A modified cement-based piezoelectric composite sensor and its manufacturing method

Abstract

The present invention discloses a modified cement-based piezoelectric composite material sensor and its manufacturing method. The sensor includes a piezoelectric composite body, which includes a basic phase and a functional phase. The basic phase is a cement matrix adapted to the reinforced concrete main structure, and carbon nanotubes for improving the electrochemical difference between the basic phase and the functional phase are arranged in the basic phase. The functional phase includes piezoelectric ceramic columns and piezoelectric ceramic particles. The included angle between the carbon nanotubes and the vertical piezoelectric ceramic columns is an acute angle. The manufacturing method includes the following steps: adding carbon nanotubes to acetone and performing ultrasonic dispersion; adding cement and piezoelectric ceramic particles and performing ultrasonic dispersion; adding distilled water and stirring; adding piezoelectric ceramic columns and evacuating; performing electric field induction; curing; and secondary polarization. In the present invention, the basic phase is a cement matrix, so that it is better compatible with the object to be detected. Through the electric field induction process, the carbon nanotubes are arranged in a directional inclination to solve the electrochemical difference between the basic phase and the functional phase.

Description

Technical Field

[0001] The present invention belongs to the field of health monitoring of construction engineering, and particularly relates to a modified cement-based piezoelectric composite sensor and a manufacturing method thereof. Background Art

[0002] At present, the use of intelligent monitoring systems in construction engineering to implement online health monitoring and forecasting of building structures has become a cutting-edge research direction in the construction industry. Some relatively common structural sensors include, for example, optical fibers, piezoelectric ceramics, shape memory alloys, etc. There are often significant problems with the compatibility of these materials with reinforced concrete structures. The compatibility problems will further affect the sensing accuracy to a certain extent, and the monitoring effect will also be greatly reduced. Summary of the Invention

[0003] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a modified cement-based piezoelectric composite sensor and a manufacturing method thereof.

[0004] The technical solution of the present invention is: a modified cement-based piezoelectric composite sensor, including a piezoelectric composite body, the piezoelectric composite body includes a basic phase and a functional phase, the basic phase is a cement matrix adapted to the main body structure of reinforced concrete, the functional phase is placed in the basic phase, and carbon nanotubes for improving the electrochemical difference between the basic phase and the functional phase are arranged in the basic phase.

[0005] Furthermore, the functional phase includes piezoelectric ceramic columns and piezoelectric ceramic particles.

[0006] Furthermore, the piezoelectric ceramic columns are arranged vertically in the cement matrix, and the piezoelectric ceramic particles are evenly distributed in the cement matrix.

[0007] Furthermore, the included angle between the carbon nanotubes and the vertical piezoelectric ceramic columns is an acute angle.

[0008] Furthermore, the included angle between the carbon nanotubes and the vertical piezoelectric ceramic columns is 30°.

[0009] Furthermore, the carbon nanotubes are arranged in the cement matrix by electric-induced tilt and orientation.

[0010] Furthermore, copper meshes and electrodes are arranged at the upper and lower ends of the piezoelectric composite body.

[0011] Furthermore, leads are also arranged at the upper and lower ends of the piezoelectric composite body, and the leads are embedded in the grooves of the piezoelectric composite body.

[0012] Furthermore, the leads are fixed by soldering at the solder joints.

[0013] A method for manufacturing a modified cement-based piezoelectric composite material sensor comprises the following steps:

[0014] ⅰ. Add carbon nanotubes to acetone for ultrasonic dispersion

[0015] ⅱ. Add cement and piezoelectric ceramic particles to the mixture in step ⅰ, and ultrasonically disperse

[0016] ⅲ. Add distilled water to the mixture in step ⅱ and stir;

[0017] ⅳ. Add the mixture in step ⅲ to the piezoelectric ceramic column and evacuate;

[0018] ⅴ in a DC high voltage electric field in step ⅳ the mixture of carbon nanotubes induced alignment, the induced electric field direction and the piezoelectric ceramic column tilt;

[0019] ⅵ. Place the specimen obtained in step ⅴ in a curing box for curing;

[0020] ⅶ. After the cement is cured, the specimen is placed in silicone oil for secondary polarization to complete the preparation of the piezoelectric composite;

[0021] ⅸ. Install copper mesh, electrodes and leads.

