JP4745811B2 - Corrosion detection member and corrosion sensor - Google Patents

Description

  The present invention relates to a corrosion detection member and a corrosion sensor used to detect the progress of corrosion of a metal detection object.

  Various steel materials such as a reinforcing bar, a steel sheath tube, and a PC steel material are embedded in the reinforced concrete structure and the prestressed concrete structure. When these steel materials are corroded, cracks and peeling of the concrete occur, the soundness of the structure is lost due to the reduced load resistance performance of the steel bars or PC steel materials, and there are various aesthetics, durability and safety of the structure. Problems arise.

  In addition, steel structures such as steel bridges, water pipes, and caissons lose the soundness of the structure when the steel is corroded, because the cross section of the steel decreases or cracks occur due to reduced load resistance. However, various problems occur in durability and safety. Thus, various methods for detecting and predicting the corrosion status of these steel materials have been studied.

  Patent Document 1 discloses a method of diagnosing the corrosion probability or degree of corrosion of a reinforcing bar in a concrete structure by measuring a natural potential. In this method, the measured natural potential is corrected by the moisture content of the concrete in the cover part of the concrete structure, corrected by the presence or absence of salt in the concrete, and corrected by the carbonation depth of the concrete. Diagnose the corrosion probability or degree of corrosion.

Patent Document 2 describes a method for predicting corrosion of an embedded structure material by measuring the electrical resistance of the wire material after embedding a wire material having corrosivity equivalent to that of an embedded structure material in a concrete structure. Yes. Patent Document 3 describes a technique of burying a thin wire made of the same material as the steel material in a concrete structure in the concrete structure and measuring when the fine wire is cut. In Patent Document 4, a rust-proof coated conductor is embedded along a PC steel material in a prestressed concrete structure, a part of the rust-coated conductor is used as an uncoated portion, and the conductor is periodically energized to measure current. A technique for detecting a corrosion portion of a PC steel material by a change in value is described. In Patent Document 5 and Patent Document 6, in order to grasp the corrosive environment of the detection object and the progress of corrosion of the steel structure, a metal thin film is installed in the vicinity of the measurement object, and the degree of discoloration of the metal thin film is evaluated. Describes a method for evaluating the degree of corrosion.
Japanese Patent No. 3096240 JP-A 64-29748 Japanese Patent Laid-Open No. 11-153568 JP 2002-243687 A JP 2002-139416 A JP-A-2005-121510.

  However, the corrosion state detection method as described above cannot detect the corrosion start time of the metal material to be detected early and clearly.

  In the method for measuring the natural potential as described in Patent Document 1, there are large uncertain factors, and the actual diagnosis results also vary and lack reliability.

  With the corrosion detection methods described in Patent Document 2 and Patent Document 3, it is difficult to detect corrosion of the target steel material at an early stage using a normal wire. On the other hand, if a thin wire is used, it can be detected at an early stage, but it is difficult to produce a thin wire with a metal material such as iron, which is often used in concrete structures and steel structures. In addition, it is difficult to manufacture by changing the diameter of the thin wire rod, and the cost increases. In addition, a thin wire rod has a drawback that it is difficult to handle from the viewpoint of installation and electrical connection, for example, a wire breakage occurs even with a light force such as holding by hand and soldering is not easy.

  In the corrosion detection method as described in Patent Document 4, a lead wire that is a pseudo-corrosion material is installed along the PC steel material, a part of the lead wire is a rust-proof coated wire, and a part is a non-rust-proof coated wire. Yes. In this method, since a rust-proof portion and a non-rust-proof portion are mixed in one conductor, it is difficult to clearly grasp the change in electrical characteristics of the conductor by energization. Moreover, since a wire is used, the same problem as in Patent Document 2 or Patent Document 3 may occur.

  In the measurement methods described in Patent Document 5 and Patent Document 6, since the discoloration of the metal thin film installed in the vicinity of the geodetic object is an indicator of the degree of corrosion, the installation position of the metal thin film can be confirmed the discoloration degree. It is limited to. Further, since the discoloration is an event that appears on the metal surface, the degree of corrosion of the detection object does not necessarily appear accurately, and varies greatly depending on the exposure environment of the detection object.

  The present invention has been made in view of such circumstances, and provides a corrosion detection member and a corrosion sensor that have high sensitivity and can accurately predict the corrosion start time of a metal detection object. Objective.

  (1) In order to achieve the above object, a corrosion detection member according to the present invention is a corrosion detection member of a corrosion sensor used to detect the progress of corrosion of a metal detection target, and the detection target A base material made of a metal or an alkali-soluble metal that is more easily corroded than the metal of the object to be detected in the environment of use, and is formed by covering at least part of the base material and corrodes in the environment of use of the object to be detected It consists of the detection part formed with the coating film which consists of the metal which carries out, and the base material for hold | maintaining the said detection part.

  Thus, the corrosion detection member according to the present invention includes a coating formed on a base material that is corroded under the environment in which the detection target is used. The base material is made of a metal that is more easily corroded than the metal to be detected or an alkali-soluble metal. Therefore, after the coating is corroded by a corrosive factor, the base material also corrodes early, or when it is embedded in a concrete structure, it dissolves due to the alkali component in the concrete, so that the electrical characteristics of the detection unit change. As a method for detecting changes in electrical characteristics, for example, when the electrical connection of the detection unit is disconnected, the resistance suddenly increases, or the potential difference between both ends of the detection unit is almost zero before the disconnection. However, a potential difference is caused by the disconnection. Furthermore, this change may be detected from the outside by electromagnetic waves or electromagnetic induction, utilizing the fact that the magnetism of the detector changes before and after corrosion of the detector. By using the corrosion sensor provided with the corrosion detection member of the present invention, it is possible to detect the corrosion of the coating early and clearly by detecting the change in the electrical characteristics. Therefore, by installing the corrosion detection member of the present invention in the vicinity of the detection target, it is possible to predict the corrosion start time of the detection target early from the corrosion of the coating.

  In addition, by adjusting the thickness of the above-described coating, it becomes possible to detect corrosion with higher sensitivity than the fine line. For example, if a technique such as plating is used, the film can be formed thinner than the thin line. In addition, if a technique such as plating is used, a coating corresponding to a base material having a complicated shape can be easily produced, so that the degree of freedom of the size and shape of the detection unit is increased. In addition, the detection unit can be manufactured at low cost.

  By using a corrosion sensor equipped with such a corrosion detection member, it is possible to predict the corrosion start time earlier than before in the case of detection objects including reinforcing bars, steel frames, PC steel materials, steel sheath tubes, and other steel materials. it can. In addition, structures including steel materials provided in valleys and mountainous areas often have poor scaffolding, and are difficult to check depending on the location. As described above, even in a place where it is difficult to visually confirm the corrosion, the corrosion can be easily diagnosed by using the corrosion sensor provided with the corrosion detection member of the present invention. Furthermore, based on the grasped information, it is possible to determine whether or not the structure needs to be repaired and to establish the construction guidelines accurately and in a short time, and it is possible to maintain and maintain the structure in a healthy state.

  (2) The corrosion detection member according to the present invention is a corrosion detection member for a corrosion sensor used for detecting the progress of corrosion of a metal detection object, and is a base made of a conductive paint or a conductive resin. And a detection part formed by a coating made of a metal that covers at least a part of the base material and corrodes under the environment in which the detection target is used, and a base material for holding the detection part It is characterized by becoming.

  Thus, the corrosion detection member according to the present invention includes a coating formed on a base material that is corroded under the environment in which the detection target is used. The base material is formed of a conductive paint or a conductive resin. Therefore, after the coating is corroded by the corrosion factor, the electrical characteristics of the detection unit change. For example, when a conductive paint or conductive resin whose resistance is sufficiently larger than that of the metal of the coating is used as the base material, the resistance of the detection unit rapidly increases after the electrical disconnection of the metal coating. In addition, if a conductive paint or conductive resin using a material that is more susceptible to corrosion than the metal of the detection target or an alkali-soluble material as the conductive material is used as the base material, When the base material is also corroded early or embedded in a concrete structure, it dissolves due to the alkali component in the concrete, so that the electrical characteristics of the detection unit change. For example, when the electrical connection of the detection unit is disconnected, the resistance increases rapidly. In the corrosion sensor including the corrosion detection member of the present invention, it is possible to detect the corrosion of the coating early and clearly by detecting the change in the electrical characteristics. Therefore, by installing the corrosion detection member of the present invention in the vicinity of the detection target, it is possible to predict the corrosion start time of the detection target early from the corrosion of the coating.

  Further, by adjusting the thickness of the coating film, it becomes possible to detect corrosion with higher sensitivity than the fine line. In addition, since a coating corresponding to a base material having a complicated shape can be easily produced by a technique such as plating, the degree of freedom of the size and shape of the detection unit is increased. In addition, the detection unit can be manufactured at low cost.

  By using a corrosion sensor provided with such a corrosion detection member, as with the corrosion detection member according to claim 1, corrosion is detected for detection objects including reinforcing bars, steel frames, PC steel materials, steel sheath tubes, and other steel materials. The start time can be predicted earlier than before. In addition, structures including steel materials provided in valleys and mountainous areas often have poor scaffolding, and are difficult to check depending on the location. As described above, even in a place where it is difficult to visually confirm the corrosion, the corrosion can be easily diagnosed by using the corrosion sensor provided with the corrosion detection member of the present invention. Furthermore, based on the grasped information, it is possible to determine whether or not the structure needs to be repaired and to establish the construction guidelines accurately and in a short time, and it is possible to maintain and maintain the structure in a healthy state.

  Moreover, since the formation method by printing can be applied by using a conductive paint or conductive resin for the base material, the base material can be manufactured efficiently and inexpensively. In addition, when a conductive paint or conductive resin whose resistance is sufficiently larger than that of the metal of the coating is used as the base material, corrosion detection can be performed by corrosion of only the coating. In this case, the corrosion detection does not require the base material to be corroded or dissolved in alkali, so that the detection time is shortened accordingly.

  (3) Moreover, in the preferable one aspect | mode which uses the corrosion detection member which concerns on this invention, the said detection target object is steel materials, The said film consists of iron, It is characterized by the above-mentioned.

