Method for predicting hardening characteristics of hydraulic composition, method for manufacturing hydraulic composition, and hydraulic composition

Abstract

To provide a prediction method capable of rapidly predicting the hardening characteristics of hydraulic compositions containing volcanic ejecta deposits.SOLUTION: The present invention relates to a method for predicting the setting characteristics of a hydraulic composition containing a volcanic ejecta deposit, and the prediction method includes a prediction step of predicting the setting characteristics of the hydraulic composition using at least one measured value selected from the group consisting of: the SiO2 content; Al2O3 content; Na2O content; K2O content; R2O content; heat of hydration; BET specific surface area; Fe3+ ion ratio to the total amount of Fe3+ and Fe2+; the a value in the Lab color system; and the b value in the Lab color system of the volcanic ejecta deposit.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for predicting the setting characteristics of a hydraulic composition, a method for producing a hydraulic composition, and a hydraulic composition. [Background technology]

[0002] Volcanic ejecta deposits are an abundant material in Japan, and volcanic glass contained in volcanic ash is used as an admixture for concrete. Weathering of volcanic ejecta deposits produces clay minerals such as allophane and halloysite. However, the proportion of clay minerals contained in volcanic ejecta deposits varies from one volcanic ejecta deposit to another. The acid-alkali alternating dissolution method is known as a method for quantifying allophane contained in volcanic ejecta deposits (Non-Patent Document 1).

[0003] In order to reduce carbon dioxide emissions (CO2), the use of inorganic minerals in hydraulic compositions has been considered. However, when inorganic minerals are used, strength development changes. In Patent Document 2, 27 The relationship between the Al coordination number obtained by Al-NMR analysis and the compressive strength of hydraulic compositions has been investigated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-127724 [Non-patent literature]

[0005] [Non-Patent Document 1] Yasuo Kitagawa, "Study on the Quantitative Analysis of Allophane and Amorphous Inorganic Components in Soil," Report of the National Institute of Agricultural Sciences, Soil and Fertilizer, No. 29, pp. 1-48 (1977) Summary of the Invention [Problem to be solved by the invention]

[0006] Allophane contained in volcanic ejecta deposits is a component that can affect the setting characteristics of hydraulic compositions. However, as shown in Non-Patent Document 1, the method for quantifying allophane requires a considerable number of days for analysis, and therefore adjusting the formulation depending on the allophane content is inefficient. Therefore, one aspect of the present disclosure provides a prediction method capable of quickly predicting the setting characteristics of a hydraulic composition containing volcanic ejecta deposits. Another aspect of the present disclosure provides a method for manufacturing a hydraulic composition capable of quickly predicting the setting characteristics of the hydraulic composition. Another aspect of the present disclosure provides a hydraulic composition having excellent setting characteristics. [Means for solving the problem]

[0007] One aspect of the present disclosure is a method for predicting the setting characteristics of a hydraulic composition containing a volcanic ejecta deposit, the method comprising: determining the SiO content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe content, and the like of the volcanic ejecta deposit. 3+ and Fe 2+ Fe relative to the total amount of 3+ The present invention provides a prediction method, which includes a prediction step of predicting the setting characteristics of the hydraulic composition using at least one measured value selected from the group consisting of an ion ratio of the above-mentioned ionic species, an a value in the Lab color system, and a b value in the Lab color system.

[0008] The above prediction method uses the SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe 3+ and Fe 2+ Fe relative to the total amount of 3+ At least one measured value selected from the group consisting of the ion ratio of 0.01 to 0.15, the a value in the Lab color system, and the b value in the Lab color system is used. Each of these measured values ​​can be obtained more quickly than by actually measuring the allophane content. Furthermore, each of these measured values ​​has a high correlation with the allophane content. Therefore, the above-mentioned prediction method can quickly predict the setting characteristics of a hydraulic composition using each measured value.

[0009] One aspect of the present disclosure provides a method for producing a hydraulic composition, which includes a blending step of blending at least an allophane-containing volcanic ejecta deposit and an alkaline activator as raw materials, and a prediction step of predicting the setting characteristics of the hydraulic composition by the above-mentioned prediction method. This production method makes it possible to quickly predict the setting characteristics of the hydraulic composition to be produced.

[0010] One aspect of the present disclosure provides a hydraulic composition comprising volcanic ejecta deposits and Portland cement, wherein the volcanic ejecta deposits content is 10% by mass or more and the volcanic ejecta deposits contain 50% by mass or more of allophane. Such a hydraulic composition has excellent hardening properties despite containing a predetermined amount of volcanic ejecta deposits. [Effects of the Invention]

[0011] According to one aspect of the present disclosure, it is possible to provide a prediction method capable of quickly predicting the setting characteristics of a hydraulic composition containing a deposit of volcanic ejecta. According to one aspect of the present disclosure, it is possible to provide a manufacturing method for a hydraulic composition capable of quickly predicting the setting characteristics of a hydraulic composition. According to one aspect of the present disclosure, it is possible to provide a hydraulic composition having excellent setting characteristics. [Brief explanation of the drawings]

