Hydraulic compositions, hydraulic composition blends and hardeners

Abstract

The subject of this invention is to propose a hydraulic composition capable of stably retaining or storing CO2 recovered from the atmosphere and achieving cost reduction, and a hardened body formed from the hydraulic composition. This invention is a hydraulic composition containing calcium carbonate. The proportion of calcium carbonate in the material is in the range of 30% to 95% by mass. Furthermore, it contains at least one of blast furnace slag, expanded material, hydrated lime, quicklime, fly ash, and Portland cement. In the case of containing Portland cement, the proportion of Portland cement in the materials other than calcium carbonate is 30% or less by mass. Furthermore, in the case of containing expanded material, the proportion of expanded material in the material is 2% to 9% by mass.

Description

Technical Field

[0001] This invention relates to a hydraulic composition containing calcium carbonate, a hydraulic composition mixture containing the hydraulic composition, and a hardened body formed from the hydraulic composition or the hydraulic composition mixture. Prior Technology

[0002] In the construction of building components, calcium carbonate is sometimes added to concrete, mortar, and cement paste to reduce CO2 (carbon dioxide) emissions and improve fire resistance. For example, the cement-based material disclosed in Patent Document 1 contains: cement, calcium carbonate, aggregate, additives, and porous materials. In recent years, technology has been developed to recycle CO2 to produce calcium carbonate. Calcium carbonate produced using this technology fixes CO2 from the atmosphere and emitted gases. If calcium carbonate is included in hydraulic compositions, it can fix or store CO2, thus reducing CO2 emissions. Furthermore, because calcium carbonate undergoes an endothermic reaction at high temperatures, it absorbs heat from its surroundings and exhibits self-extinguishing properties. Therefore, building materials using calcium carbonate will become highly fire-resistant materials. [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-051117 Summary of the Invention

[0004] [The problem that the invention aims to solve]

[0005] The subject of this invention is to propose: a hydraulic composition capable of stably retaining or storing CO2 recovered from the atmosphere and achieving cost reduction, a hydraulic composition mixture containing the hydraulic composition, and a hardened body formed from the hydraulic composition or the hydraulic composition mixture. (Methods for solving problems)

[0006] This invention relates to: a hydraulic composition containing calcium carbonate, a hydraulic composition mixture containing the hydraulic composition, and a hardened body formed from the hydraulic composition or the hydraulic composition mixture. The proportion of calcium carbonate contained in the hydraulic composition is in the range of 30% to 95% by mass, preferably 40% to 95% by mass, and more preferably 60% to 95% by mass. The hydraulic composition preferably contains, in addition to calcium carbonate, at least one material selected from blast furnace slag, expanded material, hydrated lime, quicklime, fly ash, and Portland cement. Particularly preferred is the presence of blast furnace slag, hydrated lime, and expanded material. Furthermore, in the case of materials containing Portland cement, the proportion of Portland cement in materials other than calcium carbonate is 70% or less by mass, preferably 30% or less by mass. Furthermore, the preferred ratio of the expandable material to the total hydraulic composition material is 2-9% by mass. According to this hydraulic composition, it exhibits good fluidity before hardening, presents the necessary strength after hardening, and can reduce CO2 emissions by reducing cement usage, and can stably retain (or store) CO2 due to the use of calcium carbonate. Furthermore, because this hydraulic composition contains a large amount of industrial byproducts such as blast furnace slag and fly ash, it makes a significant contribution to the efficient utilization of resources, and because it contains a large amount of calcium carbonate, it can be used to manufacture components with excellent refractory properties. Furthermore, according to this hydraulic composition, in addition to retaining CO2 by using calcium carbonate, a neutralization reaction occurs during the supply period, which allows it to absorb CO2 from the atmosphere.

[0007] When the hydraulic composition of the present invention is used to construct reinforced concrete structures, if a neutralization reaction occurs beyond what is necessary during the supply period, it may impair the rust prevention effect of reinforcing materials such as steel bars inside the concrete. In such cases, it is preferable that the hydraulic composition contains nitrate compounds at a ratio of 1 to 3% by mass relative to 100% by mass of nitrate ions (NO3-, formula 62). Furthermore, the hydraulic composition mixture of the present invention may also contain at least one of the following: the above-mentioned hydraulic composition, fiber material, bone material and chemical mixture. By adding water to the above-mentioned hydraulic composition or the mixture of the above-mentioned hydraulic composition and mixing, and after a predetermined curing period, a hardened body formed from the above-mentioned hydraulic composition or the mixture of the above-mentioned hydraulic composition can be obtained. [Invention Effects]

[0008] According to the present invention, the hydraulic composition, the hydraulic composition mixture and the hardener, by adding a large amount of calcium carbonate, CO2 emissions can be reduced, CO2 can be stably maintained (or stored) and costs can be reduced. Simple Explanation of the Diagram

[0009] Figure 1 shows the experimental results for the hydraulic composition, illustrating the relationship between the calcium carbonate ratio and the neutralization rate. Figure 2 shows the relationship between the strength of the hardened hydraulic composition mixture and the amount of cement per unit weight after 28 days. Figure 3 shows the relationship between the calcium carbonate ratio of the hydraulic composition and the compressive strength of the hardened material of the hydraulic composition mixture containing the hydraulic composition after 28 days. Figure 4 shows the relationship between the proportion of Portland cement in the powder other than calcium carbonate in the hydraulic composition and the compressive strength ratio when the proportion of Portland cement in the powder other than calcium carbonate is set to 100%. Figure 5 shows the relationship between the number of days since initial setting and shrinkage strain when the amount of expandable material added in the hydraulic composition mixture is varied. Figure 6 shows the relationship between the number of days since initial setting and shrinkage strain in hydraulic composite mixtures when the amount of expandable material added varies; and... Figure 7 shows the results of the accelerated weathering test on the hardened body, and the relationship between color difference and acceleration time. Implementation

[0010] (The form in which the invention is implemented)

[0011] This embodiment describes a hydraulic composition, a hydraulic composition blend, and a hardener that can recover a large amount of CO2 from the atmosphere for the purpose of reducing CO2 emissions and stably maintaining (or storing) CO2. The hydraulic composition of this embodiment is composed of powder containing, in addition to calcium carbonate (CaCO3), at least one of blast furnace slag, expanding material, hydrated lime, quicklime, fly ash and Portland cement. In addition to the hydraulic composition described above, the hydraulic composition of this embodiment also contains, for example: aggregates such as sand and gravel; agents such as chemical admixtures for concrete; metals; and fiber materials formed from polymer materials. The hardening system of the hydraulic composition is obtained by mixing water into the aforementioned hydraulic composition to obtain a slurry, and then hardening the slurry. Alternatively, the hardening system of the hydraulic composition mixture is obtained by mixing water into the aforementioned hydraulic composition mixture to obtain a mixture (equivalent to freshly mixed mortar or freshly mixed concrete), and then hardening it, equivalent to mortar or concrete.

