JP2007332620A - Method of reinforcing marine structure for anticorrosion and marine structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of reinforcing a marine structure for anticorrosion capable of efficiently providing the surface of the marine structure with a reformed sulfur material cover layer excellent in salt resistance, mechanical strength, water shielding properties and the like, and effectively controlling the corrosion of the marine structure, erosion by waves, and the impact of collisions with floating material over a long period. <P>SOLUTION: The method of reinforcing for anticorrosion includes a process A for providing a seawater blocking member in such a manner as to surround at least the tidal-zone area of the surface of the marine structure, and providing a working space closed at the bottom; a process B for draining seawater in the working space; a process C for drying the surface of the marine structure in the working space; and a process D for providing the reformed sulfur material cover layer on the desired portion of the surface of the marine structure in the working space after the process C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an anticorrosion reinforcing method for an offshore structure and an anticorrosion reinforcing method capable of suppressing erosion caused by corrosion or waves in an offshore structure such as a bridge foundation made of steel bars or steel reinforced concrete, a seawall, a breakwater, a submarine oilfield platform, etc. Relates to the offshore structure.

An offshore structure is usually constructed of reinforced concrete, steel reinforced concrete, steel, or the like. In such an offshore structure, at least the surface corresponding to the tidal zone is in contact with seawater and outside air alternately over a long period of time, and because the environment changes drastically, it is easily corroded. Susceptible to impact from floating objects.
Therefore, in order to protect the surface of such a marine structure in a specific area, a method for covering the specific area with resin, rubber, paint, non-corrosive metal, etc., and a system for preventing corrosion are installed. Many methods have been proposed. For example, Patent Document 1 proposes that an anticorrosion structure be provided at least in a part of an offshore structure that contacts seawater.

By the way, in recent years, a large number of sulfur-containing materials, including, for example, Patent Documents 2 and 3, have been proposed and used as civil engineering and construction materials that replace concrete.
Since such a sulfur-containing material is excellent in salt resistance, mechanical strength, water shielding, and the like, it can be expected to be used as a protective layer for anticorrosion and reinforcement in the marine structure.
However, since the melting temperature of the modified sulfur contained in the sulfur-containing material usually needs to be 120 ° C. or higher, the sulfur-containing material is used to protect the surface of the part of the marine structure that contacts seawater on the surface. It was impossible to set up because of the presence of seawater.
JP 2003-286591 A JP 2001-163649 A JP 2005-82475 A

  An object of the present invention is to efficiently provide a modified sulfur material coating layer excellent in salt resistance, mechanical strength, water shielding, etc. on the surface corresponding to the tidal zone region of the surface of the marine structure. Corrosion, erosion due to waves, and further, anti-corrosion reinforcement method for marine structures capable of effectively and effectively suppressing impact due to collision of suspended matter, etc., and anti-corrosion, impact resistance, An object of the present invention is to provide an offshore structure having excellent wear resistance and the like.

According to the present invention, a step (A) of providing a seawater damming member so as to surround at least the tidal zone region of the surface of the offshore structure and providing a work space with a closed bottom, and draining the seawater in the work space Step (B), drying the surface of the marine structure in the work space (C), and after step (C), the surface of the marine structure in the work space is modified to a desired location. And a step (D) of providing a sulfur material coating layer.
According to the present invention, there is provided an offshore structure characterized by having a modified sulfur material coating layer at least in a portion corresponding to a tidal zone region on the surface of the offshore structure subjected to the anticorrosion reinforcement method.

  Since the anticorrosion reinforcing method for marine structures of the present invention includes the steps (A) to (D) above, at least the surface corresponding to the tidal zone region of the marine structure surface, salt resistance, mechanical strength, water shielding, etc. It is possible to efficiently provide an improved modified sulfur material coating layer, and to effectively prevent the corrosion of marine structures, the erosion by waves, and the impact caused by the collision of suspended matters over a long period of time. Therefore, it is useful for anticorrosion reinforcement of existing offshore structures and anticorrosion reinforcement of newly installed offshore structures.

Hereinafter, the present invention will be described in more detail.
The marine structure for anticorrosion reinforcement in the present invention is not particularly limited as long as it is a structure that continuously contacts the sea and the outside air with the sea surface as a boundary. For example, a bridge foundation made of reinforced concrete, steel reinforced concrete, steel, etc. Department, revetment, breakwater, subsea oil field platform, etc. In particular, the present invention is effective for a marine structure made of reinforced concrete or steel-framed reinforced concrete, in which the anticorrosion reinforcing action of the present invention is remarkable.

