Concrete formwork and construction methods using concrete formwork

Abstract

To provide concrete formwork that enables efficient pouring of foundation concrete. [Solution] The concrete formwork 1 is a mesh-like formwork comprising a plurality of first linear members 11 extending in a first direction at predetermined intervals, and a plurality of second linear members 12 extending in a second direction intersecting the first direction at predetermined intervals, and overlapping the plurality of first linear members 11 so as to intersect with them. The second linear members 12 are connected so as to be rotatable relative to the first linear members 11, with the intersection of the first linear members 11 and the second linear members 12 as the pivot point. The concrete formwork 1 can be switched between a usage state in which it holds the foundation concrete and a rotation state in which the second linear members 12 are moved towards the first linear members 11 by rotating the second linear members 12 relative to the first linear members 11 from the usage state.

Description

Technical Field

[0001] The present invention relates to a concrete formwork and a construction method using the concrete formwork, and particularly relates to a net-shaped concrete formwork used when placing foundation concrete to form the foundation of a building and a construction method using the concrete formwork.

Background Art

[0002] Conventionally, a net-shaped formwork (concrete formwork) has been used when placing foundation concrete to form the foundation of a building (for example, a ground beam). The net-shaped formwork, also referred to as a lath formwork or a mesh formwork, is installed in a pair so as to surround a reinforcing bar (reinforcement structure) composed of, for example, main reinforcing bars and stirrups (shear reinforcement bars) from the outside in the width direction. Then, by placing foundation concrete in the space surrounded by the formwork, the foundation of the building can be formed (see, for example, Patent Documents 1 and 2). By using the net-shaped formwork, the installation work and removal work of the formwork can be efficiently performed as compared with ordinary steel formworks. In addition, the net-shaped formwork is lightweight and easy to carry as compared with ordinary steel formworks.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the net-shaped concrete formwork as described above, a net-shaped formwork capable of more efficiently performing the placement work of foundation concrete has been demanded. For example, there was a need for a mesh formwork with a structure that was easier to carry. Or, there was a need for a mesh formwork that was lighter and easier to handle.

[0005] The object of the present invention is to provide a concrete formwork and a construction method using the concrete formwork that enable efficient placement of foundation concrete. Another object of the present invention is to provide a mesh-like concrete formwork that is lightweight and easy to carry, and a construction method using the concrete formwork. [Means for solving the problem]

[0006] The aforementioned problems are solved by the concrete formwork of the present invention, which is a mesh concrete formwork used when pouring foundation concrete to form the foundation of a building, comprising: a plurality of first linear members extending in a first direction at predetermined intervals; and a plurality of second linear members extending in a second direction intersecting the first direction at predetermined intervals and overlapping the plurality of first linear members so as to intersect with them, wherein the second linear members are connected so as to be rotatable with respect to the first linear members, with the intersection of the first linear members and the second linear members as the pivot point, and the concrete formwork is switchable between a usage state that holds the foundation concrete and a rotation state in which the second linear members are moved toward the first linear members by rotating the second linear members relative to the first linear members from the usage state. The above configuration makes it possible to create a concrete formwork that allows for efficient pouring of foundation concrete. Specifically, the concrete formwork described above can be switched between a "used state" that holds the foundation concrete and a "rotated state" in which the second linear member is rotated relative to the first linear member, bringing the second linear member closer to the first linear member. This allows the concrete formwork to be stored or transported in the "rotated state," for example. Then, when it is time to pour the foundation concrete, the concrete formwork can be switched from the "rotated state" to the "used state." This makes it easier to transport the concrete formwork to the work site and also makes it easier to set up the concrete formwork at the work site.

[0007] In this case, the first linear member and the second linear member are formed from a resin material, the first linear member and the second linear member are rotatably connected to each other, the concrete formwork is unfolded into a frame shape with a plurality of the first linear members and a plurality of the second linear members, and it is preferable that the formwork be switchable between the usage state in which the foundation concrete is held and the rotation state in which the second linear member is folded by rotating the second linear member relative to the first linear member from the usage state. With the above configuration, the first and second linear members are formed from resin material, resulting in a lighter design compared to steel formwork. For example, forming these linear members from recycled plastic material can reduce costs and contribute to environmental protection. Furthermore, the above configuration allows the concrete formwork to be folded. This makes it easier to store the concrete formwork, reducing storage costs in warehouses and other facilities. In addition, it makes the concrete formwork easier to transport, thus reducing transportation costs.

