Formwork, concrete production method, and concrete

Abstract

Formwork according to the present disclosure is for pouring fresh concrete thereinto. The formwork comprises a plurality of boards. The plurality of boards have at least one board-like shaped object in which a surface that contact the fresh concrete has formed therein a lamination mark caused by additive manufacturing. The board-like shaped object is disposed such that, during formwork removal, the board-like shaped object can be removed toward a specific direction from concrete that is formed by curing the fresh concrete. The specific direction is the direction in which the lamination mark extends and a direction perpendicular to the direction in which layers constituting the board-like shaped object are stacked.

Description

Formwork, concrete manufacturing method and concrete

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

[0002] Concrete is generally obtained by pouring fresh concrete into a formwork, curing it, and then removing the formwork. Conventionally, wooden frames and metal frames have been used as formwork.

[0003] In recent years, formwork made by a 3D printer (hereinafter also referred to as "3DP formwork") has been used to easily produce concrete with complex three-dimensional shapes. Patent Document 1 discloses a 3DP formwork. In the 3DP formwork disclosed in Patent Document 1, the surface that comes into contact with the hardening material is formed of a plastic material having predetermined properties.

[0004] Patent Document 1: U.S. Patent Application Publication No. 2015-0336297

[0005] A 3D printed object typically has layering marks on its surface. In this disclosure, the term "layering marks" refers to a plurality of streak-like irregularities formed on the surface of the object due to the stacking of the modeling layers. The streak-like irregularities typically extend in a direction perpendicular to the stacking direction of the modeling layers.

[0006] The layering marks of the 3DP formwork are usually transferred to the concrete. For example, as shown in FIG. 8 , when removing a 3DP formwork 910 into which concrete 920 has been poured, if the concrete 920 is pulled along a direction F1 parallel to the stacking direction D1 of the modeling layers 911, the layering marks LT of the 3DP formwork 910 may get caught on the concrete 920, making it difficult to remove the 3DP formwork 910 from the concrete 920. In this case, in order to remove the 3DP formwork 910 from the concrete 920, it may be necessary to destroy the 3DP formwork 910 using a tool (e.g., a grinder). However, destroying the 3DP formwork 910 using a tool or the like may damage the concrete 920. In addition, the destroyed 3DP formwork 910 may not be able to be used repeatedly to pour fresh concrete.

[0007] In order to prevent the 3DP formwork from being damaged when it is demolded, it is conceivable to remove the lamination marks on the surface that comes into contact with the concrete by cutting or the like. However, the process of removing the lamination marks requires time and cost.

[0008] To easily remove the 3DP form from the concrete, it is possible to adjust the setting parameters of the 3D printer (e.g., layer pitch, etc.) to create a 3DP form with relatively small layer marks. However, creating a 3DP form with relatively small layer marks using a 3D printer requires a significant amount of manufacturing time.

[0009] The embodiments of the present disclosure have been made in consideration of the above, and have an objective of providing a formwork that can be removed without being destroyed even if it has layering marks, a method for manufacturing concrete, and concrete.

[0010] Means for solving the above problems include the following embodiments: <1> A formwork into which fresh concrete is poured, comprising a plurality of sheathing boards, each of the plurality of sheathing boards having at least one sheathing-like structure on which lamination marks due to additive manufacturing are formed on a surface that contacts the fresh concrete, the sheathing-like structure being positioned so that, when demolded, the sheathing-like structure can be removed from the concrete formed by hardening the fresh concrete in a specific direction, the specific direction being perpendicular to the extension direction of the lamination marks and the stacking direction of the modeling layers that make up the sheathing-like structure. <2> The formwork according to <1>, wherein the sheathing-like structure has at least one sheathing-like object split mold, the sheathing-like object split mold having a plurality of sheathing-like object segments separated by at least one parting line, the extension direction of the parting line being perpendicular to the extension direction of the lamination marks. <3> The formwork according to <1> or <2>, wherein the plurality of sheathing boards are composed of a plurality of sheathing-like structures. <4> The formwork according to any one of <1> to <3>, further comprising shoring for fixing the plurality of sheathing boards. <5> The formwork according to any one of <1> to <4>, wherein the sheathing-like structure contains a thermoplastic resin, and wherein the thermoplastic resin has a tensile modulus of elasticity of 400 MPa or more. <6> The formwork according to any one of <1> to <5>, wherein the sheathing-like structure is an object formed by a material extrusion method or a powder bed fusion method. <7> The formwork according to any one of <1> to <6>, wherein the sheathing-like structure contains a resin, and wherein the resin includes used resin. <8> The formwork according to any one of <1> to <7>, wherein the sheathing-like structure contains a resin, and wherein the resin includes a biomass-derived resin. <9> A method for producing concrete, comprising: preparing a formwork and the fresh concrete according to any one of <1> to <8>; pouring the fresh concrete into the formwork, curing it, and forming the concrete; and removing the sheathing-like object from the concrete in the specific direction.<10> The method for producing concrete according to <9>, further comprising applying a release agent two or more times to the surface of the sheathing-like shaped object that comes into contact with the fresh concrete, wherein the application of the release agent is carried out after the step of preparing the formwork and before the step of forming the concrete. <11> Concrete produced by the method for producing concrete according to <9> or <10>.

