JP2975211B2 - Concrete formwork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete formwork used for manufacturing structures such as walls, beams and floors made of materials such as concrete.

[0002]

2. Description of the Related Art Conventionally, as a concrete casting formwork, a plywood (for example, a plywood having a size of 1800 mm in length, 900 mm in width, and 12 mm in thickness) in which veneers such as Lauan materials are overlapped is made of a wooden board. Concrete forms reinforced with nails to piers have been used. However, due to the curvature of the pier and the low dimensional accuracy, it is easy for misalignment to occur between the adjacent dies when the dies are assembled because of the curvature of the pier and the low dimensional accuracy. After that, it was necessary to repair by hanging work and mortar prying. In particular, there were problems in the case of the concrete release method or the method of attaching an interior cloth directly to the concrete casting surface.

[0003] Accordingly, a concrete formwork in which a metal pier is screwed to a plywood instead of a wooden pier has been developed. FIG. 13 shows an example of this concrete formwork. In this concrete formwork, a metal pier 51 is screwed to the back of a plywood 50, and the two plywoods 50 are erected at predetermined intervals according to the height and width of a wall or the like to be constructed. At the same time, a separator 53 having a cone 52 screwed to both ends is interposed between the two plywoods 50, and a tie rod (for example, a foam tie) 54 is inserted into a hole 55 formed in the plywood 50, and the tie rod 54 is inserted into the cone. By connecting to the separator 53 via the cone 52 by screwing to 52,
In order to withstand the pressure of the cast concrete, a metal reinforcing pipe 56 is disposed at a right angle to the pier 51, and a nut 57 screwed to the tie rod 54 is tightened. The reinforcing pipe 56 is fixed to the crosspiece 51 (for example, Japanese Patent Publication No. 63-23 / 1988).
347).

[0004]

However, the above-mentioned conventional concrete form has the following drawbacks. That is, the hole 55 formed in the plywood 50 has the same diameter as the tie rod 54 at first, but the hole 55
Becomes large, and a clearance is generated between the hole 55 and the tie rod 54, and the concrete to be poured enters the clearance, making it difficult to disassemble the form, or forming a gap between the form and the tie rod 54 by the clearance. May be loosened, and a desired product may not be obtained.

[0005] In addition, the concrete form after dismantling is severely damaged and cannot be used again and again. In addition, since a release agent, that is, a release agent, is applied to the surface of the plywood 50 so that the plywood 50 can be easily removed from the concrete, it is difficult to dispose the plywood 50. Will do.

[0006] Moreover, the plywood currently used is only one of the southern Rawan timbers, but it is expected that the supply of Rawan timber will be difficult in the future due to the shortage of forest resources, or cutting of Rawan timber is prohibited due to global environmental problems. There are situations where it is possible to do so. Therefore, it is necessary to consider in the future to use conifers such as northern timber and domestic timber to address these problems. In that case, due to the woody nature of the conifers that are easily knotted or broken, conifers cannot be thinly cut in the circumferential direction by rotary lace to make veneers, and plywood with a large area like Rawan plywood must be made. Is not possible at the moment. And plywood made from softwood has to be small. However, in the above-mentioned conventional concrete casting formwork which lacks means for connecting small plywoods, there is a problem that plywood made of softwood cannot be applied, and furthermore, it becomes impossible to cope with Lauan plywood that becomes increasingly thin. There's a problem.

[0007] Since a reinforcing bar or the like is usually provided between the plywoods 50 arranged opposite to each other, the separator 5
In some cases, the axis of 3 cannot be aligned with the center of the hole 55 formed in the plywood 50. In that case, the separator 53 and the tie rod 54 cannot be connected well via the cone 52. In such a case, the work of drilling a hole in the plywood 50 with a woodworking drill at the momentum site is performed, and there is a risk that the hand may be swung crazy or an electric shock accident may occur in rainy weather or the like.

The work of removing old plywood from a metal pier and reattaching new plywood is usually performed at a construction site or a nearby work place. At that time, a position matching the screw hole of the metal pier is scribed on a new plywood, and a hole is accurately made with a woodworking drill at that position. As shown in FIG. 14, the plywood 50 and the metal pier 51 are attached. It must be screwed with bolts 59 and nuts. The work of drilling a hole at an accurate position at the construction site and screwing it requires manpower and time, which has been a major drawback of the construction method using the metal pier 51 with excellent precision.

