Formwork, formwork production method, and concrete production method

Abstract

Formwork according to the present disclosure is forwork into which fresh concrete is poured. The formwork is provided with a resin molded article that has been additively manufactured by a 3D printer. The resin molded article has: a cylindrical section the inner surface of which comes into contact with fresh concrete; and at least one protruding section that protrudes from the outer surface of the cylindrical section. The protruding section has separation surfaces facing each other along the axial direction of the cylindrical section and the protruding direction of the protruding section.

Description

Formwork, method for manufacturing formwork, and method for manufacturing concrete

[0001] This disclosure relates to formwork, a method for manufacturing formwork, and a method for manufacturing concrete.

[0002] Concrete is generally obtained by pouring fresh concrete into formwork, curing it, and then removing the formwork. Traditionally, wooden and metal forms have been used. In recent years, formwork made with 3D printers has been used to easily produce concrete with complex three-dimensional shapes.

[0003] Patent Document 1 discloses a method for constructing a molded object. The method includes an outer frame molding step, a reinforcement step, and an outer frame removal step. In the outer frame molding step, an outer frame (hereinafter also referred to as "mold") having a shape corresponding to at least a part of the outer frame of the target molded object and surrounding a hollow space is integrally molded using a 3D printer that molds three-dimensional objects. In the reinforcement step, the target molded object is reinforced by filling the hollow space with a reinforcing material. In the outer frame removal step, the outer frame molded in the outer frame molding step is removed after filling with the reinforcing material in the reinforcement step. Examples of molding materials include thermoplastics, thermosetting plastics, metals, glass, ceramics, concrete, and wood. Examples of reinforcing materials include concrete and resin materials.

[0004] Patent Document 1: Specification of Japanese Patent No. 6277033

[0005] However, Patent Document 1 does not specifically disclose the structure of the formwork that is removed after the reinforcing material has been filled.

[0006] When manufacturing concrete formwork using a 3D printer, it may be necessary to divide the formwork into multiple separate parts to facilitate demolding.

[0007] The dimensions of objects produced by a 3D printer may not match the dimensions of the 3D model data due to factors such as warping of the printed object. When a formwork is composed of multiple individually manufactured segmented parts, gaps may form between the segmented parts when they are stacked and integrated. If gaps form, the fresh concrete poured into the formwork may leak out.

[0008] The embodiments of this disclosure have been made in view of the above, and aim to provide a formwork that prevents fresh concrete from leaking out, a method for manufacturing the formwork, and a method for manufacturing concrete.

[0009] The means for solving the above problems include the following embodiments: <1> A formwork into which fresh concrete is poured, comprising a resin molded by a 3D printer, wherein the resin molded has a cylindrical portion whose inner surface is in contact with the fresh concrete, and at least one protruding portion that extends outward from the outer surface of the cylindrical portion, and the protruding portion has separation surfaces that face each other along the axial direction of the cylindrical portion and the protruding direction of the protruding portion. <2> The formwork according to <1>, wherein the opposing separation surfaces are separated into two for demolding, and the separation surfaces include a cut surface formed by cutting at least a part of the protruding portion. <3> The formwork according to <2>, wherein the cut surface is formed along the axial direction, only at the tip of the protruding portion of the separation surface in the protruding direction. <4> The mold according to <3>, wherein the resin molded object is formed by stacking molded layers formed in a single continuous path along the axial direction, and when the protruding portion is viewed from the axial direction, the protruding portion includes a pair of straight portions that extend side by side along the protruding direction and are not connected to each other, and the cut surface is a surface formed by cutting a folded portion that connects the ends of the pair of straight portions in the protruding direction. <5> The mold according to any one of <1> to <4>, wherein the resin molded object is a resin molded object produced by a material extrusion method. <6> The mold according to any one of <1> to <5>, wherein the resin molded object includes used resin. <7> The mold according to any one of <1> to <6>, wherein the resin molded object includes biomass-derived resin. <8> A method for manufacturing a mold as described in <1> above, comprising: using a 3D printer to build up layers along the axial direction to produce a resin molded object in which a cut surface formed by cutting at least a part of the protruding portion is not formed. <9> The method for manufacturing a mold as described in <8> above, further comprising: cutting at least a part of the protruding portion of the resin molded object in which a cut surface is not formed to form the cut surface.<10> The method for manufacturing a formwork according to <9>, wherein when the overhang is viewed from the axial direction, the overhang includes a pair of straight sections that extend in parallel along the overhang direction and are not connected to each other, the molded layer is formed in a single continuous path by a material extrusion method in forming the resin molded object, the resin molded object without a cut surface has the pair of straight sections and a folded section that connects the ends of the pair of straight sections, and in forming the cut surface, at least a part of the overhang is the folded section. <11> The method for manufacturing concrete, comprising: preparing the formwork according to any one of <2> to <7> and the fresh concrete; pouring the fresh concrete into the resin molded object whose separation surfaces overlap and the overhang is fixed, curing it to form concrete; and separating the separation surfaces and demolding the resin molded object from the concrete.

[0010] According to embodiments of this disclosure, a formwork that prevents fresh concrete from leaking out, a method for manufacturing the formwork, and a method for manufacturing concrete are provided.

[0011] Figure 1 is a perspective view of the formwork according to the first embodiment. Figure 2 is a perspective view of the formwork according to the first embodiment. Figure 3 is a partially enlarged perspective view of the formwork according to the first embodiment. Figure 4 is a diagram illustrating the concrete manufacturing method of the first embodiment. Figure 5 is a diagram illustrating the concrete manufacturing method of the first embodiment. Figure 6 is a partially enlarged perspective view of the formwork according to the second embodiment. Figure 7 is a perspective view of the formwork according to the third embodiment. Figure 8 is a diagram illustrating the concrete manufacturing method of the third embodiment. Figure 9 is a diagram illustrating the concrete manufacturing method of the third embodiment. Figure 10 is a diagram illustrating the concrete manufacturing method of the third embodiment. Figure 11 is a perspective view of the 3D model data of the formwork according to the third embodiment.

[0012] In this disclosure, the "~" indicating a numerical range is used to mean that the numbers before and after it are included as the lower and upper limits. In numerical ranges described in stages in this disclosure, the upper or lower limit described in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. In numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. In this disclosure, the term "process" is included not only in the sense of an independent process, but also in the sense that the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. In this disclosure, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, it means the total amount of the multiple substances present in the composition unless otherwise specified.

[0013] (1) Formwork The formwork of the present disclosure is formwork into which fresh concrete is poured. The formwork comprises a resin molded object that is additively manufactured by a 3D printer. The resin molded object has a cylindrical portion whose inner surface is in contact with the fresh concrete, and at least one protruding portion that extends outward from the outer surface of the cylindrical portion. The protruding portion has separation surfaces that face each other along the axial direction of the cylindrical portion and the direction of protrusion of the protruding portion.

