Device for diagnosing deterioration of concrete structure and method for diagnosing deterioration of concrete structure

Abstract

The present invention is characterized by comprising at least: a light source which emits inspection light having wavelengths in a visible light range and a near-infrared range; a measurement unit which irradiates a portion to be inspected with the inspection light and receives reflected light that has been reflected; a light dispersing means which disperses the reflected light into a plurality of measurement light rays in mutually different wavelength ranges; and a plurality of photodetectors which output a light intensity signal for each of the measurement light rays dispersed by the light dispersing means.

Description

Concrete structure deterioration diagnosis device and concrete structure deterioration diagnosis method

[0001] The present invention relates to a deterioration diagnosis device and a deterioration diagnosis method for concrete structures that diagnose the aging deterioration of concrete structures. This application claims priority to Japanese Patent Application No. 2024-044758, filed on March 21, 2024, the contents of which are incorporated herein by reference.

[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, 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 infiltrated water, corrosion of steel (reinforcing bars) due to salt damage, and carbonation due to the loss of calcium hydroxide. Therefore, 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.

[0007] JP 2016-024034 A JP 2005-043197 A U.S. Pat. No. 8,164,747 A

[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.

[0012] In order to solve the above problems, a deterioration diagnosis device for a concrete structure according to one embodiment of the present invention proposes the following means: (1) A deterioration diagnosis device for a concrete structure according to aspect 1 of the present invention is characterized by having 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 splits 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 split by the spectroscopic means.

[0013] (2) Aspect 2 of the present invention is characterized in that in the deterioration diagnosis device for a concrete structure of aspect 1, the spectroscopic means includes any one of a diffraction grating, a prism, or a band-pass filter.

[0014] (3) Aspect 3 of the present invention is characterized in that in the deterioration diagnosis device for a concrete structure according to aspect 1 or 2, 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) Aspect 7 of the present invention is characterized in that, in the deterioration diagnosis device for a concrete structure of aspect 6, 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) Aspect 9 of the present invention is characterized in that, in the deterioration diagnosis device for concrete structures of aspect 8, the light source is composed of any one of an LED light source, a semiconductor laser light source, 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 part to be inspected in the measurement unit and receiving the reflected light, a spectroscopic step of dispersing the reflected light with the spectroscopic means into a plurality of measurement lights of mutually different wavelength ranges, 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.

[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.

[0023] Fig. 1 is a schematic configuration diagram showing a concrete structure deterioration diagnosis device of a first embodiment of the present invention. Fig. 2 is a schematic configuration diagram showing a concrete structure deterioration diagnosis device of a second embodiment of the present invention. Fig. 3 is a schematic configuration diagram showing a concrete structure deterioration diagnosis device of a third embodiment of the present invention. Fig. 4 is a flowchart showing a concrete structure deterioration diagnosis method of one embodiment of the present invention in stages. Fig. 5 is an explanatory diagram showing the state of an inspected part when a deterioration diagnosis of a concrete structure is performed. Fig. 6 is an explanatory diagram showing a method for calculating the moisture content and salt concentration of an inspected part.

[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 a concrete structure deterioration diagnosis device of the 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, a plurality of photodetectors 14a to 14f (six in this embodiment), and a control unit 15.

[0026] The light source 11 may be a lamp light source or an LED light source capable of emitting inspection light with wavelengths in the visible light and near-infrared regions. 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 portion S, receives the reflected light of the inspection light reflected by the inspection portion S, and transmits the light to the spectroscopic means 13. In this embodiment, the measuring unit 12 is configured as 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 portion 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 portion S.

[0028] The probe constituting the measuring section 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 inspected portion S inside the concrete structure.

[0029] The spectroscopic means 13 separates the reflected light having a wavelength range of 350 nm to 2500 nm that is reflected by the inspected portion S 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 separates the reflected light, which includes light having a wavelength range of 350 nm to 2500 nm, into a plurality of wavelength components, for example.

[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 composed of a light-shielding member having a plurality of slits 23a to 23f (six slits in this embodiment) formed in a portion of the 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 portion 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] Because of 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. The control unit 15 calculates the moisture content, calcium hydroxide content, and salinity concentration of the inspection portion S measured by the measurement unit 12 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 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 salt 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 narrow detection ranges that can receive only the light of the first to sixth wavelengths required to identify the moisture content, calcium hydroxide content, and salinity concentration.

[0039] Therefore, it is possible to construct 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 measurement light of 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 constructed using only photodiodes, it is easier to reduce noise and improve the signal-to-noise ratio compared to when image sensors or the like are used, and a degradation diagnosis device 10 with high detection accuracy can be realized.

[0041] (Concrete structure deterioration diagnosis device: Second embodiment) Fig. 2 is a schematic diagram showing 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 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 inspection light having a first wavelength (1300 nm), a second wavelength (1412 nm), and a third wavelength (1425 nm) used to detect the moisture content and calcium hydroxide content. The second near-infrared light source 21b emits inspection light having a fourth wavelength (2230 nm), a fifth wavelength (2266 nm), and a sixth wavelength (2300 nm) used to detect the salinity concentration. The first near-infrared light source 21a and the second near-infrared light source 21b can be, for example, a near-infrared halogen lamp or an LED light source.

