JP2012052313A - Method of coating surface of iron structure and iron structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of coating a surface of an iron structure excellent in fire resistance, exfoliation prevention and corrosion phenomenon prevention.SOLUTION: In the method of coating the surface of the iron structure, a cement lightweight coating material is coated on the surface of the iron structure so as to bury an exfoliation preventing material provided on the surface of the iron structure. The method includes: a step A of providing a non-through hole 3 on the iron structure; a step B of screwing a tapping screw 5 to the non-through hole 3; a step C of clamping the exfoliation preventing material by the screwed tapping screw 5 and the iron structure surface and fixing the exfoliation preventing material to the iron structure surface; and a step D of coating the cement lightweight coating material on the iron structure surface so as to bury the exfoliation preventing material.

Description

  The present invention relates to a method for coating an iron structure surface and an iron structure.

  Iron (for example, steel, cast iron) is used for structures such as tunnels and viaducts. And the iron material which is a structural material (component material) was often exposed on the surface of the said structure. However, in the event of a fire, the strength of iron is severely reduced. Iron is easy to transmit heat. In view of such circumstances, cement-based lightweight coating materials are often coated on the surface of iron structures (structures made of iron).

  By the way, there is a possibility that the cementitious lightweight coating material covering the surface may peel off. Then, even if the coated cementitious lightweight coating material peeled from the surface of an iron structure, prevention of peeling of the said cementitious lightweight coating material was proposed. That is, it has been proposed that a net-like, rod-like or mesh-like peeling prevention material is attached to the surface of an iron structure, and the cement-type lightweight coating material is coated so that the peeling prevention material is embedded.

  Various methods have been proposed (Japanese Patent Application Laid-Open No. 2009-235890) as a method of attaching the anti-stripping material to the surface of the iron structure. For example, a method has been proposed in which a hole is formed in an iron structure, a post-fixed anchor (bolt) is fixed to the hole, and a peeling prevention material is fastened to the surface of the iron structure with a nut passed through the bolt. Alternatively, a method has been proposed in which a hole provided with a thread is provided in an iron structure, a bolt is screwed into the hole, and a peeling prevention material is fastened to the surface of the iron structure with a nut passed through the bolt. . Alternatively, a bolt-fastening insert or nut is fixed to the back side of the hole provided in the steel structure, and a bolt is screwed into the bolt-fastening insert or the like. A method of fastening by fastening to the surface has been proposed.

JP 2009-235890 A

  However, the method of attaching the proposed anti-slipping material to the surface of the iron structure takes time. Therefore, a technique that is easy to construct is required.

  By the way, when the peeling prevention material is provided, there is a concern that a corrosion phenomenon occurs in the vicinity of the contact portion between the peeling prevention material and the iron structure. As a result of consideration of this corrosion phenomenon, it has been found that this may be based on the following. That is, in most cases, the iron structure and the peeling prevention material or the peeling prevention material fixing metal fitting are dissimilar metals. It is no exaggeration to say that there is no case where the constituent material of the iron structure is the same material as the constituent material of the peeling prevention material or the peeling prevention material fixing bracket. Incidentally, the material of the iron structure is carbon steel (ordinary steel) or cast iron, and the material of the peeling prevention material or the peeling prevention material fixing bracket is stainless steel. However, the corrosion phenomenon does not occur simply by saying that it is a dissimilar metal. That is, when the constituent material is a dissimilar metal and water intervenes, a local battery is formed between the two and a corrosion phenomenon occurs. As a result, the iron structure is easily corroded.

  The surface of the iron structure is generally subjected to anticorrosion coating. However, the anticorrosion coating is only performed from the viewpoint of general anticorrosion. In other words, it was not an anti-corrosion coating from the viewpoint of preventing corrosion at the joint between the steel structure and the anti-separation material or anti-separation material fixing bracket. No anticorrosive coating was performed up to the inside of the (through hole). Moreover, complete anticorrosion coating up to the inside of the hole is very time-consuming and requires attention. Therefore, such processing is costly and difficult to perform in reality.

  Therefore, the problem to be solved by the present invention is that even when a fire is encountered, the fire does not directly hit the iron material of the iron structure, so that the mechanical strength of the iron material is not significantly reduced. When a cement-type lightweight coating material is coated on the surface of a structure, and when the anti-separation material or anti-separation material fixing bracket is used to prevent the cement-type lightweight coating material from peeling off, the corrosion phenomenon occurs. It is an object of the present invention to provide a technique that does not easily occur and is easy to prevent the corrosion phenomenon.

