JP5220295B2 - Method and material for reinforcing damaged reinforcing bars - Google Patents

Description

  The present invention relates to a method for reinforcing damaged reinforcing bars. For example, when a reinforcing bar disposed in a concrete structure is broken or corroded by an alkali aggregate reaction or the like, the method and the reinforcement for reinforcing damaged bars are disclosed. It relates to materials.

  Reinforcing bars are disposed in the reinforced concrete structure, and it is known that these reinforcing bars are damaged by alkali aggregate reaction, salt damage, neutralization of concrete, and the like. And if the reinforcing bar arrange | positioned in a reinforced concrete structure is damaged, the yield strength and rigidity of a reinforced concrete structure may fall remarkably.

Conventionally, various techniques have been proposed for repairing broken or corroded reinforcing bars.
In general, for the sake of convenience, a method is used in which a supplementary bar is disposed across the fracture surface and the reinforcing bar is welded to the reinforcing bar. As such a method, for example, when it is found that the rebar has broken, after the concrete is lifted to expose the damaged portion of the rebar, repair metal fittings are disposed at the broken portion, and the rebar and the repair metal fitting are welded. Is disclosed (see Patent Document 1).
In the technique described in Patent Document 1, after the concrete is lifted to expose the damaged portion of the reinforcing bar, the repair metal fitting and the repairing reinforcing bar are arranged so as to sandwich the fractured portion, By welding the repairing reinforcing bar, the damaged part of the reinforcing bar is reinforced.

Moreover, when it turns out that the reinforcing bar has broken, a method of drilling from the surface of the concrete structure to the broken part of the reinforcing bar and welding the broken portion is disclosed (see Patent Document 2).
The technique described in Patent Document 2 is a high temperature generated by a chemical reaction between a metal oxide and aluminum by drilling from the surface of the concrete until the fracture portion of the reinforcing bar is exposed, without removing the concrete from the outside. The molten metal is poured to cast the periphery of the fractured portion, and the broken reinforcing bars are welded together to reinforce the damaged portion of the reinforcing bars.
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JP 2006-38752 A JP 2005-238296 A

  However, in many cases where the rebar breaks, breakage occurs at the bending portion of the rebar, so it is difficult to repair this properly and reliably, and the above-described conventional technique has taken sufficient measures. I couldn't say that.

  That is, in the technique described in Patent Document 1 described above, since the accessory bars are arranged and welded at the broken portions of the reinforcing bars, the material of the reinforcing bars may be damaged by the welding heat. Furthermore, if the expansion due to the alkali aggregate reaction or the like has not converged, even if repair is performed, the reinforcing bars may be damaged by the expansion after the repair. Furthermore, since the accessory bar is used, there is a possibility that the specified minimum covering thickness cannot be satisfied after the repair.

  Further, in the technique described in Patent Document 2 described above, when the reinforcing bars break over a wide range, that is, when the distance between the remaining reinforcing bars is large, there is a possibility that the broken portion cannot be reliably welded. It was.

  As described above, the conventional repairing method for fractured or corroded reinforcing bars cannot perform appropriate and reliable repairing.

  The present invention has been proposed in view of the above-described circumstances, and even when a reinforcing bar disposed in a reinforced concrete structure is damaged by an alkali aggregate reaction or the like, it is repaired appropriately and reliably, and a reinforced concrete structure is provided. It is an object of the present invention to provide a reinforcing method and a reinforcing material for damaged reinforcing bars capable of maintaining the strength and rigidity of an object.

In order to achieve the above-described object, the damaged reinforcing bar reinforcing method and reinforcing material according to the present invention have the following features.
That is, the method for reinforcing a damaged reinforcing bar according to the present invention relates to a method for reinforcing a damaged reinforcing bar when a reinforcing bar disposed in a reinforced concrete structure is damaged by alkali aggregate reaction, salt damage, neutralization of concrete, or the like. And includes the following four steps.

A 1st process is a process of picking up the concrete of the part with which the reinforcing bar was damaged, and exposing the damaged part of a reinforcing bar. The second step is a step of attaching a reinforcing material made of carbon fiber, which is a long fiber , to the damaged portion of the reinforcing bar while being electrically insulated from the reinforcing bar . A 3rd process is a process of filling a filler in the space | gap of the reinforcing steel bar and concrete after reinforcement. The fourth step is a step of repairing the cross section by filling the cross-section repair material into the portion where the concrete is suspended.

  By carrying out such a process, it is possible to reinforce the reinforcing bars whose fractures or cross sections are reduced and to maintain the proof strength and rigidity of the reinforced concrete structure.

