JP2016200566A - Degradation testing method and layer thickness testing method of multilayer body, and degradation testing apparatus and layer thickness testing apparatus of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which precise degradation information can be obtained, even when an error pattern wave form is obtained from a thickness measuring point in a back layer, by using the wave form as information source of the degradation information of the multilayer body.SOLUTION: A degradation testing method of a multilayer body comprises a first determination step and a second determination step. The first determination step, for the multilayer body accumulating a surface layer and a back layer determines, when reflection waves of supersonic wave dispatched from the surface layer side to the back layer side are a first reflection wave, a second reflection wave and a third reflection wave in a detection order, whether an intensity of the first reflection wave is within a reference range, and determines that the surface of the surface layer is excessively degraded when it is not within the reference range. The second determination step determines, when the first determination step determines that the intensity of the first reflection wave is within the reference range, whether an intensity of the second reflection wave is within the prescribed range, and determines that the surface layer is internally excessively degraded or interfacially peeled between the surface layer and the back layer when it is not within the prescribed range.SELECTED DRAWING: Figure 17

Description

  The present invention relates to a method for testing a multilayer body. More specifically, this invention relates to the technique which can investigate the deterioration state of a multilayer body in detail.

Conventionally, a method of measuring the thickness of a constituent layer of a multilayer body by a nondestructive method has been adopted.
For example, in Japanese Patent Laid-Open No. 60-123712 (Patent Document 1), an ultrasonic probe is installed on the surface of a tube to emit ultrasonic waves in the radial direction and detect a reflected wave from the inner surface of the opposite lining. A method for measuring the inner surface lining thickness is disclosed, wherein the lining thickness is measured from the energy loss of the reflected wave.

  Japanese Patent Application Laid-Open No. 63-3211 (Patent Document 2) discloses a method for measuring the thickness of a fiber-reinforced composite layer formed integrally with a surface of a metal main body and made of a reinforcing fiber and a metal matrix. The ultrasonic wave is transmitted toward the surface of the fiber reinforced resin composite layer and the reflected wave is sequentially received, and the time from the transmission of the ultrasonic wave to the reception of the final reflected wave by the reinforcing fiber is converted into the thickness of the fiber reinforced composite layer. A method for measuring the thickness of a fiber-reinforced composite layer using ultrasonic waves is disclosed.

JP-A-60-123712 Japanese Patent Laid-Open No. Sho 63-3211

The method of patent document 1 measures the thickness of the concrete lining layer of the composite pipe comprised from a metal and concrete. In this method, it is necessary to install a contact-type ultrasonic probe outside the composite tube. Therefore, when applied to the buried pipeline, an excavation work is required. Furthermore, the method of Patent Document 1 is a method of measuring the lining thickness that is the surface layer on the ultrasonic incident side, and does not describe measuring the thickness of the metal layer that is a deep layer.
The method of patent document 2 measures the thickness of the fiber reinforcement layer which is the surface layer of the ultrasonic wave incidence side by a water immersion type ultrasonic method. However, it is not described that the thickness of the metal layer which is a deep layer can be measured.

  If the ultrasonic wave is transmitted to the multi-layered body composed of the surface layer and its deep layer (back layer) and the thickness of the deep layer (back layer) can be measured from the incident side, the deterioration state of the back layer is nondestructive. Can be examined. In order to measure the thickness of the back layer, in principle, an appropriate waveform including the reflected wave from the surface layer-back layer interface and the reflected wave from the back surface of the back layer, detected after the reflected wave from the surface of the surface layer. Need to get. However, the aspect of deterioration of the multilayer body is various, and an appropriate waveform that can measure the thickness of the back layer is not always obtained. From the waveform of the error pattern, not only thickness information but also deterioration information other than thickness is not determined. Even if a waveform that seems to be appropriate is obtained, errors due to multiple reflections in the surface layer may occur, so the actual measurement error is large, and such error patterns are not identified. .

  Therefore, the object of the present invention is to use such a waveform as an information source for deterioration information of a multilayer body even when a waveform that becomes an error pattern is obtained from the point of measuring the thickness of the back layer. Another object of the present invention is to provide a method capable of acquiring detailed deterioration information.

As a result of intensive studies, the present inventor has found that the object of the present invention can be achieved by sieving the waveform characteristics that do not contribute to the measurement of the thickness of the back layer according to a unique standard and associating it with the deterioration information of the multilayer. The present invention has been completed.
The present invention includes the following inventions.

(1)
The degradation test method for a multilayer body of the present invention includes a first determination step and a second determination step.
In the first determination step, a reflected wave of an ultrasonic wave transmitted in a direction from the surface layer side toward the back layer side with respect to the multilayer body in which the surface layer and the back layer are laminated, the first reflected wave in the detection order, When the second reflected wave and the third reflected wave are used, it is determined whether or not the intensity of the first reflected wave is included in the reference range. And the case where it is not contained in a reference | standard range is determined as the surface excessive deterioration of a surface layer.
In the second determination step, when it is determined in the first determination step that the intensity of the first reflected wave is included in the reference range, it is determined whether or not the intensity of the second reflected wave is included in the predetermined range. And the case where it does not fall within a predetermined range is determined as internal excessive deterioration of the surface layer or interface peeling between the surface layer and the back layer.

  With this configuration, it is possible to determine the surface overdeterioration of the surface layer of the multi-layer body, and when it does not correspond to the surface overdeterioration of the surface layer, determine the internal overdeterioration of the surface layer or the interface peeling between the surface layer and the back layer. Can do.

  The surface overdeterioration of the surface layer means that the surface of the surface layer has deteriorated to such an extent that ultrasonic waves are scattered by rough irregularities and are not incident on the inside of the surface layer (the same applies hereinafter). The excessive internal deterioration of the surface layer means that the inside of the surface layer is deteriorated to such an extent that the ultrasonic waves are scattered due to the cavitation due to the roughness and the incident ultrasonic waves cannot sufficiently travel in the surface layer (the same applies hereinafter). ).

(2)
In the first determination step, it is preferable to set the reference range so as to correspond to an intensity range of 40% or more when the intensity of the first reflected wave on the surface layer when there is no surface deterioration is set to 80%.

  Thereby, the surface excessive deterioration of the surface layer of the multilayer body can be determined more accurately.

(3)
In the second determination step, the case where the intensity of the second reflected wave is below a predetermined range may be determined as internal excessive deterioration of the surface layer, and the case where the intensity exceeds the upper limit of the predetermined range may be determined as interface peeling between the surface layer and the back layer. .

  Thereby, it is possible to discriminate between excessive internal deterioration of the surface layer and interface peeling. It is also possible to determine interface peeling that causes multiple reflection in the surface layer. Therefore, erroneous measurement can be reduced when the layer thickness is measured.

(4)
The second determination step is preferably performed with a higher gain than the first determination step.

  Thereby, the second determination step can be performed more accurately.

(5)
In the second determination step, the predetermined range is set so as to correspond to an intensity range of 17% or more and 70% or less when the intensity of the first reflected wave on the surface layer is 240% when there is no surface deterioration. Is preferred.

  As a result, it is possible to more accurately determine the internal excessive deterioration and interfacial peeling of the surface layer of the multilayer body.

(6)
The degradation test method for a multilayer body of the present invention may further include a third determination step. It is determined whether the intensity of the third reflected wave exceeds the lower limit of the predetermined range. And the case below a minimum is determined as the back surface excessive deterioration of a back layer.

  Thereby, it is possible to determine the back surface excessive deterioration of the back layer which is different from the surface excessive deterioration and the interface peeling.

  In addition, the back surface excessive deterioration of the back layer means that ultrasonic waves are scattered back by rough unevenness and deteriorated to the extent that they are not sufficiently reflected (the same applies hereinafter).