[0012] [Figure 1] Figures 1(A) and (B) are graphs showing the measurement results of the hydration heat rate and integrated value of the hydration heat value of volcanic ejecta deposits. [Figure 2] Figure 2 is a graph showing the correlation between the allophane content (mass%) of volcanic ejecta deposits and various properties of the volcanic ejecta deposits (SiO content, AlO content, NaO content, KO content, RO content, and calorific value of hydration). [Figure 3]Figure 3 is a graph showing the correlation between the allophane content (mass%) of volcanic ejecta deposits and various properties of the volcanic ejecta deposits (BET specific surface area, a value in the Lab color system, b value in the Lab color system, and the ion ratio of Fe3+ to the sum of Fe3+ and Fe2+ (T-Fe)). [Figure 4] Fig. 4 is a graph plotting the relationship between the allophane content of a hydraulic composition determined from the allophane content (actually measured value) of volcanic ejecta deposits and the ratio of the compressive strength of a set body of the hydraulic composition to that of a set body of a hydraulic composition containing only an alkali activator (compressive strength ratio I) for each material age. Fig. 4(A) shows data when the content of volcanic ejecta deposits or limestone in the hydraulic composition is 10% by mass, Fig. 4(B) shows data when the content of volcanic ejecta deposits or limestone in the hydraulic composition is 30% by mass, and Fig. 4(C) shows data when the content of volcanic ejecta deposits or limestone in the hydraulic composition is 50% by mass. [Figure 5] Fig. 5 is a graph plotting the relationship between the allophane content of a hydraulic composition determined from the allophane content (actually measured value) of volcanic ejecta deposits and the ratio of the compressive strength of a hardened body of the hydraulic composition to that of a hardened body of a hydraulic composition containing only an alkali activator and limestone (compressive strength ratio II) for each material age. Fig. 5(A) shows data when the content of volcanic ejecta deposits or limestone is 10% by mass, Fig. 5(B) shows data when the content of volcanic ejecta deposits or limestone is 30% by mass, and Fig. 5(C) shows data when the content of volcanic ejecta deposits or limestone is 50% by mass. [Figure 6] Figures 6(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 7 days of age and the predicted values ​​of compressive strength ratio I at 7 days of age predicted from each multiple regression equation shown in Table 6. [Figure 7] Figures 7(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 7 days of age and the predicted values ​​of compressive strength ratio I at 7 days of age predicted from each multiple regression equation shown in Table 6. [Figure 8] Figures 8(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 7 days of age and the predicted values ​​of compressive strength ratio I at 7 days of age predicted from each multiple regression equation shown in Table 6. [Figure 9] Figures 9(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 7 days of age and the predicted values ​​of compressive strength ratio I at 7 days of age predicted from each multiple regression equation shown in Table 6. [Figure 10] Figures 10(A) to (E) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 7 days of age and the predicted values ​​of compressive strength ratio I at 7 days of age predicted from each multiple regression equation shown in Table 6. [Figure 11] Figures 11(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 28 days of age and the predicted values ​​of compressive strength ratio I at 28 days of age predicted from each multiple regression equation shown in Table 7. [Figure 12] Figures 12(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 28 days of age and the predicted values ​​of compressive strength ratio I at 28 days of age predicted from each multiple regression equation shown in Table 7. [Figure 13] Figures 13(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 28 days of age and the predicted values ​​of compressive strength ratio I at 28 days of age predicted from each multiple regression equation shown in Table 7. [Figure 14] Figures 14(A) to (F) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 28 days of age and the predicted values ​​of compressive strength ratio I at 28 days of age predicted from each multiple regression equation shown in Table 7. [Figure 15] Figures 15(A) to (E) are graphs showing the correlation between the measured values ​​of compressive strength ratio I at 28 days of age and the predicted values ​​of compressive strength ratio I at 28 days of age predicted from each multiple regression equation shown in Table 7. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described. However, the following embodiments are merely examples for explaining the present disclosure and are not intended to limit the present disclosure to the following content. The symbol "to" used in a numerical range indicates a numerical range that includes the upper and lower limit values. For example, "X to Y" indicates a numerical range "greater than or equal to X and less than or equal to Y." Numerical ranges in which the upper and / or lower limits are replaced with numerical values ​​described in the examples are also included in the content of the present disclosure. Multiple exemplified components or materials may be used alone or in combination.

[0014] In the present specification, numerical ranges in which the upper or lower limit of one numerical range is replaced with the upper or lower limit of another numerical range are also included in the present disclosure. In the present specification, numerical ranges in which the upper or lower limit of a numerical range is replaced with a value shown in the examples are also included in the present disclosure.

[0015] According to one embodiment, a method for predicting the hardening characteristics of a hydraulic composition containing a volcanic ejecta deposit includes determining the SiO content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe content, and the like of the volcanic ejecta deposit. 3+ and Fe 2+ Fe relative to the total amount of 3+ The method includes a prediction step of predicting the setting characteristics of the hydraulic composition using at least one measured value selected from the group consisting of the ion ratio, the a value in the Lab color system, and the b value in the Lab color system.

[0016] The volcanic ejecta deposits may be obtained from strata deposited during volcanic eruptions. The strata may contain at least one of volcanic ash, volcanic lapilli, pumice, pyroclastic flow deposits, and the like. Alternatively, such natural deposits may be subjected to pretreatment such as sieving or calcination. The volcanic ejecta deposits contain allophane.

[0017] Allophane is a mineral formed by the long-term weathering and hydrothermal alteration of volcanic ash and feldspar in volcanic deposits. For example, it has a hollow spherical structure with a particle size of 0.05 to 0.2 μm, and the outer part of the hollow sphere (shell) has an octahedral sheet of Al2O3, and the inner part of the hollow sphere (shell) has a tetrahedral sheet of SiO2.

[0018] The volcanic ejecta deposits used in this embodiment may be natural products, or may have been pretreated to such an extent that all of the allophane is not altered into other minerals. Examples of pretreatment include particle size adjustment and calcination. Calcination may be performed, for example, by heating in an inert gas atmosphere such as nitrogen gas at 500 to 900°C for 1 to 4 hours. Such pretreatment can sufficiently preserve the allophane contained in the volcanic ejecta deposits while increasing the strength of the hydraulic composition obtained by blending the volcanic ejecta deposits with the alkaline activator. The volcanic ejecta deposits may be commercially available products, or may be commercially available products that have been pretreated as described above. Examples of commercially available products include Kanuma soil, Satsuma soil, Kuroboku soil, and SEKADO P-1 (trade name, manufactured by Shinagawa General Co., Ltd.).

[0019] The SiO2 content of the volcanic ejecta deposits may be 30 to 80 mass%, or 35 to 75 mass%. The Al2O3 content of the volcanic ejecta deposits may be 5 to 45 mass%, or 10 to 40 mass%. The Na2O content of the volcanic ejecta deposits may be 0.1 to 5 mass%, or 0.3 to 4 mass%. The K2O content of the volcanic ejecta deposits may be 0.1 to 5 mass%, or 0.2 to 4 mass%. The R2O content of the volcanic ejecta deposits may be 0.1 to 10 mass%, or 0.4 to 8 mass%. The R2O content in this disclosure is the alkali content, calculated as the Na2O content + 0.658K2O content. The contents of these chemical components can be determined by quantifying each metal element by X-ray fluorescence analysis and converting it to its oxide. When volcanic deposits weather, they tend to have low SiO2, Na2O, K2O, and R2O contents, and high Al2O3 contents.

[0020] The calorific value of hydration of volcanic ejecta deposits can be measured with a commercially available conduction calorimeter using a sample prepared by mixing the volcanic ejecta deposits and water in a 1:1 mass ratio. The calorific value of hydration may be, for example, the integrated value over one hour (integrated calorific value). This reduces the variability of the measured values, allowing the setting characteristics of hydraulic compositions to be predicted with sufficiently high accuracy.

[0021] The integrated value (1 hour) of the calorific value of hydration of volcanic ejecta deposits measured by the above procedure may be 0 to 50 J / g, or 0 to 40 J / g. In this disclosure, [J / g] refers to the calorific value per 1 g of volcanic ejecta deposits. The calorific value of hydration tends to increase as the allophane content in volcanic ejecta deposits increases.

[0022] The BET specific surface area of ​​volcanic ejecta deposits can be measured using a commercially available measuring device, for example, by the nitrogen adsorption method. The BET specific surface area of ​​volcanic ejecta deposits is in the range of 5 to 500 m. 2 / g, or 8 to 300m 2 / g. Volcanic deposits tend to have a high BET specific surface area when weathered.

