JP2019215289A - System for monitoring corrosion prevention state of steel structure - Google Patents

Abstract

To provide a system for monitoring a corrosion prevention state of a steel structure capable of diagnosing a corrosion prevention state of a steel structure without going to an actual place.SOLUTION: The system for monitoring a corrosion prevention state of a steel structure comprises a metal piece 11 fixed to a steel structure 10, a current measurement unit 18 for measuring current which flows by corrosion of the metal piece 11, a data collection unit 19 for collecting chronological data of the current to transmit the data to a server 21 of the Internet 20, and a monitoring terminal 23 for monitoring a corrosion prevention state of the steel structure 10 through communication with the server 21. The server 21 includes a storage unit for storing the chronological data, a computation unit for computing corrosion speed of the steel structure 10 and a determination unit for determining a corrosion state of the steel structure 10. The monitoring terminal 23 displays the corrosion speed of the steel structure 10 obtained by the computation unit and a determined result obtained by the determination unit.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a corrosion prevention state monitoring system for steel structures such as steel pipe piles, steel sheet piles, and steel sheet piles covered with an anticorrosion material exposed to the ocean or river.

  Conventionally, petrolatum coating, underwater curing type coating, and the like have been implemented as a corrosion prevention structure for a steel structure exposed to a marine environment or the like. The petrolatum coating is a composite type anticorrosion structure in which a petrolatum-based anticorrosion material is used as an anticorrosion material, and the anticorrosion material is protected by a plastic or corrosion-resistant metal protective cover. The underwater curing type coating is an anticorrosion structure of a type in which an epoxy-based paint or putty that cures even in water is used as an anticorrosion material and applied to a steel structure. In recent years, as a new coated anticorrosion structure, there is a structure in which a resin such as urethane added with a rust inhibitor or the like is mounted on a steel material in an uncured state.

  Known anti-corrosion structures are often provided on steel structures for a long period of time, and the steel structures are provided with a coated anti-corrosion structure. Cannot be determined appropriately. For example, when a typhoon causes waves, drifting objects, or other unusual environmental changes, deterioration of the anticorrosion material or the like may progress more quickly. Therefore, in Patent Literature 1, a pair of electrodes having different potentials in water are embedded in a coated anticorrosive body provided on a base material, and a current flowing between the electrodes when water infiltrates the coated anticorrosive body is detected. Then, a technique for detecting a corrosion state inside the coated anticorrosive body has been proposed.

JP 2007-132010 A

  However, in the technology described in Patent Document 1, in order to maintain and manage a steel structure, it is necessary to continuously monitor the internal state of the coated and anticorrosion structure. Therefore, the manager must go to the site periodically and measure a large number of locations, which requires a great deal of labor and cost. Furthermore, when an electrode is provided on the surface of a steel structure to detect the internal state of the coated and anticorrosion structure, it is necessary to fix the electrode to the surface of the steel structure. Patent Document 1 discloses the fixing means. There is no.

  Accordingly, an object of the present invention is to provide a steel structure anticorrosion state monitoring system capable of appropriately diagnosing the anticorrosion state of a steel structure according to the on-site environment without going to the site and further reducing the cost.

The present invention relates to an anticorrosion state monitoring system for a steel structure that monitors an anticorrosion state of a steel structure covered with an anticorrosion material,
A metal material that is fixed to the surface of the steel structure in a state of being electrically insulated from the steel structure, and is coated with the anticorrosion material, and has an electrochemical order lower than that of the steel structure. A metal piece composed of
A current measuring unit that measures a current flowing between the metal piece and the steel structure by water being directly in contact with the metal piece and corroding the metal piece,
A data collection unit that collects data over time of the current obtained in the current measurement unit and transmits the data to a server on the Internet.
Comprising a monitoring terminal that monitors the anticorrosion state of the steel structure by communicating with the server through the Internet,
A storage unit that stores the temporal data transmitted from the data collection unit,
Based on the aging data, calculate the amount of electricity from the current flowing between the metal piece and the steel structure, based on the correlation between the previously determined amount of electricity and the corrosion rate of the steel structure. A computing unit that determines a corrosion rate of the steel structure from the calculated amount of electricity,
Based on the corrosion rate of the steel structure obtained by the arithmetic unit, comprising a determination unit that determines the anticorrosion state of the steel structure,
The monitoring terminal is to provide a corrosion prevention state monitoring system for a steel structure that displays a corrosion rate of the steel structure by the calculation unit and a determination result by the determination unit.

