Plate, connection plate, and concrete foundation manufacturing method

Abstract

To provide a plate allowing a placing joint to be lower than GL and capable of improving workability in construction of a foundation.SOLUTION: A plate 10 is constituted so that a placing joint of an outer peripheral surface of a concrete foundation is positioned below a ground line when the concrete foundation is manufactured by double placing method. The plate 10 is fitted to a reinforcement so as to be partially positioned below the ground line.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to plates used in constructing a concrete foundation by the two-cast construction method, a connecting plate for connecting the plates, and a method for manufacturing a concrete foundation by the two-cast construction method. [Background technology]

[0002] A known method for constructing concrete foundations (hereinafter simply referred to as "foundations") is the two-stage pouring method, in which concrete is poured in two stages. In the two-stage pouring method, the first (first) concrete is poured to build the base section, and after the concrete for the base section has hardened, the second (second) concrete is poured to build the riser section on top of the base section, and the riser section is constructed by allowing the concrete to harden. Generally, when a foundation is constructed using the two-stage pouring method, a pouring joint is created as the boundary between the base section and the riser section.

[0003] Since the appearance of a foundation is poor if the construction joints are exposed, in order to hide the construction joints, the foundation is constructed so that the construction joints are positioned below the ground line (hereinafter referred to as "GL"). Conventionally, a notched plate 100 shown in FIG. 21 has been used as a jig for lowering the construction joints below the GL. Below, the notched plate 100 and a foundation construction method using the notched plate 100 will be described with reference to FIGS. 21 and 22.

[0004] The notched plate 100 is formed by bending a steel plate into a J-shape. A release agent is applied to the notched plate 100 before pouring the concrete to facilitate the notched plate 100 being released from the concrete. As shown in FIG. 22(a), the notched plate 100 is attached to a formwork (outer frame) P using a plurality of rare earth magnets M so that its bottom is lower than GL. As shown in FIGS. 22(b) and 22(c), the notched plate 100 is removed from the formwork P and the base portion X after the construction of the base portion X is completed. Because the notched plate 100 is positioned so that its bottom is lower than GL, the outer surface of the constructed base portion X will be lower than GL. Thereafter, a second formwork (inner frame) is set up on the horizontal surface of the base portion X (not shown), and a second concrete is poured around the outer periphery of the base portion X between the first formwork (outer frame) P and the second formwork (inner frame), including the area where the notched plate 100 was removed (the area recessed from the horizontal surface), thereby constructing a rising portion on the base portion X. In this way, a concrete foundation having a base portion X and a rising portion with the pouring joint lower than GL can be constructed. Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional notched plates are heavy because they are made of iron, so many rare earth magnets are required to attach them to the formwork and position them. Furthermore, if an insufficient amount of rare earth magnets is used, or if the rare earth magnets weaken due to deterioration, the notched plate may shift out of position relative to the formwork, causing the first concrete pour to build the base to fail and hindering the work. Therefore, further improvement of the workability of conventional construction methods is an issue.

[0006] The present invention has been made to solve the above problems, and aims to provide a plate that can lower the construction joint below GL and improve workability in foundation construction. Another aim of the present invention is to provide a connecting plate for connecting the plates at the positions where the corners of the concrete foundation are to be formed. A further aim of the present invention is to provide a method for constructing a concrete foundation using the plate by the two-cast construction method. [Means for solving the problem]

[0007] (Item 1) The plate of one embodiment of the present invention comprises: A plate for positioning the concrete foundation joint on the outer periphery below the ground line when manufacturing a concrete foundation by a two-cast construction method, It is characterized in that it is attached to the reinforcing bar so that a portion of it is located below the ground line.

[0008] (Item 2) A further aspect of the present invention is the plate according to item 1, a first plate portion having a first surface facing the concrete and a second surface opposite to the first surface and extending in the vertical direction; a second plate portion having a first surface facing the concrete and a second surface opposite to the first surface, the second plate portion being provided below the first plate portion, inclined relative to the first plate portion and extending toward the formwork, with at least a portion of the second plate portion being located below the ground line; Equipped with When concrete is poured, the first plate portion absorbs the pressure of the concrete from the horizontal direction, and a part of the second plate portion comes into direct or indirect contact with the formwork, preventing the concrete from blowing up from below and forming a space between the formwork and the plate.

[0009] (Item 3) A further embodiment of the plate of the present invention is the plate according to item 2, The angle between the second surface of the first plate portion and the second surface of the second plate portion is smaller than 180 degrees.

