JPH0657956A - Construction of concrete structure - Google Patents

Abstract

PURPOSE:To obviate the assembly of a form at a site and maintain the quality of concrete on the surface of a skeleton. CONSTITUTION:A square cylindrical precast concrete external form 2 corresponding to each of the peripheral shapes of a plurality of parts cut up and down of a structure 1 to be constructed and a square cylindrical precast concrete internal form 3 corresponding to each of the circumferential shapes of a plurality of parts cut up and down of the structure 1 are manufactured on the ground. First of all, the external form 2 corresponding to the peripheral shape of the lowest part of the structure 1 is installed on the foundation floor slab, and the internal form 3 corresponding to the circumferential shape of the lowest part of the structure 1 is drawn to the inside thereof to set internal and external forms. After a reinforced cage 6 is drawn to a gap between both internal and external forms to arrange, cast-in-place concrete 7 is placed in the gap so as to leave a space section to a certain extent in the upper part thereof. An external form 2 and an internal form 3 are drawn on the external form 2 and the internal form 3 to join and, at the same time, the reinforced cage 6 is drawn into a gap between both internal and external forms to arrange. The cast-in-place concrete 7 is placed into the gap so as to leave a space section to a certain extent in the upper part thereof, and after that, the same stage of work is repeated to construct the structure 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly uses a construction method for a concrete structure such as a concrete tower in which a beam is erected between left and right towers, and particularly uses a precast concrete formwork for constructing the frame or beam surface of the structure. It relates to a construction method that is integrated with the cast-in-place concrete that has been placed inside.

[0002]

2. Description of the Related Art As a construction method for a concrete structure,
Conventionally, a form casting method has been generally used, in which form forms are assembled sequentially from the lower floors, and are reinforced inside, and are constructed by pouring in-place concrete.

As a construction method for a high-rise concrete structure, there is also known a prefabricated construction method in which pillars, beams, wall panels, etc. are precast concrete members manufactured by a factory and assembled on site.

[0004]

In the above-mentioned form casting method, there are many on-site work steps such as form assembling, dismantling and moving, rebar assembling, concrete placing, etc., and construction of a high-rise concrete structure. In this case, there is a problem that it takes a lot of work period, it is not easy to maintain the quality of concrete, and it is difficult to secure the work safety because it requires work at a high place.

Further, the above-mentioned prefabricated construction method has problems in workability and safety, such as work at high places such as assembling and transporting concrete members, installing formwork at joints, and placing concrete.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a rectangular tubular precast concrete outer mold 2 corresponding to each outer peripheral shape of a portion obtained by cutting a plurality of structures 1 to be constructed up and down, and a structure 1. Square tubular precast concrete inner formwork 3 corresponding to the inner peripheral shape of the part cut up and down 3
First, the outer mold 2 corresponding to the outer peripheral shape of the lowermost part of the structure 1 is installed on the foundation floorboard, and the inner mold corresponding to the inner peripheral shape of the lowermost part of the structure 1 is installed inside thereof. Suspend the frame 3 to set the inner and outer molds, suspend the rebar cage 6 in the space between the molds, and arrange the bars.
Is placed so that some space is left on the upper part, and the outer mold 2 and the inner mold 3 are further suspended and joined on the outer mold 2 and the inner mold 3, and at the same time, in this mold gap. Reinforcing bar cages 6 are laid and arranged, and in-situ concrete 7 is placed again in this gap to the extent that some space remains at the top, and then the same steps are repeated to construct structure 1. It proposes the construction method of the concrete structure.

Further, according to the present invention, a U-shaped beam formwork 1 made of precast concrete is supported in a cantilever shape by a large number of slanted tie rods 10 on the opposing surfaces of the left and right columnar structures 1.
1 hang the ends of the beams, but
On-site cast concrete 12, 13 is placed in a thickness such that the weight of concrete can be supported by the tie rods 10 and 11, and the exposed tie rod 10 is cut off when the strength as a beam is sufficiently developed. Further, the present invention proposes a construction method for a concrete structure in which concrete 14 and 15 are sequentially placed on it and integrated as needed.

[0008]

Operation: Since the cast-in-place concrete 7 is placed in the gap between the outer mold 2 and the inner mold 3 of the precast concrete constituting the frame surface of the structure 1, the mold is assembled and dismantled on the site. Since there is no work, the construction period can be shortened, and there is little external work, especially at high places, and work safety can be improved.

