Concrete form fixture and method for installing concrete form

Abstract

To provide a concrete form fixture and a method for installing a concrete form, which can suppress reduction in building frame accuracy of the concrete form.SOLUTION: By this concrete form fixture, in a state where a first cylindrical part is inserted into an insertion hole of a concrete form so as to bring a first flange into contact with the inner wall surface of the concrete form from the inner wall surface side of the concrete form made of a corrugated board and a second cylindrical part is inserted into the insertion hole of the concrete form so as to bring a second flange into contact with the outer wall surface of the concrete form from the outer wall surface side of the concrete form, one end of a separator can be inserted into the first cylindrical part from the inner wall surface side of the concrete form.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a jig for a concrete form and a method for installing a concrete form. [Background technology]

[0002] Conventionally, when forming the foundation of a building, a concrete formwork is used to pour concrete. A rod-shaped separator with a P-con at the end is inserted into the insertion hole of the concrete formwork. The separator inserted into the insertion hole of the concrete formwork is screwed into a fastening member, so that the concrete formwork can be kept at a predetermined interval. For example, Patent Document 1 discloses a concrete formwork that uses cardboard instead of plywood. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-201650 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in this method of installing a concrete form, since the concrete form is made of cardboard, there is a risk that the concrete form may be deformed when the separator inserted into the insertion hole of the concrete form is screwed into the fastening member. Thus, it is desired to suppress the deterioration of the structural accuracy of the concrete form by suppressing the deformation of the concrete form. [Means for solving the problem]

[0005] A concrete formwork jig that solves the above-mentioned problems comprises a first jig and a second jig, wherein the first jig has a first cylindrical portion and a first flange portion provided at a base end of the first cylindrical portion, and the second jig has a second cylindrical portion and a second flange portion provided at a base end of the second cylindrical portion, and one end of a separator can be inserted into the first cylindrical portion from the inner wall surface side of the concrete formwork made of cardboard, in a state in which the first cylindrical portion is inserted into an insertion hole of the concrete formwork so that the first flange portion abuts against the inner wall surface of the concrete formwork from the inner wall surface side of the concrete formwork, and the second cylindrical portion is inserted into the insertion hole of the concrete formwork so that the second flange portion abuts against the outer wall surface of the concrete formwork from the outer wall surface side of the concrete formwork.

[0006] A method of installing a concrete formwork that solves the above-mentioned problems is a method of installing a concrete formwork using a jig for a concrete formwork, the jig for the concrete formwork having a first jig and a second jig, the first jig having a first cylindrical portion and a first flange portion provided at a base end of the first cylindrical portion, and the second jig having a second cylindrical portion and a second flange portion provided at a base end of the second cylindrical portion, and includes inserting the first cylindrical portion into an insertion hole of the concrete formwork from an inner wall surface side of the concrete formwork made of cardboard so that the first flange portion abuts against the inner wall surface of the concrete formwork, inserting the second cylindrical portion into an insertion hole of the concrete formwork from an outer wall surface side of the concrete formwork so that the second flange portion abuts against the outer wall surface of the concrete formwork, and inserting one end of a separator into the first cylindrical portion from the inner wall surface side of the concrete formwork. Effect of the Invention

[0007] According to the present invention, it is possible to suppress a decrease in the structural accuracy of a concrete formwork made of corrugated cardboard. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a concrete formwork of the first embodiment. [Diagram 2]FIG. 2 is a perspective view showing the concrete formwork, a spacer, a fastening member, and a jig for a concrete formwork of the first embodiment. [Diagram 3] FIG. 3 is a perspective view showing the first jig of the first embodiment. [Figure 4] FIG. 4 is a perspective view showing the second jig of the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing the concrete form, the spacer, the fastening member, and the jig for the concrete form of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] An embodiment of a concrete formwork jig and a method for installing a concrete formwork will be described. Hereinafter, the concrete formwork will be simply referred to as a formwork. In the following description, a direction intersecting with the vertical direction Z will be referred to as a width direction X, and a direction intersecting with the vertical direction Z and the width direction X will be referred to as a thickness direction Y. The width direction X is a direction along the width of the formwork. The thickness direction Y is a direction along the thickness of the formwork. The thickness direction Y is also a direction that becomes the thickness of the concrete to be poured. The direction in the thickness direction Y where the concrete pouring surface is formed will be referred to as an inward direction Y1, and the direction in the thickness direction Y where the concrete pouring surface is not formed will be referred to as an outward direction Y2.

