KR20120133868A - Seismic Retrofit of Reinforced Concrete Columns Using Multi-Layers of FRP Wires Jackets - Google Patents

Abstract

PURPOSE: A construction method of a column structure using multi-layer FRP wire jackets is provided to prevent damage to the surface of a column by not requiring a device for fixing an anchor to the surface of the column. CONSTITUTION: A construction method of a column structure using multi-layer FRP wire jackets is s follows. One end of an FRP wire touches the surface of a column structure(100), and the FRP wire surrounds the column structure. The FRP wire is fixed to the surface of the column structure using a high-strength adhesive. Tensile force is applied to the FRP wire to wind the FRP wire around the surface of the column structure. An FRP wire jacket(A1) is formed on the column structure by attaching the other end of the FRP wire to the surface of the column structure. Multiple FRP wire jackets are formed by repeating the processes. Epoxy is spread on the outermost FRP wire jacket.

Description

Seismic Retrofit of Reinforced Concrete Columns Using Multi-Layers of FRP Wires Jackets}

The present invention relates to a pillar structure construction method using a multilayer FRP wire jacket. More specifically, the present invention relates to a pillar structure construction method using a multi-layer FRP wire jacket to reinforce the pillar structure more effectively by forming the FRP wire jacket in a multilayer structure on the pillar structure using the FRP wire.

Reinforced concrete columns that do not have sufficient seismic performance require seismic reinforcement.

The seismic reinforcement techniques currently in use vary according to the type of material and the type of material used.

Typical materials used are steel, steel strips and steel strips, and composite materials (FRP, Fiber Reinforced Plastic) use FRP sheets. Recently, reinforcement techniques using shape memory alloy wire have been introduced.

The most critical factor in the technique for attaching a member of any material to a reinforced concrete column to improve seismic performance is to make the member fully adhere to the surface of the column. To this end, each material uses the following technique depending on its characteristics.

First, the steel sheet attachment technique is introduced, which is a method of welding a steel sheet and attaching it to the column with a gap, and filling it with a filler between the pillar and the steel sheet to completely adhere the steel sheet to the surface of the pillar.

In addition, the grouting method is also introduced to the outside of the column, and the grouting process is uneven in appearance due to uneven construction and increases in the cross section of the column. There is a difficulty.

In addition, the steel strip attachment technique can be easily attached to the steel strip using a simple device, there is an advantage that can be installed regardless of the shape of the pillar. In addition, it is easy to design because there is no change in the characteristics of the structure, such as steel plate adhesion by grouting. However, when the steel strip is installed, the appearance is not good, and durability of the connecting member of the strip may be a problem.

In addition, in the FRP sheet attaching technique, the FRP sheet has no resistance to compression but resistance to tension, so it is very important to completely expand and attach it to the concrete column.

In general, when the epoxy is attached using the epoxy does not fully expand the reinforcing effect can be reduced.

In order to prevent this, techniques are introduced that introduce prestressing to the FRP sheet. However, large equipment is needed to tension the FRP sheet and attach it to the concrete surface. The use of such equipment may not be available depending on the site conditions of the bridge or building, and may be limited in construction.

In the method of reinforcing the column structure by winding the reinforcement fiber on the column structure and by hardening the wound reinforcement fiber by applying hardening resin such as resin, it is the form of the column structure such as the piers or wells constructed on land as well as in water Regardless of the cross-sectional shape, size, and the like, a means for efficiently winding the reinforcing fibers in the columnar structure has been disclosed, which is illustrated in FIG. 1.

That is, in the case of the reinforcement device 10 using a conventional reinforcing fiber, Figure 1 is a reinforcement target structure while rotating and raising the rotating frame 2 and the lifting frame 3 itself mounted with one or a plurality of winding machine (1) ( 4) Wire reinforcing fiber is wound around.

However, there was a problem that the method of simply impregnating with respect to the method of coating the cured resin does not have a great effect on the reinforcement of the desired columnar structure.

Accordingly, the present invention is to provide a pillar structure construction method using a multi-layer FRP wire jacket to reinforce the pillar structure using the FRP wire and hardening resin to provide a more effective reinforcement effect and construction method Shall be.

