JP2015184215A - Method, device and program for determining presence of carbonation of concrete, and method, device and program for estimating carbonation range of concrete, and method, device and program for estimating diffusion coefficient of target element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow for accurate determination of a presence of the occurrence of carbonation in a hardened concrete, quantitative and direct estimation of a progress of carbonation, and appropriate estimation of a diffusion coefficient concerning salt penetration.SOLUTION: An emission spectrum at a plurality of sample axial center direction positions of a concrete sample is measured (S1), an equation of regression line representing a relationship between the emission intensity of carbon specified based on the emission spectrum and the emission intensity of calcium is calculated (S2), the confidence band of the regression line is calculated (S3), carbonation is determined to occur at a measuring point at which the emission intensity of carbon is greater than the emission intensity of calcium and a combination of the emission intensity of carbon and the emission intensity of calcium does not enter the confidence band of the regression line (S4), and a percentage of the occurrence of carbonation of the sample axial center direction position is calculated using a result of the determination (S5).

Description

  The present invention relates to a method for determining the presence or absence of carbonation of concrete, a determination device and a determination program, a method for estimating the carbonation range of concrete, an estimation device and an estimation program, and a method for estimating and estimating the diffusion coefficient of a target element of concrete. The present invention relates to an apparatus and an estimation program. More specifically, the present invention relates to a technique for determining the presence or absence of carbonation, and a technique for estimating a carbonation range and a diffusion coefficient, which are suitable for evaluation of the state of carbonation and the diffusion coefficient in the depth direction of hardened concrete.

1) Carbonation Carbonation is one of the main causes of deterioration of reinforced concrete. Carbonation in concrete is a phenomenon in which calcium carbonate increases in concrete due to absorption of carbon dioxide into concrete. Carbonation causes the pH value of concrete to change from alkaline to neutral, and when it is no longer alkaline, it becomes a state called neutralization. Therefore, carbonation is always accompanied when neutralization occurs. And, the concrete that has been neutralized is reinforced by rebar corrosion, resulting in a decrease in yield strength.

  As a neutralization index, a method of spraying a phenolphthalein solution is generally used. This method is an inspection method with high visibility because it uses the property that the phenolphthalein liquid does not exhibit red coloration at the neutralization site, but the pH value itself cannot be known. In fact, it is estimated that neutralization gradually proceeds due to an increase in calcium carbonate due to carbonation, and the pH value continuously changes in the depth direction from the concrete surface.

  In addition to the neutralization index as described above, as a conventional method for evaluating the degree of carbonation, combusted concrete is burned using oxygen as a support gas, and carbonation is performed from the amount of carbon dioxide produced by the combustion. There is one that measures the ratio of (Patent Document 1).

  As a conventional method for evaluating the degree of carbonation, the concrete surface is gradually excavated using a drill, and the neutralization range of the excavated surface is obtained by spraying with phenolphthalein liquid each time, thereby reducing the excavation area. There is a technique for obtaining the neutralization depth with the ratio of the neutralization range occupied (Patent Document 2).

  In addition, an experiment was conducted to measure carbon contained in cement paste using laser-induced breakdown spectroscopy (LIBS (abbreviation of Laser-Induced Breakdown Spectroscopy)), and cement paste with a high carbon content. It has been clarified that the emission intensity of carbon is so high (Non-patent Document 1), and as a conventional method for evaluating the degree of carbonation utilizing this knowledge, the carbon in concrete is used by using LIBS. Some measure the ratio between the emission intensity and the emission intensity of silicon, and determine that carbonation occurs as the ratio increases (Patent Document 3).

2) Diffusion coefficient One of the main causes of deterioration of reinforced concrete is the corrosion of steel bars due to the penetration of salt in seawater. An apparent diffusion coefficient is an index for quantitatively evaluating salt penetration in reinforced concrete. By obtaining an apparent diffusion coefficient, it is possible to know the rate of salt penetration through reinforced concrete, and based on this rate, predict the time it takes for salinity to reach the reinforcement and corrosion of the reinforcement. An evaluation can be performed.

  An estimation formula for calculating the apparent diffusion coefficient using the water-cement ratio is proposed in the technical standard of the Japan Society of Civil Engineers. Also, the distribution of chloride ion concentration in the depth direction is measured by potentiometric titration or electron beam microanalyzer (Non-Patent Document 2), and the diffusion coefficient is obtained by fitting the diffusion equation represented by Equation 1 to the measurement result. There is an experimental calculation method.

ここで、Ｃ ：元素濃度［kg／ｍ³］，
Ｃo：コンクリート表面での元素濃度［kg／ｍ³］，
erｆ：誤差関数，
ｚ ：コンクリート表面からの深さ［ｍ］，
Ｄa：見かけの拡散係数［ｍ²／ｓ］，
ｔ ：塩害環境に暴露された期間［ｓ］ をそれぞれ表す。

Where C: element concentration [kg / m ³ ],
Co: Element concentration on the concrete surface [kg / m ³ ],
erf: error function,
z: Depth from concrete surface [m],
Da: Apparent diffusion coefficient [m ² / s],
t: Represents the period of time [s] exposed to the salt damage environment.

  As a method of improving the method using the diffusion equation of Formula 1 and measuring the diffusion coefficient, there is a method of calculating the diffusion coefficient after separating the aggregate and the mortar (Patent Document 4).

Japanese Patent Laid-Open No. 3-100460 JP2011-226916A JP 2002-296183 A JP 2004-301628 A

Kenichiro Tsurugi, Satoru Miura, Kiichiro Kagawa, Takahide Wada: "Measurement of concrete neutralization by laser spectroscopy", Abstracts of Annual Conference of Architectural Institute of Japan, 2003 Japanese Industrial Standard JIS A 1154: Test method for chloride ions contained in hardened concrete

  However, the method for measuring the carbonation degree of Patent Document 1 has a problem that much labor and time are required for pulverization and combustion. In addition, the result may change depending on the setting at the time of combustion. For this reason, it is difficult to say that the reproducibility is high, and therefore it is difficult to say that the property evaluation method is highly reliable.

  Further, in the method of measuring the neutralization depth of Patent Document 2, although the neutralization depth can be obtained, the evaluation of carbonation that is a cause of neutralization cannot be performed, and further, gradually. There is a problem that the progress of carbonation / neutralization cannot be quantitatively evaluated.

  Further, in the carbonation measurement method of Patent Document 3, since the object is a cement paste, the presence of aggregates cannot be taken into account. For this reason, it cannot be applied to hardened concrete as it is, and hardened. Ingenuity is necessary to apply to concrete. In addition, although the carbon emission intensity or the ratio of carbon emission intensity to silicon emission intensity can be used to qualitatively evaluate the degree of carbonation in the concrete core, the actual carbonation rate is quantitative. And there is a problem that it cannot be directly evaluated.

  In addition, in the method for measuring the diffusion coefficient of Patent Document 4, since an electron beam microanalyzer is used, a lot of labor and time are required for the pretreatment of cutting the concrete accurately and flatly for accurate measurement. There is a problem that. Moreover, since a vacuum apparatus is used, there exists a problem that many test bodies cannot be measured. Furthermore, it is known that in concrete where carbonation (in other words, neutralization due to carbonation) has occurred, the chloride ion concentration decreases at the location where carbonation has occurred. On the other hand, when all the data of the distribution of the chloride ion concentration in the depth direction are used, there is a problem that an appropriate diffusion coefficient cannot be calculated.

  Then, an object of this invention is to provide the determination method, determination apparatus, and determination program of the presence or absence of carbonation of concrete which can determine correctly the presence or absence of carbonation in hardened concrete.

  Another object of the present invention is to provide a concrete carbonation range estimation method, estimation device, and estimation program capable of quantitatively and directly estimating the progress of carbonation in hardened concrete.

  Further, the present invention makes use of the results obtained by the above estimation method, and can appropriately estimate the diffusion coefficient related to salt penetration in hardened concrete. And an estimation program.

  In order to achieve such an object, according to the method for determining the presence or absence of carbonation of concrete according to the present invention, the emission spectra at a plurality of axial positions of the specimen are measured, and the carbon specified based on the emission spectrum is measured. A regression line formula representing the relationship between the emission intensity and the emission intensity of calcium is calculated and a confidence band of the regression line is calculated, and the emission intensity of carbon is greater than the emission intensity of calcium and the emission intensity of carbon. It is determined that carbonation has occurred at measurement points where the combination with the luminescence intensity of calcium does not fall within the confidence line of the regression line.

