Temporary structure and construction method

Abstract

[Problem] To provide a temporary structure composed of a thin film body and a foamed resin layer, which uses a reduced amount of resin material, is free from fireproof sheet breakage and irregular bulges and depressions, has a regular shape, and is easy to dispose of. [Solution] A temporary structure and construction method, the temporary structure 100 being composed of a shell body that surrounds a space where people stay, wherein the shell body is made of a composite material in which a foamed resin layer is adhered to a thin film body, the thin film body 101 is a sheet that is widely used in the market, such as a flameproof sheet 10 (see Fig. 1), the foamed resin layer is composed of continuous air bubbles, the composite material is formed by adhering a foamed resin layer 60 composed of continuous air bubbles to the inner surface of the thin film body of which the inside is closed, the thin film body 101 extends along a surface forming the shell body by pressurizing the inside of the closed thin film body, the foamed resin layer 60 extends along the surface forming the shell body by the continuous foaming of the resin material, the elongation of the thin film body is balanced with the elongation of the foamed resin layer, which is made of continuous air bubbles and has a density of 4 kg / m3 to 20 kg / m3 inclusive, and the shell body has a regular shape.

Description

Temporary structures and construction methods

[0001] The present invention relates to a temporary structure and a construction method that can be provided in a short time and at low cost, and more specifically to a temporary structure and a construction method that form a regular shell using construction materials and equipment that are widely available on the market and easily available, and that can be provided to people who need emergency housing in natural disasters such as earthquakes and hurricanes, in conflict areas, etc.

[0002] More specifically, the present invention relates to a temporary structure and construction method that is widely used as temporary construction materials, etc., and is made by spraying an open-cell foamed resin material that can be used by many resin foaming contractors onto the inner surface of a membrane body that is cut from a large sheet and joined together, thereby forming a shell in which the membrane body and the foamed resin layer are integrated, and that can be shaped easily and easily disposed of.

[0003] In detail, the present invention relates to a temporary structure and construction method in which a closed membrane body is made using fireproof sheets for construction work, vinyl used in agricultural greenhouses, etc., and the membrane body is inflated using air pressure, and a foamed resin material is sprayed onto the inner surface, and a foamed resin layer consisting of open bubbles is attached to form a shell body, which has a regular shape and is easy to dispose of.

[0004] The inventor of the present invention has disclosed in Patent Document 1 a technology for easily providing a structure, in which a gas-mixed material is fixed to the inner surface of a thin film inflated with air to form a shell body. The foamed resin layer constituting the gas-mixed material body disclosed in Patent Document 1 is given internal compressive stress by the expansion of air bubbles that foam in a short period of time.

[0005] The thin film to which the foamed resin layer is attached is subjected to internal tensile stress due to being inflated and stretched, as well as internal tensile stress due to the thin film stretching as the foamed resin layer expands. A shell in which the internal compressive stress of the foamed resin layer and the internal tensile stress of the thin film are balanced will be a structure with excellent wind pressure resistance and stable shape.

[0006] Furthermore, Patent Document 2 discloses a technology for an architectural structure in which, after installation, the shell can be divided into segments, which can then be moved to another location for reconstruction. The segments made of a foamed resin layer disclosed in the technology described in Patent Document 2 are segments divided along radially arranged vertical planes passing through the center line of the shell. To make the segments themselves less likely to split, the foamed resin layer is a polyurethane foam layer with closed cells, and, as in Patent Document 1, the internal compressive stress of the foamed resin layer before being divided into segments is balanced with the internal tensile stress of the thin film.

[0007] The segments described in Patent Document 2 are also segments in which the internal compressive stress and the internal tensile stress are balanced, so the segments themselves have a regular shape, and both the segments and the architectural structure are structurally stable, both during transportation to another location and after assembly and relocation. In other words, the structural stability is achieved by fixing a foamed resin layer made of closed cells in which the internal tensile stress of the thin film and the internal compressive stress of the foamed resin layer are balanced.

[0008] In a foamed resin layer made of closed cells, the air trapped in the cells is less likely to escape, and even if it is deformed, it easily returns to its original shape, resulting in high strength. Therefore, it is suitable for constructing a one-piece structure or for constructing a one-piece structure, then dividing it into pieces, assembling the pieces, and relocating and rebuilding it in another location. However, a foamed resin layer made of closed cells has the problem of being difficult to crush because it becomes a rigid urethane foam layer with high strength, making it difficult to dispose of.