To this end,

First, the FRP wire is fixed to the columnar surface, and then wound several times, and this part is bonded using a strong adhesive. The bonded FRP wire is attached to the post and no longer requires a fixed point.

Next, the FRP wire is wound up to a predetermined length and attached to the column structure. At this time, it should be wound with tension for complete attachment of the FRP wire.

Next, after winding the FRP wire to the required height, attach the FRP wire with a strong adhesive about 10 mm at the top with the tension applied. If the tension is removed and the wire is cut after attachment, the wire is attached to the surface of the column, and it is wound with the introduction of the tension force, thus allowing for a close contact.

Next, the FRP wire is attached to the bottom and top only with a strong adhesive, and the rest of the FRP wire is not coated with the adhesive.

Next, the FRP wire is wound again, which repeats the method described above.

Accordingly, a multilayer FRP wire jacket can be formed in the columnar structure.

Finally, after forming a multilayer FRP wire jacket on the column structure, epoxy is applied to the outermost layer of the multilayer to attach between the FRP wires. This technique prevents the wire from breaking when the wire breaks, so that it can continuously maintain the restraining effect on the column, thereby greatly improving the seismic performance of the column.

The present invention

A first step of allowing one end of the FRP wire to contact the surface of the column structure and having the FRP wire wrapped around the column structure several times, and fixing the FRP wire to the surface of the column structure by a strong adhesive; A second step of winding the FRP wire while applying a tension force upward to a predetermined height on a surface of the column structure; And attaching the other end of the FRP wire to the surface of the column structure with a strong adhesive to form the FRP wire jacket A1 of the first layer on the column structure.

Repeating the steps 1, 2 and 3 on the FRP wire jacket A1 of the first layer to form a multi-layered FRP wire jacket in the column structure;

It provides a pillar structure construction method using a multilayer FRP wire jacket comprising the step of applying epoxy to the outermost FRP wire jacket (A2) of the multilayer FRP wire jacket.

Also preferably,

FRP wire constituting the FRP wire jacket of each layer by the step of applying epoxy to the outermost FRP wire jacket (A2) is a layer that does not have epoxy applied to the column structure side and epoxy is applied to wrap them with a tension force Provided is a pillar structure construction method using a multilayer FRP wire jacket to be divided into layers.

Also preferably,

The FRP wire is a wire form having a diameter of 1-3 mm to provide a column structure construction method using a multi-layer FRP wire jacket to be wound around the column structure by introducing a tension force to the attraction.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

FRP wire used in the present invention is not large tensile rigidity can be tensioned by the attraction force can be easily introduced tension in the process of winding the column. Therefore, it can be installed without large equipment like the existing FRP sheet tension.

In addition, the FRP wire winding process is performed using a strong adhesive, so there is no need to install a device for fixing the anchor on the column surface, thereby preventing the occurrence of damage to the column surface.

In addition, when epoxy is applied to the outermost layer of the FRP wire jacket, each wire ring has an interference effect, so that even if a single ring is broken, the entire wire does not loosen, and it causes continuous restraint effect on the column. Can be. This epoxy application is a critical factor in making the wire jacket function like a tube.

In addition, FRP wire is economical in construction because the material is not expensive because the material is the same as the existing FRP sheet.

1 is a perspective view of a winding means for winding a conventional FRP wire in a columnar structure,
Figure 2a, 2b, 2c, 2d and 2e is a flow chart of a column structure construction method using a multi-layer RF wire jacket according to the present invention.
3 is an experimental photograph according to the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

[Step 1]

First, the reinforcement target structure can be confirmed as shown in FIG. 2A. Such a reinforcement target structure may be referred to as a column structure 100.

The pillar structure 100 is constructed so that the FRP wire 200 of the present invention is wound around the surface.

The FRP wire 200 is manufactured in various forms ranging from very small diameters of 1 mm or less to large ones of 5 mm or more. FRP wires that can be used to reinforce reinforced concrete columns have sufficient ductility and are suitable for winding on columns, so 1-3 mm diameter is considered appropriate.

The characteristics of these FRP wires show that the stress-strain curve behaves linearly and breaks like FRP plates or sheets.

