JP4852473B2 - Reinforcing bar diagnostic device and reinforcing bar diagnostic method using the same - Google Patents

Description

  The present invention relates to a reinforcing bar diagnostic apparatus for diagnosing the state of a reinforcing bar inside a concrete pole and a reinforcing bar diagnostic method using the same.

  Conventionally, in a structure using reinforced concrete, the strength is maintained by the strength of the concrete itself and the reinforcing bars existing inside the concrete. Therefore, it is necessary to grasp the condition of the concrete and the reinforcing bar itself for the maintenance and management of the reinforced concrete structure.

  Regarding the deterioration of concrete, in addition to inspecting cracks and precipitates that can be observed on the surface, methods for taking out test pieces from the concrete itself and confirming them are known. In addition, diagnosing the number and deterioration of reinforcing bars in the interior is indispensable for ensuring the safety of the structure, but it is impossible to directly observe the reinforcing bars inside the concrete. Various nondestructive inspection devices using ultrasonic waves, magnetic fields (magnetic fields), electromagnetic waves, X-rays, etc. have been developed, manufactured and sold. There is also known a method of directly checking by peeling concrete and exposing the reinforcing bars.

Furthermore, as one of such nondestructive inspection methods, a method of grasping the state by heating a reinforcing bar has been proposed (see Non-Patent Documents 1 to 3).
http://www.penta-ocean.co.jp/d_news20040116.html http://www.penta-ocean.co.jp/d_news20050926.html "Study on non-destructive inspection method for local corrosion of reinforcing bars in concrete based on thermal image processing by forced reinforcement heating" Hiroaki Horie, Keisuke Usuki, Hideyoshi Ohshita: Summary of the 32nd Kanto Branch Technical Research Presentation 2005.3.35-16

  However, in a conventional nondestructive inspection apparatus that uses ultrasonic waves, magnetic fields, electromagnetic waves, and X-rays, handling and measurement procedures are complicated and require specialized knowledge.

  Further, the sensor and the oscillator part are expensive, so that the entire apparatus is also expensive.

  In addition, the measurement results using ultrasonic waves and the measurement results using magnetic fields have problems such as requiring experience and knowledge for the determination.

  In addition, there is a method of peeling concrete and directly confirming the state of the reinforcing bars, but there is a possibility that the strength of the structure may be lost, which is not a realistic method.

  In addition, the nondestructive inspection method performed by heating the reinforcing bar is for a planar structure such as a wall surface, and the electromagnetic induction heating device has a planar configuration suitable for it. However, when heating the inside of a cylindrical concrete structure such as a concrete pole, if it is heated with a planar induction coil, the position of the material to be heated (rebar, etc.) will be uneven depending on the location. As a result, heating unevenness occurred, and it was difficult to accurately diagnose the state of the reinforcing bar.

  An object of the present invention has been made in view of the above, and a reinforcing bar diagnostic apparatus capable of efficiently heating a reinforcing bar in a concrete pole and accurately and easily diagnosing the state of the reinforcing bar, and using the same. It is to provide a method for diagnosing reinforcing bars.

In order to solve the above-mentioned problem, the present invention according to claim 1 is for diagnosing the state of a reinforcing bar disposed inside a concrete pole by generating heat by electromagnetic induction by a magnetic field and observing the temperature change thereof. In order to generate the magnetic field necessary for the electromagnetic induction in the longitudinal direction of the concrete pole by forming a ring by winding a plurality of conductors around the circumference of the concrete pole in the circumferential direction. The induction coil is composed of three or more split coil element portions that can be attached to and detached from each other on the circumference of the ring, and each split coil element portion is composed of an array of a plurality of conductors. A part of the induction coil and a connection connector disposed at each end of the plurality of conductors are provided.

According to a second aspect of the present invention, in the first aspect , the induction coil includes a magnetic body on an outer periphery in a circumferential direction of the ring.

According to a third aspect of the present invention, in the second aspect , the magnetic body is disposed on a surface of a flexible belt-shaped member and is deformable together with the belt-shaped member.

Moreover, the present invention according to claim 4 is the method according to any one of claims 1 to 3 , further comprising a temperature detection unit for observing the temperature change, and detecting the temperature on a surface of a flexible sheet-like member. A plurality of parts can be arranged and deformed according to the surface of the concrete pole.

