A buried concrete structure monitoring device and method

Abstract

The application discloses a kind of buried concrete structure monitoring device and method, including substrate, hollowly arranged lead tube being passed through middle part of substrate;Strain resistance wire, fixedly arranged on the upper surface of substrate, two ends of strain resistance wire pass through the wall of lead tube, and from the upper end of lead tube and detection mechanism electrically connected;Excitation coil, sleeve joint is on the steel bar to be measured, two ends of excitation coil are along the sidewall of steel bar and go out and detection mechanism electrically connected upwards;Induction coil, fixedly built-in in lead tube, with excitation coil height flush, two ends of the induction coil pass through the wall of lead tube, and from the upper end of lead tube and detection mechanism electrically connected;Through the combination of excitation coil and induction coil, the corrosion of steel bar in concrete can be monitored, the combination of crack monitoring and corrosion monitoring can realize the monitoring of concrete durability.

Description

Technical Field

[0001] This invention relates to the field of building engineering, and in particular to an underground concrete structure monitoring device and method. Background Technology

[0002] With economic development, the durability of concrete structures is attracting increasing attention. The main factors affecting concrete structures are biological corrosion sources, freeze-thaw damage, and physicochemical effects. Under the combined action of these three factors, concrete components may deform, weather and erode, the effective load-bearing structure may deform and its load-bearing capacity may decrease, and even interface peeling may occur, which greatly affects the service life of concrete structures.

[0003] Buried concrete structures mainly include underground box culverts and underground water storage tanks. These concrete structures are exposed to harsh environments with various physical, chemical, and biological corrosive sources for a long time, making the concrete prone to weathering and erosion, which reduces its strength. Therefore, it is necessary to conduct regular strength tests on buried concrete structures.

[0004] Currently, the common practice for testing the strength of buried concrete components is to excavate a large area of ​​the soil covering the slab, and then conduct strength tests on the exposed concrete surface. Backfilling is required after testing, which is time-consuming, labor-intensive, and costly. Furthermore, existing testing methods can only perform fixed-point tests and cannot provide real-time monitoring of the concrete structure. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of inconvenience in the detection of buried concrete and the inability to monitor in real time, and to provide a device and method for monitoring buried concrete structures.

[0006] An underground concrete structure monitoring device, comprising

[0007] substrate,

[0008] A hollow conduit that penetrates the middle of the substrate;

[0009] The strain resistance wire is fixedly mounted on the upper surface of the substrate. The two ends of the strain resistance wire pass through the wall of the lead tube and exit from the upper end of the lead tube to be electrically connected to the detection mechanism.

[0010] An excitation coil is sleeved on the steel bar to be tested, and both ends of the excitation coil extend upward along the side wall of the steel bar and are electrically connected to the testing mechanism.

[0011] An induction coil is fixedly built into a conduit, at the same height as the excitation coil. Both ends of the induction coil pass through the conduit wall and emerge from the top of the conduit to be electrically connected to the detection mechanism.

[0012] Furthermore, the detection mechanism includes a crack detection component, a corrosion detection component, a controller, and a wireless transmission module;

[0013] The crack detection component includes

[0014] A DC power supply is connected to both ends of the strain gauge wire.

[0015] The first ammeter is installed between the DC power supply and the strain gauge wire to measure the current change of the strain gauge wire; the first ammeter is electrically connected to the wireless transmission module to transmit the current data to the terminal.

[0016] The first on / off switch is located between the first ammeter and the DC power supply, and is electrically connected to the controller to control the closing of the crack detection circuit;

[0017] The corrosion detection component includes

[0018] An alternating current source is connected to both ends of the excitation coil;

[0019] The second ammeter is connected to the induction coil and is used to measure the current change of the induction coil; the second ammeter is electrically connected to the wireless transmission module to transmit the current data to the terminal.

[0020] The second on / off switch is located between the alternating current source and the excitation coil, and is electrically connected to the controller to control the closure of the corrosion detection circuit.

[0021] Furthermore, the conduit includes a tube body, the upper end of which is provided with a tube sleeve; the lower end of the tube body passes through the substrate and is integrally provided with a tube nozzle; a storage part is provided in the middle of the tube body, and the induction coil is disposed in the storage part.

[0022] Furthermore, the strain resistance wires are configured in multiple groups and arranged radially on the substrate.