  In this case, the detection portion of the corrosion detection member includes a coating made of iron. This coating made of iron is subject to almost the same influence on the corrosion factor as the steel material that is the object to be detected, so if a corrosion sensor equipped with this corrosion detection member is installed near the steel material, the corrosion of the coating made of iron Therefore, it is possible to predict the corrosion start time of steel materials early.

  (4) Further, the corrosion detection member according to the present invention is characterized in that an insulating coating is applied to at least a part of the substrate surface on the side where the detection unit is held.

  As a result, it is possible to protect a portion that is vulnerable to corrosion, such as a connection portion between the base material and the wiring and the base material. Moreover, a short circuit between wirings can also be prevented.

  (5) Further, in the corrosion detection member according to the present invention, the base material is formed in a linear or thin plate shape, and a plurality of the base materials are formed in a ladder shape, stepped shape, or the like on the base material. It is characterized in that it is provided in any form of double rings arranged side by side.

  Thereby, it becomes possible to grasp | ascertain the corrosion of a detection part in steps, and it becomes possible to predict the progress of corrosion of detection objects, such as steel materials, in detail. For example, in the vicinity of a reinforcing bar to be detected in a reinforced concrete structure, by installing a detection member in which a plurality of base materials in which a coating is formed in a ladder shape is installed in parallel along the penetration direction of the corrosion factor, The progress of corrosion of reinforcing bars can be predicted. Further, when the plurality of base materials in the detection unit are provided in a step shape, the other base materials do not affect the invasion of the corrosion factors, and therefore the corrosion situation can be detected more accurately.

  (6) Moreover, the corrosion detection member which concerns on this invention is characterized by the said base material being a board | substrate for printed wiring.

  Technology has been accumulated over many years for printed wiring. If the base material is a base material for printed wiring, the base material and the wiring can be formed on the substrate using this printed wiring technology, so that the corrosion detecting member can be easily produced.

  (7) Moreover, the corrosion detection member according to the present invention is characterized in that the base material is made of aluminum.

  Since aluminum is an amphoteric metal and is acid-soluble and alkali-soluble, when the coating on the detection part of the corrosion detection member is corroded in an alkaline environment such as in concrete, a base material made of aluminum is used. Corrosion or dissolution occurs relatively quickly due to either an acidic corrosion factor or an alkaline factor from concrete, so that corrosion of the coating is detected in a short period of time from the start of coating corrosion. Aluminum is highly workable and is often used for printed wiring boards. Therefore, since the base material can be formed on the substrate using the printed wiring technique, the production of the corrosion detecting member is facilitated.

(8) Moreover, the corrosion sensor according to the present invention includes, in addition to the corrosion detection member, a corrosion detection unit that detects corrosion of the detection unit in the corrosion detection member by measuring electrical characteristics of the detection unit, It is characterized by comprising a corrosion sensor provided with a wireless communication unit that wirelessly transmits a detection result of corrosion to a reading device. This eliminates the need for wiring from the inside of the concrete to the outside, prevents corrosion factors from entering the inside of the concrete through the wiring, and improves detection accuracy. In addition, it can be easily detected from the outside.
In addition, the wiring of the corrosion sensor including the detection unit is printed on the base material, and the electronic components and wirings constituting the corrosion detection unit and the wireless communication unit integrally form a circuit on the base material. It is characterized by having.

  Since the corrosion detection unit, corrosion detection unit, and wireless communication unit are integrally formed on the substrate by printed wiring technology, a corrosion sensor can be manufactured in an efficient manufacturing process and a compact corrosion sensor Can be made. Accordingly, it becomes easy to install the corrosion sensor in the vicinity of the detection target.

  Further, the corrosion sensor wirelessly transmits corrosion detection information to the reading device by the wireless communication unit. As a result, it is not necessary to provide wiring to the reading device, and labor such as installation of a corrosion sensor can be reduced. When a corrosion sensor is embedded in concrete and used, it is not necessary to install a transmission cable or the like from the vicinity of the object to be detected to the outside of the concrete, so rebar corrosion deterioration factors may enter inside through the wiring path. It can be eliminated and durability can be improved. In addition, the beauty is not lost. Furthermore, since it is only necessary to hold the reader during communication, it is possible to eliminate the complexity of wiring and install a corrosion sensor in places where the burden of corrosion confirmation work such as bridges and high places is heavy. By doing so, the burden can be reduced.

  (9) Further, the corrosion sensor according to the present invention includes a corrosion detection unit for detecting the corrosion of the detection unit in the corrosion detection member by measuring the electrical characteristics of the detection unit, and a reading device for the detection result of the corrosion. A corrosion sensor including a wireless communication unit that wirelessly transmits to the detector, and includes a cathode member made of a metal having a potential higher than that of the material of the detection unit, and the detection unit and the cathode member It is electrically connected and functions as a cathode for the detection unit.

  Thus, the corrosion sensor of this invention has the member for cathodes formed with a metal more precious than the metal of the film formed on the base material of a detection part. Since the coating is formed of a metal material that corrodes in the environment in which the detection object is used, the corrosion due to the macrocell corrosion proceeds by providing the cathode member. In this way, the corrosion sensor can be placed under the same conditions for a detection object that causes macrocell corrosion.

  (10) Moreover, in the usage pattern of the corrosion sensor according to the present invention, the detection object is a reinforcing bar embedded in a concrete structure, and the corrosion detection member has a base material for detecting the corrosion. It is preferable that the attachment part for attaching a member to the said reinforcing bar is provided.

  Thereby, installation of a corrosion sensor, correction of an installation position, etc. become easy. And the labor of the measurement preparation before concrete placement can be reduced, and a preparation period can be shortened. The attachment portion may be detachable from the reinforcing bar.

  According to one of the corrosion detection members which concerns on this invention, the film formed with the metal corroded in the use environment of the said detection target object is provided on the base material. The base material is made of a metal that is more easily corroded than the metal to be detected or an alkali-soluble metal. Therefore, after the coating corrodes due to a corrosion factor, the base material also corrodes early, or when it is embedded in a concrete structure, it dissolves due to the alkali component in the concrete, so that the coating corrosion starts very slowly. At no time, the electrical characteristics of the detector change. For example, when the electrical connection of the base material is broken by the mechanism, the resistance rapidly increases. Also, these coatings and base materials are thinner and thinner than conventional fine wires. Therefore, in the corrosion sensor provided with the corrosion detection member of the present invention, the corrosion of the coating can be detected early and clearly by detecting the change in the electrical characteristics. Therefore, by installing the corrosion detection member of the present invention in the vicinity of the detection target, it is possible to predict the corrosion start time of the detection target early from the corrosion of the coating.

  In addition, by adjusting the thickness of the coating, it is possible to detect corrosion with higher sensitivity than fine lines. In addition, since a coating corresponding to a base material having a complicated shape can be easily produced by a technique such as plating, the degree of freedom of the size and shape of the detection unit is increased. In addition, the detection unit can be manufactured at low cost.

  By using a corrosion sensor equipped with such a corrosion detection member, it is possible to predict the corrosion start time earlier than before in the case of detection objects including reinforcing bars, steel frames, PC steel materials, steel sheath tubes, and other steel materials. it can. In addition, structures including steel materials provided in valleys and mountain areas often have poor scaffolding, and are difficult to check depending on the location. As described above, even in a place where it is difficult to visually confirm the corrosion, the corrosion can be easily diagnosed by using the corrosion sensor provided with the corrosion detection member of the present invention. Furthermore, based on the grasped information, it is possible to determine whether or not the structure needs to be repaired and to establish the construction guidelines accurately and in a short time, and it is possible to maintain and maintain the structure in a healthy state.

  Moreover, according to one of the corrosion detection members which concern on this invention, the film formed with the metal corroded in the use environment of a detection target object is provided on the base material. The base material is formed of a conductive paint or a conductive resin. Therefore, after the coating is corroded by the corrosion factor, the electrical characteristics of the detection unit change. For example, when a base material having a resistance sufficiently higher than that of metal is used, the resistance rapidly increases after electrical disconnection of the film made of metal. In the corrosion sensor of the present invention, it is possible to detect the corrosion of the coating early and clearly by detecting the change in the electrical characteristics. Therefore, by installing the corrosion sensor of the present invention in the vicinity of the detection object, it is possible to predict the corrosion start time of the detection object early from the corrosion of the coating.

  In addition, by adjusting the thickness of the coating, it is possible to detect corrosion with higher sensitivity than fine lines. In addition, since a coating corresponding to a base material having a complicated shape can be easily produced by a technique such as plating, the degree of freedom of the size and shape of the detection unit is increased. In addition, the detection unit can be manufactured at low cost.

  By using a corrosion sensor equipped with such a corrosion detection member, it is possible to predict the corrosion start time earlier than before in the case of detection objects including reinforcing bars, steel frames, PC steel materials, steel sheath tubes, and other steel materials. it can. In addition, structures including steel materials provided in valleys and mountainous areas often have poor scaffolding, and are difficult to check depending on the location. As described above, even in a place where it is difficult to visually confirm the corrosion, the corrosion can be easily diagnosed by using the corrosion sensor provided with the corrosion detection member of the present invention. Furthermore, based on the grasped information, it is possible to accurately determine the time for repair of a structure, to formulate construction guidelines, etc. in a short time, and to maintain and maintain the structure in a healthy state.

  In addition, since the base material is formed of a conductive paint or a conductive resin and can be formed by printing, the base material can be manufactured at low cost. In addition, since the conductive paint or conductive resin whose resistance is sufficiently larger than the metal of the coating is used as the base material, the corrosion detection can be performed by the corrosion of only the coating. In this case, the corrosion detection does not require the base material to be corroded or dissolved in alkali, so that the detection time is shortened accordingly.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, in order to facilitate understanding of the description, the same reference numerals are given to the same components in the respective drawings, and duplicate descriptions are omitted.

(Embodiment 1)
The inventors of the present invention attempted to construct a highly accurate corrosion detection member by further thinning a metal thin wire constituting the detection portion of the corrosion detection member to easily cause disconnection or the like. In the process, the present inventors have a limit in making a thin metal wire thin. Therefore, the detection unit is composed of a base material and a thin film covering the base material, and changes in the film are detected. The present inventors have found that corrosion can be detected with high accuracy and have completed the present invention.

