Nondestructive detection device and method for grouting defects of concrete components based on impact echo

Abstract

The present invention discloses a nondestructive detection device and method for grouting defects of concrete components based on impact echo, which specifically relates to the technical field of building structure detection, including a mounting base, a bracket fixedly provided at the middle of one end of the top surface of the mounting base and a support platform fixedly provided at the middle of the other end, a vertical plate fixedly provided at the position corresponding to the edge of the bracket on one side of the top surface of the mounting base, a driving mechanism provided between the vertical plate and the bracket, a hammering and impacting mechanism provided between the bracket and the support platform, and a linkage between the driving mechanism and the hammering and impacting mechanism. The present invention collects signals of grouting compact concrete components and grouting sleeve components to be detected by using impact echo, takes the component signal of sleeve grouting compactness as a comparison signal, and uses the signal thickness frequency and main frequency amplitude obtained by Fourier transform to judge whether the grouting in the sleeve has defects in real time, and simultaneously locates the sleeve with grouting defects, which is simple to operate, convenient to detect, and has good applicability.

Description

Technical Field

[0001] The present invention relates to the field of building structure detection technology, and in particular to a novel structure nondestructive detection technology using the difference in signal main frequency amplitude obtained by Fourier transform as an indicator. More specifically, the present invention relates to a device and method for nondestructive detection of grouting defects of concrete components based on impact echo. Background Art

[0002] Prefabricated concrete structures have the advantages of high industrialization, fast construction speed, high quality of building products, low noise and pollution in on-site construction, etc., which meet the national strategic needs of sustainable social development such as industrialization, informatization, and urbanization. Prefabricated concrete shear wall structure system has the advantages of high lateral stiffness, high bearing capacity, regular interior space, and rich building facades, and is most widely used in high-rise residential buildings in my country.

[0003] In actual engineering construction, there are often phenomena such as lax management and extensive construction. Due to human factors, technical limitations and other reasons, the grouting density cannot meet the relevant standards. If the grouting of the prefabricated sleeve-connected concrete structure is not dense, it will seriously affect the bearing capacity and seismic performance of the load-bearing components, and may even lead to the destruction of the entire structure, causing safety accidents and property and economic losses. Therefore, it is of great application significance to detect the defects of the grouting sleeve. At the same time, since non-destructive testing does not damage components and facilities, it is more suitable for prefabricated building structures.

[0004] From the characteristics of the impact echo itself, the impact echo has good guidance and strong penetration ability. When the impact echo encounters a grouting defect during the propagation of the grouting sleeve concrete, the signal will be reflected and diffracted, causing a significant change in the signal received by the signal receiver. Fourier frequency domain analysis of the signal can extract the characteristics of the grouting defect. Since the acoustic impedance of concrete and sleeve is much higher than that of air, the reflection coefficient is approximately equal to 1. Therefore, when the stress wave propagating in the concrete reaches the air interface, the stress wave is almost completely reflected, which is why the impact echo locates concrete defects.

[0005] From the perspective of the characteristics of Fourier transform itself, Fourier transform includes fast Fourier transform and discrete Fourier transform. After Fourier transform, the amplitude spectrum of the signal can represent the energy of the corresponding frequency, while the phase spectrum can represent the phase characteristics of the corresponding frequency. Fourier transform can transform time domain signals into frequency domain signals, which can show more differences in signals.

[0006] However, in the prior art, there is a lack of reliable non-destructive testing for the compactness of the grouting sleeve, and the impact device used to detect the compactness of the grouting sleeve has a complex structure and is prone to damage the concrete component.

[0007] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0008] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a device and method for nondestructive detection of grouting defects of concrete components based on impact echo, which drives the impact component to hammer the designated position on the concrete component to be inspected by utilizing the restoring force generated by the compression of the spring telescopic rod. At the same time, combined with the characteristics of the impact echo and Fourier transform, the compactness of the grouting sleeve is reliably nondestructively detected to solve the problems raised in the above-mentioned background technology.

[0009] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a nondestructive detection device for grouting defects of concrete components based on impact echo, comprising a mounting base, characterized in that a bracket is fixedly provided at the middle of one end of the top surface of the mounting base and a support is fixedly provided at the middle of the other end.

[0010] Furthermore, a vertical plate is fixedly provided on one side of the top surface of the mounting substrate at a position corresponding to an edge of the bracket, and a driving mechanism is provided between the vertical plate and the bracket.

