Building materials for 3D printers, manufacturing method for building materials for 3D printers, and manufacturing method for buildings

Abstract

To provide a building material for a 3D printer that can reduce the environmental load, a manufacturing method for the building material for a 3D printer, and a manufacturing method for a building. [Solution] The building material for 3D printers according to the present invention comprises soil, a binder, and a fibrous additive, the binder having blast furnace slag and slaked lime, the blast furnace slag being contained in the binder in an amount of 100 to 200 parts by mass per 100 parts by mass of the slaked lime, and the soil content being 25 to 90% by mass of the entire building material for 3D printers.

Description

[Technical Field]

[0001] The present invention relates to a building material for a 3D printer, a method for manufacturing a building material for a 3D printer, and a method for manufacturing a building. [Background technology]

[0002] In recent years, the use of 3D printers to construct buildings such as houses has been attracting attention. Construction using such 3D printers is carried out by loading drawing data created by CAD or the like into the 3D printer, which then ejects and deposits building materials based on the loaded drawing data.

[0003] As a building material for construction using a 3D printer, for example, Patent Document 1 discloses a building material for a 3D printer that contains cement, aggregate, water, and synthetic fibers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2024-87560 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, growing awareness of environmental issues has led to calls to reduce carbon dioxide emissions into the atmosphere, and in particular, so-called carbon offsetting has attracted attention, in which product manufacturers and sellers reduce the amount of carbon dioxide emitted throughout the product's life cycle, thereby offsetting any carbon dioxide that remains. However, with building materials containing cement, such as the building material for 3D printers disclosed in Patent Document 1, a large amount of carbon dioxide is emitted during the manufacturing process of the raw material, cement, which poses a significant environmental burden.

[0006] Furthermore, in the case of building materials containing cement as described above, the water-cement ratio must be sufficiently high to ensure sufficient fluidity so that they can be discharged from the discharge unit of a 3D printer. Therefore, since the building materials have low self-supporting properties after discharge and are difficult to deposit, it is difficult to adjust the water-cement ratio to achieve an appropriate viscosity that can achieve both fluidity and self-supporting properties.

[0007] The present invention was made in consideration of these circumstances, and its objective is to provide building materials for 3D printers that can reduce the environmental burden, a method for manufacturing building materials for 3D printers, and a method for manufacturing buildings. [Means for solving the problem]

[0008] The building material for 3D printers according to the present invention is The method comprises: soil, a binder, a fibrous additive, and water; The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the slaked lime, The content of the soil is 25% by mass or more and 90% by mass or less with respect to the entire building material for 3D printers.

[0009] According to this configuration, the blast furnace slag hardens under strong alkali conditions, so the soil becomes strongly alkaline due to the action of the slaked lime, and the blast furnace slag hardens within the soil. Furthermore, the fibrous additive is mechanically and sufficiently attached to the particles contained in the soil and the hardened blast furnace slag, firmly bonding the raw materials together and reducing cracking in the building. This allows the 3D printer building material to be used to construct a building with sufficient strength simply by depositing it using a 3D printer.

[0010] Here, because the 3D printer building materials contain natural soil, they can significantly reduce carbon dioxide emissions compared to conventional 3D printer building materials containing cement. Furthermore, because the 3D printer building materials contain blast furnace slag, a waste product generated during steelmaking, they can be recycled to conserve resources and energy. Therefore, the 3D printer building materials can reduce the environmental impact.

[0011] In the building material for 3D printers according to the present invention, the soil may contain clay.

[0012] According to this configuration, the building material for 3D printers has excellent viscosity when discharged and excellent strength after hardening, so it has better self-standing properties while ensuring fluidity suitable for discharge from the discharge section of the 3D printer.

[0013] The building material for 3D printers according to the present invention may further contain fine aggregate having a particle size of 0.3 mm or more and 1.7 mm or less.

[0014] According to this configuration, the building material for 3D printers can suppress cracks in buildings by suppressing shrinkage of the material.

[0015] The building material for 3D printers according to the present invention may further contain fine aggregate having a particle size of 2.4 mm or more and 3.4 mm or less.

[0016] According to this configuration, the building material for 3D printers can suppress shrinkage of the material in the building, thereby suppressing cracks and improving the strength of the building.

[0017] The building material for 3D printers according to the present invention may further contain water, and the content of the water may be 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag.

