Fabricated structure sleeve slurry anchor grouting quality non-contact detection method

Abstract

The invention provides a non-contact detection method for grouting quality of a prefabricated structure sleeve slurry anchor, and belongs to the technical field of prefabricated building quality detection. The method comprises the steps of determining a sleeve projection position; drawing the direction of the sleeve on the surface of the assembly type structure based on the determined projection position, and arranging measuring points; knocking the surface of the measuring line prefabricated column corresponding to the sleeve by using a knocking force hammer with a built-in acceleration sensor, and synchronously collecting and storing a knocking force signal along a measuring point; processing the knocking force signal, and respectively extracting the maximum voltage amplitude and integral total energy of the force hammer recording signal and the sound pressure energy signal; stabilizing the extraction result and the knocking signal; calculating a fusion energy index; when the fusion energy index is larger than a preset threshold value, it is judged that the sleeve has the grouting defect. The defects (safety problem, low detection efficiency, accuracy and the like) of an existing method are overcome, and the method for detecting the grouting fullness of the assembly type sleeve is provided by combining the change characteristics of signal voltage and energy.

Description

Technical Field

[0001] This invention pertains to the quality inspection of prefabricated buildings, and particularly relates to a non-contact method for inspecting the grouting quality of prefabricated structural sleeve anchors. Background Technology

[0002] Grouting connections using rebar sleeves are core force-transfer nodes in prefabricated concrete structures, and their quality directly determines the structure's seismic resistance, durability, and overall safety. Statistics show that approximately 30% of quality accidents in prefabricated structures stem from grouting defects (such as voids, insufficient compaction, and inadequate rebar anchorage). Current industry pain points in quality inspection are as follows: 1) Difficulty in identifying hidden defects: The grouting state inside the sleeve is not visible, and traditional methods rely on experience to judge, resulting in a high rate of missed detection. 2) Conflict between detection efficiency and cost: X-ray methods require a radiation-proof environment and the equipment is expensive; the pre-embedded sensor method requires pre-embedded components, increasing costs by more than 20%. 3) Insufficient quantitative accuracy: Ultrasonic and impact-echo methods can only qualitatively determine defects, with low recognition rates for micro-defects (<0.5mm) and double-row sleeves.

[0003] Existing contact detection technologies include the pre-embedded sensor method, which works by the principle that the amplitude of the damped probe changes with the grouting medium. Its drawback is that the probe is easily blocked by the grouting material, resulting in a high false alarm rate. The pre-embedded steel wire pull-out method works by statistically inferring the fullness of the pull-out load value. Its drawback is that it is a destructive test and cannot be used for comprehensive inspection. The impact echo method works by stress wave reflection spectrum analysis. Its drawback is that the double-row sleeve signal interference is severe, and the defect location is unclear.

[0004] Existing non-contact inspection technologies include: X-ray imaging, which has the advantage of being able to see through the internal structure of the sleeve and providing intuitive imaging, but is limited by heavy equipment, radiation risks, and a penetration thickness of ≤300mm, making it unsuitable for widespread field application; Phased array ultrasound (PAUT), which has the advantage of generating 3D defect images by deflecting the sound beam with electrons, but is limited by the need for a coupling agent, poor compatibility with curved components, and insufficient shallow resolution; and electrical methods (emerging technologies): Case study: Guangzhou Construction Research Institute's electrical testing instrument judges fullness by changes in resistance, and its cost is only 1 / 20 of that of the X-ray method, but it is limited to conductive grouting materials and is significantly affected by humidity.

[0005] In summary, there is currently no mature solution for determining grouting defects in prefabricated structures using non-contact acoustic intensity signal energy thresholds. Summary of the Invention

[0006] In view of the above-mentioned shortcomings in the prior art, the present invention provides a non-contact detection method for the grouting quality of prefabricated sleeves, which solves the drawbacks of the existing methods (safety issues, low detection efficiency, accuracy, etc.). Combining the characteristics of signal voltage and energy changes, it provides a method for detecting the fullness of grouting in prefabricated sleeves.

