Hydraulic components, hydraulic component mixtures, hardened materials

Abstract

To propose a hydraulic composition capable of stably retaining and storing CO2 collected from the atmosphere and reducing costs, a mixed material containing the hydraulic composition, and hardened bodies formed thereof.SOLUTION: A hydraulic composition contains light calcium carbonate. The light calcium carbonate constitutes 30-95 mass% of the material. It is preferable that the hydraulic composition contains at least one among blast furnace slag fine powder, an expansive admixture, hydrated lime, quick lime, fly ash, and Portland cement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present 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. [Background technology]

[0002] When constructing construction members, calcium carbonate is sometimes added to concrete, mortar, and cement paste for the purposes of reducing CO2 (carbon dioxide) emissions and improving fire resistance. For example, Patent Document 1 discloses a cement-based material containing cement, calcium carbonate, aggregate, additives, and a porous material. In recent years, technology has been developed to produce calcium carbonate by capturing CO2. Calcium carbonate produced using this technology fixes CO2 in the atmosphere and exhaust gases. By incorporating calcium carbonate into hydraulic compositions, CO2 can be fixed or stored, thereby reducing CO2 emissions. Furthermore, calcium carbonate undergoes an endothermic reaction at high temperatures, absorbing surrounding heat and exhibiting self-extinguishing properties. Therefore, building materials that use calcium carbonate are fire-resistant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-051117 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a hydraulic composition that can stably retain and store CO2 captured from the atmosphere and reduce costs, a hydraulic composition mixture containing this hydraulic composition, and a hardened body formed from the hydraulic composition or the hydraulic composition mixture. [Means for solving the problem]

[0005] The present invention relates to calcium carbonate and Portland cement The present invention relates to a hydraulic composition comprising the above-mentioned calcium carbonate, a hydraulic composition mixture containing the above-mentioned hydraulic composition, and a hardened body formed from the hydraulic composition or the hydraulic composition mixture. The calcium carbonate is light calcium carbonate. The proportion of the calcium carbonate contained in the hydraulic composition is 30% by mass to 95% by mass, preferably 40% by mass to 95% by mass. More preferably, more than 50% by mass and not more than 95% by mass. More preferably, it is in the range of 60% by mass to 95% by mass. The hydraulic composition is calcium carbonate and Portland cement In addition, blast furnace slag, expansive agent, slaked lime, quicklime and Fly Assy Yu's It is preferable that the composition contains at least one material selected from the group consisting of blast furnace slag, hydrated lime, and an expanding material. Also, Portland cement To The proportion of the Portland cement in the materials other than calcium carbonate is preferably 70% by mass or less, more preferably 30% by mass or less. The proportion of the expansive material is preferably 2 to 9 mass % based on the total materials of the hydraulic composition. Such hydraulic compositions exhibit good fluidity before hardening and exhibit the necessary strength after hardening, and also reduce CO2 emissions by reducing the amount of cement used, and enable stable retention and storage of CO2 by using light calcium carbonate. In addition, since the hydraulic compositions contain a large amount of industrial by-products such as blast furnace slag and fly ash, they contribute to the effective use of resources. Furthermore, since it contains a large amount of calcium carbonate, it is possible to manufacture components with excellent fire resistance. Furthermore, such a hydraulic composition not only retains CO2 by using calcium carbonate, but also causes a neutralization reaction during its service life, making it possible to capture CO2 from the atmosphere.

[0006] When the hydraulic composition of the present invention is used to construct a reinforced concrete structure, if the carbonation reaction occurs more than necessary during the service life, the rust prevention effect of reinforcing materials such as steel bars inside the concrete may be impaired. In such a case, it is recommended to use nitrate ions (NO ) in an amount of 100% by mass of the hydraulic composition. 3- It is preferable that the nitrate compound is contained in an amount of 1 to 3 mass % in terms of formula weight 62). The hydraulic composition mixture of the present invention may contain the hydraulic composition and at least one material selected from the group consisting of a fiber material, an aggregate, and a chemical admixture. Water is added to and mixed with the hydraulic composition or the hydraulic composition mixture, and after a predetermined curing period has elapsed, a hardened body formed from the hydraulic composition or the hydraulic composition mixture is obtained. [Effects of the Invention]

[0007] According to the hydraulic composition, hydraulic composition mixture, and hardened body of the present invention, by adding a large amount of precipitated calcium carbonate, it becomes possible to reduce CO2 emissions, stably retain and store CO2, and also reduce costs. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a graph showing the results of an experiment conducted on a hydraulic composition, illustrating the relationship between the proportion of calcium carbonate and the rate of carbonation. [Figure 2] 1 is a graph showing the relationship between the strength of a hardened body of a hydraulic composition mixed material containing a hydraulic composition at 28 days old and the unit cement amount. [Figure 3] 1 is a graph showing the relationship between the proportion of calcium carbonate in a hydraulic composition and the compressive strength of a hardened body of a hydraulic composition mixture containing the hydraulic composition at an age of 28 days. [Figure 4] 1 is a graph showing the relationship between the proportion of Portland cement in the powder other than calcium carbonate of a hydraulic composition and the compressive strength ratio when the proportion of Portland cement in the powder other than calcium carbonate is 100%. [Figure 5] 1 is a graph showing the relationship between the number of days elapsed since the start of setting and shrinkage strain when the amount of expansive agent added to a hydraulic composition mixture is changed. [Figure 6] 1 is a graph showing the relationship between the number of days elapsed since the start of setting and shrinkage strain when the amount of expansive agent added to a hydraulic composition mixture is changed. [Figure 7] 1 is a graph showing the results of an accelerated weathering test conducted on a cured product, illustrating the relationship between color difference and acceleration time. DETAILED DESCRIPTION OF THE INVENTION

[0009] In this embodiment, a hydraulic composition, a hydraulic composition mixture, and a hardened product that can recover a large amount of CO2 from the atmosphere will be described, with the aim of reducing CO2 emissions and stably retaining and storing CO2. The hydraulic composition of this embodiment is made of powder containing, in addition to calcium carbonate (CaCO3), at least one of blast furnace slag, expansive material, hydrated lime, quicklime, fly ash, and Portland cement. The hydraulic composition mixture of this embodiment contains, in addition to the hydraulic composition, aggregates such as sand and gravel, chemical agents such as chemical admixtures for concrete, and fiber materials made of metals or polymeric materials. The hardened hydraulic composition is obtained by hardening a paste obtained by kneading the hydraulic composition with water. The hardened hydraulic composition mixture is obtained by hardening a mixture (equivalent to fresh mortar or fresh concrete) obtained by kneading the hydraulic composition mixture with water, and corresponds to mortar or concrete.

