Steel bar corrosion monitoring device combined with special-shaped embedded part

Abstract

The utility model discloses a reinforcing steel bar corrosion monitoring device combined with a special-shaped embedded part, which comprises a binding concrete column, an embedded plate arranged below the binding concrete column, a packaging shell arranged below the embedded plate, a U-shaped magnetic core wound with a coil arranged in the packaging shell, a first Hall sensor and a second Hall sensor symmetrically arranged at two ends of the U-shaped magnetic core, and a sensor arranged below the first Hall sensor and the second Hall sensor. The first Hall sensor is connected with the stirrup connecting anchor bar, one end, with the two Hall sensors, of the packaging shell is attached to the embedded plate, the second Hall sensor is connected with the longitudinal bar connecting anchor bar, the two ends of the coil penetrate out of the packaging shell to be connected with the direct-current power source, and the output ends of the two Hall sensors are electrically connected with the data processing unit. Stable magnetic field excitation is provided under the condition of constant coil turns and current, the two Hall sensors respectively collect magnetic field information and output corresponding Hall voltage, the corrosion rate is calculated through the data processing unit, and the defects and blank of an existing steel bar corrosion monitoring method can be made up through the steel bar corrosion monitoring device.

Description

Technical Field

[0001] The utility model relates to the field of construction engineering, in particular to a steel bar corrosion monitoring device combined with special-shaped embedded parts. Background Art

[0002] Since cement was invented in 1824, concrete has become the world's most widely used building material. Due to its abundant raw materials, simple production process, low cost, and high compressive strength, it is widely used in industrial and civil construction, bridges, tunnels, and other civil engineering fields. In 1991, the Second International Conference on Concrete Durability highlighted chloride erosion leading to steel corrosion as the most serious and common durability problem in concrete structures.

[0003] Rebar corrosion not only reduces the load-bearing capacity of reinforced concrete structures, but also reduces the effective cross-sectional area of ​​the steel bars and the bond strength between the steel and concrete. Therefore, quantifying and monitoring the extent of rebar corrosion in reinforced concrete structures is crucial for developing rational maintenance plans and ensuring the safety of reinforced concrete structures.

[0004] Currently, there are two types of monitoring methods for steel corrosion: destructive testing and non-destructive testing. Destructive testing provides more accurate measurements, but requires dismantling the reinforced concrete structure to remove the rebar, which causes irreversible damage and is not suitable for reinforced concrete structures currently in service. Non-destructive testing methods are currently a hot topic of research, primarily including half-cell potential testing, acoustic emission technology, and built-in monitoring techniques. The half-cell potential method uses the potential change caused by the electrochemical reaction of steel bar corrosion to measure the corrosion status of steel bars. However, its accuracy is low and it can only qualitatively determine the probability of steel bar corrosion, and there is no unified determination standard. Acoustic emission technology, based on parameters such as the cumulative number of impacts, can only qualitatively determine the probability of corrosion occurrence and cannot quantitatively measure the steel bar corrosion rate. Regarding steel bar corrosion monitoring methods based on magnetic field principles, Chinese utility model patent publication number CN109374726A discloses a "Sensor and system for non-destructive dynamic monitoring of steel bar corrosion in concrete based on magnetic fields" and Chinese utility model patent publication number CN208420791U discloses a "device with electromagnetic field-variable response to steel bar corrosion." Both patents provide a steel bar corrosion monitoring sensor embedded in concrete. This sensor can accurately measure the uniformity of steel bar corrosion, but there are still some shortcomings: the embedded monitoring sensor clamps the steel bar, restricting the corrosion expansion of the steel bar and affecting the natural corrosion pattern of the steel bar. Moreover, this sensor can only accurately measure the uniformity of steel bar corrosion, but steel bar corrosion in natural environments often exhibits unevenness. In addition, the sensor built into the concrete can only be used once, which is very expensive. The Chinese utility model patent with publication number CN108469514A discloses "a monitoring device and method for the corrosion behavior of steel bars in concrete". The sensor involved in this patent is an external sensor and has its shortcomings. It cannot connect the magnetic circuits of stirrups and longitudinal bars separately to monitor steel corrosion. It is inconsistent with the actual corrosion monitoring situation of reinforced concrete components and is not targeted. Therefore, the above patents cannot accurately monitor the corrosion of steel bars in reinforced concrete structures.

