Deterioration diagnostic device of concrete structure, and deterioration diagnostic method of concrete structure
The concrete structure deterioration diagnosis device employs a targeted wavelength light source and photodetectors to enhance sensitivity and reduce costs, enabling accurate moisture, calcium hydroxide, and salt concentration measurements.
Patent Information
- Application Number
- JP2024044758
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-21
- Publication Date
- 2025-10-03
AI Technical Summary
Conventional concrete inspection devices are costly due to the use of expensive components like halogen lamps and wideband image sensors, and suffer from low inspection sensitivity due to unnecessary wavelength ranges, leading to inefficient detection of concrete structure deterioration.
A deterioration diagnosis device using a light source that emits specific wavelengths in the visible and near-infrared regions, combined with a spectroscopic means and low-cost photodetectors to separate and measure reflected light at defined wavelengths, allowing for precise detection of moisture, calcium hydroxide, and salt concentration.
The device achieves high sensitivity and low-cost detection of concrete deterioration with improved accuracy and reduced noise, utilizing a simplified configuration and affordable photodiodes for precise moisture, calcium hydroxide, and salt concentration measurements.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a deterioration diagnosis device and a deterioration diagnosis method for a concrete structure that diagnoses the age-related deterioration of a concrete structure. [Background technology]
[0002] Many concrete structures, such as high-rise buildings and viaducts, have been constructed around the world. However, the deterioration of these concrete structures over time has become a problem. The deterioration of concrete structures over time is mainly caused by salt and other substances penetrating through cracks in the concrete material, causing corrosion of the steel inside. In particular, concrete structures that have been built more than 50 years ago without proper maintenance often show significant deterioration over time. For this reason, it is important to regularly measure the degree of deterioration of concrete structures and carry out appropriate repairs.
[0003] The deterioration of such concrete structures over time is mainly caused by cracks caused by the freezing and thawing of seeping water, corrosion of steel (reinforcing bars) due to salt damage, and carbonation due to the loss of calcium hydroxide. For this reason, when diagnosing the degree of deterioration of a concrete structure, it is important to measure the moisture content, salt concentration, and calcium hydroxide content of the inspected part. Conventionally, to diagnose the deterioration of such concrete structures over time, concrete deterioration diagnosis devices have generally been used, which irradiate the measurement point of the concrete structure with electromagnetic waves and detect the degree of deterioration by analyzing the resulting reflected waves.
[0004] For example, Patent Document 1 discloses a concrete inspection device that includes a light source that irradiates light containing wavelength components in the near-infrared wavelength region, and a semiconductor light-receiving element that is sensitive to light in the near-infrared wavelength region.
[0005] Furthermore, Patent Document 2 discloses a concrete inspection method in which electromagnetic waves are transmitted to a concrete structure and reflected waves are received, and the type of defect is determined based on a specific calculation formula relating to the initial peak of the measured internal defect reflected waves.
[0006] Furthermore, Patent Document 3 discloses a light source capable of irradiating light in a wide wavelength range from visible light to infrared light, and a multi-channel spectrometer capable of measuring the state of an object by using an image sensor after separating the reflected light in this wide wavelength range. [Prior art documents] [Patent documents]
[0007] [Patent Document 1] Japanese Patent Application Publication No. 2016-024034 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-043197 [Patent Document 3] U.S. Patent No. 8,164,747 Summary of the Invention [Problem to be solved by the invention]
[0008] However, conventional concrete inspection devices use a light source capable of emitting inspection light over a wide wavelength range, including the wavelengths required for inspecting deterioration of concrete structures, and then use a light receiving device, such as an image sensor, after the wide wavelength range of inspection light reflected by the inspected part is separated into separate wavelengths.
[0009] This has led to the problem of high costs for concrete inspection equipment due to the use of expensive components such as halogen lamps that can emit light of wavelengths not necessary for inspecting deterioration of concrete structures, and wideband image sensors.
[0010] In addition, by using light with a wide wavelength range, including light in a wavelength range that is not necessary for inspecting deterioration of concrete structures, the light intensity in the wavelength range necessary for inspecting deterioration of concrete structures becomes relatively weak, which poses the problem of low inspection sensitivity.