[0008] In this case, the formwork comprises a formwork body having a plurality of first linear members and a plurality of second linear members, and a first support member and a second support member fixed to both ends of the formwork body in the left-right or up-down direction, extending along the outer edge of the formwork body and supporting the formwork body, wherein the first support member has an engaging portion that is detachably engaged with an engaging portion provided on the second support member. Furthermore, the first support member has a support body portion extending along the outer edge of the formwork body portion and an engaging portion provided on the end face of the support body portion and formed along the support body portion, and the second support member has a support body portion extending along the outer edge of the formwork body portion and an engaged portion provided on the end face of the support body portion and formed along the support body portion, and the engaging portion preferably has a shape that allows it to be detachably engaged with the engaged portion by being attached from the extending direction of the second support member. With the above configuration, a concrete formwork reinforced by the first and second support members can be realized. Furthermore, when installing multiple concrete formworks side by side along the foundation of a building, adjacent concrete formworks can be easily and securely assembled.

[0009] In this case, the device is provided with a plurality of connecting shafts, each provided at the intersection of the first linear member and the second linear member, which connect the second linear member to the first linear member so that it can rotate. The connecting shafts are mounted so as to penetrate the intersection from a direction perpendicular to the surface formed by the first linear member and the second linear member, and the second linear member is rotatably connected to the first linear member with the connecting shafts as the pivot point. With the above configuration, the concrete formwork can be switched between a "used state" and a "rotated state" using a simple rotating structure (hinge structure).

[0010] In this configuration, the second linear member is provided at the intersection of the first linear member and the second linear member, and has a plurality of winding portions that are wound around the first linear member; the first linear member has a pair of movement restricting portions positioned to sandwich the winding portions; the second linear member is rotatably connected to the first linear member with the winding portions as the pivot point; the pair of movement restricting portions restrict the movement of the winding portions and, when in the rotatable state, contact the winding portions to support them. With the above configuration, the concrete formwork can be switched between a "used state" and a "rotating state" using a simple braided structure.

[0011] Furthermore, the aforementioned problems are solved by the construction method of the present invention, which is a construction method using the above-mentioned concrete formwork, comprising a preparation step of preparing a plurality of the concrete formworks, an installation step of installing the plurality of concrete formworks, and a pouring step of pouring foundation concrete to form the foundation of a building, wherein in the preparation step, the concrete formwork is switched from the rotational state to the usage state, and in the installation step, the first concrete formwork and the second concrete formwork are installed side by side, and the engaging portion provided on the other end of the second concrete formwork is engaged from above and below with the engaging portion provided on one end of the first concrete formwork. The above configuration enables a construction method that allows for efficient placement of foundation concrete. [Effects of the Invention]

[0012] According to the concrete formwork and construction method using the concrete formwork of the present invention, it is possible to efficiently perform the pouring work of foundation concrete. Furthermore, it becomes possible to create a mesh-like concrete formwork that is lightweight and easy to carry. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram shows the state after multiple concrete formwork has been installed. [Figure 2] This is a front view of the concrete formwork. [Figure 3] This is a front view of the concrete formwork in its "used state." [Figure 4] This is a front view of the concrete formwork in the "rotating state (storage state)". [Figure 5] This diagram shows the connection structure in the "used state". [Figure 6] This diagram shows the coupling structure when the device is in the "rotating state". [Figure 7] It is a perspective view of the connection structure of the concrete formwork of the second embodiment. [Figure 8] It is a diagram showing the connection structure in the "usage state". [Figure 9] It is a diagram showing the connection structure in the "rotating state".

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9. This embodiment relates to a "net-like concrete formwork" that enables efficient placement work of foundation concrete. It also relates to a "building construction method using a net-like concrete formwork".

[0015] <Overall Configuration> As shown in FIG. 1, the concrete formwork 1 is a net-like formwork used when placing foundation concrete to form a building foundation (for example, a ground beam). The concrete formwork 1 is also referred to as a lath formwork or a mesh formwork. Specifically, the concrete formwork 1 is installed on the left and right so as to surround the reinforcing bars B (reinforcing bar structure) extending along the building foundation from both sides in the width direction. By placing foundation concrete in the space surrounded by the concrete formwork 1, the building foundation is formed.

