Construction method for building, and molding frame

Abstract

In order to facilitate a construction method of a building using a resin composition as a material of a skeleton, the construction method of a building 11 executes: a molding-frame installation step for installing a molding frame 10 having flexible sheet materials 1, 2 and being provided with, when a space partitioned by the sheet materials 1, 2 is expanded, a space 6 for a skeleton having a shape corresponding to the shape of a skeleton 12 of the building 11 to be constructed; and a skeleton formation step for forming the skeleton 12 of the building 11 comprising a foam resin by foaming a resin composition 13 containing a foaming agent in the space 6 for the skeleton and curing the resin composition 13 foamed in the space 6 for the skeleton in a state in which the space 6 for the skeleton is expanded. The molding frame 10 includes an inner film 1 and an outer film 2 as sheet materials. The space 6 for the skeleton is provided between the inner film 1 and the outer film 2. In the molding-frame installation step, the inner space 5 of the inner film 1 is filled with a gas to build up the inner film 1 in the molding frame 10, and the skeleton formation step is executed in a state in which the inner film 1 is built up.

Description

Building construction methods and formwork

[0001] The present invention relates to a method for constructing a building using foamed resin as a structural material.

[0002] Commonly used building materials include wood, stone, steel, concrete, and reinforced concrete. Non-Patent Document 1, on the other hand, describes a method for constructing buildings using expanded polystyrene foam as a method for constructing buildings using special materials. In this construction method, expanded polystyrene building components are manufactured using molds.

[0003] Wataru Sekine and four others, "Development of a Dome House Using Expanded Polystyrene Part 1 Microtremor Tests and Free Vibration Tests", Volume: 2011, Pages: 841-842, July 20, 2011, Abstracts of Academic Lectures, Architectural Institute of Japan, B-1, Structure 1 (Academic Lectures, Architectural Institute of Japan, B-1, Structure 1, Load / Reliability, Applied Mechanics / Structural Analysis, Foundation Structure, Shell / Spatial Structure)

[0004] However, in the building construction method of Non-Patent Document 1, it takes time to prepare the molds used to manufacture the polystyrene foam building components. Also, the polystyrene foam building components are manufactured in a factory, and because the building components are bulky, they are not easy to transport to the building construction site.

[0005] The present invention has been made in view of the above circumstances, and has an object to simplify the method of constructing a building using a resin composition as a building frame material.

[0006] In order to solve the above-mentioned problems, the present invention provides a method for constructing a building, which includes a formwork installation step of installing a formwork having a flexible sheet material and a body space that is partitioned by the sheet material and that, when the space is expanded, takes a shape that corresponds to the body shape of the building to be constructed, and a body formation step of foaming a resin composition containing a foaming agent in the body space and, with the body space expanded, curing the resin composition foamed in the body space to form the body of the building made of foamed resin, the formwork having inner and outer membranes as sheet materials, with the body space provided between the inner and outer membranes, and during the formwork installation step, the inner space of the inner membrane is filled with gas to erect the inner membrane of the formwork, and the body formation step is carried out with the inner membrane erected.

[0007] In the present invention, a building is constructed using a formwork having a flexible sheet material. The formwork has a space for a skeleton, which is a space partitioned by the sheet material and expands to form a shape corresponding to the skeleton shape of the building to be constructed. The space for a skeleton is provided between an inner membrane and an outer membrane. During the formwork installation step, the inner space of the inner membrane is filled with gas to erect the inner membrane of the formwork, and the skeleton formation step is performed with the inner membrane erected. In the skeleton formation step, a resin composition containing a foaming agent is foamed in the space for a skeleton, and the foamed resin composition in the space for a skeleton is cured while the space for a skeleton is expanded, thereby forming the skeleton of the building made of foamed resin. Therefore, there is no need to spend time preparing a mold as in the conventional method. Furthermore, since a building made of foamed resin is formed on-site, it is easy to transport. According to the present invention, it is possible to facilitate the construction of a building using a resin composition as a skeleton material.

[0008] FIG. 1 is a schematic diagram showing the appearance of a building constructed by a method for constructing a building according to an embodiment. FIG. 2 is a schematic diagram showing the cross-sectional configuration of a formwork used in the method for constructing a building according to an embodiment. FIG. 3 is a schematic diagram showing a state at the completion of a foundation construction step in the method for constructing a building according to an embodiment. FIG. 4 is a schematic diagram showing a state at the completion of temporary installation of a formwork in a formwork installation step in the method for constructing a building according to an embodiment. FIG. 5 is a schematic diagram showing a state after the inner membrane of the formwork has been installed in the formwork installation step in the method for constructing a building according to an embodiment. FIG. 6 is a schematic diagram showing a state during a resin injection step in the method for constructing a building according to an embodiment. FIG. 7 is a schematic diagram of a mixer system used in the resin injection step in the method for constructing a building according to an embodiment. FIG. 8 is a schematic diagram showing a state during a foam hardening step in the method for constructing a building according to an embodiment. FIG. 9 is a schematic diagram showing a state at the completion of a finishing step in the method for constructing a building according to an embodiment. FIG. 10 is a schematic diagram showing a state after the inner membrane of the formwork has been installed in the formwork installation step in the method for constructing a building according to a first modified example of the embodiment. Fig. 11 is a schematic diagram showing the state immediately after the foaming and hardening step in the method for constructing a building according to a first modified embodiment. Fig. 12 is a schematic diagram showing the state immediately after the foaming and hardening step in the case where an intermediate membrane is provided adjacent to the indoor surface of the outer membrane in the method for constructing a building according to a first modified embodiment. Fig. 13 is a schematic diagram showing the state after the inner membrane of the form has been erected in the formwork installation step in the method for constructing a building according to a second modified embodiment. Fig. 14 is a schematic diagram showing the state after the outer membrane has been installed so as to cover the inner membrane in the formwork installation step in the method for constructing a building according to a second modified embodiment. Fig. 15 is a schematic diagram showing the state after the inner membrane of the formwork has been erected in the formwork installation step in the method for constructing a building according to a third modified embodiment. Fig. 16 is a schematic diagram showing the state at the completion of temporary installation of the formwork in the formwork installation step in the method for constructing a building according to a fourth modified embodiment.FIG. 17 is a schematic diagram showing the state after the inner membrane of the formwork has been erected in the formwork installation step in the building construction method according to the fourth modified embodiment. FIG. 18 is a schematic diagram showing the state immediately after the foam hardening step in the building construction method according to the fourth modified embodiment. FIG. 19 is a schematic diagram showing the state during the resin injection step in the building construction method according to another modified embodiment. FIG. 20 is a schematic diagram showing the state at the completion of the foundation construction step in the building construction method according to the reference embodiment. FIG. 21 is a schematic diagram showing the state at the completion of the formwork installation step in the building construction method according to the reference embodiment. FIG. 22 is a schematic diagram showing the state at the completion of the resin injection step in the building construction method according to the reference embodiment. FIG. 23 is a schematic diagram showing the state during the foam hardening step in the building construction method according to the reference embodiment. FIG. 24 is a schematic diagram showing the state at the completion of the foam hardening step in the building construction method according to the reference embodiment. FIG. 25 is a schematic diagram showing the state at the completion of the finishing step in the building construction method according to the reference embodiment.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are merely examples of the present invention and are not intended to limit the scope of the present invention, its applications, or its uses.