[0010] <Formwork 10> As shown in Fig. 1, the formwork 10 is a member for shaping concrete when pouring it. The formwork 10 is made of corrugated cardboard. In particular, the formwork 10 is made of corrugated cardboard having a water-resistant surface.

[0011] The formwork 10 includes a dam portion 11. The dam portion 11 is a portion for forming a concrete pouring surface when pouring concrete. The dam portion 11 has a plate shape perpendicular to the thickness direction Y. The dam portion 11 is made of corrugated cardboard having a water-resistant surface.

[0012] The sheathing board portion 11 has an inner wall surface 12 and an outer wall surface 13. The inner wall surface 12 is a surface perpendicular to the thickness direction Y. The inner wall surface 12 is a surface for forming a concrete pouring surface. The outer wall surface 13 is a surface opposite to the inner wall surface 12. The outer wall surface 13 is a surface perpendicular to the thickness direction Y.

[0013] The dam plate portion 11 has an insertion hole 14. The dam plate portion 11 may have a plurality of insertion holes 14. The insertion holes 14 are provided so as to penetrate the dam plate portion 11 in the thickness direction Y. The insertion hole 14 is a hole that communicates between the inner wall surface 12 side and the outer wall surface 13 side. The insertion hole 14 is a hole for inserting one end portion 20A of a separator 20 described later.

[0014] The formwork 10 has a side plate portion 15. The formwork 10 may have two side plate portions 15. The side plate portions 15 are provided on both side ends of the sheathing board portion 11. The side plate portions 15 are provided so as to protrude outward Y2 from the outer wall surface 13. The side plate portions 15 are made of cardboard, and in this case, it is preferable that the side plate portions 15 are made of cardboard having a water-resistant surface, and they may also be made of wood. The side plate portions 15 are provided integrally with the sheathing board portion 11, but may also be provided separately from the sheathing board portion 11.

[0015] Each of the side plate portions 15 has a plurality of insertion holes 16. The insertion holes 16 are provided so as to penetrate the side plate portions 15 in the width direction X. A connecting member (not shown) can be inserted into the insertion holes 16. The insertion holes 16 are holes for connecting adjacent multiple formworks 10 by inserting the connecting member. As a result, adjacent multiple formworks 10 are temporarily fixed in a connected state.

[0016] The formwork 10 includes a reinforcing plate portion 17. The formwork 10 may include a plurality of reinforcing plate portions 17. The reinforcing plate portion 17 is provided between the side plate portions 15. The reinforcing plate portion 17 is provided so as to protrude outward Y2 from the outer wall surface 13. The reinforcing plate portion 17 is made of cardboard, and in this case, it is preferable that the reinforcing plate portion 17 is made of cardboard having a water-resistant surface, and may be made of wood. The reinforcing plate portion 17 is provided integrally with the dam plate portion 11, but may be provided separately from the dam plate portion 11.

[0017] The multiple formwork 10 are connected along the width direction X. As a result, the multiple formwork 10 are installed in a row along the width direction X. In Fig. 1, the formwork 10 installed on one side of the width direction X is shown by a two-dot chain line, and the formwork 10 installed on the other side of the width direction X is omitted.

[0018] The multiple forms 10 are installed in two rows so that the inner wall surfaces 12 face each other. In this manner, when pouring concrete, fresh concrete is poured into a space 18 surrounded by the two rows of inner wall surfaces 12.

[0019] <Separator 20 and Fastening Member 30> As shown in FIG. 2, a separator 20 and a fastening member 30 are used to install the formwork 10. The separator 20 is attached between the formwork 10 whose inner wall surfaces 12 face each other. The separator 20 is a member for maintaining the distance between the two rows of formwork 10. The separator 20 may be in the shape of a round bar. One end 20A of the separator 20 is configured in the same manner as the other end (not shown). For this reason, one end 20A of the separator 20 will be described as a representative example.

[0020] A P-con 21 is attached to one end 20A of the separator 20. The P-con 21 can be adjusted in the thickness direction Y by screwing it to the separator 20. The P-con 21 has a first pressing surface 21A. The first pressing surface 21A is a surface that faces the inner wall surface 12 of the formwork 10 when the separator 20 is inserted into the insertion hole 14 and screwed to the fastening member 30. The first pressing surface 21A is a surface that presses the inner wall surface 12 of the formwork 10 when the separator 20 is inserted into the insertion hole 14 and screwed to the fastening member 30.

