A device and method for detecting bond strength of steel-concrete interface

Abstract

The present invention provides a device and method for detecting the bonding strength of a steel-concrete interface, comprising: a point sound source sound transmitter, a ring sound receiver and a controller; the controller comprises: a signal amplifier, a noise filtering module, a signal analysis module, a data calculation module, a two-dimensional image processing module and a display module connected in sequence. The device of the present invention utilizes that at the same temperature, the speed of the sound signal in the air is much smaller than the speed in the solid, and the presence of micropores will cause the detection sound signal to lag in time compared to the reception of the standard signal. Based on this principle, the defects of the bonding strength of the steel-concrete interface can be accurately and efficiently detected, and the size of the bonding strength of the steel-concrete interface can be calculated by the degree of the defects, and a cloud map of the bonding strength of the steel-concrete interface can be generated and displayed on the display screen. The staff can accurately and efficiently detect the areas where the strength does not meet the standards based on the detection results, and use this as a basis for acceptance or repair.

Description

Technical Field

[0001] The invention belongs to the technical field of steel-concrete interface bonding strength detection, and relates to a steel-concrete interface bonding strength detection device and method. Background Art

[0002] The steel-concrete interface is the weak link of the steel-concrete structure. The bond strength of the steel-concrete interface directly affects the strength, stiffness and stability of the steel-concrete components, especially the structure or component of the steel outside the concrete (for example: steel tube concrete). The bond strength of the steel-concrete interface is affected by the tightness of the bond between the steel and the concrete. The presence of micropores in the steel-concrete interface greatly reduces the bond strength. Therefore, there is an urgent need for a device and method for detecting the bond strength of the steel-concrete interface based on the distribution of the micropores. Summary of the invention

[0003] In order to overcome the deficiencies in the prior art, the present invention provides a detection device and method for analyzing the micropore content of the steel-concrete interface by utilizing the different sound velocities in different media to determine the bonding strength of the steel-concrete interface.

[0004] The invention provides a steel-concrete interface bonding strength detection device, comprising: a point sound source sound transmitter, a ring sound receiver and a controller; the point sound source sound transmitter is installed below the controller for transmitting a detection sound signal, the main body of the ring sound receiver is a plurality of ring brackets which are concentrically arranged with the point sound source sound transmitter as the center of the circle, the plurality of ring brackets are fixedly connected to the controller through a plurality of support frames, a plurality of miniature acoustic-electric transducers are evenly arranged on each ring bracket for receiving the detection sound signal and converting it into an analog electric signal and then sending it to the controller; the controller is used for converting the analog electric signal into a detection digital signal, and calculating the first wave time difference between the detection first wave time node and the standard first wave time node of the detection digital signal, and judging the position of micropores, the pore size and the bonding strength of the steel-concrete interface according to the first wave time difference.

[0005] In the steel-concrete interface bonding strength detection device of the present invention, the sound source scale of the point sound source sound emitter is much smaller than the wavelength of the detection sound signal it emits, the phases of the vibrations of various parts of the point sound source sound emitter are approximately the same, and the generated sound field is evenly distributed on a spherical surface with the point sound source sound emitter as the center.

[0006] In the steel-concrete interface bonding strength detection device of the present invention, the controller comprises: a signal amplifier, a noise filtering module, a signal analysis module, a data calculation module, a two-dimensional image processing module and a display module connected in sequence;

[0007] The signal amplifier is used to amplify the analog electrical signal;

[0008] The noise filtering module is used to filter out interference signals in the analog electrical signal;

[0009] The signal analysis module is used to process the analog electrical signal into a detection digital signal, and extract the detection first wave time node of the detection digital signal and compare it with the standard first wave time node to obtain the first wave time difference;

[0010] The data processing module is used to process the first wave time difference, determine the location of the micropores according to the angular coordinate information of the transducer, and calculate the pore size and the bonding strength of the steel-concrete interface;

[0011] The two-dimensional image processing module is used to draw the steel-concrete interface bonding strength result into a two-dimensional cloud map, and display it in real time through the display module.

[0012] In the steel-concrete interface bonding strength detection device of the present invention, the noise filtering module compares each band time node received by each annular receiver with the standard signal time node, and the first wave band that lags behind or is equal to the time node is a valid signal, and the remaining signals are interference noise and signals transmitted by paths in non-detection areas, and these signals are filtered out.

