Neutralization depth measurement method, co2 fixation amount measurement method, and neutralization depth measurement device

Abstract

To provide a method for measuring neutralization depth that can accurately measure the neutralization depth even on the horizontal surface of a concrete structure, a method for measuring the amount of CO2 fixed using the method for measuring neutralization depth, and a neutralization depth measuring device used in the method for measuring neutralization depth.SOLUTION: The method for measuring neutralization depth according to the present invention includes the following steps (1) to (3): step (1): drilling a hole in a concrete structure and sucking up the excavation powder generated by the excavation, step (2): spraying the sucked excavation powder onto a test paper that has absorbed a phenolphthalein solution and moving the test paper to change the spray position, and step (3): determining the neutralization depth by measuring the depth of the excavated hole at the time when the phenolphthalein contained in the test paper changes color.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for measuring neutralization depth, a method for measuring the amount of CO2 fixation, and a neutralization depth measuring device. [Background technology]

[0002] Carbonation depth, which is one of the durability indicators of concrete, is an index used to confirm the extent to which concrete has been neutralized from the surface to the depth of a concrete structure. One example of measuring carbonation depth is to first take a core from the concrete structure, split the core if necessary, spray a phenolphthalein solution onto the side or split surface of the core, and determine the carbonation depth as the depth from the top of the core to the point at which the phenolphthalein turns reddish-purple.

[0003] However, the above-mentioned method for measuring carbonation depth requires drilling holes directly into the concrete structure to collect cores, and since cores can only be collected from locations that do not pose a structural problem, the carbonation depth is limited. Also, for aesthetic reasons, drilling large holes in concrete structures may be avoided altogether. Therefore, various methods have been proposed to measure carbonation depth without drilling large holes in concrete structures.

[0004] For example, Non-Patent Document 1 discloses a method for determining the depth of neutralization by drilling a hole in a concrete structure using a drill, placing a test paper absorbed in a phenolphthalein solution at a position where the drilling powder produced by the drilling will fall, moving the test paper to change the contact position while allowing the drilling powder to adhere to the test paper, and measuring the depth of the drilled hole at the point when the phenolphthalein changes color. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] NDIS3419:2022 "Test method for carbonation depth of concrete structures using drilled powder" Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method described in Non-Patent Document 1 is intended to measure the sides and bottom surfaces of concrete structures, and is therefore excluded from the scope of application for horizontal surfaces such as pavement surfaces and slab top surfaces, because it is difficult to collect drilling powder from these surfaces. Therefore, there is a need for a method that can accurately measure the carbonation depth even on horizontal surfaces of concrete structures.

[0007] Furthermore, in recent years, interest in the ability to absorb and fix CO2 has been growing due to the growing momentum toward carbon neutrality. However, measuring the amount of fixed CO2 requires taking cores from the concrete structure, and the method described in Non-Patent Document 1 makes it difficult to determine the amount of fixed carbon dioxide.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and its objective is to provide a method for measuring carbonation depth that can accurately measure the carbonation depth even on horizontal surfaces of concrete structures, a method for measuring the amount of CO2 fixed using the method for measuring carbonation depth, and a carbonation depth measuring device for use in the method for measuring carbonation depth. [Means for solving the problem]

[0009] The method for measuring the carbonation depth according to the present invention is a method for measuring the carbonation depth of a concrete structure, and includes the following steps (1) to (3). Step (1): Drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color.

[0010] According to the above-described configuration, the method for measuring the depth of neutralization of the present invention involves sucking up the drilling powder produced by drilling and then spraying it onto a test paper absorbed with a phenolphthalein solution, thereby enabling the depth of neutralization to be measured accurately even on the horizontal surface of a concrete structure.

[0011] In the method for measuring neutralization depth according to the present invention, the speed at which a hole is drilled into the concrete structure may be 0.1 mm / s or more and 2.0 mm / s or less.

[0012] According to the method for measuring carbonation depth of the present invention, the method can drill a hole in a concrete structure while checking the color change of phenolphthalein, thereby enabling more accurate measurement of carbonation depth.

[0013] In the method for measuring neutralization depth according to the present invention, the speed at which the drilling powder is sprayed onto the test paper may be 15 m / s or more and 53 m / s or less.