In addition, the step of attaching a reinforcing material made of carbon fiber, which is a long fiber , to the damaged portion of the reinforcing bar is bundled in advance so as to have a required cross-sectional area, and both ends of the carbon fiber are solidified with a resin and a protruding portion , And electrically insulating the reinforcing bar, and fixing to the reinforcing bar using a fastening member formed of the same material or plastic as the polymer adhesive and the reinforcing bar. Such a reinforcing material attaching step is useful particularly when there are many damaged portions of the reinforcing bars, and quick repair can be performed by preparing a plurality of reinforcing materials in advance.

The reinforcing material for damaged reinforcing bars according to the present invention relates to a reinforcing material for damaged reinforcing bars arranged in a reinforced concrete structure. This reinforcing material is bundled so as to have a required cross-sectional area in accordance with the damaged portion of the reinforcing bar, and the carbon fiber , which is a long fiber electrically insulated from the reinforcing bar, and both ends of the carbon fiber are fixed with resin. And a fixing member for fixing both ends of the carbon fiber to a reinforcing bar, wherein the fixing member is made of the same material or plastic as the reinforcing bar. It is.

According to the method for reinforcing a damaged reinforcing bar according to the present invention, even when a reinforcing bar disposed in a reinforced concrete structure is damaged due to an alkali aggregate reaction or the like, the repair of the reinforced concrete structure is performed appropriately and reliably. Yield strength and rigidity can be maintained. Moreover, since the local battery is not formed between the surface of the reinforcing bar and the carbon fiber by electrically insulating the surface of the reinforcing bar and the carbon fiber, the corrosion of the reinforcing bar can be prevented. Further, by forming the fastening member with the same material or plastic as the reinforcing bar, corrosion due to the difference in potential between the reinforcing bar and the fastening member can be prevented.

  In particular, the method for reinforcing damaged reinforcing bars according to the present invention is not a special member to be used, and since the process is simple, construction is easy, construction time can be shortened and construction cost is reduced. can do. Moreover, since welding is not required, there is no possibility that the rebar will suffer secondary damage. Further, even if expansion due to alkali aggregate reaction or the like has not converged and expansion occurs after repair, excessive stress that may occur in the reinforcing bar can be absorbed in the reinforcing bar damaged portion. Furthermore, even if the apparent reinforcing bar diameter increases due to reinforcement, since the long fibers used are non-corrosive, there is almost no influence due to the reduction in covering thickness.

Hereinafter, with reference to the drawings, embodiments of a reinforcing method and a reinforcing material for damaged reinforcing bars according to the present invention will be described.
The reinforcing method and reinforcing material for damaged reinforcing bars according to the present invention is a technique applied when reinforcing bars arranged in a reinforced concrete structure are damaged by alkali aggregate reaction, salt damage, concrete neutralization, etc. , Mainly including the following four steps.

  In the first step, the damaged part of the concrete is picked up to expose the damaged part of the reinforcing bar. In the subsequent second step, a reinforcing material made of long fibers is attached to the damaged portion of the reinforcing bar. In a subsequent third step, a filler is filled in the space between the reinforcing steel bar and the concrete after reinforcement. In the subsequent fourth step, the cross-section is repaired by filling the cross-section repair material into the portion where the concrete is suspended.

<First Embodiment>
Next, the 2nd process which is a main process of the reinforcement method of the damaged reinforcement concerning the present invention is explained.
1 to 3 are diagrams for explaining a damaged reinforcing bar reinforcing method and a reinforcing material according to the first embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a reinforcing bar reinforcing procedure, and FIG. FIG. 3 is a perspective view of a damaged reinforcing bar reinforcing material. FIG.

  In the reinforcing method for damaged reinforcing bars according to the first embodiment, a reinforcing member 10 as shown in FIG. 3 is used. This reinforcing material 10 is made of long fibers in a sheet form, and as shown in FIG. 2, the sheet-like long fibers are laminated in layers and attached to the surface of the reinforcing bar 20, whereby the damaged portion of the reinforcing bar 20 ( Reinforcement of fracture surface 30).

  As the long fibers, for example, carbon fibers, aramid fibers, vinylon fibers and the like can be used. The long fibers are not limited to these materials, and other materials may be used as long as the strength and elastic modulus of the fibers have sufficient values for reinforcement.

