JP3498111B2 - Reinforcement method of concrete structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing concrete structures, for example, concrete girders for bridges, and more particularly to measures for reinforcing main girders due to an increase in design live load, and re-stressing of prestress due to damage to existing PC steel materials. Suitable for introduction.

[0002]

2. Description of the Related Art An outer cable construction method is known as a conventional method for reinforcing concrete structures. In the outer cable method, anchoring devices are installed at both ends of the concrete structure with anchor bolts, etc., tension materials are installed, and by installing tension materials, prestress is introduced into the concrete structure to prevent stress overload. It is a construction method.

This method is extremely effective as a reinforcing method for concrete structures, but has some problems.

In the outer cable construction method, the anchor portion of the outer cable is installed by installing anchor bolts on the concrete structure. Therefore, it is necessary to perform a detailed steel material position search in advance so as not to damage the steel material (PC steel material, rebar) of the concrete structure. For example, PC steel material is concentrated at the girder end of a general PC bridge, which makes it very difficult to determine the anchor anchor drilling position.

Further, in a general PC bridge, since the fixing portion of the outer cable is post-constructed, the bearings, cross girders, etc. become obstacles and are to be provided in front of the end of the concrete girder. For this reason, the prestress of the outer cable is introduced between the fixing parts located in front of the girder end part, not only the prestress is not introduced into the girder end part, but also the tensile force is generated from the rear part of the girder part to the girder end part. Will need further reinforcement.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems of damaging a concrete structure in the outer cable construction method and the problems of not introducing prestress to the ends by the following points. is there.

[0007]

First, a continuous fiber belt is wound around a concrete structure, and the continuous fiber belt is pretensioned by pulling an end portion of the continuous fiber belt. In this state, the continuous fiber belt is tensioned. To give this tension to
Provided is a method for reinforcing a concrete structure, characterized in that pre-stress is introduced into the concrete structure by bringing opposite ends of the continuous fiber belt close to each other and connecting the ends.

Next, a continuous fiber belt is partially wound around the concrete structure, PC steel wires are arranged between the end portions of the continuous fiber belt to bond the mutual end parts, and the PC steel wire is tensioned. This provides a method for reinforcing a concrete structure, which is characterized by introducing prestress into the concrete structure.

As a concrete example, a continuous fiber belt is partially wound around a concrete structure, a PC steel wire is arranged between the end portions 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 prestressing is introduced into the concrete structure by connecting the steel wires with each other and tensioning the PC steel wire by pulling the PC steel wire with a tension device provided in the connecting device.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below according to a procedure for reinforcing concrete girders of bridges.

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 with an adhesive 3 such as an epoxy resin. This corner bracket 2
This is because the continuous fiber belt is wound around the main girder 1 to prevent the continuous fiber belt from being damaged when it is tensioned.

Next, as shown in FIG. 3, a continuous fiber belt 4 having a length defined around the main girder 1, that is, a length capable of connecting the ends when the main tension is made as will be described later. Wrap around. The method of winding the continuous fiber belt 4 is not necessarily specified, but as shown in FIG.
The books may be arranged so that their ends face each other, or one end may face each other as shown in FIG.

Here, in this embodiment, the continuous fiber belt 4 is, as shown in FIG. 6, appropriately spaced at both ends and inside thereof, that is, after the continuous tension is applied to the continuous fiber belt 4 which will be described later. Cylindrical fitting portions 5 and 6 are formed at positions where they can be inserted. Although these fitting portions 5 and 6 are not always necessary, they are for facilitating the pulling work by the pulling device as described later.

When the continuous fiber belt 4 is tensioned, in the case shown in FIG. 4, one of the facing fiber belts is connected and the two continuous fiber belts are continuously connected to the other facing end portion side only. May be pulled or both sides of one and the other facing ends may be pulled, and in the case shown in FIG. 5, only the facing ends may be pulled.

The tension of the continuous fiber belt 4 is determined by the preliminary tension and the book.
Divide into tension. When pretensioning is performed, the tension is released at the end of the continuous fiber belt to be joined at the time of the main tension, and the joining operation is easy.

As shown in FIG. 7, the pretensioning is performed by using a fitting device 5 at the opposite ends of the continuous fiber belt 4 and a pulling device such as a cheer hole 7. Specifically, the preliminary tension bolts 8 having rope retaining rings 9 at both ends are inserted into the fitting portions 5 facing each other, the rope 11 is bridged between the rope retaining ring 9 and the hook 10 of the cheerhole 7, and the cheerhole 7 is operated. Then, the continuous fiber belt 4 is pulled until the slack is removed.

The main tension is carried out by using a pulling tool, for example, a winch 12, utilizing a fitting portion 6 formed at an appropriate position inside the opposite ends of the continuous fiber belt 4. Winch 1
When pulling at 2, the cheerhole 7 may be removed. Specifically, the main 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 formed by a known pulling method. Tension 4

After the continuous fiber belt 4 is tensioned to the position where the opposite ends of the continuous fiber belt 4 can be joined, the pretension bolt 8 is removed as shown in FIG. A fixing metal fitting is attached to and the facing ends of the continuous fiber belt 4 are joined together. In this embodiment, the fixing fitting is composed of a connecting pin 17, a bolt 18, and a nut 19, and the connecting pin 17 has bolt insertion portions formed at both ends thereof and is inserted into the fitting portions 5 at the opposite ends. The bolt 18 is inserted through the insertion portion 20 and the nut 19 is tightened to eliminate the slack in the L section. At the time of connection, the inner side of the end portion of the continuous fiber belt is tensioned with a winch from the fitting portion 6 at an appropriate spacing position, but the tension is released between the fitting portion 5 and the fitting portion 6. Therefore, the connecting work becomes easy. After joining the ends, the pulling device such as the winch 12, pulley 15, rope 16 etc. is removed.

