Construction methods

Abstract

To reduce construction cost of a concrete structure installed on a rooftop of a building.SOLUTION: In a manufacturing step 12, at a construction site of a building, a concrete member is manufactured in a top-bottom reversed state. A plurality of concrete members having different heights may be manufactured using one mold. In a lifting step 14, the manufactured concrete member is lifted in a top-bottom reversed manner. In an installation step 16, the lifted concrete member is installed on a rooftop of a building. Furthermore, in a placement step 18, ready mixed-concrete may be placed and hardened in the concrete member installed on the rooftop.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a construction method for constructing a concrete structure on the roof of a building.

Background Art

[0002] Patent Document 1 discloses a construction method for constructing a structure such as a cubicle pedestal foundation, a parapet, or a machine foundation by placing concrete in a bent PC foundation formwork.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technique disclosed in Patent Document 1 requires transporting the bent PC foundation formwork manufactured in a factory to the building construction site, resulting in high transportation costs. In addition, when constructing a plurality of structures with different heights, it is necessary to manufacture a bent PC foundation formwork according to each structure, resulting in high manufacturing costs. An object of this invention is to solve such problems, for example.

Means for Solving the Problems

[0005] At the building construction site, a concrete member is manufactured in an upside-down state, the manufactured concrete member is lifted in an upside-down state, and the lifted concrete member is installed on the roof of the building. In the step of manufacturing the concrete member, a plurality of concrete members with different heights may be manufactured using one formwork. Fresh concrete may be placed and hardened in the concrete members installed on the roof. [Effects of the Invention]

[0006] Since concrete components are manufactured on-site at the building construction site, transportation costs for these components can be reduced. Since the concrete members are manufactured in an inverted state, multiple concrete members of different heights can be manufactured using the same formwork. [Brief explanation of the drawing]

[0007] [Figure 1] A flowchart illustrating an example of a construction method. [Figure 2] A side view cross-sectional diagram showing an example of formwork. [Figure 3] A side view cross-sectional diagram showing an example of the manufacturing process. [Figure 4] A side view showing an example of a concrete member. [Figure 5] A side view showing an example of the lifting process. [Figure 6] A side view showing an example of the lifting process. [Figure 7] A side view showing an example of the lifting process. [Figure 8] A side view showing an example of the installation process. [Figure 9] A side view showing an example of the installation process. [Modes for carrying out the invention]

[0008] Referring to Figure 1, a construction method 10 for constructing a concrete structure on the roof of a building will be explained. Examples of concrete structures include equipment foundations and pigeon coops. The construction method 10 includes, for example, a manufacturing process 12, a lifting process 14, an installation process 16, and a concrete pouring process 18.

[0009] First, in manufacturing process 12, concrete members are manufactured. The concrete member may be the concrete structure itself installed on the roof, or it may be a formwork member that becomes a concrete structure by integrating with the placed concrete after placing fresh concrete into it after installing the concrete member on the roof. The place where the concrete member is manufactured is within the site of the building construction site, but it is a different place (e.g., on the ground) from the roof where the concrete structure will ultimately be installed. That is, the concrete member is manufactured by on-site precast (PCa). Also, the concrete member is manufactured in a state where it is upside down compared to the state when it is installed on the roof.

[0010] Next, in the hoisting process 14, the concrete member manufactured in the manufacturing process 12 is lifted and inverted using a hoisting device such as a crane, and further lifted to the roof of the building where the concrete member is to be installed.

[0011] And in the installation process 16, the concrete member hoisted in the hoisting process 14 is installed at the place to be installed on the roof of the building (e.g., on the slab).

[0012] When the concrete member installed in the installation process 16 is a formwork member, finally, in the placing process 18, fresh concrete is placed into the concrete member and hardened to construct the concrete structure.

[0013] Referring to FIGS. 2 to 4, the manufacturing process 12 will be described in detail. As shown in FIG. 2, the formwork 20 has a top formwork 21, an outer formwork 22, and an inner formwork 23. The top formwork 21 is a flat plate such as a panel. [[ID=​​The inner formwork 23 is, for example, in the shape of a square cylinder and is fixed on top of the top surface formwork 21 within the outer formwork 22. If the concrete member is not a formwork member, the inner formwork 23 may not be necessary.

