KR100353575B1 - Rehabilitation of Steel Structures by Carbon Fiber Composites with Vacuum Bag Method - Google Patents

Abstract

The present invention relates to a method for reinforcing steels of steel structures constituting civil engineering, architectural structures and plant facilities, in the present invention by vacuum decompression to a carbon fiber woven fabric

Provided is a method for reinforcing steel structures by vacuum forming adhesion of a carbon fiber composite material, characterized in that the carbon fiber composite material formed by impregnating a resin is integrally attached to the surface of the steel to be reinforced.

According to the reinforcement method of the present invention, it is applicable to steel structures of any shape, does not cause any damage during the reinforcement work to the target steel to be reinforced, and almost self-weight at any site without separate load removal work by having to the target structure, etc. The steel can be easily and simply reinforced without increasing the number, and in the case of steel structures such as storage tanks or pipelines, the area to be reinforced can be easily reinforced without emptying the interior of the structure.

Description

Rehabilitation of Steel Structures by Carbon Fiber Composites with Vacuum Bag Method}

The present invention relates to a method for reinforcing steel structures by vacuum forming adhesion of carbon fiber composite materials. Specifically, the present invention relates to steel materials used in steel bridges, steel buildings, plant facilities, steel temporary facilities, and the like. It relates to a method of reinforcing by vacuum forming adhesion using a carbon fiber composite material having a.

Steels used in civil and building structures or steel structures that make up plant facilities have reduced cross sections of steel due to corrosion from the external environment, cracks in joints due to excessive loads, fatigue due to repeated dynamic loads, and cracks in welds due to design errors. When damage occurs to the steel due to or the like, or when it is necessary to improve the structural performance of the steel, appropriate reinforcement is required. As a conventional method of reinforcing steels used in steel structures, a method of reinforcing a separate reinforcing steel such as an angle, a steel plate, or the like by welding or bolting has been mainly used.

For example, when structural reinforcement is required due to corrosion, crack, etc. damage to steel materials of steel bridges or steel structure structures, the member to be reinforced currently supports its own weight and working load. If drilling is performed for bolting or heating for welding, the member may be damaged and cause structural safety problems.

Therefore, in the conventional reinforcement method as described above, the load applied to the member must be removed in advance before the reinforcement work is started. By the way, the load removal operation that must be performed before the reinforcement work is dangerous, in some cases it may be very difficult to have, and since the additional work for having a reinforcement is required, the reinforcement cost is greatly increased. Due to this problem, in many cases, the conventional reinforcing work is performed to join the reinforcing steel by drilling or welding bolt holes in the target steel to be reinforced while taking structural risks without additional load removal measures.

Steel structures such as steel storage tanks and steel pipelines in plant facilities are often filled with materials such as flammables, hazardous chemicals, and flammable gases, and by conventional reinforcement work using drilling or welding. When reinforcing the steel of such steel structures, the inside of the storage tank or pipeline must be emptied prior to bolt hole drilling or welding. Therefore, in addition to the resulting costs, because the storage tank or the pipeline must be emptied, the production line is stopped, and in addition to the reinforcement work costs, additional costs incurred due to the shutdown of the facility.

In steel temporary installations used in opening sections of subway construction sections or in excavation works for foundation works of high-rise buildings, when the excavation width is wide, strut beams that cross the excavation width are used. H-beams are used as strut beams. In this case, when the excavation width exceeds the maximum width the H-section steel of the largest dimension can support, a temporary pillar is to be provided at the center of the beam. However, in some cases, in order to avoid the installation of temporary columns, the flange section of the H-shaped steel may be reinforced and used. If the section of the H-shaped steel is reinforced by the conventional reinforcement method, in addition to the weight, This increases the deflection of the strut beam beyond the allowable range.

The present invention was developed to solve the disadvantages and problems of the conventional steel reinforcement method as described above, is applicable to any steel structure of any shape, does not damage the target steel to be reinforced at the time of reinforcement work, the target structure It is possible to reinforce steel easily and simply without increasing its own weight almost at any site without separate load removal work due to the lack of load.In the case of steel structures such as storage tanks or pipelines, the area to be reinforced without having to empty the interior of the structure An object of the present invention is to provide a method of reinforcing steel that can be easily reinforced.

1 is a cross-sectional view showing a shape of applying the reinforcing method according to the invention to the H-shaped steel.

Figure 2 is an elevation view showing the shape of the reinforcing method according to the invention applied to the steel plate.

Figure 3 is a perspective view of the shape after applying the reinforcement method according to the invention to the H-shaped steel.

Figures 4a and 4b shows the shape after applying the reinforcement method according to the invention to the steel pipe and storage tank of the plant facility.