[0005] In actual construction projects, there is still no sensor or testing method to accurately measure the corrosion rate of such steel bars. Therefore, the utility model proposes a steel bar corrosion monitoring device combined with special-shaped embedded parts to achieve accurate corrosion monitoring of steel bars in reinforced concrete structures. Utility Model Content

[0006] In view of the problems existing in the prior art, the purpose of the present utility model is to provide a steel bar corrosion monitoring device combined with special-shaped embedded parts. The method of the present utility model has high stability, simple operation, can monitor steel bar corrosion for stirrups and longitudinal bars, and can jointly realize in-situ and dynamic movement testing.

[0007] To achieve the above purpose, the technical solution of the utility model is as follows:

[0008] A steel bar corrosion monitoring device combined with special-shaped embedded parts includes a tied concrete column, an embedded plate is provided below the tied concrete column, the anchor bars connected to the stirrups and the anchor bars connected to the longitudinal bars in the tied concrete column are all connected to the embedded plate by welding, an encapsulation shell is provided below the embedded plate, a U-shaped magnetic core with a coil wound therein is provided inside the encapsulation shell, a first Hall sensor and a second Hall sensor are symmetrically provided at both ends of the U-shaped magnetic core, the first Hall sensor is connected to the anchor bars connected to the stirrups, one end of the encapsulation shell with the two Hall sensors is in contact with the embedded plate, the second Hall sensor is connected to the anchor bars connected to the longitudinal bars, the two ends of the coil pass through the encapsulation shell and are connected to a DC power supply, the output ends of the two Hall sensors are respectively electrically connected to a data processing unit.

[0009] Furthermore, the data processing unit includes a signal collector, a signal processor and a central controller electrically connected in sequence, the input end of the signal collector is electrically connected to the signal output ends of the two Hall sensors, the signal collector is electrically connected to the signal processor, and the signal processor is electrically connected to the central controller.

[0010] Furthermore, a signal light is installed between the signal collector and the first Hall sensor and the second sensor.

[0011] Furthermore, the anchor bars connected to the stirrups are straight sections, the length of which is generally the thickness of the concrete cover, and are at the same elevation as the location of the stirrups to be measured. The anchor bars connected to the stirrups and the stirrups to be measured form a magnetic circuit to monitor the corrosion of the stirrups to be measured.

[0012] Furthermore, the anchor bar connected to the longitudinal reinforcement has a straight section and a bent section. The straight section passes through the stirrup to be measured and then is connected to the magnetic circuit of the longitudinal reinforcement to be measured through the bent section. The anchor bar connected to the longitudinal reinforcement and the longitudinal reinforcement to be measured form a magnetic circuit to monitor stirrup corrosion.

[0013] Furthermore, the anchor bars connected to the longitudinal bars and the stirrups to be measured are located at different elevations.

[0014] Furthermore, the anchor bars connecting the embedded plate to the stirrups and the anchor bars connecting the longitudinal bars are welded by perforation plug welding.

[0015] Furthermore, the U-shaped magnetic core is made of silicon steel, the packaging shell is made of plastic, and the packaging shell includes a shell body and a cover body, wherein a U-shaped magnetic core placement groove is provided inside the shell body, and the U-shaped magnetic core is placed in the magnetic core placement groove.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1) Based on the principle of magnetic medium, this utility model uses a coil, a DC power supply, and a magnetic core to form an electromagnet excitation. It also uses special-shaped embedded anchor bars to form a magnetic circuit with the stirrups and longitudinal steel bars. The electromagnetic force generated by the electromagnet is interconnected with the electromagnetic force formed by the embedded parts. At the same time, it uses the difference in magnetic permeability of the concrete cover, air, and steel bars as a principle to monitor steel corrosion, breaking through the limitations of traditional testing methods in terms of test stability, accuracy, and number of uses.

[0018] 2) The method for monitoring steel corrosion using the device of the utility model is highly stable and easy to operate. It can monitor steel corrosion on both stirrups and longitudinal bars, and can realize both in-situ and dynamic movement testing. This allows the device to perform both in-situ and dynamic testing, breaking through the limitations of traditional testing methods in terms of test stability, accuracy, and number of uses. The testing method is applicable to both reinforced concrete columns and reinforced concrete beams. The measured steel corrosion results can be used in safety assessments of construction projects.