[0016] The reinforcing bars B serve to reinforce the foundation (ground beam), and mainly include a plurality of main reinforcing bars B1 extending along the building foundation, and a plurality of stirrup bars B2 arranged at intervals in the extending direction of the foundation and attached so as to surround the plurality of main reinforcing bars B1. The main reinforcing bars B1 are composed of, for example, upper end bars and lower end bars (a plurality of upper end bars are shown in FIG. 1). The stirrup bars B2, also referred to as shear reinforcing bars, are assembled so as to surround the upper end bars and the lower end bars. Furthermore, the concrete formwork 1 is connected to both ends of the stirrup B2 in the width direction using binding members (not shown). Alternatively, spacers (not shown) are attached to the stirrup B2, and the concrete formwork 1 is connected to the spacers using binding members. This ensures that the left and right concrete formwork 1 are held in an upright position.

[0017] As shown in Figure 1, the concrete formwork 1 is installed in pairs on both sides in the width direction of the reinforcing bar B, and multiple formsworks are arranged in a row in the length direction of the reinforcing bar B. Adjacent concrete formwork pieces 1 are interlocked and assembled together. Concrete formwork 1 is a mesh-like formwork that is lightweight and easy to transport. The concrete formwork 1 will be described in detail below.

[0018] <Concrete formwork> The concrete formwork 1 (formwork 1) can be switched between the "usage state" shown in Figures 1 to 3 and the "rotation state (storage state)" shown in Figure 4. This allows the concrete formwork 1 to be kept in a "rotating state" when storing or transporting it. Then, when pouring the foundation concrete, the concrete formwork 1 can be switched from the "rotating state" to the "usable state." This makes it easier to transport the concrete formwork 1 to the work site. It also makes it easier to set up the concrete formwork 1 at the work site.

[0019] The concrete formwork 1 comprises a rectangular formwork body 10, and first support members 20 and second support members 30 fixed to both ends of the formwork body 10 in the left-right direction, extending along the outer edge of the formwork body 10 and supporting the formwork body 10. The left-right direction of the formwork body 10 corresponds to the length direction of the concrete formwork 1 (formwork body 10). The formwork body 10 is a mesh-like formwork body and has a plurality of first linear members 11, a plurality of second linear members 12, and a plurality of connecting shafts 13.

[0020] The first linear member 11 is a wire member that extends in a first direction at predetermined intervals, and specifically extends in a direction inclined at a predetermined angle (for example, 45 degrees) with respect to the height direction of the formwork 1 when viewed from the front of the formwork 1. The second linear member 12 is a wire member that extends in a second direction intersecting the first direction at a predetermined interval, and specifically extends in a direction perpendicular to the first linear member 11 when viewed from the front of the formwork 1. The second linear member 12 is provided overlapping with a plurality of first linear members 11 so as to intersect with them, and is rotatably connected to the first linear members 11 with the intersection of the first linear members 11 and the second linear member 12 as the pivot point.

[0021] The first linear member 11 has a long linear main body portion 11a and a connecting hole portion 11b (connecting portion) that is connected to the second linear member 12. The second linear member 12 similarly has a long linear main body portion 12a and a connecting hole portion 12b (connecting portion) that is connected to the first linear member 11. The connecting holes 11b and 12b are provided at the points where the first linear member 11 and the second linear member 12 intersect. A connecting shaft 13 is attached to the portion where the connecting hole 11b of the first linear member 11 and the connecting hole 12b of the second linear member 12 are in communication.

[0022] The connecting shaft 13 is, for example, a connecting pin, and is installed so as to penetrate the connecting holes 11b and 12b from a direction perpendicular to the plane formed by the first linear member 11 and the second linear member 12. The second linear member 12 is rotatably connected to the first linear member 11 with the connecting shaft 13 as the pivot point. More specifically, the first linear member 11 and the second linear member 12 are rotatably connected to each other.

[0023] With the above configuration, as shown in Figures 1 to 4, the concrete formwork 1 can be switched between a "used state" in which it is unfolded into a frame shape with a plurality of first linear members 11 and a plurality of second linear members 12, and a "rotated state" in which the second linear members 12 are rotated relative to the first linear members 11 from the used state. Specifically, in the "usage state" shown in Figures 1 to 3, the concrete formwork 1 can hold the foundation concrete (reinforcement bars B). In this "usage state," as shown in Figure 5, the first linear member 11 and the second linear member are arranged so as to be perpendicular to each other. In the "rotation state" shown in Figures 4 and 6, the concrete formwork 1 folds the second linear member 12 toward the first linear member 11. In this "rotation state," as shown in Figure 6, the second linear member 12 is moved toward the first linear member 11 with the connecting shaft 13 as the pivot point. In reality, the first linear member 11 is also moved toward the second linear member 12 with the connecting shaft 13 as the pivot point. In other words, both rotate toward each other with the connecting shaft 13 as the pivot point.