[0012] The proportion of calcium carbonate (CaCO3) in the above-mentioned powder (the proportion of calcium carbonate (CaCO3) in the hydraulic composition) is in the range of 30% to 95% by mass, preferably 40% to 95% by mass, and even more preferably 60% to 95% by mass. The calcium carbonate (CaCO3) can be, for example, natural calcium carbonate, commonly known as "heavy calcium carbonate (CaCO3)," which is produced by crushing and classifying limestone; and synthetic calcium carbonate, commonly known as "light calcium carbonate," which is produced by precipitating fine crystals through a chemical reaction. Furthermore, since calcium carbonate produced by recovering CO2 is also synthesized from the reaction of calcium and CO2, it can also be treated as light calcium carbonate.

[0013] The blast furnace slag should preferably be the blast furnace slag powder used in JIS (Japanese Industrial Standard) R5211 "Blast Furnace Cement" or the blast furnace slag powder suitable for JIS A6206 "Blast Furnace Slag for Concrete". Furthermore, the blast furnace slag should preferably have a specific surface area of ​​2000~10000 cm² / g, preferably 3500~7000 cm² / g. Expansive materials can be any materials specified in JIS A6202 "Expansive Materials for Concrete". It is preferable to add the expansive material at a ratio of 2-9% by mass relative to the total hydraulic composition. Slaked lime can be any type specified in JIS R9001 "Industrial Lime". Furthermore, since quicklime turns into slaked lime upon contact with water, slaked lime can be used instead of the quicklime specified in JIS R9001 "Industrial Lime". In this case, it is best to pre-fill the required amount of water for the quicklime to be converted into slaked lime. For fly ash, any fly ash that conforms to JIS A6201 "Fly Ash for Concrete" is acceptable. Portland cement can use ordinary Portland cement, but other types of Portland cement, such as medium-heat Portland cement, low-heat Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, and sulfate-resistant Portland cement, can also be used, as specified in JIS R5210 "Portland cement" and JIS R5214 "Environmentally friendly cement".

[0014] When the hydraulic composition contains Portland cement, the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) is set to 70% by mass or less, preferably 30% by mass or less. Furthermore, when using Portland cement, blast furnace slag, or fly ash, it can be used separately or separately as a premixed form of the same component, such as JIS R5211 "blast furnace cement" or JIS R5213 "fly ash cement", or they can be used in combination.

[0015] The hydraulic composition according to this embodiment exhibits the necessary strength after hardening. Furthermore, the hydraulic composition according to this embodiment reduces CO2 emissions from Portland cement production and stably retains (or stores) CO2 recovered from the atmosphere or exhaust gases by reducing the amount of cement used or omitting Portland cement. In a highly environmentally friendly hydraulic composition containing at least one of blast furnace slag, expanding material, hydrated lime, quicklime, fly ash, and Portland cement, the hydraulic composition of this embodiment, incorporating calcium carbonate (CaCO3), exhibits reduced strength even with an increased ratio of calcium carbonate (CaCO3) to powder compared to a hydraulic composition incorporating calcium carbonate (CaCO3) in ordinary Portland cement. Moreover, the reduction in strength is further suppressed by incorporating a large amount of blast furnace slag. Furthermore, the hydraulic composition of this embodiment contains a large amount of calcium carbonate (CaCO3), thus enabling the manufacture of components with excellent fire resistance. Because calcium carbonate (CaCO3) undergoes an endothermic reaction at high temperatures (500~900℃) to produce CaCO3 → CaO + CO2, the hydraulic composition of this embodiment is self-extinguishing in the event of a fire.

[0016] The experimental results of the hydraulic composition of this embodiment will be described below. (1) Neutralization speed First, the proportion of calcium carbonate (CaCO3) in the hydraulic composition was set to 0-50% by mass. For the hardened bodies (Case a-j) of the hydraulic compositions containing other materials mixed in the proportions shown in Table 1, the rate of CO2 absorption from the atmosphere (i.e., neutralization rate) was measured under a CO2 concentration of 5%. As shown in Table 1, in Cases a-c, the powder materials other than calcium carbonate (CaCO3) constituting the hydraulic composition contained blast furnace slag, expanded material, and hydrated lime, respectively, according to different formulations. In Case d, the powder material contained only Portland cement and blast furnace slag; in Case e, the powder material constituting the hydraulic composition contained calcium carbonate (CaCO3), Portland cement, and blast furnace slag. Also, in Case f, the powder material contained Portland cement, blast furnace slag, and fly ash. Furthermore, in Cases d and f, calcium carbonate (CaCO3) was not used, and formulations were adopted to reduce environmental impact. Case g: The powder material contains calcium carbonate (CaCO3), Portland cement, blast furnace slag, and fly ash. Cases h-j: The powder material other than calcium carbonate (CaCO3) contains only Portland cement, and the amount is in the range of 50-100% by mass. Here, cases a, b, d, f, h, i, where the amount of calcium carbonate (CaCO3) is less than 30% by mass relative to the total amount of the hydraulic composition material, are comparative examples, while cases c, e, g, j, where the amount is 30% by mass or more, are examples.

[0017] The following materials were used in the experiment: Water: Public tap water Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, BET specific surface area 5.0 m2 / g Portland cement: Ordinary Portland cement, density 3.16 g / cm³, Bryan specific surface area 3270 cm² / g, JIS R5210 Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Fly ash: Type II fly ash, density 2.30 g / cm³, Brønsted specific surface area 4640 cm² / g, JIS A6201

[0018] [Table 1] CaCO3 percentage (%) The percentage of Portland cement powder other than CaCO3 (%) W / P Water W(g) Hydraulic composition P(g) Portland Cement Blast furnace slag Expanded material Slaked lime fly ash CaCO3 Case a 8.6 0.0 0.50 50.0 0.0 77.1 6.9 7.4 0.0 8.6 Case b 25.0 0.0 0.50 50.0 0.0 63.3 5.6 6.0 0.0 25.0 Case c 50.0 0.0 0.50 50.0 0.0 42.2 3.8 4.0 0.0 50.0 Case d 0.0 30.0 0.50 50.0 30.0 70.0 0.0 0.0 0.0 0.0 Case e 50.0 30.0 0.50 50.0 15.0 35.0 0.0 0.0 0.0 50.0 Case f 0.0 30.0 0.50 50.0 30.0 40.0 0.0 0.0 30.0 0.0 Case g 50.0 30.0 0.50 50.0 15.0 20.0 0.0 0.0 15.0 50.0 Case h 0.0 100.0 0.50 50.0 100.0 0.0 0.0 0.0 0.0 0.0 Case i 25.0 100.0 0.50 50.0 75.0 0.0 0.0 0.0 0.0 25.0 Case j 50.0 100.0 0.50 50.0 50.0 0.0 0.0 0.0 0.0 50.0

[0019] For the hydraulic compound P prepared according to the formula shown in Table 1, water W was added and mixed according to the water-to-powder ratio W / P of 0.50. The resulting mixture (slurry) was then used to prepare specimens with a diameter of approximately 3 cm and a height of approximately 5 cm, which were then sealed and cured. The specimens were demolded at 28 days of age and stored at 20°C and 60% humidity for 7 days after demolding. Then, except for the bottom surface, the specimens were covered with aluminum adhesive tape and placed in an environment with an air temperature of 20°C, a humidity of 60%, and a CO2 concentration of 5% to conduct a neutralization promotion test. After 14 or 28 days, the specimens were cut, and a 1% phenolphthalein alcohol solution was sprayed onto the cut surface. The uncolored area was designated as the neutralization area, and the depth of neutralization was measured. The results are shown in Table 2. It is known that the neutralization rate is proportional to the square root of the neutralization period. When the relationship between the change in neutralization depth and the square root of the neutralization period is approximated by a straight line (linear approximation), the slope of the line can be taken as the neutralization rate. That is, the neutralization rate represents the proportion of the change in neutralization depth to the square root of the change during the neutralization period. Figure 1 shows the relationship between the calcium carbonate (CaCO3) ratio and the neutralization rate.