  The base material is made of a metal that is more easily corroded than the metal to be detected or an alkali-soluble metal. Therefore, after the coating is corroded by a corrosive factor, the base material also corrodes early, or when it is embedded in a concrete structure, it dissolves due to the alkali component in the concrete, so that the electrical characteristics of the detection unit change. For example, when the electrical connection of the detection unit is disconnected, the resistance increases rapidly. The corrosion sensor of the present invention can detect the corrosion of the coating early and clearly by detecting the change in the electrical characteristics. Therefore, by installing the corrosion sensor of the present invention in the vicinity of the detection object, it is possible to predict the corrosion start time of the detection object early from the corrosion of the coating.

  Such a corrosion detection member constitutes a part of the corrosion sensor, and when actual detection is performed, detection is performed by operating the entire corrosion sensor. For ease of explanation, before explaining the structure of the corrosion detection member, first, the structure of the entire corrosion sensor will be explained, and the role of the corrosion detection member in the corrosion sensor will be explained. Will be explained. Moreover, the following description is an example of embodiment and this invention is not necessarily limited to this.

A. (Configuration of corrosion sensor as a whole)
FIG. 1 is a block diagram showing an electrical configuration of the corrosion sensor 100. The corrosion sensor 100 communicates information about detected corrosion to the reading device by communicating with the reading device via electromagnetic waves. The reading device consists of an antenna, a modulation / demodulation device, a memory, a CPU, and a power supply unit for supplying power, and outputs information from the corrosion detection unit directly or data processing to other devices as necessary. Let The corrosion sensor 100 includes a corrosion detection circuit 110, a characteristic detection circuit 120 (corrosion detection unit), and a wireless communication unit 130.

Corrosion detection circuit 110, the parallel connection detection unit A ₁ to A _n and provided by, resistors element R ₁ to R _n which are connected in series to each sensing portion. The detection units A _{1 to An} are a part of the corrosion detection member 111. The detection units A _{1 to An} are laid in the vicinity of a metal detection object or the detection object. The metal detection object referred to in the present invention is, for example, a reinforcing bar in a concrete structure, a PC steel wire, a steel sheath tube, a PC cable in a bridge, a column or beam in a steel structure, a girder, a tension material, or the like. .

By laying the detection unit in the vicinity of the object to be detected, it is possible to eliminate various factors that affect the measured electrical characteristics. Furthermore, a measuring instrument for measuring and measuring the natural potential is unnecessary, and the detection accuracy of the corrosion state of the detection target can be increased at low cost. The resistance elements R _{1 to} R _n are used for the purpose of increasing the detection accuracy such as the presence or absence of corrosion of the detection units A _{1 to An} , the change in the corrosion state, or the identification of the corrosion location. Any corrosion of the detecting block A ₁ to A _n (corrosion coating or film and the base material), the resistance of the corroded detection unit is greatly increased. The corrosion sensor 100 indirectly detects the corrosion of the detection object by detecting a change in the electrical resistance of the detection unit in such a corrosion detection member.

Resistive element _R 1 to R _n are connected in series to the sensing portion _A 1 to A _n. When any of the detection units corrode, the resistance value of the circuit increases, so that the corrosion of the detection unit can be detected. For example, the resistance element _R 1 to R the resistance value of _n is assumed to be _r 1 ~r _n, the resistance value of the corrosion detection circuitry 110 when no corrosion _{r 1 r 2 ··· r n /} (r 1 + a r ₂ + ··· + r _n), but then corrosion detection unit a _n which are connected in series, when a part or all is electrically disconnected to the resistance element R _n, corrosion detection circuitry 110 The resistance value is r ₁ r ₂ ... R _n-1 / (r ₁ + r ₂ +... + R _n-1 ), and the resistance increases. Therefore, corrosion can be detected by detecting the resistance value. Incidentally, without connecting the resistor element R ₁ to R _n to the detection unit A ₁ to A _n, it may detect corrosion by the resistance of the detection unit itself.

By connecting in this way the detection unit _A 1 to A _n resistance elements _R 1 to R _n, also slightly the current flowing through the sensing portion _A 1 to A _n, accuracy corrosion state of the detection unit _A 1 to A _n It is possible to detect well. On the other hand, the power consumed by the detectors A _{1 to An} and the resistance elements R _{1 to} R _n can be reduced.

In order to reduce the power consumption, it is preferable to combine the resistance elements R _{1 to} R _n so that the resistance value of the entire corrosion detection circuit 110 is increased. The resistance value of the entire corrosion detection circuit 110 is preferably in the range of 10 kΩ to 1 MΩ, for example. When it is smaller than 10 kΩ, the amount of current flowing through the corrosion detection circuit 110 increases, and the power consumption consumed by the corrosion detection circuit 110 increases. On the other hand, if it is greater than 1 MΩ, the amount of current flowing through the corrosion detection circuit 110 decreases, but the voltage applied to the entire corrosion detection circuit 110 increases and the power consumption increases.

  The characteristic detection circuit 120 (corrosion detection unit) includes a signal transmission circuit 121 and a detection circuit 126 of the RFID IC 125. The signal transmission circuit 121 is a circuit that connects the corrosion detection circuit 110 and the RFID IC 125 and transmits signals to each other. The RFID IC 125 includes a detection circuit 126 and a wireless communication circuit 131. The detection circuit 126 applies a voltage to the corrosion detection circuit 110 and detects electrical characteristics between the terminals 110a and 110b. The electrical characteristics include voltage (potential difference) between the terminals 110a and 110b, electrical resistance, impedance, capacitance, and the like, and these can be detected. In the present embodiment, the corrosion sensor 100 detects a voltage between the terminals 110a and 110b.

  The RFID IC 125 includes a control unit such as a power rectifier circuit, a modulation / demodulation device, a charging / power source unit, a memory, and a CPU. The memory stores a unique identification number registered in advance, information from the outside, a record of state changes in the concrete structure, and other necessary information. The power supply unit may have a power storage function and temporarily store a dielectric voltage from an electromagnetic wave supplied from the outside. The CPU and control unit control the characteristic detection circuit 120. For example, the CPU performs data processing of transmission / reception signals, digital conversion of analog information, power supply control, and other data processing.

  The detection circuit 126 of the RFID IC 125 measures an electrical characteristic such as a resistance value or a potential of the corrosion detection circuit 110. The detection circuit 126 includes various circuits necessary for measuring electrical characteristics, such as a high output current circuit, an inverting amplifier circuit, an in-phase amplifier circuit, a voltage follow circuit, an integration amplifier circuit, a comparison operation circuit, and a comparison operation for hysteresis characteristics. Various resistance elements, capacitors, coils and the like are incorporated so as to constitute a circuit, a multivibrator circuit, a current-voltage conversion circuit, and the like. When measuring the potential difference, the potential difference can be detected more accurately by using a device such as an operational amplifier.

  The memory of the detection circuit 126 includes a ROM that stores an operating system that performs overall control, an EEPROM or FRAM that stores programs for detecting data rewriting and the state of structures, and a RAM that records detected information. It consists of The ID number of the sensor unit may be mounted in the memory, or information regarding the position of the detection unit may be written in the RAM from the reading device, and the information may be read by the reading device together with the information detected by the sensor.

  The wireless communication unit 130 includes a wireless communication circuit 131 of the RFID IC 125, an antenna 132, and a bridge 135. The wireless communication circuit 131 wirelessly transmits the detection result of the detection circuit 126 to an external reading device via the antenna 132.

  The wireless communication circuit 131 includes a modulation circuit, a charging / power supply unit, a memory, and the like. This power supply unit may be of a type equipped with a battery, or may be of a so-called battery-less type, that is, having a power storage function and temporarily storing an induced voltage due to electromagnetic waves supplied from the outside. good. The memory included in the wireless communication circuit 131 includes a ROM that stores an operating system that performs overall control, an EEPROM that stores programs for detecting data rewriting and the state of structures, and a RAM that records detected information. Etc. The ID number of the corrosion sensor may be mounted in the memory, or information on the position of the detection unit may be written in the RAM from the reading device, and the information may be read by the reading device together with the information detected by the sensor.

  In this way, the wireless communication circuit 131, on the one hand, processes the information sent from the detection circuit 126 so that it can be wirelessly transmitted, and on the other hand, the instruction from the reading device received via the antenna 132 is sent to the detection circuit 126. Tell.

  The antenna 132 transmits and receives information wirelessly to and from the reading device. The antenna 132 is made of metals, carbon fiber, ferrite, or the like. For the antenna 132, it is desirable to use a hollow winding, a magnetic winding, or a substrate formed using a printing technique, and the above material is sandwiched between films such as polyethylene terephthalate. May be. As the antenna 132, an antenna formed into an appropriate shape such as a ring shape, a rod shape, or a disk shape may be used.

  The bridge 135 is formed so as not to touch the antenna 132, and the circuit is closed. The corrosion sensor 100 has a configuration for performing wireless communication, but may be connected to the reading device by wire instead of the wireless communication circuit 131.

  The corrosion sensor 100 may be laid on the surface of an insulating steel sheath tube with an insulator such as a resin film interposed therebetween, or may be attached to the outer periphery of a resin sheath tube through which a PC steel wire is inserted. .

B. (Configuration of corrosion detection member)
Next, the corrosion detection member 111 of the present invention will be described. FIG. 2 is a plan view (a) and a cross-sectional view (b) of the corrosion detection member 111. The figure shows an example in which there are three detection units. The cross-sectional view of FIG. 2B is a view of the cross-section S1 of the plan view of FIG.

As shown in FIG. 2, the corrosion detection member 111 includes detection portions A _{1 to} A ₃ , a substrate 113 (base material) for holding the detection portion, and a resin coating 115 for protecting the wiring and preventing a short circuit. ing.
The detection units A _{1 to} A ₃ are connected to the signal transmission circuit 121 by wiring L and are connected in parallel. In this case, the detection units A _{1 to} A ₃ are arranged side by side in a ladder shape on the substrate. The detection units A _{1 to} A ₃ are further configured by base materials B _{1 to} B ₃ and coatings C _{1 to} C ₃ .

