Visual detection method of concrete crack depth indicator tracer radar

Abstract

The present invention discloses a concrete crack depth indicator tracing radar visualization detection method, which relates to the technical field of concrete crack depth detection; the detection method comprises the following steps: determining the amount of indicator for single injection in each stage; performing single injection of the indicator in each stage, during which the radar antenna moves relatively back and forth across the crack on the surface of the concrete crack, and emitting radar waves to the deep part of the concrete crack in real time; controlling the duration of single injection, observing the real-time radar pseudo-color image during the injection, and when the indication signal in the radar pseudo-color image disappears, injecting the indicator in the next stage; circulating the single injection of the indicator until the indicator reaches the deep tip of the concrete crack; emitting radar waves of corresponding incident angles in sequence, and recording the position information of the indicator indication signal in the radar pseudo-color image respectively; and obtaining the depth of the tip position of the concrete crack marked by the indicator. The present invention designs the indicator injection amount and the relay injection method to improve the accuracy of crack depth detection.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete crack depth detection, and in particular relates to a concrete crack depth indicator tracer radar visualization detection method. Background Art

[0002] Crack depth is a direct indicator of the risk of concrete cracking. However, since cracks are distributed inside the concrete structure along the depth direction, and the closer to the deep tip, the smaller the crack width, it is very difficult to accurately detect the crack depth. The currently widely used ultrasonic depth measurement method is also limited to the detection of concrete crack depth within 500mm deep, and the measurement error is often more than 10%. The lack of crack depth detection capability is an important reason for the long-term characterization of crack destructiveness based on crack width.

[0003] At present, there are few studies on crack depth detection. There is a publicly reported method for detecting crack depth with a publication number of CN102944195A, which discloses a tracer-based electromagnetic radar method for detecting crack depth. This method injects a tracer into the deep tip of the crack. After the injection is completed, radar waves are emitted to the concrete crack area. The tracer accumulated at the bottom of the crack is clearly displayed on the radar scanning image, so the position of the bottom of the crack can be determined, and the depth of the crack can be obtained. However, this method cannot realize the visualization of the injection process, and it is not clear whether the tracer has been injected to the tip of the crack; in addition, for the situation where the crack tip angles are different in actual engineering, there is a lack of effective detection and response methods to ensure the accuracy of depth detection.

[0004] A method and device for judging the trend of the tip of a concrete oblique crack with publication number CN116337895A discloses a method for the trend of the tip of an oblique crack in concrete, by recording the position and depth of the first fluctuation point on the radar development map, rotating a number of new measurement lines with the first measurement line as the reference line, obtaining the position and depth of the first fluctuation point of each new measurement line, sorting the fluctuation points according to the measurement line sequence, drawing a connection diagram, obtaining the trend curve of the tip of the oblique crack, combining the measurement method from far to near, multi-angle, multi-measurement point and the reflection law of metal powder to radar waves, measuring the multi-point position and depth of the tip of the concrete oblique crack, and then effectively judging the trend of the crack tip. However, there is an error between the trend curve of the oblique crack tip obtained by drawing a connection diagram and the actual trend of the crack tip, which affects the detection of the deep tip position of the concrete crack.

[0005] In the above detection method, when using the indicator tracer radar for detection, there are several problems that affect the detection of the deep tip position of the concrete crack:

[0006] First, the indicator pouring process is a "black box", and there is no corresponding method to judge whether the indicator has been poured to the tip of the crack. If the indicator does not reach the tip of the crack after the pouring is completed, radar waves are emitted to the concrete crack area, and the indicator uses its own reflection of the radar wave to produce a response signal, then the detection result obtained is not the deepest depth of the crack tip.

[0007] Second, when the indicator is poured, the impact of the amount of indicator poured on the accuracy of depth detection is not considered. When the indicator is poured (especially when the method of full slamming the crack cavity is used), the indicator exists in a large number of fragments of the entire crack cavity, which will cause the radar wave to be reflected by the indicator accumulated in other parts of the crack cavity before reaching the crack tip, affecting the crack depth detection. In addition, when the indicator is poured along the crack cavity, the side wall of the crack cavity is usually attached to the indicator, and the amount of indicator adhesion on the side wall is related to the amount of indicator poured; when the amount of side wall adhesion reaches a certain level, there is also the possibility of interfering with the reflection signal of the crack tip.

