Method for manufacturing concrete column members, and concrete column members

Abstract

The objective is to improve the carbon dioxide fixation efficiency for the outer precast concrete (PCa) members that form the outer shell of concrete column members in a carbonation curing tank. [Solution] The concrete column member manufacturing method comprises a carbonation curing step in which an outer shell PCa piece 20, which forms a part of the outer shell of the concrete column member 10 in cross-sectional view, is cured in a carbonation curing tank 30, and an outer shell PCa piece 20, which is made of concrete mixed with a carbon dioxide fixing admixture, is cured in a carbonation curing tank 30, and a concrete filling step in which filling concrete 16 is filled into the space 14 surrounded by a plurality of outer shell PCa pieces 20.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a concrete column member and a concrete column member.

Background Art

[0002] In cross-sectional view, an outer shell precast concrete (PCa) column member divided into a plurality of pieces is known (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, from the viewpoint of reducing the emission amount of carbon dioxide (CO2), it is conceivable to fix carbon dioxide to the cylindrical outer shell PCa member forming the outer shell of the concrete column member. In this case, a carbon dioxide-fixing admixture that reacts with carbon dioxide is blended into the concrete, and the outer shell PCa member is fixed with carbon dioxide by curing in a carbonation curing tank filled with high-concentration carbon dioxide.

[0005] However, since there is a limit to the number of outer shell PCa members that can be installed in the carbonation curing tank, the carbon dioxide fixation efficiency for the outer shell PCa members may decrease.

[0006] In consideration of the above facts, an object of the present invention is to increase the carbon dioxide fixation efficiency for the outer shell PCa member forming the outer shell of the concrete column member in the carbonation curing tank.

Means for Solving the Problems

[0007] The concrete column member manufacturing method according to claim 1 is a carbonation curing step in which an outer shell PCa piece, which forms a part of the outer shell of a concrete column member in cross-sectional view, is cured in a carbonation curing tank, wherein the outer shell PCa piece, which is made by mixing a carbon dioxide fixing admixture into concrete, is cured in a carbonation curing tank. The system includes a concrete filling step of filling the space surrounded by a plurality of the aforementioned outer shell PCa pieces with filling concrete.

[0008] According to the concrete column member manufacturing method of claim 1, first, in the carbonation curing process, an outer shell PCa piece, which forms a part of the outer shell of the concrete column member in cross-sectional view, and in which a carbon dioxide fixing admixture is mixed into the concrete, is cured in a carbonation curing tank.

[0009] Next, in the concrete filling process, concrete is filled into the space surrounded by multiple precast concrete (PCa) shell pieces. This integrates the multiple PCa shell pieces through the concrete, and a concrete column member is fabricated with the multiple PCa shell pieces as the outer shell.

[0010] In this carbonation curing process, carbon dioxide is fixed to the outer PCa pieces by curing them in a carbonation curing tank. Therefore, carbon dioxide emissions can be reduced.

[0011] In this case, when forming the outer shell of a concrete column member using a single cylindrical precast concrete (PCa) shell member, the space inside the PCa shell member becomes dead space when it is installed in the carbonation curing tank. Therefore, it is difficult to efficiently install the PCa shell member in the carbonation curing tank.

[0012] In contrast, in the present invention, the outer shell PCa piece forms a part of the outer shell of the concrete column member. In other words, in the present invention, the outer shell of the concrete column member is formed by multiple outer shell PCa pieces.

[0013] Therefore, when installing outer shell PCa pieces in a carbonation curing tank, dead space is less likely to occur, and multiple outer shell PCa pieces can be efficiently installed in the carbonation curing tank. Consequently, the carbon dioxide fixation efficiency for the outer shell PCa pieces, i.e., the outer shell PCa members, can be increased.

[0014] Furthermore, by forming the outer shell of the concrete column member with multiple precast concrete (PCa) pieces, the specific surface area of ​​the PCa pieces that come into contact with carbon dioxide increases. Therefore, the carbon dioxide fixation efficiency of the PCa pieces can be further enhanced.

[0015] The concrete column member according to claim 2 comprises a plurality of outer shell PCa pieces, each containing a carbon dioxide-fixing admixture, arranged to surround a space, and filling concrete that fills the space.

[0016] According to the concrete column member of claim 2, a plurality of outer shell PCa pieces are arranged to surround a space. This space is filled with filling concrete. As a result, the plurality of outer shell PCa pieces are integrated through the filling concrete, and a concrete column member is manufactured with the plurality of outer shell PCa pieces as the outer shell.

[0017] In this process, a carbon dioxide-fixing admixture is incorporated into the concrete of the outer PCa shell pieces. Therefore, by curing the outer PCa shell pieces in a carbonation curing tank, carbon dioxide is fixed within the outer PCa shell pieces. Consequently, carbon dioxide emissions can be reduced.

[0018] In this case, when forming the outer shell of a concrete column member using a single cylindrical precast concrete (PCa) shell member, the space inside the PCa shell member becomes dead space when it is installed in the carbonation curing tank. Therefore, it is difficult to efficiently install the PCa shell member in the carbonation curing tank.

[0019] In contrast, in this invention, the outer shell of the concrete column member is formed by multiple outer shell PCa pieces. Therefore, when the outer shell PCa pieces are installed in the carbonation curing tank, dead space is less likely to occur, and multiple outer shell PCa pieces can be efficiently installed in the carbonation curing tank. Consequently, the carbon dioxide fixation efficiency for the outer shell PCa pieces, i.e., the outer shell PCa members, can be increased.