Further, the present invention provides a steel structure anticorrosion state monitoring system for monitoring the anticorrosion state of a steel structure covered with an anticorrosion material,
An atmospheric corrosion sensor fixed to a surface of the steel structure in a state of being electrically insulated from the steel structure, and coated with the anticorrosive material;
A current measuring unit that measures a current output by the atmospheric corrosion sensor by the atmospheric corrosion sensor being in direct contact with water and corroding the atmospheric corrosion sensor;
A data collection unit that collects data over time of the current obtained in the current measurement unit and transmits the data to a server on the Internet.
Comprising a monitoring terminal that monitors the anticorrosion state of the steel structure by communicating with the server through the Internet,
A storage unit that stores the temporal data transmitted from the data collection unit,
Based on the time data, calculate the amount of electricity from the current output by the atmospheric corrosion sensor, based on the correlation between the previously obtained amount of electricity and the corrosion rate of the steel structure, the calculated amount of the A calculation unit for determining the corrosion rate of the steel structure from the quantity of electricity,
Based on the corrosion rate of the steel structure obtained by the arithmetic unit, comprising a determination unit that determines the anticorrosion state of the steel structure,
The monitoring terminal is to provide a corrosion prevention state monitoring system for a steel structure that displays a corrosion rate of the steel structure by the calculation unit and a determination result by the determination unit.

  ADVANTAGE OF THE INVENTION According to the anticorrosion state monitoring system of this invention, since it can diagnose the anticorrosion state of a steel structure without going to the site, it is very efficient and is very useful also in maintaining and managing a steel structure. Further, since the corrosion prevention state of the steel structure can be monitored by the monitoring terminal, the cost for maintenance and management of the steel structure can be reduced.

FIG. 1 is a schematic view showing a configuration of a part of a corrosion prevention state monitoring system for a steel structure according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a schematic perspective view showing an enlarged main part of FIG. FIG. 4 is a schematic diagram showing an outline of the corrosion prevention state monitoring system for a steel structure according to the present invention. FIG. 5 is a flowchart for explaining a monitoring method using the anticorrosion state monitoring system for a steel structure according to the present invention. FIG. 6 is a schematic diagram of a corrosion specimen in a monitoring method using the corrosion prevention state monitoring system for a steel structure shown in FIG. 5. FIG. 7 is a diagram for explaining an immersion test in the monitoring method using the corrosion prevention state monitoring system for a steel structure shown in FIG. 5. FIG. 8 is a schematic diagram (corresponding to FIG. 1) showing a configuration of a part of the corrosion prevention state monitoring system for a steel structure according to another embodiment of the present invention. FIG. 9A is a plan view showing the atmospheric corrosion sensor, and FIG. 9B is a sectional view taken along line bb in FIG. 9A. FIG. 10 is a graph showing the relationship between the quantity of electricity and the corrosion rate using an atmospheric corrosion sensor.

  Hereinafter, the present invention will be described based on preferred embodiments. FIG. 1 shows an embodiment of the anticorrosion state monitoring system of the present invention. The system of this embodiment is for monitoring the anticorrosion state of various steel structures 10 including a steel pipe pile. In the system according to the present embodiment, as shown in FIGS. 1 and 2, a metal piece 11 is fixed to a surface of a steel structure 10 in a state where the metal piece 11 is electrically insulated from the steel structure 10. Is covered with an anticorrosive material 12.

