CONCRETE FORM FOR UNDERGROUND WALL

Abstract: Drive-in type concrete forms for an underground wall (10, 56, 60, 62, 64, 74, 76, 78 and 80) include water permeable layers (28) and water conduits (30) for discharging leaked water and the like from a concrete wall (14). When the concrete wall is molded by use of the forms, cement paste of concrete is impregnated in the water permeable layer (28), so that the forms (10, 56, 60, 62, 64, 74, 76, 78 and 80) can be jointed to the concrete wall (14). Surplus water before curing of the concrete, leaked water after the curing of the concrete or the like flow into the water conduits (30) through the water permeable layer, flow down the water conduits (30) and are discharged from the bottom portions of the forms (10, 56, 60, 62, 64, 74, 76, 78 and 80). Furthermore, heat from the concrete wall is insulated by an insulating layer (24) provided closer to the interior of a chamber than the water conduits are.

Description: TECHNICAL FIELD The present invention relates to a permanent form for placing a basement concrete wall. More particularly, the present invention relates to a permanent form which is left integrally with a basement concrete wall placed and can discharge redundant water in a fresh concrete, artesian spring, leakage water or the like through the basement concrete wall. PRIOR ART One example of conventional forms for placing an basement concrete wall is disclosed in Figure 2 in Japanese Utility Model Publication No. 3-2867⊘ published on May 19, 1991. The prior art is so adapted as to affix a sheet having a flute serving as a water-conduit channel and a cloth serving as a percolation layer to a substrate having predetermined strength and using the sheet affixed to the substrate as a concrete form. If a basement concrete wall is placed using this concrete form, redundant water in fresh concrete flows into the flute through the cloth, flows downward through the flute, and is discharged from the bottom of the form before hardening the concrete, so that the hardening rate of the concrete is increased, to improve the surface state and physical properties thereof. After hardening the concrete, the form is removed from the basement concrete wall. However, there are some problems in the prior art. For example, the sheet must be affixed to the substrate, resulting in poor workability. In addition, the form is removed from the concrete, thereby to make it impossible to prevent the entrance of water leakage into the interior due to, for example, the occurrence of a crack after hardening the concrete. Therefore, a permanent form having a water-conduit channel, a percolation layer and a substrate integrally formed in advance is disclosed in Japanese Patent Laid-Open Gazette No. 3-281863 laid open on December 12, 1991 and Japanese Patent Laid-Open Gazette No. 4-7⊘467 laid open on March 5, 1992. According to the prior arts, a sheet need not be affixed to the substrate, thereby to make it possible to improve workability. Moreover, the form need not be removed from the placed concrete, so that water leakage after hardening the concrete can be discharged from the bottom of the form, thereby to make it possible to prevent the entrance of the water leakage into the interior. Since the form is so constructed that the water-conduit channel and the percolation layer are affixed to the substrate, however, there are some problems. Specifically, the function, especially the strength of the form is greatly changed depending on the material of the substrate (veneer or the like). In addition, the strength of the form depends on only the substrate. If an attempt to obtain sufficient strength is made, therefore, the thickness of the entire form is increased and the weight thereof is increased. It is also known from JP-4070467 to provide a permanent form for forming one face of a basement concrete wall to subsequently become an integral part thereof, comprising a main body defining interior surface which, in use, will be generally parallel to said concrete wall and spaced therefrom, a percolation layer on said main body to absorb water from said concrete wall and a water discharge conduit interposed between said percolation layer and said surface down which the water absorbed by the percolation layer flows. Therefore, a principal object of the present invention is to provide a new permanent form for placing a basement concrete wall. Another object of the present invention is to provide a permanent form for placing a basement concrete wall capable of improving workability and the leak-prevention function for the basement concrete wall. Still another object of the present invention is to provide a permanent form for placing a basement concrete wall being lightweight and having practically sufficient strength. A further object of the present invention is to provide a permanent form for placing a basement concrete wall capable of preventing dew condensation. A permanent form according to the present invention is characterised in that said water discharge conduit comprises a plurality of channels formed within the main body. The panel and the water-conduit channel support a form structure in cooperation, thereby making it possible to so form the permanent form for placing a