JPH0639845B2 - Construction method of formwork for dome type building - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a method for constructing a formwork used for building a dome-shaped building such as a concrete shell.

(Prior art and problems) A construction method of a dome-shaped building using an air film is already known (for example, RN Dent, translated by Mikio Sasaki and Takao Sasaki, January 15, 1975, Kashima Publishing). Issue
Construction of air film structures (see pages 139-142).

The so-called Neff construction method by Wallace Neff, which is described in the above publication, has the problems as described therein, that is, it is difficult to use the construction method in a short time, and concrete is blown. The applied balloon pressure is not sufficient to prevent excessive deformation caused by the weight of the concrete under construction, resulting in cracking of the concrete, necessary to reduce the deformation to prevent such cracking. The use of large internal pressures entails the problems of necessarily larger and more expensive foundations that seem necessary. And, as disclosed in the above publication, the vinyl shell by Dante Vini is fixed to the surrounding base, and the concrete is pre-cast into the surface of the closed and stretchable neoprene film, and the film is applied to the film. It is a construction method that pressurizes and expands, and when the concrete hardens, the pressurization is released and the neonprene film is removed. When this means is used, means for preventing concrete from flowing out due to the expansion of the neoprene film, means for preventing cracks (reinforcing means), etc. are required. As these means, vibration is applied to concrete and concrete is reinforced with mesh-shaped reinforcing bars. Means such as things have been clarified,
In addition to the disadvantage of requiring extra effort and extra materials, there is also the problem that if a large expansion force is used, a heavy foundation is required as a weight, and complicated bar arrangement becomes uneconomical. is doing. Also, the construction method by Heim Heifetz, as disclosed in the publication, instead of placing concrete on the ground, is sprayed on a balloon that has already been inflated with a large pressure, the large pressure is attached radially, The reaction force is removed by a removable truss or reinforced concrete slab.
When this means is used, it is necessary to assemble and dispose the truss, slab, and the like, so that there is a problem that a long construction time is required. In addition to these problems, all three mentioned above
It is necessary to have a technique to fix the surroundings of balloons and neoprene membranes to the ground with good airtightness, high pressure must be applied to support the concrete layer formed on the surface, and those balloons and neoprene membranes, etc. There is a problem to be solved such as the need for considerable strength.

The present invention has been made in view of the above circumstances, does not require a large internal pressure, does not crack in the mold even without applying the crack generation preventing means of the mold and the outflow preventing means of the mold, and the mold There is no concern that water will flow out, there is no need to assemble and dispose trusses, reinforced concrete slabs, etc. Furthermore, the use of bags such as the well-known balloons and neoprene membranes that do not require steric cutting, and the construction period is greatly shortened. The purpose is to propose a useful construction method for a dome-shaped building formwork.

(Means for Solving the Problems) Means of the present invention for achieving the above-mentioned object does not fix the air-impermeable flat membrane bag body anywhere on the ground, and allows the cord to be loosely removed. When the fluid is fed into the flat bag body only by hanging it, the periphery of the bag body freely moves in the vertical plane and the horizontal plane, and the upper part of the flat bag body swells and is regulated by the tensioned rope. To form a solid bag with a cross-sectional shape, form a quick-setting lightweight mortar cement layer on the surface of the solid bag, cure it in a short time, and then drain the fluid from the solid bag, and then remove the solid bag. This means that the body is returned to the flat bag body and removed together with the cord.

(Example) The structure of a member to be used and the construction method will be described in this order with reference to the drawings.

The flat bag body (1) is formed by normally cutting an impermeable material (for example, thermoplastic vinyl chloride resin) into a flat circular shape, a flat rectangular shape, or any other suitable flat shape, and cutting the flat membrane (1 ').
It is constructed by stacking two sheets and welding the surroundings to each other. The two flat membranes (1 ') forming the flat bag body (1) do not need to be three-dimensionally cut. When welding the periphery of the two flat membranes (1 '), a reinforcing tape (5) may be welded. The flat bag body (1) is provided with a fluid inlet port (2) also serving as a fluid outlet on one flat membrane (1 '), and a fluid such as water, air, or other gas is fed from the inlet port. It is configured to be able to enter and also to be able to remove the used fluid. The rope (3) is made of a sturdy material such as a rope or a cable, and is provided with a separable connecting tool (6) such as a hook, carabiner or turnbuckle at both ends, and the connecting tool is used to place the rope on the ground. It is configured so that it can be connected and separated to the connecting tool (8) of the fixed rope (7) that has been installed, and can be removed freely after the formwork construction. When placing the rope (3) on the flat bag body (1) when constructing the formwork, it depends on whether it is cross-mounted (right-angled cross-mounted, oblique cross-mounted, etc.),
Parallel mounting and various other special-shaped mountings are conceivable. In any case, after being loosened and mounted, it is detachably connected to the fixed rope (7) as described above. Although not shown, the cords (3) placed on the flat bag body (1) do not shift in position in the process of the flat bag body (1) swelling and becoming the three-dimensional bag body (1). In order to do so (to prevent the ropes from being displaced and completing the formwork having a cross-sectional shape different from the designed one), the intersections of the ropes (3) are alternately stopped or a flat surface is formed. The flat membrane (1 ') and the cord (3) forming the bag body (1) may be stopped at desired positions. The stopper (not shown) used in such cases is
Use a structure that can be easily removed (for example, clothespins, office clips, other clips, adhesive tape, velvet fasteners, strings, etc.). The quick-setting lightweight mortar cement layer (4) is a mortar cement having a lighter specific gravity than well-known mortar cement or lightweight mortar cement, and is a cement quick-setting agent (for example, a product name of Asano Supernatom Powder manufactured by Nippon Cement Co., Ltd. , POSOLIS Bussan Co., Ltd. product name QP-500LS
(Liquid) is added so that it can be cured in a short time.