The detection unit has a two-layer structure of a base material and a coating, but the overall dimensions are, for example, a range of thickness 5 μm to 250 μm, a length of 10 mm to 100 mm, and a width of 0.05 mm to 30 mm. It is preferable to be formed in a strip shape in the range. Each interval of the detection unit _A 1 to A ₃ is about the range, for example, 3.0mm or 30mm or less. By setting the installation interval to a range of about 3.0 mm or more and 30 mm or less, for example, it is possible to clarify the progress of corrosion in the depth direction of the reinforcing bars or the like in a reinforced concrete structure. When the corrosion detecting member 111 is used in concrete, it is preferable that the length of the detecting portion is in the range of 20 mm to 80 mm. When the aggregate used for concrete accidentally comes directly above the detection unit, accurate detection may be difficult. If the length of the detection part is larger than the maximum diameter of the aggregate, it is possible to prevent the influence on the detection due to the accidental arrangement of the aggregate. By setting the length of the detection portion in the range of 20 mm or more and 80 mm or less, the length of the detection portion can be made larger than the maximum diameter of the concrete aggregate to be used, and corrosion can be reliably detected. However, since the aggregate size of concrete varies depending on the use of the structure in which the corrosion sensor is embedded, the bar spacing, and the cover thickness, the preferable range is not limited to the above.

In addition, when the width of the detection portion of the corrosion detection member is too small, handling becomes difficult at the time of manufacture and use, and the width of the detection portions A _{1 to} A ₃ is 0.05 mm or more, although it varies depending on the application. A range of 30 mm or less is preferable.

B-1-1. (Base material)
The base material is placed on the substrate to hold the coating and to detect corrosion in relation to the coating. As the base material, a base material made of a metal or an alkali-soluble metal that is more easily corroded than the metal to be detected, and a conductive paint or conductive resin is used.

Base material _B 1 .about.B ₃ is formed as a preferred embodiment, for example, of aluminum. The thickness of the base materials B _{1 to} B ₃ is, for example, about 1 μm or more and 200 μm or less when formed by an aluminum foil etching method, and about 0.01 μm or more and 1 μm or less when formed by aluminum dry plating. When formed by printing with filler ink or the like, the thickness is about 0.5 μm or more and 100 μm or less. The base materials B _{1 to} B ₃ are required to have a function as a base for holding the film. Further, when the coatings C _{1 to} C ₃ are produced on the base materials B _{1 to} B ₃ by electroplating, the base materials B _{1 to} B ₃ are required to have conductivity as a base. In this specification, “aluminum foil” refers to a thin film produced by rolling aluminum or a metal containing aluminum as a main component, regardless of the thickness.

On the other hand, the base materials B _{1 to} B ₃ are required to quickly detect corrosion when the coating corrodes. Material for the base material B ₁ .about.B ₃ is, when the film C ₁ -C ₃ is corroded, as long as the material corrodes rapidly, since the detection unit electrical characteristics are changed by breakage, corrosion detection It becomes possible. In this case, the material of the base materials B _{1 to} B ₃ may be any metal that is more easily corroded than the metal of the detection target object in the usage environment of the detection target object such as steel.

Further, in the case of buried concrete, mortar, corrosion sensor 100 in the cement hardened body containing paste, since the concrete has an alkaline material of the base member B ₁ .about.B ₃ may be any alkali-soluble metal . In this way, the base material exposed by the corrosion of the coating is quickly dissolved and disconnected by the alkaline environment of the atmosphere. Thereby, the change of the electrical characteristic in a circuit can be detected clearly.

From the above circumstances, if the steel of the concrete structure in is detected object, by using the aluminum as the base material, after the coating has corroded, to rapidly dissolved in alkali in the concrete, the base material B ₁ aluminum is suitable as a material for .about.B _3. Even a material other than aluminum as long as the above conditions are satisfied metals, it can be used for the material of the base member B ₁ ~B _3.

In addition to materials that rapidly corrode or dissolve when the coatings C _{1 to} C ₃ corrode, the coatings C _{1 to} C ₃ have conductivity (conductivity that is significantly smaller than that of metals) that allows the coatings C _{1 to} C ₃ to be produced. Any material can be used as the base material B _{1 to} B ₃ as long as the material remains without corroding or dissolving much after the coatings C _{1 to} C ₃ are corroded and having a resistance value higher than a certain value. In that case, corrosion can be detected by measuring the electrical resistance value of the detection part when the coatings C _{1 to} C ₃ are corroded. That is, due to the corrosion of the coatings C _{1 to} C ₃ and the disappearance or deterioration of the conductivity, the electricity flowing through the detection coating flows to the conductive paint as the base material, thereby changing the electrical resistance of the entire characteristic detection circuit. To do. Thereby, the corrosion sensor 100 detects corrosion of a film.

Examples of the material that satisfies the above conditions include a filler-type conductive paint, a conductive resin, or a mixture thereof. In particular, a material having fluidity and curability after application is suitable for the base material. The filler type conductive paint is a mixture of conductive particles (filler) and a resin serving as a medium, and includes a so-called conductive paste. Since the resistance value of the filler-type conductive paint, conductive resin, or mixture thereof can be adjusted to about 10 ⁻⁶ to 10 ⁸ Ω depending on the mixing ratio or the like, a base material corresponding to the usage environment of the corrosion sensor is formed. be able to.

  Examples of the simple material used for the filler of the filler type conductive paint include gold, silver, copper, nickel, aluminum, graphite, tin, lead, zinc, iron, titanium, palladium, indium and gallium. Examples of the material of the compound include stainless steel, solder, copper alloy, zinc oxide, tin oxide, indium oxide, titanium carbide, titanium nitride, aluminum oxide, and other alloys of the above materials, oxides, carbides or nitrides.

  Among these, silver, copper, nickel, iron, gold, tin, graphite, and aluminum are particularly practical and suitable as fillers. The filler is contained in the conductive paint in the form of fine particles or fibers.

The conductive resin is a special polymer having conductivity in itself. Examples of the conductive resin include polyacetylene, polypyrrole, polythiophene, polyaniline, polyparaphenylin, and polyacene.
Thus, conductive paint or a conductive resin is also suitable as a material for the base material B ₁ ~B _3.

  In addition, although the above conductive paints and conductive resins have fluidity and curability after application, conductive films, conductive tapes, conductive plastics, conductive ceramics, and conductive glasses are used. The base material may be used.

B-1-2 (coating)
The coating is formed on the base material as a main material for detecting corrosion.
As a preferred embodiment, the coatings C _{1 to} C ₃ are formed of, for example, iron or a metal whose main component is iron, and respectively cover the base materials B _{1 to} B ₃ . The thickness of the coatings C _{1 to} C ₃ is practically preferably in the range of 3 μm or more and 40 μm or less, but can also be formed in the range of 1.0 μm or more and 100 μm or less. The coatings C _{1 to} C ₃ are metals that corrode in the usage environment of the detection target. In the present invention, the portion where corrosion is directly detected is formed into a film, so that corrosion can be detected earlier and more clearly than the conventional thin wire. Moreover, when such a corrosion detection member is installed in or near the detection object, it is possible to predict the corrosion start time of the detection object early from the corrosion of the coating. The coatings C _{1 to} C ₃ may be any metal that corrodes under the environment in which the detection object is used, and the metal of the coating is such that the main component of the metal constituting the coating is the same as the main component of the metal of the detection target. Is preferably selected. For example, when the detection target is a reinforcing bar, the material of the coatings C _{1 to} C ₃ is preferably iron. It is also preferable that the metal constituting the coating is a metal that is more easily corroded than the metal of the object to be detected. For example, when stainless steel is an object to be detected, iron is included in an equal or greater amount.

Base material _B 1 .about.B ₃ is a aluminum, corrosion sensors or corrosion sensing member when used in embedded in the concrete, if the base material _B 1 .about.B ₃ is of the film _C 1 -C ₃ containing this If it happens to be exposed to the concrete prior to corrosion, disconnection in the circuit of the detection unit will be dissolved base member B ₁ .about.B ₃ is the alkaline component in the concrete before the coating is corroded occur. Therefore, in such a case, it is necessary to form the coatings C _{1 to} C _{3 so} as to protect the base material so that the base materials B _{1 to} B ₃ are not exposed to the concrete. The same applies to the case where the base materials B _{1 to} B ₃ are formed of a conductive paint or the like because the conductive particles and the resin are easily dissolved by the alkali component.

It should be noted that iron suitable as a material for the coatings C _{1 to} C ₃ can usually be handled by iron plating if the detection target is a steel material, except that it is made of a metal equivalent to the detection target. Considering the ionization and passivation tendency of metals, iron or iron-based metals are practically the most oxidizable metals in the atmosphere where the detection target is used, such as air or water. Positioned.

A method for forming the coatings C _{1 to} C _{3 made} of a specific metal on the base material is preferable because plating is simple. When the detection part is made of an iron thin wire as in the prior art, it is the limit when the thickness is reduced to about 0.1 mm. However, if plating is used, a coating can be formed even if the thickness is 0.1 mm or less. Even when the thickness is about 0.005 mm, the coating film can be formed. As a result, the time from the start of corrosion of the coating to electrical disconnection is shortened, and the sensitivity of corrosion detection is increased. By adjusting the film thickness in this way, it is possible to form a detection portion that is thinner than a thin line and has good sensitivity, and the sensitivity can be adjusted. Moreover, since a film can be easily formed on a base material having a complicated shape by a technique such as plating, the degree of freedom of the size and shape of the detection unit is increased. In addition, it is possible to manufacture the detection unit at a lower cost compared to manufacturing an extremely fine wire. In addition, if the film is formed by plating, the components of the film can be easily adjusted.

Further, iron plating is more excellent in resistance to mechanical action as it is used for improving the wear resistance of aluminum products, and is easier to handle than fine steel wires. The plating referred to here includes film forming techniques such as chemical plating, electroplating, vapor deposition, melting, and sputtering. In addition, if the coatings C _{1 to} C ₃ are formed thin, the sensitivity of corrosion detection is improved, so the coating formation method is not necessarily limited to plating.