  As shown in FIG. 1, the steel structure 10 is immersed in water such as seawater or river water. The steel structure 10 has a lower end buried in water and an upper end exposed on the water surface. The side surface of the steel structure 10 is covered with an anticorrosion material 12. The anticorrosion material 12 continuously covers the entire side surface of the steel structure 10 from the submerged underwater portion of the steel structure 10 to the above-water portion exposed on the water surface W.

  The anticorrosion material 12 can be composed of, for example, a petrolatum-coated anticorrosion material or a water-curable resin. When using a petrolatum-based anticorrosion material as the anticorrosion material 12, it is preferable to protect the anticorrosion material 12 with a protective cover 13 made of plastic or corrosion-resistant metal, as shown in FIG. The cushioning member 14 can be arranged on the inner surface of the protective cover 13. The protective cover 13 and the cushioning material 14 may be fixed with an adhesive. Examples of the cushioning material 14 include foams such as polyethylene, polyurethane, polystyrene, and synthetic rubber.

  As the underwater-curable resin, the same resin as conventionally used as this kind of resin can be used without any particular limitation. For example, an epoxy resin, a urethane resin, a silicone resin, a polysulfide resin, a polyester resin, or the like can be used.

  The metal piece 11 fixed to the surface of the steel structure 10 is preferably made of a metal material whose electrochemical order is low relative to the steel structure 10. Examples of such a metal material include zinc, magnesium, and aluminum.

  As described above, the metal piece 11 is fixed to the steel structure 10 while being electrically insulated from the steel structure 10. The metal piece 11 may be fixed in a detachable manner or in a non-detachable manner. When the steel structure 10 is a magnetic material, the metal piece 11 can be detachably fixed to the steel structure 10 using magnetic force. For this purpose, a magnetic layer 15 can be formed on the surface of the metal piece 11 facing the steel structure 10, as shown in a partially cutaway perspective view in FIG. The magnetic layer 15 can be composed of, for example, a magnet sheet, but is not limited to this. Since the magnet sheet has flexibility, the metal piece 11 can be fixed to the side surface or the lower surface of the steel structure 10 by using the magnet sheet as the magnetic layer 15. Further, by deforming the metal piece 11 so as to follow the shape of the steel structure 10, the metal piece 11 can be fixed even if the steel structure 10 has a curved surface shape. Further, by using the magnet sheet, the work of attaching and detaching the metal piece 11 to and from the steel structure 10 can be performed easily and quickly, and the work efficiency can be improved. In addition, after the metal piece 11 is covered with the anticorrosive material 12, the position of the metal piece 11 can be detected from the outside by using a magnetic detector, so that the metal piece 11 can be easily replaced. The magnetic layer 15 and the steel structure 10 may be joined with an adhesive in order to secure the metal piece 11 and the steel structure 10 securely.

  The metal piece 11 needs to be fixed to the surface of the steel structure 10 while being electrically insulated from the steel structure 10. For this purpose, it is advantageous to provide an electrically insulating layer 16 between the metal piece 11 and the magnetic layer 15, as shown in the partially broken perspective view of FIG. The electrical insulating layer 16 can be made of, for example, an insulating paint or an insulating tape, but is not limited thereto.

  As shown in FIG. 3, one end of a cable 17 is connected to the metal piece 11. The cable 17 is arranged inside the anticorrosion material 12. The cable 17 extends upward to the surface of the water, and the other end is connected to the current measuring unit 18 shown in FIG. The cable 17 electrically connects the metal piece 11 and the current measuring unit 18.

  The current measuring unit 18 is for measuring a current flowing between the metal piece 11 and the steel structure 10 when water directly contacts the metal piece 11 and corrodes the metal piece 11. Therefore, one of the two inputs of the current measuring unit 18 is connected to the cable 17 described above. The other input is connected to steel structure 10. For example, a two-pole non-resistance ammeter can be used as the current measuring unit 18 from the viewpoint of measuring a weak current with high sensitivity.