[0010] (Item 4) A further embodiment of the plate of the present invention is the plate according to item 3, The angle is characterized by being greater than 90 degrees.

[0011] (Item 5) A further embodiment of the plate of the present invention is the plate according to item 1 or 2, The plate is characterized in that it is attached to the reinforcing bar using a mounting fixture.

[0012] (Item 6) A connecting plate according to one embodiment of the present invention comprises: A connecting plate for connecting a plurality of plates according to claim 1 or 2 at a position where a corner portion of the concrete foundation is to be formed, a first connecting plate portion; a second connecting plate portion that intersects the first connecting plate portion at a right angle; The present invention is characterized by comprising:

[0013] (Item 7) In one aspect of the present invention, the method comprises: A method for manufacturing a concrete foundation by a double casting method in which the outer surface joint is located below the ground line, providing a plate; Attaching the plate to a reinforcing bar so that a portion of the plate is located below a ground line; The present invention is characterized by comprising:

[0014] (Item 8) A further aspect of the present invention is a method according to item 7, further comprising: The plate is a first plate portion having a first surface facing the concrete and a second surface opposite to the first surface and extending in the vertical direction; a second plate portion having a first surface facing the concrete and a second surface opposite to the first surface, the second plate portion being provided below the first plate portion, inclined relative to the first plate portion and extending toward the formwork; It is equipped with the plate is arranged such that a portion of the first plate portion is located above a ground line and a portion of the second plate portion is located below the ground line; The method further includes pouring concrete after attaching the plate to the rebar; The first plate portion withstands the pressure of the concrete from the horizontal direction, a portion of the second plate portion comes into direct or indirect contact with the formwork, the second plate portion prevents concrete from blowing up from below, and forms a space between the formwork and the plate.

[0015] (Item 9) A further aspect of the present invention provides the method according to item 7 or 8, further comprising: The plate is attached to the reinforcing bar by attaching a mounting fixture to the plate and attaching the mounting fixture to the reinforcing bar.

[0016] (Item 10) A further aspect of the present invention provides the method according to item 7 or 8, further comprising: The method includes a step of arranging the two plates at right angles at the position where the corner of the concrete foundation is to be formed, connecting the first connecting plate portion of the connecting plate described in claim 6 to one of the plates, and connecting the second connecting plate portion of the connecting plate to the other plate, thereby connecting the two plates via the connecting plates.

[0017] (Item 11) An apparatus according to one aspect of the present invention comprises: 1. A device for forming a recess in an outer periphery of a base portion of a concrete foundation, the base portion having a (central) horizontal surface at a position higher than a ground line, the recess being recessed from the horizontal surface, the device comprising: A plate according to any one of items 1 to 5, The connecting plate of item 6, and a mounting fixture for attaching the plate to a reinforcing bar. [Effects of the Invention]

[0018] The plate of the present invention can lower the joint height below GL when used in a two-cast concrete foundation construction, and can also improve workability during foundation construction. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is a perspective view of a plate according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the plate of FIG. 1. [Figure 3] 3 is a cross-sectional view of the plate of FIG. 2 taken along line AA. [Figure 4] FIG. 2 is a perspective view of a connecting plate according to an embodiment of the present invention. [Figure 5] FIG. 5 is a plan view of the connecting plate of FIG. [Figure 6] 6 is a cross-sectional view of the connecting plate of FIG. 5 taken along line BB. [Figure 7] FIG. 1 is a perspective view of a wearing tool according to an embodiment of the present invention. [Figure 8] 8A and 8B are a front view and a rear view of the wearing tool of FIG. 7. [Figure 9] 8A and 8B are a plan view and a bottom view, respectively, of the wearing fixture of FIG. 7. [Figure 10] FIG. 8 is a side view of the wearing tool of FIG. 7. [Figure 11] The side view of the wearing tool in FIG. 10 shows a modified form in which the plate is clamped. [Figure 12] FIG. 2 is a schematic diagram showing the state after the plate of one embodiment of the present invention has been installed and before the first concrete has been poured. [Figure 13] FIG. 13 is a schematic perspective view showing a state in which the plate is attached to the reinforcing bar using the attachment fixture in the embodiment of FIG. 12. [Figure 14] FIG. 13 is a schematic diagram showing a configuration in which two plates are connected using a connecting plate at a position where a corner of a concrete foundation is to be formed in the configuration of FIG. 12. [Figure 15] 15 is a cross-sectional view taken along CC in the embodiment of FIG. 14. [Figure 16] FIG. 10 is a schematic diagram showing how the plate tilts due to the pressure of the concrete when the first concrete is poured. [Figure 17] FIG. 10 is a schematic diagram showing the shape of a corner portion where the plate tilts due to the pressure of the concrete when the first concrete is poured. [Figure 18] This is a schematic diagram after the base portion has been constructed by pouring the first concrete. [Figure 19] This is a schematic diagram after the first concrete has hardened and the plate has been removed. [Figure 20] This is a cross-sectional view of the constructed base after the second concrete has been poured in the area where the plate was removed. [Figure 21] FIG. 1 is a perspective view of a conventionally used notched plate. [Figure 22] (a) Cross-sectional view after installation of the notched plate and before pouring concrete in the base part, (b) cross-sectional view after pouring concrete in the base part, (c) cross-sectional view after removing the notched plate. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described below with reference to the drawings. Note that the shapes of the drawings referred to in the following description are conceptual or schematic diagrams for explaining preferred shapes and dimensions, and the dimensional ratios and the like do not necessarily correspond to the actual dimensional ratios. In other words, the present invention is not limited to the dimensional ratios in the drawings. Furthermore, the embodiment described below merely illustrates one specific example of the present invention. The present invention is not limited to the embodiment described below, and can be modified as appropriate within the scope of the present invention.

