Production method of reinforced concrete structure

Abstract

To provide a production method of a reinforced concrete structure capable of holding a tube body at a specific position relating to a mold for constructing the reinforced concrete structure and releasing holding thereof easily.SOLUTION: A reinforced concrete structure 100 in which concrete 140, vertical axial steel bars 112 arranged inside thereof, and a steel tube 120 fitted on a joint part 112X at the vertical axial steel bars 112 are embedded comprises: a foundation part 101 where lower vertical axial steel bars 112a forming the vertical axial steel bars 112 are buried; and a column part 102 where upper vertical axial steel bars 112b forming the vertical axial steel bars 112 are buried. The steel tube 120 is arranged on an upper end in a state in which an upper part is allowed to open in the foundation part 101 and the steel tube 120 is detachably held with a steel tube fixation tool 1 at a specific position with respect to a mold 130 forming the foundation part 101 through installation of fresh concrete.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a reinforced concrete structure in which axial reinforcing bars, such as deformed bars, are embedded. [Background technology]

[0002] Conventionally, many reinforced concrete structures have been constructed in which reinforcing bars with high tensile strength are placed inside concrete, which has high compressive strength but low tensile strength. Such reinforced concrete structures are composed of individual reinforced concrete members.

[0003] In reinforced concrete members, the concrete contains reinforcement bars such as axial bars (also called main bars) that run along the length of the member, with stress calculated based on the design load, distribution bars that are placed perpendicular to the axial bars to distribute stress, stirrups which are horizontal bars that surround the axial bars, and tie bars that surround the axial bars and are placed at right angles to them to prevent buckling of the axial bars and provide shear reinforcement.

[0004] In the case of a reinforced concrete member having such a structure, for example, a tall reinforced concrete member such as a column, the reinforced concrete member may be constructed by dividing it into upper and lower halves. In this case, the axial reinforcing bars are also divided and connected to each other using special joint parts so that stress can be transmitted.

[0005] For example, the joint structure of concrete members described in Patent Document 1 proposes ensuring strength against tensile forces acting along the axial direction of the reinforcing bars without using dedicated parts in the joint parts. In detail, the joining structure of concrete members in Patent Document 1 involves opposing a first concrete member having a hollow tube (reinforcing member) with an opening, a first reinforcing bar embedded inside the tube so that its end protrudes, and a second concrete member having a second reinforcing bar embedded so that its end protrudes from a second joint surface, and the end of the second reinforcing bar is inserted into the inside of the tube through the opening, and the end of the first reinforcing bar and the end of the second reinforcing bar are joined together along the axial direction of the tube by hardening the hardening agent filled inside the tube.

[0006] In the above-mentioned joint structure, the second reinforcing bar protruding from the second joint surface of the second concrete member is provided in the first concrete member and inserted into the hollow tube (reinforcing member) in which the first reinforcing bar is embedded, so it was necessary to precisely install the hollow tube (reinforcing member) in a predetermined position relative to the first concrete member.

[0007] For this reason, the pipe (reinforcing member) was fixed in advance by welding or the like to a guide plate that was formed so that it could be positioned in a predetermined position relative to the formwork into which fresh concrete was poured to construct the first concrete member. Then, fresh concrete was poured into the formwork, and the guide plate was removed after the poured fresh concrete had hardened, so that the hollow pipe (reinforcing member) was precisely placed in the predetermined position relative to the first concrete member.

[0008] However, both the work of fixing the tube body (reinforcing member) to the guide plate by welding or the like, and the work of cutting the welded parts and removing the guide plate after the fresh concrete has hardened, were extremely time-consuming and labor-intensive, making it impossible to efficiently manufacture reinforced concrete members. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2020-29721 A Summary of the Invention [Problem to be solved by the invention]

[0010] In view of the above-mentioned problems, the present invention aims to provide a method for manufacturing a reinforced concrete structure which can easily hold and release a pipe body in a predetermined position relative to a formwork for constructing the reinforced concrete structure. [Means for solving the problem]

[0011] The present invention is a manufacturing method for a reinforced concrete structure in which concrete, axial reinforcing bars arranged inside the concrete, and a tubular body of a predetermined length that fits externally to at least a portion of the joint locations of the axial reinforcing bars are embedded, wherein the reinforced concrete structure is composed of a first concrete member placed below and in which a first axial reinforcing bar constituting the axial reinforcing bar is embedded, and a second concrete member placed above the first concrete member and in which a second axial reinforcing bar constituting the axial reinforcing bar is embedded, the tubular body is placed at the upper end of the first concrete member so that its top is openable, the tubular body is detachably held at a predetermined position relative to a formwork in which fresh concrete is poured to construct the first concrete member by a retaining member, the fresh concrete is poured inside the formwork with the tubular body held by the retaining member, and after the fresh concrete has hardened, the retention of the tubular body by the retaining member is released.

[0012] The holding member may hold the tube by magnetic attraction using a magnet, by negative pressure or by suction cups, or by locking or adhesion.

[0013] The tubular body may be a cylindrical body having an appropriate cross-sectional shape such as a circular ring cross-section, an elliptical ring cross-section, or a polygonal cross-section.