[0011] The present invention has been proposed in view of the above-mentioned problems, and aims to provide a deterioration diagnosis device for concrete structures that can detect the degree of deterioration with high sensitivity, has a simple configuration, and is low-cost, and a deterioration diagnosis method for concrete structures using the same. [Means for solving the problem]
[0012] In order to solve the above problems, the concrete structure deterioration diagnosis device according to one embodiment of the present invention proposes the following means. (1) A deterioration diagnosis device for a concrete structure according to a first aspect of the present invention is characterized by comprising at least a light source that emits inspection light having wavelengths in the visible light region and the near-infrared region, a measurement unit that irradiates the inspection light onto an inspection target portion and receives the reflected light, a spectroscopic means that separates the reflected light into a plurality of measurement lights having mutually different wavelength regions, and a plurality of photodetectors that output a light intensity signal for each of the measurement lights separated by the spectroscopic means.
[0013] (2) A second aspect of the present invention is characterized in that in the deterioration diagnosis device for a concrete structure of the first aspect, the spectroscopic means includes any one of a diffraction grating, a prism, or a band-pass filter.
[0014] (3) A third aspect of the present invention is characterized in that in the deterioration diagnosis device for a concrete structure according to the first or second aspect, the photodetector is a photodiode.
[0015] (4) Aspect 4 of the present invention is characterized in that, in the deterioration diagnosis device for concrete structures of any one of aspects 1 to 3, the light source is composed of a halogen lamp capable of emitting light including at least a continuous wavelength range of 350 nm or more and 2500 nm or less.
[0016] (5) Aspect 5 of the present invention is characterized in that, in the deterioration diagnosis device for concrete structures of any one of aspects 1 to 3, the light source is composed of a first near-infrared light source capable of emitting light including a continuous wavelength range of 1300 nm or more and 1500 nm or less, and a second near-infrared light source capable of emitting light including a continuous wavelength range of 2000 nm or more and 2500 nm or less.
[0017] (6) Aspect 6 of the present invention is characterized in that, in the deterioration diagnosis device for concrete structures of any one of aspects 1 to 5, the photodetector is composed of six photodetectors that respectively receive the measurement light of six wavelengths from the first wavelength to the sixth wavelength, and the first wavelength is 1300 nm, the second wavelength is 1412 nm, the third wavelength is 1425 nm, the fourth wavelength is 2230 nm, the fifth wavelength is 2266 nm, and the sixth wavelength is 2300 nm.
[0018] (7) A seventh aspect of the present invention is characterized in that, in the deterioration diagnosis device for a concrete structure of the sixth aspect, it has a control unit that calculates the moisture content of the inspected portion based on the light intensity signals of the measurement light of the first wavelength and the third wavelength, calculates the calcium hydroxide content of the inspected portion based on the light intensity signals of the measurement light of the second wavelength and the third wavelength, and calculates the salt concentration of the inspected portion based on the light intensity signals of the measurement light of the fourth wavelength, the fifth wavelength, and the sixth wavelength.
[0019] (8) A deterioration diagnosis device for a concrete structure according to aspect 8 of the present invention is characterized by having at least a light source that sequentially emits inspection light of six different wavelengths, a measuring unit that irradiates the inspection light onto the part to be inspected and receives the reflected light of the six wavelengths, and one photodetector that sequentially outputs light intensity signals for each of the reflected light of the six wavelengths.
[0020] (9) A ninth aspect of the present invention is characterized in that, in the deterioration diagnosis device for concrete structures of the eighth aspect, the light source is composed of any one of an LED, a semiconductor laser, or a lamp light source capable of emitting light of six wavelengths from the first wavelength to the sixth wavelength, and the first wavelength is 1300 nm, the second wavelength is 1412 nm, the third wavelength is 1425 nm, the fourth wavelength is 2230 nm, the fifth wavelength is 2266 nm, and the sixth wavelength is 2300 nm.