[0014] As shown in FIG. 3, fresh concrete is placed and cured within the formwork 20 formed in this way to manufacture the concrete member 30. The fresh concrete is placed in an amount such that the concrete member 30 reaches a predetermined height. In other words, the amount of fresh concrete placed is adjusted according to the required height of the concrete member 30. Thereby, a plurality of concrete members 30 with different heights can be manufactured using the same single formwork 20.

[0015] After the concrete member 30 has hardened, as shown in FIG. 4, the outer formwork 22 and the inner formwork 23 are removed. The concrete member 30 has, for example, a cylindrical portion 31 and a flange portion 32, and has a through hole 33 that vertically penetrates the center. The cylindrical portion 31 is, for example, in the shape of a rectangular cylinder. The flange portion 32 is, for example, in the shape of a rectangular frame and is below the cylindrical portion 31. However, since this is the state of being upside down, when installed on the roof, the flange portion 32 is arranged above the cylindrical portion 31. When the concrete member 30 has a shape with a portion protruding horizontally such as the flange portion 32 on the upper side, if it is manufactured without being turned upside down, it takes time to remove the outer formwork 22. In some cases, the outer formwork 22 has to be destroyed, and a plurality of concrete members 30 cannot be manufactured using the same single formwork 20. On the other hand, if it is manufactured by being turned upside down in this way, the outer formwork 22 can be removed by simply lifting the outer formwork 22. In addition, the outer formwork 22 and the inner formwork 23 may have a slightly tapered shape so that the outer formwork 22 and the inner formwork 23 can be easily removed.

[0016] Next, referring to FIGS. 5 to 7, the lifting process 14 will be described in detail. First, as shown in Figure 5, the rotating jigs 41 and 42 are attached to the side of the flange portion 32 of the concrete member 30 using an impact wrench or similar tool. Although not shown, the rotating jigs 41 and 42 are also attached to the same position on the opposite side. In total, four rotating jigs 41 and 42 are attached to the concrete member 30. The rotating jigs 41 and 42 each have, for example, an insert and a link. The insert is driven into the structure of the concrete member 30. The link is rotatably attached to the insert.

[0017] Then, when the two wires 51 attached to the lifting device such as a crane are hooked onto the link parts of the two rotating jigs 41 and lifted, the concrete member 30 rotates on the top formwork 21, with the opposite edge of the flange 32 acting as a pivot point, as shown in Figure 6.

[0018] In this way, the concrete member 30 is inverted to the correct orientation, and then, as shown in Figure 7, the other two wires 52 attached to a lifting device such as a crane are hooked onto the link parts of the two rotating jigs 42. Then, the concrete member 30 is lifted using four wires 51 and 52 and hoisted onto the roof of the building.

[0019] The installation process 16 and the concrete pouring process 18 will be explained in detail with reference to Figures 8-9. As shown in Figure 8, the rooftop of the building is pre-installed with, for example, a rooftop slab 61 and reinforcing bars 62 protruding from the rooftop slab 61. Next, the concrete member 30 that was lifted in the lifting process 14 is moved and positioned so that the reinforcing bars 62 are inserted into the through holes 33, as shown in Figure 9, and the rotating jigs 41 and 42 are removed using an impact wrench or the like. Subsequently, ready-mix concrete is poured into the through-hole 33 and allowed to harden, thereby integrating it with the concrete member 30 and constructing a concrete structure.

[0020] Alternatively, instead of installing the concrete member 30 on top of the rooftop slab 61, the concrete member 30 may be placed at the intended height using spacers or the like after the reinforcement work is completed before the rooftop slab 61 is poured, and the rooftop slab 61 may be poured at the same time as the ready-mix concrete is poured into the through-hole 33.

[0021] Because equipment is installed on steel frames and other structures that span across multiple equipment foundations, the height of the top surfaces must be consistent and the steel frames must be horizontal. In contrast, the roof slab 61 has a slope for drainage and other purposes. Therefore, the height of the equipment foundations must be varied according to their installation location. As described above, by manufacturing the concrete member 30 by inverting it upside down at the site PCa, multiple concrete members 30 of different heights can be manufactured using the same single formwork 20.