B-2. (Base material)
The substrate 113 (base material) is made of an insulating material, and holds the detection units A _{1 to} A ₃ , wirings, circuits, and the like. The board | substrate 113 (base material) is a board | substrate for printed wiring as a preferable aspect, for example. Technology has been accumulated for many years with respect to printed wiring, and since a base material and wiring can be formed on a substrate using this printed wiring technology, a corrosion detection member can be easily manufactured. The substrate 113 (base material) is preferably formed of a material that is stable against corrosion factors and the surrounding environment, and is less likely to deteriorate over time. Moreover, it is preferable that adhesion performance with a base material is favorable. Since the adhesiveness varies depending on the base material used and the method of forming the base material, a material having good compatibility with the base material may be used as the material of the substrate 113.

Insulating materials used for the substrate 113 include glass epoxy used for printed wiring boards, glass composites, paper phenol, glass, polycarbonate used for flexible substrates, polyethylene terephthalate, polyethylene naphthalate, polyarylate, polyimide, cyclic Examples thereof include olefinic polymers, aromatic polyether ketones, aromatic polyether sulfones, wholly aromatic polyketones, and liquid crystal polymers. Further, materials used for the plastic substrate are also suitable. The substrate 113 and the base member _B 1 .about.B _3, for example, are bonded by resin. Further, a hard type printed circuit board such as glass composite or glass epoxy, or a soft flexible printed circuit board such as polyethylene terephthalate or polyimide can be used depending on the application. Among the above materials, polyethylene terephthalate and polyimide are particularly suitable for the material of the substrate 113 in view of practicality including availability and a large amount of information. Polyethylene terephthalate is a material that has good aluminum adhesion and is available at low cost.

B-3. (Insulating coating)
The base material surface is coated with an insulating coating material for the purpose of protecting the detection unit, wiring, and circuit formed on the base material and preventing a short circuit.

The resin coating 115 (insulating coating) covers the ends of the detection portions A _{1 to} A ₃ and the wiring L on the substrate 113. Thereby, protecting the weak point in corrosion of such connecting portion of the base member _B 1 .about.B ₃ and wiring L and the base member _B 1 ~B _3. On the other hand, the resin coating 115 has an uncoated opening portion 116 at the center, and the detection portions A _{1 to} A ₃ are exposed to the same use environment as the detection object such as a steel material in the opening portion 116. As a material of the resin coating 115, for example, polyester film, vinyl chloride, polyethylene, silicon, fluororesin, tetrafluoroethylene resin, each material used for the base material, other polymer materials, these sheets, tapes, Examples thereof include curable coating agents and adhesives.

  As described above, the insulating coating is not limited as long as it is an insulating material and can protect the circuit on the substrate surface. The insulating coating is required to have hermeticity for sealing the circuit and protecting it from the surrounding environment and adhesion to the substrate 113. It is also required that the material is stable against corrosion factors and the surrounding environment, and that it does not easily deteriorate over time. In addition to the above, when a film is formed by immersing and energizing the plating bath in the manufacture, it also serves to protect the circuit and prevent the film from being formed on the circuit. As the insulating coating, glass coating or ceramic coating can be used in addition to the resin coating.

C. (Corrosion detection member manufacturing method)
Next, an example of the manufacturing method of the corrosion detection member comprised as mentioned above is demonstrated. The following example is a manufacturing method when selecting aluminum, iron as a coating C ₁ -C ₃ as a base material B ₁ .about.B ₃ corrosion sensing member. First, the selection of a method for forming a thin film of the base material _B 1 ~B _3. Thin film forming methods include dry plating, adhesion of aluminum foil, and printing of aluminum paint. For example, when there is a commercially available substrate in which an aluminum foil is bonded to a base material, it is easy to select the bonding of the aluminum foil. As a material of the substrate 113, for example, PET (polyethylene terephthalate) can be selected from the viewpoint of heat resistance and cost.

  Next, the circuit is baked and etched. For example, in a substrate in which an aluminum foil is bonded to the substrate 113, the circuit portion is masked, the masked substrate 113 is immersed in an etching solution for dissolving aluminum, and only the circuit portion is left on the substrate 113 to complete the etching. .

  Next, an element constituting the circuit is inserted into a predetermined portion of the circuit. Then, an insulating coating material is selected. For example, PET can be used as an insulating coating material.

Subsequently, the PET film for insulating coating is punched out so that the substrate 113 and the circuit can be covered while leaving the detection portion. Then, the coating PET film is adhered to the substrate with an adhesive or the like to complete the coating. When the coating is completed, it performs the film formation of the iron by plating on the base material B ₁ ~B _3.

In the plating, the substrate 113 formed as described above is immersed in a plating solution (plating bath), energized for a predetermined time, and an iron film is formed on the base materials B _{1 to} B ₃ by electroplating. When film formation is completed, the process ends.

  Although the above manufacturing method uses a subtracting method in which a wiring pattern is formed by etching, an additive method in which a wiring pattern is formed by electroless plating or the like may be used. In addition, the circuit can be printed using aluminum paint instead of bonding the aluminum foil. In this case, mass production of the corrosion detection member becomes possible by printing.

  Of the plating methods for forming a film, the wet plating method is preferably an electroplating method or a chemical plating method. In the dry plating method, vacuum deposition, sputtering, and chemical vapor deposition are preferable.

  The electroplating method is a method in which a metal is electrochemically reduced and deposited on the surface of an object by an external current from an aqueous solution of a metal salt. A wide range of metals can be plated, including heavy metals such as Zn, Cd, Sn, Ni, Co, Fe, Cu, and Cr, and noble metals such as Ag, Au, and Rh. Even if the film by electroplating is comparatively thin, it is formed as a dense deposited layer and is easy to use for the film of the detection part.

  The chemical plating method is a method in which metal ions in a solution are chemically reduced and deposited without using an external current. One of them is electroless plating. There are two types of chemical plating methods: autocatalytic and non-autocatalytic. The autocatalytic type is a technique in which metal deposition occurs due to the action of the reducing agent and the catalyst. . The non-autocatalytic chemical plating method is a plating method using a plating solution in which metal deposition continues as long as a reducing agent is present. The main metals of chemical plating in practical use are Ni, Cu, Sn, Au and the like. The greatest feature is that the film thickness is uniform and the dimensional accuracy is extremely high, and a film capable of accurate detection can be produced.

  Vacuum deposition is a method in which a metal is evaporated in a vacuum vessel and the evaporated metal molecules are condensed on the surface of an object to form a thin film of 0.05 to 0.1 μm. The undercoat of the thin film requires an undercoat for smoothing the material and improving adhesion. Single metal such as Al, Cu, Ag, Zn can be deposited. Practically used for aluminum and is suitable for the production of aluminum base materials.

  Sputtering introduces argon gas into a vacuum vessel, applies a DC high electric field between the cathode (plating metal) and the anode (coating object), discharges argon into argon ions and electrons, and plating the argon ions. This is a plating technique in which metal atoms are knocked out and metal atoms are ejected (sputtering phenomenon) to form a thin film on the coating object.

  Vacuum plating (PVD), represented by vacuum deposition and sputtering, can be used for plating various metals and alloys as well as simple metals such as Al, Ti, W, etc. Therefore, it is effective for forming a film.

  The chemical vapor deposition (CVD) is a technique for obtaining a plating film by decomposing or substituting a metal surface such as a metal halide under a normal pressure or a reduced pressure, or substituting or reducing with hydrogen. Many pure metals and compounds can be plated. There are thermal CVD, photo CVD, and plasma CVD, and various functional films can be obtained.

  In addition to the plating method described above, a plating method suitable for the application of the corrosion sensor and each material can be applied. In the dry plating method, an immersion plating method, a contact plating method, and an impact plating method can be applied. Further, in the wet plating method, ion plating, hot dipping method and gold film method can be applied.

  As described above, the corrosion detection member of the present invention can be manufactured.

D-1. (How to use wireless)
Next, the usage example of the corrosion sensor 100 of this invention is demonstrated. FIG. 3 is a cross-sectional view illustrating an example in which the corrosion sensor 100 is embedded in the concrete structure 150 to indirectly predict the corrosion of the reinforcing bars 155. As shown in FIG. 3, the concrete structure 150 is formed by embedding a reinforcing bar 155 in concrete, and the corrosion sensor 100 is disposed in the vicinity of the reinforcing bar 155 that is a detection target. In this case, the corrosion factor penetrates in the direction of arrow D from the surface of the concrete structure 150. Therefore, in order to detect the invasion state of the corrosion factor, the corrosion sensor 100 is embedded so that the detection units A _{1 to} A ₃ are arranged in a ladder shape in parallel with the invasion direction of the corrosion factor. By adopting such an arrangement, it becomes possible to grasp the invasion state of the corrosion factor with time in a stepwise direction in the cover depth direction. Also, certain position information can be obtained. In FIG. 3, portions other than the corrosion detection member 111 are omitted.

In order to predict the corrosion start time of the reinforcing bar 155 from the corrosion of the detection units A _{1 to} A ₃ in the corrosion sensor 100, for example, position information of the reinforcing bar 155 and the detection units A _{1 to} A ₃ from the surface of the concrete structure 150. From the time elapsed until the corrosion of each of the detection units A _{1 to} A ₃ , the difference method may be used.

  FIG. 4 is a perspective view showing an example in which the corrosion sensor 100 is used to detect corrosion of a part of the bridge. As shown in FIG. 4, the bridge 160 includes a concrete pier 161, an iron plate 162, a steel truss structure 163, an iron plate 165, a concrete plate 166, an asphalt 167, and a handrail 169. The truss structure 163 is taken so that it can withstand an impact when a vehicle or the like passes over the asphalt 167, but the iron plate 162 under the truss structure 163 has the most burden. In FIG. 4, details of the corrosion sensor are omitted.

  Further, when such a bridge is constructed in the sea or estuary, seawater splashes on a relatively low position such as the iron plate 162. In addition, the upper iron plate 165 can visually confirm the corrosion state directly from the top of the bridge, but the lower iron plate 162 is difficult to confirm from the top of the bridge, and the burden of confirmation work is high at high places. . In such a situation, the corrosion state of the iron plate 162 can be easily confirmed by installing the corrosion sensor 100 having the wireless communication unit on the surface of the lower iron plate 162. Even in cases other than the above-described use examples of concrete structures and bridges, the effect of using the corrosion sensor 100 is particularly great when corrosion is likely to occur and it is difficult to confirm directly by visual observation or the like.

