Main material, kit for preparing two component mixing type hydraulic composition, two component mixing type hydraulic composition and method for producing same, hardened product and method for producing same, and construction system

Abstract

To provide a main material which can maintain excellent fluidity while suppressing the occurrence of compaction when formed into a slurry, and can achieve both of excellent lamination properties and compression strength when used for a two liquid mixing type hydraulic composition for a 3D printer, and to provide a kit for preparing a two liquid mixing type hydraulic composition for a 3D printer including the main material.SOLUTION: The main material is used for a two component mixing type hydraulic composition for a 3D printer, and includes a hydraulic binder, a water reducing agent, a retarder, and fine aggregates. The hydraulic binder comprises cement and silica fume. The kit for preparing a two component mixing type hydraulic composition for a 3D printer includes the main material or a first slurry containing the main material, and a hardening material or a second slurry containing the hardening material in a separated state. The hardening material includes an accelerator, a gelling agent, silica fume, and fine aggregate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a base material, a two-component hydraulic composition preparation kit, a two-component hydraulic composition and a method for producing the same, a hardened product and a method for producing the same, and an application system. [Background technology]

[0002] Additive manufacturing methods are known in which materials such as resins, metals, and ceramics are layered based on three-dimensional data of a desired object. A known additive manufacturing method is a material extrusion method in which a modeling material is extruded from a nozzle of a 3D printer and layered. For example, Patent Document 1 discloses a one-component cementitious material for three-dimensional modeling in construction, and a three-dimensional modeling method in which such a material is mixed with water and discharged from a nozzle to layer the material to construct a model. Patent Document 2 also discloses a one-component wet cement mortar for three-dimensional modeling in construction, and a three-dimensional modeling method in which such a wet cement mortar is discharged from a nozzle to layer the material to construct a model. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-140906 [Patent Document 2] International Publication No. 2023 / 22089 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the use of two-component hardening compositions, which contain a separate base material containing a hydraulic binder and a hardener, to create 3D printer models has been investigated. When using two-component hardening compositions, the preparation of a base slurry can result in a significant loss of fluidity at a very early age, a phenomenon known as "compaction." Although a compacted base slurry can be remixed to regain its fluidity and be used as a slurry, compaction reduces work efficiency. Furthermore, compaction can impede smooth mixing of the base slurry with the hardener slurry, or the smooth construction of a model using the resulting two-component hydraulic composition obtained by mixing the base slurry with the hardener slurry. In addition to compaction, the fluidity of the base slurry decreases over time due to the hydration reaction (hardening) of cement. To ensure proper delivery as a material for 3D printers, the base slurry used in two-component hydraulic compositions must maintain excellent fluidity.

[0005] The present disclosure provides a main material that can maintain excellent fluidity while suppressing the occurrence of clumping when made into a slurry, and that can achieve both excellent lamination properties and compressive strength when used in a two-component hydraulic composition for 3D printers, as well as a two-component hydraulic composition preparation kit that includes such a main material. The present disclosure also provides a two-component hydraulic composition that is easy to apply, a method for producing the same, and an application system that is excellent in workability. The disclosure also provides a cured product that is easy to apply and has an excellent appearance, and a method for producing the same. [Means for solving the problem]

[0006] One aspect of the present disclosure provides a main material used in a two-component hydraulic composition for a 3D printer, the main material including a hydraulic binder, a water-reducing agent, a retarder, and a fine aggregate, and the hydraulic binder including cement and silica fume.

[0007] The above-mentioned main material can maintain excellent fluidity while suppressing compaction when made into a slurry, and can achieve both excellent buildability and compressive strength when used in a two-component hydraulic composition for 3D printers. The inventors speculate that the reason for this effect is as follows. The compaction of the main material slurry used in a two-component hydraulic composition for 3D printers is believed to be due to the formation of a calcium-derived gel around the cement. The above-mentioned main material contains silica fume as a hydraulic binder. Silica fume has a significantly larger specific surface area than cement, so it can adsorb to the cement. The silica fume adsorbed to the cement is believed to inhibit the formation of calcium-derived gel around the cement when made into a slurry. As a result, it is believed that compaction is suppressed and excellent fluidity can be maintained. Furthermore, by using such a main material, it is possible to prepare a two-component hydraulic composition for 3D printers that is easy to apply and has both excellent buildability and compressive strength. However, the reasons for these effects are not limited to those described above.

[0008] One aspect of the present disclosure provides a two-component mixing hydraulic composition preparation kit for a 3D printer, which includes a main material or a first slurry containing the main material, and a hardening material or a second slurry containing the main material, in a separated state, wherein the main material is the above-mentioned main material, and the hardening material includes a quick-setting agent, a gelling agent, silica fume, and fine aggregate.

[0009] The two-component hydraulic composition preparation kit includes a main material or a first slurry containing the main material, and a hardening material or a second slurry containing the main material, in a separated state. With such a two-component hydraulic composition preparation kit, compaction of the main material slurry is suppressed and the fluidity of the main material slurry is maintained, improving work efficiency and enabling smooth preparation of a two-component hydraulic composition for 3D printers at the construction site.

[0010] One aspect of the present disclosure provides a two-part hydraulic composition for 3D printers, obtained by mixing a first slurry containing the above-mentioned main material and water with a second slurry containing a hardening agent including an accelerator, a gelling agent, silica fume, and fine aggregate, and water. Such a two-part hydraulic composition is easy to apply because the first slurry maintains excellent fluidity, and by mixing the two parts and discharging them, a laminate that exhibits both excellent lamination properties and compressive strength can be formed with favorable workability.

[0011] One aspect of the present disclosure provides a cured product obtained by curing the two-part hydraulic composition. Because such a cured product is obtained by curing the two-part hydraulic composition, it is easy to apply and has excellent aesthetics.

[0012] One aspect of the present disclosure provides a method for producing a two-part hydraulic composition for 3D printers, comprising the step of mixing a first slurry containing the above-mentioned main material and water with a second slurry containing a hardening agent including an accelerator, a gelling agent, silica fume, and fine aggregate, and water. The two-part hydraulic composition obtained by this production method is easy to apply because the main material maintains excellent fluidity, and by mixing the two parts and discharging them, a laminate that exhibits both excellent lamination properties and compressive strength can be formed with favorable workability.

[0013] One aspect of the present disclosure provides a method for producing a cured product, comprising the steps of discharging the two-component hydraulic composition obtained by the above-mentioned production method from a discharge unit of a 3D printer, laminating the laminate, and curing the laminate to obtain a cured product. Since this production method uses the two-component hydraulic composition obtained by the above-mentioned production method, it is possible to produce a cured product that is easy to apply and has excellent aesthetics.

[0014] One aspect of the present disclosure provides a construction system including: a first supply unit that supplies a first slurry containing the above-mentioned main material and water; a second supply unit that supplies a second slurry that contains a hardening agent including a quick-setting admixture, silica fume, a gelling agent, and fine aggregate, and water; a mixing unit that merges and mixes the first slurry and the second slurry to obtain a mixed slurry; and a discharge unit that discharges the mixed slurry.