[0023] Furthermore, the excitation coil is provided in multiple sets, which are respectively installed on the reinforcing bars in the buried concrete.

[0024] A monitoring method for buried concrete structures, including crack detection and corrosion detection.

[0025] The crack detection includes

[0026] The controller controls the first open to close, forming a crack detection circuit. At this time, the first ammeter measures the current of the strain resistance wire and transmits the data to the terminal through the wireless transmission module.

[0027] The corrosion detection includes

[0028] The controller controls the second switch to open and close. At this time, the alternating current passes through the excitation coil, which generates a magnetic field. Under the action of the magnetic field, the induction coil generates an induced current. The second ammeter measures the induced current and transmits the data to the terminal through the wireless transmission module.

[0029] The beneficial effects of this invention are:

[0030] 1. By attaching a strain gauge wire to the inside of buried concrete, when cracks occur inside the concrete, the resistance of the strain gauge wire changes. The resistance of the strain gauge wire can be measured by a first ammeter to determine the crack condition inside the concrete. By combining an excitation coil and an induction coil, the corrosion of the steel reinforcement inside the concrete can be monitored. Combining crack monitoring and corrosion monitoring can achieve the monitoring of concrete durability.

[0031] 2. By optimizing the design of the device, real-time monitoring of the internal structure of concrete can be achieved without large-scale excavation, saving testing procedures, improving the convenience of testing, and enabling dynamic monitoring with high timeliness. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the device;

[0033] Figure 2 This is a top view of the device's structure.

[0034] Figure 3 This is a schematic diagram of the structure of surface AA;

[0035] Figure 4 This is a schematic diagram of the detection circuit;

[0036] In the figure, 1-substrate, 11-through hole, 2-conductor, 21-tube body, 22-tube sleeve, 23-storage part, 24-nozzle, 3-strain resistance wire, 4-excitation coil, 5-detection mechanism, 6-induction coil, 7-crack detection component, 71-DC power supply, 72-first ammeter, 73-first on / off switch, 8-corrosion detection component, 81-alternating current source, 82-second ammeter, 83-second on / off switch, 9-wireless transmission module, 10-controller. Detailed Implementation

[0037] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0038] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0039] Example 1

[0040] like Figures 1-4 As shown, an underground concrete structure monitoring device includes a base plate 1, which is specifically a plate structure made of hydrogel or other strain gauge bonding material. Preferably, the shape of the base plate 1 can be circular or square.

[0041] To facilitate installation, multiple through holes 11 are provided on the surface of the substrate 1 for passing through the reinforcing bars.

[0042] A hollow conduit 2 is provided that penetrates the middle of the substrate 1; the conduit 2 is made of a hollow tube of corrosion-resistant material and the size of the tube is as small as possible so as not to affect the structural strength of the buried concrete.

[0043] The detection mechanism 5 includes a crack detection component 7, a corrosion detection component 8, a controller 10, and a wireless transmission module 9;

[0044] The crack detection component 7 includes a DC power supply 71 connected to both ends of the strain resistance wire 3; a first ammeter 72 installed between the DC power supply 71 and the strain resistance wire 3 for measuring the current change of the strain resistance wire 3; the first ammeter 72 is electrically connected to the wireless transmission module 9 to transmit the current data to the terminal; by attaching the strain resistance wire 3 to the inside of the buried concrete, when cracks occur inside the concrete, the resistance value of the strain resistance wire changes, and the resistance value of the strain resistance wire can be measured by the first ammeter 72 to determine the crack condition inside the concrete.

[0045] Specifically, the strain gauge wire 3 is fixedly attached to the upper surface of the substrate 1. Both ends of the strain gauge wire 3 pass through the wall of the conduit 2 and exit from the upper end of the conduit 2, electrically connecting to the detection mechanism 5. Since the strain gauge wire 3 is fixedly attached to the upper surface of the substrate 1, when cracks appear in the concrete, the strain gauge wire 3 on the substrate 1 is stretched, causing a change in resistance. When a constant voltage is applied, the current changes. That is, by monitoring the change in the current flowing through the strain gauge wire 3, the phenomenon of concrete cracking can be detected.