[0023] Volcanic deposits may contain iron compounds. Examples of iron compounds containing divalent iron ions include FeO. Examples of iron compounds containing trivalent iron ions include Fe2O3. Among the iron ions that make up iron compounds, Fe 2+ and Fe 3+ Fe relative to T-Fe, which is the sum of 3+ Percentage of Fe 3+ / T-Fe) has a high correlation with the allophane content. 3+ / T-Fe) may be 0.1 to 2, 0.2 to 1.5, or 0.2 to 1.0. 3+ / Fe 2+ may be 0.1 to 10, or 0.2 to 8.

[0024] Fe in volcanic deposits 3+ and Fe2+ The Fe content may be measured by spectrophotometry, Mössbauer spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, or X-ray absorption fine structure analysis. When volcanic deposits are weathered, the Fe content increases. 3+ Percentage of Fe 3+ / T-Fe) tends to increase.

[0025] The a value in the Lab color system of volcanic ejecta deposits may be 0.1 to 10, or 0.3 to 8. The b value in the Lab color system of volcanic ejecta deposits may be 1 to 20, or 3 to 18. Minerals containing Fe(III) ions are often yellowish-brown, while minerals containing Fe(II) ions are often light green. The a value in the Lab color system is thought to be related to the content of Fe(III) ions. The a value and b value in the Lab color system of the present disclosure can be measured using a commercially available spectrocolorimeter according to the method of Hunter 1948.

[0026] The hydraulic composition is obtained by blending at least volcanic ejecta deposits and an alkaline activator as raw materials. The hydraulic composition may contain other components in addition to the volcanic ejecta deposits and the alkaline activator. Examples of other components include inorganic fine powder, gypsum, carbonates, etc. The content of other components may be 40 mass% or less, 20 mass% or less, or 15 mass% or less based on the total amount of the hydraulic composition. Examples of alkaline activators include Portland cement clinker, Portland cement, tricalcium silicate (3CaO·SiO2, represented by C3S), slaked lime, alkaline carbonates, etc.

[0027] The setting characteristics of the hydraulic composition predicted in the prediction step are not particularly limited as long as they are an index related to the setting of the hydraulic composition. For example, it may be the compressive strength of a hardened product at an age of 7 days or 28 days, measured in accordance with the method described in JIS R 5201:2015 "Physical Testing Methods for Cement." Alternatively, it may be the ratio of the compressive strength of the hardened product of the hydraulic composition to the compressive strength of a reference hardened product. The reference hardened product may be a hardened product of a hydraulic composition prepared under the same conditions as the hydraulic composition whose setting characteristics are to be predicted, except that it does not contain volcanic ejecta deposits. Alternatively, it may be a hardened product of a hydraulic composition blended with limestone instead of volcanic ejecta deposits.

[0028] A regression equation creation step may be provided before the prediction step, and a regression equation created using measured values ​​of each property of the volcanic ejecta deposit used to create the regression equation may be used. The regression equation may be a simple regression equation or a multiple regression equation. The regression equation in the present disclosure includes both simple regression equations and multiple regression equations. The explanatory variables include the above-mentioned SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe 3+ and Fe 2+ Fe relative to the total amount of 3+ At least one measured value selected from the group consisting of the ion ratio, the a value in the Lab color system, and the b value in the Lab color system can be used. If one measured value is used as the explanatory variable, a simple regression equation can be obtained. If two or more measured values ​​are used as explanatory variables, a multiple regression equation can be obtained. If a multiple regression equation is used, the setting characteristics of the hydraulic composition to be predicted can be predicted with even higher accuracy. The dependent variable is the setting characteristics of the hydraulic composition containing the volcanic ejecta deposits used to create the regression equation. Specific examples of setting characteristics are as described above.

[0029] The hardening characteristics of hydraulic compositions containing volcanic deposits and alkali activators are thought to depend on the allophane content. The SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, and Fe content of the volcanic deposits were 3+ and Fe 2+Fe relative to the total amount of 3+ The ion ratio, the a value in the Lab color system, and the b value in the Lab color system (hereinafter collectively referred to as "sediment properties") have a high correlation with the allophane content in volcanic ejecta deposits. Measurement of each property can be carried out more easily and quickly than measurement of the allophane content. Therefore, according to the prediction method of this embodiment, the setting properties of a hydraulic composition can be predicted quickly and with high accuracy.

[0030] The allophane content in the volcanic ejecta deposits used to create the regression equation and in the volcanic ejecta deposits contained in the hydraulic composition to be predicted may be 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more. Since each property of the volcanic ejecta deposits is highly correlated with the allophane content, a higher allophane content enables more accurate prediction of the setting characteristics of the hydraulic composition. The allophane content in the volcanic ejecta deposits can be measured, for example, by the acid-alkali alternating dissolution method.

[0031] The numerical ranges and measurement methods for each property of the volcanic ejecta deposit used to create the regression equation may be the same as or different from those for the volcanic ejecta deposit described above. If the volcanic ejecta deposit used to create the regression equation has the same properties as the volcanic ejecta deposit contained in the hydraulic composition to be predicted, the setting characteristics of the hydraulic composition can be estimated with higher accuracy. Furthermore, if the measurement methods for each property are the same, the setting characteristics of the hydraulic composition can be predicted with higher accuracy.

[0032] The regression equation creation step and the prediction step may be performed using a conventional calculator or computer. Measured values ​​of each property of the volcanic ejecta deposit used to create the regression equation are input into the computer, and the regression equation is derived using software. The regression equation may be stored in the memory of the computer, and measured values ​​of each property of the volcanic ejecta deposit used to prepare the hydraulic composition to be predicted may be input into the computer, so that the hardening characteristics of the hydraulic composition to be predicted are output.

[0033] According to the prediction method of this embodiment, it is possible to quickly and accurately predict the hardening characteristics of a hydraulic composition containing a deposit of volcanic ejecta.

[0034] A method for producing a hydraulic composition according to one embodiment includes a blending step of blending at least volcanic ejecta deposits and an alkaline activator as raw materials, and a prediction step of predicting the setting characteristics of the hydraulic composition by the above-described prediction method. By including such a prediction step, the setting characteristics of the resulting hydraulic composition can be predicted in advance. For example, it can be determined before the mixing step whether the hydraulic composition satisfies the desired setting characteristics.

[0035] In the blending step, the blending ratio of the raw materials may be adjusted based on the hardening characteristics predicted in the prediction step. For example, if the hardening characteristics predicted in the prediction step are too high or too low, a hydraulic composition having the desired hardening characteristics can be obtained by adjusting the blending ratio of the raw materials. This makes it possible to prevent or reduce the generation of a non-standard hardened body.