The above issues are
A method of coating a surface of an iron structure in which a cementitious lightweight coating material is coated on the surface of the iron structure so that a peeling prevention material provided on the surface of the iron structure is embedded,
Step A in which a non-through hole is provided in the iron structure;
Step B in which a tapping screw is screwed into the non-through hole;
Step C in which the peeling prevention material is sandwiched between the screwed tapping screw and the surface of the iron structure, and the peeling prevention material is fixed to the surface of the iron structure;
Step D in which the surface of the iron structure is coated with a lightweight cementitious coating so that the anti-peeling material is embedded.
It solves by the coating method of the surface of an iron structure characterized by comprising.

  Preferably, the method for coating a surface of an iron structure, further comprising a step E in which a threaded portion between the non-through hole and the tapping screw is waterproofed. Solved by.

  Preferably, the method for coating the surface of the iron structure, wherein the waterproof treatment step includes a waterproof elastic packing between the surface of the iron structure and the mounting portion and / or the mounting portion and the tapping screw. This is solved by a method for coating the surface of an iron structure, characterized by comprising a step of being sandwiched between the head and the head.

  The above-described problem is solved by an iron structure formed by performing the method for coating the surface of the iron structure.

  Since the surface is coated with a cement-based lightweight coating material, even when a fire occurs, the fire does not directly hit the iron material of the iron structure. Therefore, even when a fire is encountered, a significant decrease in the mechanical strength of the iron material is prevented.

  Even if the cementitious lightweight coating material coated on the surface is peeled off, peeling off is difficult to occur. That is, for example, a net-like, rod-like, wire-like, mesh-like or perforated sheet-like exfoliation preventive material is attached, and the anti-exfoliation material is embedded in a cementitious lightweight coating material. Even if the lightweight coating material is peeled off, peeling does not easily occur.

  Since the technique of the present invention is employed in the structure for attaching the anti-slipping material, the structure is such that water does not easily enter a portion where corrosion easily occurs, and corrosion is unlikely to occur. As a result, the durability of the structure is excellent.

  Furthermore, since the technique of the present invention is employed in the structure for mounting the anti-slipping material, workability is good. As a result, the work cost is low.

Process drawing which becomes 1st Embodiment of the coating method which becomes this invention Schematic plan view of stainless steel wire mesh (anti-peeling material) Schematic plan view of a state in which a stainless steel wire mesh (strip prevention material) is attached to the surface of a steel structure with a tapping screw Side view of tapping screw Process drawing which becomes 2nd Embodiment of the coating method which becomes this invention Process drawing which becomes 3rd Embodiment of the coating method which becomes this invention

  The first aspect of the present invention is a coating method (coating method). In particular, this is a method for coating the surface of an iron structure. Among them, a coating method in which the surface of an iron structure is coated with a cement-based lightweight coating material. A peeling prevention material is provided on the surface of the iron structure, and the peeling prevention material is embedded by the coated cementitious lightweight coating material. In addition, although this embedment is preferably a complete embedment, a case of partial exposure and partial embedment can be considered. This method has the process A which provides a non-through hole in the said iron structure. The method includes a step B in which a tapping screw is screwed into the non-through hole. The method includes a step C in which the anti-strip material is sandwiched between the screwed tapping screw and the surface of the iron structure, and the anti-strip material is fixed to the surface of the iron structure. The method includes a step D in which a cementitious lightweight coating material is coated on the surface of the iron structure so that the anti-peeling material is embedded. The method preferably further includes a step E in which a threaded portion between the non-through hole and the tapping screw is waterproofed. The step E preferably includes a step in which the waterproof elastic packing is sandwiched between the surface of the iron structure and the mounting portion and / or between the mounting portion and the head of the tapping screw.

  The second aspect of the present invention is an iron structure. It is an iron structure which becomes the implementation of the coating method (coating method) according to the first aspect of the present invention. That is, it is an iron structure in which the surface of the iron structure is covered with a cement-based lightweight coating material. A peeling prevention material is provided on the surface of the iron structure. The exfoliation preventing material has, for example, a net shape, a rod shape, a line shape, a mesh shape, or a perforated sheet shape. Of course, these structures may be appropriately combined. The anti-peeling material is embedded in the coated cementitious lightweight coating material. In addition, although this embedment is preferably a complete embedment, a case of partial exposure and partial embedment can be considered. The iron structure is provided with a non-through hole. A tapping screw is screwed into the non-through hole. The peeling prevention material is sandwiched and fixed between the screwed tapping screw and the surface of the iron structure. Preferably, the threaded portion between the non-through hole and the tapping screw is waterproofed. For example, an insulating and waterproof elastic packing (for example, rubber packing) is sandwiched between the surface of the iron structure and the mounting portion. The elasticity of the elastic packing mentioned here is not limited to a complete elastic body such as rubber. That is, it is only necessary that the screw can be deformed to some extent when the screwing force from the tapping screw is applied. The elastic packing may be made of water-expandable rubber. The elastic packing is preferably thicker than the thickness of the attachment portion of the anti-slipping material.