  In many cases, steel structures such as bridges are coated with paint or resin on the surface in order to enhance corrosion resistance. Therefore, from the viewpoint of corrosion detection, the corrosion of the steel material can be detected more accurately when the corrosion detection member is also in the same condition. FIG. 5 is a front view (a) and a cross-sectional view (b) showing a usage example in which the corrosion sensor 100 having the antirust coating 175 applied on the surface of the truss portion 170 of the bridge is installed. In the example shown in FIG. 5, the detection target is a steel material of the truss portion 170 of the steel bridge. Therefore, it is preferable that the coating of the detection unit is made of iron. In this case, the corrosion sensor is preferably a wireless communication system because it is a difficult place for corrosion detection work. When the corrosion sensor 100 is used in an application for detecting corrosion of a steel material coated with paint or resin on the surface, it is preferable to coat the detection unit with the paint or resin applied to the object to be detected. In this way, the corrosion sensor 100 can also be used to determine when to repaint the surface anticorrosive paint 175.

D-2 (Usage method for wired)
In the above description, the corrosion sensor 100 capable of transmitting corrosion detection information to the reading device by wireless communication is described. However, the corrosion detection information may be read by wire. FIG. 6 is a conceptual diagram showing an example in which the corrosion sensor 100 of the present invention is used to detect corrosion of a steel pipe 180 embedded in the ground. In the usage example illustrated in FIG. 6, the corrosion sensor 100 includes a wired interface instead of the wireless communication unit 130. As shown in FIG. 6, the corrosion sensor 100 and the reader are connected by a general-purpose two-wire shielded wire 183 and can communicate with each other. The detection object is a fuel pipe, a gas pipe, a water pipe, a cable pipe, or other industrial underground buried steel pipe 180. For example, assuming that general structural carbon steel is used as the material of the detection object, it is preferable to use an iron coating formed by plating. For the base material, for example, a conductive paint (silver paste ink) can be used. The resistance of the conductive paint can be sufficiently detected if it is about 200Ω, but can be arbitrarily changed depending on the content ratio of the metal powder. The base material can be adhered to the steel pipe using, for example, polyimide. By detecting corrosion in a wired manner in this way, noise to the detection result can be prevented.

(Embodiment 2)
(Corrosion detection circuit is R-2R circuit)
In the first embodiment described above, the corrosion sensor, the resistance element R ₁ to R _n to each of the plurality of sensing portions A ₁ to A _n are connected in series, constitute a corrosion detection circuitry 110 by these parallel connected However, a resistance element may be connected so as to be an R-2R circuit, and a circuit capable of detecting up to which detection unit has corroded may be configured. FIG. 7 is a block diagram showing an electrical configuration of the corrosion sensor 200 in which the corrosion detection circuit 210 is configured as an R-2R circuit.

The corrosion sensor 200 includes a corrosion detection circuit 210, a characteristic detection circuit 220 (corrosion detection unit), and a wireless communication unit 230. In the corrosion detection circuit 210, resistance elements P _{1 to} P _n are connected between the detection units A _{1 to An} and the signal transmission circuit 221. That is, the resistor element P ₁ is connected between the signal transmission circuit 221 and the resistor element R ₁ , the resistor element P ₂ is connected between the resistor element R ₁ and the resistor element R _2, and hereinafter R _i and R _i connecting the P _i between the _+1. Finally, P _n is connected between the resistance element R _n and the signal transmission circuit 221. Corrosion sensor 200, a detection unit _A 1 to A _n which the resistance element _R 1 to R _n serially connected are arranged in parallel a plurality of the detection unit _A 1 to A by measuring the electrical resistance or potential corrosion detection circuitry 210 Check if _n is corroded or corroded. By thus utilizing the R-2R circuit can identify the sensing unit A ₁ to A _n which is corroded. The detection units A _{1 to An} are included in the corrosion detection member 211.

  The characteristic detection circuit 220 (corrosion detection unit) includes a signal transmission circuit 221 and a detection circuit 226 of the RFID IC 225. The detection circuit 226 of the RFID IC 225 measures an electrical characteristic such as a resistance value or a potential of the corrosion detection circuit 210. The wireless communication unit 230 includes a wireless communication circuit 231 of the RFID IC 225, an antenna 232, and a bridge 235. The wireless communication circuit 231 wirelessly transmits the detection result of the detection circuit 226 to an external reading device via the antenna 232. The bridge 235 is formed so as not to touch the antenna 232, and the circuit is closed. The antenna 232 transmits and receives information to and from the reading device wirelessly.

(Embodiment 3)
(Corrosion detection member with a single detector)
In the above embodiment, the corrosion detection circuits 110 and 210 are provided with a plurality of detection units, but only a single detection unit may be provided. FIG. 8 is a plan view (a) and a cross-sectional view (b) showing a corrosion detecting member 311 having only a single detecting portion A. The cross-sectional view of FIG. 8B is a view of the cross-section S2 of the plan view of FIG.

  As shown in FIG. 8, the corrosion detection member 311 includes a detection unit A, a substrate 313 (base material), and a resin coating 315. The detection unit A is connected to the signal transmission circuit by a wiring L. The detection unit A is further configured by a base material B and a coating C. The resin coating 315 covers the end of the detection unit A and the wiring L on the substrate 313. The resin coating 315 has an opening 316 at the center, and in the opening 316, the detection unit A is exposed to a use environment such as a steel material. Such a corrosion detection member 311 having only a single detection unit A is effective when it is desired to detect corrosion locally, for example, when it is desired to easily detect one location of a reinforcing bar in concrete.

(Embodiment 4)
(A form of corrosion detection member with detectors provided in steps)
In the above-described embodiment, an example in which a plurality of detection units are provided in a ladder shape on the substrate of the corrosion detection member has been described, but may be provided in a staircase shape depending on the application. FIG. 9 and FIG. 10 are perspective views showing corrosion detection members 411 and 421 in which _four detection portions A _{1 to} A ₄ are provided in a step shape. In both figures, resin coating and wiring are omitted, and the corrosion detecting member 411 is shown.

In the example shown in FIG. 9, the corrosion detection member 411 is formed by disposing the detection units A _{1 to} A ₄ on each step of the base material 413 having a stepped shape. By providing the detection unit in a staircase shape, it is possible to make it less susceptible to the influence of other detection units. For example, if the corrosion detection member 411 arranged in a ladder shape is provided along the intrusion direction of the corrosion factor, the detection unit in the back is affected by the detection unit in front of the intrusion direction. Therefore, by providing the detection units in a staircase shape, it is possible to create a state in which there is no detection unit on the invasion path of the corrosion factor for each detection unit. The base material 413 has a concave portion 417 (attachment portion) at a corner portion, and can be fitted into the reinforcing bar 455 in the concave portion 417.

On the other hand, in the example shown in FIG. 10, the corrosion detection member 421 is formed by arranging the detection portions A _{1 to} A ₄ on the side surfaces of the respective steps of the base material 423 having a stepped shape. Similarly to the above, by providing the detection units in a staircase shape, each detection unit can be hardly affected by other detection units. Since the detection units A _{1 to} A ₄ are arranged on the side surfaces of the steps, the detection units can be arranged step by step on the side where the corrosion factors easily enter. The base material 423 is formed of an insulating material such as glass or resin, has a concave portion 427 at a corner portion, and can be fitted into the reinforcing bar 455 in the concave portion 427.

(Embodiment 5)
(Corrosion detection member configuration with a detector in a double ring)
In the above embodiment, the plurality of detection units are provided in a ladder shape on the substrate of the corrosion detection member, but the detection units may be arranged in parallel in the form of a double ring depending on the application. The term “double ring” refers to a form in which a plurality of ring members are arranged side by side. 11 and 12 are diagrams showing corrosion detection members 511 and 521 in which a plurality of annular detection units are arranged in parallel. In addition, since the detection part of an arc shape acts similarly to a cyclic | annular thing, an arc shape shall also include an arc shape. In each figure, the corrosion detection member is shown by omitting resin coating and wiring.

FIG. 11 is a perspective view of the corrosion detection member 511 in which the annular detection units A _{1 to} A ₃ are arranged side by side with the flexible substrate 513 as a base material. In the example shown in FIG. 11, the corrosion detection member 511 is installed so as to be wound around the reinforcing bar 555. The corrosion detection member 511 is formed by arranging the detection portions A _{1 to} A ₃ along the longitudinal direction of the flexible substrate 513 (base material). Therefore, the corrosion detecting member 511 has flexibility and can be wound around the reinforcing bar 555 as shown in FIG. By arranging detectors in a ring shape, members that are long in the axial direction, such as reinforcing bars and steel frames, can cope with the invasion of corrosion factors from all directions around the shaft.

FIG. 12 is a front view of a corrosion detection member 521 in which annular detection portions A _{1 to} A ₃ are arranged side by side using a joint member 523 of a sheath tube as a base material. The sheath tube is a tube that is embedded in prestressed concrete and allows a steel material to pass through. As shown in FIG. 12, the joint member 523 of the sheath tube is provided with detection portions A _{1 to} A ₃ along the outer peripheral surface. The corrosion sensor can detect the corrosion of the sheath tube itself or predict the corrosion of the PC steel wire inside the sheath tube by measuring its electrical characteristics. In particular, since there is a high possibility that a corrosion factor enters the sheath tube from the joint portion of the joint member 523, it is effective to give the joint member 523 a corrosion detection function. Incidentally, in the above example it is provided with a detecting portion A ₁ to A ₃ on the outer peripheral surface, but may be provided on the inner peripheral surface. Further, by connecting other circuits to form a corrosion sensor and transporting it to a concrete construction site, work efficiency can be improved as compared to mounting the corrosion sensor at the construction site.

  Similarly, a corrosion detection member may be formed by arranging an annular detection portion side by side on a base material having an attachment portion detachable from a sheath tube or the like. To be detachable means, for example, that it can be fitted.