[0021] The fastening member 30 is a member for fastening the separator 20. The fastening member 30 may be a fastening metal fitting for fastening the separator 20. The fastening member 30 is a member into which the separator 20 can be screwed.

[0022] A dish plate 31 is attached to the base end 30A of the fastening member 30. The dish plate 31 has a second pressing surface 31A. The second pressing surface 31A is a surface that faces the outer wall surface 13 of the formwork 10 when the separator 20 is inserted into the insertion hole 14 and screwed into the fastening member 30. The second pressing surface 31A is a surface that presses the outer wall surface 13 of the formwork 10 when the separator 20 is inserted into the insertion hole 14 and screwed into the fastening member 30.

[0023] In this manner, when the separator 20 is inserted into the insertion hole 14 and screwed into the fastening member 30, the first pressing surface 21A presses the inner wall surface 12, and the second pressing surface 31A presses the outer wall surface 13. In this manner, the formwork 10 is sandwiched between the first pressing surface 21A and the second pressing surface 31A in the thickness direction Y. As a result, the formwork 10 is held between the first pressing surface 21A and the second pressing surface 31A.

[0024] When adjusting the distance between two rows of formwork 10 whose inner wall surfaces 12 face each other, separators 20 and fastening members 30 are used, but in addition to the separators 20 and fastening members 30, formwork jigs 40 are also used.

[0025] <Formwork jig 40> The formwork jig 40 is a jig for suppressing deformation of the formwork 10. The formwork jig 40 includes a first jig 41 and a second jig 42. The first jig 41 is a jig that is inserted into the insertion hole 14 from the inner Y1 side of the formwork 10. The second jig 42 is a jig that is inserted into the insertion hole 14 from the outer Y2 side of the formwork 10.

[0026] The first jig 41 and the second jig 42 are waterproof. The first jig 41 and the second jig 42 are made of a resin such as plastic, but may be made of a metal such as aluminum.

[0027] 3 and 5, the first jig 41 has a first through hole 41A. The first through hole 41A is provided to extend in the thickness direction Y. The first through hole 41A is provided to penetrate the first jig 41. The first through hole 41A is provided to penetrate a first cylindrical portion 43 and a first flange portion 44, which will be described later.

[0028] The first through hole 41A has a diameter D11. The diameter D11 is longer than the diameter of one end 20A of the separator 20. Therefore, the first jig 41 can accommodate the one end 20A of the separator 20 in the first through hole 41A.

[0029] The diameter D11 is shorter than the diameter D32 of the P conduit 21. Therefore, the P conduit 21 is not accommodated in the first through hole 41A. As a result, when one end 20A of the separator 20 is accommodated in the first through hole 41A, the P conduit 21 is disposed so that the first pressing surface 21A abuts against the first flange portion 44 (described later) from the inner Y1 side.

[0030] The first jig 41 includes a first tubular portion 43 and a first flange portion 44. The first tubular portion 43 is provided integrally with the first flange portion 44, but may be provided separately from the first flange portion 44. The first tubular portion 43 has a cylindrical shape, but any shape may be used as long as it is a cylindrical shape. The first tubular portion 43 extends in the thickness direction Y.

[0031] The first tubular portion 43 has a first base end 43A and a first tip end 43B. The first tip end 43B is the end opposite to the first base end 43A. The first tubular portion 43 has a first inner circumferential surface 43C and a first outer circumferential surface 43D. The first outer circumferential surface 43D has a diameter D12. The diameter D12 is shorter than the inner diameter of the insertion hole 14. Therefore, the first tubular portion 43 can be inserted into the insertion hole 14.

[0032] The first tubular portion 43 has a length L1. The length L1 is longer than the thickness T2 of the formwork 10. The length L1 is the same as the sum of the thickness T2 of the formwork 10 and the thickness T1 of the second flange portion 46 described later. In other words, the first tubular portion 43 has the same length as the sum of the thickness T2 of the formwork 10 and the thickness T1 of the second flange portion 46 described later. Therefore, the first tip portion 43B does not protrude outward Y2 from the second flange portion 46 described later, but is located on the same plane as a fourth abutment surface 46B of the second flange portion 46 described later.