[0036] The raw materials include volcanic deposits and alkaline irritants. The volcanic deposits are listed above. The alkaline irritants include Portland cement clinker, Portland cement, tricalcium silicate (3CaO SiO 2、 C3S), slaked lime, alkali carbonate, etc.

[0037] Portland cement clinker can use Portland cement clinker used for preparing various Portland cements specified in JIS R 5210:2003 "Portland Cement". Examples of the various Portland cements include ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, medium-heat Portland cement, low-heat Portland cement, sulfate-resistant Portland cement, and the like. The Portland cement clinker may be a Portland cement clinker used for preparing ordinary Portland cement and early-strength Portland cement.

[0038] The mineral composition of Portland cement clinker can be calculated by the Bogue formula. Here, the Bogue formula is a formula widely used to calculate the content ratio of main minerals in Portland cement clinker from the content ratio of chemical composition. By using the Bogue formula shown below, the content of tricalcium silicate (3CaO·SiO 2、 Denoted as C3S.), dicalcium silicate (2CaO·SiO 2、 Denoted as C2S.), and tricalcium aluminate (3CaO·Al2O 3、 Denoted as C3A.) in Portland cement clinker can be calculated. In the following formula, "%" means "mass %". The chemical formula represents the content ratio (mass %) of each compound shown by the chemical analysis value according to JIS R 5204:2019 "Fluorescent X-ray Analysis Method for Cement".

[0039] <Bogue formula> C3S [%]=(4.07×CaO [%])-(7.60×SiO2 [%])-(6.72×Al2O3 [%])-(1.43×Fe2O3 [%])-(2.85×SO3 [%]) C2S [%]=(2.87×SiO2 [%])-(0.754×C3S [%]) C3A [%]=(2.65×Al2O3 [%])-(1.69×Fe (2O3 [%]) C4AF [%]=3.04×Fe2O3 [%]

[0040] Examples of alkali carbonates include sodium carbonate decahydrate (Na2CO3·10H2O), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), and sodium sesquicarbonate dihydrate (Na3H(CO3)2·NaHCO3·2H2O). These alkali carbonates may be used alone or in combination of two or more.

[0041] The content of the alkaline activator in the hydraulic composition may be, for example, 20 to 90% by mass based on the total amount of the hydraulic composition. From the viewpoint of sufficiently increasing the compressive strength of the hardened body, the lower limit of the content may be 30%, 40%, 50%, or 60% by mass. From the viewpoint of effectively utilizing volcanic ejecta deposits, the upper limit of the content may be 80%, 70%, or 60% by mass.

[0042] The content of the volcanic ejecta deposits in the hydraulic composition may be, for example, 10 to 90% by mass based on the total amount of the hydraulic composition. From the viewpoint of more effective use of the volcanic ejecta deposits, the lower limit of the content may be 20%, 30%, 40%, or 50% by mass. From the viewpoint of sufficiently increasing the compressive strength of the hardened body, the upper limit of the content may be 80%, 70%, or 60% by mass.

[0043] From the viewpoint of sufficiently increasing the compressive strength of the hardened body, the total content of the volcanic ejecta deposits and alkaline activator in the hydraulic composition may be 60 mass% or more, 70 mass% or more, 90 mass% or more, or even 100 mass% (consisting essentially of volcanic ejecta deposits and alkaline activator) based on the total amount of the hydraulic composition.

[0044] The allophane content in the hydraulic composition may be 2% by mass or more, 4% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, based on the total amount of the hydraulic composition, from the viewpoint of reducing carbon dioxide emissions. The allophane content in the hydraulic composition deposit may be 40% by mass or less, 35% by mass or less, 30% by mass or less, or 25% by mass or less, based on the total amount of the hydraulic composition, from the viewpoint of increasing the compressive strength of the hardened body at an age of 7 days. An example of the allophane content in the hydraulic composition is 2 to 40% by mass. The allophane content in the volcanic ejecta deposit may be 20% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, based on the total amount of the volcanic ejecta deposit, from the viewpoint of sufficiently increasing the compressive strength of the hardened body at an age of 28 days. The allophane content in the volcanic ejecta deposits may be 90 mass % or less, or 80 mass % or less, from the viewpoints of easy availability and reduced production costs.

[0045] The hydraulic composition may contain other components in addition to the volcanic ejecta deposits and the alkaline activator. Examples of the other components include inorganic fine powder, gypsum, carbonates, etc. The content of the other components may be 40% by mass or less, 20% by mass or less, or 15% by mass or less based on the total amount of the hydraulic composition.

[0046] The hydraulic composition may contain a carbonate. The carbonate promotes the hydration reaction between the alkaline activator and volcanic glass contained in volcanic deposits. The carbonate may be a carbonate other than an alkali metal salt, such as an alkaline earth metal carbonate or a hydrate thereof, such as calcium carbonate (limestone) or magnesium carbonate. Examples of limestone include commonly available limestone powder and powders containing calcium carbonate as the main component, such as kansui stone powder. The limestone preferably includes one that complies with the minor mixing components described in JIS R 5210:2009 "Portland Cement."

[0047] From the viewpoint of fluidity, the content of carbonate in the hydraulic composition may be 20 mass % or less based on the total amount of the hydraulic composition.

[0048] The use of inorganic fine powder can further increase the compressive strength of the hardened body. Examples of inorganic fine powder include powdered materials such as silica stone and crushed stone. The content of the inorganic fine powder in the hydraulic composition may be more than 0 mass % and 15 mass % or less based on the total amount of the hydraulic composition, from the viewpoint of achieving both high levels of fluidity and compressive strength.

[0049] Gypsum has the function of adjusting the hydration reaction rate in the hydraulic composition. Examples of gypsum include gypsum dihydrate, gypsum hemihydrate, and anhydrous gypsum. The content of gypsum in the hydraulic composition may be more than 0 mass% and 5 mass% or less based on the total amount of the hydraulic composition.

[0050] In the blending step, the raw materials are mixed together: the volcanic ejecta deposit, the alkaline activator, and the other optional components. The other components may be mixed together when the volcanic ejecta deposit and the alkaline activator are mixed. The raw materials may be blended in a ratio that will result in the content of the hydraulic composition described above.

[0051] In the blending step, each raw material may be pulverized. When pulverization is performed, the order of mixing and pulverization is not particularly limited. That is, the raw materials may be mixed and then pulverized, or each raw material may be pulverized individually and then mixed, or each raw material may be mixed and pulverized simultaneously. The mixing may be performed using a mixer such as a pan mixer, a tilting mixer, or a ribbon mixer. Alternatively, the raw materials may be mixed and pulverized using a pulverizer such as a ball mill, a vertical roller mill, or a roller press. Alternatively, each raw material may be pulverized individually and then mixed using a mixer such as a mechanical mixer. In this way, a hydraulic composition with excellent hardening properties can be produced.