  FIG. 1 shows a state in which one metal piece 11 is attached to the steel structure 10, but the number of metal pieces 11 attached is not limited to this. For example, as shown in FIG. Two or more metal pieces 11 may be attached to various parts of the steel structure 10. In that case, the current measuring unit 18 may be a multi-channel type having a plurality of input terminals that can be electrically connected to each metal piece 11.

  In FIG. 1, one current measuring unit 18 is used for one steel structure 10, but the relationship between the two is not limited to this, and a plurality of current measuring units 18 are used for one steel structure 10. May be used. When there are a plurality of steel structures 10 to be monitored, for example, as shown in FIG. 4 described later, the number of current measuring units 18 corresponding to the number of the steel structures 10 can be used.

  The principle of monitoring the anticorrosion state in the anticorrosion state monitoring system of the present embodiment is as follows. When the metal piece 11 is completely covered with the anticorrosion material 12 and the surface of the metal piece 11 is not exposed at all, the metal piece 11 and the steel structure 10 are insulated by the anticorrosion material 12. . Therefore, no current flows between the metal piece 11 and the steel structure 10, and the current measuring unit 18 does not detect the current. In this state, it is determined that no corrosion has occurred. On the other hand, when the anticorrosion material 12 is deteriorated and water enters the anticorrosion material 12, the water reaches the surface of the steel structure 10. As a result, a galvanic current is generated by a potential difference generated between the metal piece 11 and the steel structure 10. In this case, since the metal piece 11 is made of a metal material whose electrochemical order is lower than that of the steel structure 10, the metal piece 11 serves as an anode and the steel structure 10 serves as a cathode. Since the galvanic current generated between the metal piece 11 and the steel structure 10 has a positive correlation with the amount of corrosion of the metal material, the corrosion rate of the steel structure 10 is quantitatively evaluated by measuring the galvanic current. it can. When the metal piece 11 is made of a metal material having a noble electrochemical order with respect to the steel structure 10, the steel structure 10 serves as an anode and the metal piece 11 serves as a cathode. It is not preferable because the corrosion of the structure 10 proceeds.

  Next, the overall configuration of the anticorrosion state monitoring system of the present embodiment will be described. As shown in FIG. 4, the anticorrosion state monitoring system includes a data collection unit 19. The data collection unit 19 has a function of collecting current temporal data obtained by the current measurement unit 18. The data collection unit 19 is electrically connected to each of the current measurement units 18 via the cable 22. As a result, it is possible to input the time-dependent data of the current obtained in each current measuring unit 18 to the data collecting unit 19. The data collection unit 19 also has a function of transmitting the collected temporal data to the server 21 on the Internet 20. The data collection unit 19 is connected to the Internet 20 by wire or wirelessly.

  The anticorrosion state monitoring system includes one or a plurality of monitoring terminals 23. The monitoring terminal 23 has a function of monitoring the anticorrosion state of the steel structure 10 by communicating with the server 21 via the Internet 20. As a result, the time data of the current acquired and collected by the current measuring unit 18 can be input to the monitoring terminal 23. The monitoring terminal 23 is configured to display the determination result of the corrosion rate and the anticorrosion state of the steel structure 10 calculated by the server 21 based on the current time data obtained by the current measuring unit 18. Thus, the anticorrosion state of the steel structure 10 is monitored. The monitoring terminal 23 is connected to the Internet 20 by wire or wirelessly.

