Main material, two-component hydraulic composition preparation kit, two-component hydraulic composition and its manufacturing method, cured product and its manufacturing method, and 3D printer construction system.

Abstract

To provide a main material that can produce a two-component mixed hydraulic composition that maintains excellent fluidity when formed into a slurry under low-temperature conditions, while also exhibiting excellent strength development. [Solution] The present invention provides a main component for use in a two-component hydraulic composition for 3D printers, wherein the main component comprises a binder, a water-reducing agent, a retarder, fine aggregate, and at least one of an alkali metal carbonate and a bicarbonate, the binder comprises cement and silica fume, and the retarder content is 0.5 parts by mass or more per 100 parts by mass of the binder.

Description

[Technical Field]

[0001] This disclosure relates to a main material, a kit for preparing a two-component hydraulic composition, a two-component hydraulic composition and a method for producing the same, a cured product and a method for producing the same, and a 3D printer construction system. [Background technology]

[0002] Additive manufacturing is a known method that involves layering materials such as resin, metal, and ceramics based on three-dimensional data of the target object. Among additive manufacturing methods, a material extrusion method is known in which the material is extruded from the nozzle of a 3D printer and layered. As for the material, a two-component mixture type, consisting of a main component and a curing initiator, is known. For example, Patent Document 1 proposes a system in which the main component and curing initiator are provided separately, with the main component containing a hydraulic binder and a retarder, and the curing initiator containing alum and a basic aluminum salt. Patent Document 2 proposes a construction system comprising a mixing unit that combines and mixes a main component slurry and a curing initiator slurry to obtain a mixed slurry, and a dispensing unit that discharges the mixed slurry. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-98085 [Patent Document 2] Japanese Patent Publication No. 2024-93922 [Overview of the project] [Problems that the invention aims to solve]

[0004] The construction system described in Patent Document 2 is also intended for outdoor use. The slurry used in such a construction system is required to have good fluidity. However, of the main material slurry and the curing initiator slurry, the main material slurry usually has a higher binder content than the curing initiator slurry, so there is a concern that its fluidity will decrease in winter, making it prone to clogging in the piping, mixer and discharge nozzle.

[0005] Therefore, this disclosure provides a main material that enables obtaining a two-component hydraulic composition that maintains excellent fluidity when made into a slurry in a low-temperature environment while also exhibiting excellent strength development. Furthermore, by using such a main material, this disclosure provides a two-component hydraulic composition that is excellent in workability in low-temperature environments and exhibits excellent strength development, as well as a method for manufacturing the same, and a kit for preparing such a two-component hydraulic composition that can be easily obtained. In addition, this disclosure provides a cured product having high compressive strength and a method for manufacturing the same, and a 3D printer construction system that can stably produce a cured product that is excellent in workability in low-temperature environments and has high compressive strength. [Means for solving the problem]

[0006] One aspect of this disclosure is a main material used in a two-component hydraulic composition for 3D printers, The main material comprises a binder, a water-reducing agent, a retarder, fine aggregate, and at least one of an alkali metal carbonate and a bicarbonate. The binder comprises cement and silica fume. The present invention provides a main material in which the content of the retarder is 0.5 parts by mass or more per 100 parts by mass of the binder.

[0007] The above main material allows for the production of a two-component mixed hydraulic composition that maintains excellent fluidity when formed into a slurry under low-temperature conditions while also exhibiting excellent strength development. One possible factor contributing to the maintenance of excellent fluidity under low-temperature conditions is the inclusion of a predetermined amount or more of a retarder. However, increasing the retarder content tends to reduce the strength development of the two-component mixed hydraulic composition under low-temperature conditions. Therefore, the above main material contains at least one of an alkali metal carbonate and a bicarbonate. This makes it possible to prepare a two-component mixed hydraulic composition that maintains excellent fluidity under low-temperature conditions while also exhibiting excellent strength development.

[0008] One aspect of this disclosure provides a two-component hydraulic composition preparation kit for a 3D printer, comprising a main material or a main material slurry containing the same, and a curing initiator or a curing initiator slurry containing the same, wherein the curing initiator comprises a binder, a curing accelerator, and fine aggregate.

[0009] The above-described two-component hydraulic composition preparation kit comprises the main material or a main material slurry containing the main material, and a curing initiator or a curing initiator slurry containing the main material, in a separated state. In such a two-component hydraulic composition preparation kit, the main material slurry can maintain excellent fluidity even in low-temperature environments. Therefore, a two-component hydraulic composition for 3D printers with excellent strength development properties can be smoothly prepared at the construction site, even in low-temperature environments such as winter. Thus, the above-described two-component hydraulic composition preparation kit offers excellent workability in low-temperature environments. Furthermore, compared to a one-component hydraulic composition, the curing accelerator contained in the curing initiator can be dispersed with high uniformity within the two-component hydraulic composition. Therefore, variations in the properties of the cured product can be reduced.

[0010] One aspect of this disclosure provides a two-component hydraulic composition for 3D printers, obtained by mixing a main material slurry containing the main material and water, a curing initiator slurry containing a binder, a curing accelerator, and fine aggregate, and water. Such a two-component hydraulic composition offers excellent workability in low-temperature environments because the main material slurry maintains excellent fluidity in low-temperature environments. This two-component hydraulic composition also exhibits excellent strength development in low-temperature environments because it contains the main material slurry.

[0011] One aspect of this disclosure is the provision of a cured product obtained by curing the above-mentioned two-component hydraulic composition. Because such a cured product uses the above-mentioned two-component hydraulic composition, it exhibits excellent workability in low-temperature environments and also has excellent strength development, resulting in high compressive strength. Furthermore, compared to a one-component hydraulic composition, the curing accelerator contained in the curing initiator can be dispersed with high uniformity within the two-component hydraulic composition. Therefore, variations in the properties of the cured product can be reduced.

[0012] One aspect of this disclosure provides a method for manufacturing a two-component hydraulic composition for 3D printers, comprising the step of mixing a main material slurry containing the main material and water, a curing initiator slurry containing a binder, a curing accelerator, and fine aggregate, and water. The two-component hydraulic composition obtained by such a manufacturing method has excellent workability in low-temperature environments because the main material maintains excellent fluidity. This two-component hydraulic composition also has excellent strength development in low-temperature environments because it contains the main material slurry.