  The iron structure of the present invention is, for example, a steel (particularly, ordinary steel) or cast iron structure. More specifically, for example, a segment made of ordinary steel or cast iron. Alternatively, it is a synthetic segment made of plain steel or cast iron and concrete. Or it is an ordinary steel tank. Or it is an ordinary steel pier on a highway or a railway. Or it is a viaduct made of ordinary steel on a highway or a railway. Or it is a building provided with the wall, roof, pillar, beam, or floor which consists of a steel pipe, a steel frame, a steel plate, and / or a steel pipe filling concrete. Or it is an artificially constructed tunnel such as a steel shell submerged tunnel or shield tunnel. Of course, it is not limited to the above.

  The non-through hole (blur hole) provided in the iron structure preferably has an inner diameter smaller than the diameter of the tapping screw used. In the present invention, the reason why the non-through hole (blur hole) is used is to make it difficult for water to enter. In the case of a through-hole, water easily enters and corrosion tends to occur.

  The shape and size of the tapping screw used in the present invention are determined by a non-through hole (blind hole) formed in the iron structure. Furthermore, what is necessary is just to have the total weight of a cement-type lightweight coating | covering material and a peeling prevention material, and can endure it. In addition, from the viewpoint of preventing corrosion, it is preferable that the material for the flaking prevention material and the material for the tapping screw are the same (identical or equivalent). Incidentally, the anti-peeling material is often made of stainless steel. Accordingly, the material of the tapping screw is also preferably stainless steel.

  The exfoliation preventing material of the present invention is composed mainly of one or more selected from metal, ceramic, resin, glass, and carbon. Specifically, it is a material that hardly corrodes or rusts such as stainless steel, rust-prevented metal, resin, alkali-resistant glass, and carbon. From the viewpoint of fire resistance, nonflammable or flame retardant materials are preferred. For these reasons, stainless steel, rust-proof metal, ceramic, alkali-resistant glass, and the like are particularly preferable. Of these, stainless steel is preferable.

  The shape of the exfoliation preventing material may be any selected from a net shape, a rod shape, a line shape, a mesh shape, or a perforated sheet shape. In addition, when arrange | positioning a cement-type coating | covering material on the structure surface by a spraying construction method, the shape of a peeling prevention material has a net | network shape, rod shape, or a linear form from the sprayability of a cement-type coating | covering material.

  In the present invention, the attachment portion of the peeling prevention material may be a part of the peeling prevention material. At the time of attachment, a fitting or a resin or ceramic attachment member may be used.

  In the present invention, the cementitious lightweight coating material includes a fireproof coating mortar made of cement, water, an admixture, a lightweight aggregate, and the like. Or the heat insulation mortar of the same composition is mentioned. Or, a fireproof covering material, a heat insulating material, a heat insulating material, a sound absorbing material, etc. made of a mixture of mineral fibers such as rock wool, cement, water, and an admixture mixed if necessary Can be mentioned. Or the foam mortar which has the bubble bubbled by the foaming agent in the cement mortar with which cement, water, the fine aggregate, and the admixture were mixed is mentioned. Or the light mortar etc. with which cement, water, the foaming agent, and the other admixture were mixed are mentioned. Of course, it is not limited to these.