[0010] The proportion of calcium carbonate (CaCO3) in the powder (the proportion of calcium carbonate (CaCO3) in the hydraulic composition) is within the range of 30% to 95% by mass, preferably 40% to 95% by mass, and more preferably 60% to 95% by mass. Examples of calcium carbonate (CaCO3) that can be used include natural calcium carbonate known as heavy calcium carbonate (CaCO3), which is obtained by crushing and classifying limestone, and synthetic calcium carbonate known as light calcium carbonate, which is obtained by precipitating fine crystals through a chemical reaction. Calcium carbonate produced by recovering CO2 can also be treated as light calcium carbonate, since it is synthesized by the reaction of calcium and CO2.

[0011] It is desirable to use ground granulated blast furnace slag used in JIS (Japanese Industrial Standards) R5211 "Blast furnace cement" or ground granulated blast furnace slag conforming to JIS A6206 "Blast furnace slag for concrete." In addition, blast furnace slag should have a specific surface area of ​​2000 to 10000 cm. 2 / g, preferably 3500 to 7000 cm 2 It is desirable to use one with a saturation of 0.15 to 0.25 g. The expansive material may be, for example, one specified in JIS A6202 “Expansive materials for concrete.” The expansive material is preferably added in an amount of 2 to 9 mass % based on the total amount of the hydraulic composition. For example, slaked lime specified in JIS R9001 "Industrial Lime" can be used. Furthermore, because quicklime becomes slaked lime when it comes into contact with water, quicklime specified in JIS R9001 "Industrial Lime" can be used instead of slaked lime. In this case, it is advisable to adjust the amount of water required to convert quicklime into slaked lime. The fly ash used may be one that conforms to JIS A6201 "Fly ash for concrete," for example. Ordinary Portland cement is used as Portland cement, but other types of Portland cement, such as moderate-heat Portland cement, low-heat Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, and sulfate-resistant Portland cement, as specified in JIS R5210 "Portland cement," and JIS R5214 "Ecocement" can also be used.

[0012] 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, and preferably 30% by mass or less. Furthermore, when Portland cement and blast furnace slag or fly ash are used, the components may be pre-mixed, for example, JIS R5211 "blast furnace cement" or, for example, JIS R5213 "fly ash cement," and the pre-mixed components may be used alone or in combination.

[0013] The hydraulic composition of this embodiment exhibits the required strength after hardening. Furthermore, the hydraulic composition of this embodiment reduces the amount of cement used or eliminates Portland cement, thereby reducing CO2 emissions associated with Portland cement production and enabling stable retention and storage of CO2 captured and fixed from the atmosphere or exhaust gases. The hydraulic composition of this embodiment, which incorporates calcium carbonate (CaCO3) into an environmentally friendly hydraulic composition containing blast furnace slag and at least one of an expansive additive, hydrated lime, quicklime, fly ash, and Portland cement, can suppress strength loss even when the ratio of calcium carbonate (CaCO3) to the powder amount is increased, compared to a hydraulic composition incorporating calcium carbonate (CaCO3) in ordinary Portland cement. Furthermore, a composition containing a large amount of blast furnace slag can further suppress strength loss. Furthermore, since the hydraulic composition of this embodiment contains a large amount of calcium carbonate (CaCO3), it is possible to manufacture components with excellent fire resistance. Calcium carbonate (CaCO3) undergoes an endothermic reaction of CaCO3 → CaO + CO2 at high temperatures (500 to 900°C), so the hydraulic composition of this embodiment has self-extinguishing properties in the event of a fire.

[0014] The results of experiments carried out on the hydraulic composition of this embodiment will be described below. (1)Neutralization rate First, the rate of atmospheric CO2 absorption (i.e., carbonation rate) was measured for hardened hydraulic compositions (Cases a to j) containing 0 to 50% calcium carbonate (CaCO3) by mass and other materials in the proportions shown in Table 1 under accelerated conditions with a CO2 concentration of 5%. As shown in Table 1, Cases a to c contain blast furnace slag, expansive additive, and hydrated lime in different proportions as powder materials other than calcium carbonate (CaCO3) that constitute the hydraulic composition. Case d contains only Portland cement and blast furnace slag as powder materials, while Case e contains calcium carbonate (CaCO3), Portland cement, and blast furnace slag as powder materials that constitute the hydraulic composition. Case f contains Portland cement, blast furnace slag, and fly ash as powder materials. Note that Cases d and f are formulations that aim to reduce environmental impact by not using calcium carbonate (CaCO3). In case g, calcium carbonate (CaCO3), Portland cement, blast furnace slag, and fly ash were added as powder materials. Furthermore, in cases h to j, only Portland cement was added as a powder material other than calcium carbonate (CaCO3) in the range of 50 to 100 mass%. Here, cases a, b, d, f, h, and i in which the amount of calcium carbonate (CaCO3) relative to the total material of the hydraulic composition is less than 30 mass% are comparative examples, and cases c, e, g, and j in which the amount is 30 mass% or more are working examples.