[0013] One aspect of this disclosure provides a method for manufacturing a cured product, comprising the steps of extruding a two-component hydraulic composition obtained by the above manufacturing method from the extrusion section of a 3D printer, stacking the stacks, and curing the stacks to obtain a cured product. Because such a manufacturing method uses a two-component hydraulic composition obtained by the above manufacturing method, it offers excellent workability in low-temperature environments and can produce a cured product with high compressive strength.

[0014] One aspect of the present disclosure provides a 3D printer construction system including a kit for preparing a two-component hybrid hydraulic composition, and a mixer for mixing a main material slurry containing the main material and a curing initiator slurry containing the curing initiator.

[0015] Since the 3D printer construction system includes the kit for preparing the two-component hybrid hydraulic composition, it has excellent workability in a low-temperature environment. In addition, since it includes a mixer for mixing the main material slurry and the curing initiator slurry, a cured product having high compressive strength can be stably manufactured.

Advantages of the Invention

[0016] The present disclosure can provide a main material capable of obtaining a two-component hybrid hydraulic composition that maintains excellent fluidity when made into a slurry and also has excellent strength development properties in a low-temperature environment. Further, by using such a main material, a two-component hybrid hydraulic composition having excellent workability and excellent strength development properties in a low-temperature environment, a manufacturing method thereof, and a kit for preparing a two-component hybrid hydraulic composition that can easily obtain such a two-component hybrid hydraulic composition can be provided. In addition, a cured product having high compressive strength, a manufacturing method thereof, and a 3D printer construction system capable of stably manufacturing a cured product having excellent workability and high compressive strength in a low-temperature environment can be provided.

Brief Description of the Drawings

[0017] [Figure 1] It is a diagram schematically showing a state where silica fume is adsorbed on cement. [Figure 2] It is a diagram showing an example of a 3D printer construction system. [Figure 3] It is a table summarizing a part of the formulation of Table 2 of the examples, the results of Table 3 and Table 5.

Modes for Carrying Out the Invention

[0018] Embodiments of the present disclosure are described below. However, the following embodiments are illustrative examples for illustrating the present disclosure and are not intended to limit the present disclosure to the following. In the description, the same reference numerals are used for elements that are the same or have the same function, and redundant explanations are omitted where necessary. Also, unless otherwise specified, positional relationships such as up, down, left, and right are 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 the ratios shown. The numerical ranges illustrated as "a~b" are numerical ranges that include a and b, with a lower limit being a and an upper limit being b. The present disclosure also includes the case in which the upper or lower limit of each numerical range is replaced with the numerical values ​​of any embodiment. When multiple materials are illustrated, one of them may be used alone, or multiple may be used in combination.

[0019] In this disclosure, the "two-component hydraulic composition" is a fluid slurry comprising a main component containing a binder and a curing initiator having the function of hardening the main component. The curing initiator may also contain a binder. The binder has the property of hardening upon reaction with water and, after hardening, constitutes at least a part of the hardened product. While the "two-component hydraulic composition" is fluid, the product in which the hydraulic composition has hardened and lost its fluidity is referred to as the "hardened product." In this disclosure, the "3D printer" is a device that extrudes a two-component hydraulic composition from an extrusion port to create a physical three-dimensional object, and the "3D printer construction system" is a system equipped with such a device.

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

[0021] Examples of cement include various types of Portland cement such as ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening 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 type of cement may be used, or multiple types may be mixed and used. Among these, from the viewpoint of improving the hardening characteristics when used in a two-component hydraulic composition, the cement preferably includes at least one selected from the group consisting of ordinary Portland cement, rapid-hardening Portland cement, and ultra-rapid-hardening Portland cement, and more preferably includes rapid-hardening Portland cement.

[0022] The specific surface area of ​​cement is 3000-5000 cm². 2 / g, 3500~4900cm 2 / g, or 4000-4800cm 2 It may be / g. The Blaine specific surface area in this specification is measured in accordance with JIS R 5201:2015 "Physical Testing Methods for Cement".

[0023] Silica fume can be exemplified by those specified in JIS A 6207:2016 "Silica fume for concrete". The BET specific surface area of ​​silica fume is 10 m². 2 / g or more, 14m 2 / g or more, or 16m 2 The amount may be greater than or equal to / g. As shown in Figure 1, since silica fume 1 has a larger specific surface area than cement 3, it can be adsorbed around cement 3. As a result, silica fume 1 is thought to suppress the formation of calcium-derived gel around cement 3. Therefore, by adding silica fume to the main material slurry, the occurrence of "settlement" can be suppressed.

[0024] In this disclosure, "consolidation" refers to the phenomenon in which the fluidity of the main material slurry is impaired in the very early stages of development. Although a consolidated main material slurry can regain its fluidity and be used as a slurry by re-stirring, consolidation reduces work efficiency. Therefore, by including silica fume in the main material slurry, re-stirring is unnecessary when using the main material slurry, and excellent workability can be maintained. The presence or absence of consolidation can be confirmed by visually judging whether the main material slurry flows after being left to stand for 20 minutes after preparation. If the main material slurry does not flow even when the container is tilted, it can be said that consolidation has occurred. The BET specific surface area of ​​silica fume is, for example, 10 to 30 m². 2 / g is acceptable.

[0025] The silica fume content may be 3 parts by mass or more, or 5 parts by mass or more, per 100 parts by mass of the first binder, from the viewpoint of improving mixability, compressive strength of the hardened product, and appearance. Furthermore, the silica fume content may be 40 parts by mass or less, 25 parts by mass or less, or 15 parts by mass or less, per 100 parts by mass of the first binder, from the viewpoint of promoting the reaction between the cement and the retarder and improving the fluidity retention time (pot life). For example, the silica fume content may be 3 to 40 parts by mass, 5 to 25 parts by mass, or 5 to 15 parts by mass, per 100 parts by mass of the first binder.

[0026] The silica fume content may be 5 parts by mass or more, 8 parts by mass or more, or 10 parts by mass or more per 100 parts by mass of cement, from the viewpoint of improving mixability, compressive strength of the hardened product, and appearance. Furthermore, the silica fume content 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 cement and retarder, maintaining the fluidity of the main material, and improving pot life. For example, the silica fume content may be 5 to 50 parts by mass, 8 to 40 parts by mass, or 10 to 35 parts by mass per 100 parts by mass of cement.

