Termite-proof foundation construction method and termite-proof foundation structure

Abstract

In the present invention, a means for joining together a base part formwork and a rising part formwork using a paper panel is rationalized, and a uniform termite-proof line is efficiently provided to a placing joint between a rising part (43) and earthen floor concrete (6). An intermediate part (12) of a paper panel (1) is folded along a lower frame member (34) of a steel panel (3), and an upper part (11) of the paper panel (1) is disposed upright along the outside surface of the steel panel (3), then folded downward, and provisionally fixed in a state of being engaged with the lower frame member (34) of the steel panel (3). A termite-proof surface (15) formed in advance on the paper panel (1) is positioned in accordance with the height of a placing joint location between the rising part (43) and the earthen floor concrete (6), and is embedded in the lower side of the earthen floor concrete (6) in a state of being bent along the lower corner part of the placing joint location.

Description

Termite-proof foundation construction method and termite-proof foundation structure

[0001] The invention disclosed in this application relates to a termite-proof foundation construction method applicable to continuous foundations of houses and the like, and to a termite-proof foundation structure constructed by the termite-proof foundation construction method.

[0002] Inverted T-shaped continuous footing foundations, which have a base buried underground and a rising section above it, are widely used as foundation structures for homes and other small- to medium-sized buildings. The formwork for constructing these continuous footings typically consists of a base formwork and a rising formwork. The applicant has developed and put into practical use a foundation construction method that uses steel panels (metal forms) for the rising formwork and synthetic resin disposable formwork with a cross section shaped like a quarter-circle arc for the base formwork, thereby improving the quality of formwork construction and ease of work during concrete pouring and removal. The applicant has also disclosed related technologies in Patent Documents 1 to 3, etc.

[0003] This foundation construction method is designed to pour concrete from the base section to the rising section all at once. Therefore, before pouring the concrete, it is necessary to firmly connect the upper edge of the base section formwork to the lower frame material of the rising section formwork to prevent the base section formwork from disintegrating or floating up due to the pressure of pouring the concrete. Patent documents 1 to 3 also propose clamps, support members, connecting members, etc. as means for connecting the base section formwork. However, there is room for further improvement in these connecting means in terms of construction effort, cost, etc.

[0004] Furthermore, in recent years, with the rise in environmental awareness, there has been growing resistance to burying disposable formwork made of synthetic resin underground. Disposable formwork made of biodegradable plastic is also available, but there are also contractors who have negative views of it. Furthermore, biodegradable plastic formwork tends to be less popular than conventional general-purpose resin formwork in terms of quality and cost.

[0005] With a strip footing, the ground surface (earth floor) other than the foundation is exposed below the floor. To prevent moisture from entering the ground surface, concrete floor (moisture-proof concrete) is poured over the entire area surrounded by the raised sections. However, if gaps remain at the joints between the concrete floor and the raised sections, termites may invade the floor through the gaps. To block such termite entry routes (termite trails), a band of anti-termite chemicals is sprayed along the joints. However, this method not only takes time to carry out on-site construction, but also leads to variations in the amount and range of chemicals sprayed, making construction quality unstable.

[0006] A construction method in which anti-termite sheeting is laid around the concrete floor to block termite trails is also known. For example, Patent Documents 4 to 6 propose various forms of application of anti-termite sheeting to the joints between the concrete floor and the rising section. These anti-termite sheets include resin sheeting material with anti-termite chemicals kneaded into it, and stainless steel mesh with mesh sizes large enough to prevent termites from passing through. However, it is not particularly easy to accurately lay and temporarily secure anti-termite sheeting around the floor in parallel with the construction of the formwork for the strip footing or after the concrete for the strip footing has been poured, and there is still room for improvement in terms of construction effort, cost, etc.

[0007] When the problems with the resin disposable formwork mentioned above and the problems with anti-termite construction on the sides of the rising section are considered comprehensively, one option emerges: to use anti-termite treated paper formwork material for the formwork that will be buried underground.Patent document 7 discloses an invention in which the formwork for the base section is made of cardboard that has been treated with an agent to prevent termites.