[0007] To achieve the above objectives, the technical solution adopted by this invention is: a non-contact detection method for the grouting quality of prefabricated structure sleeve anchors, comprising the following steps: S1. Determine the projected position of the sleeve; S2. Based on the determined projection position, trace the sleeve direction on the surface of the prefabricated structure and arrange the measuring points; S3. Using a hammer with a built-in acceleration sensor, strike the surface of the precast column corresponding to the measuring line of the sleeve, and simultaneously collect and save the striking force signal along the measuring point. S4. Process the impact force signal to extract the maximum voltage amplitude and total integrated energy of the hammer recording signal and the sound pressure energy signal respectively. S5. Stabilize the extraction results of S4 with the tapping signal; S6. Calculate the fusion energy index based on the stable processing results; S7. When the fusion energy index is greater than the preset threshold, it is determined that there is a grouting defect in the sleeve, and the non-contact detection of the grouting quality of the prefabricated structure sleeve is completed.

[0008] The beneficial effects of this invention are as follows: This invention is based on the detection technology of vibration impedance characteristics of elastic waves. It uses a vibration tool with a built-in sensor (referring to the impact hammer with a built-in acceleration sensor in S2) and a non-contact physical sound-absorbing pickup device (referring to a dedicated pickup) to pick up signals. A stabilization processing method is employed, combining voltage and energy parameters to fuse multiple physical quantities, thus replacing the pre-embedded sensor method, impact echo method, and X-ray method for detecting the grouting quality of prefabricated structures. This solves the shortcomings of existing methods (safety issues, low detection efficiency, accuracy, etc.). By combining the characteristics of signal voltage and energy changes, it provides a method for detecting the fullness of grouting in prefabricated sleeves. It provides a faster and more accurate detection and evaluation method that is more adaptable to engineering sites, offering an important detection method for improving the grouting volume of prefabricated sleeves.

[0009] Furthermore, the sound pressure energy signal is a voltage signal picked up by a microphone with sound insulation function.

[0010] The beneficial effects of the above-mentioned further solution are: it provides a practical solution to the technical bottleneck of unclear defect channel positioning in the process of judging defects in multi-row grout anchors and sleeve grouting using the impact echo method. This solution can significantly improve the randomness of the sleeve and grout anchor detection process in precast structures, thereby effectively strengthening the dynamic monitoring efficiency of engineering construction quality and providing reliable technical support for engineering quality control.

[0011] Furthermore, the stabilization process specifically includes: The same impact pickup signal is stabilized and processed into a 0-channel signal and a 1-channel signal. The pickup signal is the maximum voltage amplitude and the total integrated energy. Channel 1 is the impact hammer with a built-in acceleration sensor, and channel 0 is a dedicated microphone.

[0012] The beneficial effects of the above-mentioned further solution are: it provides a practical solution to the technical bottleneck of unclear defect channel positioning in the process of judging defects in multi-row grout anchors and sleeve grouting using the impact echo method. This solution can significantly improve the randomness of the sleeve and grout anchor detection process in precast structures, thereby effectively strengthening the dynamic monitoring efficiency of engineering construction quality and providing reliable technical support for engineering quality control.

[0013] Furthermore, the dedicated microphone is a sensor built into the vibration tool to pick up signals.

[0014] The beneficial effects of the above-mentioned further solution are: it provides a practical solution to the technical bottleneck of unclear defect channel positioning in the process of judging defects in multi-row grout anchors and sleeve grouting using the impact echo method. This solution can significantly improve the randomness of the sleeve and grout anchor detection process in precast structures, thereby effectively strengthening the dynamic monitoring efficiency of engineering construction quality and providing reliable technical support for engineering quality control.

[0015] Furthermore, the first i The expression for the fusion energy index of the measuring point is as follows: ; ; ; ; in, Indicates the first i Fusion energy index at measuring points and These represent the weights of sound pressure and energy values, respectively. Indicates the first i The maximum voltage of channel 0 at measurement point. Indicates the first i The maximum voltage of channel 1 at measurement point 1 Indicates the voltage reference value. Indicates the energy reference value. Indicates the ungrouted sleeve. j The second test was conducted on the maximum voltage of channel 0. Indicates the ungrouted sleeve. j The next test will measure the maximum voltage of channel 1. Indicates the number of dense channel sleeves j The second test was conducted on the maximum voltage of channel 0. Indicates the number of dense channel sleeves j The next test will measure the maximum voltage of channel 1. Indicates the ungrouted sleeve. j The second test was conducted on channel 0 energy. Indicates the ungrouted sleeve. j The energy of channel 1 was tested next. Indicates the ungrouted sleeve. j The second test was conducted on channel 0 energy. Indicates the ungrouted sleeve. j The energy of channel 1 was tested next. Indicates the first i The energy of channel 0 at measurement point Indicates the first i Energy of channel 1 at measurement point.