  In addition, the determination device for the presence or absence of carbonation of concrete according to the present invention provides the carbon emission intensity and the calcium emission intensity specified based on the emission spectra measured at a plurality of axial positions of the concrete specimen. Means for reading the combination data of the specimen axial direction position from the storage device, means for calculating a regression line expression representing the relationship between the emission intensity of carbon and the emission intensity of calcium using the combination data, and the regression line Carbon dioxide is calculated at the measurement point where the carbon emission intensity is greater than the calcium emission intensity and the combination of the carbon emission intensity and the calcium emission intensity is not within the regression line confidence band. Means for determining that it has occurred.

  In addition, the determination program for the presence or absence of carbonation of the concrete according to the present invention provides the carbon emission intensity and the calcium emission intensity specified based on the emission spectra measured at a plurality of axial positions of the concrete specimen. Means for reading combination data with specimen axial center position from storage device, means for calculating regression line equation expressing relationship between carbon emission intensity and calcium emission intensity using combination data, reliability of regression line Means for calculating the band, carbonation occurs at measurement points where the emission intensity of carbon is greater than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line The computer is made to function as a means for judging that.

  Therefore, since the absolute value of the emission intensity of carbon changes depending on the experimental conditions, when focusing only on the emission intensity of carbon, the carbonation intensity of these concretes can only be qualitatively shown. According to the presence / absence determination method, determination apparatus, and determination program, the change in emission intensity due to experimental conditions is canceled by comparing the emission intensity of carbon and the emission intensity of calcium.

  In addition, in order to achieve the above-mentioned object, the estimation method of the carbonation range of concrete according to the present invention is based on the measurement of emission spectra at a plurality of axial positions of specimens in the concrete specimen. A regression line equation representing the relationship between the emission intensity of carbon and the emission intensity of calcium is calculated and a confidence band for the regression line is calculated, and the emission intensity of carbon is greater than the emission intensity of calcium and Carbonation is determined to occur at measurement points where the combination of emission intensity and calcium emission intensity does not fall within the regression line confidence band. The ratio of occurrence is calculated.

  In addition, the concrete carbonation range estimation apparatus of the present invention provides the carbon emission intensity and the calcium emission intensity specified based on the emission spectra measured at a plurality of specimen axial positions of the concrete specimen. Means for reading the combination data of the specimen axial direction position from the storage device, means for calculating a regression line expression representing the relationship between the emission intensity of carbon and the emission intensity of calcium using the combination data, and the regression line Carbon dioxide is calculated at the measurement point where the carbon emission intensity is greater than the calcium emission intensity and the combination of the carbon emission intensity and the calcium emission intensity is not within the regression line confidence band. It has means for determining that it has occurred, and means for calculating the rate of carbonation by position in the axial direction of the specimen using the result of the determination. It has to.

  In addition, the concrete carbonation range estimation program of the present invention is provided with the carbon emission intensity and the calcium emission intensity specified based on the emission spectra measured at a plurality of axial positions of the concrete specimen. Means for reading combination data with specimen axial center position from storage device, means for calculating regression line equation expressing relationship between carbon emission intensity and calcium emission intensity using combination data, reliability of regression line Means for calculating the band, carbonation occurs at measurement points where the emission intensity of carbon is greater than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line Computation as a means for determining the amount of carbonation by position in the axial direction of the specimen using the determination result. So that the functioning of the data.

  Therefore, since the absolute value of the emission intensity of carbon changes depending on the experimental conditions, when focusing only on the emission intensity of carbon, the carbonation intensity of these concretes can only be qualitatively shown. According to the range estimation method, estimation apparatus, and estimation program, the change in the emission intensity due to the experimental conditions is canceled by comparing the emission intensity of carbon and the emission intensity of calcium.

  Further, by utilizing the results obtained by the above estimation method, the method of estimating the diffusion coefficient of the target element of the concrete of the present invention measures the emission spectra at a plurality of axial positions of the concrete specimen. The equation shown in Formula 2 using only the combination data of the measurement points where the neutralization of concrete has not occurred among the combination data of the emission intensity of chlorine or sodium specified based on the emission spectrum and the axial position of the specimen. By performing this fitting, the apparent diffusion coefficient Da is calculated.

  In addition, the estimation device for the diffusion coefficient of the target element of the concrete of the present invention is the chlorine and sodium emission intensity and the specimen specified based on the emission spectrum measured at a plurality of axial positions of the concrete specimen. Apparent by fitting the equation shown in Equation 2 using only the combination data of the measurement points where the neutralization of the concrete is not generated among the combination data, and the means for reading the combination data with the axial center position from the storage device Means for calculating the diffusion coefficient Da.

  Further, the program for estimating the diffusion coefficient of the target element of the concrete according to the present invention includes the luminescence intensity of chlorine or sodium specified based on the luminescence spectrum measured at a plurality of axial positions of the concrete specimen and the specimen. The means for reading the combination data with the axial center position from the storage device, and by fitting the equation shown in Equation 2 using only the combination data of the measurement points where the neutralization of the concrete has not occurred among the combination data. The computer is made to function as a means for calculating the diffusion coefficient Da.

ここで、Ｉ ：塩素若しくはナトリウムの発光強度［任意単位］，
Ｉo：コンクリート表面での塩素若しくはナトリウムの発光強度から
Ｉbを差し引いた発光強度［任意単位］，
erｆ：誤差関数，
ｚ ：供試体軸心方向位置［ｍ］，
Ｄa：見かけの拡散係数［ｍ²／ｓ］，
ｔ ：塩害環境に暴露された期間［ｓ］，
Ｉb：塩素若しくはナトリウム濃度が一定となる（ゼロを含む）
供試体軸心方向位置における発光強度［任意単位］ をそれぞれ表す。

Here, I: emission intensity of chlorine or sodium [arbitrary unit],
Io: From the luminescence intensity of chlorine or sodium on the concrete surface
Luminous intensity [arbitrary unit] minus Ib,
erf: error function,
z: Specimen axial position [m],
Da: Apparent diffusion coefficient [m ² / s],
t: period [s] of exposure to salt damage environment,
Ib: Chlorine or sodium concentration is constant (including zero)
Represents the emission intensity [arbitrary unit] at the axial position of the specimen.

  Therefore, since the chloride ion concentration decreases at the neutralized location, it is not possible to calculate an appropriate diffusion coefficient using the chloride ion concentration data including the neutralized location. According to the estimation method, estimation device, and estimation program for the diffusion coefficient of elements, only the combination data of the measurement points where the neutralization of concrete has not occurred is used, so that the cause of the calculation error of the diffusion coefficient is eliminated. .

  According to the determination method, determination apparatus, and determination program for the presence or absence of carbonation of concrete according to the present invention, the emission intensity of carbon is compared with the emission intensity of calcium, so that the change in emission intensity due to experimental conditions is offset. Therefore, regardless of the experimental conditions, it is possible to accurately determine whether carbonation has occurred, and it is possible to improve reliability as a method for evaluating the properties of concrete.

  In addition, according to the estimation method, estimation apparatus and estimation program for the carbonation range of concrete according to the present invention, the emission intensity of carbon and the emission intensity of calcium are compared. Therefore, regardless of the experimental conditions, it is possible to accurately estimate the rate of occurrence of carbonation, and it is possible to improve the reliability as a method for evaluating the properties of concrete.

  According to the estimation method, estimation apparatus, and estimation program for the carbonation range of concrete according to the present invention, the rate of carbonation by position in the axial direction of the specimen can be calculated. Can be quantitatively and directly evaluated, and the usefulness as a method for evaluating the properties of concrete can be improved.

  Further, according to the estimation method, estimation apparatus, and estimation program for the diffusion coefficient of the target element of the concrete of the present invention, only the combination data of the measurement points where the concrete is not neutralized is used. This makes it possible to properly estimate the diffusion coefficient by eliminating the cause of the calculation error, and to improve the reliability as a method for evaluating the performance of concrete.