Next, the construction method will be described.

Build a concrete foundation (10) with anchor bolts (9) standing on the ground at the construction site. The plane shape of the concrete foundation (10) may be similar to or different from the plane shape of the plane bag body (1), but is constructed to be relatively small compared to the plane shape of the plane bag body (1). . Next, the flat bag body (1) is placed at the construction site so that the periphery is close to the anchor bolts (9). At this time, the flat bag (1)
Does not fix to the ground. The relaxed cord (3) is placed on the flat bag body (1) and connected to the fixed cord (7) connected to the anchor bolt (9). A fluid is introduced into the flat bag body (1) through the fluid inlet (2). When the fluid is introduced into the flat bag body (1), the periphery of the flat bag body (1) starts to move freely in the vertical plane and in the flat plane, and the upper portion starts to bulge as the internal pressure increases. The flat bag body (1) that has begun to swell expands until the cord (3) is tensioned, and further expands to a smaller diameter between the cords (3) to give strength and rigidity, and at the same time, is regulated by the tension of the cord. Cross-sectional shape (for example, a substantially oval cross-sectional shape,
It becomes a three-dimensional bag body (1) having a substantially bun-shaped cross section. When the three-dimensional bag (1) is formed, while maintaining the internal pressure as it is, an extremely thin lightweight mortar cement layer (4) having a rib on the inner surface is sprayed with an extremely thin light-setting mortar cement sprayed on the surface of the bag. ) Is formed. When spraying this mortar cement, the lightweight mortar cement layer (4) around the three-dimensional bag body (1) is sprayed so as to be integrated with the concrete foundation (10), and the concrete foundation is used for the formwork. Make it function as a weight for (11). Then, when the lightweight mortar cement layer (4) hardens, the fluid in the three-dimensional bag body (1) is drained, this three-dimensional bag body is returned to the flat bag body (1) again, and removed, and the cord (3) is removed. Separate from the fixed cord (7) and remove.

Thus, the extremely thin formwork (11) formed of the lightweight mortar cement layer (4) having the strength improved by the ribs is completed.

The formwork (11) is used as a formwork for a structure, and a concrete shell (12) is constructed as a structure on the formwork. The construction of the concrete shell (12) is a normal construction method in which the reinforcing bars are arranged on the formwork (11) and the concrete is placed, and the steel fiber reinforced concrete (SFRC) is placed on the formwork (11). ) Is to be appropriately selected from the construction method of placing or spraying.

By the way, even if the fluid removal from the three-dimensional bag body (1) and the work of removing the cord (3) are not performed at the time when the formwork (11) is completed, the concrete shell (1
It does not matter if it is done after forming 2).

Further, although the fluid is extracted and returned to the flat bag body (1) again, the removal work may be performed either at the completion of the form (11) or at the completion of the concrete shell (12).

Then, the doorway (not shown) to be formed in the formwork (11)
Can be opened during construction of the formwork or after the concrete shell (12) is completed, but use the above-mentioned doorway to remove the flat bag body (1) and the cord (3) after fluid removal. And do it.

(Effect of the invention) The present invention, as described above, without forming concrete feed in advance on the surface of the air-impermeable flat bag body before fluid feeding.
And the flat bag is placed on the construction site without fixing it anywhere on the ground, and the rope is loosely removed and hung freely, and when the fluid is fed into the flat bag, the periphery of the bag is changed accordingly. Since it can move freely in the vertical plane and the horizontal plane, the flat bag can be inflated without giving a large stretch to the flat membrane for the flat bag, and the cross section regulated by the tensioned cords. It is easy to form a three-dimensional bag. Then, the quick-setting thin lightweight mortar cement layer formed on the surface of the three-dimensional bag body is set and hardened immediately after formation, so that the deformation of the three-dimensional bag body is reduced even if the internal pressure of the three-dimensional bag body is low. Therefore, there is an effect that generation of cracks and outflow are not caused during the forming work. Furthermore, since the flat bag can be constructed without being cut three-dimensionally, its processing is easy, and after construction of the formwork, construction of the structure with concrete on the surface of the formwork, reforming of the cement layer of the same quality as the formwork. The other advantages are that the exterior can be constructed as the client desires.

[Brief description of drawings]

The drawings show an example in which the plane shape of the flat bag body used in the construction method of the present invention is a plane circular shape. FIG. 1 is a longitudinal sectional view of the bag body, and FIG. Fig. 3 is a vertical cross-sectional view showing the start of construction, Fig. 4 is a plan view of the same, Fig. 5 is a vertical cross-sectional view showing the fluid feeding, and Fig. 6 is a vertical cross-section showing the formation of a lightweight mortar cement layer. FIG. 7 is a vertical sectional view showing the completion of the mold. In the figure (1) …… flat bag (3D bag) (2) …… fluid inlet, (3) …… rope (4) …… quick-setting lightweight mortar cement layer (11) …… Formwork

Claims (1)

[Claims] 1. A fluid bag inlet provided with a fluid bag inlet in a flat bag body made of an air-impermeable flat membrane, the bag body being placed at a construction site, and the cords being laid loosely and detachably. Then, the fluid is fed into the flat bag body and inflated, and a light-weight mortar cement layer with quick-setting property is formed on the surface of the bulged solid bag body, and after the mortar cement layer is hardened, the fluid in the solid bag body is removed. A method for constructing a dome-type building formwork, characterized in that the flat bag body is returned to the flat bag body and the flat bag body and the rope are removed.