[0024] As shown in Figures 1 and 2, the first support member 20 and the second support member 30 are members that have the function of reinforcing the formwork body 10 and the function of connecting adjacent concrete formwork 1s. The first support member 20 is a column member provided on the left end face of the formwork body 10. The second support member 30 is a column member provided on the right end face of the formwork body 10. These support members 20 and 30 may also be referred to as restraining members.

[0025] The first support member 20 includes a support body portion 21 that extends vertically along the outer edge of the formwork body portion 10, and an engagement key 22 provided on the left end face of the support body portion 21 and formed along the support body portion 21. The second support member 30 has a support body portion 31 that extends vertically along the outer edge of the formwork body portion 10, and an engagement hole 32 provided on the end face of the support body portion 31 and formed along the support body portion 31. The engagement key 22 has a shape that allows it to be detachably engaged with the engagement hole 32, and the engagement hole 32 has a shape that allows it to be detachably engaged with the engagement key 22. Furthermore, the engagement key 22 and engagement hole 32 are formed along the support body portions 21 and 31, respectively. "Formed along the support body portions 21 and 31" includes not only being formed continuously with the support body portions 21 and 31, but also being formed at a distance from the support body portions 21 and 31.

[0026] With the above configuration, as shown in Figure 1, the engagement key 22 of the first formwork 1 and the engagement hole 32 of the second formwork 1 adjacent to the first formwork 1 can be detachably engaged. At this time, the two formworks 1 can be firmly assembled together by attaching the engagement hole 32 of the second formwork to the engagement key 22 of the first formwork from the height direction of the first formwork.

[0027] In the above configuration, the first linear member 11 and the second linear member 12 are formed from resin wire members, and the connecting shaft 13 is similarly formed from resin material. This allows for weight reduction compared to steel formwork. For example, by forming these linear members 11, 12 and connecting shafts 13 from recycled plastic materials, costs can be reduced and environmental measures can be implemented. Furthermore, by procuring plastic materials using waste plastic materials discharged from factories, etc., a circular economy model can be established within the company. Furthermore, the mold body 10 can be formed by resin molding. Furthermore, since the first support member 20 and the second support member 30 are also formed from resin material, cost reductions and environmental benefits can be achieved compared to steel formwork.

[0028] With the above configuration, a concrete formwork 1 can be realized that can be switched between "used state" and "rotated state" using a simple rotating structure (hinge structure). By using concrete formwork 1, a lightweight and easily transportable mesh-like formwork can be realized. Furthermore, by using this formwork 1, the concrete pouring work for the foundation can be carried out efficiently.

[0029] <Building Construction Methods> Next, the construction method of a building using concrete formwork 1 (method of pouring foundation concrete) will be explained based on Figures 1 to 6. The method includes at least a "preparation step" of preparing multiple concrete formwork 1, an "installation step" of setting up multiple concrete formwork 1, a "concrete pouring step" of pouring foundation concrete to form the building's foundation, and a "removal step" of removing the concrete formwork 1. A detailed explanation follows below. Regarding the construction of the building, explanations of construction processes other than those mentioned above will be omitted.

[0030] First, the workers perform a "preparation process" (Step 1 (S1)) in which they prepare multiple concrete formwork 1 at the work site. Specifically, the worker switches the concrete formwork 1, which is in the "rotating state" shown in Figure 4, from the "rotating state" to the "used state" shown in Figure 3. For example, concrete formwork 1 is stored and transported to the work site in a folded state that allows for rotation. It is preferable that concrete formwork 1 be stored and transported in a stacked state.

[0031] Then, the workers perform the "installation process" (S2) in which they install multiple concrete formwork 1 at the work site. Specifically, as shown in Figure 1, the worker places reinforcing bars B at the location that will form the foundation of the building, and then places multiple concrete formworks 1 around the reinforcing bars B. More specifically, the workers install concrete formwork 1 on both sides so as to surround the reinforcing bar B (reinforced concrete structure) that extends along the foundation of the building from both sides in the width direction. In addition, multiple concrete formwork 1 are installed in a row along the length direction of the reinforcing bar B. At this time, the worker engages the engagement key 22 provided at one end of the first concrete formwork 1 with the engagement hole 32 provided at the other end of the second concrete formwork 1 from above and below. This makes it easy to assemble adjacent concrete formwork 1 when installing multiple concrete formworks 1 side by side, and allows for a strong and secure assembly.

