Device for monitoring amount of co2 fixed to hydraulic hardened body, method for monitoring amount of co2 fixed to hydraulic hardened body, carbonation curing system for hydraulic hardened body, and method for monitoring amount of co2 fixed to hydraulic hardened body in system

Abstract

To provide a device and a method capable of monitoring a CO2 fixed amount of a hydraulic hardened body by an inexpensive and simple method, a carbonation curing system for the hydraulic hardened body, and a CO2 fixed amount monitoring method therefor.SOLUTION: The monitoring device includes a first tank that contains a first hydraulic hardened body and can be supplied with a first carbon dioxide-containing gas having a CO2 concentration of 0.5% or more, a second tank that contains a second hydraulic hardened body that is the same as the first hydraulic hardened body and can be supplied with a second gas having a CO2 concentration of less than 0.1%, a mass variation measuring unit that measures a mass variation of the first hydraulic hardened body and a mass variation of the second hydraulic hardened body when the first carbon dioxide-containing gas is supplied to the first tank and the second gas is supplied to the second tank, and a CO2 fixation amount calculating unit that calculates a mass difference between the mass variation of the first hydraulic hardened body and the mass variation of the second hydraulic hardened body measured by the mass variation measuring unit and measures a CO2 fixation amount of the first hydraulic hardened body based on the mass difference.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a device for monitoring the amount of CO2 fixation in a hydraulically hardened body, a method for monitoring the amount of CO2 fixation, a carbonation curing system for a hydraulically hardened body, and a method for monitoring the amount of CO2 fixation in the system. [Background technology]

[0002] Various CO2 reduction technologies are being investigated in order to achieve a carbon-neutral society by 2050. Among these, great expectations are being placed on the potential of technologies related to CO2 absorption and fixation in hydraulic hardened materials such as concrete.

[0003] For hydraulic hardened bodies that absorb and fix CO2 (hereinafter collectively referred to as CO2 fixation), it is of great value to know how much CO2 has been absorbed and fixed in the hydraulic hardened body. For this reason, methods such as differential thermogravimetric analysis and inorganic carbon analysis have been published mainly in papers as methods for measuring the amount of CO2 fixed in hydraulic hardened bodies.

[0004] However, tests such as differential thermogravimetric analysis and inorganic carbon analysis have various disadvantages, including the need for specialized and expensive measurement equipment, the time-consuming and labor-intensive pretreatment of hydraulically hardened concrete to allow measurement of CO2 fixation in the hardened concrete, the need for advanced expertise and techniques for these tests, measurement equipment, and pretreatment methods, the high costs of outsourcing these tests, and the fact that these tests are destructive, meaning that the hardened concrete used for the measurements is destroyed and discarded. Furthermore, even if the carbonation curing of a hydraulically hardened concrete is determined to be complete after a specified period of time has elapsed, the destructive test results may reveal that the hardened concrete did not achieve the target CO2 fixation amount due to, for example, changes in CO2 concentration during curing. To avoid these problems, measures such as extending the carbonation curing period beyond what is necessary result in significant productivity losses.

[0005] Due to these issues, it takes a great deal of effort and cost to measure the amount of CO2 fixed by hydraulic hardened materials in order to obtain CO2 credits or certification from public institutions for hydraulic hardened materials that fix CO2.

[0006] Patent Document 1 also describes a concrete manufacturing method including a carbon dioxide supply amount calculation step of calculating the amount of carbon dioxide to be supplied to the enclosed space, an outflow carbon dioxide amount calculation step of calculating the amount of carbon dioxide that flows out from the enclosed space, and a carbon dioxide fixation amount calculation step of calculating the amount of carbon dioxide fixed in the cured concrete based on the amount of carbon dioxide calculated in the carbon dioxide supply amount calculation step and the amount of carbon dioxide calculated in the outflow carbon dioxide amount calculation step.

[0007] The manufacturing method of Patent Document 1 requires accurate measurement of the amount of carbon dioxide supplied to the sealed space and the amount of carbon dioxide that flows out from the sealed space. Therefore, although the above manufacturing method makes it possible to grasp the amount of carbon dioxide fixed in the concrete undergoing carbonation curing in real time, there is room for improvement in terms of simplicity. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2023-180952 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a device and method for monitoring the amount of CO2 fixation in hydraulic hardened bodies, which can monitor the amount of CO2 fixation in hydraulic hardened bodies in an inexpensive and simple manner, as well as a carbonation curing system for hydraulic hardened bodies and a method for monitoring the amount of CO2 fixation in such a system. [Means for solving the problem]