[0015] In the construction system, the first slurry and the second slurry are supplied from different supply units. This allows the first slurry and the second slurry to be stored separately. Furthermore, the main material maintains sufficient fluidity over time. This allows the first slurry and the second slurry to be stably stored for a long period of time in the state before they are mixed. Furthermore, since the construction system is provided with a mixing unit that mixes the first slurry and the second slurry and a discharge unit that discharges the mixed slurry, the first slurry and the second slurry can be mixed and then quickly discharged to produce a discharged product, a laminate, a shaped object, etc. Therefore, the construction system has excellent workability. [Effects of the Invention]

[0016] The present disclosure can provide a main material that can maintain excellent fluidity while suppressing the occurrence of clumping when made into a slurry, and that can achieve both excellent lamination properties and compressive strength when used in a two-component hydraulic composition for 3D printers, as well as a two-component hydraulic composition preparation kit that includes such a main material. The present disclosure can also provide a two-component hydraulic composition that is easy to apply, a method for producing the same, and an application system that is excellent in workability. It can also provide a cured product that is easy to apply and has an excellent appearance, and a method for producing the same. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram showing silica fume adsorption on cement. [Figure 2] FIG. 1 is a diagram illustrating an example of a construction system. [Figure 3]FIG. 1 is an exploded perspective view showing an example of a static mixer. [Figure 4] 10 is a graph showing the relationship between elapsed time and 15-shot flow value in Comparative Examples 1 to 8. [Figure 5] 10 is a graph showing the relationship between elapsed time and 15 stroke flow value in Comparative Examples 9 to 13. [Figure 6] 13 is a graph showing the relationship between elapsed time and 15 stroke flow value in Example 6. [Figure 7] 1A is a photograph of a laminate produced using the main material slurry of Example 5, and FIG. 1B is a photograph of a laminate produced using the main material slurry of Example 6. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Embodiments of the present disclosure will be described below. However, the following embodiments are merely examples for explaining the present disclosure and are not intended to limit the present disclosure to the following content. In the description, the same reference numerals will be used for identical elements or elements having the same functions, and redundant explanations will be omitted where appropriate. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships based on the orientation of the reference numerals shown in the drawings. The dimensional ratios of each element are not limited to those shown. The numerical ranges exemplified as "a to b" are numerical ranges inclusive of a and b, with a lower limit being a and an upper limit being b. The present disclosure also includes those in which the upper or lower limit of each numerical range is replaced with the numerical value of any of the examples. When multiple materials are exemplified, one of the materials may be used alone, or multiple materials may be used in combination.

[0019] The "two-component hydraulic composition" in this disclosure is a fluid slurry containing a main material including a binder and a hardening agent that hardens the main material. The binder has the property of hardening upon reacting with water, and constitutes at least a part of a hardened product after hardening. While the "two-component hydraulic composition" has fluidity, a hydraulic composition that has lost its fluidity as it hardens is called a "hardened product." The "3D printer" in this disclosure is a device that ejects a two-component hydraulic composition from an ejection port to form a physical three-dimensional object.

[0020] The main material is used to prepare a two-component hydraulic composition for 3D printers. The main material includes at least a hydraulic binder, a water-reducing agent, a retarder, and fine aggregate. The hydraulic binder in this disclosure is a binder that hardens upon reacting with water. The hydraulic binder of this embodiment includes at least cement and silica fume. The main material may be in a solid form such as a powder, and may be mixed with water to form a main material slurry (first slurry).

[0021] Examples of cement include various types of Portland cement, such as normal Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, moderate-heat Portland cement, low-heat Portland cement, and sulfate-resistant Portland cement, as well as various blended cements, such as blast-furnace cement and fly ash cement. Only one of these cements may be used, or multiple types may be mixed and used. Among these, from the viewpoint of improving the hardening characteristics of the hydraulic composition slurry for additive manufacturing, it is more preferable to use at least one type of Portland cement selected from the group consisting of normal Portland cement, high-early-strength Portland cement, and ultra-high-early-strength Portland cement.

[0022] The water contained in the first slurry is not particularly limited and may be, for example, tap water, distilled water, deionized water, etc. The content of water in the first slurry may be 15 to 60 parts by mass, 20 to 50 parts by mass, 25 to 45 parts by mass, or 30 to 40 parts by mass relative to 100 parts by mass of the hydraulic binder.

[0023] In this disclosure, "compaction" refers to a phenomenon in which the first slurry significantly loses fluidity at a very early age. Although a first slurry that has become compacted can regain fluidity and be used as a slurry by re-stirring, the occurrence of compaction reduces work efficiency. Compaction is thought to be a phenomenon caused by the formation of calcium-derived gel around the cement. The occurrence of compaction can be confirmed by leaving the first slurry to stand for 20 minutes after preparation and visually determining whether the first slurry flows. If the first slurry does not flow even when the container is tilted, compaction is said to have occurred.

[0024] The fluidity of the first slurry can be evaluated by a flow test described in "JIS R5201:2015 Physical Testing Methods for Cement." The flow value evaluated by the above test is sometimes referred to as the "15-stroke flow value." From the viewpoint of smoother application of the first slurry, the 15-stroke flow value may be 140 to 300 mm, 150 to 280 mm, 160 to 250 mm, or 160 to 230 mm.

[0025] It is preferable that the first slurry maintain excellent fluidity for a long period of time. For example, the first slurry can maintain the 15-shot flow value for at least two days, more preferably at least four days, even more preferably at least six days, and even more preferably at least seven days. This eliminates the need to discharge and clean the first slurry from the construction system, even when construction is suspended, for example, on holidays, thereby improving work efficiency.

[0026] The density of the first slurry can be measured, for example, by the method described in the Examples. The density of the first slurry is 1.0 to 3.0 g / cm 3 , 1.3~2.7g / cm 3 , or 1.5 to 2.5 g / cm 3 may be.

[0027] Examples of silica fume include those specified in JIS A 6207:2016 "Silica fume for concrete." The BET specific surface area of ​​silica fume is 10 m 2 / g or more, 14m 2 / g or more, or 16m 2 / g or more. As shown in FIG. 1, silica fume 100 has a larger specific surface area than cement 150, and therefore can be adsorbed around cement 150. It is believed that silica fume 100 can thereby inhibit the formation of calcium-derived gel around cement 150 when the main material is made into a slurry. Therefore, by adding silica fume to the main material, it is possible to inhibit the occurrence of compaction of the main material. The BET specific surface area of ​​silica fume is, for example, 10 to 30 m 2 / g.

[0028] The content of silica fume may be 3 parts by mass or more, 5 parts by mass or more, or 10 parts by mass or more per 100 parts by mass of hydraulic binder, from the viewpoint of improving mixability and the compressive strength and appearance of the cured product. Furthermore, the content of silica fume may be 40 parts by mass or less, 30 parts by mass or less, or 25 parts by mass or less per 100 parts by mass of hydraulic binder, from the viewpoint of promoting the reaction between cement and retarder to improve the fluidity retention time (pot life) and improving the rubber hardness of the two-component hydraulic composition. The content of silica fume may be, for example, 3 to 40 parts by mass, 5 to 30 parts by mass, or 10 to 25 parts by mass per 100 parts by mass of hydraulic binder.

[0029] The content of silica fume may be 3 parts by mass or more, 5 parts by mass or more, or 6 parts by mass or more per 100 parts by mass of cement, from the viewpoint of improving mixability and the compressive strength and appearance of the cured product. Furthermore, the content of silica fume may be 50 parts by mass or less, 40 parts by mass or less, or 35 parts by mass or less per 100 parts by mass of cement, from the viewpoint of promoting the reaction between the cement and the retarder to further maintain the fluidity of the main material, while improving the rubber hardness of the two-component hydraulic composition and improving lamination properties. The content of silica fume may be, for example, 3 to 50 parts by mass, 5 to 40 parts by mass, or 6 to 35 parts by mass per 100 parts by mass of cement.