[0032] Then, the workers perform the "concrete pouring process" (S3) in which they pour the foundation concrete to form the building's foundation. After the foundation concrete has been cured and the foundation is formed, the workers perform the "removal process" (S4) in which they remove the concrete formwork 1. When removing the concrete formwork 1, the worker removes the second formwork 1 (engagement hole 32) by pulling it up and down relative to the first formwork 1 (engagement key 22). The worker removes the concrete formwork 1 by repeating this process. After completing steps S1 to S4 described above, the series of work processes is finished. The above construction method allows for efficient placement of foundation concrete.

[0033] <Concrete formwork of the second embodiment> Next, the concrete formwork 1 of the second embodiment will be described based on Figures 7 to 9. Note that explanations that overlap with the above-mentioned concrete formwork 1 will be omitted.

[0034] The concrete formwork 1 comprises a rectangular formwork body 110, a first support member 20, and a second support member 30. The formwork body 110 is a mesh-like formwork body and has a plurality of first linear members 111 and a plurality of second linear members 112.

[0035] The first linear member 111 has a long linear main body portion 111a and a plurality of movement restricting portions 111b formed on the linear main body portion 111a. The second linear member 112 has a long linear main body portion 112a and a plurality of winding portions 112b that are wrapped around the first linear member 111. The movement restricting portion 111b is formed as a mass of resin on the linear main body portion 111a. The pair of movement restricting portions 111b restrict the movement of the winding portion 112b. In other words, the movement restricting portions 111b restrict the movement of the winding portion 112b so that it does not move freely. In other words, it can be said that the first linear member 111 penetrates the winding portion 112b of the second linear member 112.

[0036] In the above configuration, the concrete formwork 1 can be switched between the "usage state" shown in Figures 3, 7, and 8, and the "rotation state (storage state)" shown in Figures 4 and 9. Specifically, the second linear member 112 is rotatably connected to the first linear member 111 with the winding portion 112b as the pivot point. The concrete formwork 1 can be switched between a "used state" and a "rotated state" by rotating the second linear member 112 relative to the first linear member 111. When in the "rotating state" shown in Figure 9, the winding portion 112b abuts against the pair of movement restricting portions 111b and is supported by the pair of movement restricting portions 111b.

[0037] With the above configuration, a concrete formwork 1 can be realized that can switch between a "used state" and a "rotating state" using a simple braided structure.

[0038] <Other> In the above embodiment, as shown in Figures 6 and 9, the concrete formwork 1 is configured to switch between a "usage state" and a "rotating state (storage state)" by a hinge structure or a woven structure, but this is not particularly limited. The concrete formwork 1 may be extended or retracted using an expansion / contraction structure other than a hinge structure or a woven structure, allowing it to switch between a "used state" and a "storage state (unused state, contracted state)". For example, the concrete formwork 1 may be switched between a "used state (unfolded state)" and a "storage state (folded state)" by an accordion-like retractable structure. Alternatively, the concrete formwork 1 may be equipped with a retractable structure like a bamboo screen.

[0039] In the above embodiment, as shown in Figure 6, the concrete formwork 1 is configured to switch between a "usage state" and a "rotation state," but it is not necessarily required that it not be used when in the "rotation state." For example, the size of the concrete formwork 1 may be changed to match the shape of the building's foundation. If a compact size of concrete formwork 1 is desired, it may be set to a "rotating state (contracted state)" and a concrete formwork 1 that has been reduced to a certain size may be used to form the foundation. Concrete formwork 1 may be switchable between three or more states.

[0040] In the above embodiment, the first linear member 11, the second linear member 12, the first support member 20, and the second support member 30 are formed from a resin material, but are not particularly limited and can be changed. The first support member 20 and the second support member 30 may be made of steel, or the concrete formwork 1 as a whole may be made of steel.

[0041] In the above embodiment, the first support member 20 and the second support member 30 are fixed to both ends of the formwork body 10 in the left-right direction, but this is not particularly limited and can be changed. For example, the first support member 20 and the second support member 30 may be fixed to both ends of the formwork body 10 in the vertical direction. In that case, it becomes possible to use the concrete formwork 1 arranged in the vertical direction. The vertical direction of the formwork body 10 corresponds to the height direction of the concrete formwork 1 (formwork body 10).