[0010] [1] A CO2 fixation monitoring device for a hydraulic hardened body, comprising: a first curing tank for accommodating a first hydraulic hardened body therein and capable of supplying a first carbon dioxide-containing gas having a CO2 concentration of 0.5% or more therein; a second curing tank for accommodating a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body therein and capable of supplying a second gas having a CO2 concentration of less than 0.1% therein; a mass change measuring unit for measuring a mass change of the first hydraulic hardened body and a mass change of the second hydraulic hardened body while the first carbon dioxide-containing gas is being supplied to the first curing tank and the second gas is being supplied to the second curing tank; and a CO2 fixation amount calculating unit for calculating a mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured by the mass change measuring unit and measuring the amount of CO2 fixation of the first hydraulic hardened body based on the mass difference. [2] The CO2 fixation amount monitoring device for hydraulic hardened bodies described in [1] above, wherein the CO2 concentration of the first carbon dioxide-containing gas is 5.0% or more higher than the CO2 concentration of the second gas. [3] A method for monitoring the amount of CO2 fixation in a hydraulic hardened body, the method comprising: a mass change measuring step of measuring a mass change of a first hydraulic hardened body and a mass change of a second hydraulic hardened body, while supplying a first carbon dioxide-containing gas having a CO2 concentration of 0.5% or more into a first curing tank containing a first hydraulic hardened body and supplying a second gas having a CO2 concentration of less than 0.1% into a second curing tank containing a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body; and a CO2 fixation amount calculating step of calculating a mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured in the mass change measuring step, and measuring the amount of CO2 fixation of the first hydraulic hardened body based on the mass difference. [4] A carbonation curing tank that accommodates a hydraulic hardened body inside and is capable of supplying a carbon dioxide-containing gas having a CO2 concentration of 0.5% or more inside; a first curing tank that accommodates a first hydraulic hardened body that is the same as or substantially the same as the hydraulic hardened body inside and is capable of supplying a first carbon dioxide-containing gas having the same or substantially the same CO2 concentration as the carbon dioxide-containing gas inside; a second curing tank that accommodates a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body inside and is capable of supplying a second gas having a CO2 concentration of less than 0.1% inside; a mass change measuring unit that measures a mass change of the first hydraulic hardened body and a mass change of the second hydraulic hardened body while the first carbon dioxide-containing gas is supplied to the first curing tank and the second gas is supplied to the second curing tank; and a CO2 fixation amount calculating unit that calculates a mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured by the mass change measuring unit and measures an amount of CO2 fixation of the hydraulic hardened body based on the mass difference. [5] A method for monitoring the amount of CO2 fixation in a carbonation curing system for hydraulic hardened bodies, the method comprising: a mass change measuring step of measuring a mass change of a first hydraulic hardened body and a mass change of a second hydraulic hardened body, the mass changes being measured while a carbon dioxide-containing gas having a CO2 concentration of 0.5% or more is supplied into a carbonation curing tank accommodating a hydraulic hardened body, the first hydraulic hardened body being the same as or substantially the same as the hydraulic hardened body, a first carbon dioxide-containing gas having the same or substantially the same CO2 concentration as the carbon dioxide-containing gas is supplied into a first curing tank accommodating a first hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body, and a second gas having a CO2 concentration of less than 0.1% is supplied into a second curing tank accommodating a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body; and a CO2 fixation amount calculating step of calculating a mass difference between the mass changes of the first hydraulic hardened body and the second hydraulic hardened body measured in the mass change measuring step, and measuring the amount of CO2 fixation of the hydraulic hardened body based on the mass difference. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a CO2 fixation amount monitoring device for hydraulic hardened bodies and a CO2 fixation amount monitoring method therefor, which can monitor the CO2 fixation amount of hydraulic hardened bodies in an inexpensive and simple manner, as well as a carbonation curing system for hydraulic hardened bodies and a method for monitoring the CO2 fixation amount within the system. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an example of a device for monitoring the amount of CO2 fixation in a hydraulically hardened body according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of a carbonation curing system for a hydraulic hardened body according to an embodiment. [Figure 3] FIG. 3 is a schematic diagram showing an example of the appearance of a carbonation curing system for a hydraulic hardened body according to an embodiment. [Figure 4] FIG. 4 is a graph showing the relationship between the curing time and the mass increase rate in Examples 1 to 3. [Figure 5] FIG. 5 is a graph showing the relationship between the amount of CO2 fixed obtained in Examples 1 to 3 and the amount of CO2 fixed obtained in Comparative Examples 1 to 3. [Figure 6] FIG. 6 is a graph showing the difference between the measurement results of the amount of CO2 fixed obtained in Comparative Examples 1 to 3 and the measurement results of the amount of CO2 fixed obtained in Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a detailed description will be given based on an embodiment.

[0014] The CO2 fixation amount monitoring device for hydraulic hardened bodies of the present invention includes a first curing tank that houses a first hydraulic hardened body and is capable of supplying a first carbon dioxide-containing gas having a CO2 concentration of 0.5% or more into the tank; a second curing tank that houses a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body and is capable of supplying a second gas having a CO2 concentration of less than 0.1% into the tank; a mass change measuring unit that measures the mass changes of the first hydraulic hardened body and the second hydraulic hardened body while the first carbon dioxide-containing gas is being supplied to the first curing tank and the second gas is being supplied to the second curing tank; and a CO2 fixation amount calculating unit that calculates the mass difference between the mass changes of the first hydraulic hardened body and the second hydraulic hardened body measured by the mass change measuring unit and measures the amount of CO2 fixation of the first hydraulic hardened body based on the mass difference.

[0015] The method for monitoring the amount of CO2 fixation in a hydraulic hardened body of the present invention includes a mass change measuring step of measuring the mass change of a first hydraulic hardened body and the mass change of a second hydraulic hardened body while supplying a first carbon dioxide-containing gas with a CO2 concentration of 0.5% or more into a first curing tank containing a first hydraulic hardened body and a second gas with a CO2 concentration of less than 0.1% into a second curing tank containing a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body; and a CO2 fixation amount calculating step of calculating the mass difference between the mass changes of the first hydraulic hardened body and the second hydraulic hardened body measured in the mass change measuring step and measuring the amount of CO2 fixation of the first hydraulic hardened body based on the mass difference.