The anticorrosion reinforcing method of the present invention includes a step (A) of providing a seawater damming member so as to surround at least a tidal zone region on the surface of an offshore structure and providing a work space with a closed bottom.
The seawater damming member used in the step (A) surrounds at least the tidal zone region of the surface of the marine structure where the working space, that is, the upper part is opened and the lower part and the side face are closed, and prevents the circulation of seawater. If it can, it will not specifically limit, Usually, a steel member can be used.
The form of the seawater damming member is, for example, a form that can secure a work space in which a work for providing a modified sulfur material coating layer to be described later can be performed at a location corresponding to at least the tidal zone region of the surface of the marine structure, or It may be in the form of a mold for forming the modified sulfur material coating layer. Further, the vertical length of the seawater damming member is not particularly limited as long as it can at least surround the tidal zone region, but is usually about 1 m longer than the upper and lower limits of the tidal zone region. It can be.

In the step (A), in order to provide the sea surface damming member on the surface of the marine structure, for example, the sea dam is placed at a predetermined position lower than the water level at low tide on the surface of the marine structure so as to surround the marine structure. A recess or projection for fixing the stop member is provided in the offshore structure. On the other hand, the seawater damming member is provided with a convex portion or a concave portion that can be fitted into the concave portion or the convex portion provided on the surface of the offshore structure, and the seawater damming member is It can be provided on the surface of the structure.
At this time, the seawater damming member is usually divided into a plurality of parts, and each seam damming member is finally integrated so as to surround at least the tidal zone region of the surface of the marine structure, and a seawater damming member having a desired form is provided. be able to.
The concave portion or the convex portion provided in the offshore structure can be provided at the time of newly installing the offshore structure, or can be provided on the existing offshore structure when the anticorrosion reinforcing method of the present invention is performed.

The anticorrosion reinforcing method of the present invention includes a step (B) of draining seawater in the work space provided in the step (A).
Seawater drainage in the step (B) can be carried out using a known drainage pump or the like.

The anticorrosion reinforcing method of the present invention includes the step (C) of drying the surface of the marine structure in the work space.
The drying in the step (C) may be natural drying, but can usually be performed using a heating device such as a burner.

The anticorrosion reinforcing method of the present invention includes a step (D) of providing a modified sulfur material coating layer at a desired location on the surface of the marine structure in the work space after the step (C).
For the material for forming the modified sulfur material coating layer used in the step (D), conventionally proposed, for example, sulfur produced by desulfurization of natural products or petroleum or natural gas, etc. by a sulfur modifier. Modified melt-modified sulfur can be used.

Examples of the sulfur modifier include olefinic hydrocarbons or diolefinic hydrocarbons having 4 to 20 carbon atoms, specifically, cyclic olefinic hydrocarbons such as limonene and pinene, styrene, vinyltoluene, methylstyrene, and the like. Aromatic hydrocarbons, dicyclopentadiene and oligomers thereof, cyclopentadiene, tetrahydroindene, vinylcyclohexene, vinyl norbornene, ethylidene norbornene, and diene hydrocarbons such as cyclooctadiene, or a mixture of two or more thereof. .
The modified sulfur can be obtained by melt-mixing sulfur and a sulfur modifier. Under the present circumstances, the usage-amount of a sulfur modifier is 0.1-20 mass% normally with respect to sulfur, and 1.0-10 mass% is especially preferable.
If the ratio of the sulfur modifier is less than 0.1% by mass, sulfur cannot be sufficiently modified, and desired mechanical strength or the like may not be exhibited.

In addition to the modified sulfur, the modified sulfur material coating layer is blended with fine aggregates, other fillers, etc. in order to obtain other effects without impairing the desired effects of the present invention. Can do.
As the fine aggregate, an inorganic fine aggregate having a particle diameter of 5 mm or less, preferably 1 mm or less can be used. For example, coal ash, silica sand, silica fume, quartz powder, sand, glass powder, electricity Dust collection ash, ferronickel slag powder, etc. are effective.
The blending ratio of the fine aggregate is usually 20 to 200 parts by mass, particularly 40 to 150 parts by mass with respect to 100 parts by mass of the modified sulfur. When the blending ratio of the fine aggregate is less than 20 parts by mass, the desired mechanical strength or the like may not be exhibited.
Examples of other fillers include fibrous fillers, fibrous particles, flaky particles, and the like.
Examples of the fibrous filler include vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, carbon fiber, or a mixture thereof.

