JP2001182153A - Reinforcing method for concrete structure body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem, where in the external cable construction method, a hole for fixing an anchor is drilled, causing scars on a concrete structure body. SOLUTION: Around a concrete structure body, a continuous fabric belt is wound and the belt is tensed or, the belt is partially wound and a PC steel wire is provided for connection between both ends of the belt before the PC steel wire is tensed thus, the concrete structure body is prestressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reinforcing a concrete girder, for example, a concrete girder of a bridge, and more particularly, to a measure for reinforcing a main girder by increasing a design live load, and a method of restoring prestress due to damage of existing PC steel. Suitable for introduction.

[0002]

2. Description of the Related Art As a conventional method for reinforcing a concrete structure, an outer cable method is known. For the outer cable method, fixing devices are installed at both ends of the concrete structure with anchor bolts, etc., tension materials are installed, and prestress is introduced into the concrete structure by installing the tension materials, preventing excessive stress loading It is a construction method.

Although this method is extremely effective as a method for reinforcing a concrete structure, it has several problems.

[0004] In the outer cable method, an anchoring portion of the outer cable is attached by installing an anchor bolt on a concrete structure. Therefore, it is necessary to carry out a detailed steel position survey in advance so as not to damage the steel material (PC steel material, reinforcing steel) of the concrete structure. For example, PC steel material is concentrated at the end of the girder of a general PC bridge, and it is very difficult to determine the anchor drilling position.

Further, in a general PC bridge, since the fixing portion of the outer cable is post-constructed, the support, the cross beam, and the like become obstacles and are provided before the end of the concrete girder. For this reason, the pre-stress of the outer cable is introduced between the fixing portions in front of the end of the girder, not only the pre-stress is not introduced at the end of the girder, but also a tensile force is generated from the back of the fixing portion to the end of the girder, and in some cases, Requires further reinforcement.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problem of damaging a concrete structure in the external cable construction method and the problem that prestress is not introduced to the ends, as described below. is there.

[0007]

First, a continuous fiber belt is wound around a concrete structure, tension is applied to the continuous fiber belt, and prestress is introduced into the concrete structure by joining the ends. The present invention provides a method for reinforcing a concrete structure characterized by the following.

Preferably, a continuous fiber belt is wound around the concrete structure, and an end of the continuous fiber belt is pulled to apply a preliminary tension to the continuous fiber belt. In this state, the continuous fiber belt is fully tensioned. To provide a method for reinforcing a concrete structure, characterized in that opposing ends of a continuous fiber belt are brought closer to each other, and the ends are joined to introduce prestress into the concrete structure. I do.

Next, a continuous fiber belt is partially wound around the concrete structure, a PC steel wire is arranged between the ends of the continuous fiber belt, and the ends are connected to each other, and the PC steel wire is tensioned. Accordingly, a method for reinforcing a concrete structure characterized by introducing prestress into the concrete structure is provided.

As a specific example, a continuous fiber belt is partially wound around a concrete structure, a PC steel wire is arranged between ends of the continuous fiber belt, and a connecting device provided with jacks at both ends. The present invention provides a method for reinforcing a concrete structure, characterized in that prestress is introduced into a concrete structure by tensioning a PC steel wire by using a tensioning device provided in a connecting device to apply tension.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in accordance with the procedure for reinforcing a concrete girder of a bridge.

First, as shown in FIGS. 1 and 2, corner metal fittings 2 are bonded to the four corners of a main girder 1 of a concrete girder using an adhesive 3 such as epoxy resin. This corner fitting 2
Is to prevent the continuous fiber belt from being damaged when the continuous fiber belt is wound around the main girder 1 and tensioned.

Next, as shown in FIG. 3, a continuous fiber belt 4 having a length determined around the main girder 1, that is, a length capable of joining the ends thereof when fully tensioned as described later. Wrap. Although the method of winding the continuous fiber belt 4 is not necessarily specified, as shown in FIG.
The books may be arranged with their ends facing each other, or one book may be arranged with their ends facing as shown in FIG.

In this embodiment, as shown in FIG. 6, the continuous fiber belt 4 is further tensioned after the pretensioning of the continuous fiber belt 4, which will be described later. The cylindrical fitting portions 5 and 6 are formed at positions where they can be inserted. Although these fitting portions 5 and 6 are not necessarily required, they are provided for facilitating a pulling operation by a pulling instrument as described later.

