JPS61274012A - Reinforcing and corrosion prevention of marine steel structure - Google Patents

Abstract

PURPOSE:To easily reinforce a marine steel structure by a method in which the reinforcing range of a steel structure set on the sea is surface prepared and attached with a reinforcing plate, and a water-curable resin is packed or coated between the steel structure and the reinforcing plate and on the outside of the reinforcing plate. CONSTITUTION:The ebb and flow zone 12 and splash zone 13 of a steel pile 11 to be used as the strut of concrete part 10 are measured by a supersonic thickness meter, and on the basis of the thickness so measured, the corrosion condition of the pile 11 is surveyed. The whole surface of a reinforcing range determined from the corrosion condition is treated with surface preparation, the corroded portion is removed, and two-halved reinforcing materials 14 and 15 are welded to the periphery of the steel tube 11 exposed to the surface. A water-curable resin, e.g., liquid epoxy resin, etc., is packed between the pile 11 and the reinforcing materials 14 and 15 and coated on the outside of the materials 14 and 15. The life of the marine structure so repaired can thus be lengthened and the strength of the corroded portion can also be raised.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for reinforcing and preventing corrosion of marine steel structures, and in particular, the use of an underwater-curing paint made of a synthetic resin material on the surface of a final finished marine steel structure. This invention relates to a method for reinforcing and preventing corrosion of marine steel structures coated with

[Conventional technology]

In recent years, marine steel structures using steel piles, steel sheet piles, etc. have been constructed in various places, but at the time of construction, these marine steel structures are coated with paint or other suitable anti-corrosion treatment. but,
In particular, in the tidal zone (also called the soubrush zone) and its splash zone, the current situation is that it gradually corrodes over time due to the influence of oxygen in the air and seawater. These marine steel structures are not normally located in accessible locations like land-based steel structures, and due to problems such as landing on a ship, the period of corrosion protection is delayed, and when it comes time to apply anti-corrosion treatment,
In some cases, the wall thickness of marine steel structures such as steel piles and steel sheet piles has already become so thin that they no longer have durable strength.

In addition, in some cases, when surface treatment such as sandblasting was performed, holes were already found in some cases.

Therefore, before such cases, the corroded parts of the marine steel structure were demolished and rebuilt again.

However, in recent years, in some cases, bars are stand-welded to the corroded parts of marine steel structures, reinforcement is placed on the bars, a frame is built around it, and mortar or concrete is poured inside. The marine steel structures mentioned above were also reinforced with reinforced concrete structures.

[Problem that the invention seeks to solve]

The method of reinforcing the marine steel structure with the above-mentioned reinforced concrete structure has the disadvantage that the equipment becomes large, so it has had the problem that it has only been employed experimentally at present.

Furthermore, the method of reinforcing the above-mentioned marine steel structures with the above-mentioned reinforced concrete structure has the problem that the construction period is long.

It is also possible to demolish the corroded marine steel structure and rebuild it, but if the marine steel structure is large, the construction cost will be high and the construction will take time. There was a problem that.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for reinforcing and preventing corrosion of marine steel structures, which is relatively easy to perform and also has a short construction period.

c) Means for Solving Problems] A method for reinforcing and preventing corrosion of a marine steel structure according to the first invention in accordance with the above-mentioned object includes a step of measuring the wall thickness of a target marine steel structure and determining a reinforcement range. 1 step, and a 2nd step of performing surface treatment on the reinforced area of the marine steel structure, attaching a reinforcing plate to the reinforced area of the marine steel structure that has undergone the surface treatment, and furthermore, installing a reinforcing plate on the back side of the reinforcing plate. A third step of filling an underwater curing reinforcing auxiliary material made of a synthetic resin material, a fourth step of preparing the surface of the outer surface of the marine steel structure including the reinforcing area to which the reinforcing material is attached in the above step, and a synthetic resin material. and a fifth step of applying an underwater curable paint made of a resin material to the surface of the marine steel structure whose outer surface has been subjected to surface preparation.

Here, the term "marine steel structure" refers to steel piles, sheet piles, etc. that are constructed underwater, as in the second invention, and the term "base treatment" refers to appropriately treating the surface of the marine steel structure. It means to perform keren treatment.