basement concrete wall as to be lightweight and have high strength. In addition, the necessity of affixing a sheet to a substrate is eliminated, thereby improving workability. In the preferred embodiment, the percolation layer is made from non-woven fabric and acts so as to cushion the form and thereby prevent any displacement of the concrete wall from being transmitted to the main body. Preferably the form includes a heat insulating layer in said main body interposed between said water discharge conduits and said surface. Preferably, anchor means are included on the main body which, in use, become embedded in the concrete wall to provide a join between the concrete wall and the form. Conveniently, an opening is provided in the percolation layer through which concrete may be introduced into a corresponding number of channels to improve the join between the concrete wall and the form. When the concrete is laid, the percolation layer absorbs redundant water in the concrete. The redundant water absorbed by the percolation layer flows downward through the percolation layer or the water-conduit channel and is discharged from the bottom of the form. After hardening the concrete, the percolation layer and the concrete are firmly integrated with each other to form a wall structure, and water leakage from a crack occurring in the basement concrete wall is discharged similarly to the above described redundant water. In a preferred embodiment, heat from the basement concrete wall is cut off by the heat insulating layer. Since heat from the base concrete wall can be cut off by the heat insulating layer, therefore, it is possible to prevent dew condensation on the surface of the form. If the water-conduit channel and the heat insulating layer are integrally formed of synthetic resin such as polyvinyl chloride, and a foam resin layer or an air layer is used as the heat insulating layer, the form can be so formed as to be more lightweight and have higher strength than the conventional form. Furthermore, if a non-woven fabric is used as the percolation layer, the percolation layer (the non-woven fabric) can be displaced as the basement concrete wall is displaced due to the occurrence of the crack, so that the displacement of the basement concrete wall can be prevented from being transmitted to the form, thereby to make it possible to prevent the form from being cracked, for example. Conveniently, the percolation layer, the water-conduit channel and the heat insulating layer may be formed from a transparent member, so that it is possible to construct the form while visibly confirming that the concrete has been correctly laid thereby making it possible to improve workability. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention given by way of example only and taken in conjunction with the accompanying drawings, in which: Figure 1 is an illustrated showing one embodiment of the present invention; Figure 2 is an illustrated showing the use state of the embodiment shown in Figure 1; Figure 3 is a perspective view showing the use state of the embodiment shown in Figure 1; Figure 4 is an illustration showing a state where an inlet and a reservoir portion are formed in the embodiment shown in Figure 1; Figure 5 is an illustration showing another embodiment of the present invention; Figure 6 is an illustration showing another embodiment of the present invention; Figure 7 is an illustration showing another embodiment of the present invention; Figure 8 is an illustration showing a state where an anchor portion is formed in the embodiment shown in Figure 7; Figure 9 is an illustration showing a modified example of the anchor portion; Figure 10 is an illustration showing a state where an inlet and a reservoir portion are formed in the embodiment shown in Figure 5; Figure 11 is an illustration showing a state where an inlet and a reservoir portion are formed in the embodiment shown in Figure 6; Figure 12 is an illustration showing a state where an inlet and a reservoir portion are formed in the embodiment shown in Figure 8; Figure 13 is an illustration showing a further embodiment of the present invention; Figure 14 is an illustration showing a further embodiment of the present invention; Figure 15 is an illustration showing a further embodiment of the present invention; and Figure 16 is an illustration showing a further embodiment of the present invention. Referring to Figures 1 to 3, a form 10 in this embodiment shown is for placing a basement concrete wall 14 of a base (Figure 2), and comprises a first panel 16 and a second panel 18 which are arranged parallel to each other. The first panel 16 and the second panel 18 are connected to each other by a plurality of ribs 20 extending in the longitudinal direction. Air layers each formed by the first panel 16, the second panel 18 and the ribs 20 connect with each other in the transverse direction, to be a heat insulating layer 24. In addition, a plurality of supporting members or pieces 26, which are in a substantially T shape in cross section, extending in the longitudinal direction are formed for each spacing on a major surface on the side of the basement concrete wall 14 of the first panel 16, and a percolation layer 28 such as a non-woven fabric is affixed