  In the present invention, from the viewpoint of preventing corrosion, it is preferable that a joint portion (screwed portion) between the non-through hole (blur hole) and the tapping screw is waterproofed. In particular, when the material of the structure is ordinary steel coated with anticorrosion and the material of the tapping screw is stainless steel, the connecting portion (screwing portion) between the non-through hole (blind hole) and the tapping screw ) Is preferably waterproofed. Here, the following method is employed as the waterproofing treatment. For example, a caulking material made of silicon resin (organopolysiloxane), modified silicon resin (polyether having a silyl group at its end), polyurethane resin, chloroprene rubber, etc. is provided around the screwed portion. is there. Alternatively, after the tapping screw is screwed into the hole, a waterproof paint is applied around the screwed portion. Alternatively, a waterproof elastic packing is sandwiched between the surface of the iron structure and the mounting portion. Alternatively, a waterproof elastic packing is sandwiched between the attachment portion and the head of the tapping screw. Among the above methods, it is preferable to use elastic packing from the viewpoint of workability. In addition, when using an elastic packing, it is preferable that the waterproof elastic packing thicker than the thickness of the attachment part of a peeling prevention material is used. The caulking material, elastic packing and waterproof paint include limestone fine powder, slag fine powder, inorganic powder such as cement, fine aggregate such as land sand and crushed sand, fiber, foaming agent, super absorbent polymer, dye and Colorants such as pigments, rust preventives, viscosity modifiers, and the like may be added as appropriate. When a tapping screw is used, it is preferable that, for example, a washer (flat shear) is provided between the head of the tapping screw and the elastic packing. That is, when the washer is sandwiched between the tapping screw head and the elastic packing, the area where the elastic packing is pressed against the surface of the structure is increased, and the waterproofness is improved.

  Hereinafter, the present invention will be described with reference to the drawings.

  FIGS. 1A, 1B, 1C and 1D are process diagrams of a coating method according to the present invention. FIG. 2 is a schematic plan view of a peeling prevention material made of a stainless steel wire mesh. FIG. 3 is a schematic plan view showing a state in which a peeling prevention material made of a stainless steel wire mesh is attached to the surface of the steel structure. FIG. 4 is a side view of the tapping screw.

  In each figure, 1 is an iron structure in various structures such as buildings and tunnels. Reference numeral 2 denotes a wire mesh (a peeling prevention material). Reference numeral 3 denotes a non-through hole (blind hole) formed at a desired location of the iron structure 1. 4 is a cement-type lightweight coating | covering material. 5 is a tapping screw and 6 is a flat washer. 7 is a waterproof / insulating elastic packing. Reference numeral 8 denotes an attachment portion of the wire mesh 2. As can be seen from FIG. 2, the attachment portion 8 is configured by bending and projecting a part of the wire rod and shortening the width between the wire rod and the wire rod. That is, the wire mesh 2 can be attached with the tapping screw 5 by configuring the width of the wire to be shorter than the diameter of the flat washer 6 or the width of the head of the tapping screw 5. Reference numeral 9 denotes the surface of the iron structure 1. Reference numeral 10 denotes a screwed portion between the non-through hole (blur hole) 3 and the tapping screw 5. Reference numeral 11 denotes a head of the tapping screw 5. Reference numeral 12 denotes a screw hole (cross hole).

  First, as shown in FIG. 1 (a), a non-through hole 3 that does not penetrate an iron material such as a steel plate constituting an iron structure is formed at a desired location of the iron structure 1. This process is a process A in which a non-through hole is provided in an iron structure. The depth of the non-through hole 3 depends on the axial length of the tapping screw 5, but may be slightly longer or shorter than the axial length. However, when the tapping screw 5 is screwed in, the non-through hole 3 must not be a through hole. In this sense, the axial length of the tapping screw 5 is the sum of the thickness of the iron material of the iron structure 1, the thickness of the attachment portion of the peeling prevention material (the thickness of the wire rod of the wire mesh attachment portion), and the thickness of the flat washer 6. Must be shorter. And since it was set as the non-through-hole 3, the water | moisture content from the back side (in FIG. 1, the left side of the iron structure 1) of the iron structure 1 is the water | moisture content from the front side of the iron structure 1 (in FIG. 1, the iron structure 1). On the right side). Incidentally, if it is a through-hole instead of the non-through-hole 3, the moisture from the back side of the iron structure 1 (left side of the iron structure 1 in FIG. 1) is transferred to the front side of the iron structure 1 (FIG. 1). Inside, right side of the iron structure 1).

  Next, as shown in FIG. 1B, the elastic packing 7, the wire mesh 2, and the flat washer 6 are disposed on the iron structure 1. This process is a preliminary (front) process of the process E in which the threaded portion between the non-through hole and the tapping screw is waterproofed. The elastic packing 7 used here has a thickness greater than the thickness of the wire mesh 2.