[0019] 3) The device of this utility model has the advantages of easy fixation, clear principle, simple method, fast measurement speed, repeated use and good stability, etc., which can make up for the shortcomings and gaps of existing steel corrosion monitoring methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the top view of the structure of the device of the utility model applied to the working test of reinforced concrete columns;

[0021] Figure 2 This is a schematic diagram of the test structure of the device of the utility model applied to a working test of a reinforced concrete column;

[0022] Figure 3 This is a schematic structural diagram of the U-shaped magnetic core of the utility model;

[0023] Figure 4 This is a side view of the special-shaped embedded part of the utility model;

[0024] Figure 5 This is a schematic diagram of the connection between the anchor bars and the embedded plate connected with the stirrups of the utility model;

[0025] Figure 6 This is a schematic diagram of welding the anchor bars and embedded plates connected to the stirrups of the utility model;

[0026] Figure 7 Schematic diagram of the connection between the anchor bars and the embedded plate connected to the longitudinal bars of the utility model;

[0027] Figure 8 Schematic diagram of welding the anchor bars and embedded plates connected to the longitudinal bars of this utility model

[0028] Reference numerals in the figure: 1. longitudinal reinforcement to be measured; 2. stirrups to be measured; 3. embedded plate; 4-1. anchor bars connected to stirrups; 4-2. anchor bars connected to longitudinal reinforcement; 5-1. first Hall effect sensor; 5-2. second Hall effect sensor; 6. U-shaped magnetic core; 7. packaging shell; 8. coil; 9. signal light; 10. signal collector; 11. signal processor; 12. central controller; 13. DC power supply. DETAILED DESCRIPTION

[0029] The following is further described with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to the scope described above.

[0030] Please refer to Figure 1 A steel bar corrosion monitoring device combined with special-shaped embedded parts includes a tied concrete column 14, an embedded plate 3 is provided under the tied concrete column 14, the anchor bars 4-1 connected to the stirrups and the anchor bars 4-2 connected to the longitudinal bars in the tied concrete column 14 are both connected to the embedded plate 3 by welding, and an encapsulation shell 7 is provided under the embedded plate 3, and a U-shaped magnetic core 6 with a coil 8 wound therein is provided inside the encapsulation shell 7, a first Hall sensor 5-1 and a second Hall sensor 5-2 are symmetrically provided at both ends of the U-shaped magnetic core 6, the first Hall sensor 5-1 is connected to the anchor bar 4-1 connected to the stirrups, and one end of the encapsulation shell 7 with the two Hall sensors is in contact with the embedded plate 3.

[0031] The second Hall sensor 5-2 is connected to the longitudinal reinforcement and the anchor reinforcement 4-2. Both ends of the coil 8 pass through the packaging shell 7 and are connected to the DC power supply 13. The output ends of the two Hall sensors are electrically connected to the data processing unit respectively.

[0032] A DC power supply 13, coil 8, and U-shaped magnetic core 6 form an electromagnet, providing a stable magnetic field excitation at a constant coil number and current. Two Hall sensors collect magnetic field information and output corresponding Hall voltages, which are then calculated using the data processing unit to determine the corrosion rate. Based on the principle of magnetic media, the present utility model utilizes coil 8, DC power supply 13, and U-shaped magnetic core 6 to form an electromagnet excitation. Special-shaped embedded anchor bars form a magnetic circuit with the stirrups and longitudinal reinforcement, respectively. The electromagnetic force generated by the electromagnet is interconnected with the electromagnetic force generated by the embedded bars. Furthermore, the utility model utilizes the difference in magnetic permeability between the concrete cover, air, and reinforcement to monitor reinforcement corrosion, thus overcoming the limitations of traditional testing methods in terms of test stability, accuracy, and number of uses.

[0033] There is no air or concrete gap between the embedded plate 3 of the embedded part and the electromagnet. The embedded plate 3 and the electromagnet are directly attracted by electromagnetic force. Iron and iron are in direct contact, so there is no gap and the magnetic resistance is small. The electromagnetic force generated can effectively connect the embedded part 3 and the electromagnet, thereby achieving a fixing effect, reducing the loss of magnetic signals to a certain extent, and enhancing the accuracy of corrosion monitoring.