[0021] (10) Aspect 10 of the present invention is a method for diagnosing deterioration of a concrete structure using the deterioration diagnosis device for a concrete structure of any one of aspects 1 to 7, characterized in that it comprises at least an inspection light irradiation step of irradiating the inspection light of wavelengths in the visible light range and near-infrared range from the light source, a measurement step of irradiating the inspection light onto the inspected part in the measurement unit and receiving the reflected light, a spectroscopic step of dispersing the reflected light into multiple measurement lights of different wavelength ranges using the spectroscopic means, and a light intensity signal output step of outputting a light intensity signal for each measurement light dispersed by the spectroscopic means in the photodetector. [Effects of the Invention]
[0022] According to the present invention, it is possible to provide a deterioration diagnosis device for concrete structures that can detect the degree of deterioration with high sensitivity, has a simple configuration, and is low-cost, and a deterioration diagnosis method for concrete structures using the same. [Brief explanation of the drawings]
[0023] [Figure 1] 1 is a schematic configuration diagram showing a deterioration diagnosis device for a concrete structure according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic configuration diagram showing a deterioration diagnosis device for a concrete structure according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic configuration diagram showing a deterioration diagnosis device for a concrete structure according to a third embodiment of the present invention. [Figure 4] 1 is a flowchart showing a method for diagnosing deterioration of a concrete structure according to an embodiment of the present invention in a step-by-step manner. [Figure 5] FIG. 1 is an explanatory diagram showing the state of an inspected portion during deterioration diagnosis of a concrete structure. [Figure 6] 10A and 10B are explanatory diagrams showing a method for calculating the moisture content and salt concentration of an inspection target portion. DETAILED DESCRIPTION OF THE INVENTION
[0024] Hereinafter, a concrete structure deterioration diagnosis device and a concrete structure deterioration diagnosis method using the same according to one embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is specifically described to provide a better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. Furthermore, the drawings used in the following description may show essential parts enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional proportions of each component may not necessarily be the same as those in reality.
[0025] (Concrete structure deterioration diagnosis device: First embodiment) FIG. 1 is a schematic diagram showing the configuration of a deterioration diagnosis device for a concrete structure according to a first embodiment of the present invention. The concrete structure deterioration diagnosis device 10 of this embodiment (hereinafter simply referred to as the deterioration diagnosis device) includes a light source 11, a measurement unit 12, a spectroscopic means 13, multiple, in this embodiment six, photodetectors 14a to 14f, and a control unit 15.
[0026] The light source 11 may be a lamp or LED light source capable of emitting inspection light with wavelengths in the visible light region and near-infrared region. In this embodiment, a halogen lamp capable of emitting visible light and near-infrared light with wavelengths in the range of 350 nm to 2500 nm is used as the light source 11.
[0027] The measuring unit 12 may be any component that irradiates the inspection light from the light source 11 toward the inspection part S, receives the reflected light of the inspection light reflected by the inspection part S, and propagates it to the spectroscopic means 13. In this embodiment, the measuring unit 12 is configured from an elongated probe that includes a first optical fiber 12a having one end connected to the light source 11 and the other end forming an output end that irradiates the inspection light toward the inspection part S, and a second optical fiber 12b having one end connected to the spectroscopic means 13 and the other end forming an input end that receives the reflected light reflected by the inspection part S.
[0028] The probe constituting the measuring unit 12 is inserted, for example, into a small hole opened in the concrete structure for inspection, and guided to a position where the end faces the portion S to be inspected inside the concrete structure.
[0029] The spectroscopic means 13 separates the reflected light, which is reflected by the inspection target portion S and has a wavelength range of 350 nm to 2500 nm, into a plurality of measurement lights having mutually different wavelength ranges. In this embodiment, a diffraction grating 13a and a slit plate 13b are used as the spectroscopic means 13. The diffraction grating 13a disperses reflected light containing light in a wavelength range of, for example, 350 nm to 2500 nm, and separates the light into a plurality of wavelength components.
[0030] In this embodiment, a diffraction grating 13a is used as the spectroscopic means 13, but other means such as an optical prism or a bandpass filter can also be used as the spectroscopic means 13, and the spectroscopic means 13 is not limited to this.
[0031] The slit plate 13b is configured by forming multiple slits 23a to 23f (six slits in this embodiment) in a part of a light-blocking member. As shown in Fig. 1, each slit 23 is a narrow hole that transmits only the measurement light corresponding to six specific wavelengths out of the measurement light dispersed and expanded by the diffraction grating 13a. The slit plate 13b blocks measurement light in wavelength ranges other than the six specific wavelengths.
