JP2022511176A - ECT sensors, systems and processes for monitoring internal moisture permeation of concrete components - Google Patents

Abstract

PROBLEM TO BE SOLVED: To disclose an ECT sensor, a system and a process for monitoring the internal moisture permeation of a concrete member. SOLUTION: A circular design is adopted to optimize the structure of electrode plates, clamps, and water storage pipes, abandon the conventional sensor structural design suitable for two-phase flow measurement of pipelines, and vertical arrangement and non-closed design. The copper foil electrode plate is attached to the outer wall of the PVC insulating tube, the hardware structure is simplified by the size and number of the electrode plates, and the metal outer shield case is used for sealing. Reservoir pipes and tanks facilitate the study of water permeation processes inside concrete specimens when water is injected from different angles. Its high sensitivity, low cost, non-radiation, simple and portable, non-destructive monitoring can be realized, and the imaging results can be compared with the photographs of the specimens taken, making up for the lack of verification methods for the imaging results of conventional sensors. ， Understand the law of moisture permeation inside concrete and provide scientific basis for studying the durability of concrete.

Description

The present invention belongs to the technical field of the durability monitoring device for concrete members, and is an ECT sensor for monitoring internal moisture permeation of concrete members, which can realize visual monitoring of internal moisture permeation of concrete members, and monitoring. Regarding the system and monitoring process.

The safety and economic problems caused by the inadequate durability of concrete are becoming more serious and need to be resolved urgently. Moisture is the main cause of the durability of concrete. Visual monitoring of moisture and quantification of its distribution are key to studying the durability of concrete. The ECT technology, developed in the 1980s, is a specific image reconstruction algorithm that obtains the distribution of permittivity inside a material by reversing with respect to changes in capacitance parameters measured by an array sensor. ECT technology can realize non-destructive visualization of the water distribution state inside the material. The ECT system mainly consists of a capacitance sensor, a data collection and information processing system, and an imaging computer. The capacitance sensor is the core part of the ECT system, and the sensor is manufactured in two dimensions inside the cement-based material. As an important prerequisite for achieving unsaturated moisture permeation imaging, sensors provide experimental and theoretical support for improving the durability design and evaluation mechanism of concrete structures.

Currently, sensor research focuses on two main aspects. On the one hand, the length and placement of the capacitance plate of the sensor are improved, and the accuracy of the sensor is improved by increasing the number of electrode pairs. Disclosed a capacitive tomography sensor equipped with a rotating electrode, the main structure is composed of two layers of freely rotatable circular tubes, that is, an outer layer rotating tube and an inner layer rotating tube, and is constant between the two layers. There is a gap, a shield electrode is installed on the outer periphery of the outer layer rotary tube, and a fixing base is installed on the lower part of the main body. The capacitance measuring unit includes a voltage excitation signal source, a capacitance measuring system formed by a capacitance measuring circuit, and a ground of an instrument, and at least one excitation electrode is bonded to the inner wall of the inner layer rotary tube. , At least one measuring electrode and a protective electrode are adhered to the inner wall of the outer layer rotating tube. When the capacitance measurement system is functioning, the excitation electrode is connected to the voltage excitation signal source. The measurement electrode is connected to the capacitance measurement circuit, the measurement is performed via the capacitance measurement system, the excitation electrode is connected to the capacitance measurement circuit, and the measurement electrode is connected to the voltage excitation signal source. If so, the measurement is performed through a capacitance measurement system and is in a virtual ground potential state. The protective electrode and shield electrode are connected to the ground of the equipment and are at the ground potential. Due to the problem of insufficient resolution of the reconstructed image due to the limited measurement data provided by the array capacitance sensor, the capacitance between the electrodes can be measured from any angle, two layers. Capacitive tomography sensors with rotating electrodes are provided and the capacitive measurements between the electrode pairs are increased to improve the resolution of the reconstructed image.

Patent Document 2 discloses a capacitive imaging sensor for measuring oil-gas-water three-phase circulation parameters, including a measuring tube and an electrode group. The electrode groups are at least two groups and are attached to the outer wall of the measuring tube in a relative positional relationship, each electrode group includes an internal electrode and an external electrode, and the external electrode is provided around the internal electrode. The internal and external electrodes form a "circle" -shaped structure. When measuring the oil-water ratio parameter of a three-phase cyclic fluid, the internal electrode is used as the excitation electrode and the external electrode is used as the measurement electrode. When measuring the gas-liquid ratio parameter of a three-phase cyclic fluid, at least one pair of counter electrode groups is used, of which the internal electrode of one electrode group is the excitation electrode and the other facing it. The internal electrode of the electrode group is grounded to the measurement electrode, and the external electrode of the two electrode groups is grounded. It optimizes the design of the electrode structure of the ECT sensor and calculates the water content and gas-liquid ratio of the oil-gas-water three-phase flow using only the capacitance value by controlling the sensitive field spacing of the measurement. can.