[0014] In this disclosure, “formwork” refers to a temporary structure that maintains the shape and dimensions of poured fresh concrete and supports it until the concrete reaches an appropriate strength. “Fresh concrete” refers to concrete in an unhardened state. “3D printer” refers to a device used for 3D printing. “3D printing” refers to a method of creating an object by depositing material using two-dimensional printing technology (e.g., a print head and nozzle). “Resin molded object” refers to a molded object made from a resin composition. “Molded object” refers to a laminate formed by joining molded layers based on 3D model data using a 3D printer. The surface of a resin molded object has layer lines. “Layer lines” refers to a plurality of striated irregularities formed on the surface of a resin molded object due to the stacking of molded layers. The striated irregularities usually extend in a direction perpendicular to the direction of stacking of the molded layers.

[0015] Because the formwork of this disclosure has the above configuration, fresh concrete is less likely to leak out. This effect is presumed to be due to, but is not limited to, the following reasons. In this disclosure, the resin molded object has at least one protruding portion, and the protruding portion has a separation surface. Therefore, when the separation surfaces of the protruding portions overlap, the area in which the separation surfaces overlap is larger than when the resin molded object does not have a protruding portion (for example, when the resin molded object is a cylinder). Therefore, fresh concrete poured into the resin molded object is less likely to leak out. From the above, it is presumed that because the formwork of this disclosure has the above configuration, fresh concrete is less likely to leak out.

[0016] The size and shape of the formwork in this disclosure are not particularly limited and can be appropriately selected according to the size and shape of the concrete.

[0017] (1.1) Resin molded object The mold of the present disclosure comprises a resin molded object. The resin molded object constitutes a mold for forming fresh concrete.

[0018] Resin-based molded objects are produced by additive manufacturing using a 3D printer. The additive manufacturing process for resin-based molded objects is not particularly limited and is appropriately selected depending on the material of the resin-based molded object and the size of the concrete, etc. Examples of additive manufacturing processes include material extrusion (MEX), powder bed fusion (PBF), binder injection (BJT), directed energy deposition (DED), material jetting (MJT), sheet deposition (SHL), and vat photopolymerization (VPP).

[0019] Preferably, the resin molded object is a resin molded object produced by additive manufacturing using the material extrusion method (MEX). This allows for the production of larger resin molded objects (length: 1 m or more) than those produced by other additive manufacturing processes other than the material extrusion method (MEX). Furthermore, the resin molded object can be produced at a higher speed than those produced by other additive manufacturing processes other than the material extrusion method (MEX).

[0020] Resin-molded objects typically have layer lines on surfaces other than the cut edges, resulting from the additive manufacturing process. The size and number of these layer lines are not particularly limited and are selected appropriately according to the shape and size of the concrete, etc.

[0021] The shape and size of the resin-molded object are not particularly limited and are selected as appropriate according to the shape and size of the concrete, etc.

[0022] The resin-molded object has a cylindrical portion and at least one protruding portion. The cylindrical portion and the protruding portion are formed as a single unit by a 3D printer.

[0023] (1.1.1) The inner surface of the cylindrical part is in contact with the fresh concrete. In other words, the surface of the fresh concrete that is in contact with the inner surface of the cylindrical part is formed to conform to the shape of the inner surface of the cylindrical part.

[0024] The cross-sectional shape perpendicular to the axial direction of the cylindrical section is not particularly limited and may include circular, triangular, square, pentagonal, hexagonal, elliptical, and wave-shaped sections. The shape and size of the cylindrical section are not particularly limited and may be appropriately selected according to the shape and size of the concrete, etc.

[0025] (1.1.2) The protruding portion extends outward from the outer surface of the cylindrical portion. The protruding portion has separating surfaces that face each other along the axial direction and the direction of the protrusion of the protruding portion.

[0026] The number of overhangs is at least one, and is appropriately selected according to the shape and size of the concrete, etc. The number of overhangs may be one to twenty, one to ten, one to four, one, or two.

[0027] It is preferable that the protruding portion is formed from one end to the other in the axial direction of the cylindrical portion. This makes it less likely for the fresh concrete poured into the resin molded object to leak out compared to when the protruding portion is not formed from one end to the other in the axial direction of the cylindrical portion.

[0028] The opposing separation surfaces may or may not be separated for demolding purposes.

[0029] The opposing separation surfaces are separated into two for demolding, and it is preferable that the separation surfaces include a cut surface formed by cutting at least a portion of the overhang. In other words, the overhang is not formed by stacking multiple parts individually manufactured by a 3D printer. Therefore, when the separation surfaces of the overhang are stacked, gaps are unlikely to occur between them. As a result, fresh concrete poured into the resin molded object is less likely to leak out. Furthermore, the statement that "the overhang has two separation surfaces separated along the axial direction and the overhang direction of the overhang" indicates that the overhang is separable into two parts. Therefore, by separating the overhang into two parts during demolding, the resin molded object can be easily removed from the concrete without the layer lines on the inner surface of the resin molded object catching on the concrete. In other words, demolding is easy. In addition, the formwork of this disclosure allows for the production of concrete without damaging the concrete with tools, etc., by separating the overhang into two parts during demolding. The formwork of this disclosure is not destroyed during demolding and can therefore be repeatedly used for pouring fresh concrete.

[0030] The shape of the "cut surface" may be a shape that does not have layer lines, or a shape that is formed by intentionally not adding resin composition during additive manufacturing. The shape of the "cut surface" may be different from the shape of the surface of parts of the resin-molded object that are not the cut surface.

[0031] In the following description of the protruding portion, the opposing separation surfaces are separated into two for demolding, and the description refers to a protruding portion that includes a cut surface formed by cutting at least a part of the protruding portion.

[0032] If there are at least two protruding sections, the resin molded object may consist of multiple resin molded object divisions separated by parting lines formed by overlapping separation surfaces. The number of resin molded object divisions is the same as the number of protruding sections. The direction of extension of the parting lines is the axial direction and the direction of protrusion of the protruding sections. This makes demolding easier for the formwork of the present disclosure. As a result, the formwork of the present disclosure can mold concrete having more complex three-dimensional shapes (e.g., curved surfaces) or surface textures (e.g., uneven shapes).

[0033] A "parting line" refers to a line that represents the boundary between multiple resin-molded parts when a resin-molded object is formed by stacking multiple resin-molded parts together.

[0034] The separation surface includes a cut surface formed by cutting at least a portion of the protruding portion. The cut surface may be the entire separation surface or a portion of the separation surface.

[0035] Preferably, the cut surface is formed only at the tip of the protruding portion of the separation surface in the direction of protrusion (hereinafter also referred to as the "tip") along the axial direction. This makes it easier to form the separation surface of the protruding portion compared to the case where the cut surface is not limited to the tip of the separation surface (especially when the cut surface covers the entire surface of the separation surface). Furthermore, gaps are less likely to form between the overlapping separation surfaces. As a result, the fresh concrete poured into the resin molded object is less likely to leak out.