[0008] The formwork is constructed of cardboard plates that surround the peripheral wall of the base, and is reinforced by fastening retaining plates at the joints between the plates, fastening rods to maintain spacing across the width, and attaching anti-tip members to the outside of the plates. Concrete is poured into the formwork to first form the base, and after curing, the formwork for the rising portion is assembled on top of the base, and concrete is poured into the formwork to form the rising portion. After the rising portion is removed from the formwork, a cover made of insect-proof cardboard is prepared and used to cover the area from the bottom of the rising portion to the top of the base.

[0009] The cardboard formwork surrounding the base wall and top edge is buried, but it decomposes and assimilates with the soil in a relatively short period of time. Furthermore, cardboard formwork is lightweight, making it easy to construct, and its water-retentive properties make it highly effective for curing. However, the cardboard formwork disclosed in Patent Document 7 is not structured to allow the base and rising sections to be molded simultaneously. Its assembly method is also inefficient, and there is room for further improvement in terms of workability, etc.

[0010] Japanese Patent Laid-Open No. 07-018860 Japanese Patent Laid-Open No. 08-020959 Japanese Patent Laid-Open No. 2023-008484 Japanese Patent Laid-Open No. 2002-371643 Japanese Patent Laid-Open No. 2003-056087 Japanese Patent Laid-Open No. 2003-247281 Japanese Patent Laid-Open No. 08-092968

[0011] The invention disclosed in this application was conceived after a comprehensive review of the various conventional technologies mentioned above, and aims to solve the problem of first providing an anti-termite foundation construction method with excellent workability, which employs environmentally friendly paper disposable formwork as the base formwork of a continuous footing, streamlining the means of connecting the base formwork with the rising formwork, and efficiently forming a uniform anti-termite line at the joint between the rising part and the concrete floor.

[0012] Additionally, the invention disclosed in this application provides a termite-proof foundation structure constructed by the termite-proof foundation construction method.

[0013] To achieve the above-mentioned object, the invention of the termite-proof foundation construction method disclosed in this application is characterized by using a bendable paper panel as the base formwork and a steel panel as the rising formwork, and forming a termite-proof line at the joint between the continuous footing and the concrete floor by the following [Steps 1] to [Steps 11]. [Step 1] A termite-proof treatment is applied in advance to a predetermined position in the height direction of the paper panel to form a termite-proof surface extending in the width direction of the paper panel. [Step 2] The steel panel is erected on appropriate support members installed on the construction surface to form the rising formwork. [Step 3] The middle part of the paper panel in the height direction is placed on the bottom frame material of the erected steel panel, and the paper panel is folded to fit the shape of the bottom frame material. [Step 4] The upper part of the paper panel is raised along the outer surface of the steel panel, abutted against the underside of the horizontal rib on the outer surface, and folded downward. The folded upper edge is engaged with the middle part folded along the shape of the bottom frame material of the steel panel and fixed to the steel panel. [Step 5] The lower part of the paper panel is inclined to flare out to match the shape of the base part of the continuous footing, and its lower edge is fixed to the construction surface to form a base part formwork. [Step 6] Concrete is poured into the formwork space surrounded by the base part formwork and the rising part formwork to form the base part and the rising part. [Step 7] After the concrete has cured, the engagement is released, and the middle part and upper part of the paper panel are removed from the steel panel, and the steel panel is demolded. [Step 8] The upper part of the paper panel is raised along the side of the rising part after demolding and temporarily fixed. [Step 9] Backfill soil is poured into the earthen floor space surrounded by the strip footing, burying it up to halfway along the height of the rising section, and then the earthen floor is leveled so that it is positioned in the area of ​​the termite-resistant surface of the paper panel. [Step 10] The upper part of the paper panel exposed above the earthen floor is folded along the earthen floor and overlapped on the earthen floor. [Step 11] Earthen floor concrete is poured into the earthen floor.

[0014] Furthermore, the termite-proof foundation construction method of the invention disclosed in this application is characterized in that in the above-mentioned [Step 4], the side edge portion of the paper panel that has been raised along the outer surface of the steel panel is folded toward the outer surface of the steel panel, and the upper part of the paper panel is fixed by pushing the side edge portion between the horizontal rib and the lower frame material.

[0015] Furthermore, in the above-mentioned [Step 8], the side edge portions of the folded paper panels are unfolded, and the upper portions of adjacent paper panels are abutted or overlapped with each other.