[0014] According to the method for measuring the carbonation depth of the present invention, when the drilling powder is sprayed onto the test paper, the color of the phenolphthalein is improved, thereby enabling the carbonation depth to be measured more accurately.

[0015] The method for measuring the amount of CO2 fixation according to the present invention is a method for measuring the amount of CO2 fixation in a concrete structure, and includes the following steps (1') to (4'). Step (1'): A step of drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2'): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3'): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color. Step (4'): A step of calculating the amount of CO2 fixed using the neutralization depth according to the following formula (I):

[0016]

number

[0017] Here, in formula (I), CO 2pt : CO2 potential amount (kg / m) calculated from the following formula (II) 3 )

[0018]

number

[0019] CO 2fir : The initial amount of CO2 fixed (kg / m) calculated from the following formula (III) 3 )

[0020]

number

[0021] C: Carbonation depth (mm) Z: Thickness of concrete structure (mm)

[0022] According to the configuration of the method for measuring the amount of CO2 fixation of the present invention, the amount of CO2 fixation is calculated from the carbonation depth. This allows the amount of CO2 fixation to be measured with high accuracy without having to extract a core from the concrete structure. Furthermore, the amount of CO2 fixation can be measured more simply and quickly than methods for measuring the amount of CO2 fixation using analytical equipment (e.g., thermal analysis, etc.).

[0023] The neutralization depth measuring device of the present invention comprises a drilling section having a drill at the tip and configured to be able to drill holes in a concrete structure, a suction section that sucks up the drilling powder produced by drilling, a discharge section that discharges the sucked up drilling powder, and a test paper fixing section that is positioned forward of the discharge section in the discharge direction and is configured to be able to fix a test paper that has absorbed a phenolphthalein solution.

[0024] According to this configuration, the neutralization depth measuring device of the present invention sucks up the drilling powder generated by drilling in the drilling section using the suction section and sprays it from the discharge section onto the test paper fixed to the test paper fixing section, so that the neutralization depth can be measured accurately even on the horizontal surface of a concrete structure.

[0025] In the neutralization depth measuring device according to the present invention, the diameter of the drill in the hole-making portion may be 4 mm or more and 22 mm or less.

[0026] The carbonation depth measuring device according to the present invention has such a configuration that the diameter of the drilled hole can be made relatively small while obtaining a sufficient amount of drilling powder for relatively accurate measurement, thereby enabling the carbonation depth to be measured accurately without damaging the appearance of the concrete structure.

[0027] In the neutralization depth measuring device according to the present invention, the discharge portion may include a discharge port having an inner diameter of 6 mm or more and 50 mm or less.

[0028] According to the above-described configuration, the carbonation depth measuring device of the present invention can prevent the drilling powder from being dispersed around the test paper when spraying the drilling powder onto the test paper, thereby enabling more accurate measurement of the carbonation depth. [Effects of the Invention]

[0029] According to the present invention, it is possible to provide a method for measuring carbonation depth that can accurately measure the carbonation depth even on horizontal surfaces of concrete structures, a method for measuring the amount of CO2 fixed using the method for measuring carbonation depth, and a carbonation depth measuring device used in the method for measuring carbonation depth. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a graph showing the correlation between the carbonation depth obtained by the carbonation depth measurement method according to the present invention in an example and the carbonation depth obtained by a method in accordance with JIS A 1152. [Figure 2] FIG. 2 is a graph showing the correlation between the amount of CO2 fixed obtained by the method for measuring the amount of CO2 fixed according to the present invention in the examples and the amount of CO2 fixed obtained by thermal analysis. DETAILED DESCRIPTION OF THE INVENTION

[0031] The method for measuring the neutralization depth, the method for measuring the amount of fixed CO2, and the neutralization depth measuring device according to this embodiment will be described below.

[0032] (Method for measuring carbonation depth) The method for measuring the carbonation depth according to this embodiment is a method for measuring the carbonation depth of a concrete structure, and includes the following steps (1) to (3). Step (1): Drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color.

