Method for producing hydraulic hardened body, flowable composition, and hydraulic hardened body

Abstract

To provide a method for producing a hydraulic hardened body, capable of increasing a fixed amount of carbon dioxide and compressive strength by using a raw material made by carbonating and hydrating a material that is not difficult to obtain and whose production volume is large, a flowable composition capable of increasing the fixed amount of carbon dioxide and compressive strength of the hydraulic hardened body, and the hydraulic hardened body having the increased fixed amount of carbon dioxide and the increased compressive strength.SOLUTION: A method for producing a hydraulic hardened body includes: a preparation step of preparing a flowable composition that contains water, cement, and a hydrous-carbonated sludge powder that contains moisture and is carbonated; and a hardening step of casting and hardening the flowable composition obtained in the preparation step to obtain a hydraulic hardened body.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a hydraulically set product, a flowable composition, and a hydraulically set product. [Background technology]

[0002] Various technological studies are being conducted with the aim of reducing carbon dioxide. In the construction field, technologies related to cement and concrete that reduce and fix carbon dioxide are also being considered and developed. For example, CO2-SUICOM (registered trademark), a technology developed to fix carbon dioxide in concrete, achieves this through carbonation curing, in which carbon dioxide is absorbed and fixed in the concrete in the early stages of hardening in a curing tank supplied with carbon dioxide gas (carbon dioxide, CO2).

[0003] Here, concrete, which has a relatively high strength, generally has a dense structure that is difficult for gases such as carbon dioxide to pass through, so it is technically difficult to fix carbon dioxide inside the concrete by carbonation curing.

[0004] Therefore, technology is being developed to fix carbon dioxide in concrete by using materials (such as aggregates, powders, and cement) in which carbon dioxide has already been fixed as raw materials.

[0005] For example, Patent Document 1 describes a hydraulic composition containing powders including calcium carbonate, Portland cement, and blast furnace slag, and the ratio of calcium carbonate to the powders is within a specified range. The calcium carbonate contained in the hydraulic composition fixes carbon dioxide in exhaust gas or air by blowing exhaust gas or air into a calcium solution. However, it is not easy to efficiently produce such calcium carbonate, and the amount produced is small. Therefore, it is difficult to widely use such calcium carbonate as a concrete material. Furthermore, as the content of calcium carbonate increases, the compressive strength of the hydraulic hardened body decreases. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2022-40262 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a method for producing a hydraulic hardened body capable of increasing the amount of carbon dioxide fixed and the compressive strength by using raw materials that are readily available and are produced in large quantities by carbonating and hydrating them; a flowable composition capable of increasing the amount of carbon dioxide fixed and the compressive strength of a hydraulic hardened body; and a hydraulic hardened body having an improved amount of carbon dioxide fixed and compressive strength. [Means for solving the problem]

[0008] [1] A method for producing a hydraulic hardened body, comprising: a preparation step of preparing a flowable composition containing water, cement, and a water-containing carbonated sludge powder that contains moisture and is carbonated; and a hardening step of pouring and hardening the flowable composition obtained in the preparation step to obtain a hydraulic hardened body. [2] The method for producing a hydraulic hardened body described in [1] above, wherein the water content of the hydrous carbonated sludge powder is 25.0% or less. [3] A method for producing a hydraulic hardened body described in [1] or [2] above, wherein the volume ratio (R2 / R1) of the content ratio (R1) of the cement contained in the flowable composition to the content ratio (R2) of the hydrous carbonated sludge powder contained in the flowable composition is 0.02 or more and 1.70 or less. [4] The method for producing a hydraulic hardened body described in any one of the above [1] to [3], wherein the content (R2) of the hydrous carbonated sludge powder in the flowable composition is 0.02 volume % or more and 1.70 volume % or less. [5] The method for producing a hydraulically hardened body according to any one of the above [1] to [4], wherein in the hardening step, the fluid composition is sealed and cured to obtain the hydraulically hardened body. [6] A flowable composition comprising water, cement, and a water-containing carbonated sludge powder that is water-containing and carbonated. [7] A hydraulic hardening body containing water, cement, and carbonated carbonated sludge powder. Effect of the Invention

[0009] According to the present invention, it is possible to provide a method for producing a hydraulic hardened body capable of increasing the amount of carbon dioxide fixed and the compressive strength by using a raw material that is not difficult to obtain and is produced in large quantities, by carbonating and hydrating the raw material; a flowable composition capable of increasing the amount of carbon dioxide fixed and the compressive strength of a hydraulic hardened body; and a hydraulic hardened body with an improved amount of carbon dioxide fixed and compressive strength. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a detailed description will be given based on an embodiment.