[0016] Furthermore, in the above-mentioned [Step 5], the lower portions of the adjacent paper panels are abutted or overlapped with each other.

[0017] In the above-mentioned anti-termite foundation construction method, it is also preferable to pre-process fold lines at the locations where the paper panel will be folded.

[0018] Furthermore, the invention of the anti-termite foundation structure disclosed in this application is characterized in that paper panels are arranged continuously from the outer surface of the base portion of the slab footing, extending upward along the side of the upright portion, via the connection between the base portion and the upright portion, and bending toward the floor along the lower corner of the joint between the concrete floor poured at mid-way height of the upright portion and the upright portion, up to a predetermined range around the periphery of the underside of the concrete floor, and the paper panels form an anti-termite surface that has been treated with an anti-termite treatment within a predetermined range that encompasses the lower corner of the joint.

[0019] The termite-proof foundation construction method described above involves folding the middle of the paper panel over the bottom frame of the steel panel, then raising the top of the paper panel along the outer surface of the steel panel, then folding it back down and temporarily fastening it to the bottom frame of the steel panel. By temporarily fastening the paper panel to the bottom frame of the steel panel in this manner, the means for connecting the base and riser formworks can be streamlined. As a result, it is possible to significantly reduce the need for clamps, support members, connecting members, etc., which were previously required to connect the upper edge of the base formwork to the bottom frame of the riser formwork. Pre-creating fold lines in the paper panel at predetermined locations further improves construction efficiency.

[0020] By folding the anti-termite surface of the paper panel so that it fits along the lower corner of the joint between the rising part of the continuous footing and the concrete floor, a uniform anti-termite line can be efficiently formed at the joint. The process of spraying anti-termite chemicals at the construction site can be eliminated, shortening the construction period and stabilizing the construction quality in terms of anti-termite performance. The absence of disposable formwork made of synthetic resin also reduces the burden on the soil environment.

[0021] 1 is a plan view showing an example of a paper panel used in the base formwork of a continuous footing. FIG. 1 is a perspective view showing an image of the paper panel of FIG. 1 attached to a steel panel. FIG. 1 is a cross-sectional view for explaining [Step 2] to [Step 5] of the termite-proof foundation construction method disclosed in the present application. FIG. 1 is a cross-sectional view for explaining [Step 6]. FIG. 1 is a cross-sectional view for explaining [Step 7]. FIG. 1 is a cross-sectional view for explaining [Step 8]. FIG. 1 is a cross-sectional view for explaining [Step 9]. FIG. 1 is a cross-sectional view for explaining [Step 10]. FIG. 1 is a cross-sectional view for explaining [Step 11]. FIG. 12 is a plan view showing a modified paper panel. FIG. 13 is a perspective view showing an image of the paper panel of FIG. 10 attached to a steel panel. FIG. 14 is a perspective view showing the paper panel of FIG. 11 unfolded and erected after the steel panel has been removed from the form. FIG. 15 is a perspective view showing an image of the paper panel of FIG. 12 folded and laid on the dirt floor.

[0022] Hereinafter, embodiments of the invention disclosed in the present application will be described in accordance with the steps set forth in the claims, with reference to the drawings.

[0023] This termite-proof foundation construction method uses a bendable paper panel 1 as the base formwork for a continuous footing, and a steel panel 3 as the rising formwork. First, with reference to Figures 2 and 3, the steel panel 3 used in this termite-proof foundation construction method will be described. The steel panel 3 is not particularly different from conventionally used panels. It is constructed by joining frame members (vertical frame members 32, upper frame members 33, and lower frame members 34) to the back (outside) of the four periphery of a face plate 31, which has been surface-treated to enhance concrete peelability. In the illustrated embodiment, a flat rectangular cross-section member is used for the vertical frame member 32, and an irregular L-shaped cross-section member (see Figure 3) is used for the upper frame member 33 and lower frame member 34. The L-shaped cross-section member is joined so that its long side 35 is perpendicular to the face plate 31 and its short side 36 extends inward.