[0010] <Embodiment> This embodiment is a construction method (hereinafter referred to as "this construction method") for constructing a building 11 having a living space as an architectural structure. The building 11 has a dome shape as shown in Figure 1. This construction method uses a formwork (flexible formwork) 10 made of flexible sheet materials 1, 2, and 7. The formwork 10 is foldable, making it easy to transport.

[0011] [1. About the formwork] First, the formwork 10 will be described. As shown in Figure 2, the formwork 10 is provided with an inner membrane 1 and an outer membrane 2 as flexible sheet materials 1, 2. The formwork 10 is provided with a space 6 partitioned by the sheet materials 1, 2, called a skeleton space 6, which, when expanded, takes a shape corresponding to the shape of a skeleton 12 (see Figure 9) of a building 11 to be constructed. The skeleton space 6 is provided between the inner membrane 1 and the outer membrane 2. The skeleton space 6 has a volume of, for example, 0.5 m when fully expanded. ３ That's all.

[0012] In the formwork 10, the inner space 5 of the inner membrane 1 is provided as a gas-filled space 5 filled with a gas such as air. The gas-filled space 5 is an enclosed space. The gas-filled space 5 is defined by the inner membrane 1 and a bottom sheet 7. The bottom sheet 7 is also made of a flexible sheet material. The inner membrane 1 is connected to the outer periphery of the bottom sheet 7. When the gas-filled space 5 is filled with gas, the inner membrane 1 assumes a dome shape (approximately hemispherical shape).

[0013] The outer membrane 2 is a sheet material having substantially the same shape as the inner membrane 1, but slightly larger. The outer membrane 2 is connected to the outer periphery of the bottom sheet 7, outside the connection point of the inner membrane 1. When the gas-filled space 5 and the space for the body 6 are fully expanded, the outer membrane 2 assumes a dome shape, as shown in Figure 2, and faces the inner membrane 1 at a distance corresponding to the wall thickness of the body 12. The space for the body 6 is partitioned by the inner membrane 1, the outer membrane 2, and the bottom sheet 7.

[0014] In this embodiment, a flexible sheet material integrated with the inner membrane 1 and the outer membrane 2 is used for the bottom sheet 7, but a hard plate material may also be used. In the former case, the bottom sheet 7 is joined to the inner membrane 1 and the outer membrane 2 in advance, for example, in a factory. In the latter case, the bottom sheet 7 may be joined to the inner membrane 1 and the outer membrane 2 in advance, for example, in a factory, or may be joined to the inner membrane 1 and the outer membrane 2 at the construction site of the building 11.

[0015] The formwork 10 is provided with a gas injection port 3 for injecting gas to inflate the gas-filled space 5, and a resin injection port 4 for injecting a resin composition containing a foaming material (hereinafter referred to as the "resin material for the body") 13 into the space for the body 6.

[0016] The gas inlet 3 can be provided at a location that will become the opening 9 (the opening 9 where the window glass 21 or the door 23 or the like is installed) that connects the external space with the internal space 5 in the completed skeleton 12. In this case, the gas inlet 3 is provided so as to penetrate the inner membrane 1 and the outer membrane 2. The gas inlet 3 may also be provided at another location (for example, the bottom sheet 7).

[0017] The formwork 10 has a resin injection port 4 provided, for example, on the bottom side. The number of resin injection ports 4 in the formwork 10 may be one or two or more. For example, if the size of the building 10 is large, providing multiple resin injection ports 4 makes it possible to easily distribute the body resin material 13 throughout the body space 6.

[0018] In the area of ​​the sheet materials 1 and 2 of the formwork 10 that defines the space for the main body 6 (the area facing the space for the main body 6), a ventilation section is provided in the space next to the space for the main body 6 sandwiched between the sheet materials 1 and 2 (the outer space or inner space 5 of the outer membrane 2) to allow air to escape from the space for the main body 6 as the resin material for the main body 13 foams.

[0019] When the sheet materials 1, 2 (inner membrane 1, outer membrane 2) are breathable mesh sheets (such as cloth), the ventilation portions are gaps between the threads forming the mesh (mesh gaps (or weave)) over the entire surface of the mesh sheet. The mesh sheet has many gaps (ventilation portions) formed by the mesh. Each mesh gap is formed, for example, to a size that allows air to pass through but prevents the body resin material 13 from passing through. Note that the sheet materials 1, 2 may also be breathable nonwoven sheets. In this case, the ventilation portions are gaps between entangled fibers over the entire surface of the nonwoven sheet. The nonwoven sheet has many gaps (ventilation portions) formed by the entangled fibers. Each fiber gap is formed, for example, to a size that allows air to pass through but prevents the body resin material 13 from passing through. The ventilation portion may also be one or more small holes provided in the sheet materials 1, 2. In this case, the small holes are formed to a size that allows air to pass through but does not allow the body resin material 13 to pass through, or a size that allows only a small amount of the body resin material 13 to pass through.

[0020] A sheet material with ventilation (such as a breathable mesh sheet, a breathable nonwoven sheet, or a sheet with one or more small holes) is used for one or both of the inner membrane 1 and the outer membrane 2. The nonwoven sheet is a sheet of entangled fibers, such as nonwoven fabric or paper. This prevents voids (areas not filled with resin) from occurring during foaming and curing of the skeleton resin material 13.

[0021] For example, a sheet material having a ventilation portion may be used for the outer membrane 2 of the inner membrane 1 and outer membrane 2. In this case, a breathable sheet material is not used for the inner membrane 1. A sheet material without a ventilation portion (non-breathable sheet material) may be used for the inner membrane 1. Japanese Patent Laid-Open Publication No. 51-51129 describes a method for constructing a structure in which the inner membrane body is supported via spacers on an outer membrane body formed into a dome shape by pressurizing the air inside the outer membrane body to make it self-standing. In this case, recesses are formed on the inner surface of the frame at the positions of each spacer. In contrast, in this example of the present embodiment, a sheet material having a ventilation portion is used for the outer membrane 2, allowing air in the frame space 6 to escape to the outside and suppressing voids, while a sheet material without a ventilation portion is used for the inner membrane 1. Therefore, it is easy to maintain the inner membrane 1 in a constant shape by pressurizing the inner membrane 1 from the inner space 5. Furthermore, since the inner membrane 1 is supported by the pressure of the inner space 5, the above-mentioned spacer is not necessary, and it is possible to form a body 12 with a smooth inner surface overall.

[0022] [2. Building Construction Method] Next, this construction method will be explained. This construction method involves performing the following steps in this order: foundation construction, formwork installation, resin injection, and foam hardening. The resin injection and foam hardening steps constitute the framework formation step.

[0023] The foundation construction step is a step of constructing a foundation 15 based on the planar shape of the skeleton 12 to be constructed. The material of the foundation 15 can be, for example, concrete or reinforced concrete. As shown in FIG. 3 , the foundation 15 is constructed so that at least the lower part of the foundation 15 is buried in the ground. Although the upper surface of the foundation 15 is located above the ground in FIG. 3 , it may be located below the ground. The foundation 15 has a wall-like portion that follows the outer periphery of the skeleton 12 to be constructed in a plan view.

[0024] It should be noted that foamed resin may be used as the material for the foundation 15. In this case, a flexible formwork (not shown) can be used, similar to the formwork 10. This formwork has a flexible sheet material and is provided with a space for a body, which is defined by the sheet material and expands to form a shape corresponding to the shape of the foundation 15 to be constructed.