  For example, the detection portion is formed in an arc shape, and the attachment portion of the corrosion detection member has a shape similar to the outer shape of the sheath tube so as to be fitted to the outer shape of the sheath tube. The detection unit is arranged in parallel on the outer periphery of the mounting unit, and when the detection unit is corroded, the electrical characteristic information is transmitted to the signal transmission circuit through the wiring connected to the detection unit.

(Embodiment 6)
(Corrosion sensor configuration with cathode members connected)
In the above embodiment, macro cell corrosion of the detection target is not considered, but when there is a possibility that macro cell corrosion may occur in the detection target, a cathode member is connected to the detection unit to cause macro cell corrosion. A corrosion sensor is preferred. Macrocell corrosion refers to corrosion in which corrosion of a base portion having a low potential is promoted by forming a macroscopic battery (macrocell) in which a base portion having a relatively low potential and a noble portion form a macroscopic battery. FIG. 13 and FIG. 14 are block diagrams showing an electrical configuration of corrosion sensors 600 and 650 including a cathode member.

In the example illustrated in FIG. 13, the corrosion sensor 600 includes a corrosion detection circuit 610, a characteristic detection circuit 620 (corrosion detection unit), a wireless communication unit 630, and a cathode member E. The corrosion detection circuit 610 includes detection units A _{1 to An} and resistance elements R _{1 to} R _n connected in series to the detection units. The detection units A _{1 to An} are provided in parallel connection and constitute a part of the corrosion detection member 611. A cathode member E is connected between the corrosion detection circuit 610 and the signal transmission circuit 621.

Cathode member E is an electrode functioning as a cathode with respect to the film of the detecting portion A ₁ to A _n, it is formed by, for example, platinum coating. Functionally, platinum has the most excellent characteristics as an electrode material. Platinum is a chemically stable substance and has a feature that it is easy to obtain high-purity platinum in terms of engineering in addition to a small hydrogen overvoltage, and further easy to process. Platinum is a material that can be easily coated as a plating or formed into a thin film. Therefore, the plated platinum film has excellent uniformity and becomes a stable quality film. Thus, the platinum film formed by plating is most suitable as a member for a cathode. The plating method includes the above-described wet plating method and dry plating method.

  The cathode member E may be made of only gold. With regard to the original function of the cathode member for advancing corrosion, platinum is superior to gold, but gold is superior in that it has good workability and is easy to use for plating. Moreover, you may use a semiconductor as such a member for cathodes.

Further, the cathode member may be an electrode formed of titanium alone. Titanium has high corrosion resistance and chemical stability, and has high dimensional stability (8.4 × 10 ⁻⁶ / K) with respect to temperature and high rigidity as a metal, and is therefore effective as a member for a cathode.

  In addition to the above configuration, the surface is formed of a metal that is nobler than iron as a coating material, such as platinum, gold, titanium, nickel, tin, lead, copper, stainless steel, or an alloy thereof. Can be used. Alternatively, platinized titanium may be used. Platinum-plated titanium is obtained by applying platinum plating to the surface of a titanium member. Platinum-plated titanium is excellent in corrosion resistance (stability) because both platinum and titanium have high corrosion resistance.

  Thus, the corrosion sensor 600 has the cathode member E formed of a metal that is nobler than the metal that is the material of the coating. Since the coating is formed of a metal material that corrodes in the environment in which the detection target is used, the corrosion proceeds rapidly due to macrocell corrosion caused by the connection of the cathode member E. In this way, the corrosion sensor 600 can be placed under the same conditions with respect to a detection target in which macrocell corrosion occurs.

  Further, by connecting the cathode member E, the corrosion rate of the detection unit can be adjusted. For example, the sensitivity of the corrosion sensor 600 can be increased by speeding up the corrosion. This method is effective when you want to know the possibility of corrosion of the detection object locally at an early stage. When the number of detection units is large, it is preferable to connect the single cathode member E as described above because a simple structure is obtained.

  In the manufacturing process of the corrosion sensor 600 configured as described above, for example, the cathode member E can be formed on the printed circuit board. A cathode energizing terminal is provided in advance at a predetermined position on the substrate for forming the cathode member E, and the cathode member E is formed by plating platinum.

In the example of corrosion sensor 650 illustrated in FIG. 14, the cathode member _E 1 to E _n in each of the sensing portion _A 1 to A _n are connected. Description of the configuration of other parts is the same as that of the corrosion sensor 600 of FIG. When the number of detection units is not large, it is preferable to produce a cathode member for each detection unit and install it near the detection unit. This is because the resistance of the concrete affects when the cathode member is installed far away.

(Embodiment 7)
(Corrosion sensor form in which circuit is integrally formed on the substrate)
In the above embodiment, the corrosion detection member and the other parts are separately manufactured and connected by wiring, so that the corrosion sensor is formed. However, other parts such as RFID IC are also installed on the substrate and integrally formed. May be.

  FIG. 15 is a plan view (a), cross-sectional views (b) and (c), and a bottom view (d) showing a corrosion sensor 700 in which a circuit is integrally formed on a substrate 713. The cross-sectional views of FIGS. 15B and 15C are views of cross-sections S3 and S4 in the plan view of FIG. As shown in FIG. 15, the corrosion sensor 700 is provided with a circuit across the front and back of the substrate 713 (base material). The corrosion detection member 711 is formed on one surface of the substrate 713 shown in FIG. 15A, and the collective circuit 716 and the antenna 732 are installed on the other surface.

The corrosion sensor 700 on one surface of the substrate 713 includes a corrosion detection member 711, a collective circuit 716, and an antenna 732. Corrosion sensing member 711 is constituted by the detection unit A ₁ to A _n which are provided in a parallel connection. Set circuit 716, the detection unit _A 1 to A resistance element connected in series to each of _n, is obtained by an integrated circuit comprising characteristic detecting circuit and RFIDIC. The antenna 732 transmits a signal between the RFID IC of the collective circuit 716 and the reader.

On one surface of the substrate 713, the corrosion detection member 711 is configured by detection units A _{1 to} A ₃ , a substrate 713 (base material), and a resin coating 715. The detection units A _{1 to} A ₃ are connected to the signal transmission circuit 721 by the wiring L, and are connected in parallel. The detection units A _{1 to} A ₃ are further configured by base materials B _{1 to} B ₃ and coatings C _{1 to} C ₃ . The coatings C _{1 to} C ₃ are made of iron and cover the base materials B _{1 to} B ₃ , respectively. Material for the base material _B 1 .about.B ₃ is aluminum, coating _C 1 -C ₃ is formed by plating. The substrate 713 (base material) is formed of an insulating material, and holds the detection units A _{1 to} A ₃ . The resin coating 715 covers the ends of the detection units A _{1 to} A ₃ and the wiring L on the substrate 713. Resin coating 715, center has an opening 715a of the uncoated, the detection unit A ₁ to A ₃ in the opening 715a is exposed to the same use environment and steel material sense target. The wiring L is connected to the other surface of the substrate 713 through a through hole 714. As shown in FIG. 15D, the collective circuit 716 and the antenna 732 are installed on the other surface of the substrate 713, and a resin coating 715 is applied.

  In this way, since the electronic components such as the corrosion detection member 711, the collective circuit 716, and the antenna 732 and the wiring form a circuit integrally on the substrate 713, the corrosion sensor 700 can be manufactured by an efficient manufacturing process. . Further, a compact corrosion sensor 700 can be manufactured by being integrally formed on the printed wiring board 713. Thereby, it becomes easy to install the corrosion sensor 700 on or near the detection target.

(Embodiment 8)
(Corrosion detection member with a mounting part)
In the above embodiment, the corrosion detection member is mainly a simple plate, but an attachment portion may be provided on the corrosion detection member. FIG. 16 is a perspective view showing a corrosion detecting member 811 having a mounting portion. A corrosion detection member 811 shown in FIG. 16 includes detection portions A _{1 to} A ₃ , a substrate 813 (base material), a resin coating 815, and a band 820 (attachment portion). The substrate 813 is coupled to the band 820 on one surface, and holds the detection units A _{1 to} A ₃ on the other surface. Bonding is performed by bonding with an adhesive resin or the like. The band 820 is made of a resin or the like, and includes a belt-shaped portion and a stopper at one end thereof, and a ring having a desired length can be formed by passing the other end of the belt through the stopper. . The corrosion detection member 811 can be attached to the reinforcing bar 855 by winding the belt portion of the band 820 around the reinforcing bar 855 and fastening it with a stopper. Thereby, installation of a corrosion sensor, correction of an installation position, etc. become easy. And the labor of the measurement preparation before concrete placement can be reduced, and a preparation period can be shortened.

  Further, since the corrosion detecting member 811 is directly wound around the reinforcing bar 855 with the band 820 and fixed, the corrosion detecting member 811 can be stably fixed to the reinforcing bar 855. In addition, since the reinforcing bar 855 is fastened by adjusting the length of the belt using the stopper, it can be adapted and fixed to the reinforcing bar 855 having a desired size. Thereby, it is possible to flexibly cope with various sizes of reinforcing bars or when the number of reinforcing bars increases. In addition, since the band 820 is not metal, the influence on communication can be eliminated even when a wireless communication unit is provided in the vicinity of the attachment unit.

  In the above, an example in which the attachment portion is the band 820 is described, but the attachment portion is not limited to the band, and a fitting type resin molded product may be used. Moreover, it can utilize not only for the use which attaches the corrosion detection member 811 to the reinforcing bar 855 of a concrete structure but for the attachment to the structure in a support | pillar or other concrete structures.

(Embodiment 9)
(Corrosion detection by electromagnetic wave radar method or electromagnetic induction method)
In the above embodiment, corrosion is detected by connecting the wiring to the detection unit and measuring the electrical characteristics. However, the corrosion is detected by the electromagnetic wave radar method or the electromagnetic induction method as a measurement method of the electrical characteristics. Also good. The electromagnetic wave radar method and the electromagnetic induction method are particularly effective methods for detecting corrosion of reinforcing bars in concrete.

  In the electromagnetic wave radar method, when the electromagnetic wave is radiated from the transmitter of the exploration equipment toward the concrete, the electromagnetic wave reflected at the interface with the substance (corrosion detection member) with different electrical properties is received by the receiver, This is a method of detecting a detection member. In this method, the position of the corrosion detection member can also be estimated.