[0033] <Process (1)> In step (1), holes are drilled in a concrete structure, and the drilling powder generated by the drilling is suctioned. From the viewpoint of improving work efficiency, drilling and suction are preferably performed continuously. That is, in one embodiment of step (1), holes are drilled in a concrete structure, and the drilling powder generated by the drilling is suctioned.

[0034] The speed at which holes are drilled into the concrete structure (hereinafter referred to as the drilling speed) is preferably 0.1 mm / s or more and 2.0 mm / s or less, and more preferably 0.5 mm / s or more and 1.5 mm / s or less, from the viewpoint of drilling the concrete structure while checking the color change of phenolphthalein.

[0035] The air volume for sucking the drilling powder (hereinafter referred to as the dust collection volume) is not particularly limited, and may be, for example, 0.04 m 3 / s or more 10.0m 3 / s or less, 0.05m 3 / s or more 3.0m 3 / s or less.

[0036] The location to be drilled may be a horizontal surface of the concrete structure, or may be, for example, a side surface or bottom surface of the concrete structure.

[0037] <Process (2)> In step (2), the drilling powder sucked in in step (1) is sprayed onto a test paper that has absorbed a phenolphthalein solution, while the test paper is moved to change the spraying position.

[0038] To absorb the phenolphthalein solution into the test paper, a method of spraying the phenolphthalein solution onto the test paper using a sprayer or the like can be used. The phenolphthalein solution may be prepared by dissolving 1.0 g of phenolphthalein in 90 mL of ethanol (95%) and adding water to make a total volume of 100 mL. This method can be performed in accordance with NDIS3419:2022 "Test method for carbonation depth of concrete structures using drilled powder."

[0039] It is also preferable that the test paper is used in a state where it is sufficiently wetted with the phenolphthalein solution.

[0040] The speed at which the drilling powder is sprayed onto the test paper (hereinafter referred to as the spraying speed) is preferably 15 m / s or more and 53 m / s or less, and more preferably 20 m / s or more and 45 m / s or less, from the viewpoint of preventing the drilling powder from diffusing around the test paper.

[0041] Examples of test papers include filter paper and absorbent paper specified in JIS P 3801.

[0042] The shape of the test paper may be, for example, circular, angular, etc. When the test paper is circular, the spray position can be changed by rotating the test paper in the circumferential direction.

[0043] When the test paper is circular, the diameter of the test paper may be, for example, 110 mm or more and 600 mm or less, or 185 mm or more and 360 mm or less.

[0044] <Process (3)> In step (3), the depth of the drilled hole is measured at the time when the phenolphthalein contained in the test paper changes color, thereby determining the neutralization depth.

[0045] The depth of the drilled hole can be measured using, for example, a vernier caliper equipped with a depth bar, a laser displacement meter, a general-purpose displacement meter, or the like.

[0046] The above steps (1) to (3) may be carried out continuously.

[0047] The method for measuring the carbonation depth according to this embodiment comprises the above steps (1) to (3), in which the drilling powder generated by drilling is sucked up and then sprayed onto a test paper absorbed with a phenolphthalein solution, thereby enabling the carbonation depth to be measured accurately even on the horizontal surface of a concrete structure.

[0048] (Method for measuring CO2 fixation) In one aspect, the method for measuring the amount of CO2 fixation according to this embodiment is a method for measuring the amount of CO2 fixation in a concrete structure, and includes the following steps (1') to (4'). Step (1'): A step of drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2'): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3'): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color. Step (4'): A step of calculating the amount of CO2 fixed using the neutralization depth according to the following formula (I):

[0049]

number

[0050] Here, in formula (I), CO 2pt : CO2 potential amount (kg / m) calculated from the following formula (II) 3 )

[0051]

number

[0052] CO 2fir : The initial amount of CO2 fixed (kg / m) calculated from the following formula (III) 3 )

[0053]

number

[0054] C: Carbonation depth (mm) Z: Thickness of concrete structure (mm)

[0055] Steps (1') to (3') are the same as steps (1) to (3) in the method for measuring the carbonation depth according to this embodiment.

[0056] <Process (4')> In step (4'), the amount of CO2 fixed is calculated from the neutralization depth using the following formula (I).

