JP2019038130A - Method for constructing columnar member, and bar-shaped member of prestressed steel-framed reinforced concrete construction - Google Patents

Abstract

To provide a method for constructing a columnar member capable of easily introducing prestress and also capable of easily molding installed concrete into a columnar shape.SOLUTION: Provided is a method for constructing a bar-shaped column 1 comprising: a step S1 where a cross-sectional arc-like, lower face flask material 50, side face flask material 51, and upper face flask material 52 covering the outer circumferential face other than the uppermost face of the bar-shaped column 1 in a state where the bar-shaped column 1 is laid, and a cross-sectional arc-like uppermost face flask material 53 covering the uppermost face of the bar-shaped column 1 are prepared, and a core material 11 and a PC steel 13 are arranged at the inside of the flask materials 50 to 52; steps S3, S4 where concrete is installed at the inside of the flask materials 50 to 52; a step S5 where the uppermost flask material 53 is fitted to an opening part 58 in a space of the upper face flask material 52; and a step S6 where, after the installed concrete is cured, the flame materials 50 to 53 are decomposed.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a method for constructing a columnar member made of concrete, and a bar member made of prestressed steel reinforced concrete in which a PC steel material into which prestress is introduced is disposed surrounding a steel core.

2. Description of the Related Art Conventionally, a prestressed steel reinforced concrete structure (hereinafter referred to as SPC structure) in which a steel frame and prestressed concrete are combined is known. Since this SPC structure can increase the axial rigidity of the member, it is often applied to long beams and columns.
For example, Patent Documents 1 to 3 show a large span building structure using long beams made of SPC.

By the way, when precasting a long cylinder made of SPC, there are a method of constructing this cylinder in a standing state and a method of constructing the cylinder in a laid state. In either case, prestress is introduced into the cylinder. Therefore, it is necessary to arrange a prestress introduction device on both ends of the cylinder.
First, when building a column in a standing state, a cylindrical form extending in the vertical direction is built, and concrete is placed in the form. In this case, the placed concrete can be reliably formed into a columnar shape, but the prestress introduction device cannot be arranged on the upper end side of the column, and it becomes difficult to introduce the prestress.
On the other hand, when constructing in a state where the column is laid down, a cylindrical formwork extending in the horizontal direction is built, and concrete is placed in the formwork from a concrete placement opening provided on the upper surface of the formwork. In this case, since the prestress introduction device can be arranged on both ends of the cylinder, prestress can be easily introduced, but it becomes difficult to form the concrete surface exposed to the concrete placement port into a circle.

Japanese Patent Laid-Open No. 1-137034 JP-A 64-1836 JP-A-3-290543

  An object of the present invention is to propose a method for constructing a columnar member and a rod-shaped member having a prestressed steel reinforced concrete structure in which prestress can be easily introduced and cast concrete can be easily formed into a columnar shape.

  The present inventors have arranged the PC steel material, in which prestress is introduced, as the SPC-made rod-shaped member so as to surround the steel core material embedded in the rod-shaped concrete body, so that the inside of the cross-section of the rod-shaped concrete is substantially equal. As the axial stiffness and cracking strength of this rod-shaped concrete body increase, the cracks that have occurred in the rod-shaped concrete can be prevented when the external load is relatively low. The present invention has been reached. In addition, as a method of constructing a concrete columnar member typified by a prestressed steel reinforced concrete structure, the present inventors have a first mold having an arcuate cross section along the material axis direction to form the columnar member. After installing the material and placing concrete inside the first mold member, the second mold member having an arc-shaped cross section is attached to the uppermost opening of the first mold member. Has been confirmed by experiments to be able to be molded into a circular arc cross section, and the present invention has been achieved.

  A columnar member construction method according to a first aspect of the present invention is a concrete columnar member (for example, a rod-shaped column 1 described later), and the columnar member is placed in the state in which the columnar member is laid down. A first mold material (for example, a lower surface mold material described later) covering an outer peripheral surface (for example, an upper surface 10B, both side surfaces 10C, and a lower surface 10D described later) excluding an upper surface (for example, an uppermost surface 10A described later). 50, side surface formwork material 51, top surface formwork material 52) and a second formwork material having an arc cross section covering the uppermost surface of the cylindrical member (for example, an uppermost surface formwork material 53 described later). Preparing and placing concrete inside the first mold member (for example, steps S3 and S4 described later), and an opening (for example, an opening described later) on the uppermost surface of the first mold member; Step 58) for attaching the second formwork material to the portion 58) (for example, step S5 described later) When, after the concrete has been pouring has cured, the first mold material and the step of dismantling the second mold member (e.g., step S6 will be described later), characterized in that it comprises a and.