[0016] The carbonation curing system for hydraulic hardened bodies of the present invention includes a carbonation curing tank that accommodates a hydraulic hardened body therein and is capable of supplying a carbon dioxide-containing gas having a CO2 concentration of 0.5% or more therein, a first curing tank that accommodates a first hydraulic hardened body that is the same as or substantially the same as the hydraulic hardened body therein and is capable of supplying a first carbon dioxide-containing gas having the same or substantially the same CO2 concentration as the carbon dioxide-containing gas therein, and a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body therein and is capable of supplying a second carbon dioxide-containing gas having a CO2 concentration of less than 0.1% therein. The apparatus includes a second curing tank capable of supplying gas therein, a mass change measuring unit that measures the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body while a carbon dioxide-containing gas is being supplied to the carbonation curing tank, a first carbon dioxide-containing gas is being supplied to the first curing tank, and a second gas is being supplied to the second curing tank, and a CO2 fixation amount calculating unit that calculates the mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured by the mass change measuring unit and measures the amount of CO2 fixation in the hydraulic hardened body based on the mass difference.

[0017] The method for monitoring the amount of CO2 fixation in a carbonation curing system for hydraulic hardened bodies of the present invention includes a mass change measuring step of measuring a mass change of a first hydraulic hardened body and a mass change of a second hydraulic hardened body while supplying a carbon dioxide-containing gas with a CO2 concentration of 0.5% or more into a carbonation curing tank containing the hydraulic hardened body, supplying a first carbon dioxide-containing gas with the same or substantially the same CO2 concentration as the carbon dioxide-containing gas into a first curing tank containing a first hydraulic hardened body that is the same or substantially the same as the hydraulic hardened body, and supplying a second gas with a CO2 concentration of less than 0.1% into a second curing tank containing a second hydraulic hardened body that is the same or substantially the same as the first hydraulic hardened body, and a CO2 fixation amount calculating step of calculating the mass difference between the mass changes of the first hydraulic hardened body and the second hydraulic hardened body measured in the mass change measuring step and measuring the amount of CO2 fixation of the hydraulic hardened body based on the mass difference.

[0018] Fig. 1 is a schematic diagram showing an example of a CO2 fixation amount monitoring device for a hydraulically hardened body according to an embodiment. As shown in Fig. 1, the CO2 fixation amount monitoring device for a hydraulically hardened body (hereinafter simply referred to as a CO2 fixation amount monitoring device) 1 includes a first curing tank 11, a second curing tank 12, a mass change measuring unit 20, and a CO2 fixation amount calculating unit 30.

[0019] The first curing tank 11 constituting the CO2 fixation amount monitoring device 1 accommodates a first hydraulic hardened material H1 therein. The first hydraulic hardened material H1 is a hydraulic hardened material such as concrete or mortar. The internal space of the first curing tank 11 is a space sealed from the outside of the first curing tank 11.

[0020] The first curing tank 11 can be supplied with a first carbon dioxide-containing gas G1 having a CO2 concentration of 0.5% or more. The first carbon dioxide-containing gas G1 is supplied from a first supply unit 11a provided in the first curing tank 11. For example, the first carbon dioxide-containing gas G1 is carbon dioxide gas (undiluted carbon dioxide gas) or a gas obtained by diluting carbon dioxide gas with air or N2 gas. Since the CO2 concentration of the first carbon dioxide-containing gas G1 is 0.5% or more, when the first carbon dioxide-containing gas G1 is supplied into the first curing tank 11, the inside of the first curing tank 11 becomes an atmosphere in which the first hydraulic hardened body H1 is carbonation cured.

[0021] The first curing tank 11 is provided with an exhaust unit (not shown) that exhausts gas inside the first curing tank 11 to the outside of the first curing tank 11. Furthermore, inside the first curing tank 11, a control unit (not shown) that controls the temperature and humidity inside the first curing tank may be provided.

[0022] The second curing tank 12 of the CO2 fixation amount monitoring device 1 accommodates the second hydraulic hardened body H2 therein. The internal space of the second curing tank 12 is a space sealed from the outside of the second curing tank 12.

[0023] The second curing tank 12 can be supplied with a second gas G2 having a CO2 concentration of less than 0.1%. The second gas G2 is supplied from a second supply unit 12a provided in the second curing tank 12. Since the second gas G2 has a CO2 concentration of less than 0.1%, it is not a gas that intentionally contains CO2, i.e., a carbon dioxide-containing gas. For example, the second gas G2 is a gas such as N2 gas or air that contains no or a trace amount of CO2. Since the CO2 concentration of the second gas G2 is less than 0.1%, even if the second gas G2 is supplied into the second curing tank 12, the atmosphere inside the second curing tank 12 does not become one in which the second hydraulic hardened body H2 is carbonation-cured, as compared to the first curing tank 11.

[0024] The second curing tank 12 is provided with an exhaust unit (not shown) that exhausts gas inside the second curing tank 12 to the outside of the second curing tank 12. In addition, the second curing tank 12 may be provided with a control unit (not shown) inside that controls the temperature and humidity inside the second curing tank.

[0025] The first hydraulic hardened body H1 provided in the first curing tank 11 is the same as or substantially the same as the second hydraulic hardened body H2 provided in the second curing tank 12. "The first hydraulic hardened body H1 is the same as the second hydraulic hardened body H2" means that the factors affecting carbonation of the first hydraulic hardened body H1, such as the material, configuration, shape, dimensions, quantity, and age, are the same as those of the second hydraulic hardened body H2, including the range of variation. "The first hydraulic hardened body H1 is substantially the same as the second hydraulic hardened body H2" means that the factors affecting carbonation of the first hydraulic hardened body H1 may be different from those of the second hydraulic hardened body H2, including the range of variation, to the extent that the amount of CO2 fixation of the first hydraulic hardened body H1 can be monitored by the CO2 fixation amount monitoring device 1.