[0036] The resin molded object is formed by stacking molding layers formed by a single stroke path along the axial direction. When the protruding portion is viewed from the axial direction, the protruding portion includes a pair of straight portions that are arranged side by side and extend along the protruding direction and are not connected to each other. It is preferable that the cut surface is a surface formed by cutting a folded-back portion that connects the tips of the pair of straight portions in the protruding direction. Thereby, the separation surface of the protruding portion is more likely to be formed. Further, it is less likely for gaps to occur between the overlapping separation surfaces. As a result, the fresh concrete driven into the resin molded object is less likely to leak out. The width of the straight portion when viewed from the axial direction may be substantially the same length as the discharge width of the molding layer discharged by a 3D printer using the material extrusion method (MEX), or may be a multiple (for example, 2 times, 3 times, etc.) of the discharge width of the molding layer. The shape of the folded-back portion is not limited as long as it connects the tips of the pair of straight portions in the protruding direction.

[0037] The shape and size of the protruding portion are not particularly limited and are appropriately selected according to the shape and size of the concrete, etc. The length of the protruding portion in the protruding direction is usually longer than the wall thickness of the cylindrical portion. The width of one line portion of the single stroke path is not particularly limited and is appropriately selected according to the material of the resin molded object, etc. The width of the line portion may be 1 mm to 10 mm or may be 10 mm to 100 mm.

[0038] The protruding portion may have an attachment shape (for example, through holes, screw holes, etc.) for attaching a fixture described later for maintaining the state where the separation surfaces are overlapped.

[0039] (1.1.3) Bottom plate portion The resin molded object may have a bottom plate portion that closes the bottom of the cylindrical portion. The resin molded object may not have a bottom plate portion.

[0040] (1.1.4) Materials (1.1.4.1) Thermoplastic resin The resin molded article contains a thermoplastic resin, and the tensile elastic modulus of the thermoplastic resin at 25°C is preferably 400 MPa or more. Thereby, the resin molded article has sufficient hardness. Therefore, when fresh concrete is driven, the resin molded article is difficult to deform. As a result, the formwork of the present disclosure can mold concrete having a desired shape. The tensile elastic modulus of the thermoplastic resin is more preferably 1000 MPa or more, and even more preferably 2000 MPa or more, from the viewpoint of reducing the thickness of the resin molded article in order to ensure the rigidity required for a concrete formwork.

[0041] The tensile elastic modulus is measured in accordance with JIS K7161-2:2014. The test piece is of type 1A, the test temperature is 23 degrees, and the test speed is 1.0 mm / min.

[0042] The resin molded article may contain a thermoplastic resin or may be made of a thermoplastic resin.

[0043] In the present disclosure, the "thermoplastic resin" refers to a thermoplastic resin having a tensile elastic modulus of 6.0×10 ８ Pa or more.

[0044] The thermoplastic resin is not particularly limited, and known thermoplastic resins can be used. Examples include general-purpose plastics, engineering plastics, and super engineering plastics. Examples of general-purpose plastics include high-density polyethylene (HDPE), low-density polyethylene (LDPE), propylene polymers (propylene homopolymer (PP), etc.), polyvinyl chloride (PVC), polyvinylidene chloride polystyrene (PS), polyvinyl acetate (PVAc), polytetrafluoroethylene (PTFE), acrylonitrile butadiene styrene resin (ABS resin), styrene acrylonitrile copolymer (AS resin), and acrylic resin (PMMA, etc.). Examples of engineering plastics include polyamide (PA), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (m-PPE, modified PPE, PPO), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), syndiotactic polystyrene (SPS), and cyclic polyolefin (COP). Examples of super engineering plastics include polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polysulfone (PSF), polyethersulfone (PES), amorphous polyarylate (PAR), polyetheretherketone (PEEK), thermoplastic polyimide (PI), and polyamideimide (PAI). Thermoplastic resins may be used individually or in combination of two or more types.

[0045] If the resin molded object contains thermoplastic resin, the thermoplastic resin content may be 0.1% to 100% by mass, 10% to 70% by mass, or 20% to 60% by mass, relative to the total mass of the resin molded object.

[0046] (1.1.4.2) Filler resin molded product may contain a filler. Examples of fillers include inorganic powders, glossy inorganic powders, composite inorganic powders, and inorganic fibers. Examples of inorganic powders include talc, titanium dioxide, black titanium dioxide, and ultramarine. Examples of glossy inorganic powders include bismuth oxychloride, titanium dioxide coated mica, iron oxide coated mica, and iron oxide coated titanium mica. Examples of composite inorganic powders include fine particle titanium dioxide coated titanium mica, fine particle zinc oxide coated titanium mica, barium sulfate coated titanium mica, and titanium dioxide-encapsulated silica. Examples of inorganic fibers include glass fibers. A single type of filler may be used, or two or more types may be used in combination.

[0047] The shape of the filler may be spherical, plate-shaped, or needle-shaped. The filler may be porous or non-porous.

[0048] If the resin molded object contains a filler, the filler content may be 5% to 70% by mass relative to the total mass of the resin molded object.

[0049] (1.1.4.3) Thermoplastic elastomer resin molded products may contain a thermoplastic elastomer or may consist of a thermoplastic elastomer.

[0050] A "thermoplastic elastomer" is a material that possesses rubber-like elasticity. Specifically, a "thermoplastic elastomer" has a tensile modulus of 6.0 × 10⁻⁶ at 25°C. ８ This refers to thermoplastic resins with a Pa rating of less than 1.5.

[0051] The thermoplastic elastomer may be a copolymer containing structural units derived from an α-olefin and structural units derived from another olefin different from the α-olefin. Examples of α-olefins include 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, and 1-octene. Preferred other olefins different from the α-olefin are olefins having 2 to 4 carbon atoms, such as ethylene, propylene, and butene.

[0052] If the resin molded product contains a thermoplastic elastomer, the thermoplastic elastomer content may be 0.1% to 100% by mass or 10% to 70% by mass, relative to the total amount of the resin molded product.

[0053] (1.1.4.4) Used resin: It is preferable that the resin molded product contains used resin. This reduces the environmental burden.

[0054] The used resin is not particularly limited as long as it is a used resin. The used resin may be the resin used in the resin molded object of the mold of the disclosure, or it may be the resin used in an object other than the resin molded object of the mold of the disclosure.

[0055] (1.1.4.5) Biomass-derived resin: It is preferable that the resin molded product contains a biomass-derived resin. Since biomass-derived resin is a carbon-neutral material, it can reduce the environmental burden in the manufacturing of resin molded products.