[0034] Please refer to Figure 2 The data processing unit includes a signal collector 10, a signal processor 11 and a central controller 12 which are electrically connected in sequence. The input end of the signal collector 10 is electrically connected to the signal output ends of the two Hall sensors, the signal collector 10 is electrically connected to the signal processor 11, and the signal processor 11 is electrically connected to the central controller 12.

[0035] A signal light 9 is installed between the signal collector 10 and the first Hall sensor 5-1 and the second Hall sensor 5-2. The indicator light prompts whether the signal collector 10, the first Hall sensor 5-1 and the second Hall sensor 5-2 are working normally.

[0036] Please refer to Figure 5-Figure 7 The anchor bar 4-1 connected to the stirrup is a straight section, and its length is generally the thickness of the concrete cover. The thickness of the concrete cover refers to the thickness from the outermost steel bar to the outer edge of the concrete. It is at the same elevation as the location of the stirrup 2 to be tested. The anchor bar 4-1 connected to the stirrup and the stirrup 2 to be tested form a magnetic circuit to monitor the corrosion of the stirrup 2 to be tested.

[0037] The longitudinal reinforcement anchor bar 4-2 has a straight section and a curved section. The straight section passes through the stirrup bar 2 to be tested, and then through the curved section to connect magnetically to the longitudinal reinforcement 1 to be tested. This forms a magnetic circuit with the longitudinal reinforcement 1 to be tested, enabling stirrup corrosion monitoring. The longitudinal reinforcement anchor bar 4-2 and the stirrup bar 2 to be tested are located at different elevations.

[0038] Please refer to Figure 8 The welding method of the anchor bar 4-1 connecting the embedded plate 3 to the stirrups and the anchor bar 4-2 connecting the longitudinal bars is perforation plug welding to avoid uneven fillet welds causing magnetic field signal disorder and affecting the steel corrosion monitoring results.

[0039] Please refer to Figure 3 The U-shaped magnetic core 6 is made of silicon steel, and the packaging shell 7 is made of plastic. The packaging shell 7 includes a shell body and a cover body, wherein a U-shaped magnetic core placement groove is provided inside the shell body, and the U-shaped magnetic core 6 is placed in the magnetic core placement groove. Example 1

[0040] Taking the 500×500 concrete column in the project as an example, the embedded part size is 200×200. The specific implementation steps are as follows:

[0041] S1: First, connect the stirrup-connected anchor bar 4-1 and the embedded plate 3, and the longitudinal reinforcement-connected anchor bar 4-2 and the embedded plate 3 by punching and plug welding.

[0042] S2: Then tie the longitudinal reinforcement 1 and stirrup 2 to be tested of the concrete column 14, place the stirrup-connected anchor bar 4-1 and the stirrup 2 to be tested on the same elevation and connect them to the embedded plate 3, and place the longitudinal reinforcement-connected anchor bar 4-2, the embedded plate 3, and the stirrups on different elevations (to prevent collision) and connect them to the longitudinal reinforcement 1;

[0043] S3: Then pour the concrete column;

[0044] S4: Bind the U-shaped magnetic core 6 with the coil 8 and encapsulate it with the first Hall sensor 5-1 and the second Hall sensor 5-2 in the encapsulation housing 7. Connect the two Hall sensors to the data processing unit and connect the coil 8 to the DC power supply 13.

[0045] S5: Place one end of the package housing 7 with the two Hall sensors in contact with the embedded plate 3. Power is supplied to the electromagnet composed of the DC power supply 13, coil 8, and U-shaped magnetic core 6. A stable magnetic field excitation is provided at a constant number of turns and current of the coil 8. This magnetic field is connected to the embedded plate 3 to form an electromagnetic attraction, magnetically connecting the test system to the embedded plate 3. Simultaneously, the acquisition frequency of the signal collector 10 is controlled by the central controller 12. The Hall sensors 5-1 and 5-2 are powered on to test and ensure that the two Hall sensors are performing normal acquisition work.