[0018] With this configuration, the building material for 3D printers can exhibit excellent fluidity and self-sustaining properties because the blast furnace slag is easily hardened while maintaining fluidity suitable for discharge from the discharge section of the 3D printer.

[0019] The manufacturing method of a building material for a 3D printer according to the present invention includes a mixing step of mixing soil, a binder, and a fibrous additive, The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the slaked lime, The content of the soil is 25% by mass or more and 90% by mass or less with respect to the entire building material for 3D printers.

[0020] According to this configuration, the manufacturing method for 3D printer building materials can produce building materials for 3D printers that can reduce the environmental burden.

[0021] In the manufacturing method of the building material for 3D printers according to the present invention, in the mixing step, the soil, the binder, the fibrous additive, and further water are mixed, and the content of the water may be 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag.

[0022] According to this configuration, the manufacturing method for the building material for 3D printers makes it easier for the blast furnace slag to harden while ensuring fluidity suitable for discharge from the discharge section of the 3D printer, thereby making it possible to manufacture a building material for 3D printers that has excellent fluidity and self-sustaining properties.

[0023] The manufacturing method of a building according to the present invention is a method of manufacturing a building using a 3D printer, A manufacturing process for producing building materials for 3D printers; A deposition process in which the building material for 3D printers is deposited while being discharged using a 3D printer, The building material for 3D printers includes soil, a binder, and a fibrous additive; The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the slaked lime, The content of the soil is 25% by mass or more and 90% by mass or less with respect to the entire building material for 3D printers.

[0024] According to the above-described method for manufacturing a building, it is possible to manufacture a building that can reduce the environmental load throughout its life cycle.

[0025] In the method for manufacturing a building according to the present invention, the building material for a 3D printer may further contain water, and the content of the water may be 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag.

[0026] According to this configuration, the method for manufacturing buildings allows for efficient manufacturing of buildings because the building material for 3D printers has a fluidity suitable for being discharged from the discharge section of the 3D printer, and the blast furnace slag hardens quickly and is easily self-supporting. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a building material for a 3D printer, a manufacturing method of a building material for a 3D printer, and a manufacturing method of a building that can reduce the environmental burden. DETAILED DESCRIPTION OF THE INVENTION

[0028] (Building materials for 3D printers) The following describes the construction material for 3D printers according to this embodiment.

[0029] The construction material for 3D printers according to this embodiment includes soil, a binder, and a fibrous additive. The construction material for 3D printers according to this embodiment can be used for construction using a 3D printer.

[0030] [soil] In this specification, soil refers to a granular material containing organic matter derived from the decomposition of plants and animals and inorganic matter derived from rock, with a particle size of less than 0.3 mm. Note that this soil does not contain coarse aggregate or coarse fine aggregate (e.g., fine aggregate with a particle size of 0.3 mm or more). Here, particle size refers to the value obtained by the soil particle size test method specified in JIS A 1204:2020.

[0031] The soil preferably contains clay, from the viewpoint of exhibiting excellent viscosity when discharged and excellent strength after hardening. In this specification, clay refers to viscous soil in which the particle size of the granular material constituting the soil is 0.005 mm or less. Examples of such clay include alluvial clay, diluvial clay, and Kanto loam. Of these, alluvial clay is preferred, from the viewpoint of ensuring fluidity when discharged.

[0032] When the soil contains clay, the clay content is preferably 25.0% by mass or more, more preferably 35.0% by mass or more, based on the total soil, from the viewpoint of exhibiting excellent viscosity at the time of discharge and excellent strength after hardening. The clay content may be, for example, 50.0% by mass or less, based on the total soil.

[0033] Examples of clay-containing soil include loam, clay loam, and clay soil. Among these, the clay-containing soil is preferably at least one of loam and clay loam, because it ensures fluidity during discharge and has excellent self-supporting properties. In this specification, loam, clay loam, and clay soil refer to soils classified according to the soil texture classification of the Agricultural Society of Japan. Specifically, loam refers to soil with a clay content of 25.0% by mass or more but less than 37.5% by mass, clay loam refers to soil with a clay content of 37.5% by mass or more but less than 50.0% by mass, and clay soil refers to soil with a clay content of more than 50.0% by mass.