[0032] In this embodiment, slit 23a transmits measurement light with a first wavelength of 1300 nm. Similarly, slit 23b transmits measurement light with a second wavelength of 1412 nm, slit 23c transmits measurement light with a third wavelength of 1425 nm, slit 23d transmits measurement light with a fourth wavelength of 2230 nm, slit 23e transmits measurement light with a fifth wavelength of 2266 nm, and slit 23f transmits measurement light with a sixth wavelength of 2300 nm.
[0033] The photodetectors 14a to 14f are each composed of a low-cost photodiode. The photodetector 14a is disposed adjacent to the rear side (exit side) of the slit 23a of the slit plate 13b constituting the spectroscopic means 13. Similarly, the photodetector 14b is disposed adjacent to the rear side (exit side) of the slit 23b, the photodetector 14c is disposed adjacent to the rear side (exit side) of the slit 23c, the photodetector 14d is disposed adjacent to the rear side (exit side) of the slit 23d, the photodetector 14e is disposed adjacent to the rear side (exit side) of the slit 23e, and the photodetector 14f is disposed adjacent to the rear side (exit side) of the slit 23f. Note that if the size of the light receiving section of the photodetector is small enough to enable wavelength selection, the photodetector itself will function as a slit, and the slits may be omitted.
[0034] With this configuration, photodetector 14a receives measurement light with a wavelength of 1300 nm, which is the first wavelength, photodetector 14b receives measurement light with a wavelength of 1412 nm, which is the second wavelength, photodetector 14c receives measurement light with a wavelength of 1425 nm, which is the third wavelength, photodetector 14d receives measurement light with a wavelength of 2230 nm, which is the fourth wavelength, photodetector 14e receives measurement light with a wavelength of 2266 nm, which is the fifth wavelength, and photodetector 14f receives measurement light with a wavelength of 2300 nm, which is the sixth wavelength, and outputs a light intensity signal according to the light intensity of the received measurement light to control unit 15.
[0035] Due to this configuration, the photodetectors 14a to 14f can be configured with only low-cost photodiodes with narrow detection ranges that can receive only the light of each of the first to sixth wavelengths.
[0036] The control unit 15 is composed of, for example, a CPU, a memory, an interface, a liquid crystal monitor, etc. Based on the light intensity signals of the measurement light of the first to sixth wavelengths input to the photodetectors 14a to 14f, the control unit 15 calculates the water content, calcium hydroxide content, and salinity concentration of the inspection portion S measured by the measurement unit 12. The control unit 15 then outputs the results to, for example, a liquid crystal monitor.
[0037] More specifically, the control unit 15 calculates the moisture content of the inspection portion S based on the light intensity signals of the measurement light having the first wavelength of 1300 nm and the third wavelength of 1425 nm. It also calculates the calcium hydroxide content of the inspection portion S based on the light intensity signals of the measurement light having the second wavelength of 1412 nm and the third wavelength of 1425 nm. It also calculates the salinity concentration of the inspection portion S based on the light intensity signals of the measurement light having the fourth wavelength of 2230 nm, the fifth wavelength of 2266 nm, and the sixth wavelength of 2300 nm.
[0038] According to the deterioration diagnosis device 10 of the first embodiment configured as described above, the photodetectors 14a to 14f are configured solely from low-cost photodiodes with a narrow detection range that can receive only the light of each of the first to sixth wavelengths required to identify the moisture content, calcium hydroxide content, and salt concentration.
[0039] Therefore, it is possible to configure a deterioration diagnosis device 10 for concrete structures at a lower cost than conventional deterioration diagnosis device configurations that use expensive image sensors to receive measurement light over a wide range of wavelengths, including the wavelengths required to determine moisture content, calcium hydroxide content, and salt concentration, and perform image signal processing using highly functional integrated circuits that control such image sensors.
[0040] Furthermore, if the photodetectors 14a to 14f are configured using only photodiodes, it is easier to reduce noise and improve the S / N ratio compared to when an image sensor or the like is used, and a degradation diagnostic device 10 with high detection accuracy can be realized.