[0052] The method may include a step of calcining the volcanic deposits prior to the blending step. The calcination temperature may be 500°C or higher from the viewpoint of increasing compressive strength. Furthermore, the calcination temperature may be 950°C or lower from the viewpoint of suppressing the use of tetrahedral Al and pentahedral Al in the formation of other minerals (e.g., mullite). From these viewpoints, the calcination temperature may be 600 to 900°C. The calcination time is not particularly limited, and may be 0.5 to 5 hours or 1 to 4 hours from the viewpoint of the effect on the crystal structure. By including the calcination step, a hardened body having even higher compressive strength can be obtained.

[0053] A hydraulic composition according to one embodiment includes a volcanic ejecta deposit and an alkaline activator. The components contained in the hydraulic composition and the content of each component may be the same as those described in the method for producing the hydraulic composition. The alkaline activator is Portland cement. The Portland cement has been described above.

[0054] The content of Portland cement in the hydraulic composition may be, for example, 20 to 90% by mass based on the total amount of the hydraulic composition. From the viewpoint of sufficiently increasing the compressive strength of the hardened body, the lower limit of the content may be 30%, 40%, 50%, or 60% by mass. From the viewpoint of effectively utilizing volcanic ejecta deposits, the upper limit of the content may be 80%, 70%, or 60% by mass.

[0055] The content of volcanic ejecta deposits in the hydraulic composition may be 10% by mass or more based on the total amount of the hydraulic composition. From the viewpoint of reducing carbon dioxide emissions by using volcanic ejecta deposits, the lower limit of the content may be 20%, 30%, 40%, or 50% by mass. From the viewpoint of sufficiently increasing the compressive strength of the hardened body, the upper limit of the content may be 80%, 70%, or 60% by mass.

[0056] The allophane content in the volcanic ejecta deposits may be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, based on the total amount of the volcanic ejecta deposits, from the viewpoint of sufficiently increasing the compressive strength of the hardened body at an age of 28 days. The allophane content in the volcanic ejecta deposits may be, for example, 90% by mass or 80% by mass, from the viewpoint of ease of availability. Hydraulic compositions containing such volcanic ejecta deposits have excellent hardening properties, despite containing volcanic ejecta deposits. The allophane content in volcanic ejecta deposits can be measured by an acid-alkali alternating dissolution method.

[0057] The allophane content of the hydraulic composition may be 4% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, based on the entire hydraulic composition, from the viewpoint of reducing carbon dioxide emissions. The allophane content of the hydraulic composition deposit may be 40% by mass or less, 35% by mass or less, 30% by mass or less, or 25% by mass or less, based on the entire hydraulic composition, from the viewpoint of increasing the compressive strength of the hardened body at an age of 7 days. An example of the allophane content of the hydraulic composition is 2 to 40% by mass. The allophane content of the hydraulic composition may be measured by an acid-alkali alternating dissolution method using the hydraulic composition, or may be calculated from the allophane content of the volcanic ejecta deposit measured by the acid-alkali alternating dissolution method and the blending ratio of the volcanic ejecta deposit.

[0058] When the compressive strength of a hardened body S of a hydraulic composition at an age of 7 or 28 days is SP, and the compressive strength of a hardened body C (standard) of a hydraulic composition containing limestone instead of volcanic ejecta deposits at an age of 7 or 28 days is CP, the compressive strength ratio II calculated by SP x 100 / CP may be 90 or more, 100 or more, or 110 or more at an age of 7 days, and may be 110 or more, 120 or more, 130 or more, or 140 or more at an age of 28 days. Hydraulic compositions whose compressive strength ratio II falls within the above range at at least one of the ages of 7 days and 28 days can exhibit significantly higher compressive strength than those containing limestone, and are therefore suitable for use in applications requiring high compressive strength. Hydraulic compositions whose compressive strength ratio II falls within the above range at both the ages of 7 days and 28 days can be even more suitable for use in applications requiring high compressive strength.

[0059] The compressive strength of the hydraulic composition in the present disclosure is measured in accordance with "Compressive Strength" in JIS R 5201:2015 "Physical Testing Methods for Cement." The mass-based content of volcanic ejecta deposits in the hydraulic composition for obtaining hardened body S is the same as the mass-based content of limestone in the hydraulic composition for obtaining hardened body C. In other words, the hydraulic composition for obtaining hardened body C corresponds to a hydraulic composition for obtaining hardened body S in which the volcanic ejecta deposits are replaced with limestone.

[0060] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. For example, the content described in one embodiment of the method for predicting the setting characteristics of a hydraulic composition, the method for manufacturing a hydraulic composition, and the hydraulic composition also applies to the other embodiments. The present disclosure includes the following embodiments [1] to

[13] .

[0061] [1] A method for predicting hardening characteristics of a hydraulic composition containing a volcanic ejecta deposit, comprising: The SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, and Fe 3+ and Fe 2+Fe relative to the total amount of 3+ a prediction step of predicting the setting characteristics of the hydraulic composition using at least one measured value selected from the group consisting of an ion ratio of [2] SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe of volcanic deposits used to create the regression equation 3+ and Fe 2+ Fe relative to the total amount of 3+ a regression equation creation step of creating a regression equation using at least one measured value selected from the group consisting of the ion ratio of the volcanic eruption product, the a value in the Lab color system, and the b value in the Lab color system as an explanatory variable, and the hardening characteristics of a hydraulic composition containing the volcanic eruption product deposits for creating the regression equation as a response variable, The prediction method according to [1], wherein the prediction step predicts the hardening characteristics using the regression equation. [3] In the regression equation creation step, the SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe of the volcanic ejecta deposits used to create the regression equation are calculated. 3+ and Fe 2+ Fe relative to the total amount of 3+ a multiple regression equation is created using at least two measured values ​​selected from the group consisting of the ion ratio of the volcanic ash, the a value in the Lab color system, and the b value in the Lab color system as explanatory variables, and the hardening characteristics of the hydraulic composition containing the volcanic ash deposits used to create the regression equation as a response variable; The prediction method according to [2], wherein the prediction step predicts the hardening characteristics using the multiple regression equation. [4] The prediction method according to any one of [1] to [3], wherein the allophane content of the volcanic ejecta deposit is 10 mass% or more. [5] The prediction method according to any one of [1] to [4], wherein the volcanic ejecta deposit has an SiO2 content of 30 to 80 mass%, an Al2O3 content of 5 to 45 mass%, and an R2O content of 0.1 to 10 mass%. [6] The a value of the volcanic ejecta deposits used to create the regression equation is 0.1 to 10, and the b value is 1 to 20; In the regression equation creation step, the regression equation is created using at least one or both of the measured values ​​of the a value and the b value as explanatory variables; The prediction method according to any one of [2] to [5], wherein the prediction step predicts the setting characteristics of the hydraulic composition using the regression equation. [7] The integrated value of the heat of hydration of the volcanic ejecta deposits used to create the regression equation is 0 to 50 J / g; In the regression equation creation step, the regression equation is created using at least the measured values ​​of the heat of hydration as explanatory variables; The prediction method according to any one of [2] to [6], wherein the prediction step predicts the setting characteristics of the hydraulic composition using the regression equation. [8] The BET specific surface area of ​​the volcanic deposits used to create the regression equation is 5 to 500 m 2 / g, In the regression equation creation step, the regression equation is created using at least the measured value of the BET specific surface area as an explanatory variable; The prediction method according to any one of [2] to [7], wherein the prediction step predicts the setting characteristics of the hydraulic composition using the regression equation. [9] A method for producing a hydraulic composition, comprising a blending step of blending at least an allophane-containing volcanic ejecta deposit and an alkaline activator as raw materials, A method for producing a hydraulic composition, comprising a step of predicting the setting characteristics of the hydraulic composition by the prediction method according to any one of [1] to [8].