It is a flowchart explaining an example of embodiment of the estimation method of the carbonation range of the concrete of this invention. It is a functional block diagram of the estimation apparatus of the concrete carbonation range implement | achieved by the said program in the case of implementing the estimation method of the concrete carbonation range of embodiment using the estimation program of the concrete carbonation range. It is a figure explaining the method of measuring the emitted light intensity with respect to a concrete specimen. (A) is a figure explaining the example which bisects a cylindrical specimen to an axial center direction, and performs a measurement. (B) is a figure explaining the example which measures with respect to the outer peripheral surface of a columnar specimen. It is a flowchart explaining an example of embodiment of the estimation method of the diffusion coefficient of the target element of the concrete of this invention. Functional block of the apparatus for estimating the diffusion coefficient of the target element of the concrete realized by the program for estimating the diffusion coefficient of the target element of the concrete of the embodiment using the estimation program of the diffusion coefficient of the target element of the concrete FIG. It is a figure which shows the example of the emission spectrum obtained by the measurement of the concrete test body using LIBS in Example 1. FIG. It is a figure which shows the calculation result of the plot of the combination light emission intensity data in Example 1, and the confidence band of a regression line. It is a figure which shows the calculation result of the ratio of the carbonation according to depth from the concrete housing | casing surface in Example 1. FIG. It is a figure which shows the comparison result of the luminescence intensity of chlorine calculated | required by LIBS in Example 2, and the chloride ion concentration calculated | required by the potentiometric titration method.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

(1) Estimation of Carbonation Range of Concrete FIG. 1 to FIG. 3 show the determination method, determination apparatus and determination program for the presence / absence of carbonation of concrete according to the present invention, and the estimation method, estimation apparatus and estimation of the carbonation range of concrete. An example of an embodiment of a program is shown.

  The method for determining whether or not concrete is carbonated is based on the measurement of emission spectra at multiple axial positions of the specimen, and the difference between the emission intensity of carbon and the emission intensity of calcium specified based on the emission spectrum. The regression line equation representing the relationship between the two is calculated and the confidence line of the regression line is calculated, the emission intensity of carbon is greater than the emission intensity of calcium, and the combination of the emission intensity of carbon and the emission intensity of calcium is a regression line. It is determined that carbonation has occurred at measurement points that are not within the confidence band.

  The determination device for the presence or absence of carbonation of the concrete is based on the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at the axial positions of the specimens. Means for reading the combination data from the storage device, means for calculating the regression line expression representing the relationship between the emission intensity of carbon and the emission intensity of calcium using the combination data, and calculating the confidence band of the regression line The carbon emission intensity is greater than the calcium emission intensity, and the carbon dioxide and calcium emission intensity combinations are not within the confidence line of the regression line. Means.

  The determination program for the presence or absence of carbonation of concrete is based on the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at multiple axial positions of the specimen. Means for reading the combination data from the storage device, means for calculating a regression line expression representing the relationship between the luminescence intensity of carbon and the luminescence intensity of calcium using the combination data, means for calculating the confidence line of the regression line As a means of determining that carbonation has occurred at measurement points where the emission intensity of carbon is greater than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line. Make the computer work.

  Moreover, as shown in FIG. 1, the estimation method of the carbonation range of concrete measured the emission spectrum in the axial direction position of the some specimen of a concrete specimen (S1), and was specified based on this emission spectrum. A regression line equation representing the relationship between the emission intensity of carbon and the emission intensity of calcium is calculated (S2), and a confidence band of the regression line is calculated (S3), and the emission intensity of carbon is calculated from the emission intensity of calcium. And carbon dioxide and calcium emission intensity are determined to be carbonated at measurement points where the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence line of the regression line (S4). The rate at which carbonation by position in the axial direction occurs is calculated (S5).

  The estimation device for the carbonation range of concrete is based on the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at multiple axial positions of the specimen. Means for reading the combination data from the storage device, means for calculating the regression line expression representing the relationship between the emission intensity of carbon and the emission intensity of calcium using the combination data, and calculating the confidence band of the regression line The carbon emission intensity is greater than the calcium emission intensity, and the carbon dioxide and calcium emission intensity combinations are not within the confidence line of the regression line. And means for calculating the rate at which carbonation has occurred for each position in the axial direction of the specimen using the determination result.

  The program for estimating the carbonation range of concrete is based on the luminescence intensity of carbon and the luminescence intensity of calcium and the axial position of the specimen specified based on the luminescence spectra measured at multiple specimen axial positions of the concrete specimen. Means for reading the combination data from the storage device, means for calculating a regression line expression representing the relationship between the luminescence intensity of carbon and the luminescence intensity of calcium using the combination data, means for calculating the confidence line of the regression line Means for determining that carbonation has occurred at measurement points where the emission intensity of carbon is greater than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line; Let the computer function as a means to calculate the rate of carbonation by position in the axial direction of the specimen using the judgment result. .

  In the execution of the method for determining the presence or absence of carbonation of concrete and the method for estimating the carbonation range of concrete, first, the emission intensity of the concrete specimen is measured using laser-induced breakdown spectroscopy (hereinafter referred to as LIBS). Performed (S1).

  In the present invention, a concrete specimen collected from a concrete skeleton to be evaluated is used. The shape and size of the concrete specimen is not limited to a specific shape and size as long as it has a shape and size in the depth direction corresponding to the depth analyzed from the surface of the concrete frame. For example, it can be appropriately adjusted in consideration of the shape and size that can be collected from the concrete frame to be evaluated. Specifically, for example, a core sampled in accordance with the concept such as the size of a specimen in Japanese Industrial Standard JIS A 1107 “Method for sampling core and compressive strength test method from concrete” is used as a concrete specimen in the present invention. obtain. In the following, the depth direction from the concrete surface in the concrete frame to be evaluated from which the concrete specimen was collected is referred to as the axial direction of the specimen.

  Then, the luminescence intensity of carbon and the luminescence intensity of calcium of the concrete specimen are measured simultaneously (in other words, at the same measurement point) using LIBS. That is, a pulsed laser beam is applied to the concrete specimen, the concrete is ablated, and the emission spectrum from the plasma substance is measured. Based on this emission spectrum, the emission intensity of carbon and the emission intensity of calcium are determined. Identified. Since LIBS itself is a well-known technique, details thereof are omitted here (see, for example, Japanese Patent Application Laid-Open No. 2013-190411 and Japanese Patent No. 3500159).

  The method of laser beam irradiation is not limited to a specific mode as long as it is a mode in which plasma is generated by irradiating at least one laser beam to a concrete specimen. For example, a single laser beam is used. You may make it irradiate light, or you may make it irradiate with two laser beams coaxially, or irradiate one from the direction which is slanting or perpendicular to the normal direction of concrete. You may do it.

  The measurement of luminescence intensity is to obtain the change in luminescence intensity due to the difference in depth from the concrete skeleton surface, in other words, the distribution of the luminescence intensity on the concrete specimen surface in the axial direction of the specimen, in other words, A plurality of positions with respect to the axial direction of the specimen (that is, a plurality of depths with respect to the depth from the surface of the concrete casing) and a plurality of positions with the same axial position of the specimen (that is, the concrete casing) At a plurality of positions having the same depth from the surface).

  It should be noted that a plurality of positions within a band-like range having a predetermined width in a direction orthogonal to the axial direction of the specimen may be set as a plurality of positions at, for example, the central position (depth) of the band-like range.

  In addition, the measurement of the emission intensity may be performed on the cut surface by cutting the specimen in the axial direction, or may be performed on the outer peripheral surface of the specimen.

  Specifically, for example, as shown in FIG. 3 (A), concrete is applied to a cut surface 20b when a columnar concrete specimen 20 taken from a concrete frame to be evaluated is divided into two in the axial direction. For each of the depths d1, d2, d3, d4 from the housing surface 20a, the emission intensity of carbon and the emission intensity of calcium are measured at a plurality of positions (measurement points 21). Alternatively, as shown in FIG. 3B, the depths d1, d2, d3 from the concrete body surface 20a with respect to the outer peripheral surface 20c of the columnar concrete specimen 20 taken from the concrete body to be evaluated, etc. For each d4, the emission intensity of carbon and the emission intensity of calcium are measured at a plurality of positions (measurement points 21). Note that FIG. 3 is merely an image diagram for explaining how to measure the emission intensity using LIBS, and does not strictly represent how to set actual measurement points.

  In general, carbon and calcium are in a proportional relationship in both the mortar part and the aggregate part. Therefore, in measuring, consider whether the measurement point 21 is the mortar part or the aggregate part. There is no need.

  By measuring the luminescence intensity using LIBS, the combination data of the position in the axial direction of the concrete specimen (that is, the depth from the surface of the concrete frame), the luminescence intensity of carbon and the luminescence intensity of calcium at each measurement point is obtained. To be acquired.