On the other hand, by improving the sensor structure, the performance of the sensor that can withstand complicated conditions such as high temperature, high pressure, and corrosion is improved. For example, Patent Document 3 is arranged on the inner pipe wall of the measurement fluid pipeline and has the same structure. Disclosed a high precision ECT smart sensor containing multiple signal processing circuit boards of the same structure as multiple sensitive capacitor plates, said multiple sensitive capacitor plates are evenly circumferential inside the same cross section of the measurement fluid pipeline. Distributed in a distributed manner, one side of each sensitive condenser plate is fixedly electrically connected to one end of the stud, the stud passes radially outward through the tube wall of the measurement fluid pipeline, and the stud is of the measurement fluid pipeline. It is fixedly electrically connected to the signal processing circuit board at the outer end, and the other side of the sensitive capacitor plate is coated with a coating. The signal processing circuit board is individually addressed by the flash memory of the one-chip microcomputer, and each signal processing circuit board is connected via the CAN bus, and at the same time, the CAN bus is connected to the imaging computer via the CAN-USB converter. Connected to the USB interface of, each signal processing circuit board receives and executes commands from the imaging computer via the CAN bus, and the collected analog signals are converted into digital signals required for imaging through the signal processing circuit board. It is converted and sent to the remote imaging computer via the CAN bus. The outside of the smart sensor is surrounded by a shield layer, and a CAN bus is drawn from the inside of the shield layer and used to communicate with an imaging computer. Teflon-treated anticorrosion electrodes can come into direct contact with the measured fluid, reducing the effect of tube wall capacitance on the imaging effect and making the measurement results more stable.

Patent Document 4 discloses a method and system for measuring the temperature field of polymer melt based on capacitive tomography, which is static between capacitor plates by measuring a calibrated capacitive polymer melt temperature field sensor. Determine the capacitance value. Reconstruct the algorithm based on the capacitive tomographic image. The measured capacitance value is reconstructed into the dielectric constant distribution of the polymer melt, and a relational model between the dielectric constant of the polymer melt and the temperature is established. The dielectric constant distribution of the polymer melt is transformed into the temperature field of the corresponding polymer melt according to the relational model.

Patent Document 5 discloses a capacitive tomography sensor applied to a high temperature environment of 300 ° C., and the sensor includes an array dispersion measuring electrode that can withstand a high temperature of 300 ° C., a shaft end shield electrode, an insulating separation layer, and an external surface. A shield case and a signal transmission line are included, where the array dispersion measuring electrode includes N measuring electrodes, where the value of N is an integer from 8 to 16. The signal transmission line is composed of a cable core, an insulating layer, and a shielded wire mesh, and includes a normal temperature part and a high temperature part that can withstand 300 ° C. And here, the shaft end shield electrode is connected to the external shield case, is drawn out from the shield wire mesh of the signal transmission line, and is then grounded through the ground wire of the signal acquisition device of the capacitive tomography system. The insulation separation layer insulates the array dispersion measurement electrode and the shaft end shield electrode from the external shield case, and fixes the entire sensor. One end of the cable core in the high temperature portion of the signal transmission line is connected to the array dispersion measurement electrode, and the other end is connected to the signal acquisition device of the capacitive tomography system via the normal temperature portion of the signal transmission line. The signal acquisition device sends the collected data to a computer for image reconstruction, and the array dispersion measurement electrode is made by corroding and hollowing out a brass plate having a thickness of 0.01 mm to 0.1 mm. Moreover, the array dispersion measurement electrode is fixed to the outer wall of the fluidized layer heat insulating pipe by a method of arranging a hollow integrated adhesive. It has improved the drawback that conventional capacitive tomography sensors are not resistant to high temperatures.

After more than 30 years of development, ECT technology is maturing and has achieved certain research results. However, the ECT sensor of the prior art is mainly used for solid phase concentration measurement, flow pattern recognition measurement and related speed measurement, and there are few reports of related patents on ECT sensor in the field of cement-based materials, and a specific technology. There is a target and theoretical gap, and further improvement is needed.