[10] The method for producing a hydraulic composition according to [9], wherein in the blending step, the blending ratio of the raw materials is adjusted based on the hardening characteristics predicted in the prediction step.

[11] The method for producing a hydraulic composition according to [9] or

[10] , which comprises a pretreatment step of calcining the volcanic ejecta deposit before the mixing step.

[12] Volcanic deposits and Portland cement, The content of the volcanic ejecta deposits is 10% by mass or more, The hydraulic composition, wherein the allophane content in the volcanic ejecta is 50% by mass or more.

[13] The hydraulic composition according to

[12] , wherein the compression strength ratio based on the case where limestone is included instead of the deposit of the volcanic ejecta satisfies at least one of the following (1) and (2). (1) The compression strength ratio at 7 days of age is 90 or more (2) The compression strength ratio at 28 days of age is 110 or more

Examples

[0062] Hereinafter, the content of the present disclosure will be described more specifically with reference to specific examples. However, the present disclosure is not limited to the following examples.

[0063] <Preparation of raw materials> As deposits of volcanic ejecta (hereinafter referred to as "deposits"), as shown in Table 1, Secard P-1 (manufactured by Shinagawa General Co., Ltd., trade name), Kanuma soil (manufactured by Akagi Horticulture Co., Ltd.), sweet potato soil (manufactured by Yamakazu Pumice Co., Ltd.), VGP-1 (manufactured by Principle Co., Ltd., trade name), and black peat soil (commercially available product) were prepared.

[0064] <Measurement of chemical components> Fluorescent X-ray analysis (XRF) of the above-mentioned deposits was performed to measure the contents of Si, Al, Na, and K. These were converted into oxides respectively to obtain the SiO2 content, Al2O3 content, Na2O content, and K2O content. The R2O content was calculated as Na2O content + 0.658K2O content. The results are shown in Table 1.

[0065] <Measurement of heat of hydration> The heat of hydration of the above-mentioned deposits was measured. Each deposit and water were mixed at a mass ratio of 1:1 to prepare a measurement sample. Using a conduction calorimeter (manufactured by TA Instruments, device name: TAMAir), the heat of hydration of each measurement sample was measured. The heat of hydration rate and the integrated value of the heat of hydration were as shown in FIGS. 1(A) and (B). The integrated heat of evolution for 1 hour is shown in Table 1. The numbers in FIGS. 1(A) and (B) are the same as the numbers shown in Table 1.

[0066] <Measurement of BET specific surface area> Each deposit was dried by heating at 105°C for 1 hour under a nitrogen gas atmosphere. After heating, the amount of nitrogen gas adsorbed by each deposit was measured using a Microtrack-Bell BELSORPMINI. The specific surface area was calculated based on the measurement results. The results are shown in Table 1.

[0067] <Color measurement> The color of each deposit was measured three times using a spectrophotometer (SE7700, manufactured by Nippon Denshoku Industries Co., Ltd.) according to the Hunter 1948 method, with the L value, a value, and b value being averaged. The results are shown in Table 2.

[0068] <Fe 2+ and Fe 3+ Measurement of content> In accordance with JIS K 0102:2016 "Testing Methods for Industrial Wastewater," Fe in each sediment was measured using an ultraviolet-visible spectrophotometer (U-2900 model: Hitachi High-Tech Science Corporation). 2+ and Fe 3+ The results are shown in Table 2. In Table 2, T-Fe represents Fe 2+ and Fe 3+ means the total amount of Fe 2+ , Fe 3+ and T-Fe contents are the ratio of the number of these cations to the cations in each sediment (cation %).

[0069] [Table 1]

[0070] [Table 2]

[0071] <Measurement of allophane content> The allophane content of each sediment was measured by the acid-alkali alternating dissolution method. Specifically, the measurement was performed according to the following procedure.

[0072] First, organic matter was removed from the volcanic ejecta deposits using the following method. Specifically, the sample was first sieved through a 0.425 mm sieve. 50 ml of 10% by mass hydrogen peroxide solution was added to the sample that passed through the sieve, and the mixture was heated in a water bath. Next, 20 ml of 30% by mass hydrogen peroxide solution was added, and the mixture was heated in a water bath for 24 hours. After that, a sufficient amount of distilled water was added to the sample, and the aqueous phase was separated by centrifugation (2800 rpm, 6 minutes) to wash the sample. The washing was performed twice. The washed sample was then dried at 105°C for 24 hours.

[0073] The dried sample was subjected to the following series of steps (1) to (7) five times. (1) 50 ml of 8 M hydrochloric acid was added to the sample (volcanic deposit) and shaken for 30 minutes. (2) A sufficient amount of distilled water was added to the sample, and the sample was washed by separating the aqueous phase by centrifugation (2800 rpm, 6 minutes). (3) 50 ml of 0.5 M aqueous sodium hydroxide solution was added to the washed sample, and the sample was heated in a water bath at 60°C for 5 minutes. (4) The aqueous phase was separated by centrifugation (2800 rpm, 6 minutes) and the sample was washed. (5) A sufficient amount of distilled water was added to the sample, and the sample was washed by separating the aqueous phase by centrifugation (2800 rpm, 6 minutes). (6) After washing, the sample was dried at 105°C for 24 hours. (7) After drying, the weight of the sample was measured. By repeating the series of steps (1) to (7) five times, it was confirmed that the weight change of the sample due to leaching had almost completely disappeared. The allophane content was calculated based on the weight loss rate. The results are shown in Table 3.