The amount of long fibers necessary as the reinforcing material 10 is as follows.
In the case of carbon fiber, an amount of about 1/8 of the reinforcing bar area is required as a tensile strength of 3000 N / mm ² . In the case of an aramid fiber, an amount of about 1/5 of the reinforcing bar area is required as a tensile strength of 2000 N / mm ² . In the case of vinylon fibers, an amount of about 1 / 2.5 of the reinforcing bar area is required as a tensile strength of 1000 N / mm ² .
In the case where long fibers of other materials are used, the necessary amount can be obtained in the same manner.

  The length of the reinforcing material 10 varies depending on the strength of the long fibers used and the thickness of the sheet. However, when the strength is high or the sheet thickness is large, the bonding length of one layer is long. However, since the number of bonding points is reduced, the standard total bonding length is about 8 to 10 cm.

  In addition, when using a carbon fiber as a long fiber, it is preferable to electrically insulate the surface of the reinforcing bar 20 and the long fiber. That is, the carbon fiber is useful as a long fiber used in the present invention from the viewpoints of strength and elastic modulus. However, it is known that when the carbon fiber and the reinforcing bar 20 are in contact with each other, a local battery is formed at the contact portion, and the reinforcing bar 20 may be corroded. Therefore, corrosion of the reinforcing bar 20 can be prevented by electrically insulating the surface of the reinforcing bar 20 and the long fibers.

  In the method for reinforcing a damaged reinforcing bar according to the first embodiment, as shown in FIG. 1, when it is discovered that the reinforcing bar 20 disposed in the reinforced concrete structure is broken (a), the reinforcing bar 20 is The damaged portion of the concrete 40 is removed to expose the damaged portion 30 of the reinforcing bar 20 (b). In addition, in order to discover the breakage of the reinforcing bar 20, the outer surface of the concrete structure may be visually observed to search for a crack, or a known nondestructive inspection may be performed. The method of nondestructive inspection is described in, for example, JP-A-2005-181302.

  Subsequently, the reinforcing material 10 in the form of a sheet is pasted on the surface of the reinforcing bar 20 in a layered manner using a polymer adhesive (c). The amount of long fibers necessary for the reinforcing material 10 and the length of the reinforcing material 10 are as described above.

  Subsequently, the filler 50 is filled in the space between the reinforcing reinforcing bar 20 and the concrete 40 (d). As the filler 50, for example, a polymer, a polymer mortar, a cement mortar, or the like can be used.

  Subsequently, the cross-section repair material 60 is filled in the portion where the concrete 40 is suspended to repair the cross-section (e). For the cross-sectional repair material 60, for example, SBR-based, EVA-based, PAE-based polymer cement mortar, polyester resin-based, epoxy resin-based, acrylic resin-based polymer mortar, or the like is used as a resin-based cross-sectional repair material. it can. Further, as a cement-based cross-sectional repair material, ordinary cement mortar or concrete containing cement such as ordinary Portland cement, early-strength Portland cement, super-hard cement, etc., an aggregate, an admixture for concrete, and the like can be used.

  The method for reinforcing damaged reinforcing bars and the reinforcing member 10 according to the first embodiment are particularly useful when there are few damaged portions of the reinforcing bars 20, and can be repaired appropriately and reliably according to the damaged state.

<Second Embodiment>
4 to 6 illustrate a reinforcing method and a reinforcing material for damaged reinforcing bars according to the second embodiment of the present invention. FIG. 4 is a longitudinal sectional view showing a reinforcing procedure for damaged reinforcing bars, and FIG. FIG. 6 is a perspective view of a damaged reinforcing bar reinforcing material. FIG.

  In the reinforcing method for damaged reinforcing bars according to the second embodiment, a reinforcing material 110 as shown in FIG. 6 is used. This reinforcing material 110 includes long fibers 111 that are bundled so as to have a required cross-sectional area corresponding to the damaged portion 30 of the reinforcing bar 20, protrusions 112 that are formed by fixing both ends of the long fibers 111 with a resin, It consists of a fastening member 113 for fixing both ends of the fiber 111 to the reinforcing bar 20. Then, as shown in FIG. 5, the damaged portion 30 of the reinforcing bar 20 is reinforced by fixing the reinforcing member 110 to the surface of the reinforcing bar 20 using a polymer adhesive and the fastening member 113.

  The material, required amount, required length, and the like of the long fiber 111 are the same as those in the first embodiment. Moreover, when using carbon fiber as the long fiber 111, it is preferable to electrically insulate the surface of the reinforcing bar 20 and the long fiber 111 from each other.