[0021] In this embodiment, when constructing a concrete foundation using the two-cast construction method, an apparatus including a plate 10, a connecting plate 20, and a mounting fixture 30 is used so that the construction joint Z is lower than ground line GL. In other words, when constructing a base portion X of a concrete foundation having a (central) horizontal surface higher than ground line GL, the combination of the plate 10, the connecting plate 20, and the mounting fixture 30 makes it possible to form a recess on the outer periphery of the base portion X that is recessed from the horizontal surface and has a construction joint surface on its upper surface. The outer periphery of the recess (or the construction joint surface) forms a construction joint Z located below ground line GL. In other words, this embodiment makes it possible to manufacture a concrete foundation using the two-cast construction method in which the construction joint Z on the outer periphery is located below ground line GL. Each component will be described below.

[0022] The configuration of a plate 10 according to one embodiment of the present invention will be described in detail with reference to Figures 1 to 3. Figure 1 is a schematic perspective view of the plate 10. Figure 2 is a plan view of the plate 10. Figure 3 is a cross-sectional view of the plate 10 taken along line AA.

[0023] The plate 10 of one embodiment of the present invention is used to lower the pouring joint Z below ground level when constructing a foundation using the two-pour pouring method. Specifically, the plate 10 is used when constructing a concrete foundation using the two-pour pouring method, and is an intrusion prevention plate that prevents at least water (or other fluids) from entering through the pouring joint surface of the concrete foundation. That is, the plate 10 of the present invention is installed before the first concrete pour and is used to lower the outer surface of the base portion X constructed by the first concrete pour below ground level. Specifically, one or more plates 10 are attached to reinforcing bars T along the periphery of the base portion X or formwork P to be constructed, with a portion of the plate 10 positioned below ground level, thereby blocking fresh concrete (fluid) and enabling the level (height) of the outer periphery of the constructed base portion X to be positioned lower than the horizontal plane (the central portion forming the horizontal top surface) of the base portion X and the level of ground level. The pouring joint Z is formed at the position of the upper surface of the outer periphery of the base portion X.

[0024] As shown in FIGS. 1 to 3 , the plate 10 is composed of a curved, rigid plate-like body of a predetermined thickness. The plate 10 includes a first plate portion 11 having a first surface 11a facing the concrete and a second surface 11b opposite the first surface 11a, and extending in the vertical direction. The second plate portion 12 has a first surface 12a facing the concrete and a second surface 12b opposite the first surface 12a. The second plate portion 12 is provided below the first plate portion 11 and extends at an angle relative to the first plate portion 11. In other words, the first plate portion 11 and the second plate portion 12 are curved relative to each other. The first plate portion 11 has an attachment portion 13 that is attached to the reinforcing bar T. In this embodiment, the attachment portion 13 is a portion near the upper end of the first plate portion 11. While any means for attaching the attachment portion 13 to the reinforcing bar T can be selected, it is preferable to use a mounting fixture 30 described below.