Chinese Patent 201310420106.2. Chinese Patent 2016103625333.3 Chinese patent 2010102611469.2 Chinese patent 2012100894791. Chinese patent 2015106237689.9

The present invention overcomes the drawbacks of the prior art, that is, the complicated structure, the inability to quantitatively monitor the internal moisture content of concrete, and the inability to visually monitor the internal moisture permeation of concrete, and the internal moisture of concrete parts. The purpose is to realize two-dimensional unsaturated moisture permeation imaging of cracked concrete, including the design of ECT sensor to monitor permeation, and to track the moisture permeation process of concrete in real time.

The technical solutions adopted by the present invention to achieve the above object are as follows.

In the first aspect, the present invention provides an ECT sensor for monitoring moisture permeation inside a concrete member, which includes a water storage pipe, an insulating pipe, an electrode plate, a radial shield electrode, an insulating layer, a clamp, and a top plate. Includes bottom plate, spacer, lead hole, electrode lead, fixing hole, buttless.

The water storage pipe is attached to the peripheral side surface of the concrete specimen, an insulating pipe is fitted on the peripheral surface of the concrete specimen to which the water storage pipe is not attached, and electrode plates are equidistantly spaced on the outer surface of the insulating pipe in the circumferential direction. The radial shield electrode is placed between the adjacent electrode plates, the outer circumference of the electrode plate and the radial shield electrode is covered with an insulating layer, and the outer circumference of the insulating layer is sandwiched by a clamp to realize fixing of the entire device.

A top plate is installed on the top surface of the concrete specimen, a bottom plate is installed on the bottom surface of the concrete specimen, a spacer is installed between the concrete specimen and the bottom plate, a lead hole is opened in the center of the bottom plate, and the electrode plate is connected. The electrode leads are pulled out from the lead holes, fixing holes are made in the bottom plate, and the corners of the bottom plate are connected to the buttress.

As a further technical solution, the concrete specimen is cylindrical and the axis of the water storage pipe is perpendicular to the axis of the concrete specimen.

As a further technical solution, the water storage pipe has a scale.

As a further technical solution, the electrode plate is a copper-platinum electrode plate, and it is possible to prevent the concrete specimen from being contaminated or the circuit from being short-circuited due to direct contact between the concrete specimen and the electrode lead.

As a further technical solution, the clamp is provided with an opening, the opening extends outward, the opening is connected and fixed to the nut by a threaded rod, and a connecting member is installed in the opening, left and right of the clamp. ， An iron plate with a through hole is welded to the bottom.

As a further technical solution, the material of the insulating layer is foamed plastic.

As a further technical solution, the material of the clamp is stainless steel which can reduce electromagnetic interference.

In a second aspect, the invention also provides a system for monitoring the internal moisture permeation of a concrete member, the ECT sensor, a data acquisition device and an imaging computer for monitoring the internal moisture permeation of the concrete member described above. The lead of the electrode plate is connected to the port of the data collection device, and the data collection device is connected to the imaging computer.

を使用して，画像再構成を行い，ここで，

は正規化された静電容量ベクトル，

は正規化された敏感なフィールド行列，

は正規化された誘電率ベクトルであることと，
コンクリート供試体なしでコンクリート部材内部の水分透過を監視するＥＣＴセンサーの静電容量値を測定して最小静電容量値として，同時に，コンクリート部材内部の水分透過を監視するＥＣＴセンサーの静電容量と結合容量を測定し，データ収集装置に保存することと，
乾燥したコンクリート供試体を取り，ステップ２でコンクリート部材の内部水分透過を監視するＥＣＴセンサーの内部に固定し，貯水管を貯水タンクに接続し，毎回一定量の水を貯水管に追加し，テストの最小静電容量値と最大静電容量値を順番に測定して校正することと，
校正されたコンクリート供試体を取り出し，異なる水セメント比のコンクリート供試体を順番に入れて測定し，測定中，データ収集装置は，校正によって測定された誤差静電容量を自動的に除去し，最終的なイメージング結果をイメージングコンピューターに提示することと，
コンクリート部材の内部水分透過を監視するＥＣＴセンサーを１８０度回転させ，貯水管，貯水池の水位をコンクリート供試体の上面と一致させて，測定プロセス中に水とコンクリート供試体が接触していることを確認し，さまざまな角度で水注入中のコンクリート供試体における水分の透過プロセスを観察することと，
測定が完了したら，データをエクスポートしてデータ処理を実行し，異なる水セメント比コンクリート供試体の水分透過変化曲線を描き，時間とともにコンクリート供試体に入る水分の誘電率の変化曲線を描き，相誘電率と吸水体積の間の関数関係に従って，水分の進入の定量的情報を取得し，コンクリート供試体の２次元水分透過イメージング画像をコンクリート供試体の正面から撮影した写真と比較して，イメージングの精度を確認することとを含む。 In the third aspect, in the process of imaging the two-dimensional unsaturated moisture permeation inside the cracked concrete based on the above-mentioned ECT sensor system for monitoring the internal moisture permeation of the concrete part of the present invention, the electrode lead is used as a data acquisition device. Connect to the port, connect the data collection device to the imaging computer, configure the ECT system with the ECT sensor for monitoring the internal moisture permeation of the concrete member, the data collection device and the imaging computer, and excite, ground, and measure. Two measurement modes and linear back projection algorithm