[0009] In addition, the structure described in Patent Document 1 was brought to Turkey in 2023 to be used as emergency temporary housing for the earthquake that occurred there, but it was found that there were few local contractors who could spray foam resin material to form a foam resin layer made of closed cells, making it difficult to provide many temporary structures in a short period of time, and that this was a similar issue in other developing countries. Therefore, the present inventors have made extensive efforts to research temporary structures that can be provided worldwide, quickly, and inexpensively.

[0010] In order to provide temporary structures quickly and inexpensively that can be provided not only in emergencies immediately after major earthquakes in Japan, but also to people around the world who are homeless and in need, such as refugees due to conflicts, the challenge is to provide temporary structures that use materials that are widely available on the market, in a way that can be constructed by many construction companies, and that requires minimal construction materials.

[0011] Therefore, it was decided to use a foamed resin layer made of open cells, and to use the thin film as a temporary sheet for construction work, etc. First, compared to a foamed resin layer made of closed cells, which has an expansion ratio of about 15 to 30 times, a foamed resin layer made of open cells has an expansion ratio of about 100 times, so the amount of resin material used can be reduced to about 1 / 7 to 1 / 3. In addition, since a foamed resin layer made of open cells is used as a thermal insulation material inside the walls of buildings, there are many construction companies in developing countries that can install it, making it suitable for building temporary structures.

[0012] Furthermore, as a thin film sheet, a flame-retardant sheet is widely used as a temporary sheet for construction work for soundproofing, dust protection, privacy, etc. Furthermore, vinyl sheets for agricultural greenhouses are also widely used for agricultural purposes. An issue has been to provide a construction method that can provide a temporary structure with a stable shape in a short time and at low cost using this flame-retardant sheet or vinyl sheet as a thin film.

[0013] Furthermore, since temporary structures are discarded after completing their temporary use for several years, it is also important that they be easily discarded. There is also the issue that it may be necessary to extend the period of use of temporary structures.

[0014] Japanese Patent Application No. 2023-192114

[0015] The problem that the present invention aims to solve is to provide a temporary structure and a construction method in which an easy-to-construct open-cell foamed resin material is sprayed onto the inner surface of a membrane formed from a commonly used sheet, so that the membrane and the foamed resin layer are integrated, the structure has a uniform shape, and is easily disposable.

[0016] A first aspect of the present invention is a temporary structure comprising a shell surrounding a space where people stay, the shell comprising a composite material in which a foamed resin layer is attached to a thin film, the thin film comprising either a fireproof sheet or a vinyl sheet, the foamed resin layer comprising open cells, the composite material comprising the thin film having a closed interior and the foamed resin layer comprising open cells attached to the inner surface of the thin film, the thin film stretches along the surface of the shell by pressurizing the inside of the closed thin film, and the foamed resin layer has a density of 4 kg / m 3 More than 20kg / m 3 The resin material is continuously foamed, so that it expands along the surface forming the shell, and the expansion of the thin film and the expansion of the foamed resin layer are balanced, resulting in a stable shape of the shell.

[0017] The thin film forming the shell may be either a large-area fire-retardant sheet or a vinyl sheet that is widely available on the market as temporary sheeting for construction work, etc. The fire-retardant sheet may be made of polyester or the like, and the vinyl sheet may be made of polyvinyl chloride or the like, without any particular restrictions. Specifically, in the case of fire-retardant sheets with a polyester or polypropylene base material, fire-retardant sheets coated with vinyl chloride are available on the market. In the case of fire-retardant sheets with a polyethylene base material, fire-retardant sheets with only the base material without a vinyl chloride coating are also available on the market. In addition, in the case of fire-retardant sheets with a polypropylene base material, fire-retardant mesh sheets that ensure visibility are also available.

[0018] In terms of size, the market is generally available in large-area fireproof sheets measuring 10 m wide and 10 m long, long fireproof sheets measuring 2 m wide and 50 m long, and vinyl sheets for greenhouses measuring 5 m wide and 20 m long. Both fireproof sheets and vinyl sheets are readily available in sheets with larger areas than tent fabrics and the like.