The concrete structure here includes a prestressed steel reinforced concrete structure, a prestressed steel reinforced concrete structure, and a reinforced concrete structure.
According to this invention, the concrete is placed inside the first mold member having the arc shape in cross section, and then the opening on the uppermost surface of the first mold member is formed by the second mold member having the arc shape in cross section. By closing, the columnar member made of concrete can be constructed in a laid state.
Moreover, after placing concrete inside the first mold member having an arc shape in cross section, a second form material having an arc shape in cross section is attached to the uppermost opening of the first mold member. The columnar member can be easily constructed by forming the concrete surface exposed at the opening of the first formwork member into a circular arc shape.
Moreover, since a prestress introduction apparatus can be arrange | positioned at the both ends of a cylindrical member, when building a prestressed concrete columnar member, prestress can be easily introduce | transduced into a cylindrical member.

  In the construction method of the columnar member according to the second aspect of the invention, the opening on the uppermost surface of the first mold member having the arcuate cross section has an opening width of 100 mm or more and 200 mm or less, and the second mold member is A pressing part (for example, a pressing part 70 described later) for pressing the concrete surface exposed from the opening, and a locking part (for example, described later) provided on the pressing part and locked to the first formwork material. A non-woven fabric (for example, non-woven fabric 73 described later) and a woven fabric (for example, non-woven fabric 74 described later) are laminated and attached to the lower surface of the pressing portion. Features.

  According to this invention, the nonwoven fabric and the woven fabric are laminated and attached to the lower surface of the pressing portion that closes the opening. Therefore, surplus water and air bubbles floating on the concrete surface permeate the woven fabric, and surplus water that permeate the woven fabric is drained to the outside by the nonwoven fabric. Therefore, the surplus water that has floated on the concrete surface can be drained without providing a through hole in the second formwork material.

  The rod-shaped member (for example, a rod-shaped column 1 described later) of the third invention is a rod-shaped member made of prestressed steel reinforced concrete, and is embedded in the rod-shaped concrete body (for example, a concrete body 10 described later) and the concrete body. A steel core material (for example, a core material 11 described later) and a plurality of PC steel materials (for example, a PC steel material 13 described later) extending in the axial direction of the concrete body, the PC steel material having a tensile force Is introduced, and is arranged so as to surround the core material in a cross-sectional view.

Here, examples of the rod-shaped member include a columnar member having a circular cross section and a square columnar member having a rectangular cross section.
PC steel is a tension material that introduces tensile force into prestressed concrete (PC). PC steel wire (high-strength steel with a diameter of 9 mm or less), PC steel rod (high-strength steel with a diameter exceeding 9 mm), and PC. Steel strands (those combined with PC steel wires) are included.
According to the present invention, since the PC steel material is disposed so as to surround the core material in a sectional view, substantially uniform compressive stress is generated in the concrete in the cross section of the rod-shaped member. Therefore, the bias of the shaft rigidity in the cross section of the rod-shaped member is reduced, and a rod-shaped member having substantially uniform shaft rigidity can be realized. Moreover, the crack which arises in the concrete body of a rod-shaped member can be prevented by making concrete in the cross section of a rod-shaped member into a substantially uniform compressive stress state.

  ADVANTAGE OF THE INVENTION According to this invention, the construction method of a column-shaped member and the rod-shaped member of a prestressed steel reinforced concrete structure which can introduce | transduce prestress easily and can shape | mold cast concrete easily in a column shape can be provided.