When the continuous fiber belt 4 is to be tensioned, in the case shown in FIG. 4, one of the facing places is joined to connect the two continuous fiber belts continuously, and only the other facing end side is connected. Or both the one and the other facing end side may be pulled. In the case shown in FIG. 5, the pulling may be performed such that only the facing ends are joined.

The continuous fiber belt 4 may be tensioned at a time, but it is better to divide the continuous fiber belt 4 into a pretension and a final tension. The tension is released and the joining work is easy to perform.

As shown in FIG. 7, the pre-tension is performed by using a tensioning device, for example, a cheer hole 7, by using a fitting portion 5 at the opposite end of the continuous fiber belt 4. More specifically, a pretensioning bolt 8 having a rope retaining ring 9 at each end is inserted into each of the fitting portions 5 facing each other, a rope 11 is bridged between the rope retaining ring 9 and a hook 10 of the cheer hole 7, and the cheer hole 7 is operated. Then, the continuous fiber belt 4 is pulled until the slack is removed.

The tensioning is performed by using a tensioning device such as a winch 12 by using a fitting portion 6 formed at an appropriate position inside the facing end portion of the continuous fiber belt 4. Winch 1
When the tension is performed at 2, the cheer hole 7 may be removed. Specifically, the tension bolt 13 is inserted into each of the fitting portions 6, the winch 12 is attached to the anchor attached to the abutment 14, the pulley 15 and the rope 16 are arranged, and the continuous fiber belt is pulled by a known tension method. Tension 4

After the continuous fiber belt 4 is tensioned to a position where the facing ends of the continuous fiber belt 4 can be joined, the pretensioning bolt 8 is removed as shown in FIG. And a fixing metal fitting is attached to the end of the continuous fiber belt 4 to join the opposite ends. In this embodiment, the fixing bracket includes a connecting pin 17, a bolt 18, and a nut 19. The connecting pin 17 is inserted into a fitting portion 5 at the opposite end with a bolt insertion portion opened at both ends. The bolt 18 is inserted through the insertion portion 20, and the nut 19 is tightened to eliminate slack in the L section. At the time of joining, the inside of the continuous fiber belt is tensioned by the winch from the fitting portion 6 at an appropriate interval inside the end portion, but the tension is released between the fitting portion 5 and the fitting portion 6. Therefore, the joining operation becomes easy. After joining the ends together, the tensioning devices such as winch 12, pulley 15, rope 16 and the like are removed.

Thus, tension is applied to the continuous fiber belt 4 and prestress is introduced into the main girder 1. In this embodiment, the continuous fiber belt used was an aramid continuous fiber belt.

Next, another embodiment of the present invention will be described.

First, as shown in FIGS. 10 and 11, corner fittings 52 are bonded to the four corners of a main girder 51 of a concrete girder using an adhesive 53 such as epoxy resin. The corner metal fitting 52 is for winding the continuous fiber belt around the main girder 51 and preventing the continuous fiber belt from being damaged when being tensioned.

Next, as shown in FIGS. 12 and 13, a continuous fiber belt 54 is wound around both ends of the main girder 51 and temporarily fixed, and a PC steel wire 55 is arranged between the ends of the continuous fiber belt 54. The PC steel wire 55 preferably has a rust-proofing effect after being subjected to rust-proofing treatment. The connection between the end portions of the continuous fiber belt 54 and the PC steel wire 55 is performed via a connecting device 56 such as a fixing bracket.

After connecting the continuous fiber belt 54 and the PC steel wire 55, the temporary fixing is released and the PC steel wire 55 is tensioned.

The tension is first applied until the slack of the PC steel wire 55 is removed, and then until the predetermined tension is reached. Thereafter, the PC steel wire 55 is fixed to the beam 51.

Although the method of tensioning the PC steel wire 55 is not limited, as shown in FIGS. 14 and 15, a tension device 57 such as a center hole jack operated by hydraulic pressure is provided in the connecting device, and the tension device is tensioned. It is easy to perform the operation by connecting the end of the PC steel wire to 57 and operating the tensioning device 57. When the connecting device 56 does not include the pulling device 57, the connecting device 56 is pulled by rotating a nut 58 screwed to the end of the PC steel wire.

Thus, tension is applied to the continuous fiber belt 54, and prestress is introduced to the main girder 51. In this embodiment, the continuous fiber belt used was an aramid continuous fiber belt.

[0028]

Since the present invention is a method for reinforcing a concrete structure as described above, it has the following effects.

