Cement-based intelligent aggregate and temperature compensation method

Abstract

The invention provides a cement-based intelligent aggregate and a temperature compensation method, and relates to the technical field of intelligent materials and structural health monitoring, and the method comprises the steps: obtaining a plurality of impedance signals of the cement-based intelligent aggregate, the impedance signals comprising a reference signal and a target signal; respectively carrying out normalization processing on the reference signal and the target signal; calculating a local cost matrix according to the normalized reference signal and the target signal; recursively calculating an accumulated cost matrix according to the local cost matrix; according to the cumulative cost matrix, determining an optimal distortion path; and reconstructing the target signal through the optimal distortion path to carry out temperature compensation so as to obtain a compensation signal. According to the invention, the interference of temperature change caused by the temperature sensitivity of the piezoelectric ceramic on the impedance signal of the intelligent aggregate is avoided, the influence of the temperature change and structural damage on the superimposed effect of the impedance signal of the intelligent aggregate is reduced, and the monitoring precision of the intelligent aggregate under the complex temperature change working condition is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent materials and structural health monitoring, and in particular to a cement-based intelligent aggregate and a temperature compensation method. Background Art

[0002] As civil engineering structures become increasingly complex, structural health monitoring technology has become a key means to ensure engineering safety. Electromechanical impedance technology has been widely used in the field of concrete structure damage identification due to its high sensitivity and real-time monitoring advantages. However, piezoelectric ceramics, as core sensing elements, have problems such as interface compatibility with concrete matrix and signal stability that require breakthrough solutions.

[0003] In the existing technology, although the material compatibility can be improved by packaging piezoelectric ceramics into smart aggregates and embedding them into concrete structures, there are still significant defects: the smart aggregates are difficult to replace and maintain after solidification and burial, and a single piezoelectric unit can only provide a single set of impedance signals. The lack of signal redundancy leads to doubts about reliability.

[0004] At present, most of the existing smart aggregates rely on statistical indicators of impedance signals to quantify the state changes of the structure, such as root mean square deviation, mean absolute percentage deviation and correlation coefficient deviation, which are highly dependent on the selection of frequency range. In actual application, repeated trials are required to determine the effective frequency band, and there is a lack of universal evaluation standards.

[0005] In addition, due to the temperature sensitivity of piezoelectric ceramics themselves, temperature changes will interfere with the impedance signal of smart aggregates. The effects of temperature changes and structural damage on the impedance signal of smart aggregates are superimposed on each other, resulting in a significant decrease in the monitoring accuracy of smart aggregates under complex temperature change conditions. Summary of the invention

[0006] In order to solve the problems that traditional smart aggregates are difficult to replace and maintain after solidification and burial, a single piezoelectric unit can only provide a single set of impedance signals, insufficient signal redundancy leads to doubtful reliability, and rely on statistical indicators of impedance signals to quantify the state changes of the structure, which has a strong dependence on the selection of frequency range. In practical applications, it is necessary to repeatedly calculate and determine the effective frequency band, lack of universal evaluation standards, and due to the temperature sensitivity of piezoelectric ceramics themselves, temperature changes will interfere with the impedance signal of smart aggregates. The effects of temperature changes and structural damage on the impedance signal of smart aggregates are superimposed on each other, resulting in a significant decrease in the monitoring accuracy of smart aggregates under complex temperature change conditions. The present invention provides a cement-based smart aggregate and a temperature compensation method.

[0007] The technical solution provided by the embodiment of the present invention is as follows:

[0008] First aspect:

[0009] A cement-based intelligent aggregate provided by an embodiment of the present invention includes: a cement matrix, multiple wires, multiple piezoelectric units, and a waterproof and insulating protective layer;

[0010] The cement matrix is made by pouring in a casting mold;

[0011] The casting mold includes multiple bases, multiple side plates, and a bottom plate. The side plates include multiple openings, and the bottom plate includes multiple positioning grooves. The bases are fixed by fixing bolts;

[0012] The piezoelectric units are embedded in the positioning grooves;

[0013] The wires are connected to the respective piezoelectric units through the respective openings;

[0014] The waterproof and insulating protective layer is provided on the surface of the piezoelectric units.