In addition, in the third step, filling of the underwater hardening reinforcing material is carried out after fixing the reinforcing plate to the reinforcing area of the marine steel structure.
It is possible to perform this by injecting it into the back of the reinforcing plate, but it may also be done by applying it to the back of the reinforcing plate to be attached or the reinforced area of the marine steel structure.

Note that it is also possible to use the same underwater-curable reinforcing material and underwater-curable paint.

A method for reinforcing and preventing corrosion of a marine steel structure according to a second invention in accordance with the above object includes a first step of measuring the wall thickness of a target marine steel structure and determining a reinforcement range; A second step of performing surface treatment on the reinforced area of the steel structure, a third step of attaching a reinforcing plate to the reinforced area of the marine steel structure that has undergone the surface treatment, and a reinforcing area on which reinforcing materials have been attached in the above steps. The fourth step is to prepare the external surface of marine steel structures including
and a fifth step of applying an underwater curable paint made of a synthetic resin material to the surface of the marine steel structure whose outer surface has been subjected to surface preparation.

[Effect]

Next, to explain the effects of the method for reinforcing and preventing corrosion of marine steel structures according to the first invention, first, in the first step, the tidal zone and the splash zone of the most corroded part of the target marine steel structure. Measure the wall thickness of the corroded area and determine the area to be reinforced.

Then, in the second step, the surface treatment of the reinforced area is performed. This surface treatment is performed by first removing shells and the like attached to the marine steel structure with a scraper and removing corrosive substances such as rust by sandblasting, which is an example of scraping. This is done by removing the steel structure to expose the non-corroded parts of the marine steel structure.

Next, in a third step, a reinforcing plate previously manufactured in a predetermined shape is attached to the reinforced area where the base has been treated by welding, riveting, gluing, etc. to reinforce the marine steel structure.

In this case, the back side of this reinforcing member is filled with an underwater curable reinforcing auxiliary material made of a synthetic resin material. As a result, the space between the marine steel structure and the reinforcing material is filled with the underwater hardening reinforcing auxiliary material, and the marine steel structure is further reinforced by the underwater hardening reinforcing auxiliary material.

After that, in the fourth step, the surface of the marine steel structure to which the reinforcing material has been attached is subjected to surface preparation by sandblasting, etc. This removes mackerel, etc. on the surface of the marine steel structure and forms an anchor pattern. let

Next, in a fifth step, an underwater curable paint is applied to the surface of the surface-treated marine steel structure. In this case, since the above-mentioned anchor pattern is formed on the surface of the surface-treated marine steel structure, the bonding area increases and
Underwater curing paints adhere easily. Since the surface of the marine steel structure is protected by this underwater curable paint, the coated part will no longer corrode.

Next, regarding the effects of the method for reinforcing and preventing corrosion of marine steel structures according to the second invention, differences in the method for reinforcing and preventing corrosion for marine steel structures according to the first invention will be explained. The method for reinforcing and preventing corrosion of marine steel structures is different from the method for reinforcing and preventing corrosion of marine steel structures according to the first invention in the following points.
In the third step, the back side of the reinforcing plate is not filled with an underwater curing reinforcing material made of a synthetic resin material. this is,
This is because some marine steel structures are corroded in a plane, and in particular, there are cases where it is not necessary to fill the gap between the marine steel structure and the reinforcing plate with a reinforcing material or the like.

〔Example〕

Next, embodiments embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention.

Here, FIG. 1 is a partially cutaway side sectional view of a steel pile which is an example of a marine steel structure to which the method for reinforcing and preventing corrosion of a marine steel structure according to an embodiment of the first invention is applied. .

First, a method for reinforcing and preventing corrosion of a marine steel structure according to the first invention will be explained.

The steel piles 11 used as supports for the existing concrete section 10 in the marine steel structure shown in FIG.