[0011] The present inventors focused on sludge, an industrial waste generated in large quantities at ready-mix concrete plants and other facilities. Sludge cake, the solid fraction obtained by solid-liquid separation of paste-like sludge, is obtained in the process of manufacturing high-purity calcium carbonate powder, and is generated in an amount equivalent to about 40 times the amount of calcium carbonate powder. This sludge cake fixes about 10% of carbon dioxide, so by using it as part of the raw material for hydraulic hardened bodies, it is possible to obtain about 1 m of hydraulic hardened bodies. 3 This can increase the amount of carbon dioxide fixed per unit of energy.

[0012] However, it was found that a flowable composition containing sludge powder obtained by drying and then pulverizing a sludge cake had poor fresh properties. In this regard, it was found that by imparting moisture to the sludge powder, that is, by hydrating the sludge powder, it was possible to suppress the deterioration of the fresh properties of the flowable composition and further increase the compressive strength of the hydraulic hardened body.

[0013] On the other hand, carbonated sludge powder obtained by carbonating sludge powder has a larger amount of carbon dioxide fixed than sludge powder because carbon dioxide is fixed in the sludge powder. Therefore, the amount of carbon dioxide fixed in the hydraulic hardened body obtained by hardening a flowable composition containing carbonated sludge powder can be increased. Furthermore, it was found that the hydraulic hardened body obtained by hardening a flowable composition containing carbonated sludge powder has improved compressive strength compared to a hydraulic hardened body not containing carbonated sludge powder.

[0014] Based on this knowledge, the inventors have found that by using as a raw material a hydrated carbonated sludge powder obtained by carbonate-hydraulic sludge powder, which is readily available and produced in large quantities, it is possible to manufacture a hydraulic hardened body having a high carbon dioxide fixation amount and a high compressive strength. The present invention has been completed based on this knowledge.

[0015] First, the method for producing the hydraulically hardened product of the present invention will be described.

[0016] The method for producing a hydraulic hardened body of the present invention includes a preparation step of preparing a flowable composition containing water, cement, and hydrous carbonated sludge powder that contains moisture and is carbonated, and a hardening step of pouring and hardening the flowable composition obtained in the preparation step to obtain a hydraulic hardened body.

[0017] The method for producing a hydraulically hardened body includes a preparation step S1 and a hardening step S2.

[0018] In the preparation step S1, a flowable composition containing water, cement, and water-containing carbonated sludge powder is prepared. In the preparation step S1, the flowable composition can be prepared by kneading these raw materials.

[0019] The cement contained in the fluid composition is preferably Portland cement. In addition to ordinary Portland cement, there are types of Portland cement such as early strength, super early strength, moderate heat, and low heat sulfate resistance, which are specified in JIS R 5210:2019. In the fluid composition, one or more of these various Portland cements can be used.

[0020] In addition, blast furnace cement (mixed cement) containing ground granulated blast furnace slag and cement materials may be used as the cement. The blast furnace cement specified in JIS R 5211:2009 can be used. If it is blast furnace cement type B, it is possible to further reduce carbon dioxide emissions.

[0021] The hydrous, carbonated sludge powder contained in the flowable composition is sludge powder that has been carbonated and hydroused, and thus contains moisture and is carbonated.

[0022] The sludge powder can be obtained, for example, as follows.

[0023] The raw material for the sludge powder is sludge, which is the excess cement paste separated and discharged as waste in the centrifugal molding process during the production of secondary concrete products. Examples of such sludge include concrete sludge, mortar sludge, and cement sludge, which are generated in large quantities as industrial waste. Examples of the production of secondary concrete products include concrete pillars and concrete piles made by solidifying concrete materials consisting of cement, water, fine aggregate, coarse aggregate, and admixtures.

[0024] The paste-like sludge is then subjected to solid-liquid separation and dewatering, and then dried and pulverized to obtain sludge powder. The sludge powder fixes carbon dioxide from the atmosphere during the drying process. The particle size of the sludge powder is appropriately set according to the application and characteristics of the flowable composition and hydraulic hardened body, and is, for example, about 10 μm to 20 mm.