  Next, using the combination data of the specimen axial direction position, the carbon emission intensity, and the calcium emission intensity for each measurement point acquired by the processing of S1, calculation of an expression representing the relationship between the two is performed. (S2).

  Here, the processing after S2 in the estimation method of the carbonation range of the concrete of the present invention (including the determination method of the presence or absence of carbonation of the concrete as part of it) is the estimation apparatus for the carbonation range of the concrete of the present invention. (A determination device for the presence or absence of carbonation of concrete is included as a part thereof. The same applies hereinafter).

  And the process after S2 in the estimation method of the carbonation range of the concrete of this invention and the carbonation range estimation apparatus which performs these processes are the carbonation range estimation program of the present invention (the carbonation of concrete as a part thereof). It can also be realized by executing on a computer a determination program for determining whether or not to convert to the same. In this specification, the carbonation range estimation apparatus which performs the process after S2 is implement | achieved by running the estimation program of the carbonation range of concrete on a computer, and after S2 in the estimation method of a carbonation range A case where processing is executed will be described.

  FIG. 2 shows an overall configuration of a computer 10 (which is also a carbonation range estimation apparatus 10 in the present embodiment) for executing the carbonation range estimation program 17. The computer 10 (the carbonation range estimation device 10) includes a control unit 11, a storage unit 12, an input unit 13, a display unit 14, and a memory 15, and is connected to each other by a signal line such as a bus.

  The control part 11 performs the calculation which concerns on the control of the computer 10 whole with the carbonation range estimation program 17 memorize | stored in the memory | storage part 12, determination of the presence or absence of carbonation of concrete, and estimation of a carbonation range, for example, CPU (Central Processing Unit).

  The storage unit 12 is a device that can store at least data and programs, and is, for example, a hard disk.

  The input unit 13 is an interface for giving at least an operator's command to the control unit 11, and is, for example, a keyboard.

  The display unit 14 performs drawing / display of characters, graphics, and the like under the control of the control unit 11 and is, for example, a display.

  The memory 15 serves as a memory space that is a work area when the control unit 11 executes various controls and operations, and is, for example, a RAM (abbreviation of Random Access Memory).

  In the present embodiment, combination data of the specimen axial direction position, the carbon emission intensity, and the calcium emission intensity for each measurement point measured and acquired in the above-described processing of S1 is stored as the combined emission intensity database 18. Stored (saved) in the unit 12.

  Then, the control unit 11 of the computer 10 (which is also the carbonation range estimation device 10 in the present embodiment) executes the carbonation range estimation program 17 to execute the measurement measured and acquired in the process of S1. Data reading unit 11a that performs processing for reading combination data of the emission intensity of carbon and the emission intensity of calcium for each point and the position in the axial direction of the specimen from the storage unit 12 as a storage device, and the emission intensity of carbon using the combination data Is a regression equation calculation unit 11b that performs a process of calculating a regression line expression representing the relationship between the light emission intensity of calcium and calcium, a confidence band calculation unit 11c that performs a process of calculating a confidence line of the regression line, and the emission intensity of carbon is Measurement points that are larger than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence line of the regression line Is a carbonation determination unit 11d that performs a process of determining that carbonation has occurred, and a carbonation ratio calculation that performs a process of calculating the rate of carbonation by position in the axial direction of the specimen using the determination result. Part 11e is configured.

  As specific processing by executing the carbonation range estimation program 17, first, the processing of S1 is performed by the data reading unit 11a configured in the control unit 11 of the computer 10 (carbonation range estimation device 10). The combination data of the specimen axial direction position, the carbon emission intensity, and the calcium emission intensity for each measurement point recorded in the combined emission intensity database 18 that is measured and acquired and stored in the storage unit 12 (hereinafter referred to as the emission intensity of calcium) , Referred to as combined emission intensity data). Then, the read combination emission intensity data is stored in the memory 15 by the data reading unit 11a.

  Subsequently, an equation representing a relationship between the emission intensity of carbon and the emission intensity of calcium is calculated by the regression equation calculation unit 11b configured in the control unit 11 using the combined emission intensity data for each measurement point.

  More specifically, the regression equation calculation unit 11b uses the combined emission intensity data for each measurement point stored in the memory 15 and uses regression analysis to represent the relationship between the emission intensity of carbon and the emission intensity of calcium. A linear equation, in other words, an approximate equation representing the dependence of the emission intensity of calcium on the emission intensity of carbon is calculated. In the regression analysis, the regression analysis is performed by integrating the combined light emission intensity data in all the specimen axial direction positions without being classified by the value of the specimen axial direction position.

  Here, in the process of S2, only the combined luminescence intensity data measured at a deep position from the surface of the concrete frame, which is considered to have no neutralization of the concrete, among the combined luminescence intensity data acquired by the process of S1. Is used. Here, hereinafter, a depth at which neutralization is considered not to occur (actually set as a range deeper than a certain depth) is referred to as a non-neutralized depth range.

  In addition, the depth of the boundary of the occurrence of neutralization that divides the depth range where neutralization is considered to occur and the depth range where neutralization is considered not to occur is limited to a specific value. However, the value is appropriately set with reference to the results of the occurrence of neutralization in concrete having the same specifications and conditions. The non-neutralization depth range (the value of the boundary depth when neutralization occurs) is defined in advance in the carbonation range estimation program 17.

  The regression formula calculation unit 11b refers to the value of the specimen axial direction position for each combination light emission intensity data, and extracts only data in which the value of the specimen axial direction position is within the non-neutralization depth range. Then, the process of S2 is performed.

  The method of regression (in other words, the type of regression equation) is not limited to a specific one, and may be linear regression or linear regression. Further, the method of regression analysis (in other words, the regression equation calculation method) is not limited to a specific method, and specifically, for example, a least square method may be used.

  It should be noted that the types of regression equations and the calculation method of the regression equations may be specified in advance in the carbonation range estimation program 17, or the operator may input the input unit at the stage of performing S2. 13 and the display unit 14 may be used for input or selection from among a plurality.

  Then, the regression formula calculation unit 11b stores parameters related to the calculated regression formula in the memory 15.

  Next, the confidence band of the regression line expressed by the regression equation calculated by the process of S2 is calculated (S3).

  Specifically, the confidence band calculation unit 11c configured in the control unit 11 uses the parameters related to the regression equation stored in the memory 15 in the process of S2, and uses the regression band confidence band (that is, the regression equation represented by the regression equation). , A band defined by a lower limit and an upper limit of the confidence interval of the regression line is calculated.

  The confidence level for calculating the confidence band is not limited to a specific value, and can be adjusted as appropriate. Specifically, for example, it may be set at any value in the range of about 80 to 99%, preferably set at any value in the range of 85 to 95%, and 85 to 90%. Is more preferably set to any value in the range of 90%, and most preferably 90%.

  By obtaining the confidence band, the relative intensity of the emission intensity of carbon to the emission intensity of calcium when neutralization does not occur is specified.

  Then, the parameter relating to the confidence band of the regression line is stored in the memory 15 by the confidence band calculation unit 11c.

  Next, it is determined whether or not carbonation has occurred at each measurement point using the confidence band of the regression line calculated by the process of S3 (S4).

Specifically, by the carbonation determination unit 11d configured in the control unit 11, the parameters related to the confidence band of the regression line stored in the memory 15 in the process of S3 and the combined emission intensity stored in the memory 15 in the process of S2 Whether or not the following conditions 1) and 2) are satisfied is determined for each combination emission intensity data.
1) The emission intensity of carbon is greater than the emission intensity of calcium.
2) The combination of the light emission intensity of carbon and the light emission intensity of calcium (data point) is not within the confidence band of the regression line.

  When both of the above conditions 1) and 2) are satisfied, it is determined that carbonation has occurred at the measurement point where the combined emission intensity data is measured, while 1) and 2 above. ) Is not satisfied, it is determined that no carbonation occurs at the measurement point where the combined emission intensity data is measured.

  Then, for each combination light emission intensity data stored in the memory 15, the carbonation determination unit 11 d adds information (flag) on whether or not carbonation has occurred at the measurement point of the data to be stored in the memory 15.

  Here, the above-mentioned processes from S1 to S4 are processes as a method for determining the presence or absence of carbonation of the concrete according to the present invention. The data reading unit 11a, regression equation calculating unit 11b, confidence band calculating unit 11c, and carbonation determination unit 11d correspond to the concrete carbonation determination device according to the present invention. What is the determination program for the presence or absence of carbonation of the concrete of the present invention.