In the first and second aspects of the present invention, the method of introducing prestress into a concrete structure can be performed only by winding a continuous fiber belt around the concrete structure and applying tension to the continuous fiber belt. ,
Since it is not necessary to form an anchor hole or the like for the cable anchoring portion as in the case of the outer cable method, a predetermined prestress can be introduced without damaging the concrete structure. In addition, since the continuous fiber belt is wound around the whole, prestress is introduced to both ends.

According to the third and fourth aspects, the method of introducing prestress into a concrete structure is to partially wind a continuous fiber belt around the concrete structure and arrange a PC steel wire between the continuous fiber belts. , Combine with each other, P
Since it is only necessary to apply tension to the C steel wire, there is no need to drill holes for anchoring the cable as in the case of the external cable method, so prestressing can be performed without damaging the concrete structure Can be introduced. Moreover, since the whole is wound by a continuous fiber belt and a PC steel wire, prestress is introduced to both ends.

[Brief description of the drawings]

FIG. 1 is a front view showing a state in which corner fittings are attached to four corners of a main girder of a concrete girder.

FIG. 2 is an AA end view of FIG. 1;

FIG. 3 is a front view showing a state where a continuous fiber belt is wound around a main girder of a concrete girder.

FIG. 4 is a BB end view showing how to wind a continuous fiber belt wound around a main girder of a concrete girder.

FIG. 5 is a BB end view and a partially enlarged view showing another example of a method of winding a continuous fiber belt wound around a main girder of a concrete girder.

FIG. 6 is a plan view showing an example of a continuous fiber belt.

FIG. 7 is an explanatory view showing a work of preliminary tension.

FIG. 8 is an explanatory view showing the work of this tension.

FIG. 9 is an explanatory view showing an operation of joining the facing ends.

FIG. 10 is a front view showing a state where corner fittings are attached to four corners of the main girder of the concrete girder.

11 is a sectional view taken along the line CC of FIG. 10;

FIG. 12 is a front view showing a state where a continuous fiber belt is wound around a main girder of a concrete girder.

FIG. 13 is a DD end view showing how to wind a continuous fiber belt wound around a main girder of a concrete girder.

FIG. 14 is a plan view of the connecting device.

FIG. 15 is a front view of the connection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main girder of concrete girder 2 Corner fitting 3 Adhesive 4 Continuous fiber belt 5 Insertion part 6 Insertion part 7 Cheer hole 8 Pre-tension bolt 9 Rope retaining ring 10 Hook 11 Rope 12 Winch 13 Tension bolt 14 Abutment 15 Pulley DESCRIPTION OF SYMBOLS 16 Rope 17 Connecting pin 18 Bolt 19 Nut 20 Bolt insertion part 51 Main girder of concrete girder 52 Corner fitting 53 Adhesive 54 Continuous fiber belt 55 PC steel wire 56 Connecting device 57 Pulling device 58 Nut

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichi Hida 3-7-7 Iidabashi, Chiyoda-ku, Tokyo Inside Chiyoda Consultant Co., Ltd. (72) Inventor Hideaki Ibuki 2-1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo (72) Inventor Michiya Takada 3-18 Kanda Nishikicho, Chiyoda-ku, Tokyo F-term in Shobond Construction Co., Ltd. 2D059 AA05 BB39 GG01 GG40 2E176 AA04 BB29

Claims (4)

[Claims] 1. A continuous fiber belt is wound around a concrete structure, and tension is applied to the continuous fiber belt.
A method for reinforcing a concrete structure, characterized by introducing prestress into the concrete structure by joining the ends. 2. A continuous fiber belt is wrapped around a concrete structure, and an end of the continuous fiber belt is pulled to apply a pretension to the continuous fiber belt. In this state, a continuous tension is applied to the continuous fiber belt. A method for reinforcing a concrete structure, characterized in that opposite ends of a continuous fiber belt are brought close to each other and pre-stress is introduced into the concrete structure by joining the ends. 3. A continuous fiber belt is partially wound around a concrete structure, a PC steel wire is arranged between ends of the continuous fiber belt, and the ends are joined together and a tension is applied to the PC steel wire. A method for reinforcing a concrete structure, characterized by introducing a prestress into the concrete structure. 4. A continuous fiber belt is partially wrapped around a concrete structure, a PC steel wire is arranged between ends of the continuous fiber belt, and the ends of the continuous fiber belt are connected to each other using a connecting device. A method for reinforcing a concrete structure, characterized in that a prestress is introduced into a concrete structure by tensioning a PC steel wire by pulling the steel wire with a tension device provided.