[0020] [Table 2]

[0021] As shown in Table 2 and Figure 1, the amounts of calcium carbonate (CaCO3) in cases a to c increase sequentially to 8.6%, 25%, and 50% by mass, respectively. The neutralization rates of these formulations are 0.507, 0.646, and 0.861 cm / s, respectively. The neutralization rate increases with the amount of calcium carbonate (CaCO3). Furthermore, under the same condition of W / P=0.5, the cases d~g of different powder compositions showed that the neutralization rate increased with the increase of calcium carbonate (CaCO3). Furthermore, in case h~j, the neutralization rate also increases with the increase of calcium carbonate (CaCO3). Therefore, there is a tendency that the more calcium carbonate (CaCO3) content increases, the faster the neutralization rate. In addition, the neutralization rate of case j is smaller than that of cases c, e, and g containing the same amount of calcium carbonate (CaCO3).

[0022] Furthermore, as shown in Figure 1, compared to cases h, d, and f where no calcium carbonate (CaCO3) was added, reducing the amount of Portland cement in the powder other than calcium carbonate (CaCO3) to below 30% by mass resulted in a larger neutralization rate. On the other hand, if the amount of calcium carbonate (CaCO3) relative to the total hydraulic composition (powder) material is set to 30% by mass or more, then the formulation, regardless of the powder other than calcium carbonate (CaCO3), can be expected to have a neutralization rate of the same level or higher as Case f (where the amount of Portland cement is set to 30% by mass or less, and a formulation that reduces environmental impact is not used) and if the amount of calcium carbonate (CaCO3) is set to 40% by mass or more, then the formulation, regardless of the powder other than calcium carbonate (CaCO3), can be expected to have a neutralization rate of the same level or higher as Case d (where the amount of Portland cement is set to 30% by mass or less, and a formulation that reduces environmental impact is not used) and a formulation that reduces environmental impact. That is, if the amount of calcium carbonate (CaCO3) in the powder is set to 30% or more by mass, preferably 40% or more by mass, then regardless of the composition of the powder other than calcium carbonate (CaCO3), the same level or higher effect as the case of reducing the proportion of Portland cement in the powder can be obtained. This confirms that hydraulic complexes that increase the neutralization rate are expected to absorb more atmospheric CO2 after hardening, and thus increase the amount of atmospheric CO2 fixed during supply.

[0023] Comparing cases c, g, e, and j where the proportion of calcium carbonate (CaCO3) in the hydraulic composition is equal, increasing the proportion of blast furnace slag in the hydraulic composition (i.e., increasing the proportion of blast furnace slag in powders other than calcium carbonate (CaCO3)) tends to accelerate the neutralization process. Therefore, when the hydraulic composition contains blast furnace slag, it is preferable to increase the proportion of blast furnace slag in powders other than calcium carbonate (CaCO3), such as blast furnace slag, Portland cement, expansive materials, hydrated lime, and fly ash. More preferably, the proportion of blast furnace slag in powders other than calcium carbonate (CaCO3) should be set to 40% by mass or more.

[0024] (2) Compressive strength When hydraulic compositions are used as structural components, it is preferable to have compressive strength capable of withstanding applied loads. Here, a hydraulic composition mixture containing a hydraulic composition and fine aggregate (sand) is used to measure the compressive strength after hardening (7-day strength and 28-day strength) when the proportion of calcium carbonate (CaCO3) in the hydraulic composition, the types and amounts of other materials in the hydraulic composition besides calcium carbonate (CaCO3), and the water-to-powder ratio are changed.

[0025] The following materials were used in the experiment: Water: Public tap water Portland cement: Ordinary Portland cement, density 3.16 g / cm³, specific surface area 3270 cm² / g, JIS R5210 Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Fly ash: Type II, density 2.30 g / cm³, specific surface area 4640 cm² / g, JIS A6201 Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, BET specific surface area 5.0 m2 / g Fine aggregate: A mixture of mountain sand from Kimitsu, crushed sand from Tsuhimi, and crushed sand from Tokai; surface dry density 2.60 g / cm³; water absorption 2.07%.

[0026] Table 3 shows the formulation. Table 4 shows the strength test results. Additionally, Table 4 shows the strength ratios (compressive strength ratio = Case 1-4 / Case A, B) between Cases 1-4 (containing blast furnace slag) and Cases A and B (composed of Portland cement and calcium carbonate (CaCO3)), where the water-to-powder ratio (W / P) and the calcium carbonate (CaCO3) ratio are the same. Here, the numbers "25", "50", etc., after Cases 1-4 and Cases A, B indicate the proportion (mass%) of calcium carbonate (CaCO3) in the hydraulic composition. Therefore, in Cases 1-4 and Cases A, B, those marked with "0", "25", and "99" are comparative examples, while the others are exemplary examples. Furthermore, in Table 4, the compressive strength ratios recorded in columns 1-50 and 2-50 are strength ratios relative to Case A-50, and the compressive strength ratios recorded in column 4-70 are strength ratios relative to Case B-70. Also, the compressive strength ratios recorded in columns 1-25 and 2-25 are strength ratios relative to Case A-25.

[0027] [Table 3] CaCO3 ratio (%) W / P Unit quantity (kg / m3) water W Water hardening composition P Fine aggregate Portland Cement Blast furnace slag Expanded material Slaked lime fly ash CaCO3 Case 1-25 (Comparative Example) 25 0.50 239 0 302 27 29 0 119 1431 Case 1-50 50 237 0 200 18 19 0 237 1422 Case 1-70 70 237 0 120 11 11 0 332 1422 Case 1-90 90 237 0 40 4 4 0 427 1422 Case 2-25 (Comparative Example) 25 240 108 252 0 0 0 120 1440 Case 2-50 50 238 72 167 0 0 0 238 1430 Case 2-70 70 238 43 100 0 0 0 333 1427 Case 2-90 90 237 14 33 0 0 0 426 1420 Case 3-25 (Comparative example) 25 238 54 232 0 0 71 119 1427 Case 3-70 70 237 twenty one 92 0 0 28 331 1420 Case 4-25 (Comparative example) 25 0.35 180 326 29 31 0 0 129 1545 Case 4-70 70 179 130 12 12 0 0 358 1535 Case A-0 (Comparative Example) 0 0.50 244 487 0 0 0 0 0 1461 Case A-25 (Comparative Example) 25 241 362 0 0 0 0 121 1448 Case A-50 50 240 240 0 0 0 0 240 1440 Case A-70 70 238 143 0 0 0 0 334 1430 Case A-80 80 238 95 0 0 0 0 380 1425 Case A-90 90 237 47 0 0 0 0 427 1422 Case A-95 95 237 twenty four 0 0 0 0 450 1422 Case A-99 (Comparative Example) 99 237 5 0 0 0 0 468 1419 Case B-25 (Comparative Example) 25 0.35 183 392 0 0 0 0 131 1568 Case B-50 50 182 260 0 0 0 0 260 1557 Case B-70 70 180 155 0 0 0 0 361 1545