[0008] Third, there is also a lack of corresponding judgment methods to determine whether the depth of the indicator detected by the radar is the depth of the crack marked by the indicator. When the indicator is poured to the tip of the crack, because the indicator accumulates at the tip of the crack in a certain volume, when the incident radar wave reaches the indicator, the reflected signal reflects the part of the indicator that first contacts the incident radar wave, resulting in the indicator using its own reflection of the radar wave to produce a response signal. The signal obtained is not the deepest point of the crack tip reached by the indicator, that is, the actual depth of the crack. This point also affects the judgment of the crack depth when the electromagnetic radar method based on the indicator is used to detect the crack depth.

[0009] In view of the above problems, this application proposes a concrete crack depth indicator tracer radar visualization detection method. During the indicator pouring process, the indicator pouring process is visualized by emitting radar waves in real time. On this basis, by proposing a method for judging whether the indicator has been poured to the tip of the deep crack and a method for eliminating the interference of the indicator on the accuracy of radar depth measurement, the visualization of crack depth in the electromagnetic radar field is realized with high efficiency and accuracy. Summary of the invention

[0010] The purpose of the present invention is to provide a concrete crack depth indicator tracer radar visualization detection method to solve the problems of the prior art proposed in the above background technology, such as the influence of the indicator injection amount on the depth detection accuracy when detecting the crack depth by electromagnetic radar method, and the judgment of whether the indicator is injected to the crack tip and whether the response signal is the depth reached by the indicator.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] The concrete crack depth indicator tracer radar visualization detection method comprises the following steps:

[0013] S1. Determine the amount of indicator for single injection in each stage according to the thickness of the object to be tested along the depth direction of the concrete crack;

[0014] S2, a single pouring is performed to pour the indicator from the concrete crack surface to the deep concrete crack. During the pouring process, the radar antenna moves back and forth across the crack on the concrete crack surface. During the movement, the radar antenna is perpendicular to the concrete crack surface and moves toward the deep concrete crack, emitting radar waves to the deep concrete crack in real time;

[0015] S3, controlling the duration of a single pouring, observing the real-time radar pseudo-color image during the pouring process, tracking the indication signal of the indicator in the radar pseudo-color image moving along the concrete crack cavity, and when the indication signal in the radar pseudo-color image disappears, the next stage of pouring the indicator;

[0016] S4, looping steps S2 to S3 until the indicator reaches the deep tip of the concrete crack;

[0017] The criterion for judging whether the indicator reaches the deep tip of the concrete crack is that during the single pouring, the indicator signal in the radar pseudo-color image continues to exist and remains stationary at a certain position within the duration of the single pouring.

[0018] S5. After the indicator reaches the tip of the deep part of the concrete crack, during the recording time, adjust the angle of the radar antenna on the surface of the concrete crack to transmit radar waves to the deep part of the concrete crack, and successively transmit radar waves with corresponding incident angles, and record the position information of the indicator signal in the radar pseudo-color image respectively;

[0019] S6. Read the position information of the indicator signal in the radar pseudo-color image at each incident angle of the radar wave, compare it, and obtain the depth of the tip of the concrete crack marked by the indicator.

[0020] Preferably, the amount of the indicator for a single perfusion in each stage is determined in S1 as follows:

[0021] When the thickness of the tested object along the direction of the concrete crack depth does not exceed 500mm, 5ml of indicator is poured for the first time, 10ml and 20ml for the second and third times respectively, and 20ml for each subsequent time;

[0022] When the thickness of the inspected object along the depth direction of the concrete crack is 500-1500mm, 15ml of indicator is poured for the first time, 15ml for the second time, 30ml for the third time, and 30ml for each subsequent time.

[0023] When the thickness of the tested object along the depth direction of the concrete crack is 1500-3000mm, 30ml of indicator is poured for the first time, 40ml for the second time, and 50ml for each subsequent time;

[0024] When the thickness of the tested object along the direction of the concrete crack depth is greater than 3000mm, 120ml is poured each time.

[0025] Preferably, in S2, the indicator is poured from the surface of the concrete crack to the deep part of the concrete crack, a pouring port is reserved on the surface of the concrete crack, and the indicator is pressed from the pouring port into the deep part of the concrete crack by external pressure.

[0026] Furthermore, a pouring port is reserved on the surface of the concrete crack, the surface of the concrete crack is sealed except for the pouring port, and the indicator is pressed into the deep part of the concrete crack from the pouring port.