[0033] The first flange 44 is provided on the first base end 43A of the first cylindrical portion 43. The first flange 44 has a diameter D31. The diameter D31 is longer than the diameter D12 of the first outer circumferential surface 43D. In other words, the first flange 44 is a flange having a diameter longer than the first outer circumferential surface 43D of the first cylindrical portion 43. The diameter of the first flange 44 is preferably 1.5 times or more larger than the diameter of the first cylindrical portion 43, and may be 2 times or more larger than the diameter of the first cylindrical portion 43. The first flange 44 has a thickness T1.

[0034] The first flange portion 44 has a first contact surface 44A and a second contact surface 44B. The second contact surface 44B is the surface opposite to the first contact surface 44A. The first contact surface 44A is a surface that can contact the inner wall surface 12. The second contact surface 44B is a surface that can contact the first pressing surface 21A of the P capacitor 21.

[0035] 4 and 5, the second jig 42 has a second through hole 42A. The second through hole 42A is provided to extend in the thickness direction Y. The second through hole 42A is provided so as to penetrate the second jig 42. The second through hole 42A is provided so as to penetrate a second cylindrical portion 45 and a second flange portion 46, which will be described later.

[0036] The second through hole 42A has a diameter D21. The diameter D21 is longer than the diameter D12. Therefore, the second jig 42 is capable of housing the first cylindrical portion 43 in the second through hole 42A. The diameter D21 is shorter than the diameter D33 of the plate 31. Therefore, the plate 31 is not accommodated in the second through hole 42A. As a result, the plate 31 is disposed so that the second pressing surface 31A abuts against the second flange portion 46 (described later) from the outer Y2 side.

[0037] The second jig 42 includes a second tubular portion 45 and a second flange portion 46. The second tubular portion 45 is provided integrally with the second flange portion 46, but may be provided separately from the second flange portion 46. The second tubular portion 45 has a cylindrical shape, but any shape may be used as long as it is a cylindrical shape. The second tubular portion 45 extends in the thickness direction Y.

[0038] The second tubular portion 45 has a second base end portion 45A and a second tip end portion 45B. The second tip end portion 45B is an end portion on the opposite side to the second base end portion 45A. The second tubular portion 45 has a second inner circumferential surface 45C and a second outer circumferential surface 45D. The second outer circumferential surface 45D has a diameter D22. The diameter D22 is the same as the inner diameter of the insertion hole 14. Therefore, the second tubular portion 45 can be inserted into the insertion hole 14.

[0039] The second tubular portion 45 has a length L2. The length L2 is the same as the thickness T2 of the formwork 10. In other words, the second tubular portion 45 has the same length as the thickness T2 of the formwork 10. Therefore, the second tip portion 45B of the second tubular portion 45 is located on the same plane as the inner wall surface 12 without protruding inward Y1 from the inner wall surface 12.

[0040] The second flange 46 is provided at the second base end 45A of the second tubular portion 45. The second flange 46 has a diameter D31, similar to the first flange 44. The diameter D31 is longer than the diameter D12 of the first outer circumferential surface 43D. In other words, the second flange 46 is a flange having a diameter longer than the second outer circumferential surface 45D of the second tubular portion 45. The diameter of the second flange 46 is preferably 1.5 times or more larger than the diameter of the second tubular portion 45, and may be twice or more larger than the diameter of the second tubular portion 45. The second flange 46 has a thickness T1, similar to the first flange 44.

[0041] The second flange portion 46 includes a third contact surface 46A and a fourth contact surface 46B. The fourth contact surface 46B is the surface opposite to the third contact surface 46A. The third contact surface 46A is a surface that can contact the outer wall surface 13. The fourth contact surface 46B is a surface that can contact the second pressing surface 31A of the plate 31.

[0042] <Operation of the First Embodiment> The operation of the first embodiment will be described. The formwork 10 is installed at the site by installing a plurality of formworks 10 next to each other. In particular, the plurality of formworks 10 are installed so that their inner wall surfaces 12 face each other and are arranged in two rows. This provides a space 18 between the inner wall surfaces 12 of the formworks 10.