[0011] According to an embodiment of the present disclosure, a formwork is provided that can be demolded without being destroyed and can support poured concrete even if it has layer marks.

[0012] FIG. 1 is a diagram illustrating demolding of a formwork according to an embodiment of the present disclosure. FIG. 2 is a perspective view of a formwork according to Example 1 of the present disclosure. FIG. 3 is a perspective view of a formwork according to Comparative Example 1 of the present disclosure. FIG. 4 is a perspective view of 3D data of the formwork according to Comparative Example 1 of the present disclosure. FIG. 5 is a perspective view of a dam-like structure formed by a formwork according to Example 2 of the present disclosure. FIG. 6 is a perspective view of two dam-like structure segments constituting the dam-like structure formed by a formwork according to Example 2 of the present disclosure. FIG. 7 is a perspective view of 3D data of the dam-like structure formed by a formwork according to Example 2 of the present disclosure. FIG. 8 is a diagram illustrating demolding of a conventional formwork.

[0013] In the present disclosure, when a numerical range is indicated by "to," the numerical values ​​before and after the "to" symbol are used to mean that the upper and lower limits are included. In the present disclosure, in numerical ranges described in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. In the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples. In the present disclosure, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved. In the present disclosure, when referring to the amount of each component in a composition, if the composition contains multiple substances corresponding to each component, it means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0014] (1) Formwork The formwork disclosed herein is a formwork into which fresh concrete is poured. The formwork includes a plurality of sheathing boards. The plurality of sheathing boards have at least one sheathing-like structure on whose surface in contact with the fresh concrete (hereinafter also referred to as the "molding surface") there is formed a lamination mark resulting from additive manufacturing. The sheathing-like structure is positioned so that, when demolding, the sheathing-like structure can be removed in a specific direction (hereinafter also referred to as the "demolition direction") from the concrete formed by hardening the fresh concrete. The specific direction indicates a direction perpendicular to the extension direction of the lamination mark and the stacking direction (hereinafter also referred to as the "stacking direction") in which the modeling layers constituting the sheathing-like structure are stacked.

[0015] In this disclosure, "formwork" refers to a temporary structure that maintains poured fresh concrete in a predetermined shape and dimensions and supports it until the concrete reaches an appropriate strength. "Siding" refers to a plate-like object that is part of the formwork and in direct contact with the concrete. "Fresh concrete" refers to concrete in an unhardened state. "Siding-like object" refers to an object that has the shape of a siding. "Object" refers to a layered structure formed by combining modeling layers using a 3D printer based on 3D model data.

[0016] In the formwork of the present disclosure, the sheathing-like object is positioned so that it can be removed from the concrete in the demolding direction during demolding. Therefore, even if there are layering marks, the layering marks on the molding surface of the sheathing are unlikely to get caught on the concrete during demolding. This allows the sheathing-like object to be easily removed from the concrete. Specifically, in the present disclosure, as shown in FIG. 1 , when the sheathing-like object 10 is demolded from the concrete 20, it can be pulled along the demolding direction F2. The demolding direction F2 indicates a direction perpendicular to the extension direction D2 of the layering marks LT and the stacking direction D1 of the molding layers 11 that make up the sheathing-like object 10. This allows the sheathing-like object 10 to be easily removed from the concrete 20 without getting caught on the concrete 20. As a result, the formwork of the present disclosure allows demolding without destruction, even if there are layering marks.

