JPS6218693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a formwork apparatus used for constructing wall-like or column-like concrete structures.

In the construction of concrete structures such as walls and columns, large-sized formwork has come to be used in order to improve the construction efficiency of the formwork, and has achieved considerable success. Furthermore, in order to further improve the construction efficiency of this type of formwork, efforts have been made to reduce the number of formwork tightening bolts as much as possible. By the way, most of the formwork tightening bolts are buried through the concrete body, which causes water leakage, and from this point of view as well, it is necessary to reduce the number of tightening bolts. However, if you try to reduce the number of formwork tightening bolts, you will need batten material with a large cross section, which not only increases the weight and is uneconomical, but also makes it difficult to handle, which is not desirable. isn't it.

Therefore, the idea was to create a truss structure for the butter to increase its rigidity, making it relatively lightweight and easy to handle.However, by adding a deflection adjustment device to the truss structure of the butter, it was possible to make the truss butter even stronger. Efforts are being made to reduce the weight of the One example that has been successfully put into practical use is the support material for the bottom forms of concrete floors.

When constructing floor concrete, etc., the span of the formwork increases depending on the width of the formwork, and the formwork bends downward and bulges under the weight of the poured concrete, so it is necessary to prevent this. Various measures are being taken. Most commonly, the formwork is supported from the bottom with many supports to resist the weight of the poured concrete. However, this method requires a large amount of material for supports and the like, resulting in extremely poor workability. Therefore, it is possible to install a deflection device in the batter material that supports the weir plate, and apply a deflection in the opposite direction to the formwork during concrete pouring, which corresponds to the degree of deformation due to the weight of the concrete when the formwork is set. Lightweight truss butter material is used.

Generally, when selecting formwork flaps, it is necessary to ensure that the stress generated in the member due to the pressure of concrete does not exceed the allowable stress level, and the amount of deflection must be within the allowable range. The allowable amount of deflection is usually about ±3 mm. By the way, when actually designing a member, in most cases the amount of deflection is the problem, and the degree of stress is usually more than enough on the safe side. Therefore, if a method is devised to suppress deflection, a small cross-section member will be sufficient. One method of suppressing deflection is to turn the member toward the concrete side and allow it to deflect before pouring the concrete, and the present invention is one of those methods based on that technical idea. .

When constructing structures such as walls and columns that are long in the vertical direction, it is conceivable to apply a deflection in the opposite direction before pouring concrete.

Figure 1 shows a case in which a formwork equipped with deflection means, which is used in the construction of conventional floor concrete, is applied as is to the construction of wall concrete. A deflection adjusting device 4 is provided on the back surface of the mold body 1 to form a mold body 1, and such mold bodies 1, 1 are connected facing each other.

The deflection adjustment device 4 has diagonal members 5 and 5 having one end pivotally connected to the upper and lower parts of the vertical flap 3, and the other ends of the diagonal members 5 and 5 being pivotally connected 9 to each other.
At the same time, a vertical member 6 having a threaded portion 7 with a nut 8 screwed onto the tip thereof is further pivotally attached to the pivot point, and the tip of the vertical member 6 is inserted through the vertical butterfly 3, and the nut is tightened. By doing this, the central part of the vertical butterfly 3 is pushed out as shown by the arrow, and the form body 1 is deformed to bulge inward as shown by the chain line. In this case, the upper and lower parts of the formwork bodies 1 and 1 are set to maintain a predetermined distance, but the lower part is, for example, sandwiched between both sides of the existing structure 10 as shown in the figure, and is connected to the buried bolts. 11 is tightened and fixed with a through nut, and bolts 12 are passed through a spacer 13 of a predetermined length at the upper part of the formwork body 1 and tightened and fixed with a nut.