[0015] Second aspect:

[0016] A temperature compensation method provided by an embodiment of the present invention is applied to the cement-based intelligent aggregate in the first aspect and includes:

[0017] S1: Obtain multiple impedance signals of the cement-based intelligent aggregate, where the impedance signals include a reference signal and a target signal;

[0018] S2: Perform normalization processing on the reference signal and the target signal respectively;

[0019] S3: Calculate a local cost matrix according to the normalized reference signal and target signal;

[0020] S4: Recursively calculate an accumulated cost matrix according to the local cost matrix;

[0021] S5: Determine an optimal warping path according to the accumulated cost matrix;

[0022] S6: Reconstruct the target signal through the optimal warping path to perform temperature compensation and obtain a compensation signal.

[0023] The beneficial effects brought by the technical solutions provided by the embodiments of the present invention at least include:

[0024] In the embodiments of the present invention, a cement-based intelligent aggregate is made by combining and casting a cement matrix, multiple wires, multiple piezoelectric units, and a waterproof and insulating protective layer, which avoids the difficulty of replacement and maintenance after the intelligent aggregate is cured and buried, no longer relies on a single piezoelectric unit to provide a single set of impedance signals, improves the signal redundancy and reliability, determines the optimal distortion path, and reconstructs the target signal through the optimal distortion path for temperature compensation to obtain a compensated signal. It no longer relies on the statistical indicators of impedance signals to quantify the structural state changes, has no strong dependence on the selection of the frequency range, and does not require repeated calculations to determine the effective frequency band during the actual application process. It has a universal evaluation criterion, avoids the interference of temperature changes caused by the temperature sensitivity of piezoelectric ceramics on the impedance signal of the intelligent aggregate, reduces the influence of the superposition effect of temperature changes and structural damage on the impedance signal of the intelligent aggregate, and improves the monitoring accuracy of the intelligent aggregate under complex temperature change conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 FIG. is a schematic structural diagram of a cement-based intelligent aggregate provided by an embodiment of the present invention;

[0027] Figure 2 FIG. is a result display diagram of a self-calibration function provided by an embodiment of the present invention;

[0028] Figure 3 FIG. is a schematic flowchart of a temperature compensation method provided by an embodiment of the present invention;

[0029] Figure 4 FIG. is a comparison diagram of measurement results of a wireless impedance measurement system provided by an embodiment of the present invention;

[0030] Figure 5 FIG. is a compensation result display diagram of a temperature compensation algorithm provided by an embodiment of the present invention.

[0031] Reference numerals: 1, cement-based piezoelectric intelligent aggregate; 2, cement-based intelligent aggregates connected in series; 3, cement-based intelligent aggregates connected in parallel; 4, cement matrix; 5, wire; 6, piezoelectric unit; 7, waterproof and insulating protective layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The following will describe the technical solutions in the present invention with reference to the drawings.

[0033] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to give examples, illustrations or explanations. Any embodiment or design solution described as an "example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of the word "example" is intended to present concepts in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one of the two.

[0034] To make the technical problems to be solved, technical solutions and advantages of the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] Refer to the attached Figure 1 of the specification, which shows a schematic structural diagram of a cement-based intelligent aggregate provided by an embodiment of the present invention.

[0036] An embodiment of the present invention provides a cement-based intelligent aggregate, including: a cement matrix 4, a plurality of wires 5, a plurality of piezoelectric units 6, and a waterproof and insulating protective layer 7.

[0037] Specifically, the cement-based piezoelectric intelligent aggregate 1 is composed of a cement matrix 4, four wires 5, two piezoelectric units 6, and a waterproof and insulating protective layer 7, with dimensions of 30mm×70mm×23mm.

