A device and method for quickly detecting grouting fullness using three-axis acceleration

Abstract

The present invention discloses a device for quickly detecting the fullness of grouting by three-axis acceleration, including a smart hammer and a cloud system, the smart hammer and the cloud system are connected, the smart hammer includes a hammer head and a handle, the hammer head and the handle are connected, and a three-axis acceleration sensor is arranged in the hammer head. A device for quickly detecting the fullness of grouting is made by adopting the above technical scheme. The present invention avoids the drawbacks of the current sleeve grouting quality detection such as high cost, poor randomness, and easy missed detection. By using a smart hammer with a three-axis acceleration sensor to hammer the surface of the slurry outlet channel, the acceleration sensor has high sensitivity, low cost, and no calibration required compared to the commonly used piezoelectric force sensor, and can capture all acceleration data after starting work, so that those plastic deformations that are invisible to the naked eye can be well captured without causing damage to the component, and the fullness of the slurry can be accurately judged.

Description

Technical Field

[0001] The invention relates to the technical field of prefabricated buildings, and in particular to a device and method for quickly detecting grouting fullness using three-axis acceleration. Background Art

[0002] Concrete structures can be divided into cast-in-place concrete structures (cast-in-place concrete structures) and prefabricated concrete structures according to the construction method. Cast-in-place concrete structures are widely used because of their excellent overall performance and seismic performance during the use stage of the structure. However, this construction method is mainly completed by workers on site, with high labor intensity and complex processes. The noise and dust generated during the construction process will seriously affect the normal life of surrounding residents and have an adverse impact on the environment. Prefabricated concrete structures can effectively solve the above problems with their own advantages and characteristics in the production and construction process of the structure, and are an inevitable way for the mechanization, automation and intelligence of construction development. Compared with traditional buildings, prefabricated concrete structures have the advantages of high productivity, high quality of building products, greatly shortened construction period and high resource utilization rate. Grouting sleeve connection is one of the important connection methods for prefabricated prefabricated concrete structure nodes. The emergence of grouting sleeves allows components to be produced separately in the factory and directly connected to the construction site through sleeves. The entire project is fast and orderly, and the construction site is clean and environmentally friendly. However, due to the complexity of grouting construction and the fact that the grouting construction process is not yet perfect, the prefabricated concrete structure has shortcomings such as poor integrity and substandard node requirements during the production process, which leads to its unstable structure, poor seismic resistance, and potential safety hazards. Therefore, quality inspection of prefabricated concrete structures, especially the inspection of the fullness of sleeve grouting, is very necessary. Since the steel sleeve grouting connection structure is complex and belongs to a hidden project, the inspection of grouting fullness is a recognized problem at home and abroad.

[0003] At present, the main methods for detecting the fullness of sleeve grouting in prefabricated concrete structures are: pre-buried steel wire pulling method, damped vibration sensor method, ultrasonic method, core drilling method, etc.

[0004] The pre-buried steel wire drawing method inserts a steel wire into the grouting port, then grouts from the grouting port. After the grouting material flows out of the grouting port, the grouting port is immediately blocked, and a drawing test is performed on the pre-buried steel wire. The grouting fullness is judged according to the drawing value. However, this method is prone to on-site disturbance or damage before testing because the steel wire drawing section is left outside the surface of the prefabricated component for too long.

[0005] The vibration sensor method with damping requires pre-embedded devices or sensors in the building structure. Since the elastic modulus of different media (such as liquid and gas) inside the object to be tested is different, the larger the elastic modulus of the medium that the sensor contacts, the smaller the amplitude of the sensor. Therefore, the pre-embedded sensor method uses this characteristic to make a judgment on the medium condition inside the object to be tested based on the attenuation of the amplitude. However, it also has some shortcomings, such as the inability to meet the requirements of random structural detection, high detection cost, and limited number of detections.

[0006] Ultrasonic testing is a non-destructive testing technology that does not cause damage to components. This method can reflect the internal conditions and compactness of concrete through the propagation of sound waves. However, since the size of the cavity between the sleeve and the steel bar is smaller than the wavelength of ultrasonic waves, the resolution of defects in this method is not high, and defects are often missed. In addition, the ultrasonic method is affected by multiple factors during the detection process, and the situation is relatively complicated, and the measurement data error is relatively large.