  The electromagnetic induction method radiates a magnetic field line (primary magnetic field) from the magnetic field generator of the exploration equipment toward the concrete, and generates a secondary magnetic field caused by the induced current generated in the conductive material (corrosion detection member) in the concrete. This is a technique for detecting a corrosion detecting member by detecting the magnetic field detecting unit and comparing the increase and decrease of the primary magnetic field and the secondary magnetic field, and measuring the position thereof.

  FIG. 17 is a plan view (a) and a cross-sectional view (b) showing a corrosion detecting member 911 in which an electromagnetic wave radar method or an electromagnetic induction method is used. The cross-sectional view of FIG. 17B is a view of the cross-section S5 in the plan view of FIG.

  As shown in FIG. 17, the corrosion detection member 911 includes a detection unit A and a substrate 913 (base material). The detector A is composed of a base material B and a coating C.

  The substrate 913 (base material) is made of a non-metallic material or a non-magnetic material, and holds the detection unit A. Examples of the material used for the substrate 913 include polyimide and ABS resin. The substrate 913 and the base material B are bonded with resin.

  When the electromagnetic wave radar method or the electromagnetic induction method is used, it is only necessary that the detection unit has an area that can be detected by these methods, and wiring connected to the detection unit is unnecessary. Therefore, various shapes of base materials can be used. For example, the base material may be formed in a cylindrical shape. FIG. 18 is a plan view (a) and a cross-sectional view (b) showing a corrosion detection member in which a detection part is formed on a predetermined direction side of a cylindrical base material. The cross-sectional view of FIG. 18B is a view of the cross-section S6 of the plan view of FIG.

  As shown in FIG. 18, the corrosion detection member 921 includes a detection unit A and a base material 923. The detector A is composed of a base material B and a coating C.

  The base material 923 is formed in a cylindrical shape from an insulating material, and holds the detection unit A. The diameter of the cylinder is about the same as the reinforcing bar. By placing the corrosion detection member under the same conditions as the reinforcing bars, corrosion of the reinforcing bars can be clearly predicted. The insulating material used for the base material 923 is the same as that of the substrate 913. The base material 923 and the base material B are bonded with resin.

  In the case of using a cylindrical base material, the detection unit may be provided on the entire circumference. FIG. 19 is a plan view (a) and a cross-sectional view (b) showing a corrosion detection member in which a detection part is formed on the entire circumference of a cylindrical base material. The cross-sectional view of FIG. 19B is a view of the cross-section S7 in the plan view of FIG.

  As shown in FIG. 19, the corrosion detection member 931 includes a detection unit A and a base material 933. The detection unit A is formed on the entire circumference of the base material 933. By forming the detection part A on the entire circumference, the manufacturing process such as impregnation is facilitated, and the condition for placing the corrosion detection member is close to that of the reinforcing bar. The detector A is composed of a base material B and a coating C.

  The base material 933 is formed in a cylindrical shape from an insulating material, and holds the detection unit A. The diameter of the cylinder is about the same as the reinforcing bar. By placing the corrosion detection member under the same conditions as the reinforcing bars, corrosion of the reinforcing bars can be clearly predicted. The insulating material used for the base material 933 is the same as that of the substrate 913. The base material 933 and the base material B are bonded with resin.

  Next, an example of how to use the corrosion detection member when using the electromagnetic wave radar method or the electromagnetic induction method will be described. First, the corrosion detection member is embedded in a concrete structure. When the corrosion detection member is used to predict corrosion of the reinforcing bar, it is preferable to install the corrosion detecting member at a position similar to the reinforcing bar with respect to the penetration of the corrosion factor or a position shallower than the reinforcing bar with respect to the penetration of the corrosion factor. Moreover, it installs in the position a little away from the reinforcing bar so that corrosion detection of the detection part in the corrosion detecting member is not hindered by the reinforcing bar. Then, a rebar survey is performed at regular intervals to detect the corrosion of the detection unit, and the corrosion of the rebar is predicted based on the detected corrosion.

It is a block diagram which shows the electrical structure of the corrosion sensor which concerns on this invention. (Embodiment 1) (A) It is a top view of the corrosion detection member which concerns on this invention. (B) It is sectional drawing of the corrosion detection member which concerns on this invention. It is sectional drawing which shows the usage example of the corrosion sensor which concerns on this invention. It is a perspective view which shows the usage example of the corrosion sensor which concerns on this invention. (A) It is a front view which shows the usage example of the corrosion sensor which concerns on this invention. (B) It is sectional drawing which shows the usage example of the corrosion sensor which concerns on this invention. It is a conceptual diagram which shows the usage example of the corrosion sensor which concerns on this invention. It is a block diagram which shows the electrical structure of the corrosion sensor which concerns on this invention. (Embodiment 2) (A) It is a top view of the corrosion detection member which concerns on this invention. (B) It is sectional drawing of the corrosion detection member which concerns on this invention. (Embodiment 3) It is a perspective view which shows the corrosion detection member which installed the detection part in step shape. (Embodiment 4) It is a perspective view which shows the corrosion detection member which installed the detection part in step shape. It is a perspective view which shows the corrosion detection member which arranged the cyclic | annular detection part in parallel. (Embodiment 5) It is a front view which shows the corrosion detection member which arranged the cyclic | annular detection part in parallel. It is a block diagram which shows the electrical structure of the corrosion sensor which concerns on this invention. (Embodiment 6) It is a block diagram which shows the electrical structure of the corrosion sensor which concerns on this invention. (A) It is a top view of the corrosion detection member which concerns on this invention. (B) It is sectional drawing of the corrosion detection member which concerns on this invention. (C) It is sectional drawing of the corrosion detection member which concerns on this invention. (D) It is a bottom view of the corrosion detection member which concerns on this invention. (Embodiment 7) It is a perspective view which shows the example of installation of the corrosion sensor which concerns on this invention. (Embodiment 8) (A) It is a top view of the corrosion detection member which concerns on this invention. (B) It is sectional drawing of the corrosion detection member which concerns on this invention. (Embodiment 9) (A) It is a top view of the corrosion detection member which concerns on this invention. (B) It is sectional drawing of the corrosion detection member which concerns on this invention. (A) It is a top view of the corrosion detection member which concerns on this invention. (B) It is sectional drawing of the corrosion detection member which concerns on this invention.

Explanation of symbols

100,200,600,650,700 corrosion sensor 110,210,610 corrosion sensing circuit _A, A 1 to A _n detection unit _P 1 to P _n resistive elements _R 1 to R _n resistive elements L lines 110a, 110b contact 120, 220, 620 Characteristic detection circuit (corrosion detector)
121,221,621,721 Signal transmission circuit 125,225,625 RFIDIC
126, 226, 626 Detection circuit 130, 230, 630 Wireless communication unit 131, 231, 631 Wireless communication circuit 132, 232, 632, 732 Antenna 135, 235, 635 Bridge 111, 211, 311, 411, 421, 511, 521 , 611,711,811,911,921,931 corrosion sensing member _B, B 1 .about.B ₃ base member _C, C 1 -C ₃ film S1, S2, S3, S4, S5, S6, S7 position of the cross-section
113, 313, 413, 423, 713, 813, 913 Substrate (base material)
115, 315, 715, 815 Resin coating 116, 316, 715a Opening 150 Concrete structure 155, 455, 555, 855 Reinforcement D Arrow 160 indicating direction of penetration of corrosion factor Bridge 161 Bridge pier 162, 165 Iron plate 163, 170 Truss 166 Concrete board 167 asphalt 169 handrail
175 Anticorrosion paint 180 Steel pipe 183 Shield wire for communication 417, 427 Recessed part (mounting part)
513 Flexible substrate (base material)
523 Joint member 714 Through hole 716 Collective circuit 820 Band (mounting part)
_E, E 1 ~E _n cathode member 923,933 substrate

Claims (9)

A corrosion detection member of a corrosion sensor that is buried in concrete and used to detect the progress of corrosion of a nearby metal detection object,
A base material made of an alkali-soluble metal, and a detection unit formed by coating the base material so that the base material is not exposed , and formed of a coating made of a metal that corrodes in the environment in which the detection object is used; ,
A corrosion detection member for a corrosion sensor, comprising: a base material for holding the detection unit. The detection object is a steel material,
The corrosion detection member for a corrosion sensor according to claim 1 , wherein the coating is made of iron. The corrosion detection member for a corrosion sensor according to claim 1 or 2 , wherein an insulating coating is applied to at least a part of the substrate surface on the side where the detection unit is held. The base material is formed in a linear shape or a thin plate shape, and a plurality of the base materials are provided in a ladder shape, a staircase shape, or a multiple annular shape arranged side by side on the base material. The corrosion detection member for a corrosion sensor according to any one of claims 1 to 3 , wherein the corrosion detection member is provided. 5. The corrosion detecting member for a corrosion sensor according to claim 1, wherein the base material is a printed wiring board. The corrosion detection member for a corrosion sensor according to any one of claims 1 to 5 , wherein the base material is made of aluminum. A corrosion detection unit for detecting corrosion of the detection unit in the corrosion detection member according to claim 5 by measuring electrical characteristics of the detection unit;
A corrosion sensor comprising: a wireless communication unit that wirelessly transmits the detection result of the corrosion to a reader;
The wiring of the corrosion sensor including the detection unit is printed on the base material, and the electronic components and wirings constituting the corrosion detection unit and the wireless communication unit integrally form a circuit on the base material. Corrosion sensor characterized by that. A corrosion detection unit that detects corrosion of the detection unit in the corrosion detection member according to any one of claims 1 to 6 by measuring electrical characteristics of the detection unit;
A corrosion sensor comprising a wireless communication unit that wirelessly transmits the corrosion detection result to a reader,
A corrosion sensor, further comprising an electrode that is connected to the detection unit, is made of a metal that is nobler than the metal of the coating, and functions as a cathode for the detection unit. The detection object is a rebar embedded in a concrete structure,
The corrosion sensor according to any one of claims 1 to 6 , wherein a base for the corrosion detection member is provided with an attachment portion for attaching the corrosion detection member to the reinforcing bar.

Images