[0013] In the steel-concrete interface bonding strength detection device of the present invention, the signal analysis module calculates the first wave time difference according to the following formula:

[0014] t N =t N探测 -t N标准

[0015]

[0016] Among them, t N represents the first wave time difference, t N探测 To detect the first wave time node, t N标准 is the standard first wave time node, v is the propagation speed of sound in concrete, 1.3v is the propagation speed of sound in steel, N is the serial number of the miniature acoustic-electric transducer on the same diameter; D is the thickness of the steel plate.

[0017] In the steel-concrete interface bonding strength detection device of the present invention, the data processing module calculates the pore size of the micropores and the steel-concrete interface bonding strength according to the following formula:

[0018] d N =t N ×v a

[0019]

[0020] Among them, d N represents the pore size of micropores, v a is the propagation speed of sound in the air; η is the aperture ratio, and A is the measurement area of ​​the micro-acoustic-electric transducer;

[0021] At the same time, the data processing module calculates the steel-concrete interface bonding strength of the local measurement area according to the following formula:

[0022]

[0023]

[0024] Among them, f b It represents the unit bond strength of square steel tube concrete, B is the side length of the square steel tube, t is the wall thickness of the square steel tube, L is the length of the square steel tube, α is the surface coefficient of the square steel tube, and β is the safety factor, which is taken as 1 during the detection process.

[0025] The present invention also provides a method for detecting the bond strength of a steel-concrete interface, comprising:

[0026] Step 1: Send out a detection sound signal through a point sound source transmitter;

[0027] Step 2: Receive the detection sound signal through multiple micro-acoustic-electric transducers and convert it into an analog electrical signal;

[0028] Step 3: Amplify the analog electrical signal;

[0029] Step 4: Filter out interference signals in the analog electrical signal;

[0030] Step 5: Process the analog electrical signal into a detection digital signal, extract the detection first wave time node of the detection digital signal and compare it with the standard first wave time node to obtain the first wave time difference;

[0031] Step 6: Process the first wave time difference, determine the location of the micropores based on the angular coordinate information of the transducer, and calculate the pore size and the bonding strength of the steel-concrete interface;

[0032] Step 7: Draw the steel-concrete interface bond strength results into a two-dimensional cloud map and display it in real time through the display module.

[0033] In the steel-concrete interface bonding strength detection method of the present invention, the first wave time difference is calculated according to the following formula in step 5:

[0034] t N =t N探测 -t N标准

[0035]

[0036] Among them, t N represents the first wave time difference, t N探测 To detect the first wave time node, t N标准is the standard first wave time node, v is the propagation speed of sound in concrete, 1.3v is the propagation speed of sound in steel, N is the serial number of the miniature acoustic-electric transducer on the same diameter; D is the thickness of the steel plate.

[0037] In the steel-concrete interface bonding strength detection method of the present invention, the pore size of the micropores and the steel-concrete interface bonding strength are calculated according to the following formula in step 6:

[0038] d N =t N ×v a

[0039]

[0040] Among them, d N represents the pore size of micropores, v a is the propagation speed of sound in the air; η is the aperture ratio, and A is the measurement area of ​​the micro-acoustic-electric transducer;

[0041] The steel-concrete interface bond strength of the local measurement area is calculated according to the following formula:

[0042]

[0043]

[0044] Among them, f b It represents the unit bond strength of square steel tube concrete, B is the side length of the square steel tube, t is the wall thickness of the square steel tube, L is the length of the square steel tube, α is the surface coefficient of the square steel tube, and β is the safety factor, which is taken as 1 during the detection process.

[0045] The device and method for detecting the bond strength of a steel-concrete interface of the present invention have at least the following beneficial effects:

[0046] 1. By using the principle that the speed of sound is affected by different media at the same temperature, the defects of the bonding strength of the steel-concrete interface can be accurately and efficiently detected, filling the technical gap.

[0047] 2. Compared with parallel sound transmitters and receivers, point sound source sound transmitters and ring sound receivers have strong integration and are easy to operate. The combined use of point sound sources, ring receivers and signal amplifiers can reduce the number of sound sources, thereby reducing sound source errors, eliminating interference between sound sources, and reducing power consumption. The density of acoustic and electrical transducers can be increased to improve detection accuracy.

[0048] 3. The noise filtering module can further reduce the interference of the external environment on the detection results and further improve the accuracy of the results.

[0049] 4. The signal analysis module can accurately calculate the detection first wave time node and compare it with the standard first wave time node to obtain the first wave time difference. The data processing module can calculate the location and pore size of the micropores and the bonding strength of the steel-concrete interface at the micropores based on the first wave time difference.