[0027] Preferably, in S2, the indicator is poured from the concrete crack surface to the deep concrete crack, a pouring port is reserved on the concrete crack surface to connect with the indicator, and a negative pressure environment is formed in the concrete crack cavity, and the indicator is sucked from the pouring port into the deep concrete crack by the negative pressure.

[0028] Furthermore, a pouring port is reserved on the surface of the concrete crack to connect the indicator, and then the surface of the concrete crack is sealed, and the air in the concrete crack cavity is extracted to create a negative pressure condition in the cavity, so that the indicator is sucked into the deep part of the crack.

[0029] Preferably, the duration of a single perfusion in S3 is controlled within 300 to 600 seconds, and the duration of recording in S5 is controlled within 600 seconds.

[0030] Preferably, the indication signal of the indicator in the radar pseudo-color image in S3 refers to a specific expression form of the reflected wave caused by the indicator in the electromagnetic radar field in the radar pseudo-color image, that is, a crescent-shaped strip in the radar pseudo-color image with an amplitude suddenly increased relative to the surrounding area.

[0031] Preferably, the radar waves with corresponding incident angles are emitted in sequence in S5, specifically:

[0032] Radar waves with 9 incident angles are emitted, and the incident angles of the emitted radar waves are 0°, ±30°, ±45°, ±60°, and ±75°, respectively. Radar waves are emitted in the order of 0°, positive angle from small to large, and negative angle from small to large. The incident angle of the radar wave refers to the angle between the incident direction of the radar wave and the direction from the vertical concrete crack surface to the deep part of the concrete crack. The positive and negative signs refer to the components of the incident direction of the radar wave along the direction perpendicular to the deep part of the crack, which are in opposite directions.

[0033] Since the directions of the tips of different cracks vary greatly, the angles at which the indicator is attached to the tip of the concrete crack are also different. Each filling angle corresponds to an optimal radar wave incident angle, so that the radar wave can detect the deepest part of the indicator at the filling angle. Therefore, when the indicator reaches the tip of the crack, it can be detected at the radar incident angle to the greatest extent possible to approximate the true depth of the crack.

[0034] Preferably, the judgment criterion for the depth of the concrete crack tip position marked by the indicator in S6 is to obtain corresponding 9 radar pseudo-color images based on radar wave detection at 9 incident angles, and the deepest position of the concrete crack where the indicator indication signal is located in the 9 radar pseudo-color images represents the depth of the concrete crack tip position.

[0035] Preferably, the frequency range of the radar wave is 100 to 2600 MHz;

[0036] When the thickness of the detected object along the depth direction of the concrete crack does not exceed 500mm, a radar antenna with a center frequency of 2600MHz is selected;

[0037] When the thickness of the detected object along the depth direction of the concrete crack is 500-1000mm, a radar antenna with a center frequency of 900MHz is selected;

[0038] When the thickness of the detected object along the depth direction of the concrete crack is 1000-3000mm, a radar antenna with a center frequency of 400MHz is selected;

[0039] When the thickness of the detected object along the depth direction of the concrete crack is greater than 3000mm, a radar antenna with a center frequency of 100MHz is selected.

[0040] Preferably, the indicator is a liquid high dielectric material.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The radar visualization tracing detection method of the present invention can obtain the movement trajectory of the indicator in the concrete crack cavity in real time, and designs the indicator injection amount and relay injection method, thereby avoiding the situation where a large amount of liquid indicator accumulates at the crack tip and the adjacent crack cavity, causing the upper part of the liquid indicator to first contact the incident radar wave and interfere with the lower part of the liquid indicator indicating the bottom of the crack tip, thereby improving the accuracy of crack depth detection.

[0043] (2) The present invention has a criterion for determining whether the indicator has reached the crack tip. The present invention determines that the indicator has reached the crack tip when the indicator signal in the radar pseudo-color image persists and remains stationary at a certain position, thereby improving the accuracy of crack depth detection.

