A reinforced concrete structure corrosion depth monitoring device and use method thereof

Abstract

The present invention relates to a corrosion depth monitoring device for reinforced concrete structure and a method for using the same. The device comprises a conductive ceramic resistance sensor, a monitoring interface device and a wire. The conductive ceramic resistance sensor is composed of a steel test piece and a plurality of conductive ceramic plates. The first interfaces of the plurality of conductive ceramic plates are respectively connected to different resistance positions of the steel test piece. A plate protection box is provided outside the connection part. The second interfaces of the plurality of conductive ceramic plates extend into the interior of the concrete and are respectively connected to the monitoring interface device through wires. The monitoring interface device comprises a support frame and a plurality of monitoring-end conductive ceramic plates arranged on the lower side thereof. The support frame comprises an embedded part and an exposed part. A plurality of measuring contacts are provided on the upper side of the exposed part. The inner ends of the monitoring-end conductive ceramic plates are respectively connected to corresponding wires, and the outer ends are respectively connected to corresponding measuring contacts through the support frame. The device is conducive to long-term and stable monitoring of reinforced concrete structures.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering structure monitoring, and in particular relates to a reinforced concrete structure corrosion depth monitoring device and a use method thereof. Background Art

[0002] Coastal engineering structures such as cross-sea bridges and port terminals are located in a relatively complex environment. They are often affected by adverse factors such as rising and falling tides, waves, alternating dry and wet environments, sand and gravel scouring, high salt fog and wind. These factors cause the performance of structural materials to deteriorate over time, affecting the durability and safety of the structures.

[0003] For reinforced concrete structures, carbonization and spalling of the concrete protective layer and steel corrosion caused by corrosion are the main factors affecting the durability of the structure. Among them, concrete carbonization and chloride ion erosion are important causes of steel corrosion, which directly affect the safety of the structure. Therefore, in reality, effective monitoring methods can be used to detect potential risks that may cause steel corrosion as early as possible so that measures can be taken for targeted prevention. Compared with anti-corrosion treatment after the steel begins to corrode, the maintenance cost during the life cycle of the structure is lower, and the maintenance effect on safety and durability is better.

[0004] In recent years, various types of concrete structure corrosion monitoring and detection devices have been developed at home and abroad, but most of them are relatively complex and costly to manufacture. Most existing sensors contain easily corroded metals and electronic components, which are easily corroded when exposed to repeated high salt fog infiltration for a long time, resulting in the uncertainty of the accuracy of the measured data, which has a serious impact on the subsequent bridge safety analysis and may even lead to wrong judgments.

[0005] Traditional detection methods include core sampling, half-cell potential, linear polarization, macrocurrent, pulse current, etc. The latter are used for electrochemical sensors. The core sampling method can measure the corrosion rate of steel bars more accurately, but it will destroy the integrity of the structure; the electrochemical testing technology has little effect on the structure, the measurement principle is mature, and the measurement results are theoretically more reliable, but the sensor has high requirements for the internal environment, and the reliability of the test results is easily affected by the quality of its own lines and the surrounding environment. Newer corrosion monitoring technology can use fiber grating sensors, which have better corrosion resistance than traditional electrochemical sensors. However, due to the large geometric dimensions of coastal reinforced concrete structures, the degree of internal corrosion varies greatly. The corrosion conditions of various parts are mostly affected by their own structure and construction or the external environment. At the same time, the packaging of the sensor also has a certain impact on corrosion monitoring.

[0006] For corrosion monitoring of reinforced concrete structures in coastal areas, higher requirements are placed on the corrosion resistance and measurement stability of sensors in the wetted area. Therefore, it is necessary to develop a corrosion sensor that meets the requirements in terms of durability and accuracy. Summary of the invention