[0056] Monomers used as raw materials for biomass-derived thermoplastic resins can be obtained by cracking biomass naphtha or by synthesis from biomass-derived ethylene. Biomass-derived thermoplastic resins are obtained by polymerizing the biomass-derived monomers synthesized in this way using the same method as when using conventionally known petroleum-derived thermoplastic resins. Polymers of thermoplastic resins synthesized using bio-derived monomers as raw materials become biomass-derived thermoplastic polymers. The content of bio-derived thermoplastic polymer in the raw material monomers is greater than 0% by mass, may be 100% by mass, or less than 100% by mass, relative to the total amount of raw material monomers. The "biomass content" indicates the content of biomass-derived carbon and is calculated by measuring radioactive carbon (C14). Atmospheric carbon dioxide contains a certain percentage of C14 (approximately 105.5 pMC). Therefore, it is known that the C14 content in plants that grow by taking in atmospheric carbon dioxide (e.g., corn) is also about 105.5 pMC. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the proportion of C14 in the total carbon atoms in the polymer, the biomass-derived carbon content in the raw material can be calculated. The thermoplastic polymer used as a raw material in this disclosure may include a thermoplastic polymer obtained by recycling, so-called recycled polymer. "Recycled polymer" includes polymers obtained by recycling waste polymer products, and can be produced, for example, by the method described in DE102019127827 (A1). The recycled polymer may include a marker that identifies it as having been obtained by recycling.

[0057] (1.2) Molding Members The mold of this disclosure may further comprise molding members different from the resin molded object. The molding members mold fresh concrete. Examples of molding members include formwork (e.g., formwork that closes the bottom of the cylindrical part) and cores. "Core" refers to a mold placed inside the cylindrical part of the resin molded object to form a hollow part in the concrete. Examples of materials for the molding members include wood, metal and resin. The molding members may also be known molding members.

[0058] (1.3) Fixing Devices The formwork of the present disclosure may further include fixing devices for fixing the protruding parts in order to maintain the state in which the separating surfaces of the protruding parts are overlapped. By further including solid devices in the formwork of the present disclosure, the resin molded product can be sufficiently fixed even without the shoring described later. The fixing devices are not particularly limited and include bolts, nuts, screws, rivets, pins, and clamps. The fixing devices may be any known fixing devices.

[0059] (1.4) Support structure The formwork of the present disclosure preferably further comprises a support structure for fixing the resin molded object.

[0060] "Scaffolding" refers to temporary structures used to fix resin-molded objects in a predetermined position.

[0061] The formwork of this disclosure, by further comprising shoring, ensures that the resin molded object is more securely held by the poured fresh concrete by the predetermined mold than a formwork without shoring.

[0062] The shoring may be any known type of shoring. Examples of materials for the shoring include resin, metal, and resin.

[0063] (2) Method for manufacturing a mold The method for manufacturing a mold according to the present disclosure is a method for manufacturing a mold according to the present disclosure. The manufacturing method comprises using a 3D printer to build up layers along the axial direction and to produce a resin molded object in which no cut surface formed by cutting at least a part of the protruding portion is formed (hereinafter also referred to as the "molding process").

[0064] Because the method for manufacturing formwork of this disclosure has the above configuration, it is possible to manufacture formwork that is less prone to leakage of fresh concrete.

[0065] (2.1) Molding Process The mold manufacturing method of the present disclosure includes a molding process. In the molding process, a 3D printer is used to stack molding layers along the axial direction to produce the resin molded object in which the cross-section has not been formed.

[0066] The resin molded object in which the aforementioned cross-section is not formed is the same as the resin molded object in which the aforementioned cross-section is formed, except that the aforementioned cross-section is not formed.

[0067] The additive manufacturing process for the 3D printer should be the same as the method exemplified in "(1.1) Resin-Printed Objects". The 3D printer's settings parameters should be adjusted as appropriate according to the additive manufacturing process and the size of the resin-printed object.

[0068] In the molding process, the molded layer may be formed in a single continuous path by material extrusion (MEX). When viewed from the axial direction of the cylindrical portion, the resin molded object obtained in the molding process may have a pair of straight sections extending along the direction of the protrusion, corresponding to the protruding portion, and a folded-over section connecting the ends of the pair of straight sections.

[0069] (2.2) Cutting step The method for manufacturing a mold according to the present disclosure preferably includes a cutting step. In the cutting step, at least a portion of the protruding part of the resin molded product that does not have a cut surface formed by cutting at least a portion of the protruding part is cut to form the cut surface. As a result, the opposing separation surfaces of the protruding part are separated into two for demolding. The cutting step is performed after the molding step is carried out.

[0070] The cutting method is not particularly limited and can include methods using cutting tools (e.g., scissors, knives, cutters, and contour machines).

[0071] (2.3) Processing Steps The method for manufacturing a mold according to the present disclosure may include processing steps depending on the type of fasteners, etc. In the processing steps, a mounting shape for attaching fasteners is formed on the protruding portion of the resin molded object. The processing steps are performed after the processing steps have been completed.

[0072] The method for forming the mounting shape is not particularly limited and may be selected as appropriate depending on the type of fastener, etc., and may be a known method.

[0073] (2.4) Fixing step The method for manufacturing a formwork of the present disclosure may further include a fixing step. In the fixing step, a fixing device is attached to the protruding portion in which the separated surfaces are overlapped, thereby fixing the protruding portion. The fixing step is performed after the cutting step.

[0074] The method of attaching the fasteners is not particularly limited and may be selected appropriately depending on the type of fasteners, etc., and may be a publicly known method.

[0075] (2.5) Installation Step If the formwork is equipped with fasteners, the method for manufacturing the formwork of the present disclosure may further include an installation step. In the installation step, the fasteners are attached to the resin molded object. The installation step is performed after the fastening step has been completed. If the formwork is equipped with at least one of a molding member and a support structure, in the installation step, at least one of the molding member and the support structure may be attached to the resin molded object.

[0076] The method for attaching at least one of the molded member and the support structure to the resin molded object is not particularly limited and may be a known method.

[0077] (2.6) Preferred Embodiments When the method for manufacturing a mold of the present disclosure has a cutting step, when the protruding portion is viewed from the axial direction, the protruding portion includes a pair of straight portions that extend side by side along the protruding direction and are not connected to each other, in forming the resin molded product (i.e., the molding step), the molded layer is formed in a single continuous path by a material extrusion method, the resin molded product without a cut surface has the pair of straight portions and a folded portion that connects the ends of the pair of straight portions, and in forming the cut surface (i.e., the cutting step), it is preferable that at least a part of the protruding portion is the folded portion. This makes it possible to easily manufacture a resin molded product in which the cut surface is formed only at the end of the protruding portion of the separation surface in the protruding direction.

[0078] (3) Method for manufacturing concrete The method for manufacturing concrete according to the present disclosure includes: preparing the formwork according to the present disclosure and the fresh concrete, with the separation surface including the cut surface, using the method for manufacturing formwork according to the present disclosure (hereinafter also referred to as the "preparation step"); pouring the fresh concrete into the resin molded object, whose separation surfaces are overlapped and whose overhang is fixed, and curing it to form the concrete (hereinafter also referred to as the "concrete forming step"); and separating the separation surfaces and demolding the resin molded object from the concrete (hereinafter also referred to as the "demolition step"). The preparation step, the concrete forming step and the demolition step are carried out in this order. The preparation step is carried out before the concrete forming step.

[0079] Because the concrete manufacturing method of this disclosure has the above configuration, it is possible to manufacture concrete with complex shapes without damaging the surface.

[0080] (3.1) Preparation Step The concrete manufacturing method of the present disclosure includes a preparation step. In the preparation step, the formwork of the present disclosure and fresh concrete are prepared, the separation surface includes the cut surface.