  The method of monitoring the anticorrosion state using the anticorrosion state monitoring system of the embodiment shown in FIG. 4 is performed, for example, according to the flowchart shown in FIG. First, before the steel structure 10 is coated with the anticorrosion material 12, a corrosion test measurement is performed. First, a corrosion test specimen is prepared. As shown in FIG. 6, the corrosion test body 24 is formed by fixing a reference metal piece 26 made of the same material as the metal piece 11 to a steel plate 25 made of the same material as the steel structure 10, and the anticorrosion material 12 covering the steel structure 10. One surface of the steel plate 25 is covered with the anticorrosion material 27 of the same material as that described above, and the other surface of the anticorrosion material 27 opposite to the steel plate 25 is covered with the cushioning material 39. The anticorrosion material 27 covers the entire surface of the steel plate 25 to which the reference metal piece 26 is fixed. Cables 28a and 28b are electrically connected to the steel plate 25 and the reference metal piece 26, respectively. The cable 28 b connected to the reference metal piece 26 is embedded in the anticorrosion material 27. The ends of the cables 28 a and 28 b are drawn out of the corrosion test body 24. A protective cover 29 made of an insulator such as plastic is disposed on each surface of the steel plate 25. The steel plate 25 and the reference metal piece 26 are sandwiched between a pair of protective covers 29. These members are integrally fixed by fastening means 30 composed of bolts and nuts.

  An immersion test is performed using the corrosion test body 24 having the above-described configuration. In this immersion test, water actually contacting the steel structure 10 is collected, and as shown in FIG. 7, a part of the corrosion test body is naturally immersed in the water. One ends of cables 28 a and 28 b are connected to the steel plate 25 and the reference metal piece 26, respectively, and the other ends of the cables 28 a and 28 b are connected to the current measuring unit 31. As the current measuring unit 31, a non-resistance ammeter or the like can be used similarly to the current measuring unit 18 shown in FIG. By this immersion test, the quantity of electricity and the corrosion rate of the corrosion specimen are obtained as reference data. In this reference data acquisition, the amount of electricity (hereinafter referred to as “reference amount of electricity”) is calculated based on the current value measured by the current measuring unit 31 and the elapsed time. As the reference amount of electricity, an accumulated amount of electricity is used, or a daily average amount of electricity, that is, an accumulated amount of electricity per day is used. The corrosion rate (hereinafter, referred to as “reference corrosion rate”) is determined by removing corrosion products adhered to the reference metal piece 26 after a predetermined time has elapsed after the immersion of the corrosion test piece 24 is performed. The mass loss amount of 26 is obtained and calculated from the value. Here, the “mass reduction amount of the reference metal piece 26” is “the erosion depth of the reference metal piece 26”, that is, the depth of the portion of the reference metal piece 26 that has been lost due to the removal of corrosion products (the thickness of the portion). ), The erosion depth can be used to calculate the reference corrosion rate. Therefore, the reference corrosion rate is defined by [erosion depth of reference metal piece 26 / hour]. If the erosion depth of the reference metal piece 26 is partially different, the maximum value of the erosion depth is used for calculating the reference corrosion rate.

  Next, on-site measurement is performed as shown in the flowchart of FIG. In the on-site measurement, first, a metal piece setting operation for setting the metal piece 11 is performed. In the metal piece installation operation, the metal piece 11 is fixed to one or a plurality of portions of the steel structure 10, and the steel structure 10 and the metal piece 11 are covered with the anticorrosion material 12. Then, the anticorrosion material 12 is protected by a protective cover 13 via a cushioning material 14 as necessary.

  When the metal piece installation operation is completed, the current flowing between the steel structure 10 and the metal piece 11 is measured by the current measuring unit 18 as shown in FIG. The time data of the current is collected by the data collection unit 19. The data collection unit 19 transfers the temporal data to the server 21 on the Internet 20. The server 21 includes a storage unit, a calculation unit, and a determination unit as described below.

  The storage unit of the server 21 stores the time-lapse data transmitted from the data collection unit 19. The storage unit stores the reference data obtained by the immersion test described above, that is, the reference electricity amount and the reference corrosion rate. The reference amount of electricity and the reference corrosion rate are input in the monitoring terminal 23 and stored in the storage unit via the Internet 20. The stored data, for example, current aging data, time-current relationship, electric quantity and time-electric quantity relation can be displayed on the monitoring terminal 23, and the anticorrosion state can be monitored.