[0057]

number

[0058] Here, in formula (I), CO 2pt : CO2 potential amount (kg / m) calculated from the following formula (II) 3 )

[0059]

number

[0060] CO 2fir : The initial amount of CO2 fixed (kg / m) calculated from the following formula (III) 3 )

[0061]

number

[0062] C: Carbonation depth (mm) Z: Thickness of concrete structure (mm)

[0063] The cement is not particularly limited, and examples thereof include Portland cements such as ordinary Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, moderate-heat Portland cement, sulfate-resistant Portland cement, and white Portland cement, as defined in JIS R 5210:2019; mixed cements such as blast-furnace cement, fly ash cement, and silica cement; and known cements such as ultra-high-speed hardening cement and alumina cement.

[0064] The CaO content in cement can be measured using an X-ray fluorescence analyzer (for example, ZSX Primus IV manufactured by Rigaku Corporation) according to the method specified in JIS R 5204:2019.

[0065] The thickness of the concrete structure may be, for example, a value stated in the construction drawings, specifications, etc. of the concrete structure, or a value determined by non-destructive testing (for example, electromagnetic induction method, electromagnetic wave radar method, impact elastic wave method, etc.).

[0066] Another aspect of the method for measuring the amount of CO2 fixation according to this embodiment is a method for measuring the amount of CO2 fixation in a concrete structure, and includes the following steps (1') to (4'). Step (1'): A step of drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2'): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3'): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color. Step (4'): A step of calculating the amount of CO2 fixed using the neutralization depth according to the following formula (I'):

[0067]

number

[0068] Here, in formula (I'), CO 2pt : CO2 potential amount (kg / m) calculated from the following formula (II) 3 )

[0069]

number

[0070] CO2fir : The initial amount of CO2 fixed (kg / m) calculated from the following formula (III) 3 )

[0071]

number

[0072] r: Carbonation C: Carbonation depth (mm) Z: Thickness of concrete structure (mm)

[0073] Hereinafter, differences from the method for measuring the amount of fixed CO2 according to one aspect of the above embodiment will be described.

[0074] In step (4'), the amount of CO2 fixed is calculated from the following formula (I') using the neutralization depth.

[0075]

number

[0076] Here, in formula (I'), r: Carbonation and CO 2pt , CO 2pt , C and Z are the same as those in formula (I) above.

[0077] Here, the carbonation degree is an index showing the rate at which CaO contained in cement is converted to calcium carbonate through carbonation. The carbonation degree can be changed depending on the actual conditions of the concrete structure, such as the type of cement, the location where the carbonation depth is measured, the environmental conditions during carbonation (e.g., temperature, humidity, whether or not it is exposed to rain, etc.), the period of carbonation, the water-cement ratio of the concrete, the porosity of the concrete, and the age of the concrete.

[0078] The carbonation level may be a value given in the literature.

[0079] In the above formula (I'), by including the degree of carbonation as a parameter, the amount of CO2 fixation can be calculated more accurately, taking into account the actual conditions of the concrete structure.

[0080] The method for measuring the amount of CO2 fixation according to this embodiment includes the steps (1') to (4') described above, and therefore the amount of CO2 fixation can be measured accurately without taking cores from the concrete structure, since the amount of CO2 fixation is calculated from the carbonation depth. Furthermore, the amount of CO2 fixation can be measured more simply and quickly than methods for measuring the amount of CO2 fixation using analytical equipment (for example, thermal analysis, etc.).

[0081] (Neutralization depth measuring device) The neutralization depth measuring device according to this embodiment includes a hole drilling section, a suction section, a discharge section, and a test paper fixing section.

[0082] The hole-boring portion has a drill at its tip and is configured to be able to bore holes in concrete structures.

[0083] The diameter of the drill in the hole-drilling section is preferably 4 mm or more and 22 mm or less, more preferably 10 mm or more and 18 mm or less, from the viewpoint of obtaining a sufficient amount of drilling powder for relatively accurate measurement while keeping the diameter of the hole formed by drilling relatively small.

[0084] The suction section sucks up drilling powder generated by drilling.

[0085] The suction section has a suction port that sucks the drilling powder, and the inner diameter of the suction port may be, for example, 6 mm or more and 50 mm or less, or 23 mm or more and 35 mm or less.