The third determination step may be performed subsequent to the above-described second determination step. That is, the third determination step may be performed when it is determined in the second determination step that the intensity of the second reflected wave is included in the predetermined range. (Illustrated in FIG. 17)
The third determination step may be performed subsequently after the above-described second determination step and a later-described fourth determination step are performed in this order. That is, the third determination step may be performed when it is determined in the fourth step described later that the phase of the second reflected wave and the phase of the third reflected wave are opposite. (Illustrated in FIG. 20)

(7)
In the degradation test method for a multilayer body according to any one of (1) to (6) above, a fourth determination step may be further included. In the fourth determination step, it is determined whether or not the phase of the second reflected wave and the phase of the third reflected wave are opposite. And the case where the phase is not reversed is determined as the interface peeling between the surface layer and the back layer.

  As a result, it is possible to avoid oversight of interface peeling that causes multiple reflections in the surface layer. Therefore, erroneous measurement can be further reduced when the layer thickness is measured.

The fourth determination step may be performed subsequent to the third determination. That is, the fourth determination step may be performed when it is determined in the third determination step that the intensity of the third reflected wave exceeds the lower limit of the predetermined range. (Illustrated in FIG. 18)
The fourth determination may be performed subsequent to the second determination. That is, the fourth determination step may be performed when it is determined in the second determination step that the intensity of the second reflected wave is included in the predetermined range. (Illustrated in FIG. 19)

(8)
The layer thickness test method for a multilayer body of the present invention includes a degradation test step for performing the degradation test method for a multilayer body according to any one of (1) to (7) above, and a layer thickness derivation step. In the layer thickness deriving step, the second reflected wave is determined when the deterioration test step determines that none of the surface over-deterioration of the surface layer, the internal over-deterioration of the surface layer, and the interfacial delamination between the surface layer and the back layer. The thickness of the back layer is derived from the propagation time of the third reflected wave.

  With this configuration, waveforms that are not suitable for layer thickness measurement are preliminarily discarded, and deterioration information other than the layer thickness can be obtained from the discarded waveform pattern, while from waveforms narrowed down as suitable for layer thickness measurement, Correct layer thickness information can be acquired.

When the third determination step, which is an optional step, is performed in the deterioration test step, the waveforms narrowed down as being suitable for the layer thickness measurement are the surface over-deterioration of the surface layer, the internal over-deterioration of the surface layer, and the surface layer and the back layer. In addition, it is more reliable in that it is determined not to fall under excessive deterioration of the back surface of the back layer.
In addition, when the fourth determination step, which is an optional step, is performed in the deterioration test step, the waveform narrowed down as being suitable for the layer thickness measurement more accurately indicates that the interface peeling between the surface layer and the back layer has not occurred. Since it is determined, it is preferable in terms of high reliability.

(9)
The multilayer body deterioration test apparatus of the present invention includes a first determination unit and a second determination unit.
In the first determination unit, the reflected wave of the ultrasonic wave transmitted in the direction from the surface layer side toward the back layer side is first reflected in the detection order in the detection order with respect to the multilayer body in which the surface layer and the back layer are laminated. In the case of the wave, the second reflected wave, and the third reflected wave, it is determined whether or not the intensity of the first reflected wave is included in the reference range. To do.
The second determination unit determines whether or not the intensity of the second reflected wave is included in the predetermined range when the intensity of the first reflected wave is included in the reference range in the first determination unit, and is included in the predetermined range. The case where there is no surface is judged as internal excessive deterioration of the surface layer or interface peeling between the surface layer and the back layer.

  With this configuration, it is possible to determine the surface overdeterioration of the surface layer of the multi-layer body, and when it does not correspond to the surface overdeterioration of the surface layer, determine the internal overdeterioration of the surface layer or the interface peeling between the surface layer and the back layer. Can do.

(10)
The multi-layer degradation test apparatus of the present invention may further include a third determination unit. The third determination unit determines whether or not the intensity of the third reflected wave exceeds the lower limit of the predetermined range. And the case below a minimum is determined as the back surface excessive deterioration of a back layer.

  Thereby, it is possible to determine the back surface excessive deterioration of the back layer which is different from the surface excessive deterioration and the interface peeling.

The third determination unit may be executed when the second determination unit determines that the intensity of the second reflected wave is included in the predetermined range. (Illustrated in FIG. 17)
In addition, the third determination unit may be executed when it is determined in a later-described fourth part that the phase of the second reflected wave and the phase of the third reflected wave are opposite. (Illustrated in FIG. 20)

(11)
The multilayer body deterioration test apparatus of the present invention may further include a fourth determination unit. The fourth determination unit determines whether or not the phase of the second reflected wave and the phase of the third reflected wave are opposite. The case where it is not the reverse is determined as interface peeling between the surface layer and the back layer.

  As a result, it is possible to avoid oversight of interface peeling that causes multiple reflections in the surface layer. Therefore, erroneous measurement can be further reduced when the layer thickness is measured.

The fourth determination unit may be executed when the third determination unit determines that the intensity of the third reflected wave exceeds the lower limit of the predetermined range. (Illustrated in FIG. 18)
The fourth determination unit may be executed when the second determination unit determines that the intensity of the second reflected wave is included in the predetermined range. (Illustrated in FIG. 19)

(12)
The layer thickness test apparatus of the present invention further includes a layer thickness deriving section in the deterioration test apparatus according to any one of (9) to (11).
When the layer thickness deriving unit determines that the deterioration test apparatus does not correspond to at least any of the surface over-deterioration of the surface layer, the internal over-deterioration of the surface layer, and the interface peeling between the surface layer and the back layer, the second reflected wave The thickness of the back layer is derived from the propagation time of the third reflected wave.

  With this configuration, waveforms that are not suitable for layer thickness measurement are preliminarily discarded, and deterioration information other than the layer thickness can be obtained from the discarded waveform pattern, while from waveforms narrowed down as suitable for layer thickness measurement, Correct layer thickness information can be acquired.

In addition, when the deterioration test apparatus includes a third determination unit having an arbitrary configuration, the waveform narrowed down as being suitable for the layer thickness measurement includes surface overdeterioration of the surface layer, internal overdeterioration of the surface layer, and surface layer and back layer. In addition to the interfacial peeling, the reliability is higher in that it is determined not to correspond to the excessive deterioration of the back surface of the back layer.
Further, when the deterioration test apparatus includes a fourth determination unit having an arbitrary configuration, the waveform narrowed down as being suitable for the layer thickness measurement is more accurately determined that the interface peeling between the surface layer and the back layer has not occurred. Therefore, it is preferable in terms of high reliability.

It is a block diagram of an example of the deterioration test apparatus and layer thickness test apparatus of this invention. FIG. 2 is a partially cutaway view schematically showing an example of an embodiment of a deterioration test method and a layer thickness test method using the apparatus of FIG. 1. It is the schematic diagram which looked at the embodiment of FIG. 2 from the axial direction of the multilayer tube to be tested. It is a typical partial enlarged view explaining an example of a deterioration test method and a layer thickness test method. It is a block diagram which shows a part of deterioration test apparatus and a layer thickness test apparatus. The peak pattern (a) in the most appropriate type for deriving the thickness of the target layer and the ultrasonic wave propagation mode (b) in the multilayer tube are shown. The peak pattern (a) in another type suitable for deriving the thickness of the target layer and the ultrasonic wave propagation mode (b) in the multilayer tube are shown. The peak pattern (a) in still another type suitable for deriving the thickness of the target layer and the ultrasonic wave propagation mode (b) in the multilayer tube are shown. The peak pattern (a) and the ultrasonic wave propagation mode (b) in a multilayer tube that are not suitable for deriving the thickness of the target layer are shown. The peak pattern (a) and the ultrasonic wave propagation mode (b) in a multilayer tube that are not suitable for deriving the thickness of the target layer are shown. The peak pattern (a) and the ultrasonic wave propagation mode (b) in a multilayer tube that are not suitable for deriving the thickness of the target layer are shown. The peak pattern (a) and the ultrasonic wave propagation mode (b) in a multilayer tube that are not suitable for deriving the thickness of the target layer are shown. The waveform phase in a suitable type for deriving the thickness of the target layer is shown. The phase of the waveform in a type that is not suitable for deriving the thickness of the target layer is shown. The peak pattern (a) in a type not suitable for deriving the thickness of the target layer and the propagation mode (b) of ultrasonic waves in the multilayer tube, which are determined by phase comparison, are shown. The other peak pattern (a) in the type which is not suitable in order to derive | lead-out the thickness of a target layer discriminate | determined by phase comparison, and the propagation aspect (b) of the ultrasonic wave in a multilayer tube are shown. It is an example of the flowchart of a deterioration test method. It is an example (continuation) of the flowchart of a deterioration test method. It is another example of the flowchart of a deterioration test method. It is another example (continuation) of the flowchart of a deterioration test method. It is an example of the flowchart of a layer thickness test method. It is a partially cutaway view schematically showing an example of a deterioration test method or a layer thickness test method using another example of the deterioration test device or the layer thickness test device. It is a more specific external view of the other example of a deterioration test apparatus or a layer thickness test apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same elements are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[1. Outline of configuration of deterioration test apparatus and layer thickness test apparatus]
FIG. 1 is a block diagram of an example of a deterioration test apparatus and a layer thickness test apparatus according to the present invention. FIG. 2 shows a deterioration test method and a layer thickness test method using a deterioration test apparatus and a layer thickness test apparatus (hereinafter simply referred to as an apparatus when they are collectively referred to as an apparatus). It is a partially cutaway view schematically showing an example of an embodiment of (described). FIG. 3 is a schematic view of the embodiment of FIG. 2 viewed from the axial direction of the multilayer tube to be tested.