[0025] A connecting member 16 is integrated with the foundation 15 as a member for connecting the foundation 15 and the skeleton 12. A portion of the connecting member 16 is embedded in the foundation 15, and the remainder is exposed from the foundation 15. The exposed portion of the connecting member 16 is disposed in the space occupied by the lower part of the skeleton 12. In FIG. 3 , the connecting member 16 protrudes from the upper surface of the foundation 15.

[0026] Furthermore, pillars (pillar members) 17 are integrated into the foundation 15 as members for supporting the formwork 10 from below. The lower ends of the pillars 17 are embedded in the foundation 15, and the remainder protrudes upward from the foundation 15. In Fig. 3, the upper ends of the pillars 17 are provided so as to support the top of the formwork 10. Note that the pillars 17 may be omitted.

[0027] The formwork installation step is a step of installing the formwork 10 in accordance with the foundation 15. In the formwork installation step of this embodiment, after the formwork 10 is temporarily installed, the inner membrane 1 of the formwork 10 is erected by filling the gas filling space 5 with gas. "Erection" means that all or part of the formwork 10 is shaped to correspond to the shape of the skeleton 12.

[0028] Temporarily installing the formwork 10 involves installing the formwork 10 while the gas-filled space 5 and the body space 6 remain in a contracted state (there is almost no air in the gas-filled space 5 and the body space 6), as shown in Figure 4. The formwork 10 is temporarily installed so that it covers the supports 17 from above. The formwork 10 is temporarily installed so that the lower end of the inner membrane 1 is located near the upper end of the inner surface of the foundation 15, and the lower end of the outer membrane 2 is located near the upper end of the outer surface of the foundation 15. The outer periphery of the bottom sheet 7 is placed on the wall-like portion of the foundation 15. The bottom sheet 7 is installed so as to block the inner space of the wall-like portion of the foundation 15.

[0029] 5, the inner membrane 1 is erected in the formwork 10 by filling the gas filling space 5 with gas through the gas inlet 3. For example, a hose extending from the outlet of an air pump (not shown) is connected to the gas inlet 3, and gas is discharged from the air pump, thereby filling the gas filling space 5 through the gas inlet 3.

[0030] The resin injection step is a step of injecting a body resin material 13 into the body space 6 through the resin injection port 4 in the formwork 10. As shown in Fig. 6, the body resin material 13 is injected into the body space 6 from a state in which almost no gas is present in the body space 6. This makes it possible to prevent voids from being formed in the body 12 of the building 11.

[0031] For example, when a plurality of different raw resins are blended to obtain a structural body resin material 13 at the construction site of the building 11, mixers 41, 42 (e.g., FIG. 7 ) are installed at the construction site of the building 11, and the outlet of the mixer 42 is connected to the resin injection port 4. Although a plurality of mixers 41, 42 are used in FIG. 7 , the number of mixers 41, 42 may be one. Then, by supplying the raw resins from a plurality of containers 43, each containing a plurality of raw resins, to the mixers 41, 42 by a pump 44, the structural body resin material 13 blended with the plurality of raw resins is supplied from the resin injection port 4 to the structural body space 6.

[0032] The foaming and curing step is a step of foaming the body resin material 13 in the body space 6 to expand the body space 6, and then curing the foamed body resin material 13 in the body space 6 while the body space 6 is in an expanded state, thereby forming the body 12 of the building 11 made of foamed resin. In the foaming and curing step, the body resin material 13 foams, causing the body space 6 to expand, as shown in Fig. 8, and the outer membrane 2 is erected, forming a dome shape. The body resin material 13 then gradually hardens, and after a predetermined time has passed, the body 12 of the building 11 is completed.

[0033] After the skeleton 12 is completed, a finishing step is performed. In the finishing step, the inner membrane 1 and the outer membrane 2 are removed, and then exterior work, interior work, floor installation work, window installation work, and the like may be performed.

[0034] In the exterior construction work, an outermost layer 18 is provided by plastering or the like to cover the outer surface of the skeleton 12. In the interior construction work, an innermost layer 19 is provided by plastering or the like to cover the inner surface of the skeleton 12. In the floor installation work, floorboards 20 are provided so as to be supported by the foundation 15 or the like. In the window installation work, window glass 21 is provided at the location of the opening 9 where the injection port 3 is provided. Figure 9 shows the state after these construction works have been completed. In Figure 9, braces 22 are provided to reinforce the building 11.

[0035] In this embodiment, the opening 9 is provided in the formwork 10 in order to provide the opening 9 in the skeleton 12 for installing the door 23 or window 21. In this case, a plastic or metal frame material (a frame material for the door 23 or window 21) may be attached in advance to the skeleton space 6 of the formwork 10 so as to surround the opening 9. Note that the opening 9 may be provided by cutting the skeleton 12 after the skeleton resin material 13 has foamed and hardened.

[0036] In addition, in order to increase the strength of the completed building 11, in addition to the supports 17, reinforcing members such as beams may be attached in advance to match the formwork 10 during the formwork installation step, or the foam may be processed and installed after foaming.

[0037] [3. Materials, etc.] <3-1. Formwork Materials> The materials for the sheet materials 1, 2, and 7 in the formwork 10 can be one or more of the following: organic films made of polyvinyl chloride, polystyrene resins including polystyrene, polyolefins such as polypropylene and polyethylene, polyesters such as polyacetal, polyethylene terephthalate, and polybutylene terephthalate, thermoplastic resins such as (meth)acrylic resin, AS resin, and ABS resin, metal films made of aluminum, and cloths made of organic fibers (natural fibers, synthetic fibers, carbon fibers, etc.), inorganic fibers, or metal fibers. Furthermore, the materials for the sheet materials 1, 2, and 7 can also be cloths or sheets other than cloths not listed in this paragraph.

[0038] The sheet materials 1, 2, and 7 may be composed of one or more of an organic film having a tensile modulus of elasticity of 50 GPa or less, a metal film having a tensile modulus of elasticity of 150 GPa or less, or a cloth. The tensile modulus of the organic film is not limited as long as it does not impair the effects of this embodiment, and can be, for example, 50 GPa or less, preferably 30 GPa or less, and more preferably 20 GPa or less. The tensile modulus of the metal film is not limited as long as it does not impair the effects of this embodiment, and can be, for example, 150 GPa or less, preferably 100 GPa or less, and more preferably 80 GPa or less. The elastic modulus of the cloth is not limited as long as it does not impair the effects of this embodiment.

[0039] Furthermore, the thickness of the sheet materials 1, 2, and 7 used in the formwork 10 is not limited as long as it does not impair the effects of this embodiment, and can be, for example, 10 mm or less, preferably 8 mm or less, and more preferably 5 mm or less.

[0040] <3-2. Resin Composition> The foamed resin (foam) constituting the framework 12 of the building (e.g., structure) 11 can be made of at least one resin selected from the group consisting of urethane resins containing isocyanate, vinyl resins including urea resins, (meth)acrylic resins, and styrene resins, epoxy resins, phenolic resins, ester resins, and amide resins, or a mixture of two or more of the above resins. The foamed resin can be obtained by foaming and curing a resin composition or by evaporating a solvent that serves as a foaming agent. The resin composition (framework resin material) used as the source of the foamed resin contains a monomer compound (A), a curing agent, a catalyst, and a foaming agent, and preferably also contains a foam stabilizer and a flame retardant. In the case of vinyl resins including (meth)acrylic resins and styrene resins, a radical generator (B) that generates radicals upon exposure to heat or actinic rays is used instead of a curing agent.