[0015] The following materials were used in the experiment: Water: Tap water Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.67 g / cm 3 , BET specific surface area 5.0m 2 / g Portland cement: Ordinary Portland cement, density 3.16g / cm 3 , Blaine specific surface area 3270 cm 2 / g, JIS R5210 Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special edition, density 2.20g / cm 3 , 600μm sieve, JIS R9001 Fly ash: Type II fly ash, density 2.30 g / cm 3 , Blaine specific surface area 4640 cm 2 / g, JIS A6201

[0016] [Table 1]

[0017] Water W was added to hydraulic composition P according to the formulation in Table 1 so that the water-powder ratio W / P was 0.50, and the mixture was kneaded. The resulting mixture (paste) was used to prepare specimens measuring approximately 3 cm in diameter and 5 cm in height, which were then sealed and cured. The specimens were demolded after 28 days and stored at a temperature of 20°C and humidity of 60% for 7 days. All but one side of the bottom was then coated with aluminum adhesive tape, and the specimens were left to stand in an environment of a temperature of 20°C, humidity of 60%, and a CO2 concentration of 5%, whereupon an accelerated carbonation test was performed. After 14 or 28 days, the specimens were split and a 1% alcohol solution of phenolphthalein was sprayed onto the cross section. The area where no coloration occurred was considered to be the area where carbonation had progressed, and the accelerated carbonation depth was measured. The measurement results are shown in Table 2. It is known that carbonation progresses in proportion to the square root of the carbonation period, and when the relationship between the change in accelerated carbonation depth and the square root of the carbonation period is approximated by a straight line (linear approximation), the slope of the line can be taken as the carbonation rate. In other words, the carbonation rate is the rate of change in carbonation depth relative to the change in the square root of the accelerated carbonation period. Figure 1 shows the relationship between the proportion of calcium carbonate (CaCO3) and the carbonation rate.

[0018] [Table 2]

[0019] As shown in Table 2 and Figure 1, in cases a to c, the amount of calcium carbonate (CaCO3) was increased to 8.6 mass%, 25 mass%, and 50 mass%, and the carbonation rates for these blends were 0.507, 0.646, and 0.861 cm / √d, respectively, indicating that the carbonation rate increased as the amount of calcium carbonate (CaCO3) increased. In addition, in cases d to g, where the effect of different powder compositions was confirmed under the same conditions fixed at W / P = 0.5, the carbonation rate increased as the amount of calcium carbonate (CaCO3) increased. Furthermore, in cases h to j, the carbonation rate increases as the amount of calcium carbonate (CaCO3) increases. Thus, the carbonation rate tended to increase as the amount of calcium carbonate (CaCO3) increased. Note that the carbonation rate of Case j was lower than that of Cases c, e, and g, which contained the same amount of calcium carbonate (CaCO3).

[0020] As shown in Figure 1, a comparison of cases h, d, and f, in which calcium carbonate (CaCO3) is not added, shows that the carbonation rate can be increased by reducing the amount of Portland cement in the powder other than calcium carbonate (CaCO3) to 30 mass% or less. On the other hand, if the amount of calcium carbonate (CaCO3) relative to the total material of the hydraulic composition (powder) is 30 mass% or more, regardless of the blend of powders other than calcium carbonate (CaCO3), it is expected that the carbonation rate will be equal to or greater than that of case f, in which the amount of Portland cement is 30 mass% or less (a blend in which the environmental impact is reduced without using calcium carbonate (CaCO3)), and if the amount of calcium carbonate (CaCO3) is 40 mass% or more, it is expected that the carbonation rate will be equal to or greater than that of case d, in which the amount of Portland cement is 30 mass% or less (a blend in which the environmental impact is reduced without using calcium carbonate (CaCO3)), regardless of the blend of powders other than calcium carbonate (CaCO3). In other words, if the amount of calcium carbonate (CaCO3) in the powder is 30 mass% or more, preferably 40 mass% or more, an effect equal to or greater than that obtained when the proportion of Portland cement in the powder is reduced can be obtained, regardless of the composition of the powder other than calcium carbonate (CaCO3). In this way, it was confirmed that hydraulic mixtures with increased carbonation rates are expected to absorb more CO2 from the atmosphere after hardening, and that an increase in the amount of CO2 fixed in the atmosphere during use can be expected.

[0021] Comparing cases c, g, e, and j, in which the proportion of calcium carbonate (CaCO3) in the hydraulic composition is the same, the carbonation rate tends to increase as the proportion of blast furnace slag in the hydraulic composition increases (i.e., as the proportion of blast furnace slag in the powders other than calcium carbonate (CaCO3) increases). Therefore, when blast furnace slag is contained in the hydraulic composition, it is preferable to increase the proportion of blast furnace slag in the powders other than calcium carbonate (CaCO3) among the powders other than calcium carbonate (CaCO3) (blast furnace slag, Portland cement, expansive agent, hydrated lime, fly ash), and more preferably, the proportion of blast furnace slag in the powders other than calcium carbonate (CaCO3) is 40 mass% or more.

[0022] (2) Compressive strength When using a hydraulic composition as a structural member, it is desirable that the hydraulic composition has a compressive strength that can withstand the applied load. Therefore, for a hydraulic composition mixture containing a hydraulic composition and fine aggregate (sand), the compressive strength after hardening (strength at 7 days and strength at 28 days) was measured when the proportion of calcium carbonate (CaCO3) in the hydraulic composition, the type and amount of each material other than calcium carbonate (CaCO3) in the hydraulic composition, and the water-powder ratio were changed.