  As shown in FIG. 1, the apparatus 100 according to the present embodiment includes a moving unit 110 and a control analysis unit 120. The mobile unit 110 and the control analysis unit 120 are physically and electrically connected by a cable 190.

  The moving unit 110 is a movable part, and moves in the axial direction of the multilayer tube 900 when inserted into the multilayer tube 900 shown in FIGS. 2 and 3. The moving unit 110 includes a cylinder part (shaft part) 200, an expansion / contraction part 300, an expansion / contraction arm 400, and a wheel 500. In addition, the moving unit 110 includes a motor 610 and a detection unit 700.

  The cylindrical portion 200 is located in the center of the moving unit 110 as viewed from the front (see FIG. 3), and is disposed in the multilayer tube 900 so as to extend in the axial direction of the inner wall surface (see FIG. 2). The cylinder part 200 is composed of a shaft housing part 210 and a connecting member 220. A desired member such as the cable 190 can be accommodated in the shaft housing portion 210. The expansion / contraction part 300 (not shown, for example, an air cylinder) may be configured as a part of the shaft housing part 210. The connecting member 220 connects the cylindrical part 200 with the expansion / contraction part 300 and the expansion / contraction arm 400, and connects the expansion / contraction part 300 with the expansion / contraction arm 400.

  The expansion / contraction part 300 causes the expansion / contraction operation of the expansion / contraction arm 400 via the connecting member 220 due to the expansion / contraction.

  As shown in FIG. 3, the expansion / contraction arm 400 protrudes in a radial direction centered on the axis of the cylindrical portion 200 connected via the connection member 220, that is, in a radial direction outward from the center of the multilayer tube 900. Established. In addition, the expansion / contraction arm 400 constitutes a link mechanism that links expansion / contraction of the expansion / contraction part 300 connected via the connecting member 220 with expansion / contraction operation of the expansion / contraction arm 400. Therefore, the amount of protrusion in the radial direction is changed by the expansion / contraction of the expansion / contraction part 300. A wheel 500 capable of traveling in the axial direction of the multilayer tube 900 is provided at the tip of the expansion / contraction arm 400. In the present embodiment, three sets of the expansion / contraction arm 400 and the wheel 500 are provided so as to be equally spaced around the axis. When the expansion / contraction arm 400 is expanded in the multilayer tube 900 and the wheel 500 comes into contact with the inner wall, the shaft housing portion 210 is aligned with the axis of the inner wall and the moving unit 110 is stably held.

  The motor 610 (not shown) is disposed so that the center of rotation is located on the axis of the inner wall surface of the multilayer tube 900, and is connected to a constituent member (described later) of the detection unit 700, thereby detecting the detection unit. 700 components are rotated. In the apparatus 100, the motor 610 is a solid shaft motor and is accommodated in the shaft housing portion 210.

  As shown in FIGS. 2 and 3, the detection unit 700 is configured by connecting an ultrasonic probe 710 to an arm member 733 via a sensor holder 732. The arm member 733 is connected to the motor 610 in the shaft housing unit 210 via the rotation shaft 250, and the ultrasonic probe 710, the sensor holder 732, and the arm member 733 are arranged in the radial direction of the multilayer tube 900. Arranged to be coaxial. When the motor 610 accommodated in the shaft housing unit 210 is driven to rotate, the detection unit 700 is rotated via the rotation shaft 250.

  The ultrasonic probe 710 generates ultrasonic waves and transmits / receives ultrasonic beams. The ultrasonic probe 710 may be a focus type probe or a straight-ahead type probe. The ultrasonic probe 710 is a single transmission / reception integrated ultrasonic probe based on the one-probe method. However, the transmitting probe and the receiving probe are based on the two-probe method. It may be a combination. The ultrasonic probe 710 rotates along the inner peripheral surface while maintaining an angle (perpendicular) to the inner peripheral surface of the multilayer tube 900 along with the rotation of the rotary shaft 250 driven by the motor 610 ( 2 and 3).

  The control analysis unit 120 is a part operated outside the pipe, and includes an expansion / contraction control unit 131, an input unit such as a motor control unit 132, a progress control unit 133, and a detection condition control unit 134, a detection information analysis unit 140, An output unit 150 is included.

  The expansion / contraction control unit 131 controls expansion / contraction of the expansion / contraction arm 400 by controlling expansion / contraction of the expansion / contraction unit 300. The motor control unit 132 controls the rotation of the motor 610. The progress control unit 133 controls the winding and sending of the cable 190. The detection condition control unit 134 controls the detection unit 700 such as control of input information such as measurement conditions and feedback control based on output information such as measurement results. The detection information analysis unit 140 analyzes information obtained from the detection unit 700 by performing the method of the present invention (described later). The output unit 150 outputs information obtained from the detection unit 700.

[2. Test target]
As shown in FIGS. 2 and 3, the test object of the apparatus 100 in the method of the present invention is a multilayer tube 900. In this embodiment, the multilayer tube 900 that is a multilayer body has a configuration in which a cement-containing layer 920 that is a surface layer is lined on the inner surface of a metal tube 910 that is a target layer whose thickness is to be measured. The multilayer pipe 900 is buried in the ground, and examples thereof include waterworks, sewers, industrial waterworks, and agricultural waterworks pipes.

Examples of the material of the metal tube 910 include iron (particularly cast iron) and steel.
Cast iron is an iron-carbon alloy containing about 2.0% or more of carbon. Generally, the carbon content is 2.0% or more and 4.5% or less and silicon is 0.5% or more and 3.0% or less, and manganese is 1.0% or less, phosphorus and / or sulfur 0.1%. Often further includes a degree (% is based on weight).

  Types of cast iron include white cast iron, mottled cast iron and gray cast iron as normal cast iron, and reinforced cast iron as tough cast iron, spheroidal graphite cast iron (for example, nodular cast iron, ductile cast iron), malleable cast iron and alloys Cast iron is mentioned. In the case of water pipes, specifically, Japanese Industrial Standards (JIS G 5521, 5522, 5523, 5524, 5526, 5527), Japan Waterworks Association Standards (JWSA G 102, 103, 105, 106, 108, 109, 110, 111, 113, 114, 114-2), Japan Sewerage Association Standard (JSWAS G-1, G-2), Japan Ductile Iron Pipe Association Standard (JDPA G 1001, 1002, 1003, 1004, 1007, 1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015, 1016, 1017, 1018, 1019, 1020, 1021, 1022, 1024, 1025, 1026, 1027, 1028, 1029, 1030, 1031, 1032, 1033, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 1043, 1044, 1045, 1046, 1047, 1048).