[0007] The core drilling method does not require the establishment of a curve relationship between a certain parameter and the strength of the concrete structure. The detection method is relatively intuitive and simple. After obtaining the test piece, the internal conditions of the concrete structure can be directly observed and understood systematically. It is the most accurate method among various detection results. However, when the core drilling method is used to detect prefabricated components, the steel bars are inevitably damaged and are limited by the position and quantity. While reducing the number of core samples as much as possible, it cannot accurately reflect the continuity and comprehensiveness of the components.

[0008] Therefore, an urgent problem to be solved in the detection of the fullness of the sleeve grouting of prefabricated concrete structures is: how to find a detection method and device that is fast, simple, widely applicable, less destructive, and has small errors. Summary of the invention

[0009] In order to solve the above problems, the present invention provides a device and method for rapid detection of grouting fullness by triaxial acceleration. The purpose of the present invention is to solve the problems of high destructiveness, large error, incomplete detection, poor randomness and complex operation in the detection of grouting fullness of prefabricated concrete structure sleeves.

[0010] A device for quickly detecting grouting fullness using three-axis acceleration in the present invention comprises a smart hammer and a cloud system, wherein the smart hammer is connected to the cloud system, the smart hammer comprises a hammer head and a handle, the hammer head is connected to the handle, and a three-axis acceleration sensor is arranged in the hammer head.

[0011] In the above scheme, the end of the hammer head is a spherical end, the handle is also provided with an LED indicator light, the handle is provided with an embedded system and a power supply, and the end of the handle is provided with a charging port.

[0012] In the above solution, the three-axis acceleration sensor is connected to the embedded system, the embedded system is connected to the LED indicator light, the embedded system is connected to the power supply, and the embedded system is connected to the cloud system.

[0013] In the above solution, a wireless communication module is provided in the embedded system, and the embedded system is wirelessly connected to the cloud system via the wireless communication module.

[0014] In the above scheme, when the triaxial acceleration sensor is built into the hammer groove, the accelerations in three directions are respectively X-direction is parallel to the axis of the hammer, Y-direction is perpendicular to the operating handle, and Z-direction is parallel to the operating handle.

[0015] A method for quickly detecting grouting fullness using triaxial acceleration comprises the following steps:

[0016] S1: Fully charge the power of the smart hammer through the charging port;

[0017] S2: Use the handle to drive the hammer head to vertically strike the grouting full component in the precast concrete component;

[0018] S3: Gradually increase the impact acceleration to exceed the specified threshold, and the triaxial acceleration sensor starts to work normally;

[0019] S4: All the collected acceleration signals are transmitted to the embedded system. When the qualified component reaches the critical state of being destroyed and undergoing plastic deformation, the impact acceleration at this time is recorded;

[0020] S5: Receive signals and analyze the data using built-in algorithms;

[0021] S6: restore the differentiated acceleration by inverse transformation through an algorithm;

[0022] S7: Test the components that are not fully grouted;

[0023] S8: For the incompletely grouted component, hammer it three times with the same impact acceleration to determine whether the grouting of the component is incomplete.

[0024] In the above scheme, in S3, when the three-axis acceleration sensor is built into the hammer groove, the accelerations in three directions are respectively parallel to the axis of the hammer in the X direction, perpendicular to the operating handle in the Y direction, and parallel to the operating handle in the Z direction. The acceleration direction of the X-axis of the three-axis acceleration sensor is perpendicular to the surface of the slurry outlet hole of the precast concrete component to ensure that the deflection angle θ in the X direction is less than 15°.

[0025] In the above solution, in S5, the signal of the three-axis acceleration sensor is received by the embedded system.

[0026] In the above scheme, S6 specifically comprises: performing numerical transformation on the received signal, algorithmically adding 500 to the acceleration in the X direction, keeping the acceleration in the Y direction unchanged, and subtracting 500 from the acceleration in the Z direction, thereby distinguishing the accelerations in the three directions, and restoring the distinguished accelerations by inverse transformation.

[0027] In the above scheme, the S6 judges whether the operation of the restored acceleration is effective, and judges whether |Y / X|<tan15°, |Z / X|<tan15° meets the working requirements. When the knocking direction does not meet the working requirements, the LED indicator light shows yellow, indicating that the direction of the hammering during this knocking process is not vertical and exceeds the maximum deflection angle, so the collected results are questionable and need to be sent to the cloud system for secondary judgment; if the LED indicator light shows green, the data collected this time is valid and the grouting is full.