[0081] The method for preparing the formwork of this disclosure, in which the separation surface includes the cut surface, is not particularly limited and includes, for example, purchasing from a supplier and manufacturing the formwork by the formwork manufacturing method of this disclosure described above. The method for preparing the fresh concrete is not particularly limited and may be any known method.

[0082] The composition of fresh concrete is not particularly limited and is appropriately selected depending on the intended use of the concrete. Fresh concrete may contain cement, aggregate, and water, and may further contain admixtures. Examples of cement include ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening Portland cement, low-heat Portland cement, and moderate-heat Portland cement. The unit cement content is preferably 270 kg / m³. ３ ~500 kg / m ３It may be. Examples of the aggregate include fine aggregate (e.g., river sand, mountain sand, and land sand, etc.) and coarse aggregate (e.g., river gravel, mountain gravel, and crushed stone, etc.). The unit amount of the aggregate may be 500 kg / m ３ to 1100 kg / m ３ It may be. Examples of the water include tap water and treated sewage water, etc. The unit amount of water may be 100 kg / m ３ to 200 kg / m ３ It may be. Examples of the admixture include air-entraining agent (AE agent), water reducing agent, foaming agent, blowing agent, setting regulator, hardening accelerator, waterproof agent, water repellent, water retention agent, rust preventive, thickening agent, pigment, and efflorescence preventive, etc.

[0083] (3.2) Release agent coating step The method for manufacturing concrete of the present disclosure preferably further includes applying a release agent to the surface of the resin molded article that contacts the fresh concrete (hereinafter, also referred to as the "release agent coating step"). The application of the release agent (release agent coating step) is carried out after the implementation of the preparation of the mold (i.e., the preparation step) and before the implementation of the formation of the concrete (concrete formation step). Thereby, a release agent layer is likely to be formed on the molding surface of the resin molded article. Therefore, it is easier to demold than when the release agent coating step is not carried out.

[0084] The release agent is not particularly limited, and examples thereof include fluorine compound type release agents (e.g., triperfluorooctyl phosphate and triperfluorododecyl phosphate, etc.), silicone compound type release agents (dimethylpolysiloxane and amino-modified dimethylpolysiloxane, etc.), fatty acid ester type release agents (e.g., butyl stearate and hydrogenated castor oil, etc.), and waxes (paraffin wax and microcrystalline wax, etc.). The release agent may contain an organic solvent (e.g., toluene and n-hexane, etc.). The application method of the release agent is not particularly limited and may be a known method. The amount of the release agent applied once is not particularly limited and may be an amount commonly used (e.g., 200 cc / m ２ ).

[0085] (3.3) Concrete Forming Process The concrete manufacturing method of the present disclosure includes a concrete forming step. In the concrete forming step, fresh concrete is poured into the resin molded object in which the separation surfaces overlap and the protruding portion is fixed, and the concrete is formed by curing.

[0086] The method of driving in the concrete and the method of curing are not particularly limited and any known method is acceptable.

[0087] (3.4) Demolding Process The concrete manufacturing method of this disclosure includes a demolding process. In the demolding process, the resin molded object is removed from the concrete in the demolding direction.

[0088] The method for removing the resin-molded object in the demolding direction is not particularly limited and may be a known method.

[0089] (3.5) Concrete The shape and size of the concrete obtained by the concrete manufacturing method of this disclosure are not particularly limited and are appropriately selected according to the use of the concrete. Examples of concrete uses include building materials for civil engineering structures and building structures.

[0090] (4) An example of the formwork of the present disclosure will be described below with reference to Figures 1 to 5.

[0091] (4.1) Formwork The formwork 1A according to the first embodiment is a formwork into which fresh concrete 20U is poured. The formwork 1A includes a resin molded object 10A. The resin molded object 10A is a resin molded object that is additively manufactured by a material extrusion (MEX) 3D printer.

[0092] As shown in Figure 1, the resin molded object 10A has a cylindrical portion 11 and two protruding portions 12A. The inner surface S12A of the cylindrical portion 11 is in contact with the fresh concrete 20U. The protruding portions 12A extend from one end to the other of the cylindrical portion 11 in the axial direction D1, relative to the outer surface S12B of the cylindrical portion 11. The cylindrical portion 11 and the two protruding portions 12A are formed as a single unit.

[0093] As shown in Figure 2, the protruding portion 12A has a separation surface S12 for demolding. The separation surface S12 is separated into two parts along the axial direction D1 and the protruding direction D2 of the protruding portion 12A. The separation surface S12 includes a cut surface S121 formed by cutting a part of the protruding portion 12A and an unprocessed surface S122 that has not been cut. The cut surface S121 is formed along the axial direction D1, only at the tip of the separation surface S12 in the protruding direction D2 of the protruding portion 12A. The unprocessed surface S122 is the portion of the separation surface S12 that is not the cut surface S121.

[0094] The resin molded object 10A is formed by stacking molded layers 100 along the axial direction D1. Layer lines LT are formed on the surface of the resin molded object 10A where the molded layers 100 are adjacent to each other, due to the material extrusion method (MEX). The cut surface S121 has layer lines LT. The unprocessed surface S122 does not have layer lines LT.

[0095] The mold 1A is composed of two resin molded parts 10AU separated by a parting line PL (see Figure 1). The parting line PL is formed by overlapping separation surfaces S12. The number of resin molded parts 10AU is two, the same as the number of protruding parts 12A. The extension direction of the parting line PL is the axial direction D1 and the protruding direction D2 of the protruding part 12A.

[0096] The resin molded part 10AU has a cylindrical part 11U and a protruding part 12U. When the separation surfaces S12 of the two resin molded part 10AU are superimposed, the two cylindrical part 11U form one cylindrical part 11, and the two protruding part 12U form one protruding part 12A.

[0097] A material extrusion (MEX) 3D printer forms the build layer 100 in a single continuous path R (see Figure 3). The resin object 10A is formed by stacking the build layers 100, formed in the single continuous path R, along the axial direction D1.

[0098] Figure 3 is a perspective view of the resin molded object 10A (hereinafter also referred to as "resin molded object precursor 10AT") in a state in which the cross-section S121 has not been formed. The resin molded object precursor 10AT is the same as the resin molded object 10A except that the cross-section S121 has not been formed. As shown in Figure 3, the resin molded object precursor 10AT includes a pair of straight sections R12A and a folded section R12B. The pair of straight sections R12A extend side by side along the extension direction D2 when viewed from the axial direction D1 to the extension section 12A, and are not connected to each other. The pair of straight sections R12A are included in the extension section 12A. The folded section R12B connects the ends of the pair of straight sections R12A in the extension direction D2 of the extension section 12A. The cross-section S121 of the resin molded object 10A is the surface formed by cutting the folded section R12B. The width L of the straight section R12A as viewed from the axial direction D1 is approximately the same as the extrusion width of the build layer 100 extruded by the material extrusion (MEX) 3D printer.