[0022] The present invention designs the basic phase in the piezoelectric composite to be a cement matrix, so that it is better compatible with the reinforced concrete structure of the detected object, fundamentally and thoroughly solving the introduction of compatibility errors. At the same time, through the electric field induction process, the carbon nanotubes are arranged at a directional inclination angle to solve the electrochemical differences between the basic phase and the functional phase. The present invention is groundbreaking in solving the compatibility error from the fundamental point of view and ensuring the sensing precision and monitoring accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view of the present invention;

[0024] Figure 2 yes Figure 1 Longitudinal section of

[0025] Figure 3 It is a schematic diagram of the top structure of the present invention;

[0026] in:

[0027] 1 Piezoelectric composite 2 Copper mesh

[0028] 3 Electrodes 4 Leads

[0029] 5 Cement matrix 6 Piezoelectric ceramic column

[0030] 7 Piezoelectric ceramic particles 8 Carbon nanotubes

[0031] 9 Groove 10 Solder joint. Detailed implementation mode

[0032] Hereinafter, the present invention will be described in detail with reference to the drawings and embodiments:

[0033] As Figures 1 to 3 shown, a modified cement-based piezoelectric composite material sensor includes a piezoelectric composite body 1, the piezoelectric composite body 1 includes a basic phase and a functional phase, the basic phase is a cement matrix 5 adapted to the reinforced concrete main structure, the functional phase is placed in the basic phase, and carbon nanotubes 8 for improving the electrochemical difference between the basic phase and the functional phase are arranged in the basic phase.

[0034] The functional phase includes piezoelectric ceramic columns 6 and piezoelectric ceramic particles 7.

[0035] The piezoelectric ceramic columns 6 are arranged vertically in the cement matrix 5, and the piezoelectric ceramic particles 7 are evenly distributed in the cement matrix 5.

[0036] The included angle between the carbon nanotubes 8 and the vertical piezoelectric ceramic columns 6 is an acute angle.

[0037] The carbon nanotubes 8 are arranged in the cement matrix 5 in an inclined and oriented manner through electro-induced orientation.

[0038] Copper meshes 2 and electrodes 3 are arranged at the upper and lower ends of the piezoelectric composite body 1.

[0039] Leads 4 are also arranged at the upper and lower ends of the piezoelectric composite body 1, and the leads 4 are embedded in the grooves 9 of the piezoelectric composite body 1.

[0040] The leads 4 are fixed by welding through solder joints 10.

[0041] The basic phase of the piezoelectric composite body 1 uses the cement matrix 5, which can be well compatible with the reinforced concrete main structure, thus completely solving the problem of poor compatibility between optical fibers, piezoelectric ceramics, shape memory alloys and the reinforced concrete main structure, avoiding the introduction of compatibility errors into the monitoring results, and improving the sensing accuracy.

[0042] Preferably, the piezoelectric ceramic columns 6 are type 1 piezoelectric ceramic columns, and the piezoelectric ceramic particles 7 are type 0 piezoelectric ceramic particles, improving the functional materials in the whole sensor.

[0043] Another embodiment

[0044] A modified cement-based piezoelectric composite material sensor includes a piezoelectric composite body 1, the piezoelectric composite body 1 includes a basic phase and a functional phase, the basic phase is a cement matrix 5 adapted to the reinforced concrete main structure, the functional phase is placed in the basic phase, and carbon nanotubes 8 for improving the electrochemical difference between the basic phase and the functional phase are arranged in the basic phase.

[0045] The functional phase includes piezoelectric ceramic columns 6 and piezoelectric ceramic particles 7.

[0046] The piezoelectric ceramic columns 6 are arranged vertically in the cement matrix 5, and the piezoelectric ceramic particles 7 are evenly distributed in the cement matrix 5.

[0047] Preferably, the included angle between the carbon nanotubes 8 and the vertical piezoelectric ceramic columns 6 is 30°.

[0048] The carbon nanotubes 8 are arranged in the cement matrix 5 by electro-induced tilting and orientation.

[0049] Copper meshes 2 and electrodes 3 are arranged at the upper and lower ends of the piezoelectric composite body 1.