[0019] If temporary construction sheets that are widely available on the market are used, the necessary sheets can be easily obtained even in emergencies when stocks tend to be in short supply, and if thin film components are cut out from a large sheet, the work required to join the thin film can be reduced, allowing the thin film to be made quickly and inexpensively.

[0020] Temporary sheets have lower tensile strength and higher elasticity than tent fabrics, which are made of a closed-cell foam resin layer. Therefore, when pressurizing the shell of the temporary sheet with air, it is necessary to inflate it with low air pressure so as not to tear the seams of the sheet. Pressurization with low air pressure can be achieved using a construction blower, which is easy to prepare, and is suitable for use in emergencies without distorting the shell's shape, making construction easy.

[0021] Compared with closed-cell foams, open-cell foams require less foam resin material to form the same volume of resin layer, and have a density of 4 kg / m 3 From 15 kg / m 3 Not only that, but the adhesive strength is only about 1 / 20 of that of the original, and the compressive strength is also extremely low (see Table 1). In addition, the sprayed foamed resin layer, which is made of open cells, slowly hardens over a period of about 3 minutes while expanding in a direction in which the surrounding area is not constrained, while connecting the cells together. Therefore, the adhesion of the foamed resin layer made of open cells does not add large internal tensile stress to the thin film. 3 If so, the amount of resin used is smaller, which is more preferable.

[0022] Therefore, even if a foamed resin layer made of open cells is attached to the inner surface of a thin film that has been pressurized and inflated with a small air pressure, no large internal tensile stress is generated in the thin film, and the seams of the thin film are not pulled and broken.Furthermore, the foamed resin layer does not expand so as to push out part of the thin film, causing the shape of the shell to become distorted.

[0023] The foamed resin layer, consisting of open cells, is sprayed onto the inner surface of the thin film inflated with air, and due to its small adhesive strength, becomes a composite material that adheres to the inflated thin film, forming a shell shape surrounded by gently curved surfaces that forms a space for people to stay in.

[0024] The thin film has no ruptures at its seams, no irregularly bulging or sagging parts, the foamed resin layer is attached without leaving any gaps between it and the thin film, and no cracks have occurred in any part of it. In other words, the elongation of the thin film and the foamed resin layer are balanced, resulting in a temporary structure in which the shape of the shell is stable. The first invention has the effect of enabling a well-shaped temporary structure to be provided quickly and inexpensively, even in an emergency, using materials and equipment commonly available on the market and with a small amount of foamed resin material.

[0025] A second aspect of the present invention is the temporary structure of the first aspect, characterized in that the thin film is made of a thin film that does not transmit ultraviolet light. The thin film that does not transmit ultraviolet light may be a flame-resistant mesh sheet without small holes to ensure visibility, or a vinyl sheet that has been treated to block ultraviolet light.

[0026] The treatment to prevent transmission of ultraviolet light may be, for example, painting the outer or inner surface of a transparent vinyl sheet in black or the like, or attaching an ultraviolet-blocking film, etc. When a small window through which the outside can be seen is provided in the shell using a transparent sheet, it is preferable to use a transparent sheet to which an ultraviolet-blocking film is attached.

[0027] According to the second invention, since the thin film does not transmit ultraviolet light, the foamed resin layer attached to the inner surface of the thin film is not easily deteriorated by ultraviolet light, even if it is a foamed resin layer that is easily deteriorated by ultraviolet light, such as a foamed resin layer made of polyurethane resin. According to the second invention, even in an emergency, materials for the temporary structure are easily obtained, construction is easy, and the foamed resin layer that forms the shell is not easily deteriorated.

[0028] A third aspect of the present invention is the temporary structure of the first aspect, characterized in that the foamed resin layer has a thermal conductivity of 0.040 or less, an adhesive strength of 5 kPa or more, a compressive strength of 5 kPa or more, and an expansion ratio in water expansion of 100. The adhesive strength and compressive strength of 5 kPa or more merely specify the minimum limits for an open-cell rigid polyurethane foam layer, and the upper limit may be 20 kPa or less.

[0029] The foamed resin material is not limited, but polyurethane resin conforming to the standard of JIS A9526A Type 3 (see Table 1) may be used. The expansion ratio of the open cells is not limited, but the foamed resin layer may be a rigid polyurethane foam layer with open cells expanded at an expansion ratio of approximately 100 times, using carbon dioxide gas generated by the reaction of water and isocyanate, known as water foaming. The foamed resin layer has a thermal conductivity of 0.040 or less, making it a temporary structure with high thermal insulation properties.