[0016] The beneficial effects of the above-mentioned further solution are: it provides a practical solution to the technical bottleneck of unclear defect channel positioning in the process of judging defects in multi-row grout anchors and sleeve grouting using the impact echo method. This solution can significantly improve the randomness of the sleeve and grout anchor detection process in precast structures, thereby effectively strengthening the dynamic monitoring efficiency of engineering construction quality and providing reliable technical support for engineering quality control. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a non-contact testing method for the compaction quality of prefabricated structure sleeve grouting anchor based on the fusion of multiple physical quantities.

[0018] Figure 2 This is a flowchart of the method of the present invention.

[0019] Figure 3 This is a diagram of the prefabricated column structure being tested.

[0020] Among them, 1-precast column, 2-grout outlet, 3-measuring point, 4-precast sleeve component, 5-grouting hole, 6-non-contact sensor, 7-impact hammer (built-in sensor), 8-detection host, 9-industrial plate. Detailed Implementation

[0021] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0022] Example Based on the background technology description, the innovative necessity of the non-contact detection technology for the grouting quality of prefabricated structure sleeve anchors based on the fusion of multiple physical quantities is as follows: 1) Existing technologies generally suffer from the problem of "single-parameter one-sidedness": Energy integral (total energy): Characterizes the overall signal attenuation, can identify large-area holes, but ignores high-frequency transient response.

[0023] 2) The core value of multi-physical quantity fusion: (1) Anti-interference complementarity: sound pressure resists vibration noise, and energy integral resists random interference. (2) Improved quantification accuracy: the recognition rate of grouting non-compactness is improved through the weighted fusion model.

[0024] 3) Engineering adaptability: Non-contact sound insulation testing supports curved components and noisy outdoor environments, with a single-point testing time of less than 1 minute.

[0025] like Figure 2 As shown, this invention provides a non-contact detection method for the grouting quality of prefabricated structure sleeve anchors, the implementation method of which is as follows: S1. Determine the projected position of the sleeve; S2. Based on the determined projection position, trace the sleeve direction on the surface of the prefabricated structure and arrange the measuring points; S3. Using a hammer with a built-in acceleration sensor, strike the surface of the precast column corresponding to the measuring line of the sleeve, and simultaneously collect and save the striking force signal along the measuring point. S4. Process the impact force signal to extract the maximum voltage amplitude and total integrated energy of the hammer recording signal and the sound pressure energy signal, respectively; wherein, the sound pressure energy signal is the voltage signal picked up by a microphone with sound insulation function; S5. Stabilize the extraction results of S4 with the tapping signal, specifically as follows: The same impact pickup signal is stabilized and processed into a 0-channel signal and a 1-channel signal. The pickup signal is the maximum voltage amplitude and the total integrated energy. Channel 1 is the impact hammer with a built-in acceleration sensor, and channel 0 is a dedicated microphone. The dedicated microphone is a sensor for the pickup signal built into the vibration tool. The dedicated microphone can avoid the influence of environmental noise. S6. Calculate the fusion energy index based on the stable processing results; S7. When the fusion energy index is greater than the preset threshold, it is determined that there is a grouting defect in the sleeve, and the non-contact detection of the grouting quality of the prefabricated structure sleeve is completed.