[0024] Stiffening ribs (vertical ribs 37, horizontal ribs 38) are joined to the middle part of the back surface of the face plate 31. The vertical ribs 37 and horizontal ribs 38 in the illustrated embodiment are made of flat plate material and are arranged in a crisscross pattern so as to divide the height and width of the steel panel 3 into multiple locations. The number and spacing of these vertical ribs 37 and horizontal ribs 38 are set appropriately depending on the overall size of the steel panel 3, etc., but the paper panel 1 described below is prepared in advance to correspond to the rib arrangement of the steel panel 3.

[0025] In the present specification, the shallow recessed space, rectangular in front view and formed on the back side of the steel panel 3 and partitioned by these frame members 32, 33, 34 and ribs 37, 38, will be referred to as the "inter-rib recess" (no reference numeral). For convenience of the following explanation, the opposing distance between the lower frame member 34 and the horizontal rib 38, or the opposing distance between the horizontal ribs 38, 38, will be defined as the "height of the inter-rib recess," and the opposing distance between the vertical frame member 32 and the vertical rib 37, or the opposing distance between the vertical ribs 37, 37, will be defined as the "horizontal width of the inter-rib recess." In the illustrated embodiment, all nine inter-rib recesses are set to have the same height A and horizontal width B, but the size of the inter-rib recesses may vary depending on the location.

[0026] [Step 1] Fig. 1 shows the planar shape of a paper panel 1 prepared to match the above-mentioned steel panel 3. The paper panel 1 is made using a material such as thick processed paper or thin cardboard that has appropriate rigidity to withstand the filling pressure when pouring concrete, and water resistance and water repellency to the extent that it will not soften due to the moisture in the concrete.

[0027] The illustrated paper panel 1 is a vertically elongated rectangle, and its width W is formed to match the width B of the inter-rib recess of the steel panel 3. In the height (vertical side) direction, the upper portion 11, middle portion 12, and lower portion 13 are integrally continuous. The upper portion 11 is set to a height approximately twice the height A of the inter-rib recess of the steel panel 3. More specifically, the height of the upper portion 11 is set to an appropriate height that allows the upper edge 14 of the upper portion 11 to engage with the recessed corner between the long pieces 35 and short pieces 36 of the lower frame member 34 in step 4, which will be described later. The middle portion 12 has a height corresponding to the cross-sectional dimension of the lower frame member 34 of the steel panel 3 (the total dimension of the long pieces 35 and short pieces 36). The lower portion 13 has a height corresponding to the length of the oblique side of the base portion, which has a substantially trapezoidal cross-sectional shape. A plurality of fold lines 21 to 25 extending in the width direction are formed in the area from the boundary between the middle portion 12 and the lower portion 13 to the upper portion 11. The specific positions and functions of these fold lines 21 to 25 will be described later with reference to Figure 3 and other figures showing the procedure for attaching the paper panel 1 to the steel panel 3.

[0028] Additionally, a termite-proof surface 15 extending in a strip shape in the width direction is formed on the upper portion 11 of the paper panel 1. This termite-proof surface 15 is formed by an appropriate termite-proof treatment, such as applying or impregnating a chemical agent to the base paper of the paper panel 1, or by attaching a flexible sheet material mixed with a chemical agent. However, the present invention does not particularly limit the detailed method of the termite-proof treatment or the chemical agent components. The termite-proof surface 15 may be formed on either the front or back surface of the paper panel 1, or on both the front and back surfaces. The specific position and function of this termite-proof surface 15 will be described later with reference to FIG. 7.

[0029] [Step 2] When constructing the continuous footing, appropriate support members 54 for supporting the continuous footing formwork and reinforcing bars 53 are placed on the construction surface, which has been prepared with groundwork such as broken gravel 51 and basal concrete 52, and the steel panels 3 are then erected on top of these to form the rising formwork. U-pins, separators, fasteners, and other formwork peripheral components used to connect the steel panels 3 are not shown, but in this invention, conventionally known components can be used in combination as appropriate.