[0041] (Concrete structure deterioration diagnosis device: second embodiment) 2 is a schematic diagram showing the configuration of a concrete structure deterioration diagnosis device according to a second embodiment of the present invention. Note that the same components as those in the first embodiment described above are given the same reference numerals, and redundant explanations will be omitted.
[0042] The degradation diagnosis device 20 of this embodiment is configured with a first near-infrared light source 21a and a second near-infrared light source 21b as the light source 21. The first near-infrared light source 21a may be any light source capable of emitting near-infrared light having a continuous wavelength range of 1300 nm to 1500 nm, and the second near-infrared light source 21b may be any light source capable of emitting near-infrared light having a continuous wavelength range of 2000 nm to 2500 nm.
[0043] The first near-infrared light source 21a emits test light of a first wavelength (1300 nm), a second wavelength (1412 nm), and a third wavelength (1425 nm) used to detect the water content and calcium hydroxide content, while the second near-infrared light source 21b emits test light of a fourth wavelength (2230 nm), a fifth wavelength (2266 nm), and a sixth wavelength (2300 nm) used to detect the salinity concentration. For example, a near-infrared halogen lamp or an LED light source can be used as the first near-infrared light source 21a and the second near-infrared light source 21b.
[0044] According to the deterioration diagnosis device 20 of this embodiment, the light source 21 can be made low cost by using, as the light source 21, a first near-infrared light source 21a having a relatively narrow wavelength range including light of the first wavelength, light of the second wavelength, and light of the third wavelength used for detecting moisture content and calcium hydroxide content, or a second near-infrared light source 21b having a relatively narrow wavelength range including light of the fourth wavelength, light of the fifth wavelength, and light of the sixth wavelength used for detecting salt concentration.
[0045] In addition, by dividing the light source into two wavelength ranges, the intensity of the measurement light for detecting the moisture content, the intensity of the measurement light for detecting the calcium hydroxide content, and the intensity of the measurement light for detecting the salinity concentration can each be increased, making it possible to further improve the measurement accuracy of the moisture content, calcium hydroxide content, and salinity.
[0046] (Concrete structure deterioration diagnosis device: third embodiment) 3 is a schematic diagram showing the configuration of a concrete structure deterioration diagnosis device according to a third embodiment of the present invention. Note that the same components as those in the first embodiment described above are given the same reference numerals, and redundant explanations will be omitted. The degradation diagnostic device 30 of this embodiment includes a light source 31, a measuring unit 12, one photodetector , and a control unit .
[0047] The light source 31 is made up of light sources 31a to 31f that emit inspection light of six different wavelengths. Each of the light sources 31a to 31f may be made up of, for example, a near-infrared LED light source or a near-infrared semiconductor laser light source.
[0048] Of these, light source 31a emits test light containing light of a first wavelength (1300 nm) used to detect the moisture content. Similarly, light source 31b emits test light containing light of a second wavelength (1412 nm) used to detect the calcium hydroxide content, light source 31c emits test light containing light of a third wavelength (1425 nm) used to detect the moisture content and the calcium hydroxide content, light source 31d emits test light containing light of a fourth wavelength (2230 nm) used to detect the salinity concentration, light source 31e emits test light containing light of a fifth wavelength (2266 nm) used to detect the salinity concentration, and light source 31f emits test light containing light of a sixth wavelength (2300 nm) used to detect the salinity concentration.
[0049] The photodetector 34 is composed of a near-infrared photodiode capable of receiving reflected light in at least the wavelength range from the first wavelength (1300 nm) to the sixth wavelength (2300 nm).
[0050] The control unit 35 controls the light emission of the light sources 31a to 31f. For example, the control unit 35 controls the light sources 31a to 31f to emit light sequentially at regular intervals. As a result, the inspection light of six wavelengths, from the first wavelength to the sixth wavelength, is sequentially irradiated onto the inspection target portion S via the measurement unit 12.
[0051] In addition, based on the reflected light of six wavelengths, from the first wavelength to the sixth wavelength, which are input with a time difference, the photodetector 34 sequentially outputs light intensity signals of the reflected light of these six wavelengths, from the first wavelength to the sixth wavelength, to the control unit 35.