It is a side view of the rod-shaped member as a rod-shaped member which concerns on one Embodiment of this invention, and a column-shaped member. It is an axial sectional view of a rod-shaped column. It is AA sectional drawing (FIG. 2 (a)) and BB sectional drawing (FIG.2 (b)) of the rod-shaped pillar of FIG. It is the top view and side view of a formwork apparatus and prestress introduction apparatus for constructing a rod-shaped pillar. It is CC sectional drawing of the formwork apparatus of FIG. It is DD sectional drawing of the formwork apparatus of FIG. It is sectional drawing of the state which laid the rod-shaped pillar. It is sectional drawing which shows operation | movement of a formwork apparatus. It is a longitudinal cross-sectional view of the width direction of the upper part of a formwork apparatus. It is a longitudinal cross-sectional view of the length direction of the upper part of a formwork apparatus. It is sectional drawing of the holding | suppressing part of the uppermost formwork which comprises a formwork apparatus. It is a flowchart of the construction procedure of a rod-shaped column. It is explanatory drawing (sectional drawing of a formwork apparatus) of the construction procedure of a rod-shaped pillar. It is sectional drawing (the 1) of the rod-shaped pillar which concerns on the modification of this invention. It is sectional drawing (the 2) of the rod-shaped pillar which concerns on the modification of this invention.

  The present invention is an SPC-made rod-shaped member and a method for constructing a concrete-made columnar member in which the column cross section of the rod-shaped member is limited to a circular shape. The present invention is characterized in that, in an SPC-made rod-shaped member, a PC steel material in which prestress is introduced is disposed so as to surround a steel core material embedded in a rod-shaped concrete body (FIGS. 3, 14, and 15). ). The present invention also relates to a method of constructing a columnar member in which a steel steel material and a PC steel material are embedded in a concrete body, and an arc-shaped formwork that extends in the material axis direction of the columnar member and is provided with an opening in a part thereof. Arc-shaped formwork (uppermost formwork) in which materials (lower surface formwork material 50, side face formwork material 51, upper surface formwork material 52) are installed and a water-permeable sheet is attached to the lower surface in the opening. The material 53) is installed, and the concrete surface is formed into a cylindrical shape (FIGS. 4 to 11).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a rod-shaped member 1 and a rod-shaped column 1 as a columnar member according to an embodiment of the present invention. FIG. 2A is an axial sectional view showing a bar arrangement state of the rod-shaped column 1, and FIG. 2B is an axial sectional view showing the core member 11 embedded in the rod-shaped column 1. FIG. 3 is an AA cross-sectional view and a BB cross-sectional view of the rod-shaped column 1 of FIG.
The rod-shaped column 1 is a precast prestressed steel reinforced concrete column extending in the vertical direction. The columnar reinforced concrete concrete body 10 and the concrete body 10 are embedded in the concrete body 10 and extend in the axial direction (vertical direction). A steel core 11, a column rebar 12, and a PC steel 13. A tensile force is introduced into the PC steel material 13 by a pretension method.

The core material 11 is provided at a column steel frame 20 which is an H-shaped steel extending in the vertical direction, a joint portion 21 extending laterally from an intermediate height of the column steel frame 20, and a PC steel material 13 provided at a lower end portion of the column steel frame 20. And a fixing member 23 provided at the lower end portion of the column steel frame 20 to which the below-described column main bars 30 are joined.
The column steel frames 20 protrude from the upper and lower end surfaces of the concrete body 10 and are joined to the column steel frames 24 of the upper and lower columns. The joint portion 21 protrudes laterally from the outer peripheral surface of the concrete body 10 and is joined to the beam steel frame 25.

The column reinforcement 12 includes eight column reinforcements 30 arranged in an annular shape surrounding the column steel 20 in a horizontal sectional view, and a plurality of circles wound around the column reinforcements 30 and provided at predetermined intervals in the vertical direction. And an annular hoop muscle 31.
The PC steel material 13 is disposed substantially evenly around the core material 11 inside the column rebar 12 in a horizontal sectional view, and is inserted through the guide member 22. A tensile force is introduced into these PC steel materials 13, and thereby compressive stress is generated in the concrete body 10.
In order to construct the above rod-shaped column 1, the following formwork apparatus 40 and prestress introduction apparatus 2 are used.