[0014] According to the present invention, it is possible to easily hold and release a pipe body in a predetermined position relative to a formwork for constructing a reinforced concrete structure. In detail, when constructing a reinforced concrete structure composed of a first concrete member disposed below and having a first axial reinforcing bar embedded therein that constitutes the axial reinforcing bar, and a second concrete member disposed above the first concrete member and having a second axial reinforcing bar embedded therein that constitutes the axial reinforcing bar, the pipe body disposed at the upper end of the first concrete member, the upper part of which is openable, is detachably held by a holding member at a predetermined position relative to a formwork in which fresh concrete is poured to construct the first concrete member, so that the pipe body can be easily positioned at a predetermined position. Then, the fresh concrete is poured inside the formwork while the holding member holds the pipe body, and the holding of the pipe body by the holding member is released after the fresh concrete has hardened, so that the first concrete member can be constructed with the pipe body disposed at a predetermined position. Therefore, a reinforced concrete structure in which concrete, axial reinforcing bars arranged inside the concrete, and a pipe body of a predetermined length that fits around at least a part of the joint of the axial reinforcing bar are embedded can be easily and reliably manufactured. The above-mentioned reinforced concrete structure may be a part of a structure.

[0015] In one aspect of the invention, a support stand may be provided above the formwork, and the holding member may be provided with a fixed part to be placed on the support stand, a holding part main body that holds the tube, and an arm that suspends the holding part main body from the fixed part, and the tube may be suspended and held by the holding part main body suspended via the arm from the fixed part placed on the support stand. According to this invention, the pipe body held by the holding portion main body can be suspended and supported from the support base without interfering with the pouring of the fresh concrete into the formwork in which the fresh concrete is poured.

[0016] As a further aspect of the present invention, the pipe may be held by a plurality of the holding portion bodies at predetermined intervals in the circumferential direction relative to the inner circumferential surface of the pipe. According to this invention, the pipe can be stably held without leaving the holding portion main body inside the first concrete member.

[0017] In more detail, since the retaining body holds the pipe against the inner circumferential surface thereof, the retaining body can be easily removed after the fresh concrete has hardened without being left inside the first concrete member. Also, since a plurality of the retaining body are arranged at predetermined intervals in the circumferential direction on the inner surface of the pipe and held by the plurality of the retaining body, the pipe can be held by the retaining member more stably than when the pipe is held by a single retaining body.

[0018] As a further aspect of the present invention, the holder body may be a magnet that can be switched on and off. The above-mentioned magnet that can switch its magnetism on and off may be a magnet that has two built-in magnets and is configured to switch its magnetism on and off by matching or reversing the polarity of the relative orientation of the two magnets, or it may be an electromagnet that is configured to switch its magnetism on and off by passing electricity through it and cutting it off. According to this invention, by switching between holding by magnetic force and releasing the holding, the pipe body can be easily switched between being held by the holding member and being released, thereby improving workability.

[0019] As a further aspect of the present invention, the holding unit body may be provided with an operating unit for switching magnetism on and off. According to this invention, the operating portion provided on the holding portion main body that holds the tube can be directly operated to switch between holding the tube by the holding portion main body and releasing the hold.

[0020] As a further aspect of the present invention, the fixed portion may be provided with an operating portion for switching the magnetism on and off. According to this invention, the operating portion provided on the fixed portion placed on the support base can be operated to switch between holding and releasing the tube body by the holding portion main body.

[0021] In another aspect of the present invention, the holding portion main body may have a plurality of abutment portions that abut against the inner surface of the tube at a predetermined interval in the circumferential direction, and the plurality of abutment portions may be held by abutting against the inner surface of the tube at a predetermined interval in the circumferential direction.

[0022] According to this invention, the pipe can be held by the holding portion main body more stably. In more detail, when the surface of the holding body is held against the inner surface of the pipe, unless the inner surface of the pipe and the surface of the holding body are formed with high precision, there will be no surface contact and it will be difficult to achieve a stable holding state. In contrast, since the multiple abutment parts provided on the holding body abut against the inner surface of the pipe at a predetermined interval in the circumferential direction, the abutment is ensured at multiple points, resulting in a stable holding state. Therefore, even when pouring fresh concrete, it is possible to prevent the pipe from moving inadvertently and shifting from the specified position.

[0023] As another aspect of the present invention, the support base may be disposed at a predetermined distance from the top of the concrete. With this invention, a predetermined space is created between the support base and the top of the concrete, so that finishing work on the top of the concrete can be carried out using a pressure trowel while the pipe body is suspended and held by the holding member. Effect of the Invention

[0024] According to the present invention, a method for manufacturing a reinforced concrete structure can be provided that can easily hold and release a pipe body in a predetermined position relative to a formwork for constructing a reinforced concrete structure. [Brief description of the drawings]

[0025] [Figure 1] FIG. [Diagram 2] An explanatory diagram of a steel pipe fixing device. [Diagram 3] Cross-section of a reinforced concrete structure. [Figure 4] Flow diagram of the construction method of a reinforced concrete structure. [Diagram 5] Cross-sectional view explaining the construction of the foundation. [Figure 6] Cross-sectional view explaining the construction of the foundation. [Figure 7] Cross-sectional view explaining the construction of the pillar section. [Figure 8] Cross-sectional view explaining the construction of the beam section. [Figure 9] Cross-sectional view explaining the construction of the beam section. [Figure 10] FIG. 4 is a cross-sectional view of a reinforced concrete structure according to another embodiment. [Figure 11] FIG. 11 is a cross-sectional view illustrating construction of a reinforced concrete structure according to another embodiment. [Figure 12] FIG. 11 is a cross-sectional view illustrating construction of a reinforced concrete structure according to another embodiment. [Figure 13] FIG. 11 is a cross-sectional view of a reinforced concrete structure according to yet another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 shows an explanatory diagram of a perspective view of a steel pipe fixing fixture 1, and Fig. 2 shows an explanatory diagram of the steel pipe fixing fixture 1. Note that Fig. 1(a) shows a support plate 10 in a see-through state, and Fig. 1(b) shows a steel pipe 120 and the like that are not visible due to the support plate 10 by dashed lines.