Since the outer mold 2 and the inner mold 3 are molded on the ground, it is possible to reliably maintain the quality of concrete, which is required to be solid and homogeneous as the surface of the skeleton.

Further, since the outer mold 2 and the inner mold 3 are formed of precast concrete in a cylindrical shape, a wide rebar space can be secured, and the rebar baskets can be easily suspended and bound.

When constructing the horizontal beam B, the tie rod 10 is provided with the weight of the concrete itself in a U-shaped beam form made of precast concrete that is supported in a cantilever shape by the tie rod.
Since the cast-in-place concrete 12 is cast to a thickness that can be supported by, it is not necessary to carry out support work or dismantle the formwork, and at the time when the strength as a beam is sufficiently developed after the concrete is cast, it will be It is possible to support the load of the concrete 14 and 15 that is cast into the ground, and to minimize the use of support materials.

[0012]

EXAMPLE The present invention method is applied to the main tower A having a hollow rectangular cross-section and a tapered wedge shape in a high-rise hollow concrete tower in which a plurality of horizontal beams B are vertically installed between the left and right main towers A shown in FIG. An example of constructing the concrete structure 1 whose cross-sectional shape is gradually reduced and changed from the lower side to the upper side will be described.

As shown in FIG. 5, a precast concrete outer mold 2 having a rectangular cylindrical shape corresponding to each outer peripheral shape of a portion obtained by cutting the structure 1 to be constructed up and down and a plurality of the structures 1 up and down. A rectangular tubular precast concrete inner formwork 3 corresponding to the inner peripheral shape of the cut portion is manufactured on the ground.

First, the outer formwork 2 corresponding to the outermost shape of the lowermost part of the structure 1 is installed on the foundation floorboard, and the inner formwork corresponding to the innermost shape of the lowermost part of the structure 1 is installed inside thereof. 3 is hung by the crane 4 via the hanging frame 5 to set the inner and outer molds.

Next, after the reinforcing bar cage 6 is suspended and arranged in the gap between the outer mold 2 and the inner mold 3, the cast-in-place concrete 7 is struck in the gap to the extent that some space is left above. Set up.

At this time, the concrete 7 cast at this time has a curing mat 8 placed on the upper surface thereof, and is cured while preventing evaporation of moisture and heat dissipation. Clean it.

Next, the outer mold 2 and the inner mold 3 are further suspended and joined on the outer mold 2 and the inner mold 3, and joints 9 and 9'provided inside the mutual joints are provided. After connecting and integrating, the reinforcing bar cage 6 is hung in the gap between the outer mold 2 and the inner mold 3 to bind them together, and the cast-in-place concrete 7 is again placed in the gap to form a space. Place it so that the

Thereafter, the same steps as described above are repeated to construct the structure 1.
To build.

On the other hand, as shown in FIG. 14, the left and right main towers A,
When laying a plurality of upper and lower horizontal beams B between A,
As shown in Fig. 1, the left and right columnar main towers A, which are the structures 1, are supported in a cantilevered manner by a large number of diagonal tie rods 10 on the opposing surfaces, and are made of precast concrete in which reinforcing bars are prearranged inside. After suspending the U-shaped beam formwork 11 and treating the space between the opposite ends of the beam formwork 11, 11 with caulking material, the tie rod 10 can support the weight of the beam formwork 11, 11 and the concrete itself. Pour in-situ concrete 12 to the thickness.

After the concrete 12 is sufficiently cured and hardened, concrete 13 is further placed thereon, and the exposed tie rod 10 is cut off when the strength as a beam is sufficiently developed. Concretely, concrete 14 and 15 are sequentially cast on it and integrated with each other.

Since the construction of the horizontal beam B can be carried out concurrently with the construction of the structure 1, it does not affect the whole construction period.

10 and 11 show specific examples of the tie rod 10. Most of the outer periphery of the tie rod 10 made of PC steel rod is covered with a thin steel pipe sheath 16 and is provided at the lower end of the steel pipe sheath 16. Screw the lower end of the tie rod 10 into one end of the screw hole of the coupler 17,
The rear end of the anchor steel rod 18 whose tip is embedded in the bottom plate of the beam formwork 11 is screwed into the other end of the screw hole of the above, and the upper end of the tie rod 10 is further held by a holder 19 fixed to the main tower A. I am nervous as I connect it to the hole jack 20.

