JPH0477082B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) This invention relates to the so-called earth retaining method used in bank protection work, landslide prevention work, residential land preparation work, etc., and in particular, the present invention relates to the so-called earth retaining method used in bank protection work, landslide prevention work, residential land preparation work, etc. Regarding the earth retaining method that takes into consideration the following. (Background of the Invention) In recent years, environmental conservation and maintenance of the scenery of scenic spots have become more important, and even in the above-mentioned construction projects, the aesthetic appearance after construction is often an issue. For example, rivers,
In the construction of shore protection for lakes and marshes, it is not enough to simply achieve the construction purpose of earth retention; after construction, consideration must be given to ensure that the parts that are particularly visible to the public blend in well with the surrounding environment. On the other hand, in order to reduce construction costs, it is necessary to use materials as cheap as possible and to proceed with construction efficiently. Civil engineering materials that meet these requirements include steel sheet piles, steel pipe piles, and shaped steel. However, these steel materials themselves develop rust, which is characteristic of steel materials, in environments where civil engineering works are carried out, and they do not maintain their aesthetic appearance for a long time after construction. Therefore, civil engineering steel materials are sometimes subjected to some kind of surface treatment to prevent rust and maintain their aesthetic appearance, but as will be explained later, the methods proposed so far have either been ineffective or require too much effort to be put into practical use. There is no sex. Therefore, there is currently a strong demand for an earth retaining method that is easy to construct and can maintain its aesthetic appearance over a long period of time. (Prior Art) Civil engineering steel materials are, in principle, used as hot-rolled without any special surface treatment. However, when used in areas where corrosion is particularly severe, such as on the coast,
Zn plating and application of anti-rust paint are carried out in some areas as anti-rust treatment. However, such surface treatments are not particularly aesthetically pleasing and do not match the surrounding environment of the construction site. Zn
Silver-white plating and vermillion rust-prevention paint often stand out from the surrounding natural environment and spoil the landscape. One possible way to solve the above problem is to cover the surface of the steel material, especially the parts that are visible to the public after construction, with a decorative material that matches the surrounding environment. There are many types of such decorative materials, such as plastic mortar such as polymer cement mortar (PCM), resin mortar, artificial stone panels, synthetic resins, and wood.
However, even if these decorative materials are attached to steel materials, such as steel sheet piles, the adhesive strength is low, so
When steel is placed during earth retaining work, the decorative material will peel off due to shock and vibration. Even if decorative materials remain after construction, they are not durable and will fall off in a short period of time. Therefore, when using such decorative materials, it is best to first pour bare steel and carry out construction. After finishing the work, we will have to do some more cosmetic finishing work. FIG. 4 is a conceptual diagram illustrating such conventional earth retaining construction using decorative materials. That is, after completing the earth retaining work in which steel materials (for example, steel sheet piles) 10 are installed as shown in Figure 4A, the water is dammed up as shown in Figure 4B, and forms and scaffolding are erected to construct decorative materials. 11 is injected, pasted, or sprayed. Even with such extremely time-consuming construction work, the inherent weak adhesive strength between the steel and decorative materials has not been resolved, so over time the decorative materials will peel off and rust will appear in those areas. The aesthetic appearance is significantly impaired. In short, until now there has been no decorative steel material for civil engineering that can withstand pouring and other installation work at construction sites and maintain its aesthetic appearance over a long period of time, so the extra construction work described above has been forced. Moreover, it has not fully achieved its purpose. (Problems to be Solved by the Invention) An object of the present invention is to provide a new construction method, especially an earth retaining construction method, for constructing decorative steel materials in places that are visible to the public after construction, and further,
This was done with the aim of maintaining its decorative quality long after construction and contributing to environmental conservation. (Means for Solving the Problems) The gist of the present invention lies in the following earth retaining methods (1) and (2). (1) At least part of the surface has been chemically treated