FIG. 4A is a plan view of the formwork device 40 and the prestress introduction device 2, and FIG. 4B is a side view of the formwork device 40 and the prestress introduction device 2. 5 is a cross-sectional view taken along the line C-C of the formwork device 40 of FIG. 4, and FIG. 6 is a cross-sectional view of the formwork device 40 of FIG.
This formwork apparatus 40 is constructed in a state where the rod-shaped column 1 is laid down. As shown in FIG. 7, in a state where the rod-like column 1 is laid down, a portion of the outermost surface of the concrete body 10 of the rod-like column 1 having a predetermined width (here, 100 mm) is defined as the uppermost surface 10A. The parts on both sides of 10A are the upper surface 10B. Moreover, the part used as both side surfaces among the outer peripheral surfaces of the concrete body 10 is made into the side surface 10C, and the part used as a lower surface is made into the lower surface 10D.

The formwork device 40 includes a lower column formwork device 41 that constructs the lower part of the rod-shaped column 1, a column intermediate part formwork device 42 that constructs the middle part of the rod-shaped column 1, and a column upper part that constructs the upper part of the rod-shaped column 1 A formwork device 43; a support portion 44 that supports both ends of the column steel frame 20 of the core material 11 from below; a portal-type suspension support portion 45 that supports the joint portion 21 of the core material 11 from above; Is provided.
The column lower mold device 41, the column intermediate mold device 42, and the column upper mold device 43 are arranged on a straight line.

  The column lower mold unit 41 and the column upper mold unit 43 include a lower surface mold member 50 as a first mold member having a circular arc shape covering the lower surface 10D of the rod column 1 and both side surfaces 10C of the rod column 1. A pair of side surface mold materials 51 as a first mold material having an arc-shaped cross section to be covered, and a pair of upper surface mold materials 52 as a first mold material having an arc-shaped cross-section to cover the upper surface 10B of the rod-like column 1 The uppermost mold member 53 as a second mold member having a circular arc cross section covering the uppermost surface 10A of the rod-like column 1 and an opening / closing mechanism 54 for opening and closing the pair of side face member members 51 are provided.

  The opening / closing mechanism 54 includes a rail 60 that extends in a direction orthogonal to the axial direction of the rod-shaped column 1 and a pair of traveling portions 61 that travel on the rail 60. Each of the pair of side surface formwork members 51 is mounted on the traveling unit 61. When the traveling unit 61 travels on the rail 60, as shown in FIG. 8, the pair of side surface frame members 51 approach or separate from each other, and the side surface frame material 51 is opened and closed. In addition, the pair of side surface mold materials 51 are temporarily fixed by attaching bolts 55 to the lower surface mold material 50 and connecting the upper ends of the pair of side surface mold materials 51 with a connecting member 56 in a closed state. It is possible.

  As shown in FIG. 8, the pair of upper surface mold members 52 are provided on the pair of side surface mold members 51 so as to be openable and closable. Further, the pair of upper surface mold members 52 can be temporarily fixed to the pair of side surface mold members 51 with bolts 57 in a closed state. The opening 58 between the pair of upper surface formwork members 52 has an opening width d of 100 mm or more and 200 mm or less (see FIG. 9).

9 is a longitudinal sectional view in the width direction of the upper part of the mold apparatus 40, and FIG. 10 is a longitudinal sectional view in the length direction of the upper part of the mold apparatus 40.
A plurality of uppermost mold members 53 are arranged in a straight line on the opening 58 between the pair of upper surface mold members 52. The uppermost mold member 53 is provided on the pressing portion 70 that is a metal bar having a curved cross section, a locking portion 71 that is provided on the upper surface of the pressing portion 70 and protrudes to the side, and the pressing portion 70. A grip portion 72 that is gripped by an operator.
As shown in FIG. 11, a water permeable sheet in which a nonwoven fabric 73 and a woven fabric 74 are laminated is attached to the lower surface of the pressing portion 70. Specifically, a plate-like nonwoven fabric 73 is attached to the lower surface of the pressing portion 70, and a plate-like woven fabric 74 is attached to the lower surface of the nonwoven fabric 73.
By placing and engaging the locking portion 71 of the uppermost mold member 53 on the pair of upper surface mold members 52, the pressing portion 70 of the uppermost mold member 53 blocks the opening 58. The concrete surface C is pressed down.