[0028] [Table 4] CaCO3 ratio (%) The percentage of Portland cement powder other than CaCO3 (%) Compressive strength (N / mm2) Compression strength ratio 7d 28d 7d 28d Case 1-25 (Comparative Example) 25 0 17.6 24.9 0.662 0.743 Case 1-50 50 0 13.6 19.7 1.12 1.13 Case 1-70 70 0 8.68 9.23 1.69 1.10 Case 1-90 90 0 1.61 3.96 1.04 1.54 Case 2-25 (Comparative Example) 25 30 19.7 29.3 0.741 0.875 Case 2-50 50 30 12.9 18.4 1.07 1.06 Case 2-70 70 30 8.21 11.6 1.59 1.39 Case 2-90 90 30 2.02 3.93 1.30 1.53 Case 3-25 (Comparative Example) 25 15 13.0 18.4 0.489 0.549 Case 3-70 70 15 5.26 12.2 1.02 1.46 Case 4-25 (Comparative Example) 25 0 25.2 36.3 0.655 0.831 Case 4-70 70 0 13.7 17.4 1.22 1.12 Case A-0 (Comparative Example) 0 100 39.1 51.9 - - Case A-25 (Comparative Example) 25 100 26.6 33.5 - - Case A-50 50 100 12.1 17.4 - - Case A-70 70 100 5.15 8.37 - - Case A-80 80 100 3.41 5.43 - - Case A-90 90 100 1.55 2.57 - - Case A-95 95 100 0.916 1.19 - - Case A-99 (Comparative Example) 99 100 Unhardened Unhardened - - Case B-25 (Comparative Example) 25 100 38.5 43.7 - - Case B-50 50 100 21.9 29.3 - - Case B-70 70 100 11.2 15.6 - -

[0029] Figure 2 shows the compressive strength per unit cement weight (kg / m³) and after 28 days (28d) (refer to Table 4). To clarify the characteristics of the hydraulic composition mixture, the results of hardened mortar with a W / P ratio of 0.5 and a W / P ratio of 0.5 are recorded. In Case A (where all powder materials other than calcium carbonate (CaCO₃) in the hydraulic composition are Portland cement), increasing the proportion of calcium carbonate (CaCO₃) and reducing the amount of Portland cement used (per unit cement weight) results in a decrease in strength. On the other hand, in Cases 1-3 (where the powder materials other than calcium carbonate (CaCO₃) in the hydraulic composition contain powders other than Portland cement), even with a lower amount of cement per unit weight, the compressive strength is significantly increased compared to Case A. Therefore, hydraulic compositions containing calcium carbonate (CaCO₃) still have sufficient strength in practical applications even with a significant reduction in the amount of Portland cement used.

[0030] In Figure 2, dashed lines A to D represent approximate lines connecting the strengths of blends with the same proportion of calcium carbonate (CaCO3) in the hydraulic composition. Dashed line A (comparative example), where the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 25% by mass, shows a decrease in strength when the amount of cement per unit volume is reduced; even adjusting the materials and proportions of the hydraulic composition does not improve strength. On the other hand, dashed lines B to D (executives), where the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 50-90% by mass, show an increase in strength when the amount of cement per unit volume is reduced. In other words, in this embodiment, the higher the proportion of calcium carbonate (CaCO3) in the hydraulic composition, the greater the effect of not weakening compressive strength and reducing the amount of cement per unit volume.

[0031] Furthermore, lines i-iv in Figure 2 represent approximate lines connecting the strength changes of blends where the proportion of Portland cement in the powder (excluding calcium carbonate (CaCO3)) is equal for each case. The approximate lines represent the measurement points where the strength effect occurs when the proportion of calcium carbonate (CaCO3) in the hydraulic composition reaches 50% by mass or more. Line i represents the case where the proportion of Portland cement in the powder (excluding calcium carbonate (CaCO3)) is set to 100% by mass, while lines ii, iii, and iv represent the cases of 30% by mass, 15% by mass, and 0% by mass, respectively. From lines i-iii in Figure 2, it can be seen that the smaller the proportion of Portland cement in the powder (excluding calcium carbonate (CaCO3)), the greater the rate of increase in strength relative to the increase in unit cement content. That is, when using blast furnace slag, expanded materials, hydrated lime, and fly ash in the powder system (excluding calcium carbonate (CaCO3)), reducing the proportion of Portland cement can achieve a significant increase in compressive strength without increasing the unit cement content.

[0032] Figure 3 shows the compressive strength ratios over 28 days (28d) as shown in Table 4. As shown in Figures 2 and 3, and Table 4, if the calcium carbonate (CaCO3) proportion is 25% by mass (Case 1-25, 2-25, 3-25, 4-25), the compressive strength is lower than that of Case A-25 and B-25, which contain only calcium carbonate (CaCO3) and Portland cement. On the other hand, if the calcium carbonate (CaCO3) proportion is 50% by mass or higher (Case 1-50, 1-70, 1-90, 2-50, 2-70, 2-90, 3-70, 4-70), the compressive strength is higher than that of Case A-50, A-70, A-90, B-50, and B-70, which contain only calcium carbonate (CaCO3) and Portland cement. That is, if the proportion of calcium carbonate (CaCO3) exceeds 25% by mass, there is a possibility that the compressive strength ratio will exceed 1. As can be confirmed by Figure 3, if the proportion of calcium carbonate (CaCO3) exceeds 30% by mass, the compressive strength ratio will exceed 1. Therefore, if the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 30% by mass or more, even if Portland cement is replaced with materials using at least one of blast furnace slag, expansive materials, hydrated lime, quicklime, fly ash, and Portland cement, it can still exhibit the same or higher strength as the hydraulic composition mixture of calcium carbonate (CaCO3) and Portland cement alone. If the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 40% by mass or more, it is better because the compressive strength ratio is approximately greater than 1.2, and if it is 60% by mass or more, it is even better because the compressive strength ratio is approximately greater than 1.4.

[0033] Figure 4 shows the ratio of the slopes of lines ii to iv in Figure 2 to line i. Since the slopes of lines i to iv represent the compressive strength per unit amount of cement, the ratio of the slopes of lines ii to iv to line i can be regarded as the ratio of the compressive strength per unit amount of cement, and the vertical axis represents it according to the compressive strength ratio. If the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) decreases, the compressive strength ratio increases, confirming the effect of the present invention. If the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) is below 70% by mass, the compressive strength ratio exceeds 2; if it is below 30% by mass, the compressive strength ratio is approximately above 4. Therefore, the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) is preferably below 70% by mass, and more preferably below 30% by mass.

[0034] Furthermore, based on the results of cases 1-50, 1-70, 1-90, and 2-50, 2-70, 2-90, where the proportion of Portland cement in powders other than calcium carbonate (CaCO3) is set to 30% or less, it is evident that the compressive strength tends to increase with the increase in the proportion of blast furnace slag. Therefore, in hydraulic compositions where the proportion of Portland cement in powders other than calcium carbonate (CaCO3) is 30% or less, the preferred proportion of blast furnace slag in the powders other than calcium carbonate (CaCO3) is 70% or more, and more preferably 80% or more.