[0041] Each resin is made up of one or more types of resin, and it is not a problem if multiple resin systems are mixed. In addition, by attaching functional groups of multiple resin systems to one compound, it is possible to construct a complex network system.

[0042] <3-3. Raw Materials for Resin Composition> <<3-3-1: Raw Materials for Urea and Urethane Resin Compositions>> <<<3-3-1-1: Monomer Compound (A): Polyisocyanate Compound>>> The polyisocyanate compound (A) used in the resin composition (resin material for the framework) of this embodiment is not particularly limited as long as it does not impair the effects of this embodiment. Examples of the polyisocyanate compound (A) include monomeric polyisocyanates and polymeric polyisocyanates. Monomeric polyisocyanates are compounds in which multiple isocyanate groups are present at the terminals of the monomer structure. Polymeric polyisocyanates are compounds in which multiple isocyanate groups are present at the terminals of the polymer structure. These polyisocyanate compounds (A) can be used alone or in combination.

[0043] Examples of monomeric polyisocyanates include aromatic polyisocyanates such as polymeric MDI and xylylene diisocyanate (XDI), and aliphatic polyisocyanates such as isophorone diisocyanate, as well as modified polyisocyanates and derivatives thereof. Examples of modified polyisocyanates and derivatives thereof include isocyanurate compounds of diisocyanate compounds, adduct compounds of diisocyanate compounds, biuret compounds of diisocyanate compounds, allophanate compounds of diisocyanate compounds, and carbodiimide-modified polyisocyanate compounds. These polyisocyanate compounds can be used alone or in combination.

[0044] The polymeric polyisocyanate compound includes a prepolymer obtained by reacting an active hydrogen compound having two or more active hydrogen groups, such as a polyol compound or a polyamine compound, with an excess amount of a polyisocyanate compound.

[0045] The NCO % of the polyisocyanate compound (A) is not limited as long as it does not impair the effects of the present embodiment, and can be, for example, 5 to 40%, preferably 10 to 35%, and more preferably 15 to 35%. When the NCO % of the polyisocyanate compound (A) is large, a foam having low thermal conductivity and capable of suppressing deterioration over time in a humid and hot environment can be obtained.

[0046] <<<3-3-1-2: Curing agents and catalysts: polyols, polyamine compounds, trimerization catalysts (B)>>> Polyol compounds form urethane bonds when they react with isocyanates. Polyamine compounds form urea bonds when they react with isocyanates. Trimerization catalysts form isocyanuric rings when they react with isocyanates.

[0047] The polyol compound is not particularly limited as long as it does not impair the effects of this embodiment. Examples of the polyol compound (B) include polyester polyols and polyether polyols. Examples of polyester polyols include those obtained by the condensation reaction of polyhydric alcohols and polycarboxylic acids. Examples of polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, butylene glycol, glycerin, and trimethylolpropane. Examples of polycarboxylic acids include glutaric acid, adipic acid, maleic acid, phthalic acid, terephthalic acid, and isophthalic acid. These compounds can be used alone or in combination. Examples of polyester polyols include those obtained by ring-opening condensation of caprolactone, methylvalerolactone, and the like.

[0048] Examples of polyether polyols include those obtained by addition polymerization of an oxide such as ethylene oxide with a polyhydric alcohol such as ethylene glycol glycerin. These may be used alone or in combination.

[0049] The polyamine compound is not particularly limited as long as it does not impair the effects of this embodiment. Examples of the polyamine compound (B) include aliphatic polyamines such as triethylenetetramine, aromatic polyamines such as metaphenylenediamine, and alicyclic polyamines such as isophoronediamine. Examples of commercially available products include Elastomer 250P and Elastomer 1000P manufactured by Kumiai Chemical Industry Co., Ltd., and Ethacure 420 manufactured by Albemarle. These compounds can be used alone or in combination.

[0050] Examples of trimerization catalysts include metal oxides such as lithium oxide, sodium oxide, and potassium oxide; alkoxides such as sodium methoxy; organometallic salts of potassium acetate and potassium octoate; tertiary amines such as 2,4,6-tris(dimethylaminomethyl)phenol and N,N',N"-tris(dimethylaminopropyl)hexahydrotriazine; ethyleneimine derivatives; chelates of alkali metals, aluminum, and the like; quaternary ammonium salts; diazabicycloundecene (DBU); and the like. These can be used alone or in combination. Of these, it is more preferable to use tertiary amines, organometallic salts, and diazabicycloundecene, and it is even more preferable to use tertiary amines and diazabicycloundecene. A foam with excellent adhesiveness during application can be obtained.

[0051] <<3-3-2: Blowing Agent>> The blowing agent according to this embodiment is not particularly limited as long as the effects of this embodiment are not impaired. Examples of blowing agents include water, hydrocarbons (preferably C4 to C6), hydrofluoroolefins, carbon dioxide gas, and nitrogen gas. Specific examples include carbon dioxide gas generated by the reaction of isocyanate with water, cyclopentane, HFO (1336mzz), HFO (1233zd), carbon dioxide gas, and 2-methylpropene. These can be used alone or in combination.

[0052] <<3-3-3: Foam stabilizer>> The foam stabilizer according to this embodiment is not particularly limited as long as it does not impair the effects of this embodiment. Examples of foam stabilizers include polymers, silicone compounds, and nonionic surfactants. These can be used alone or in combination.

[0053] <<3-3-4: Flame retardant>> The resin composition (resin material for the frame) according to this embodiment may contain a flame retardant. The flame retardant is not particularly limited as long as it does not impair the effects of this embodiment, and examples thereof include red phosphorus, phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides. These may be used alone or in combination. When the urea resin composition according to this embodiment contains a flame retardant, a polyurea foam can be obtained that has excellent flame retardancy and shape retention during combustion, can suppress deterioration over time in a humid and hot environment, and has excellent adhesion to an adherend during coating. Furthermore, other flame retardants besides these flame retardants may be contained.

[0054] <<3-3-5: Other Additives>> In addition to the additives described above, other additives may be added to the resin composition (resin material for the body) according to this embodiment, as long as the effects of this embodiment are not impaired. Examples of other additives that can be added include foaming catalysts, balancing catalysts, antioxidants, ultraviolet absorbers, antibacterial agents, insect repellents, termite repellents, powders, and other known additives.

[0055] <3-4. Characteristics of foam> <<3-4-1: Density>> The density of the foam is not particularly limited as long as it does not impair the effects of this embodiment, but is preferably 10 to 500 kg / m ３ and 20 to 400 kg / m ３ is preferred, and 25 to 300 kg / m ３ More preferably, 30 to 200 kg / m ３ When the density of the foam is within this range, it is possible to obtain a foam that provides sufficient workability in building the framework 12 and sufficient strength for the framework 12. The density of the foam is measured in accordance with JIS K7222:2005 "Foamed plastics and rubber - Determination of apparent density."