In the step (D), the modified sulfur material coating layer is formed by melting and modifying the working seam surrounded by the mold and the surface of the marine structure when the seawater dam member is installed as a mold. The modified sulfur material coating layer can be provided by filling the solid sulfur material and solidifying it.
In addition, when a working space other than the formwork provided with the modified sulfur material coating layer is secured by the seawater damming member, for example, the modified sulfur is formed on the surface portion corresponding to at least the tidal zone region of the marine structure. The modified sulfur material coating layer can be provided by the method (1) for adhering the material plates or the method (2) for spraying the molten modified sulfur material. The mold does not necessarily need to be removed after the modified sulfur material coating layer is formed, but when the modified sulfur material coating layer is formed by the above method, a step of removing the seawater damming member from the offshore structure ( E) can be carried out.
Before spraying the melt-modified sulfur material in the method (2), heating the surface of the marine structure where the modified sulfur material coating layer is provided strengthens the adhesion and fixing of the modified sulfur material coating layer. Therefore, it is preferable.

Preparation of the melt-modified sulfur material filled in the formwork or sprayed by the method (2) is, for example, a modified sulfur melt and the specific fine aggregate or other fillers 120 ~ It can carry out by mixing at 160 degreeC.
On the other hand, the modified sulfur material plate used in the method (1) is prepared by, for example, mixing the modified sulfur melt with the specific fine aggregate or other filler at 120 to 160 ° C. It can be obtained by a method of introducing into a form mold and cooling and solidifying while applying vibration, ultrasonic waves, or the like.
The modified sulfur melt is obtained by melting and mixing sulfur and a sulfur modifier in a range of 120 to 160 ° C. using a known various warmable mixer, for example, to sufficiently reform sulfur. And the viscosity at 140 ° C. is usually 0.05 to 1.0 Pa · s, preferably 0.05 to 0.5 Pa · s.
The modified sulfur melt, fine aggregate and other fillers can be mixed by preheating the fine aggregate to about 120 to 160 ° C. and mixing at a desired temperature that maintains the molten state.
The desired effect can be maintained for a long time by setting the thickness of the modified sulfur material coating layer to 1 to 100 mm, preferably 5 to 30 mm.

The method (1) can be carried out by sticking a modified sulfur material plate to an area where the modified sulfur material coating layer is formed using an epoxy-based adhesive or the like.
In carrying out the method (2), the surface of the marine structure forming the modified sulfur material coating layer is roughened by forming irregularities or the like, thereby strengthening the fixation of the modified sulfur material coating layer. Can do.

The offshore structure of the present invention has a modified sulfur material coating layer on the outer surface corresponding to at least the tidal zone region on the surface of the offshore structure subjected to the above-described anticorrosion reinforcing method of the present invention.
The region for forming the modified sulfur material coating layer is preferably a wide area of about 1 m above and below the tidal zone region, and the thickness of the modified sulfur material coating layer is usually 1 to 100 mm, preferably It is about 5-30 mm.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
FIG. 1 is a schematic cross-sectional view for explaining a preferred embodiment of the anticorrosion reinforcing method for an offshore structure of the present invention, wherein 10 includes a tidal zone region of a concrete pier 11 made of an offshore structure. The state in which the modified sulfur material coating layer 13 is provided around is shown.
In FIG. 1, a concave portion 11 a that protrudes radially is provided below the pier 11, and a steel seawater damming member 12 that tapers downward is provided with a convex portion 12 a provided below the member 12. Is fitted into the recess 11a. The attachment can be usually performed by using a plurality of seawater damming members 12 and joining the members 12 together.
A working space 14 is formed by the seawater damming member 12 and the outer surface of the pier 12. Moreover, in FIG. 1, 15 shows the wave front of seawater.

In the anticorrosion reinforcing method of the aspect shown in FIG. 1, the bottom portion is closed by fitting the seawater damming member 12 and the convex portion 12a to the concave portion 11a so as to surround at least the tidal zone region of the outer surface of the pier 11. A working space 14 is provided.
Immediately after the seawater damming member 12 is installed, seawater has entered the working space 14 up to the height of the wavefront 15 of the seawater.
Therefore, seawater (not shown) in the work space 14 is drained using a drainage pump or the like.
The outer surface of the pier 11 after drainage is in a moist state and seawater is often infiltrated into the inside, and it is difficult to install the modified sulfur material coating layer as it is. dry.

  Next, in order to form the modified sulfur material coating layer 13 around the pier 11 in the work space 14, for example, when the outer surface of the pier 11 is a rectangular parallelepiped or the like, the modified sulfur material plate shown in FIG. When the outer surface of the pier 11 is a curved surface using a plurality of modified sulfur material plates 30 having the curved surface shown in FIG. 3, the following method can be used. . Each modified sulfur material plate (20, 30) can be prepared by the above-described method using the above-described materials.