[0074] [Table 3]

[0075] <Relationship between allophane content and properties> The correlation (simple correlation) between the allophane content in Table 3 and each property shown in Tables 1 and 2 was investigated. The results are shown in Figures 2 and 3. The coefficient of determination for each correlation, R 2 The regression equations are shown in the graphs of each figure. In the regression equations, x is the allophane content (mass%), and y is each measured value shown in Tables 1 and 2. Each property showed a high correlation with the allophane content. For the measured values ​​related to iron ions, Fe 3+ / Fe 2+ and Fe 3+ / T-Fe showed a high correlation with the allophane content.

[0076] <Production of hydraulic composition> The five types of deposits shown in Table 2 were calcined in air at 900°C for 1 hour in a calcination furnace (pretreatment). Separately, commercially available Portland cement (manufactured by UBE Mitsubishi Cement Corporation) was prepared as an alkaline activator. Limestone (325 mesh fine limestone powder, manufactured by Ube Material Industries, Ltd.) was also prepared.

[0077] <Production of hydraulic composition> Hydraulic compositions Nos. 1 to 24 were prepared by mixing the calcined sediment and / or limestone prepared as described above with an alkaline activator according to the formulations shown in Table 4. Nos. 5, 15, and 24 are hydraulic compositions prepared using only the alkaline activator and limestone without using any sediment. Table 4 shows the allophane content in the hydraulic compositions calculated from the blending ratio of the sediment and the measured value of the allophane content shown in Table 3.

[0078] [Table 4]

[0079] <Preparation of hardened body> The prepared hydraulic composition was mixed with water and standard sand for cement strength testing provided by the Japan Cement Association as fine aggregate, and hardened body S was prepared in accordance with the method described in JIS R 5201:2015 "Physical test methods for cement." The prepared hardened body S was cured underwater in a thermostatic chamber at 20°C until it was 7 days and 28 days old.

[0080] <Compression strength measurement> The compressive strength SP of each hardened body S was measured at ages of 7 days and 28 days. Each compressive strength was measured in accordance with the method described in JIS R 5201:2015 "Physical testing methods for cement." Table 5 shows the compressive strength ratio I (%) and compressive strength ratio II (%) of the hardened body S calculated from the measured compressive strength SP.

[0081] The compressive strength ratio I (%) is the ratio calculated by SP × 100 / AP, where AP is the compressive strength at each age of hardened body A, which was produced using only the alkaline activator used in the production of the hydraulic composition, and SP is the compressive strength at each age of hardened body S, which was produced using raw materials including calcined sediments. The compressive strength ratio II (%) is the ratio calculated by SP × 100 / CP, where CP is the compressive strength of hardened body C (Nos. 5, 15, and 24), which used only limestone instead of volcanic deposits as the mineral. In other words, the compressive strength ratio II (%) is the compressive strength ratio when limestone is used instead of volcanic deposits.

[0082] [Table 5]

[0083] Figures 4(A), (B), and (C) are graphs in which data for each sample is plotted, with the horizontal axis representing the allophane content of the hydraulic composition shown in Table 4 and the vertical axis representing the "compressive strength ratio I (%)" from Table 5. Figure 4(A) shows data for a sample containing 10% by mass of volcanic ejecta deposits or limestone. Figure 4(B) shows data for a sample containing 30% by mass of volcanic ejecta deposits or limestone. Figure 4(C) shows data for a sample containing 50% by mass of volcanic ejecta deposits or limestone. In each of Figures 4(A), (B), and (C), the open plots represent data at an age of 7 days, and the solid plots represent data at an age of 28 days.

[0084] As shown in Figures 4(A), (B), and (C), the compressive strength ratio I tended to be higher when volcanic ejecta deposits with a higher allophane content were used. Many of the hardened bodies had compressive strengths equivalent to those produced using only alkali-stimulated materials.

[0085] Figures 5(A), (B), and (C) are graphs in which data for each sample is plotted, with the horizontal axis representing the allophane content of the hydraulic composition shown in Table 4 and the vertical axis representing the "compressive strength ratio II (%)" from Table 5. Figure 5(A) shows data for a sample containing 10% by mass of volcanic ejecta deposits or limestone. Figure 5(B) shows data for a sample containing 30% by mass of volcanic ejecta deposits or limestone. Figure 5(C) shows data for a sample containing 50% by mass of volcanic ejecta deposits or limestone. In each of Figures 5(A), (B), and (C), the open plots represent data at an age of 7 days, and the solid plots represent data at an age of 28 days.

[0086] As shown in Figures 5(A), (B), and (C), the use of volcanic ejecta deposits with a high allophane content tended to result in a higher compressive strength ratio II compared to limestone. It was also confirmed that hardened bodies made from volcanic ejecta deposits containing allophane had compressive strengths equal to or greater than those made from limestone. As shown in Figures 2 and 3, there is a high correlation between the various properties of the deposits and the allophane content, confirming that the hardening characteristics of hydraulic compositions can be predicted with high accuracy based on the various properties of the deposits.

[0087] <Prediction accuracy of hardening characteristics> The ten properties shown in Tables 1 and 2 (SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, Fe 3+ and Fe 2+ Fe relative to the total amount of 3+ Two measured values ​​selected from the following (ion ratio, a value in the Lab color system, and b value in the Lab color system) were used as explanatory variables (X value 1, X value 2), and the compressive strength ratio I at 7 days or 28 days of age in Table 5 was used as the objective variable (Y value). The coefficient that minimizes the sum of squares of the residuals using the least squares method was determined, and based on these results, the multiple regression equation expressed as the following equation (I) was derived.

[0088] Y=αX1+βX2+γ (I)

[0089] The multiple regression equation was derived for any combination of two measured values. The coefficients α, β, and intercept γ of the multiple regression equation derived using the compressive strength ratio I at 7 days of age, as well as the correlation coefficient, are shown in Table 6. The coefficients α, β, and intercept γ of the multiple regression equation derived using the compressive strength ratio I at 28 days of age, as well as the correlation coefficient, are shown in Table 7.

[0090] [Table 6]

[0091] [Table 7]

[0092] The correlation between the measured values ​​of compressive strength ratio I at 7 days of age shown in Table 5 and the predicted values ​​of compressive strength ratio I at 7 days of age derived from each multiple regression equation shown in Table 6 was examined. Figures 6 to 10 show graphs in which the horizontal axis shows the measured values ​​of compressive strength ratio I at 7 days of age and the vertical axis shows the predicted values ​​of compressive strength ratio I at 7 days of age derived from each multiple regression equation are plotted. Table 6 shows the figure numbers corresponding to each multiple regression equation. In Figures 6 to 10, (%) indicates (mass%).