[0027] The main material may include binders other than cement and silica fume. Examples of such binders include blast furnace slag fine powder (e.g., those conforming to JIS A 6206:2013 "Blast Furnace Slag Fine Powder for Concrete"), limestone fine powder, fly ash, and gypsum. The Blaine specific surface area of the blast furnace slag fine powder may be 2500~10000 cm 2 / g, 3000~9000 cm 2 / g, or 4000~8000 cm 2 / g. Examples of fly ash include those defined in JIS A 6201:2015 "Fly Ash for Concrete". Examples of gypsum include dihydrate gypsum (CaSO4·2H2O), hemihydrate gypsum (CaSO4·1 / 2H2O), and anhydrous gypsum.

[0028] The content of the blast furnace slag fine powder may be 10~50 parts by mass, 10~40 parts by mass, or 15~35 parts by mass with respect to 100 parts by mass of the first binder. When the first binder contains blast furnace slag fine powder, the content of cement with respect to 100 parts by mass of the first binder may be 40 parts by mass or more and less than 70 parts by mass. From the perspective of promoting the reaction between cement and retarder in a low-temperature environment and sufficiently maintaining the excellent fluidity of the main material slurry, the content of cement with respect to 100 parts by mass of the first binder may be 45 parts by mass or more, or 50 parts by mass or more. From the perspective of improving the mixing property of the main material slurry, the content of cement with respect to 100 parts by mass of the first binder may be 65 parts by mass or less. The content of cement with respect to 100 parts by mass of the first binder may be, for example, 45 parts by mass or more and less than 70 parts by mass, 50 parts by mass or more and less than 70 parts by mass, 40~65 parts by mass, or 50~65 parts by mass.

[0029] The water contained in the main material slurry is not particularly limited, and may be, for example, tap water, distilled water, deionized water, etc. The water-binder ratio Z (the ratio of water to the first binder) in the main material slurry may be 0.15~0.65, 0.20~0.55, 0.20~0.45, or 0.30~0.40 from the perspective of maintaining a sufficiently high fluidity and improving the strength development property when made into a two-component type hydraulic composition.

[0030] The fluidity of the main material slurry can be evaluated by the flow test described in "JIS R5201:2015 Physical Test Methods for Cement". In this disclosure, the measured flow value evaluated by the above test is referred to as the "15-pour flow value". From the viewpoint of providing a main material slurry that can maintain excellent fluidity in low-temperature environments such as winter, when a slurry is prepared by mixing 33 parts by mass of water with 100 parts by mass of the first binder at an environment of 5°C, the 15-pour flow value for ages 0 to 7 days may be in the range of 170 to 290 mm. Such a main material slurry allows for the omission of tasks such as replacing and cleaning containers and piping, even when construction is temporarily suspended during weekends or holidays. Then, work can be smoothly resumed at the beginning of the week or after the holidays. Therefore, excellent workability can be achieved in low-temperature environments such as winter. The above 15-pour flow value may be in the range of 190 to 280 mm or 200 to 280 mm.

[0031] The retarders contained in the main material have the effect of slowing down the hardening reaction of cement. Examples of retarders include sodium gluconate, oxycarboxylic acids, sugars, and inorganic retarders. Oxycarboxylic acids include oxycarboxylic acids and their salts. Examples of oxycarboxylic acids include gluconic acid, tartaric acid, citric acid, malic acid, succinic acid, and heptonic acid. Examples of salts of oxycarboxylic acids include alkali metal salts (sodium salts, potassium salts, etc.) and alkaline earth metal salts (calcium salts, magnesium salts, etc.).

[0032] Of the aforementioned retarders, it is preferable to include sodium gluconate and sodium L-tartrate. It is thought that sodium gluconate and sodium L-tartrate exert their retarding effects at different times. That is, it is thought that sodium gluconate exerts its retarding effect first, followed by sodium L-tartrate. By including multiple types of retarders that exert their retarding effects at different times in this way, it is thought that excellent fluidity can be maintained for a long period of time when the slurry is made in a low-temperature environment.

[0033] The content of the retarder is 0.5 parts by mass or more, preferably 0.6 parts by mass or more, more preferably 0.7 parts by mass or more, and even more preferably 0.8 parts by mass or more, per 100 parts by mass of the first binder. This allows the retarder to make sufficient contact with the cement even if silica fume 1 is adsorbed around the cement 3 as shown in Figure 1, thereby moderately delaying the hardening of the cement and extending the pot life of the main material slurry. From the viewpoint of sufficiently increasing the strength development of the hardened product of the two-component mixed hydraulic composition, the content of the retarder may be 5.0 parts by mass or less, 4.0 parts by mass or less, or 3.0 parts by mass or less, per 100 parts by mass of the first binder.

[0034] The mass ratio α of the sodium L-tartrate content to the sodium gluconate content is 1.0 or higher. This allows the main slurry to maintain excellent fluidity in low-temperature environments such as winter. The mass ratio α may be greater than 1.0, 1.2 or higher, or 1.5 or higher. This reduces the range of fluctuations in fluidity over time in both normal and low-temperature environments. From a similar viewpoint, the mass ratio α may be 20 or less, 11 or less, 10 or less, 8.0 or less, 5.5 or less, 4.0 or less, or 3.5 or less. For example, the mass ratio α may be between 1.0 and 20.

[0035] The main material may contain retarders other than sodium gluconate and sodium L-tartrate. From the viewpoint of fully obtaining the effect of improving fluidity by sodium gluconate and sodium L-tartrate, the total ratio of sodium gluconate and sodium L-tartrate to the total retarder may be 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. The retarder may consist only of sodium gluconate and sodium L-tartrate.

[0036] The main material contains at least one of an alkali metal carbonate and / or bicarbonate as a hardening accelerator. The hardening accelerator accelerates the hydration reaction of cement and promotes the hardening of the hydraulic composition. Normally, there is a concern that the fluidity will decrease when a hardening accelerator is added, but a hardening accelerator containing at least one of an alkali metal carbonate and / or bicarbonate can improve the strength development of a two-component hydraulic composition obtained by mixing the main material slurry and the hardening initiator slurry in a low-temperature environment without impairing the effect of fluidity improvement by the retarder. Examples of alkali metal carbonates include sodium carbonate, lithium carbonate, and potassium carbonate. Examples of alkali metal bicarbonates include sodium bicarbonate, lithium bicarbonate, and potassium bicarbonate.