<Brief description of the main parts of the drawing>

1 Steel 2 Carbon Fiber Woven

3 peel ply 4 resin distribution network

5 Bleeder 6 Vacuum Film

7 Resin Injection Channel 8 Vacuum Suction Channel

9 Sealing material 10 Resin injection pipe

11 Resin Container 12 Vacuum Trap

13 Vacuum pump 14 Vacuum suction line

20 Carbon Fiber Composite 100 Steel Pipe

200 storage tank

In order to achieve the above object, the present invention provides a reinforcement method characterized by integrally attaching and reinforcing carbon fiber composite materials using vacuum pressure to steel materials to be strengthened for steel structures constituting civil engineering and building structures or plant facilities. .

Specifically, in the present invention, as a method for reinforcing steel materials of civil engineering, architectural structures, and plant facilities, the surface of steel materials to be reinforced by carbon fiber composite material formed by impregnating carbon fiber woven fabric with resin by vacuum pressure reduction. Provided is a method for reinforcing steel structures by vacuum forming attachment of a carbon fiber composite material, wherein the carbon fiber composite material is integrally attached to and reinforced.

As an embodiment of the present invention, the surface of the steel to be reinforced, the surface is treated, the carbon fiber woven fabric is placed on the surface of the steel material so that the carbon fibers are arranged in a predetermined direction and thickness, and the resin distribution on the carbon fiber woven fabric A network-shaped resin distribution network for smoothing is provided, a fill ply is disposed between the carbon fiber woven fabric and the resin distribution network, and a vacuum suction channel for sucking air and a resin injection channel for injecting resin are provided. A pore is formed in the lower portion of the suction channel to install a bleeder for smoothly discharging the air inside the vacuum film, and the vacuum film is covered with the vacuum film on the carbon fiber woven fabric, the vacuum suction channel, and the resin injection channel. Sealing the surroundings, the air inside the vacuum film through the vacuum suction channel to discharge the vacuum pressure with a vacuum pump to vacuum the inside of the vacuum film After the resin injection channel, the liquid resin is injected into the vacuum film by the pressure difference, and the carbon fiber woven fabric is impregnated with the resin, and the impregnated carbon fiber woven fabric is cured to form a carbon fiber composite material. By removing the carbon fiber composite material is integrally attached to the surface of the steel material to be reinforced to provide a reinforcement method characterized in that the reinforcement of the steel is completed. As the resin used in the reinforcing method of the present invention, an epoxy resin is preferable.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and embodiment of the present invention.

1 is a cross-sectional view showing the shape of applying the reinforcement method according to the invention to the H-shaped steel, Figure 2 is a view showing the shape of applying the reinforcement method according to the invention to the steel plate in elevation.

First, the surface of the steel is surface-treated so that no impurities remain on the surface of the steel 1 to be reinforced. Surface treatment of the steel surface is based on the conventional surface treatment method using sand blasting, sand paper and the like. The degree of reinforcement is determined according to the result of structural calculation on the load, etc., of the steel material 1 to be reinforced, and the lamination structure is determined according to the fiber placement direction and fiber amount determined according to the degree of reinforcement, and accordingly carbon fiber woven fabric (2) is placed in a position where reinforcement of the steel surface is required. On the carbon fiber woven fabric (2), a resin distribution network (4) having a mesh shape is installed on the carbon fiber woven fabric (2) so that the resin can be evenly distributed and impregnated throughout the carbon fiber woven fabric (2).

After covering the carbon fiber woven fabric 2 placed on the reinforcing portion of the steel 1 with the vacuum film 6, the edge of the vacuum film 6 is sealed using a sealing material 9 such as a double-sided adhesive tape. Before covering the vacuum film 6, inside the vacuum film 6, a resin injection channel 7 for injecting a liquid resin and a vacuum suction channel 8 for discharging air in the sealed vacuum film 6 are provided. Is installed.

One end of the resin injection channel 7 is connected to the resin injection pipe 10, so that the resin contained in the resin container 11 is supplied to the resin injection channel 7 via the resin injection pipe 10. A vacuum suction tube 14 is connected to one end of the vacuum suction channel 8, and the vacuum suction tube 14 is connected to the vacuum trap 12 and the vacuum pump 13. As will be described later, air inside the sealed vacuum film 6 is discharged through the vacuum suction channel 8 by the operation of the vacuum pump 13. In FIG. 1, the resin injection tube 10 and the vacuum suction tube 14 are briefly illustrated as thick lines for convenience of expression.