[0038] In the present invention, through the combined design of a plurality of wires and a plurality of piezoelectric units, this cement-based intelligent aggregate has higher signal stability and adaptability. The waterproof and insulating protective layer provides good protection, enabling it to adapt to more complex environments. The cement matrix and precise dimensional control improve its structural stability and monitoring accuracy during long-term applications.

[0039] The cement matrix is made by pouring into a casting mold.

[0040] Specifically, the cement paste with a preset water-cement ratio or the concrete with a preset ratio is slowly poured into the casting mold, and fully oscillated to remove air bubbles. Subsequently, the mold is placed steadily for 24 hours. After the cement matrix is initially solidified, the mold is removed, and it is cured under standard conditions for 28 days. After curing is completed, the dimensions of the cement matrix are precisely finished by combining a numerical control grinding machine and manual grinding to ensure that it meets the specification requirements.

[0041] It should be noted that those skilled in the art can set the sizes of the preset water-cement ratio and the preset ratio according to actual needs, and the present invention does not make any limitations here.

[0042] In the present invention, a casting mold is used to fabricate the cement matrix, and methods such as vibration to remove air bubbles, standard curing time, and precision finishing with a CNC grinding machine are employed to ensure the uniformity, strength, dimensional accuracy, and stability of the cement matrix. The flexible ratio design provides customized options, enabling the adjustment of the characteristics of the cement matrix according to actual requirements.

[0043] The casting mold includes a plurality of bases, a plurality of side plates, and a bottom plate. The side plates include a plurality of openings, and the bottom plate includes a plurality of positioning grooves. The bases are fixed by fixing bolts.

[0044] Specifically, the casting mold includes two bases, two side plates, and a bottom plate. Each of the two side plates includes two openings, and the bottom plate includes two positioning grooves.

[0045] In the present invention, this casting mold design ensures the accurate positioning of the piezoelectric unit, precise control of the casting process, reusability of the mold, and production consistency through the combination of a plurality of bases, side plates, and bottom plates, as well as the design of openings and positioning grooves.

[0046] Optionally, the bases are made by 3D printing technology, the side plates and the bottom plate are made by grinding acrylic plates, and the side plates and the bottom plate are adhered to the bases with epoxy AB glue.

[0047] In the present invention, the bases are manufactured by 3D printing technology, the side plates and the bottom plate are made by grinding acrylic plates, and epoxy AB glue is used for bonding, which improves the accuracy, design flexibility, and complexity of the mold, enhances the strength, durability, and stability of the mold, and ensures that no damage occurs during long-term use.

[0048] The piezoelectric unit is embedded in the positioning groove.

[0049] Optionally, the piezoelectric unit is specifically: a piezoelectric ceramic block or a piezoelectric stack, with the material being PZT-5H, the size being 15mm×10mm×25mm, the distance between two piezoelectric units being 16mm, the distances from the top piezoelectric unit to the upper surface and the side surface of the smart aggregate being 17mm and 7.5mm respectively, and the distances from the bottom piezoelectric unit to the lower surface and the side surface of the smart aggregate being 17mm and 7.5mm respectively.

[0050] In the present invention, by embedding the piezoelectric unit in the positioning groove, using PZT-5H material and precisely controlling its size, spacing, and installation position, the structural stability, signal sensing ability, and long-term reliability of the cement-based smart aggregate can be effectively ensured.

[0051] The wires are connected to the respective piezoelectric units through the respective openings.

[0052] Specifically, the piezoelectric unit includes a positive electrode surface and a negative electrode surface.

[0053] The wire is welded to the positive electrode surface or the negative electrode surface of each piezoelectric unit through each opening.

[0054] In the present invention, by welding the wire to the electrode surface of the piezoelectric unit through the opening, the present invention provides significant advantages in ensuring signal stability, reducing the risk of poor electrical contact, enhancing the adaptability of the working environment, and simplifying the production process.

[0055] Refer to the attached Figure 2 illustrates a diagram showing the results of a self-calibration function provided by an embodiment of the present invention.