[0046] Another approach, in order to increase the accuracy and range of monitoring, usually selects multiple strain resistance wires 3 and arranges them radially on the substrate 1. The multiple strain resistance wires 3 are connected in parallel as a whole. Each strain resistance wire 3 is equipped with a corresponding first ammeter 72. By monitoring the value change of the first ammeter 72, the generation of cracks at different locations can be realized.

[0047] The corrosion detection component 8 includes an alternating current source 81 connected to both ends of the excitation coil 4; a second ammeter 82 connected to the induction coil 6 for measuring current changes in the induction coil 6; the second ammeter 82 is electrically connected to a wireless transmission module 9 to transmit current data to a terminal; and a second on / off switch 83, located between the alternating current source 81 and the excitation coil 4, and electrically connected to a controller 10 to control the closure of the corrosion detection circuit. By combining the excitation coil 4 and the induction coil 6, the corrosion of steel reinforcement inside concrete can be monitored.

[0048] Specifically, the excitation coil 4 is sleeved on the steel bar to be tested. Both ends of the excitation coil 4 extend upwards along the side wall of the steel bar and are electrically connected to the detection mechanism 5. In use, the alternating current source 81 is connected to the excitation coil 4, generating a magnetic field. Since the magnetic field generated by the alternating current source is variable, the induction coil 6 receives the variable magnetic field and generates an induced current. Note that to ensure corrosion of the sleeved steel bar, there should be a certain gap between the turns of the excitation coil 4. The induction coil 6 is fixedly built into the conduit 2, flush with the height of the excitation coil 4. Both ends of the induction coil 6 pass through the wall of the conduit 2 and extend out from the top of the conduit 2, electrically connected to the detection mechanism 5. The first on / off switch 73 is located between the first ammeter 72 and the DC power supply 71, and is electrically connected to the controller 10 to control the closure of the crack detection circuit.

[0049] Specifically, the magnetic field generated by excitation coil 4 ,in, The relative permeability, The magnetic field strength is the value of the magnetic field attached to the reinforcing bar. This refers to the magnetic field strength in the air. Since uncorroded steel bars are primarily composed of Fe, their relative permeability is typically between 200 and 400. When corrosion occurs, rust (Fe₂O₃) forms, and the material becomes a mixture of iron and rust. Consequently, the relative permeability decreases. Therefore, the magnitude of the magnetic field B generated under the action of excitation coil 4 differs depending on whether the steel bar is corroded. For induction coil 6... Where E is the electromotive force of induction coil 6, t represents time, and S represents the area of ​​induction coil 6. That is, when the relative permeability changes, The value also changed, due to Since t and S are constants, the electromotive force E will increase, meaning the current generated in induction coil 6 will also change. This change in current represents the change in relative permeability, which is then used to demonstrate corrosion of the steel reinforcement surface.

[0050] On the other hand, in order to monitor multiple reinforcing bars within the concrete, an induction coil 6 is installed on each reinforcing bar. By cyclically powering multiple induction coils 6, the degree of corrosion of multiple reinforcing bars can be monitored. Specifically, the controller 10 controls the first second on / off switch 83 to close, while the other second on / off switches 83 are open, to monitor the degree of corrosion of the first reinforcing bar. Then, the first second on / off switch 83 is opened, and the second second on / off switch 83 is closed, and so on, to monitor the corrosion status of different reinforcing bars.

[0051] To achieve precise corrosion monitoring of buried concrete, several of these devices can be stacked and combined to achieve multi-level monitoring at different heights. Specifically: the conduit 2 includes a tube body 21, with a sleeve 22 at the upper end; the lower end of the tube body 21 passes through the base plate 1 and is integrally provided with a nozzle 24; a storage section 23 is provided in the middle of the tube body 21, and the induction coil 6 is disposed in the storage section 23. In use, the nozzle 24 of the previous device is inserted into the sleeve 22 of the next device.

[0052] This device has two installation methods.

[0053] The first method involves placing the entire device on the upper surface of a concrete structure, wherein the substrate 1 is glued to the surface of the concrete structure using gel, and the excitation coil 4 is sleeved on the reinforcing steel extending from the concrete.

[0054] The second method involves installing the device during the manufacturing process of the buried concrete structure. Initially, the structure consists of a frame structure made of reinforcing steel and surrounding panels. Concrete is first poured into this structure, and after reaching a certain height, the device is installed on the surface of the uncured concrete. Then, more concrete is poured to install the device inside the buried concrete structure.