  Steel is an iron-carbon based alloy containing about 2.0% or less of carbon (% is based on weight). Examples include carbon steel and stainless steel.

  Further, the nominal diameter of the metal tube 910 is, for example, 100 or more, more specifically, 100 or more and 300 or less.

  The material of the cement-containing layer 920 may be a lining material containing cement. Examples of the cement include pollite cement, mixed cement (for example, blast furnace cement, fly ash cement, silica cement), eco cement, hydrated cement, and unhydrated cement. Typical pollite cements fire a mixture of limestone and clay, silica, and iron oxide, and clinker such as tricalcium silicate, dicalcium silicate, tricalcium aluminate, iron tetracalcium aluminate After that, a small amount of gypsum was added to the clinker and pulverized. In addition to the components described above, air and / or water may be present in the cement.

  The cement-containing layer 920 is formed by laminating the above-described material containing cement. In materials containing cement, examples of materials mixed with cement include fine aggregates such as sand, coarse aggregates such as gravel and crushed stone, and admixtures. More specifically, materials containing cement include mortar and concrete (eg, fresh concrete, hardened concrete).

  In general, mortar is obtained by adding a fine aggregate alone to cement or adding both a fine aggregate and an admixture to cement. In the case of water pipes, specifically, it is stipulated in Japanese Industrial Standard (JIS A5314), Japan Water Works Association Standard (JWWA A 107, JWWA A 113), Japan Ductile Iron Pipe Association Standard (JDPA Z 2013, JDPA Z 2015), etc. ing. When the blending ratio of the cement and fine aggregate is 1: 1.5 or more and 1: 3.5 or less as a composition in a healthy state (that is, an undegraded state), and an admixture is blended , Is defined as 15% or less relative to the cement mass (% is based on weight).

  Furthermore, the cement-containing layer 920 may have yet another coating or seal coat on the inner surface of the layer of cement-containing material. The material of the further another coating layer includes, for example, a resin, more specifically, an acrylic resin and a vinyl chloride resin.

[3. Deterioration Test Method and Layer Thickness Test Method, Deterioration Test Device and Layer Thickness Test Device]
As shown in FIGS. 2 and 3, when the method of the present invention is performed, the multilayer tube 900 is filled with water W, and the apparatus 100 is disposed inside the multilayer tube 900.
FIG. 4 is a schematic partially enlarged view for explaining an example of the method of the present invention. FIG. 5 is a block diagram showing a part of the layer thickness test apparatus.

[3-1. Transmission and reception of ultrasonic waves]
As shown in FIG. 4, an ultrasonic wave (transmitted wave T) is transmitted from the head portion of the ultrasonic probe 710. The transmitted wave T is transmitted so as to be perpendicular to the tangent TL of the inner peripheral surface Ls of the cement-containing layer 920. The distance D between the head portion of the ultrasonic probe 710 and the cement-containing layer 920 may vary depending on the wavelength of the transmitted ultrasonic wave, the characteristics (linear type and focal type) of the ultrasonic probe 710, and the like. Therefore, it is not particularly limited. For example, from the viewpoint of easily maintaining good detection sensitivity, the distance D can be 5 mm or more, preferably 10 mm or more and 200 mm or less, and more preferably 10 mm or more and 100 mm or less.

  The wavelength of the transmitted ultrasonic wave is particularly limited because it can vary depending on the characteristics (linear type and focal type) of the ultrasonic probe 710, the distance between the head portion of the ultrasonic probe 710 and the surface of the cement-containing layer 920, and the like. For example, the ultrasonic wavelength range is 1 MHz or more. Preferably, the lower limit of the wavelength range may be 1.5 MHz, 1.8 MHz, or 2 MHz. The upper limit value of the ultrasonic wavelength range is, for example, 10 MHz, and preferably 9 MHz, 7.5 MHz, 5 MHz, or 3.5 MHz. By being equal to or more than the above lower limit value, the dead zone (that is, the skirt width of each peak) is narrow, the layer thickness measurement accuracy is good, and a wide layer thickness measurable range can be secured. By being below the upper limit, the sensitivity is good with respect to the signal noise ratio (S / N ratio).

  In an appropriate type for deriving the thickness of the metal tube 910 in the layer thickness test method, the transmitted wave T reaches the outer surface Lb of the metal tube 910 as shown in FIG. Reflected on the inner peripheral surface Ls, the boundary surface Li between the cement-containing layer 920 and the metal tube 910, and the outer surface Lb of the metal tube 910, respectively, the reflected wave S reflected on the inner peripheral surface Ls, and first reflected on the boundary surface Li The reflected wave I1 and the reflected wave B1 first reflected by the outer surface Lb are received by the ultrasonic probe 710. When the reflected waves received by the ultrasonic probe 710 are the first reflected wave R-1, the second reflected wave R-2, and the third reflected wave R-3 in the order of reception (detection order), the metal tube 910 In a suitable type for deriving the thickness, the first reflected wave R-1 is the reflected wave S, the second reflected wave R-2 is the reflected wave I1, and the third reflected wave R-3 is the reflected wave B1. Each of them is received with an appropriate strength.

[3-2. Acquisition of reflected wave waveform]
The reflected wave received by the detection unit 700 (ultrasonic probe 710 in the present embodiment) is processed by the detection information analysis unit 140 (see FIG. 1). In the degradation test apparatus of the present invention, as shown in FIG. 5, the detection information analysis unit 140 includes a waveform acquisition unit 141 and a determination unit 142. The determination unit 142 includes at least a first determination unit and a second determination unit, and further includes a third determination unit and a fourth determination unit in the present embodiment. The layer thickness test apparatus of the present invention further includes a layer thickness calculator 149.

  The waveform acquisition unit 141 acquires the waveform of the reflected wave received by the detection unit 700. For example, the reflected wave signal is converted into a reflected wave intensity waveform with respect to the propagation time. More specifically, the received wave (in the case of FIG. 4, the first reflected wave R-1, the second reflected wave R-2, and the third reflected wave R-3) is amplified by a signal amplifier, and a bandpass filter or the like Then, the noise is removed, digitized by the A / D converter, and then the waveform is obtained by performing averaging processing of adding and averaging the digitized waveforms on the same time axis. The acquired waveform is stored together with the measurement position information. The waveform acquired by the waveform acquisition unit 141 can also be displayed on the output unit 150.

[3-3. Peak pattern to be classified: Classification by peak intensity]
FIG. 6A shows a peak pattern of the most appropriate type for deriving the thickness of the metal tube 910 used for acquiring the layer thickness information in the layer thickness test method of the present invention. FIG. 6B schematically shows the propagation mode of the transmitted wave T in FIG. Further, a peak pattern allowed as an appropriate type for deriving the thickness of the metal tube 910 is shown in FIGS. 7A and 8A, and the propagation mode of the transmitted wave T in the multilayer tube 900 is shown. FIG. 7B and FIG. 8B schematically show similarly.

  In order to narrow down the peak patterns shown in FIG. 6A, FIG. 7A and FIG. 8A from the waveform acquired by the waveform acquisition unit 141, the determination unit 142 of the apparatus of the present invention starts with the present invention. By implementing the deterioration test method, it is possible to identify a peak pattern of a type that is not appropriate for deriving the thickness of the metal tube 910, and acquire deterioration information other than the layer thickness of the multilayer tube 900 using these peak patterns. To do. FIG. 9A, FIG. 10A, FIG. 11A, and FIG. 12A are peak patterns used for acquiring deterioration information in the deterioration test method of the present invention, and FIG. 10 (b), FIG. 11 (b), and FIG. 12 (b) are schematic modes of propagation modes of the transmitted wave T corresponding to the respective peak patterns.

  In the peak pattern shown in FIG. 6A, the horizontal axis indicates the propagation time, and the vertical axis indicates the signal intensity (the same applies to all peak patterns hereinafter). The peak pattern in FIG. 6A shows the case of both low gain output (L) and high gain output (H). As shown in FIG. 6A, the first reflected wave R-1 is the reflected wave S, the second reflected wave R-2 is the reflected wave I1, and the third reflected wave R-3 is the reflected wave B1. Yes, each is received at the appropriate strength.