When the air inside the vacuum film 6 begins to be discharged through the vacuum suction channel 8, the sealed vacuum film 6 is decompressed and the vacuum film 6 is made of steel 1 or carbon fiber woven fabric 2. When the vacuum film 6 is in close contact with air, the air is not discharged, and thus, a bleeder 5 having predetermined pores is installed. That is, when the bleeder 5 is installed on the carbon fiber woven fabric 2 and the vacuum suction channel 8 is placed on the bleeder 5, the inside of the vacuum film 6 is depressurized and the vacuum film 6 is Although in close contact, air inside the vacuum film 6 is continuously discharged through the pores in the bleeder 5 to completely vacuum the inside of the vacuum film 6.

The carbon fiber woven fabric used in the reinforcing method of the present invention is a carbon fiber fabric produced in the form of a woven fabric or a stitched fabric.

When the sealing of the edge of the vacuum film 6 is completed, the resin injection pipe 10 is blocked, and then the vacuum pump 13 is operated so that the air inside the vacuum film 6 sealed through the vacuum suction channel 8. By discharging the inside of the vacuum film 6, the vacuum or reduced pressure is made.

When the inside of the vacuum film 6 is in a vacuum state or a reduced pressure state, the resin injection pipe 10 is opened to allow resin to be injected into the vacuum film 6 from the resin container 11 by a pressure difference.

Since the inside of the vacuum film 6 is in a vacuum state or a reduced pressure state, the injected resin is quickly impregnated into the carbon fiber woven fabric 2. At this time, the injected resin is evenly spread throughout the carbon fiber woven fabric 2 along the mesh-shaped resin distribution network 4 so that the carbon fiber woven fabric 2 is uniformly impregnated with the resin as a whole. When the carbon fiber woven fabric 2 is cured for a predetermined time in the state impregnated with the resin, and then the vacuum film 6 is removed, the carbon fiber composite material 20 is firmly attached to the steel material 1 so that the reinforcing work is completed. do.

After the resin is cured, the resin distribution network 4 may remain at the reinforcing portion and the surface may be rough. If necessary, it is necessary to remove the resin distribution network 4 after curing the resin. To this end, a peel ply 3 may be placed on the carbon fiber woven fabric 2 and a resin distribution network 4 may be installed thereon to allow resin to be injected. In this case, the resin distribution network 4 together with the peel ply 3 can be easily removed from the cured resin by pulling the peel ply 3 after the resin has cured.

In the process of curing the resin, by using a separate external heating device (not shown) or by installing a built-in heating wire inside the vacuum film 6, it is possible to promote the curing of the resin.

As shown in FIG. 3, the carbon fiber composite material 20 formed of the carbon fiber woven fabric 2 and the resin formed by the above-described method is permanently attached to the steel material 1 to be reinforced. The carbon fiber composite material 20 has a tensile strength of about 10,000 kg / cm ² or more, up to about four times the normal structural steel, the elastic modulus is equal to or greater than the steel, the weight is about 20 of the weight of the steel So light as a percentage. As such, the carbon fiber composite material 20 has excellent physical properties such as light weight, high strength, high elasticity, and high durability, in which the specific strength is 10 times or more than that of steel, thereby exhibiting a superior reinforcing effect than conventional reinforcing methods using steel materials. .

Figure 4a is a perspective view showing the shape of the reinforcing the curved portion of the steel pipe 100 with a carbon fiber composite material 20 by the reinforcement method of the present invention described above, Figure 4b is a surface of the steel storage tank 200 A perspective view showing a form reinforced with a carbon fiber composite material 20 by the reinforcing method of the present invention is shown.

In the above described the reinforcement method of the present invention taking the H-beam, steel pipe and storage tank as an example, which is an example to which the reinforcement method of the present invention is applied, the reinforcement method of the present invention in addition to the illustrated structure is applied to various kinds of steel structures Can be applied,

As described above, in the reinforcement method of the present invention, since the bolt hole for bolting is not drilled or the heating for welding is not performed on the steel to be reinforced, it does not damage the steel. No work is required to remove the loads supported by the steel structure prior to the required reinforcement.

In addition, according to the conventional reinforcement method of bolting or welding the separate steel, additional reinforcing steel is further attached to the steel to be reinforced, so that the weight of the steel structure is further increased, and as a result, the load on the structure is further increased. Although the carbon fiber composite material used in the reinforcement method of the present invention is lightweight, there is almost no increase in load due to reinforcement. In particular, the carbon fiber composite material used in the reinforcement method of the present invention has a thin thickness, and thus no problem of building clearance due to reinforcement occurs.

When reinforcing steel bridges, when reinforcing by the conventional reinforcement method, the vehicle must be controlled during the reinforcement work to reduce the live load applied to the bridge, but according to the reinforcement method of the present invention, Since reinforcement is performed by attaching material, reinforcement work can be performed without disturbing traffic.