An earth retaining method characterized by installing a decorative steel material covered with a mechanical plating film of Fe-Zn alloy or Fe-Zn-Al alloy and a decorative material layer formed on the film. (2) At least a part of the surface is Zn, Al or
A plating layer of Zn-Al alloy, a mechanical plating film of Fe-Zn alloy or Fe-Zn-Al alloy formed on this plating layer and chemically treated, and a decorative film formed on this film. An earth retaining method characterized by installing decorative steel covered with a layer of steel. Before explaining each construction method of the present invention, the knowledge that forms the basis of the present invention will be described. Conventionally, the reason why it has not been possible to construct steel materials to which decorative materials have been applied in advance in the same way as general steel materials is because the durability of the adhesive force between the steel materials and the decorative materials is weak, as described above. As-rolled steel or this
Even if a decorative material such as the one described above is attached to a steel plated with Zn, Al, etc., the adhesive durability decreases, especially during pouring work during construction. However, if the adhesive strength is increased to improve durability and to withstand installation work, the work can be carried out in the same way as when using ordinary steel materials, and the total cost of work can be reduced significantly. The present inventor focused on applying surface treatment technology, which has recently made remarkable progress, to the production of steel materials for civil engineering, and as a result of numerous tests, the inventor applied a special base treatment to the surface of the steel material before pasting the decorative material. It was confirmed that the above-mentioned adhesive strength and adhesive durability can be greatly improved by applying the adhesive. Moreover, this surface treatment also contributes to rust prevention of steel materials, extending the life of steel materials in harsh corrosive environments. First, the construction method of the first invention of the present application will be explained. FIG. 1 is a schematic cross-sectional view of the steel used in this construction method. As shown in the figure, there is a mechanical plating film 3 on the surface of the steel material 1, and a decorative material 2 is placed on the mechanical plating film 3. This mechanical plating film uses Fe-Zn alloy or Fe-Zn alloy as steel ball core material.
- Fe-
Zn alloy or Fe-Zn-Al alloy is mechanically applied. The basic technology of this mechanical plating is disclosed in Japanese Patent Publication No. 59-9312, but the mechanical plating used in the present invention is not limited to that introduced in the above-mentioned publication.
Any method that can mechanically form a predetermined alloy film on the surface of the steel material can be used, such as a method of spraying a mixture of Zn grains and Fe grains. In addition, Fe-Zn alloy or Fe is used as the mechanical plating film.
-Zn-Al alloy was chosen because these films have excellent corrosion resistance and are inexpensive, and the mechanical plating technology has also been completed. Note that even with Fe-Zn alloys, pure Zn phase is often mixed in the film because it is mechanically plated. In the present invention, such a film is also referred to as a mechanical plating alloy film. The film formed by mechanical plating is more porous than the normal plated metal film obtained by electroplating or molten metal plating (dobu-metal plating). There are many entrances and exits on the surface, and the so-called roughness is large.
According to the inventor's actual measurement results, this roughness is 5 in R _nax .
~20. With such a surface, the adhesion to the decorative material is extremely good as described above. For example, when spray painting cement-based decorative materials,
Even in cases where panels of wood or artificial stone are attached using adhesives, mechanical plating films have good wettability with cement mortar and adhesives, and their moderate roughness provides an anchoring effect. It has sufficient workability. Mechanical plating as a surface treatment is a so-called dry plating method that does not use an aqueous solution or heat like electroplating or melt plating, and if the equipment is devised, it not only allows continuous plating of long materials. It has many advantages such as being able to perform plating treatment at civil engineering construction sites. However, as mentioned above, since the film is porous, the corrosion resistance is somewhat inferior compared to normal plating. In order to improve this point, chemical conversion treatment is applied to the mechanical plating film. A suitable chemical conversion treatment is chromate treatment or phosphate treatment, and when this treatment is performed, the coating is impregnated with a chromate or phosphate treatment agent, and corrosion resistance is dramatically improved. In particular, the present applicant and others previously proposed a chemical conversion treatment method for Fe-Zn mechanical plating film (see Japanese Patent Application Laid-Open No. 62-93383).