  Receiving with appropriate intensity means that the intensity of the first reflected wave R-1 is included in the reference range sr (see waveform at low gain L), and the second reflected wave R-2 and the third reflected wave. It means that all the intensities of R-3 are included in the predetermined range dr (see waveform at high gain H). FIG. 6A shows the most ideal peak pattern, and the intensity of the third reflected wave R-3 is larger than the intensity of the second reflected wave R-2.

  However, the first reflected wave R-1 is the reflected wave S, the second reflected wave R-2 is the reflected wave I1, the third reflected wave R-3 is the reflected wave B1, and the intensity of the first reflected wave R-1 is As long as it is included in the reference range sr, the intensity of the second reflected wave R-2 is included in the predetermined range dr, and the intensity of the third reflected wave R-3 exceeds the lower limit value of the predetermined range dr, the second reflection The intensity relationship between the wave R-2 and the third reflected wave R-3 does not matter.

For example, in the peak pattern shown in FIG. 6A, the intensity of the third reflected wave R-3 is within the predetermined range dr, but it is also acceptable if it exceeds the upper limit of the predetermined range dr.
In addition, the second reflected wave R-2 and the third reflected wave R-3 have the same intensity as shown in FIG. 7A, and the second reflected wave R as shown in FIG. 8A. The case where the intensity of -2 is larger than the intensity of the third reflected wave R-3 is also permitted.
7 (b) and FIG. 8 (b) are the same as FIG. 6 (b), but FIG. 7 (a) and FIG. Attached to (a).

  In any case, since the reflected waves detected after the second reflected wave R-2 tend to be significantly smaller in intensity than the first reflected wave, the reflected waves after the second reflected wave R-2. In the case of examining the intensity, it is preferable to switch to a higher gain (H) output from the viewpoint of accuracy. For example, it can be set by increasing the gain to 2.5 times or more and 3.5 times or less, for example, 3 times.

  The reference range sr is a cement-containing layer corresponding to the cement-containing layer 920, and when the intensity of the reflected wave on the inner peripheral surface Ls obtained when the transmitted wave T is transmitted to an undegraded layer is 80%, It may be 40% or more, preferably 50% or more. The predetermined range dr is 17% or more and 70% or less, preferably, when the intensity of the reflected wave on the inner peripheral surface Ls obtained when transmitting the transmitted wave T to the cement-containing layer 920 without deterioration is 240%. May be 20% or more and 60% or less. Reference range sr and predetermined range shown in FIGS. 6 (a), 7 (a), 8 (a), 9 (a), 10 (a), 11 (a) and 12 (a). dr is an example.

  When the above-mentioned conditions are met, the waveform acquired by the waveform acquisition unit 141 is transmitted from the cement-containing layer 920 as shown in FIGS. 6 (b), 7 (b), and 8 (b). It can be determined that the waveform of the reflected wave is obtained by appropriately entering the metal tube 910 and appropriately reflecting on the boundary surface Li and the outer surface Lb. Therefore, in this case, the second reflected wave R-2, that is, the reflected wave I1 first reflected by the boundary surface Li and the third reflected wave R-3, that is, the reflected wave B1 first reflected by the outer surface Lb, are the thickness of the metal tube 910. Can be used to correctly derive.

  In the peak pattern shown in FIG. 9A, the intensity of the first reflected wave R-1 is less than the reference range sr. And 2nd reflected wave R-2 and 3rd reflected wave R-3 are not detected substantially (the intensity | strength is less than a detection limit). From such a waveform, as shown in FIG. 9 (b), the inner peripheral surface Ls is so rough that the transmitted wave T cannot enter the cement-containing layer 920 due to scattering by the inner peripheral surface Ls. It can be determined that only the first reflected wave R-1, that is, the reflected wave S reflected by the inner peripheral surface Ls, has been detected with a weak intensity. Such a propagation mode may occur when the inner peripheral surface Ls of the cement-containing layer 920 is excessively deteriorated due to corrosion.

  In the peak pattern shown in FIG. 10A, the intensity of the first reflected wave R-1 is within the reference range sr, but at least the intensity of the second reflected wave R-2 is below the lower limit of the predetermined range dr. From such a waveform, as shown in FIG. 10B, the inner peripheral surface Ls of the cement-containing layer 920 is not deteriorated as in the case of FIG. Although the reflected wave S reflected by the circumferential surface Ls is detected with the intensity within the reference range sr, the amount of ultrasonic waves reaching the boundary surface Li and the outer surface Lb is small, so the second reflected wave R-2, that is, the boundary surface Li It can be determined that both the reflected wave I1 reflected first and the third reflected wave R-3, that is, the reflected wave B1 first reflected by the outer surface Lb, were detected only with extremely small intensity.

  Thus, the propagation mode in which the amount of ultrasonic waves reaching the boundary surface Li and the outer surface Lb decreases can occur, for example, when the cement-containing layer 920 is abnormal. More specifically, a case where the inside of the cement-containing layer 920 is in an excessively deteriorated state can be mentioned. The deterioration state of the cement-containing layer 920 is considered to be caused by, for example, at least one of an increase in porosity, a decrease in the weight ratio of cement, and a decrease in calcium concentration. More specifically, when the weight ratio of the cement is 20% by weight or less, when the calcium concentration is 100,000 ppm or less, the porosity of the cement-containing layer 920 is 0.5% or more.

  In the peak pattern shown in FIG. 11A, the intensity of the first reflected wave R-1 is within the reference range sr, but at least the intensity of the second reflected wave R-2 exceeds the upper limit of the predetermined range dr. From such a waveform, as shown in FIG. 11 (b), an air layer is generated on the boundary surface Li due to the separation of the cement-containing layer 920 and the metal tube 910, so that the transmitted wave T enters the metal tube 910. Therefore, it can be determined that multiple reflection occurs between the inner peripheral surface Ls of the cement-containing layer 920 and the boundary surface Li. Therefore, the second reflected wave R-2 is detected as the reflected wave I1 first reflected by the boundary surface Li, but the third reflected wave R-3 is detected as the reflected wave I2 second reflected by the boundary surface Li. Is done.

  In the peak pattern shown in FIG. 12A, the intensity of the first reflected wave R-1 is within the reference range sr and the second reflected wave R-2 is also within the predetermined range dr, but the third reflected wave R- 3 is below the lower limit of the predetermined range dr. From such a waveform, as shown in FIG. 12B, the outer surface Lb is so rough that the outgoing wave T incident on the metal tube 910 cannot be sufficiently reflected by being scattered by the outer surface Lb. It can be determined that the reflected wave B1 first reflected by the outer surface Lb was detected only with an extremely small intensity. Such a propagation mode can occur, for example, when the outer surface Lb is excessively deteriorated due to corrosion.

[3-4. Peak pattern to be classified: Classification by peak phase]
In the method of the present invention, in order to obtain more accurate deterioration information or more accurate layer thickness information, determination based on the peak phase can be combined with determination based on the peak intensity. Thereby, the presence or absence of multiple reflection in the cement-containing layer 920 can be examined in more detail.

FIG. 13 shows the phase of the waveform in an appropriate type to derive the thickness of the target layer.
As shown in FIG. 13, when the peak of the reflected wave corresponds to an appropriate peak pattern for deriving the thickness of the metal tube 910, the phases of the second reflected wave R-2 and the third reflected wave R-3 are Vice versa. Specifically, the second reflected wave R-2 once rises positively and swings greatly to the minus, whereas the third reflected wave R-3 once swings negatively and then rises greatly to the plus.

  When the phases of the second reflected wave R-2 and the third reflected wave R-3 are thus reversed, the first reflected wave R-1 is the reflected wave S reflected by the inner peripheral surface Ls, and the second reflected wave R-2 can be identified as the reflected wave I1 first reflected by the boundary surface Li, and the third reflected wave R-3 can be identified as the reflected wave B1 first reflected by the outer surface Lb.