[0030] [Step 3] Next, as shown in Figures 3(a) and 3(b), the middle portion 12 of the paper panel 1 is placed on the bottom frame member 34 of the steel panel 3 so that its width matches the inter-rib recess of the steel panel 3, and the fold lines 21, 22, and 23 formed in the middle portion 12 are folded and folded along the inside of the bottom frame member 34 of the steel panel 3. In other words, in this paper panel 3, the fold line 21 is set to be the boundary line between the lower portion 13 and the middle portion 12, and the fold line 23 is set to be the boundary line between the middle portion 12 and the upper portion 11. In the illustrated embodiment, the lowest fold line 21 shown in Figure 1 is folded in a mountain direction as seen by the worker and is placed on the upper edge of the short piece 36 of the bottom frame member 34. The second-lowest fold line 22 is folded in a valley direction and placed against the inside corner between the short piece 36 and the long piece 35 of the bottom frame member 34. The third fold line 23 from the bottom is folded in a valley and pressed into the corner between the long piece 35 of the bottom frame material 34 and the face plate 31. If the fold lines 21 to 23 are formed accurately to match the cross-sectional dimensions of the bottom frame material 34, the paper panel 1 can be temporarily fixed to the steel panel 3 just by this pressing.

[0031] [Step 4] In the illustrated embodiment, when the upper portion 11 of the paper panel 1 is raised along the outer surface of the steel panel 3, the uppermost fold line 25 is formed at a position where it abuts the underside of the horizontal rib 38 directly above the bottom frame member 34, as shown in Figure 3(c). The upper portion 11 of the paper panel 1 is then folded downward along this fold line 25, and the folded upper edge 14 is placed over the middle portion 12, which has been folded along the shape of the bottom frame member 34, and engaged by being pressed into the corner between the long piece 35 and the short piece 36 of the bottom frame member 34. As a result, the portion from the fold line 25 to the upper edge 14 is stretched diagonally between the bottom frame member 34 and the horizontal rib 38, pressing the middle portion 12 against the bottom frame member 34. In other words, the dimension from the fold line 25 to the upper edge 14 of the upper portion 11 of the paper panel 1 is set to correspond to the distance between the bottom frame member 34 and the horizontal rib 38. This type of engagement secures the middle portion 12 and upper portion 11 of the paper panel 1 between the lower frame material 34 of the steel panel 3 and the horizontal rib 38 directly above it. It is also possible to set the height of the folded portion of the upper portion 11 of the paper panel 1 slightly higher in advance, and then position the upper edge 14 on-site by bending or cutting it to match the height of the recess between the ribs.

[0032] [Step 5] Once the upper and middle sections 11 and 12 of the paper panel 1 have been fixed to the steel panel 3, the lower section 13 of the paper panel 1 is inclined to flare out to match the shape of the base, as shown in Figure 3(d), and the bottom edge is fixed to the construction surface in an appropriate location. This completes the base formwork.

[0033] [Step 6] Next, as shown in Figure 4, concrete is poured into the form space surrounded by the base formwork (lower part 13 of paper panel 1) and the rising part formwork (steel panel 3), integrally forming the base part 41 and the rising part 43. At this time, the filling pressure of the concrete acts from inside the base formwork in a direction that pushes the lower part 13 of the paper panel 1 outward, but because the middle part 12 of the paper panel 1 is fixed in a state where it is folded over onto the bottom frame material 34 of the steel panel 3, the shape of the lower part 13 is suitably maintained.

[0034] [Step 7] After the concrete has hardened after a predetermined curing time, the upper edge 14 of the paper panel 1 engaged with the lower frame material 34 of the steel panel 3 is pulled outward, as shown in Figure 5, to release the engagement state of [Step 4]. Then, the middle portion 12 and upper portion 11 of the paper panel 1 are opened outward and pulled away from the steel panel 3, and only the steel panel 3 is removed from the mold. At this time, the lower portion 13 of the paper panel 1 is stuck to the concrete of the base portion 41, but even if it peels off slightly, it can be simply reattached.

[0035] [Step 8] After the steel panel 3 has been demolded, the middle portion 12 of the paper panel 1 is folded again over the connection between the base portion 41 and the rising portion 43, as shown in Figure 6. The cross-sectional dimensions of the bottom frame material 34 of the steel panel 3 and the cross-sectional dimensions of the concrete surface after demolding will differ by the thickness of the face plate 31 and bottom frame material 34 of the steel panel 3, but this area will be backfilled in the next step, so a small gap is not a problem. The upper portion 11 of the paper panel 1 is extended upward along the side of the rising portion 43 and temporarily fixed to the concrete surface with adhesive tape (not shown) or the like.