[0026] 1 and the following FIG. 2, the number of first hydraulic hardened bodies H1 provided in the first curing tank 11 is one, but the number of first hydraulic hardened bodies H1 is not particularly limited and may be multiple. Similarly, the number of second hydraulic hardened bodies H2 provided in the second curing tank 12 may be one or multiple.

[0027] Furthermore, the first curing tank 11 is the same as or substantially the same as the second curing tank 12. The first curing tank 11 being the same as the second curing tank 12 means that the factors affecting carbonation of the first curing tank 11, such as the temperature, humidity, volume, and configuration of the supply unit, are the same as those of the second curing tank 12, including the range of variation. The first curing tank 11 being substantially the same as the second curing tank 12 means that the factors affecting carbonation of the first curing tank 11 may be different from those of the second curing tank 12, including the range of variation, to the extent that the amount of CO2 fixation in the first hydraulic hardened body H1 can be monitored by the CO2 fixation amount monitoring device 1.

[0028] The mass change measuring unit 20 of the CO2 fixation amount monitoring device 1 measures the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 when the first carbon dioxide-containing gas G1 is supplied to the first curing tank 11 and the second gas G2 is supplied to the second curing tank 12. The temperature inside the first curing tank 11 when the first carbon dioxide-containing gas G1 is being supplied and the temperature inside the second curing tank 12 when the second gas G2 is being supplied are between -10°C and 70°C.

[0029] When measuring using the mass change measuring unit 20, the supply amount of the first carbon dioxide-containing gas G1 may be the same as the supply amount of the second gas G2, or may be different from the supply amount of the second gas G2 to the extent that the CO2 fixation amount of the first hydraulic hardened body H1 can be monitored by the CO2 fixation amount monitoring device 1.

[0030] When the first carbon dioxide-containing gas G1 is supplied into the first curing tank 11, the first curing tank 11 is provided with an atmosphere suitable for carbonation curing of the first hydraulic hardened body H1, and therefore the first hydraulic hardened body H1 is carbonation cured in the first curing tank 11. On the other hand, even if the second gas G2 is supplied into the second curing tank 12, the second curing tank 12 is not provided with an atmosphere suitable for carbonation curing of the second hydraulic hardened body H2, and therefore the second hydraulic hardened body H2 in the second curing tank 12 is not carbonation cured. In other words, the mass change measuring unit 20 continues to measure the mass change of the first hydraulic hardened body H1 during carbonation curing and the mass change of the second hydraulic hardened body H2 that is not carbonation cured.

[0031] Regarding the measurement mode of the mass change of the first hydraulic hardened body H1 when the first carbon dioxide-containing gas G1 is being supplied and the mass change of the second hydraulic hardened body H2 when the second gas G2 is being supplied, the mass change measuring unit 20 may measure continuously or intermittently.

[0032] Furthermore, the configuration of the mass change measuring unit 20 is not particularly limited as long as it can measure the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 when the first carbon dioxide-containing gas G1 is supplied to the first curing tank 11 and the second gas G2 is supplied to the second curing tank 12. For example, the mass change measuring unit 20 is composed of a first mass meter that measures the mass of the first hydraulic hardened body H1 and a second mass meter that measures the mass of the second hydraulic hardened body H2.

[0033] The CO2 fixation amount calculation unit 30 of the CO2 fixation amount monitoring device 1 calculates the mass difference between the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 measured by the mass change measurement unit 20, and measures the amount of CO2 fixation of the first hydraulic hardened body H1 in the first curing tank 11 based on this mass difference. The mass difference means that the amount of CO2 fixation of the first hydraulic hardened body H1 can be measured from the difference between the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2, and is preferably the difference in mass between them or the difference in mass change rate between them.

[0034] Figure 1 and the following Figure 2 show a configuration in which the CO2 fixation amount calculation unit 30 is connected to the mass change measurement unit 20 via a wired connection, but the CO2 fixation amount calculation unit 30 may also be connected to the mass change measurement unit 20 wirelessly or otherwise.

[0035] As described above, the mass change measuring unit 20 measures the mass change of the first hydraulic hardened body H1 during carbonation curing and the mass change of the second hydraulic hardened body H2 that is not carbonation cured. During the supply of the first carbon dioxide-containing gas G1, CO2 is fixed in the first hydraulic hardened body H1 as the first hydraulic hardened body H1 undergoes carbonation curing. Therefore, the mass of the first hydraulic hardened body H1 during the supply of the first carbon dioxide-containing gas G1 increases compared to before the supply of the first carbon dioxide-containing gas G1. On the other hand, during the supply of the second gas G2, the second hydraulic hardened body H1 does not undergo carbonation curing. Therefore, the mass of the second hydraulic hardened body H2 during the supply of the second gas G2 is smaller than the mass of the first hydraulic hardened body H1 during the supply of the first carbon dioxide-containing gas G1.