[0025] In addition, carbon dioxide may be forcibly fixed in the sludge powder by supplying a gas containing carbon dioxide during drying in the production of the sludge powder.

[0026] The hydrous carbonated sludge powder fixes a larger amount of carbon dioxide than sludge powder because a gas containing carbon dioxide is supplied to the sludge powder to further fix the carbon dioxide (carbonation). Therefore, the hydraulic hardened body obtained by hardening a flowable composition containing hydrous carbonated sludge powder can fix a larger amount of carbon dioxide than a hydraulic hardened body containing sludge powder.

[0027] From the viewpoint of efficiently reducing carbon dioxide in the atmosphere, the source of carbon dioxide in the gas containing carbon dioxide is preferably exhaust gas from a thermal power plant, exhaust gas from a boiler, exhaust gas containing carbon dioxide emitted in the manufacturing process of other products, high-concentration carbon dioxide gas in which the carbon dioxide concentration in the exhaust gas is increased, etc. Furthermore, the humidity and temperature of these gases may be adjusted.

[0028] Furthermore, the hydraulic hardened body obtained by hardening a flowable composition containing hydrous carbonated sludge powder can have a higher compressive strength than a hydraulic hardened body not containing hydrous carbonated sludge powder or a hydraulic hardened body containing sludge powder. Since the compressive strength of the hydraulic hardened body obtained by hardening a flowable composition containing hydrous carbonated sludge powder can be increased, the unit cement amount of the hydraulic hardened body can be reduced. As a result, the amount of cement used, which emits a large amount of carbon dioxide during production, can be reduced, and the carbon dioxide emission unit of the hydraulic hardened body can be reduced.

[0029] The hydrous carbonated sludge powder is obtained by hydrating the above-mentioned sludge powder or carbonated sludge powder obtained by carbonating the sludge powder, and contains water. For example, the sludge powder or carbonated sludge powder can be hydrated by immersing it in water for a predetermined period of time. The water content of the hydrous carbonated sludge powder can be controlled by the immersion time in water.

[0030] A hydraulic hardened body obtained by hardening a flowable composition containing a hydrous carbonated sludge powder can have improved compressive strength compared to a hydraulic hardened body obtained by hardening a flowable composition containing a non-hydrous sludge powder or a carbonated sludge powder. By hydrating the sludge powder, the compressive strength of the hydraulic hardened body can be increased, and therefore the unit cement amount of the hydraulic hardened body can be reduced, thereby reducing the carbon dioxide emission unit of the hydraulic hardened body.

[0031] Furthermore, in a flowable composition containing non-hydrated sludge powder or carbonated sludge powder, the sludge powder absorbs and retains a large amount of water from the raw materials during kneading of the flowable composition, deteriorating the fresh properties of the flowable composition. On the other hand, by including hydrous carbonated sludge powder in the flowable composition, the hydrous carbonated sludge powder contains moisture, which prevents the hydrous carbonated sludge powder from absorbing and retaining water from the raw materials during kneading of the flowable composition, thereby preventing deterioration of the fresh properties of the flowable composition.

[0032] The carbonation and hydration of the sludge powder may be performed in either order, or may be performed simultaneously. From the viewpoint of efficiently fixing carbon dioxide in the sludge powder and easily controlling the moisture content of the hydrated, carbonated sludge powder, it is preferable to prepare a carbonated sludge powder by carbonating the sludge powder, and then hydrating the carbonated sludge powder to obtain a hydrated, carbonated sludge powder.

[0033] The particle size of the hydrous carbonated sludge powder is approximately the same as that of the sludge powder, for example, about 10 μm to 20 mm.

[0034] From the viewpoint of improving the compressive strength of the hydraulic hardened body, the moisture content of the hydrated carbonated sludge powder contained in the flowable composition is preferably 25.0% or less. Furthermore, when the moisture content of the hydrated carbonated sludge powder is within the above range, the fresh properties of the flowable composition are good. In particular, when the objective is to increase the compressive strength, it is more preferable that the moisture content of the hydrated carbonated sludge powder is 10.0% or less, and when the objective is to improve the fresh properties of the flowable composition, it is more preferable that the moisture content of the hydrated carbonated sludge powder is 10.0% or more.

[0035] Furthermore, with regard to the volume ratio (R2 / R1) of the content ratio (R1) of the cement contained in the flowable composition to the content ratio (R2) of the hydrous carbonated sludge powder contained in the flowable composition, the lower limit is preferably 0.02 or more, more preferably 0.10 or more, and even more preferably 0.20 or more, and the upper limit is preferably 1.70 or less, more preferably 1.30 or less, and even more preferably 1.00 or less.