Water-based chromate treatment is the most suitable chemical conversion treatment. That is, chromic acid compound 0.1~
It is immersed in an aqueous solution containing 50 g/l of sulfuric acid and 0.01 to 5 g/l of sulfuric acid, or coated or sprayed with this solution. The mechanical plating film that has been chemically treated as described above has excellent corrosion resistance by itself, so even if the decorative material on the steel surface cracks or is partially missing during long-term use. , there is no risk of the base rusting rapidly and damaging the aesthetics. The thickness of the mechanical plating film can be selected depending on the environment in which the steel material is used (corrosion conditions, etc.), but is generally about 3 to 5 μm. Various materials can be used as the decorative material 2 depending on the purpose of use of the steel material, especially the environment in which earth retaining work is performed. For example, for bank protection work around a dam, a cement-based decorative material that matches the dam's concrete structure is appropriate, while for scenic spots such as lakes and marshes, panels of natural stone, similar artificial stone, or wood-based materials are selected. Examples of such decorative materials are listed below. Wood-based: Cedar, cypress, paulownia, etc. boards, plywood, etc. Metal-based: Aluminum, copper, titanium, stainless steel, etc. thin plates, synthetic resin-based: Acrylic resin, epoxy resin, urethane resin, etc. Plastic mortar-based: Polymer cent mortar, resin mortar, etc. Others Natural stone, artificial stone panels, crushed stone mixed materials, ceramic tiles, etc. These decorative materials can not only be used alone, but also by stacking them or changing the type depending on the steel part. Of course, this is also possible. For example, when plastic mortar is used as a decorative material, this mortar is applied by spraying with various types of guns such as a mortar gun, but if a decorative film is further applied to the surface using various paints such as urethane resin paint, it can be used. You can add any pattern that blends well with your environment. Plastic mortar is extremely strong against bending, tension, impact, etc.
The water permeability is also very low compared to ordinary cement mortar, and together with its good adhesion to steel materials, it prevents damage such as cracking and peeling of the coating layer and corrosion of steel materials over a long period of time. It is possible to prevent this from spreading and achieve excellent durability. If a panel of wood or artificial stone is used as the decorative material, for example, it will be adhered to the underlying mechanical plating film using a suitable adhesive. As the adhesive, the above-mentioned plastic mortar, etc. can be used, and acrylic adhesive, epoxy adhesive, polyimide adhesive, etc. can also be used. Next, the construction method of the second invention of the present application will be explained. FIG. 2 is a view similar to FIG. 1 of the steel materials used in this construction method. Here, there is a plating layer 4 and a mechanical plating film 3 between the steel material 1 and the decorative material 2. The plating layer 4 is a normal (not mechanical plating) plating layer of Zn, Al, or Zn-Al alloy. This is melting (dobuzuki),
It is applied to the surface of steel by common methods such as electroplating or thermal spraying. Its thickness is approximately 20~
The thickness is preferably about 100 μm, but since a mechanical plating film is formed thereon, it may be thinner than 20 μm, and chemical conversion treatment is also unnecessary.
Due to the presence of this plating layer 4, the corrosion resistance of the steel material is
This is a further improvement over that shown in FIG. The mechanical plating film 3 in FIG.
It is formed in the same manner as in FIG. 1 and subjected to chemical conversion treatment. Then, the above-mentioned decorative material is layered on top of this. Although the steel materials shown in FIGS. 1 and 2 have been described above, it is not necessary to coat the entire surface of the steel material with such a decorative material. That is, after the construction of the earth retaining is completed, it is sufficient to cover only the parts that are likely to be seen by the public (in the case of bank protection work, the parts that are above the water surface) with decorative material. However, in order to prevent corrosion of steel materials, it is recommended that even just a surface treatment be applied to the entire surface. Now, the construction of earth retaining using decorative steel materials as described above can be carried out by, for example, driving (placing) using pressing force, vibration, and impact, spiral descent, excavation installation using jets, etc., and combinations thereof. I can do it. In the present invention, the installation of steel materials refers to arranging decorative steel materials for the purpose of earth retaining using various construction methods such as those described above. The adhesive durability of the decorative steel materials used in the method of the present invention is extremely high against shocks, vibrations, and collisions with earth and sand during the installation work as described above, and there is no possibility that the decorative material will peel off during the installation work. Never.