Use to perform image reconstruction, where

Is a normalized capacitance vector,

Is a normalized sensitive field matrix,

Is a normalized permittivity vector and
The capacitance value of the ECT sensor that monitors the moisture permeation inside the concrete member without a concrete specimen is measured and used as the minimum capacitance value, and at the same time, the capacitance value of the ECT sensor that monitors the moisture permeation inside the concrete member. Measuring the combined capacitance and storing it in a data collection device,
Take a dry concrete specimen, fix it inside the ECT sensor that monitors the internal moisture permeation of the concrete member in step 2, connect the water storage pipe to the water storage tank, add a certain amount of water to the water storage pipe every time, and test. The minimum capacitance value and the maximum capacitance value of are measured and calibrated in order, and
The calibrated concrete specimen is taken out, concrete specimens with different water-cement ratios are put in order and measured, and during the measurement, the data acquisition device automatically removes the error capacitance measured by the calibration and finally. Presenting the imaging results to an imaging computer,
The ECT sensor that monitors the internal moisture permeation of the concrete member is rotated 180 degrees, the water level of the water storage pipe and the reservoir is aligned with the upper surface of the concrete specimen, and the water and the concrete specimen are in contact during the measurement process. To confirm and observe the water permeation process in concrete specimens during water injection from various angles.
After the measurement is completed, the data is exported and the data processing is executed, the water permeation change curve of the concrete specimen with different water-cement ratio is drawn, the change curve of the dielectric constant of the water entering the concrete specimen over time is drawn, and the phase dielectric. Quantitative information on water ingress is obtained according to the functional relationship between rate and water absorption volume, and the accuracy of imaging is compared with the two-dimensional water permeation imaging image of the concrete specimen compared with the photograph taken from the front of the concrete specimen. Including confirming.

The present invention has the following effects as compared with the prior art.
1. 1. The present invention employs a circular design to optimize the structure of electrode plates, clamps and water reservoirs, provides non-destructive monitoring of two-dimensional unsaturated moisture permeation imaging of cracked concrete, and the moisture permeation process in concrete. In real time.
2. 2. The present invention abandons the conventional sensor structural design suitable for pipeline two-phase flow measurement and adopts vertical arrangement and non-closed design, which changes the internal capacitance signal of the cracked concrete specimen in real time. Useful for monitoring with.
3. 3. The copper foil electrode plate of the present invention is attached to the outer wall of the PVC insulating tube, and it is possible to prevent the electrode plate from coming into direct contact with the concrete specimen, and to avoid contamination of the concrete specimen and circuit short circuit. ..
4. The design of the electrode plates simplifies the hardware structure, improves the data acquisition speed, and reduces the edge effect between the electrode plates. An external metal shield case is used for sealing, effectively suppressing electromagnetic and noise interference during the measurement process.
5. Reservoir pipes and tanks facilitate the study of the moisture permeation process inside concrete specimens when water is injected from different angles and more realistically simulate the permeation of moisture inside concrete in a real environment. .. Its high sensitivity, low cost, non-radiation, simple and portable, non-destructive monitoring can be realized, and the imaging results make up for the lack of verification method of the imaging results of the conventional sensor when compared with the photograph of the specimen taken. ， Understand the law of moisture permeation inside concrete and provide scientific basis for studying the durability of concrete.

The drawings of the specification that form part of this application are used to provide a further understanding of this application, and exemplary embodiments and explanations thereof of this application are used to illustrate this application. It does not constitute an inappropriate limitation of this application.