[0050] 5. The two-dimensional image processing module can visualize the detection results on the screen, so that the location and degree of the bonding strength defects can be understood more intuitively. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a structural schematic diagram of a steel-concrete interface bonding strength detection device of the present invention;

[0052] Figure 2 It is a bottom view of a steel-concrete interface bonding strength detection device of the present invention;

[0053] Figure 3 is the block diagram of the controller;

[0054] Figure 4 This is the schematic diagram of signal lag time calculation;

[0055] Figure 5 It is the path diagram of the detection sound signal. DETAILED DESCRIPTION

[0056] like Figure 1 and Figure 2 As shown, a steel-concrete interface bonding strength detection device of the present invention comprises: a point sound source sound transmitter 1, a ring sound receiver 2 and a controller 3. The point sound source sound transmitter 1 is installed below the controller 3 to transmit a detection sound signal, and the main body of the ring sound receiver 2 is a plurality of ring brackets 21 arranged concentrically with the point sound source sound transmitter 1 as the center of the circle, and the plurality of ring brackets 21 are fixedly connected to the controller 3 through a plurality of support frames 22, and a plurality of miniature acoustic-electric transducers 4 are evenly arranged on each ring bracket 21 to receive the detection sound signal and convert it into an analog electrical signal and then send it to the controller 3. The controller 3 is used to convert the analog electrical signal into a detection digital signal, and calculate the first wave time difference between the detection first wave time node and the standard first wave time node of the detection digital signal, and judge the location of the micropores, the pore size and the bonding strength of the steel-concrete interface according to the first wave time difference.

[0057] In specific implementation, the sound source scale of the point sound source sound transmitter 1 is much smaller than the wavelength of the detection sound signal it emits, and the phases of the vibrations of each part of the point sound source sound transmitter 1 are approximately the same, and the generated sound field is evenly distributed on the sphere with the point sound source sound transmitter as the center. During the detection, the steel-concrete interface bonding strength detection device is placed on the outer surface of the steel plate, and the concrete area is below the steel plate. The micro-acoustic-electric transducer 4 is installed on the bottom surface of the annular bracket 21, so that the micro-acoustic-electric transducer 4 is close to the steel plate, and the micro-acoustic-electric transducer 4 is coated with a coupling agent. The controller 3 is also provided with a handle 31 to facilitate the carrying and transportation of the device.

[0058] like Figure 3 As shown, the controller 3 includes: a signal amplifier, a noise filtering module, a signal analysis module, a data calculation module, a two-dimensional image processing module and a display module which are connected in sequence.

[0059] The signal amplifier is used to amplify the analog electrical signal. The noise filtering module is used to filter out interference signals in the analog electrical signal. Specifically, the noise filtering module compares each band time node received by each ring receiver with the standard signal time node, and the first band that lags behind or is equal to the time node is the valid signal, and the remaining signals are interference noise and signals transmitted by the path in the non-detection area, and the signals are filtered out.

[0060] The signal analysis module is used to process the analog electrical signal into a detection digital signal, and extract the detection first wave time node of the detection digital signal and compare it with the standard first wave time node to obtain the first wave time difference.

[0061] like Figure 4 As shown in the figure, the propagation time of the detection sound signal at the steel-concrete interface with micropores will lag behind the propagation time of the normal steel-concrete interface. In specific implementation, the signal analysis module calculates the first wave time difference according to the following formula:

[0062] t N =t N探测 -t N标准

[0063]

[0064] Among them, t N represents the first wave time difference, t N探测 To detect the first wave time node, t N标准 is the standard first wave time node, v is the propagation speed of sound in concrete, 1.3v is the propagation speed of sound in steel, N is the serial number of the miniature acoustic-electric transducer on the same diameter; D is the thickness of the steel plate.

[0065] The data processing module is used to process the first wave time difference, determine the location of the micropores according to the angular coordinate information of the transducer, and calculate the pore size and the bonding strength of the steel-concrete interface.

[0066] like Figure 5 As shown, the detection sound signal is transmitted to each acoustic-electric transducer through different paths, and the path length is calculated by the following formula:

[0067] L N =NX×2D

[0068] Among them, L N is the path length of the detection sound signal propagated in the steel plate and concrete by the micro-acoustic-electric transducer on the Nth ring bracket with the point sound source sound transmitter as the center. X is the transducer spacing; D is the steel plate thickness.