In the case of plant facilities such as storage tanks or pipelines, unlike conventional reinforcement methods, carbon fiber composite materials can be attached to steel without reinforcing the storage tanks or pipelines. The problem does not occur at all.

In the excavation work for the foundation of the subway attachment section or high-rise building, when the strut beam reinforced with carbon fiber composite material is used according to the reinforcement method of the present invention, the cross-sectional bearing capacity of the beam is increased without increasing the deflection, Even if it is large, it is not necessary to install additional temporary pillars in the center, thereby reducing construction costs and increasing the convenience of excavation, thereby reducing the overall air and reducing construction costs.

Furthermore, since the carbon fiber composite material used in the reinforcing method of the present invention has corrosion resistance, reinforcing the steel with the carbon fiber composite material according to the reinforcing method of the present invention provides a permanent reinforcing effect without fear of lowering the load capacity due to corrosion. It can be exhibited, and a separate antirust coating is unnecessary. In addition, since the carbon fiber composite material has excellent watertightness, when the plant facility is reinforced with the carbon fiber composite material, there is no fear of leakage of fluid or gas in the reinforcement part, and the carbon fiber composite material has an external environmental impact. However, it has strong resistance to chemical reactions, and is harmless and non-toxic, so it can be environmentally friendly reinforcement work.

Since the carbon fiber composite material used in the reinforcing method of the present invention is lightweight and high elasticity, the reinforcing effect of the conventional reinforcing steel is about 1/10 the weight of the reinforcing steel used in the conventional reinforcing method. The above effect can be exhibited.

Once the inside of the vacuum film is decompressed or vacuumed during reinforcement work, the carbon fiber woven fabric can remain attached to the steel without additional support means, so the reinforcement work is very much compared with the conventional reinforcing steel. It becomes easy.

In addition, the reinforcement method of the present invention is easy to place the carbon fiber woven fabric not impregnated by the dry method on the steel surface to be reinforced, and the resin is injected after making the inside of the vacuum film under reduced pressure or vacuum, the operator Since it is not touched or handled directly, the work environment can be kept clean during reinforcement work, and workability is excellent.

In particular, all materials forming the carbon fiber composite material have flexibility, so that even when the surface of the steel to be reinforced is not smooth and has an arbitrary shape, the carbon fiber composite material can be easily reinforced by attaching the carbon fiber composite material to the surface of the steel. have.

In the above described the configuration and features of the present invention based on the embodiment according to the present invention, the present invention is not limited to this, it is possible to be freely modified according to the technical idea of the present invention.

Claims (4)

A method of reinforcing steel materials (1) of steel structures constituting civil engineering, building structures, and plant facilities, wherein the carbon fiber composite material (20), which is formed by impregnating the carbon fiber woven fabric (2) with resin by vacuum pressure reduction, is subjected to reinforcement. Reinforcing the steel structure by vacuum forming adhesion of the carbon fiber composite material, characterized in that the reinforcement by integrally attached to the surface of the steel material (1). The process of claim 1, wherein the carbon fiber composite material 20 is integrally attached to the surface of the target steel material 1 and reinforced. The surface 1 of the steel to be reinforced is treated, and a carbon fiber woven fabric 2 is placed on the surface of the steel so that the carbon fibers are arranged in a predetermined direction and fiber amount, and a resin is placed on the carbon fiber woven fabric 2. A network-shaped resin distribution network 4 for evenly distributing is provided, and a vacuum suction channel 8 for discharging air and a resin injection channel 7 for injecting resin are provided. Pores are formed in the lower part to install a bleeder 5 for smoothly discharging air in the vacuum film 6, and the carbon fiber woven fabric 2, the vacuum suction channel 8 and the resin injection channel ( 7) the vacuum film 6 is covered to cover the vacuum film 6, and the air inside the vacuum film 6 is discharged through the vacuum suction channel 8 to seal the inside of the sealed vacuum film 6. Is made into a vacuum state, and the water is discharged by the pressure difference through the resin injection channel (7). When the carbon fiber woven fabric 2 is impregnated with a resin by impregnating the carbon fiber woven fabric 2 with a resin, and the carbon fiber woven fabric 2 impregnated with the resin is hardened to produce a carbon fiber composite material 20. 6) steel structure reinforcement method by vacuum forming adhesion of the carbon fiber composite material, characterized in that consisting of the process of removing. 3. The method according to claim 2, wherein the peel ply (3) is disposed between the carbon fiber woven fabric (2) and the resin distribution network (4). The method of claim 1 or 2, wherein the resin is an epoxy resin, the steel structure reinforcement method by vacuum forming adhesion of the carbon fiber composite material.