[0036] Therefore, the CO2 fixation amount calculation unit 30 measures the amount of CO2 fixation of the first hydraulic hardened body H1 in the first curing tank 11 based on the mass difference between the mass of the first hydraulic hardened body H1 while the first carbon dioxide-containing gas G1 is being supplied and the mass of the second hydraulic hardened body H2 while the second gas G2 is being supplied.The CO2 fixation amount calculation unit 30 can monitor the amount of CO2 fixation of the first hydraulic hardened body H1 by continuing to measure the amount of CO2 fixation of the first hydraulic hardened body H1 while the first carbon dioxide-containing gas G1 and the second gas G2 are being supplied.

[0037] Furthermore, from the viewpoint of improving the accuracy of monitoring the amount of CO2 fixed in the first hydraulic hardened body H1, the CO2 concentration of the first carbon dioxide-containing gas G1 supplied to the first curing tank 11 is preferably at least 5.0% higher than the CO2 concentration of the second gas G2 supplied to the second curing tank 12, more preferably at least 30.0%, and even more preferably at least 50.0% higher.

[0038] In this way, the CO2 fixation amount monitoring device 1 can monitor the amount of CO2 fixation in the first hydraulic hardened body H1 during carbonation curing in an inexpensive and simple manner, based on the change in mass of the first hydraulic hardened body H1 and the second hydraulic hardened body H2 during the supply of the first carbon dioxide-containing gas G1 and the second gas G2.

[0039] Next, a method for monitoring the amount of CO2 fixed in a hydraulic hardened body according to an embodiment will be described.

[0040] The method for monitoring the CO2 fixation amount of a hydraulically hardened body (hereinafter also simply referred to as the CO2 fixation amount monitoring method) is a method carried out by the CO2 fixation amount monitoring device 1 of the above embodiment, and includes a mass change measurement step S10 and a CO2 fixation amount calculation step S11.

[0041] In the mass change measurement step S10 of the CO2 fixation amount monitoring method, a first carbon dioxide-containing gas G1 having a CO2 concentration of 0.5% or more is supplied to the inside of a first curing tank 11 containing a first hydraulic hardened body H1, and a second gas G2 having a CO2 concentration of less than 0.1% is supplied to the inside of a second curing tank 12 containing a second hydraulic hardened body H2, and the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 are measured.

[0042] In addition, in the CO2 fixation amount calculation step S11, the mass difference between the mass change of the first hydraulic hardened body H1 measured in the mass change measurement step S10 and the mass change of the second hydraulic hardened body H2 is calculated, and the CO2 fixation amount of the first hydraulic hardened body H1 is measured based on this mass difference.

[0043] In this way, the CO2 fixation amount monitoring method can monitor the amount of CO2 fixation in the first hydraulic hardened body H1 during carbonation curing in an inexpensive and simple manner, using the mass change of the first hydraulic hardened body H1 and the second hydraulic hardened body H2 during the supply of the first carbon dioxide-containing gas G1 and the second gas G2 as an estimated value.

[0044] Next, a carbonation curing system for a hydraulic hardened body according to an embodiment will be described.

[0045] Fig. 2 is a schematic diagram showing an example of a carbonation curing system for a hydraulic hardened body according to an embodiment. Fig. 3 is a schematic diagram showing an example of the appearance of a carbonation curing system for a hydraulic hardened body according to an embodiment. As shown in Figs. 2 and 3, a carbonation curing system for a hydraulic hardened body (hereinafter simply referred to as a carbonation curing system) 2 includes a carbonation curing tank 10, a first curing tank 11, a second curing tank 12, a mass change measuring unit 20, and a CO2 fixation amount calculating unit 30. That is, the carbonation curing system 2 includes the carbonation curing tank 10 in addition to the CO2 fixation amount monitoring device 1 of the above embodiment.

[0046] The carbonation curing tank 10 constituting the carbonation curing system 2 accommodates therein the hydraulically hardened body H. The internal space of the carbonation curing tank 10 is a space sealed from the outside of the carbonation curing tank 10.

[0047] The carbonation curing tank 10 can be supplied with a carbon dioxide-containing gas G having a CO2 concentration of 0.5% or more. The carbon dioxide-containing gas G is supplied from a supply unit 10a provided in the carbonation curing tank 10. For example, the carbon dioxide-containing gas G is carbon dioxide gas or a gas obtained by diluting carbon dioxide gas with air or N2 gas. Since the CO2 concentration of the carbon dioxide-containing gas G is 0.5% or more, when the carbon dioxide-containing gas G is supplied into the carbonation curing tank 10, the atmosphere inside the carbonation curing tank 10 becomes one in which the hydraulic hardened body H is carbonation cured.

[0048] The carbonation curing tank 10 is provided with an exhaust unit (not shown) that exhausts gas inside the carbonation curing tank 10 to the outside of the carbonation curing tank 10. In addition, a control unit (not shown) that controls the temperature and humidity inside the carbonation curing tank may be provided inside the carbonation curing tank 10.

[0049] As will be described later, the CO2 fixation amount calculation unit 30 measures the amount of CO2 fixation of the hydraulic hardened material H in the carbonation curing tank 10 based on the mass difference between the mass change of the first hydraulic hardened material H1 and the mass change of the second hydraulic hardened material H2 measured by the mass change measurement unit 20. Therefore, it is preferable that the volume / surface area ratio of the hydraulic hardened material H is the same as or substantially the same as the volume / surface area ratio of the first hydraulic hardened material H1. The volume / surface area ratio of the hydraulic hardened material H being substantially the same as that of the first hydraulic hardened material H1 means that the two may differ to such an extent that the amount of CO2 fixation of the hydraulic hardened material H can be monitored by the carbonation curing system 2.