[0036] [Step 9] Next, as shown in Figure 7, backfill soil 5 is poured into the earthen floor space surrounded by the strip footing, buried up to a point halfway along the height of the rising portion 43, and then compacted and leveled to prepare the earthen floor surface 51. The middle portion 12 and lower portion 13 of the paper panel 1 are buried in the backfill soil 5, and approximately half of the upper portion 11 is exposed above the earthen floor surface 51. The termite-resistant surface 15 previously formed on the paper panel 1 is positioned so that it roughly matches the height of the earthen floor surface 51. In other words, the earthen floor surface 51 is prepared to match the center of the area of ​​the termite-resistant surface 15 formed on the paper panel 1. A fold line 24 is then formed near the center of the height of the termite-resistant surface 15.

[0037] In the illustrated embodiment, the center of the anti-termite surface 15 and the fold line 24 are positioned below the fold line 25 that abuts against the horizontal rib 38 of the steel panel 3, but the relative positions of these fold lines 24, 25 may be reversed up and down depending on the height of the horizontal rib 38 of the steel panel 3 and the level of the dirt floor 51. Furthermore, the anti-termite surface 15 does not necessarily have to be provided with equal widths above and below the fold line 24, and may be provided over a wider area or over the entire surface of the paper panel 1.

[0038] [Step 10] Next, as shown in Figure 8, the upper part 11 of the paper panel 1 exposed above the earthen floor 51 is folded along the fold line 24 so as to fit along the earthen floor 51, and is laid on top of the earthen floor 51. At this time, the termite-proof surface 15 is also bent into an L-shaped cross section.

[0039] [Step 11] As shown in Figure 9, concrete floor (basic concrete) 6 is poured onto the floor surface 51. As a result, the paper panel 1 extends from the outer surface of the base portion 41, via the connection between the base portion 41 and the rising portion 43, along the side of the rising portion 43 to the height of the floor surface 51, bends toward the floor along the lower corner of the joint between the rising portion 43 and the concrete floor 6, and continues to a predetermined range around the periphery of the underside of the concrete floor 6. In this way, a termite-proof foundation structure is completed, with termite-proof surfaces placed at the lower corners of the joints.

[0040] Figures 10 to 13 show modified examples of paper panels used in the above-mentioned anti-termite foundation construction method. The paper panel 1 shown in Figure 1 is formed so that its width W matches the width B of the inter-rib recess in the steel panel 3. Therefore, when the upper portion 11 of the paper panel 1 is unfolded upward or to the side after the steel panel 3 is removed, a gap corresponding to the thickness of the vertical rib 37 or vertical frame member 32 is formed between the side edges of adjacent paper panels 1. To close this gap, the paper panel 10 in Figure 10 has a wider width than the paper panel 1 in Figure 1.

[0041] The paper panel 10 in Figure 10 has the same width W as the paper panel 1 in Figure 1, with widened sections 16, 16 added to both the left and right sides of the central section. The width X of the widened section 16 in the illustrated embodiment is set to be approximately the same as the depth of the recess between the ribs of the steel panel 3. The vertical positional relationship of the multiple fold lines 21-25 formed in the width direction of this paper panel 10 and the termite-proof surface 15 is the same as that of the paper panel 1 in Figure 1.

[0042] Vertical fold lines 26, 26 are formed in the upper portion 11 and middle portion 12 of the paper panel 10 between the central portion and the widened portions 16, 16. In addition, notches 17 having the same dimension as the width X of the widened portion 16 are formed at both ends of the fold line 21, which forms the boundary between the middle portion 12 and the lower portion 13. When engaging the upper portion 11 and middle portion 12 with the steel panel 3, the widened portions 16, 16 on the outside of the fold line 26 are overlapped with the central portion, or as shown in Figure 11, are folded so as to align with the vertical ribs 37 or vertical frame members 32 (including the lower frame member 34 if necessary) surrounding the inter-rib recess, and the folded side edge portions (the widened portions 16, or the overlapping portions between the widened portions 16 and the central portion) are fixed by pushing them into the height A and width B of the inter-rib recess.