[0055] Specifically, the installation method of the device follows the principle that the excitation coil 4 is sleeved on the steel bar and the base plate 1 is attached to the concrete curing surface. As for how to place, install and fix it, these are not the contents that need to be protected in this plan.

[0056] Example 2

[0057] A monitoring method for buried concrete structures, including crack detection and corrosion detection.

[0058] The crack detection includes

[0059] The controller 10 controls the first on / off switch 73 to close, forming a crack detection circuit. At this time, the first ammeter 72 measures the current of the strain resistance wire 3 and transmits the data to the terminal through the wireless transmission module 9.

[0060] The corrosion detection includes

[0061] The controller 10 controls the second on / off switch 83 to close. At this time, the alternating current passes through the excitation coil 4, which generates a magnetic field. Under the action of the magnetic field, the induction coil 6 generates an induced current. The second ammeter 82 measures the induced current and transmits the data to the terminal through the wireless transmission module 9.

[0062] By optimizing the design of the device, real-time monitoring of the internal structure of concrete can be achieved without large-scale excavation, saving testing procedures, improving the convenience of testing, and enabling dynamic monitoring with high timeliness.

[0063] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A buried concrete structure monitoring device, characterized in that: include base plate (1), A hollow conduit (2) that penetrates the middle of the substrate (1); The strain resistance wire (3) is attached and fixed on the upper surface of the substrate (1). The two ends of the strain resistance wire (3) pass through the wall of the wire tube (2) and pass out from the upper end of the wire tube (2) to be electrically connected to the detection mechanism (5). The excitation coil (4) is sleeved on the steel bar to be tested, and the two ends of the excitation coil (4) pass through the side wall of the steel bar and are electrically connected to the detection mechanism (5); The induction coil (6) is fixedly built into the conductor tube (2) and is level with the excitation coil (4). The two ends of the induction coil (6) pass through the tube wall of the conductor tube (2) and come out from the upper end of the conductor tube (2) to be electrically connected to the detection mechanism (5). The detection mechanism (5) includes a crack detection component (7), a corrosion detection component (8), a controller (10), and a wireless transmission module (9). The crack detection component (7) includes A DC power supply (71) is connected to both ends of the strain gauge wire (3); The first ammeter (72) is installed between the DC power supply (71) and the strain resistance wire (3) to measure the current change of the strain resistance wire (3); the first ammeter (72) is electrically connected to the wireless transmission module (9) to transmit the current data to the terminal; The first on / off switch (73) is set between the first ammeter (72) and the DC power supply (71), and is electrically connected to the controller (10) to control the closing of the crack detection circuit; The corrosion detection component (8) includes An alternating current source (81) is connected to both ends of the excitation coil (4); The second ammeter (82) is connected to the induction coil (6) and is used to measure the current change of the induction coil (6); the second ammeter (82) is electrically connected to the wireless transmission module (9) to transmit the current data to the terminal; The second on / off switch (83) is set between the alternating current source (81) and the excitation coil (4), and is electrically connected to the controller (10) to control the closing of the corrosion detection circuit; The conduit (2) includes a tube body (21), and a tube sleeve (22) is provided at the upper end of the tube body (21); the lower end of the tube body (21) passes through the substrate (1) and is integrally provided with a nozzle (24); a storage part (23) is provided in the middle of the tube body (21), and the induction coil (6) is disposed in the storage part (23); The strain resistance wires (3) are arranged in multiple groups and radially arranged on the substrate (1); The excitation coil (4) is provided in multiple sets, which are respectively set on the steel bars in the buried concrete.

2. A method for monitoring buried concrete structures, characterized in that: This includes using the monitoring device described in claim 1 for crack detection and corrosion detection. The crack detection includes The controller (10) controls the first on / off switch (73) to close, forming a crack detection circuit. At this time, the first ammeter (72) measures the current of the strain resistance wire (3) and transmits the data to the terminal through the wireless transmission module (9). The corrosion detection includes The controller (10) controls the second on / off switch (83) to close. At this time, the AC current passes through the excitation coil (4), the excitation coil (4) generates a magnetic field, and the induction coil (6) generates an induced current under the action of the magnetic field. The second ammeter (82) measures the induced current and transmits the data to the terminal through the wireless transmission module (9).

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