The modified sulfur material plate (20, 30) can be attached to a predetermined portion of the pier 11 using an adhesive.
As a method not using the modified sulfur material plate (20, 30), the modified sulfur material coating layer 13 is formed by a method of spraying the molten modified sulfur material onto a predetermined portion of the pier 11 using a spraying machine. It can be formed around the pier 11. At this time, before the spraying, the predetermined portion of the pier 11 is heated in advance by a burner or the like, or the surface of the pier 11 is roughened, thereby fixing the modified sulfur material coating layer 13 formed by the spraying. Can be strong.
After the modified sulfur material covering layer 13 is formed around the pier 11, the seawater damming member 12 is removed from the pier 11 so that the ocean having the modified sulfur material covering layer 13 at least in a portion corresponding to the tidal zone region. A structure can be obtained.

FIG. 4 is a schematic cross-sectional explanatory view for explaining another aspect of the anticorrosion reinforcing method for an offshore structure of the present invention. 40 is a tidal zone region of a concrete pier 11 made of concrete that is an offshore structure. The state which provided the formwork 42 for providing a modified sulfur material coating layer in the circumference | surroundings containing is shown.
In FIG. 4, a recess 41 a is provided in a circular shape below the pier 41, and a seawater damming member 42 for forming a steel mold for forming a modified sulfur material coating layer is provided on the pier 41. The convex part 42a provided under the member 42 is attached by fitting the concave part 41a. The attachment can be usually performed by using a plurality of seawater damming members 42 and installing them by a method of joining the members 42, and the installed members 42 form a modified sulfur material coating layer. It can be used as a mold having the working space 43.
Moreover, in FIG. 4, 45 shows the wave surface of seawater.

In the anticorrosion reinforcing method of the aspect shown in FIG. 4, the bottom is closed by fitting the seawater damming member 42 and the convex portion 42a to the concave portion 41a so as to surround at least the tidal zone region of the outer surface of the pier 41. A working space 43 is provided.
Immediately after installing the seawater damming member 42, the seawater has entered the work space 43 to the height of the wavefront 45 of seawater.
Therefore, seawater (not shown) in the work space 43 is drained using a drainage pump or the like.
Since the outer surface of the pier 41 after drainage is in a moist state and seawater is often infiltrated into the inside, it is difficult to install the modified sulfur material coating layer as it is. Dry thoroughly with a burner.

Next, a modified sulfur material coating layer (not shown) can be provided by filling the work space 43 with the above-described melt-modified sulfur material and solidifying it.
The seawater damming member 42, which is a mold after forming the modified sulfur material coating layer, can be removed, but the modified sulfur material coating layer is provided at least at a location corresponding to the tidal zone region as it is. It can also be set as a marine structure having

It is a cross-sectional schematic explanatory drawing for demonstrating the one aspect | mode of the anticorrosion reinforcement method of this invention. It is a schematic perspective view which shows an example of the modified sulfur material board used for the anticorrosion reinforcement method of this invention. It is a schematic perspective view which shows another example of the modified sulfur material board used for the anticorrosion reinforcement method of this invention. It is a cross-sectional schematic explanatory drawing for demonstrating the other one aspect | mode of the anticorrosion reinforcement method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 41: Pier 11a, 42a: Convex part 12: Seawater blocking member 12a, 41a: Concave part 13: Modified sulfur material coating layer 14, 43: Work space 15, 45: Wave surface 20, 30 of seawater Material plate 42: formwork

Claims (6)

A step (A) of providing a seawater damming member so as to surround at least the tidal zone region of the surface of the offshore structure and providing a work space with a closed bottom;
Draining the seawater in the work space (B),
Drying the surface of the marine structure in the work space (C),
A step (D) of providing a modified sulfur material coating layer at a desired location on the surface of the marine structure in the work space after the step (C).   The seawater dam member is a mold, and in step (D), the work space enclosed by the mold and the surface of the marine structure is filled with molten modified sulfur material and a modified sulfur material coating layer is provided. The anticorrosion reinforcement method according to claim 1.   In step (D), the modified sulfur material coating layer is formed by a method (1) for adhering the modified sulfur material plate to a surface portion corresponding to at least the tidal zone region or a method (2) for spraying a molten modified sulfur material. And the step (E) of removing the seawater damming member from the offshore structure after the step (D).   In performing a process (A), the recessed part or convex part for joining the said seawater damming member is provided in the predetermined location of the offshore structure surface, The any one of Claims 1-3 characterized by the above-mentioned. Anti-corrosion reinforcement method.   The anticorrosion reinforcement method according to any one of claims 1 to 4, wherein the surface of the offshore structure where the modified sulfur material coating layer is provided is made of cement concrete.   An offshore structure characterized by having a modified sulfur material coating layer at a position corresponding to at least a tidal zone region on the surface of the offshore structure, which has been subjected to the anticorrosion reinforcing method according to any one of claims 1 to 5.

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