[0025] The second plate portion 12 is configured so that when a portion of the first plate portion 11 (attached portion 13) is attached to the reinforcing bar T, at least a portion of it is located below GL. Preferably, the plate 10 can be configured so that a portion of the first plate portion 11 is located below GL and the entire second plate portion 12 is located below GL. Furthermore, the plate 10 can be configured so that a portion (upper portion) of the first plate portion 11 and the attached portion 13 are located above the horizontal line of the base portion X.

[0026] Furthermore, the plate 10 has a width (left-right direction in FIG. 2) that is disposed in a substantially vertical direction when installed, and a length (up-down direction in FIG. 3) that is disposed in a substantially horizontal direction. The width of the plate 10 is disposed along the outer periphery of the formwork P (or base portion X). The width of the plate 10 is set to be longer than the length. Therefore, the width direction of this plate 10 is also referred to as the longitudinal direction. In this embodiment, since the formwork P (or base portion X) is quadrilateral (or polygonal), the width of the plate 10 may be set to match the length of each side. Alternatively, multiple plates 10 may be used to match the length of each side of the formwork P (or base portion X).

[0027] As will be described later, when concrete is poured (i.e., when fresh concrete is poured into formwork P while attached to reinforcing bars T), plate 10 functions such that first plate portion 11 absorbs the horizontal pressure of the concrete, and a portion of second plate portion 12 comes into direct or indirect contact with formwork P, preventing concrete from blowing up from below and forming a space between formwork P and plate 10.

[0028] In the plate 10 of this embodiment, as shown in FIG. 3, the angle (reflection angle) between the second surface 11b of the first plate portion 11 and the second surface 12b of the second plate portion 12 is smaller than 180 degrees. This angle is preferably larger than 90 degrees. With this configuration, when the first plate portion 11 is attached to the reinforcing bar T so as to hang down vertically, the second plate portion 12 extends toward the formwork P, making it easier for the leading edge (lower edge) of the second plate portion 12 to come into contact with the formwork P. Furthermore, so that the plate 10 can span between the formwork P and the reinforcing bar T, it is preferable that the sum of the length of the first plate portion 11 in the vertical width direction and the length of the second plate portion 12 in the vertical width direction be sufficiently larger than the minimum distance (horizontal distance) between the inner surface of the formwork P and the outer surface of the reinforcing bar T. In particular, the vertical width of the plate 10 placed between the formwork P and the reinforcing bar T is larger than the distance between the formwork P and the reinforcing bar T, so that the plate 10 can be installed in a predetermined position without using any other components.

[0029] The plate 10 of this embodiment is configured to be rotatably supported on the formwork P via the attachment portion 13. When pressure is applied from the first surfaces 11a, 12a of the plate 10 when fresh concrete is poured, the plate 10 tilts outward (toward the formwork P), and its lower end (the tip of the second plate portion 12) moves closer to the formwork P. In this embodiment, the vertical width of the first plate portion 11 is greater than the vertical width of the second plate portion 12, but due to the ratio of these lengths, the first plate portion 11 is likely to tilt toward the formwork P when it receives pressure from the fresh concrete from the horizontal direction. However, this length ratio can be changed as desired.

[0030] The plate 10 of this embodiment is preferably formed from a synthetic resin plate material such as polypropylene resin or polycarbonate resin. The plate 10 of this embodiment may be formed by bending a metal plate, but using a synthetic resin plate material makes it lighter and more workable. More preferably, as shown in the enlarged view of FIG. 3, the plate 10 may be formed from a hollow structure plate made of synthetic resin, such as plastic corrugated cardboard, which has a hollow structure consisting of an aggregate of many cells. Hollow structure plates are lighter and easier to process because they can be bent by scoring the inside surface.

[0031] Next, the configuration of connecting plate 20 according to one embodiment of the present invention will be described in detail with reference to Fig. 4 to Fig. 6. Fig. 4 is a schematic perspective view of connecting plate 20. Fig. 5 is a plan view of connecting plate 20. Fig. 6 is a BB cross-sectional view of connecting plate 20.

[0032] A connecting plate 20 according to one embodiment of the present invention is configured to connect a plurality of adjacent (two) plates 10 at a position where a corner of a concrete foundation is to be formed (see FIG. 14 ), and to fill a gap between two plates 10 arranged at a predetermined corner angle (a right angle in this embodiment). The connecting plate 20 includes a first connecting plate portion 21 extending in a first direction and a second connecting plate portion 22 intersecting the first connecting plate portion 21 at a right angle. The first connecting plate portion 21 and the second connecting plate portion 22 of the connecting plate 20 are connected to the plates 10, 10 via connecting portions 23 defined at their upper ends. In this embodiment, the connecting portions 23 are connected to the plates 10, 10 by clips 24 attached to the first connecting plate portion 21 and the second connecting plate portion 22, respectively (see FIG. 14 ). The first connecting plate portion 21 and the second connecting plate portion 22 are configured to allow the connected plates 10, 10 to rotate around the connecting portion 23 in the direction of approaching or separating from each other.

