JPH11230927A - Concrete structure capable of detecting defect in coated reinforcing bar and its detecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a defect in a coated reinforcing bar after concrete is placed. SOLUTION: In a concrete structure 1 in which a reinforcing bar 3 coated with an epoxy resin 2 is buried, a conductor 4 for detection is connected to the reinforcing bar 3 coated with the epoxy resin 2. The end part of the conductor 4 for detection is exposed on the surface of the concrete structure 1. The conductor 4 for detection is connected to a potentiometer 5, and an electrode 6 for collation is connected separately to the potentiometer 5. Then, the collation electrode 6 is brought into contact with the surface of the concrete structure 1, and a defect is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete structure capable of detecting a defect in a painted reinforcing bar and a method for detecting the same.

[0002]

2. Description of the Related Art In a reinforced concrete structure or a prestressed concrete structure, when the reinforcing bar is corroded, deterioration such as a reduction in the cross section of the reinforcing bar itself, a decrease in the adhesive force with the concrete, or generation of cracks in the concrete due to corrosion products occurs. Sometimes. For this purpose, a so-called epoxy resin coated reinforcing bar, in which the surface of the reinforcing bar is coated with an epoxy resin to significantly improve the rust prevention effect of the reinforcing bar, has been developed and used.

[0003]

Conventionally, there is a method of detecting pinholes in an epoxy resin coating process. However, a concrete structure capable of detecting a defective portion of a reinforcing bar after being embedded in concrete, or a concrete structure capable of detecting a defect. The way to do it was not developed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a concrete structure and a method of detecting the same, which can detect a defect in a coated reinforcing bar after placing concrete. With the goal.

[0005]

In order to achieve the above-mentioned object, a concrete structure capable of detecting a defect in a coated reinforcing bar according to the present invention is a concrete structure in which a reinforcing bar coated with an epoxy resin is embedded. It features a concrete structure that can detect defects in painted rebar by connecting detection wires to resin-coated rebar and exposing the ends of the detection wires to the concrete surface. It is.

Further, in the method for detecting defects in a coated reinforcing bar according to the present invention, in a concrete structure in which a reinforcing bar coated with an epoxy resin is embedded, a part of the concrete is peeled off to expose the reinforcing bar coated with the epoxy resin. Detecting wire is connected to the exposed part, this detecting wire is connected to a potentiometer, an electrode is connected to the potentiometer separately for verification, and the verification electrode is brought into contact with the concrete surface. Is characterized by the detection method of

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a concrete structure capable of detecting a defect in a coated steel bar according to the present invention, and a method of detecting the same.

<A> Concrete structure. 1 is a concrete structure in which a reinforcing steel bar 3 coated with an epoxy resin 2 is embedded. A part of the reinforcing bar 3 covered with the epoxy resin 2 is removed, and a lead 4 for detection is connected to the exposed portion. The connection portion is protected by a material 8 having a rust prevention effect equal to or higher than that of the epoxy resin 2 so as not to be detected as a defective portion. Concrete is cast in a state where the end portion 5 of the detection conducting wire 4 is pulled out long, and the concrete structure 1 is completed. The detection conductor 4 is provided with an appropriate rust-preventing effect so that the conductor 4 itself does not corrode or accelerate the corrosion of the reinforcing bar 3.

<B> A method of exposing a reinforcing bar. The embodiment shown in FIG. 1 is a method in which a conductor 4 for detecting a defect is buried in advance when the concrete structure 1 is constructed. However, as shown in FIG. 2, when the conductor 4 is not buried in advance, a part of the concrete is peeled off to expose the epoxy resin 2. The exfoliated concrete part is repaired in cross section by an appropriate method. And epoxy resin 2
Is peeled off to expose the reinforcing bar 3. The conductor 4 is fixed to the exposed portion of the reinforcing bar 3, and the other end of the conductor 4 is drawn out of the concrete structure 1.

<C> Detection method When detecting a defect in the reinforcing bar 3 coated with the epoxy resin 2, the detecting lead 4 is connected to a potentiometer 5. Further, a reference electrode 6 is separately connected to the potentiometer 5 for comparison. As the reference electrode 6, an electrode such as a copper sulfate electrode, a saturated calomel electrode, a saturated silver chloride electrode, or a lead electrode can be used. The detection is performed by bringing the tip of the reference electrode 6 into contact with the surface of the concrete structure 1 in a state where the tip is protected by a protective material 7 such as sponge. In addition to the type protected by the protective material 7, the reference electrode 6 includes a rotary type that can be continuously measured, and can also be detected by this.

<D> Detection result. Connect the tip of the reference electrode 6 of the potentiometer 5 to the concrete structure 1
When the coating of the epoxy resin 2 has a defect when the surface is contacted, the reinforcing bar 3 shows a spontaneous potential at that portion. Therefore, the potentiometer 5 shows a certain value. In a position where there is no defect, the reinforcing bar 3 and the surface of the concrete structure 1 are in an insulated state. Therefore, the potential of the potentiometer 5 shows a value close to zero. If a sudden change in potential is observed at a certain position by the potentiometer 5 in this way, it can be detected that the epoxy resin 2 inside the concrete has a defect near that position.

[0012]

The concrete structure and the method for detecting a defect of a coated reinforcing bar according to the present invention have been described above, and the following effects can be obtained. <A> Conventionally, only a defective portion such as a pinhole or a scratch is detected in the process of coating an epoxy resin, and there is no method for detecting a defect of a coated reinforcing bar buried in a concrete structure. However, if the structure of the present invention is employed or the detection method is employed, it is possible to detect a defective portion of the epoxy resin-coated reinforcing bar inside the concrete. <B> By detecting a defective portion from the outside, it is possible to early identify a portion where maintenance and management are to be focused.
Therefore, the reliability of the structure can be maintained for a long time. <C> Even during the operation of the concrete structure, the state of corrosion of the defective portion can be grasped and estimated without breaking, which is extremely economical.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of a concrete structure capable of detecting a defect of a reinforcing bar coated with an epoxy resin.

FIG. 2 is an explanatory diagram of an embodiment of a detection method.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenichi Horiguchi 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation

Claims (3)

[Claims] 1. A concrete structure in which a reinforcing bar coated with an epoxy resin is embedded, a detecting wire is connected to the reinforcing bar coated with the epoxy resin, and an end of the detecting wire is exposed on the surface of the concrete. Concrete structures that can detect defects in painted rebar 2. A concrete structure in which a reinforcing bar coated with an epoxy resin is embedded, a part of the concrete is peeled off to expose a reinforcing bar coated with an epoxy resin, and a detecting wire is connected to the exposed portion. A method of detecting defects in painted rebar by connecting a detection conductor to a potentiometer, connecting an electrode to the potentiometer separately for verification, and bringing the reference electrode into contact with the concrete surface. 3. The method according to claim 2, wherein an electrode such as a copper sulfate electrode, a saturated calomel electrode, a saturated silver chloride electrode, or a lead electrode is used as the reference electrode.