[0043] The lower portion 13 of the paper panel 10 protrudes outside the steel panel 3 with the upper portion 11 and middle portion 12 fixed in the inter-rib recesses, so the vertical fold line 26 does not extend to the lower portion 13. The lower portions 13 protruding outside the steel panel 3 overlap with the lower portions 13 of adjacent paper panels 10. The overlapping lower portions 13 may be attached to each other with tape or the like. By overlapping the lower portions 13 of adjacent paper panels 10, the strength of the base formwork is increased.

[0044] After the paper panels 10 are fixed to the steel panel 3 in this manner, concrete is poured to integrally form the base portion 41 and the rising portion 43. Then, as shown in FIG. 12 , after the steel panel 3 is removed from the mold, the widened portions 16 of the paper panels 10 are unfolded, and the widened portions 16, 16 of adjacent paper panels 10 are overlapped along the sides of the rising portion 43. After the floor is backfilled, the widened portions 16, 16 of adjacent paper panels 10 are folded while still overlapping and placed on the floor surface 51 ( FIG. 8 ), as shown in FIG. 13 . The termite-resistant surfaces 15 of adjacent paper panels 10 are then bent while overlapping and laid underneath the concrete floor 6. Thus, a gap-free termite-resistant line can be formed at the joint between the rising portion 43 and the concrete floor 6.

[0045] In addition, the width X of the widened portion 16 of the paper panel 10 described above can be changed as needed to form a gap-free anti-termite line. For example, the width X of the left and right widened portions 16 may be set so that when the paper panels 10 are unfolded after the steel panel 3 is removed, the side edges of adjacent paper panels 10 abut against each other. Alternatively, the widened portion 16 may be added to only one of the left and right sides of the center portion so that when the adjacent paper panels 10 are unfolded, the widened portion 16 overlaps the other edge of the center portion of the adjacent paper panel 10. Furthermore, the width X of the widened portion 16 may be changed as needed between the upper portion 11 and middle portion 12 and the lower portion 13 of the paper panel 10. Furthermore, the cuts 17 may be formed at appropriate locations depending on the folding method, other than the fold line 21 that defines the boundary between the middle portion 12 and the lower portion 13.

[0046] As explained above, this termite-proofing construction method involves folding the middle section of the paper panel over the bottom frame of the steel panel, then raising the top of the paper panel along the outer surface of the steel panel, then folding it back down and temporarily fastening it in a state where it is engaged with the bottom frame of the steel panel. By temporarily fastening the paper panel to the bottom frame of the steel panel in this manner, the means for connecting the base formwork and the rising formwork can be streamlined. As a result, it is possible to significantly reduce the need for clamps, support members, connecting members, etc., which were previously required to connect the upper edge of the base formwork to the bottom frame of the rising formwork. Pre-creating fold lines in the paper panel at predetermined positions further improves construction ease.

[0047] The anti-termite surface of the paper panel is positioned along the lower corner of the joint between the rising section and the concrete floor, and by folding it along the lower corner, a uniform anti-termite line can be efficiently formed at the joint. The process of spraying anti-termite chemicals at the construction site can be eliminated, shortening the construction period and stabilizing the construction quality in terms of anti-termite performance. The absence of disposable formwork made of synthetic resin also reduces the burden on the soil environment.

[0048] The technical scope of the invention disclosed herein should not be construed as being limited by the exemplified embodiments, but should be construed conceptually based on the claims. The names of elements used in the claims and the specification are for convenience in making the invention easier to understand, and the names do not unnecessarily limit the concepts or properties of the elements. When implementing the invention disclosed herein, the detailed shape, dimensions, structure, materials, quantity, connection form with other elements, relative positional relationship, etc. of elements not specifically specified in the claims may be appropriately modified within the scope of utilizing an operating principle substantially equivalent to the exemplified embodiments or within the scope of obtaining effects substantially equivalent to or greater than those of the exemplified embodiments.

[0049] Specifically, the width of the illustrated paper panel was set to correspond to the width B of the inter-rib recess in the steel panel, but it is also possible to use a wider paper panel that spans multiple inter-rib recesses and perform the same construction. Also, even if the bottom frame material of the steel panel is not an L-shaped cross-section member as illustrated but a rectangular cross-section member or other member, it is possible to improve construction ease and obtain similar anti-termite performance by temporarily fastening the paper panel to the bottom frame material of the steel panel with simple clips, adhesive tape, etc.