[0042] In the above embodiments, the concrete formwork and construction method using the concrete formwork according to the present invention were mainly described. However, the embodiments described above are merely examples to facilitate understanding of the present invention and do not limit it. The present invention can be modified and improved without departing from its spirit, and of course, equivalents thereof are included. [Explanation of Symbols]

[0043] B. Reinforcement (reinforced concrete structure) B1 Main reinforcement (upper end reinforcement, lower end reinforcement) B2 Ribs (shear reinforcement) Binding member 1. Concrete formwork (formwork) 10 Formwork main body 11. First linear member 11a Linear main body 11b Connection hole (connection part) 12 Second linear member 12a Linear main body 12b Connection hole (connection part) 13. Connecting shaft (connecting pin) 20 First support member 21 Support body part 22 Engaging key (engaging part) 30 Second support member 31 Support body part 32 Engagement hole (engaged part) 110 Formwork main body 111 First linear member 111a Linear main body 111b Movement Control Department 112 Second linear member 112a Linear main body 112b Wrapping section

Claims

1. A mesh-like concrete formwork used when pouring foundation concrete to form the foundation of a building, A plurality of first linear members extending in a first direction at predetermined intervals, It comprises a plurality of second linear members that extend in a second direction intersecting the first direction at predetermined intervals and overlapping the plurality of first linear members, The second linear member is connected to the first linear member so as to be rotatable with respect to the first linear member, with the intersection of the first linear member and the second linear member as the pivot point. The aforementioned concrete formwork is The usage state for holding the aforementioned foundation concrete, A concrete formwork characterized in that it is possible to switch between the above-mentioned usage state and a rotated state in which the second linear member is moved toward the first linear member by rotating the second linear member relative to the first linear member.

2. The first linear member and the second linear member are formed from a resin material. The first linear member and the second linear member are rotatably connected to each other. The aforementioned concrete formwork is The multiple first linear members and the multiple second linear members are arranged in a frame shape, and the usage state is such that the foundation concrete is held in place. The concrete formwork according to claim 1, characterized in that it is possible to switch between the above-mentioned usage state and the above-mentioned rotated state in which the second linear member is folded by rotating the second linear member relative to the first linear member.

3. A formwork body having a plurality of first linear members and a plurality of second linear members, The formwork body comprises a first support member and a second support member, which are fixed to both ends of the formwork body in the left-right or up-down direction, extend along the outer edge of the formwork body, and support the formwork body. The concrete formwork according to claim 1, characterized in that the first support member has an engaging portion having a shape that detachably engages with an engaging portion provided on the second support member.

4. The first support member has a support body portion extending along the outer edge of the formwork body portion, and an engagement portion provided on the end face of the support body portion and formed along the support body portion, The second support member has a support body portion extending along the outer edge of the formwork body portion, and an engaged portion provided on the end face of the support body portion and formed along the support body portion, The concrete formwork according to claim 3, characterized in that the engaging portion has a shape that allows it to be detachably engaged with the engaged portion by being attached from the extending direction of the second support member.

5. The device comprises a plurality of connecting shafts provided at the intersection of the first linear member and the second linear member, which connect the second linear member to the first linear member in such a way that the second linear member can rotate relative to it. The connecting shaft is installed so as to penetrate the intersection portion from a direction perpendicular to the surface formed by the first linear member and the second linear member. The concrete formwork according to any one of claims 1 to 4, characterized in that the second linear member is rotatably connected to the first linear member with the connecting shaft as the pivot point.

6. The second linear member is provided at the intersection of the first linear member and the second linear member, and has a plurality of winding portions that are wound around the first linear member. The first linear member has a pair of movement restricting portions positioned to sandwich the winding portion, The second linear member is rotatably connected to the first linear member with the winding portion as the pivot point, The concrete formwork according to any one of claims 1 to 4, characterized in that the pair of movement restricting parts restrict the movement of the winding part and contact the winding part to support it when it is in the rotational state.

7. A construction method using concrete formwork as described in claim 1, A preparation step of preparing multiple concrete formwork, Installation process for installing multiple concrete formwork, The process includes pouring the aforementioned foundation concrete to form the foundation of the building, In the preparation step, the concrete formwork is switched from the rotating state to the usage state. In the aforementioned installation process, The first concrete formwork and the second concrete formwork are set up side by side. A construction method using concrete formwork, characterized in that an engaging portion provided at one end of the first concrete formwork is engaged from above and below with an engaging portion provided at the other end of the second concrete formwork.

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