[0052] The values of the light intensity signals of the reflected light of six wavelengths, the first wavelength to the sixth wavelength, which are input sequentially, are then stored, for example, in a memory. The values of the light intensity signals of the first and third wavelengths are then read out to calculate the moisture content of the inspection portion S. The values of the light intensity signals of the second and third wavelengths are also read out to calculate the calcium hydroxide content of the inspection portion S. The values of the light intensity signals of the fourth, fifth, and sixth wavelengths are also read out to calculate the salinity concentration of the inspection portion S. The results are then output, for example, to an LCD monitor.
[0053] According to the degradation diagnosis device 30 of the third embodiment configured as described above, the light source is configured with six light sources 31a to 31f capable of emitting test light of each of the first to sixth wavelengths required to identify the moisture content, calcium hydroxide content, and salt concentration, and these test light of the first to sixth wavelengths are emitted sequentially. As a result, the reflected light from the test portion S obtained by the measurement unit 12 is light of the first to sixth wavelengths emitted sequentially, making a spectroscopic means unnecessary. This greatly simplifies the configuration of the degradation diagnosis device 30 and makes it possible to significantly reduce manufacturing costs.
[0054] Furthermore, by irradiating the inspected portion S with only the inspection light of the specific wavelengths required to identify the moisture content, calcium hydroxide content, and salt concentration, the light intensity of the inspection light of each wavelength can be increased. This makes it possible to realize a deterioration diagnosis device 30 that can measure the moisture content, calcium hydroxide content, and salt concentration with high accuracy using a simple configuration.
[0055] (Method for diagnosing deterioration of concrete structures) FIG. 4 is a flowchart showing a step-by-step method for diagnosing deterioration of a concrete structure according to one embodiment of the present invention. In the deterioration diagnosis method for a concrete structure of this embodiment (hereinafter simply referred to as the deterioration diagnosis method), for example, a deterioration diagnosis device 10 of the first embodiment shown in FIG. 1 is used.
[0056] First, a small hole is formed that is large enough to allow the insertion of a probe constituting the measuring unit 12, leading from the outside of the concrete structure to the inspection target portion S. Then, the probe is inserted into this small hole (see the schematic diagram of FIG. 5).
[0057] Next, the control unit 15 is operated to start the deterioration diagnosis. First, the control unit 15 causes the light source 11 to emit inspection light. As a result, the inspection light is emitted from the first optical fiber 12a onto the inspection target portion S (inspection light irradiation step S1). Then, this inspection light is reflected by the inspection target portion S, enters the entrance end of the second optical fiber 12b as reflected light, and propagates toward the spectroscopic means 13.
[0058] Next, the reflected light incident on the spectroscopic means 13 is separated into a plurality of wavelength components by the diffraction grating 13a, and then separated into measurement light of six wavelengths, from the first wavelength to the sixth wavelength, by six slits 23a to 23f formed in the slit plate 13b (spectroscopic step S2).
[0059] Next, the separated measurement light beams of six wavelengths (first wavelength to sixth wavelength) are incident on the six photodetectors 14a to 14f, respectively. The photodetectors 14a to 14f output light intensity signals of the respective wavelengths to the control unit 15 based on the light intensities of the incident measurement light beams of different wavelengths (first wavelength to sixth wavelength) (light intensity signal output step S3).
[0060] The control unit 15 calculates the water content, calcium hydroxide content, and salt concentration based on the input light intensity signals of the measurement light of each wavelength (calculation step S4). 6, the control unit 15 determines the moisture content of the test portion S based on the difference in absorbance between the measurement light of the third wavelength and the measurement light of the first wavelength, which changes depending on the moisture content of the test portion S. The control unit 15 also determines the calcium hydroxide content of the test portion S based on the difference in absorbance between the measurement light of the second wavelength and the measurement light of the third wavelength. The control unit 15 also determines the salinity concentration of the test portion S based on the differential spectrum of the measurement light of the fourth, fifth, and sixth wavelengths.