[0056] <<3-4-2: Expansion Ratio>> The expansion ratio is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. The expansion ratio is calculated using the following formula 1. [Formula 1] Expansion ratio = density before expansion / apparent density of foam

[0057] <<3-4-3: Compressive Modulus>> The compressive modulus of the polyurea foam can be, for example, 1 MPa or more, preferably 2 MPa or more, more preferably 3 MPa or more, and even more preferably 4 MPa or more. When the compressive modulus is within this range, a polyurea foam having the effects of this embodiment can be obtained. The compressive modulus is measured by the method described in JIS K7220:2006, "Rigid foam plastics - Determination of compression characteristics."

[0058] <3-5. Method for Manufacturing Foam> The resin composition (resin material for the framework) of this embodiment is formed by blending multiple mixed liquids each having different components. The resin material for the framework is prepared by pre-mixing the monomer compound (A), the curing agent and catalyst, the radical generator (B), the blowing agent, the foam stabilizer, red phosphorus, other flame retardants, and other additives. A known method can be used to mix the resin composition. Specifically, the resin compositions shown below were mixed by an appropriate method.

[0059] Furthermore, the viscosity of each mixed liquid is not limited as long as it does not impair the effects of this embodiment, and is, for example, preferably 50,000 mPa·sec or less, more preferably 40,000 mPa·sec or less, even more preferably 30,000 mPa·sec or less, and even more preferably 20,000 mPa·sec or less.

[0060] <<3-5-1: Foam Production Using Urea and Urethane Resin Compositions>> Raw materials other than the isocyanate compound (A) are mixed in a mixer (e.g., a mixer equipped with a propeller-type mixing blade) to prepare a polyol and polyamine mixture. Subsequently, the isocyanate compound (A) and the polyol and polyamine mixture are each cooled to a predetermined temperature (e.g., 10°C). The isocyanate (A) and the polyol and polyamine mixture are then mixed in a mixer (e.g., by stirring at 2000 rpm for 5 seconds using the mixer), foamed, and cured to obtain a polyurethane and urea foam. When used in the construction method (construction method) of this embodiment, a mixed liquid (I) containing the isocyanate compound (A) as the main component and a mixed liquid (II) containing the other raw materials are heated (10°C to 80°C) and supplied by a pump or the like, mixed in mixers 41, 42, etc., and filled into a formwork 10 to obtain a foam. For example, it can be handled as a two-component system liquid of a polyol / polyamine mixed liquid in which raw materials other than polyisocyanate have been mixed in advance, and the polyisocyanate compound (A). Note that a flame retardant, a foam stabilizer, a blowing agent, a dispersant, and other additives that do not react with the polyisocyanate compound (A) can also be mixed with the polyisocyanate compound (A) and handled as a system liquid. Furthermore, three or more components may be used depending on the compatibility of the respective compounds.

[0061] 4. Effects of the Present Embodiment In the present embodiment, a building 11 is constructed using a formwork 10 having flexible sheet materials 1, 2, and 7. The formwork 10 has a skeleton space 6, which is a space partitioned by the sheet materials 1, 2, and 7. When the space is expanded, the skeleton space 6 assumes a shape corresponding to the shape of the skeleton 12 of the building 11 to be constructed. The skeleton space 6 is provided between the inner membrane 1 and the outer membrane 2. During the formwork installation step, the inner space 5 of the inner membrane 1 is filled with gas, thereby erecting the inner membrane 1 of the formwork 10. With the inner membrane 1 erected, the skeleton formation step is performed. In the skeleton formation step, a resin composition 13 containing a foaming agent is foamed in the skeleton space 6 to expand the skeleton space 6, and the resin composition 13 foamed in the skeleton space 6 is cured to form the skeleton 12 of the building 11 made of foamed resin. Therefore, there is no need to spend time preparing a mold, as in the past. Furthermore, the building 11 made of foamed resin is formed on-site, eliminating the need for transportation. Furthermore, the formwork 10 can be easily transported because the flexible sheet materials 1, 2, and 7 can be folded. This embodiment facilitates the construction of buildings that use resin compositions as the framework material.

[0062] In this embodiment, since the support columns 17 are provided to support the inner membrane 1 from the indoor side, deformation of the inner membrane 1 due to the weight of the resin composition 13 is suppressed, and the change in the volume of the body space 6 before and after foaming is also suppressed. In this embodiment, the support columns 17 are provided before the formwork installation step, but the support columns 17 may be provided after the formwork installation step. In this case, a relatively large opening (for example, an opening for providing the door in FIG. 1 ) is provided in the formwork 10, and the support columns 17 are carried into the gas-filled space 5 through this opening after the formwork installation step, and the support columns 17 are installed.

[0063] In this embodiment, in the body formation step, foaming of the body resin material 13 is started from a state in which the body space 6 is contracted, thereby expanding the body space 6. According to this embodiment, the amount of gas in the body space 6 is small at the timing when foaming of the body resin material 13 is started, and therefore, the generation of voids when the body resin material 13 is foamed and hardened is suppressed.

[0064] 5. First Modification of the Embodiment In this modification, an intermediate membrane 50 is provided between the inner membrane 1 and the outer membrane 2. As shown in Figs. 10 and 11 , the intermediate membrane 50 is provided close to the surface of the inner membrane 1 on the outdoor side. The intermediate membrane 50 is superimposed on the inner membrane 1. In this case, the space for the body 6 is provided between the intermediate membrane 50 and the outer membrane 2 in the space between the inner membrane 1 and the outer membrane 2. The intermediate membrane 50 defines the space for the body 6 from the indoor side, and the inner membrane 1 supports the intermediate membrane 50 from the indoor side.

[0065] In the form setting step, similar to the above-described embodiment, after the form 10 is temporarily set up, the inner membrane 1 of the form 10 is erected by filling the gas filling space 5 with gas through the gas inlet 3. Fig. 10 shows the state after the inner membrane 1 has been erected. Then, with the inner membrane 1 erected, the skeleton formation step is carried out.

[0066] As in the above-described embodiment, the skeleton formation step involves a resin injection step in which skeleton resin material 13 is injected into skeleton space 6 through resin injection port 4, and a foaming and curing step in which skeleton resin material 13 is foamed in skeleton space 6 to expand skeleton space 6, and then, while skeleton space 6 is in an expanded state, the foamed skeleton resin material 13 is cured in skeleton space 6. During the foaming and curing step, skeleton resin material 13 hardens to form skeleton 12 of building 11 made of foamed resin. Figure 11 shows the state immediately after the foaming and curing step.

[0067] If the intermediate film 50 is not provided, the material, etc. of the inner film 1 that separates the body 12 from the indoor side must be determined taking into consideration conditions such as the need to prevent air from leaking when the inner space 5 is inflated. In contrast, in this modified example in which the intermediate film 50 is provided, the material, etc. of the intermediate film 50 that separates the body 12 from the indoor side does not need to be determined taking into consideration the above conditions, etc., because the inner film 1 is provided. This modified example increases the freedom of selection of the sheet material that separates the body 12 from the indoor side.

[0068] In this modification, the intermediate film 50 may be made of a sheet material that is different from the inner film 1 but is made of the same material as the outer film 2. For example, the outer film 2 and the intermediate film 50 may be made of a breathable sheet material (e.g., a mesh sheet) with high tensile strength. In this case, the outer film 2 and the intermediate film 50 may be left in place without being removed when performing the finishing step. That is, the outer film 2 may be embedded inside the outermost layer 18, and the intermediate film 50 may be embedded inside the innermost layer 19 (not shown). This increases the surface strength of the outer and inner walls of the skeleton 12. In this case, the inner film 1 (e.g., a non-breathable sheet material) may be removed after the foaming and curing step and before the finishing step, or may be left in place together with the intermediate film 50.