[0027] FIG. 3 shows a cross-sectional view of the reinforced concrete structure 100, and FIG. 4 shows a flow diagram of a method for constructing the reinforced concrete structure 100. 5 and 6 show cross-sectional views explaining the construction of the foundation portion 101, FIG. 7 shows a cross-sectional view explaining the construction of the column portion 102, and FIGS. 8 and 9 show cross-sectional views explaining the construction of the beam portion 103.

[0028] As shown in Figure 3, the reinforced concrete structure 100 is composed of a horizontal foundation portion 101, a beam portion 103, and a column portion 102 extending vertically between the foundation portion 101 and the beam portion 103, and is configured so that the beam portion 103 is supported by the column portion 102.

[0029] In the reinforced concrete structure 100, horizontal reinforcing bars 111 extending horizontally and vertical reinforcing bars 112 extending vertically are embedded. The horizontal reinforcing bars 111 are mainly arranged inside the foundation portion 101 and the beam portion 103, and the vertical reinforcing bars 112 are mainly arranged inside the column portion 102.

[0030] The foundation 101 is a reinforced concrete member of a predetermined thickness extending in the horizontal direction. The foundation 101, which is a horizontal reinforced concrete member, has horizontal axial reinforcing bars 111 arranged vertically at intervals, and reinforcing bars 113 arranged perpendicular to the horizontal axial reinforcing bars 111, forming a lattice shape in a plan view. Stirrups 114 are provided to surround the horizontal axial reinforcing bars 111 arranged vertically at intervals. In this way, the foundation 101 is constructed by pouring concrete 140 into the reinforcing bars in which the horizontal axial reinforcing bars 111, reinforcing bars 113, and stirrups 114 are assembled at predetermined intervals. In addition, a steel pipe 120 is embedded in the foundation 101, which extends vertically and has a joint portion 112X of the vertical axial reinforcing bar 112 arranged therein. Furthermore, the lower portion of the vertical axial reinforcing bar 112 is arranged. The base portion 101 must have a height equal to or greater than the length of the steel pipe 120 disposed therein.

[0031] The beam 103 is a reinforced concrete member of a predetermined thickness extending horizontally. The beam 103, which is a horizontal reinforced concrete member, has horizontal axial reinforcing bars 111 arranged vertically at intervals, and has tie bars 115 surrounding the horizontal axial reinforcing bars 111 arranged vertically at intervals. In this manner, the beam 103 is constructed by pouring concrete 140 into the horizontal axial reinforcing bars 111 and tie bars 115 assembled at predetermined intervals. In addition, a horizontal axis reinforcing bar 111 protrudes in a U-shape from the end of the beam portion 103 toward the column portion 102.

[0032] 2, the pillar portion 102 is a reinforced concrete member extending in the vertical direction and having a square shape in a plan view. The pillar portion 102, which is a reinforced concrete member, includes a vertical axial reinforcing bar 112 and concrete 140.

[0033] A protruding portion 104 is provided on the upper portion of the column portion 102, and above the protruding portion 104, horizontal axial reinforcing bars 111 are arranged at a predetermined interval in the vertical direction and protrude laterally in a U-shape. The space between the column 102 placed on the overhang 104 and the beam 103 is integrated by filling with grout 141 so as to enclose the horizontal axial reinforcing bar 111 protruding laterally in a U-shape.

[0034] As shown in Fig. 3, the vertical axial rebars 112 are deformed rebars with nodes formed on the outer peripheral surface, and a plurality of them are provided at predetermined intervals along a position that ensures a predetermined cover thickness from the outer peripheral surface of a square shape in a plan view. In addition, the upper and lower ends of the vertical axial rebars 112 are bent at right angles to form L-shaped portions that are tied to the vertical axial rebars 112 of the foundation portion 101 and the beam portion 103.

[0035] In addition, the vertical axial reinforcing bar 112 configured as described above is formed by connecting a lower vertical axial reinforcing bar 112a arranged inside the foundation portion 101 and an upper vertical axial reinforcing bar 112b arranged mainly inside the column portion 102.

[0036] More specifically, the upper vertical axial reinforcing bar 112b protrudes downward from the bottom of the column portion 102, and the lower vertical axial reinforcing bar 112a and the upper vertical axial reinforcing bar 112b are joined by overlapping them in the vertical direction by a predetermined length inside the foundation portion 101. In this manner, inside the foundation portion 101, the outside of the joint portion 112X, which is the overlap portion where the lower vertical axial reinforcing bar 112a and the upper vertical axial reinforcing bar 112b overlap in the vertical direction, is fitted with the steel pipe 120. The steel pipe 120 fitted around the base of the vertical reinforcing bar 112 is cylindrical with a predetermined thickness and has a diameter that ensures a predetermined gap between the steel pipes 120 fitted around the joints 112X.

[0037] In addition, the joint portion 112X arranged inside the steel pipe 120 has two lower vertical axial bars 112a arranged at a predetermined interval in the depth direction in FIG. 3, and two upper vertical axial bars 112b arranged at a predetermined interval in the width direction.