According to a fifth aspect of the present invention, in the fourth aspect , the temperature detectors are arranged in a matrix at equal intervals, and the light emitting means are arranged one-on-one with the positions of the temperature detectors arranged in a matrix. Plurally arranged so as to correspond to each other, the detection signals output from the one-to-one corresponding temperature detectors are respectively supplied to the light emitting means to emit light, thereby visually grasping the temperature distribution on the surface of the concrete pole. Temperature distribution display means is provided.

Moreover, this invention of Claim 6 is a reinforcing bar diagnostic method for diagnosing the condition of the reinforcing bar in a concrete pole using the reinforcing bar diagnostic apparatus in any one of Claims 1-5, Comprising: Temperature change Continuously observing the temperature change distribution on the surface of the concrete pole by the observation means, and storing the temperature change distribution obtained by the observation by the observation data storage means in association with time information as observation data; Have.

Moreover, the present invention described in claim 7 includes the step of cooling the surface temperature of the concrete pole, which is increased in accordance with heat generation of the reinforcing bar by electromagnetic induction, by the cooling means in claim 6 .

  ADVANTAGE OF THE INVENTION According to this invention, the reinforcing bar diagnostic apparatus which can heat the reinforcing bar in a concrete pole efficiently, can diagnose the state of a reinforcing bar accurately and easily, and a reinforcing bar diagnostic method using the same can be provided.

<First Embodiment>
FIG. 1 shows an explanatory diagram when the reinforcing bar diagnostic apparatus of the present invention is applied to a columnar concrete pole as a first embodiment of the present invention.

  FIG. 1A shows a concrete pole 7 containing a reinforcing bar 8 to be diagnosed, an induction heating section 1 for heating the reinforcing bar 8 by winding the concrete pole 7 in the outer circumferential direction, and this induction. A cable 6 serving as a conductor when supplying high-frequency current by connecting to the heating unit 1, a high-frequency signal generating unit 2 connected to the cable 6 to generate and supply high-frequency current to the induction heating unit 1, and an induction heating unit The temperature detector 5 for observing the temperature change of the reinforcing bar 8 heated by 1, the cable 9 connected to the temperature detector 5 for transmitting observation data to the outside, and the temperature connected to this cable 9 A temperature measurement unit 3 for receiving the observation data from the detection unit 5 and measuring the temperature, and a temperature display for displaying the diagnosis result of the state of the reinforcing bar 8 based on the temperature measurement result in the temperature measurement unit 3 so as to be visible. Part 4 It is shown.

  FIG. 1B shows an example of the display of the diagnosis result of the reinforcing bar 8 displayed on the temperature display unit 4.

  As shown in FIG. 1A, the induction heating unit 1 is wound so as to surround the circumference of the concrete pole 7 in the circumferential direction. A high-frequency signal output from the high-frequency signal generating unit 2 is supplied to the induction heating unit 1 via the cable 6. An induction coil (not shown) is disposed inside the induction heating unit 1, and the concrete pole 7 is positioned in an annular ring formed by the induction coil.

  By applying the high frequency signal generated by the high frequency signal generator 2 to the induction heating unit 1, a high frequency current flows through an induction coil (not shown), and a high frequency magnetic field is formed inside the concrete pole 7. Here, since the magnetic permeability of the reinforcing bar 8 is higher than that of the concrete pole 7 and air, the generated magnetic field is relatively concentrated inside the reinforcing bar 8, and thereby flows in the circumferential direction of the reinforcing bar 8 inside the reinforcing bar 8. High frequency eddy currents are generated. This eddy current heats the reinforcing bar 8 itself, and the direction of the magnetic field and the direction of the central axis in the longitudinal direction of the reinforcing bar 8 are parallel, so that the reinforcing bar 8 inside the concrete pole 7 can be heated uniformly.

  Next, FIG. 2 shows an explanatory diagram for explaining the induction coil arranged inside the induction heating unit 1.

  FIG. 2 shows an induction coil 11 that is arranged inside the induction heating unit 1 and generates a magnetic field when a high frequency current is applied, a magnetic flux 12 generated by the induction coil 11, and the induction coil 11. The concrete pole 7 located in the inside of the ring to perform, and the high-permeability magnetic body layer 10 surrounding the circumferential direction outer periphery of the induction coil 11 are shown.