[0034] In addition to clay, the soil may contain, for example, silt, sandy soil, decomposed granite soil, and shirasu. When the soil contains silt, the content of the silt may be, for example, 20.0 mass % or more, or 50.0 mass % or more, based on the total soil. Furthermore, the soil may be, for example, soil generated at a construction site.

[0035] The water content of the soil may be, for example, 6.0% by mass or more, 8.0% by mass or more, 30.0% by mass or more, or 50.0% by mass or more. The water content of the soil may be, for example, 150.0% by mass or less, 80.0% by mass or less, or 50.0% by mass or less. The water content of the soil can be calculated using the following formula (I): Moisture content = {(mass of soil before drying) - (mass of soil after drying)} / (mass of soil after drying) ×100 (I)

[0036] From the viewpoint of reducing the environmental load, the content of the soil is 25% by mass or more and 90% by mass or less, and preferably 30% by mass or more and 50% by mass or less, based on the entire building material for 3D printers.

[0037] [Binding material] The binder includes blast furnace slag and hydrated lime.

[0038] In this specification, blast furnace slag refers to molten slag discharged from a blast furnace in a steelworks, specifically meaning slag in which components other than iron, such as silica contained in iron ore, and ash from coke, a reducing agent, are combined with limestone. Note that the concept of blast furnace slag does not include blast furnace cement, which is a mixture of cement and blast furnace slag (specifically, granulated blast furnace slag, which will be described later).

[0039] The blast furnace slag has the property of hardening (latent hydraulicity) by which, under strong alkali conditions, the chain bonds of the silicon dioxide and aluminum oxide contained in the blast furnace slag are broken, and calcium oxide, aluminum oxide, magnesium oxide, and other solid-solution components in the blast furnace slag are eluted, generating calcium silicate hydrate and calcium aluminate hydrate. The building material for 3D printers according to this embodiment has a binder containing the blast furnace slag and slaked lime, which makes the soil strongly alkaline due to the action of the slaked lime, allowing the blast furnace slag to harden within the soil, thereby demonstrating sufficient self-supporting properties.

[0040] Furthermore, since the blast furnace slag is a waste product discharged during steelmaking, from the viewpoint of recycling, it is possible to conserve resources and energy throughout the life cycle of a building.

[0041] In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less, preferably 100 parts by mass or more and 150 parts by mass or less, per 100 parts by mass of the slaked lime, from the viewpoint of reducing the environmental load and improving self-sustainability.

[0042] The blast furnace slag is mainly classified into air-cooled blast furnace slag, which is slowly cooled from a molten state and solidifies into a rock-like substance, and granulated blast furnace slag, which is rapidly cooled from a molten state with water and becomes a sand-like amorphous substance. The blast furnace slag is preferably granulated blast furnace slag, from the viewpoint that it hardens easily and is easily mixed uniformly with the soil.

[0043] The blast furnace slag is preferably in the form of powder, from the viewpoints that it can be easily mixed uniformly with the soil and that its small surface area facilitates hardening.

[0044] The slaked lime is preferably in powder form, since it can be uniformly mixed with the soil to easily harden the blast furnace slag uniformly.

[0045] The slaked lime can be produced by adding water to quicklime obtained by calcining limestone and reacting the quicklime with the water. The slaked lime can also be produced using calcium-containing waste materials such as shells (e.g., scallop and oyster shells), waste gypsum board, waste concrete, and concrete sludge, instead of limestone. The use of slaked lime produced from calcium-containing waste materials can reduce carbon dioxide emissions during the limestone mining process, and can also contribute to resource and energy conservation throughout the life cycle of a building by effectively utilizing waste materials.

[0046] From the viewpoint of improving self-supporting property, the content of the binder relative to the soil is preferably 10% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 30% by mass or less.

[0047] [Fiber additive] Examples of the fibrous additive include plant fibers, regenerated fibers, acetate fibers, vinylon fibers, etc. Among these, from the viewpoint of reducing carbon dioxide emissions in the raw material procurement process, the fibrous additive is preferably plant fibers, regenerated fibers, or acetate fibers, more preferably plant fibers. Examples of the plant fibers include hemp, straw, and cotton.

[0048] The fibrous additive may be short fibers, which in this specification refer to fibers with individual lengths ranging from several mm to several tens of cm.