[0038] Further, the number of steel pipes 120 provided corresponds to the number of joint portions 112X. Therefore, in the cross section of the column portion 102, a plurality of steel pipes 120 corresponding to the number of joint portions 112X are provided. The inside of the steel pipe 120 is filled with grout 141 , and the joint portion 112 X formed by the four vertical axial reinforcing bars 112 is restrained inside the steel pipe 120 .

[0039] By filling the inside of the steel pipe 120 with grout 141, the lower vertical axial reinforcing bar 112a and the upper vertical axial reinforcing bar 112b can be joined with a predetermined strength by the constrained joint portion 112X to form the vertical axial reinforcing bar 112. For this purpose, the four vertical reinforcing bars 112 must be arranged at a predetermined interval inside the steel pipe 120, and the grout 141 must be firmly attached. For this purpose, the steel pipe 120 must be arranged in a precise position relative to the lower vertical reinforcing bars 112a.

[0040] Furthermore, since the steel pipes 120 are embedded in the foundation 101 constructed by pouring concrete 140, the steel pipes 120 must be accurately positioned relative to the formwork 130 in which the concrete 140 is poured to construct the foundation 101.

[0041] Next, a steel pipe fixing device 1 that can easily position a steel pipe 120 in an accurate position relative to a formwork 130 in which concrete 140 is poured to construct a foundation 101 will be described. The steel pipe fixing device 1, which enables the steel pipe 120 to be accurately and easily positioned relative to the formwork 130, is composed of a support plate 10 arranged above the formwork 130 at a predetermined distance, and a detachable fixture 20.

[0042] 1 and 2, the support plate 10 is made of a plate material with a predetermined strength and thickness that is placed at a predetermined distance from the top end of the foundation part 101 in a formwork 130 for constructing the foundation part 101. The support plate 10 is provided with a circular opening 11 with a diameter larger than the outer diameter of the steel pipe 120 at a location corresponding to the steel pipe 120. The circular openings 11 are provided at positions corresponding to the plurality of steel pipes 120 provided according to the number of joint portions 112X.

[0043] The support plate 10 configured in this manner is positioned a predetermined distance above the top surface Cu (which in this embodiment coincides with the upper end of the formwork 130) of the foundation portion 101 to be constructed by pouring into the formwork 130. As described above, the support plate 10 arranged at a predetermined position relative to the formwork 130 may be fixed to the formwork 130 or may be fixed from a member separate from the formwork 130.

[0044] As shown in Figures 1 and 2, the detachable fixture 20 comprises a fixed body 30 that is placed on and fixed to the support plate 10, a holding body 40 that is magnetically attached to the inner surface of the steel pipe 120 to hold the steel pipe 120, and an arm body 50 that connects the fixed body 30 and the holding body 40 and suspends the holding body 40 from the fixed body 30.

[0045] The fixed body 30, which is placed on and fixed to the support board 10, has a magnet (not shown) inside a rectangular parallelepiped housing 31, and the bottom surface of the fixed body 30 can be fixed to the support board 10 by the magnetic force of the magnet, and an operation unit 32 for turning the magnet on and off (not shown) is provided on the upper surface of the housing 31. Note that the shape of the fixed body 30 is not limited to the above-mentioned shape and can be any appropriate shape as long as it can be fixed in a state where it is placed on the support board 10.

[0046] The holder body 40 has a magnet (not shown) inside a housing 41 made of a magnetic material, and the holder body 40 can be brought into contact with the inner surface of the steel pipe 120 and magnetically attached thereto by the magnetic force of the magnet. The housing 41 is generally rectangular parallelepiped long in the vertical direction, and is provided with a triangular cross-sectional groove 42 that is concave with a triangular cross section and extends in the vertical direction on the side that abuts against the inner surface of the steel pipe 120 (the side of the housing 41 closer to the detachable fixture 20).

[0047] In addition, when the abutment portion 43 is in a holding state with the inner surface of the steel pipe 120 abutting, the side away from the steel pipe 120 (the side of the housing 41 farther from the detachable fixture 20) is provided with an operating portion 44 for turning the magnet (not shown) on and off.

[0048] The fixed body 30 and the holding unit main body 40 have two magnets built in, and the relative orientation of the two magnets is configured and built in so that the magnetism can be switched ON / OFF by operating the operating units 32, 44 to match or reverse the polarity.

[0049] The arm body 50 connects the fixed body 30 placed on the support plate 10 described above to the holding body 40 which holds the steel pipe 120 by abutting it against its inner surface, and supports the holding body 40 by suspending it from the fixed body 30. The arm body 50 is formed in an inverted L-shape when viewed from the front.

[0050] In detail, the arm body 50 is formed in an inverted L-shape by a plate-shaped horizontal portion 51 extending horizontally from the side of the fixed body 30, and a cylindrical vertical portion 52 extending downward from the end of the horizontal portion 51 and connected to the upper surface of the holding portion main body 40.

[0051] In addition, the horizontal portion 51 is formed with a length such that the end from which the vertical portion 52 extends extends radially inward of the circular opening 11 when the detachable fixing device 20 is set on the support plate 10, and is formed with a thickness such that it will not bend due to the weight of the vertical portion 52, the holding portion main body 40 connected to the lower end of the vertical portion 52, and the steel pipe 120 to which the holding portion main body 40 is magnetically attached.