Accordingly, one end S1 of the FRP wire 200 is in contact with the surface of the columnar structure, and several times the columnar structure 100 is wrapped around the FRP wire 200, and then on the surface of the columnar structure 100 by a strong adhesive. The FRP wire 200 is fixed.

This is to facilitate the winding operation of the additional FRP wire 200 by using one end of the FRP wire 200 as a fixed point.

[Step 2]

Next, as shown in FIG. 2B, the FRP wire 200 is wound up to a predetermined height upward on the surface of the column structure 200. In this case, the FRP wire 200 may be wound while giving a tension force P, which may be a manpower, or may be used as shown in FIG. 1.

The important thing is to give a tension force, which is to force the FRP wire 200 to the columnar structure and to prevent the phenomenon that the wound state is unwinded by the restoring force of the FRP wire 200.

[Step 3]

Next, after winding the FRP wire 200 using the tension force to the required height as shown in Figure 2c is to attach the other end (S2) of the FRP wire 200 to the columnar structure 100 surface with a strong adhesive.

When the FRP wire 200 is cut in such an attached state, the wire is attached to the column structure by the tension force.

As described above, the FRP wire 200 jacket of the first layer is installed by the first, second, and third steps. In this state, only one end and the other end of the FRP wire 200 are attached to the column structure, and the FRP between one end and the other end. The wire 200 is not coated with epoxy and is simply in a state where only a tension force is introduced.

[Step 4]

Next, as shown in FIG. 2D, the FRP wire jacket J2, J3 --- Jn of the second and third layers is subjected to the first, second, and third steps again to the first layer of FRP wire J1 jacket. It is formed.

[Step 5]

Next, after the final FRP wire 200 jacket is formed in multiple layers as shown in FIG. 2E, the epoxy 300 is applied to the outermost layer of the FRP wire 200 jacket. This epoxy has the effect of impregnating the outermost FRP wire (Jn) and the inner part of the FRP wire (Jn-1).

Thus, in the present invention, the FRP wire 200 constituting the FRP wire jacket (J) can be seen that is divided into a layer that is not coated with epoxy on the column structure and the epoxy coated layer surrounding them with a tension force, the epoxy When cured, it can be seen that the epoxy-coated layer can be constrained (tube confinement effect) as a kind of tube.

Accordingly, even if some of the FRP wire 200 installed in contact with the column structure by the load action is broken, it is possible to prevent the loosening of the FRP wire 200 by the tube binding effect.

In addition, the outermost FRP wire jacket 300 is very advantageous in terms of maintenance because it can completely block the water penetrating into the column structure as a kind of protective layer.

3 is an experimental photograph for confirming the column structure reinforcement action by the tube binding effect according to the present invention, in particular, the FRP wire jacket (A2) is formed on the outermost side confirmed to have a tube binding effect of the column structure You can do it.

100: columnar structure
200: FRP wire
300: FRP wire jacket

Claims (3)

One end of the FRP wire 200 is in contact with the surface of the columnar structure and the FRP wire 200 to wrap several times the columnar structure 100, the FRP wire 200 on the surface of the columnar structure 100 by a strong adhesive Fixing the first step; A second step of winding the FRP wire 200 on the surface of the column structure 200 while giving a tension force upward to a predetermined height; And attaching the other end of the FRP wire 200 to the surface of the column structure 100 with a strong adhesive to form the FRP wire jacket A1 of the first layer on the column structure.
Repeating the steps 1, 2 and 3 on the FRP wire jacket A1 of the first layer to form a multi-layered FRP wire jacket in the column structure;
A method of constructing a pillar structure using a multilayer FRP wire jacket, comprising applying an epoxy to the outermost FRP wire jacket (A2) of the multilayer FRP wire jacket. The method of claim 1,
The FRP wire 200 constituting the jacket of the FRP wire 200 of each layer by applying epoxy to the outermost FRP wire jacket (A2) is a layer in which epoxy is not applied to the column structure side and the tension force thereof A pillar structure construction method using a multilayer FRP wire jacket characterized in that it is divided into a coating layer coated epoxy. The method of claim 1,
The FRP wire is a wire structure having a diameter of 1-3 mm in the form of a column structure construction method using a multi-layer FRP wire jacket characterized in that it can be wound around the column structure by introducing a tension force to the attraction.

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