[0069] In specific implementation, the data processing module calculates the pore size of micropores and the bond strength of the steel-concrete interface according to the following formula:

[0070] d N =t N ×v a

[0071]

[0072] Among them, d N represents the pore size of micropores, v a is the propagation speed of sound in the air; η is the aperture ratio, and A is the measurement area of ​​the micro-acoustic-electric transducer;

[0073] The present invention takes square steel tube concrete as an example and calculates the unit steel-concrete interface bonding strength by the following differential formula:

[0074]

[0075] Finally, the steel-concrete interface bonding strength of the local measurement area was calculated according to the following formula:

[0076]

[0077] Among them, f b It represents the unit bond strength of square steel tube concrete, B is the side length of the square steel tube, t is the wall thickness of the square steel tube, L is the length of the square steel tube, α is the surface coefficient of the square steel tube, and β is the safety factor, which is taken as 1 during the detection process.

[0078] Finally, the two-dimensional image processing module is used to draw the steel-concrete interface bond strength results into a two-dimensional cloud map, and the display module is used to display it in real time.

[0079] The specific process of monitoring using the above-mentioned steel-concrete interface bonding strength detection device is as follows:

[0080] Step 1: Send out a detection sound signal through a point sound source transmitter;

[0081] Step 2: Receive the detection sound signal through multiple micro-acoustic-electric transducers and convert it into an analog electrical signal;

[0082] Step 3: Amplify the analog electrical signal;

[0083] Step 4: Filter out interference signals in the analog electrical signal;

[0084] Step 5: Process the analog electrical signal into a detection digital signal, extract the detection first wave time node of the detection digital signal and compare it with the standard first wave time node to obtain the first wave time difference. Specifically, the first wave time difference is calculated according to the following formula:

[0085] t N =t N探测 -t N标准

[0086]

[0087] Among them, t N represents the first wave time difference, t N探测 To detect the first wave time node, t N标准 is the standard first wave time node, v is the propagation speed of sound in concrete, 1.3v is the propagation speed of sound in steel, N is the serial number of the miniature acoustic-electric transducer on the same diameter; D is the thickness of the steel plate.

[0088] Step 6: Process the first wave time difference, determine the location of the micropores based on the angular coordinate information of the transducer, and calculate the pore size and the bonding strength of the steel-concrete interface;

[0089] The pore size of micropores and the bond strength of the steel-concrete interface are calculated according to the following formula:

[0090] d N =t N ×v a

[0091]

[0092] Among them, d N represents the pore size of micropores, v a is the propagation speed of sound in the air; η is the aperture ratio, and A is the measurement area of ​​the micro-acoustic-electric transducer;

[0093] The steel-concrete interface bond strength of the local measurement area is calculated according to the following formula:

[0094]

[0095]

[0096] Among them, f b It represents the unit bond strength of square steel tube concrete, B is the side length of the square steel tube, t is the wall thickness of the square steel tube, L is the length of the square steel tube, α is the surface coefficient of the square steel tube, and β is the safety factor, which is taken as 1 during the detection process.

[0097] Studies have shown that when the surface of the steel pipe is rusted and not treated, the α value is 1.3, after manual rust removal, the value is 1, and after mechanical rust removal or manual rust removal and further rust removal by applying chemical reagents on the surface, the value is 0.7.

[0098] Step 7: Draw the steel-concrete interface bond strength results into a two-dimensional cloud map and display it in real time through the display module.

[0099] The above method is used to calculate the steel-concrete interface bonding strength in each transducer measurement area, thereby determining the size of the steel-concrete interface bonding strength and the weak points of the strength to be measured.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the concept of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A steel-concrete interface bonding strength detection device, characterized in that: include: Point source sound transmitter, ring sound receiver and controller; The point sound source sound transmitter is installed below the controller to transmit the detection sound signal. The main body of the annular sound receiver is a plurality of annular brackets which are concentrically arranged with the point sound source sound transmitter as the center of the circle. The plurality of annular brackets are fixedly connected to the controller through a plurality of support frames. A plurality of miniature acoustic-electric transducers are evenly arranged on each annular bracket to receive the detection sound signal and convert it into an analog electrical signal and then send it to the controller. The controller is used to convert the analog electrical signal into a detection digital signal, and calculate the first wave time difference between the detection first wave time node and the standard first wave time node of the detection digital signal, and judge the location of the micropores, the pore size and the bonding strength of the steel-concrete interface according to the first wave time difference.

2. The steel-concrete interface bonding strength detection device according to claim 1, characterized in that: The sound source scale of the point sound source sound transmitter is much smaller than the wavelength of the detection sound signal it emits, the phases of vibrations of various parts of the point sound source sound transmitter are approximately the same, and the generated sound field is evenly distributed on a sphere with the point sound source sound transmitter as the center.