[0050] Leads 4 are also arranged at the upper and lower ends of the piezoelectric composite body 1, and the leads 4 are embedded in the grooves 9 of the piezoelectric composite body 1.

[0051] The leads 4 are fixed by soldering at the solder joints 10.

[0052] The basic phase of the piezoelectric composite body 1 uses the cement matrix 5, which can be well compatible with the reinforced concrete main structure, thus completely solving the problem of poor compatibility between optical fibers, piezoelectric ceramics, shape memory alloys and the reinforced concrete main structure, avoiding the introduction of compatibility errors into the monitoring results, and improving the sensing accuracy.

[0053] Preferably, the piezoelectric ceramic columns 6 are type 1 piezoelectric ceramic columns, and the piezoelectric ceramic particles 7 are type 0 piezoelectric ceramic particles, improving the functional materials in the whole sensor.

[0054] The carbon nanotubes 8 are modification materials for the cement matrix 5, improving the electrochemical difference between the matrix phase and the functional phase.

[0055] Preferably, the modification effect is improved by the arranged orientation angle. The included angle between the carbon nanotubes 8 and the vertical piezoelectric ceramic columns 6 is 30°, and the carbon nanotubes are arranged in the matrix by electric field induction.

[0056] The process of electric field induction is as follows:

[0057] Before the cement base is cured, the specimen is placed in a DC high-voltage electric field to induce the arrangement of the carbon nanotubes. The direction of the induced electric field forms an angle of 30 degrees with the piezoelectric ceramic column, the induced voltage is 600 V / cm, and the induced time is 30 min.

[0058] The grooves 9 accommodate the leads 4 and the solder joints 10, preventing the leads from falling off during use.

[0059] The cement in the cement matrix 5 uses 42.5 ordinary Portland cement.

[0060] The length of the carbon nanotubes 8 is 5 - 15 μm.

[0061] Preferably, the volume fraction of the carbon nanotubes 8 in the matrix phase is 0.7%, the volume fraction of the piezoelectric ceramic particles 7 in the matrix phase is 20%, and the volume fraction of the piezoelectric ceramic columns 6 in the matrix phase is 40%.

[0062] A manufacturing method of a modified cement - based piezoelectric composite sensor includes the following steps:

[0063] ⅰ. Add the carbon nanotubes into acetone and perform ultrasonic dispersion.

[0064] ⅱ. Add cement and piezoelectric ceramic particles to the mixture in step ⅰ and perform ultrasonic dispersion.

[0065] ⅲ. Add distilled water to the mixture in step ⅱ and stir.

[0066] ⅳ. Add piezoelectric ceramic columns to the mixture in step ⅲ and evacuate.

[0067] ⅴ. Induce the alignment of the carbon nanotubes in the mixture in step ⅳ in a DC high - voltage electric field, and the direction of the induced electric field is inclined to the piezoelectric ceramic columns.

[0068] ⅵ. Place the specimen obtained in step ⅴ in a curing box for curing.

[0069] ⅶ. After the cement is cured, place the specimen in silicone oil for secondary polarization to complete the preparation of the piezoelectric composite.

[0070] ⅸ. Install the copper mesh, electrodes, and leads.

[0071] Preferably, a manufacturing method of a modified cement - based piezoelectric composite sensor includes the following steps:

[0072] ⅰ. Add the carbon nanotubes into acetone and perform ultrasonic dispersion for 24 h.

[0073] ⅱ. Add cement and piezoelectric ceramic particles to the mixture in step ⅰ and perform ultrasonic dispersion for 2 h.

[0074] ⅲ. Add distilled water to the mixture in step ⅱ and stir for 10 minutes.

[0075] ⅳ. Add piezoelectric ceramic columns to the mixture in step ⅲ and evacuate for 5 minutes.

[0076] ⅴ. Induce the alignment of the carbon nanotubes in the mixture in step ⅳ in a DC high - voltage electric field, and the direction of the induced electric field is inclined to the piezoelectric ceramic columns, where the included angle between the direction of the induced electric field and the piezoelectric ceramic columns is 30 degrees, the induced voltage is 600 V / cm, and the induced time is 30 min.