In this formwork, as shown by the chain line in Figure 1,
If the deflection adjustment device 4 is operated to deflect the formwork bodies 1 inwardly toward each other, when concrete is poured, the formwork bodies 1 are pushed outward by the pressure and the deflection is eliminated. However, in the construction of walls, etc., scaffolding for assembling reinforcing bars is usually installed, so the formwork shown in Figure 1 If a large number of diagonal members 5, etc. for imparting deflection are installed, not only will the scaffolding become a hindrance and it will be very difficult to set up, but as mentioned above,
The structure is complicated, requiring diagonal members 5, vertical members 6, etc. to provide deflection, and tension members 14 must be provided to set the normal line and prevent the formwork from collapsing. As a result, the formwork itself and its handling became unavoidably complicated.

The present invention solves the above-mentioned problems.
In the construction of structures such as columns, it is possible to use vertically long formwork, and the extremely simple structure and operation for applying deflection allows even small cross-section members to be easily moved outward from the formwork during concrete pouring. The aim is to prevent deformation, enable highly accurate construction, and improve construction efficiency and economy.

Embodiments of the present invention will be described below with reference to the drawings.

2 and 3 are side views showing an example of constructing a wall using a formwork provided with a deflection adjustment device,
In the figure, 1 and 1 indicate, for example, an existing lower part of the wall to be constructed or another structure 1 having the same thickness as the wall.
The formwork bodies 1 and 1 are arranged oppositely along the outer surface of the frame body 1, and both formwork bodies 1, 1 have the same structure.

In the form body 1, as is normally practiced, a weir plate 2 is constructed on the inner surface of vertical butterflies 3, 3... placed upright at required intervals, and each vertical butterfly 3, 3 is constructed with a plurality of horizontal butterflies. 20. A deflection adjustment device 15 is provided at the lower end of the vertical flaps 3, 3, . . . as required.

The deflection adjustment device 15 has a pressing member protruding inward from the vertical butterfly 3, and generally a screw type or hydraulic type jack is preferably used. The illustrated embodiment shows a deflection adjustment device using a screw jack. This device 15
A threaded rod 17 is rotatably provided in a cylinder 16, and a pin 18 protrudes from a nut screwed into the threaded rod 17 and projects outward from a guide elongated hole 19 of the cylinder 16, rotating the screw rod 17. By doing this, pin 1
8 is adapted to be moved along a guide elongated hole 19, and this pin 18 is pivotally connected to the vertical butterfly 3. Therefore, when the screw rod 17 is rotated, the device 15 is moved in and out of the vertical butterfly 3 using the pin 18 as a fulcrum.

As shown in FIG. 2, the formwork bodies 1, 1 face each other so as to sandwich the existing structure 10 from both sides, and the middle part of the formwork body 1 is connected to the mounting bolts 11 buried in the upper part of the existing structure 10. Installed by. A connecting bolt 12 is inserted into the upper end of the form bodies 1, 1 with a spacing member 13 made of a pipe or the like interposed therebetween, and is tightened with a nut 21 to maintain a predetermined spacing. From this state, next, the respective deflection adjustment devices 15, 15 of both formwork bodies 1, 1 are operated.

That is, as shown in FIG. 2, the threaded rod 17 is rotated so that the cylindrical body 16 projects inward of the formwork. Then, the front end of the cylinder 16 is in contact with the existing structure 10 and cannot be moved inward, so the lower end of the vertical butterfly 3 is moved outward, that is, in the direction away from the existing structure. It turns out. However, the middle part of the vertical butterfly 3 is attached to the existing structure 10 with bolts 11, and is prevented from moving inward by the existing structure 10.
In addition, since the upper end portions are fixed at a predetermined distance by the spacing member 13 and the bolt 12, the vertical butterflies 3, 3 are curved inwardly from the middle to the upper portions to prevent bending. will be granted. Therefore, the frame bodies 1, 1 as a whole are bent inwardly relative to each other.

In this case, since the fulcrum of the lower part that causes the deflection is on both sides a of the upper end of the existing structure 10, the connection point with the bolt 11 located below will open slightly outward, so the vertical movement at this point will be 3 and the existing structure 10 must be loosely connected.