[0022] As described above, regarding the construction method for the foundation concrete of equipment installed on the rooftop, the rooftop equipment foundation concrete is precast concrete (PCa) on-site and then lifted and installed using a crane. By reversing the top and bottom of the foundation during the PCa fabrication process, it is possible to accommodate differences in foundation height due to the slab slope. First, the foundation concrete is constructed using site precast concrete. Next, the foundation is lifted into place (rotated vertically). Then, the foundation is set on top of the slab concrete. Finally, concrete is poured into the center of the foundation. Using precast concrete (PCa) shortens the construction process. Pouring concrete upside down eliminates the need for top-edge bracing. The pouring height can be specified, allowing for the reuse of formwork. Pouring upside down allows for adjustments to the foundation height due to floor slope. It can also be applied to pigeon coops. Installation can be done before pouring the slab concrete. The rooftop equipment foundations are precast concrete (PCa) within the construction site. Because the foundation height varies depending on the rooftop slope, the foundations are created upside down. Then, lifting inserts are driven into the structure. Next, a rotating jig is used to rotate the foundations. In this state, the foundations are lifted onto the rooftop and set in place. After setting them on the rooftop, concrete is filled into the central section. If anchor sets are present, they are installed before concrete pouring. During the construction of the lower structure, the rooftop foundation is constructed using precast concrete (PC) on the ground, allowing the parapet PC and equipment foundation structure to be installed while the steel frame is being erected, thus shortening the construction period. Because the upper slab has a slope, the height of the foundation varies from place to place, so it is created upside down to achieve the design height. Since the work is performed on the ground, the number of times rebar and formwork materials need to be lifted is reduced, shortening the construction period. Because the work is performed on the ground, the time workers spend going back and forth to the rooftop is eliminated, improving efficiency. The risk of materials scattering is reduced. Formwork dismantling is also done on the ground, making it safer and eliminating the need to lift materials. A rotating jig is used, and the parts are attached and removed with an impact wrench. Using an impact wrench reduces the time required for PC setup.

[0023] The embodiments described above are examples intended to facilitate understanding of the present invention. The present invention is not limited thereto and includes various modifications, changes, additions, or deletions without departing from the scope defined by the appended claims. This will be readily apparent to those skilled in the art from the above description. [Explanation of Symbols]

[0024] 10 Construction method, 12 Manufacturing process, 14 Lifting process, 16 Installation process, 18 Pouring process, 20 Formwork, 21 Top formwork, 22 Outer formwork, 23 Inner formwork, 30 Concrete member, 31 Cylindrical section, 32 Flange section, 33 Through hole, 41, 42 Rotating jig, 51, 52 Wire, 61 Rooftop slab, 62 Reinforcing bars.

Claims

1. A construction method for installing a concrete structure on top of a building slab, A manufacturing process in which a concrete member is manufactured in a location different from the slab, in a state that is inverted compared to when it is installed on the slab, The process involves lifting the concrete member and inverting it so that it is in the position to be placed on the slab, and further moving the concrete member onto the slab. Includes, The aforementioned lifting process is, The method includes attaching a first rotating jig and a second rotating jig to the concrete member, hooking a first wire onto the first rotating jig, hooking a second wire onto the second rotating jig, rotating the concrete member in a direction that inverts it so that it is in the position to be installed on the slab by lifting the concrete member with the first wire, and lifting the concrete member up to the slab using the first wire and the second wire. Construction method.

2. The concrete member has a cylindrical portion and a flange portion. The construction method according to claim 1, wherein the first rotating jig and the second rotating jig are attached to the flange portion.

3. A construction method for installing a concrete structure on a building slab, A manufacturing process in which a concrete member is manufactured in a location different from the slab, in a state that is inverted compared to when it is installed on the slab, The process involves lifting the concrete member and inverting it so that it is in the position to be placed on the slab, and further moving the concrete member onto the slab. Includes, The concrete member has a cylindrical portion and a flange portion. In the manufacturing process described above, the concrete member is manufactured such that the cylindrical portion is positioned on the top side and the flange portion is positioned on the bottom side. In the lifting process, the concrete member is inverted so that the cylindrical portion is on the ground side and the flange portion is on the top side. Construction method.

4. The construction method according to claim 2 or 3, wherein the flange portion has a portion that protrudes laterally and intersects with the outer circumferential surface of the cylindrical portion.

5. The manufacturing process includes producing the concrete member by pouring ready-mix concrete into a formwork and allowing it to harden. The formwork comprises a top formwork that defines the top surface of the flange portion and an outer formwork that defines the outer circumferential surface of the cylindrical portion. The outer formwork is removed from the concrete member by lifting it along the outer surface of the cylindrical portion so as to separate it from the top formwork before the lifting process. The construction method according to any one of claims 2 to 4.

6. The construction method according to any one of claims 1 to 5, wherein the slab is a rooftop slab.

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