[0030] Rigid polyurethane foam conforming to JIS A9526 Type A 3, which is open-cell foam expanded 100 times, is considered low-density and non-load-bearing. Compared to Type A 2H of the same standard, which is closed-cell foam expanded 30 times, its adhesive strength is about 1 / 20 and its compressive strength is about 1 / 30 (see Table 1). It can be easily crushed by hand if desired, and is easy to dispose of.

[0031] The open cells that make up the foamed resin layer of the third invention are partially connected to adjacent cells, and expand in a direction that is not constrained by the surrounding area, releasing gas pressure from one cell to the next, and solidify slowly over a period of about three minutes. As a result, internal compressive stress is dispersed during the solidification process, making it difficult for internal tensile stress to be added to the thin film to which the open cells are attached.

[0032] According to the third invention, the compressive strength is such that it will partially dent when an object is placed against it unless an attempt is made to crush it intentionally, which not only means that it can be used without any problems as a temporary structure in an emergency, but also has the effect of being easily crushed and discarded if desired.

[0033] The fourth invention of the present invention is characterized in that, in the temporary structures of the first to third inventions, the outer surface of the flame-retardant sheet or vinyl sheet forming the thin film attached to the foamed resin layer is painted with weather-resistant paint.

[0034] Fireproof sheets currently available on the market are temporary construction materials that are said to last for several years, and vinyl sheets allow sunlight to pass through, which can easily cause deterioration of the attached foamed resin layer. Weather-resistant paint can be applied to the outer surface of the thin film when extending its use as a temporary structure. According to the fourth invention, because the outer surface of the shell is protected by weather-resistant paint, it is possible to achieve the effect of continuing use for the required service life, even if materials with low weather resistance are used.

[0035] A fifth aspect of the present invention is a method for constructing a temporary structure comprising a shell that surrounds a space where people stay, wherein the shell is made of a composite material having a foamed resin layer attached to a thin film, the thin film being either a fire-retardant sheet or a vinyl sheet, the foamed resin layer being open-celled, the elongation of the thin film along the surface that forms the shell and the elongation of the foamed resin layer along the surface that forms the shell being balanced, and the shape of the shell is stable, the method comprising the steps of: a first step of pressurizing the inside of the closed thin film at an air pressure that is 5 hPa to 25 hPa higher than the outside air pressure to inflate it; a second step of spraying the open-cell foamed resin material onto the inner surface of the thin film in vertical stripes, leaving gaps between them; and a third step of spraying the open-cell foamed resin material in vertical stripes so as to eliminate the gaps in the thin film.

[0036] Unlike closed-cell foams, which complete foaming and harden in a few seconds, open-cell foams require about three minutes to harden while foaming. Therefore, if an upper open-cell foamed resin layer is sprayed in layers on top of an open-cell foamed resin layer in a lower layer that has not yet completed foaming and hardened, the lower foamed resin material, which has foamed later, may pile up the open-cell foamed resin in the upper layer, which is still in the foaming process, resulting in an uneven layer thickness.

[0037] According to the fifth invention, compared to the case of tent fabric onto which closed bubbles are sprayed, in the first step, the inside of the closed thin film such as a flame-retardant sheet is pressurized at an air pressure 5 to 25 hPa higher, which is approximately half the additional air pressure relative to the outside, so that the flame-retardant sheet forming the thin film does not tear at the seams and expands to the shape of the designed shell.

[0038] In the second step, a foamed resin material with open cells is sprayed onto the inner surface of the expanded thin film in vertical stripes with gaps, like a watermelon pattern. The vertical spraying can be done by spraying from bottom to top, or conversely, by spraying from top to bottom. While the open cells are being sprayed in stripes with gaps, the previously sprayed open cells complete their foaming and solidification. This prevents the foamed resin layer from being sprayed on top of an unsolidified layer, making it less likely that the thickness of the foamed resin layer will be uneven.

[0039] In the third step, the entire inner surface of the thin film is covered with open cells so that vertical streaky gaps are eliminated. Since the open cells sprayed in the second step have already been foamed and solidified, the open cells sprayed in the third step should be sprayed so that the surface of the open-cell foamed resin layer is aligned with the gaps sprayed in the second step.