[0046] S6: After the embedded plate 3 is coated with high-strength corrosion-resistant material, the Hall voltages of the two Hall sensors under a certain stable magnetic field are recorded as V 1I , V 2I ;

[0047] S7: Disconnect the power supply and allow the reinforced concrete components to rust under natural conditions;

[0048] S8: After natural corrosion occurs, repeat steps S1-S5 to perform in-situ detection and record the Hall voltages of the two Hall sensors after the reinforced concrete component is corroded. 1II , V 2II ;

[0049] S9: Preliminary laboratory testing and simulation of the linear fitting coefficient α between the Hall voltage ▲Va and the longitudinal reinforcement corrosion rate ▲La and the stirrup corrosion rate ▲Lb, and then the Hall voltage V before and after the corrosion is measured. 1II , V 2II , V 1I , V 2I , the average corrosion rates ▲La and ▲Lb are obtained, and the calculation formulas are shown in formulas (1) and (2):

[0050] ▲La=α(V 1II -V 1I ) (1)

[0051] ▲Lb=α(V 2II -V2I ) (2)。

Claims

1. A steel bar corrosion monitoring device combined with special-shaped embedded parts, comprising a tied concrete column (14), an embedded plate (3) is provided below the tied concrete column (14), and the anchor bars (4-1) connected to the stirrups and the anchor bars (4-2) connected to the longitudinal bars in the tied concrete column (14) are connected to the embedded plate (3) by welding, characterized in that A packaging shell (7) is provided below the embedded plate (3), and a U-shaped magnetic core (6) wound with a coil (8) is provided inside the packaging shell (7). A first Hall sensor (5-1) and a second Hall sensor (5-2) are symmetrically provided at both ends of the U-shaped magnetic core (6), and the first Hall sensor (5-1) is connected to the anchor bar (4-1) connected to the stirrups. One end of the packaging shell (7) with the two Hall sensors is in contact with the embedded plate (3), and the second Hall sensor (5-2) is connected to the anchor bar (4-2) connected to the longitudinal bars. Both ends of the coil (8) pass through the packaging shell (7) and are connected to a DC power supply (13), and the output ends of the two Hall sensors are respectively electrically connected to a data processing unit.

2. A steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 1, characterized in that The data processing unit comprises a signal collector (10), a signal processor (11) and a central controller (12) which are electrically connected in sequence, wherein the input end of the signal collector (10) is electrically connected to the signal output ends of the two Hall sensors, the signal collector (10) is electrically connected to the signal processor (11), and the signal processor (11) is electrically connected to the central controller (12).

3. A steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 2, characterized in that A signal light (9) is installed between the signal collector (10), the first Hall sensor (5-1), and the second Hall sensor (5-2).

4. The steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 1 is characterized in that The stirrup-connected anchor bar (4-1) is a straight section, the length of which is generally the thickness of the concrete cover, and the stirrup (2) to be tested is at the same elevation. The stirrup-connected anchor bar (4-1) and the stirrup (2) to be tested form a magnetic circuit to monitor the corrosion of the stirrup (2) to be tested.

5. The steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 1 is characterized in that The longitudinal reinforcement-connected anchor bar (4-2) has a straight section and a bent section. The straight section passes through the stirrup bar (2) to be tested and then is connected to the longitudinal reinforcement (1) to be tested through the bent section. The longitudinal reinforcement-connected anchor bar (4-2) and the longitudinal reinforcement (1) to be tested form a magnetic circuit to monitor stirrup corrosion.

6. A steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 5, characterized in that The anchor bars (4-2) connected to the longitudinal bars and the stirrups (2) to be measured are located at different elevations.

7. The steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 1 is characterized in that The embedded plate (3) is welded to the anchor bars (4-1) connected to the stirrups and the anchor bars (4-2) connected to the longitudinal bars by perforation plug welding.

8. The steel bar corrosion monitoring device combined with special-shaped embedded parts according to claim 1 is characterized in that The U-shaped magnetic core (6) is made of silicon steel, the packaging shell (7) is made of plastic, and the packaging shell (7) comprises a shell body and a cover body, wherein a U-shaped magnetic core placement groove is provided inside the shell body, and the U-shaped magnetic core (6) is placed in the magnetic core placement groove.

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