[0017] In addition, the formwork of the present disclosure does not require the cost and time required to remove layer marks. The formwork of the present disclosure can produce concrete without damaging the concrete with tools or the like. The formwork of the present disclosure is not destroyed when demolded, so it can be used repeatedly to pour fresh concrete. The formwork of the present disclosure can produce concrete in which layer marks are transferred to the surface (i.e., concrete that is less reflective).

[0018] The size and shape of the formwork of the present disclosure are not particularly limited and are selected appropriately depending on the size and shape of the concrete.

[0019] (1.1) Sheathing The formwork of the present disclosure includes a plurality of sheathings. The plurality of sheathings constitute a mold for forming fresh concrete. The shape, size, and number of the sheathings are not particularly limited and are selected appropriately depending on the shape, size, etc. of the concrete.

[0020] The plurality of sheathings each have at least one sheathing-like structure that is arranged so that the sheathing-like structure can be removed from the concrete in a demolding direction during demolding.

[0021] (1.1.1) Sheathing-like object The sheathing-like object has lamination marks on its molding surface due to additive manufacturing. The size and number of lamination marks are not particularly limited and are selected appropriately depending on the shape and size of the concrete, etc.

[0022] The sheathing-like object preferably has at least one sheathing-like object split mold, and the sheathing-like object split mold preferably has a plurality of sheathing-like object segments separated by at least one parting line. The extension direction of the parting line is parallel to the stacking direction. This allows the formwork of the present disclosure to produce concrete with more complex three-dimensional shapes (e.g., curved surfaces) and surface textures (e.g., uneven shapes), and allows the concrete to be demolded without being destroyed even if it has stacking marks.

[0023] The term "parting line" refers to a line that indicates the boundary between the divided pieces of a sheathing-like object when the divided pieces of the sheathing-like object are integrated to form a sheathing-like object split mold.

[0024] The sheathing-like object is additively manufactured using a 3D printer. The additive manufacturing process for the sheathing-like object is not particularly limited and can be appropriately selected depending on the material of the sheathing-like object, the size of the concrete, etc. Examples of additive manufacturing processes include material extrusion (MEX), powder bed fusion (PBF), binder jetting (BJT), directed energy deposition (DED), material jetting (MJT), sheet lamination (SHL), and vat photopolymerization (VPP).

[0025] The dam-like structure is preferably a structure produced by additive manufacturing (MEX) or powder bed fusion (PBF), which allows for larger dam-like structures (e.g., 1 m or more by 1 m or more) than structures produced by other additive manufacturing processes other than MEX or PBF.

[0026] (1.1.1.1) Thermoplastic resin The sheathing-like object preferably contains a thermoplastic resin, and the thermoplastic resin preferably has a tensile modulus of elasticity of 400 MPa or more at 25°C. This provides the sheathing-like object with sufficient hardness. Therefore, the sheathing-like object is less likely to deform when fresh concrete is poured into it. As a result, the formwork of the present disclosure is capable of molding concrete having a desired shape. The tensile modulus of elasticity of the thermoplastic resin is more preferably 1000 MPa or more, and even more preferably 2000 MPa or more, from the viewpoint of being able to reduce the thickness of the sheathing-like object in order to ensure the necessary rigidity as a concrete formwork.

[0027] The tensile modulus is measured in accordance with JIS K7161-2: 2014. The test piece is 1A type, the test temperature is 23 degrees, and the test speed is 1.0 mm / min.

[0028] The sheathing-like shaped object may contain or consist of a thermoplastic resin.

[0029] In the present disclosure, the term "thermoplastic resin" refers to a resin having a tensile modulus of elasticity of 6.0 × 10 at 25°C. ８ This indicates a thermoplastic resin having a modulus of elasticity of 100 Pa or more.

[0030] The thermoplastic resin is not particularly limited, and known thermoplastic resins can be used. Examples of thermoplastic resins 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 (such as propylene homopolymer (PP)), 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 resins (such as PMMA). 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). The thermoplastic resins may be used alone or in combination of two or more.

[0031] When the sheathing-like object contains a thermoplastic resin, the content of the thermoplastic resin may be 0.1% by mass to 100% by mass, 10% by mass to 70% by mass, or 20% by mass to 60% by mass, relative to the total mass of the sheathing-like object.