Therefore, in view of the problems of the prior art as described above, in order to form a mold using small panels (including plywood) and to provide a separator and a tie rod for fixing a reinforcing pipe, The problem was how to configure the panels so that they could be interconnected without drilling holes.

[0010] Therefore, an object of the present invention is to solve the above-mentioned problems, so that not only Rawan plywood but also other small-sized plate materials can be used in place of Rawan plywood. In addition to manufacturing plywood made of softwood, etc., there is no need to drill holes in the plywood for separators at construction sites, etc. Another object of the present invention is to provide a concrete formwork having a strength equivalent to that of the formwork and a sufficient function of the formwork.

[0011]

SUMMARY OF THE INVENTION The present invention is configured as follows in order to achieve the above object. That is, the present invention provides a rod body having a fitting hole passing therethrough, a holding member including a cylindrical portion inserted into the fitting hole and a flange portion integrally formed with the cylindrical portion, and a rod member interposed therebetween. A panel having end faces arranged in abutting state, a contact member having a flat surface cooperating with the flange portion to clamp the panel, and a flange portion of the pressing member fixed to the rod body are opposed to each other. The present invention relates to a concrete formwork comprising: a separator to be formed; and a tie rod which is screwed into a screw provided in the cylindrical portion to tighten the holding member and the abutment member.

Further, in this concrete formwork, the panel can use a plywood manufactured by stacking a plurality of veneers obtained by cutting softwood in the longitudinal direction. In some cases, the panel is not limited to plywood, but may be another plate material such as a metal plate, a synthetic resin plate concrete plate, a plywood waste material, or a composite plate material.

Further, in this concrete formwork, it is preferable that the contact member is constituted by a cylindrical triangular support.

Further, the concrete formwork has a reinforcing member intersecting a plurality of the abutting members arranged in a spaced state and fixing the abutting member.

Further, in this concrete formwork, the reinforcing member can use the same cylindrical triangular support as the contact member.

Further, in the concrete formwork, the ends of the contact members can be connected at a predetermined angle by using a joint.

[0017]

The concrete formwork according to the present invention is constructed as described above and operates as follows. About this concrete form, first, it arrange | positions so that the end surfaces of a pair of panels may abut each other across a rod body, and then fits the cylinder part of a holding member into a rod body by screwing in, etc., A contact member is applied to the rod from the side opposite to the pressing member, and a pair of panels is sandwiched to form a panel row. In this way, a pair of assembled panel rows is prepared, and a pair of panel rows is arranged so that the flange sections face each other at a predetermined interval corresponding to the thickness of the wall, and a separator is arranged between the flange sections. Then, the tie rod is screwed into the inner peripheral surface of the cylindrical portion to tighten the holding member and the abutment member with the panel interposed therebetween, and the tip of the tie rod is connected to the separator via a connecting tool such as a cone. Furthermore, a reinforcing member made of the same member as the contact member is fixed so as to intersect the plurality of rods,
This completes the concrete formwork.

In this way, the structure is such that the formwork is assembled by sandwiching the panel between the pressing member and the contact member, so that a panel having a small area can be used. In addition, since the tie rod penetrates the screw hole of a rod such as a long rectangular bar and is connected to the separator, the concrete formwork can be assembled without making any holes in the panel.

The contact member is preferably a cylindrical triangular support (commonly called triangular flap material). Further, in order to prevent crushing of the concrete casting formwork due to internal pressure at the time of concrete casting, the abutment member intersects the abutment member at a right angle or the like and via a reinforcing member disposed over a plurality of the abutment members. It is preferable to connect them. Further, in order to reduce the number of parts, it is preferable that the reinforcing member is also used as the contact member which is a cylindrical triangular support. In addition, by making the ends of the abutment members connectable at a predetermined angle using a joint, concrete forms of various shapes can be manufactured.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a concrete formwork according to the present invention will be described below with reference to the drawings. 1 and 2 are exploded perspective views showing components of a concrete formwork according to the present invention.