[0050] The first curing tank 11 of the carbonation curing system 2 has the same configuration as the first curing tank 11 of the CO2 fixation amount monitoring device 1, and accommodates the first hydraulic hardened body H1 therein.

[0051] The first carbon dioxide-containing gas G1 supplied to the first curing tank 11 is the same as or substantially the same as the carbon dioxide-containing gas G supplied to the carbonation curing tank 10. "The first carbon dioxide-containing gas G1 is the same as the carbon dioxide-containing gas G" means that the factors affecting carbonation, such as the components contained in the first carbon dioxide-containing gas G1 and the concentrations of each component, such as the CO2 concentration, are the same as those of the carbon dioxide-containing gas G, including the range of variation. "The first carbon dioxide-containing gas G1 is substantially the same as the carbon dioxide-containing gas G" means that the factors affecting carbonation of the first carbon dioxide-containing gas G1 may be different from those of the carbon dioxide-containing gas G, including the range of variation, to the extent that the amount of CO2 fixed in the hydraulic hardened body H can be monitored by the carbonation curing system 2.

[0052] The second curing tank 12 of the carbonation curing system 2 has the same configuration as the second curing tank 12 of the CO2 fixation amount monitoring device 1.

[0053] For example, as shown in FIGS. 2 and 3 , the carbonation curing tank 10 is housed inside a first housing 41, and the CO2 fixation amount monitoring device 1 including the first curing tank 11 and the second curing tank 12 is housed inside a second housing 42. The CO2 fixation amount monitoring device 1 is smaller than the carbonation curing tank 10 including the hydraulic hardened body H. The hydraulic hardened body H is smaller than the first hydraulic hardened body H1 and the second hydraulic hardened body H2. The first housing 41 is a container or the like, and the second housing 42 is a housing smaller than the container or the like. The first housing 41 and the second housing 42 are provided on a support 50. The carbonation curing tank 10 does not have to be housed inside the first housing 41. In this case, the carbonation curing tank 10 may be a container or the like.

[0054] The mass change measuring unit 20 of the carbonation curing system 2 measures the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 when the carbon dioxide-containing gas G is supplied to the carbonation curing tank 10, the first carbon dioxide-containing gas G1 is supplied to the first curing tank 11, and the second gas G2 is supplied to the second curing tank 12. The temperatures in the carbonation curing tank 10 when the carbon dioxide-containing gas G is being supplied, the first curing tank 11 when the first carbon dioxide-containing gas G1 is being supplied, and the second curing tank 12 when the second gas G2 is being supplied are -10°C or higher and 70°C or lower.

[0055] When measuring using the mass change measuring unit 20, the supply amount of the carbon dioxide-containing gas G, the supply amount of the first carbon dioxide-containing gas G1, and the supply amount of the second gas G2 may all be the same, or at least one of these supply amounts may be different from the others to the extent that the amount of CO2 fixed in the hydraulic hardened body H can be monitored by the carbonation curing system 2.

[0056] When the carbon dioxide-containing gas G is supplied into the carbonation curing tank 10 and the first carbon dioxide-containing gas G1 is supplied into the first curing tank 11, the atmosphere in the carbonation curing tank 10 becomes one in which the hydraulic hardened body H is carbonated and the atmosphere in the first curing tank 11 becomes one in which the first hydraulic hardened body H1 is carbonated. Therefore, both the hydraulic hardened body H in the carbonation curing tank 10 and the first hydraulic hardened body H1 in the first curing tank 11 are carbonated and cured.

[0057] The CO2 fixation amount calculation unit 30 calculates the mass difference between the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 measured by the mass change measurement unit 20, calculates the amount of CO2 fixation of the first hydraulic hardened body H1 in the first curing tank 11 from this mass difference, and then measures the amount of CO2 fixation of the hydraulic hardened body H in the carbonation curing tank 10 based on the amount of CO2 fixation of the first hydraulic hardened body H1, taking into account the volume / surface area ratio of the hydraulic hardened body H, etc. The CO2 fixation amount calculation unit 30 can monitor the amount of CO2 fixation of the hydraulic hardened body H by continuously measuring the amount of CO2 fixation of the hydraulic hardened body H while the carbon dioxide-containing gas G, the first carbon dioxide-containing gas G1, and the second gas G2 are being supplied. The monitoring results of the CO2 fixation amount calculation unit 30 may be displayed on a display unit 42a provided on the outer surface of a second housing 42 that houses the CO2 fixation amount monitoring device 1, as shown in FIG. 3 .

[0058] The carbonation curing system 2 does not directly monitor (measure) the amount of CO2 fixed in the hydraulic hardened body H contained in the carbonation curing tank 10, but monitors the amount of CO2 fixed in the first hydraulic hardened body H1 contained in the small first curing tank 11, thereby making it possible to indirectly monitor the amount of CO2 fixed in the hydraulic hardened body H from the measured value of the amount of CO2 fixed in the first hydraulic hardened body H1.

[0059] In this way, the carbonation curing system 2 can monitor the amount of CO2 fixed in the hydraulic hardened body H during carbonation curing in an inexpensive and simple manner, based on the mass change of the first hydraulic hardened body H1 and the second hydraulic hardened body H2 during the supply of the carbon dioxide-containing gas G, the first carbon dioxide-containing gas G1, and the second gas G2.

[0060] Next, a method for monitoring the amount of CO2 fixed in a carbonation curing system for a hydraulic hardened body according to an embodiment will be described.