[0032] (1.1.1.2) Filler The sheathing-shaped object may contain a filler. Examples of fillers include inorganic powder, shiny inorganic powder, composite inorganic powder, and inorganic fiber. Examples of inorganic powders include talc, titanium oxide, black titanium oxide, and fertilizer. Examples of shiny inorganic powders include bismuth oxychloride, titanium oxide-coated mica, iron oxide-coated mica, and iron oxide-coated mica titanium. Examples of composite inorganic powders include titanium oxide-coated mica titanium fine particles, zinc oxide-coated mica titanium fine particles, barium sulfate-coated mica titanium, and titanium oxide-encapsulated silica. Examples of inorganic fiber include glass fiber. One type of filler may be used alone, or two or more types may be used in combination.

[0033] The shape of the filler may be any of spherical, plate-like, and needle-like. The filler may be porous or non-porous.

[0034] When the sheathing-like shaped object contains a filler, the content of the filler may be 5% by mass to 70% by mass relative to the total mass of the sheathing-like shaped object.

[0035] (1.1.1.3) Thermoplastic Elastomer The sheathing-like shaped object may contain or consist of a thermoplastic elastomer.

[0036] The term "thermoplastic elastomer" refers to a material having rubber-like elasticity. Specifically, the term "thermoplastic elastomer" refers to a material having a tensile modulus of elasticity of 6.0×10 at 25° C. ８ This refers to a thermoplastic resin having a modulus of less than 100 Pa.

[0037] The thermoplastic elastomer may be a copolymer containing structural units derived from an α-olefin and structural units derived from an olefin other than 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 olefins other than the α-olefins are olefins having 2 to 4 carbon atoms, such as ethylene, propylene, and butene.

[0038] When the sheathing-like shaped object contains a thermoplastic elastomer, the content of the thermoplastic elastomer may be 0.1% by mass to 100% by mass, or 10% by mass to 70% by mass, relative to the total amount of the sheathing-like shaped object.

[0039] (1.1.1.4) Used Resin The sheathing-like object preferably contains resin, and the resin preferably contains used resin, thereby reducing the environmental impact.

[0040] The used resin is not particularly limited as long as it is a resin that has been used. The used resin may be a resin that has been used for a dam-like object formed using the formwork of the present disclosure, or a resin that has been used for an object other than the dam-like object formed using the formwork of the present disclosure.

[0041] (1.1.1.5) Biomass-derived resin The sheathing-like structure preferably contains a resin, and the resin preferably contains a biomass-derived resin. Biomass-derived resin is a carbon-neutral material, and therefore can reduce the environmental impact of producing the sheathing-like structure.

[0042] Monomers used as raw materials for biomass-derived thermoplastic resins can be obtained by cracking biomass naphtha or synthesizing them from biomass-derived ethylene. Biomass-derived thermoplastic resins can be obtained by polymerizing the biomass-derived monomers synthesized in this manner using methods similar to those used for conventional petroleum-derived thermoplastic resins. Thermoplastic resin polymers synthesized using bio-derived monomers are biomass-derived thermoplastic polymers. The content of bio-derived thermoplastic polymers in the raw material monomers can be greater than 0% by mass, 100% by mass, or less, relative to the total amount of raw material monomers. "Biomass content" indicates the content of biomass-derived carbon and is calculated by measuring radiocarbon (C14). Carbon dioxide in the atmosphere contains a certain percentage of C14 (approximately 105.5 pMC). Therefore, it is known that the C14 content in plants (e.g., corn) that grow by absorbing carbon dioxide from the atmosphere is also approximately 105.5 pMC. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the proportion of C14 carbon atoms in the total carbon atoms in the polymer, the content of biomass-derived carbon in the raw material can be calculated. The thermoplastic polymer used as the raw material of the present disclosure may include a thermoplastic polymer obtained by recycling, i.e., a so-called recycled polymer. "Recycled polymer" includes a polymer obtained by recycling waste polymer products, and can be produced, for example, by the method described in DE 102019127827 (A1). The recycled polymer may include a marker that identifies it as having been obtained by recycling.

[0043] (1.1.2) Other sheathing The multiple sheathings may include, in addition to the sheathing-like structure, other sheathings different from the sheathing-like structure, depending on the shape of the concrete, etc. Examples of other sheathings include wooden sheathings and metal sheathings. The other sheathings may be known sheathings.

[0044] In particular, the plurality of sheathing boards preferably consist of a plurality of sheathing-like structures. In other words, the plurality of sheathing boards preferably consist solely of a plurality of sheathing-like structures. This allows the formwork of the present disclosure to mold concrete having a more complex three-dimensional shape (e.g., a curved surface) that is more difficult to demold than when the plurality of sheathing boards include other sheathing boards, and allows the concrete to be demolded without being destroyed even if it has layering marks.