FIG. 1 shows a rod body 1 such as a long square bar before assembly, panels 8 and 9 made of plywood or the like made of softwood, a holding member 10, and a backing member 15. The rod 1 has a screw hole 4 which is a fitting hole extending from the front surface 2 to the back surface 3. A convex portion 5 is formed on the front surface 2 and is formed in a step-like shape. The end surfaces of the pair of panels 8 and 9 are in contact with the side surfaces 6 and 7. The holding member 10 has a cylindrical portion 11 such as a cylindrical portion.
And a flange portion 12 formed integrally with the cylindrical portion 11
It is composed of A male screw 13 is provided on the outer peripheral surface of the cylindrical portion 11.
Are formed, and a female screw 14 is formed on the inner peripheral surface.
For example, the contact member 15 can use a so-called triangular flap material or the like, which is a cylindrical triangular support having a triangular cross section, and at least one surface is formed on the flat surface 16. A groove 17 is formed at the center of the flat surface 16, and the width of the groove 17 is substantially the same as the width of the protrusion 5 of the rod 1, and the protrusion 5 fits into the groove 17 of the contact member 15. It is formed so that it may fit. Also,
A plurality of holes 18 are formed at predetermined intervals on the top of the contact member 15 on the side facing the groove 17. Resting member 15
The flat surface 16 cooperates with the flange portion 12 of the holding member 10 to hold the panels 8 and 9 therebetween.

FIG. 2 shows the tightening member 19, the tie rod (for example, a foam tie) 28, and the claw member 33. The tightening member 19 includes a stopper 20 such as a triangular prism, a screw body 22 such as a threaded cylindrical body with a flange 21, a receiving member 23 mounted on the top of the contact member 15, which is a triangular flap material,
It consists of a fastening nut 24. Since the width of the stopper 20 is slightly smaller than the width of the groove 17 of the contact member 15, the stopper 2
0 can be inserted from the groove 17. The screw body 22 and the stopper 20 are assembled by inserting the screw body 22 into a hole formed in the stopper 20. At this time, the flange 21 functions as a stopper. The male screw part 25 of the screw body 22 can be inserted into the hole 26 of the seat member 23. The angle of the V groove 27 of the seat member 23 is formed equal to the apex angle of the contact member 15. The tightening nut 24 is screwed into the male screw portion 25 of the screw body 22.

The tie rod 28 has a male screw 29 engraved at the tip, and a flange 30 is formed at the end of the male screw 29. A hexagonal head 31 is formed at the opposite end of the tie rod 28. Hole 26 of seat member 23
Is large enough to allow the hexagonal head 31 to pass through. The flange 30 of the tie rod 28 has a size that can be inserted into a through hole 32 formed in the center of the flange 21.

The claw member 33 has a pair of claws 34 and 35, and the distance between the claw 34 and the claw 35 is equal to the width of the groove 17 of the contact member 15 which is a triangular fluttering material. The protrusion 5 of the rod 1 fits exactly between the hook 35 and the hook 35. Also,
Since the width of the claw member 33 is smaller than the width of the groove 17 of the contact member 15, the claw member 33 can be inserted from the groove 17. The claw member 33 has a screw hole 36 formed therein, and the tie rod 2
Eight male screws 29 are screwed together.

FIG. 3 is a perspective view showing a part of the assembled state of the concrete formwork. FIG. 4 is a cross-sectional view showing a state cut along a horizontal plane including a chain line XX in FIG. The procedure for assembling the concrete formwork will be described with reference to these drawings.

First, the cylindrical portion 11 of the holding member 10 is screwed into the screw hole 4 of the rod 1 as far as the root of the flange portion 12 to fix the rod 1 and the pressing member 10 integrally.
On the other hand, the stopper 20 and the cylindrical screw body 22 are integrally assembled, and the assembled
Then, the screw portion 25 of the screw body 22 is inserted into the hole 18 of the contact member 15. Next, the tie rod 28 is inserted from the thread portion 25 side of the screw body 22, the tip of the tie rod 28 is projected from the groove 17 of the contact member 15, and the claw member 33 is screwed into the tip of the tie rod 28. At that time, the tie rod 28
Is screwed in such a way that the tip of the tab projects from the claw member 33 or does not project.

Further, the tie rod 28 is pulled into the contact member 15 so that the claw member 33 does not hit the groove 17, and the tie rod 28 is rotated to bring the tips of the claws 34 and 35 into contact with the edge of the groove 17. . The end faces of the pair of panels 8 and 9 are brought into contact with the respective side surfaces 6 and 7 of the rod 1 integrated with the holding member 10, and the groove 17 of the contact member 15 and the claws 34 and 35 of the claw member 33 are held. The convex portion 5 of the rod 1 is fitted between them. In this state, the tie rod 28 is turned while being pressed against the edge of the groove 17, and the tie rod 28 is screwed into the female screw 14 of the cylindrical portion 11 of the holding member 10. At this time, the projection 5 functions as a stopper for the claw member 33. Further, the tie rod 28
When the tip of the claw member protrudes from the holding member 10, the claw member 33 comes into contact with the flange 30 and cannot be screwed any more, and at the same time, the claws 34 and 35 of the claw member 33 are strongly applied.
Of the groove 17 is pressed. In this state, the pair of panels 8 and 9 are sandwiched between the flange portion 12 of the holding member 10 and the flat surface 16 of the abutment member 15 and tightened. And
According to the above procedure, panels are sequentially connected using the required number of rods 1 to form a panel row 38.