[0086] From the viewpoint of efficiently collecting the drilling powder, the suction unit preferably has a suction port provided near the hole formed by drilling. Note that the vicinity of the hole formed by drilling means the area up to 30 mm from the outer periphery of the hole.

[0087] The discharge portion discharges the sucked drilling powder.

[0088] The discharge part has a discharge port for discharging the drilling powder. The inner diameter of the discharge port is preferably 6 mm or more and 50 mm or less, more preferably 6 mm or more and 23 mm or less, from the viewpoint of preventing the drilling powder from being dispersed around the test paper when sprayed onto the test paper.

[0089] In the neutralization depth measuring device according to this embodiment, the suction unit and the discharge unit may be integrally configured. Examples of the tool having the suction unit and the discharge unit integrally configured include a blower, a blower vacuum, and a vacuum cleaner with a blower function.

[0090] The test paper fixing part is located forward of the discharge part in the discharge direction and is configured to be able to fix a test paper that has absorbed a phenolphthalein solution.

[0091] The test paper fixing part is configured so that the spray position can be changed after fixing the test paper.

[0092] The carbonation depth measuring device according to this embodiment is used in the carbonation depth measuring method according to the embodiment described above.

[0093] Specifically, in step (1) of the method for measuring neutralization depth according to this embodiment, a hole is drilled in a concrete structure using the drilling section, and the drilling powder generated by the drilling is sucked up using the suction section.

[0094] In addition, in step (2) of the method for measuring neutralization depth according to this embodiment, the drilling powder sucked by the suction part is sprayed by the discharge part onto the test paper fixed by the test paper fixing part, while the test paper is moved to change the spraying position.

[0095] The carbonation depth measuring device of this embodiment is equipped with the above-mentioned hole drilling section, suction section, discharge section, and test paper fixing section, so that the drilling powder generated by drilling in the hole drilling section is sucked in by the suction section and sprayed from the discharge section onto the test paper fixed to the test paper fixing section, thereby making it possible to accurately measure the carbonation depth even on the horizontal surface of a concrete structure.

[0096] The method for measuring carbonation depth, the method for measuring the amount of CO2 fixation, and the carbonation depth measuring device according to the present embodiment are not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. Furthermore, configurations, methods, etc. of embodiments other than those described above may be arbitrarily adopted and combined, and configurations, methods, etc. of one embodiment described above may be applied to configurations, methods, etc. of other embodiments described above.

[0097] The present invention includes the following aspects. [1] A method for measuring the carbonation depth of a concrete structure, comprising the following steps (1) to (3): Step (1): Drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color. [2] A method for measuring neutralization depth described in [1], in which the drilling speed into the concrete structure is 0.1 mm / s or more and 2.0 mm / s or less. [3] A method for measuring neutralization depth described in [1] or [2], wherein the speed at which the drilling powder is sprayed onto the test paper is 15 m / s or more and 53 m / s or less. [4] A method for measuring the amount of CO2 fixed in a concrete structure, comprising the following steps (1') to (4'): Step (1'): A step of drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2'): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3'): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color. Step (4'): A step of calculating the amount of CO2 fixed using the neutralization depth according to the following formula (I):

number

number

number

[0098] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0099] [Test 1: Evaluation of neutralization depth and CO2 fixation amount] <Examples 1 to 40> (Preparation of concrete specimens) Using the materials shown in Table 1 and according to the mix proportions shown in Table 2, concrete compositions Nos. 1 to 9 were obtained.

[0100] Specifically, cement, fine aggregate, and coarse aggregate were first dry-mixed for 15 seconds using a forced mixing twin-shaft mixer, and then water and admixtures were added and mixed for 60 seconds to obtain each concrete composition.

[0101] Each concrete composition obtained was poured into a 10 cm x 10 cm x 40 cm formwork, and then demolded the next day. The concrete specimens were subjected to accelerated carbonation to the specified ages listed in Table 3 in accordance with the method specified in JIS A 1153, thereby obtaining concrete specimens for each example. Each concrete specimen was then used to evaluate the carbonation depth and the amount of CO2 fixation described below.