[0044] (3) The present invention has a criterion for judging whether the indicator depth detected by the radar when the indicator reaches the crack tip is the depth of the crack marked by the indicator. When the indicator is in the same position, the indicator reflection parts corresponding to radar waves of different incident angles are different, resulting in different indicator depths obtained when detecting at different radar incident angles; therefore, the deepest position of the indicator at the crack tip measured by radar waves of different incident angles is an accurate reflection of the actual depth of the crack. The present invention proposes to detect crack depth at multiple radar incident angles, thereby improving the accuracy of crack depth detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the radar antenna in the concrete crack depth indicator tracer radar visualization detection method of the present invention transmitting radar waves in real time to the deep part of the concrete crack in a direction perpendicular to the concrete crack surface while moving;

[0046] Figure 2 It is a schematic diagram of the radar antenna emitting radar waves with an incident angle of 0° after the indicator in the concrete crack depth indicator tracing radar visualization detection method of the present invention reaches the deep tip of the concrete crack;

[0047] Figure 3 It is a schematic diagram of the radar antenna emitting forward radar waves with incident angles of 30°, 45°, 60° and 75° after the indicator in the concrete crack depth indicator tracer radar visualization detection method of the present invention reaches the deep tip of the concrete crack;

[0048] Figure 4 It is a schematic diagram of the radar antenna emitting negative radar waves with incident angles of 30°, 45°, 60° and 75° after the indicator in the concrete crack depth indicator tracer radar visualization detection method of the present invention reaches the deep tip of the concrete crack;

[0049] Figure 5 This is the radar detection pseudo-color image of Example 1 of the present invention.

[0050] In the figure: 1. Radar antenna mobile vehicle; 2. Indicator loading tank; 3. Indicator delivery pipe; 4. Filling port; 5. Mobile ramp. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Embodiment 1:

[0053] See also Figure 1-4 The concrete crack depth indicator tracing radar visualization detection method adopts concrete crack depth radar visualization detection equipment, the detection equipment includes a radar antenna mobile vehicle 1 and an indicator loading tank 2, the radar antenna mobile vehicle 1 is equipped with a radar antenna, the indicator loading tank 2 is loaded with an indicator, and the indicator loading tank 2 is installed on the loading vehicle.

[0054] The indicator loading tank 2 is connected to the pouring port 4 through the indicator delivery pipe 3, which is used to deliver the indicator inside the indicator loading tank 2 to the pouring port 4, and then transport the indicator from the surface of the concrete crack to the deep part of the concrete crack.

[0055] A mobile ramp 5 is placed on the surface of the concrete crack. The mobile ramp 5 can adjust its own inclination angle. The radar antenna mobile vehicle 1 moves back and forth on the mobile ramp 5. The radar antenna mobile vehicle 1 moves on the mobile ramp 5, so that the radar antenna detects at different incident angles and emits radar waves to the deep part of the crack.

[0056] The concrete crack depth indicator tracer radar visualization detection method comprises the following steps:

[0057] S1. Determine the amount of indicator for each single injection according to the thickness of the object to be tested along the crack depth direction;

[0058] In this embodiment, the indicator is a liquid high dielectric material.

[0059] Determine the amount of indicator to be used for a single infusion, specifically:

[0060] When the thickness of the object to be tested along the crack depth direction does not exceed 500mm, 5ml of liquid indicator is poured for the first time, 10ml and 20ml for the second and third times respectively, and 20ml for each subsequent time;

[0061] When the thickness of the detected body along the crack depth direction is 500-1500mm, 15ml of liquid indicator is poured for the first time, 15ml for the second time, 30ml for the third time, and 30ml for each subsequent time.

[0062] When the thickness of the object to be tested along the crack depth direction is 1500-3000mm, 30ml of liquid indicator is poured for the first time, 40ml for the second time, and 50ml for each subsequent time;

[0063] When the thickness of the object to be tested along the crack depth direction is greater than 3000mm, 120ml is poured each time.

[0064] S2. When the indicator is poured once, the liquid indicator is poured from the surface of the concrete crack to the deep part of the crack. During the pouring process, the radar antenna moves back and forth across the crack on the surface of the concrete crack. During the movement, the radar antenna emits radar waves to the deep part of the crack in real time in a direction perpendicular to the surface crack (i.e., the incident angle of the radar wave is 0°). Figure 1 , 2 As shown;

[0065] In this embodiment, the liquid indicator injection method includes: reserving an injection port 4 on the crack surface, sealing the crack surface except the injection port 4, and pressing the liquid indicator into the deep part of the crack from the injection port 4; or reserving an injection port 4 on the crack surface to connect the liquid indicator, then sealing the crack surface, and extracting air from the crack cavity to create a negative pressure condition in the cavity, so that the indicator is sucked into the deep part of the crack.