[0052] The vertical section 52 extending downward from the end of the horizontal section 51 is formed to a length such that, when the detachable fixing device 20 is set on the support plate 10, the holding section main body 40 connected to the tip is positioned at the top of the inner surface of the steel pipe 120 placed in a predetermined position relative to the formwork 130.

[0053] In this way, the detachable fixing device 20 having the fixed body 30, holding body 40 and arm body 50 configured as described above can be configured by placing the fixed body 30 on the upper surface of the support plate 10, passing the vertical part 52 of the arm body 50 through the circular opening 11, and positioning the holding body 40 at a predetermined position below the support plate 10.

[0054] Then, by turning on the operating unit 32 of the fixed body 30 placed in an appropriate position relative to the support plate 10, the fixed body 30 can be fixed to the support plate 10 by the magnetic force of the magnet built into the housing 31.

[0055] In addition, by turning the operating unit 44 ON while the abutment portion 43 is abutting against the inner surface of the steel pipe 120, the magnetic force of the magnet built into the housing 41 causes the abutment portion 43 to abut against the inner surface of the steel pipe 120, magnetically attaching the holding unit main body 40 and the steel pipe 120 to each other.

[0056] Therefore, the detachable fixture 20 can support the steel pipe 120, which is magnetically attached to the support board 10 to which the fixing body 30 is magnetically attached, by suspending the holding portion main body 40 connected via the arm body 50.

[0057] A method for constructing (manufacturing) a reinforced concrete structure 100 using the steel pipe fixing device 1 configured in this manner will be described in detail below. The reinforced concrete structure 100 is constructed (manufactured) by constructing (manufacturing) a foundation 101, assembling columns 102 to the constructed foundation 101, and assembling beams 103 to the columns 102.

[0058] Specifically, in order to construct the foundation 101, the reinforcing bars (horizontal reinforcing bars 111, distribution bars 113, and stirrups 114) are installed, and the lower vertical reinforcing bars 112a are assembled in a predetermined position. Then, the formwork 130 is assembled around the installed reinforcing bars (reinforcing bar / formwork assembly process: step s1). At this time, the formwork 130 is assembled so that the upper end of the formwork 130 becomes the top surface Cu of the foundation 101.

[0059] Next, the steel pipes 120 are placed in predetermined positions in the assembled formwork 130, and the steel pipes 120 are held by the steel pipe fixing fixtures 1 (steel pipe installation process: step s2). Specifically, two steel pipe fixing fixtures 1 are used to hold the steel pipes 120 in predetermined positions in the formwork 130. In other words, two steel pipe fixing fixtures 1 are used for one steel pipe 120, so that in total, twice as many steel pipe fixing fixtures 1 are used as the number of installed steel pipes 120.

[0060] Then, the holding portion body 40 of one of the steel pipe fixing devices 1 is placed against the steel pipe 120 so that the abutment portion 43 abuts against the inner surface of the upper part of the steel pipe 120, and the operating portion 44 is turned ON to magnetically attach the holding portion body 40 to the steel pipe 120. As a result, one steel pipe fixing device 1 is fixed to the steel pipe 120. Then, the holding portion bodies 40 of the remaining steel pipe fixing devices 1 are placed so as to face each other in the radial direction inside the steel pipe 120, and the operating portion 44 is turned ON to magnetically attach the holding portion body 40 to the steel pipe 120. As a result, two steel pipe fixing devices 1 are fixed to the steel pipe 120.

[0061] The steel pipe 120 thus integrated with the two steel pipe fixing fixtures 1 by the two holding portion bodies 40 is passed through the circular opening 11 from above and placed at a predetermined position in the formwork 130. The fixing bodies 30 of the two steel pipe fixing fixtures 1, whose holding portion bodies 40 are magnetically attached to the steel pipe 120 placed at the predetermined position in the formwork 130, are magnetically attached and fixed to the support plate 10 by turning on the operating unit 32.

[0062] As a result, the steel pipe 120 to which the holding portion main body 40, which is suspended via the arm body 50 from the fixed body 30 fixed to the support plate 10, is magnetically attached is held in a predetermined position relative to the support plate 10 by the two steel pipe fixing devices 1. Inside the steel pipe 120, two lower vertical axial reinforcing bars 112a are arranged at a predetermined distance in the depth direction.

[0063] In this manner, with the steel pipe 120 suspended from the support plate 10 by the two steel pipe fixing devices 1 positioned in a predetermined position in the formwork 130, fresh concrete is poured inside the formwork 130 (concrete pouring process: step s3). When the poured fresh concrete starts to harden, the top surface Cu of the concrete 140 is pressed down with a trowel or the like according to the hardening stage, and the top surface Cu of the concrete 140 is finished (concrete finishing process: step s4).

[0064] In addition, since the support plate 10 is disposed above the top surface Cu of the concrete 140 at a predetermined distance, a work space of a predetermined height is formed between the top surface Cu of the concrete 140 and the support plate 10. Therefore, in the work space, the top surface Cu of the concrete 140 can be pressed down with a pressing trowel or the like to finish it.