[0028] The advantages and beneficial effects of the present invention are as follows: The present invention provides a device and method for quickly detecting the fullness of grouting by three-axis acceleration. 1. The present invention avoids the drawbacks of the current sleeve grouting quality detection, such as high cost, poor randomness, and easy missed detection. By using an intelligent hammer with a three-axis acceleration sensor to hammer the surface of the slurry outlet channel, the acceleration sensor has high sensitivity, low cost, and no need for calibration compared to the commonly used piezoelectric force sensor. It can capture all acceleration data after starting work, so that it can achieve good capture of those plastic deformations that are invisible to the naked eye without causing damage to the component, and accurately judge the fullness of the slurry.

[0029] 2. The present invention judges through the ratio of accelerations generated by the intelligent hammer. The detection principle is ingenious, the detection method is convenient, and it is not affected by the detection environment. Not only is it easy for the personnel of the detection unit to master it, but also the experienced workers on the front line can quickly get started to self-check the quality of the grouting of the prefabricated concrete structure sleeve.

[0030] 3. The present invention ensures that the acceleration direction of the X-axis of the three-axis acceleration sensor is installed parallel to the axis of the hammer head, thereby ensuring that each X-axis acceleration can be effectively collected for judgment.

[0031] 4. The present invention has high detection efficiency. Considering the improper operation of workers in actual projects, wireless communication (such as Bluetooth) is built into the embedded system to connect to the cloud system, which is convenient for professionals to perform online diagnosis of questionable data and provide timely feedback to on-site workers.

[0032] 5. The present invention has little destructiveness to prefabricated concrete structures and will not pose a safety hazard. It can be used in conjunction with a quantitative detection method to first quickly and accurately determine the grouting fullness of the prefabricated concrete structure, and then use a quantitative detection method to accurately measure the detected unqualified components, which can greatly reduce workload and improve work efficiency.

[0033] 6. The present invention uses a built-in algorithm in the embedded system. When the impact acceleration does not reach the specified threshold value in an abnormal working state, the smart hammer will not start; and in order to make the hammering direction as perpendicular to the surface of the slurry outlet hole as possible, a maximum deflection angle is specified, and the color indicated by the LED is used to determine whether the detection work is effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 It is a structural schematic diagram of the intelligent hammer of the present invention;

[0036] Figure 2 It is a system schematic diagram of the present invention;

[0037] Figure 3 A schematic diagram of the working direction of the three-axis acceleration sensor of the present invention;

[0038] Figure 4 The three-axis acceleration curve, maximum and minimum values ​​and ratio of the device of the present invention under hammer grouting full sleeve;

[0039] Figure 5 It is the three-axis acceleration curve, maximum and minimum values ​​and ratio of the device of the present invention under the condition of hammer grouting an incomplete sleeve.

[0040] In the figure: 1. Smart hammer 2. Hammer head 3. Handle 4. Three-axis acceleration sensor 5. LED indicator 6. Embedded system 7. Power supply 8. Charging port 9. Cloud system 10. Wireless communication module DETAILED DESCRIPTION

[0041] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0042] like Figure 1 As shown, the present invention is a device for quickly detecting grouting fullness by three-axis acceleration, including a smart hammer 1 and a cloud system 9, the smart hammer 1 is connected to the cloud system 9, the smart hammer 1 includes a hammer head 2 and a handle 3, the hammer head 2 is connected to the handle 3, and a three-axis acceleration sensor 4 is provided in the hammer head 2.

[0043] The end of the hammer head 2 is a spherical end, which can achieve a better impact effect relative to a plane. The handle 3 is also provided with an LED indicator 5, an embedded system 6 and a power supply 7 are provided in the handle 3, and a charging port 8 is provided at the end of the handle 3. The hammering direction of the hammer head 2 should be kept as vertical as possible to the surface of the slurry outlet hole of the assembled concrete structure.

[0044] like Figure 2 As shown, the triaxial acceleration sensor 4 is connected to the embedded system 6, the embedded system 6 is connected to the LED indicator 5, the embedded system 6 is connected to the power supply 7, and the embedded system 6 is connected to the cloud system 9. The fullness of the experimental object is automatically determined by judging the color of the LED indicator connected to the embedded system 6. Green means that the experimental object is full, red means that the experimental object is not full, and yellow means that the experiment is doubtful and needs cloud system diagnosis and analysis.

[0045] The embedded system 6 is provided with a wireless communication module 10, and the embedded system 6 is wirelessly connected to the cloud system 9 via the wireless communication module 10. The embedded system 6 is installed inside the handle, and uses I 2 The high-speed communication rate of protocols such as C or SPI matches the output rate of the serial port of the three-axis acceleration sensor 4, thereby avoiding the loss of collected data or additional noise and increasing the accuracy of the detection result. The embedded system 6 specifies the trigger threshold of the three-axis acceleration sensor 4 through a pre-built-in algorithm to prevent the failure of the collected signal due to mis-touch during operation. Only when the impact acceleration exceeds the specified threshold, the three-axis acceleration sensor 4 starts to work and collect acceleration signals. The sampling time of each time is written into the algorithm according to actual requirements.