[0011] Furthermore, a hammering and impacting mechanism is provided between the bracket and the support platform, and the driving mechanism is linked with the hammering and impacting mechanism.

[0012] Furthermore, the driving mechanism includes a motor fixedly mounted on a side of the vertical plate away from the bracket and a shift plate arranged on the top of the bracket, and a round rod 2 is arranged on a side of the vertical plate facing the bracket.

[0013] Furthermore, a round rod is fixedly embedded on one side of the shift plate facing the vertical plate, a ring plate is fixedly sleeved on one end of the outer circumference of the round rod close to the vertical plate, and the ring plate is rotatably connected to the vertical plate through a bearing.

[0014] Furthermore, the output shaft end of the motor is fixedly connected to a rotating shaft, and the end of the rotating shaft away from the motor moves through the vertical plate and the center position of the second round rod in sequence.

[0015] Technical effects and advantages of the present invention:

[0016] 1. The present invention utilizes a driving mechanism to drive the hammering impact mechanism to perform reciprocating hammering on the designated position on the concrete member to be inspected. The structural design is simple and ingenious, and the restoring force generated by the compression of the spring telescopic rod is used to drive the impact assembly to hammer the designated position on the concrete member to be inspected, which will not cause impact damage. In addition, the hammer head or the mounting plate can be replaced quickly and conveniently.

[0017] 2. The present invention effectively controls the input of the motor by establishing a voltage motor torque equation for the motor. The established equation can accurately control the output to drive the detection device to control, thereby ensuring the controllability of the non-destructive testing device. This method is based on the prior art and combined with the specific practice of the present invention. The equation is easy to understand and operate, and can be promoted and applied;

[0018] 3. The present invention collects signals from grouted compact concrete components and grouting sleeve components to be tested by using impact echoes, and uses the component signals of the sleeve grouted compact as comparison signals. The signal thickness frequency and main frequency amplitude obtained by Fourier transform can be used to judge in real time whether the grouting in the sleeve has defects, and at the same time locate the sleeve with grouting defects, thereby solving the problem of lack of reliable non-destructive testing for the compactness detection of grouting sleeves in the prior art. The method is simple to operate, convenient to detect, and has a clear principle. It is suitable for concrete components connected by full grouting sleeves and half grouting sleeves. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the present invention. The embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention.

[0021] Figure 2 It is a schematic diagram of the structure of the rotating shaft portion of the driving mechanism of the device of the present invention.

[0022] Figure 3 It is a schematic diagram of the structure of the paddle part of the driving mechanism of the device of the present invention.

[0023] Figure 4 It is a schematic diagram of the straight bar structure of the device of the present invention.

[0024] Figure 5 It is a schematic diagram of the mounting plate structure of the device of the present invention.

[0025] Figure 6 It is the assembly diagram of the hammer head and T-block of the device of the present invention.

[0026] Figure 7 It is a schematic diagram of the support structure of the device of the present invention.

[0027] Figure 8 This is an exploded view of the spring telescopic rod of the device of the present invention.

[0028] Fig. 9 The figure is a schematic diagram of vertical detection of double-sleeve dense grouting concrete using the method of the present invention.

[0029] Fig.10It is a schematic diagram of vertical detection of proximal sleeve grouting defects of double-sleeve grouting concrete using the method of the present invention.

[0030] Fig.11 It is a schematic diagram of vertical detection of grouting defects of the far-end sleeve of double-sleeve grouting concrete using the method of the present invention.

[0031] Fig.12 It is a schematic diagram of vertical detection of double-sleeve defect grouting concrete using the method of the present invention.

[0032] Fig.13 The figure is a schematic diagram of double-sleeve dense grouting concrete level detection using the method of the present invention.

[0033] Fig.14 It is a schematic diagram of horizontal detection of proximal sleeve grouting defects of double-sleeve dense grouting concrete using the method of the present invention.

[0034] Fig.15 It is a schematic diagram of the horizontal detection of grouting defects of the far-end sleeve of double-sleeve dense grouting concrete using the method of the present invention.

[0035] Fig.16 It is a schematic diagram of double-sleeve defect grouting concrete level detection using the method of the present invention.

[0036] Fig.17 The signal thickness frequency distribution of different grouting states of the present invention using the method of the present invention.

[0037] Fig.18 This is a comparison diagram of the signal main frequency amplitudes of different grouting states of the present invention using the method of the present invention.