[0037] The total content of alkali metal carbonates and bicarbonates in the main material may be 0.01 to 2.0 parts by mass per 100 parts by mass of the first binder in the main material. This allows for sufficiently high strength development of the two-component hydraulic composition while maintaining a sufficiently high level of fluidity of the main material slurry in a low-temperature environment. From the viewpoint of achieving an even higher level of balance between the fluidity of the main material slurry and the strength development of the two-component hydraulic composition, the total content of alkali metal carbonates and bicarbonates in the main material may be 0.05 to 1.0 parts by mass, or 0.08 to 0.8 parts by mass per 100 parts by mass of the first binder in the main material.

[0038] The water-reducing agent contained in the main material has the effect of improving the liquid-feeding properties when a main material slurry containing the main material and water is prepared. Examples of water-reducing agents include polycarboxylic acid-based, melamine sulfonic acid-based, naphthalene sulfone-based, and lignin sulfonic acid-based agents. From the viewpoint of suppressing the occurrence of clumping, 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 first 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-feeding properties of the main material slurry can be further improved.

[0039] 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 main material, it is preferable to include MELFLUX AP101F. On the other hand, from the viewpoint of adsorbing the water-reducing agent to the cement early and stabilizing the quality changes of the main material over time, the early-adsorption type MELFLUX 6681F may be used.

[0040] The fine aggregate contained in the main material may include concrete aggregate, silica sand used in 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 transferability when it is in slurry form. 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 fine aggregate in the main material relative to 100 parts by mass of the first binder in the main material may be 50 to 300 parts by mass, 70 to 200 parts by mass, or 80 to 150 parts by mass.

[0041] The main material may contain chemical admixtures other than water-reducing agents. The main material may also contain thickeners as chemical admixtures. The thickener has the effect of suppressing material separation when a main material slurry containing the main material and water is prepared. Examples of thickeners include organic thickeners such as cellulose-based thickeners, starch-based thickeners, guar gum-based thickeners, and vinyl-based thickeners, and 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 first 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, or 0.04 to 0.15 parts by mass, or 0.05 to 0.1 parts by mass.

[0042] The main material may contain an antifoaming agent as a chemical admixture. Known antifoaming agents can be used. Specific examples of antifoaming agents include, for example, synthetic substances such as mineral oil-based, silicone-based, alcohol-based, and polyether-based substances, or natural substances derived from plants. Of these, from the viewpoint of dispersibility and persistence, 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 first binder 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.

[0043] A curing initiator is used to prepare a two-component hydraulic composition for 3D printers. The curing initiator may contain a binder (second binder), a curing accelerator, and fine aggregate. The curing initiator may be in solid form, such as a powder, or may be mixed with water to form a curing initiator slurry. The curing accelerator has the effect of curing the binder. The second binder in the curing initiator preferably contains silica fume, and more preferably contains silica fume and metakaolin. The second binder in the curing initiator does not necessarily contain cement. This allows the fluidity of the curing initiator slurry to be maintained for a long period of time.

[0044] The silica fume contained in the second binder of the curing initiator can be the same as the silica fume contained in the first binder of the main material. The silica fume contained in the curing initiator may be the same type as the silica fume contained in the main material, or it may be a different type. The silica fume content in the curing initiator may be 1 to 20 parts by mass, 2 to 10 parts by mass, or 3 to 8 parts by mass per 100 parts by mass of the first binder contained in the main material to be mixed. By having the silica fume content in the curing initiator within the above range, the excellent fluidity of the two-component hydraulic composition can be maintained for an even longer period of time.

[0045] The curing accelerator may include what is called a rapid setting agent used to accelerate initial curing. Examples of such curing accelerators include alum, sulfates (alkali metal sulfates, aluminum sulfate, magnesium sulfate), carbonates (sodium carbonate, potassium carbonate, lithium carbonate), calcium thiocyanate, and calcium chloride. Alum is a double salt of a monovalent cation sulfate and a trivalent metal ion sulfate. Examples of alum include potassium alum, ammonium alum, sodium alum, iron alum, chromium alum, and their anhydrous forms (calcined alum). One of these alums may be used alone, or a combination of several may be used. From the viewpoint of obtaining a two-component mixed-type hydraulic composition that can achieve a sufficiently high level of both miscibility and curability, it is preferable that the alum includes potassium alum. Potassium alum is a double salt of potassium sulfate and aluminum sulfate, represented by the chemical formula KAl(SO4)2·12H2O.

[0046] Commercially available alum may be used, or it may be crushed using a ball mill or the like. By reducing the particle size of the alum to a certain extent, it is possible to make it easier to exert its hardening-accelerating effect while maintaining ease of handling. This makes it possible to reduce the alum content in the hardening initiator. From this viewpoint, the average particle size of the alum may be 0.01~1.0 mm, 0.02~0.3 mm, 0.03~0.2 mm, or 0.04~0.1 mm. Furthermore, when using potassium alum, from the viewpoint of suppressing the occurrence of white spots after application, the average particle size of the potassium alum may be 0.01~0.2 mm, 0.03~0.2 mm, or 0.04~0.1 mm.

[0047] Unless otherwise specified, the average particle size in this disclosure can be determined from the volume-based frequency distribution measured by a laser diffraction / scattering particle size distribution analyzer. For example, the "SALD-2200" manufactured by Shimadzu Corporation is used as the laser diffraction / scattering particle size distribution analyzer, and measurements are taken under dry conditions. The average particle size can be calculated as a weighted average value of the logarithm of the particle size, weighted by the volume-based frequency for that particle size, based on the relationship between the volume-based frequency and the particle size obtained from the above measurement.

[0048] Alkali metal sulfates contain sulfate ions (SO4 2- ) can become a source of sulfate ions (SO4) in the curing initiator. 2- Even if the proportion of alum supplying the two-component hydraulic composition is locally insufficient due to factors such as uneven mixing, it is believed that the action of alkali metal sulfates can ensure both the miscibility and curability of the two-component hydraulic composition, and that a cured product with high compressive strength can be stably obtained. The alkali metal sulfates may be water-soluble. From the viewpoint of ensuring a sufficiently high level of both the miscibility and curability of the two-component hydraulic composition, the alkali metal sulfates preferably contain at least one selected from the group consisting of potassium sulfate, sodium sulfate, and lithium sulfate, and preferably contain sodium sulfate.