to ends of the supporting members 26. A space enclosed by the supporting members 26, the first panel 16 and the percolation layer 28 becomes a water-conduit channel 3⊘. A first engaging member or piece 32 and a second engaging member or piece 34 are respectively formed in one end and the other end of the heat insulating layer 24 so as to be connectable to another form 1⊘. A slit width a, a thickness b, a rib pitch P and a rib thickness t are respectively set to 12.5 mm, 32 mm, 25 mm and 1 mm. The first panel 16, the second panel 18, the ribs 2⊘ and the supporting members 26 are integrally formed by extrusion of hard synthetic resin which is low in thermal conductivity such as polyvinyl chloride. Referring to Figure 2, when the basement concrete wall 14 is placed, a drainage ditch 4⊘ is first formed on the upper surface of a slab 38 having an artesian spring tank 36 formed in its part, and a water channel 42 is located in the drainage ditch 4⊘. The form 1⊘ is assembled on the water channel 42 so that its bottom surface abuts against a stopper 44 of the water channel 42. At this time, a first engaging member 32 of one form 1⊘ and a second engaging member 34 of another form 1⊘ are joined to each other by a waterproofed double-faced tape 44 such as a butyl rubber tape, as can be seen from Figures 1 and 3. The basement concrete wall 14 is placed between the form 1⊘ and a sheathing basement concrete wall 46. If the basement concrete wall 14 is placed, the percolation layer 28 is impregnated with cement paste of concrete, whereby the basement concrete wall 14 and the form 1⊘ are firmly joined to each other without using a special joining member after hardening the concrete. Before hardening the basement concrete wall 14, redundant water in the concrete flows into the water-conduit channel 3⊘ through the percolation layer 28, flows downward through the water-conduit channel 3⊘, and is discharged to the artesian spring tank 36 through the water channel 42 and a water pipe 48 provided in the slab 38. On the other hand, after hardening the basement concrete wall 14, water leaking out to the surface of the basement concrete wall 14 through a crack 5⊘ (Figure 3) occurring in the basement concrete walls 14 and 46 is discharged to the artesian spring tank 36 similarly to the previous redundant water. When the surface of the basement concrete wall 14 is displaced due to, for example, the occurrence of the crack 5⊘, the percolation layer 28 is displaced with the displacement. Consequently, the displacement is prevented from being transmitted to a main body of the form 1⊘, thereby to prevent the form 1⊘ from being cracked or bent, for example. The percolation layer 28 also functions as a cushioning layer. Furthermore, heat from the basement concrete wall 14 is cut off by the heat insulating layer 24. Consequently, dew condensation on the surface of the form 1⊘ (the second panel 18) is not brought about. As shown in, for example, Figure 4, if an inlet 52 introducing concrete is formed in the percolation layer 28 and a reservoir portion 54 is formed so as to expand toward the depth from the inlet 52 so that concrete placed is accumulated in the reservoir portion 54, the basement concrete wall 14 and the form 1⊘ can be joined to each other more firmly. In a form 56 according to another embodiment shown in Figure 5, a plurality of hollow blocks 58 extending in the longitudinal direction are formed for each predetermined spacing in place of the supporting members or pieces 26 in the above described embodiment, and a percolation layer 28 such as a non-woven fabric is affixed to a major surface on the side of a basement concrete wall 14 of each of the blocks 58. A space enclosed by a first panel 16, the blocks 58 and the percolation layer 28 becomes a water-conduit channel 3⊘. A slit width a, a thickness b, a rib pitch P and a rib thickness t are respectively set to, for example, 12.5 mm, 32 mm, 25 mm and 1 mm. Also in the present embodiment, the first panel 16, a second panel 18, ribs 2⊘ and the blocks 58 are integrally formed by extrusion of synthetic resin such as polyvinyl chloride. However, more stable forming is structurally possible, as compared with the previous embodiment. Although in the above described embodiments, a heat insulating layer 24 is formed by an air layer, a heat insulating layer 24 (and supporting members or pieces 26) may be formed of foam synthetic resin such as foam hard polyvinyl chloride as in, for example, a form 6⊘ shown in Figure 6. This form 6⊘ allows an interior finish to be nailed on an inner surface of the form 6⊘ more firmly. A third panel 66 may be formed integrally with supporting members or pieces 26 (or blocks 58) and provided with a plurality of percolation holes 68 to be a percolation layer as in, for example, a form 64 shown in Figure 7. This form 64 eliminates the necessity of affixing a non-woven fabric in the subsequent process, thereby to make it possible to simplify the manufacturing processes. Furthermore, an anchor portion 7⊘ embedded in a basement concrete wall 14 may be formed on a major surface on the side of the basement concrete wall 14 of a third panel 66 as in a form 64 shown in Figure 8 to improve joining properties of the form 64 and the basement