[0030] The main material may contain a hydraulic binder other than cement and silica fume. Examples of such hydraulic binders include ground granulated blast furnace slag (e.g., one conforming to JIS A 6206:2013 "Ground granulated blast furnace slag for concrete"), ground limestone, fly ash, and gypsum. The Blaine specific surface area of ​​ground granulated blast furnace slag is 2500 to 10000 cm. 2 / g, 3000-9000cm 2 / g, or 4000 to 8000 cm 2 / g. Examples of fly ash include those specified in JIS A 6201:2015 "Fly ash for concrete." Examples of gypsum include gypsum dihydrate (CaSO4·2H2O), gypsum hemihydrate (CaSO4·1 / 2H2O), and anhydrous gypsum.

[0031] The fine aggregate may include silica sand used in concrete aggregates, building materials, etc., as specified in JIS A 5308:2019, etc. The particle size of the fine aggregate is preferably less than 1.0 mm, more preferably less than 0.5 mm, from the viewpoint of liquid transportability when made into a slurry. The particle size of the aggregate can be measured using several sieves with different mesh sizes as specified in JIS Z 8801-1:2019. The content of the fine aggregate in the main material relative to 100 parts by mass of the hydraulic binder in the main material may be 50 to 300 parts by mass, 70 to 200 parts by mass, more preferably 80 to 150 parts by mass.

[0032] The retarder is not particularly limited, and examples thereof include hydroxycarboxylic acids, sugars, and inorganic retarders. The retarder may include hydroxycarboxylic acids. The hydroxycarboxylic acids are a general term for hydroxycarboxylic acids and their salts. Examples of hydroxycarboxylic acids include gluconic acid, tartaric acid, citric acid, malic acid, succinic acid, and heptonic acid.

[0033] Examples of the salt of hydroxycarboxylic acid include alkali metal salts (sodium salt, potassium salt, etc.) and alkaline earth metal salts (calcium salt, magnesium salt, etc.). Of these, sodium salts and sodium gluconate may be included in view of the setting retardation effect, availability, and cost. The hydroxycarboxylic acid and its salt may be used alone or in combination of two or more.

[0034] The content of the retarder in the main material relative to 100 parts by mass of the hydraulic binder in the main material may be 0.05 to 1.5 parts by mass, 0.1 to 1.0 part by mass, or 0.15 to 0.5 parts by mass. By setting the content of the retarder within the above range, the usable time of the prepared two-component hydraulic composition can be set within a suitable range.

[0035] A water-reducing agent is used to improve the liquid transportability when preparing a first slurry containing a main material and water. Examples of water-reducing agents include polycarboxylic acid-based, melamine sulfonic acid-based, naphthalene sulfonic acid-based, and lignin sulfonic acid-based agents. From the viewpoint of suppressing the occurrence of compaction to some extent, polycarboxylic acid-based water-reducing agents are preferred. Specific examples of polycarboxylic acid-based water-reducing agents include polyether-polycarboxylic acid-based water-reducing agents and modified polycarboxylic acid-based water-reducing agents. One of these may be used alone, or two or more may be used in combination. The content of the water-reducing agent in the main material relative to 100 parts by mass of the total amount of hydraulic binder in the main material may be 0.05 to 1.2 parts by mass, 0.05 to 0.8 parts by mass, or 0.1 to 0.5 parts by mass. By setting the content of the water-reducing agent within the above range, the liquid transportability can be further improved.

[0036] Specific examples of modified polycarboxylic acid-based water-reducing agents include MELFLUX AP101F (trade name, manufactured by BASF Japan Ltd.). Specific examples of polyether-polycarboxylic acid-based water-reducing agents include MELFLUX 2641F, MELFLUX 2651F, MELFLUX 5581F, MELFLUX 4930F, MELFLUX 6681F, and MELFLUX SELECT 4411F (trade names, manufactured by BASF Japan Ltd.). From the viewpoint of suppressing stickiness of the base material, it is preferable to include MELFLUX AP101F. On the other hand, from the viewpoint of allowing the water-reducing agent to be quickly adsorbed by the cement and stabilizing changes in the quality of the base material over time, it is preferable to include early-adsorption type MELFLUX 6681F.

[0037] The main material may further contain a thickener. The thickener can sufficiently suppress material separation when preparing a first slurry containing the main material and water. Examples of thickeners include organic thickeners such as cellulose-based thickeners, starch-based thickeners, guar gum-based thickeners, and vinyl-based thickeners, as well as inorganic thickeners such as bentonite, kaolinite, and talc. One of these may be used alone, or two or more may be used in combination. The content of the thickener in the main material relative to 100 parts by mass of the hydraulic binder in the main material may be 0.01 to 1.0 parts by mass, 0.02 to 0.5 parts by mass, 0.03 to 0.3 parts by mass, 0.04 to 0.15 parts by mass, or 0.05 to 0.1 parts by mass.

[0038] The main material may further contain an antifoaming agent. The antifoaming agent can improve the strength development of the cured product of the two-component hydraulic composition. Known antifoaming agents can be used. Specific examples of antifoaming agents include synthetic substances such as mineral oil-based, silicone-based, alcohol-based, and polyether-based substances, as well as natural substances derived from plants. Among these, from the viewpoints of dispersibility and durability, the antifoaming agent may be a polyether-based antifoaming agent or a mineral oil-based antifoaming agent. One of these may be used alone, or two or more may be used in combination. The content of the antifoaming agent in the main material relative to 100 parts by mass of the hydraulic binder in the main material may be 0.01 to 1.0 parts by mass, 0.05 to 0.7 parts by mass, 0.1 to 0.4 parts by mass, or 0.1 to 0.3 parts by mass.

[0039] The hardener is used to prepare a two-component hydraulic composition for 3D printers. The hardener may contain at least an accelerator, a gelling agent, silica fume, and fine aggregate. The hardener may be in a solid form such as powder, and may be mixed with water to form a hardener slurry (second slurry). The accelerator and gelling agent have the effect of hardening the main hydraulic binder.

[0040] The water contained in the second slurry is not particularly limited and may be, for example, tap water, distilled water, deionized water, etc. The content of water in the second slurry may be 5 to 40 parts by mass, 10 to 30 parts by mass, or 10 to 25 parts by mass relative to 100 parts by mass of the hydraulic binder contained in the main material to be mixed.

[0041] Examples of accelerators include alum, sulfates (aluminum sulfate, sodium sulfate, potassium sulfate, lithium sulfate, magnesium sulfate), carbonates (sodium carbonate, potassium carbonate, lithium carbonate), calcium thiocyanate, and calcium chloride. Alum is a double salt of a sulfate of a monovalent cation and a sulfate of a trivalent metal ion. Examples of alum include potassium alum, ammonium alum, sodium alum, iron alum, chromium alum, and their anhydrides (calcined alum). These alums may be used alone or in combination. From the viewpoint of obtaining a two-component hydraulic composition that achieves sufficiently high levels of mixability and hardening properties, it is preferable that the alum contains potassium alum. Potassium alum is a double salt of potassium sulfate and aluminum sulfate, represented by the chemical formula KAl(SO4)2·12H2O.