[0093] The correlation between the measured values ​​of compressive strength ratio I at 28 days of age shown in Table 5 and the predicted values ​​of compressive strength ratio I at 28 days of age derived from each multiple regression equation shown in Table 7 was examined. Figures 11 to 15 show graphs in which the horizontal axis represents the measured values ​​of compressive strength ratio I at 28 days of age and the vertical axis represents the predicted values ​​of compressive strength ratio I at 28 days of age derived from each multiple regression equation. Table 7 shows the figure numbers corresponding to each multiple regression equation.

[0094] Each graph in Figures 6 to 15 shows the coefficient of determination R of the correlation between the measured and predicted values ​​of the compressive strength ratio I. 2 The regression equations are shown in Tables 6 and 7. In the regression equations, x is the measured value (%) of the compressive strength ratio I, and y is the predicted value (%) of the compressive strength ratio I. The coefficient of determination R 2 is shown to three decimal places.

[0095] As shown in the graphs in Figures 6 to 15, it was confirmed that there was a sufficiently high correlation between all of them. From these results, it was found that the SiO2 content, Al2O3 content, Na2O content, K2O content, R2O content, calorific value of hydration, BET specific surface area, and Fe 3+ and Fe 2+ Fe relative to the total amount of 3+ It has been confirmed that the hardening characteristics of a hydraulic composition containing deposits can be predicted with sufficiently high accuracy based on two measured values ​​selected from the group consisting of the ion ratio, the a value in the Lab color system, and the b value in the Lab color system.

[0096] Of the hydraulic compositions Nos. 1 to 24 shown in Tables 4 and 5, the blending ratios of the volcanic eruption deposits and the alkaline activator (ordinary Portland cement) are the same for hydraulic compositions Nos. 1 to 24, and Table 9 shows the blending ratios of the hydraulic compositions Nos. 1 to 24 shown in Tables 4 and 5, and the compressive strength ratios I and II are shown in Table 8. As shown in Tables 8 and 9, it was confirmed that hydraulic compositions containing Sekado P-1, Kanuma soil, and Satsuma soil, which are volcanic eruption deposits with an allophane content of 40% by mass or more, can achieve higher compressive strength ratios I and II than hydraulic compositions containing Ando soil, which has an allophane content of less than 40% by mass.

[0097]

Table 8

[0098]

Table 9

Claims

1. A method for predicting hardening characteristics of a hydraulic composition containing volcanic ejecta deposits, comprising: SiO of the volcanic deposits ２ Content, Al ２ O ３ Content, Na ２ O content, K ２ O content, R ２ O content, hydration calorific value, BET specific surface area, Fe ３＋ and Fe ２＋ Fe relative to the total amount of ３＋ a prediction step of predicting the setting characteristics of the hydraulic composition using at least one measured value selected from the group consisting of an ion ratio of

2. SiO of volcanic deposits for creating regression equations ２ Content, Al ２ O ３ Content, Na ２ O content, K ２ O content, R ２ O content, hydration calorific value, BET specific surface area, Fe ３＋ and Fe ２＋ Fe relative to the total amount of ３＋ a regression equation creation step of creating a regression equation using at least one measured value selected from the group consisting of the ion ratio of the volcanic eruption product, the a value in the Lab color system, and the b value in the Lab color system as an explanatory variable, and the setting characteristics of a hydraulic composition containing the volcanic eruption product deposits for creating the regression equation as a response variable, The prediction method according to claim 1 , wherein the prediction step predicts the hardening characteristics using the regression equation.

3. In the regression equation creation step, SiO of the volcanic ejecta deposits used to create the regression equation is ２ Content, Al ２ O ３ Content, Na ２ O content, K ２ O content, R ２ O content, hydration calorific value, BET specific surface area, Fe ３＋ and Fe ２＋ Fe relative to the total amount of ３＋ a multiple regression equation is created using at least two measured values ​​selected from the group consisting of the ion ratio of the volcanic eruption product, the a value in the Lab color system, and the b value in the Lab color system as explanatory variables, and the hardening characteristics of the hydraulic composition containing the volcanic eruption product deposits used to create the regression equation as a response variable; The prediction method according to claim 2 , wherein the prediction step predicts the hardening characteristics using the multiple regression equation.

4. The prediction method according to any one of claims 1 to 3, wherein the allophane content of the volcanic ejecta deposit is 10 mass% or more.

5. SiO of the volcanic deposits ２ Content is 30-80% by mass, Al ２ O ３ The content is 5 to 45 mass%, R ２ The prediction method according to any one of claims 1 to 3, wherein the O content is 0.1 to 10 mass%.

6. the a value of the volcanic ejecta deposits used to create the regression equation is 0.1 to 10 and the b value is 1 to 20; In the regression equation creation step, the regression equation is created using at least one or both of the measured values ​​of the a value and the b value as explanatory variables; The prediction method according to claim 2 or 3, wherein the prediction step predicts the setting characteristics of the hydraulic composition using the regression equation.

7. the integrated value of the heat of hydration of the volcanic ejecta deposit for creating the regression equation is 0 to 50 J / g; In the regression equation creation step, the regression equation is created using at least the measured values ​​of the heat of hydration as explanatory variables; The prediction method according to claim 2 or 3, wherein the prediction step predicts the setting characteristics of the hydraulic composition using the regression equation.

8. The BET specific surface area of ​​the volcanic ejecta deposits used to create the regression equation is 5 to 500 m ２ / g, In the regression equation creation step, the regression equation is created using at least the measured value of the BET specific surface area as an explanatory variable; The prediction method according to claim 2 or 3, wherein the prediction step predicts the setting characteristics of the hydraulic composition using the regression equation.

9. A method for producing a hydraulic composition, comprising a blending step of blending at least an allophane-containing volcanic ejecta deposit and an alkali activator as raw materials, A method for producing a hydraulic composition, comprising a step of predicting the setting characteristics of the hydraulic composition by the prediction method according to any one of claims 1 to 3.

10. The method for producing a hydraulic composition according to claim 9 , wherein in the blending step, a blending ratio of the raw materials is adjusted based on the hardening characteristics predicted in the prediction step.

11. The method for producing a hydraulic composition according to claim 9, further comprising a pretreatment step of calcining the volcanic ejecta deposit prior to the mixing step.

12. Volcanic deposits and Portland cement, The content of the volcanic ejecta deposits is 10% by mass or more, The hydraulic composition, wherein the allophane content in the volcanic ejecta is 40 mass% or more.

13. 13. The hydraulic composition according to claim 12, wherein the compressive strength ratio of the hydraulic composition based on the compressive strength ratio of the hydraulic composition containing limestone instead of the volcanic ejecta deposit satisfies at least one of the following (1) and (2): (1) Compressive strength ratio at 7 days is 90 or more (2) Compressive strength ratio at 28 days is 110 or more

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