concrete wall 14. If a crack 5⊘ (Figure 3) occurs in the basement concrete wall 14, the position of the anchor portion 7⊘ is shifted. If a form body 72 follows the shift, the form 64 is liable to be cracked. In order to prevent the form body 72 from following the shift of the anchor portion 7⊘, therefore, the anchor portion 7⊘ is formed of a soft material such as an elastomer or soft polyvinyl chloride or is formed into a structure which can be easily cut as shown in Figure 1⊘. If the anchor portion 7⊘ is formed of the soft material, both the soft material of the anchor portion 7⊘ and a hard material of the form body 72 are extruded (are subjected to tow-layer extrusion). Furthermore, a first panel 16, a second panel 18, the third panel 66 and the like in the form 64 (Figures 7 and 8) may be formed of a transparent material such as polycarbonate or acrylic resin. If they are formed of a transparent material, the form 64 can be constructed while confirming the placed state of concrete from the side of the interior, thereby to make it possible to rapidly improve workability as well as improve joining properties to the basement concrete wall 14. Also in the forms 56, 6⊘, 62 and 64, an inlet 52 and a reservoir portion 54 may be formed to improve joining properties to the basement concrete wall 14, as shown in, for example, Figures 10 to 12. Additionally, an interior finish such as a gypsum board or a tile may be mounted as required on a major surface on the side of the interior of the heat insulating layer 24 in each of the above described embodiments using a nail, adhesives or the like in advance or after the construction. The results of flexural rigidity (E · I) and maximum allowable bending moment (f · Z) found with respect to the present form and the form 1⊘ (Figure 1) and the form 56 (Figure 5) according to the embodiments are summarized in Table 1. The strength of the form is generally evaluated by deflection δ at the time of placing which is represented by an equation 1 and maximum allowable bending moment M which is represented by an equation 2. δ = 5Wl 4 384 · E · I W : maximum side pressure at the time of placing concrete l : spacing between battens E : Young's modulus of form I : geometrical moment of inertia of form M = f · Z f : maximum allowable bending stress Z : modulus of section of form If E · I and f · Z in a certain form are not less than E · I and f · Z in the present form from the equations 1 and 2, it can be judged that the form has practically sufficient strength. As can be seen from Table 1, therefore, the form 1⊘ (Figure 1) and the form 56 (Figure 5) allow practically sufficient strength to be ensured by suitably setting the size or the material. In addition, the forms can be rapidly made more lightweight than the present form. It goes without saying that the forms 6⊘, 62 and 64 shown in Figures 6 to 8 allow sufficient strength to be ensured by suitably setting the size or the material. Although in the form 56 shown in Figure 5, the plurality of hollow blocks 58 extending in the longitudinal direction are formed between the ribs 2⊘, such hollow blocks 58 may be formed in positions laid across a rib 2⊘ as in, for example, a form 74 shown in Figure 13. Further, in order to increase the strength particularly in the transverse direction of a form, a rib 82 for obliquely connecting a first panel 16 and a second panel 18 to each other may be formed as in, for example, forms 76, 78 and 8⊘ respectively shown in Figures 14 to 16. The form 76 shown in Figure 14 is a form in which such a rib 82 is added in the form 56 shown in Figure 5, the form 78 shown in Figure 15 is a form in which such a rib 82 is formed in a substantially V shape, and the form 8⊘ shown in Figure 16 is a form in which such a rib 82 is formed in a substantially X shape. The results of flexural rigidity in the longitudinal direction E · Ix (kg · cm 2 ), flexural rigidity in the transverse direction E · Iz (kg · cm 2 ) and weight (W kg / m 2 ) respectively found with respect to the form 74 (Figure 13), the form 76 (Figure 14), the form 78 (Figure 15) and the form 8⊘ (Figure 16) as in Table 1 are summarized in Table 2. Apparent flexural rigidity is found by bending tests as the flexural rigidity in the transverse direction. Form 74 Form 76 Form 78 Form 8⊘ E·Ix (kg ·cm 2 ) 14,2⊘⊘ (1) 15,8⊘⊘ (1.11) 15,6⊘⊘ (1.⊘9) 16,4⊘⊘ (1.15) E·Iz (kg ·cm 2 ) 23.4 (1) 1,28⊘ (54.6) 1,29⊘ (55) 1,79⊘ (76.5) Weight W kg /m 2 6.1 (1) 7.7 (1.26) 7.4 (1.21) 8.2 (1.34) As can be seen from Table 2, it is possible to significantly increase the strength in the transverse direction of the form by forming the rib 82 for obliquely connecting the first panel 16 and the second panel 18 to each other. Furthermore, in a conventional permanent form for placing, water from a basement concrete wall 14 is liable to leak out to the interior through a separator hole 86 left in a form 84, as shown in, for example, Figure 17. In the form according to the present invention, however, water drops in a hollow portion such as a water-conduit channel 3⊘ or a heat insulating layer 24, as shown in Figure 18, so that such a leak of water does not develop. Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being limited only by the terms of the appended claims.