[0038] The accompanying drawings are marked as follows: 1 mounting base plate, 2 vertical plate, 3 bracket, 4 support platform, 5 driving mechanism, 51 motor, 52 rotating shaft, 53 square column, 54 round rod one, 55 slot, 56 round rod two, 57 ring plate one, 58 dial plate, 6 hammering impact mechanism, 61 disc, 62 straight bar, 63 boss, 64 belt, 65 spring one, 66 ring plate two, 67 impact assembly, 671 mounting plate, 672 T-slot, 673 hammer head, 674 T-block, 675 strip plate one, 676 strip plate two, 677 dovetail groove, 678 straight groove, 679 mounting hole, 68 spring telescopic rod, 681 sleeve rod one, 682 sleeve rod two, 683 mounting plate, 684 limiting plate, 685 through hole, 686 spring two, 69 wedge block, 7 clamping strip, 8 clamping slot, 9 straight plate, 10 through hole. DETAILED DESCRIPTION

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present disclosure will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0040] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0041] Example 1

[0042] Refer to the instruction manual Figure 1-7 A nondestructive detection device for grouting defects of concrete components based on impact echo according to an embodiment of the present invention comprises a mounting base plate 1, a bracket 3 is fixedly provided in the middle of one end of the top surface of the mounting base plate 1 and a support platform 4 is fixedly provided in the middle of the other end, a vertical plate 2 is fixedly provided at a position corresponding to the edge of the bracket 3 on one side of the top surface of the mounting base plate 1, a driving mechanism 5 is provided between the vertical plate 2 and the bracket 3, a hammering impact mechanism 6 is provided between the bracket 3 and the support platform 4, and the driving mechanism 5 and the hammering impact mechanism 6 are linked.

[0043] Furthermore, the driving mechanism 5 includes a motor 51 fixedly mounted on the vertical plate 2 away from the side of the bracket 3 and a dial plate 58 arranged on the top of the bracket 3, a round rod 2 56 is arranged on the side of the vertical plate 2 facing the bracket 3, a round rod 1 54 is fixedly embedded on the side of the dial plate 58 facing the vertical plate 2, a ring plate 1 57 is fixedly sleeved on the end of the outer circumference of the round rod 2 56 close to the vertical plate 2, and the ring plate 1 57 is rotatably connected to the vertical plate 2 through the bearing, the output shaft end of the motor 51 is fixedly connected to the rotating shaft 52, and the end of the rotating shaft 52 away from the motor 51 is movable through the vertical plate 2 and the center position of the round rod 2 56 in turn. The first round rod 54 is provided with a slot 55 at one end thereof close to the second round rod 56, and the second round rod 56 at one end thereof close to the dial plate 58 is movably inserted in the slot 55. A square column slot is provided at the center of the inner end surface of the slot 55, and the square column 53 is movably inserted in the square column slot. Two clamping strips 7 symmetrically arranged about the central axis of the first round rod 54 are fixedly provided at one end of the inner circumference of the slot 55 away from the dial plate 58, and a clamping slot 8 is provided at a position corresponding to the clamping strip 7 at one end of the outer circumference of the second round rod 56 away from the ring plate 1 57, and the clamping strip 7 is slidably connected to the inside of the clamping slot 8 at the corresponding position.

[0044] Further, the hammering impact mechanism 6 includes a straight bar 62 fixedly connected to the top of the side of the bracket 3 facing the vertical plate 2 and a ring plate 66 rotatably sleeved on the outer circumference of the round rod 54 through a bearing, and a disc 61 is movably sleeved at the position of the outer circumference of the round rod 54 between the ring plate 66 and the dial plate 58, a circular hole is penetrated at the center of the straight bar 62, and the part of the round rod 54 located between the ring plate 66 and the dial plate 58 is movably penetrated inside the circular hole, and a belt 64 is fixedly connected to the outer circumference of the disc 61, and the disc 61 is away from the edge of one side of the vertical plate 2. A convex column 63 is fixedly provided at the position, a spring 65 is fixedly connected between the ring plate 1 57 and the ring plate 2 66, an impact assembly 67 is provided at the end of the belt 64 away from the disc 61, a straight plate 9 is fixedly provided at the end of the top surface of the support platform 4 close to the bracket 3, a through hole 10 is penetrated through the top of one side of the straight plate 9, and the belt 64 connecting the impact assembly 67 and the disc 61 is movably passed through the through hole 10, a spring telescopic rod 68 is provided between the straight plate 9 and the impact assembly 67, and a wedge block 69 is fixedly provided at the end of the bracket 3 away from the vertical plate 2 close to the support platform 4.