Returning to FIG. 6, the column intermediate part mold apparatus 42 has the same configuration as the column lower mold apparatus 41 and the column upper mold apparatus 43 except for the following points.
That is, in the column intermediate part formwork device 42, the pair of side face formwork members 51 can be temporarily fixed to the bottom face formwork member 50 with the bolts 55, but the opening / closing mechanism 54 is not provided.
In addition, the pair of upper surface mold members 52 can be temporarily fixed to the pair of side surface mold members 51 with bolts 57, but are not configured to be openable and closable with the pair of side surface mold members 51.
Further, the uppermost mold member 53 is disposed with the flange of the joint portion 21 sandwiched from both sides, and can be temporarily fixed to the pair of upper mold members 52 with bolts 59.

  Returning to FIG. 4, the prestress introduction device 2 introduces a tensile force to the PC steel material 13. The prestress introduction device 2 is arranged on one end side of the mold apparatus 40 and fixed to the one end side of the PC steel material 13, and is arranged on the other end side of the mold apparatus 40 and the PC steel material 13. And a jack 4 for introducing a tensile force by pulling the end side.

A procedure for constructing the rod-shaped column 1 using the above-described formwork device 40 and the prestress introduction device 2 will be described with reference to the flowchart of FIG.
In step S <b> 1, the core material 11, the column reinforcement 12, and the PC steel material 13 are arranged inside the mold apparatus 40.
That is, first, the above-described formwork device 40 is prepared, and as shown in FIG. 8, the uppermost formwork material 53 is removed, and the side surface formwork material 51 and the upper surface formwork material 52 of the formwork device 40 are opened. Keep it. In this state, the core material 11 is supported by the support portion 44 and the suspension support portion 45 and is disposed above the lower surface formwork material 50. Next, the reinforcing bars 12 are arranged and the PC steel material 13 is arranged. Next, as shown in FIG. 13, the side surface mold material 51 of the mold apparatus 40 is closed with the upper surface mold material 52 opened.

  In step S <b> 2, a tensile force is introduced into the PC steel material 13. That is, one end side of the PC steel material 13 is fixed to the fixing device 3 of the prestress introduction device 2, and the other end side of the PC steel material 13 is pulled by the jack 4 of the prestress introduction device 2 to introduce a tensile force to the PC steel material 13. To do.

In step S <b> 3, as shown in FIG. 13, the concrete is placed inside the lower surface mold material 50, the side surface mold material 51, and the upper surface mold material 52 of the mold device 40 to a height near the upper end of the side surface mold material 51. To cast. At this time, since the upper surface formwork material 52 is open, the concrete placement hose can be easily inserted into the formwork device 40, and the placement of concrete is easy.
In step S <b> 4, the upper surface mold member 52 is closed, and concrete is continuously placed up to the uppermost surface inside the mold device 40 through the opening 58 between the upper surface mold members 52.
In step S <b> 5, the uppermost mold member 53 is attached to the opening 58 between the upper mold members 52, and the concrete surface C exposed from the opening 58 is pressed.

  In step S6, after the cast concrete has hardened, the mold apparatus 40 is disassembled. That is, the uppermost mold member 53 is removed, and the upper mold member 52 and the side mold member 51 are opened. In this state, the constructed rod-shaped column 1 is lifted and moved.

According to this embodiment, there are the following effects.
(1) Since the PC steel material 13 is disposed substantially uniformly surrounding the core material 11 in a sectional view, a substantially uniform compressive stress is generated in the concrete in the cross section of the rod-shaped column 1. Therefore, the deviation of the axial rigidity in the cross section of the rod-shaped column 1 is reduced, and the rod-shaped column 1 having substantially the same shaft rigidity can be realized. Moreover, the crack which arises in the concrete body 10 of the rod-shaped column 1 can be prevented by making concrete in the cross section of the rod-shaped column 1 into a substantially uniform compressive stress state.