  Then, as shown in FIGS. 1B and 1C, the tapping screw 5 is arranged, and the tapping screw 5 is screwed into the non-through hole 3. As a result, the wire mesh 2 is fixed. In this step, the peeling prevention material is sandwiched between the step B in which the tapping screw is screwed into the non-through hole, and the screwed tapping screw and the surface of the iron structure, and the peeling prevention material is fixed to the surface of the iron structure. Process C. Furthermore, this step completes the step of waterproofing the threaded portion between the non-through hole and the tapping screw. That is, the metal mesh 2 is sandwiched between the elastic packing 7 pressed against the surface 9 of the iron structure 1 and the flat washer 6, and the flat washer 6 has a tapping screw 5 screwed into the non-through hole 3. Power is acting. Accordingly, the wire mesh 2 is firmly fixed to the iron structure 1. In addition, as a result, waterproofing is performed. Therefore, even if the iron structure 1 and the wire mesh 2 are dissimilar metals, there is an insulating (non-metallic) elastic packing 7 between them, so that moisture exists temporarily. However, it is difficult to form a local battery. That is, corrosion hardly occurs. The opening of the non-through hole 3 is sealed by the elastic packing 7, the flat washer 6, and the head 11 of the tapping screw 5, and there is no risk of moisture entering the non-through hole 3. This means that even if the tapping screw 5 and the iron structure 1 are made of different metals and the tapping screw 5 and the iron structure 1 are coupled (joined) in the non-through hole 3, Local batteries are difficult to form. That is, corrosion hardly occurs. In the case of FIG. 1, if the wire mesh 2, the tapping screw 5, and the flat washer 6 are made of the same material, it is difficult to form a local battery even if moisture is present here. That is, corrosion hardly occurs.

  Thereafter, as shown in FIG. 1 (d), fireproof coating mortar or the like is applied so that the wire mesh 2 is embedded, and the surface 9 of the iron structure 1 is covered with the cementitious lightweight coating material 4. This process is a process D in which the cementitious lightweight coating material is coated on the surface of the iron structure so that the peeling prevention material is embedded.

5A, 5B, 5C, and 5D are process diagrams of a coating method according to another embodiment of the present invention.
In the present embodiment, the caulking material 13 is used instead of the elastic packing, and the caulking material 13 is provided in a substantially circular shape around the threaded portion 10. Since the caulking material 13 is used, when the tapping screw 5 is screwed in, the caulking material 13 is greatly deformed. The caulking material 13, the flat washer 6, and the head 11 of the tapping screw 5 open the non-through hole 3. The part is sealed, and there is no risk of moisture entering the non-through hole 3. For this reason, corrosion is unlikely to occur as in the first embodiment. Since other basic technical ideas are the same as those in the above-described embodiment, detailed description thereof is omitted.

6A, 6B, 6C, and 6D are process diagrams of a coating method according to another embodiment of the present invention.
The present embodiment and the first embodiment differ only in the initial arrangement position of the elastic packing 7. As can be seen from FIG. 6C, after the tapping screw 5 is screwed in, the arrangement (order) of the elastic packing 7 and the wire mesh attaching portion 8 is substantially the same with different degrees. The opening of the non-through hole 3 is sealed by the elastic packing 7, the flat washer 6, and the head 11 of the tapping screw 5, and there is no possibility that moisture will enter the non-through hole 3. For this reason, corrosion is unlikely to occur as in the first embodiment. Since other basic technical ideas are the same as those in the above-described embodiment, detailed description thereof is omitted.

1 Iron structure 2 Wire mesh (peeling prevention material)
3 Non-through holes (blind holes)
4 Cement-based lightweight coating material 5 Tapping screw 6 Flat washer 7 Waterproof / insulating elastic packing 8 Wire mesh mounting portion 9 Steel structure surface 10 Screwed portion 11 between the non-through hole (blind hole) and the tapping screw 11 Tapping screw Head 12 Screw hole (cross hole)
13 Caulking material

Claims (4)

A method of coating a surface of an iron structure in which a cementitious lightweight coating material is coated on the surface of the iron structure so that a peeling prevention material provided on the surface of the iron structure is embedded,
Step A in which a non-through hole is provided in the iron structure;
Step B in which a tapping screw is screwed into the non-through hole;
Step C in which the peeling prevention material is sandwiched between the screwed tapping screw and the surface of the iron structure, and the peeling prevention material is fixed to the surface of the iron structure;
Step D in which the surface of the iron structure is coated with a lightweight cementitious coating so that the anti-peeling material is embedded.
A method for coating a surface of an iron structure, comprising: Process E in which the threaded portion between the non-through hole and the tapping screw is waterproofed
The method for coating a surface of an iron structure according to claim 1, further comprising: The waterproof treatment step includes a step in which the waterproof elastic packing is sandwiched between the surface of the iron structure and the attachment portion and / or between the attachment portion and the head of the tapping screw. The method for coating an iron structure surface according to claim 2. An iron structure obtained by performing the method for coating a surface of an iron structure according to any one of claims 1 to 3.