[0102] [Table 1]

[0103] [Table 2]

[0104] (Evaluation of neutralization depth) The horizontal surface of the concrete specimen for each example was drilled in the thickness direction at a drilling speed of 1.0 to 2.0 mm / s using an electric drill (Makita Corporation HR2601F, drill diameter 10 mm). The drilled powder was sucked using a blower (Makita Corporation UB144D, outlet inner diameter 6 mm) while a circular filter paper (diameter: 185 mm, area: 26880.3 mm) soaked in phenolphthalein solution was placed at the outlet of the blower.2 The test paper was sprayed at a discharge speed of 35 m / s using filter paper specified in JIS P 3801 (prepared in accordance with NDIS3419:2022 "Test Method for Carbonation Depth of Concrete Structures Using Drilling Powder"). The test paper was rotated circumferentially while the drilling powder was sprayed onto it. When the phenolphthalein contained in the test paper turned reddish-purple, drilling was stopped, and the depth of the hole formed at the top of the concrete specimen was measured. The measured value was used as the carbonation depth. This procedure was repeated at five points on the horizontal surface of the concrete specimen, and the average carbonation depth measured at each of the five points was calculated. The results are shown in Table 3. The thickness direction refers to the direction toward the bottom surface of the concrete specimen, with the horizontal surface considered to be the top surface.

[0105] In addition, the carbonation depth of the concrete specimens of each example was measured using a method in accordance with JIS A 1152. The average carbonation depth measured at each of the five points was calculated in the same manner as above, and compared with the average carbonation depth obtained using the above method. The results are shown in Table 3.

[0106] (Evaluation of CO2 fixation amount) Using the average value of the carbonation depth obtained above, the amount of CO2 fixed in the concrete specimen of each example was calculated from the following formula (I). The results are shown in Table 3.

[0107]

number

[0108] Here, in formula (I), CO 2pt : CO2 potential amount (kg / m) calculated from the following formula (II) 3 )

[0109]

number

[0110] CO 2fir: The initial amount of CO2 fixed (kg / m) calculated from the following formula (III) 3 )

[0111]

number

[0112] C: Carbonation depth (mm) Z: Thickness of concrete specimen (mm)

[0113] In addition, after crushing the entire concrete specimens of each example, the amount of CO2 fixation was measured by simultaneous thermogravimetry and differential thermal analysis (thermal analysis) using a STA 2500 (TG-DTA simultaneous measurement device; manufactured by NETZSCH Japan). The results are shown in Table 3.

[0114] [Table 3]

[0115] [Drilling speed] <Examples 41 to 42> Using the concrete specimens of Example 7 in Test 1, the carbonation depth was determined in the same manner as in Test 1, except that the drilling speeds shown in Table 4 were used. The carbonation depth was compared with the carbonation depth determined using the concrete specimens in accordance with JIS A 1152, and evaluated as follows. The drilling speed was measured using a laser displacement meter (LD080PI, manufactured by Makita Corporation). The results are shown in Table 4. ○: The difference from the JIS method was less than 5 mm. ×: The difference from the JIS method was 5 mm or more.

[0116] [Table 4]

[0117] [Inner diameter of blower outlet] <Examples 43 to 45> Using the concrete specimen of Example 7 in Test 1, drilling powder was discharged in the same manner as Test 1, except that the inner diameter of the blower outlet (hereinafter referred to as the outlet inner diameter) was set as shown in Table 5. The test paper was observed to see if the phenolphthalein contained therein turned a reddish-purple color. The diameter of the drilling powder sprayed onto the filter paper (hereinafter referred to as the drilling powder diameter) was measured, and the difference between the diameter of the drilling powder and the outlet inner diameter was calculated as the diffusion distance of the drilling powder. Based on the diffusion distance of the drilling powder, the coloration of the phenolphthalein was evaluated as follows. The outlet inner diameter was adjusted by attaching an attachment with a corresponding inner diameter to the blower outlet. The results are shown in Table 5. ◎: The diffusion distance of the drilling powder was less than 5 mm, and the diffusion of the drilling powder was relatively small, so a clearer color change was confirmed. ○: The diffusion distance of the drilling powder was 5 mm or more, and the diffusion of the drilling powder was relatively large, so sparse and light coloring was confirmed. ×: No color change was observed.