[0049] The amount of rapid setting agent contained in the curing initiator may be 0.1 to 10.0% by mass, 0.5 to 8.0% by mass, 1.0 to 5.0% by mass, 1.5 to 4.0% by mass, or 2.0 to 3.0% by mass, relative to the total amount of the first binder contained in the main material and the second binder contained in the curing initiator. This makes it easier to obtain suitable rapid hardening and strength development when mixed with the main material slurry.

[0050] The alum content of the rapid setting agent may be 0.05 to 5.0% by mass, 0.25 to 4.0% by mass, 0.50 to 2.0% by mass, or 1.0 to 1.5% by mass, relative to the total amount of the first binder contained in the main material to be mixed and the second binder contained in the curing initiator.

[0051] The alkali metal sulfate content of the rapid setting agent may be 0.05 to 5.0% by mass, 0.25 to 4.0% by mass, 0.50 to 2.0% by mass, or 0.60 to 1.5% by mass, relative to the total amount of the first binder contained in the main material to be mixed and the second binder contained in the curing initiator.

[0052] The curing accelerator may also contain a gelling agent. Examples of such curing accelerators include basic aluminum salts. Basic aluminum salts are basic salts containing aluminum ions and hydroxy acid ions having 2 to 6 carbon atoms. Here, a basic salt is defined as a hydroxide ion (OH). - It is a salt containing ). In other words, a basic aluminum salt is a salt in which some of the anions in the salt of aluminum and a hydroxy acid are replaced with hydroxide ions. The general formula for a basic aluminum salt is: Al(OH) 3-x It can be represented as Yb, where x and b are selected such that the basic aluminum salt as a whole is electrically neutral. By using a basic aluminum salt, floc formation can be suppressed and the miscibility of each component can be improved when a two-component hydraulic composition is prepared.

[0053] The number of carbon atoms in the hydroxy acid ion contained in the basic aluminum salt may be 2 to 4, or 2 or 3, and may be 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 also be in hydrate form. A single basic aluminum salt may be used alone, or two or more may be used in combination.

[0054] 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 "Taxelam M-160P" (manufactured by Takagi Chemical Co., Ltd.). The content of the gelling agent contained in the curing initiator may be 0.1 to 5.0% by mass, 0.5 to 3.0% by mass, or 1.0 to 2.0% by mass with respect to the total of the first binder contained in the main material to be mixed and the second binder contained in the curing initiator.

[0055] When the curing accelerator contains a quick-setting agent and a gelling agent, the content of the gelling agent may be 20 to 60% by mass, or 30 to 50% by mass with respect to the total amount of the quick-setting agent and the gelling agent. When the ratio of the quick-setting agent and the gelling agent is within the above range, suitable laminability and quick-hardening properties can be obtained when mixed with the main material slurry. In addition, abnormal coagulation and a decrease in strength development can be sufficiently suppressed.

[0056] The fine aggregate contained in the curing initiator can be the same as the fine aggregate contained in the main material. The fine aggregate contained in the curing initiator may be of the same type or different types as the fine aggregate contained in the main material. The content of the fine aggregate in the curing initiator may be 5 to 100 parts by mass, 10 to 70 parts by mass, or 25 to 55 parts by mass with respect to 100 parts by mass of the first binder contained in the main material to be mixed.

[0057] Metakaolin, which can be contained as the second binder in the curing initiator, contains SiO2 and Al2O3. Therefore, when the curing accelerator contains alum, when the content of alum is insufficient, metakaolin is Al 3+It can serve as a source of [material]. By including metakaolin, the miscibility and curability of the two-component hydraulic composition can be improved to an even higher level, and a cured product with even higher compressive strength can be stably obtained. The Al2O3 content in metakaolin may be 43% by mass or more, or 45% by mass or more. By using metakaolin with such a high Al2O3 content, the amount of alum can be further reduced, and the miscibility and curability of the two-component hydraulic composition can be improved to an even higher level. The amount of metakaolin in the curing initiator relative to 100 parts by mass of the first binder contained in the main material to be mixed may be 3 to 30 parts by mass, 5 to 20 parts by mass, or 7 to 15 parts by mass. The average particle size of metakaolin may be 1 to 10 μm, or 2 to 8 μm.

[0058] The water contained in the curing initiator slurry is not particularly limited and may be, for example, tap water, distilled water, or deionized water. The water-to-binder ratio Y (ratio of water to the second binder) in the curing initiator slurry may be 0.40 to 1.20, 0.20 to 0.70, 0.30 to 0.65, 0.40 to 0.65, or 0.50 to 0.62, from the viewpoint of maintaining sufficiently high fluidity of the curing initiator slurry while improving the curing characteristics when it is made into a two-component hydraulic composition.

[0059] The ratio of the water-binder ratio Z of the main material slurry to the water-binder ratio Y of the curing initiator slurry (Z / Y) may be 1.625 or less, 1.5 or less, 1.0 or less, 0.8 or less, 0.7 or less, or 0.6 or less. By setting Z / Y within this range, both the main material slurry and the curing initiator slurry can have excellent fluidity, and the uniformity of the mixing of the main material slurry and the curing initiator slurry can be sufficiently high. From a similar viewpoint, Z / Y may be 0.125 or more, 0.2 or more, 0.3 or more, or 0.4 or more. For example, Z / Y may be between 0.125 and 1.625.

[0060] The ratio of the total amount of water WA contained in the main slurry and the curing initiator slurry to the total amount of binder BA (= sum of the first binder and the second binder) contained in the main slurry and the curing initiator slurry (WA / BA) may be 0.20 to 0.55, 0.25 to 0.50, 0.30 to 0.45, or 0.35 to 0.40. By setting WA / BA within this range, the uniformity of the mixing of the main slurry and the curing initiator slurry can be sufficiently high.

[0061] The curing initiator may contain chemical admixtures. Examples of chemical admixtures are those similar to those listed for the main material. For example, the curing initiator may contain defoamers and thickeners. The defoamers and thickeners may be those listed in the description of the main material. The components of the main material and curing initiator are not limited to those described above.

[0062] For the manufacture of a two-component hydraulic composition, a kit for preparing a two-component hydraulic composition may be used, which comprises the main component or a main component slurry containing the main component and the curing initiator or a curing initiator slurry containing the main component, in a separated state. The main component or main component slurry containing the main component and the curing initiator or curing initiator slurry containing the main component may be housed in separate containers. Such a kit for preparing a two-component hydraulic composition allows for stable storage over a long period of time in slurry form because the two components are isolated and not mixed. Furthermore, the two-component hydraulic composition can be smoothly prepared at the construction site by mixing the main component slurry and the curing initiator slurry, for example, using a 3D printer. At the construction site, the main component and the curing initiator may be mixed with water to prepare the main component slurry and the curing initiator slurry, respectively, and then the two slurries may be mixed to obtain a mixed slurry of the two-component hydraulic composition.