The principle schematic diagram of the main structure of this invention. Schematic diagram of a cross section of the main structure of the present invention. Schematic diagram of the present invention in the vertical direction. Schematic diagram of the present invention in the horizontal direction. The schematic diagram of the structure of the bottom plate which concerns on this invention. It is a block diagram of the ECT system which concerns on step 1 of Example 1 of this invention. It is a schematic diagram of the inverted arrangement measurement state which concerns on step 5 of Example 1 of this invention.

In the figure, 1 concrete specimen, 2 water storage pipe, 3 insulating pipe, 4 electrode plate, 5 radial shield electrode, 6 insulating layer, 7 clamp, 8 threaded rod, 9 nut, 10 connecting member, 11 through hole, 12 iron plate. , 13 top plate, 14 bottom plate, 15 spacer, 16 lead hole, 17 electrode lead, 18 fixing hole, 19 buttless, 20 water storage tank

It should be noted that the following detailed description are all exemplary and are intended to provide further description of the invention. Unless otherwise stated, all technical and scientific terms used in the present invention have the same meaning as commonly understood by one of ordinary skill in the art.

It should be noted that the terms used herein are for illustration purposes only and are not intended to limit the exemplary embodiments according to the invention. As used herein, the singular is also intended to include the plural, unless expressly indicated otherwise, and the terms "prepared" and / or "contains" herein. It should also be understood that when is used, they indicate that there are features, steps, behaviors, devices, components, and / or combinations thereof.

Hereinafter, the present invention will be further described with reference to Examples and Drawings.

Example 1:
The main structure of the ECT sensor for monitoring the moisture permeation inside the concrete member according to this embodiment is a concrete specimen 1, a water storage pipe 2, an insulating pipe 3, an electrode plate 4, a radial shield electrode 5, an insulating layer 6, a clamp 7, It includes a threaded rod 8, a nut 9, a connecting member 10, a through hole 11, an iron plate 12, a top plate 13, a bottom plate 14, a spacer 15, a lead hole 16, an electrode lead 17, a fixing hole 18, and a buttless 19.

In this embodiment, the concrete specimen 1 has a cylindrical structure, a water storage pipe is attached to the peripheral side surface of the concrete specimen 1, and the axis of the water storage pipe 2 is perpendicular to the axis of the concrete specimen 1. An insulating pipe 3 is fitted on the peripheral side surface of the concrete specimen 1 to which the water storage pipe 2 is not attached, and a plurality of electrode plates 4 are attached to the outer surface of the insulating pipe 3 at equal intervals in the circumferential direction. Is arranged between the adjacent electrode plates 4, the outer periphery of the electrode plate 4 and the radial shield electrode 5 is covered with the insulating layer 6, the outer periphery of the insulating layer 6 is sandwiched by the clamp 7, and an opening is provided in the clamp 7. The opening extends outward, the opening is connected to and fixed to the nut 9 by a threaded rod 8, a connecting member 10 is installed in the opening, and an iron plate 12 with a through hole 11 is provided on the left, right, and bottom of the clamp 7. Welded, the top plate 13 is installed on the upper surface of the concrete specimen 1, the bottom plate 14 is installed on the bottom surface of the concrete specimen 1, the spacer 15 is installed between the concrete specimen 1 and the bottom plate 14, and the bottom plate 14 A lead hole 16 is opened in the center, the electrode lead 17 connected to the electrode plate 4 is pulled out from the lead hole 16, a fixing hole 18 is made in the bottom plate 14, and the corner portion of the bottom plate 14 is connected to the buttless 19. There is.

The concrete specimen 1 and the water storage pipe 2 according to this embodiment are attached and connected via a silicone adhesive. The concrete specimen 1 is a columnar body having a diameter of 15 cm and a height of 5 cm, and the water storage pipe 2 is a columnar body. It is a plastic tank with a length of 25 cm, a width of 7 cm, and a height of 5 cm. The gap is filled with a silicone adhesive, and a scale is printed on the water storage pipe 2. Of course, in other embodiments, it is easy to understand that the concrete specimen 1 and the water storage pipe 2 can be attached with another adhesive. Further, the size of the water storage pipe 2 is not limited to that disclosed in this embodiment, and the size of the water storage pipe 2 can be designed according to the size of the cylindrical body.

The insulating tube 3 according to this embodiment is a PVC insulated tube having a diameter of 15.5 cm, a height of 5 cm, and a thickness of 0.5 cm. Its diameter is slightly larger than the diameter of the concrete specimen 1 and can fit just outside the concrete specimen 1.