[0056] In a possible implementation manner, by changing the wiring method between the wires, two working modes of series connection and parallel connection are achieved, obtaining the cement-based smart aggregate 2 connected in series and the cement-based smart aggregate 3 connected in parallel. In actual application, the developed cement-based smart aggregate can output two sets of effective data for self-calibration, ensuring the effectiveness and accuracy of the impedance signal.

[0057] The waterproof and insulating protective layer is disposed on the surface of the piezoelectric unit.

[0058] Optionally, the waterproof and insulating protective layer is specifically: liquid insulating electrical tape.

[0059] In the present invention, by disposing the waterproof and insulating protective layer on the surface of the piezoelectric unit and using liquid insulating electrical tape, the piezoelectric unit can be effectively protected from the effects of moisture, corrosion, chemical contamination, and electrical interference, improving the durability, reliability, and long-term stability of the smart aggregate.

[0060] The beneficial effects brought by the technical solution provided by the embodiment of the present invention at least include:

[0061] In the embodiment of the present invention, the cement-based smart aggregate is made by combining and casting a cement matrix, multiple wires, multiple piezoelectric units, and a waterproof and insulating protective layer, avoiding the difficulty of replacement and maintenance after the smart aggregate is cured and buried, and no longer relying on a single piezoelectric unit to provide a single set of impedance signals, improving the signal redundancy and reliability.

[0062] Refer to the attached Figure 3 illustrates a schematic flow diagram of a temperature compensation method provided by the present invention.

[0063] The present invention also provides a temperature compensation method, including:

[0064] S1: Obtain multiple impedance signals of the cement-based smart aggregate, where the impedance signals include a reference signal and a target signal.

[0065] Specifically, based on the direct and inverse piezoelectric effects of the piezoelectric unit, an impedance analyzer is used to measure and obtain multiple impedance signals of the cement-based smart aggregate.

[0066] It should be noted that the impedance signal refers to the change in impedance (the combined manifestation of resistance, inductance, and capacitance) in piezoelectric materials or other sensor materials due to the action of an external voltage or mechanical force.

[0067] It should be noted that an impedance analyzer is a device used to measure the impedance characteristics (the ratio of voltage to current) of materials or electronic components at different frequencies. It calculates the impedance value by applying an alternating current signal with a known frequency and measuring the amplitude and phase of the response signal.

[0068] Among them, the reference signal is the impedance signal obtained by measuring the cement-based smart aggregate at room temperature, and the target signal is the impedance signal obtained by measuring the cement-based smart aggregate at different temperatures:

[0069]

[0070] Among them, Z ref represents the reference signal, and Z aim represents the target signal.

[0071] In the present invention, by acquiring the reference signal and the target signal and using an impedance analyzer for high-precision measurement, the present invention can accurately evaluate the influence of temperature on the impedance of the cement-based smart aggregate, providing reliable data support for subsequent temperature compensation and structural health monitoring. This approach not only improves the effect of temperature compensation but also makes the signal analysis more accurate and stable, contributing to enhancing the performance and reliability of the overall monitoring system.

[0072] Optionally, in order to save labor costs and achieve the function of remote real-time monitoring, the present invention further designs a wireless impedance measurement system as an alternative to the impedance analyzer. The system includes: an impedance measurement module, a power supply module, a communication module, and a microcontroller module.

[0073] Among them, the impedance measurement module uses the impedance measurement chips AD5933 / AD5941 to perform the impedance signal measurement function.

[0074] Among them, the power supply module has a specification of 12V / 2A and is used to provide electrical energy for the wireless impedance measurement system.

[0075] Among them, the communication module is a 4G DTU communication module and is used to upload the impedance signal data to the cloud platform.

[0076] Among them, the microcontroller module consists of an STM32F103C8T6 single-chip microcomputer, a reset circuit, a clock circuit, a program download and debugging interface, and an LED for debugging, and is used to coordinate the normal operation of the entire wireless impedance measurement system.