[0007] The purpose of the present invention is to provide a device for monitoring the corrosion depth of a reinforced concrete structure and a method for using the device, which is conducive to long-term and stable monitoring of the reinforced concrete structure.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a reinforced concrete structure corrosion depth monitoring device, including a conductive ceramic resistance sensor, a monitoring interface device and a wire, the conductive ceramic resistance sensor is placed in the concrete protective layer interval before the structure is cast, the monitoring interface device is set in a dry area or a position convenient for detection, and the structure is cast after the installation of the entire device is completed; the conductive ceramic resistance sensor is composed of a steel test piece and a plurality of conductive ceramic plates, the steel test piece has a plurality of different resistance positions, the first interfaces of the plurality of conductive ceramic plates are respectively connected to the different resistance positions of the steel test piece, and the first interfaces of the plurality of conductive ceramic plates are respectively connected to the different resistance positions of the steel test piece. An electric plate protection box is provided on the outside of the connection part between the interface and the different resistance positions of the steel test piece, and the second interfaces of the multiple conductive ceramic plates extend into the interior of the concrete and are respectively connected to the monitoring interface device along the steel bar laying direction through wires; the monitoring interface device includes a support frame and multiple monitoring-end conductive ceramic plates, the support frame includes an embedded part embedded in the concrete and an exposed part exposed to the external environment, a plurality of measuring contacts are provided on the upper side of the exposed part of the support frame, and the multiple monitoring-end conductive ceramic plates are arranged on the lower side of the support frame, and the inner ends thereof are respectively connected to the corresponding wires, and the outer ends are respectively connected to the corresponding measuring contacts through the support frame.

[0009] Furthermore, the first interface of the conductive ceramic plate is connected to different resistance positions of the steel test piece via screw buckles; the second interface of the conductive ceramic plate is connected to the wire via screw buckles; the outer end of the conductive ceramic plate at the monitoring end is connected to the measuring contact via screw buckles.

[0010] Furthermore, the conductive ceramic plate of the conductive ceramic resistor sensor, the conductive ceramic plate at the monitoring end of the conductive ceramic monitoring interface device, and the screw buckle are all made of silicon carbide conductive ceramic material.

[0011] Furthermore, the wire is a Teflon wire.

[0012] Furthermore, the circuit board protection box is filled with epoxy resin to further seal the circuit structure.

[0013] Furthermore, the embedded part to the exposed part of the support frame is tilted downward at a set angle to facilitate rapid drainage in rainy and snowy weather.

[0014] Furthermore, the low resistance position of the steel test piece is close to the concrete surface, and the high resistance position is close to the stressed steel bars.

[0015] Furthermore, the conductive ceramic resistor sensor is fixed by bridging an extended steel bar on the internal steel bars of the structure, and the extended steel bar does not exceed the steel test piece.

[0016] The present invention also provides a method for using the above reinforced concrete structure corrosion depth monitoring device, which is used for any part to be tested of the reinforced concrete structure; first, before the structure is cast, a conductive ceramic resistor sensor is placed in the concrete protective layer interval, and the low resistance position of the steel test piece is close to the concrete surface, and the high resistance position is close to the stressed steel bar, and an extended steel bar is overlapped on the steel bar inside the structure for binding and fixing the conductive ceramic resistor sensor, and the extended steel bar does not exceed the steel test piece;

[0017] Point the interface of the conductive ceramic resistor sensor toward the inside of the concrete, then connect the interface of the conductive ceramic resistor sensor with a wire, and lay it along the steel bars to the monitoring interface device;

[0018] Install the monitoring interface device: first install the support frame of the monitoring interface device in a dry area or a convenient location for detection. A part of the support frame is embedded in the concrete, and the rest is exposed to the external environment. The same fixing method as the sensor is used, that is, the support frame is fixed by tying and fixing the support frame by overlapping the extended steel bars on the steel bars;

[0019] The conductive ceramic plate at the monitoring end is installed on the lower side of the support frame, the inner ends of the conductive ceramic plate at the monitoring end are respectively connected to the corresponding wires, and the outer ends are respectively connected to the measuring contacts on the upper side of the support frame through the support frame for monitoring the contacts;

[0020] After the installation of the whole device is completed, the structure is cast; after casting, a multimeter is used to monitor whether the detection circuits of the high resistance position and the low resistance position are normal, and a resistance meter is used to obtain the initial state resistance value; the corrosion depth and corrosion rate are determined by long-term monitoring of the changes in the resistance of the high and low resistance positions.