[0099] As shown in Figure 3, the shape of the folded portion R12B, as viewed from the axial direction D1, is a straight line extending in a direction perpendicular to the axial direction D1 and the overhanging direction D2. The folded portion R12B is formed along the axial direction D1.

[0100] The protruding portion 12A has a plurality of through holes TH. Fasteners (i.e., bolts and nuts) for fixing the two protruding portion divisions 12U together when the separating surfaces S12 are overlapped are attached to the through holes TH.

[0101] The resin molded object 10A preferably contains used resin. The resin molded object 10A preferably contains biomass-derived resin.

[0102] (4.1.1) Effects of Operation As explained with reference to Figures 1 to 3, the formwork 1A includes a resin molded object 10A that is additively manufactured by a 3D printer. The resin molded object 10A has a cylindrical portion 11 and two protruding portions 12A. The protruding portions 12A have separation surfaces S12 that face each other along the axial direction D1 and the protruding direction D2 of the protruding portions 12A. As a result, when the separation surfaces S12 of the protruding portions 12A are superimposed, the area in which the separation surfaces S12 overlap is larger than when the resin molded object 10A does not have protruding portions 12A (for example, when the resin molded object consists of a cylindrical portion 11). Therefore, the fresh concrete 20U poured into the resin molded object 10A is less likely to leak out. As explained with reference to Figures 1 to 3, the opposing separation surfaces S12 are separated into two for demolding, and the separation surfaces S12 include a cut surface S121. The protruding portion 12A is not formed by stacking multiple parts individually manufactured by a 3D printer. Therefore, when the separation surfaces S12 of the protruding portion 12A are stacked, gaps are unlikely to occur between the separation surfaces S12. As a result, the fresh concrete 20U poured into the resin molded object 10A is less likely to leak out. Furthermore, by separating the protruding portion 12A into two during demolding, the resin molded object 10A can be easily removed from the concrete 20 without the layer lines on the inner surface S11A of the resin molded object 10A catching on the concrete 20. In other words, demolding is easy. In addition, by separating the protruding portion 12A into two during demolding, the formwork 1A can manufacture concrete without damaging the concrete with tools or the like. Since formwork 1A is not destroyed during demolding, it can be reused for pouring fresh concrete.

[0103] As explained with reference to Figures 1 to 3, the cut surface S121 is formed only at the tip of the protruding portion 12A of the separation surface S12 in the protruding direction D2 along the axial direction D1. As a result, the separation surface S12 of the protruding portion 12A is more easily formed compared to the case where the cut surface S121 is not only at the tip of the separation surface S12 (especially when the cut surface S121 covers the entire surface of the separation surface S12). Furthermore, gaps are less likely to form between the overlapping separation surfaces S12. As a result, the fresh concrete 20U poured into the resin molded object 10A is less likely to leak out.

[0104] As explained with reference to Figures 1 to 3, the resin molded object 10A is formed by stacking molded layers 100, formed by a single continuous path R, along the axial direction D1. The protruding portion 12A includes a pair of straight sections R12A. The cut surface S121 is the surface formed by cutting the folded portion R12B. As a result, the separation surface S12 of the protruding portion 12A is more easily formed. Furthermore, gaps are less likely to occur between the overlapping separation surfaces S12. Consequently, the fresh concrete 20U poured into the resin molded object 10A is less likely to leak out.

[0105] As explained with reference to Figures 1 to 3, the resin molded object 10A is a resin molded object produced by additive manufacturing using the material extrusion method (MEX). This results in a larger resin molded object 10A (length: 1 m or more) than those produced by other additive manufacturing processes other than the material extrusion method (MEX).

[0106] The resin-molded object 10A preferably contains used resin. This reduces the environmental impact.

[0107] The resin molded object 10A preferably contains a biomass-derived resin. Since biomass-derived resins are carbon-neutral materials, they can reduce the environmental impact of manufacturing the resin molded object 10A.

[0108] (4.2) Method for manufacturing formwork The method for manufacturing formwork of the first embodiment is a method for manufacturing formwork 1A. This manufacturing method includes a molding step, a cutting step, a processing step, and an installation step. The molding step, cutting step, processing step, and installation step are carried out in this order.

[0109] (4.2.1) Molding Process In the molding process, a resin molded object 10A (i.e., a resin molded object precursor 10AT) is produced by stacking molded layers 100 along the axial direction D1 using a material extrusion (MEX) 3D printer, without a cross-section S121. The molded layers 100 are formed in a single continuous path R.

[0110] (4.2.2) Cutting Process In the cutting process, the folded portion R12B of the protruding portion 12A of the resin molded object 10A (i.e., the resin molded object precursor 10AT) which does not have a cut surface S121 formed thereon is cut along the axial direction D1 with a cutting tool to form a cut surface S121.

[0111] (4.2.3) Processing Process In the processing process, multiple through holes TH for attaching fasteners are formed in the protruding portion 12A of the resin molded object 10A.

[0112] (4.2.4) Installation process In the installation process, fasteners (i.e., screws and nuts) (not shown) are attached to the through holes TH of the resin molded object 10A. As a result, the separation surfaces S12 of the protruding portion 12A are fixed in an overlapping state.

[0113] (4.2.4) Effects and Effects As explained with reference to Figures 1 to 3, the method for manufacturing the formwork of the first embodiment is a method for manufacturing formwork 1A. This manufacturing method includes a molding step. As a result, the method for manufacturing the formwork of the first embodiment can manufacture formwork 1A in which fresh concrete 20U is less likely to leak out.

[0114] As explained with reference to Figures 1 to 3, the method for manufacturing the formwork of the first embodiment includes a cutting step. As a result, the method for manufacturing the formwork of the first embodiment can produce a formwork 1A that is less likely to leak fresh concrete 20U and is easy to demold.

[0115] As explained with reference to Figures 1 to 3, when the protruding portion 12A is viewed from the axial direction D1, the protruding portion 12A includes a pair of straight portions R12A that extend side by side along the protruding direction D2 and are not connected to each other. In the molding process, the molded layer 100 is formed in a single continuous path R by the material extrusion method (MEX). The resin molded object 10A (i.e., the resin molded object precursor 10AT) without a cut surface S121 has a pair of straight portions R12A and a folded portion R12B. In the cutting process, the folded portion R12B is cut to form a cut surface S121. This makes it easy to manufacture a resin molded object 10A in which the cut surface S121 is formed only at the tip of the separation surface S12 in the protruding direction D2.

[0116] (4.3) Method for manufacturing concrete The method for manufacturing concrete according to the first embodiment includes a preparation step, a concrete forming step, and a demolding step. The preparation step, the concrete forming step, and the demolding step are carried out in this order. The preparation step is carried out before the concrete forming step.

[0117] (4.3.1) Preparation Process In the preparation process, formwork 1A and fresh concrete 20U are prepared. Formwork 1A is manufactured by the formwork manufacturing method of the first embodiment.

[0118] (4.3.2) Concrete Forming Process In the concrete forming process, as shown in Figure 4, fresh concrete 20U is poured into the resin molded object 10A, which has its protruding portion 12A fixed by overlapping the separation surfaces S12, and then cured to form the concrete 20.