[0043] 5, with the formwork 10 installed, the second jig 42 is inserted into the insertion hole 14 from the outer Y2 side. More specifically, the second tubular portion 45 is inserted into the insertion hole 14 from the outer Y2 side. In this case, the second tip portion 45B is flush with the inner wall surface 12 without protruding from the inner wall surface 12.

[0044] Further, the third contact surface 46A contacts the outer wall surface 13. In this manner, the second cylindrical portion 45 is inserted into the insertion hole 14 from the outer wall surface 13 side of the formwork 10 so that the second flange portion 46 contacts the outer wall surface 13.

[0045] The first jig 41 is inserted into the insertion hole 14 from the inner Y1 side. More specifically, the first tubular portion 43 is inserted into the insertion hole 14 from the inner Y1 side. In this case, the first tip portion 43B protrudes from the outer wall surface 13. The first tip portion 43B does not protrude from the fourth abutment surface 46B that abuts against the outer wall surface 13, but is flush with the fourth abutment surface 46B.

[0046] Further, the first abutment surface 44A abuts against the inner wall surface 12. In this manner, the first tubular portion 43 is inserted into the insertion hole 14 from the inner wall surface 12 side of the formwork 10 so that the first flange portion 44 abuts against the inner wall surface 12 of the formwork 10. In particular, the first tubular portion 43 is housed in the second tubular portion 45.

[0047] Next, the fastening member 30 is placed from the outer wall surface 13 side of the formwork 10 with the second pressing surface 31A of the plate plate 31 abutting against the fourth abutment surface 46B. Also, the separator 20 is inserted into the first through hole 41A from the inner wall surface 12 side of the formwork 10. In this way, the separator 20 is inserted into the first cylindrical portion 43 from the inner wall surface 12 side of the formwork 10. In this case, the separator 20 is placed with the first pressing surface 21A of the P-con 21 abutting against the second abutment surface 44B. Then, the separator 20 is screwed into the fastening member 30. As a result, the separator 20 and the fastening member 30 can hold the formwork 10 by clamping the formwork 10 in the thickness direction Y via the formwork jig 40.

[0048] In such a method for installing the formwork 10, by using the separator 20, the fastening members 30, and the formwork jig 40, the pressing force from the separator 20 is transmitted to the formwork 10 in a dispersed state by the first flange 44. In addition, the pressing force from the fastening members 30 is transmitted to the formwork 10 in a dispersed state by the second flange 46. Therefore, deformation of the formwork 10 due to the pressing forces from the separator 20 and the fastening members 30 can be suppressed.

[0049] Next, fresh concrete is poured into the space 18 between the inner wall surfaces 12 of the formwork 10. In this case, the formwork 10 is made of cardboard having a water-resistant surface. This makes it possible to prevent moisture contained in the fresh concrete from seeping into the formwork 10 from the surface thereof.

[0050] In particular, the first abutment surface 44A of the first flange portion 44 abuts against the inner wall surface 12, and the first through hole 41A of the first jig 41 penetrates from the inner wall surface 12 side to the outer wall surface 13 side. This makes it possible to prevent moisture contained in the fresh concrete from seeping into the formwork 10 through the insertion hole 14.

[0051] <Advantages of the First Embodiment> The effects of the first embodiment will be described. (1) The first tube portion 43 is inserted into the insertion hole 14 of the formwork 10 from the inner wall surface 12 side of the formwork 10 made of corrugated cardboard so that the first flange portion 44 abuts against the inner wall surface 12 of the formwork 10. The second tube portion 45 is inserted into the insertion hole 14 of the formwork 10 from the outer wall surface 13 side of the formwork 10 so that the second flange portion 46 abuts against the outer wall surface 13 of the formwork 10. The separator 20 can be inserted into the first tube portion 43 from the inner wall surface 12 side of the formwork 10. Therefore, when the separator 20 inserted into the insertion hole 14 of the formwork 10 is screwed into the fastening member 30, the pressing force from the P cone 21 of the separator 20 is in contact with the first flange portion 44 and is distributed through the first flange portion 44 and transmitted to the formwork 10. Furthermore, when the dish plate 31 of the fastening member 30 is in contact with the second flange 46, the pressing force from the dish plate 31 is dispersed and transmitted to the formwork 10 via the second flange 46. In this way, the pressing force against the formwork 10 is dispersed around the periphery of the insertion hole 14 of the formwork 10, thereby making it possible to suppress deformation of the formwork 10. Therefore, it is possible to suppress a decrease in the structural accuracy of the formwork 10 made of cardboard.