[0045] (1.2) Shoring Preferably, the formwork of the present disclosure further includes shoring for fixing the plurality of sheathing boards.

[0046] "Shoring" refers to a temporary structure used to secure sheathing in place.

[0047] The formwork of the present disclosure further includes shoring, so that the multiple sheathing plates more securely hold the poured fresh concrete in the specified shape than in a configuration in which the formwork does not include shoring.

[0048] The support may be a known support, and examples of the material of the support include resin and metal.

[0049] (2) Concrete Manufacturing Method The concrete manufacturing method of the present disclosure includes preparing the formwork of the present disclosure and the fresh concrete (hereinafter also referred to as the "preparation step"), pouring the fresh concrete into the formwork, curing it, and forming the concrete (hereinafter also referred to as the "concrete forming step"), and removing the sheathing-like object from the concrete in the specific direction (hereinafter also referred to as the "form stripping step"). The preparation step, concrete forming step, and form stripping step are carried out in this order.

[0050] The concrete manufacturing method of the present disclosure has the above-described configuration, and therefore can manufacture concrete having a complex shape without damaging the surface.

[0051] (2.1) Preparation Step The concrete manufacturing method of the present disclosure includes a preparation step in which the formwork and fresh concrete of the present disclosure are prepared.

[0052] (2.1.1) Formwork The method for preparing the formwork may be any known method, except that the dam-like object is formed using a 3D printer. The additive modeling process of the 3D printer may be the same as the method exemplified in "(1.1.1) Dam-like object." The setting parameters of the 3D printer may be adjusted as appropriate depending on the additive modeling process, the size of the dam-like object, etc.

[0053] (2.1.2) Fresh Concrete The method for preparing fresh concrete is not particularly limited, and any known method may be used.

[0054] The composition of fresh concrete is not particularly limited and is appropriately selected depending on the application of the concrete, etc. Fresh concrete may contain cement, aggregate, and water, and may further contain admixtures. Examples of cement include ordinary Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, low-heat Portland cement, and moderate-heat Portland cement. The unit cement amount is preferably 270 kg / m ３ ~500 kg / m ３ Examples of the aggregate include fine aggregate (e.g., river sand, mountain sand, land sand, etc.) and coarse aggregate (e.g., river gravel, mountain gravel, crushed stone, etc.). The unit amount of the aggregate is 500 kg / m ３ ~1100 kg / m ３ Examples of water include tap water and treated sewage water. The unit amount of water is 100 kg / m ３ ~200 kg / m ３ Examples of the admixture include air-entraining agents (i.e., air-entraining agents), water-reducing agents, foaming agents, foaming agents, setting regulators, hardening accelerators, waterproofing agents, water-repellent agents, water-retention agents, rust inhibitors, thickeners, pigments, and anti-efflorescence agents.

[0055] (2.2) Release Agent Application Step Preferably, the concrete manufacturing method of the present disclosure further includes applying a release agent two or more times to the surface of the sheathing-like object that comes into contact with the fresh concrete (hereinafter also referred to as the "release agent application step"). The application of the release agent (release agent application step) is carried out after the formwork is prepared (preparation step) and before the concrete is formed (concrete formation step). This makes it easier to form a release agent layer on the forming surface of the sheathing-like object. Therefore, it is easier to remove the sheathing-like object from the concrete in the demolding direction than if the release agent application step is not carried out.

[0056] The release agent is not particularly limited, and examples thereof include fluorine compound-type release agents (e.g., triperfluorooctyl phosphate, triperfluorododecyl phosphate, etc.), silicone compound-type release agents (dimethylpolysiloxane, amino-modified dimethylpolysiloxane, etc.), fatty acid ester-type release agents (e.g., butyl stearate, hardened castor oil, etc.), and waxes (paraffin wax, microcrystalline wax, etc.). The release agent may contain an organic solvent (e.g., toluene, n-hexane, etc.). The method for applying the release agent is not particularly limited, and may be a known method. The amount of release agent applied at one time is not particularly limited, and may be a commonly used amount (e.g., 200 cc / m ２ ) may also be used.

[0057] (2.3) Concrete Forming Step The concrete manufacturing method of the present disclosure includes a concrete forming step. In the concrete forming step, the fresh concrete is poured into the formwork and cured to form the concrete.