[0063] A two-component hydraulic composition contains the components of the main material and the components of the curing initiator. The ratio of solid content in the curing initiator to solid content in the main material in the two-component hydraulic composition may be 10 to 45% by mass, or 15 to 40% by mass. A kit for preparing a two-component hydraulic composition may include a main material (main material slurry) and a curing initiator (curing initiator slurry) such that the ratio of solid content is within the above range.

[0064] The cured product obtained by curing a two-component hydraulic composition may be a molded object having a layered structure. Since the cured product is manufactured using a main material slurry that exhibits excellent fluidity in low-temperature environments, it exhibits excellent strength development even in low-temperature environments. The compressive strength of a cured product prepared and cured at 5°C at 7 days of age is 15 N / mm². 2 More than 18N / mm 2 Above or above, or 20 N / mm 2 The above is acceptable. The compressive strength of a cured material prepared and cured at 5°C at 28 days of age is 40 N / mm². 2 Above 45 N / mm 2 Above or above, or 50 N / mm 2 The above is sufficient. Furthermore, the above cured material exhibits excellent strength development under normal temperature conditions. The compressive strength of a cured material prepared and cured at 20°C at 7 days of age is 50 N / mm². 2 Above or above, or 55 N / mm 2 That's all.

[0065] The two-component hydraulic composition and the cured product may be manufactured using a 3D printing system comprising a kit for preparing a two-component hydraulic composition and a mixer for mixing a main material slurry and a curing initiator slurry.

[0066] The 3D printer construction system 100 in Figure 2 comprises a two-component mixed hydraulic composition preparation kit 50 having a first storage section 51 for storing the main material slurry and a second storage section 52 for storing the curing initiator slurry; a confluence section 30 for combining the main material slurry and the curing initiator slurry; a mixer 40 for mixing the combined slurry generated in the confluence section 30; a flow path 32 connecting the confluence section 30 and the mixer 40; a nozzle 60 (discharge section) provided on the outlet side of the mixer 40; and a position adjustment section 70 for adjusting the position of the discharged material discharged from the nozzle 60. The first storage section 51 and the second storage section 52 may be transportable containers, tank trucks, or tanks installed on the ground.

[0067] The first containment section 51 and the junction section 30 are connected by a first liquid delivery section 10 having a first liquid delivery pump 14, and the second containment section 52 and the junction section 30 are connected by a second liquid delivery section 20 having a second liquid delivery pump 24. Various types of pumps can be used for the first liquid delivery pump 14 and the second liquid delivery pump 24. Of these, the first liquid delivery pump 14 and the second liquid delivery pump 24 may be pulsation-free pumps or pulsation-free metering pumps. This makes it possible to maintain a constant mixing ratio of the main material slurry and the curing initiator slurry with high precision. Therefore, the quality of the discharged material, laminate, and cured material (molded product) can be made sufficiently high.

[0068] The main material slurry and the hardening initiator slurry, which are supplied from the first containment section 51 and the second containment section 52 by the first liquid supply section 10 having a first liquid supply pump 14 and the second liquid supply section 20 having a second liquid supply pump 24, merge at the confluence section 30 to form a combined slurry. The combined slurry generated at the confluence section 30 is introduced into the mixer 40.

[0069] From the viewpoint of further improving workability, mixer 40 preferably has an in-line mixer. The mixer may be a static mixer from the viewpoint of simplifying and reducing the weight of the equipment, or it may be a dynamic mixer from the viewpoint of improving uniformity through mixing. A static mixer is a mixer that does not have a drive unit and is also called a static mixer or stationary mixer. A dynamic mixer is a mixer that has a drive unit and is also called a dynamic mixer.

[0070] The mixed slurry obtained in the mixer 40 is discharged from the nozzle 60 and layered. By curing the laminate 80 formed in this way, a hardened product (molded object) can be obtained. The hardened product may be a hardened mortar body. The position of the nozzle 60 is adjusted by the position adjustment unit 70. This makes it possible to obtain hardened products with various shapes. The hardened product is not particularly limited and may be, for example, a building or structure. Examples include precast concrete products, embedded formwork, buildings and benches installed in parks or campgrounds, etc.

[0071] The position adjustment unit 70, which moves the mixer 40 and nozzle 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 manufacturing even if the laminate 80 and cured product are large. The mixer 40 may be movable together with the nozzle 60 by the position adjustment unit 70 that adjusts the discharge position of the mixed slurry. This shortens the distance between the mixer 40 and the nozzle 60, thereby significantly reducing the loss of mixed slurry that occurs at the end of construction.

[0072] The 3D printing system 100 can manufacture a laminate 80 and its cured product by mixing a main material slurry, which can maintain excellent fluidity in low-temperature environments, with a curing initiator slurry in a mixer 40, and then quickly discharging the mixed slurry from a nozzle 60. Therefore, it is possible to prevent the mixed slurry from being stored for long periods or the generation of excess mixed slurry. Furthermore, because the mixed slurry discharged from the nozzle 60 has sufficiently high uniformity and excellent lamination properties, the occurrence of sagging in the laminate 80 is sufficiently suppressed, and a cured product with excellent aesthetics can be obtained. In addition, since this cured product exhibits excellent strength development even in low-temperature environments, it can be used regardless of the season. Thus, the two-component mixed hydraulic composition obtained by mixing the main material slurry and the curing initiator slurry offers a high degree of freedom in construction, excellent workability, and excellent strength development.

[0073] The two-component hydraulic composition (mixed slurry) and the cured product may be manufactured using the 3D printer construction system 100 shown in Figure 2, or using other systems. In the manufacturing method of the two-component hydraulic composition (mixed slurry), the mixing step of mixing the main material slurry and the curing initiator slurry may be performed using a device other than the mixer 40. The manufacturing method of the cured product may include a step of extruding from a nozzle 60 to form a laminate and curing the laminate 80, or a step of curing the extruded laminate using another device.