[0042] Commercially available alum may be used, or the commercially available product may be pulverized using a ball mill or the like. By reducing the particle size of the alum to a certain extent, the effect of the accelerator can be more easily exerted while maintaining ease of handling. This allows the alum content in the hardener to be reduced. From this perspective, the average particle size of the alum may be 0.01 to 1.0 mm, 0.02 to 0.3 mm, 0.03 to 0.2 mm, or 0.04 to 0.1 mm. Furthermore, when potassium alum is used, from the perspective of suppressing the occurrence of white spots after application, the average particle size of the potassium alum may be 0.01 to 0.2 mm, 0.03 to 0.2 mm, or 0.04 to 0.1 mm.

[0043] The average particle size in this disclosure is determined from a volume-based frequency distribution measured using a laser diffraction / scattering particle size distribution analyzer. Measurements are performed under dry conditions using, for example, a laser diffraction / scattering particle size distribution analyzer, such as the "SALD-2200" manufactured by Shimadzu Corporation. The average particle size is calculated as a weighted average of the logarithmic values ​​of particle sizes, with the volume-based frequency for that particle size being used as the weight, based on the relationship between the volume-based frequency and the particle size obtained in the above measurement.

[0044] The content of the quick-setting admixture contained in the hardener may be 1 to 10 parts by mass, 2 to 7 parts by mass, or 3 to 6 parts by mass relative to 100 parts by mass of the hydraulic binder contained in the main material to be mixed. By having the alum content within the above range, it is possible to obtain suitable rapid hardening properties and strength development when mixed with the first slurry (main material slurry).

[0045] Examples of gelling agents include basic aluminum salts. The basic aluminum salt is a basic salt containing an aluminum ion and a hydroxy acid ion having 2 to 6 carbon atoms. Here, the basic salt is a salt containing a hydroxide ion (OH - In other words, a basic aluminum salt is a salt of aluminum and a hydroxy acid in which part of the anion has been replaced with a hydroxide ion. A basic aluminum salt has the general formula: Al(OH) 3-x Yb, where x and b are selected so that the basic aluminum salt as a whole is electrically neutral. The use of a basic aluminum salt can suppress the formation of flocs, thereby improving the mixability in particular.

[0046] The number of carbon atoms contained in the hydroxy acid ion contained in the basic aluminum salt is preferably 2 to 4, more preferably 2 or 3, and even more preferably 3. Examples of basic aluminum salts include basic aluminum lactate, basic aluminum hydroxyacetate, basic aluminum citrate, and basic aluminum tartrate, with basic aluminum lactate being preferred. These may be hydrates. The basic aluminum salts may be used alone or in combination of two or more.

[0047] Basic aluminum lactate has the general formula Al(OH) 3-x (Lac. acid) xIt is a compound represented by (0 < x < 3), and those with a molar ratio of Al2O3 / lactic acid of 0.3 to 2.0 are preferred. Lac.acid is a lactate ion. Basic aluminum lactate may be a hydrate. Examples of commercially available basic aluminum lactate include "Taxeram M-160P" (manufactured by Takaki Chemical Co., Ltd.). The content of the gelling agent contained in the hardening material may be 0.1 to 5.0 parts by mass, 0.5 to 3.0 parts by mass, or 0.8 to 2.5 parts by mass with respect to 100 parts by mass of the hydraulic binder contained in the main material to be mixed.

[0048] When the hardening material slurry contains a quick-setting agent (gypsum) and a gelling agent (basic aluminum salt), the content of the gelling agent may preferably be 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 20 to 30% by mass with respect to the total amount of the quick-setting agent and the gelling agent. When the contents of the quick-setting agent and the gelling agent are within this range, suitable lamination properties and quick-hardening properties can be obtained when mixed with the main material slurry, and abnormal coagulation or a decrease in strength development tendency can be suppressed.

[0049] The hardening material may contain silica fume as a siliceous powder. The silica fume contained in the hardening material can be the same as that contained in the main material. The silica fume contained in the hardening material may be of the same type or different types as that contained in the main material. The content of the silica fume contained in the hardening material may be 3 to 40 parts by mass, 5 to 35 parts by mass, or 10 to 35 parts by mass with respect to 100 parts by mass of the hydraulic binder contained in the main material to be mixed. By the content of the silica fume contained in the hardening material being within the above range, the content of the silica fume in the two-component mixed hydraulic composition increases, and the rubber hardness of the two-component mixed hydraulic composition can be improved. Thereby, the lamination property can be improved.

[0050] The fine aggregate contained in the hardening material can be the same as the fine aggregate contained in the main material. The fine aggregate contained in the hardening material may be the same type as the fine aggregate contained in the main material, or a different type. The content of the fine aggregate in the hardening material may be 5 to 100 parts by mass, 10 to 70 parts by mass, or 20 to 50 parts by mass per 100 parts by mass of the hydraulic binder contained in the main material to be mixed.

[0051] The hardening agent may further contain metakaolin. Metakaolin contains SiO2 and Al2O3. Therefore, if the accelerator contains alum, when the alum content is insufficient, metakaolin will dissolve Al 3+ This can be a source of Al2O3. Therefore, by including metakaolin, the two-component hydraulic composition can achieve both high levels of mixability and hardening property, and a hardened product with even higher compressive strength can be stably obtained. The content of Al2O3 in the metakaolin may be 43% by mass or more, or 45% by mass or more. By using metakaolin with such a high content of Al2O3, the amount of alum can be further reduced, and the two-component hydraulic composition can achieve both high levels of mixability and hardening property. The content of metakaolin in the hardener may be 3 to 30 parts by mass, 5 to 20 parts by mass, or 7 to 15 parts by mass relative to 100 parts by mass of the hydraulic binder contained in the main material to be mixed. The average particle size of the metakaolin may be 0.3 to 2 μm, or 0.5 to 1.5 μm.

[0052] The hardener may further contain sodium sulfate. Sodium sulfate is a sulfate ion (SO4 2- ) in the hardener. 2-Even if the content of alum to supply the saturation point is insufficient, the inclusion of sodium sulfate in the hardening agent allows both the mixability and hardening properties of the two-component hydraulic composition to be achieved, and a hardened product with high compressive strength can be stably obtained. The content of sodium sulfate in the hardening agent relative to 100 parts by mass of hydraulic binder contained in the main material to be mixed may be 0.5 parts by mass or more, or 1.0 part by mass or more, from the viewpoint of stably obtaining a hardened product with sufficiently high compressive strength. The content of sodium sulfate in the hardening agent relative to 100 parts by mass of hydraulic binder contained in the main material to be mixed may be 5 parts by mass or less, 4 parts by mass or less, or 3 parts by mass or less, from the viewpoint of suppressing an increase in the discharge pressure of a liquid delivery pump when preparing a slurry two-component hydraulic composition. For example, the content of sodium sulfate in the hardening agent relative to 100 parts by mass of hydraulic binder contained in the main material to be mixed may be 0.5 to 5 parts by mass.

[0053] The components of the main material and the hardener are not limited to those described above. The main material may contain various additives, such as an expanding agent. The hardener may also contain an antifoaming agent and a thickener. The antifoaming agent and the thickener may be those listed in the description of the main material.