[0035] (3) Compressive strength when the calcium carbonate (CaCO3) content varies between 42% and 70%. Secondly, for the hydraulic composition mixture containing the hydraulic composition of this embodiment, fine aggregate (sand), and coarse aggregate (gravel), the proportion of calcium carbonate (CaCO3) in the hydraulic composition was varied between 42% and 70% to confirm the properties. Specifically, the slump or slump flow of the mixture of hydraulic composition and water (hereinafter also referred to as "fresh concrete") and the compressive strength (1-day strength, 7-day strength, and 28-day strength) of the hardened mixture (hereinafter also referred to as "concrete") were measured. The compressive strength test specimen (concrete) was demolded at 2 days and then cured in standard water at 20°C. In Examples 33, 35, and 38, the compressive strength at 1 day was measured after 2 hours of sealed curing at 20°C and then 2.5 hours of steam curing at 60°C.

[0036] The following materials were used in the experiment: Water: Public tap water Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, BET specific surface area 5 m2 / g Fine aggregate: A mixture of mountain sand from Kimitsu, crushed sand from Tsukumi, and crushed sand from Tokai; surface dry density 2.60 g / cm³; water absorption 2.07%. Coarse aggregate: Crushed stone from Qingmei, particle size 20mm, surface dry density 2.66g / cm3, water absorption rate 0.60%. Table 5 shows the formulation used in this experiment. Table 6 shows the results of the strength test.

[0037] [Table 5] CaCO3 percentage (%) W / P Unit quantity (kg / m3) water W Water hardening composition P Fine aggregate coarse aggregate Blast furnace slag Expanded material Slaked lime CaCO3 Example 31 42.3 0.292 200 333 30 32 290 503 794 Example 32 43.0 0.230 155 333 30 32 290 633 781 Example 33 45.0 0.241 155 310 28 29 277 617 832 Example 34 45.0 0.305 175 269 twenty four 26 256 623 839 Example 35 45.0 0.399 155 182 16 17 173 720 971 Example 36 49.0 0.226 155 333 30 32 280 538 887 Example 37 52.1 0.212 175 333 30 32 430 432 793 Example 38 70.0 0.281 155 140 13 13 386 635 893

[0038] [Table 6] Slump (cm) Collapse density (cm) 1-day strength (N / mm²) 7-day strength (N / mm²) 28-day strength (N / mm²) Strength after 1 day of steam curing (N / mm2) Example 31 - 63.8×62.0 5.85 29.5 40.7 - Example 32 - 64.4 × 60.0 5.96 38.9 50.8 - Example 33 - 48.0×46.0 13.1 35.7 44.1 27.0 Example 34 - 60.0 × 57.9 - 26.3 34.4 - Example 35 13.5 - - 17.7 22.4 12.4 Example 36 - 67.4 × 63.6 1.40 37.7 53.7 - Example 37 - 60.0×60.0 1.83 40.4 55.7 - Example 38 20.0 - - 18.2 26.0 12.5 * "-" indicates that the symbol was not determined.

[0039] As shown in Table 6, the fresh concrete mixes in Examples 31, 32, 33, 34, 36, and 37 all had a slump exceeding 46.0 cm, exhibiting high fluidity. These also did not experience material segregation and were classified as high-flowability fresh concrete suitable for workability. Furthermore, the fresh concrete mixes in Examples 35 and 38 had slumps of 13.5 cm and 20 cm, respectively. Therefore, ordinary fresh concrete mixes without high fluidity can also be manufactured. In addition, JIS A 5308 specifies the slump or slump flow range for ordinary concrete. According to JIS, a slump of 5.5–22.5 cm or a slump flow of 37.5–70.0 cm is required, and the fresh concrete mixes manufactured in this study all meet these standards.

[0040] The compressive strength of the 31-38 series materials at 7 days of age is 17-40 N / mm², and at 28 days of age is 22-55 N / mm². Even with the addition of large amounts of anhydrous and reactive calcium carbonate (CaCO₃), accounting for 42-70% of the total powder in the hydraulic composition, a compressive strength of over 20 N / mm² can still be ensured. Furthermore, by setting the W / P ratio below 0.241, high-strength concrete exceeding 40 N / mm² can be manufactured. As mentioned above, it can be confirmed that a formulation in which the proportion of calcium carbonate (CaCO3) in the powder constituting the hydraulic composition is set to 42-70% by mass can produce fresh concrete with the same workability as ordinary concrete used in structural components such as reinforced concrete, and can produce concrete with the same compressive strength as ordinary concrete.

[0041] (4) Neutralization rate of hydraulic composite materials containing nitrate or nitrite compounds A hydraulic composition with a calcium carbonate (CaCO3) content of 45% by mass and the remaining materials in the proportions shown in Table 7 was mixed with a nitrate compound mixture (hydraulic composition mixture) in water at a W / P ratio of 0.305 to prepare a slurry of the hydraulic composition mixture, which was then hardened. Furthermore, when the nitrate compound contained bound water, the amount of water added was reduced by the amount of bound water. Also, the amount of nitrate compound added was 0.45% by mass of nitrogen atoms (N) relative to 100% by mass of the hydraulic composition (equivalent to 2% by mass of nitrate ions (NO3-)). The nitrate compound could be mixed with the hydraulic composition in powder form or dissolved in water before mixing. Additionally, Ca(NO2)2·H2O and NaNO2 are nitrite compounds, but in the nitrite compounds described in this invention, nitrite ions (NO2-) are converted to nitrate ions (NO3-).

[0042] The following materials were used in the experiment: Water: Public tap water Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, BET specific surface area 5.0 m2 / g Ca(NO2)2·H2O: Manufactured by Kanto Chemical Co., Ltd., Kanto Chemical Co., Ltd. Grade I standard (purity ≥ 90.0% (titration method)) Ca(NO3)2·4H2O: Manufactured by Kanto Chemical Co., Ltd., JIS K8549 (purity ≥ 99.0% (residue method)) Mg(NO3)2·6H2O: Manufactured by Kanto Chemical Co., Ltd., JISK8567 (purity ≥99.0% (titration method)) NaNO2: Manufactured by Kanto Chemical Co., Ltd., JIS K8019 (purity ≥ 98.5% (titration method)) NaNO3: Manufactured by Kanto Chemical Co., Ltd., JIS K8542 (purity ≥ 99.0% (titration method)) KNO3: Manufactured by Kanto Chemical Co., Ltd., JIS K8548 (purity ≥ 99.0% (titration method)) NH4 NO3: Manufactured by Kanto Chemical Co., Ltd., JIS K8545 (purity ≥ 99.0% (titration method))

[0043] [Table 7] Types of nitrate compounds CaCO3 percentage (%) W / P NO3 - (P×%) Water W(g) (Including bound water in nitrate compounds) Hydraulic composition P(g) Nitrate compounds (g) Blast furnace slag Expanded material Slaked lime CaCO3 nitrate-free compounds 45.0 0.305 0.0 305 46.4 4.18 4.42 45.0 0.0 Ca(NO2)2·H2O 45.0 0.305 2.0 305 33.9 Ca(NO3)2·4H2O 45.0 0.305 2.0 305 53.3 Mg(NO3)2·6H2O 45.0 0.305 2.0 305 57.9 NH4 NO3 45.0 0.305 2.0 305 20.1 NaNO2 45.0 0.305 2.0 305 15.6 NaNO3 45.0 0.305 2.0 305 19.2 KNO3 45.0 0.305 2.0 305 33.9