The tidal zone 12, which is the middle part of L, and the splash zone 13, which receives seawater splashes from waves, etc., usually receive a sufficient supply of oxygen from the air, so they corrode and become thinner. There is. Therefore, in order to repair and prevent corrosion of this part, the method for reinforcing and preventing corrosion of marine steel structures according to the first invention is applied. After exposing the surface of the steel pile 11 using an ultrasonic thickness needle or the like, the wall thickness of the steel pile 11 is measured to examine the corrosion situation and determine the reinforcement area (first step).
Next, the entire surface of the reinforced area is treated to remove oyster shells, Fujibbo, etc., and corroded parts, and the surface of the steel pile 11 is exposed. In this case, apply plastic polishing to the part where the reinforcing plate is installed and the back side of the reinforcing material.
(Second step) Then, reinforcing members 14 and 15, which have been made in a predetermined shape and divided into two parts, are attached to the steel pile 11 by welding the periphery thereof to this reinforcing area. In this case, either drill a hole in an appropriate location or provide a part that will not be welded.
From there, an epoxy resin, which is an example of a liquid underwater-curable reinforcing auxiliary member, is injected into the gap between the reinforcing area of the steel pile 11 and the reinforcing plate to fill it.

Note that filling the above epoxy resin can also be done by applying the epoxy resin to either or both of the reinforcing range part or the reinforcing material 14.15 in advance and then welding it to the reinforcing range part (as described above). , 3rd step).

Then, after waiting for the epoxy resin, which is an example of these reinforcing auxiliary members, to harden, the reinforcing materials 14 and 15 are added.
The surface of the steel pile 11 including the surface of the steel pile 11 is subjected to a scuffing treatment, which is an example of no surface treatment. The area to be subjected to this cleaning treatment is not only the tidal zone 12 and the splash zone 13, but also all the areas that are expected to corrode even under the sea surface.

Then, in this keren treatment, sandblasting is used for both the upper part of the water and the underwater part, and the blast polishing is 5a-2, 5 or more, and the anchor pattern is finished with silica sand to have an anchor pattern of 2 mil or more (fourth step).

After this, the underwater curable epoxy resin 16 is applied by hand method.
311--Apply to a thickness of 5 mm. The properties of this underwater curable epoxy resin are shown in Table 1 below.

Table 1 Accordingly, this underwater-curable epoxy resin 16 has a certain strength when hardened, so it serves as a reinforcing material for the steel pile 11, and since it is applied to the surface of the steel pile 11, it has a corrosion-preventing effect. It will have an effect (fifth step).

Next, the differences between the method for reinforcing and preventing corrosion of a marine steel structure according to the second invention and the method for reinforcing and preventing corrosion for a marine steel structure according to the first invention will be explained. The difference is that an underwater hardening reinforcing material is not filled between the plates 14 and 15 and the steel pile 11 rather than a synthetic resin material.

This is because depending on the corrosion state of the steel pile 11, it may not necessarily be necessary to fill the space between the reinforcing plate 14, 15 and the steel pile 11 with an underwater-curable reinforcing material instead of a synthetic resin material.

Of course, in this case as well, the underwater curable epoxy resin is ultimately applied to the surface, thereby reinforcing the steel pile 11 and preventing corrosion of the steel pile 11.

In the above embodiment, the reinforcing plate 14.15 has a two-divided structure, but it can also be divided into three or more parts. Also, the reinforcing plate 14.15 can be further supported at the bottom of the reinforcing plate 14.15. It is also possible to attach the supporting plate 17 by welding or the like. In this case, in order to increase the welded portion with the steel pile 11, it is also possible to appropriately form holes in the reinforcing plate and the support plate and weld overlay in these portions.

Next, in the first step of the method for reinforcing and preventing corrosion of marine steel structures according to the embodiments of the first and second inventions, as a result of measuring the wall thickness of a steel pile, which is an example of a marine steel structure, it was found that corrosion This section explains what to do when the wall thickness of the steel pile becomes too thin or there are holes.

Here, FIG. 2 is a perspective view for explaining a method for reinforcing and preventing corrosion of a marine steel structure according to a modification of the present invention, and FIG. 3 is a side view for explaining the above method. As shown,
When we measured the thickness of the steel pile 20, which is an example of a marine steel structure, we found that the tidal zone and splash zone portions were too corroded. The steel pile 23 is cut and removed, and a new steel pile 23 manufactured to a predetermined length is inserted into the cut portion, and the entire area around it is welded.

Thereafter, the portion to be corroded is subjected to surface treatment in the same manner as the fourth step of the method for reinforcing and preventing corrosion of marine steel structures according to the embodiment of the first invention, and In the same operation as Step 5, an underwater curable epoxy resin is applied to the surface of the steel piles 20 and 23 that have undergone surface treatment to prevent corrosion.