[0023] The following materials were used in the experiment: Water: Tap water Portland cement: Ordinary Portland cement, density 3.16g / cm 3 , specific surface area 3270cm 2 / g, JIS R5210 Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3 , 600μm sieve, JIS R9001 Fly ash: Type II, density 2.30 g / cm 3 , specific surface area 4640cm 2 / g, JIS A6201 Calcium carbonate (CaCO3): Light calcium carbonate, density 2.67g / cm 3 , BET specific surface area 5.0m 2 / g Fine aggregate: A mixture of mountain sand from Kimitsu, crushed sand from Tsukumi, and crushed sand from Watarai. Surface dry density: 2.60 g / cm 3 Water absorption rate 2.07%

[0024] Table 3 shows the blending ratios. Table 4 shows the strength test results. Table 4 also shows the strength ratios (compressive strength ratio = Cases 1-4 / Case A, B) between Cases 1-4, in which the hydraulic composition contains blast furnace slag, and Cases A and B, in which the hydraulic composition consists of Portland cement and calcium carbonate (CaCO3), when the water-to-powder ratio (W / P) and the calcium carbonate (CaCO3) ratio are the same. Here, the numbers "25," "50," and so on, added after Cases 1-4 and Cases A and B, indicate the percentage (mass %) of calcium carbonate (CaCO3) in the hydraulic composition. Therefore, among Cases 1-4 and Cases A and B, those with the numbers "0," "25," and "99" are comparative examples, and the rest are working examples. In Table 4, for example, the compressive strength ratios listed in the Case 1-50 and Case 2-50 columns are ratios to the strength of Case A-50, and the compressive strength ratios listed in the Case 4-70 column are ratios to the strength of Case B-70. Also, the compressive strength ratios listed in the Case 1-25 and Case 2-25 columns are ratios to the strength of Case A-25.

[0025] [Table 3]

[0026] [Table 4]

[0027] Figure 2 shows the unit cement content (kg / m 3The graph shows the compressive strength at 28 days (28d) (see Table 4). To clarify the characteristics of the hydraulic composition mixture, the W / P ratio was standardized to 0.5, and the results for the hardened specimens (mortars) of the mixtures with a W / P ratio of 0.5 are shown. In Case A (where all powder materials constituting the hydraulic composition except for calcium carbonate (CaCO3) were Portland cement), the strength decreased as the proportion of calcium carbonate (CaCO3) increased and the amount of Portland cement used (unit cement amount) decreased. On the other hand, in Cases 1 to 3 (where powder materials constituting the hydraulic composition included powders other than Portland cement other than calcium carbonate (CaCO3)), the compressive strength was significantly higher than that of Case A, even when the unit cement amount was low. Thus, hydraulic compositions containing calcium carbonate (CaCO3) have sufficient strength for practical use even when the amount of Portland cement used is significantly reduced.

[0028] In FIG. 2, dotted lines A to D are approximate lines connecting the strengths of mixtures with the same proportion of calcium carbonate (CaCO3) in the hydraulic composition. Dotted line A (Comparative Example), where the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 25% by mass, shows that the strength decreases as the unit cement content decreases, and adjusting the materials used and their proportions in the hydraulic composition does not improve the strength. On the other hand, dotted lines B to D (Examples), where the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 50 to 90% by mass, show that the strength increases as the unit cement content decreases. In other words, the hydraulic composition and hydraulic composition mixture according to this embodiment have a significant effect in that the higher the proportion of calcium carbonate (CaCO3) in the hydraulic composition, the more the unit cement content can be reduced without weakening the compressive strength.

[0029] In addition, lines i through iv in Figure 2 are approximate lines of strength change for mixes with the same proportion of Portland cement in the powder excluding calcium carbonate (CaCO3). The approximate lines are for measurement points where the proportion of calcium carbonate (CaCO3) in the hydraulic composition was 50% by mass or more and where a strength effect was observed. Line i represents the case where the proportion of Portland cement in the powder excluding calcium carbonate (CaCO3) was 100% by mass, while lines ii, iii, and iv represent the cases where the proportion of Portland cement in the powder excluding calcium carbonate (CaCO3) was 30%, 15%, and 0%, respectively. As can be seen from lines i through iii in Figure 2, the smaller the proportion of Portland cement in the powder excluding calcium carbonate (CaCO3), the greater the rate of increase in strength per unit cement content. In other words, by using blast furnace slag, expansive additive, slaked lime, or fly ash as powder excluding calcium carbonate (CaCO3) and reducing the proportion of Portland cement, a significant effect can be achieved: compressive strength can be increased without significantly increasing the unit cement content.

[0030] Figure 3 is a graph of the compressive strength ratio at 28 days (28d) shown in Table 4. As shown in Figures 2 and 3 and Table 4, when the calcium carbonate (CaCO3) content was 25 mass% (Cases 1-25, 2-25, 3-25, and 4-25), the compressive strength was lower than that of Cases A-25 and B-25, which contained only calcium carbonate (CaCO3) and Portland cement. On the other hand, when the calcium carbonate (CaCO3) content was 50 mass% or more (Cases 1-50, 1-70, 1-90, 2-50, 2-70, 2-90, 3-70, and 4-70), the compressive strength was higher than that of Cases A-50, A-70, A-90, B-50, and B-70, which contained only calcium carbonate (CaCO3) and Portland cement. Specifically, when the proportion of calcium carbonate (CaCO3) exceeds 25% by mass, the compressive strength ratio may exceed 1. From the graph in Figure 3, it can be seen that when the proportion of calcium carbonate (CaCO3) exceeds 30% by mass, the compressive strength ratio exceeds 1. Therefore, as long as the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 30% by mass or more, even if Portland cement is replaced with a material containing blast furnace slag and at least one of an expansive additive, hydrated lime, quicklime, fly ash, and Portland cement, the hydraulic composition can exhibit strength equal to or greater than that of a mixed material containing only calcium carbonate (CaCO3) and Portland cement. When the proportion of calcium carbonate (CaCO3) in the hydraulic composition is 40% by mass or more, the compressive strength ratio generally exceeds 1.2, which is preferable, and when it is 60% by mass or more, the compressive strength ratio generally exceeds 1.4, which is even more preferable.