[0058] The method of applying and curing the concrete is not particularly limited, and any known method may be used.

[0059] (2.4) Demolding Step The concrete manufacturing method of the present disclosure includes a demolding step, in which the sheathing-like shaped object is removed from the concrete in the demolding direction.

[0060] The method for removing the sheathing-like object in the demolding direction is not particularly limited, and any known method may be used.

[0061] The concrete of the present disclosure is produced by the method for producing concrete of the present disclosure.

[0062] The concrete of the present disclosure has the above-described configuration, and therefore has the layering marks of the sheathing-like structures transferred onto its surface, making it less likely to reflect light and having a complex shape.

[0063] The shape and size of the concrete of the present disclosure are not particularly limited, and are selected appropriately depending on the application of the concrete of the present disclosure, etc.

[0064] Applications of the concrete of the present disclosure include construction materials for civil engineering structures and architectural structures.

[0065] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples.

[0066] [1] Preparation of Materials The following materials were mixed, melted, and extruded to prepare virgin pellets (size: φ2.5×3 mm) as materials for three-dimensional modeling.

[0067] [1.1] Materials for sheathing-shaped objects [1.1.1] Thermoplastic resins J105G: Prime Polypro J-105G (propylene homopolymer, Prime Polymer Co., Ltd.)

[0068] [1.1.2] Filler Talc: Volume average particle size 5 μm to 10 μm

[0069] [1.1.3] Thermoplastic elastomers ・XM7090: Toughmer XM-7090 (Mitsui Chemicals, Inc.)

[0070] [1.2] Materials for fresh concrete [1.2.1] Cement Ordinary Portland cement: Sumitomo Osaka Cement Co., Ltd.

[0071] [1.2.2] Aggregate ・Fine aggregate: fine sand, crushed sand ・Coarse aggregate: crushed stone

[0072] [1.2.3] Admixtures - High-performance AE damping material: Pozzolith Solutions Co., Ltd.

[0073] [2] Example 1 [2.1] Preparation Process [2.1.1] Formwork The formwork 100 shown in Figure 2 was fabricated. The formwork 100 is a rectangular box-like object with an opening facing upward (positive Z-axis direction). The formwork 100 is composed of a bottom plate 110 (a sheathing-like structure), a rectangular wooden cylindrical frame 120 (another sheathing), and shoring (not shown). The bottom plate 110 is placed inside the wooden cylindrical frame 120.

[0074] The wooden tubular frame 120 and shoring were prepared in a known manner.

[0075] The bottom plate 110 was prepared by additive manufacturing using a 3D printer as described below.

[0076] The bottom plate 110 was fabricated using a material extrusion (MEX) 3D printer ("EXF-12" manufactured by ExtraBold Co., Ltd., nozzle diameter: 6 mm) and application software ("Cura" manufactured by Ultimaker).

[0077] Pellets of a material for 3D modeling were obtained by mixing 17 parts by mass of a thermoplastic resin, 40 parts by mass of a filler, and 43 parts by mass of a thermoplastic elastomer. The pellets were placed in a hopper and fed into a cylinder via the hopper. The material for 3D modeling was then heated to a temperature of 180°C to 240°C using a heater attached to the cylinder, and melted.

[0078] Using application software, the following 3D data was sliced ​​to generate multiple 2D data. Based on the multiple 2D data, the application software's setting parameters were set as follows, and a rectangular box was additively manufactured using the material extrusion (MEX) method. A flat plate portion (210 x 300 mm) of the rectangular box was cut out to obtain the bottom plate 110. Multiple layer marks LT were formed on the molding surface S110 of the bottom plate 110 at predetermined intervals in the X direction. The layer marks LT extended along the Y axis direction.

[0079] [2.1.1.1] 3D data Three-dimensional shape: rectangular box (not shown) Length in the X-axis direction: 375 mm Length in the Y-axis direction: 375 mm Length in the Z-axis direction: 310 mm

[0080] [2.1.1.2] Setting parameters Stacking direction: X-axis direction (see Figure 2) Build speed: 1800 mm / min Nozzle temperature: 200°C Layer pitch: 3.0 mm Filling rate: 100% Filling pattern: solid

[0081] [2.1.2] Fresh Concrete Fresh concrete was obtained 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.

[0082] [2.2] Concrete Forming Step Fresh concrete was poured into the formwork 100. After pouring the fresh concrete, it was left to stand for one day to cure. In this way, concrete was formed.