[0065] When the concrete reaches a predetermined strength, the formwork 130 is removed, and the steel pipe fixing device 1 that has held the steel pipe 120 in a predetermined position is removed (formwork removal / steel pipe fixing device removal process: step s5). Specifically, by turning off the operating part 44 of the holding part main body 40 that is magnetically attached to the inner surface of the steel pipe 120, the magnetic attachment of the holding part main body 40 to the steel pipe 120 is released, and the steel pipe 120 is no longer held by the steel pipe fixing fixture 1. In this state, the two steel pipe fixing fixtures 1 may be removed together with the support plate 10, or the operating part 32 of the fixing body 30 may be turned off to remove the steel pipe fixing fixture 1 from the support plate 10, and the support plate 10 and the steel pipe fixing fixture 1 may be removed separately.

[0066] The construction of the foundation 101 is completed by removing the formwork 130 and the steel pipe fixing fixtures 1 in the formwork removal / steel pipe fixing fixture removal process (step s5). In order to connect the column portion 102 to the foundation portion 101 constructed in this manner, first, grout 141 is filled inside the steel pipe 120 which is buried in the foundation portion 101 and contains the upper portion of the lower vertical axial reinforcing bar 112a (grout filling process: step s6).

[0067] Then, before the grout 141 filled inside the steel pipe 120 hardens, the column portion 102, which has been manufactured in advance at a factory or the like, is attached to the base portion 101. Specifically, the column 102, in which the lower side of the upper vertical axial reinforcing bar 112b protrudes downward from the bottom surface, is lowered from above the foundation 101 and assembled to connect the foundation 101 and the column 102 (column connection process: step s7). At this time, the upper vertical axial reinforcing bar 112b protruding downward from the bottom surface of the column 102 is assembled so as to be housed inside the steel pipe 120 filled with grout 141.

[0068] As the grout 141 contained inside the steel pipe 120 together with a portion of the lower vertical axial reinforcing bar 112a and a portion of the upper vertical axial reinforcing bar 112b hardens, the joint portion 112X between the lower vertical axial reinforcing bar 112a and the upper vertical axial reinforcing bar 112b is connected in a manner that allows stress to be transmitted by the grout 141 constrained by the steel pipe 120 to form the vertical axial reinforcing bar 112, and the connection between the foundation portion 101 and the column portion 102 is completed.

[0069] Furthermore, the beam section 103 is placed on the protrusion section 104 provided on the upper part of the column section 102 (beam connection process: step s8), and grout 141 is poured into the space between the side surface of the column section 102 and the end face of the beam section 103 so as to enclose the U-shaped portion of the horizontal axial reinforcing bar 111 arranged in the space, thereby fixing the beam section 103 to the column section 102 (grout fixing process: step s9). Then, when the grout 141 hardens and develops a predetermined strength, the construction (manufacturing) of the reinforced concrete structure 100 is completed.

[0070] As described above, in the manufacturing method for a reinforced concrete structure 100 in which concrete 140, vertical axial reinforcing bars 112 arranged inside the concrete 140, and steel pipes 120 of a predetermined length fitted onto joint portions 112X of the vertical axial reinforcing bars 112 are embedded, the reinforced concrete structure 100 is composed of a foundation portion 101 in which a lower vertical axial reinforcing bar 112a constituting the vertical axial reinforcing bar 112 is embedded below, and a column portion 102 in which an upper vertical axial reinforcing bar 112b constituting the vertical axial reinforcing bar 112 is embedded above the foundation portion 101. The steel pipe 120 is placed at the upper end of the foundation 101 so that the top can be opened, and the steel pipe 120 is removably held at a predetermined position relative to the formwork 130 in which fresh concrete is poured to construct the foundation 101 (steel pipe installation process: step s2), fresh concrete is poured inside the formwork 130 with the steel pipe 120 held by the steel pipe fixing device 1 (concrete pouring process: step s3), and after the fresh concrete has hardened, the steel pipe 120 is released from its hold by the steel pipe fixing device 1 (formwork removal / steel pipe fixing device removal process: step s5).

[0071] Therefore, the steel pipe 120 can be easily held in a predetermined position relative to the formwork 130 that constructs the foundation 101 of the reinforced concrete structure 100 and released from the hold. In detail, when constructing a reinforced concrete structure 100 consisting of a foundation part 101 in which a lower vertical axial reinforcing bar 112a constituting the vertical axial reinforcing bar 112 is buried and a column part 102 in which an upper vertical axial reinforcing bar 112b constituting the vertical axial reinforcing bar 112 is buried, the steel pipe 120, which is arranged at the upper end of the foundation part 101 so that the upper part can be opened, is detachably held by the steel pipe fixing device 1 at a predetermined position relative to a formwork 130 in which fresh concrete is poured to construct the foundation part 101, so that the steel pipe 120 can be easily placed at a predetermined position. Then, fresh concrete is poured inside the formwork 130 while the steel pipe 120 is held by the steel pipe fixing device 1, and the holding of the steel pipe 120 by the steel pipe fixing device 1 is released after the fresh concrete has hardened, so that the foundation part 101 in which the steel pipe 120 is placed at a predetermined position can be constructed. Therefore, a reinforced concrete structure 100 in which concrete 140, vertical axial reinforcing bars 112 arranged inside the concrete 140, and steel pipes 120 of a predetermined length fitted onto the joint portions 112X of the vertical axial reinforcing bars 112 are embedded can be easily and reliably manufactured.

[0072] In addition, a support plate 10 is provided above the formwork 130, and the steel pipe fixing device 1 is provided with a fixed body 30 to be placed on the support plate 10, a holding body 40 that holds the steel pipe 120, and an arm body 50 that suspends the holding body 40 from the fixed body 30, and the steel pipe 120 is suspended and held by the holding body 40 suspended via the arm body 50 from the fixed body 30 placed on the support plate 10.