  As shown in FIG. 2, the magnetic field generated inside the induction coil 11 (inside the annular ring forming the induction coil 11) spreads from the end of the induction coil 11 toward the outside. By providing the magnetic material layer 10 having a high magnetic permeability, the magnetic flux 12 spreading outside is efficiently confined in the vicinity of the induction coil 11, and the influence of the magnetic flux 12 leaking to the outside is reduced.

  Next, FIG. 3 is an explanatory diagram for explaining a configuration when the induction heating unit 1 shown in FIG. By making it possible to divide into two, the work of mounting the induction heating unit 1 on the concrete pole 7 can be facilitated.

  FIG. 3 shows an induction coil 11 divided into two in the diameter direction of the ring, a coil conductor fixing member 13 for holding the induction coil 11 in a mechanically stable manner, and leakage from the induction coil 11. A high permeability magnetic layer 10 for shielding magnetic flux, a connection connector (male) 14 and a connection connector (female) 15 that are electrical contacts for electrically connecting the two-divided induction coil 11, and 2 A holding grip 16 for fastening the divided induction heating units 1 to each other is shown.

  As shown in FIG. 3, the induction heating unit 1 is divided into two parts to form two semicircular two-part coils. A connector terminal (for example, a banana plug and a structure for receiving it) is provided at the end of the conductor constituting the winding of the induction coil 11. This connector terminal is realized by a combination of a connection connector (male) 14 and a connection connector (female) 15.

  The combination of the connection connector (male) 14 and the connection connector (female) 15 makes it possible to easily remove the connection portions of the conductors constituting the induction coil 11 and to perform electromagnetic and mechanical coupling.

  In addition, since the induction heating unit 1 is divided into two parts, it can be easily wound around the concrete pole 7, and in order to reinforce the winding, two joints on the outer periphery of the induction heating unit 1 are provided. It is preferable to provide a fixing grip 16 for fixing the semicircular structure. The fixing gripping tool 16 has a structure for achieving mechanical fastening with each other, and an existing buckle structure, clamping structure, or the like may be used.

  Next, FIG. 4 shows an explanatory diagram for explaining a configuration when the induction heating unit 1 is divided into three or more divisions. FIG. 4A shows a divided coil element portion 20 having a configuration in which no lead wire is drawn out of the divided portion of the induction heating unit 1, and FIG. 4B shows a configuration having a lead wire drawn to the outside. The split coil connecting portion 21 is shown. 4C shows an example in which the divided coil element portion 20 and the divided coil connecting portion 21 are connected in combination, and FIG. 4D shows a combination of the divided coil element portion 20 and the divided coil connecting portion 21. The bird's-eye view at the time of comprising the annular induction heating part 1 is shown.

  As shown in FIG. 4 (a), a part of the induction coil 11 composed of an array of a plurality of short conductors, and a connection connector (male) 14 and a connection connector (female) 15 disposed at each end thereof are provided. A plurality of divided coil element portions 20 provided are configured.

  Further, as shown in FIG. 4B, a high frequency signal mark applying conductor 17 for applying a high frequency signal to both ends of the conductor is connected and drawn out to the outside. In addition, a connection connector (male) 14 and a connection connector (female) 15 are also provided, and a connection between the connection connector (male) 14 and the connection connector (female) 15 is shifted by a conductor and the split coil connection portion. 21 is constituted.

  Then, as shown in FIG. 4C, one split coil connection portion 21 and a plurality of split coil element portions 20 are connected to each other by a connection connector (male) 14 and a connection connector (female) 15. By making this connection into a substantially circular shape as shown in FIG. 4D, it is possible to efficiently wind around the concrete pole 7 having an arbitrary radius.

  Note that the high permeability magnetic layer 10 and the coil conductor fixing material 13 included in each of the divided coil element portion 20 and the divided coil connecting portion 21 are materials that can be flexibly deformed and can maintain insulation between conductors (for example, rubber). As a result, it is possible to efficiently assemble and wrap the divided induction heating unit 1 into a circular shape.

  1A is detected by the temperature detection unit 5, the temperature rise is measured by the temperature measurement unit 3, and the temperature distribution is displayed by the temperature display unit 4. . As a configuration for temperature detection, measurement, and display by the temperature measurement unit 3 or the temperature detection unit 5, for example, an existing thermography measurement device can be used.