[0040] In order to prevent the resin liquid material from sliding and dripping down on the thin film, which causes uneven adhesion of the resin liquid material to the thin film, the first layer of open bubbles is sprayed in stripes in the second and third steps to prevent unevenness in the thickness of the foamed resin layer. However, from the second layer onwards, the lower foamed resin layer made of open bubbles onto which the foamed resin liquid is sprayed has already solidified, so the sprayed foamed resin liquid blends in with the lower layer and is less likely to drip, and so it is not necessarily necessary to repeat the second and third steps.

[0041] According to the fifth invention, the air pressure applied inside the thin film is small, the internal tensile stress generated in the thin film is small, and the expansion of the foamed resin layer makes it difficult for the fireproof sheet, etc. to break, and the shell does not become distorted in shape, and the inner surface of the foamed resin layer of the shell that forms the temporary structure also has a regular shape.

[0042] The first aspect of the present invention provides an unprecedented advantageous effect of providing a well-formed temporary structure quickly and inexpensively, even in an emergency, using commonly available materials and equipment and a small amount of foamed resin material. The second aspect of the present invention provides the advantages of easy acquisition of materials for temporary structures, easy construction, and the foamed resin layer forming the shell being resistant to deterioration, even in an emergency. The third aspect of the present invention provides the advantages of a shell with a compressive strength that is such that it will partially dent when hit with an object unless intentionally crushed, allowing it to be used without hindrance as a temporary structure in an emergency, and also allowing it to be easily crushed and discarded if desired. The fourth aspect of the present invention provides the advantages of protecting the outer surface of the shell with weather-resistant paint, allowing it to be used for the required service life, even if materials with low weather resistance are used. - According to the fifth invention of the present invention, the flame retardant sheet etc. is less likely to break, the shell does not become distorted in shape, and the inner surface of the foamed resin layer of the shell that forms the temporary structure also has the effect of having a regular shape.

[0043] Extraction of thin film members from a fireproof sheet (Example 1). Explanatory diagram of a temporary structure (Example 1). Explanatory diagram of a construction method (Example 1). Explanatory diagram of a construction method (Example 1). Explanatory diagram of a construction method (Example 1). Explanatory diagram of a construction method (Example 1). Explanatory diagram of a construction method (Example 1).

[0044] In this invention, a flameproof sheet that is widely available on the market is used as a thin film, and a polyurethane foam resin material is sprayed onto the thin film that is inflated by air pressure to form a foamed resin layer consisting of open cells, thereby realizing a temporary structure that can be provided in an emergency and is easy to dispose of, without breaking the thin film and without irregular bulges or depressions in the shell, even when the amount of resin material used is reduced.

[0045] In Example 1, an outdoor temporary structure 100 in which a foamed resin layer made of open cells is attached to the inner surface of a thin film made of a fireproof sheet will be described with reference to Figures 1 to 8. Figure 1 is an explanatory diagram showing the cutting out of a thin film member of a thin film 101 (see Figure 3(A)) that forms the temporary structure from a fireproof sheet 10 for temporary construction work, and Figure 2 shows the shape of the temporary structure 100. Figures 3 to 7 show the process of spraying a foamed resin layer made of open cells onto the inside of the thin film.

[0046] The thin film members that form the outer shell of the temporary structure are cut out from a 10 m square flame-retardant sheet 10. The flame-retardant sheet 10 is primarily used as a screen around scaffolding and temporary enclosures at construction sites. It also functions as a sunshade against direct sunlight and dust, and any sheet that meets the fire-retardant performance requirements of the Fire Service Act and JIS L 1091 will do.

[0047] The shape of the temporary structure 100 (see Figure 2(A)) is 1.8 m high, with a conical roof 30 rising at a 45-degree angle from the top of a wall 20 that is circular in plan view and 5 m in diameter, and one entrance / exit 22 for people to enter and exit is provided in the wall 20, with the thin film of the wall and the thin film of the entrance being opened and closed by a zipper 23. A bottom rib 24 is formed on the outer periphery of the lower outer side of the wall 20 to secure it to the ground (see Figure 2(A)).