[0083] [2.3] Demolding process The wooden cylindrical frame 120 and shoring (not shown) were removed from the formwork 100. Next, the concrete was lifted in the positive direction of the Z axis (see FIG. 2) (the demolding direction), and the bottom plate 110 was easily removed from the concrete (see FIG. 1). The demolding direction (positive Z axis) (see FIG. 2) was perpendicular to the extension direction of the layer traces LT (the Y axis direction) and the stacking direction of the modeling layers (the X axis direction).

[0084] From the above, it was found that the formwork 100 of Example 1 is a formwork that can be removed without being destroyed even if it has lamination marks.

[0085] [3] Comparative Example 1 [3.1] Preparation Step [3.1.1] Formwork The formwork 200 shown in Fig. 3 was prepared. The formwork 200 was a boat-shaped object with an opening facing upward (positive Z-axis direction). The formwork 200 consisted only of a sheathing-like object.

[0086] A mold 200 was obtained by additive manufacturing similar to that in Example 1, except that the 3D data and setting parameters were changed to the following conditions. The mold 200 has a bottom 210 and an overhang 220 that overhangs upward (in the positive direction of the X-axis) from the bottom 210. The molding surface S200 of the mold 200 has an inner surface S210 of the bottom 210 and an inner surface S220 of the overhang 220. No lamination marks were formed on the inner surface S210 of the bottom 210. A plurality of lamination marks LT were formed on the inner surface S220 of the overhang 220 at predetermined intervals in the Z direction. The lamination marks LT extended along the inner circumferential direction of the inner surface S220 of the overhang 220.

[0087] [3.1.1.1] 3D data ・3D shape: Ship-shaped object D200 (see Figure 4) ・Top X-axis length: 258 mm ・Bottom X-axis length: 200 mm ・Z-axis length: 57 mm

[0088] [3.1.1.2] Setting parameters Stacking direction: Z-axis direction (see Figure 3) Build speed: 1500 mm / min Nozzle temperature: 200°C Layer pitch: 3.0 mm Filling rate: 100% Filling pattern: solid

[0089] [3.1.2] Fresh concrete Fresh concrete was obtained in the same manner as in Example 1.

[0090] [3.2] Concrete Forming Step Fresh concrete was poured into the formwork 200. After pouring the fresh concrete, it was left to stand for one day to cure. In this way, concrete was formed.

[0091] [3.3] Demolding process When the concrete was lifted in the positive direction of the Z axis (see FIG. 3) (the demolding direction), the formwork 200 did not come off the concrete (see FIG. 8). The demolding direction (positive direction of the Z axis) (see FIG. 3) was not perpendicular to the extension direction of the layer traces LT (the inner circumferential direction of the inner surface S220 of the protruding portion 220) and the stacking direction of the modeling layers (the Z axis direction).

[0092] A grinder was used to make cuts in the overhanging portion 220 of the formwork 200, and the formwork 200 was removed from the concrete. Cuts made by the grinder were confirmed on the surface of the concrete.

[0093] As described above, it was found that the formwork 200 of Comparative Example 1 is not a formwork that can be removed without being destroyed even if it has lamination marks.

[0094] [4] Example 2 [4.1] Preparation Step [4.1.1] Formwork The formwork 300 shown in Figures 5 and 6 was fabricated. The formwork 300 is a rectangular box-like object with an opening facing upward (positive Z-axis direction). The formwork 300 is composed of a rectangular tubular object 310 (a sheathing-like object), a wooden bottom plate 320 (another sheathing), and shoring (not shown). The rectangular tubular object 310 consists only of a sheathing-like object split mold.

[0095] A rectangular cylindrical object 310 was obtained by additive manufacturing in the same manner as in Example 1, except that the 3D data and setting parameters were changed to the following conditions. A plurality of layer marks LT were formed at predetermined intervals in the Z direction on the inner molding surface S310 of the rectangular cylindrical object 310. The layer marks LT extended along the inner circumferential direction of the rectangular cylindrical object 310. The rectangular cylindrical object 310 was cut into two pieces, a dam-shaped object segment 311 and a dam-shaped object segment 312, as shown in FIG. 6 . The extension direction (Z-axis direction) of the parting line PL between the dam-shaped object segment 311 and the dam-shaped object segment 312 was parallel to the stacking direction (Z-axis direction) of the modeling layers. In other words, the extension direction (Z-axis direction) of the parting line PL was perpendicular to the extension direction of the layer marks LT. In FIG. 6, the lamination marks LT are omitted.