[0031] Figure 4 shows the ratio of the slopes of lines ii to iv to line i shown in Figure 2. Because the slopes of lines i to iv indicate the compressive strength per unit cement content, the ratio of the slopes of lines ii to iv to line i can be considered the ratio of compressive strengths for the same unit cement content, and this is shown on the vertical axis as the compressive strength ratio. As the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) decreases, the compressive strength ratio increases, confirming the effects of the present invention. When the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) is 70 mass% or less, the compressive strength ratio exceeds 2, and when it is 30 mass% or less, the compressive strength ratio generally exceeds 4. Therefore, the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) is preferably 70 mass% or less, and more preferably 30 mass% or less.

[0032] Furthermore, as can be seen from the results of Cases 1-50, 1-70, 1-90, and 2-50, 2-70, and 2-90, in which the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) was 30 mass% or less, the compressive strength tends to increase as the proportion of blast furnace slag increases. Therefore, in the hydraulic composition, when the proportion of Portland cement in the powder other than calcium carbonate (CaCO3) is 30 mass% or less, the proportion of blast furnace slag in the powder other than calcium carbonate (CaCO3) is preferably 70 mass% or more, and more preferably 80 mass% or more.

[0033] (3) Compressive strength when the calcium carbonate (CaCO3) content is changed between 42 and 70% Next, the properties of hydraulic composition mixtures containing the hydraulic composition of this embodiment, fine aggregate (sand), and coarse aggregate (gravel) were examined by varying the proportion of calcium carbonate (CaCO3) in the hydraulic composition between 42 and 70%. Specifically, the slump or slump flow of a mixture of the hydraulic composition mixture and water (hereinafter sometimes referred to as "fresh concrete") and the compressive strength (strength at 1 day, 7 days, and 28 days) of the hardened mixture (hereinafter sometimes referred to as "concrete") were measured. The test specimens (concrete) for compressive strength were demolded at 2 days and then subjected to standard underwater curing at 20°C. Furthermore, in Examples 33, 35, and 38, the specimens were subjected to sealed curing at 20°C for 2 hours, followed by steam curing at 60°C for 2.5 hours, and the compressive strength at 1 day was measured.

[0034] The following materials were used in the experiment: Water: Tap water Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3 , 600μm sieve, JIS R9001 Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.67 g / cm 3 , BET specific surface area 5m 2 / g Fine aggregate: A mixture of mountain sand from Kimitsu, crushed sand from Tsukumi, and crushed sand from Watarai. Surface dry density: 2.60 g / cm 3 Water absorption rate 2.07% Coarse aggregate: Crushed stone from Ome, maximum particle size 20 mm, surface dry density 2.66 g / cm 3 Water absorption rate 0.60% The composition of this experiment is shown in Table 5, and the strength test results are shown in Table 6.

[0035] [Table 5]

[0036] [Table 6]

[0037] As shown in Table 6, the fresh concretes of Examples 31, 32, 33, 34, 36, and 37 all had slump flows exceeding 46.0 cm, demonstrating high fluidity. These fresh concretes did not experience material segregation and were suitable for use as high-fluidity concrete. Furthermore, the fresh concretes of Examples 35 and 38 had slumps of 13.5 cm and 20 cm, respectively. Thus, it is possible to produce ordinary fresh concrete that does not have high fluidity. JIS A 5308 specifies the ranges for slump and slump flow for ordinary concrete. According to JIS, a slump of 5.5 to 22.5 cm or a slump flow of 37.5 to 70.0 cm is required, and all of the fresh concrete produced in this study met these standards.

[0038] In Examples 31 to 38, the compressive strength was 17 to 40 N / mm at 7 days of age. 2 At 28 days old, the strength is 22 to 55N / mm 2 Even when calcium carbonate (CaCO3), which has no hydration activity, was added in large amounts of 42 to 70% of the total powder of the hydraulic composition, the strength of the concrete was 20 N / mm 2 Furthermore, by keeping the W / P ratio below 0.241, it was possible to achieve a compressive strength of 40N / mm 2 This enabled the production of high-strength concrete exceeding this limit. As described above, it was confirmed that when the proportion of calcium carbonate (CaCO3) in the powder that makes up the hydraulic composition is 42 to 70 mass%, it is possible to produce fresh concrete with workability similar to that of general concrete used in structural components such as reinforced concrete, and that it is possible to produce concrete with compressive strength similar to that of general concrete.

[0039] (4) Neutralization rate of hydraulic composition mixtures containing nitrate compounds or nitrite compounds A hydraulic composition mixed material (hydraulic composition mixed material) containing 45% by mass of calcium carbonate (CaCO3) and other materials in the proportions shown in Table 7 was mixed with water to give a W / P ratio of 0.305 to prepare a paste of the hydraulic composition mixed material, which was then hardened. When the nitrate compound contains bound water, the amount of water to be added was determined by dividing the value of the bound water. The amount of the nitrate compound to be added was determined so that the amount of nitrogen atoms (N) was 0.45% by mass (nitrate ions (NO3)) relative to 100% by mass of the hydraulic composition. - The nitrate compound may be mixed with the hydraulic composition in a powder state, or may be dissolved in water and then mixed with the hydraulic composition. Although Ca(NO2)2·H2O and NaNO2 are nitrite compounds, they are described as nitrite compounds in the present invention, and the nitrite ions (NO2 - ) is the nitrate ion (NO3 - ) was calculated.