The above-mentioned panel rows 38 are erected on both sides at an interval corresponding to the thickness of the wall to be built, that is, may be laid horizontally in some cases. At that time, FIG.
As shown in the figure, the flange 12 is arranged inside. That is, the flanges 12 are arranged so as to face each other. A separator 39 is provided between the pair of panel rows 38.
Are disposed, and both ends of the separator 39 are connected to the ends of the tie rods 28 protruding from the back surface of the flange portion 12 via cones 40, respectively.

Next, a reinforcing triangular butter member as a reinforcing member 37 which is orthogonal to the contact members 15 sandwiching the panels 8 and 9 and contacts over the plurality of contact members 15 is attached. In this example, the contact member 15 is also used as the reinforcing triangular butter material, but is a triangular butter material having no groove 17 on the flat surface 16 and a plurality of holes 1 on the top and the flat surface.
A triangular flap material in which 8 are formed at equal intervals may be used.

The attachment of the reinforcing member 37 will be described. In a state where the panels 8 and 9 are connected in series, the tie rod 28 and the cylindrical screw body 22 project from the top of the backing member 15. 28 and the screw body 22 are inserted into the holes 18 of the reinforcing member 37. Then, the seat member 23 is fitted to the screw body 22, and the seat member 23 is placed on the top of the reinforcing member 37, and
And tighten the nut 24 by screwing. Thus, it is possible to prevent the panel rows 38 from being crushed due to the internal pressure during concrete placement. Through the steps described above, the concrete casting formwork is assembled.

When the concrete formwork is assembled in this way, concrete is poured. Concrete is cast in the space between the panel rows 38 arranged opposite to each other. After the concrete is cast, the concrete is hardened, and after curing, the concrete form is disassembled. That is, the formwork rotates the tie rod 28 in the opposite direction to the tie rod 2.
8 is removed from the cone 40. At this time, the cone 40 and the separator 39 are left in the concrete, and can be seen from the surface of the concrete on which the cone 40 is cast. However, since a circular concave portion is formed by the flange portion 12 on the concrete surface around the cone 40, if necessary, the concave portion is covered with putty or the like so as to cover the cone 40 and at the same time to cover the concrete surface. Can be made flat.

After the concrete is poured into the concrete form to an appropriate height, the concrete form is mounted thereon again, and the tie rod 28 is removed from the cone 40 when the height of the wall is to be added sequentially. At this time, the fixing between the contact member 15 and the reinforcing member 37 is not released. Then, while the form and the reinforcing member 37 are in an integrated state, the entire form is moved upward, and the lower tie rod 28 is screwed into the upper cone 40 left in the concrete. Of the tie rod 28 through the cone 40 and the separator 39
Should be connected to Therefore, when concrete is repeatedly poured, formwork assembling work can be performed extremely easily and efficiently. Of course, the movement of the concrete casting formwork in the horizontal direction, that is, in the horizontal direction, and in some cases, in the downward direction, etc.
The concrete form can be moved by repeating the same steps.

In this concrete form, if the holding member 10 is removed from the rod 1, the panel can be partially removed. Therefore, the panel can be partially removed even in the work of drawing out on the wall surface in work such as electric wiring work, gas or water plumbing work performed before concrete casting, so that this kind of work is extremely easy. Will be able to do it. In this embodiment, the holding member 1
Although the flange portion 12 of 0 is circular, for example, if the width is smaller than the width of the rod 1 and the length is longer than the width of the rod 1, the pressing member 10 can be rotated by 90 degrees. You can partially remove the panel just by doing
This type of construction is much easier.

In this embodiment, an example in which a triangular flap is used as the contact member 15 is shown. However, since the triangular flap has a regular triangular cross section, it is naturally excellent in strength. There is an excellent advantage that there is no waste in terms of securing storage space at the construction site because the accumulation is easy, but any cylindrical member having a flat surface 16 and, in some cases, a columnar member can be used. For example, it may be a semi-cylindrical column or a quadrangular column. Of course, the contact member 15 does not need to have a regular triangular cross section.