[0045] It should be noted that: (1) in the process of the opposite ends of round rod 1 54 and round rod 2 56 changing from the intersecting state to the separated state, the end of square column 53 close to round rod 1 54 always remains inserted into the square column groove inside slot 55; (2) in the initial state, the end of round rod 2 56 close to round rod 1 54 is inserted into the slot 55, and spring 1 65 is in a stretched state, but in this state, the rotation of disk 61 will not be affected by straight bar 62; (3) the thickness of boss 63 is less than the thickness of wedge block 69, and the end surface of wedge block 69 facing the rotation direction of dial plate 58 is inclined; (4) the device can be mounted on an engineering vehicle or a movable platform to facilitate the change of position for detection; (5) boss 63 is always located at the lowest point of disk 61 before being moved.

[0046] When inspecting the grouting defects of the target concrete component, it is only necessary to move the device to the inspection station and make the impact assembly 67 face the knocking point on the concrete component to be inspected, and then start the motor 51 to drive the rotating shaft 52 to rotate, thereby driving the round rod 1 54 to rotate, and then driving the dial plate 58 to make a circular motion. When the dial plate 58 rotates to contact with the protruding column 63, it will continue to push the protruding column 63 to rotate synchronously, thereby driving the disc 61 to rotate. During the rotation of the disc 61, the belt 64 will be driven to wrap around the outer circumference of the disc 61. In the process of the belt 64 wrapping around the outer circumference of the disc 61, the impact assembly 67 will be synchronously pulled to move in the direction of the straight plate 9 facing the top of the support platform 4, and the spring telescopic rod 68 will be compressed. When the dial plate 58 rotates to contact with the wedge block 69 and moves along the inclined surface on the wedge block 69 to the vertical surface, the dial plate 58 will be moved by the wedge block 69 to the side away from the vertical plate 2 and the spring 1 65 will be stretched. At this time, the card strip 7 on the round rod 1 54 is gradually separated from the card slot 8 on the round rod 2 56. After the dial plate 58 is completely transitioned from the inclined surface on the wedge block 69 to the vertical surface at its position, the card strip 7 is completely separated from the card slot 8, and the spring telescopic rod 68 is compressed to the maximum limit. Subsequently, the impact assembly 67 will strike the knocking point once as the spring telescopic rod 68 is reset. During this process, one end of the belt 64 connected to the impact assembly 67 will also move in the direction of the impact assembly 67 as the spring telescopic rod 68 is reset, thereby driving the disc 61 to reset, so that the protrusion 63 returns to the lowest point of the disc 61. When the dial plate 58 is rotated to be completely separated from the wedge block 69, the round rod 1 54 moves in the direction of the round rod 2 56 under the action of the restoring force of the spring 1 65. At this time, the insertion strip is just inserted into the card slot 8 at the corresponding position again. In this way, it can be achieved that as the dial plate 58 makes a circular motion, the impact assembly 67 is driven to intermittently hammer the knocking point.

[0047] The voltage equation of the motor can be expressed as:

[0048]

[0049]

[0050] In the formula, u a 、u b 、u c is the phase voltage of the three-phase stator winding; R is the resistance of each phase winding of the stator; i a 、i b 、i c is the phase current of the three-phase stator winding; L is the self-inductance of the three-phase stator winding; M is the mutual inductance of the three-phase stator winding; e a 、e b 、e c is the back electromotive force of the three-phase stator winding; u n is the neutral point voltage.

[0051] The motor torque model is:

[0052]

[0053] Where, T e Represents the motor torque, i d 、i q are the equivalent d-axis and q-axis currents, respectively, f is the equivalent flux of permanent magnet, L d , L q are the equivalent inductances of d and q axes respectively, and p is the number of motor pole pairs.

[0054] By establishing a voltage-motor torque equation for the motor, the input of the motor can be effectively controlled. The established equation can accurately control the output to drive the detection device to control, thereby ensuring the controllability of the non-destructive testing device. This method is based on the existing technology and combined with the specific practice of the present invention. The equation is simple to understand and easy to operate, and can be promoted and applied.