[0046] When the triaxial acceleration sensor 4 is built into the groove of the hammer head 2, the accelerations in three directions are respectively parallel to the axis of the hammer head in the X direction, perpendicular to the operating handle in the Y direction, and parallel to the operating handle in the Z direction. The ports of the triaxial acceleration sensor 4 are connected one-to-one with the ports of the embedded system 6.

[0047] A method for quickly detecting grouting fullness using triaxial acceleration comprises the following steps:

[0048] S1: Fully charge the power of the smart hammer through the charging port;

[0049] S2: Use the handle to drive the hammer head to vertically strike the grouting full component in the precast concrete component;

[0050] S3: Gradually increase the impact acceleration to exceed the specified threshold, and the triaxial acceleration sensor starts to work normally;

[0051] S4: All the collected acceleration signals are transmitted to the embedded system. When the qualified component reaches the critical state of being destroyed and undergoing plastic deformation, the impact acceleration at this time is recorded;

[0052] S5: Receive signals and analyze the data using built-in algorithms;

[0053] S6: restore the differentiated acceleration by inverse transformation through an algorithm;

[0054] S7: Test the components that are not fully grouted;

[0055] S8: For the incompletely grouted component, hammer it three times with the same impact acceleration to determine whether the grouting of the component is incomplete.

[0056] In the above scheme, in S3, when the triaxial acceleration sensor is built into the hammer groove, the accelerations in three directions are respectively parallel to the axis of the hammer in the X direction, perpendicular to the operating handle in the Y direction, and parallel to the operating handle in the Z direction. The acceleration direction of the X axis of the triaxial acceleration sensor is perpendicular to the surface of the slurry outlet hole of the precast concrete component to ensure that the deflection angle θ in the X direction is less than 15°, such as Figure 3 shown.

[0057] In the above scheme, in S5, the signal of the three-axis acceleration sensor is received through the embedded system. The collected acceleration signal is analyzed by the built-in algorithm in the embedded system, mainly including: intelligently distinguishing the signals of the three axes of X, Y, and Z from the original signal, automatically extracting the maximum and minimum values ​​of the three axes as the impact acceleration and rebound acceleration, and automatically judging the fullness of the experimental object, such as Figure 4 Among them, the maximum and minimum values ​​of the three axes are automatically extracted by writing MAX and MIN functions in the built-in algorithm of the embedded system to quickly obtain the maximum and minimum values ​​of each test, which is convenient for judging the fullness.

[0058] In the above scheme, S6 specifically comprises: performing numerical transformation on the received signal, algorithmically adding 500 to the acceleration in the X direction, keeping the acceleration in the Y direction unchanged, and subtracting 500 from the acceleration in the Z direction, thereby distinguishing the accelerations in the three directions, and restoring the distinguished accelerations by inverse transformation.

[0059] In the above scheme, S6 judges whether the restored acceleration operation is effective, and judges whether |Y / X|<tan15°, |Z / X|<tan15° meets the working requirements. When the knocking direction does not meet the working requirements, the LED indicator lights up yellow, indicating that the direction of the hammering during this knocking process is not vertical and exceeds the maximum deflection angle, so the collected results are questionable and need to be sent to the cloud system for secondary judgment; if the LED indicator lights up green, the data collected this time is valid and the grouting is full.

[0060] Specifically, the LED indicator displays green because the ratio of the absolute values ​​of the maximum value to the minimum value on the X-axis is within the range of statistical values ​​after a large number of experiments and using the acceleration data in the Y and Z directions as an aid, the ratio of the minimum values ​​of the two axes to the minimum value of the X-axis satisfies |Y / X|<tanθ,|Z / X|<tanθ; the reason why the LED indicator displays red is that the ratio of the absolute values ​​in the X-axis direction is not within the statistical range of values; the reason why the LED indicator displays yellow is that the X-axis direction in actual operation is not perpendicular to the surface of the slurry outlet channel, and when using the acceleration data in the Y and Z directions as an auxiliary judgment, the ratio of the minimum values ​​of the two axes to the minimum value of the X-axis does not meet the requirements and exceeds the maximum deflection angle allowed by regulations.