[0033] As shown in FIG. 5, the first connecting plate portion 21 and the second connecting plate portion 22 are bent at approximately a right angle in plan view to match the angle of the corner of the concrete foundation. The first connecting plate portion 21 and the second connecting plate portion 22 have the same trapezoidal shape, with the upper base located vertically above being smaller than the lower base. The height of this trapezoidal shape (the distance between the upper and lower bases) is approximately equal to or smaller than the vertical width of the first plate portion 11 of the plate 10. As shown in FIG. 6, the connecting plate 20 is inclined with respect to a vertical plane (parallel to the inner surface of the formwork P) so that the upper end is closer to the reinforcing bar T than the lower end. Due to this inclination, when the plate 10 suspended from the reinforcing bar T is connected to the connection portion 23 at the upper end of the first connecting plate portion 21 (or the second connecting plate portion 22), a gap is formed between the second surface 21b of the plate 10 and the inner surface (facing the reinforcing bar T) of the first connecting plate portion 21 (or the second connecting plate portion 22) (see FIG. 15). This gap allows the plate 10 to tilt toward the formwork P.

[0034] The connecting plate 20 of this embodiment is preferably formed from a plate material made of synthetic resin, such as polypropylene resin or polycarbonate resin. The connecting plate 20 of this embodiment may be formed by bending a metal plate, but using a plate material made of synthetic resin makes it lighter and more workable. More preferably, the connecting plate 20 may be formed from a hollow structure plate made of synthetic resin, such as plastic corrugated cardboard, which has a hollow structure consisting of an aggregate of many cells, similar to the plate 10. A hollow structure plate is lighter and easier to process because it can be bent by scoring it from the inside.

[0035] Next, the configuration of the mounting device 30 of one embodiment of the present invention will be described in detail with reference to Figures 7 to 11. Figure 7 is a schematic perspective view of the mounting device 30. Figures 8(a) and 8(b) are a front view and a rear view of the mounting device 30. Figures 9(a) and 9(b) are a plan view and a bottom view of the mounting device 30. Figure 10 is a side view of the mounting device 30. Figure 11 is a side view of the mounting device 30 after elastic deformation. Here, the front of the mounting device 30 is the surface facing the formwork P.

[0036] The mounting fixture 30 of one embodiment of the present invention is used to mount the plate 10, which is used when manufacturing a concrete foundation, to a reinforcing bar T. As shown in FIG. 7, the mounting fixture 30 is formed by bending a single wire of spring steel. The mounting fixture 30 includes a pair of holding portions 31 that hold the plate 10, and one mounting portion 33 for mounting the plate 10 to the reinforcing bar T. An intermediate portion 34 extends between the holding portions 31 and the mounting portion 33. This intermediate portion 34 allows the holding portion 31 and the mounting portion 33 to be spaced apart in the thickness direction of the plate 10 (or in the radial direction of the reinforcing bar T).

[0037] As shown in FIGS. 8 and 9, the mounting portion 33 is disposed between a pair of holding portions 31. Each holding portion 31 includes a first clamping portion 31a and a second clamping portion 31b that clamps the plate 10 between the first clamping portion 31a and the second clamping portion 31b. The first clamping portion 31a abuts against the first surface 11a of the plate 10, and the second clamping portion 31b abuts against the second surface 11b. The first clamping portion 31a is formed at a bent portion of the wire rod, and the second clamping portion 31b is formed at a linear portion extending vertically in the wire rod. As shown in FIG. 11, the first clamping portion 31a elastically deforms so as to move away from the second clamping portion 31b, thereby forming an insertion opening vertically downward, through which the plate 10 can be inserted and clamped.