[0048] The thin film member forming the roof portion 30 was a membrane 31 in the shape of a partially cut circle with a radius of approximately 3.5 m and a circumference of approximately 22 m, cut out from a square-shaped fire-retardant sheet 10 with sides of 10 m. The thin film member forming the wall portion was two rectangular membranes 21, each approximately 1.8 m long and 8 m wide, cut out from the same sheet. The thin film member forming the underside was a circular membrane 40 with a radius of 2.5 m cut out from another square-shaped fire-retardant sheet 10 with a length of 10 m. Two rectangular membranes 21 were joined together to form the thin film member forming the wall portion 20. The joined rectangular membranes 21, 21 forming the wall portion 20 were joined to the partially cut-out circular membrane 31 forming the roof portion and the circular membrane 40 forming the underside member to form the thin film 101 forming the shell.

[0049] The membranes that make up the roof, wall, and underside members may be joined together by adhesive, stitching with thread, adhesive tape, or heat welding, and are not limited to this method. Thin membranes 101 that make up two temporary structures 100 were cut out from three square-shaped fireproof sheets 10 with sides of 10 m.

[0050] Flame retardant sheets melt at 150 to 200°C, continue to burn if there is a fire source, but stop burning when the fire source is removed, and flame retardant sheets that are strong enough to stop falling objects on their own are classified as Class 1, while flame retardant sheets that are not strong enough to stop falling objects on their own are classified as Class 2. In this invention, a Class 1 flame retardant sheet was used because the perimeter was sewn together, but if the strength of the peripheral seams is increased, either Class 1 or Class 2 may be used, as only open bubbles will be attached to the inner perimeter.

[0051] There are also various types of fire-retardant sheets, such as PVC-coated fire-retardant sheets, which are sheets made of polyester or polypropylene coated with vinyl chloride dispersed with fire-retardant agents, mesh sheets with small holes that allow light to pass through, and polyethylene fire-retardant sheets, which do not contain chlorine and do not produce dioxins when burned.The foam resin material attached to the inner surface of the fire-retardant sheet is polyurethane foam, which is easily degraded by ultraviolet rays, so the polyethylene fire-retardant sheet does not allow light to pass through and is suitable for disposal by burning, but this is not limited to this.

[0052] Here, the foamed resin material forming the open-cell foamed resin layer may be in conformity with JIS A9256 A-type 3. Table 1 compares the compressive strength, etc., of the same standard A-type 2H, which is expanded 30 times to form closed cells, with the same standard A-type 3, which is expanded 100 times to form open cells.

[0053]

[0054] In terms of thermal conductivity, sprayed rigid polyurethane foam with open cells expanded 100 times (hereinafter referred to as the open-cell foam resin layer) and sprayed rigid polyurethane foam with closed cells expanded 30 times (hereinafter referred to as the closed-cell layer) both have low thermal conductivity and excellent insulating performance, making them suitable for temporary buildings where evacuees will stay.

[0055] In emergencies when it is difficult to obtain sufficient amounts of polyurethane resin, an open-cell foamed resin layer has an expansion ratio of 100 times, which reduces the amount of resin used to about one-third of the amount used for a closed-cell layer with an expansion ratio of 30 times. However, the minimum standard compressive strength and adhesive strength of an open-cell foamed resin layer are both lower than those of a closed-cell layer (see Table 1). The moisture permeability of an open-cell foamed resin layer, 31.7 times, is seven times that of a closed-cell layer, but is lower than that of plaster (52.1), gypsum board (39.7), and calcium silicate board (52.1), making it suitable as a material for forming the inner surfaces of temporary structures.

[0056] Conventionally, the thin film layers described in Patent Documents 1 and 2 have been suitable for tent fabrics, but because the tensile strength of fire-retardant sheets is lower than that of tent fabrics, there was a concern that if the inside of a thin film made of a fire-retardant sheet were pressurized to the same air pressure as when a conventional shell with fixed closed cells is inflated to generate tension, the seams of the fire-retardant sheet would separate.

[0057] Therefore, when the additional pressure of 40 hPa, which was used to inflate the membrane formed by the tent fabric by spraying the closed-cell layer, was reduced to half that, at 20 hPa, the fire-retardant sheeting expanded satisfactorily to form a shell with the designed three-dimensional shape. The designed three-dimensional shape was such that the roof section 30 bulged slightly upward, and slight vertical streaks 32 formed in the fire-retardant sheeting at the horizontal position of the wall top formed by the top of the wall and the bottom of the roof due to tension (see Figure 2).