[0026] This invention discloses a non-contact detection method for the grouting quality of prefabricated structure sleeve anchors based on multi-physical quantity fusion. To achieve this invention, a vibration tool for signal acquisition was developed, with a built-in sensor for signal pickup. A dedicated sound pickup device to avoid the influence of environmental noise was adopted, and a detection method that accurately reflects the grouting quality of the sleeve was proposed. Measurement points are arranged at certain intervals on the surface of prefabricated columns, walls, and other structures that have been completed or are in operation. The dedicated vibration tool is used to strike the measurement points, and the signal reaches the surface and interior of the sleeve. When grouting defects exist inside the steel pipe, the characteristic parameters of the signal (maximum signal voltage, impact energy) will change compared to dense areas. The sensor picks up this signal, processes it through a signal conditioning device, and then transmits it to the host for storage and analysis. Prior to this detection system, this detection technology method was first invented, which uses a dedicated vibration tool for vibration and receives and processes the resulting signal, resulting in significant breakthroughs in detection efficiency and accuracy. The non-contact detection method for the grouting quality of prefabricated structure sleeve anchors based on multi-physical quantity fusion is as follows: Testing of ungrouted sleeve precast components: a. Determine the projected position of the sleeve on the structural surface; b. Draw the sleeve's path on the precast structural surface and arrange measuring points at certain intervals; c. Connect the excitation tool, microphone, and testing host using a signal connection cable, turn on the host power, open the testing software, and set the parameters; d. The testing host collects and saves the test signals along the measuring points, performs noise and other signal processing on the test signals, analyzes and determines the characteristic parameters (maximum voltage, energy) of the ungrouted sleeve measuring point position, and performs stabilization processing with the corresponding impact signal; Testing of grout-filled precast components with dense grouting sleeves: The steps are the same as those for testing ungrouted precast components with sleeves. Analyze and calculate the calibration reference values ​​V0 and E0; The grouting quality of the template sleeve is inspected as follows: a. Determine the projected position of the sleeve on the structural surface; b. Draw the sleeve's path on the prefabricated structure surface and arrange measuring points at certain intervals; c. Connect the excitation tool, microphone, and testing host using a signal connection cable, turn on the host power, open the testing software, and set the parameters; d. The testing host collects and saves the test signals along the measuring points, performs noise and other signal processing on the test signals, analyzes and determines the characteristic parameters (maximum voltage, energy) of the measuring points on the ungrouted sleeve, and performs stabilization processing with the corresponding impact signal to calculate the fusion energy index K; e. Determine the location of grouting defects based on the fusion energy index K value.

[0027] like Figure 1 As shown, this invention utilizes a hammer with a built-in accelerometer to strike the object under test, and then detects the changes in the characteristics of the signals picked up by two channels.

[0028] Projection lines are drawn on the test surface of the prefabricated assembled structural sleeve. The detection system is used to calibrate the grouting and non-grouting positions. The reference values ​​are calculated according to formulas (1) to (2): ; ; The grouting fullness of the target sleeve is detected based on the detection benchmark value. First, a projection line is drawn on the test surface of the sleeve, and measuring points with equal spacing are marked. The detection system is used to measure each measuring point of the sleeve sequentially and the data is saved. The maximum voltage amplitude and integrated total energy of the hammer impact signal and sound pressure signal are analyzed and calculated. The test signals are processed as follows to calculate the fusion energy index: ; in, , Indicates the first i Fusion energy index at measuring points and These represent the weights of sound pressure and energy values, respectively. Indicates the first i The maximum voltage of channel 0 at measurement point. Indicates the first i The maximum voltage of channel 1 at measurement point 1 Indicates the voltage reference value. Indicates the energy reference value. Indicates the ungrouted sleeve. j The second test was conducted on the maximum voltage of channel 0. Indicates the ungrouted sleeve. j The next test will measure the maximum voltage of channel 1. Indicates the number of dense channel sleeves j The second test was conducted on the maximum voltage of channel 0. Indicates the number of dense channel sleeves j The next test will measure the maximum voltage of channel 1. Indicates the ungrouted sleeve. j The second test was conducted on channel 0 energy. Indicates the ungrouted sleeve. j The energy of channel 1 was tested next. Indicates the ungrouted sleeve. j The second test was conducted on channel 0 energy. Indicates the ungrouted sleeve. j The energy of channel 1 was tested next. Indicates the first i The energy of channel 0 at measurement point Indicates the first i Energy of channel 1 at measurement point.

[0029] The fusion energy index K is compared with the preset threshold Kth (1.05 in this invention). If K>Kth, it is determined that there is a grouting defect in the sleeve.

[0030] The present invention will now be further described.

[0031] This invention was used to test the grouting quality of precast column sleeves in a prefabricated building project. The precast column under test is shown in the figure. Figure 3 .

[0032] Based on the provided information, the cross-sectional dimensions of the object being tested are 0.5m x 0.5m, the sleeve is made of cast iron, the inner diameter of the sleeve is 45mm, and the center embedment depth of the sleeve is 60mm. The projection line of the sleeve's center is drawn on the test surface, and measurement points are drawn at 100mm intervals, with measurement points also drawn on denser areas away from the sleeve.