[0077] Refer to the attached instructions Figure 4, showing a comparison chart of the measurement results of a wireless impedance measurement system provided by the present invention.

[0078] Specifically, a wireless impedance measurement system is used to replace an impedance analyzer to obtain multiple impedance signals of cement-based intelligent aggregates.

[0079] Furthermore, a personal computer is used to download the impedance signal data and compare it with the impedance signal data measured by the impedance analyzer. It is determined that there is a high degree of consistency between the results measured by the impedance analyzer and those measured by the wireless impedance measurement system, verifying the accuracy and reliability of the wireless impedance measurement system. Therefore, through the wireless impedance measurement system designed by the present invention, the traditional impedance analyzer can be perfectly replaced to obtain the impedance signals of cement-based intelligent aggregates, and the measurement result error is small.

[0080] In the present invention, by using a wireless impedance measurement system to replace the traditional impedance analyzer to obtain multiple impedance signals of cement-based intelligent aggregates, a more flexible and efficient data acquisition method can be provided in practical applications. It saves labor costs and realizes the function of remote real-time monitoring.

[0081] S2: Normalize the reference signal and the target signal respectively.

[0082] In a possible implementation manner, S2 is specifically:

[0083] Normalize the reference signal and the target signal respectively according to the following formula:

[0084]

[0085] Where represents the impedance value of the impedance signal after normalization processing, z represents the impedance value of the impedance signal, z min represents the minimum impedance value in the impedance signal, z max represents the maximum impedance value in the impedance signal.

[0086] In the present invention, the amplitude difference between different signals is eliminated through normalization processing, making the subsequent signal analysis and processing more accurate, stable, and improving the processing efficiency. By standardizing the reference signal and the target signal, the signals can be compared on the same scale, providing a more reliable data basis for subsequent temperature compensation and structural health monitoring.

[0087] S3: Calculate the local cost matrix according to the normalized reference signal and target signal.

[0088] In a possible implementation manner, S3 is specifically:

[0089] Calculate the local cost matrix according to the following formula:

[0090]

[0091] Among them, C(m,n) represents the local cost between the impedance value of the m-th frequency point of the normalized reference signal and the impedance value of the n-th frequency point of the target signal. represents the impedance value of the m-th frequency point of the normalized reference signal, represents the impedance value of the n-th frequency point of the normalized target signal.

[0092] In the present invention, by calculating the local cost matrix, quantitative difference data is provided for subsequent signal matching and optimization, enabling the algorithm to accurately compare the impedance signals at each frequency point. This not only improves the accuracy of signal alignment but also enhances the temperature compensation effect, ensuring that the influence of temperature changes on the signal is effectively eliminated. Through this method, the algorithm can more efficiently and accurately achieve signal compensation, providing more reliable data support for structural health monitoring.

[0093] S4: Recursively calculate the cumulative cost matrix according to the local cost matrix.

[0094] In one possible implementation, S4 is specifically:

[0095] Recursively calculate the cumulative cost matrix according to the following formula:

[0096]

[0097] Among them, T(j,k) represents the cumulative cost from the starting point (1,1) to the current point (j,k), min represents taking the minimum value, and j and k respectively represent the number of rows and columns in the cumulative cost matrix.

[0098] In the present invention, through recursive calculation, the optimal path for each frequency point in the signal matching process can be obtained, thereby minimizing the matching error to ensure that the compensated signal is as close as possible to the reference signal. The method of recursively calculating the cumulative cost matrix, through local minimum recursion, does not require global search, reducing the computational complexity. By means of recursion, the calculation of each point is gradually advanced, reducing unnecessary computational volume and improving computational efficiency.

[0099] S5: Determine the optimal warping path according to the cumulative cost matrix.

[0100] Specifically, along the diagonal direction of the cumulative cost matrix, trace back from T(j,k) to T(1,1), and determine the optimal warping path W i =(j i ,k i)。During the backtracking process, select the minimum cumulative cost value and extract the corresponding coordinate points to form the optimal warping path.