[0118] [Table 5]

[0119] [Discharge speed] <Examples 46 to 52> Using the concrete specimen of Example 7 in Test 1, drilling powder was discharged in the same manner as Test 1, except that the discharge rate was set as shown in Table 6. The phenolphthalein contained in the test paper was observed to turn reddish-purple, and the results were evaluated as follows. The wind speed was measured using a multi-function anemometer (KANOMAX CLIMOMASTER; 6501-00). The results are shown in Table 6. ○: Coloration was confirmed. ×: No color change was observed.

[0120] [Table 6]

[0121] As can be seen from Table 3 and Figure 1, the carbonation depth obtained by the carbonation depth measurement method of the present invention showed results comparable to those obtained by the method conforming to JIS A 1152. This shows that the carbonation depth measurement method of the present invention can accurately measure the carbonation depth even on the horizontal surface of a concrete structure.

[0122] Furthermore, as can be seen from Table 3 and Figure 2, the CO2 fixation amount obtained by the CO2 fixation amount evaluation method according to the present invention was comparable to the CO2 fixation amount obtained by simultaneous thermogravimetry and differential thermal analysis. This shows that the CO2 fixation amount measurement method according to the present invention can accurately measure the CO2 fixation amount without having to extract cores from the concrete structure. Furthermore, the CO2 fixation amount can be measured more simply and quickly than methods using analytical equipment (such as thermal analysis).

[0123] Furthermore, as can be seen from Table 4, the carbonation depth measuring method according to the present invention can measure the carbonation depth more accurately by setting the drilling speed to 0.1 mm / s or more and 2.0 mm / s or less.

[0124] Furthermore, as can be seen from Table 5, the method for measuring carbonation depth according to the present invention can measure the carbonation depth with higher accuracy by setting the inner diameter of the discharge portion to 6 mm or more and 50 mm or less.

[0125] Furthermore, as can be seen from Table 6, the method for measuring the carbonation depth according to the present invention can measure the carbonation depth more accurately by setting the discharge velocity to 15 m / s or more and 53 m / s or less.

Claims

1. A method for measuring the carbonation depth of a concrete structure, comprising the following steps (1) to (3): Step (1): A step of drilling a hole in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color.

2. A method for measuring carbonation depth as described in claim 1, wherein the speed of drilling into the concrete structure is 0.1 mm / s or more and 2.0 mm / s or less.

3. 3. A method for measuring carbonation depth according to claim 1 or 2, wherein the speed at which the drilling powder is sprayed onto the test paper is 15 m / s or more and 53 m / s or less.

4. CO in concrete structures ２ A method for measuring the amount of immobilization of CO, comprising the following steps (1') to (4'): ２ How to measure the amount of fixation. Step (1'): A step of drilling holes in a concrete structure and suctioning the drilling powder generated by the drilling. Step (2'): A step of spraying the sucked drilling powder onto a test paper that has absorbed a phenolphthalein solution, and moving the test paper to change the spraying position. Step (3'): A step of determining the carbonation depth by measuring the depth of the drilled hole at the time when the phenolphthalein contained in the test paper changes color. Step (4'): Using the neutralization depth, CO is calculated from the following formula (I): ２ Process for determining fixed amount [Equation 1] Here, in formula (I), CO ２ｐｔ : CO calculated from the following formula (II) ２ Potential amount (kg / m ３ ) [Equation 2] CO ２ｆｉｒ : Initial CO calculated from the following formula (III) ２ Fixed amount (kg / m ３ ) [Equation 3] C: Carbonation depth (mm) Z: Thickness of concrete structure (mm)

5. a drilling unit having a drill at a tip and configured to be able to drill holes in a concrete structure; a suction unit that sucks up drilling powder generated by drilling; a discharge unit that discharges the sucked drilling powder; a test paper fixing part located forward of the discharge part in the discharge direction and configured to fix a test paper that has absorbed a phenolphthalein solution; A neutralization depth measuring device comprising:

6. The carbonation depth measuring device according to claim 5 , wherein the diameter of the drill in the hole-drilling portion is 4 mm or more and 22 mm or less.

7. The neutralization depth measuring device according to claim 5 or 6, wherein the discharge portion has a discharge port having an inner diameter of 6 mm or more and 50 mm or less.

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