  On the other hand, FIG. 14 shows the waveform phase in a type that is not suitable for deriving the thickness of the target layer. As shown in FIG. 14, when the peak of the reflected wave does not correspond to an appropriate peak pattern for deriving the thickness of the metal tube 910, the phases of the second reflected wave R-2 and the third reflected wave R-3 are Be the same. Specifically, both of the second reflected wave R-2 and the third reflected wave R-3 are once swung to a minus and then greatly rise to a plus.

  Thus, when the phases of the second reflected wave R-2 and the third reflected wave R-3 are not reversed, it can be determined that multiple reflection occurs between the inner peripheral surface Ls and the boundary surface Li. Therefore, the second reflected wave R-2 is the reflected wave I1 that is first reflected by the boundary surface Li, but the third reflected wave R-3 is identified as the reflected wave I2 that is secondly reflected by the boundary surface Li. Can do.

FIG. 15A and FIG. 16A show peak patterns in the case of interface multiple reflection that can be discriminated by phase comparison. FIGS. 15 (a) and 16 (a) are very similar to FIGS. 7 (a) and 8 (a), which are appropriate peak patterns, respectively, and cannot be determined only by examining the peak intensity. Therefore, more accurate deterioration information or more accurate layer thickness information can be obtained by phase comparison.
15 (b) and 16 (b) are the same as FIG. 11 (b), but FIG. 15 (a) and FIG. Attached to (a).

[3-5. Example of deterioration test method flow]
FIG. 17 is an example of a flowchart of the degradation test method, and FIG. 18 is an example of a flowchart that can be continued from FIG.

[3-5-1. Waveform acquisition process]
As described above, the waveform acquisition unit 141 (see FIG. 5) acquires the waveform of the reflected wave received by the detection unit 700 (S00 in FIG. 17).
The acquired waveform is the first reflected wave R-1 by the first determination unit and the second determination unit of the determination unit 142, or the first determination unit, the second determination unit, and the third determination unit (see FIG. 5). , Second reflected wave R-2, and third reflected wave R-3 are compared in order of the intensity of the peak of the reflected wave received in the order of FIG. 9A to FIG. 11A, and further to FIG. It is used to determine which is applicable. The acquired waveform can be used by the fourth determination unit (see FIG. 5) of the determination unit 142 to determine which one of FIGS. 13 and 14 corresponds to the phase comparison of the peak of the reflected wave.

  In the waveform acquisition step, a tube having a cement-containing layer without deterioration is prepared as a calibration tube, and the waveform of the multilayer tube 900 can be acquired and the waveform of the calibration tube can also be acquired. In this case, the reference range sr and the predetermined range dr are set based on the intensity of the first reflected wave R-1 (S) of the waveform acquired from the calibration tube, and each of the waveforms acquired from the multilayer tube 900 is set. Peak intensity can be examined.

[3-5-2. First determination step: peak intensity comparison]
The first determination step is performed by the first determination unit (see FIG. 5) of the determination unit 142. In the first determination step, it is determined whether or not the intensity of the first reflected wave R-1 is within the reference range sr in the acquired waveform (S10).

  Specifically, when the intensity of the first reflected wave R-1 is not included in the reference range sr (No in S10), that is, in this embodiment, as shown in FIG. 9A, the lower limit of the reference range sr. If it is less than, it can be determined that the inner peripheral surface Ls of the cement-containing layer 920 is excessively degraded as shown in FIG. 9B (S11). The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S12).

  When the intensity of the first reflected wave R-1 is included in the reference range sr (Yes in S10), the waveform is supplied to S20 of the second determination step.

[3-5-3. Second determination step: Comparison of peak intensity]
The second determination step is performed by the second determination unit (see FIG. 5) of the determination unit 142. In the second determination step, it is determined whether or not the intensity of the second reflected wave R-2 is within a predetermined range dr (S20).

  Specifically, when the intensity of the second reflected wave R-2 is not included in the predetermined range dr as shown in FIG. 10A and falls below the predetermined range dr (No in S20), FIG. 10B. It can be determined that the inside of the cement-containing layer 920 is excessively degraded as shown in (S21). The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S22).

  When the intensity of the second reflected wave R-2 is not included in the predetermined range dr as shown in FIG. 11A and exceeds the predetermined range dr (No in S20), as shown in FIG. It can be determined that the boundary surface Li between the cement-containing layer 920 and the metal tube 910 is peeled off due to deterioration, and multiple reflection occurs between the inner peripheral surface Ls and the boundary surface Li (S23). The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S24).

  When the intensity of the second reflected wave R-2 is included in the predetermined range dr (Yes in S20), excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, excessive deterioration inside the cement-containing layer 920, and cement content Since there is a high possibility that none of the separation of the boundary surface Li between the layer 920 and the metal tube 910 has occurred, the determination based on the comparison of peak intensities can be completed with the acquisition of the deterioration information. That is, it is allowed to proceed to a later-described fourth determination step (S40) or a later-described layer thickness test step (after S51) without passing through a later-described third determination step (S30). However, in the present embodiment, in order to obtain more detailed deterioration information, the waveform remaining in the second determination step can be further provided to S30 of the third determination step.

[3-5-4. Third determination step: peak intensity comparison]
The third determination step illustrated in FIG. 17 is performed by the third determination unit (see FIG. 5) of the determination unit 142. In the third determination step, it is determined whether or not the intensity of the third reflected wave R-3 exceeds the lower limit of the predetermined range dr (S30).

  Specifically, when the intensity of the third reflected wave R-3 is equal to or lower than the lower limit of the predetermined range dr as shown in FIG. 12A (No in S30), as shown in FIG. It can be determined that the outer surface Lb of the metal tube 910 is excessively deteriorated (S31). The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S32).

  When the intensity of the third reflected wave R-3 exceeds the lower limit of the predetermined range dr (Yes in S30), excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, excessive deterioration inside the cement-containing layer 920, cement Since there is a high possibility that neither the separation of the boundary surface Li between the containing layer 920 and the metal tube 910 nor the excessive deterioration of the outer surface Lb of the metal tube 910 has occurred, the determination based on the peak intensity comparison ends.

  Since the waveform narrowed down in the third determination step (S30) is likely to be a waveform suitable for layer thickness measurement, the layer thickness test described later is not performed without the fourth determination step (S40) described later. You may apply to a process (after S51). However, since the first determination step (S10) to the third determination step (S30) are based on the peak intensity, excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, the inside of the cement-containing layer 920, Among the waveforms determined that none of the excessive deterioration of the surface, peeling of the boundary surface Li between the cement-containing layer 920 and the metal tube 910, and excessive deterioration of the outer surface Lb of the metal tube 910 occurred in FIG. In addition to the peak patterns shown in a), FIG. 7 (a) and FIG. 8 (a), the waveforms having the peak patterns shown in FIG. 15 (a) and FIG. There is a possibility. Therefore, in this embodiment, in order to make the deterioration test and the layer thickness test more accurate, the waveform narrowed down in the third determination step (S30) is subjected to a fourth determination step (FIG. 18) described later. In addition, more accurate information can be obtained.

[3-5-5. Fourth determination step: peak phase comparison]
The fourth determination step illustrated in FIG. 18 is performed by the fourth determination unit (see FIG. 5) of the determination unit 142. In the fourth determination step, it is determined whether or not the phase of the second reflected wave R-2 and the phase of the third reflected wave R-3 of the waveforms narrowed down by the peak intensity comparison are opposite (S40). .

  Specifically, when the second reflected wave R-2 and the third reflected wave R-3 have the same phase (see FIG. 14) (No in S40), as described in FIG. It can be determined that the boundary surface Li between the containing layer 920 and the metal tube 910 is peeled off due to deterioration, and multiple reflection occurs between the inner peripheral surface Ls and the boundary surface Li (S41). Therefore, the second reflected wave R-2 is the reflected wave I1 that is first reflected by the boundary surface Li, but the third reflected wave R-3 is identified as the reflected wave I2 that is secondly reflected by the boundary surface Li. Can do. The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S42).