[0069] As shown in Figure 12, the intermediate film 50 may be provided adjacent to the indoor surface of the outer film 2. The intermediate film 50 is superimposed on the outer film 2. In this case, the space for the main body 6 is provided between the inner film 1 and the intermediate film 50. The intermediate film 50 defines the space for the main body 6 from the outside of the room, and the outer film 2 supports the intermediate film 50 from the outside of the room. In this case, the sheet material that defines the main body 12 from the outside of the room is not limited to a sheet material suitable for the outer film 2, and there is greater freedom in selecting the sheet material that defines the main body 12 from the outside of the room.

[0070] The number of intermediate films 50 is not limited to one, but may be two or more. For example, a first intermediate film 50 adjacent to the surface of the inner film 1 facing the outdoor side and a second intermediate film 50 adjacent to the surface of the outer film 2 facing the indoor side may be provided at the same time.

[0071] 6. Second Modification of the Embodiment In this modification, the inner membrane 1 and the outer membrane 2 are separate bodies.

[0072] In the formwork installation step in this modified example, the following construction procedures can be adopted, for example. However, the formwork installation step is not limited to these construction procedures. Construction Procedure 1: Temporarily installing the inner membrane 1, erecting the inner membrane 1, installing the outer membrane 2 Construction Procedure 2: Temporarily installing the inner membrane 1, installing the outer membrane 2, erecting the inner membrane 1 Construction Procedure 3: Temporarily installing the outer membrane 2, erecting the outer membrane 2, temporary installing the inner membrane 1, erecting the inner membrane 1 Note that "temporarily installing" the inner membrane 1 refers to installing the inner membrane 1 in a deflated state without inflating it. Installing the outer membrane 2 in a deflated state is called "temporarily installing" only when erecting the outer membrane 2 (construction procedure 3).

[0073] In the case of execution procedure 1, the inner membrane 1 is temporarily installed at the planned installation location of the main body 12 with the gas-filled space 5 in a shrunk state. The inner membrane 1 is fixed to the foundation 15. Then, the inner membrane 1 is erected by filling the gas-filled space 5 with gas. Figure 13 shows the state after the inner membrane 1 has been erected. Then, with the inner membrane 1 erected, the outer membrane 2 is installed so as to cover the inner membrane 1. The outer membrane 2 is fixed to the foundation 15. Figure 14 shows the state after the outer membrane 2 has been installed so as to cover the inner membrane 1. In this state, the gas-filled space 5 is inflated, but the main body space 6 is in a shrunk state (there is almost no air in the main body space 6).

[0074] In the case of execution procedure 2, the inner membrane 1 is temporarily installed at the planned installation location of the structure 12 with the gas-filled space 5 in a deflated state, and the outer membrane 2 is installed so as to cover the inner membrane 1 in a deflated state from above. The inner membrane 1 and the outer membrane 2 are each fixed to the foundation 15. Then, the inner membrane 1 is erected by filling the gas-filled space 5 with gas. This state is the same as that shown in Figure 14.

[0075] In the case of execution procedure 3, the outer membrane 2 is temporarily installed in the planned installation location of the body 12 with the gas-filled space 5 in a deflated state, and the space inside the outer membrane 2 is filled with gas, causing the outer membrane 2 to expand into a dome shape and enter a built-in state. Next, the inner membrane 1 is temporarily installed in a deflated state inside the outer membrane 2. Then, the gas-filled space 5 is filled with gas, thereby erecting the inner membrane 1. In this case, if a breathable mesh sheet is used for the outer membrane 2, air in the body space 6 will escape through the ventilation part of the outer membrane 2.

[0076] In either construction procedure, after the formwork installation step, a resin injection step is performed in which the skeleton resin material 13 is injected into the skeleton space 6 through the resin injection port 4. Next, a foaming and curing step is performed in which the skeleton resin material 13 is foamed in the skeleton space 6 to expand the skeleton space 6, and with the skeleton space 6 in an expanded state, the foamed skeleton resin material 13 in the skeleton space 6 is cured. This completes the skeleton 12 of the building 11.

[0077] In construction procedure 1, after erection of the inner membrane 1 and before installation of the outer membrane 2, construction work for electricity, water, etc. (installation work for piping, etc.) is carried out in the space occupied by the skeleton 12 without the outer membrane 2. In construction procedure 3, after erection of the outer membrane 2 and before temporary installation of the inner membrane 1, construction work for electricity, water, etc. is carried out in the space occupied by the skeleton 12 without the inner membrane 1. This makes it easier to carry out this construction work.

[0078] An intermediate film 50 may be provided as in the first modified example described above. In this case, the outer film 2 is made to be separate from the inner film 1 and the intermediate film 50. The inner film 1 and the intermediate film 50 may be integral or separate.

[0079] 15, in the formwork 10 of the above-described embodiment, a gas outlet 14 is provided in addition to the gas inlet 3. In this case, when the inner membrane 1 of the formwork 10 is erected, the gas-filled space 5 does not become an airtight space, and gas is continuously sent from the gas inlet 3 to the gas-filled space 5 to cause the inner membrane 1 to expand, and in this state, gas overflowing from the gas-filled space 5 is discharged from the gas outlet 14. Then, in this state, the skeleton formation step is carried out.

[0080] Here, when only the gas inlet 3 out of the gas inlet 3 and the gas outlet 14 is provided in the formwork 10, the gas inlet 3 is closed to stop the supply of gas to the inner space 5, for example, in order to maintain the pressure in the inner space 5 after the inner membrane 1 is erected. However, when constructing a structure large enough to have a living space, for example, it takes time for the resin composition 13 to foam and harden, and there is a risk that gas will escape through gaps or a small amount of gas will permeate through the inner membrane 1, causing a decrease in the pressure in the inner space 5. In this case, it is difficult to stabilize the shape of the skeleton 12 that is finally constructed.

[0081] In contrast, in this modified example, while the inner membrane 1 is erected, gas is continuously fed from the gas inlet 3 into the inner space 5 of the inner membrane 1 to inflate the inner membrane 1, and in this state, gas overflowing from the inner space 5 is discharged from the gas outlet 14, making it easy to maintain the pressure in the inner space 5 in the skeleton formation step after the inner membrane 1 is erected. Therefore, according to this modified example, the shape of the skeleton 12 that is finally constructed can be stabilized.

[0082] [8. Fourth Modification of the Embodiment] In this modification, at least one of the inner membrane 1 and the outer membrane 2 comprises upper formworks 1a, 2a using a flexible sheet material, and lower formworks 1b, 2b using a sheet material or plate material (hereinafter referred to as "hard material") harder than the upper formworks 1a, 2a. In this modification, the inner membrane 1 and the outer membrane 2 each comprise upper formworks 1a, 2a and lower formworks 1b, 2b, as shown in Figures 16 to 18. The lower formwork 1b of the inner membrane 1 and the lower formwork 2b of the outer membrane 2 are each fixed to a foundation 15.

[0083] Of the inner membrane 1 and the outer membrane 2, only the outer membrane 2 may be provided with lower formwork 1b, 2b made of a hard material. Also, of the inner membrane 1 and the outer membrane 2, only the inner membrane 1 may be provided with lower formwork 1b, 2b made of a hard material.