Since the concrete formwork according to the present invention is configured as described above, the panels 8 and 9 can use plate materials having a small area. For example, panel 8,
Various plate materials such as plywood, raw material of rawan plywood, iron plate, concrete plate and the like manufactured from conifers can be used. Here, an embodiment of manufacturing plywood from softwood will be described with reference to FIGS. 9 and 10 and FIGS. 11 and 12.
9 is a perspective view showing an example of a state before bonding a veneer manufactured from softwood, FIG. 10 is a side view of a plywood manufactured from the veneer shown in FIG. 9, and FIG. 11 is a veneer manufactured from softwood. 12 is a perspective view showing another example of a state before bonding, and FIG. 12 is a side view of a plywood manufactured from the veneer of FIG.

FIGS. 9 and 10 illustrate one embodiment of making a plywood made of softwood. When softwood is cut in the circumferential direction with a rotary lace like rawan wood, cracks and the like occur in the wood grain due to the nature of the wood, and it is not possible to manufacture a thin plate. Accordingly, the softwood is split in the longitudinal direction with a saw or the like to produce a large number of thin single plates 8V. Therefore, 1
The single veneer 8V has a narrow width. As shown,
A plurality of these veneers 8V (four in the figure) are arranged so that the grain direction is alternately orthogonal to each other, and an adhesive such as glue is applied to both surfaces between the veneers 8V. Then, an assembly of the single plate 8V and the sheet 49 is manufactured with a sheet 49 of synthetic resin or the like interposed therebetween. Next, this assembly is pressed with a press or the like to produce a softwood plywood 8P.

As described above, in the plywood 8P made of softwood, since the sheet 49 is interposed between the veneers 8V, even if the veneer 8V has many nodes, or the veneer 8V has one Even if only the sheet is easily broken, each veneer 8V can be sufficiently fixed by the sheet 49 and can sufficiently function as a plate material of the concrete formwork, that is, the panels 8,9.

When the veneers 8V are sequentially stacked one by one as described above, the plywood 8P has a small area. Therefore, as shown in FIG. 11 and FIG.
The end faces 9E of the two sheets are brought into contact with each other, and a plurality of veneers 9V are arranged on one surface to form a composite veneer. Sheet 49
To produce an assembly of the composite veneer and the sheet 49. Next, this assembly is pressed with a press or the like to produce a softwood plywood 9P. Therefore, if the plywood 9P is manufactured in this way, panels 8 and 9 having a large area can be obtained.

The case where a wall is constructed has been described above. Next, a case where a main body such as a floor or a beam is constructed by concrete casting will be described. FIG. 5 is a cross-sectional view showing an example of a concrete formwork assembled to form a floor and a beam. This formwork is formed by assembling a concrete casting formwork 41 forming a side wall of a beam, a concrete formwork 42 forming a bottom surface of a beam, and a concrete formwork 43 forming a floor. The structure of the concrete formwork itself is as described with reference to FIGS. 1, 2, 3, and 4, and a description thereof will be omitted. Although not shown in FIG. 5, the reinforcing member 37 made of a triangular fluttering material may be supported by a support from the ground or the floor, if necessary.

FIG. 6 is an enlarged view of the area Y in FIG. The contact member 15 of the concrete formwork 41 forming the side surface of the beam and the contact member 15 of the concrete formwork 43 forming the floor are connected by a joint 44. 7 is a front view of the joint 44, and FIG. 8 is a cross-sectional view taken along line ZZ in FIG. The joint 44 is composed of two triangular prisms having a triangular cross section, that is, cylindrical triangular column portions 45 and 46. That is, the cylindrical triangular support portions 45, 46
Are cut at an angle of, for example, 45 degrees, and the cut ends are welded to each other.
Holes 47 and 48 are formed in the joint 44 at positions corresponding to the holes of the contact member 15, and two bolts are inserted through these holes and tightened with nuts, so that The contact members 15 can be connected to each other at right angles. At this time, the seat member 23 may be placed on the ridge line, that is, the top of the contact member 15, and connected.

In the case of the contact member 15 shown in FIG.
Holes corresponding to the holes 47 and 48 of the joint 44 are present at the top, but not in the flat surface 16. Therefore, it is preferable to use a small plate having a hole formed therein, which is welded to the groove 17 of the contact member 15. The joint 44 shown in FIG.
It is for connecting the contact members 15 at a right angle, but by cutting the ends of the cylindrical triangular support portions 45 and 46 not at 45 degrees but at appropriate angles,
The contact members 15 can be connected to each other at an arbitrary angle.