[0052] (2) The first jig 41 and the second jig 42 are water-tight. With the first tubular portion 43 housed in the second tubular portion 45, the separator 20 can be inserted into the first tubular portion 43 from the inner wall surface 12 side of the formwork 10. This makes it possible to prevent moisture in the fresh concrete poured into the inner wall surface 12 side of the formwork 10 from seeping into the formwork 10 through the insertion hole 14 of the formwork 10. This makes it possible to prevent deformation of the formwork 10. This makes it possible to prevent a decrease in the structural accuracy of the formwork 10 made of cardboard.

[0053] (3) The second tubular portion 45 has the same length as the thickness T2 of the formwork 10. Therefore, the second tubular portion 45 can hold the first tubular portion 43 while housing it, and can suppress a decrease in the degree of contact between the first flange portion 44 and the inner wall surface 12 of the formwork 10. This can further suppress deformation of the formwork 10. Therefore, a decrease in the structural accuracy of the formwork 10 made of cardboard can be suppressed.

[0054] (4) The first tube portion 43 has a length equal to the total of the thickness T2 of the formwork 10 and the thickness T1 of the second flange portion 46. Therefore, the moisture of the fresh concrete poured into the inner wall surface 12 of the formwork 10 can be guided to the outer wall surface 13 of the formwork 10 through the first tube portion 43. In this way, while the dish plate 31 and the second flange portion 46 are appropriately abutted against each other, it is possible to further suppress the moisture from seeping into the formwork 10 through the insertion hole 14 of the formwork 10. This makes it possible to suppress deformation of the formwork 10. Therefore, it is possible to suppress the deterioration of the structural accuracy of the formwork 10 made of cardboard.

[0055] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0056] At least one of the first jig 41 and the second jig 42 may be provided with a locking portion so that the first jig 41 and the second jig 42 are locked together when the first cylindrical portion 43 is housed in the second cylindrical portion 45. The first jig 41 and the second jig 42 may be configured to be screwed together.

[0057] The first tip portion 43B of the first cylindrical portion 43 may be tapered. This makes it possible to easily attach the first jig 41 to the second jig 42. The second tip portion 45B of the second cylindrical portion 45 may be tapered.

[0058] The first jig 41 and the second jig 42 may have elasticity, for example, made of rubber. In particular, the first flange 44 and the second flange 46 may have elasticity, for example, made of rubber. In this case, the degree of adhesion between the first contact surface 44A and the inner wall surface 12 of the formwork 10 is increased by the pressing force from the P-con 21. In addition, the degree of adhesion between the third contact surface 46A and the outer wall surface 13 of the formwork 10 is increased by the pressing force from the fastening member 30. This further prevents moisture from seeping into the formwork 10 through the insertion hole 14 of the formwork 10.

[0059] The first jig 41 and the second jig 42 may be installed so that a part or all of the first cylindrical portion 43 is housed in the second cylindrical portion 45. In other words, the first jig 41 and the second jig 42 may be installed so that at least a part of the first cylindrical portion 43 overlaps with the second cylindrical portion 45.

[0060] The first jig 41 and the second jig 42 may be placed so that the second cylindrical portion 45 is accommodated in the first cylindrical portion 43. The first jig 41 and the second jig 42 may be placed in a state in which the first tip portion 43B and the second tip portion 45B are in contact with each other in the thickness direction Y. In other words, the first jig 41 and the second jig 42 may be placed in a state in which the first cylindrical portion 43 is not accommodated in the second cylindrical portion 45 and the second cylindrical portion 45 is not accommodated in the first cylindrical portion 43.

[0061] The first tubular portion 43 may have the same length as the thickness T2 of the formwork 10. The first tubular portion 43 may be shorter than the thickness T2 of the formwork 10. The formwork 10 may be installed by inserting the first jig 41 into the insertion hole 14, and then inserting the second jig 42 into the insertion hole 14. The formwork 10 may be installed by inserting the second jig 42 into the insertion hole 14, and then inserting the first jig 41 into the insertion hole 14.

[0062] The formwork 10 may be installed by inserting the first jig 41 into the insertion hole 14, and then inserting the second jig 42 into the insertion hole 14 in a state in which the first flange 44 is not in contact with the inner wall surface 12. The formwork 10 may be installed by inserting the second jig 42 into the insertion hole 14, and then inserting the first jig 41 into the insertion hole 14 in a state in which the second flange 46 is not in contact with the outer wall surface 13.