[0055] Example 2

[0056] Refer to the instruction manual Figure 1 and Figure 5-7The impact assembly 67 of one embodiment of the present invention includes a mounting plate 671 movably fitted to the top surface of the support platform 4, a dovetail groove 677 opened in the middle of the top surface of the support platform 4, and straight grooves 678 on both sides of the top surface of the support platform 4, a dovetail slider and a straight slider are fixedly provided at the positions corresponding to the dovetail groove 677 and the straight groove 678 on the bottom surface of the mounting plate 671, a T-slot 672 is opened on the side of the mounting plate 671 away from the bracket 3, a T-block 674 is slidably connected inside the T-slot 672, a hammer head 673 is fixedly provided at the end of the T-block 674 away from the mounting plate 671, a strip plate 2 676 is provided on the top surface of the mounting plate 671, and a strip plate 1 675 fixedly connected to the belt 64 is provided in the middle of the side close to the bracket 3, mounting holes 679 are opened at the positions corresponding to the two ends of the strip plate 1 675 and the strip plate 2 676 on the surface of the mounting plate 671, and the strip plate 1 675 and the strip plate 2 676 are fixedly connected to the mounting plate 671 by locking bolts.

[0057] It should be noted that (1) the dovetail groove 677 and the straight groove 678 are connected to the corresponding end of the support platform 4 away from the end of the straight plate 9, which can facilitate the subsequent replacement of the mounting plate 671; (2) the thickness and height of the T-block 674 are respectively equal to the groove depth and groove height of the T-slot 672, which can prevent the hammer head 673 from shaking during the impact of the striking point; (3) the mounting hole 679 at the corresponding position of the strip plate 675 is a through setting, and the distance between the two mounting holes 679 at this position is greater than the width of the hammer head 673.

[0058] Among them, when the hammer head 673 needs to be replaced, it is only necessary to loosen the locking bolt of the fixed strip plate 2 676, and separate the strip plate 2 676 from the mounting plate 671, and then move the hammer head 673 vertically upward along the T-slot 672 to slide out. Similarly, when the mounting plate 671 needs to be replaced, it is only necessary to loosen the locking bolt of the fixed strip plate 1 675 and the corresponding end of the spring telescopic rod 68, and separate the strip plate 1 675 and the corresponding end of the spring telescopic rod 68 from the mounting plate 671, and then move the mounting plate 671 horizontally along the dovetail groove 677 to slide out. The operation is convenient and quick.

[0059] Example 3

[0060] Refer to the instruction manual Figure 1 and Figure 8The spring telescopic rod 68 of one embodiment of the present invention includes a sleeve rod 682 fixedly connected to the straight plate 9 and having a hollow configuration. The end of the sleeve rod 682 away from the straight plate 9 is provided with a through hole 685 connected to the inner cavity of the sleeve rod 682. A sleeve rod 681 is movably provided inside the through hole 685. A limiting disk 684 is fixedly provided at one end of the sleeve rod 681 located inside the sleeve rod 682 and a mounting disk 683 is fixedly provided at one end of the sleeve rod 681 located outside the sleeve rod 682. The mounting disk 683 is fixedly connected to the mounting plate 671 by a locking bolt. A spring 686 is movably provided outside the sleeve rod 682, and both ends of the spring 686 are respectively fixedly connected to the straight plate 9 and the mounting disk 683.

[0061] It should be noted that the diameter of the sleeve rod 1 681 is equal to the diameter of the through hole 685 and smaller than the diameter of the limiting disk 684, and the diameter of the limiting disk 684 is equal to the inner diameter of the hollow sleeve rod 2 682. When the impact assembly 67 moves toward the direction of the straight plate 9 as the belt 64 is wound, it will directly push the sleeve rod 1 681 to move in the direction of the sleeve rod 2 682 and compress the spring 2 686, so that after the clip 7 on the round rod 1 54 is separated from the clip groove 8 on the round rod 2 56, the restoring force of the spring 2 686 after the spring telescopic rod 68 is compressed can be used to drive the impact assembly 67 to hammer the designated position on the concrete component to be inspected.

[0062] The present invention also provides a nondestructive detection method for grouting defects of concrete components based on impact echo, which specifically includes the following detection steps:

[0063] S1: Select a suitable impact hammer according to the concrete component to be tested.