[0050] The invention disclosed in this application can be widely used as a termite prevention method for continuous footings or similar foundation structures. Furthermore, as a method of forming a termite prevention line by burying anti-termite treated paper panels 1 in the ground, it can also be applied to structures and fixtures other than concrete foundations.

[0051] DESCRIPTION OF SYMBOLS 1 Paper panel 10 Paper panel 11 Upper part 12 Middle part 13 Lower part 14 Upper edge 15 Termite-proof surface 16 Widened part 21-25 (Width direction) Folding line 26 (Vertical direction) Folding line 3 Steel panel 31 Face plate 32 Vertical frame material 33 Upper frame material 34 Lower frame material 35 Long piece 36 Short piece 37 Vertical rib 38 Horizontal rib 41 Base part 43 Rising part 5 Backfill soil 51 Dirt floor ground 6 Dirt floor concrete

Claims

1. A termite-proof foundation construction method using a bendable paper panel as the base formwork and a steel panel as the rising formwork, and forming a termite-proof line at the joint between the continuous footing and the concrete slab by the following [Steps 1] to [Steps 11]. [Step 1]: Predetermining a predetermined position in the height direction of the paper panel to form a termite-proof surface extending in the width direction of the paper panel. [Step 2]: Erecting the steel panel onto suitable support members installed on the construction surface to form the rising formwork. [Step 3]: Overlaying the middle portion of the paper panel in the height direction on the bottom frame material of the erected steel panel, and folding it to conform to the shape of the bottom frame material. [Step 4]: Elevating the top of the paper panel along the outer surface of the steel panel, abutting it against the underside of a horizontal rib on the outer surface, and folding it downward, and then engaging the folded upper edge with the middle portion folded to conform to the shape of the bottom frame material of the steel panel, thereby securing it to the steel panel. [Step 5] The lower part of the paper panel is inclined to flare out to match the shape of the base part of the strip footing, and its lower edge is fixed to the construction surface to form a base part formwork. [Step 6] Concrete is poured into the formwork space surrounded by the base part formwork and the rising part formwork to form the base part and the rising part. [Step 7] After the concrete has cured, the engagement is released, the middle part and the upper part of the paper panel are removed from the steel panel, and the steel panel is demolded. [Step 8] The upper part of the paper panel is raised along the side of the rising part after demolding and temporarily fixed in place. [Step 9] Backfill soil is poured into the dirt floor space surrounded by the strip footing, burying it up to halfway in the height direction of the rising part, and then the dirt floor is prepared so that it is located in the area of the termite-resistant surface of the paper panel. [Step 10] The upper part of the paper panel exposed above the earthen floor is folded along the earthen floor and placed on top of the earthen floor. [Step 11] Earthen floor concrete is poured onto the earthen floor.

2. A termite-proof foundation construction method according to claim 1, characterized in that in step 4, the side edge portions of the paper panel that have been raised along the outer surface of the steel panel are folded toward the outer surface of the steel panel, and the upper part of the paper panel is fixed by pushing the side edge portions between the horizontal rib and the lower frame material.

3. A termite-proof foundation construction method according to claim 2, characterized in that in step 8, the side edge portions of the folded paper panels are unfolded and the upper portions of adjacent paper panels are brought into contact with or overlapped with each other.

4. A termite-proof foundation construction method according to claim 1, 2 or 3, characterized in that in step 5, the lower parts of adjacent paper panels are abutted or overlapped with each other.

5. A termite-proof foundation construction method according to claim 1, 2 or 3, characterized in that folding lines are pre-processed at the locations where the paper panels will be folded.

6. A termite-proof foundation structure characterized in that paper panels are arranged continuously from the outer surface of the base part of a slab footing, passing through the connection between the base part and the rising part, extending upward along the side of the rising part, bending towards the floor along the lower corner of the joint between the rising part and the concrete floor poured at mid-way height of the rising part, and extending over a predetermined range around the periphery of the underside of the concrete floor, and the paper panels have a termite-proof surface that has been treated with termite prevention within a predetermined range that encompasses the lower corner of the joint.

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