[0073] Therefore, the steel pipe 120 held by the holding portion main body 40 can be supported by being suspended from the support plate 10 without interfering with the pouring of the fresh concrete into the formwork 130 in which the fresh concrete is poured.

[0074] In addition, since the steel pipe 120 is held by two holding body bodies 40 at a predetermined circumferential distance from the inner surface of the steel pipe 120, more specifically at circumferentially opposing positions, the steel pipe 120 can be held stably without the holding body body 40 being left inside the foundation portion 101.

[0075] In more detail, because the retaining body 40 holds the steel pipe 120 against the inner circumferential surface thereof, the retaining body 40 can be easily removed after the fresh concrete has hardened, without being left behind inside the foundation 101. Furthermore, because two retaining body 40 are arranged at a predetermined distance in the circumferential direction against the inner surface of the steel pipe 120 and held by the two retaining body 40, the steel pipe 120 can be held by the steel pipe fixing device 1 more stably than when the steel pipe 120 is held by one retaining body 40.

[0076] In addition, since the holding body 40 is a magnet that can be switched on and off, it is possible to easily switch between holding the steel pipe 120 by the steel pipe fixing device 1 and releasing the hold by switching between holding by magnetic force and releasing the hold, thereby improving workability.

[0077] In addition, since the holding unit main body 40 is provided with an operating unit 44 for switching the magnetism ON / OFF, the operating unit 44 provided on the holding unit main body 40 which holds the steel pipe 120 can be directly operated to switch between holding the steel pipe 120 by the holding unit main body 40 and releasing its hold.

[0078] In addition, the holding portion main body 40 has two abutment portions 43 that abut against the inner surface of the steel pipe 120 at a predetermined distance in the circumferential direction, and holds the two abutment portions 43 by abutting against the inner surface of the steel pipe 120 at a predetermined distance in the circumferential direction.

[0079] Therefore, the steel pipe 120 can be held by the holding portion main body 40 more stably. In more detail, when the surface of the holding body 40 is held against the inner surface of the steel pipe 120, unless the inner surface of the steel pipe 120 and the surface of the holding body 40 are formed with high precision, there will be no surface contact, and it will be difficult to achieve a stable holding state. In contrast, the two abutment parts 43 provided on the holding body 40 abut against the inner surface of the steel pipe 120 at a predetermined distance in the circumferential direction, so that the abutment is ensured at two points, resulting in a stable holding state. Therefore, even when pouring fresh concrete, the steel pipe 120 can be prevented from moving inadvertently and shifting from the predetermined position.

[0080] Furthermore, since the support plate 10 is positioned at a predetermined distance from the top surface Cu of the concrete 140, a space of a predetermined distance is formed between the support plate 10 and the top surface Cu of the concrete 140, and in the concrete finishing process (step s4), finishing work can be performed on the top surface Cu of the concrete 140 using a pressure trowel while the steel pipe 120 is suspended and held by the steel pipe fixing device 1.

[0081] In the configuration of the present invention and the above-mentioned embodiment, the concrete of the present invention corresponds to the concrete 140. Similarly, The axial reinforcement corresponds to the vertical axial reinforcement 112; The joint part corresponds to joint part 112X. The pipe body is compatible with steel pipe 120. Reinforced concrete structures correspond to Reinforced Concrete Structures 100; The first axial rebar corresponds to the lower vertical rebar 112a; The first concrete member corresponds to the foundation portion 101, The second axial reinforcing bar corresponds to the upper vertical reinforcing bar 112b; The second concrete member corresponds to the column portion 102, The formwork is compatible with formwork 130. The holding member corresponds to the steel pipe fixing device 1, The support base corresponds to the support plate 10, The fixed part corresponds to the fixed body 30, The holder body corresponds to the holder body 40, The arm is compatible with arm body 50. The operation unit corresponds to the operation unit 44, Although the contact portion corresponds to the contact portion 43, the present invention is not limited to the configuration of the above-mentioned embodiment, and many embodiments can be obtained.

[0082] For example, in the reinforced concrete structure 100 described above, a steel pipe 120 was placed inside the foundation portion 101 and the foundation portion 101 and the column portion 102 were connected to construct (manufacture), but as shown in Figures 10 to 12, the lower column portion 102a, which is a lower part of the column portion 102, and the foundation portion 101a may be constructed as a single unit, and the upper column portion 102b, which is an upper part of the column portion 102, and the lower column portion 102a may be assembled to form the reinforced concrete structure 100a.

[0083] In this case, in the reinforcing bar / formal assembly process (step s1), reinforcing bars for the foundation 101a and the lower column 102a are assembled, and the formwork 130a for the foundation 101a and the lower column 102a is assembled. Then, in the steel pipe installation process (step s2), the steel pipe 120 is held by the steel pipe fixing device 1 so that the steel pipe 120 is placed in the part of the formwork 130a corresponding to the lower column 102a.

[0084] The reinforced concrete structure 100a can be constructed by integrally constructing the foundation portion 101a and the lower column portion 102a, and assembling the upper column portion 102b, from which the upper vertical axial reinforcing bar 112b protrudes, to the lower column portion 102a inside which the steel pipe 120 is arranged. In this way, even if the construction method (manufacturing method) using the steel pipe fixing device 1 of the reinforced concrete structure 100a, in which the foundation portion 101a and the lower column portion 102a are integrated and the upper column portion 102b is assembled to the lower column portion 102a, can achieve the same effects as the construction method (manufacturing method) using the steel pipe fixing device 1 of the above-mentioned reinforced concrete structure 100.