[0061] The method for monitoring the amount of CO2 fixation in a carbonation curing system for hydraulic hardened bodies (hereinafter also referred to simply as the method for monitoring the amount of CO2 fixation in a carbonation curing system) is a method carried out in the carbonation curing system for hydraulic hardened bodies 2 of the above embodiment, and includes a mass change measurement step S20 and a CO2 fixation amount calculation step S21.

[0062] In the mass change measuring step S20 in the method for monitoring the amount of CO2 fixation in a carbonation curing system, a carbon dioxide-containing gas G with a CO2 concentration of 0.5% or more is supplied into the carbonation curing tank 10 containing the hydraulic hardened body H therein, a first carbon dioxide-containing gas G1 is supplied into the first curing tank 11 containing the first hydraulic hardened body H1 therein, and a second gas G2 with a CO2 concentration of less than 0.1% is supplied into the second curing tank 12 containing the second hydraulic hardened body H2 therein, and the mass changes of the first hydraulic hardened body H1 and the second hydraulic hardened body H2 are measured.

[0063] In the CO2 fixation amount calculation step S21 in the method for monitoring the CO2 fixation amount in a carbonation curing system, the mass difference between the mass change of the first hydraulic hardened body H1 and the mass change of the second hydraulic hardened body H2 measured in the mass change measurement step S20 is calculated, and the CO2 fixation amount of the hydraulic hardened body H is measured based on this mass difference.

[0064] In this way, the method for monitoring the amount of CO2 fixation in a carbonation curing system is an inexpensive and simple method that can monitor the amount of CO2 fixation in the hydraulic hardened body H during carbonation curing as an estimated value from the mass changes of the first hydraulic hardened body H1 and the second hydraulic hardened body H2 during the supply of carbon dioxide-containing gas G, first carbon dioxide-containing gas G1, and second gas G2.

[0065] Although the embodiments have been described above, the present invention is not limited to the above embodiments, but includes all aspects encompassed by the concept and scope of the claims of the present disclosure, and can be modified in various ways within the scope of the present disclosure. [Example]

[0066] Next, examples and comparative examples will be described, but the present invention is not limited to these examples.

[0067] (Examples 1 to 3) The CO2 fixation amount of the hydraulic hardened body was monitored using the CO2 fixation amount monitoring device shown in Figure 1 as follows.

[0068] The raw materials shown in Table 1 were mixed in the proportions shown in Table 2, and then test specimens were collected and sealed and cured at 20°C. After one day of age, the specimens were demolded and left to stand at 20°C and 60% RH for three hours to obtain hydraulically hardened specimens for monitoring.

[0069] Next, the hydraulically hardened bodies (first hydraulically hardened body and second hydraulically hardened body) were placed in the first and second curing tanks, respectively, which were kept at a temperature of 50°C and a humidity of 40% RH. Subsequently, the flow rates to the first and second curing tanks were adjusted to 4 L / min, and a carbon dioxide-containing gas with a CO2 concentration of 99.9% was supplied to the first curing tank, while N2 gas with a CO2 concentration of 0.00% was supplied to the second curing tank. The average CO2 concentration in the first curing tank during the supply of the carbon dioxide-containing gas was 81.2%. The mass changes of the first hydraulically hardened body in the first curing tank and the second hydraulically hardened body in the second curing tank during the gas supply were measured every 6 minutes using a digital scale, and the mass changes were terminated after 136 hours. The mass increase rate due to CO2 fixation was calculated from the difference between the mass change rate of the first hydraulic hardened body cured in the first curing tank and the mass change rate of the second hydraulic hardened body cured in the second curing tank, and the amount of CO2 fixation by the first hydraulic hardened body was calculated by multiplying this value by the unit volume mass of the first hydraulic hardened body.

[0070] (Comparative Example 1) The first and second hydraulic hardened bodies were cured for 136 hours in the same manner as in Example 1, except that the mass change of the first hydraulic hardened body in the first curing tank and the mass change of the second hydraulic hardened body in the second curing tank were not measured. That is, the composition of Comparative Example 1 was the same as that of Example 1. After curing, the first and second hydraulic hardened bodies were completely crushed, and samples were collected and subjected to TG-DTA (Rigaku ThermoplusEVO2). The measurement conditions were a temperature rise of 20°C / min to 1000°C under N2 gas flow. The mass loss from 600 to 800°C was defined as the amount of CO2 due to decarbonation of CaCO3. The difference between the quantitative results of the first hydraulic hardened body and the quantitative results of the second hydraulic hardened body was calculated and this was defined as the amount of CO2 actually fixed in the first hydraulic hardened body. In this way, the results obtained in Example 1 and the results measured by TG-DTA in Comparative Example 1 were compared.

[0071] (Comparative Example 2) TG-DTA was carried out in the same manner as in Comparative Example 1, except that the formulation was the same as in Example 2, and the amount of CO2 fixed was measured.

[0072] (Comparative Example 3) TG-DTA was carried out in the same manner as in Comparative Example 1, except that the formulation was the same as in Example 3, and the amount of CO2 fixed was measured.

[0073] [Table 1]

[0074] [Table 2]

[0075] Fig. 4 is a graph showing the relationship between curing time and mass gain rate in Examples 1 to 3. Fig. 5 is a graph showing the relationship between the CO2 fixation amounts obtained in Examples 1 to 3 and Comparative Examples 1 to 3. Fig. 6 is a graph showing the difference between the CO2 fixation amount measurement results obtained in Comparative Examples 1 to 3 and the CO2 fixation amount measurement results obtained in Examples 1 to 3.