[0040] The following materials were used in the experiment: Water: Tap water Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3 , 600μm sieve, JIS R9001 Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.67 g / cm 3 , BET specific surface area 5.0m 2 / g Ca(NO2)2·H2O: Manufactured by Kanto Chemical Co., Ltd., conforming to Kanto Chemical's Grade 1 standard (purity 90.0% or more (titration method)) Ca(NO3)2·4H2O: Kanto Chemical Co., Ltd., JIS K8549 (purity 99.0% or more (difference method)) Mg(NO3)2·6H2O: Kanto Chemical Co., Ltd., JIS K8567 (purity 99.0% or higher (titration method)) NaNO2: Kanto Chemical Co., Ltd., JIS K8019 (purity 98.5% or more (titration method)) NaNO3: Kanto Chemical Co., Ltd., JIS K8542 (purity 99.0% or more (titration method)) KNO3: Kanto Chemical Co., Ltd., JIS K8548 (purity 99.0% or more (titration method)) NH4NO3: Kanto Chemical Co., Ltd., JIS K8545 (purity 99.0% or more (titration method))

[0041] [Table 7]

[0042] A hydraulic composition mixture with the composition shown in Table 7 was mixed with a specified amount of water to prepare a paste, which was then sealed and cured. The specimens were demolded after 28 days and stored at a temperature of 20°C and humidity of 60% for 7 days. All but one side of the bottom was then coated with aluminum adhesive tape, and the specimens were left to stand in an environment of a temperature of 20°C, humidity of 60%, and a CO2 concentration of 5% to undergo an accelerated carbonation test. After a specified period of time had passed, the specimen was split open, and a 1% alcohol solution of phenolphthalein was sprayed onto the cross section. The area where no coloration occurred was considered to be the area where carbonation had progressed, and the accelerated carbonation depth was measured. The measurement results are shown in Table 8. It is known that carbonation progresses in proportion to the square root of the carbonation period, and when the relationship between the change in accelerated carbonation depth and the square root of the carbonation period is approximated by a straight line (linear approximation), the slope of the line can be taken as the carbonation rate. In other words, the carbonation rate indicates the rate of change in carbonation depth relative to the change in the square root of the accelerated carbonation period.

[0043] [Table 8]

[0044] 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) had a significant inhibitory effect on neutralization, reducing the neutralization rate to less than 60% compared to when no nitrate was added. Therefore, it was confirmed that the addition of calcium nitrite, calcium nitrate, and magnesium nitrate can suppress the carbonation rate of the hardened body of the hydraulic composition mixture.

[0045] (5) Carbonation rate of hydraulic composite mixtures containing chemical admixtures A hydraulic composition mixture (hydraulic composition mixture) containing 45% by mass of calcium carbonate (CaCO3) and other materials in the proportions shown in Table 9 was mixed with water to a W / P ratio of 0.305 to prepare a paste of the hydraulic composition mixture, which was then allowed to harden. The obtained hardened product was subjected to an accelerated carbonation test, and the carbonation rate was calculated. The measurement results are shown in Table 10.

[0046] The following materials were used in this experiment: Water: Tap water Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3 , 600μm sieve, JIS R9001 Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.67 g / cm 3 , BET specific surface area 5.0m 2 / g Chemical admixture: Masterset FZP99, manufactured by Pozzolith Solutions, nitrate ion equivalent content 24% by mass

[0047] [Table 9]

[0048] A hydraulic composition mixture with the formulation in Table 9 was mixed with a specified amount of water to prepare a paste, which was then sealed and cured. The specimens were demolded after 28 days and stored at a temperature of 20°C and humidity of 60% for 7 days. All but one side of the bottom was then coated with aluminum adhesive tape, and the specimens were left to stand in an environment of a temperature of 20°C, humidity of 60%, and a CO2 concentration of 5% to undergo an accelerated carbonation test. After a specified period of time had passed, the specimen was split open, and a 1% alcohol solution of phenolphthalein was sprayed onto the cross section. The area that showed no coloration was considered to be the area where carbonation had progressed, and the accelerated carbonation depth was measured. The measurement results are shown in Table 10. It is known that carbonation progresses in proportion to the square root of the carbonation period, and when the relationship between the change in accelerated carbonation depth and the square root of the carbonation period is approximated by a straight line (linear approximation), the slope of the line can be taken as the carbonation rate. In other words, the carbonation rate indicates the rate of change in carbonation depth relative to the change in the square root of the accelerated carbonation period.

[0049] [Table 10]

[0050] As shown in Table 10, nitrate ions (NO3 - ) is added to 100% of the hydraulic composition by mass or more (NO3 - When chemical admixtures were added in amounts of 1% by mass or more (equivalent to nitrates), a significant carbonation suppression effect was observed, with the carbonation rate being halved compared to when no nitrates were added. Furthermore, the carbonation rate became slower as the amount of chemical admixture was increased. Therefore, it was confirmed that the neutralization rate of the hardened body of the hydraulic composition mixture can be suppressed by adding 1 mass % or more of nitrate, calculated as nitrate ions, to 100 mass % of the hydraulic composition.

[0051] (6) Properties when the amount of expansive material added is changed Next, the properties of hydraulic compositions containing expansive additives were confirmed. The proportion of expansive additive in the hydraulic composition (powder) was varied within the range of 2 to 9% by mass. In this experiment, a hydraulic composition mixture containing a hydraulic composition, fine aggregate (sand), and coarse aggregate (gravel) was mixed with water, and the slump or slump flow, initial and final setting times of the resulting mixture (hereinafter sometimes referred to as "fresh concrete") were measured. Furthermore, the compressive strength (strength at 28 days) and autogenous shrinkage strain of the hardened mixture (hereinafter sometimes referred to as "concrete") were measured. The initial and final setting times were measured in accordance with JIS A 1147:2019 Test method for setting time of concrete.

[0052] The autogenous shrinkage strain was measured in accordance with the autogenous shrinkage test method for high-fluidity concrete described in Report II of the Super-Fluidity Concrete Research Committee of the Japan Concrete Institute. Specifically, an embedded strain gauge was installed in the center of a 10cm x 10cm x 40cm square concrete column specimen, and after pouring the concrete, the specimen was removed from the form two days after construction, sealed with vinyl in a room at 20°C, and the amount of shrinkage measured up to 30 days after construction was completed was used as the autogenous shrinkage strain. The mix for this experiment is shown in Table 11. Table 12 and Figures 5 and 6 show the results of the compressive strength test.