  As shown in FIG. 6, the fastening member 113 is formed of a cylindrical crimp fitting having an open portion in the axial direction. When the fastening member 113 is made of metal, it is preferable to use the same material as the reinforcing bar 20 in order to prevent corrosion due to a difference in potential from the reinforcing bar 20. The fastening member 113 is not limited to the crimp fitting, and any member may be used as long as the reinforcing member 110 can be fixed to the reinforcing bar 20, and for example, a plastic binding band can be used.

  In the method for reinforcing damaged reinforcing bars according to the second embodiment, as shown in FIG. 4, when it is discovered that the reinforcing bars 20 arranged in the reinforced concrete structure are broken (a), the reinforcing bars 20 are The damaged portion of the concrete 40 is removed to expose the damaged portion 30 of the reinforcing bar 20 (b).

  Subsequently, the reinforcing material 110 is affixed to the reinforcing bar 20 with a polymer adhesive, and the fastening member 113 is positioned inside the protrusions 112 formed at both ends of the reinforcing material 110. 20 and the reinforcing material 110 are sandwiched. Then, the reinforcing member 110 is fixed to the surface of the reinforcing bar 20 by tightening the fastening member 113 (c).

  Subsequently, the filler 50 is filled in the space between the reinforcing reinforcing bar 20 and the concrete 40 (d), and the cross-section repair material 60 is filled in the portion where the concrete 40 is removed to repair the cross section (e). As the filler 50 and the cross-sectional repair material 60, the same materials as those of the first embodiment described above can be used.

  The method for reinforcing damaged reinforcing bars and the reinforcing material 110 according to the second embodiment are particularly useful when there are many damaged portions of the reinforcing bars 20, and by preparing a plurality of reinforcing materials 110 in advance, quick repair is possible. It can be carried out.

<Other embodiments>
In the above-described embodiment, an example in which the present invention is applied to a broken reinforcing bar is shown. However, the present invention corrodes not only due to a broken reinforcing bar but also due to various deterioration factors such as salt damage and neutralization of concrete. Therefore, it can be applied to reinforcement of reinforcing bars whose cross-sectional area is reduced.

  Further, the material, amount, and length of the long fiber can be appropriately changed according to the environment in which the reinforcing bar to be repaired is constructed, the diameter of the reinforcing bar, and the like.

The longitudinal cross-sectional view which shows the reinforcement procedure of the damaged reinforcement which concerns on the 1st Embodiment of this invention. The perspective view which shows the damaged reinforcement reinforced with the reinforcement method of the damaged reinforcement which concerns on the 1st Embodiment of this invention. The perspective view of the reinforcing material used for the reinforcement method of the damaged reinforcement which concerns on the 1st Embodiment of this invention. The longitudinal cross-sectional view which shows the reinforcement procedure of the damaged reinforcement which concerns on the 2nd Embodiment of this invention. The perspective view which shows the damaged reinforcement reinforced with the reinforcement method of the damaged reinforcement which concerns on the 2nd Embodiment of this invention. The perspective view of the reinforcing material used for the reinforcement method of the damaged reinforcement which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,110 Reinforcement material 20 Reinforcing bar 30 Damaged part 40 Concrete 50 Filler 60 Cross-section repair material 111 Long fiber 112 Protruding part 113 Fastening member

Claims (2)

A method for reinforcing damaged reinforcing bars arranged in a reinforced concrete structure,
Removing the damaged part of the concrete by exposing the damaged part of the concrete;
A step of attaching a reinforcing material made of carbon fiber, which is a long fiber, to the damaged portion of the reinforcing bar, electrically insulating from the reinforcing bar, and
Filling the filler into the gap between the reinforcing steel and the concrete,
Filling the cross-section repair material into the portion where the concrete is suspended, and repairing the cross-section;
Including
The step of attaching a reinforcing material made of carbon fiber, which is a long fiber, to the damaged part of the reinforcing bar,
The carbon fiber is bundled so as to have a required cross-sectional area in advance, and both ends of the carbon fiber are solidified with resin to electrically insulate the reinforcing material from the reinforcing bar, and the polymer adhesive and the reinforcing bar A method for reinforcing a damaged reinforcing bar, comprising fixing a reinforcing member using a fastening member formed of the same material or plastic. A reinforcing material for damaged reinforcing bars arranged in a reinforced concrete structure,
Carbon fibers that are long fibers that are bundled so as to have a required cross-sectional area according to the damaged portion of the reinforcing bar and are electrically insulated from the reinforcing bar,
Protrusions formed by fixing both ends of the carbon fiber with a resin;
Fastening members for fixing both ends of the carbon fiber to the reinforcing bar,
With
A reinforcing member for damaged reinforcing bars, wherein the fastening member is made of the same material or plastic as the reinforcing bars.

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