[0076] In Examples 1 to 3, the amount of CO2 fixed in the hydraulic hardened body could be monitored from the change in mass of the first hydraulic hardened body and the second hydraulic hardened body during gas supply. Furthermore, since the monitoring results of Examples 1 to 3 were similar to the results of TG-DTA analysis of Comparative Examples 1 to 3, it was found that the CO2 fixation amount monitoring device of Examples 1 to 3 can be effectively used as a substitute for TG-DTA, which is one of the existing analytical methods. [Explanation of symbols]

[0077] 1. CO2 fixation amount monitoring device for hydraulic hardened materials (CO2 fixation amount monitoring device) 2 Carbonation curing system for hydraulic hardened bodies 10 Carbonation curing tank 10a Supply section 11 1st curing tank 11a 1st supply section 12 Second curing tank 12a 2nd supply section 20 Mass change measurement unit 30 CO2 fixed amount calculation section 41 First cabinet 42 Second cabinet 42a Display section 50 Support H Hydraulic hardening body H1 1st hydraulic hardening body H2 2nd hydraulic hardening body G. Carbon dioxide-containing gas G1 First carbon dioxide-containing gas G2 Second Gas

Claims

1. The first hydraulic hardened body is accommodated inside, and ２ a first curing tank capable of supplying a first carbon dioxide-containing gas having a concentration of 0.5% or more therein; a second hydraulically hardened body that is the same as or substantially the same as the first hydraulically hardened body is accommodated inside the container; ２ a second curing tank capable of supplying a second gas having a concentration of less than 0.1% therein; a mass change measuring unit that measures a change in mass of the first hydraulic hardened body and a change in mass of the second hydraulic hardened body while the first carbon dioxide-containing gas is being supplied to the first curing tank and the second gas is being supplied to the second curing tank; A mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured by the mass change measuring unit is calculated, and the CO2 of the first hydraulic hardened body is calculated based on the mass difference. ２ Measuring a fixed amount of CO ２ A fixed amount calculation unit The hydraulic hardened body CO ２ Fixed dose monitoring device.

2. CO of the first carbon dioxide-containing gas ２ The concentration of the second gas is ２ The CO concentration of the hydraulic hardened material according to claim 1 is 5.0% or more higher than the CO concentration of the hydraulic hardened material according to claim 1. ２ Fixed dose monitoring device.

3. A first curing tank containing a first hydraulic hardened body is provided with CO ２ A first carbon dioxide-containing gas having a concentration of 0.5% or more is supplied, and a second curing tank containing a second hydraulic hardened body that is the same as or substantially the same as the first hydraulic hardened body is supplied with CO ２ a mass change measuring step of measuring a mass change of the first hydraulic hardened body and a mass change of the second hydraulic hardened body while supplying a second gas having a concentration of less than 0.1%; The mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured in the mass change measuring step is calculated, and the CO2 of the first hydraulic hardened body is calculated based on the mass difference. ２ Measuring a fixed amount of CO ２ A fixed amount calculation process and The hydraulic hardened body having ２ Fixed dose monitoring method.

4. The hydraulic hardened body is housed inside, and the CO ２ a carbonation curing tank capable of supplying a carbon dioxide-containing gas having a concentration of 0.5% or more therein; A first hydraulically hardened body that is the same as or substantially the same as the hydraulically hardened body is accommodated inside, and a CO 2 gas that is the same as or substantially the same as the carbon dioxide-containing gas is accommodated inside. ２ a first curing tank capable of supplying a first carbon dioxide-containing gas having a concentration of a second hydraulically hardened body that is the same as or substantially the same as the first hydraulically hardened body is accommodated inside the container; ２ a second curing tank capable of supplying a second gas having a concentration of less than 0.1% therein; a mass change measuring unit that measures a change in mass of the first hydraulic hardened body and a change in mass of the second hydraulic hardened body while the carbon dioxide-containing gas is being supplied to the carbonation curing tank, the first carbon dioxide-containing gas is being supplied to the first curing tank, and the second gas is being supplied to the second curing tank; The mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured by the mass change measuring unit is calculated, and the CO ２ Measuring a fixed amount of CO ２ A fixed amount calculation unit A carbonation curing system for hydraulic hardened bodies.

5. Inside the carbonation curing tank containing the hydraulic hardened body, ２ A carbon dioxide-containing gas having a concentration of 0.5% or more is supplied, and the same or substantially the same CO 2 gas as the carbon dioxide-containing gas is introduced into a first curing tank containing a first hydraulic hardened body that is the same or substantially the same as the hydraulic hardened body. ２ A first carbon dioxide-containing gas having a concentration of 1000 ppm or more is supplied to a second curing tank containing a second hydraulic hardened body having the same or substantially the same concentration as the first hydraulic hardened body. ２ a mass change measuring step of measuring a mass change of the first hydraulic hardened body and a mass change of the second hydraulic hardened body while supplying a second gas having a concentration of less than 0.1%; The mass difference between the mass change of the first hydraulic hardened body and the mass change of the second hydraulic hardened body measured in the mass change measuring step is calculated, and the CO ２ Measuring a fixed amount of CO ２ A fixed amount calculation process and CO in a carbonation curing system for a hydraulic hardened body having ２ Fixed dose monitoring method.

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