[0077] ⅵ. Place the specimens obtained in step ⅴ in a curing box for curing for 3 days;

[0078] ⅶ. After the cement is cured, place the specimens in silicone oil for secondary polarization to complete the preparation of the piezoelectric composite.

[0079] When the included angle between the induced electric field direction and the type-1 piezoelectric ceramic column is 30 degrees, the piezoelectric strain constant of the 0-3-1 type piezoelectric composite can reach 118 pC / N.

[0080] In the present invention, the basic phase in the piezoelectric composite is designed as a cement matrix, so that it is better compatible with the reinforced concrete structure of the object to be detected, fundamentally and thoroughly solving the introduction of compatibility errors. At the same time, through the electric field induction process, the carbon nanotubes are arranged in a directional inclination, solving the electrochemical difference between the basic phase and the functional phase. The present invention pioneeringly solves the compatibility error from the fundamental point, ensuring the sensing accuracy and monitoring accuracy.

Claims

1. A modified cement-based piezoelectric composite sensor, comprising a piezoelectric composite body (1), characterized in that: The piezoelectric composite body (1) includes a basic phase and a functional phase. The basic phase is a cement matrix (5) adapted to the reinforced concrete main structure. The functional phase is disposed in the basic phase, and carbon nanotubes (8) for improving the electrochemical difference between the basic phase and the functional phase are provided in the basic phase; The functional phase includes piezoelectric ceramic columns (6) and piezoelectric ceramic particles (7); The piezoelectric ceramic columns (6) are type I piezoelectric ceramic columns, and the piezoelectric ceramic particles (7) are type 0 piezoelectric ceramic particles, which improve the functional materials in the entire sensor; The carbon nanotubes (8) are modification materials for the cement matrix (5), which improve the electrochemical difference between the matrix phase and the functional phase; The modification effect is improved by arranging at a directional angle. The included angle between the carbon nanotubes (8) and the vertical piezoelectric ceramic columns (6) is 30°. Through electric field induction, the carbon nanotubes are directionally arranged in the matrix; Copper meshes (2) and electrodes (3) are provided at the upper and lower ends of the piezoelectric composite body (1).

2. The modified cement-based piezoelectric composite material sensor according to claim 1, characterized in that: The piezoelectric ceramic columns (6) are vertically arranged in the cement matrix (5), and the piezoelectric ceramic particles (7) are evenly distributed in the cement matrix (5).

3. The modified cement-based piezoelectric composite material sensor according to claim 1, characterized in that: The carbon nanotubes (8) are inclined and directionally arranged in the cement matrix (5) through electric induction.

4. A modified cement-based piezoelectric composite material sensor according to claim 1, characterized in that: Leads (4) are also provided at the upper and lower ends of the piezoelectric composite body (1), and the leads (4) are embedded in the grooves (9) of the piezoelectric composite body (1).

5. The modified cement-based piezoelectric composite material sensor according to claim 4, characterized in that: The leads (4) are fixed by soldering at solder joints (10).

6. A manufacturing method of a modified cement-based piezoelectric composite material sensor, characterized in that: It includes the following steps: (i) Add carbon nanotubes to acetone and perform ultrasonic dispersion (ii) Add cement and piezoelectric ceramic particles to the mixture in step (i) and perform ultrasonic dispersion (iii) Add distilled water to the mixture in step (ii) and stir; (iv) Add piezoelectric ceramic columns to the mixture in step (iii) and evacuate; (v) Induce the arrangement of the carbon nanotubes in the mixture in step (iv) in a DC high-voltage electric field, and the direction of the induced electric field is inclined to the piezoelectric ceramic columns; (vi) Place the specimen obtained in step (v) in a curing box for curing; (vii) After the cement is cured, place the specimen in silicone oil for secondary polarization to complete the preparation of the piezoelectric composite body; (ix) Install copper meshes, electrodes and leads; Among them, the process of electric field induction is as follows: Before the cement matrix is cured, place the specimen in a DC high-voltage electric field to induce the arrangement of the carbon nanotubes. The direction of the induced electric field forms an angle of 30 degrees with the piezoelectric ceramic columns, the induced voltage is 600 V / cm, and the induced time is 30 min.

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