  The arithmetic unit of the server 21 calculates an amount of electricity (hereinafter, referred to as “actual amount of electricity”) from a current flowing between the metal piece 11 and the steel structure 10 based on the time-lapse data stored in the storage unit. . The data of the actual amount of electricity is stored in the storage unit. Further, the calculation unit estimates a regression equation between the reference electric quantity and the reference corrosion rate, that is, a correlation, by statistical processing. The statistical processing includes, for example, processing for approximating the distribution of coordinates in a coordinate system. On the basis of this correlation, the calculation unit determines the corrosion rate of the steel structure 10 from the actual amount of electricity. The relationship between the corrosion rate of the steel structure 10 and the time-corrosion rate thus determined is stored in the storage unit of the server 21. The stored data can be displayed on the monitoring terminal 23, and the anticorrosion state can be monitored.

  The determination unit of the server 21 determines the anticorrosion state of the steel structure 10 based on the corrosion rate of the steel structure 10 obtained by the calculation unit. For the determination, a threshold value of the corrosion rate is set in advance in the determination unit, and the threshold value is compared with the corrosion rate. The determination result can be displayed on the monitoring terminal 23, and the anticorrosion state can be monitored. In the above comparison, for example, when the corrosion rate exceeds the threshold value, it is estimated that the anticorrosion material 12 has deteriorated, and a warning is transmitted from the server 21 and the warning is displayed on the monitoring terminal 23 (FIG. 5 "YES"). Conversely, when the corrosion rate is equal to or lower than the threshold value, it is estimated that the anticorrosion material 12 has not deteriorated, and the monitoring of the anticorrosion state is continued ("NO" in FIG. 5).

  According to the monitoring system as described above, the corrosion prevention state of the steel structure 10 can be constantly monitored without going to the site where the steel structure 10 is installed, so that monitoring is very efficient. In addition, since the corrosion prevention state of the steel structure 10 can be monitored by the monitoring terminal 23 installed at a place other than the installation place of the steel structure 10, the cost related to the maintenance of the steel structure 10 can be reduced.

  More specifically, the corrosion rate is estimated from the time-lapse data of the current flowing between the metal piece 11 and the steel structure 10, and the anticorrosion state of the steel structure 10 is determined based on the estimated corrosion rate. The corrosion prevention state of the steel structure 10 can be reliably grasped, and the degree of deterioration of the corrosion protection material 12 can be evaluated. In addition, by monitoring the corrosion rate freely and quantitatively, it is possible to contribute to formulating a plan for renewal of the anticorrosion material 12 and a maintenance and management plan in the future, and to reduce costs related to the maintenance and management of the steel structure 10. . Further, the manager of the steel structure 10 or a technician of a corrosion prevention-related business entity contracting with the manager can use the monitoring terminal 23 to monitor the current chronological data, the amount of electricity, the corrosion rate of the steel structure 10, and the corrosion protection. The state determination result can be browsed, and the information can be taken into the monitoring terminal 23 or a recording medium attached to the monitoring terminal 23.

  8 and 9 show another embodiment of the present invention. The description of the embodiment shown in FIGS. 1 to 7 is appropriately applied to the points which are not particularly described in this embodiment. 8 and 9, the same members as those in FIGS. 1 to 7 are denoted by the same reference numerals.