[0064] In this step, the diameters of the impact hammer (i.e., the hammer head 673 in the above-mentioned device) in the impact echo instrument used in the method are 6 mm, 10 mm, and 17 mm, wherein a 10 mm impact hammer is preferably used for a concrete member with a thickness of 200 mm; a 6 mm impact hammer is preferably used for a concrete member with a thickness less than 200 mm; and a 17 mm impact hammer is preferably used for a concrete member with a thickness exceeding 200 mm.

[0065] S2: Select appropriate impact point and signal receiving point.

[0066] In this step, the impact point and the signal receiving point can be in the same horizontal direction or the same vertical direction, and the impact point should be facing the sleeve inside the concrete. The straight-line distance between the signal receiving point and the impact point should be between 3-5 cm, and the preferred straight-line distance for detection is 4 cm.

[0067] S3: Select the densely grouted sleeve concrete component for signal calibration.

[0068] In this step, the calibrated position should maintain a flat surface without structural defects such as honeycomb surface. At the same time, the number of calibrations should be greater than or equal to 3 times, and the signal thickness frequency obtained by each calibration should be consistent. The signal thickness frequency in this step is calculated as follows:

[0069]

[0070] In this formula, f is the thickness frequency of the impact echo test; β is the cross-sectional shape adjustment coefficient, which is 0.96 for concrete walls, bridge decks and pavements, and 0.87 for square columns and beams; C is the longitudinal wave velocity inside the component; and d is the thickness of the concrete component to be tested.

[0071] S4: Perform Fourier analysis of the adopted signal.

[0072] In this step, the fast Fourier transform (FFT) is selected to perform frequency domain analysis on the signal, and then the low-frequency and high-frequency signals far away from the calibrated thickness frequency are removed, and then the main frequency value and the amplitude of the main frequency value obtained after FFT are determined. This main frequency value is also the thickness frequency of the signal.

[0073] S5: Compare the thickness and frequency differences of the impact test signal.

[0074] In this step, the standard for thickness frequency comparison is that if the thickness frequency obtained by FFT of the test signal is less than the calibrated thickness frequency of the defect-free component, it is judged as a grouting defect component.

[0075] S6: Compare the difference of the main frequency amplitude of the impact test signal.

[0076] In this step, the criterion for comparing the main frequency amplitude is that if the main frequency amplitude is smaller than the calibrated main frequency amplitude of the defect-free component, it is judged as a proximal sleeve grouting defective component; if the main frequency amplitude is greater than the calibrated main frequency amplitude of the defect-free component, it is judged as a distal sleeve grouting defective component or a double sleeve grouting defective component.

[0077] Example 4

[0078] Taking the GT4 16 grouting sleeve produced by Shanghai Liwubao Company as an example, combined with the above method, the grouting defects of double-sleeve concrete components are non-destructively tested. The physical devices used include shock wave test instruments, where the test instruments require 6mm, 10mm and 17mm impact hammers, and the resolution accuracy should be higher than 500Hz. The detection methods include vertical detection and horizontal detection, specifically:

[0079] Refer to the instruction manual Fig. 9The double-sleeve dense grouting concrete vertical detection shown in the figure, in which 1 is the sleeve close to the impact side, 2 is the impact hammer, 3 is the impact hammer striking point, 4 is the signal receiving point, 5 is the grouting material in the sleeve, 6 is the concrete, 7 is the grouting outlet, 8 is the sleeve away from the impact side, 9 is the grouting outlet, and 10 is the steel bar in the sleeve;

[0080] Refer to the instruction manual Fig.10 The double-sleeve grouting concrete proximal sleeve grouting defect vertical detection shown in the figure, in which 1 is the sleeve close to the impact side, 2 is the impact hammer, 3 is the impact hammer striking point, 4 is the signal receiving point, 5 is the grouting material in the sleeve, 6 is the concrete, 7 is the grouting outlet, 8 is the sleeve away from the impact side, 9 is the grouting outlet, and 10 is the steel bar in the sleeve;

[0081] Refer to the instruction manual Fig.11 The double-sleeve grouting concrete far-end sleeve grouting defect vertical detection shown in the figure, in which 1 is the sleeve close to the impact side, 2 is the impact hammer, 3 is the impact hammer striking point, 4 is the signal receiving point, 5 is the grouting material in the sleeve, 6 is the concrete, 7 is the grouting outlet, 8 is the sleeve away from the impact side, 9 is the grouting outlet, and 10 is the steel bar in the sleeve;