[0054] A two-component hydraulic composition and a hardened product obtained by hardening the composition may be prepared using a 3D printer as shown in Fig. 2. The 3D printer in Fig. 2 includes a first supply unit 10 that supplies a first slurry containing a base material and water, a second supply unit 20 that supplies a second slurry containing a hardener and water, a confluence unit 30 that joins the first slurry and the second slurry, a mixing unit 40 that mixes the joined slurries produced in the confluence unit 30, a flow path 32 that connects the confluence unit 30 and the mixing unit 40, a discharge unit 60 provided downstream of the mixing unit 40, and a position adjustment unit 70 that adjusts the position of the material discharged from the discharge unit 60.

[0055] The first supply unit 10 includes a first storage unit 12 that stores a first slurry, and a first liquid feed pump 14. The second supply unit 20 includes a second storage unit 22 that stores a second slurry, and a second liquid feed pump 24. The first slurry and the second slurry stored in the first storage unit 12 and the second storage unit 22 each include the above-mentioned main material and the above-mentioned hardening material. The first storage unit 12 and the second storage unit 22 may be a transportable container, a tank truck, or a tank installed on the ground.

[0056] Various pumps can be used as the first liquid feed pump 14 and the second liquid feed pump 24. Of these, the first liquid feed pump 14 and the second liquid feed pump 24 are preferably non-pulsating pumps, and more preferably non-pulsating metering pumps. This allows the mixing ratio of the first slurry and the second slurry to be stably constant. This therefore allows the quality of the extruded product, the laminate, and the cured product (modeled object) to be sufficiently high.

[0057] The first slurry and the second slurry sent from the first storage section 12 and the second storage section 22 by the first liquid feed pump 14 and the second liquid feed pump 24 join at the confluence section 30 to form a joined slurry. The first slurry and the second slurry may be mixed so that the ratio of the hardener to the main material is 15 to 40 mass % or 20 to 35 mass %. The joined slurry produced at the confluence section 30 is introduced into the mixing section 40.

[0058] From the viewpoint of further improving workability, it is preferable that the mixing section 40 has an inline mixer, and from the viewpoint of simplifying the equipment and reducing weight, it is more preferable that it has a static mixer. A static mixer is a mixer that does not have a driving part, and is also called a static mixer or static mixer. Because a static mixer does not have a driving part, it is lightweight and can simplify the structure of the construction system. This makes it easy to handle at the construction site and further improves workability.

[0059] On the other hand, static mixers tend to have poorer mixing properties than dynamic mixers such as Hobart mixers, which can lead to sagging of the laminate and a decrease in the strength of the set product. However, because the first slurry has high fluidity, even when a static mixer is used, it is possible to suppress the decrease in mixing properties, and to sufficiently suppress the occurrence of sagging of the laminate and the decrease in settling properties. Therefore, even when a static mixer is used, a two-component hydraulic composition that is easy to apply can be stably prepared.

[0060] By making the mixing section 40 a static mixer, it can be attached to the position adjustment section 70 as shown in Fig. 2 and move smoothly together with the discharge section 60. This allows the length from the confluence section 30 to the discharge section 60 to be sufficiently short, thereby reducing the amount of mixed slurry (two-component mixed hydraulic composition) remaining in the flow path 32. This allows sufficient reduction in material loss that occurs when the compositions of the first and second slurries are changed or construction is suspended.

[0061] Fig. 3 is an exploded view showing an example of a static mixer serving as a mixing section. The static mixer 40A shown in Fig. 3 has a cylindrical body 45 and an element 41 provided inside the cylindrical body 45. The element 41 is integrally formed and configured so that it can be inserted into and removed from the cylindrical body 45 along the central axis CL. When the joined slurry generated in the joining section 30 is introduced into the static mixer 40A, it is repeatedly divided and joined by the element 41 fixed inside the static mixer 40A. In this way, the joined slurries are mixed to obtain a mixed slurry (two-part hydraulic composition).

[0062] The static mixer is not limited to the example shown in FIG. 3 , and any mixer capable of mixing the main material and hardener contained in the first slurry and the second slurry by a mixing principle such as swirling, dividing, inverting, or recombining can be used without particular limitations. The element may be configured by a series of repeating units having the same shape along the central axis direction of a cylinder. The repeating unit of the element may have flow holes 42 through which the slurry flows, as in the static mixer 40A shown in FIG. 3 . This prevents clogging of the mixed slurry, sufficiently reduces pressure loss in the static mixer, and ensures a sufficient discharge rate.

[0063] Returning to FIG. 2, the mixed slurry obtained in the mixing section 40 is discharged from the discharge section 60 and layered. A hardened product (a shaped object) can be obtained by hardening the layered product 80 thus formed. The discharge section 60 may be, for example, a nozzle. The hardened product may be a hardened mortar product. The position of the discharge section 60 is adjusted by the position adjustment section 70. Therefore, hardened products having various shapes can be obtained. The hardened product is not particularly limited, and examples thereof include buildings and structures. Examples thereof include secondary concrete products, buried formwork, buildings and benches installed in parks or campsites, etc.

[0064] The mixing section 40 may be movable together with the discharge section 60 by a position adjustment section 70 that adjusts the discharge position of the mixed slurry. This shortens the distance between the mixing section 40 and the discharge section 60, making it possible to sufficiently reduce the loss of mixed slurry that occurs at the end of construction. The position adjustment section 70, which moves the mixing section 40 and the discharge section 60 to adjust the discharge position of the mixed slurry, may be, for example, a robot arm or a gantry crane. This allows for smooth production of the laminate 80 and the hardened product even if they are large.

[0065] The construction system shown in FIG. 2 suppresses the occurrence of compaction and maintains excellent fluidity by mixing the first slurry and the second slurry in the mixing section 40, and then quickly discharges the mixed slurry from the discharge section 60 to produce the laminate 80 and its hardened product. This prevents the mixed slurry from being stored for a long period of time and prevents the generation of excess mixed slurry. Furthermore, the mixed slurry discharged from the discharge section 60 has a sufficiently high mixing uniformity and excellent layerability, which sufficiently suppresses the occurrence of sagging in the laminate 80 and allows for the production of a hardened product with excellent aesthetics. Furthermore, this hardened product has high compressive strength and can be suitably used for a variety of applications. The two-component hydraulic composition obtained by mixing the first slurry and the second slurry in this way is easy to construct and exhibits both excellent layerability and compressive strength, thereby reducing the burden of on-site work.

[0066] The method for producing a two-component hydraulic composition (mixed slurry) for a 3D printer and the method for producing a hardened product may be performed using the 3D printer of Fig. 2. In the method for producing a two-component hydraulic composition (mixed slurry), the mixing step of mixing a first slurry containing a main material and water with a second slurry containing a hardener and water may be performed using a static mixer 40A. The method for producing a hardened product may involve discharging the two-component hydraulic composition obtained by the above-mentioned production method from a discharge unit 60, laminating the composition, and hardening the laminate 80 to obtain the hardened product.

[0067] Each of the above manufacturing methods may be performed using a 3D printer having a configuration different from that of the 3D printer shown in FIG. 2. In this case, too, since the first slurry containing the above-described main material is used, a two-component mixed hydraulic composition (mixed slurry) can be obtained that has a sufficiently high uniformity of the mixed state, excellent rubber hardness, and excellent strength development. A laminate formed using this two-component mixed hydraulic composition (mixed slurry) is prevented from sagging and also has excellent strength development. Therefore, the two-component mixed hydraulic composition (mixed slurry) is easy to apply and can achieve both excellent lamination properties and compressive strength. As a result, a cured product with excellent aesthetics can be obtained.