[0074] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above. For example, the mixer 40 in the 3D printer construction system 100 may consist of multiple mixers of the same type, or it may consist of a combination of two or more types of mixers. Furthermore, the position adjustment unit may not directly move the nozzle 60, but rather be configured to adjust the relative position between the nozzle 60 and the laminate 80 (the member on which the laminate 80 is placed) by moving the member on which the laminate 80 is placed.

[0075] This disclosure includes several embodiments described below. [1] A main material used in a two-component hydraulic composition for 3D printers, The main material comprises a binder, a water-reducing agent, a retarder, fine aggregate, and at least one of an alkali metal carbonate and a bicarbonate. The binder comprises cement and silica fume. The main material contains at least 0.5 parts by mass of the retarder per 100 parts by mass of the binder. [2] The main material according to [1], wherein the retarder comprises at least one of sodium gluconate and sodium L-tartrate. [3] The main material according to [1] or [2], wherein the total content of alkali metal carbonates and bicarbonates is 0.01 to 2.0 parts by mass per 100 parts by mass of the binder. [4] The main material according to any one of [1] to [3], wherein the binder contains blast furnace slag fine powder, and the content of the blast furnace slag fine powder is 10 to 50 parts by mass per 100 parts by mass of the binder. [5] The main material according to any one of [1] to [4], wherein when a slurry is prepared by mixing 33 parts by mass of water with 100 parts by mass of the binder in an environment of 5℃, the 15-strand flow value for ages 0 to 7 days is in the range of 170 to 290 mm. [6] A two-component hydraulic composition preparation kit for a 3D printer, comprising a main material or a main material slurry containing the same as described in any one of [1] to [5] above, and a curing initiator or a curing initiator slurry containing the same, in a separated state, The aforementioned curing initiator is a kit for preparing a two-component hydraulic composition for 3D printers, comprising a binder, a curing accelerator, and fine aggregate. [7] The kit for preparing a two-component hydraulic composition according to [6], wherein the binder in the curing initiator comprises silica fume. [8] The main material slurry and the curing initiator slurry are provided in a separated state, A two-component mixed hydraulic composition preparation kit according to [6] or [7], wherein the ratio (WA / BA) of the total amount of water contained in the main material slurry and the hardening initiator slurry to the total amount of binder contained in the main material slurry and the hardening initiator slurry is 0.20 to 0.55. [9] The main material slurry and the curing initiator slurry are provided in a separated state, A two-component mixed-type hydraulic composition preparation kit according to any one of [6] to [8], wherein Z is the water-binder ratio of the main material slurry and Y is the water-binder ratio of the hardening initiator slurry, and Z / Y is 0.125 or more and 1.625 or less.

[10] The curing initiator comprises metakaolin and an alkali metal sulfate, as described in any one of [6] to [9], a two-component mixed hydraulic composition preparation kit.

[11] A main material slurry containing any one of the main materials described in [1] to [5] above, and water, A two-component hydraulic composition for 3D printers, obtained by mixing a curing initiator containing a binder, a curing accelerator, and fine aggregate with a curing initiator slurry containing water.

[12] A cured product obtained by curing the two-component hydraulic composition described in

[11] above.

[13] A main material slurry containing any one of the main materials described in [1] to [5] above, and water, A method for producing a two-component hydraulic composition for a 3D printer, comprising the step of mixing a curing initiator containing a binder, a curing accelerator, and fine aggregate with a curing initiator slurry containing water.

[14] A method for producing a cured product, comprising the steps of extruding a two-component mixed hydraulic composition obtained by the manufacturing method described in

[13] above from the extrusion section of a 3D printer, stacking the stacks, and curing the stacks to obtain a cured product.

[15] A kit for preparing a two-component hydraulic composition as described in any one of [6] to [9] above, A 3D printing system comprising a mixer for mixing a main material slurry containing the main material and a curing initiator slurry containing the curing initiator. [Examples]

[0076] The contents of this disclosure will be explained in more detail below with reference to examples and comparative examples. However, this disclosure is not limited to the following examples.

[0077] The raw materials for the main slurry and the curing initiator slurry were prepared as shown in Table 1. [Table 1]

[0078] <Preparation of main material slurry> (Examples 1-6, Comparative Examples 1-3) A premix powder was prepared by blending the powdered raw materials other than water from the main slurry materials shown in Table 1 in the ratios shown in Table 2. The blending amounts for "external ratio" in Table 2 are parts by mass per 100 parts by mass of the binder (rapid-hardening Portland cement + blast furnace slag fine powder + silica fume). "-" in Table 2 indicates that the component is not included. After blending the powdered raw materials other than water, the mixture was stirred at low speed for 30 seconds in a Hobart mixer (manufactured by Hobart Japan Co., Ltd., product name: Mixer N50) (dry mixing). Then, the amount of water shown in Table 2 was added and mixed at low speed for a further 90 seconds, after which any powder or paste adhering to the sides of the container was scraped off. After that, the mixture was mixed at high speed for 90 seconds to prepare the main slurry for Comparative Examples 1-3 and Examples 1-6. The water-to-binder ratio (W / B) of the main slurry was 0.33.

[0079] [Table 2]

[0080] <Measurement of 15-stroke flow value> The 15-count flow values ​​of each prepared main material slurry were evaluated using the flow test described in "JIS R5201:2015 Physical Testing Methods for Cement". Measurements were taken at 5°C, from immediately after preparation (age 0) to 4 days after preparation of the main material slurry. The results are shown in Table 3. In Table 3, blank spaces indicate that evaluation was not performed. Also, in Table 3, a 15-count flow value of "0" indicates that the main material slurry has completely hardened and lost its fluidity.

[0081] [Table 3]

[0082] As shown in Table 3, in Comparative Examples 1 and 2, which had a low retarder content, the material hardened and lost its fluidity after 1 day. On the other hand, in Comparative Example 3 and Examples 1-6, which had an increased retarder content, good fluidity (170-290 mm) was maintained for at least 4 days. Such main material slurry can maintain good fluidity even in low-temperature environments such as winter, thus offering excellent workability.

[0083] <Preparation of curing initiator slurry> A premix powder was prepared by blending the powdered raw materials other than water from the curing initiator materials shown in Table 1 in the ratios shown in Table 4. After blending the powdered raw materials other than water, the mixture was stirred at low speed for 30 seconds (dry mixing) in a Hobart mixer (manufactured by Hobart Japan Co., Ltd., product name: Mixer N50). Then, water was added in the parts by mass shown in Table 5 and mixed at low speed for a further 90 seconds, scraping off any powder or paste adhering to the sides of the container. After that, the mixture was mixed at high speed for 90 seconds to prepare a curing initiator slurry having the composition shown in Table 4. The water-to-binder ratio (W / B) of the curing initiator slurry was 0.57. In all comparative examples and examples, a curing initiator slurry with the same composition shown in Table 4 was used. In this way, a two-component mixed type hydraulic composition preparation kit having a main material slurry and a curing initiator slurry was obtained.