[0082] Refer to the instruction manual Fig.12 The double-sleeve defect grouting concrete vertical detection shown in the figure, in which 1 is the sleeve close to the impact side, 2 is the impact hammer, 3 is the impact hammer striking point, 4 is the signal receiving point, 5 is the grouting material in the sleeve, 6 is the concrete, 7 is the grouting outlet, 8 is the sleeve away from the impact side, 9 is the grouting outlet, and 10 is the steel bar in the sleeve;

[0083] Refer to the instruction manual Fig.13 The double-sleeve dense grouting concrete level detection shown in the figure, in which 1 is fine aggregate, 2 is coarse aggregate, 3 is the sleeve far from the impact side, 4 is grouting material, 5 is the steel bar in the sleeve, 6 is mortar, 7 is grouting material, 8 is the steel bar in the sleeve, 9 is the impact hammer striking point, 10 is the signal receiving point, and 11 is the sleeve close to the impact side;

[0084] Refer to the instruction manual Fig.14 The double-sleeve dense grouting concrete proximal sleeve grouting defect level detection shown in the figure, 1 is fine aggregate, 2 is coarse aggregate, 3 is the sleeve far from the impact side, 4 is grouting material, 5 is the steel bar in the sleeve, 6 is mortar, 7 is the impact hammer knocking point, 8 is the signal receiving point, and 9 is the sleeve close to the impact side;

[0085] Refer to the instruction manual Fig.15 The double-sleeve dense grouting concrete far-end sleeve grouting defect level detection shown in the figure, in which 1 is fine aggregate, 2 is coarse aggregate, 3 is the sleeve far from the impact side, 4 is mortar, 5 is grouting material, 6 is the steel bar in the sleeve, 7 is the impact hammer striking point, 8 is the signal receiving point, and 9 is the sleeve close to the impact side;

[0086] Refer to the instruction manual Fig.16 The double-sleeve defect grouting concrete horizontal detection shown in the figure, in which 1 is fine aggregate, 2 is coarse aggregate, 3 is the sleeve away from the impact side, 4 is mortar, 5 is the impact hammer knocking point, 6 is the signal receiving point, and 7 is the sleeve close to the impact side.

[0087] Above Figure 9-12 The test results are as follows Fig.17 and Fig.18 As shown, from Fig.17 It can be seen that the method of the present invention successfully determines the existence of grouting defect sleeve concrete components and double sleeve grouting dense sleeve concrete components; Fig.18 It can be seen that the method of the present invention successfully determines the proximal grouting defective sleeve concrete component, the distal grouting defective concrete component or the double sleeve grouting defective concrete component.

[0088] Therefore, the above-mentioned nondestructive detection method for grouting defects of double-sleeve concrete components based on impact echo has good applicability. It can detect defects of full-grouting sleeve and semi-grouting sleeve concrete components. The detection range is from the sleeve grouting outlet to the sleeve grouting outlet section. It can also judge the defect situation within the full grouting size range from the grouting outlet to the grouting outlet section, thereby realizing quantitative analysis of grouting sleeve defects and positioning of grouting defective sleeves.