(2) Concrete is placed inside the lower surface mold material 50, the side surface mold material 51, and the upper surface mold material 52 having an arc shape in cross section, and then the upper surface mold frame is formed by the upper surface mold material 53 having an arc shape in cross section. By closing the opening 58 between the materials 52, the rod-shaped pillar 1 can be constructed in a laid state.
In addition, after placing concrete inside the bottom surface form material 50, the side surface form material 51, and the top surface form material 52 having a cross-section arc shape, the opening 58 between the top surface form materials 52 has a cross-section arc shape. By attaching the uppermost mold member 53, the concrete surface C exposed at the opening 58 can be formed into a circular arc shape and the rod-like column 1 can be easily constructed.
Further, since the prestress introducing device 2 can be arranged on both ends of the rod-shaped column 1, prestress can be easily introduced into the rod-shaped column 1.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.
For example, in the present embodiment, the core material 11, the column reinforcement 12 and the PC steel material 13 are embedded in the concrete body 10 as a prestressed steel reinforced concrete rod-shaped member, but the present invention is not limited thereto. For example, as shown in FIG. 14, as a rod-like column 1 </ b> A, which is a prestressed steel reinforced concrete rod-like member, a columnar concrete body 10 is not embedded with column reinforcing bars, but only a core material 11 and a PC steel material 13 are embedded. Also good. Alternatively, as a concrete rod-shaped member, only a column reinforcing bar may be embedded in a columnar concrete body without embedding the core material and the PC steel material.
In this embodiment, the concrete body 10 has a columnar shape and the hoop bar 31 has an annular shape. However, the present invention is not limited to this, and as shown in FIG. The hoop bar 31 may be rectangular and the columnar main bars 30 may be arranged at the four corners of the hoop bar 31. Moreover, as shown in FIG.15 (b), you may embed only the core material 11 and the PC steel material 13 in the square columnar concrete body 10 of the rod-shaped column 1C.

1, 1A, 1B, 1C ... rod-shaped column (bar-shaped member, columnar member)
DESCRIPTION OF SYMBOLS 2 ... Prestress introduction apparatus 3 ... Fixing apparatus 4 ... Jack 10 ... Concrete body 10A ... Top surface of concrete body 10B ... Upper surface of concrete body 10C ... Side surface of concrete body 10D ... Bottom surface of concrete body 11 ... Core material 12 ... Column reinforcement DESCRIPTION OF SYMBOLS 13 ... PC steel material 20 ... Column steel frame 21 ... Joint part 22 ... Guide member 23 ... Fixing member 24 ... Upper and lower column steel frame 25 ... Beam steel frame 30 ... Column main reinforcement 31 ... Hoop reinforcement 40 ... Formwork apparatus 41 ... Lower column formwork apparatus 42 ... Column intermediate part formwork device 43 ... Column upper part formwork device 44 ... Supporting part 45 ... Suspension support part 50 ... Lower surface formwork material (first formwork material) 51 ... Side face formwork material (first formwork) Frame material)
52... Upper surface formwork material (first formwork material) 53... Uppermost surface formwork material (second formwork material)
54 ... Opening / closing mechanism 55 ... Bolt 56 ... Connecting member 57 ... Bolt 58 ... Opening 59 ... Bolt 60 ... Rail 61 ... Running part 70 ... Holding part 71 ... Locking part 72 ... Gripping part 73 ... Nonwoven fabric 74 ... Woven cloth

Claims (3)

A method for constructing a columnar member made of concrete,
In the state where the cylindrical member is laid down, a first mold member having a circular arc cross section covering the outer peripheral surface excluding the uppermost surface of the cylindrical member, and a second cross sectional arc shape covering the uppermost surface of the cylindrical member. Prepare a formwork material,
Placing concrete inside the first formwork material;
Attaching the second formwork material to the opening on the uppermost surface of the first formwork material;
And a step of disassembling the first formwork material and the second formwork material after the placed concrete is hardened. The opening on the uppermost surface of the first mold material having an arc-shaped cross section has an opening width of 100 mm or more and 200 mm or less,
The second mold material includes a pressing part that presses the concrete surface exposed from the opening, and a locking part that is provided in the pressing part and locks to the first mold material.
The method for constructing a columnar member according to claim 1, wherein a nonwoven fabric and a woven fabric are laminated and attached to the lower surface of the pressing portion. Prestressed steel reinforced concrete rod-shaped member,
A rod-shaped concrete body,
A steel core material and a plurality of PC steel materials embedded in the concrete body and extending in the axial direction of the concrete body,
A prestressed steel reinforced concrete bar-like member, wherein the PC steel material is introduced with a tensile force and is disposed so as to surround the core material in a cross-sectional view.

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