusion into concrete.
[0014]
FIG. 4 shows the relationship between the corrosion rate of the reinforcing bars and the biological adhesion area rate. From this figure, it is recognized that the corrosion rate tends to decrease as the biological adhesion area ratio increases.
[0015]
<F> Fig. 5 shows a life model of the structure from the viewpoint of extended reinforcing steel corrosion of the concrete structure. Here, if the rebar in the structure reaches the limit rusting amount and the point of time when corrosion cracking occurs is defined as the useful life of the structure, the useful life is the incubation period until the occurrence of corrosion and the occurrence of cracking after the occurrence of corrosion. Determined by the development period.
This incubation period is mainly governed by the diffusion of chloride ions in concrete, and the evolution period is thought to be governed by oxygen diffusion. Therefore, when the adhesion amount of marine organisms increases, the chloride ion diffusion coefficient and the oxygen diffusion coefficient can be reduced, so that both the incubation period and the development period become longer, and the useful life of the structure is extended.
[0016]
【The invention's effect】
Since the anticorrosion structure and anticorrosion method of the present invention are as described above, the following effects can be obtained.
<A> The surface material is coated with a safe material mainly composed of calcium carbonate. The protective layer formed by the attachment of marine organisms has a dense structure. For this reason, it is safe and can perform corrosion prevention with a high anticorrosion effect.
<B> The protective layer mainly composed of calcium carbonate is extremely excellent in durability as compared with a conventional organic surface coating material.
<C> Since it is a natural material created by marine organisms, it can be easily disposed of even after the period of use.
[Brief description of the drawings]
FIG. 1 is an explanatory view of an embodiment of the anticorrosion structure of the present invention.
FIG. 2 is an enlarged detail view of the anticorrosion structure.
FIG. 3A is a graph showing the relationship between the chloride ion diffusion coefficient and the biofouling area ratio. (B) Relationship diagram between oxygen diffusion coefficient and biofouling amount.
FIG. 4 is a diagram showing the relationship between the corrosion rate and the biofouling area rate.
FIG. 5 is a life model of a structure from the viewpoint of reinforcing steel corrosion.
[Explanation of symbols]
1 ... Surface material 2 ... Main body

Claims (4)

An anti-corrosion structure for a marine structure composed of a main body provided with a steel material,
A surface layer material is arranged on part or all of the surface of the main body,
The surface layer material comprises a plate material or a sheet material, and a protective layer formed in advance on the ocean side surface of the plate material or sheet material,
The protective layer, a marine organism that produces the protein and calcium carbonate was formed by depositing by use of the protein,
The marine organism adhesion area ratio is 70% or more,
The protective layer has a thickness of 50 to 100 μm,
Anti-corrosion structure. An anticorrosion structure for a marine structure , comprising a surface layer material and a concrete structure constructed using the surface layer material as an embedded formwork,
The surface layer material comprises a plate material or a sheet material, and a protective layer formed in advance on the ocean side surface of the plate material or sheet material,
The protective layer, a marine organism that produces the protein and calcium carbonate was formed by depositing by use of the protein,
The marine organism adhesion area ratio is 70% or more,
The protective layer has a thickness of 50 to 100 μm,
Anti-corrosion structure. Producing a surface layer material, placing the surface layer material as an embedded formwork, and constructing by placing concrete on the inside of the embedded formwork, an anticorrosion method for an offshore structure comprising a steel material,
The surface layer material comprises a plate material or a sheet material, and a protective layer formed in advance on the ocean side surface of the plate material or sheet material,
The protective layer, a marine organism that produces the protein and calcium carbonate was formed by depositing by use of the protein,
The marine organism adhesion area ratio is 70% or more,
The protective layer has a thickness of 50 to 100 μm,
Anticorrosion method. It is a corrosion prevention method for producing a surface layer material and attaching the surface layer material to the surface of an offshore structure including an existing steel material,
The surface layer material comprises a plate material or a sheet material, and a protective layer formed in advance on the ocean side surface of the plate material or sheet material,
The protective layer, a marine organism that produces the protein and calcium carbonate was formed by depositing by use of the protein,
The marine organism adhesion area ratio is 70% or more,
The protective layer has a thickness of 50 to 100 μm,
Anticorrosion method.

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