[0036] When the volume ratio (R2 / R1) is 0.02 or more, the amount of carbon dioxide fixed in the hydraulic hardened body can be improved, and when the volume ratio (R2 / R1) is 1.70 or less, the compressive strength of the hydraulic hardened body can be improved.

[0037] Furthermore, with regard to the content ratio (R2) of hydrous carbonated sludge powder contained in the flowable composition, the lower limit is preferably 0.02 volume% or more, more preferably 0.10 volume% or more, and even more preferably 0.20 volume% or more, and the upper limit is preferably 1.70 volume% or less, more preferably 1.30 volume% or less, and even more preferably 1.00 volume% or less.

[0038] When the content (R2) is 0.02% by volume or more, the amount of carbon dioxide fixed and the compressive strength of the hydraulic hardened body can both be improved. When the content (R2) is 1.70% by volume or less, deterioration of the fresh properties of the flowable composition can be suppressed.

[0039] Depending on the application and properties of the hydraulic hardened body, the flowable composition may further contain ground granulated blast furnace slag and aggregate in addition to water, cement, and wet carbonated sludge powder.

[0040] The ground granulated blast furnace slag contained in the flowable composition is a fine powder as specified in JIS A 6206:2013 "ground granulated blast furnace slag for concrete". Granulated blast furnace slag is produced in a blast furnace at the same time as shear iron, and is rapidly cooled with water or air to produce molten blast furnace slag, with a basicity of 1.60 or more. Ground granulated blast furnace slag is produced by drying and pulverizing this granulated blast furnace slag, or by adding gypsum to it. By replacing part of the Portland cement with ground granulated blast furnace slag, it is possible to reduce carbon dioxide emissions during the cement manufacturing stage.

[0041] The types of ground granulated blast furnace slag are classified according to their specific surface area (cm 2 There are four types depending on the molecular weight (Mg) of the polymer, any of which may be used in the present invention. a) Blast furnace slag powder 3000: specific surface area is 2750 or more and less than 3500 b) Blast furnace slag powder 4000: specific surface area is 3500 or more and less than 5000 c) Blast furnace slag powder 6000: specific surface area is 5000 or more and less than 7000 d) Blast furnace slag powder 8000: specific surface area is 7000 or more but less than 10000

[0042] The aggregate contained in the hydraulic hardened body includes at least one of fine aggregate and coarse aggregate.

[0043] Fine aggregate is an aggregate defined in JIS A 5308, JIS A 5005, JIS A 5002 and JIS A 5011. Examples of fine aggregate include crushed sand, sand, river sand, sea sand, crushed lime sand, recycled aggregate, lightweight aggregate, heavy aggregate and the like.

[0044] Coarse aggregate is defined in JIS A 5308, JIS A 5005, JIS A 5002 and JIS A 5011, and is differentiated from the above fine aggregates by the size of the particles, and by whether or not it passes through a 5mm sieve. In practice, fine aggregate is defined as aggregate that passes through a 10mm sieve entirely and 85% or more of its weight passes through a 5mm sieve, and coarse aggregate is defined as aggregate that is retained by 85% or more of its weight on a 5mm sieve.

[0045] In addition, the fluid composition may further contain various functional components depending on the application and characteristics of the hydraulic hardened body. For example, CemR 3 By including ECM cement, carbon dioxide emissions can be further reduced.

[0046] In the hardening step S2 carried out after the preparation step S1, the flowable composition obtained in the preparation step S1 is poured and hardened to obtain a hydraulic hardened body. The hydraulic hardened body contains carbonated sludge powder obtained by removing moisture from the hydrous carbonated sludge powder. The hydraulic hardened body may also contain hydrous carbonated sludge powder together with the carbonated sludge powder. The particle size of the carbonated sludge powder is approximately the same as that of the hydrous carbonated sludge powder, for example, about 10 μm to 20 mm.

[0047] In the hardening step S2, it is preferable to obtain a hydraulic hardened body by sealing and curing the flowable composition. In a state where water is not supplied from the outside by sealing and curing, the water retained in the water-containing carbonated sludge powder is used for the hydration reaction of cement, so that the strength of the hydraulic hardened body can be further improved.