[0119] (4.3.3) Demolding Process In the demolding process, as shown in Figure 5, the fasteners are removed from the through holes TH, the separation surfaces S12 of the protruding portion 12A are separated, and the resin molded object 10A is demolded from the concrete 20.

[0120] (4.3.4) Effects and Operation As explained with reference to Figures 1 to 5, the concrete manufacturing method of the first embodiment includes a preparation step, a concrete forming step, and a demolding step. As a result, the concrete manufacturing method of the first embodiment can produce concrete 20 having a complex shape without damaging the surface.

[0121] (5) Second Embodiment The formwork 1B according to the second embodiment is the same as the formwork 1A according to the first embodiment, except that the shape of the folded portion R12B is different.

[0122] The mold 1B comprises a resin molded object 10B. The resin molded object 10B has a cylindrical portion 11 and two protruding portions 12B. The protruding portions 12B are the same as the protruding portion 12A, except that the shape of the tip in the protruding direction D2 (corresponding to the shape of the folded portion R12B) is different.

[0123] Figure 6 is a perspective view of the resin molded object 10B (hereinafter also referred to as "resin molded object precursor 10BT") in a state in which the cross-section S121 has not been formed. The resin molded object precursor 10BT is the same as the resin molded object precursor 10AT except that the shape of the folded portion R12B is different.

[0124] As shown in Figure 6, the shape of the folded portion R12B when viewed from the axial direction D1 is circular. The folded portion R12B is formed along the axial direction D1.

[0125] Formwork 1B is the same as formwork 1A, except that the shape of the folded-over portion R12B is different. Therefore, formwork 1B has the same effects and functions as formwork 1A.

[0126] (6) Third Embodiment (6.1) Formwork The formwork 1C according to the third embodiment is the same as the formwork 1A according to the first embodiment, except that the shape of the resin structure is different.

[0127] The formwork 1C comprises a resin molded object 10C, a core 31, and a base plate 32.

[0128] (6.1.1) Resin molded object The resin molded object 10C is similar to the resin molded object 10A according to the first embodiment, except that it has one protruding portion 12A. As shown in Figure 7, the resin molded object 10C has a cylindrical portion 11 and one protruding portion 12A.

[0129] (6.1.2) Core The core 31 forms a hollow section in the concrete 20. The core 31 is a resin molded object produced by additive manufacturing using material extrusion (MEX). The core 31 is cylindrical. The core 31 is located inside the cylindrical section 11 of the resin molded object 10C.

[0130] (6.1.3) Bottom plate The bottom plate 32 closes the bottom of the cylindrical portion 11 of the resin molded object 10C. The bottom plate 32 is a plate-like object. The bottom plate 32 is made of wood. The bottom plate 32 is attached to one end of the cylindrical portion 11 of the resin molded object 10C in the axial direction D1.

[0131] (6.1.4) Effects Formwork 1C is similar to formwork 1A, except that the shape of the resin structure is different. Therefore, formwork 1C produces the same effects as formwork 1A.

[0132] (6.2) Method for Manufacturing Formwork The method for manufacturing formwork of the third embodiment is the same as the method for manufacturing formwork of the first embodiment, except that the main difference is the mounting method. The method for manufacturing formwork of the third embodiment is a method for manufacturing formwork 1C. This manufacturing method includes a molding process, a cutting process, a processing process, and a mounting process. The molding process, cutting process, processing process, and mounting process are carried out in this order.

[0133] The molding process, cutting process, and processing process of the third embodiment are carried out in the same manner as in the first embodiment.

[0134] In the third embodiment, during the mounting process, a fastener (i.e., a screw and nut) (not shown) is attached to the through hole TH of the resin molded object 10C. Furthermore, during the mounting process, a core 31 is placed inside the cylindrical portion 11 of the resin molded object 10C, and a bottom plate 32 is attached to the resin molded object 10C. The method of arranging the core 31 and the method of attaching the bottom plate 32 can be any known method.

[0135] The method for manufacturing the formwork in the third embodiment is the same as the method for manufacturing the formwork in the first embodiment, except that the main difference is the mounting method. Therefore, the method for manufacturing the formwork in the third embodiment has the same effects and advantages as the method for manufacturing the formwork in the first embodiment.

[0136] (6.3) Method for manufacturing concrete The method for manufacturing concrete according to the third embodiment includes a preparation step, a concrete forming step, and a demolding step. The preparation step, the concrete forming step, and the demolding step are carried out in this order. The preparation step is carried out before the concrete forming step.

[0137] (6.3.1) Preparation Process In the preparation process, formwork 1C and fresh concrete 20U are prepared. Formwork 1C is manufactured by the formwork manufacturing method of the third embodiment.

[0138] (6.3.2) Concrete Forming Process In the concrete forming process, as shown in Figure 8, fresh concrete 20U is poured into the resin molded object 10C, in which the separation surfaces S12 overlap and the protruding portion 12A is fixed, and then cured to form concrete 20.

[0139] (6.3.3) Demolding Process In the demolding process, as shown in Figures 9 and 10, the fasteners are removed from the through holes TH, the separation surfaces S12 of the protruding portion 12A are separated, and the resin molded object 10C is demolded from the concrete 20.

[0140] (6.3.4) Effects of Operation As explained with reference to Figures 7 to 10, the concrete manufacturing method of the third embodiment includes a preparation step, a concrete forming step, and a demolding step. As a result, the concrete manufacturing method of the third embodiment can produce concrete 20 having a complex shape without damaging the surface.

[0141] (7) Fourth Embodiment The mold according to the fourth embodiment is the same as the mold 1A according to the first embodiment, except that the separation surface S12 does not have a cut surface S121. The mold according to the fourth embodiment includes a resin molded object 10A (i.e., a resin molded object precursor 10AT) in which the cut surface S121 has not been formed.

[0142] The formwork according to the fourth embodiment is the same as formwork 1A, except that the separation surface S12 does not have a cut surface S121. Therefore, the formwork according to the fourth embodiment has the same effects and advantages as formwork 1A.

[0143] (8) Fifth Embodiment The mold according to the fifth embodiment is the same as the mold 1B according to the second embodiment, except that the separation surface S12 does not have a cut surface S121. The mold according to the fifth embodiment includes a resin molded object 10B (i.e., a resin molded object precursor 10BT) in which the cut surface S121 has not been formed.

[0144] The formwork according to the fifth embodiment is the same as formwork 1B, except that the separation surface S12 does not have a cut surface S121. Therefore, the formwork according to the fifth embodiment has the same effects and advantages as formwork 1B.

[0145] The present disclosure will be described in further detail below based on examples. However, the present disclosure is not limited to these examples.

[0146] [1] Manufacturing of the mold [1.1] Molding process [1.1.1] Raw materials The following raw materials were prepared as raw materials for molding.