[0053] The following materials were used in the experiment: Water: Tap water Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3, 600μm sieve, JIS R9001 Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.6g / cm 3 , BET specific surface area 5.0m 2 / g Fine aggregate: A mixture of mountain sand from Kimitsu, crushed sand from Tsukumi, and crushed sand from Watarai. Surface dry density: 2.60 g / cm 3 Water absorption rate 2.07% Coarse aggregate: Crushed stone from Ome, maximum particle size 20 mm, surface dry density 2.66 g / cm 3 Water absorption rate 0.60%

[0054] [Table 11]

[0055] [Table 12]

[0056] As shown in Table 12, in all examples, the slump was 19 cm or the slump flow was 40.0 to 60.0 cm, which was within the range of 6.5 to 22.5 cm or 37.5 to 70.0 cm for ordinary concrete as specified in JIS A 5308, indicating appropriate fluidity. In addition, the compressive strength at 28 days was 30 N / mm 2 That is, the hydraulic composition mixture materials of Examples 61 to 66 had sufficient compressive strength, with the proportion of the expansive material in the hydraulic composition being 2 to 9 mass % (the amount of expansive material used being 14 to 57 kg / m 3 ), the concrete still had properties that allowed it to be manufactured and constructed.

[0057] Furthermore, as shown in Table 12 and FIG. 5, in Examples 61 and 62, the autogenous shrinkage strain was −442×10 -6 , -417×10 -6 On the other hand, when the proportion of the expansive material in the hydraulic composition was 6 mass % or 9 mass % (the amount of expansive material used was 41 kg / m 3 or 57 kg / m3 In Examples 63 and 64, the autogenous shrinkage strain was -347 × 10 -6 , -0.16×10 -6 In Examples 65 and 66, which had a larger unit water content than Examples 61 to 64, the autogenous shrinkage strain was also reduced by increasing the proportion of expansive additive (see Figure 6). It was confirmed that when the proportion of calcium carbonate (CaCO3) in the hydraulic composition was 40 to 52 mass%, and the proportion of expansive agent was changed to 2 to 9 mass%, concrete could be manufactured using the same method as normal concrete, and that the autogenous shrinkage strain could be controlled by adding expansive agent.

[0058] (7) Properties when fiber materials are added Next, the properties of the hardened product (hereinafter sometimes referred to as "concrete") of the hydraulic composition mixed material containing the hydraulic composition of this embodiment, a fiber material, fine aggregate, and coarse aggregate were confirmed. Specifically, the slump or slump flow of the mixture of the hydraulic composition mixed material and water (hereinafter sometimes referred to as "fresh concrete") and the compressive strength (strength at 1 day, 2 days, and 28 days) of the hardened product of the mixture were measured.

[0059] The following materials were used in the experiment: Water: Tap water Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3 , 600μm sieve, JIS R9001 Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.67 g / cm 3 , Blaine specific surface area 4350cm 2 / g Fine aggregate: A mixture of Namegata land sand and Sano limestone crushed sand. Surface dry density: 2.64 g / cm 3 Water absorption rate 1.91% Coarse aggregate: Sano limestone, maximum particle size 20mm, surface dry density 2.71g / cm 3 Water absorption rate 0.97% Fiber material: Steel fiber, 35 mm long (Dramix3D, Bekaert Japan) Chemical admixture: Masterset FZP99, manufactured by Pozzolith Solutions, nitrate ion equivalent content 24% by mass Table 13 shows the composition of this experiment, and Table 14 shows the strength test results.

[0060] [Table 13]

[0061] [Table 14]

[0062] As shown in Table 14, in Examples 71, 72, 73, and 74, the slump flow of the fresh concrete (hydraulic composition mixed material after the addition of steel fiber) exceeded 50.0 cm, demonstrating high fluidity. No material separation of the steel fiber or aggregate occurred, and fresh concrete that was suitable for workability was produced. JIS A 5308 specifies the slump flow range for ordinary concrete, requiring a slump flow of 37.5 to 70.0 cm. All of the fresh concrete produced in this study after the addition of steel fiber satisfied this standard.

[0063] In Examples 71, 72, 73, and 74, the compressive strength was 5 to 10 N / mm at 1 day of age. 2 The compressive strength at the age of 2 days is 14 to 23 N / mm 2 In addition, the compressive strength at 28 days was 40-58N / mm 2Although calcium carbonate (CaCO3) does not have hydration activity, even if the ratio of calcium carbonate (CaCO3) in the hydraulic composition is as high as 46.4 mass%, the 2 The above compressive strength was ensured. Furthermore, by adding steel fibers, it is expected that the compressive strength will be increased in addition to the bending strength. For example, Example 72 is substantially the same as Example 66 (see Table 11) in which steel fibers have been added, but when comparing the compressive strength at 28 days, Example 66, which does not contain steel fibers, has a compressive strength of 34 N / mm 2 In contrast, Example 72, which contained steel fibers, had a strength of 43 N / mm 2 It was. From the above results, it was confirmed that it is possible to produce concrete with workability and compressive strength similar to that of ordinary fiber-reinforced concrete, even when the proportion of calcium carbonate (CaCO3) in the hydraulic composition is increased and a hydraulic composition mixture containing added fiber material is used.

[0064] (8) Effect of polishing Next, the effect of polishing the surface of a hardened hydraulic composition mixture containing the hydraulic composition of this embodiment, fine aggregate, and coarse aggregate was confirmed. In the following hydraulic composition mixture, the proportion of calcium carbonate (CaCO3) in the hydraulic composition was 41.3% by mass. Water was added to the hydraulic composition mixture (hydraulic composition, fine aggregate, and coarse aggregate) and mixed. The mixture (fresh concrete) was poured into a formwork and allowed to harden, producing rectangular specimens measuring 15 cm x 15 cm x 1 cm thick. The specimens were sealed and cured outdoors (ambient temperature 0-7°C) for up to 14 days, then demolded and polished using a stone polisher with a grit size of #400. Table 15 shows the composition ratio.