  When the phase of the second reflected wave R-2 and the phase of the third reflected wave R-3 are opposite (see FIG. 13) (Yes in S40), excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, cement It can be determined that neither excessive deterioration inside the containing layer 920, peeling of the boundary surface Li between the cement-containing layer 920 and the metal tube 910, or excessive deterioration of the outer surface Lb of the metal tube 910 occurs. The determination by phase comparison is completed.

  Thus, the waveform narrowed down in the fourth determination step (S40) is the reflected wave I1 that the second reflected wave R-2 is first reflected by the boundary surface Li, and the third reflected wave R-3 is the outer surface Lb. Therefore, it is possible to determine that the reflected wave B1 is the first reflected wave B1 and is extremely suitable for the layer thickness measurement. For this reason, it can apply to the below-mentioned layer thickness test method.

[3-6. Other examples of deterioration test method flow]
FIG. 19 is another example of a flowchart of the deterioration test method, and FIG. 20 is an example of a flowchart that can be continued from FIG.
The flow shown in FIGS. 19 and 20 differs from the flow shown in FIGS. 17 and 18 in that the order of the third determination step and the fourth determination step is reversed.

[3-6-1. First determination step and second determination step]
The first determination step S10 and the second determination step S20 (and the accompanying steps S21 to S24) are the same as those in FIG.
When the intensity of the second reflected wave R-2 is included in the predetermined range dr (Yes in S20), the process proceeds to a phase comparison step (S30 ′) described later without going through a fourth determination step (S40 ′) described later. Is also acceptable. However, in the present embodiment, in order to obtain more detailed deterioration information, the waveform remaining in the second determination step can be further provided to S40 ′ of the fourth determination step.

[3-6-2. Fourth determination step: peak phase comparison]
The fourth determination step illustrated in FIG. 19 is performed by the fourth determination unit (see FIG. 5) of the determination unit 142. In the fourth determination step, it is determined whether or not the phase of the second reflected wave R-2 and the phase of the third reflected wave R-3 of the waveform narrowed down in the second determination step are opposite (S40 ′). ).

  Specifically, when the second reflected wave R-2 and the third reflected wave R-3 have the same phase (see FIG. 14) (No in S40 ′), as described in FIG. It can be determined that the boundary surface Li between the cement-containing layer 920 and the metal tube 910 is peeled off due to deterioration, and multiple reflection occurs between the inner peripheral surface Ls and the boundary surface Li (S41 ′). Therefore, the second reflected wave R-2 is the reflected wave I1 that is first reflected by the boundary surface Li, but the third reflected wave R-3 is identified as the reflected wave I2 that is secondly reflected by the boundary surface Li. Can do. The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S42 ').

  When the phase of the second reflected wave R-2 and the phase of the third reflected wave R-3 are opposite (see FIG. 13) (Yes in S40 ′), excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, It can be determined that neither excessive deterioration inside the cement-containing layer 920, peeling of the boundary surface Li between the cement-containing layer 920 and the metal tube 910, or excessive deterioration of the outer surface Lb of the metal tube 910 has occurred. Determination by peak phase comparison ends.

  The waveform narrowed down in the fourth determination step (S40 ′) in this way is the reflected wave I1 that the second reflected wave R-2 first reflected at the boundary surface Li, and the third reflected wave R-3 is the outer surface. Since it is the reflected wave B1 reflected first by Lb and each is detected with appropriate intensity, it can be determined that it is suitable for the layer thickness measurement. Therefore, the present invention can be applied to a later-described layer thickness test step (S51 and later) without going through a later-described third determination step (S30 '). However, in this embodiment, in order to make the deterioration test and the layer thickness test more accurate, the waveform narrowed down in the fourth determination step (S40 ′) is subjected to a third determination step (FIG. 20) described later. Thus, information with higher accuracy can be obtained.

[3-6-3. Third determination step: peak intensity comparison]
The third determination step illustrated in FIG. 20 is performed by the third determination unit (see FIG. 5) of the determination unit 142. In the third determination step, it is determined whether or not the intensity of the third reflected wave R-3 exceeds the lower limit of the predetermined range dr (S30 ′).

  Specifically, when the intensity of the third reflected wave R-3 is equal to or lower than the lower limit of the predetermined range dr as shown in FIG. 12A (No in S30 ′), as shown in FIG. It can be determined that the outer surface Lb of the metal tube 910 is excessively deteriorated (S31 ′). The obtained deterioration information can be output to the output unit 150 (see FIG. 5) (S32 ').

  When the intensity of the third reflected wave R-3 exceeds the lower limit of the predetermined range dr (Yes in S30 ′), excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, excessive deterioration inside the cement-containing layer 920, Since there is a high possibility that neither the separation of the boundary surface Li between the cement-containing layer 920 and the metal tube 910 nor the excessive deterioration of the outer surface Lb of the metal tube 910 has occurred, the determination based on the peak intensity comparison ends.

  Since the waveform narrowed down in the third determination step (S30 ') is very likely to be a waveform suitable for layer thickness measurement, it is applied to the later-described layer thickness test step (S51 and later).

[3-7. Layer thickness test method flow]
FIG. 21 is an example of a flowchart of the layer thickness test method. In the layer thickness test method, the layer thickness is calculated using the layer thickness information acquisition waveform narrowed down by discarding the waveform that is not suitable for the layer thickness measurement by the deterioration diagnosis method.

  In the present embodiment, the narrowed waveform is adopted as the waveform for obtaining the layer thickness information (S51), and the second reflected wave R-2 and the third reflected wave R- are used in the layer thickness calculator 149 (see FIG. 5). The thickness of the metal tube 910 is calculated by multiplying the difference in propagation time from 3 (μ seconds) by 1/2 and the speed of sound (S52). The calculated layer thickness information can be output to the output unit 150 (see FIG. 5) (S53).

  Note that the information output to the output unit 150 (see FIG. 5) in the first determination step, the second determination step, the third determination step, and the fourth determination step is processed so that the deterioration information can be easily visually recognized. It is preferable that For example, the side development of the multilayer pipe 900 shows the type of deterioration (excessive deterioration of the inner peripheral surface Ls of the cement-containing layer 920, excessive deterioration inside the cement-containing layer 920, boundary between the cement-containing layer 920 and the metal pipe 910). The deterioration information can be mapped according to the separation of the surface Li and the excessive deterioration of the outer surface Lb of the metal tube 910. Furthermore, layer thickness information can also be mapped as degradation information according to the degree of thinning of the layer thickness accompanying degradation. Based on the deterioration information output in this way, it is possible to predict the mechanical characteristics and life of the multilayer tube 900 that is the test object.

[4. Other examples]
The test object is not limited to the multilayer tube 900 lined with the cement-containing layer 920 having a curved surface as shown in FIGS. For example, the test object may be a multilayer body in which a cement-containing layer having a flat surface is laminated so as to be in contact with a metal plate.

  The test object is not limited to an aspect in which the surface porous layer provided on the surface of the metal tube 910 is the cement-containing layer 920. As the surface layer, various porous layers are preferably employed.

  As shown in FIGS. 2 and 3, the apparatus of the present invention has an ultrasonic transmission direction from an ultrasonic probe 710 connected to a motor 610 via a rotating shaft 250 such that the inner circumference of the cement-containing layer 920 is It is not limited to the mode of rotating along the surface.

For example, the apparatus of the present invention is fixed to the shaft center where the ultrasonic probe 710 is not rotated and maintains a distance and an angle (perpendicular) to the surface of the cement-containing layer 920 from the ultrasonic probe 710. A mode of traveling without rotating the transmission direction of the ultrasonic wave may also be used. In this case, the surface of the test object that should transmit ultrasonic waves may be a curved surface or a flat surface.