Therefore, if the decorative steel material is manufactured in a factory or in advance at a construction site, the installation work itself can be carried out in the same way as in the case of ordinary bare steel material. Figure 3 explains the earth retaining method of the present invention.
Steel material 10 with decorative material 11 applied in advance as shown in Figure A
After the installation is completed, the construction is completed by pouring the upper edge concrete 12 shown in Figure B. (Example) As shown in Table 1, test specimens were prepared by applying four types of base treatments to a steel plate and adhering cypress wood and polymer cement mortar (PCM) as decorative materials. Various tests were conducted as shown below. The steel plate is made of SS41 material with a size of 3 x 25 x 100 mm, and the decorative material, cypress wood (5 x 20 x 100 mm), is made using a two-component modified acrylic adhesive (product name: Visset).
71) at a pressure of 2 to 3 kg/cm ² . PCM was applied by spraying with a mortar gun to a thickness of approximately 2 to 3 mm. The test method shown in Table 1 is as follows. Water resistance test (according to JIS K-6857) 20℃/85%RH, 50℃ drying for 24 hours, 29 hours,
After 72 and 48 hours, it was left indoors for 7 days and the peel strength was measured. Dry-wet cycle A test (Japan Adhesive Association: Adhesive Durability Research Committee) 60±3℃ warm water immersion for 3 days and 60±3℃ open 4
Peel strength was measured every 1st, 5th, and 10th cycle, with one day being one cycle.

[Table] From the test results in Table 1, it can be seen that the steel plates prepared according to the present invention with a decorative material attached to them (test specimens A and B) showed poor performance, especially in the dry-wet cyclic test.
Test specimens C and D are superior. In addition, C is simply shot blasted unpainted steel surface, D is
is hot-dip galvanized only. Next, as shown in Table 2, the steel sheet piles were subjected to the same treatment as test pieces A and B in Table 1 (sheet piles E and F),
We conducted an installation that corresponded to the construction conditions of actual earth retaining work, and investigated the conditions at the time of installation and changes after one and two years. For comparison, on galvanized
PCM coated (G), regular galvanized material (H), anti-rust painted material (I) and unpainted material (J)
The results are also listed in Table 2. Installation was carried out using a vibration method using a vibrohammer. From the results in Table 2, it can be seen that according to the earth retaining method of the present invention, not only is there no damage to the decorative material during installation work, but there is also minimal deterioration over time after installation.

[Table] (Effects of the invention) As shown in the examples, according to the construction method of the present invention, which uses steel materials to which decorative materials are firmly attached, decorative steel materials to which decorative materials have been attached in advance can be installed as usual. By simply doing this, you can create earth retaining structures that harmonize with the surrounding landscape. In other words, it is no longer necessary to drain water again, erect scaffolding and formwork, and perform decorative finishing work after the installation work is completed, as in the past, and the effects of reducing construction costs and shortening the construction period are immeasurable. Moreover, the steel constructed using the method of the present invention far exceeds conventional steel in terms of corrosion resistance, so it will be effective for a long time both for the original purpose of earth retention and for maintaining the landscape. I can do it.

[Brief explanation of the drawing]

1 and 2 are schematic cross-sectional views of decorative steel materials used in the earth retaining method of the present invention. Figure 3 shows
FIG. 4 is a schematic diagram illustrating the earth retaining method of the present invention, and FIG. 4 is a schematic diagram illustrating a conventional earth retaining method using decorative materials.

Claims (1)

[Claims] 1. At least a part of the surface has been chemically treated.
An earth retaining method characterized by installing a decorative steel material covered with a mechanical plating film of Fe-Zn alloy or Fe-Zn-Al alloy and a decorative material layer formed on the film. 2 At least a part of the surface is Zn, Al or
A plating layer of Zn-Al alloy, a mechanical plating film of Fe-Zn alloy or Fe-Zn-Al alloy formed on this plating layer and chemically treated, and a decorative film formed on this film. An earth retaining method characterized by installing decorative steel covered with a layer of steel.