[0147] [1.1.1.1] Thermoplastic elastomer - "Toughmer (registered trademark) XM-7090" (manufactured by Mitsui Chemicals, Inc., material: propylene polymer, melting point Tm: 98°C, Shore D hardness: 58, MFR: 7.0 g / min, tensile modulus at 25°C: 6.0 × 10⁻⁶) ８ (Less than Pa) Note that the melting point Tm, Shore D hardness, and MFR values ​​are catalog values.

[0148] [1.1.1.2] Thermoplastic plastic - "Prime Polypro (registered trademark) J-105G" (manufactured by Prime Polymer Co., Ltd., material: propylene homopolymer, crystallization temperature Tc: 116.4°C, degree of crystallinity: 52.2%, tensile modulus at 25°C: 6.0 × 10⁸ Pa or higher). Note that the crystallization temperature Tc and Shore D hardness values ​​are catalog values.

[0149] [1.1.1.3] Inorganic filler - "Talc" (product average particle size: 5 μm to 10 μm)

[0150] [1.1.1.4] Molding material Thermoplastic elastomer (40 parts by mass), thermoplastic plastic (20 parts by mass), and inorganic filler (40 parts by mass) were blended and kneaded using an extruder (model number KTX-30, manufactured by Kobe Steel, Ltd.) to obtain a PP compound. The obtained PP compound was extruded from a nozzle and cut at 4 mm intervals to obtain particulate molding material measuring 4 mm × 3 mm × 2 mm. The extruder conditions were as follows: Cylinder temperature: C1 = 50°C, C2 = 90°C, C3 = 100°C, C4 = 120°C, C5 = 180°C, C6 = 200°C, C7 to C14 = 200°C, die temperature: 200°C, screw rotation speed: 500 rpm (revolutions per minute), extrusion rate: 40 kg / h.

[0151] [1.1.2] A 3D printer for additive manufacturing material extrusion (EXF-12, manufactured by Extrabold Co., Ltd.), slicer software (UltimakerCURA, manufactured by Ultimaker Inc.), and CAD software (CATIA V5, manufactured by Dassault Systèmes Inc.) were used.

[0152] Next, a 3D model data 10C1, shown in Figure 11, was prepared as the 3D model data for the resin molded object 10C. Using slicer software, the 3D model data 10C1 was sliced ​​into sections to generate multiple 2D data. Based on the multiple 2D data, the setting parameters of the application software were set as follows. Based on the setting parameters below, a resin molded object 10C without a cross-section S121 was fabricated using a 3D printer employing the material extrusion (MEX) method.

[0153] [1.1.2.1] Setting Parameters: • Printing Speed: 1200 mm / min • Nozzle Temperature: 200°C • Layer Thickness: 1.5 mm • Nozzle Diameter: 3 mm • Extrusion Width: 3.6 mm

[0154] [1.2] Cutting process The folded portion R12B of the protruding portion 12A of the resin molded object 10C, which does not have a cut surface S121 formed thereon, was cut along the axial direction D1 with a cutting tool to form a cut surface S121.

[0155] [1.3] Processing Steps Multiple through holes TH for attaching fasteners were formed in the protruding portion 12A of the resin molded object 10C.

[0156] [1.4] Installation process A fastener (i.e., a bolt) (not shown) was attached to the through hole TH of the resin molded object 10C.

[0157] As the base plate formwork 32, a wooden panel made by a known method and a core 31 to reduce the density of the concrete 20 to be made were prepared. The core 31 is a molded object made by a 3D printer under the same conditions as the resin molded object described above.

[0158] A core 31 was placed inside the cylindrical portion 11 of the resin molded object 10C. A bottom plate 32 was attached to the resin molded object 10C.

[0159] [1.5] Preparation Process Fresh concrete was prepared by mixing 30 parts by mass of cement, 50 parts by mass of aggregate, 8 parts by mass of water, and 0.3 parts by mass of admixture.

[0160] [1.6] Concrete Forming Process: Fresh concrete 20U was poured into formwork 1C. At this time, the fresh concrete 20U poured into the resin molded object 10C did not leak out.

[0161] After the pouring of the fresh concrete 20U was completed, it was left to stand for one day to cure. This formed the concrete 20.

[0162] [1.7] The fasteners (i.e., bolts) attached to the demolding through-hole TH were removed. Next, the bottom plate formwork 32 and the resin molded object 10C were removed from the concrete 20. At this time, the resin molded object 10C was opened and the concrete 20 was lifted, and the concrete 20 easily separated from the resin molded object 10C.

[0163] From the above, it was found that formwork 1C is a "formwork that prevents fresh concrete from leaking out."

[0164] The disclosure of Japanese Patent Application No. 2024-228002, filed on 24 December 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A formwork into which fresh concrete is poured, comprising a resin object manufactured by a 3D printer, wherein the resin object has a cylindrical portion whose inner surface is in contact with the fresh concrete, and at least one protruding portion that extends outward from the outer surface of the cylindrical portion, and the protruding portion has separating surfaces that face each other along the axial direction of the cylindrical portion and the direction of extension of the protruding portion.

2. The formwork according to claim 1, wherein the opposing separation surfaces are separated into two for demolding, and the separation surfaces include a cut surface formed by cutting at least a portion of the protruding portion.

3. The formwork according to claim 2, wherein the cut surface is formed along the axial direction only at the tip of the protruding portion of the separation surface in the direction of protrusion.

4. The mold according to claim 3, wherein the resin molded object is formed by stacking molded layers formed in a single continuous path along the axial direction, and when the protruding portion is viewed from the axial direction, the protruding portion includes a pair of straight portions that extend side by side along the protruding direction and are not connected to each other, and the cut surface is a surface formed by cutting a folded portion that connects the ends of the pair of straight portions in the protruding direction.

5. The mold according to claim 1, wherein the resin molded object is a resin molded object produced by additive manufacturing using a material extrusion method.

6. The mold according to claim 1, wherein the resin molded object includes used resin.

7. The mold according to claim 1, wherein the resin molded object contains a biomass-derived resin.

8. A method for manufacturing a mold for manufacturing the mold described in claim 1, comprising: using a 3D printer to build up layers along the axial direction, thereby producing a resin molded object in which no cut surface formed by cutting at least a portion of the protruding portion is formed.

9. The method for manufacturing a mold according to claim 8, further comprising cutting at least a portion of the protruding part of the resin molded object in which the cut surface has not been formed to form the cut surface.

10. The method for manufacturing a mold according to claim 9, wherein, when viewed from the axial direction, the protruding portion includes a pair of straight portions that extend side by side along the direction of the protrusion and are not connected to each other, the molded layer is formed in a single continuous path by a material extrusion method in forming the resin molded product, the resin molded product without a cut surface has the pair of straight portions and a folded portion connecting the ends of the pair of straight portions, and in forming the cut surface, at least a part of the protruding portion is the folded portion.

11. A method for manufacturing concrete, comprising: preparing a formwork and fresh concrete as described in any one of claims 2 to 7; pouring the fresh concrete into the resin molded object, whose separation surfaces are overlapped and whose overhang is fixed, curing it to form concrete; and separating the separation surfaces and demolding the resin molded object from the concrete.

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