[0084] The lower formworks 1b, 2b can be made of wooden or metal plate materials. The lower formworks 1b, 2b can also be made of bent plywood (such as bent plywood) that can be bent in one direction. The latter type of material can be transported in a rolled-up state, making transportation easier. The flexible sheet materials 1, 2, 7 mentioned above are materials that can be flexibly bent in both the vertical and horizontal directions, and do not include bent plywood that can be bent in one direction. The flexible sheet materials 1, 2, 7 can be folded with a curvature radius of 50 mm or less at the folding point.

[0085] In this modified example, the formwork 10 includes a hemispherical portion 10a formed by upper formworks 1a and 2a and a cylindrical portion 10b formed by lower formworks 1b and 2b (see FIG. 18 ). The upper formworks 1a and 2a separate the upper space of the body space 6 at a height H. The lower formworks 1b and 2b separate the lower space of the body space 6 at the height H. The lower side of the formwork 10 is prone to swelling due to the pressure of the body resin material 13 during the body formation step. The outer membrane 2 is particularly prone to swelling compared to the inner membrane 1, which is subjected to the pressure of the inner space 5 (pressure higher than atmospheric pressure). Therefore, the larger the height dimension of the formwork 10, the greater the risk of swelling of the lower portion of the body 12. In particular, the outer surface of the lower portion of the housing 12 is likely to swell.

[0086] In contrast, in this modified example, a hard material is used for the lower formworks 1b, 2b, which improves the shape and dimensional stability of the lower part of the skeleton 12. When a hard material is used for the lower formworks 1b, 2b of the inner membrane 1 and the outer membrane 2, the lower formwork 1b of the inner membrane 1 and the lower formwork 2b of the outer membrane 2 may be connected and fixed to each other via a connecting member 8 made of a hard sheet material or plate material. This eliminates the need to measure the distance between the inner membrane 1 and the outer membrane 2 while temporarily setting them up at the construction site, making it easier to temporarily set up the formwork 10.

[0087] When erecting the formwork 10 in this modified example, for example, an upper formwork 1a and a lower formwork 1b for the inner membrane 1 and a lower formwork 2b for the outer membrane 2 are temporarily installed as shown in Figure 16. Then, by filling the gas filling space 5 with gas, the inner membrane 1 of the formwork 10 is erected, and then the upper formwork 2a is attached to the lower formwork 2b for the outer membrane 2 as shown in Figure 17. Note that the upper formwork 2a may be attached to the lower formwork 2b for the outer membrane 2 before the inner membrane 1 is erected.

[0088] [9. Other Modifications] In the above-described embodiment, the resin injection port 4 is provided on the bottom side of the formwork 10, but as shown in Fig. 19, the resin injection port 4 may be provided on the ceiling side. In the skeleton formation step, the skeleton resin material 13 is injected into the skeleton space 6 from the resin injection port 4 provided on the ceiling side of the living space. In this case, the skeleton resin material 13 flows down due to gravity, and can be easily distributed over a wide area in the skeleton space 6.

[0089] In the above-described embodiment, the inner membrane 1 and the outer membrane 2 are removed during the finishing step, but the finishing step may be performed with the inner membrane 1 and the outer membrane 2 remaining.

[0090] In the above-described embodiment, the body resin material 13 is injected into the body space 6 when there is almost no gas present in the body space 6. However, if gas is present in the body space 6 at the start of the resin injection step, the gas may be sucked out of the body space 6 by a pump before the body resin material 13 is injected into the body space 6.

[0091] In the above-described embodiment, the building 11 may have a shape other than a dome shape (for example, an arch shape). When the building 11 has flat wall surfaces, such as an arch shape, a hard material can be used for the formwork of the wall surfaces, and a flexible sheet material can be used for the formwork of the curved surfaces. Specifically, when the building 11 has an arch shape, a hard material can be used for the formwork of the wall surfaces at both ends, and a flexible sheet material can be used for the formwork of the roof, which is formed into a curved surface.

[0092] <Reference Embodiment> This reference embodiment is a construction method (hereinafter referred to as the "reference embodiment construction method") for constructing a fence 31 (see FIG. 25) as a building.

[0093] The formwork 31 of this reference embodiment is provided with a flexible sheet material 30, similar to the formwork 10 of the above-described embodiment. The formwork 10 is provided with a space partitioned by the sheet material 30, which is a body space 26 that, when expanded, takes on a shape corresponding to the shape of a body 32 (see FIG. 24) of a building (fence) 31 to be constructed. The body space 26 has a volume of, for example, 0.5 m when fully expanded. ３ The formwork 30 does not have the gas-filled space 5 of the formwork 10 of the above-described embodiment.

[0094] The construction method of the reference embodiment involves carrying out a foundation construction step, a formwork installation step, a resin injection step, and a foam hardening step in this order.

[0095] 20 shows the state after the foundation construction step is completed. In this embodiment, a space 36 is formed in the foundation 35. In the foundation construction step, support members 33 for supporting the formwork 30 are installed.

[0096] After the foundation construction step is completed, the formwork installation step is carried out. In the formwork installation step, formwork 30 is installed so that the body space 26 communicates with the space 36, as shown in FIG.

[0097] After the formwork installation step is completed, the resin injection step is carried out, in which a skeleton resin material 13 is injected into the skeleton space 6 through the resin injection port 4 of the formwork 30, as shown in FIG.

[0098] 23 , in the foaming and hardening step, the body resin material 13 in the body space 26 foams, causing the body space 26 (formwork 30) to expand, and when the body space 26 is fully expanded, the body space 26 assumes a shape corresponding to the shape of the body 32 of the fence 31 to be constructed. In this embodiment, the entire formwork 30 is erected while the body resin material 13 is foaming in the body space 26. During the foaming process of the body resin material 13, the support members 33 act as a frame to correct the shape of the formwork 30.

[0099] After the body space 26 has fully expanded, the body resin material 13 gradually hardens, and after a predetermined time has passed, the body 32 of the fence 31 is completed as shown in Figure 24. This marks the end of the foaming and hardening step. The support members 33 are removed once the foaming and hardening step is complete.

[0100] After the skeleton 32 is completed, a finishing step is carried out to finish the surface of the fence 31. In the finishing step, the formwork 30 is removed, and then an outermost layer 37 is provided by plastering or the like so as to cover the surface of the skeleton 32, as shown in Figure 25.

[0101] <Uses of the Present Construction Method, etc.> The present construction method or the construction method of the reference embodiment can be used as a construction method (construction method for foam materials) for buildings used for architectural purposes (walls, ceilings, roofs, floors, etc.), storage tanks for transporting oil and gas, freezers and refrigerators, plant facilities, retaining walls that function as thermal insulation, insulation, or cold resistance mitigation materials, foundation structures (structures constructed on-site) that function as underground fill reinforcement materials during ground subsidence prevention work and road construction, structures (structures constructed on-site) that function as injection repair materials for civil engineering applications such as tunnels, bridges, or floating piers, structures (structures constructed on-site) that function as structural fillers in basements, etc., and buildings used as energy absorbers, waterproofing materials, water-stopping materials, or buoyancy materials, etc. In addition, buildings may be constructed by combining the present construction method or the construction method of the reference embodiment with wooden, reinforced concrete, or resin structures (e.g., columns, etc.).