[0066] In this embodiment, radar waves are emitted to the deep part of the crack, and the frequency range of the radar waves is 100 to 2600 MHz. Specifically:

[0067] When the thickness of the object to be inspected along the crack depth direction does not exceed 500mm, a radar antenna with a center frequency of 2600MHz is selected;

[0068] When the thickness of the object to be inspected along the crack depth direction is 500-1000mm, a radar antenna with a center frequency of 900MHz is selected;

[0069] When the thickness of the object to be inspected along the crack depth direction is 1000-3000mm, a radar antenna with a center frequency of 400MHz is selected;

[0070] When the thickness of the object to be detected along the crack depth direction is greater than 3000mm, a radar antenna with a center frequency of 100MHz is selected.

[0071] S3, control the duration of a single injection, and the injection duration is controlled within 300 to 600 seconds; observe the real-time radar pseudo-color image when the radar antenna moves back and forth across the crack; track the movement trajectory of the indication signal of the liquid indicator in the radar pseudo-color image along the crack cavity; when the indication signal in the radar pseudo-color image disappears, inject the liquid indicator again and track the indication signal trajectory;

[0072] See also Figure 5 The indication signal deep in the crack in the radar pseudo-color image refers to the specific manifestation of the reflected wave caused by the indicator in the electromagnetic radar field in the pseudo-color image, that is, the crescent-shaped strip in the pseudo-color image with a sudden increase in amplitude relative to the surrounding area.

[0073] S4, looping steps S2 to S3 until the liquid indicator reaches the deep tip of the crack;

[0074] In this embodiment, the criterion for judging whether the liquid indicator has reached the deep tip of the crack is that, during a single injection, the indicator signal in the radar pseudo-color image continuously exists and remains stationary at a certain position within the injection length.

[0075] S5, adjusting the incident angle of the radar wave emitted by the crack surface radar antenna toward the deep part of the crack, sequentially emitting radar waves with corresponding incident angles, and respectively recording the position information of the indication signal of the liquid indicator in the pseudo-color image;

[0076] The incident angle of the radar wave refers to the angle between the incident direction of the radar wave and the downward direction of the vertical crack surface; the incident angles of the transmitted radar waves are 0°, ±30°, ±45°, ±60°, and ±75°, respectively. The radar waves are transmitted in the order of 0°, +30°, +45°, +60°, +75°, -75°, -60°, -45°, and -30° within 600 seconds. Figure 2-4 As shown; the positive and negative signs refer to the components of the radar wave incident direction perpendicular to the direction of the crack depth, which are in opposite directions.

[0077] Since the directions of the tips of different cracks vary greatly, the angles at which the indicator is attached to the tip are also different. Each filling angle corresponds to an optimal radar wave incident angle, so that the radar wave can detect the deepest part of the indicator at the filling angle. Therefore, when the indicator reaches the tip of the crack, it can be detected at different radar incident angles to get close to the true depth of the crack to the greatest extent.

[0078] S6. Read the position information of the liquid indicator indication signal in the radar pseudo-color image at each incident angle of the radar wave to obtain the depth of the crack tip position marked by the indicator.

[0079] The criterion for determining the crack depth under the indicator mark is to obtain nine corresponding pseudo-color images by detecting radar waves at nine incident angles including vertical to the crack surface. The deepest position of the indicator signal at the crack in these pseudo-color images represents the depth of the crack.