[0063] The formwork 10 may be installed such that the first flange 44 comes into contact with the inner wall surface 12, and then the second flange 46 comes into contact with the outer wall surface 13. The formwork 10 may be installed such that the second flange 46 comes into contact with the outer wall surface 13, and then the first flange 44 comes into contact with the inner wall surface 12.

[0064] The term "at least any" as used herein means one or more of the desired options. As an example, the term "at least any" as used herein means only one option or both options if the number of options is two. As another example, the term "at least any" as used herein means only one option or any combination of two or more options if the number of options is three or more.

[0065] [Note] The technical ideas understood from the above-described embodiment and modified examples will be described below. (A) The second tubular portion has a length equal to the thickness of the concrete formwork.

[0066] (B) The first tubular portion has a length equal to the sum of the thickness of the concrete formwork and the thickness of the second flange portion. (C) The first jig and the second jig are made of resin.

[0067] (D) The first jig and the second jig have elasticity. (E) The first cylindrical portion and the second cylindrical portion are cylindrical, the diameter of the first flange portion is 1.5 times or more larger than the diameter of the first cylindrical portion, and the diameter of the second flange portion is 1.5 times or more larger than the diameter of the second cylindrical portion.

[0068] (F) The first and second cylindrical portions have tapered tips. [Explanation of symbols]

[0069]

[0033] 10...form, 11...dam plate portion, 12...inner wall surface, 13...outer wall surface, 14...insertion hole, 15...side plate portion, 16...insertion hole, 17...reinforcing plate portion, 18...space, 20...separator, 20A...one end portion, 21...P cone, 21A...first pressing surface, 30...fastening member, 30A...base end portion, 31...dish plate, 31A...second pressing surface, 40...form jig, 41...first jig, 41A...first through hole, 42...second jig , 42A...second through hole, 43...first cylindrical part, 43A...first base end, 43B...first tip part, 43C...first inner circumferential surface, 43D...first outer circumferential surface, 44...first flange, 44A...first contact surface, 44B... 2nd contact surface, 45...2nd cylinder part, 45A...2nd base end part, 45B...2nd tip part, 45C...2nd inner circumferential surface, 45D...2nd outer circumferential surface, 46...2nd collar part, 46A...3rd abutting surface, 46B...4th abutting surface.

Claims

1. A first jig and a second jig are provided, The first jig has a first cylindrical portion and a first flange portion provided at a base end portion of the first cylindrical portion, The second jig has a second cylindrical portion and a second flange portion provided at a base end portion of the second cylindrical portion, one end of a separator can be inserted into the first tubular portion from the inner wall surface side of the concrete formwork made of cardboard, in a state in which the first tubular portion is inserted into the insertion hole of the concrete formwork so that the first flange portion abuts against the inner wall surface of the concrete formwork from the inner wall surface side of the concrete formwork, and the second tubular portion is inserted into the insertion hole of the concrete formwork so that the second flange portion abuts against the outer wall surface of the concrete formwork from the outer wall surface side of the concrete formwork; Jig for concrete formwork.

2. The concrete formwork jig according to claim 1, The first jig and the second jig have water impermeability, With a part or the whole of the first cylindrical portion housed in the second cylindrical portion, one end of the separator can be inserted into the first cylindrical portion from an inner wall surface side of the concrete formwork. Jig for concrete formwork.

3. A method for installing a concrete form using a concrete form jig, comprising: The concrete formwork jig has a first jig and a second jig, The first jig has a first cylindrical portion and a first flange portion provided at a base end portion of the first cylindrical portion, The second jig has a second cylindrical portion and a second flange portion provided at a base end portion of the second cylindrical portion, inserting the first tubular portion into an insertion hole of the concrete form from an inner wall surface side of the concrete form made of corrugated cardboard so that the first flange portion abuts against the inner wall surface of the concrete form; inserting the second tubular portion into the insertion hole of the concrete form from an outer wall surface side of the concrete form so that the second flange portion abuts against the outer wall surface of the concrete form; inserting one end of a separator into the first cylindrical portion from an inner wall surface side of the concrete formwork; A method for installing concrete formwork, including:

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