[0101] In the present invention, by backtracking the cumulative cost matrix and selecting the minimum path value, the determination of the optimal warping path can be ensured. This means that the target signal will be adjusted to the position that best matches the reference signal, thereby maximizing the elimination of the influence of temperature changes on the signal. Recursive backtracking avoids global search and a large amount of unnecessary calculations by gradually selecting the minimum path value. This method efficiently narrows the calculation scope, reduces the complexity during the calculation process, and improves the calculation speed of the algorithm, especially suitable for processing large-scale data and complex signals.

[0102] Refer to the attached Figure 5 figures, which show a compensation result display diagram of a temperature compensation algorithm provided by an embodiment of the present invention.

[0103] S6: Reconstruct the target signal through the optimal warping path for temperature compensation to obtain the compensated signal.

[0104] In a possible implementation manner, according to the following formula, reconstruct the target signal through the optimal warping path for temperature compensation to obtain the compensated signal:

[0105] z compensated (j i ) = z aim (k i )

[0106] where, z compensated (j i ) represents the impedance value of the jth frequency point corresponding to the ith coordinate in the optimal warping path in the compensated signal, and z aim (k i ) represents the impedance value of the kth frequency point corresponding to the ith coordinate in the optimal warping path in the target signal.

[0107] In the present invention, the reconstruction of the target signal through the optimal warping path can effectively eliminate the influence of temperature changes on the signal. When the temperature change causes a change in the impedance signal, the optimal warping path corrects the deviation caused by temperature by aligning the target signal and the reference signal, so that the target signal returns to the state that matches the reference signal. Under the guidance of the optimal warping path, the reconstruction process enables the temperature compensation algorithm to automatically adapt to signal changes under different temperature conditions. This method eliminates the need for manual intervention, automatically corrects the influence of temperature on the signal, and realizes more efficient compensation.

[0108] Furthermore, the temperature compensation method further includes:

[0109] S7: Compare the resonance peak positions and anti-resonance peak positions of the reference signal and the compensation signal, and use these as the criteria for the quality of the compensation effect.

[0110] Specifically, resonance peaks and anti-resonance peaks are two important features in impedance signals, corresponding respectively to the maximum and minimum values of the electrical response of the material at specific frequencies. The matching degree of the reference signal and the compensation signal at these two positions can reflect the accuracy and effect of temperature compensation. By precisely comparing the positions of the resonance peaks and anti-resonance peaks, it can be ensured that the influence of temperature changes on the impedance signal is effectively eliminated. If the resonance peaks and anti-resonance peaks of the compensation signal are consistent with the corresponding positions of the reference signal, it indicates that the temperature compensation effect is good and the influence of temperature on the impedance signal has been successfully eliminated. On the contrary, if the peak positions of the two deviate greatly, it indicates that the compensation effect is not ideal and the compensation algorithm or parameters need to be further adjusted.

[0111] The beneficial effects brought by the technical solution provided by the embodiments of the present invention at least include:

[0112] In the embodiments of the present invention, by determining the optimal distortion path and reconstructing the target signal through the optimal distortion path for temperature compensation to obtain the compensation signal, it no longer depends on the statistical indicators of the impedance signal to quantify the structural state change, has no strong dependence on the selection of the frequency range, and does not require repeated trial calculations to determine the effective frequency band during the actual application process. It has a universal evaluation criterion, avoids the interference of temperature changes on the impedance signal of the smart aggregate caused by the temperature sensitivity of the piezoelectric ceramic itself, reduces the influence of the superposition effect of temperature changes and structural damage on the impedance signal of the smart aggregate, and improves the monitoring accuracy of the smart aggregate under complex temperature change conditions.

[0113] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0114] The following points need to be explained:

[0115] (1) The drawings of the embodiments of the present invention only relate to the structures involved in the embodiments of the present invention, and other structures can refer to the usual designs.