[0048] For the hydraulic hardened body thus obtained, the amount of carbon dioxide fixed in the hydraulic hardened body can be increased by including the hydrous carbonated sludge powder in the fluid composition, for example by replacing a part of the fine aggregate with the hydrous carbonated sludge powder in the fluid composition. Furthermore, since the hydrous carbonated sludge powder fixes more carbon dioxide than the sludge powder, the amount of carbon dioxide fixed in the hydraulic hardened body obtained by hardening the fluid composition containing the hydrous carbonated sludge powder can be further increased. Furthermore, the hydraulic hardened body can be increased in compressive strength by including the hydrous carbonated sludge powder in the fluid composition. Furthermore, since the hydraulic hardened body obtained by hardening the fluid composition containing the hydrous carbonated sludge powder can increase in compressive strength, the unit cement amount of the hydraulic hardened body can be reduced, and the carbon dioxide emission unit of the hydraulic hardened body can be reduced. The sludge powder for preparing the hydrous carbonated sludge powder is generated in large quantities as industrial waste during the production of secondary concrete products, so it is not difficult to obtain and is produced in large quantities.

[0049] Next, the flowable composition of the present invention will be described.

[0050] The flowable composition of the present invention contains water, cement, and water-containing carbonated sludge powder that contains water and is carbonated.

[0051] This flowable composition is suitably used as the flowable composition used in the manufacturing method for hydraulic hardened body of the present invention. The flowable composition preferably has the same composition as the flowable composition used in the manufacturing method for hydraulic hardened body of the present invention. Since the flowable composition of the present invention contains hydrous carbonated sludge powder, the hydraulic hardened body obtained by hardening the flowable composition can have an increased amount of carbon dioxide fixation and compressive strength. In addition, the sludge powder for preparing the hydrous carbonated sludge powder contained in the flowable composition is generated in large quantities as industrial waste during the manufacture of secondary concrete products, so it is not difficult to obtain and is produced in large quantities.

[0052] Next, the hydraulically hardened product of the present invention will be described.

[0053] The hydraulic hardened body of the present invention contains water, cement, and carbonated carbonated sludge powder.

[0054] This hydraulic hardened body preferably has the same composition as the hydraulic hardened body produced by the manufacturing method of the hydraulic hardened body of the present invention and the hydraulic hardened body obtained by hardening the flowable composition of the present invention. The hydrated carbonated sludge powder contained in the flowable composition is read as the carbonated sludge powder contained in the hydraulic hardened body. For example, the volume ratio (R3 / R1) of the content ratio (R3) of the carbonated sludge powder contained in the hydraulic hardened body to the content ratio (R1) of the cement contained in the hydraulic hardened body is preferably the same as the volume ratio (R2 / R1) of the flowable composition used in the manufacturing method of the hydraulic hardened body of the present invention. In addition, the content ratio (R3) of the hydrated carbonated sludge powder contained in the hydraulic hardened body is preferably the same as the content ratio (R2) of the hydrated carbonated sludge powder contained in the hydraulic hardened body used in the manufacturing method of the hydraulic hardened body of the present invention.

[0055] The hydraulic hardened body of the present invention contains carbonated sludge powder, which can increase the amount of carbon dioxide fixed and the compressive strength. In addition, the sludge powder for preparing the carbonated sludge powder contained in the hydraulic hardened body is generated in large quantities as industrial waste during the production of secondary concrete products, so it is not difficult to obtain and is produced in large quantities. The carbonated sludge powder contained in the hydraulic hardened body can be observed with an electron probe microanalyzer (EPMA).

[0056] According to the embodiment described above, by using hydrated carbonated sludge powder as a raw material, which is obtained by carbonated and hydrated sludge powder, which is not difficult to obtain and is produced in large quantities, it is possible to produce a hydraulic hardened body with a high carbon dioxide fixation amount and compressive strength.

[0057] Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, but includes all aspects included in 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. EXAMPLES

[0058] Next, examples and comparative examples will be described, but the present invention is not limited to these examples.

[0059] (Examples 1 to 19) First, sludge powder (PAdeCS (registered trademark), manufactured by Nippon Concrete Industries Co., Ltd.) was hydrated and carbonated to obtain hydrated, carbonated sludge powder with the particle size and moisture content shown in Table 1. Next, a flowable composition was prepared containing water (W), cement (C), hydrated, carbonated sludge powder, fine aggregate (S) and coarse aggregate (G) in the ratios shown in Table 1, and the poured flowable composition was then cured by the curing method shown in Table 1 to produce a hydraulically hardened body.