Then, as shown in FIG. 3, a hole of a predetermined size is provided in a part of the steel pile 20 above the water surface, and an air hose 24, which is an example of an air transport pipe for sending high-pressure air, is connected to the lower part of the steel pile 20. A hole is also provided on the side of the nearby steel pile 20, and the steel pile 20 is inserted inside.
A pipe 25, which is an example of an air and water transport pipe that reaches the bottom of the tank, is inserted.

After this, when air is sent into the steel pile 20 from the air hose 24, the water accumulated in the steel pile 20 comes out from the vibrator 25, and finally, the air sent from the air hose 24 comes out from the vibrator 25. become.

After such a state is reached, the pipe 25 is removed from the hole and this hole is closed by welding or the like, and the air hose 24 is removed from the upper hole and this hole is also closed by welding or the like. As a result, the water accumulated inside the steel pile 20 can be almost completely drained out, so that the steel pile 20 is less likely to be corroded from inside.

Note that although water in the steel pile 20 was drained after applying the underwater curable epoxy resin to the steel pile 20, it can also be performed before applying the underwater curable epoxy resin to the steel pile 20.

〔Effect of the invention〕

The present invention is constructed as described above, and the work is carried out by utilizing the existing marine steel structure as much as possible, so that the work can be easily carried out and the construction period can be shortened.

In addition, in the final process, an underwater curing paint made of synthetic resin material is applied to the parts of the marine steel structure that are prone to corrosion.
The lifespan of the marine steel structure after repair is extended, and since the underwater curing paint also serves as a reinforcing material, it becomes possible to compensate for parts lost due to corrosion.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side sectional view of a steel pile, which is an example of a marine steel structure to which the method for reinforcing and preventing corrosion of marine steel structures according to an embodiment of the first invention is applied, and FIG. FIG. 3 is a perspective view for explaining a method for reinforcing and preventing corrosion of a marine steel structure according to a modification of the present invention, and FIG. 3 is a side view for explaining the method. [Explanation of symbols] 11-...- Steel pile, 12-- Tidal zone, 13- Four- Splash zone, 14.15-- Reinforcement plate,
16-------...Underwater curable epoxy resin (underwater curable paint) Patent applicant: Nishinippon Tokushu Kogyo Co., Ltd. Representative Patent attorney During his lifetime: Fujio Figure 2 Figure 3

Claims (5)

[Claims] (1) A first step of measuring the wall thickness of the target marine steel structure and determining the reinforcement range; a second step of performing surface treatment for the reinforcement range of the marine steel structure; and the surface treatment. A third step is to attach a reinforcing plate to the reinforced area of the reinforced marine steel structure, and to fill the back of the reinforcing plate with an underwater curing reinforcing material made of a synthetic resin material, and to install the reinforcing material through the above steps. a fourth step of preparing the outer surface of the marine steel structure, including the reinforced area, and a fourth step of applying an underwater curable paint made of a synthetic resin material to the surface of the marine steel structure that has been subjected to the outer surface preparation treatment. A method for reinforcing and preventing corrosion of marine steel structures, comprising the steps of: (2) In the third step, filling of the underwater hardening reinforcing material is carried out after fixing the reinforcing plate to the reinforcing area of the marine steel structure.
A method for reinforcing and preventing corrosion of a marine steel structure according to claim 1, which comprises injecting into the back side of the reinforcing plate. (3) In the third step, filling of the underwater curing reinforcing auxiliary material is performed by applying it to the back of the reinforcing plate to be attached or to the reinforcing area of the marine steel structure, as set forth in claim 1. reinforcement and corrosion protection methods for marine steel structures. (4) A method for reinforcing and preventing corrosion of a marine steel structure according to claim 1, 2 or 3, wherein the marine steel structure is a steel pile or a sheet pile. (5) A first step of measuring the wall thickness of the target marine steel structure and determining the reinforcement range, a second step of performing surface treatment for the reinforcement range of the marine steel structure, and said base treatment. a third step of attaching a reinforcing plate to the reinforced area of the marine steel structure;
A fourth step of preparing the outer surface of the marine steel structure including the reinforced area where the reinforcing material is attached in the above step, and applying an underwater curable paint made of a synthetic resin material to the marine steel structure whose outer surface has been subjected to the above-mentioned surface preparation. A method for reinforcing and preventing corrosion of marine steel structures, comprising a fifth step of coating the surface.