  Further, for example, the apparatus of the present invention may have the form shown in FIG. The apparatus 100a shown in FIG. 22 is provided such that an ultrasonic probe 710 fixed to an axis that does not rotate transmits ultrasonic waves from the axial position of the multilayer tube 900 in the axial direction. In this case, an acoustic reflection unit 720a (for example, a mirror) is provided so as to be rotatable about the axis (indicated by an arrow in FIG. 22), refracts the transmitted wave T from the ultrasonic probe 710, and a cement-containing layer. An inclined surface 723a is formed on the surface of the acoustic reflection portion 720a so that the light is incident on the inner surface of the 920 at a predetermined angle (perpendicular). As a result, during the rotation of the acoustic reflector 720a, the transmission direction of ultrasonic waves from the ultrasonic probe 710 can be rotated while maintaining the distance and angle (perpendicular) with respect to the surface of the cement-containing layer 920.

  FIG. 23 shows a more specific aspect of the apparatus 100a. The apparatus 100a 'shown in FIG. 23 has an inclined surface 723a' corresponding to the inclined surface 723a of the acoustic reflector 720a of the apparatus 100a (see FIG. 22). Further, the device 100a ′ has six sets of expansion / contraction arms 400a ′ having a link mechanism different from the expansion / contraction arm 400 of the device 100 (see FIG. 2) so as to be equally spaced around the shaft housing portion 210a ′. It is more stable. The expansion / contraction arm 400a 'operates by expansion / contraction of an air cylinder (extension / contraction part 300a') constituting a part of the shaft housing part 210a '. Furthermore, the apparatus 100a ′ has a hollow shaft motor 610a ′ that is not fixed to the rotating shaft, and at least a part of the ultrasonic probe 710 is accommodated in the hollow portion, so that the moving unit 110a ′ is more compact. ing.

[Correspondence Relationship Between Each Part in Embodiment and Other Examples and Each Component in Claim]
In the present invention, the devices 100, 100a, and 100a ′ correspond to “deterioration test device” and “layer thickness test device” in the claims, and the determination unit 142 includes “first determination unit”, “second determination unit”, Corresponding to “third determination unit” and “fourth determination unit”, layer thickness calculation unit 149 corresponds to “layer thickness deriving unit”, multilayer tube 900 corresponds to “multilayer body”, and cement-containing layer 920 corresponds to the “surface layer”, the metal tube 910 corresponds to the “back layer”, the inner peripheral surface Ls corresponds to the “surface of the surface layer”, the boundary surface Li corresponds to the “interface”, and the outer surface Lb Corresponding to the “back surface of the back layer”, the transmitted wave T corresponds to “transmitted ultrasonic wave”, the first reflected wave R-1 corresponds to “first reflected wave”, and the second reflected wave R-2 Corresponding to the “second reflected wave”, the third reflected wave R-3 corresponds to the “third reflected wave”, the reference range sr corresponds to the “reference range”, and the predetermined range dr The first determination step S10 corresponds to the “first determination step”, the second determination step S20 corresponds to the “second determination step”, and the third determination steps S30 and S30 ′ correspond to the “first range”. 3 determination step ”, the fourth determination steps S40 and S40 ′ correspond to the“ fourth determination step ”, and the layer thickness calculation step S52 corresponds to the“ layer thickness derivation step ”.

  The present invention is not limited to the above-described embodiments, and various other embodiments can be made without departing from the spirit of the present invention.

100, 100a, 100a ′ apparatus (deterioration diagnosis apparatus, layer thickness test apparatus)
142 determination unit 149 layer thickness calculation unit (layer thickness deriving unit)
900 Multi-layer pipe (Multi-layer body)
910 Metal tube (back layer)
920 Cement-containing layer (surface layer)
Ls inner surface (surface of the surface layer)
Li interface Lb outer surface (back side of back layer)
T transmitted wave (transmitted ultrasonic wave)
R-1 First reflected wave R-2 Second reflected wave R-3 Third reflected wave sr Reference range dr Predetermined range S10 First determination step S20 Second determination step S30, S30 ′ Third determination step S40, S40 ′ 4 determination process S52 layer thickness calculation process (layer thickness derivation process)

Claims (12)

With respect to the multilayer body in which the surface layer and the back layer are laminated, the reflected waves of the ultrasonic waves transmitted in the direction from the surface layer side toward the back layer side are the first reflected wave and the second reflected wave in the order of detection. And determining whether the intensity of the first reflected wave is included in the reference range in the case of the third reflected wave, and determining that the surface layer is excessively deteriorated when not included in the reference range. A determination process;
When it is determined in the first determination step that the intensity of the first reflected wave is included in the reference range, it is determined whether the intensity of the second reflected wave is included in the predetermined range, And a second determination step for determining a case where the surface layer is not included as internal excessive deterioration of the surface layer or interface peeling between the surface layer and the back layer.   2. The first determination step according to claim 1, wherein in the first determination step, the reference range corresponds to an intensity range of 40% or more when the intensity of the first reflected wave of the surface layer is 80% when there is no surface deterioration. Deterioration test method for multilayers   In the second determination step, the case where the intensity of the second reflected wave is below the predetermined range is determined as internal excessive deterioration of the surface layer, and the case where the intensity exceeds the upper limit of the predetermined range is the interface between the surface layer and the back layer The deterioration test method for a multilayer body according to claim 1, wherein the deterioration is determined to be peeling.   The deterioration test method according to claim 1, wherein the second determination step is performed with a higher gain than the first determination step.   In the second determination step, the predetermined range corresponds to an intensity range of 17% or more and 70% or less when the intensity of the first reflected wave of the surface layer is 240% when there is no surface deterioration. The deterioration test method for a multilayer body according to any one of 1 to 4.   The method further includes a third determination step of determining whether or not the intensity of the third reflected wave exceeds a lower limit of the predetermined range, and determining that the lower layer is less than the lower limit as excessive deterioration of the back surface of the back layer. 6. The deterioration test method for a multilayer body according to any one of 5 above.   A fourth determination step of determining whether or not the phase of the second reflected wave and the phase of the third reflected wave are opposite, and determining that the phase separation is not the opposite is an interface separation between the surface layer and the back layer The deterioration test method for a multilayer body according to any one of claims 1 to 6, further comprising: A deterioration test step for performing a deterioration test method for a multilayer body according to any one of claims 1 to 7,
When it is determined by the deterioration test step that at least none of the surface over-deterioration of the surface layer, the internal over-deterioration of the surface layer, and the interfacial delamination between the surface layer and the back layer, the second reflected wave And a layer thickness deriving step of deriving the layer thickness of the back layer from the propagation time of the third reflected wave. With respect to the multilayer body in which the surface layer and the back layer are laminated, the reflected wave of the ultrasonic wave transmitted in the direction from the surface layer side toward the back layer side is the first reflected wave, the second reflected wave in the order of detection. In the case of the reflected wave and the third reflected wave, it is determined whether or not the intensity of the first reflected wave is included in the reference range, and if it is not included in the reference range, it is determined that the surface layer is excessively deteriorated. A first determination unit;
When the first determination unit determines that the intensity of the first reflected wave is included in the reference range, the first determination unit determines whether the intensity of the second reflected wave is included in the predetermined range. A multi-layer degradation test apparatus, comprising: a second determination unit that determines internal excess deterioration of the surface layer or interfacial peeling between the surface layer and the back layer when not included.   A third determination unit that determines whether or not the intensity of the third reflected wave exceeds a lower limit of the predetermined range, and further determines a back surface excessive deterioration of the back layer when the intensity is less than or equal to the lower limit. Deterioration test apparatus for the multilayer body described.   A fourth determination unit for determining whether or not the phase of the second reflected wave and the phase of the third reflected wave are opposite, and determining that the phase separation is not the opposite is an interface separation between the surface layer and the back layer; The deterioration test apparatus for a multilayer body according to claim 9 or 10, further comprising: The deterioration test apparatus according to any one of claims 9 to 11, further comprising a layer thickness deriving unit,
When the layer thickness deriving part determines by the deterioration test apparatus that at least none of the surface over-deterioration of the surface layer, the internal over-deterioration of the surface layer, and the interface peeling between the surface layer and the back layer falls And a layer thickness test apparatus for a multilayer body that derives the layer thickness of the back layer from the propagation times of the second reflected wave and the third reflected wave.