  The monitoring system according to the present embodiment includes a current measuring unit, a data collecting unit, a monitoring terminal, and a server, as in the above-described embodiment. The monitoring system according to the present embodiment is mainly different from the previous embodiment in that the measurement by the current measuring unit 18 is the output current of an atmospheric corrosion (Atmospheric Corrosion Monitor) sensor (hereinafter, referred to as “ACM sensor”). As shown in FIG. 8, the ACM sensor 32 is fixed to the surface of the steel structure 10. The fixing means of the ACM sensor 32 can be the same as the fixing means of the metal piece 11 in the above-described embodiment. For example, the ACM sensor 32 can be fixed to the surface of the steel structure 10 by magnetic force. The ACM sensor 32 is a metal corrosion electrochemically generated by environmental factors such as temperature, humidity, rainfall, sea salt particles flying in the air, and corrosive gas, which are atmospheric environmental factors that affect the corrosiveness of metal. It is a sensor that can directly measure current.

  FIGS. 9A and 9B show an example of the configuration of the ACM sensor 32. FIG. The ACM sensor 32 has a structure in which a plurality of insulating layers 34 (thickness: 30 to 35 μm) extending in one direction are intermittently provided on the surface of a steel substrate 33, and a conductive layer 35 is stacked on the insulating layers 34. Things. The ACM sensor 32 has a comb-shaped exposed surface of the steel substrate 33 at a substantially central position of the steel substrate 33, and has a detection unit having a circular shape as a whole. The steel substrate 33 has a thickness of about 0.1 mm to 1 mm, and is made of, for example, carbon steel. The insulating layer 34 has a thickness of about 10 μm to 100 μm, and is made of an insulating material such as silica. The conductive layer 35 has a thickness of about 10 μm to 100 μm, and is made of a metal material having a higher electrochemical order than the steel substrate 33, for example, silver.

  Cables 37a and 37b are electrically connected to the steel board 33 and the cable take-out portions 36a and 36b of the conductive layer 35, respectively. The cables 37a and 37b extend through the interior of the anticorrosion material 38 (see FIG. 8) to the surface of the water, and the other ends are connected to the current measuring unit 31 shown in FIG. The cables 37a and 37b electrically connect the ACM sensor 32 and the current measuring unit 31.

  When the ACM sensor 32 is completely covered with the anticorrosion material 38, the steel substrate 33 and the conductive layer 35 are insulated by the anticorrosion material 38. Therefore, no current flows through the ACM sensor 32, and the current measuring unit 31 does not detect the current. In this state, it is determined that no corrosion has occurred. On the other hand, when the anticorrosion material 38 deteriorates and water enters the anticorrosion material 38, a water film is formed on the surface of the ACM sensor 32. Due to this, a galvanic current is generated by a potential difference generated between the steel substrate 33 and the conductive layer 35. In this case, since the steel substrate 33 is made of a metal material whose electrochemical order is lower than that of the conductive layer 35, the steel substrate 33 functions as an anode and the conductive layer 35 functions as a cathode. As shown in FIG. 10, the ACM sensor 32 has a good correlation between the corrosion rate of the steel substrate 33 and the quantity of electricity. Therefore, the corrosion rate of the steel structure 10 can be quantitatively evaluated by measuring the galvanic current or the amount of electricity.

  In the above embodiment, the same effects as those in the embodiment shown in FIGS. In addition to this, according to the present embodiment, the following effects resulting from the use of the ACM sensor 32 are also obtained. That is, in the ACM sensor 32, the interval between the conductive layer 35, that is, the cathode, and the steel substrate 33, that is, the anode, is narrow due to its structure. Due to this, even if the thickness of the anticorrosion layer made of the anticorrosion material 12 covering the steel structure 10 is small, the anticorrosion state of the steel structure 10 can be diagnosed. Further, since the ACM sensor 32 forms an electrode pair with the conductive layer 35 and the steel substrate 33, the position where the ACM sensor 32 is fixed to the steel structure 10 is a position for monitoring the anticorrosion state of the steel structure 10. It becomes. Therefore, by dispersing and fixing the plurality of ACM sensors 32 to the steel structure 10 and monitoring the currents output from the respective ACM sensors 32, it is easy to determine where the performance deterioration of the steel structure 10 occurs. Can be specified. As a result, maintenance and repair of the steel structure 10 such as repair and renewal can be performed easily and at low cost.