[0044] Using a slurry obtained by mixing a predetermined amount of water with the hydraulic composition mixture shown in Table 7, specimens with a diameter of approximately 3 cm × height of approximately 5 cm were prepared and sealed for curing. The specimens were demolded after 28 days of age and then stored at 20°C and 60% humidity for 7 days. Then, except for the bottom side, all other sides were covered with aluminum adhesive tape and placed in an environment with a temperature of 20°C, humidity of 60%, and CO2 concentration of 5% to conduct a neutralization acceleration test. After a predetermined period, the specimen was cut, and a 1% phenolphthalein alcohol solution was sprayed onto the cross-section. The uncolored area was designated as the neutralization area, and the depth of neutralization was measured. The results are shown in Table 8. It is known that the neutralization rate is proportional to the square root of the neutralization period. When the relationship between the change in neutralization depth and the square root of the neutralization period is approximated by a straight line (linear approximation), the slope of the line can be taken as the neutralization rate. That is, the neutralization rate represents the proportion of the change in neutralization depth to the square root of the change in the neutralization period.

[0045] [Table 8] Types of nitrate compounds Promotes neutralization 14 days later (cm) Promotes neutralization 28 days later (cm) Promoted neutralization 56 days later (cm) Neutralization speed (cm / )) The rate of neutralization (with nitrate-free compounds set to 1). nitrate-free compounds - 1.39 2.30 0.299 1.00 Ca(NO2)2·H2O 0.50 0.73 - 0.137 0.46 Ca(NO3)2·4H2O 0.70 0.88 - 0.170 0.57 Mg(NO3)2·6H2O 0.66 1.00 - 0.187 0.62 NH4 NO3 1.12 1.70 - 0.317 1.06 NaNO2 1.40 1.51 - 0.302 1.01 NaNO3 1.11 1.69 - 0.315 1.05 KNO3 1.09 1.58 - 0.297 0.99 *-: No measurement possible

[0046] As shown in Table 8, the addition of calcium nitrite monohydrate (Ca(NO2)2·H2O), calcium nitrate tetrahydrate (Ca(NO3)2·4H2O), and magnesium nitrate hexahydrate (Mg(NO3)2·6H2O) showed a significant neutralization inhibition effect, with the neutralization rate reduced by less than 60% compared to the case without nitrate. Therefore, it can be confirmed that by adding calcium nitrite, calcium nitrate, and magnesium nitrate, the hardened body of the related hydraulic composition mixture can inhibit the neutralization rate.

[0047] (5) Neutralization rate of hydraulic composite materials containing chemical additives A hydraulic composition with calcium carbonate (CaCO3) comprising 45% by mass and the remaining materials in the proportions shown in Table 9 was mixed with a chemical admixture (hydraulic composition mixture) in water at a W / P ratio of 0.305 to prepare a hydraulic composition mixture slurry, which was then hardened. A neutralization acceleration test was performed on the obtained hardened body, and the neutralization rate was calculated. The test results are shown in Table 10.

[0048] In addition, the following materials were used in this experiment: Water: Public tap water Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, BET specific surface area 5.0 m2 / g Chemical mixture: MasterSet FZP99, manufactured by Pozzolith Solutions, nitrate ion content 24% by mass

[0049] [Table 9] CaCO3 percentage (%) W / P NO3 - (P×%) Water W(g) (Contains chemical mixtures) Hydraulic composition P(g) Chemical mixture (g) Blast furnace slag Expanded material Slaked lime CaCO3 nitrate-free compounds 45.0 0.305 0.0 30.5 46.4 4.18 4.42 45.0 0.0 6% chemical mixture 45.0 0.305 1.44 30.5 6.0 8% chemical mixture 45.0 0.305 1.92 30.5 8.0 10% chemical mixture 45.0 0.305 2.40 30.5 10.0 12% chemical mixture 45.0 0.305 2.88 30.5 12.0 *Chemical mixtures are added only after being dissolved in water.

[0050] Using a slurry obtained by mixing a predetermined amount of water with a hydraulic composition mixture as shown in Table 9, specimens approximately 3 cm in diameter and 5 cm in height were prepared and sealed for curing. The specimens were demolded after 28 days of age and then stored at 20°C and 60% humidity for 7 days. Then, except for the bottom surface... The rest of the sample was covered with aluminum adhesive tape and placed in an environment with a temperature of 20°C, humidity of 60%, and CO2 concentration of 5% to conduct a neutralization promotion test. After a predetermined period, the specimen was cut, and a 1% phenolphthalein alcohol solution was sprayed onto the cross-section. The uncolored area was designated as the neutralization area, and the depth of neutralization was measured. The results are shown in Table 10. It is known that the neutralization rate is proportional to the square root of the neutralization period. When the relationship between the change in neutralization depth and the square root of the neutralization period is approximated by a straight line (linear approximation), the slope of the line can be taken as the neutralization rate. That is, the neutralization rate represents the proportion of the change in neutralization depth to the square root of the change in the neutralization period.

[0051] [Table 10] Promotes neutralization 28 days later (cm) Promoted neutralization 56 days later (cm) Promoted neutralization 91 days later (cm) Neutralization rate (cm / ) The rate of neutralization (with nitrate-free compounds set to 1). nitrate-free compounds 1.39 2.30 - 0.299 1.00 6% chemical mixture 0.81 1.28 1.80 0.168 0.56 8% chemical mixture 0.64 1.03 1.77 0.135 0.45 10% chemical mixture 0.47 0.86 1.39 0.110 0.37 12% chemical mixture 0.46 0.77 1.39 0.100 0.33 *-: No measurement possible

[0052] As shown in Table 10, when 6% or more of a chemical mixture containing nitrate ions (NO3-) was added relative to 100% by mass of the hydraulic composition (equivalent to 1% or more by mass of NO3-), a significant neutralization inhibition effect was observed, and the neutralization rate was halved compared to the case without nitrates. Furthermore, the higher the dosage of the chemical mixture, the lower the neutralization rate. Therefore, by adding nitrates at a rate of 1% or more (based on nitrate ion conversion) relative to 100% of the hydraulic composition, it was confirmed that the neutralization rate of the hardened mixture of the hydraulic composition could be suppressed.

[0053] (6) Properties when the amount of expanded material added changes Secondly, the properties of the hydraulic composition containing expansive material were confirmed. The proportion of expansive material in the hydraulic composition (powder) was varied within the range of 2-9% by mass. In this experiment, a mixture of hydraulic composition containing hydraulic composition, fine aggregate (sand), and coarse aggregate (gravel) was mixed with water, and the slump or slump flow, the start and end time of setting were measured for the obtained mixture (hereinafter referred to as "fresh concrete"). Furthermore, the compressive strength (28-day strength) and autogenous shrinkage strain of the hardened mixture (hereinafter referred to as "concrete") were measured. The method for determining the start and end times of setting is based on JIS A 1147:2019 Test method for setting time of concrete.