[0065] The following materials were used in the experiment: Water: Tap water Blast furnace slag: Blast furnace slag powder 4000, density 2.89g / cm 3 , Blaine specific surface area 4480cm 2 / g, JIS A6206 Expansion agent: Expansion agent type 30 (lime-based expansion agent) Density 3.15g / cm 3 , Blaine specific surface area 3810 cm 2 / g, JIS A6202 Slaked lime: Slaked lime special density 2.20g / cm 3 , 600μm sieve, JIS R9001 Calcium carbonate (CaCO3): Precipitated calcium carbonate, density 2.67 g / cm 3 , BET specific surface area 5.0m 2 / g Fine aggregate: Granite crushed sand from Inada, surface dry density 2.60g / cm 3 Water absorption rate 0.38% Coarse aggregate: Granite crushed stone from Inada, maximum particle size 12 mm, surface dry density 2.62 g / cm 3 Water absorption rate 0.64%

[0066] [Table 15]

[0067] The test specimens (hardened bodies of hydraulic composite mixed materials) were stored indoors at a temperature of 20°C, and after 28 days, they were subjected to an accelerated weathering test using an accelerated weathering tester (XER-W75, manufactured by Iwasaki Electric) with a dry-wet cycle of 2 hours (dry 102 minutes, wet 18 minutes) and an irradiation intensity of 60 W / m 2 Accelerated testing was carried out for 5000 hours under the following conditions. At 0, 500, 1000, 2000, 3000, 4000, and 5000 hours, the L of 24 hardened areas (non-aggregate areas) of the specimen was measured using a spectrophotometer (NF333: manufactured by Nippon Denshoku Industries Co., Ltd.). * a * b * The color space (JIS Z8781-4) was measured and the average value was calculated, and the color difference with the specimen at time 0 was evaluated. Figure 7 shows the relationship between the acceleration time and the color difference.

[0068] The prepared specimen was polished to a smooth finish, with no chipped or other defects in the aggregate, making it possible to create a finished material that imitates stone materials such as marble. As shown in Figure 7, no change in color was observed even after 5,000 hours, confirming that the specimen was not subject to discoloration due to ultraviolet rays. In addition, a cylindrical specimen with a diameter of 10 cm and a height of 20 cm was separately prepared, sealed, and cured. When the specimen was subjected to a compressive strength test after 28 days, the compressive strength was 36.2 N / mm 2 It was. By polishing the hardened hydraulic composite mixture containing a large amount of calcium carbonate (CaCO3), it was possible to create a finished material that resembles stone. Furthermore, weather resistance tests confirmed that the hardened material did not discolor.

[0069] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and each of the above-described components can be appropriately modified within the scope of the present invention. For example, the materials constituting calcium carbonate (CaCO3), blast furnace slag, expansive material, hydrated lime, quicklime, fly ash, and Portland cement are not limited to those shown in the above embodiment.

Claims

1. A hydraulic composition comprising calcium carbonate, Portland cement, and blast furnace slag, The proportion of calcium carbonate is in the range of more than 50% by mass and not more than 95% by mass, A hydraulic composition, characterized in that the calcium carbonate is precipitated calcium carbonate.

2. 2. The hydraulic composition according to claim 1, comprising hydrated lime and an expanding material.

3. A hydraulic composition comprising calcium carbonate and Portland cement, Contains an expanding material in a proportion of 2 to 9 mass %; The proportion of calcium carbonate is in the range of more than 50% by mass and not more than 95% by mass, A hydraulic composition, characterized in that the calcium carbonate is precipitated calcium carbonate.

4. A hydraulic composition comprising calcium carbonate and Portland cement, Contains at least one of blast furnace slag, expansive material, slaked lime, quicklime, and fly ash, The proportion of calcium carbonate is in the range of more than 50% by mass and not more than 95% by mass, A hydraulic composition, characterized in that the calcium carbonate is precipitated calcium carbonate.

5. 5. The hydraulic composition according to claim 1, wherein the materials other than calcium carbonate contain Portland cement in an amount of 30% by mass or less.

6. A hydraulic composition mixed material comprising a hydraulic composition and a nitrate compound, The hydraulic composition contains calcium carbonate and Portland cement, and the proportion of the calcium carbonate is in the range of more than 50% by mass and not more than 95% by mass, The calcium carbonate is light calcium carbonate, The hydraulic composition mixture contains the nitrate compound in an amount of 1 to 3 mass % calculated as nitrate ions relative to 100 mass % of the hydraulic composition.

7. A hydraulic composition mixture comprising the hydraulic composition according to any one of claims 1 to 4 and at least one of a fibrous material, an aggregate, and a chemical admixture.

8. A hydraulic composition mixed material comprising a hydraulic composition, a nitrate compound, and at least one of a fibrous material, an aggregate, and a chemical admixture, The hydraulic composition contains calcium carbonate and Portland cement, and the proportion of the calcium carbonate is in the range of more than 50% by mass and not more than 95% by mass, The calcium carbonate is light calcium carbonate, The hydraulic composition mixture contains the nitrate compound in an amount of 1 to 3 mass % calculated as nitrate ions relative to 100 mass % of the hydraulic composition.

9. A hardened body formed from the hydraulic composition according to any one of claims 1 to 5.

10. The cured product according to claim 9, characterized in that the surface is polished.

11. A hardened body formed from the hydraulic composition mixture material according to any one of claims 6 to 8.

12. The cured product according to claim 11, characterized in that the surface is polished.

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