[0068] A two-component hydraulic composition (mixed slurry) may be produced using a two-component hydraulic composition preparation kit for a 3D printer, which includes the above-mentioned main material or a first slurry containing the main material, and the above-mentioned hardening material or a second slurry containing the main material, in separate states. The above-mentioned main material or a first slurry containing the main material, and the above-mentioned hardening material or a second slurry containing the main material may be contained in separate containers. Such a two-component hydraulic composition preparation kit can be stably stored for a long period of time because the two components are separate and not mixed. Furthermore, by mixing the first and second slurries at the construction site using a 3D printer, for example, as shown in FIG. 2, a two-component hydraulic composition that is easy to apply and has excellent buildability and strength development can be smoothly prepared. Alternatively, the main material and hardening material may be mixed with water at the construction site to prepare the first and second slurries, respectively, and then the two slurries may be mixed to prepare the two-component hydraulic composition.

[0069] The two-part hydraulic composition thus obtained contains the components of the main material and the components of the hardening material. The ratio of the solid content of the hardening material to the solid content of the main material in the two-part hydraulic composition may be 15 to 50 mass%, 15 to 40 mass%, or 20 to 40 mass%.

[0070] In the kit for preparing a two-component hydraulic composition, the ratio of the solid content of the hardener to the solid content of the main material in the first and second slurries may be 15 to 50 mass%, 15 to 40 mass%, or 20 to 40 mass%. When the ratio of the solid content of the hardener to the solid content of the main material is within the above range, a two-component setting hydraulic composition that is easy to apply can be prepared. The ratio of the second slurry to the first slurry may be 15 to 50 mass%, 15 to 40 mass%, or 20 to 40 mass%.

[0071] In the two-component hydraulic composition preparation kit, the volume ratio of the first slurry to the second slurry is preferably 5.0:1.0 to 2.0:1.0, more preferably 4.5:1.0 to 2.1:1.0, and even more preferably 4.0:1.0 to 2.2:1.0. This allows the slurries to be mixed appropriately, while maintaining lamination properties and allowing the strength of the laminate to be exhibited.

[0072] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. For example, the mixing unit 40 in the 3D printer is not limited to a static mixer and may be a dynamic mixer. Furthermore, multiple mixers of the same type may be used, or two or more types of mixers may be used in combination.

[0073] The present disclosure includes several embodiments as follows. [1] A main material used in a two-component hydraulic composition for 3D printers, The main material includes a hydraulic binder, a water-reducing agent, a retarder, and a fine aggregate; The hydraulic binder is a base material including cement and silica fume. [2] The main material according to [1], wherein the content of the silica fume is 3 to 40 parts by mass per 100 parts by mass of the hydraulic binder. [3] The main material according to [1] or [2], wherein the water-reducing agent includes a polycarboxylic acid-based water-reducing agent. [4] The main material according to any one of [1] to [3], further comprising a thickener. [5] The main material according to any one of [1] to [4], further comprising an antifoaming agent. [6] A two-component hydraulic composition preparation kit for a 3D printer, comprising a main material or a first slurry containing the main material and a hardening material or a second slurry containing the main material, in a separated state, The main material is a main material according to any one of [1] to [5], The hardening material is a two-component hydraulic composition preparation kit for 3D printers, which contains an accelerator, a gelling agent, silica fume, and fine aggregate. [7] The kit for preparing a two-component hydraulic composition according to [6], wherein the ratio of the solid content contained in the hardening agent to the solid content contained in the main material is 15 to 50 mass %. [8] A first slurry containing the main material according to any one of [1] to [5] above and water; A two-component hydraulic composition for 3D printers obtained by mixing a hardening agent including an accelerator, a gelling agent, silica fume, and fine aggregate with a second slurry containing water. [9] A hardened product obtained by hardening the two-component hydraulic composition described in [8] above.

[10] A first slurry containing the main material according to any one of [1] to [5] above and water; A method for producing a two-component hydraulic composition for 3D printers, comprising the step of mixing a hardening agent including an accelerator, a gelling agent, silica fume, and fine aggregate with a second slurry containing water.

[11] A method for producing a hardened product, comprising the steps of discharging the two-component hydraulic composition obtained by the method according to

[10] above from a discharge unit of a 3D printer to form a laminate, and curing the laminate to obtain a hardened product.

[12] A first supply unit that supplies a first slurry containing the main material according to any one of [1] to [5] above and water; a second supply unit that supplies a second slurry containing a hardening agent including an accelerator, a gelling agent, silica fume, and fine aggregate, and water; a mixing section in which the first slurry and the second slurry are joined and mixed to obtain a mixed slurry; and a discharge unit that discharges the mixed slurry. [Example]

[0074] The present disclosure will be described in more detail below with reference to examples and comparative examples, but the present disclosure is not limited to the following examples.

[0075] <Preparation of main material slurry> The following raw materials were prepared: Hydraulic binder 1 (C): High-early-strength Portland cement (manufactured by UBE Mitsubishi Cement Corporation, density: 3.14 g / cm 3 , Blaine specific surface area: 4530 cm 2 / g) Hydraulic binder 2 (BFS): blast furnace slag powder (K-MENT (product name), manufactured by Kobe Steel Slag Products Co., Ltd., Blaine specific surface area 4850 cm 2 / g) ·Hydraulic binder 3 (SF): Silica fume (EFACO (product name), manufactured by Tomoe Kogyo Co., Ltd., BET specific surface area: 16.9m 2 / g) Water-reducing agent 1: Modified polycarboxylic acid-based high-performance water-reducing agent (MELFLUX AP101F (product name), manufactured by BASF Japan Ltd.) Water reducing agent 2: Naphthalene sulfone-based water reducing agent (POWERCON-100 (product name), manufactured by KG Chemical Co.) Water-reducing agent 3: Melamine sulfonic acid-based water-reducing agent (MELMENT F10M (product name), manufactured by BASF Japan Ltd.) Water-reducing agent 4: Lignin sulfonic acid-based high-performance water-reducing agent (ARBO N18 (trade name), manufactured by RYAM) Water-reducing agent 5: Polyether-polycarboxylic acid-based high-performance water-reducing agent (MELFLUX 2641F (trade name), manufactured by BASF Japan Ltd.) Water-reducing agent 6: Polyether-polycarboxylic acid-based high-performance water-reducing agent (MELFLUX 4930F (product name), manufactured by BASF Japan Ltd.) Water-reducing agent 7: Polyether-polycarboxylic acid-based high-performance water-reducing agent (MELFLUX 6681F (trade name), fast-adsorption type, manufactured by BASF Japan Ltd.) Water-reducing agent 8: Polyether-polycarboxylic acid-based high-performance water-reducing agent (MELFLUX BF11F (product name), manufactured by BASF Japan Ltd.) Water-reducing agent 9: Polycarboxylic acid-based high-performance water-reducing agent (Mighty 21P (product name), manufactured by Kao Corporation) Thickener: Water-soluble methylcellulose thickener (Marporose 90MP-300T (product name), manufactured by Matsumoto Oil & Fat Co., Ltd.) Antifoaming agent: Adekanate B115F (product name), manufactured by ADEKA Corporation Retardant: Sodium gluconate (reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Fine aggregate 1: Kashima silica sand No. 6 (manufactured by Takano Shoji Co., Ltd., average particle size: 0.21 mm, density: 2.60 g / cm 3 ) ·Fine aggregate 2: No. N70 (manufactured by Nichihyogyo Co., Ltd., average particle size: 0.16 mm, density: 2.60 g / cm 3 ) Water: Tap water

[0076] (Comparative Examples 1 to 13) The powdered raw materials other than water in Table 1 and the water-reducing agent shown in Table 2 were dry-mixed in advance to prepare a premix powder. The blending ratios of the powdered raw materials are as shown in Table 1. The type of water-reducing agent used in each comparative example is shown in Table 2. The water-reducing agent was blended so that the concentration relative to the hydraulic binder was as shown in Table 2. These were mixed at low speed for 30 seconds (dry mixing) in a Hobart mixer, and then water in the amount shown in Table 1 was added and the mixture was mixed at low speed for an additional 90 seconds, scraping off any powder or paste adhering to the sides and bottom of the container. The mixture was then mixed at high speed for 90 seconds to prepare a main material slurry.