[0060] (Comparative Examples 1 to 2) In Comparative Example 1, a hydraulic hardened body was produced in the same manner as in Example 1, except that a flowable composition having the composition shown in Table 2 was used. In Comparative Example 2, a hydraulic hardened body was produced in the same manner as in Example 1, except that a flowable composition having the composition shown in Table 2 was used and that the curing method shown in Table 2 was used. That is, in Comparative Examples 1 and 2, no hydrous carbonated sludge powder was used.

[0061] (Comparative Examples 3 to 5) First, sludge powder (PAdeCS (registered trademark), manufactured by Nippon Concrete Industries Co., Ltd.) was moistened to obtain moist sludge powder with the particle size and moisture content shown in Table 1. Next, a flowable composition was prepared in which water (W), cement (C), moist sludge powder, fine aggregate (S) and coarse aggregate (G) were mixed in the ratios shown in Table 2, and the poured flowable composition was then cured by the curing method shown in Table 2 to produce a hydraulically hardened body. That is, in Comparative Examples 3 to 5, non-carbonated moist sludge powder was used.

[0062] The flowable compositions prepared in the above Examples and Comparative Examples and the hydraulically hardened bodies produced in the above Examples and Comparative Examples were subjected to the following measurements and evaluations.

[0063] [1] Slump To evaluate the fresh properties of the flowable composition, a slump test was performed on the flowable composition in accordance with JIS A 1101:2005 "Slump test method for concrete".

[0064] [2] Compressive strength The compressive strength of the hydraulic hardened bodies aged 7 days and 28 days was measured in accordance with JIS A 1108:2018 "Testing method for compressive strength of concrete."

[0065] [3] Carbon dioxide emissions As the amount of carbon dioxide fixed in the hydraulic hardened body increases, the amount of carbon dioxide emitted during the production of the hydraulic hardened body decreases, so the amount of carbon dioxide emitted during the production of the hydraulic hardened body was calculated to evaluate the amount of carbon dioxide fixed in the hydraulic hardened body. Then, the hydraulic hardened bodies were ranked according to the following criteria.

[0066] ◎: Carbon dioxide emissions are 210kg / m 3 It was less than. 〇: Carbon dioxide emissions are 210 kg / m 3 More than 240kg / m 3 It was less than. ×: Carbon dioxide emissions are 240 kg / m 3 That was all.

[0067] [Table 1]

[0068] [Table 2]

[0069] [Table 3]

[0070] [Table 4]

[0071] As shown in Tables 1 to 4, in the above examples, a flowable composition containing hydrous carbonated sludge powder was used, which prevented the deterioration of the fresh properties of the flowable composition, and further improved the amount of carbon dioxide fixed and the compressive strength of the hydraulic hardened body. On the other hand, in the above comparative examples, a flowable composition not containing hydrous carbonated sludge powder was used, so at least one of the amount of carbon dioxide fixed and the compressive strength of the hydraulic hardened body was insufficient.

Claims

1. A preparation step of preparing a flowable composition containing water, cement, and a water-containing carbonated sludge powder that contains water and is carbonated; a hardening step of casting and hardening the flowable composition obtained in the preparation step to obtain a hydraulic hardened body; The method for producing a hydraulic hardened body comprising the steps of:

2. The method for producing a hydraulic hardened body according to claim 1, wherein the water content of the hydrous carbonated sludge powder is 25.0% or less.

3. A method for producing a hydraulic hardened body as described in claim 1, wherein the volume ratio (R2 / R1) of the content ratio (R1) of the cement contained in the flowable composition to the content ratio (R2) of the hydrous carbonated sludge powder contained in the flowable composition is 0.02 or more and 1.70 or less.

4. 2. The method for producing a hydraulic hardened body according to claim 1, wherein the content (R2) of the hydrous carbonated sludge powder contained in the flowable composition is 0.02 volume % or more and 1.70 volume % or less.

5. The method for producing a hydraulically hardened body according to any one of claims 1 to 4, wherein in the hardening step, the fluid composition is sealed and cured to obtain the hydraulically hardened body.

6. A flowable composition comprising water, cement, and a water-containing carbonated sludge powder that is moistened and carbonated.

7. A hydraulic hardening body containing water, cement, and carbonated carbonated sludge powder.

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