3. The steel-concrete interface bonding strength detection device according to claim 1, characterized in that: The controller comprises: a signal amplifier, a noise filtering module, a signal analysis module, a data processing module, a two-dimensional image processing module and a display module connected in sequence; The signal amplifier is used to amplify the analog electrical signal; The noise filtering module is used to filter out interference signals in the analog electrical signal; The signal analysis module is used to process the analog electrical signal into a detection digital signal, and extract the detection first wave time node of the detection digital signal and compare it with the standard first wave time node to obtain the first wave time difference; The data processing module is used to process the first wave time difference, determine the location of the micropores according to the angular coordinate information of the transducer, and calculate the pore size and the bonding strength of the steel-concrete interface; The two-dimensional image processing module is used to draw the steel-concrete interface bonding strength result into a two-dimensional cloud map, and display it in real time through the display module.

4. The steel-concrete interface bonding strength detection device according to claim 3, characterized in that: The noise filtering module compares each band time node received by each ring receiver with the standard signal time node, and the first band that lags behind or is equal to the time node is the valid signal, and the remaining signals are interference noise and signals transmitted by paths in the non-detection area, which are filtered out.

5. The steel-concrete interface bonding strength detection device according to claim 3, characterized in that: The signal analysis module calculates the first wave time difference according to the following formula: t N =t N探测 -t N标准 Among them, t N represents the first wave time difference, t N探测 To detect the first wave time node, t N标准 is the standard first wave time node, v is the propagation speed of sound in concrete, 1.3v is the propagation speed of sound in steel, N is the serial number of the miniature acoustic-electric transducer on the same diameter; D is the thickness of the steel plate.

6. The steel-concrete interface bonding strength detection device according to claim 5, characterized in that: The data processing module calculates the pore size of the micropores and the steel-concrete interface bonding strength according to the following formula: d N =t N ×v a Among them, d N represents the pore size of micropores, v a is the propagation speed of sound in the air; η is the aperture ratio, and A is the measurement area of ​​the micro-acoustic-electric transducer; At the same time, the data processing module calculates the steel-concrete interface bonding strength of the local measurement area according to the following formula: Among them, f b It represents the unit bond strength of square steel tube concrete, B is the side length of the square steel tube, t is the wall thickness of the square steel tube, L is the length of the square steel tube, α is the surface coefficient of the square steel tube, and β is the safety factor, which is taken as 1 during the detection process.

7. A method for testing the bond strength of a steel-concrete interface, characterized in that: The detection device according to any one of claims 1 to 6 is used for detection, comprising the following detection steps: Step 1: Send out a detection sound signal through a point sound source transmitter; Step 2: Receive the detection sound signal through multiple micro-acoustic-electric transducers and convert it into an analog electrical signal; Step 3: Amplify the analog electrical signal; Step 4: Filter out interference signals in the analog electrical signal; Step 5: Process the analog electrical signal into a detection digital signal, extract the detection first wave time node of the detection digital signal and compare it with the standard first wave time node to obtain the first wave time difference; Step 6: Process the first wave time difference, determine the location of the micropores based on the angular coordinate information of the transducer, and calculate the pore size and the bonding strength of the steel-concrete interface; Step 7: Draw the steel-concrete interface bond strength results into a two-dimensional cloud map and display it in real time through the display module.

8. The steel-concrete interface bonding strength detection method according to claim 7, characterized in that: In step 5, the first wave time difference is calculated according to the following formula: t N =t N探测 -t N标准 Among them, t N represents the first wave time difference, t N探测 To detect the first wave time node, t N标准 is the standard first wave time node, v is the propagation speed of sound in concrete, 1.3v is the propagation speed of sound in steel, N is the serial number of the miniature acoustic-electric transducer on the same diameter; D is the thickness of the steel plate.

9. The steel-concrete interface bonding strength detection method according to claim 7, characterized in that: In step 6, the pore size of the micropores and the steel-concrete interface bonding strength are calculated according to the following formula: d N =t N ×v a Among them, d N represents the pore size of micropores, v a is the propagation speed of sound in the air; η is the aperture ratio, and A is the measurement area of ​​the micro-acoustic-electric transducer; The steel-concrete interface bond strength of the local measurement area is calculated according to the following formula: Among them, f b It represents the unit bond strength of square steel tube concrete, B is the side length of the square steel tube, t is the wall thickness of the square steel tube, L is the length of the square steel tube, α is the surface coefficient of the square steel tube, and β is the safety factor, which is taken as 1 during the detection process.

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