Ideally, the amount of deflection applied to the formwork body 1 should be equal to the amount by which the formwork body 1 deflects outward due to the lateral pressure of the poured concrete. Since the surface unevenness error (irregularities due to deflection of members) is allowed to be ±3 mm, the inward deflection imparted to the formwork 1 is 3 mm greater than the expected outward deflection due to the lateral pressure of the concrete.
It would also be permissible to add a certain degree of size. In this state, if the upper parts of the weir plates 2, 2 are shifted to the right with respect to the predetermined normal line and must be moved to the left, use the screws of the deflection adjustment device 15 at the bottom of the left formwork. While rotating the rod 17 to reduce the protruding length of the cylinder 16, turn the screw rod 17 of the deflection adjustment device 15 at the bottom of the right formwork to reduce the length of the cylinder 16.
When the protruding length of is increased, the upper parts of the weir plates 2, 2 gradually move to the left, and the upper parts of the weir plates can be brought into alignment with a predetermined normal line.

That is, the normal line correction work can be performed by the deflection adjustment device 15. In this way, the deflection adjustment device 15 also has the function of preventing the shaped formwork from collapsing. Therefore, the struts 14 as shown in FIG. 1 are generally not necessary or can be reduced in number.

Next, concrete is poured between both formworks 1,1. The poured concrete applies lateral pressure to the formwork bodies 1, 1 as shown by the arrows, causing the formwork bodies 1, 1 to deform outward, thereby causing the concrete in the formwork bodies 1, 1 to The installed portion will be restored to its normal state as shown in FIG. 1, or a state close to it, and the wall will be constructed to a predetermined thickness.

Once the poured concrete has hardened, the screw rod 17 of the deflection adjustment device 15 is rotated in the opposite direction to move the device 15 outward from the vertical butterfly 3 and connect it with the mounting bolt 11 and the connecting bolt 12. is released and the formwork bodies 1, 1 are removed.

Although the above embodiments have been described for the construction of a structure having a vertical wall, the present invention is not limited thereto, and can be applied to, for example, a structure having a slope, a retaining wall on a slope, etc. It can also be applied to the construction of single-sided formwork.

In FIGS. 2 and 3, for example, if the right-hand formwork 1 is replaced with a cut-up slope, the left-hand formwork becomes a single-sided formwork for slope-covered concrete.

As explained above, the present invention provides a formwork in which a deflection adjustment device that can freely protrude inward of the vertical flap is provided at the lower end of the vertical flap when constructing concrete structures such as walls and columns. Attach the middle part of the body to the existing structure and fix the upper part of the formwork, then operate the deflection adjustment device to move the lower end of the formwork away from the existing structure, and then attach the formwork to the existing structure. Since the body is given inward deflection and concrete is poured into the formwork in that state, the formwork body used for construction is no longer a complex truss structure for giving deflection like in the past. This means that the structure and handling of the formwork are greatly simplified, as the structure and handling of the formwork are greatly simplified, without the need for any other mechanism. In addition, it has many excellent benefits, such as having extremely little impact on other facility structures such as scaffolding, and eliminating the need for tensioning materials to prevent collapse and set normal lines, significantly improving construction efficiency and construction economy. It is effective.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a construction mode using a conventional formwork with a deflection adjustment device, and FIGS. 2 and 3 are side views showing embodiments of the construction method of the present invention. 1... Formwork body, 2... Weir board, 3... Vertical flap, 10...
Existing structure, 11... Mounting bolt, 12... Connection bolt, 13... Spacing member, 15... Deflection adjustment device, 2
0...Sideways.

Claims (1)

[Claims] 1 Using a formwork body configured by providing a deflection adjustment device that can freely protrude inward of the formwork at the lower end of the vertical flap,
Attach the middle part of the formwork to the top of the existing structure, fix the top of the formwork, and then operate the deflection adjustment device to move the bottom end of the formwork away from the existing structure. A formwork construction method for wall, column concrete, etc., characterized by applying inward flexure to the formwork and pouring concrete into the formwork in that state.