[0049] From the viewpoint of improving self-supporting ability and toughness, the content of the fibrous additive is preferably 0.1 mass % or more and 1.0 mass % or less, and more preferably 0.3 mass % or more and 0.8 mass % or less, relative to the soil.

[0050] [Fine aggregate] The 3D printer building material according to this embodiment may further contain fine aggregate. This configuration of the 3D printer building material can suppress material shrinkage in buildings, thereby suppressing cracking. Here, "fine aggregate" refers to aggregate that passes entirely through a 10 mm mesh sieve and at least 85% by mass passes through a 5 mm mesh sieve, and has a particle size of 0.3 mm or greater. The particle size of fine aggregate refers to the value obtained by the sieving test method for aggregates specified in JIS A 1102:2014.

[0051] Examples of the fine aggregate include sand derived from natural sources, such as river sand, land sand, mountain sand, sea sand, crushed sand, and crushed limestone sand, as specified in JIS A 5308:2024 Appendix JA Aggregates for Ready-Mixed Concrete. Silica sand produced by crushing and classifying silica may also be used. The fine aggregate may be used alone or in combination of two or more types.

[0052] The particle size of the fine aggregate is preferably 0.3 mm or more and 3.4 mm or less from the viewpoint of suppressing shrinkage of materials in buildings.

[0053] In one embodiment, the particle size of the fine aggregate is 0.3 mm or more and 1.7 mm or less, from the viewpoint of suppressing shrinkage of materials in buildings.

[0054] From the viewpoint of suppressing shrinkage of the material, the content of the fine aggregate having a particle size of 0.3 mm or more and 1.7 mm or less is preferably 1 mass % or more and 10 mass % or less, and more preferably 3 mass % or more and 7 mass % or less, of the entire building material for 3D printers.

[0055] In addition, from the viewpoint of suppressing shrinkage of the material and improving the strength of the building, the particle size of the fine aggregate is, in another embodiment, 2.4 mm or more and 3.4 mm or less.

[0056] The content of the fine aggregate having a particle size of 2.4 mm or more and 3.4 mm or less is preferably 2% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 10% by mass or less, of the entire building material for 3D printers, from the viewpoint of suppressing shrinkage of the material after construction.

[0057] The fine aggregate having a particle size of 0.3 mm or more and 1.7 mm or less may be used in combination with the fine aggregate having a particle size of 2.4 mm or more and 3.4 mm or less.

[0058] The 3D printer building material according to this embodiment may further contain water. By including water, the 3D printer building material can easily harden the blast furnace slag while maintaining a fluidity suitable for discharge from the discharge unit of the 3D printer, thereby achieving excellent fluidity and self-supporting properties. From the viewpoint of achieving both fluidity and self-supporting properties, the water content is preferably 150 parts by mass or more and 400 parts by mass or less, more preferably 180 parts by mass or more and 380 parts by mass or less, relative to 100 parts by mass of the blast furnace slag.

[0059] The 3D printer building material according to this embodiment may further contain an admixture, if necessary. Examples of the admixture include air-entraining agents, water-reducing agents, fluidizing agents, separation-reducing agents, setting retarders, setting accelerators, quick-setting additives, shrinkage-reducing agents, foaming agents, expanding agents, and waterproofing agents. One type of admixture may be used alone, or two or more types may be used in combination.

[0060] The construction material for 3D printers according to this embodiment has the above-mentioned configuration, and while it has sufficient fluidity when discharged, it also has excellent self-supporting properties after discharge. Therefore, even when the construction material for 3D printers is piled up during construction, it can be prevented from collapsing under its own weight in the downward direction of the pile-up.

[0061] Furthermore, since the building material for 3D printers according to this embodiment has the above-described configuration, buildings with sufficient strength can be easily constructed simply by depositing it using a 3D printer.

[0062] (Method of manufacturing building materials for 3D printers) The following describes the manufacturing method for building materials for 3D printers according to this embodiment.

[0063] The manufacturing method of a building material for a 3D printer according to this embodiment includes a mixing step of mixing soil, a binder, and a fibrous additive.

[0064] In a preferred embodiment of the method for producing a 3D printer building material according to the present invention, the soil, the binder, the fibrous additive, and water are mixed in the mixing step. This configuration allows the blast furnace slag to harden easily while maintaining a fluidity suitable for discharge from the discharge unit of the 3D printer, thereby producing a 3D printer building material with excellent fluidity and self-sustaining properties.