[0054] Furthermore, the method for measuring autogenous shrinkage strain was based on the autogenous shrinkage test method for high-flowability concrete described in Report II of the Super-Flowable Concrete Research Committee of the Japan Society of Concrete Engineers. Specifically, an embedded strain gauge was placed in the center of a 10cm×10cm×40cm concrete corner column specimen. After pouring concrete, the specimen was demolded after 2 days. The specimen was then sealed with plastic sheeting in an indoor environment at 20°C, and the shrinkage was measured up to 30 days. This measured value was designated as the autogenous shrinkage strain. Table 11 shows the formulation used in this experiment. Table 12 and Figures 5 and 6 show the results of the compressive strength test.

[0055] In addition, the following materials were used in the experiment: Water: Public tap water Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Calcium carbonate (CaCO3): Light calcium carbonate, density 2.6 g / cm3, BET specific surface area 5.0 m2 / g Fine aggregate: A mixture of mountain sand from Kimitsu, crushed sand from Tsukumi, and crushed sand from Tokai; surface dry density 2.60 g / cm³; water absorption 2.07%. Coarse aggregate: Crushed stone from Qingmei, maximum particle size 20mm, surface dry density 2.66g / cm3, water absorption rate 0.60%.

[0056] [Table 11] CaCO3 percentage (%) The proportion of expanded materials (%) W / P Unit quantity (kg / m3) water W Water hardening composition P Fine aggregate coarse aggregate Blast furnace slag Expanded material Slaked lime CaCO3 Example 61 39.8 2.2 0.242 155 340 14.0 32.0 255 618 982 Example 62 44.5 4.2 0.242 155 300 27.0 29.0 285 618 982 Example 63 47.4 6.4 0.242 155 271 41.0 26.0 303 618 982 Example 64 51.9 8.9 0.242 155 229 57.0 22.0 332 621 834 Example 65 49.8 7.9 0.276 175 245 50.0 23.0 316 601 808 Example 66 44.5 5.2 0.305 175 263 30.0 25.0 256 626 842

[0057] [Table 12] Slump (cm) Collapse density (cm) Initial setting time (h) Condensation termination time (h) 28-day strength (N / mm²) Self-shrinking strain (×10⁻⁶) Example 61 19.5 - 7.8 11.6 45.4 -442 Example 62 - 54.6×54.4 12.1 16.3 46.2 -417 Example 63 - 54.7×52.5 11.0 15.7 48.0 -347 Example 64 - 58.7×49.0 8.4 13.2 43.7 -0.16 Example 65 - 56.9×54.9 10.7 16.4 39.1 -222 Example 66 - 59.4 × 58.8 13.2 19.1 34.3 -353 *Expansion is represented by positive values ​​and contraction by negative values ​​in the self-contracting strain system. "-" indicates that the value was not measured.

[0058] As shown in Table 12, the slump of all embodiments is 19 cm, or the slump flowability is 40.0~60.0 cm, which is within the range of 6.5~22.5 cm slump or 37.5~70.0 cm slump for ordinary concrete as specified in JIS A 5308, exhibiting appropriate fluidity. Furthermore, the compressive strength after 28 days exceeds 30 N / mm², demonstrating sufficient compressive strength. In other words, the hydraulic composition blends of Examples 61~66 retain the manufacturability and workability of concrete even when the proportion of expansive material in the hydraulic composition varies between 2~9% by mass (expansive material usage 14~57 kg / m³).

[0059] Furthermore, as shown in Table 12 and Figure 5, Examples 61 and 62 exhibit larger values ​​of self-shrinkage strain, namely -442 × 10⁻⁶ and -417 × 10⁻⁶, respectively. On the other hand, Examples 63 and 64, where the proportion of expandable material in the hydraulic composition is set to 6% or 9% by mass (expandable material usage of 41 kg / m³ or 57 kg / m³), show a significant reduction in self-shrinkage strain to -347 × 10⁻⁶ and -0.16 × 10⁻⁶, respectively. Examples 65 and 66, with a larger unit water volume than Examples 61-64, also reduce self-shrinkage strain by increasing the proportion of expandable material (see Figure 6). A formulation with 40-52% by mass of calcium carbonate (CaCO3) in the hydraulic composition was found to be able to produce concrete using the same method as ordinary concrete when the proportion of expansive material was varied between 2-9% by mass, and the self-shrinkage strain could be controlled by adding expansive material.

[0060] (7) Properties when fiber materials are added Secondly, the properties of the hardened mixture (hereinafter also referred to as "concrete") containing the hydraulic composition of this embodiment, fiber material, fine aggregate and coarse aggregate are confirmed. Specifically, the slump or slump flow of the mixture of hydraulic composition and water (hereinafter also referred to as "fresh concrete") and the compressive strength of the hardened mixture (1-day strength, 2-day strength and 28-day strength) are measured.

[0061] The following materials were used in the experiment: Water: Public tap water Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, Blaine specific surface area 4350 cm2 / g Fine aggregate: A mixture of land sand from Gyoho and limestone crushed sand from Sano, with a surface-dry density of 2.64 g / cm³ and a water absorption rate of 1.91%. Coarse aggregate: Sano limestone crushed stone, maximum particle size 20mm, surface dry density 2.71g / cm3, water absorption rate 0.97%. Fiber material: Steel fiber, 35mm long (Dramix3D, manufactured by BEKAERT JAPAN) Chemical mixture: MasterSet FZP99, manufactured by Pozzolith Solutions, nitrate ion content 24% by mass Table 13 shows the formulation used in this experiment. Table 14 shows the results of the strength test.

[0062] [Table 13] CaCO3 percentage (%) W / P Unit quantity (kg / m3) water W Water hardening composition P Fine aggregate coarse aggregate Chemical mixture Fiber materials Blast furnace slag Expanded material Slaked lime CaCO3 Example 71 44.6 0.305 175 263 30 25 256 753 775 34.4 39.0 Example 72 44.6 0.305 175 263 30 25 256 753 775 0 39.0 Example 73 44.6 0.305 184 277 32 26 270 723 747 0 39.0 Example 74 46.4 0.305 184 270 50 15 290 719 740 0 39.0

[0063] [Table 14] Slump (cm) after fiber material is incorporated 1-day strength (N / mm²) 2D strength (N / mm²) 7-day strength (N / mm²) 28-day strength (N / mm²) Example 71 67.2 × 64.9 10.6 23.1 - 58.1 Example 72 58.1×56.4 8.02 17.1 - 43.2 Example 73 56.2 × 54.3 5.52 14.3 27.6 40.1 Example 74 56.3 × 55.9 5.35 16.3 - 46.0 *-: No measurement possible

[0064] As shown in Table 14, the fresh concrete mixtures (hydraulic composite materials with added steel fibers) in Examples 71, 72, 73, and 74 exhibit a slump exceeding 50.0 cm, demonstrating high fluidity. These fresh concrete mixtures can be manufactured without material segregation even when steel fibers or aggregates are incorporated, resulting in easily workable fresh concrete. Furthermore, the slump range for ordinary concrete, determined by JIS A 5308, is 37.5–70.0 cm. All the fresh concrete mixtures manufactured in this study after incorporating steel fibers meet this standard.