[0089] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

[0090] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0091] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0092] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A nondestructive detection device for grouting defects of concrete components based on impact echo, comprising a mounting base plate (1), characterized in that: A bracket (3) is fixedly provided in the middle of one end of the top surface of the mounting substrate (1), and a support platform (4) is fixedly provided in the middle of the other end; a vertical plate (2) is fixedly provided at a position corresponding to the edge of the bracket (3) on one side of the top surface of the mounting substrate (1); a driving mechanism (5) is provided between the vertical plate (2) and the bracket (3); a hammering impact mechanism (6) is provided between the bracket (3) and the support platform (4); and the driving mechanism (5) and the hammering impact mechanism (6) are linked; The driving mechanism (5) comprises a motor (51) fixedly mounted on a side of the vertical plate (2) away from the bracket (3) and a shift plate (58) arranged on the top of the bracket (3); a second round rod (56) is arranged on the side of the vertical plate (2) facing the bracket (3); a first round rod (54) is fixedly embedded on the side of the shift plate (58) facing the vertical plate (2); a first ring plate (57) is fixedly sleeved on one end of the outer circumference of the second round rod (56) close to the vertical plate (2); and the first ring plate (57) is rotatably connected to the vertical plate (2) via a bearing; an output shaft end of the motor (51) is fixedly connected to a rotating shaft (52); an end of the rotating shaft (52) away from the motor (51) movably penetrates the vertical plate (2) and the middle of the second round rod (56) in sequence. The first round rod (54) is provided with a slot (55) at one end close to the second round rod (56), and the second round rod (56) is provided with an end close to the dial plate (58) and is movably plugged into the slot (55). A square column slot is provided at the center of the inner end surface of the slot (55), and the square column (53) is movably plugged into the square column slot. Two clips (7) symmetrically arranged about the central axis of the first round rod (54) are fixedly provided at one end of the inner circumference of the slot (55) away from the dial plate (58), and a clip slot (8) is provided at a position corresponding to the clip strip (7) at one end of the outer circumference of the second round rod (56) away from the ring plate (57), and the clip strip (7) is slidably connected to the inside of the clip slot (8) at the corresponding position. The hammering impact mechanism (6) comprises a straight bar (62) fixedly connected to the top end of the side of the bracket (3) facing the vertical plate (2) and a second ring plate (66) rotatably sleeved on the outer peripheral surface of the first round rod (54) through a bearing, a disc (61) movably sleeved at a position of the outer peripheral surface of the first round rod (54) between the second ring plate (66) and the paddle (58), a circular hole is penetrated at the center of the straight bar (62), and a portion of the first round rod (54) located between the second ring plate (66) and the paddle (58) is movably inserted into the circular hole, a belt (64) is fixedly connected to the outer peripheral surface of the disc (61), and a belt (64) is fixedly provided at an edge position of the side of the disc (61) away from the vertical plate (2) A convex column (63), a spring (65) is fixedly connected between the ring plate (57) and the ring plate (66), an impact assembly (67) is arranged at the end of the belt (64) away from the disc (61), a straight plate (9) is fixedly arranged at the end of the top surface of the support platform (4) close to the bracket (3), a through hole (10) is opened through the top of one side of the straight plate (9), and the belt (64) connecting the impact assembly (67) and the disc (61) is movably arranged inside the through hole (10), a spring telescopic rod (68) is arranged between the straight plate (9) and the impact assembly (67), and a wedge block (69) is fixedly arranged at the end of the bracket (3) away from the vertical plate (2) close to the support platform (4).

2. A detection method using the nondestructive detection device for grouting defects of concrete components based on impact echo according to claim 1, characterized in that: include: S1: Select the impact hammer according to the concrete component to be tested; S2: Select the impact point and signal receiving point; S3: Select a sleeve concrete component with dense grouting for signal calibration. The surface of the signal calibration position is kept flat. The number of signal calibration is greater than or equal to 3 times, and the signal thickness frequency obtained by each calibration is consistent. The signal thickness frequency is calculated according to the following formula (1): Formula (1) In formula (1), f is the thickness frequency of the impact echo test; β is the cross-sectional shape adjustment coefficient, which is 0.96 for concrete walls, bridge decks and pavements, and 0.87 for square columns and beams; C is the longitudinal wave velocity inside the component; d is the thickness of the concrete component to be tested; S4: Perform Fourier analysis of the signal: select FFT to perform frequency domain analysis on the signal, then remove low-frequency and high-frequency signals far from the calibrated thickness frequency, and then determine the main frequency value and the amplitude of the main frequency value obtained after FFT, and the main frequency value is also the thickness frequency of the signal; S5: Compare the thickness frequency difference of the impact test signal: when the thickness frequency obtained by FFT of the test signal is less than the calibrated thickness frequency of the defect-free component, it is judged to be a grouting defect component; S6: Compare the difference of the main frequency amplitude of the impact test signal: when the main frequency amplitude is smaller than the calibrated main frequency amplitude of the defect-free component, it is judged to be a proximal sleeve grouting defective component; when the main frequency amplitude is larger than the calibrated main frequency amplitude of the defect-free component, it is judged to be a distal sleeve grouting defective component or a double sleeve grouting defective component.

3. The detection method according to claim 2, characterized in that: In step S1, a 10 mm impact hammer is selected for a concrete member with a thickness of 200 mm, a 6 mm impact hammer is selected for a concrete member with a thickness less than 200 mm, and a 17 mm impact hammer is selected for a concrete member with a thickness exceeding 200 mm.

4. The detection method according to claim 2, characterized in that: In step S2, the impact point and the signal receiving point are in the same horizontal direction or the same vertical direction, and the impact point is facing the sleeve inside the concrete, and the straight-line distance between the signal receiving point and the impact point is between 3-5 cm.

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