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

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

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

Next, as shown in FIGS. 12 and 13, the continuous fiber belt 54 is wound around both ends of the main girder 51 and temporarily fixed, and the PC steel wire 55 is arranged between the ends of the continuous fiber belt 54. It is preferable that the PC steel wire 55 has a rustproofing treatment and has a rustproofing effect. The end portions of the continuous fiber belt 54 and the PC steel wire 55 are connected to each other via a connecting device 56 such as a fixing fitting.

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 performed until the slack of the PC steel wire 55 is removed, and then until the predetermined tension is reached. After that, the PC steel wire 55 is fixed to the girder 51.

Although the method of tensioning the PC steel wire 55 is not limited, as shown in FIGS. 14 and 15, a tensioning device 57 such as a hydraulically operated center hole jack is provided in the connecting device to provide a tensioning device. It is easy to connect the end of the PC steel wire to 57 and operate the pulling device 57. In the connecting device 56, when the pulling device 57 is not provided, the nut 58 screwed to the end of the PC steel wire is rotated to pull it.

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

[0027]

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

According to the first aspect of the present invention, the method of introducing prestress to the concrete structure may be performed by winding the continuous fiber belt around the concrete structure and applying tension to the continuous fiber belt. Since the anchor hole for the cable fixing portion and the like are not required as in the case of 1, the predetermined prestress can be introduced without damaging the concrete structure. Further, since the continuous fiber belt is wound around the whole, prestress is introduced to both ends.

In the second and third aspects , the method of introducing prestress to the concrete structure is to wrap a part of the continuous fiber belt around the concrete structure and arrange a PC steel wire between the continuous fiber belts. , Bound to each other, P
Since it only has to be done by applying tension to the C steel wire, it does not require anchor drilling etc. for the cable fixing part unlike the case of the outer cable construction method, so it does not damage the concrete structure and prestresses it. Can be introduced. Moreover, since the whole is wound with the continuous fiber belt and the PC steel wire, prestress is introduced to both ends.

[Brief description of drawings]

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

FIG. 2 is an end view taken along the line AA of FIG.

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 how to wind 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 diagram showing a pre-tensioning operation.

FIG. 8 is an explanatory diagram showing a work of main tension.

FIG. 9 is an explanatory diagram showing a work of connecting facing ends.

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

11 is an end view taken along the line CC of FIG.

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 D-D 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 connecting device.

[Explanation of symbols]

1 Main girder of concrete girder 2 corner fittings 3 adhesive 4 continuous fiber belt 5 Fitting part 6 Fitting part 7 Cheerleaders 8 Pre-tensioning bolt 9 rope retaining ring 10 hooks 11 rope 12 winches 13 tension bolts 14 abutments 15 pulley 16 rope 17 connecting pin 18 volt 19 nuts 20 bolt insertion part 51 Main girder of concrete girder 52 corner fittings 53 Adhesive 54 continuous fiber belt 55 PC steel wire 56 Connecting device 57 Tensioner 58 nuts

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichi Hida               3-3-7 Iidabashi, Chiyoda-ku, Tokyo               Chiyoda Consultant Co., Ltd. (72) Inventor Hideaki Ibuki               2-1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo               Teijin Limited (72) Inventor Michiya Takada               3-18 Kandanishikicho, Chiyoda-ku, Tokyo               Within Showbond Construction Co., Ltd.                (56) References JP 2001-73559 (JP, A)                 Japanese Patent Laid-Open No. 10-96330 (JP, A)                 JP-A-6-322715 (JP, A)                 JP 62-94654 (JP, A)                 JP 62-10368 (JP, A)                 Special Table Flat 8-509037 (JP, A)

Claims (3)

(57) [Claims] 1. A continuous fiber belt is wound around a concrete structure, an end portion of the continuous fiber belt is pulled to give a pre-tension to the continuous fiber belt, and a continuous tension is applied to the continuous fiber belt in this state. Then, a method for reinforcing a concrete structure is characterized in that pre-stress is introduced into the concrete structure by bringing the opposite ends of the continuous fiber belt close to each other and connecting the ends. 2. A continuous fiber belt is partially wound around a concrete structure, and PC steel wires are arranged between the end portions of the continuous fiber belt to bond the end portions to each other and to apply tension to the PC steel wire. The method for reinforcing concrete structures is characterized by introducing prestress into the concrete structures. 3. A continuous fiber belt is partially wound around a concrete structure, PC steel wires are arranged between the ends of the continuous fiber belt, and the ends of the continuous fiber belt are connected by using a connecting device to form a connecting device. A method for reinforcing a concrete structure, comprising introducing prestress into the concrete structure by pulling a PC steel wire by a tensioning tool provided to apply tension.