Claims: A permanent form for forming one face of a concrete wall (14)to subsequently become an integral part thereof, comprising a main body defining an interior surface which, in use, will be generally parallel to said concrete wall (14) and spaced therefrom, a percolation layer (28) on said main body to absorb water from said concrete wall and a water discharge conduit (30) interposed between said percolation layer (28) and said surface down which the water absorbed by the percolation layer (28) flows characterised in that said water discharge conduit comprises a plurality of channels formed within the main body. A permanent form according to claim 1 characterised in that the percolation layer (28) is made from non-woven fabric and acts so as to cushion the form and thereby prevent any displacement of the concrete wall (14) being transmitted to the main body. A permanent form according to any preceding claim characterised by a heat insulating layer (24) in said main body interposed between said plurality of channels (30) and said surface. A permanent form according to any preceding claim characterised by anchor means (70) on said main body which, in use, become embedded in the concrete wall (14) to provide a join between the concrete wall (14) and the form. A permanent form according to any preceding claim characterised by at least one opening in the percolation layer (28) through which concrete may be introduced into a corresponding number of channels (30) to improve the join between the concrete wall (14) and the form. A permanent form according to claim 5 characterised in that said heat insulating layer (24) comprises a foam resin layer. A permanent form according to claim 3 characterised in that said heat insulating layer (24) comprises an air layer. A permanent form according to any preceding claim characterised in that the main body is formed from a transparent material. A permanent form according to claim 3 characterised in that the main body includes a first panel (16) and said plurality of channels (30) comprise a hollow portion formed behind the first panel (16). A permanent form according to claim 9 characterised in that said main body further comprises a second panel (18) spaced from the first panel (16), a plurality of first ribs (20) therebetween for connecting said first panel (16) to said second panel (18) to form first hollow portions between said first panel (16) and said second panel (18), wherein the first hollow portion is the heat insulating layer (24). A permanent form according to claims 9 or 10 characterised in that the main body includes a plurality of second ribs formed on a rear surface of said second panel (18) to form a plurality of second hollow portions said second hollow portions being said plurality of channels (30). A permanent form according to claim 11 characterised by a non-woven fabric affixed to the end of said second ribs said non-woven fabric being said percolation layer. A method of forming a basement concrete wall (14) using a permanent form which becomes an integral part thereof comprising the steps of: a) placing the form having a main body comprising an interior surface, a percolation layer (28) and a water discharge conduit comprising a plurality of channels (30) in position ready to form the wall (14); b) placing concrete against the form and allowing the concrete to set, whereby said percolation layer (28) becomes an integral part of the concrete wall (14) and water from said concrete is discharged into said water-discharge conduit (30) from said percolation layer (28). A permanent form as claimed in any preceding claim in combination with a basement concrete wall and forming an integral part thereof.

Inventors: HORINAKA SHUNJI, IWATAKE HIDEAKI, KAWAMURA HIROMASA, KYOMEN JUNSUKE, SAKAGUCHI MASAYUKI, TAKADA KAZUTAKA, TAKAI SHINICHIRO, TAKESAKO RYOICHI, WATANABE MICHIO, HORINAKA, SHUNJI, IWATAKE, HIDEAKI, KAWAMURA, HIROMASA, KYOMEN, JUNSUKE, SAKAGUCHI, MASAYUKI, TAKADA, KAZUTAKA, TAKAI, SHINICHIRO, TAKESAKO, RYOICHI, WATANABE, MICHIO, HORINAKA, Shunji, Muramoto Construction Co., Ltd., IWATAKE, Hideaki, Muramoto Construction Co., Ltd., KAWAMURA, Hiromasa, Muramoto Construction Co.,Ltd., KYOMEN, Junsuke, Kubota Corporation, SAKAGUCHI, Masayuki, Kubota Corporation, TAKADA, Kazutaka, Kubota Corporation, TAKAI, Shinichiro, Muramoto Construction Co., Ltd., TAKESAKO, Ryoichi, Muramoto Construction Co., Ltd., WATANABE, Michio, Kubota Corporation
Applicants: KUBOTA KK, MURAMOTO CONSTRUCTION CO LTD, KUBOTA CORPORATION, MURAMOTO CONSTRUCTION CO., LTD.
Application year: 1993
Main classification: E02D29
IPC codes: E02D31, E02D29