[0038] Furthermore, the mounting fixture 30 further has an extending portion 32 extending in a direction away from the plate 10 to which it is mounted. The extending portion 32 is provided below the first clamping portion 31a. The extending portion 32 is configured to facilitate the operation of attaching and detaching the mounting fixture 30 to and from the plate 10. Specifically, as shown in FIG. 10 , the extending portion 32 extends away from the plate 10. Also, as shown in FIG. 10 , the extending portion 32 and the second clamping portion 31b form an acute angle. When mounting the mounting fixture 30 to the plate 10, the plate 10 is inserted into the space between the second clamping portion 31b and the extending portion 32, and is pushed into the intersection of the second clamping portion 31b and the extending portion 32 (or the first clamping portion 31a), thereby easily expanding the holding portion 31 so as to move the second clamping portion 31b away from the first clamping portion 31a. On the other hand, when removing the wearing tool 30 from the plate 10, the user can easily operate the holding part 31 by hooking their finger on the extension part 32. That is, the extension part 32 functions as a guide when the holding part 31 grips the plate 10, and also functions as an operating part when removing the wearing tool 30 from the plate 10. The extension part 32 may be provided on the lower part of the second gripping part 31b instead of the first gripping part 31a, or may be provided on both the first gripping part 31a and the second gripping part 31b.

[0039] The mounting portion 33 is formed as a circularly curved portion that is open on its back surface (the reinforcing bar T side). The mounting portion 33 has a receiving space 33a that receives the reinforcing bar T and an entrance opening 33b through which the reinforcing bar T enters the receiving space 33a. The width of the entrance opening 33b is smaller than the outer diameter of the reinforcing bar T. Because the width of the entrance opening 33b is smaller than the outer diameter of the reinforcing bar T, once the reinforcing bar T passes through the entrance opening 33b (which has elastically deformed) and enters the receiving space 33a, the reinforcing bar T is less likely to come off. The mounting portion 33 is also configured to allow the reinforcing bar T that enters the receiving space 33a to tilt toward the entrance opening 33b. That is, the reinforcing bar T can be displaced from a vertical position to an inclined position relative to the plane that defines the receiving space 33a. This allows the plate 10 attached to the reinforcing bar T to tilt. Furthermore, the mounting fixture 30 is configured so that when the mounting fixture 30 is attached to the plate 10, the receiving space 33a is positioned horizontally offset from the plate 10 in a plan view (see FIG. 12).

[0040] Next, a method for producing a concrete foundation by a double pouring method, in which a construction joint Z on the outer periphery is positioned below ground level (GL), using an apparatus comprising the plate 10, connecting plate 20, and mounting fixture 30 of this embodiment for a structure including a pre-constructed formwork P and reinforcing bars T, will be described. The production method mainly includes a step of preparing the plate 10 and a step of attaching the plate 10 to the reinforcing bars T so that a portion of the plate 10 is positioned below ground level (GL). Each step will be described in detail below with reference to the drawings.

[0041] First, a plurality of plates 10 are prepared to fit the outer periphery of the base portion X to be constructed. One or more mounting fixtures 30 are attached to each plate 10 by clamping the attachment portion 13 at the upper end of the plate 10 with the first clamping portion 31a and second clamping portion 31b of the holding portion 31 of the mounting fixture 30. The number of mounting fixtures 30 attached can be increased or decreased depending on the length of the plate 10 in the longitudinal direction (width).

[0042] Next, the mounting fixture 30 that holds the plate 10 is attached to the reinforcing bar T. By pressing the mounting portion 33 of the mounting fixture 30 against the reinforcing bar T, the reinforcing bar T can be forcibly pushed into the receiving space 33a through the entrance opening 33b. In a typical concrete foundation, the horizontal surface (top surface) of the base portion X is designed to be located above ground level (GL). The plate 10 is attached at a predetermined height to the reinforcing bar T so that its upper end (attachment portion 13) is located higher than the horizontal surface of the base portion X and its lower end (tip of the second plate portion 12) is located lower than ground level when tilted until it contacts the formwork P. Then, all of the plates 10 are attached to the reinforcing bar T so that they are arranged continuously along the inner periphery of the formwork P.

[0043] 12 and 13 show a state after the multiple plates 10 have been attached to the reinforcing bars T using the mounting fixtures 30 and before the first concrete is poured. As shown in FIGS. 12 and 13, the plates 10 are supported so as to be suspended by the reinforcing bars T via the mounting fixtures 30. At this time, the first plate portions 11 of the plates 10 are arranged in a substantially vertical direction, and the second plate portions 12 extend toward the formwork P.

[0044] Then, a connecting plate 20 is prepared, and the two plates 10, 10 are arranged at right angles at the positions where the corners of the concrete foundation are to be formed, and the two adjacent plates 10, 10 are joined using the connecting plate 20. In particular, the connecting plate 20 is placed at each corner, and at each corner, the connecting portion 23 of the first connecting plate portion 21 is joined to the upper edge of one plate 10, and the connecting portion 23 of the second connecting plate portion 22 is joined to the upper edge of the other plate 10. A clip 24 is used for joining the plates. The clip 24 is a typical clip configured to clamp the two plates together using spring force.