[0061] Through the steps described above, the degradation diagnosis method of this embodiment using degradation diagnosis device 10 can be carried out. [Industrial Applicability]
[0062] This invention contributes to the development of low-cost, high-performance non-destructive testing equipment capable of diagnosing deterioration of concrete structures on-site. Furthermore, by selecting an appropriate wavelength, this invention can contribute to the development of low-cost, high-performance equipment for analysis in fields other than concrete structure deterioration diagnosis, such as food, agriculture, pharmaceuticals, medicine, and materials, where near-infrared spectroscopy can be used. Therefore, it has industrial applicability. [Explanation of symbols]
[0063] 10...Deterioration diagnosis device for concrete structures 11...Light source 12…Measuring part 12a...first optical fiber 12b...Second optical fiber 13...Spectroscopy means 13a...Diffraction grating 13b...Slit plate 14a to 14f: Photodetector 15...Control unit S...part to be inspected
Claims
1. a light source that emits inspection light having wavelengths in the visible light region and the near-infrared region; a measuring unit that irradiates the inspection light onto an inspection target portion and receives the reflected light; a spectroscopic means for separating the reflected light into a plurality of measurement lights having different wavelength ranges; a plurality of photodetectors for outputting a light intensity signal for each of the measurement lights split by the splitting means; A deterioration diagnosis device for a concrete structure, comprising at least the following:
2. 2. The deterioration diagnosis device for a concrete structure according to claim 1, wherein the spectroscopic means includes one of a diffraction grating, a prism, and a bandpass filter.
3. 3. The deterioration diagnosis device for a concrete structure according to claim 1, wherein the photodetector is a photodiode.
4. 3. The deterioration diagnosis device for a concrete structure according to claim 1, wherein the light source is a halogen lamp capable of emitting light having a continuous wavelength range of at least 350 nm to 2500 nm.
5. 3. The deterioration diagnosis device for a concrete structure according to claim 1, wherein the light source is composed of a first near-infrared light source capable of emitting light having a continuous wavelength range of 1300 nm or more and 1500 nm or less, and a second near-infrared light source capable of emitting light having a continuous wavelength range of 2000 nm or more and 2500 nm or less.
6. The deterioration diagnosis device for concrete structures described in claim 1 or 2, characterized in that the photodetector is composed of six photodetectors that respectively receive the measurement light of six wavelengths, from the first wavelength to the sixth wavelength, wherein the first wavelength is 1300 nm, the second wavelength is 1412 nm, the third wavelength is 1425 nm, the fourth wavelength is 2230 nm, the fifth wavelength is 2266 nm, and the sixth wavelength is 2300 nm.
7. 7. The concrete structure deterioration diagnosis device according to claim 6, further comprising a control unit that calculates the moisture content of the inspected portion based on the light intensity signals of the measurement light of the first wavelength and the third wavelength, calculates the calcium hydroxide content of the inspected portion based on the light intensity signals of the measurement light of the second wavelength and the third wavelength, and calculates the salt concentration of the inspected portion based on the light intensity signals of the measurement light of the fourth wavelength, the fifth wavelength, and the sixth wavelength.
8. a light source that sequentially emits inspection light of six different wavelengths; a measuring unit that irradiates the inspection light onto an area to be inspected and receives reflected light of six wavelengths; one photodetector for sequentially outputting light intensity signals of the reflected light of six wavelengths; A deterioration diagnosis device for a concrete structure, comprising at least the following:
9. The concrete structure deterioration diagnosis device of claim 8, characterized in that the light source is composed of any one of an LED, a semiconductor laser, or a lamp light source capable of emitting light of six wavelengths from the first wavelength to the sixth wavelength, wherein the first wavelength is 1300 nm, the second wavelength is 1412 nm, the third wavelength is 1425 nm, the fourth wavelength is 2230 nm, the fifth wavelength is 2266 nm, and the sixth wavelength is 2300 nm.
10. A method for diagnosing deterioration of a concrete structure using the deterioration diagnosis device for a concrete structure according to claim 1 or 2, comprising: an inspection light irradiation step of irradiating the inspection light having wavelengths in the visible light region and near-infrared region from the light source; a measuring step of irradiating the inspection light onto the inspection target portion in the measurement unit and receiving the reflected light; a spectroscopic step of splitting the reflected light into a plurality of measurement lights having different wavelength ranges; a light intensity signal output step of outputting a light intensity signal for each of the measurement lights separated by the spectroscopic means in the photodetector; A deterioration diagnosis method for a concrete structure, comprising at least the steps of:
Citation Information
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