[0058] In an emergency when a barometer is not available, the thin film can be inflated using a blower, and the inside of the thin film can be pressurized to the extent that vertical streaks of unevenness 32 appear at the horizontal position of the top of the wall. In many cases where the thin film was installed during the Noto Peninsula earthquake, it was confirmed that the pressure should be 5 to 25 hPa higher than the outside air pressure.

[0059] Here, a method for constructing the temporary structure 100 will be described with reference to Figures 3 to 7. Figure 3(A) shows the state in which the thin film 101 has been spread out on site, Figure 3(B) shows the state in which the thin film 101 has been inflated by air pressure using a construction fan 50, and Figure 3(C) shows the state in which the bottom ribs 24 of the thin film 101 have been fixed to the surrounding ground. In Figures 4 to 7, the figures with branch number 1 in each figure show side views of the interior of the room, and the figures with branch number 2 show cross-sectional views at the height of the top of the wall in each figure.

[0060] First, the thin film 101 forming the shell is spread out in an evacuation site, such as a school playground or plaza (see Figure 3(A)). The zipper 23 of the entrance / exit 22 is partially opened, and workers enter the thin film 101 forming the shell. An air hose from a construction fan 50 is introduced into the shell, and the interior is pressurized with air until the thin film assumes the designed three-dimensional shape (see Figure 3(B)). With the thin film 101 inflated, fixing shafts 25 such as screws are driven into the ground at a specified pitch at the positions of the bottom ribs 24 around the periphery of the thin film to secure it (see Figure 3(C)).

[0061] The foamed resin material may be a rigid foamed plastic made by spraying foam containing a polyisocyanate component and a polyol component as the main components, based on sprayed rigid polyurethane foam for thermal insulation of buildings (Japanese Industrial Standard JIS A 9526). Specifically, the foamed resin material may be selected from foamed plastic foam materials such as polyurethane foam, polyisocyanurate foam, phenol foam, and polystyrene foam, with open-cell polyurethane foam being preferred (JIS A 9256A Type 3).

[0062] First, a foamed resin material consisting of a first layer of open cells is introduced into the thin film 101 formed by the flame retardant sheet in vertical stripes from a foamed resin material container 51 using a hose to form a watermelon pattern on the inner surface of the thin film 101, leaving a gap of 70 to 80 cm, and the foamed resin material is sprayed into the thin film using a spray nozzle over a period of approximately 10 seconds, taking care not to let the foamed resin material drip (see Figure 4(D)).

[0063] The foamed resin material may be sprayed downward from above, or upward from below (see the arrows in FIG. 4(D-1)). While the foamed resin material that forms the initial foamed resin layer 60 is sprayed in stripes over the entire interior surface with gaps (see the arrows in FIG. 4(D-2)), the open-cell foamed resin material hardens.

[0064] Next, similar to the leading open-cell layer 60, a foamed resin material made of open cells was sprayed as a subsequent open-cell layer 62 into gaps 61 where the flame-retardant sheet was exposed and where the leading open-cell layer 60 had not been sprayed, so that the entire inner peripheral surface of the thin film 101 was covered with open cells (see FIG. 5(E)). The first layer should be sprayed thinly to form a layer approximately 2 cm thick after foaming, to prevent dripping of the unhardened foamed resin material that has just been sprayed onto the flame-retardant sheet.

[0065] The second leading open-cell layer 64 was sprayed in vertical stripes with a gap between the boundary 63 (see FIG. 5) between the first leading open-cell layer 60 and the trailing open-cell layer 62, to reduce the visibility of the unevenness at the boundary 63 (see FIG. 6F). The second trailing open-cell layer 65 was sprayed in the same manner as the first trailing open-cell layer, with the gap between the second leading open-cell layer as the center (see FIG. 7G). The second layer was sprayed with a consistent thickness because the sprayed foamed resin material blended well with the underlying open-cell foamed resin layer and did not sag.