[0045] 14 and 15 show a configuration in which two plates 10, 10 are connected using a connecting plate 20 at a corner of a formwork P. As shown in FIG. 14, in a plan view, the connecting plate 20 connects two plates 10, 10 arranged at a right angle, and fills the gap between the plates 10, 10 at its upper end. On the other hand, as shown in FIG. 15, the first connecting plate 21 (and the second connecting plate 22) are inclined with respect to the second surface 11b of the first plate 11, which is suspended from a reinforcing bar T and arranged in a substantially vertical direction, and a space is formed therebetween that allows tilting of the plate 10 (first plate 11). In this case, the second plate 12 is disposed below the first connecting plate 21 (and the second connecting plate 22), and therefore, interference with the connecting plate 20 is prevented when the plate 10 tilts.

[0046] Next, a first concrete is poured inside the formwork P to construct the base portion X. As shown in FIG. 16 , when fluid concrete (fresh concrete) is poured from at least the inside of the plate 10, the volume of the concrete inside gradually rises and contacts the first surfaces 11a and 12a of the plate 10. As the horizontal pressure of the concrete acts on the first plate portion 11, the plate 10 is pushed toward the formwork P, and the tip of the second plate portion 12 contacts the formwork P. At this time, the second plate portion 12 extends in a substantially horizontal direction. Note that an intermediate member may be installed between the tip of the second plate portion 12 and the formwork P, so that the tip of the second plate portion 12 indirectly contacts the formwork P. The first plate portion 11 receives the horizontal pressure of the concrete, and the second plate portion 12 contacts the formwork P (directly or indirectly), preventing concrete from blowing up from below and forming a groove-like space between the formwork P and the plate 10.

[0047] 17, similarly at the corners, the pressure of the concrete from the horizontal direction acts on the first plate portion 11, pushing the plate 10 toward the formwork P, causing the tip of the second plate portion 12 to come into contact with the formwork P. At this time, the second surface 11b of the first plate portion 11 tilts so as to come close to or into contact with the inclined inner surface of the first connecting plate portion 21 (or second connecting plate portion 22) of the connecting plate 20.

[0048] FIG. 18 shows the state after the concrete has hardened and the base portion X has been constructed with the first concrete. As shown in FIG. 18, the concrete has hardened inside and below the plate 10, forming a space between the base portion X and the formwork P via the plate 10. That is, a recess is formed in the outer periphery of the base portion X, located outside the first plate portion 11 and above the second plate portion 12, recessed from the top surface (horizontal plane) of the horizontal portion in the center of the base portion X. The upper surface of this recess forms a pouring joint surface for pouring the second concrete. Because the second plate portion 12 is located lower than GL, the upper surface (bottom surface of the recess) of the outer periphery of the base portion X is located lower than GL.

[0049] 19, the plate 10 and the mounting fixture 30 can be removed from the base portion X by detaching the mounting portion 33 of the mounting fixture 30 from the rebar T and peeling the plate 10 from the concrete. At the corners, the connection between the connecting plate 20 and the plate 10 can also be easily released by removing the clips 24. The connecting plate 20 is then similarly removed from the base portion X.

[0050] Next, as shown in FIG. 20, a second form P' is constructed inside the form P on the horizontal plane of the base X, and a second concrete is poured between the form P and the second form P'. As this second concrete hardens, a rising portion Y can be constructed around the periphery of the base X. A pouring joint Z is formed between the base X formed by pouring the first concrete and the rising portion Y formed by pouring the second concrete, and is exposed on the outer surface. This pouring joint Z is formed at a position lower than the ground level. In this way, a concrete foundation can be constructed having a base X and a rising portion Y, with the pouring joint Z lower than the ground level.

[0051] The present invention is not limited to the above-described embodiment, and various modifications are possible. Modifications of the present invention will be described below.

[0052] (1) The plate of the present invention is not limited to the above-described embodiment. In the above-described embodiment, the plate is attached to the reinforcing bar using a mounting fixture, but the present invention is not limited to this. For example, the plate may have a configuration in which a clamp or the like capable of holding the reinforcing bar is integrally formed as an attachment portion.