  Next, calculation of the ratio of carbonation by depth from the surface of the concrete body is performed using information on the presence or absence of carbonation for each combination emission intensity data determined and added by the process of S4 (S5). .

  Specifically, the combined light emission intensity data stored in the memory 15 in the process of S2 and the combined light emission intensity data stored in the memory 15 in the process of S4 are performed by the carbonation ratio calculating unit 11e configured in the control unit 11. The rate of carbonation is calculated for each value of the axial position of the specimen using the determination result of whether carbonation has occurred. That is, for each set of combined emission intensity data having the same value of the specimen axial direction position, the number of data in which carbonation has occurred relative to the number of all data belonging to the set (that is, the number of measurement points) ( The ratio of the number of measurement points) is calculated.

  By the above processing, the carbonation generation rate by depth from the surface of the concrete frame can be quantitatively obtained.

  If necessary, the regression line equation expressing the relationship between the two is calculated by regression analysis using the combined data of the axial position of the specimen and the carbonation occurrence rate obtained by the above processing. May be. In this case, the change of the carbonation generation rate accompanying the change of the depth from the concrete housing surface can be obtained quantitatively and continuously.

  And the control part 11 complete | finishes the process regarding the concrete specimen (combined light emission intensity data) which has been handled so far (END).

  According to the determination method, determination apparatus and determination program for the presence or absence of carbonation of concrete according to the present invention configured as described above, and the estimation method, estimation apparatus and estimation program for the carbonation range of concrete, the emission intensity of carbon is determined under experimental conditions. Since the absolute value varies depending on the value of carbon, if we focus only on the emission intensity of carbon, we can only qualitatively indicate the degree of carbonation, but by comparing the emission intensity of carbon with that of calcium The change in emission intensity due to the experimental conditions can be offset.

  Although the above-described embodiment is an example of a preferred embodiment for carrying out the present invention, the embodiment of the present invention is not limited to the above-described embodiment, and the present invention is not deviated from the gist of the present invention. Various modifications can be made. For example, in the above-described embodiment, the combined light emission intensity data (combined light emission intensity database 18) measured and acquired in the process of S1 is stored (saved) in the storage unit 12 as a storage device, and the combined light emission intensity is stored from the storage unit 12. The data is read, but the storage device in the present invention is not limited to this, and various storage devices connected so as to be able to transmit and receive signals to and from the carbonation range estimation device 10. Alternatively, the memory 15 of the carbonation range estimation device 10 may be used.

  Further, in the above-described embodiment, the emission intensity of the concrete specimen is measured by laser induced breakdown spectroscopy (LIBS), but the emission spectrum measurement method is not limited to LIBS, Spark-induced breakdown spectroscopy (also referred to as SIBS (abbreviation of Spark-Induced Breakdown Spectroscopy)) may be used.

(2) Calculation of diffusion coefficient of target element of concrete Next, FIG. 4 and FIG. 5 show an example of an embodiment of a method, an estimation apparatus, and an estimation program for a diffusion coefficient of a target element of concrete of the present invention.

  As shown in FIG. 4, the estimation method of the diffusion coefficient of the target element of the concrete is measured based on the emission spectra of the concrete specimens measured at a plurality of specimen axial center positions (S1 ′). By fitting the equation shown in Equation 3 using only the combination data of the measurement points where the neutralization of concrete has not occurred among the combination data of the luminescence intensity of chlorine or sodium and the axial position of the specimen The diffusion coefficient Da is calculated (S2 ′).

  In addition, the estimation device for the diffusion coefficient of the target element of concrete is based on the emission intensity of chlorine or sodium and the axial direction of the specimen specified based on the emission spectra measured at multiple axial positions of the concrete specimen. Apparent diffusion coefficient by means of reading the combination data with the position from the storage device and fitting the equation shown in Equation 3 using only the combination data of the measurement points where the neutralization of the concrete has not occurred among the combination data Means for calculating Da.

  In addition, the program for estimating the diffusion coefficient of the target element of concrete is based on the emission intensity of chlorine or sodium determined based on the emission spectra measured at multiple axial positions of the specimen and the axial direction of the specimen. The apparent diffusion coefficient Da is obtained by fitting the equation shown in Equation 3 using only the combination data of the measurement points where the neutralization of the concrete is not generated among the combination data, the means for reading the combination data with the position from the storage device. Let the computer function as a means to calculate

ここで、Ｉ ：塩素若しくはナトリウムの発光強度［任意単位］，
Ｉo：コンクリート表面での塩素若しくはナトリウムの発光強度から
Ｉbを差し引いた発光強度［任意単位］，
erｆ：誤差関数，
ｚ ：供試体軸心方向位置［ｍ］，
Ｄa：見かけの拡散係数［ｍ²／ｓ］，
ｔ ：塩害環境に暴露された期間［ｓ］，
Ｉb：塩素若しくはナトリウム濃度が一定となる（ゼロを含む）
供試体軸心方向位置における発光強度［任意単位］ をそれぞれ表す。

Here, I: emission intensity of chlorine or sodium [arbitrary unit],
Io: From the luminescence intensity of chlorine or sodium on the concrete surface
Luminous intensity [arbitrary unit] minus Ib,
erf: error function,
z: Specimen axial position [m],
Da: Apparent diffusion coefficient [m ² / s],
t: period [s] of exposure to salt damage environment,
Ib: Chlorine or sodium concentration is constant (including zero)
Represents the emission intensity [arbitrary unit] at the axial position of the specimen.

  In executing the method for estimating the diffusion coefficient of the target element of concrete, first, the light emission intensity of the concrete specimen is measured using laser induced breakdown spectroscopy (hereinafter referred to as LIBS) (S1 ′).

  In the estimation of the diffusion coefficient, a concrete specimen collected from the concrete frame to be evaluated can be used, and a concrete specimen similar to the concrete specimen in (1) above can be used.

  Then, the luminescence intensity of chlorine or sodium of the concrete specimen is measured using LIBS. The method of measuring the light emission intensity is the same as the method of measuring the light emission intensity described in (1) above.

  By measuring the emission intensity using LIBS, multiple sets of combination data of the position of the concrete specimen in the axial direction (ie, the depth from the surface of the concrete frame) and the emission intensity of chlorine or sodium at each measurement point are obtained. Is done.

  Next, the diffusion coefficient of chlorine or sodium is calculated using the combination data of the specimen axial direction position and the emission intensity of chlorine or sodium for each measurement point acquired by the processing of S1 (S2 ′).

  Here, the process of S2 ′ in the method for estimating the diffusion coefficient of the target element of the concrete of the present invention can be executed by the apparatus for estimating the diffusion coefficient of the target element of the concrete of the present invention.

  And the process of S2 'in the estimation method of the diffusion coefficient of the target element of the concrete of this invention and the estimation apparatus of the diffusion coefficient which performs these processes perform the estimation program of the diffusion coefficient of the target element of the concrete of this invention on a computer. It can also be realized by executing. In the present specification, a diffusion coefficient estimation device for executing the processing of S2 ′ is realized by executing a diffusion coefficient estimation program for a target element of concrete on a computer, and S2 ′ in the diffusion coefficient estimation method is realized. A case where processing is executed will be described.

  FIG. 5 shows an overall configuration of a computer 30 (which is also a diffusion coefficient estimation device 30 in the present embodiment) for executing the diffusion coefficient estimation program 37. The computer 30 (diffusion coefficient estimation device 30) includes a control unit 31, a storage unit 32, an input unit 33, a display unit 34, and a memory 35, which are connected to each other by a signal line such as a bus.

  The control unit 31, the storage unit 32, the input unit 33, the display unit 34, and the memory 35 are the same as the control unit 11, the storage unit 12, the input unit 13, the display unit 14, and the memory 15 in the above (1).

  In the present embodiment, the combination data of the specimen axial direction position and the emission intensity of chlorine or sodium for each measurement point measured and acquired in the process of S1 ′ described above is stored in the storage unit 32 as the emission intensity database 38. Stored (saved).

  Then, the control point 31 of the computer 30 (which is also the diffusion coefficient estimation device 30 in this embodiment) executes the diffusion coefficient estimation program 37 to thereby measure the measurement points obtained and acquired in the process of S1 ′. A data reading unit 31a that performs processing for reading the combination data of the axial direction position of each specimen and the emission intensity of chlorine or sodium from the storage unit 32 as a storage device, and the neutralization of the concrete has not occurred in the combination data A diffusion coefficient calculation unit 31b that performs processing for calculating the apparent diffusion coefficient Da by fitting the equation shown in Equation 3 using only the combination data of the measurement points is configured.