[0080] The above description is only used to help understand the method of the present invention and its core essence, but the protection scope of the present invention is not limited thereto. For those skilled in the art in the art, equivalent replacement or change according to the technical solution and inventive concept of the present invention within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A concrete crack depth indicator tracer radar visualization detection method, characterized in that: The following steps are involved: S1. Determine the amount of indicator for single injection in each stage according to the thickness of the object to be tested along the depth direction of the concrete crack; Determine the amount of indicator for each single perfusion phase as follows: When the thickness of the tested object along the direction of the concrete crack depth does not exceed 500mm, 5ml of indicator is poured for the first time, 10ml and 20ml for the second and third times respectively, and 20ml for each subsequent time; When the thickness of the inspected object along the depth direction of the concrete crack is 500-1500mm, 15ml of indicator is poured for the first time, 15ml for the second time, 30ml for the third time, and 30ml for each subsequent time. When the thickness of the inspected object along the depth direction of the concrete crack is 1500~3000mm, 30ml of indicator is poured for the first time, 40ml for the second time, and 50ml for each subsequent time; When the thickness of the tested object along the direction of the concrete crack depth is greater than 3000mm, 120ml is poured each time; S2, a single pouring is performed to pour the indicator from the concrete crack surface to the deep concrete crack. During the pouring process, the radar antenna moves back and forth across the crack on the concrete crack surface. During the movement, the radar antenna is perpendicular to the concrete crack surface and moves toward the deep concrete crack, emitting radar waves to the deep concrete crack in real time; S3, controlling the duration of a single pouring, observing the real-time radar pseudo-color image during the pouring process, tracking the indication signal of the indicator in the radar pseudo-color image moving along the concrete crack cavity, and when the indication signal in the radar pseudo-color image disappears, the next stage of pouring the indicator; The duration of a single infusion is controlled at 300-600s; S4, looping steps S2 to S3 until the indicator reaches the deep tip of the concrete crack; The criterion for judging whether the indicator reaches the deep tip of the concrete crack is that during the single pouring, the indicator signal in the radar pseudo-color image continues to exist and remains stationary at a certain position within the duration of the single pouring. S5. After the indicator reaches the tip of the deep part of the concrete crack, during the recording time, adjust the angle of the radar antenna on the surface of the concrete crack to transmit radar waves to the deep part of the concrete crack, and successively transmit radar waves with corresponding incident angles, and record the position information of the indicator signal in the radar pseudo-color image respectively; The recording time should be controlled within 600s; S6, reading the position information of the indicator signal in the radar pseudo-color image at each incident angle of the radar wave, comparing it, and obtaining the depth of the tip of the concrete crack marked by the indicator; The judgment criterion for the depth of the tip of the concrete crack marked by the indicator is to obtain 9 corresponding radar pseudo-color images based on radar wave detection at 9 incident angles. The deepest position of the concrete crack where the indicator indication signal is located in the 9 radar pseudo-color images represents the depth of the tip of the concrete crack.

2. The concrete crack depth indicator tracer radar visualization detection method according to claim 1 is characterized in that: In S2, the indicator is poured from the surface of the concrete crack to the deep part of the concrete crack, a pouring port is reserved on the surface of the concrete crack to connect with the indicator, and the indicator is pressed from the pouring port into the deep part of the concrete crack by external pressure.

3. The concrete crack depth indicator tracer radar visualization detection method according to claim 1 is characterized in that: In S2, the indicator is poured from the concrete crack surface to the deep part of the concrete crack, a pouring port is reserved on the concrete crack surface to connect with the indicator, and a negative pressure environment is formed in the concrete crack cavity, and the indicator is sucked into the deep part of the concrete crack from the pouring port through the negative pressure.

4. The concrete crack depth indicator tracer radar visualization detection method according to claim 1 is characterized in that: The indication signal of the indicator in the radar pseudo-color image in S3 refers to a specific expression form of the reflected wave caused by the indicator in the electromagnetic radar field in the radar pseudo-color image, that is, a crescent-shaped strip in the radar pseudo-color image with an amplitude that suddenly increases relative to the surrounding area.

5. The concrete crack depth indicator tracer radar visualization detection method according to claim 4 is characterized in that: In S5, radar waves with corresponding incident angles are emitted in sequence, specifically: Radar waves with 9 incident angles are emitted, and the incident angles of the emitted radar waves are 0°, ±30°, ±45°, ±60°, and ±75°, respectively. The radar waves are emitted in the order of incident angles of 0°, positive angles from small to large, and negative angles from small to large. The incident angle of the radar wave refers to the angle between the incident direction of the radar wave and the direction from the vertical concrete crack surface to the deep part of the concrete crack.

6. The concrete crack depth indicator tracer radar visualization detection method according to claim 1 is characterized in that: The frequency range of the radar wave is 100~2600 MHz; When the thickness of the detected object along the depth direction of the concrete crack does not exceed 500 mm, a radar antenna with a center frequency of 2600 MHz is selected; When the thickness of the detected object along the depth direction of the concrete crack is 500~1000mm, a radar antenna with a center frequency of 900 MHz is selected; When the thickness of the detected object along the depth direction of the concrete crack is 1000~3000mm, a radar antenna with a center frequency of 400 MHz is selected; When the thickness of the detected object along the depth direction of the concrete crack is greater than 3000 mm, a radar antenna with a center frequency of 100 MHz is selected.

7. The concrete crack depth indicator tracer radar visualization detection method according to claim 1 is characterized in that: The indicator is a liquid high dielectric material.

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