The electrode plate 4 according to this embodiment is a copper-platinum electrode plate, whereby direct contact between the concrete specimen 1 and the electrode leads 17 contaminates the concrete specimen 1 or short-circuits the circuit. When the number of electrode plates 4 is 10, the length is 5 cm, the width is 4 cm, and the height is 0.1 cm, the structure is simplified, the data collection speed is increased, and the edge effect between the electrode plates 4 is reduced. can. Of course, in other embodiments, electrode plates made of other materials can be used, and it is easy to understand that the number and size of the electrode plates can be changed according to the size of the concrete specimen 1.

The insulating layer 6 according to the present embodiment is formed of a plastic foam made of an existing material, and can prevent the clamp 7 from interfering with the capacitance measurement.

The clamp 7 according to this embodiment is made of stainless steel capable of reducing electromagnetic interference, and has a diameter of 16 cm, a height of 8 cm, a thickness of 0.1 cm, an opening length of 8 cm, and an outwardly extending length of 6 cm. The threaded rod 8 and the nut 9 are hexagon nuts. Of course, in other embodiments, the clamp 7 can also be made of other metallic materials that reduce electromagnetic interference, the particular size of which is not limited to the size disclosed in this embodiment. It is easy to understand that it is designed according to the size of the concrete specimen 1.

The connecting member 10 according to this embodiment has a stirrup structure, and the connecting member 10 connects the clamp 7 to the bottom plate 14. The top plate 13 is a cylindrical plastic plate having a diameter of 15 cm and a thickness of 0.5 cm, which can prevent evaporation of water and interference of noise during measurement and facilitate observation. The bottom plate 14 is a plastic plate having a length of 50 cm, a width of 30 cm, and a thickness of 0.5 cm. The specific sizes of the top plate 13 and the bottom plate 14 are not limited to the sizes disclosed in this embodiment, and are designed according to the size of the concrete specimen 1.

The number of lead holes 16 according to this embodiment is 10, the diameter is 1 cm, and the number of electrode leads 17 is 10. Generally, the number of lead holes 16 and electrode leads 17 is related to the number of electrodes, and one lead hole and one electrode lead are provided for each electrode.

The fixing holes 18 according to this embodiment have five fixing holes and a diameter of 1 cm, which correspond to the positions of the connecting member 10 and the through hole 11 of the iron plate 12, respectively, and are used for fixing the concrete specimen 1 and the clamp 7. ..

Since the buttress 19 according to this embodiment is a plastic block having a length of 30 cm, a width of 7 cm, and a height of 5 cm, the concrete specimen 1 is rotated during measurement and water is poured at different angles. 1 Permeation of water inside can be observed. The specific size is not limited to the size disclosed in this embodiment, and is designed according to the size of the concrete specimen 1.

Example 2:
The present embodiment provides a system for monitoring the internal moisture permeation of a concrete member based on the ECT sensor of the first embodiment, which includes the ECT sensor of the first embodiment, and also includes a data acquisition device and an imaging computer. The electrode leads of the ECT sensor are connected to the port of the data acquisition device and the data acquisition device is connected to the imaging computer.

As the data collection device, a PTL300E data collection box can be used. Since the data collection device is connected to the imaging computer via the RS232 port, RS485 port, or CAN bus interface, the ECT sensor that monitors the internal moisture permeation of the concrete member, the PTL300E data collection device, and the imaging computer are the ECT system. To configure.