  As specific processing by executing the diffusion coefficient estimation program 37, first, in the processing of S1 ′ by the data reading unit 31a configured in the control unit 31 of the computer 30 (diffusion coefficient estimation device 30). Combination data (hereinafter referred to as luminescence intensity data) of the specimen axial center position and the luminescence intensity of chlorine or sodium for each measurement point recorded and recorded in the luminescence intensity database 38 stored and stored in the storage unit 32. Is called). Then, the read light emission intensity data is stored in the memory 35 by the data reading unit 31a.

  Subsequently, an apparent diffusion coefficient is calculated by the diffusion coefficient calculation unit 31b configured in the control unit 31 using the emission intensity data for each measurement point.

  Specifically, the diffusion coefficient calculation unit 31b uses the emission intensity data for each measurement point stored in the memory 35 to fit the equation shown in Equation 4 to calculate the apparent diffusion coefficient Da. Of the emission intensity data, the position in the axial direction of the specimen is used as the depth z from the concrete surface of Equation 4, and the emission intensity of chlorine or sodium is given as the emission intensity I of the element of Equation 4.

ここで、Ｉ ：塩素若しくはナトリウムの発光強度［任意単位］，
Ｉo：コンクリート表面での塩素若しくはナトリウムの発光強度から
Ｉbを差し引いた発光強度［任意単位］，
erｆ：誤差関数，
ｚ ：コンクリート表面からの深さ［ｍ］，
Ｄa：見かけの拡散係数［ｍ²／ｓ］，
ｔ ：塩害環境に暴露された期間［ｓ］，
Ｉb：塩素若しくはナトリウム濃度が一定となる（ゼロを含む）
供試体軸心方向位置における発光強度［任意単位］ をそれぞれ表す。

Here, I: emission intensity of chlorine or sodium [arbitrary unit],
Io: From the luminescence intensity of chlorine or sodium on the concrete surface
Luminous intensity [arbitrary unit] minus Ib,
erf: error function,
z: Depth from concrete surface [m],
Da: Apparent diffusion coefficient [m ² / s],
t: period [s] of exposure to salt damage environment,
Ib: Chlorine or sodium concentration is constant (including zero)
Represents the emission intensity [arbitrary unit] at the axial position of the specimen.

  Here, in the process of S2 ′, only the emission intensity data of the measurement point where the neutralization of the concrete has not occurred among the emission intensity data acquired by the process of S1 ′ is used.

  At this time, it may be determined whether or not neutralization has occurred at each measurement point, and only the measurement points at which neutralization has occurred may be excluded, or the depth range where neutralization has occurred may be excluded. You may make it remove all the measurement points.

  The determination of the presence or absence of neutralization (in other words, carbonation that is the cause of neutralization) and the specification of the depth range where neutralization (carbonation) occurs are as described in (1) above. The method for determining the presence or absence of carbonation of concrete and the method for estimating the carbonation range of concrete may be used, or other methods may be used.

  In addition, determination of the presence or absence of carbonation for each measurement point and identification of the carbonation generation range (depth) are performed using the determination method of the presence or absence of carbonation of concrete and the estimation method of the carbonation range of concrete described in (1) above. In such a case, using the same concrete specimen, the above-described treatments S1 and S1 ′ in (1) are performed at the same time (in addition, chlorine on the surface of the concrete body (surface 20a in FIG. 3) or Sodium emission intensity measurement is included), and combined data of “the axial position of the specimen, the emission intensity of carbon, the emission intensity of calcium, and the emission intensity of chlorine or sodium” for each measurement point is acquired.

  Subsequently, the processing from S2 to S4 in the above (1) is performed, it is determined whether or not carbonation has occurred at each measurement point, and the specimen axis direction of the measurement point at which it is determined that carbonation has not occurred. The process of S2 ′ is performed using the combination data of the position and the emission intensity of chlorine or sodium.

  Or the depth range in which carbonation has occurred is estimated by performing the processing from S1 to S5 in the above (1), and the specimen axis of the measurement point within the range in which carbonation has not been estimated has been estimated. The process of S2 ′ is performed using the combination data of the center position and the emission intensity of chlorine or sodium.

  The method for estimating the diffusion coefficient of the target element of concrete when using the method for determining the presence or absence of carbonation of concrete described in (1) above in determining whether or not neutralization (carbonation) has occurred at each measurement point is as follows: The emission spectrum of the concrete specimen at multiple axial positions of the specimen is measured, and the regression line equation representing the relationship between the emission intensity of carbon and the emission intensity of calcium specified based on the emission spectrum is Measurement points where the confidence band of the regression line is calculated and the emission intensity of carbon is greater than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line Therefore, it is determined that carbonation has occurred, and the chlorine or sodium emission intensity specified based on the emission spectrum and the axial position of the specimen The apparent diffusion coefficient Da is calculated by fitting the equation shown in Equation 3 using the combination data obtained by removing the data of the measurement points determined to be carbonation from the combined data. ing.

  In addition, estimation of the diffusion coefficient of the target element of the concrete when the method for determining the presence or absence of carbonation of the concrete described in (1) above is used in the determination of whether or not neutralization (carbonation) has occurred at each measurement point. The apparatus consists of carbon emission intensity, calcium emission intensity, chlorine or sodium emission intensity, and axial position of the specimen specified based on emission spectra measured at a plurality of axial positions of the concrete specimen. Means for reading the combination data from the storage device, means for calculating the regression line expression representing the relationship between the emission intensity of carbon and the emission intensity of calcium using the combination data, and calculating the confidence band of the regression line A combination of the light emission intensity of carbon and the light emission intensity of calcium is greater than the light emission intensity of calcium and the light emission intensity of carbon and the light emission intensity of calcium. Means for determining that carbonation has occurred at measurement points that are not within the confidence band of the return line, and chlorine in the combination data excluding the data of the measurement points determined to have carbonation in the combination data or Means for calculating the apparent diffusion coefficient Da by fitting the equation shown in Formula 3 using the emission intensity of sodium and the axial direction position of the specimen.

  In addition, estimation of the diffusion coefficient of the target element of the concrete when the method for determining the presence or absence of carbonation of the concrete described in (1) above is used in the determination of whether or not neutralization (carbonation) has occurred at each measurement point. The program consists of carbon emission intensity, calcium emission intensity, chlorine or sodium emission intensity, and axial position of the specimen specified based on emission spectra measured at multiple axial positions of the specimen. Means for reading the combination data from the storage device, means for calculating a regression line expression representing the relationship between the luminescence intensity of carbon and the luminescence intensity of calcium using the combination data, means for calculating the confidence line of the regression line The emission intensity of carbon is greater than the emission intensity of calcium, and the combination of the emission intensity of carbon and the emission intensity of calcium is Means for determining that carbonation has occurred at measurement points that are not within the confidence band of the return line, chlorine or sodium in the combination data excluding the data of the measurement points that have been determined to have carbonation in the combination data The computer is caused to function as means for calculating the apparent diffusion coefficient Da by fitting the equation shown in Equation 3 using the emission intensity of the sample and the axial direction position of the specimen.

  Through the above treatment, the diffusion coefficient of chlorine or sodium in the concrete is obtained.

  And the control part 31 complete | finishes the process regarding the concrete specimen (luminescence intensity data) which has been handled so far (END).

  According to the estimation method, the estimation device, and the estimation program for the diffusion coefficient of the target element of the concrete of the present invention configured as described above, since the chloride ion concentration is reduced at the neutralized portion, the neutralized portion is included. When using the chloride ion concentration data, it is not possible to calculate an appropriate diffusion coefficient, but only the combination data of measurement points where no neutralization of concrete occurs is used. It is possible to appropriately estimate the diffusion coefficient by eliminating the error factor.

  In addition, the determination of the presence or absence of neutralization (carbonation) at each measurement point and the determination of the presence or absence of carbonation of the concrete explained in (1) above in the specification of the depth range where neutralization (carbonation) occurs. When the method or the estimation method of carbonation range of concrete is used, the absolute value of carbon emission intensity varies depending on the experimental conditions. While it can only be shown qualitatively, the light emission intensity of carbon is compared with the light emission intensity of calcium, so that the change in light emission intensity due to experimental conditions can be offset.