[0065] The method for mixing the soil, binder, fibrous additive, and water is not particularly limited, and examples thereof include a method in which the soil, binder, fibrous additive, and water are added simultaneously and mixed, and a method in which the soil, binder, and fibrous additive are mixed to obtain a premix powder, and water is added to the premix powder and mixed.

[0066] The soil is the same as that in the construction material for 3D printers according to the present embodiment. From the viewpoint of reducing the environmental impact, the content of the soil is 25% by mass or more and 90% by mass or less, and preferably 30% by mass or more and 50% by mass or less, of the entire construction material for 3D printers.

[0067] The binder contains blast furnace slag and slaked lime, and is similar to that used in the construction material for 3D printers according to the present embodiment. In this binder, the blast furnace slag is contained in an amount of 100 to 200 parts by mass, preferably 100 to 150 parts by mass, per 100 parts by mass of the slaked lime, from the viewpoint of reducing environmental impact and improving self-supporting properties. The binder content, from the viewpoint of improving self-supporting properties, is preferably 10 to 50% by mass, more preferably 10 to 30% by mass, relative to the soil.

[0068] The fibrous additive is the same as that in the building material for 3D printers according to the present embodiment. From the viewpoint of improving self-supporting ability and toughness, the content of the fibrous additive relative to the soil is preferably 0.1% by mass or more and 1.0% by mass or less, and more preferably 0.3% by mass or more and 0.8% by mass or less.

[0069] From the viewpoint of achieving both fluidity and self-sustainability, the water content is preferably 150 parts by mass or more and 400 parts by mass or less, and more preferably 180 parts by mass or more and 380 parts by mass or less, relative to 100 parts by mass of the blast furnace slag.

[0070] In addition to the soil, binder, fibrous additive, and water, the mixing step may further include mixing fine aggregate, admixtures, etc. The fine aggregate and admixtures are the same as those used in the 3D printer building material according to the present embodiment. When the mixing step involves mixing the soil, binder, and fibrous additive to obtain a premixed powder, and then adding and mixing water to the premixed powder, the fine aggregate may be mixed simultaneously with the soil, binder, and fibrous additive, and the admixture may be added simultaneously with the water.

[0071] In the manufacturing method of the building material for 3D printers according to this embodiment, for example, if the water content of the soil is at a value that can sufficiently exhibit fluidity and self-sustaining properties in the building material for 3D printers, it is not necessary to mix water in the mixing step.

[0072] (Building manufacturing method) The manufacturing method of a building according to this embodiment will be described below.

[0073] The manufacturing method for a building according to this embodiment includes a manufacturing process for manufacturing building materials for 3D printers, and a deposition process for depositing the building materials for 3D printers while ejecting them using a 3D printer.

[0074] A 3D printer used in the method for manufacturing a building according to this embodiment may include, for example, a supply unit for supplying the 3D printer building material; a discharge unit connected to the supply unit and discharging the 3D printer building material; a drive unit connected to the discharge unit and configured to move the position of the discharge unit; and a control unit for controlling the discharge unit and the drive unit based on drawing data transmitted from an external terminal device (e.g., a computer, smartphone, etc.). With this configuration, the 3D printer can supply the 3D printer building material to the discharge unit and discharge it from the discharge unit. The drive unit can then move the position of the discharge unit parallel and / or perpendicular to the ground to deposit the 3D printer building material. Furthermore, the control unit can control the amount of 3D printer building material dispensed and the position of the discharge unit based on the drawing data transmitted from the external terminal device, thereby depositing the 3D printer building material according to the shape of the building indicated in the drawing data.

[0075] [Manufacturing process] In the manufacturing process, building materials for 3D printers are produced.

[0076] The 3D printer building material includes soil, a binder, and a fibrous additive. Preferably, the 3D printer building material also includes water. This configuration ensures that the 3D printer building material has fluidity suitable for ejection from the ejection unit of a 3D printer, and the blast furnace slag hardens quickly and becomes self-supporting, allowing for efficient building production.

[0077] For example, when the building material for 3D printers contains water, in the manufacturing process, the building material for 3D printers can be manufactured by mixing the soil, the binder, the fibrous additive, and the water.

[0078] Examples of mixing methods include a method in which the soil, the binder, the fibrous additive, and the water are mixed in a mixer, and a method in which the soil, the binder, the fibrous additive, and the water are mixed inside the supply section of the 3D printer.