[0102] The present invention will be described with reference to examples. However, the present invention is not limited to the examples as long as the gist of the invention is not exceeded.

[0103] <<Preparation of Resin Composition (Resin Material for Body)>> <Raw Materials> Table 1 shows the resin compositions used in Examples 1 to 3.

[0104]

[0105] The following compounds are used as raw materials in Table 1: Isocyanate compound: MR-200 (manufactured by Tosoh Corporation) Polyol compound: Maximol RLK-505 (manufactured by Kawasaki Chemical Industries, Ltd.) Polyamine compound: Ethacure 420 (manufactured by Albemarle Chemical Industry Co., Ltd.) Amine catalyst: DBU (diazabicycloundecene) Silicone compound: VORASURF SZ1671 (manufactured by Dow-Toray Industries, Inc.) Nonionic surfactant: YP-1 (manufactured by Yamagata Chemical Co., Ltd.) Phosphate ester flame retardant: CR-733S (manufactured by Daihachi Chemical Industry Co., Ltd.)

[0106] The method for preparing the nonionic surfactant Polyurea YP-1 will now be described. 5 g of Stabio PDI (Mitsui Chemicals) and 5 g of Ethacure 420 (Albemarle) were mixed, heated to 60°C, and stirred for 1 hour. 32 g of Jeffamine D-2000 (Huntsman Performance Products) was added, heated to 60°C, and stirred for 1 hour. 42 g of Polyurea YP-1 was obtained. The weight-average molecular weight of Polyurea YP-1 was measured by gel permeation chromatography (standard polystyrene equivalent) to be 200,000.

[0107] <Preparation of Foam> (Preparation of Foam for Each Evaluation) The contents of the monomer compound (A), the blowing agent (Example 3 only), the foam stabilizer, and the flame retardant for each Example shown in Table 1 were weighed, heated to 30 to 80°C, and stirred for 5 to 60 minutes to dissolve the solid components in the liquid components, thereby obtaining a mixed solution (I) for each Example.

[0108] The contents of the curing agent, catalyst, and blowing agent (Examples 1 and 2 only) for each Example were weighed, heated to 20-50°C, and stirred for 5-60 minutes to obtain the mixed solution (II) for each Example.

[0109] Mixed liquid (I) was heated to 20-80°C, and each mixed liquid was pumped and mixed in a mixer. Mixed liquid (II) was mixed with mixed liquid (I) to prepare a mixed liquid. The mixed liquid was collected in a 500 mL polypropylene disposable cup. After foaming and resin curing, each foam was left at room temperature for one week to obtain each foam.

[0110] The resin composition was mixed using a pump and a mixer and then filled into the formwork using a pump. In all examples, the resin composition foamed and cured within the formwork, resulting in a structure with the designed shape. Table 2 shows the test results for each example. All structures had a compressive modulus of elasticity of 4 MPa or more, and sufficient hardness was obtained.

[0111]

[0112] The present invention is applicable to a method for constructing a building using foamed resin as a skeleton material.

[0113] DESCRIPTION OF SYMBOLS 1 Inner membrane (sheet material) 2 Outer membrane (sheet material) 3 Gas injection port 4 Resin injection port 5 Gas filling space, inner space 6 Space for skeleton 7 Sheet material 10 Formwork 11 Building, structure 12 Skeleton 13 Resin material for skeleton, resin composition containing foaming agent

Claims

1. A method for constructing a building, comprising: a formwork installation step of installing a formwork having a flexible sheet material and a structure space that, when expanded, forms a shape corresponding to the structure shape of a building to be constructed as a space partitioned by the sheet material; and a structure formation step of foaming a resin composition containing a foaming agent in the structure space, and, with the structure space expanded, curing the resin composition foamed in the structure space to form the structure of the building made of foamed resin, wherein the formwork comprises an inner membrane and an outer membrane as the sheet material, and the structure space is provided between the inner membrane and the outer membrane, and during the formwork installation step, the inner membrane of the formwork is erected by filling the space inside the inner membrane with gas, and, with the inner membrane erected, the structure formation step is carried out.

2. A method for constructing a building as described in claim 1, wherein the formwork further comprises an intermediate membrane provided between the inner membrane and the outer membrane, the intermediate membrane dividing the space for the structural body from the inside of the room and the inner membrane supporting the intermediate membrane from the inside of the room, or the intermediate membrane dividing the space for the structural body from the outside of the room and the outer membrane supporting the intermediate membrane from the outside of the room.

3. A method for constructing a building as described in claim 1, wherein in the structure formation step, foaming of the resin composition is started from a state in which the structure space is shrunk, thereby expanding the structure space.

4. The method for constructing a building according to claim 1, wherein the inner membrane does not use a breathable sheet material.

5. The method for constructing a building as described in claim 1, wherein the outer membrane is provided with a ventilation section for allowing air to escape from the space for the structure.

6. The method for constructing a building according to claim 5, wherein the sheet material is a breathable mesh sheet, and the ventilation portions are gaps between threads in the mesh sheet.

7. The method for constructing a building according to claim 5, wherein the sheet material is a breathable nonwoven sheet of intertwined fibers, and the ventilation portions are gaps between the fibers in the nonwoven sheet.

8. A method for constructing a building as described in claim 1, wherein the formwork is provided with a gas inlet and a gas outlet, and while the inner membrane is erected, gas is continuously fed from the gas inlet into the inner space of the inner membrane to cause the inner membrane to expand, and in this state, gas overflowing from the inner space is discharged from the gas outlet.

9. The method for constructing a building as described in claim 1, wherein the building has a living space, and in the structure formation step, the resin composition is injected into the structure space from a resin injection port provided in the formwork on the ceiling side of the living space.

10. The method for constructing a building as described in claim 1, wherein in the structure formation step, the gas in the structure space is sucked out by a pump, and then the resin composition is injected into the structure space from the resin injection port.

11. The method for constructing a building according to claim 1, wherein a support for supporting the inner membrane from the inside of the room is provided before or after the formwork installation step.

12. The method for constructing a building as described in claim 1, wherein at least one of the inner membrane and the outer membrane comprises an upper formwork in which the flexible sheet material is used, and a lower formwork in which a sheet material or plate material harder than the upper formwork is used.

13. A formwork used in the construction of a building, comprising a flexible sheet material, a space for a structure is provided as a space partitioned by the sheet material, which space has a shape corresponding to the shape of the structure of a building to be constructed when the space is expanded, a resin composition containing a foaming agent is foamed in the space for a structure, and while the space for a structure is in an expanded state, the resin composition foamed in the space for a structure is hardened to form the structure of the building made of foamed resin, the formwork comprises an inner membrane and an outer membrane as the sheet materials, the space for a structure is provided between the inner membrane and the outer membrane, and no breathable sheet material is used for the inner membrane.

14. A formwork used in the construction of a building, comprising a flexible sheet material, a space for a structure is provided as a space partitioned by the sheet material, the space being expanded to have a shape corresponding to the shape of the structure of a building to be constructed, a resin composition containing a foaming agent is foamed in the space for a structure, and while the space for a structure is in an expanded state, the resin composition foamed in the space for a structure is hardened to form the structure of the building made of foamed resin, the formwork comprising an inner membrane and an outer membrane as the sheet material, the space for a structure is provided between the inner membrane and the outer membrane, and the outer membrane is provided with a ventilation section for allowing air to escape from the space for a structure.

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