[0042]

The concrete form according to the present invention has the following effects since it is constructed as described above. That is, since this concrete formwork is assembled by abutting the end face of the panel made of plywood or the like on a rod body such as a long rectangular bar and sandwiching the holding member with the pressing member,
There is no need to make holes in the panel. Therefore, a problem that has occurred in the conventional formwork in which a hole is formed in a panel, that is, concrete enters the hole and makes it difficult to disassemble the formwork, or the fixing between the formwork and the tie rods is loosened and a desired product is formed There is no problem such as not being able to obtain. Moreover,
Conventionally, in the work of removing old panels from metal piers and reattaching new plywood at the site, the new panel was scribed at the position that matches the screw hole of the metal pier, and the woodwork was accurately placed at that position There is no need for any manual work such as drilling holes.

Also, a large panel which had to be discarded because the hole became large so far can be cut into small pieces and reused as a panel in the present invention.
It is economically excellent.

In particular, since this concrete form can use panels having a small area, plywood made of wood such as softwood can be used, and even if Rawan plywood becomes thin, it will be used in the future. We can respond enough.

Further, in the case where a reinforcing bar or the like standing between the panels arranged opposite to each other interferes with the provision of the separator, the reinforcing bars should be avoided by using panels of different sizes. Can be. Therefore, drilling work at the construction site or the like is not required at all in this sense, and there is no danger of causing an electric shock accident in rainy weather or the like, and a concrete form frame with high safety can be provided.

Further, if the surface of the panel is made uneven, and several kinds of such panels are prepared, by combining these appropriately, an arbitrary pattern can be formed on the wall, and paintings, figures, characters, and the like can be formed. There is also the advantage that it can be represented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing components such as a rod body, a panel, a holding member, and a contact member of a concrete formwork according to the present invention.

FIG. 2 shows a tightening member for a concrete form according to the invention;
FIG. 3 is an exploded perspective view showing components such as a tie rod and a claw member.

FIG. 3 is a perspective view showing an assembled state of a concrete formwork.

FIG. 4 is a sectional view taken along a horizontal plane including a chain line XX in FIG.

FIG. 5 is a sectional view showing an example of a concrete formwork assembled to form a floor and a beam.

FIG. 6 is an enlarged view of a region Y in FIG. 5;

FIG. 7 is a front view showing a joint.

FIG. 8 is a sectional view taken along line ZZ in FIG. 7;

FIG. 9 is a perspective view showing an example of a state before bonding a veneer manufactured from softwood.

FIG. 10 is a side view of a plywood manufactured from the veneer shown in FIG.

FIG. 11 is a perspective view showing another example of a state before bonding of a composite veneer manufactured from softwood.

FIG. 12 is a side view of a plywood manufactured from the composite veneer of FIG. 11;

FIG. 13 is an assembled sectional view of a conventional concrete formwork using a metal beam frame.

FIG. 14 is a plan view of a conventional concrete formwork using a metal beam frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rod body 4 Screw hole 8, 9 Panel 8V, 9V Veneer 8P, 9P Plywood 10 Holding member 11 Tube part 12 Flange part 13 Male screw 14 Female screw 15 Abutment member 16 Flat surface 19 Tightening member 28 Tie rod 37 Reinforcement member 39 Separator 44 Joint 49 sheets

Claims (6)

(57) [Claims] 1. A rod body having a fitting hole passing therethrough, a holding member having a cylindrical part inserted into the fitting hole and a flange part integrally formed with the cylindrical part, and an end face sandwiching the rod body. A panel in which the panels are arranged in opposition to each other, a contact member having a flat surface for cooperating with the flange and holding the panel, and the flange of the pressing member fixed to the rod are separated in an opposition. A concrete formwork comprising: a separator; and a tie rod which is screwed into a screw provided in the cylindrical portion to tighten the holding member and the abutment member. 2. The concrete formwork according to claim 1, wherein the panel is a plywood manufactured by stacking a plurality of veneers obtained by cutting softwood in a longitudinal direction. 3. The concrete formwork according to claim 1, wherein the contact member is a cylindrical triangular support. 4. The concrete formwork according to claim 1, further comprising a reinforcing member intersecting the plurality of the abutting members and fixing the abutting member. 5. The concrete formwork according to claim 4, wherein the reinforcing member is a tubular triangular support similar to the backing member. 6. The concrete formwork according to claim 1, further comprising a joint for connecting the ends of the contact member at a predetermined angle.