[0053] (2) The plate of the present invention is not limited to the above-described embodiment. In the above-described embodiment, the plate is configured to be attached to the reinforcing bar in a state in which tilting is permitted, but the present invention is not limited to this. For example, as shown in FIG. 18, the plate may be fixed to the reinforcing bar (without tilting) in a position in which the tip of the second plate portion contacts the inner surface of the formwork.

[0054] (3) The plate of the present invention is not limited to the above embodiment. In the above embodiment, the entire second plate portion of the plate is positioned lower than GL, but the present invention is not limited to this. The entire first plate portion and a portion of the second plate portion may be positioned higher than GL, and only a portion of the tip side of the second plate portion may be positioned lower than GL.

[0055] (4) The plate of the present invention is not limited to the above-described embodiment. In other words, the shape of the plate is not limited to the shape of the above-described embodiment, and can be appropriately modified by those skilled in the art based on the technical concept of the present invention.

[0056] The present invention is not limited to the above-described embodiments and modifications, and can be implemented in various forms within the technical scope of the present invention. [Explanation of symbols]

[0057] 10 plates 11 1st plate part 11a 1st page 11b Side 2 12 2nd plate part 12a 1st page 12b Side 2 13 Attached part 20 Connection plate 21 First connecting plate portion 22 Second connecting plate portion 23 Connection 24 clips 30 Wearing equipment 31 Holding part 31a First clamping part 31b Second clamping part 32 Extension part 33 Mounting part 33a Receptive Space 33b Entry opening 34 Middle section P-type frame (outer frame) P' 2nd formwork (inner frame) T-bar X base Y rising part Z joint GL Grand Line

Claims

1. A plate for positioning the concrete foundation joint on the outer periphery below the ground line when manufacturing a concrete foundation by a two-cast construction method, The reinforcing bar is attached so that a portion of the reinforcing bar is located below the ground line. plate.

2. a first plate portion having a first surface facing the concrete and a second surface opposite to the first surface and extending in the vertical direction; a second plate portion having a first surface facing the concrete and a second surface opposite to the first surface, the second plate portion being provided below the first plate portion, inclined relative to the first plate portion and extending toward the formwork, with at least a portion of the second plate portion being located below the ground line; Equipped with When concrete is poured, the first plate portion receives the pressure of the concrete from the horizontal direction, and a part of the second plate portion directly or indirectly contacts the formwork, and the second plate portion prevents the concrete from blowing up from below, forming a space between the formwork and the plate.

2. The plate of claim 1.

3. an angle between the second surface of the first plate portion and the second surface of the second plate portion is smaller than 180 degrees; 3. The plate of claim 2.

4. The angle is greater than 90 degrees.

4. The plate of claim 3.

5. The plate is attached to the rebar using a mounting fixture.

3. A plate according to claim 1 or 2.

6. A connecting plate for connecting a plurality of plates according to claim 1 or 2 at a position where a corner portion of the concrete foundation is to be formed, a first connecting plate portion; a second connecting plate portion intersecting the first connecting plate portion at a right angle; A connection plate comprising:

7. A method for manufacturing a concrete foundation by a double casting method in which the outer surface joint is located below the ground line, providing a plate; Attaching the plate to a reinforcing bar so that a portion of the plate is located below a ground line; A method for manufacturing a concrete foundation, comprising:

8. The plate is a first plate portion having a first surface facing the concrete and a second surface opposite to the first surface and extending in the vertical direction; a second plate portion having a first surface facing the concrete and a second surface opposite to the first surface, the second plate portion being provided below the first plate portion, inclined relative to the first plate portion and extending toward the formwork; It is equipped with the plate is disposed such that a portion of the first plate portion is located above a ground line and a portion of the second plate portion is located below the ground line; The method further includes pouring concrete after attaching the plate to the rebar; The first plate portion receives the pressure of the concrete from the horizontal direction, and a part of the second plate portion directly or indirectly contacts the formwork, and the second plate portion prevents the concrete from blowing up from below, forming a space between the formwork and the plate. The method for manufacturing a concrete foundation according to claim 7.

9. attaching the plate to the rebar by attaching a mounting fixture to the plate and attaching the mounting fixture to the rebar; The method for manufacturing a concrete foundation according to claim 7 or 8.

10. The method includes a step of arranging the two plates at a right angle at a position where a corner of the concrete foundation is to be formed, and connecting the first connecting plate portion of the connecting plate according to claim 6 to one of the plates and the second connecting plate portion of the connecting plate to the other of the plates, thereby connecting the two plates via the connecting plate. The method for manufacturing a concrete foundation according to claim 7 or 8.

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