[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] Furthermore, 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, thereby making it possible to further improve the measurement accuracy of the moisture content, calcium hydroxide content, and salinity.

[0046] (Deterioration diagnosis device for concrete structures: third embodiment) Figure 3 is a schematic diagram showing the configuration of a deterioration diagnosis device for concrete structures 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 deterioration diagnosis device 30 of this embodiment includes a light source 31, a measuring unit 12, one photodetector 34, and a control unit 35.

[0047] The light source 31 is composed of light sources 31a to 31f that emit inspection light of six different wavelengths. Each of the light sources 31a to 31f may be composed of, for example, a near-infrared LED light source, a near-infrared semiconductor laser light source, or a lamp 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, the photodetector 34 sequentially outputs light intensity signals of the reflected light of the six wavelengths, from the first wavelength to the sixth wavelength, to the control unit 35 based on the reflected light of the six wavelengths, from the first wavelength to the sixth wavelength, which are input with a time difference.

[0052] The values ​​of the light intensity signals of the reflected light of the six wavelengths, the first wavelength to the sixth wavelength, which are input sequentially, are then stored in, for example, 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 to, for example, 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 inspection light of the first to sixth wavelengths required to identify the moisture content, calcium hydroxide content, and salt concentration, respectively, and these inspection light of the first to sixth wavelengths are emitted sequentially. As a result, the reflected light from the inspection target portion S obtained by the measurement unit 12 is light of the first to sixth wavelengths emitted sequentially, eliminating the need for a spectroscopic means. This greatly simplifies the configuration of the degradation diagnosis device 30 and enables a significant reduction in manufacturing costs.

[0054] Furthermore, by irradiating the inspection portion S with only inspection light of 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 is simple in configuration and can measure the moisture content, calcium hydroxide content, and salt concentration with high accuracy.

[0055] (Method for diagnosing deterioration of a concrete structure) Fig. 4 is a flowchart showing the steps of a method for diagnosing deterioration of a concrete structure according to one embodiment of the present invention. In the method for diagnosing deterioration of a concrete structure according to this embodiment (hereinafter simply referred to as the deterioration diagnosis method), for example, the deterioration diagnosis device 10 according to 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 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. This causes the inspection light to be emitted from the first optical fiber 12a onto the inspection target S (inspection light irradiation step S1). This inspection light is then reflected by the inspection target S, and enters the entrance end of the second optical fiber 12b as reflected light, where it is received (measurement step S2). The received reflected light propagates from the optical fiber 12b 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 S3).

[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 S4).

[0060] The control unit 15 calculates the moisture content, calcium hydroxide content, and salt concentration based on the light intensity signals of the measurement light of each wavelength that have been input (calculation step S5). As shown in Fig. 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 varies 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. Furthermore, the control unit 15 determines the salt 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 the degradation diagnosis device 10 can be carried out.

[0062] The present 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, the present 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, the present invention has industrial applicability.

[0063] REFERENCE SIGNS LIST 10: Deterioration diagnosis device for concrete structure 11: Light source 12: Measuring unit 12a: First optical fiber 12b: Second optical fiber 13: Spectroscopic means 13a: Diffraction grating 13b: Slit plate 14a to 14f: Photodetector 15: Control unit S: Part to be inspected

Claims

1. A deterioration diagnosis device for concrete structures comprising at least a light source that emits inspection light of wavelengths in the visible light range and near-infrared range; a measurement unit that irradiates the inspection light onto the part to be inspected and receives the reflected light; a spectroscopic means that splits the reflected light into multiple measurement lights of different wavelength ranges; and a plurality of photodetectors that output light intensity signals for each of the measurement lights split by the spectroscopic means.

2. The deterioration diagnosis device for concrete structures according to claim 1, wherein the spectroscopic means includes one of a diffraction grating, a prism, or a bandpass filter.

3. A deterioration diagnosis device for concrete structures according to claim 1 or 2, characterized in that the optical detector is a photodiode.

4. A deterioration diagnosis device for concrete structures as described in claim 1 or 2, characterized in that the light source is composed of a halogen lamp capable of emitting light including at least a continuous wavelength range of 350 nm to 2500 nm.

5. A deterioration diagnosis device for concrete structures as described in claim 1 or 2, characterized in that 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. A deterioration diagnosis device for a concrete structure as described in claim 6, characterized in that 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.

8. A deterioration diagnosis device for concrete structures, comprising at least a light source that sequentially emits inspection light of six mutually different wavelengths, a measuring unit that irradiates the inspection part with the inspection light 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.

9. The deterioration diagnosis device for concrete structures according to claim 8, wherein the light source is composed of one of an LED light source, a semiconductor laser light source, 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.

10. A method for diagnosing deterioration of a concrete structure using the deterioration diagnosis device for a concrete structure described in claim 1 or 2, characterized in that it comprises at least the following steps: an inspection light irradiation step of irradiating the inspection light having wavelengths in the visible light range and near-infrared range from the light source; a measurement step of irradiating the inspection light onto the part to be inspected in the measurement unit and receiving the reflected light; a spectroscopic step of dispersing the reflected light using the spectroscopic means into a plurality of measurement lights of mutually different wavelength ranges; 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.

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