[0077] [Table 1]

[0078] [Table 2]

[0079] <Checking for tightness> The prepared main material slurry was placed in a container and allowed to stand for 20 minutes. After that, the container was tilted and visually inspected to see if the main material slurry maintained its fluidity. As a result, the main material slurries of Comparative Examples 1 to 13 all lost fluidity and were judged to have "tightening."

[0080] <15-stroke flow value measurement> The fluidity of the prepared main material slurries was evaluated by the 15-stroke flow value using the flow test described in "JIS R5201:2015 Physical Testing Methods for Cement." As mentioned above, the main material slurries of Comparative Examples 1 to 13 experienced compaction, so the flow test was conducted after re-mixing. Measurements were conducted from immediately after the preparation of the main material slurries to 18 days later. Table 3 shows the results from immediately after preparation to 6 days later, and Table 4 shows the results from 7 days later to 18 days later. Furthermore, Figure 4 shows the results of Comparative Examples 1 to 8, and Figure 5 shows the results of Comparative Examples 9 to 13. In Tables 3 and 4, cases where no measurement was performed are indicated by "-." Furthermore, the mark "hardened" indicates that the main material slurry had completely hardened, making it impossible to measure the 15-stroke flow value.

[0081] [Table 3]

[0082] [Table 4]

[0083] As shown in Tables 3, 4, Figures 4, and 5, the 15-shot flow value decreased over time in Comparative Examples 1 to 13, and fluidity decreased. These results confirmed that even if the type and amount of water-reducing agent was changed, it was not possible to avoid the occurrence of compaction of the main material slurry, and that the fluidity of the main material slurry also decreased over time due to the hydration reaction of cement.

[0084] (Examples 1 to 6, Comparative Examples 14 to 16) A main material slurry was prepared using the same procedure as in Comparative Example 1, except that the raw materials were mixed in the amounts shown in Table 5. The 15-shot flow value was measured immediately after preparation and after standing for one day. The density was also evaluated by a density test. The density test was performed using a weighing container (cylindrical, inner diameter 76 mm x height 110 mm). The main material slurry was filled into the weighing container and poked 10 times. The container was then lifted 1 cm and allowed to fall downward to remove air. The mass of the weighing container was then measured, and the density was calculated. The results are shown in Table 6. For Example 6, the 15-shot flow value was also measured after standing for 2 to 7 days. The relationship between the elapsed time and the 15-shot flow value measurement results for Example 6 is shown in Table 7 and Figure 6. In Tables 6 and 7, values ​​for which no measurement was performed are indicated by "-".

[0085] The occurrence of compaction was confirmed for each example and each comparative example. The occurrence of compaction was confirmed by leaving the main material slurry to stand for 20 minutes and then tilting the container containing the main material slurry. When the container was tilted, if the main material slurry maintained its fluidity, it was judged as "no compaction occurred," and if the main material slurry solidified without flowing, it was judged as "compaction occurred." The results are shown in Table 6. In Table 6, "no compaction occurred" is indicated by "A," and "compaction occurred" is indicated by "B."

[0086] [Table 5]

[0087] [Table 6]

[0088] [Table 7]

[0089] As shown in Tables 5 and 6, the main material slurries of Examples 1 to 6, which contained silica fume, showed significantly less compaction than the main material slurries of Comparative Examples 14 and 15, which did not contain silica fume. On the other hand, Comparative Example 16, which replaced the silica fume of Example 2 with ground granulated blast furnace slag, was rated "A" in the compaction evaluation because it flowed slightly when the container was tilted. Remixing of Comparative Example 16 was not possible. Furthermore, the 15-stroke flow values ​​of the main material slurries of Examples 1 to 6 were higher after one day than immediately after preparation, demonstrating clearly improved fluidity. Furthermore, as shown in Table 7 and Figure 6, the 15-stroke flow value of Example 6 was still 200 mm or greater even after seven days. Therefore, it was confirmed that the inclusion of silica fume in the main material suppresses compaction while maintaining fluidity and extending the usable life of the main material slurry. This is thought to be due to the silica fume adsorbing onto the cement and suppressing gel formation around the cement.

[0090] <Preparation of hardener slurry> The following materials were prepared: Accelerator: Commercially available powdered potassium alum (manufactured by Taimei Chemical Industry Co., Ltd., average particle size: 0.06 mm, density: 1.75 g / cm 3 ) Gelling agent: basic aluminum lactate (Taxeram M-160P (trade name), manufactured by Taki Chemical Co., Ltd., density: 2.42 g / cm 3 ) Silica powder: Silica fume (EFACO (trade name), manufactured by Tomoe Engineering Co., Ltd., BET specific surface area: 16.9 m 2 / g) Fine aggregate 1: Kashima silica sand No. 6 (manufactured by Takano Shoji Co., Ltd., average particle size: 0.21 mm, density: 2.60 g / cm 3 ) Water: Tap water

[0091] The powder raw materials shown in Tables 8 and 9 were dry mixed in advance in the mass ratios shown in Tables 8 and 9 to prepare premix powders. This was mixed at low speed (dry mixing) in a Hobart mixer for 30 seconds, and then water was added in the mass ratios shown in Tables 8 and 9, followed by mixing at low speed for an additional 90 seconds, after which the powder and paste adhering to the sides and bottom of the container were scraped off. The mixture was then mixed at high speed for 90 seconds to prepare two types of hardener slurries.

[0092] [Table 8]

[0093] [Table 9]

[0094] <Preparation of mixed slurry and formation of laminate> An installation system as shown in Figure 2 was prepared. A commercially available non-pulsating metering pump (Mono Pump (product name), manufactured by Heishin Soubi Co., Ltd.) was used as the first liquid feed pump 14 and the second liquid feed pump 24. Two commercially available static mixers (manufactured by Chihiro Co., Ltd., model: TA6-SUS20-3 (20A)) having the structure shown in Figure 3 were connected in series and used as the mixing section 40.

[0095] The first slurry (main material slurry) of Example 5 was stored in the first storage section 12, and the second slurry (hardening material slurry) having the composition shown in Table 8 was stored in the second storage section 22. The first and second liquid pumps 14 and 24 were activated, and the mixed slurry (two-component hydraulic composition) was discharged from the discharge section 60 (nozzle) attached downstream of the mixing section 40 to form the laminate 80. The mixing ratio of the first slurry to the second slurry was 3.3 by volume (first slurry:second slurry = 3.3:1.0). The ratio of the solid content of the hardening material to the solid content of the main material was 22.5% by mass. The discharge rate from the discharge section 60 was constant at 2.3 L / min, and the movement speed of the discharge section 60 was 120 mm / sec. The pressure (discharge pressure) in the flow path 32 upstream of the mixing section 40 when the mixed slurry was discharged from the discharge section 60 is shown in Table 10.