[0085] Furthermore, since the steel pipe 120 is disposed inside the lower column portion 102a, the thickness of the foundation portion 101a can be formed thinner than in the reinforced concrete structure 100 in which the steel pipe 120 is disposed inside the foundation portion 101. Therefore, the foundation portion 101a can be configured with a thickness that satisfies the strength required for the foundation portion 101 in the reinforced concrete structure 100.

[0086] If the thickness of the foundation 101a formed to have a sufficient strength as the foundation 101 in the reinforced concrete structure 100 is shorter than the length of the steel pipe 120 to be fitted around the joint 112X, the foundation 101b may be thickened only at the location where the steel pipe 120 is placed, as shown in Fig. 13. This allows the steel pipe 120 to be housed inside, and the foundation 101b can be configured to have a thickness sufficient to provide the foundation 101 in the reinforced concrete structure 100 with sufficient strength.

[0087] In the above-mentioned fixed body 30 and holding unit main body 40, the relative orientation of the two built-in magnets is configured to switch the magnetism on and off by matching or reversing the polarity by operating the operating units 32, 44, but it may also be an electromagnet configured to switch the magnetism on and off by passing electricity through and cutting it off.

[0088] In this case, the fixed body 30 may be provided with an operating unit 32 for switching the magnetism ON / OFF, and the operating unit 32 provided on the fixed body 30 may be configured to switch between holding and releasing the holding of the holding unit main body 40 on the steel pipe 120. This allows the holding of the steel pipe 120 by the holding unit main body 40 to be switched between being held and released by operating the operating unit 32 provided on the fixed body 30 placed on the support board 10.

[0089] Furthermore, instead of using magnets, the steel pipe 120 may be held by the holding portion main body 40 by negative pressure, adhesion by a suction cup, or by locking or adhesion, etc., and similarly, the fixed body 30 may be fixed to the support plate 10 by negative pressure, adhesion by a suction cup, or by locking or adhesion, etc.

[0090] In addition, in the above explanation, a reinforced concrete structure 100 was constructed (manufactured) using a steel pipe fixing device 1, but a reinforced concrete member that is part of a reinforced concrete structure may also be manufactured using a manufacturing method using the above-mentioned steel pipe fixing device 1. Furthermore, the steel pipe 120 may be a cylindrical body having an appropriate cross-sectional shape, such as an elliptical ring cross-section, a polygonal cross-section, or the like, in addition to a circular ring cross-section, so long as it is cylindrical. [Explanation of symbols]

[0091] 1…Steel pipe fixing device 10…Support board 30...Fixed body 40...Holding unit body 43...Contact part 44...Operation unit 50…Arm body 100...Reinforced concrete structures 101…Fundamental part 102...Column part 112...Vertical axial rebar 112a...Lower vertical axial rebar 112b...Upper vertical axial rebar 112X...Joint part 120…Steel pipe 130…Formwork 140…Concrete

Claims

1. A method for manufacturing a reinforced concrete structure in which concrete, an axial reinforcing bar arranged inside the concrete, and a pipe body of a predetermined length that fits around at least a part of a joint of the axial reinforcing bar are embedded, The reinforced concrete structure is composed of a first concrete member disposed below and having a first axial reinforcing bar embedded therein that constitutes the axial reinforcing bar, and a second concrete member disposed above the first concrete member and having a second axial reinforcing bar embedded therein that constitutes the axial reinforcing bar, and the pipe is disposed at an upper end of the first concrete member so that the upper portion can be opened, a holding member removably holding the pipe body at a predetermined position relative to a formwork in which fresh concrete is poured to construct the first concrete member; The fresh concrete is poured into the formwork while the pipe body is held by the holding member, After the fresh concrete has hardened, the holding member is released from the holding of the pipe body. A manufacturing method for reinforced concrete structures.

2. A support stand is provided above the formwork, The holding member, A fixing part to be placed on the support base; A holding portion main body for holding the pipe body; an arm that suspends the holding portion main body from the fixed portion, The pipe is suspended and held by the holding unit main body suspended via the arm from the fixing unit placed on the support base. A method for manufacturing a reinforced concrete structure according to claim 1.

3. The pipe is held by a plurality of holding portion bodies at predetermined intervals in the circumferential direction against the inner circumferential surface of the pipe. A method for manufacturing a reinforced concrete structure according to claim 2.

4. The holder body is a magnet that can be switched on and off. A method for manufacturing a reinforced concrete structure according to claim 2.

5. The holding unit body is provided with an operating unit for switching the magnet on and off. The method for manufacturing a reinforced concrete structure according to claim 4.

6. The fixed part is provided with an operating part for switching the magnet on and off. The method for manufacturing a reinforced concrete structure according to claim 4.

7. The holding body has a plurality of contact portions that contact the inner circumferential surface of the pipe at predetermined intervals in the circumferential direction, The plurality of contact portions are held in contact with the inner peripheral surface of the pipe body at predetermined intervals in the circumferential direction. The method for manufacturing a reinforced concrete structure according to claim 4.

8. The support base is disposed at a predetermined distance from the top of the concrete. A method for manufacturing a reinforced concrete structure according to any one of claims 2 to 7.

Images