  Although the above-described embodiment is an example of a preferred embodiment for carrying out the present invention, the embodiment of the present invention is not limited to the above-described embodiment, and the present invention is not deviated from the gist of the present invention. Various modifications can be made. For example, in the above-described embodiment, the emission intensity data (emission intensity database 38) measured and acquired in the process of S1 ′ is stored (saved) in the storage unit 32 as a storage device, and the emission intensity data is stored from the storage unit 32. However, the storage device in the present invention is not limited to this, and may be various storage devices connected so as to be able to transmit / receive signals to / from the diffusion coefficient estimation device 30. Alternatively, the memory 35 of the diffusion coefficient estimation device 30 may be used.

  The method for estimating the carbonation range of concrete of the present invention including the method for determining the presence or absence of carbonation of the concrete of the present invention as a part is applied to the determination of the presence or absence of carbonation in an actual concrete specimen and the estimation of the carbonation range. Examples will be described with reference to FIGS.

  In this example, a cylindrical concrete specimen having a diameter of 75 mm and a height of 150 mm collected from an actual concrete structure was used.

  Then, the cylindrical concrete specimen is divided into two axially as in the example shown in FIG. 3A, and the laser-induced break is applied to the cut surface (reference numeral 20b in the figure) when the two parts are divided. The emission intensity was measured by down spectroscopy (hereinafter referred to as LIBS) (S1).

  In this example, measurement was performed at 41 points for each depth at a pitch of 2.5 mm in a range of 2.5 to 25 [mm] from the surface of the concrete frame.

  As a result of measurement by LIBS, the results shown in FIG. 6 were obtained for the emission spectrum at a certain measurement point.

  In this example, the emission intensity from the straight line connecting both sides of the spectrum (broken line in FIG. 6) to the spectrum peak was taken as the emission intensity (C: carbon, Ca: calcium).

  Moreover, the combination data (combination data) of the position in the axial center direction of the concrete specimen (that is, the depth from the surface of the concrete frame), the emission intensity of carbon, and the emission intensity of calcium, obtained by measurement by LIBS. When the emission intensity data is plotted in a two-dimensional orthogonal coordinate system of the emission intensity of carbon and the emission intensity of calcium, the result is as shown in FIG.

  Next, using the combination data (FIG. 7) of the specimen axial direction position, the carbon emission intensity, and the calcium emission intensity for each measurement point obtained by the processing of S1, the relationship between the two is expressed. Calculation was performed (S2).

  In this example, the depth at which no neutralization was considered was set to a range deeper than 10 mm from the surface of the concrete body. That is, only data with a value of the position in the axial direction of the specimen of 12.5 or more was extracted from the combined emission intensity data acquired by the process of S1.

  Then, using the combined emission intensity data extracted as described above, a linear regression equation representing the relationship between the emission intensity of carbon and the emission intensity of calcium was calculated. The least square method was used to calculate the regression equation.

  Next, the confidence band of the regression line expressed by the regression equation calculated by the process of S2 was calculated (S3).

  In this example, the confidence level was set to 85, 90, 95, 99 [%] in order to verify the influence of the confidence level value of the confidence band on the estimation accuracy of the carbonation range of concrete.

  When the confidence level of the confidence band is 90%, the results (two upper and lower broken lines in the figure) shown in FIG. 7 are obtained as a straight line representing the lower limit of the confidence band and a straight line representing the upper limit.

  Next, it was determined whether or not carbonation occurred at each measurement point using the regression line confidence band calculated by the process of S3 (S4).

  Specifically, at the measurement point where the data point of the combination of the light emission intensity of carbon and the light emission intensity of calcium is below the straight line representing the lower limit of the confidence band shown in FIG. It was determined that carbonation had occurred.

  Next, the ratio of carbonation by depth from the surface of the concrete body was calculated using the information on the presence or absence of carbonation for each combination emission intensity data determined and added by the process of S4 (S5). ).

  Carbonation with respect to the number of all data of the depth (that is, the number of measurement points) according to the depth from the surface of the concrete body (in this embodiment, 2.5 mm pitch in the range of 2.5 to 25 [mm]). The ratio of the number of data (the number of measurement points) in which digitization has occurred was calculated.

  In this example, the carbonation occurrence ratio by depth from the surface of the concrete frame was calculated according to the confidence level of the confidence band of the regression line, and the results shown in FIG. 8 were obtained.

  From the results shown in FIG. 8, the carbonation generation rate is the highest when the depth from the concrete body surface is the shallowest depth of 2.5 mm, and the depth from the surface becomes deeper for any confidence level. The tendency for the carbonation rate to decrease was confirmed.

  Here, according to the neutralization test conducted by another method using the same concrete specimen, the concrete specimen used in this example was neutralized and carbonated to a depth of about 10 mm from the surface of the concrete body. It was confirmed that crystallization occurred. In the results shown in FIG. 8, for any confidence level, the value of the carbonation generation rate is generally constant at a low value in the range of 10 to 25 [mm], and the carbonation does not occur at a depth of 10 mm or more. Was confirmed to appear.

  From the results shown in FIG. 8, and in this example, when the confidence level of the confidence band is 95% and 99%, the confidence band becomes wider and below the lower limit straight line of the confidence band. Since a certain number of data points is reduced, it is confirmed that the number of measurement points at which carbonation has occurred is reduced, and it can be determined that no carbonation has occurred at a depth of 5 mm or more.

  On the other hand, in the case where the confidence level of the confidence band is 85% and 90%, whether or not carbonation occurs depending on whether or not the confidence band width is appropriate and is below the lower limit straight line of the confidence band. Judgment is made appropriately, and the tendency to reduce the rate of carbonation over a range of depths from 2.5 mm to 10 mm is reproduced well, and no carbonation occurs at depths of 10 mm or deeper. It was confirmed that it can be judged.

  Furthermore, in view of the fact that the value of the carbonation generation rate in a range deeper than 10 mm is further reduced, it has been confirmed that the best result can be obtained by setting the value of the confidence level to 90%. It was.

  As described above, it was confirmed that the best result was obtained when the confidence level value of the confidence line of the regression line was set to 90%. Although it can be said that good results can be obtained by setting the value of the confidence level in the range of about 90 to 95 [%] as described above, the value of the confidence level is limited to the range of 90 to 95 [%]. It does not indicate that.

  From the above results, the method for determining the presence or absence of carbonation of concrete and the method for estimating the carbonation range of concrete according to the present invention quantitatively illustrates the fact that carbonation is gradually progressing from the surface of the concrete frame to the inside. It was confirmed that it could be judged well, and it was confirmed that it was highly reliable as a method for judging whether carbonation of concrete occurred.

  From the above results, it was also confirmed that the method for estimating the carbonation range of the concrete of the present invention can quantitatively estimate the actual state that the carbonation is progressing from the concrete body surface to what depth, It was confirmed that the method of estimating the carbonation occurrence range of concrete including the change of the carbonation generation rate with the change of the depth from the concrete frame surface is highly reliable.

  An embodiment in which the method for estimating the diffusion coefficient of the target element of the concrete of the present invention is applied to the estimation of the diffusion coefficient of chlorine in an actual concrete specimen will be described with reference to FIG.

  First, the light emission intensity of the concrete specimen is measured using laser induced breakdown spectroscopy (hereinafter referred to as LIBS) (S1 ′).

  The measurement of the light emission intensity in this example was performed simultaneously with the measurement of the light emission intensity in Example 1 described above (the processing of S1 in Example 1). And the luminescence intensity of chlorine was measured as corresponding to this example. That is, for the same concrete specimen, including those corresponding to Example 1, the specimen axial direction position (that is, the depth from the surface of the concrete housing), the emission intensity of carbon, and the emission of calcium for each measurement point Combination data of intensity and luminescence intensity of chlorine were acquired. Note that the axial direction position of the specimen was set to a 2.5 mm pitch in the range of a depth of 2.5 to 80 [mm] from the surface of the concrete frame.

  As a result of measurement by LIBS, the results shown in FIG. 9 were obtained for the luminescence intensity of chlorine at different depths from the surface of the concrete frame (black circles in the figure). In this example, the average value of the luminescence intensity of chlorine at a plurality of measurement points having the same depth was used.

  Next, the diffusion coefficient of chlorine was calculated using the combination data of the specimen axial direction position for each measurement point and the luminescence intensity of chlorine obtained by the processing of S1 (S2 ′).