[0096] The first slurry (main material slurry) of Example 6 was placed in the first storage section 12, and the second slurry (hardening material slurry) having the composition shown in Table 9 was placed in the second storage section 22, to produce a laminate 80. The difference from when the main material slurry of Example 5 was used was that the mixing ratio of the first slurry to the second slurry was 2.4 on a volume basis (first slurry:second slurry = 2.4:1.0). The ratio of the solid content contained in the hardening material to the solid content contained in the main material was 33.4 mass% on a mass basis. Except for changing the mixing ratio of the first slurry to the second slurry as described above, the laminate 80 was produced using the same procedure as when the first slurry of Example 5 was used.

[0097] The volume ratio of main material slurry to hardener slurry differs between the system using the main material slurry of Example 5 and the system using the main material slurry of Example 6. This is because, in order to be able to compare the hardening performance after lamination, the volume ratios of water to hydraulic binder, water to quick-setting admixture, and water to gelling agent in the mixed slurries were adjusted so that they were the same in Example 5 and Example 6. A photograph of the laminate when the main material slurry of Example 5 was used is shown in Figure 7(A), and a photograph of the laminate when the main material slurry of Example 6 was used is shown in Figure 7(B).

[0098] <Evaluation of strength development> The mixed slurry of Example 6, prepared using the same procedure as for forming the laminate, was poured into a formwork to form a two-layer laminate structure in the vertical direction. The surface was smoothed and the formwork was filled to prepare cylindrical specimens measuring φ50 mm x 100 mm. After 6 days, the specimens were removed from the formwork and then cured in air at 20°C and 50% RH. Compressive strength tests were conducted on each specimen at ages of 7 and 28 days in accordance with JIS A 1108:2018 "Testing Method for Compressive Strength of Concrete." The measured compressive strength values ​​are shown in Table 10.

[0099] The same procedure as in Example 6 was used to conduct compressive strength tests on specimens at ages of 7 and 28 days, except that the mixed slurry of Example 5, prepared using the same procedure as for forming the laminate, was used and the specimens were rectangular parallelepipeds measuring 40 x 40 x 160 mm in length, width, and height. The measured values ​​were corrected using the correction factor specified in JIS A 1107:2017, "Method for core extraction from concrete and compressive strength test method." The corrected compressive strength of Example 5 is shown in Table 10.

[0100] <Rubber hardness evaluation> The mixed slurries of Examples 5 and 6, prepared using the same procedure as for forming the laminate, were filled into stainless steel petri dishes measuring 125 mm in diameter and 25 mm in height, and the surface was smoothed with a scraper. The surface was covered with plastic wrap, and an Asker Type F durometer (manufactured by Kobunshi Keiki Co., Ltd.) was slowly placed on the dish and the scale was read. As shown in the non-patent document (Maebori Shinpei et al., "Cement and Concrete," Cement Association, October 2020, No. 884, pp. 9-15), there is a certain relationship between the readings of the rubber hardness meter in a static state and the maximum stacking height, so rubber hardness can be used as an indicator of stackability. Table 10 shows the readings of the rubber hardness meter 3, 5, and 10 minutes after dispensing.

[0101] <Evaluation of rapid hardening> The initial setting time of the extruded material was measured using a Vicat needle device in accordance with JIS R 5201:2015 "Physical Testing Methods for Cement." The results are shown in the "Setting Time" column in Table 10. The initial setting time refers to the time until the material is sufficiently self-supporting without any deformation such as sagging.

[0102] [Table 10]

[0103] As shown in Table 10 and Figures 7(A) and 7(B), the laminates produced using the main material slurries of Examples 5 and 6 all had sufficient strength development, lamination properties, and rapid hardening properties. Therefore, it was confirmed that both Examples 5 and 6 can achieve both excellent lamination properties and compressive strength when used as two-part hydraulic compositions for 3D printers, and also have excellent workability. [Industrial Applicability]

[0104] According to the present disclosure, it is possible to provide a main material that can maintain excellent fluidity while suppressing the occurrence of hardening when made into a slurry, and that can achieve both excellent lamination properties and compressive strength when used in a two-component hydraulic composition for 3D printers, and a two-component hydraulic composition preparation kit including such a main material. Furthermore, according to the present disclosure, it is possible to provide a two-component hydraulic composition that is easy to apply, and an application system that is excellent in workability. It is also possible to provide a cured product that is easy to apply and has an excellent appearance, and a method for producing the same. [Explanation of symbols]

[0105] 100...silica fume, 150...cement, 10...first supply section, 12...first storage section, 14...first liquid feed pump, 20...second supply section, 22...second storage section, 24...second liquid feed pump, 30...junction section, 32...flow path, 40...mixing section, 40A...static mixer, 41...element, 42...flow hole, 45...cylinder, 60...discharge section, 70...position adjustment section, 80...laminated body, CL...central axis.

Claims

1. A main material used in a two-component hydraulic composition for a 3D printer, The main material includes a hydraulic binder, a water-reducing agent, a retarder, and a fine aggregate; The hydraulic binder is a base material including cement and silica fume.

2. 2. The main material according to claim 1, wherein the content of said silica fume is 3 to 40 parts by mass per 100 parts by mass of said hydraulic binder.

3. The base material according to claim 1 or 2, wherein the water-reducing agent includes a polycarboxylic acid-based water-reducing agent.

4. The base material according to claim 1 or 2, further comprising a thickener.

5. The base material according to claim 1 or 2, further comprising an antifoaming agent.

6. A two-component hydraulic composition preparation kit for a 3D printer, comprising a main material or a first slurry containing the main material, and a hardening material or a second slurry containing the hardening material, in a separated state, The main material is the main material according to claim 1 or 2, The hardening material includes a quick-setting agent, a gelling agent, silica fume, and fine aggregate, and the kit for preparing a two-component hydraulic composition for a 3D printer is provided.

7. 7. The kit for preparing a two-component hydraulic composition according to claim 6, wherein the ratio of the solid content contained in the hardening material to the solid content contained in the main material is 15 to 50 mass %.

8. A first slurry containing the main material according to claim 1 or 2 and water; A two-component hydraulic composition for 3D printers is obtained by mixing a hardening agent including a quick-setting agent, a gelling agent, silica fume, and fine aggregate with a second slurry containing water.

9. A hardened product obtained by hardening the two-component hydraulic composition according to claim 8.

10. A first slurry containing the main material according to claim 1 or 2 and water; A method for producing a two-component mixed hydraulic composition for 3D printers, comprising a step of mixing a hardening agent including a quick-setting agent, a gelling agent, silica fume, and fine aggregate with a second slurry containing water.

11. A method for producing a cured product, comprising the steps of discharging the two-component hydraulic composition obtained by the production method according to claim 10 from a discharge part of a 3D printer to form a laminate, and curing the laminate to obtain a cured product.

12. a first supply unit that supplies a first slurry containing the main material according to claim 1 or 2 and water; a second supply unit that supplies a second slurry containing a hardening agent including an accelerator, a gelling agent, silica fume, and fine aggregate, and water; a mixing section in which the first slurry and the second slurry are joined and mixed to obtain a mixed slurry; and a discharge unit that discharges the mixed slurry.

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