[0084] [Table 4]

[0085] <Evaluation of intensity development> Test specimens for compressive strength measurement were prepared using a simple Hobart mixer. Specifically, the main material slurry for each comparative example and example shown in Table 2 and the curing initiator slurry shown in Table 4 were introduced into the Hobart mixer so that they were mixed in the parts-by-mass ratios indicated in Tables 2 and 4. The mixture was then stirred at low speed in the Hobart mixer for 30 seconds. Stirring was stopped and the paste adhering to the sides of the container was scraped off. The mixture was then stirred further so that the total stirring time, including the scraping time, was 60 seconds, and a mixed slurry (two-component hydraulic composition) was prepared.

[0086] Next, the mixed slurry was poured into the formwork to form a two-layer stacked structure in the vertical direction, the surface was leveled, and the mold was filled to produce cylindrical specimens measuring φ50 mm × 100 mm. Sealed curing was performed at 5°C and 60 RH for 6 days, after which the specimens were removed from the formwork and cured in the air. Compressive strength tests were performed on each specimen at 7 days and 28 days of age in accordance with JIS A 1108:2018 "Test Method for Compressive Strength of Concrete". The test results are shown in the Compressive Strength (Temperature 5°C) column of Table 5. The results for the compressive strength at 7 days of age when cured in the air at 20°C and 60 RH are also shown in Table 5. Furthermore, Figure 3 shows a table summarizing the formulations of retarders, hardening accelerators, and chemical admixtures in Table 2, and the contents of Tables 3 and 5.

[0087] [Table 5]

[0088] As shown in Table 5, the two-component hydraulic compositions of each example were confirmed to exhibit sufficient strength development even in a low-temperature environment of 5°C. These results confirm that the main material slurry and the two-component hydraulic composition of each example maintain good fluidity while exhibiting excellent strength development in a low-temperature environment of 5°C. The compressive strength of the cured product of Comparative Example 3 was considerably lower than that of the examples in a low-temperature environment of 5°C, but the difference with the examples became considerably smaller in a 20°C environment. This indicates that the curing accelerator contained in the main material slurry of each example has a particularly high strength-enhancing effect, especially in low-temperature environments. [Explanation of Symbols]

[0089] 1...Silica fume, 3...Cement, 10...First liquid delivery section, 14...First liquid delivery pump, 20...Second liquid delivery section, 24...Second liquid delivery pump, 30...Confluence section, 32...Flow channel, 40...Mixer, 50...Kit for preparing two-component hydraulic composition, 51...First containment section, 52...Second containment section, 60...Nozzle, 70...Position adjustment section, 80...Laminate, 100...3D printer construction system.

Claims

1. A main material used in a two-component hydraulic composition for 3D printers, The main material comprises a binder, a water-reducing agent, a retarder, fine aggregate, and at least one of an alkali metal carbonate and a bicarbonate. The binder comprises cement and silica fume. The main material contains at least 0.5 parts by mass of the retarder per 100 parts by mass of the binder.

2. The main material according to claim 1, wherein the retarder comprises at least one of sodium gluconate and sodium L-tartrate.

3. The main material according to claim 1 or 2, wherein the total content of alkali metal carbonates and bicarbonates is 0.01 to 2.0 parts by mass per 100 parts by mass of the binder.

4. The main material according to claim 1 or 2, wherein the binder contains blast furnace slag fine powder, and the content of the blast furnace slag fine powder is 10 to 50 parts by mass per 100 parts by mass of the binder.

5. The main material according to claim 1 or 2, wherein when a slurry is prepared by mixing 33 parts by mass of water with 100 parts by mass of the binder in an environment of 5°C, the 15-strand flow value for the material from day 0 to day 7 is in the range of 170 to 290 mm.

6. A two-component hydraulic composition preparation kit for a 3D printer, comprising a main material or a main material slurry containing the same, and a curing initiator or a curing initiator slurry containing the same, in a separated state, The aforementioned curing initiator is a kit for preparing a two-component hydraulic composition for 3D printers, comprising a binder, a curing accelerator, and fine aggregate.

7. The two-component mixed hydraulic composition preparation kit according to claim 6, wherein the binder in the curing initiator contains silica fume.

8. The main material slurry and the curing initiator slurry are provided in a separated state. A two-component mixed hydraulic composition preparation kit according to claim 6, wherein the ratio (WA / BA) of the total amount of water contained in the main material slurry and the hardening initiator slurry to the total amount of binder contained in the main material slurry and the hardening initiator slurry is 0.20 to 0.

55.

9. The main material slurry and the curing initiator slurry are provided in a separated state. The two-component mixed-type hydraulic composition preparation kit according to claim 6, wherein when the water-binding ratio of the main material slurry is Z and the water-binding ratio of the hardening initiator slurry is Y, Z / Y is 0.125 or more and 1.625 or less.

10. The two-component mixed-type hydraulic composition preparation kit according to claim 6, wherein the curing initiator comprises metakaolin and alkali metal sulfate.

11. A main material slurry containing the main material described in claim 1 or 2 and water, A two-component hydraulic composition for 3D printers, obtained by mixing a curing initiator containing a binder, a curing accelerator, and fine aggregate with a curing initiator slurry containing water.

12. A cured product obtained by curing the two-component hydraulic composition described in claim 11.

13. A main material slurry containing the main material described in claim 1 or 2 and water, A method for producing a two-component hydraulic composition for a 3D printer, comprising the step of mixing a curing initiator containing a binder, a curing accelerator, and fine aggregate with a curing initiator slurry containing water.

14. A method for producing a cured product, comprising the steps of extruding a two-component mixed hydraulic composition obtained by the manufacturing method described in claim 13 from the extrusion section of a 3D printer, stacking the stacks, and curing the stacks to obtain a cured product.

15. A kit for preparing a two-component hydraulic composition according to claim 6, A 3D printing system comprising a mixer for mixing a main material slurry containing the main material and a curing initiator slurry containing the curing initiator.

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