Therefore, the tie rod 10 can be reused by pulling it out from the steel pipe sheath 16 after removing it from the coupler 17 at the time when the strength of the beam is secured by placing concrete on the beam formwork 11.

[0024]

As described above, according to the present invention, since the cast-in-place concrete is cast in the gap between the outer and inner molds of the precast concrete forming the surface of the frame of the structure, on-site The work of assembling and disassembling the mold is unnecessary, the construction period can be shortened, and the work safety can be improved by reducing the external work especially at high places.

Since the outer mold and the inner mold are produced on the ground, the quality of the concrete, which is required to be solid and homogeneous as the surface of the skeleton, can be reliably maintained.

Further, since the outer mold and the inner mold are made of precast concrete in a cylindrical shape, a wide rebar space can be secured, and it is possible to easily suspend and bind the reinforcing bar cage.

When constructing a horizontal beam, in-situ concrete is poured into a U-shaped beam form made of precast concrete supported by a tie rod in a cantilever shape to a thickness such that the weight of the concrete can be supported by the tie rod. Therefore, supporting work and dismantling of the formwork are unnecessary, and at the time when the strength as a beam is sufficiently developed after concrete is placed, the rigidity of the beam can support the load of the concrete to be placed later. Can be used reasonably with minimal use.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view showing one embodiment of a construction process of the present invention.

FIG. 2 is a partial vertical cross-sectional view showing another aspect of the construction process of the present invention.

FIG. 3 is a partial vertical cross-sectional view showing another aspect of the construction process of the present invention.

FIG. 4 is a partial vertical sectional view showing another embodiment of the construction process of the present invention.

FIG. 5 is a perspective view of a precast concrete outer formwork and an inner formwork according to the present invention.

FIG. 6 is a front view showing a state where the inner formwork is suspended in the present invention.

FIG. 7 is a plan view of a suspension frame for suspending the formwork according to the present invention.

FIG. 8 is a perspective view showing a suspended state of a reinforcing bar basket according to the present invention.

FIG. 9 is a vertical sectional front view showing an outline of construction of the horizontal beam of the present invention.

FIG. 10 is a vertical cross-sectional front view showing the attachment structure of the tip of the tie rod used in the present invention.

FIG. 11 is a vertical sectional front view showing a mounting structure of a rear end of a tie rod used in the present invention.

FIG. 12 is a perspective view showing an example of a structure constructed according to the present invention.

[Explanation of symbols] 1 structure 2 outer formwork 3 inner formwork 4 crane 5 hanging frame 6 rebar cage 7 concrete 8 curing mat 9 joint 9'joint 10 tie rod 11 beam formwork 12 concrete 13 concrete 14 concrete 15 concrete 16 steel pipe Sheath 17 Coupler 18 Anchor steel rod 19 Holder 20 Center hole jack

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location E04H 12/12 (72) Inventor Junichi Inoue 2-1026 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industrial Co., Ltd. (72) Kenichiro Nishino 2-10-26 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd.

Claims (2)

[Claims] 1. A square tubular precast concrete outer formwork and a precast concrete inner formwork corresponding to each outer peripheral shape and inner peripheral shape of a portion obtained by vertically cutting a structure to be constructed are manufactured on the ground, First, install an outer formwork corresponding to the outermost shape of the bottom of the structure on the foundation floor,
The inner formwork corresponding to the inner peripheral shape of the lowermost part of the structure is hung inside it to set the inner and outer formwork, and the rebar cage is hung in this formwork space to arrange the bars, and then the site is placed in this space. Pour concrete into the upper part so that some space remains, and hang the outer and inner molds on the outer and inner molds to join them together. A method for constructing a concrete structure, in which the concrete is constructed by suspending and arranging the concrete, pouring in-situ concrete into the gap so that some space remains above, and then repeating the same process. 2. A U-shaped beam form frame made of precast concrete, which is supported in a cantilever shape by a large number of oblique tie rods, on the opposing surfaces of the left and right columnar structures, the ends of which are suspended from each other, and the beam form is suspended. Pour in-situ concrete into the frame so that the weight of the concrete can be supported by the tie rods, cut off the exposed tie rods when the strength of the beam is fully developed, and then add it as necessary. A construction method for a concrete structure, characterized in that concrete is poured into each of the two and integrated.