[0021] Compared with the prior art, the present invention has the following beneficial effects: a device for monitoring the corrosion depth of reinforced concrete structures and a method for using the same are provided. The device is based on a conductive ceramic resistor sensor for corrosion monitoring, has better corrosion resistance, more stable performance, and lower cost; and the circuit board can be customized as needed, has good compressive resistance, has little impact on the concrete structure after being embedded in the measurement position, and has good engineering applicability. The conductive ceramic resistor sensor of the device has a simple structure, is not easily damaged, and is easy to construct and install. The device fully exposes the steel test piece to be corroded in the corrosive environment, ensuring the stability and reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the installation structure of the reinforced concrete structure corrosion depth monitoring device according to an embodiment of the present invention;

[0023] Figure 2 is a schematic structural diagram of a conductive ceramic resistor sensor in an embodiment of the present invention;

[0024] Figure 3 is a schematic structural diagram of a support frame of a monitoring interface device according to an embodiment of the present invention;

[0025] Figure 4 2 is a schematic diagram of the structure of a conductive ceramic plate at the monitoring end of a monitoring interface device according to an embodiment of the present invention;

[0026] Figure 5 It is a working principle diagram of the reinforced concrete structure corrosion depth monitoring device in an embodiment of the present invention.

[0027] In the figure: 1-steel test piece; 2-epoxy resin; 3-silicon carbide conductive ceramic plate; 4-plate protection box; 5, 6, 7-second interfaces of low, medium and high resistance conductive ceramic plates; 8, 9, 10-first interfaces of low, medium and high resistance conductive ceramic plates; 11-screw buckle; 100-conductive ceramic resistance sensor; 200-monitoring interface device; 300-Teflon wire. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] This embodiment provides a device for monitoring the corrosion depth of reinforced concrete structures. The device design strives to be simple in structure and to prevent components from being damaged in high-salt, high-humidity and complex load environments, so as to achieve long-term and stable monitoring of reinforced concrete structures. Figure 1-5As shown, the device includes a conductive ceramic resistor sensor 100, a monitoring interface device 200 and a wire 300. The conductive ceramic resistor sensor 100 is placed in the concrete protective layer interval before the structure is cast, and the monitoring interface device 200 is set in a dry area or a position convenient for detection. The structure is cast after the installation of the entire device is completed. The conductive ceramic resistor sensor 100 is composed of a steel test piece 1 and a plurality of conductive ceramic plates 3. The steel test piece 1 can be set with a plurality of different resistance positions according to engineering needs. The first interfaces of the plurality of conductive ceramic plates 3 are respectively connected to the different resistance positions of the steel test piece 1. A plate protection box 4 is provided outside the connection part between the first interfaces of the plurality of conductive ceramic plates 3 and the different resistance positions of the steel test piece 1. The second interfaces of the plurality of conductive ceramic plates extend into the interior of the concrete and are respectively connected to the monitoring interface device along the steel bar laying direction through wires; the monitoring interface device 200 includes a support frame 201 and a plurality of monitoring end conductive ceramic plates 202. The support frame 201 includes an embedded part embedded in the concrete and an exposed part exposed to the external environment. A plurality of measuring contacts 203 are provided on the upper side of the exposed part of the support frame 201. The plurality of monitoring end conductive ceramic plates 202 are arranged on the lower side of the support frame, and their inner ends are respectively connected to the corresponding wires, and their outer ends are respectively connected to the corresponding measuring contacts 203 through the support frame 201.

[0032] In terms of measurement principle, the conductive ceramic sensor uses the resistance change caused by the change in the cross-sectional area of ​​the steel test piece in the sensor to quantify the corrosion depth. If the corrosion of the concrete in the monitoring area is generally uniform, the resistance change of the sensor is proportional to the corrosion increment. The degree of corrosion can be understood from the change in resistance value each time it is measured, and the corrosion rate can be calculated through regular measurements. When using it, it is necessary to accurately measure the resistance R0 before corrosion and the resistance R1 after corrosion after the sensor is installed, and then calculate the corrosion amount based on the resistance change value ΔR before and after corrosion:

[0033] (1)

[0034] Where ΔR is the resistance change of the steel specimen, R0 is the original resistance value, R1 is the resistance value measured after corrosion, M0 is the original mass, M1 is the mass after corrosion, A0 is the cross-sectional area of ​​the original specimen, and A1 is the cross-sectional area of ​​the specimen after corrosion. The corrosion amount is calculated according to formula (1), and the corrosion rate can be further calculated based on the recorded time and other information.

[0035] In this embodiment, the first interface of the conductive ceramic plate is connected to different resistance positions of the steel test piece through a screw buckle; the second interface of the conductive ceramic plate is connected to the wire through a screw buckle 11; the outer end of the conductive ceramic plate at the monitoring end is connected to the measuring contact through a screw buckle.