[0116] (2) For clarity, in the drawings used to describe the embodiments of the present invention, the thickness of the layer or region is enlarged or reduced, that is, these drawings are not drawn according to the actual ratio. It can be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element can be "directly" on or under the other element or there can be intermediate elements.

[0117] (3) Without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other to obtain new embodiments.

[0118] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A cement-based smart aggregate, characterized in that: include: A cement matrix, a plurality of wires, a plurality of piezoelectric units, and a waterproof insulating protective layer; The cement matrix is ​​cast by casting a casting mold; The casting mold includes a plurality of bases, a plurality of side plates and a bottom plate, the side plates include a plurality of openings, the bottom plate includes a plurality of positioning grooves, and the bases are fixed by fixing bolts; The piezoelectric unit is embedded in the positioning groove; The wire is connected to each of the piezoelectric units through each of the openings; The waterproof insulating protection layer is arranged on the surface of the piezoelectric unit.

2. The cement-based smart aggregate according to claim 1, characterized in that: The base is made by 3D printing technology, the side panels and the bottom panel are made by polishing acrylic panels, and the side panels and the bottom panel are adhered to the base by epoxy AB glue.

3. The cement-based smart aggregate according to claim 1, characterized in that: The piezoelectric unit is specifically a piezoelectric ceramic block or a piezoelectric stack.

4. The cement-based smart aggregate according to claim 1, characterized in that: The piezoelectric unit includes a positive electrode surface and a negative electrode surface; The wire is welded to the positive electrode surface or the negative electrode surface of each piezoelectric unit through each opening.

5. The cement-based smart aggregate according to claim 1, characterized in that: The waterproof insulating protective layer is specifically: liquid insulating electrical tape.

6. A temperature compensation method, applied to the cement-based smart aggregate according to any one of claims 1 to 5, characterized in that: include: S1: Acquire multiple impedance signals of the cement-based smart aggregate, where the impedance signals include a reference signal and a target signal; S2: performing normalization processing on the reference signal and the target signal respectively; S3: Calculate the local cost matrix according to the normalized reference signal and the target signal; S4: recursively calculating a cumulative cost matrix according to the local cost matrix; S5: Determine an optimal twisted path according to the cumulative cost matrix; S6: Reconstruct the target signal through the optimal twisted path to perform temperature compensation and obtain a compensated signal.

7. The temperature compensation method according to claim 6, characterized in that: The S2 is specifically: According to the following formulas, the reference signal and the target signal are normalized respectively: in, represents the impedance value of the impedance signal after normalization, z represents the impedance value of the impedance signal, and z min Indicates the minimum impedance value in the impedance signal, z max Indicates the maximum impedance value in the impedance signal.

8. The temperature compensation method according to claim 6, characterized in that: The S3 is specifically: The local cost matrix is ​​calculated according to the following formula: Where C(m,n) represents the local cost between the impedance value of the mth frequency point of the reference signal after normalization and the impedance value of the nth frequency point of the target signal. It represents the impedance value of the mth frequency point of the reference signal after normalization. Indicates the impedance value of the target signal at the nth frequency point after normalization.

9. The temperature compensation method according to claim 6, characterized in that: The S4 is specifically: The cumulative cost matrix is ​​recursively calculated according to the following formula: Among them, T(j,k) represents the cumulative cost from the starting point (1,1) to the current point (j,k), min means taking the minimum value, j and k represent the number of rows and columns in the cumulative cost matrix respectively.

10. The temperature compensation method according to claim 6, characterized in that: The S6 is specifically: According to the following formula, the target signal is reconstructed through the optimal twist path to perform temperature compensation and obtain the compensated signal: zcompensated(ji)=zaim(ki) Among them, z compensated (j i ) represents the impedance value of the jth frequency point corresponding to the i-th coordinate in the optimal twist path in the compensation signal, z aim (k i ) represents the impedance value of the kth frequency point in the target signal corresponding to the i-th coordinate in the optimal twist path.

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