  Although the present invention has been described based on the preferred embodiments, the present invention is not limited to the above embodiments. For example, the means for detachably attaching the metal piece 11 or the ACM sensor 32 to the steel structure 10 is not limited to magnetic force.

  1 and 8, the metal piece 11 and the ACM sensor 32 are attached to a portion of the steel structure 10 located below the water surface. However, the attachment positions are not limited thereto. The metal piece 11 and the ACM sensor 32 may be attached to a portion located on the water in 10.

DESCRIPTION OF SYMBOLS 10 Steel structure 11 Metal piece 12 Anticorrosion material 15 Magnetic layer 16 Electric insulating layer 18 Current measuring unit 19 Data collecting unit 20 Internet 21 Server 23 Monitoring terminal 31 Current measuring unit 32 Atmospheric corrosion sensor 33 Steel substrate 34 Insulating layer 35 Conductive layer 36 Take-out part 38 anticorrosion material

Claims (4)

In the anticorrosion state monitoring system of the steel structure that monitors the anticorrosion state of the steel structure covered with the anticorrosion material,
A metal material that is fixed to the surface of the steel structure in a state of being electrically insulated from the steel structure, and is coated with the anticorrosion material, and has an electrochemical order lower than that of the steel structure. A metal piece composed of
A current measuring unit that measures a current flowing between the metal piece and the steel structure by water being directly in contact with the metal piece and corroding the metal piece,
A data collection unit that collects data over time of the current obtained in the current measurement unit and transmits the data to a server on the Internet.
Comprising a monitoring terminal that monitors the anticorrosion state of the steel structure by communicating with the server through the Internet,
A storage unit that stores the temporal data transmitted from the data collection unit,
Based on the aging data, calculate the amount of electricity from the current flowing between the metal piece and the steel structure, based on the correlation between the previously determined amount of electricity and the corrosion rate of the steel structure. A computing unit that determines a corrosion rate of the steel structure from the calculated amount of electricity,
Based on the corrosion rate of the steel structure obtained by the arithmetic unit, comprising a determination unit that determines the anticorrosion state of the steel structure,
The monitoring terminal is a corrosion prevention state monitoring system for a steel structure that displays a corrosion rate of the steel structure by the calculation unit and a determination result by the determination unit.   The anticorrosion state monitoring system according to claim 1, wherein the metal piece is fixed to a surface of the steel structure by a magnetic force. In the anticorrosion state monitoring system of the steel structure that monitors the anticorrosion state of the steel structure covered with the anticorrosion material,
An atmospheric corrosion sensor fixed to a surface of the steel structure in a state of being electrically insulated from the steel structure, and coated with the anticorrosive material;
A current measuring unit that measures a current output by the atmospheric corrosion sensor by the atmospheric corrosion sensor being in direct contact with water and corroding the atmospheric corrosion sensor;
A data collection unit that collects data over time of the current obtained in the current measurement unit and transmits the data to a server on the Internet.
Comprising a monitoring terminal that monitors the anticorrosion state of the steel structure by communicating with the server through the Internet,
A storage unit that stores the temporal data transmitted from the data collection unit,
Based on the time data, calculate the amount of electricity from the current output by the atmospheric corrosion sensor, based on the correlation between the previously obtained amount of electricity and the corrosion rate of the steel structure, the calculated amount of the A calculation unit for determining the corrosion rate of the steel structure from the quantity of electricity,
Based on the corrosion rate of the steel structure obtained by the arithmetic unit, comprising a determination unit that determines the anticorrosion state of the steel structure,
The monitoring terminal is a corrosion prevention state monitoring system for a steel structure that displays a corrosion rate of the steel structure by the calculation unit and a determination result by the determination unit.   The corrosion prevention state monitoring system according to claim 3, wherein the atmospheric corrosion sensor is fixed to a surface of the steel structure by a magnetic force.