[0061] If the LED indicator light is yellow, manual diagnosis is required through the cloud. By visualizing the cloud data, engineers can analyze the cause and make a judgment report based on the displayed acceleration waveform.

[0062] In the above scheme, in S7, the incompletely grouted component is tested, the critical acceleration is recorded as the impact acceleration, and steps S2-S5 are repeated to calculate the impact acceleration and rebound acceleration in each direction, such as Figure 5 As shown, through algorithm calculation and analysis, if the LED indicator light shows green, it means that the data collected this time is valid and the grouting is full; if the LED indicator light shows red, it means that the data collected this time is valid and the grouting is not full.

[0063] In order to reduce errors, for the same hammer point, maintain the same impact acceleration and hammer multiple times, observe the color of the LED light to determine whether it is consistent. If there is any doubt, send it to the cloud and judge again by the average value of multiple experiments.

[0064] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for quickly detecting grouting fullness using triaxial acceleration, characterized in that: The invention comprises an intelligent hammer and a cloud system, wherein the intelligent hammer is connected to the cloud system, the intelligent hammer comprises a hammer head and a handle, the hammer head is connected to the handle, a three-axis acceleration sensor is arranged in the hammer head, the end of the hammer head is a spherical end, an LED indicator light is also arranged on the handle, an embedded system and a power supply are arranged in the handle, a charging port is arranged at the end of the handle, the three-axis acceleration sensor is connected to the embedded system, the embedded system is connected to the LED indicator light, the embedded system is connected to the power supply, the embedded system is connected to the cloud system, a wireless communication module is arranged in the embedded system, the embedded system is wirelessly connected to the cloud system via the wireless communication module, and the three acceleration directions of the three-axis acceleration sensor when it is built into the groove of the hammer head are respectively that the X direction is parallel to the axis center line of the hammer head, the Y direction is perpendicular to the operating handle, and the Z direction is parallel to the operating handle.

2. A method for quickly detecting grouting fullness by three-axis acceleration, applied to the device for quickly detecting grouting fullness by three-axis acceleration as claimed in claim 1, characterized in that: The following steps are involved: S1: Fully charge the power of the smart hammer through the charging port; S2: Use the handle to drive the hammer head to vertically strike the grouting full component in the precast concrete component; S3: Gradually increase the impact acceleration to exceed the specified threshold, and the triaxial acceleration sensor starts to work normally; S4: All the collected acceleration signals are transmitted to the embedded system. When the qualified component reaches the critical state of being destroyed and undergoing plastic deformation, the impact acceleration at this time is recorded; S5: Receive signals and analyze the data using built-in algorithms; S6: restore the differentiated acceleration by inverse transformation through an algorithm; S7: Test the components that are not fully grouted; S8: For the incompletely grouted component, hammer it three times with the same impact acceleration to determine whether the grouting of the component is incomplete.

3. The method for rapid detection of grouting fullness by triaxial acceleration according to claim 2 is characterized in that: In S3, when the three-axis acceleration sensor is built into the hammer groove, the directions of the three accelerations are respectively X-axis parallel to the axis of the hammer, Y-axis perpendicular to the operating handle, and Z-axis parallel to the operating handle. The acceleration direction of the X-axis of the three-axis acceleration sensor is perpendicular to the surface of the slurry outlet hole of the precast concrete component to ensure that the deflection angle θ in the X-direction is less than 15°.

4. The method for rapid detection of grouting fullness by triaxial acceleration according to claim 2 is characterized in that: In S5, the signal of the three-axis acceleration sensor is received by the embedded system.

5. The method for rapid detection of grouting fullness by triaxial acceleration according to claim 2 is characterized in that: Specifically, S6 is to perform numerical transformation on the received signal, and algorithmically add 500 to the acceleration in the X direction, keep the acceleration in the Y direction unchanged, and subtract 500 from the acceleration in the Z direction, so as to distinguish the accelerations in three directions, and perform inverse transformation to restore the distinguished accelerations.

6. The method for rapid detection of grouting fullness by triaxial acceleration according to claim 5 is characterized in that: The S6 determines whether the restored acceleration is effective, and determines whether |Y / X|<tan15°, |Z / X|<tan15° meets the working requirements. When the striking direction does not meet the working requirements, the LED indicator lights up yellow, indicating that the direction of the hammering during this striking process is not vertical and exceeds the maximum deflection angle, so the collected results are questionable and need to be sent to the cloud system for secondary judgment; If the LED indicator lights green, the data collected this time is valid and the grouting is full.

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