[0096] [4.1.1.1] 3D data Three-dimensional shape: rectangular cylindrical object D310 (see Figure 7) Length in the X-axis direction: 95 mm Length in the Y-axis direction: 95 mm Length in the Z-axis direction: 200 mm

[0097] [4.1.1.2] Setting parameters Stacking direction: Z-axis direction (see Figures 5 and 6) Modeling speed: 660 mm / min Nozzle temperature: 200°C Layer pitch: 3.0 mm Filling rate: 100% Filling pattern: solid

[0098] [4.1.2] Fresh concrete Fresh concrete was obtained in the same manner as in Example 1.

[0099] [4.2] Concrete Forming Step Fresh concrete was poured into the formwork 300. After pouring the fresh concrete, it was left to stand for one day to cure. In this way, concrete was formed.

[0100] [4.3] Demolding process The wooden bottom plate 320 and shoring (not shown) were removed from the formwork 300. Next, the divided piece 311 of the dam-like object was pulled in the positive direction of the Y axis (see FIGS. 5 and 6 ) (the demolding direction), and the divided piece 311 of the dam-like object was easily removed from the concrete (see FIG. 1 ). Next, the divided piece 312 of the dam-like object was pulled in the negative direction of the Y axis (see FIGS. 5 and 6 ) (the demolding direction), and the divided piece 312 of the dam-like object was easily removed from the concrete (see FIG. 1 ). The demolding direction (positive direction of the Y axis) (see FIGS. 5 and 6 ) of the divided piece 311 of the dam-like object was perpendicular to the extension direction of the layering marks LT (the inner circumferential direction of the molding surface S310 of the rectangular cylindrical object 310) and the stacking direction of the modeling layers (the Z-axis direction). The demolding direction (negative Y-axis direction) of the plate-shaped object divided body 312 (see Figures 5 and 6) was perpendicular to the extension direction of the layer traces LT (the inner peripheral direction of the molding surface S310 of the rectangular cylindrical object 310) and the stacking direction of the molding layers (Z-axis direction).

[0101] From the above, it was found that the formwork 300 of Example 2 is a formwork that can be removed without being destroyed even if it has lamination marks.

[0102] The disclosure of Japanese Patent Application No. 2023-170526, filed on September 29, 2023, 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 was specifically and individually indicated to be incorporated by reference.

Claims

1. A formwork into which fresh concrete is poured, comprising a plurality of sheathings, each of which has at least one sheathing-like structure having lamination marks formed by additive manufacturing on the surface that contacts the fresh concrete, the sheathing-like structure being positioned so that, when demolding, the sheathing-like structure can be removed in a specific direction from the concrete formed by the hardening of the fresh concrete, the specific direction being perpendicular to the extension direction in which the lamination marks extend and the stacking direction in which the modeling layers that make up the sheathing-like structure are stacked.

2. The formwork according to claim 1, wherein the dam-shaped object has at least one dam-shaped object split mold, the dam-shaped object split mold has a plurality of dam-shaped object segments separated by at least one parting line, and the extension direction of the parting line is parallel to the stacking direction.

3. The formwork according to claim 1, wherein the plurality of sheathings are made up of a plurality of sheathing-like structures.

4. The formwork of claim 1, further comprising shoring to secure said plurality of deckings.

5. The formwork according to claim 1, wherein the sheathing-like object contains a thermoplastic resin, and the thermoplastic resin has a tensile modulus of elasticity of 400 MPa or more.

6. The formwork according to claim 1, wherein the sheathing is formed by material extrusion or powder bed fusion.

7. The formwork according to claim 1, wherein the sheathing-like object comprises a resin, and the resin comprises a used resin.

8. The formwork according to claim 1, wherein the sheathing-like structure contains a resin, and the resin contains a resin derived from biomass.

9. A method for manufacturing concrete comprising: preparing a formwork and the fresh concrete according to any one of claims 1 to 8; pouring the fresh concrete into the formwork and curing it to form the concrete; and removing the sheathing-like object from the concrete in the specific direction.

10. The method for producing concrete according to claim 9, further comprising applying a release agent two or more times to the surface of the sheathing-like structure that contacts the fresh concrete, and applying the release agent is performed after preparing the formwork and before forming the concrete.

11. Concrete produced by the method for producing concrete according to claim 9.

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