[0036] In this embodiment, the conductive ceramic plate of the conductive ceramic resistor sensor 100, the conductive ceramic plate at the monitoring end of the conductive ceramic monitoring interface device, and the screw buckle are all made of silicon carbide conductive ceramic material.

[0037] In this embodiment, the wire 300 is a Teflon wire.

[0038] In this embodiment, the circuit board protection box is filled with epoxy resin 2 to further seal the circuit structure.

[0039] In this embodiment, the embedded part of the support frame is tilted downward to a set angle to the exposed part, that is, the difference in height between two points of the longitudinal slope of the support frame surface / the horizontal distance between the two points (2~5% in this embodiment), which is used for rapid drainage in rainy and snowy weather, and the extension length can be determined according to needs.

[0040] In this embodiment, the low resistance position of the steel test piece is close to the concrete surface, and the high resistance position is close to the stressed steel bar. Figure 2 As shown in the figure, the point marked 5 is the initial point of measurement. If the point marked 6 is selected as the measurement loop, the distance between the steel test piece at point 6 and point 5 is shorter, and the position of the steel test piece in the measurement loop is a low resistance position. If the point marked 7 is selected as the measurement loop, the position of the internal steel test piece is a high resistance position.

[0041] In this embodiment, the conductive ceramic resistance sensor is fixed by tying an extended steel bar over the internal steel bars of the structure. The extended steel bar does not exceed the steel test piece, and the purpose is to ensure that the steel test piece is fully wrapped by the corrosive environment in the concrete, and to prevent the extended steel bar from affecting the environment of the protective layer concrete to be tested.

[0042] The present invention also provides a method for using the above reinforced concrete structure corrosion depth monitoring device, which is used for any part of the reinforced concrete structure to be tested (such as the repeated infiltration area of ​​the bridge pier, the deep water area, etc.). The method is carried out in the following steps:

[0043] First, before pouring the structure, place the conductive ceramic resistor sensor in the concrete cover, and make the low resistance position of the steel test piece close to the concrete surface, and the high resistance position close to the stressed steel bar. Overlap an extended steel bar on the internal steel bar of the structure to tie and fix the conductive ceramic resistor sensor. The extended steel bar does not exceed the steel test piece.

[0044] Point the interface of the conductive ceramic resistor sensor toward the inside of the concrete, then connect the interface of the conductive ceramic resistor sensor with a wire, and lay it along the steel bars to the monitoring interface device;

[0045] Install the monitoring interface device: first install the support frame of the monitoring interface device in a dry area or a location convenient for detection. A part of the support frame is embedded in the concrete, and the rest is exposed to the external environment. The same fixing method as the sensor is used, that is, the support frame is fixed by tying and fixing the support frame by overlapping the extended steel bars on the steel bars;

[0046] The conductive ceramic plate at the monitoring end is installed on the lower side of the support frame, the inner ends of the conductive ceramic plate at the monitoring end are respectively connected to the corresponding wires, and the outer ends are respectively connected to the measuring contacts on the upper side of the support frame through the support frame for monitoring the contacts;

[0047] After the installation of the whole device is completed, the structure is cast; after casting, a multimeter is used to monitor whether the detection circuits of the high resistance position and the low resistance position are normal, and a resistance meter is used to obtain the initial state resistance value; the corrosion depth and corrosion rate are determined by long-term monitoring of the changes in the resistance of the high and low resistance positions.