[0066] Once the second open-cell foamed resin layer has been sprayed, the open-cell foamed resin layer below has already solidified and the shell shape has been fixed, so from the third layer onwards, the resin layer can be sprayed horizontally in strips along the inner circumferential surface from below. Once it has been confirmed that several layers of open-cell foamed resin have been secured to a thickness of approximately 10 cm, the spraying of the foamed resin material is complete.

[0067] As shown in Table 1, the solidified open-cell layer has a compressive strength of approximately 5 kPa, which is 1 / 30 or less of that of closed-cell foam, so it can be crushed by an adult's strong pressure, and it has been confirmed that it can be easily disposed of after its use as a temporary emergency structure has been completed. Furthermore, if both the thin film 101 and the foamed resin layer are made only from petroleum-derived raw materials, they can be easily recycled when disposed of.

[0068] Because fireproof sheets are temporary sheets, their service life is said to be 7 to 10 years. If the temporary structure is to be used for a period longer than the service life of the fireproof sheet, the outer surface of the fireproof sheet can be painted with a known weather-resistant paint such as a fluororesin paint.

[0069] (Other) While the above describes an example of a thin flame-retardant sheet, the same applies to vinyl sheeting. The shell components can be cut to fit the size of the vinyl sheet and then joined together. In Example 1, the first and second layers were sprayed in stripes with vertical spacing. However, the second layer may be sprayed horizontally as long as there are no unevenness at the boundary of the first layer. The third layer may also be sprayed with vertical spacing, and the spraying direction of the second and subsequent layers is not limited. In the above example, the application for evacuation is described, but the application is not limited thereto. For example, it may be used as a temporary structure for a local community center or a temporary relief facility. The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The technical scope of the present invention is not limited to the above description, but is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included.

[0070] 100...Temporary structure, 101...Thin film, 10...Flame retardant sheet, 20...Wall portion, 21...Rectangular membrane, 22...Entrance / exit, 23...Zipper, 24...Bottom rib, 25...Fixed shaft, 30...Roof portion, 31...Membrane in the shape of a partially cut-out circle, 32...Striation-forming unevenness, 40...Circular membrane, 50...Blower, 51...Foamed resin container, 60...Prior foamed resin layer, 61...Gap, 62...Later open-cell layer, 63...Boundary, 64...Prior open-cell layer, 65...Later open-cell layer

Claims

1. A temporary structure consisting of a shell that surrounds a space where people stay, the shell is made of a composite material in which a foamed resin layer is attached to a thin film, the thin film is made of either a fireproof sheet or a vinyl sheet, the foamed resin layer is made of open cells, the composite material is made of the thin film with the open cells attached to the inner surface of the closed thin film, the thin film stretches along the surface that forms the shell by pressurizing the inside of the closed thin film, and the foamed resin layer has a density of 4 kg / m 3 More than 20kg / m 3 a resin material that is continuously foamed and thereby expands along the surface that forms the shell, the expansion of the thin film and the expansion of the foamed resin layer are balanced, and the shape of the shell is regular.

2. A temporary structure according to claim 1, characterized in that the thin film is made of a thin film that does not transmit ultraviolet light.

3. A temporary structure as described in claim 1, characterized in that the foamed resin layer has a thermal conductivity of 0.040 or less, an adhesive strength of 5 kPa or more, a compressive strength of 5 kPa or more, and an expansion ratio of 100 times when foamed with water.

4. A temporary structure as claimed in any one of claims 1 to 3, characterized in that the outer surface of the flame-retardant sheet or vinyl sheet forming the thin film attached to the foamed resin layer is painted with weather-resistant paint.

5. A method for constructing a temporary structure consisting of a shell that surrounds a space where people will be staying, wherein the shell is made of a composite material in which a foamed resin layer is attached to a thin film, the thin film being either a fireproof sheet or a vinyl sheet, the foamed resin layer being made of open cells, the expansion of the thin film along the surface that forms the shell and the expansion of the foamed resin layer along the surface that forms the shell being balanced, and the shape of the shell is stable, comprising: a first step of pressurizing the inside of the closed thin film at an air pressure that is 5 hPa to 25 hPa higher than the outside air pressure to inflate it; a second step of spraying the open-cell foamed resin material onto the inner surface of the thin film in stripes in the vertical direction, leaving gaps between them, and a third step of spraying the open-cell foamed resin material in stripes in the vertical direction so as to eliminate the gaps between the thin film and the shell.

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