  Further, since the reinforcing bar 8 is heated mainly at the position where the induction heating unit 1 is attached, the heat is propagated through the reinforcing bar 8 by continuously heating. For this reason, when rust or the like is generated due to corrosion in the reinforcing bar 8 or when the reinforcing bar 8 is broken for some reason (for example, overload or hydrogen embrittlement), the heat conduction of the portion is normal. Is different. Therefore, it is possible to confirm the state of corrosion or breakage of the reinforcing bar 8 by observing the propagation state of the heat while continuously heating the reinforcing bar 8 over time.

  Further, when the reinforcing bar 8 is continuously heated, the temperature of the surrounding concrete pole 7 also rises, so that it is difficult to distinguish the temperature difference between the two. Therefore, during the continuous heating by induction heating, the surface temperature of the concrete pole 7 is forcibly lowered in order to clarify the temperature difference from the position to be measured.

  As a means for lowering the temperature, for example, water is applied to the surface of the concrete pole 7 or air is applied to the surface of the concrete pole 7 with a fan or the like, so that the rebar 8 that is a heat supply position and the others The temperature difference can be clarified.

  For example, as shown in FIG. 1 (a), when there is a discontinuous portion in the reinforcing bar 8 in the concrete pole 7 (the breaking point of the right reinforcing bar 8 in the figure), the discontinuous point of the reinforcing bar 8 The temperature propagation is worse. Therefore, the temperature distribution detected by the temperature detection unit 5 and the temperature measurement unit 3 has a clear discontinuous point Q as compared with normal temperature propagation as in the example of FIG. 1B. It is possible to improve the detection accuracy of such discontinuous points.

<Second Embodiment>
In the second embodiment, a plate-like flexible substrate 30 as shown in FIG. 5A is used as the temperature detection unit 5 of the heating type reinforcing bar diagnostic apparatus used for the concrete pole 7 as in the first embodiment. A plurality of temperature sensors 31 are arranged on the top to constitute a temperature detection unit 35. As the temperature sensor 31, a platinum resistance thermometer, thermistor, thermocouple, IC transistor, crystal thermometer, or the like may be used. These temperature sensors 31 are arranged in a matrix at equal intervals, and a temperature detection unit. 35 is configured and used.

  By arranging the temperature sensor 31 on the plate-like flexible substrate 35, the temperature sensor 31 can be brought into close contact regardless of the diameter of the concrete pole 7. In addition, by providing the heat insulating frame 32 shown in FIG. 5B around the temperature detection unit 35, it is possible to minimize the influence of heat conduction from the part other than the part in contact with the temperature sensor 31.

  As shown in FIG. 6, by arranging the temperature sensors 31 in a matrix, not only the surface temperature distribution of the concrete pole 7 is detected, but also the position of the reinforcing bar 8 when the interval between the reinforcing bars 8 is known. Thus, the temperature sensor 31 can be disposed, and the temperature condition of the reinforcing bar 8 can be detected efficiently. When the arrangement interval of the reinforcing bars 8 is known in advance, the position of the temperature sensor 31 arranged on the substrate 35 is set according to the arrangement interval of the reinforcing bars 8. In this case, the intervals of the temperature sensors 31 are preferably equal from the viewpoint of versatility and manufacturability. However, when the reinforcing bars 8 are not equally spaced, the temperature sensors 31 may be arranged at unequal intervals.

<Third Embodiment>
FIG. 7 is an explanatory diagram for explaining a modified example of the temperature display unit 4 shown in FIG. 1. This is an example in which a temperature display unit that can be realized relatively easily is configured using the temperature detection unit 40 similar to the temperature detection unit 35 including the temperature sensor 31 having the matrix arrangement already described in the second embodiment.

  In FIG. 7, a flexible substrate 40, a plurality of temperature sensors 31 disposed on the substrate 40, and outputs of the plurality of temperature sensors 31 are detected and amplified to a predetermined level. A plurality of sensor output detection circuits 41 and light emitting diodes (light emitting means) 43 respectively connected to the plurality of sensor output detection circuits 41 are shown.

  In such a configuration of FIG. 7, the output from each temperature sensor 31 is detected by the sensor output detection circuit 41 and amplified to a predetermined signal level. On the other hand, an output from the sensor output detection circuit 41 is connected to a temperature display unit 43 including light emitting diodes 43 arranged in a matrix. The arrangement of the light emitting diodes 43 is set similar to the arrangement of the temperature sensor 31. The output from each temperature sensor 31 is supplied to one of the light emitting diodes 43 arranged at a position corresponding to the temperature sensor 31. As a result, for each light emitting diode 43 of the temperature display unit 43, the luminance, brightness, color tone, and the like of the light emission can be changed according to the output change from the temperature sensor 31. An observer (not shown) viewing the temperature display unit 43 visually observes the temperature change and state of the reinforcing bars 7 inside the concrete pole 7 through the distribution and change in luminance of the light emitting diodes 43 arranged on the temperature display unit 43, for example. Can know. Although the light emitting diode 43 has been described as the light emitting means, the light emitting means may be configured by a lamp, a surface light emitting element, or the like.