[0065] Examples 71, 72, 73, and 74 show compressive strengths of 5-10 N / mm² at 1 day and 14-23 N / mm² at 2 days. The compressive strength at 28 days is 40-58 N / mm². Although calcium carbonate (CaCO₃) is non-aqueous and non-reactive, even with a relatively high proportion of 46.4% by mass in the hydraulic composition, a compressive strength of 40 N / mm² or higher can still be guaranteed. Furthermore, by adding steel fibers, in addition to flexural strength, an increase in compressive strength can be expected. For example, Example 72 is substantially the same as Example 66 (refer to Table 11) except for the steel fibers. However, when comparing the compressive strength at 28 days, Example 66 without added steel fibers has a strength of 34 N / mm², while Example 72 with added steel fibers has a strength of 43 N / mm². The above results confirm that even with an increased proportion of calcium carbonate (CaCO3) in the hydraulic composition, and the addition of fiber materials, it is still possible to produce concrete with the same workability and compressive strength as ordinary fiber-reinforced concrete.

[0066] (8) Grinding effect Secondly, the effect of grinding the surface of the hardened body was confirmed for the hydraulic composition mixture containing the hydraulic composition of this embodiment, fine aggregate, and coarse aggregate. The hydraulic composition mixture below uses a calcium carbonate (CaCO3) content of 41.3% by mass in the hydraulic composition. Water was added to the hydraulic composition mixture (hydraulic composition, fine aggregate, and coarse aggregate) and mixed. The mixture (fresh concrete) was then poured into a mold and hardened to produce a 15cm × 15cm × 1cm thick cubic specimen. The prepared specimens were sealed and cured outdoors (outdoor temperature 0~7℃) for 14 days, then demolded and ground using a stone grinder with a grit size of #400. Table 15 shows the formulation.

[0067] In addition, the following materials were used in the experiment: Water: Public tap water Blast furnace slag: Blast furnace slag micro powder 4000, density 2.89 g / cm3, Brønsted specific surface area 4480 cm2 / g, JIS A6206 Expanding material: Expanding agent type 30 (lime-based expanding material), density 3.15 g / cm3, Bryan specific surface area 3810 cm2 / g, JIS A6202 Hydrated lime: Premium grade hydrated lime, density 2.20 g / cm³, all 600 μm sieve passed, JIS R9001. Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67 g / cm3, BET specific surface area 5.0 m2 / g Fine aggregate: Crushed granite sand from paddy fields, surface dry density 2.60 g / cm³, water absorption 0.38% Coarse aggregate: Granite crushed stone from paddy fields, maximum particle size 12mm, surface dry density 2.62g / cm3, water absorption rate 0.64%.

[0068] [Table 15] CaCO3 percentage (%) W / P Unit quantity (kg / m3) water W Water hardening composition P Fine aggregate coarse aggregate Blast furnace slag Expanded material Slaked lime CaCO3 Example 81 41.3 0.291 190 319 28.7 30.3 277 672 677

[0069] The specimen (a hardened body of the hydraulic composite material) was stored indoors at 20°C for 28 days. Then, an accelerated weathering test was conducted for 5000 hours using an accelerated weathering tester (XER-W75: Iwasaki Electric) under conditions of 2 hours of wet-dry cycling (102 minutes of drying, 18 minutes of wetting) and an irradiation intensity of 60 W / m². At 0, 500, 1000, 2000, 3000, 4000, and 5000 hours, the L*a*b* color space (JIS Z8781-4) of 24 hardened areas (non-aggregate parts) of the specimen was measured using a spectrophotometer (NF333: Nippon Denshoku Kogyo). The average value was calculated, and the color difference between the specimen at 0 hours and the specimen at 0 hours was evaluated. Figure 7 shows the relationship between accelerated weathering time and color difference.

[0070] The prepared specimens were ground smooth without any defects such as bone loss, making them suitable as polishing materials to mimic marble and other natural stones. As shown in Figure 7, even after 5000 hours, no color change was observed, and it was confirmed that there was no discoloration due to ultraviolet light. Furthermore, a cylindrical specimen with a diameter of 10cm and a height of 20cm was sealed and cured, and a compressive strength test was conducted after 28 days of material age. The result showed that the compressive strength was 36.2 N / mm2. By polishing a hardened mixture of hydraulic composite materials containing a large amount of calcium carbonate (CaCO3), a polishing material that mimics natural stone can be created. Furthermore, weather resistance tests confirm that the hardened mixture will not discolor.

[0071] The above describes the embodiments of the present invention. However, the present invention is not limited to the aforementioned embodiments, and all the above-mentioned constituent elements can be appropriately modified without departing from the spirit and scope of the present invention. For example, the materials that constitute calcium carbonate (CaCO3), blast furnace slag, expanded materials, hydrated lime, quicklime, fly ash, and Portland cement are not limited to those shown in the above embodiments.

[0072] none.

Claims

1. A hydraulic composition comprising: light calcium carbonate, blast furnace slag powder, and expanding material and hydrated lime, or Portland cement, or Portland cement and expanding material, or Portland cement and fly ash, wherein... The proportion of the aforementioned light calcium carbonate is in the range of 30% to 95% by mass, and the proportion of the aforementioned blast furnace slag micro powder in the powder other than the aforementioned light calcium carbonate is more than 40% by mass.

2. The hydraulic composition as described in claim 1, wherein, It contains expanded material at a rate of 2-9% by mass.

3. The hydraulic composition as described in claim 2, wherein, It contains slaked lime at a rate of 2.3% or more by mass.

4. The hydraulic composition as described in claim 1, wherein, Of the materials other than calcium carbonate mentioned above, there is Portland cement in a proportion of less than 30% by mass.

5. The hydraulic composition as described in claim 2, wherein, Of the materials other than calcium carbonate mentioned above, there is Portland cement in a proportion of less than 30% by mass.

6. The hydraulic composition as described in claim 3, wherein, Of the materials other than calcium carbonate mentioned above, there is Portland cement in a proportion of less than 30% by mass.

7. A hydraulic composition blend material comprising the hydraulic composition described in any one of claims 1 to 6, and a hydraulic composition blend material containing a nitrate compound; wherein, The composition contains the above-mentioned nitrate compound in a proportion of 1 to 3% by mass of nitrate ions, relative to 100% by mass of the above-mentioned hydraulic composition.

8. A hydraulic composition blend material, wherein, It contains: the hydraulic composition described in any one of claims 1 to 6, and at least one of the following: fiber material, bone material and chemical mixture.

9. A hydraulic composition blend material comprising: a hydraulic composition as described in any one of claims 1 to 6, a nitrate compound, and at least one of a fiber material, a bone material, and a chemical admixture; wherein, The composition contains, relative to 100% by mass of the above-mentioned hydraulic composition, nitrate ions in a ratio of 1 to 3% by mass of the above-mentioned nitrate compound.

10. A hardened body, wherein, It is formed from the hydraulic composition described in any one of claims 1 to 6.

11. The hardened body as described in claim 10, wherein, The surface is polished.

12. A hardened body, wherein, It is formed from the hydraulic composition mixture described in claim 7.

13. A hardened body, wherein, It is formed from the hydraulic composition mixture described in claim 8.

14. A hardened body, wherein, It is formed from the hydraulic composition mixture described in claim 9.

15. The hardened body as described in claim 12, wherein, The surface is polished.

16. The hardened body as described in claim 13, wherein, The surface is polished.

17. The hardened body as described in claim 14, wherein, The surface is polished.

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