[0033] A dedicated cable was used to connect the microphone and hammer to the main unit. The main unit and tablet computer were turned on, and the signals from the measuring points in the dense part and the ungrouted part were collected and analyzed. The test was performed three times in each of the dense part and the ungrouted part.

[0034] Through testing and analysis, V0 = 0.023E0 = 0.03 were obtained. Based on this benchmark, the grouting density of the target sleeve was tested. A total of 6 measuring points on one sleeve were tested, proceeding from top to bottom. The test results and defect judgment are shown in Table 1. The test revealed grouting defects at measuring points 1-5.

[0035] Table 1

[0036] To verify the reliability of the test results, holes were drilled in both the dense and void areas. The verification results showed that the hole drilling results were consistent with the test judgment results.

[0037] Based on the detection and verification results of grouting in precast structure sleeves using this invention, the method can accurately detect the quality of grouting inside precast structure sleeves, providing a reliable detection method for improving engineering construction.

[0038] In summary, the beneficial effects of this invention include at least the following: strong anti-interference ability, multi-parameter fusion can offset the environmental noise influence of a single parameter; improved defect resolution; and expanded applicable scenarios: it can detect shear wall grout anchors and sleeves, realizing rapid, simple and accurate detection of the grouting quality of sleeves and grout anchors in shear walls, precast columns and other structures.

Claims

1. A non-contact method for detecting the grouting quality of prefabricated structure sleeve anchors, characterized in that, Includes the following steps: S1. Determine the projected position of the sleeve; S2. Based on the determined projection position, trace the sleeve direction on the surface of the prefabricated structure and arrange the measuring points; S3. Using a hammer with a built-in acceleration sensor, strike the surface of the precast column corresponding to the measuring line of the sleeve, and simultaneously collect and save the striking force signal along the measuring point. S4. Process the impact force signal to extract the maximum voltage amplitude and total integrated energy of the hammer recording signal and the sound pressure energy signal respectively. S5. Stabilize the extraction results of S4 with the tapping signal; S6. Calculate the fusion energy index based on the stable processing results; S7. When the fusion energy index is greater than the preset threshold, it is determined that there is a grouting defect in the sleeve, and the non-contact detection of the grouting quality of the prefabricated structure sleeve is completed.

2. The non-contact detection method for the grouting quality of prefabricated structure sleeve anchors according to claim 1, characterized in that, The sound pressure energy signal is a voltage signal picked up by a dedicated microphone with sound insulation function.

3. The non-contact detection method for the grouting quality of prefabricated structure sleeve anchors according to claim 1, characterized in that, The stabilization process specifically involves: The same impact pickup signal is stabilized and processed into a 0-channel signal and a 1-channel signal. The pickup signal is the maximum voltage amplitude and the total integrated energy. Channel 1 is the impact hammer with a built-in acceleration sensor, and channel 0 is a dedicated microphone.

4. The non-contact detection method for the grouting quality of prefabricated structure sleeve anchors according to claim 3, characterized in that, The dedicated microphone is a sensor built into the vibration tool to pick up signals.

5. The non-contact detection method for the grouting quality of prefabricated structure sleeve anchors according to claim 1, characterized in that, No. i The expression for the fusion energy index of the measuring point is as follows: ； ； ； ； in, Indicates the first i Fusion energy index at measuring points and These represent the weights of sound pressure and energy values, respectively. Indicates the first i The maximum voltage of channel 0 at measurement point. Indicates the first i The maximum voltage of channel 1 at measurement point 1 Indicates the voltage reference value. Indicates the energy reference value. Indicates the ungrouted sleeve. j The second test was conducted on the maximum voltage of channel 0. Indicates the ungrouted sleeve. j The next test will measure the maximum voltage of channel 1. Indicates the number of dense channel sleeves j The second test was conducted on the maximum voltage of channel 0. Indicates the number of dense channel sleeves j The next test will measure the maximum voltage of channel 1. Indicates the ungrouted sleeve. j The second test was conducted on channel 0 energy. Indicates the ungrouted sleeve. j The energy of channel 1 was tested next. Indicates the ungrouted sleeve. j The second test was conducted on channel 0 energy. Indicates the ungrouted sleeve. j The energy of channel 1 was tested next. Indicates the first i The energy of channel 0 at measurement point Indicates the first i Energy of channel 1 at measurement point.

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