[0048] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A device for monitoring the corrosion depth of reinforced concrete structures, characterized in that: It includes a conductive ceramic resistance sensor, a monitoring interface device and a wire. The conductive ceramic resistance sensor is placed in the concrete protective layer interval before the structure is cast. The monitoring interface device is set in a dry area or a position convenient for detection. The structure is cast after the installation of the entire device is completed. The conductive ceramic resistance sensor is composed of a steel test piece and a plurality of conductive ceramic plates. The steel test piece has a plurality of different resistance positions. The first interfaces of the plurality of conductive ceramic plates are respectively connected to the different resistance positions of the steel test piece. A plate protection box is arranged outside the connection part between the first interfaces of the plurality of conductive ceramic plates and the different resistance positions of the steel test piece. The second interfaces of the plurality of conductive ceramic plates extend into the concrete and are respectively connected to the monitoring interface device through wires along the steel bar laying direction. The monitoring interface device includes a support frame and a plurality of monitoring-end conductive ceramic plates. The support frame includes an embedded part embedded in the concrete and an exposed part exposed to the external environment. A plurality of measuring contacts are arranged on the upper side of the exposed part of the support frame. The plurality of monitoring-end conductive ceramic plates are arranged on the lower side of the support frame, and their inner ends are respectively connected to the corresponding wires, and their outer ends are respectively connected to the corresponding measuring contacts through the support frame. The low resistance position of the steel test piece is close to the concrete surface, and the high resistance position is close to the stressed steel bar; The conductive ceramic resistance sensor is fixed by bridging an extended steel bar on the internal steel bars of the structure, and the extended steel bar does not exceed the steel test piece; The conductive ceramic resistance sensor uses the resistance change caused by the change in the cross-sectional area of ​​the steel test piece in the sensor to quantify the corrosion depth. After the sensor is installed, the resistance R0 before corrosion and the resistance R1 after corrosion are measured, and then the corrosion amount is calculated based on the resistance change value ΔR before and after corrosion: （1） Where ΔR is the resistance change of the steel specimen, R0 is the original resistance value, R1 is the resistance value after corrosion, M0 is the original mass, M1 is the mass after corrosion, A0 is the cross-sectional area of ​​the original steel specimen, and A1 is the cross-sectional area of ​​the steel specimen after corrosion. The corrosion amount is calculated according to formula (1).

2. A reinforced concrete structure corrosion depth monitoring device according to claim 1, characterized in that: The first interface of the conductive ceramic plate is connected to different resistance positions of the steel test piece through a screw buckle; the second interface of the conductive ceramic plate is connected to the wire through a screw buckle; the outer end of the conductive ceramic plate at the monitoring end is connected to the measuring contact through a screw buckle.

3. A reinforced concrete structure corrosion depth monitoring device according to claim 2, characterized in that: The conductive ceramic plate of the conductive ceramic resistor sensor, the conductive ceramic plate at the monitoring end of the conductive ceramic monitoring interface device and the screw buckle are all made of silicon carbide conductive ceramic material.

4. A reinforced concrete structure corrosion depth monitoring device according to claim 1, characterized in that: The wire is a Teflon wire.

5. The device for monitoring corrosion depth of reinforced concrete structure according to claim 1, characterized in that: The circuit board protection box is filled with epoxy resin to further seal the circuit structure.

6. A reinforced concrete structure corrosion depth monitoring device according to claim 1, characterized in that: The embedded part to the exposed part of the support frame is tilted downward at a set angle to be used for rapid drainage in rainy and snowy weather.

7. A method for using a reinforced concrete structure corrosion depth monitoring device according to any one of claims 1 to 6, characterized in that: It can be used for any part of reinforced concrete structure to be tested. First, before pouring the structure, place the conductive ceramic resistance sensor in the concrete protective layer, and make the low resistance position of the steel test piece close to the concrete surface, and the high resistance position close to the stressed steel bar. An extended steel bar is overlapped on the internal steel bar of the structure to tie and fix the conductive ceramic resistance sensor. The extended steel bar does not exceed the steel test piece. Point the interface of the conductive ceramic resistor sensor toward the inside of the concrete, then connect the interface of the conductive ceramic resistor sensor with a wire, and lay it along the steel bars to the monitoring interface device; Install the monitoring interface device: first install the support frame of the monitoring interface device in a dry area or a location convenient for detection. A part of the support frame is embedded in the concrete, and the rest is exposed to the external environment. The same fixing method as the sensor is used, that is, the support frame is fixed by tying and fixing the support frame by overlapping the extended steel bars on the steel bars; The conductive ceramic plate at the monitoring end is installed on the lower side of the support frame, the inner ends of the conductive ceramic plate at the monitoring end are respectively connected to the corresponding wires, and the outer ends are respectively connected to the measuring contacts on the upper side of the support frame through the support frame for monitoring the contacts; After the installation of the whole device is completed, the structure is cast; after casting, a multimeter is used to monitor whether the detection circuits of the high resistance position and the low resistance position are normal, and a resistance meter is used to obtain the initial state resistance value; the corrosion depth and corrosion rate are determined by long-term monitoring of the changes in the resistance of the high and low resistance positions.

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