を使用して，画像再構成を行い，ここで，

は正規化された静電容量ベクトル，

は正規化された敏感なフィールド行列，

は正規化された誘電率ベクトルである。
なお，上記のＰＴＬ３００Ｅデータ収集装置は，他の種類のデータ収集装置を採用することもでき，データ収集装置とイメージングコンピューターとの通信方式は，上記ＲＳ２３２ポートに限定されず，ＲＳ４８５ポート，ＣＡＮバスインタフェースなどの他のポートを介して通信することもできる，又，
２， コンクリート供試体１なしでコンクリート部材内部の水分透過を監視するＥＣＴセンサーの静電容量値を測定して最小静電容量値として，同時に，コンクリート部材内部の水分透過を監視するＥＣＴセンサーの静電容量と結合容量を測定してデータ収集装置に保存することと，
３，直径１５cm，高さ５cmの乾燥したコンクリート供試体１を，ステップ２でコンクリート部材の内部水分透過を監視するＥＣＴセンサー内に固定し，貯水管２を貯水タンク２０に接続し，毎回２５ｍｌ水を貯水管２に追加し，テストの最小静電容量値と最大静電容量値を順番に測定し，校正することと，
４，ステップ３で校正されたコンクリート供試体１を取り出し，異なる水セメント比のコンクリート供試体１を順番に入れて測定し，測定中，データ収集装置は，校正によって測定された誤差静電容量を自動的に除去し，最終的なイメージング結果をイメージングコンピューターに提示することと，
５，ステップ４のコンクリート部材の内部水分透過を監視するＥＣＴセンサーを１８０度回転させ，貯水管２，貯水タンク２０の水位をコンクリート供試体１の上面と一致させて，測定プロセス中に水とコンクリート供試体１が接触していることを確認し，さまざまな角度で水注入中のコンクリート供試体１における水分の透過プロセスを観察することと，
６，測定が完了した後，データをエクスポートしてデータ処理を実行し，異なる水セメント比コンクリート供試体１の水分透過変化曲線を描き，時間とともにコンクリート供試体に入る水分の誘電率の変化曲線を描き，相誘電率と吸水体積の間の関数関係に従って，水分の進入の定量的情報を取得し，コンクリート供試体の２次元水分透過イメージング画像をコンクリート供試体１の正面から撮影した写真と比較して，イメージングの精度を確認すること，
とを含む。 Example 3:
In this embodiment, based on the structure disclosed in Example 1, a process of imaging the permeation of two-dimensional unsaturated moisture inside the cracked concrete by using an ECT sensor that monitors the permeation of moisture inside the concrete member is performed. Offer to,
1, The electrode lead 17 is connected to the port of the PTL300E data collection device, the data collection device is connected to the imaging computer via the RS232 port, and the ECT sensor for monitoring the internal moisture permeation of the concrete member, the PTL300E data collection device. And an ECT system is configured with an imaging computer, and three measurement modes of excitation, grounding, and measurement and a linear back projection algorithm.

Use to perform image reconstruction, where

Is a normalized capacitance vector,

Is a normalized sensitive field matrix,

Is a normalized permittivity vector.
The PTL300E data acquisition device may employ other types of data collection devices, and the communication method between the data collection device and the imaging computer is not limited to the RS232 port, but the RS485 port and the CAN bus interface. It is also possible to communicate via other ports such as
2. Measure the capacitance value of the ECT sensor that monitors the moisture permeation inside the concrete member without the concrete specimen 1 and use it as the minimum capacitance value. At the same time, the static of the ECT sensor that monitors the moisture permeation inside the concrete member. Measuring the capacitance and coupling capacitance and storing them in the data collection device,
3. A dry concrete specimen 1 with a diameter of 15 cm and a height of 5 cm is fixed in an ECT sensor that monitors the internal moisture permeation of the concrete member in step 2, and the water storage pipe 2 is connected to the water storage tank 20 to 25 ml of water each time. Is added to the water storage pipe 2, and the minimum capacitance value and the maximum capacitance value of the test are measured and calibrated in order.
4, The concrete specimen 1 calibrated in step 3 is taken out, concrete specimens 1 having different water-cement ratios are put in order and measured, and during the measurement, the data acquisition device measures the error capacitance measured by the calibration. Automatically remove and present the final imaging result to the imaging computer,
5. Rotate the ECT sensor that monitors the internal moisture permeation of the concrete member in step 4 180 degrees to match the water level of the water storage pipe 2 and the water storage tank 20 with the upper surface of the concrete specimen 1, and water and concrete during the measurement process. Confirming that the specimen 1 is in contact, observing the water permeation process in the concrete specimen 1 during water injection from various angles, and
6. After the measurement is completed, export the data and execute the data processing, draw the water permeation change curve of the concrete specimen 1 with different water-cement ratio, and draw the change curve of the dielectric constant of the water entering the concrete specimen over time. Draw, obtain quantitative information on the ingress of water according to the functional relationship between the phase dielectric constant and the water absorption volume, and compare the two-dimensional water permeation imaging image of the concrete specimen with the photograph taken from the front of the concrete specimen 1. To confirm the accuracy of imaging,
And include.

The principle of the ECT sensor for moisture permeation imaging for monitoring the moisture permeation inside the concrete member according to this embodiment is as follows. The dielectric constant differs depending on the substance, and the relative permittivity of water is about 80, which is considerably larger than the relative permittivity of dry concrete (about 6 to 8). It changes, which changes the capacitance, and the change in the measured capacitance value reflects the distribution of moisture in the dry concrete, and the capacitance measured at various positions by the multi-electrode array sensor. The signal is used as projection data, and the image reconstruction algorithm can reconstruct an image that reflects the water distribution in the dry concrete.