[0079] When the mixing method is a method of mixing the soil, the binder, the fibrous additive, and the water inside the supply unit of the 3D printer, the mixing method can be performed by separately supplying the water and a premix powder obtained by premixing the soil, the binder, and the fibrous additive into the supply unit, and mixing the soil, the binder, the fibrous additive, and the water inside the supply unit.

[0080] The manufacturing process can be carried out in the same manner as the manufacturing method of the building material for 3D printers according to the present embodiment.

[0081] [Deposition process] In the deposition step, the building material for 3D printers is deposited while being ejected.

[0082] Examples of methods for depositing the 3D printer building material include a method of stacking the 3D printer building material and a method of discharging and filling the 3D printer building material into a formwork or the like.

[0083] The soil is the same as that in the construction material for 3D printers according to the present embodiment. From the viewpoint of reducing the environmental impact, the content of the soil is 25% by mass or more and 90% by mass or less, and preferably 30% by mass or more and 50% by mass or less, of the entire construction material for 3D printers.

[0084] The binder contains blast furnace slag and slaked lime, and is similar to that used in the construction material for 3D printers according to the present embodiment. In this binder, the blast furnace slag is contained in an amount of 100 to 200 parts by mass, preferably 100 to 150 parts by mass, per 100 parts by mass of the slaked lime, from the viewpoint of reducing environmental impact and improving self-supporting properties. The binder content, from the viewpoint of improving self-supporting properties, is preferably 10 to 50% by mass, more preferably 10 to 30% by mass, relative to the soil.

[0085] The fibrous additive is the same as that in the building material for 3D printers according to the present embodiment. From the viewpoint of improving self-supporting ability and toughness, the content of the fibrous additive relative to the soil is preferably 0.1% by mass or more and 1.0% by mass or less, and more preferably 0.3% by mass or more and 0.8% by mass or less.

[0086] From the viewpoint of achieving both fluidity and self-sustainability, the water content is preferably 150 parts by mass or more and 400 parts by mass or less, and more preferably 180 parts by mass or more and 380 parts by mass or less, relative to 100 parts by mass of the blast furnace slag.

[0087] The building material for 3D printers does not need to contain water, for example, as long as the water content of the soil is such that the building material for 3D printers can sufficiently exhibit fluidity and self-sustaining properties.

[0088] Furthermore, the building material for 3D printers may be the same as the building material for 3D printers according to the present embodiment.

[0089] The above describes the construction materials for 3D printers, the manufacturing method for construction materials for 3D printers, and the manufacturing method for buildings according to the present embodiment. Note that the construction materials for 3D printers, the manufacturing method for construction materials for 3D printers, and the manufacturing method for buildings according to the present invention are not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0090] The present invention includes the following aspects. [1] A method for making a soil-based concrete mix comprising: soil, a binder, a fibrous additive, and water; The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the slaked lime, The soil content of the building material for 3D printers is 25% by mass or more and 90% by mass or less based on the entire building material for 3D printers. [2] The building material for 3D printers described in [1], wherein the soil contains clay. [3] The building material for 3D printers according to [1] or [2], further comprising fine aggregate having a particle size of 0.3 mm or more and 1.7 mm or less. [4] The building material for 3D printers according to any one of [1] to [3], further comprising fine aggregate having a particle size of 2.4 mm or more and 3.4 mm or less. [5] Further, containing water, The building material for 3D printers according to any one of [1] to [4], wherein the content of the water is 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag. [6] A mixing step of mixing soil, a binder, and a fibrous additive, The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the slaked lime, A method for manufacturing building materials for 3D printers, wherein the soil content is 25% by mass or more and 90% by mass or less of the entire building material for 3D printers. [7] In the mixing step, the soil, the binder, the fibrous additive, and further water are mixed, The method for manufacturing a building material for a 3D printer described in [6], wherein the content of the water is 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag. [8] A method for manufacturing buildings using a 3D printer, A manufacturing process for producing building materials for 3D printers; A deposition process in which the building material for 3D printers is deposited while being discharged using a 3D printer, The building material for 3D printers includes soil, a binder, and a fibrous additive; The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the slaked lime, A method for manufacturing a building, wherein the soil content is 25% by mass or more and 90% by mass or less of the total building material for a 3D printer. [9] The building material for 3D printers further contains water, The method for manufacturing a building described in [8], wherein the water content is 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag. [Example]

[0091] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0092] (Examples 1 and 2) The building materials for 3D printers of Examples 1 and 2 were produced using the materials shown in Table 1 below, according to the formulations shown in Table 1. Specifically, first, using a soil mixer, soil, binder (slaked lime and blast furnace slag), fine aggregate, and fibrous additive (hemp) were dry-mixed for 1 minute, and then water and admixtures were added and mixed for 2 minutes to obtain the building materials for 3D printers of Examples 1 and 2.