  In this embodiment, carbonation occurs in a range up to a depth of 10 mm from the surface of the concrete frame by the method for determining the presence or absence of carbonation of the concrete and the estimation method of the carbonation range of the concrete according to the first embodiment. The data at the measurement points whose position in the axial direction of the specimen is within 10 was excluded based on the result (the confidence level 85%, 90% of the confidence band). From the results shown in FIG. 9, it is confirmed that the tendency of the luminescence intensity of chlorine in the range up to a depth of 10 mm (black circle in the figure) and the tendency of the luminescence intensity of chlorine in the deeper range are clearly different. It was.

  Then, using the combination data of the specimen axial direction position and the luminescence intensity of chlorine having a specimen axial position of 12.5 or more, the equation shown in Formula 4 is fitted, and the apparent diffusion coefficient Da is calculated. It was done.

  As a result of fitting the equation shown in Equation 4, a straight line indicated by a solid line in FIG. 9 was obtained.

  Here, the chloride ion concentration calculated | required by the potentiometric titration method using the same concrete test body is shown according to FIG. 9 (columnar graph in a figure). From this result, the chloride ion concentration is peculiar in the range from the surface of the concrete skeleton estimated to be carbonized in Example 1 to a depth of 10 mm compared to the deeper range (specifically, , Discontinuously low).

  From the results shown in FIG. 9, it was confirmed that the luminescence intensity of chlorine by LIBS can be satisfactorily fitted by the equation shown in Equation 4 (black circle and solid line in the figure), and the fitting result is the actual state of chloride ion concentration. (Solid line and columnar graph in the figure).

  From the above results, it was confirmed that the method for estimating the diffusion coefficient of the target element of the concrete of the present invention can satisfactorily estimate the diffusion coefficient corresponding to the actual state of diffusion of the target element in the concrete. It was confirmed that the estimation method is highly reliable.

  In addition, also from the result of the chloride ion concentration shown in FIG. 9, the presence or absence of the occurrence of carbonation of concrete by the determination method of the presence or absence of carbonation of the concrete of the present invention used in Example 1, the estimation method of the carbonation range of the concrete As a result, it was confirmed that the method is highly reliable as a method for estimating the carbonation and estimating the carbonation occurrence range.

DESCRIPTION OF SYMBOLS 10 Carbonation range estimation apparatus 17 Carbonation range estimation program 30 Diffusion coefficient estimation apparatus 37 Diffusion coefficient estimation program

Claims (9)

  Emission spectra at multiple axial positions of the specimen are measured, and a regression line equation representing the relationship between the carbon emission intensity and the calcium emission intensity specified based on the emission spectrum is calculated. And the confidence line of the regression line is calculated, the emission intensity of the carbon is greater than the emission intensity of the calcium, and the combination of the emission intensity of the carbon and the emission intensity of the calcium is the confidence band of the regression line. A method for determining the presence or absence of carbonation of concrete, characterized in that it is determined that carbonation has occurred at measurement points that are not included.   Read from the storage device the combination of the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at a plurality of specimen axial positions of the concrete specimen. Means for calculating a regression line equation representing the relationship between the luminescence intensity of the carbon and the luminescence intensity of the calcium using the combination data; means for calculating a confidence band of the regression line; It is determined that carbonation occurs at a measurement point where the emission intensity of carbon is larger than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line. And means for determining the presence or absence of carbonation of concrete.   Read from the storage device the combination of the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at a plurality of specimen axial positions of the concrete specimen. Means for calculating a regression line equation representing the relationship between the emission intensity of the carbon and the emission intensity of the calcium using the combination data; means for calculating a confidence band of the regression line; emission of the carbon As means for determining that carbonation has occurred at a measurement point whose intensity is greater than the calcium emission intensity and the combination of the carbon emission intensity and the calcium emission intensity is not within the confidence line of the regression line. A program to determine whether or not concrete is carbonated to allow the computer to function.   Emission spectra at multiple axial positions of the specimen are measured, and a regression line equation representing the relationship between the carbon emission intensity and the calcium emission intensity specified based on the emission spectrum is calculated. And the confidence line of the regression line is calculated, the emission intensity of the carbon is greater than the emission intensity of the calcium, and the combination of the emission intensity of the carbon and the emission intensity of the calcium is the confidence band of the regression line. Concrete in which carbonation is determined to occur at a measurement point that is not included, and the rate at which the carbonation is generated for each position in the axial direction of the specimen is calculated using the determination result. Of estimating the carbonation range of sucrose.   Read from the storage device the combination of the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at a plurality of specimen axial positions of the concrete specimen. Means for calculating a regression line equation representing the relationship between the luminescence intensity of the carbon and the luminescence intensity of the calcium using the combination data; means for calculating a confidence band of the regression line; It is determined that carbonation occurs at a measurement point where the emission intensity of carbon is larger than the emission intensity of calcium and the combination of the emission intensity of carbon and the emission intensity of calcium is not within the confidence band of the regression line. And means for calculating the rate of occurrence of the carbonation according to the axial position of the specimen using the result of the determination. Estimator carbonation range of concrete characterized by.   Read from the storage device the combination of the emission intensity of carbon and the emission intensity of calcium and the axial position of the specimen specified based on the emission spectra measured at a plurality of specimen axial positions of the concrete specimen. Means for calculating a regression line equation representing the relationship between the emission intensity of the carbon and the emission intensity of the calcium using the combination data; means for calculating a confidence band of the regression line; emission of the carbon Means for determining that carbonation has occurred at a measurement point whose intensity is greater than the emission intensity of the calcium and the combination of the emission intensity of the carbon and the emission intensity of the calcium is not within the confidence band of the regression line; A computer is used as means for calculating the rate at which the carbonation has occurred for each position in the axial direction of the specimen using the result of the determination. Concrete carbonation range estimation program for causing the performance. Emission spectra at a plurality of specimen axial positions of the concrete specimen are measured. Of the combined data of the chlorine or sodium emission intensity specified based on the emission spectrum and the axial position of the specimen, the concrete Using only combination data of measurement points that are not neutralized, the following formula 1

Here, I: emission intensity of chlorine or sodium [arbitrary unit],
Io: From the luminescence intensity of chlorine or sodium on the concrete surface
Luminous intensity [arbitrary unit] minus Ib,
erf: error function,
z: Specimen axial position [m],
Da: Apparent diffusion coefficient [m ² / s],
t: period [s] of exposure to salt damage environment,
Ib: Chlorine or sodium concentration is constant (including zero)
Represents the emission intensity [arbitrary unit] at the axial position of the specimen.
A method for estimating a diffusion coefficient of a target element of concrete, wherein an apparent diffusion coefficient Da is calculated by fitting the equation shown in FIG. Means for reading from the storage device the combination data of the luminescence intensity of chlorine or sodium specified based on the luminescence spectrum measured at a plurality of specimen axial positions of the concrete specimen and the specimen axial position; Using only the combination data of the measurement points where the neutralization of concrete has not occurred among the combination data, the following formula 2

Here, I: emission intensity of chlorine or sodium [arbitrary unit],
Io: From the luminescence intensity of chlorine or sodium on the concrete surface
Luminous intensity [arbitrary unit] minus Ib,
erf: error function,
z: Specimen axial position [m],
Da: Apparent diffusion coefficient [m ² / s],
t: period [s] of exposure to salt damage environment,
Ib: Chlorine or sodium concentration is constant (including zero)
Represents the emission intensity [arbitrary unit] at the axial position of the specimen.
And a means for calculating an apparent diffusion coefficient Da by fitting the equation shown in FIG. Means for reading, from a storage device, combination data of chlorine or sodium emission intensity specified based on an emission spectrum measured at a plurality of specimen axial positions of a concrete specimen, and the specimen axial position; Using only the combination data of the measurement points where the neutralization of concrete has not occurred among the combination data, the following formula 3

Here, I: emission intensity of chlorine or sodium [arbitrary unit],
Io: From the luminescence intensity of chlorine or sodium on the concrete surface
Luminous intensity [arbitrary unit] minus Ib,
erf: error function,
z: Specimen axial position [m],
Da: Apparent diffusion coefficient [m ² / s],
t: period [s] of exposure to salt damage environment,
Ib: Chlorine or sodium concentration is constant (including zero)
Represents the emission intensity [arbitrary unit] at the axial position of the specimen.
A program for estimating the diffusion coefficient of a target element of concrete for causing a computer to function as a means for calculating an apparent diffusion coefficient Da by fitting the equation shown in FIG.

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