Claims (10)

An ECT sensor that monitors the internal moisture permeation of concrete members, including water storage pipes, insulating pipes, electrode plates, radial shield electrodes, insulating layers, clamps, top plates, bottom plates, spacers, electrode leads, fixing holes and buttless. Including,
The water storage pipe is attached to the side surface of the concrete specimen, an insulating pipe is fitted to the side surface of the concrete specimen to which the water storage pipe is not attached, and electrode plates are equidistantly spaced in the circumferential direction on the outer surface of the insulating pipe. The radial shield electrode is placed between the adjacent electrode plates, the outer circumference of the electrode plate and the radial shield electrode is covered with an insulating layer, and the outer circumference of the insulating layer is sandwiched by a clamp to realize fixing of the entire device and concrete. An ECT sensor characterized in that a top plate is installed on the upper surface of the specimen and a bottom plate is installed on the bottom surface of the concrete specimen. The ECT sensor according to claim 1, wherein the concrete specimen has a cylindrical shape and the axis of the water storage pipe is perpendicular to the axis of the concrete specimen. The ECT sensor for monitoring the internal moisture permeation of a concrete member according to claim 1, wherein the water storage pipe has a scale. The ECT sensor for monitoring the internal moisture permeation of a concrete member according to claim 1, wherein the electrode plate is a copper-platinum electrode plate. An opening is installed in the clamp, the opening extends outward, the opening is connected and fixed by a threaded rod and a nut, a connecting member is installed in the opening, and through to the left, right, and bottom of the clamp. The ECT sensor for monitoring the internal moisture permeation of a concrete member according to claim 1, wherein a continuous plate with holes is welded. The ECT sensor for monitoring the internal moisture permeation of the concrete member according to claim 1, wherein the material of the insulating layer is foamed plastic. The ECT sensor for monitoring the internal moisture permeation of a concrete member according to claim 1, wherein the material of the clamp is stainless steel capable of reducing electromagnetic interference. A system for monitoring the internal moisture permeation of a concrete member, which comprises the ECT sensor for monitoring the internal moisture permeation of the concrete member according to any one of claims 1-7. The internal moisture of a concrete member according to claim 8, further comprising a data acquisition device and an imaging computer, wherein the lead of the electrode plate is connected to a port of the data collection device, and the data collection device is connected to the imaging computer. A system that monitors transparency. A process of imaging two-dimensional unsaturated moisture permeation inside cracked concrete based on the system according to claim 9.
Based on a system for monitoring the internal moisture permeation of concrete members, three measurement modes of excitation, grounding, and measurement and a linear back projection algorithm

Use to perform image reconstruction, where

Is a normalized capacitance vector,

Is a normalized sensitive field matrix,

Is a normalized permittivity vector and
The capacitance value of the ECT sensor that monitors the moisture permeation inside the concrete member without a concrete specimen is measured and used as the minimum capacitance value, and at the same time, the capacitance value of the ECT sensor that monitors the moisture permeation inside the concrete member. Measuring the combined capacitance and storing it in the data collection device,
Take a dry concrete specimen, fix it inside the ECT sensor that monitors the internal moisture permeation of the concrete member in step 2, connect the water storage pipe to the water storage tank, add a certain amount of water to the water storage pipe every time, and test. The minimum capacitance value and the maximum capacitance value of are measured and calibrated in order, and
The calibrated concrete specimen is taken out, concrete specimens with different water-cement ratios are put in order and measured, and during the measurement, the data acquisition device automatically removes the error capacitance measured by the calibration and finally. Presenting the imaging results to an imaging computer,
The ECT sensor that monitors the internal moisture permeation of the concrete member is rotated 180 degrees, the water level of the water storage pipe and water storage tank is aligned with the upper surface of the concrete specimen, and the water and the concrete specimen are in contact during the measurement process. And to observe the water permeation process in the concrete specimen during water injection from various angles.
After the measurement is completed, the data is exported and the data processing is executed, the water permeation change curve of the concrete specimen with different water-cement ratio is drawn, the change curve of the dielectric constant of the water entering the concrete specimen over time is drawn, and the phase dielectric. Quantitative information on water ingress is obtained according to the functional relationship between rate and water absorption volume, and the accuracy of imaging is compared with the two-dimensional water permeation imaging image of the concrete specimen compared with the photograph taken from the front of the concrete specimen. To confirm,
A process characterized by including.

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