[0093] (Comparative Example) A comparative example of a building material for a 3D printer was produced using the materials shown in Table 1 below, according to the formulation shown in Table 1. Specifically, first, soil, cement, slaked lime, rice husks, and a fibrous additive (straw) were dry-mixed using a Hobart mixer for 1 minute, and then water was added and mixed for 2 minutes to obtain a comparative example of a building material for a 3D printer.

[0094] [Table 1]

[0095] Using a 3D printer (manufactured by WASP), the 3D printer building materials of Examples 1 and 2 and the 3D printer building material of the comparative example were dispensed to create rectangular parallelepiped structures measuring 1.0 m wide x 0.1 mm deep x 0.3 m high. It was confirmed that all structures made using the 3D printer building materials were self-supporting without collapsing downward in the vertical direction. Furthermore, it was confirmed that all 3D printer building materials had sufficient fluidity when dispensed, as no clogging due to solidification of the material was observed when dispensed from the 3D printer.

[0096] From the above results, it can be seen that 3D printer building materials that satisfy all of the requirements of the present invention, even when using soil and blast furnace slag instead of cement, maintain fluidity during discharging while remaining sufficiently self-sustaining after discharging, similar to cement-containing 3D printer building materials. Therefore, the 3D printer building material of the present invention can significantly reduce carbon dioxide emissions compared to conventional cement-containing 3D printer building materials. Furthermore, because it contains blast furnace slag, a waste product of steelmaking, it can be recycled to conserve resources and energy, thereby reducing the environmental impact.

Claims

1. The method includes the steps of: soil, a binder, and a fibrous additive; The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the slaked lime, The content of the soil is 25% by mass or more and 90% by mass or less with respect to the entire building material for 3D printers.

2. The building material for a 3D printer according to claim 1 , wherein the soil includes clay.

3. The building material for 3D printers according to claim 1 or 2, further comprising fine aggregate having a particle size of 0.3 mm or more and 1.7 mm or less.

4. The building material for 3D printers according to claim 1 or 2, further comprising fine aggregate having a particle size of 2.4 mm or more and 3.4 mm or less.

5. A building material for 3D printers as described in claim 1 or 2, further comprising fine aggregate having a particle size of 0.3 mm or more and 1.7 mm or less, and also comprising fine aggregate having a particle size of 2.4 mm or more and 3.4 mm or less.

6. Furthermore, it contains water, The building material for 3D printers according to claim 1 or 2, wherein the content of the water is 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag.

7. A mixing step is provided for mixing soil, a binder, and a fibrous additive, The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the slaked lime, The method for manufacturing a building material for a 3D printer, wherein the content of the soil is 25% by mass or more and 90% by mass or less with respect to the entire building material for a 3D printer.

8. In the mixing step, the soil, the binder, the fibrous additive, and further water are mixed, The method for manufacturing a building material for a 3D printer according to claim 7, wherein the content of the water is 150 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the blast furnace slag.

9. A method for manufacturing a building using a 3D printer, comprising: A manufacturing process for manufacturing building materials for 3D printers; A deposition process in which the building material for 3D printers is deposited while being discharged using a 3D printer, The building material for 3D printers includes soil, a binder, and a fibrous additive; The binder comprises blast furnace slag and slaked lime, In the binder, the blast furnace slag is contained in an amount of 100 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the slaked lime, The method for manufacturing a building, wherein the content of the soil is 25% by mass or more and 90% by mass or less with respect to the entire building material for a 3D printer.

10. The building material for 3D printers further contains water, The method for manufacturing a building according to claim 9, wherein the content of the water is 150 parts by mass or more and 400 parts by mass or less with respect to 100 parts by mass of the blast furnace slag.

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