  According to the embodiment described above, the reinforcing bars inside the concrete pole can be efficiently heated, and the state can be easily diagnosed without destruction. In particular, each part of temperature detection, measurement, and display can use thermography, so it can be grasped visually, and it is possible to provide a non-destructive rebar diagnostic method that does not require special skills and know-how . Furthermore, by using a structure in which temperature sensors are arranged in a matrix in the temperature detection section and adopting a light emitting section having a matrix structure in the display section, it is possible to provide a non-destructive inspection apparatus that is simple in structure and inexpensive. Become.

Explanatory drawing at the time of applying this invention to the columnar concrete pole based on the 1st Embodiment of this invention is shown. An explanatory view for explaining magnetic field generation of an induction coil is shown. An explanatory view for explaining a 2 division type induction coil is shown. Explanatory drawing for demonstrating the induction coil divided | segmented into 3 or more is shown. The structural example of the sensor for temperature detection is shown. An explanatory view for explaining temperature detection by a temperature detection sensor is shown. An example of a structure of a temperature display part is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Induction heating part 2 ... High frequency signal generation part 3 ... Temperature measurement part 4 ... Temperature display part 5 ... Temperature detection part 6, 9 ... Cable 7 ... Concrete pole 8 ... Rebar 10 ... High permeability magnetic substance layer 11 ... Induction coil 12 ... Magnetic flux 13 ... Coil conductor fixing material 14 ... Connection connector (male)
15 ... Connector (female)
16 ... Gripping fixture

Claims (7)

In the reinforcing bar diagnostic device for diagnosing the state of the reinforcing bar by observing its temperature change by heating the reinforcing bar arranged inside the concrete pole by electromagnetic induction by a magnetic field,
A conductor is wound around the circumference of the concrete pole in a circumferential direction to form a ring, and an induction coil for generating the magnetic field necessary for the electromagnetic induction in the longitudinal direction of the concrete pole is provided .
The induction coil includes three or more split coil element portions that are attachable to and detachable from each other on the circumference of the ring, and each split coil element portion is a part of the induction coil that includes an array of a plurality of conductors. And a connecting connector disposed at each end of the plurality of conductors . The induction coil is
The reinforcing bar diagnosis apparatus according to claim 1 , wherein a magnetic body is provided on an outer circumference in a circumferential direction of the ring. The magnetic body is
The reinforcing bar diagnosis apparatus according to claim 2 , wherein the reinforcing bar diagnosis apparatus is disposed on a surface of a flexible belt-like member and is deformable together with the belt-like member. A temperature detection unit for observing the temperature change is provided, and a plurality of the temperature detection units are arranged on the surface of a flexible sheet-like member, and can be deformed and fitted to the surface of the concrete pole. The reinforcing bar diagnostic apparatus according to any one of claims 1 to 3 . The temperature detectors are arranged in a matrix at equal intervals, and a plurality of light emitting means are arranged so as to have a one-to-one correspondence with the positions of the temperature detectors arranged in a matrix. a detection signal output by the light emitting and supplied to the light emitting means from, characterized in that it comprises a temperature distribution display means for grasping a temperature distribution on the surface of the visually said concrete pole with claim 4 Reinforcing bar diagnostic device according to 1. A reinforcing bar diagnostic method for diagnosing the state of reinforcing bars in a concrete pole using the reinforcing bar diagnostic apparatus according to any one of claims 1 to 5 ,
Continuously observing the distribution of temperature change on the surface of the concrete pole by means of temperature change observation means;
Storing the temperature change distribution obtained by the observation by the observation data storage means in association with the time information as observation data;
A method for diagnosing reinforcing steel bars, comprising: The reinforcing bar diagnosis method according to claim 6 , further comprising a step of cooling a surface temperature of the concrete pole that has risen due to heat generation of the reinforcing bar by electromagnetic induction by a cooling unit.

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