[0020] Furthermore, by forming the outer shell of the concrete column member with multiple precast concrete (PCa) pieces, the specific surface area of ​​the PCa pieces that come into contact with carbon dioxide increases. Therefore, the carbon dioxide fixation efficiency of the PCa pieces can be further enhanced.

[0021] The concrete column member according to claim 3 is the concrete column member according to claim 2, comprising, in cross-sectional view, four outer shell PCa pieces arranged at each corner, four outer peripheral connecting bars arranged adjacent to the ends of adjacent outer shell PCa pieces and embedded in the filling concrete, and a central connecting bar arranged in the center of the space and embedded in the filling concrete, wherein the outer shell PCa pieces have two outer peripheral connecting bars adjacent to both ends and a rectangular annular ring surrounding the central connecting bar.

[0022] According to the concrete column member of claim 3, the four outer shell PCa pieces are arranged at each corner of the concrete column member in a cross-sectional view. The four outer perimeter connecting bars are arranged adjacent to the ends of adjacent outer shell PCa pieces in a cross-sectional view and are embedded in the filling concrete. Furthermore, the central connecting bar is arranged in the center of the space in a cross-sectional view and is embedded in the filling concrete.

[0023] Here, the outer shell PCa piece has a rectangular annular stirrup. The stirrup surrounds two perimeter connecting bars adjacent to both ends of the outer shell PCa piece, as well as a central connecting bar. As a result, shear force is transmitted between multiple outer shell PCa pieces via the stirrup, perimeter connecting bars, and central connecting bars. Therefore, the concrete column member can be efficiently shear-reinforced.

[0024] The concrete column member according to claim 4 is the concrete column member according to claim 2, wherein a carbon dioxide fixation admixture is blended in the concrete, and an internal PCa piece embedded in the filled concrete is provided.

[0025] According to the concrete column member according to claim 4, the internal PCa piece is embedded in the filled concrete. A carbon dioxide fixation admixture is blended in the concrete of this internal PCa piece. Therefore, by curing the internal PCa piece in a carbonation curing tank, carbon dioxide is absorbed by the internal PCa piece. Accordingly, the amount of carbon dioxide emissions can be further reduced.

Advantages of the Invention

[0026] As described above, according to the present invention, in the carbonation curing tank, the fixation efficiency of carbon dioxide with respect to the outer shell PCa member forming the outer shell of the concrete column member can be increased.

Brief Description of the Drawings

[0027] [Figure 1] It is a cross-sectional view (transverse cross-sectional view) showing a concrete column member according to the first embodiment. [Figure 2] It is an exploded cross-sectional view obtained by disassembling a pair of outer shell PCa pieces shown in FIG. 1. [Figure 3] It is a cross-sectional view showing a state where a plurality of outer shell PCa pieces shown in FIG. 2 are set in a carbonation curing tank. [Figure 4] It is a cross-sectional view corresponding to FIG. 1 showing a modified example of the concrete column member according to the first embodiment. [Figure 5] It is a cross-sectional view showing a concrete column member according to the second embodiment. [Figure 6] It is an exploded cross-sectional view obtained by disassembling four outer shell PCa pieces shown in FIG. 5. [Figure 7] It is a cross-sectional view showing a modified example of the concrete column member according to the second embodiment. [Figure 8]Figure 7 shows a disassembled cross-sectional view of the four outer shell PCa pieces. [Figure 9] This is a cross-sectional view showing a modified example of the concrete column member according to the second embodiment. [Figure 10] Figure 9 shows a disassembled cross-sectional view of the four outer shell PCa pieces. [Figure 11] This is a cross-sectional view showing a modified example of the concrete column member according to the second embodiment. [Figure 12] Figure 11 shows a disassembled cross-sectional view of the four outer shell PCa pieces. [Figure 13] This is a cross-sectional view showing a concrete column member according to the third embodiment. [Figure 14] Figure 13 is an exploded cross-sectional view of the four outer shell PCa pieces shown in the diagram. [Figure 15] This is a cross-sectional view showing a concrete column member according to the fourth embodiment. [Figure 16] Figure 15 is a front view of the internal PCa piece as seen from the thickness direction. [Figure 17] This is a cross-sectional view showing a modified example of the concrete column member according to the fourth embodiment. [Figure 18] Figure 17 shows an exploded cross-sectional view of the four outer PCa pieces and the two inner PCa pieces. [Figure 19] This is a cross-sectional view showing a concrete column member according to the fifth embodiment. [Figure 20] Figure 19 shows the first outer shell PCa piece and a disassembled cross-sectional view of a pair of first outer shell PCa pieces. [Figure 21] This is a cross-sectional view showing a modified example of the concrete column member according to the fifth embodiment. [Figure 22] Figure 21 shows the first outer shell PCa piece and a disassembled cross-sectional view of a pair of first outer shell PCa pieces. [Modes for carrying out the invention]

[0028] (First Embodiment) First, I will describe the first embodiment.

[0029] (Concrete column member) Figure 1 shows a concrete column member 10 manufactured (constructed) by the concrete column member manufacturing method according to this embodiment.

[0030] The concrete column member 10 is made of reinforced concrete. The concrete column member 10 is formed in a rectangular column shape. This concrete column member 10 comprises an outer shell precast concrete (hereinafter referred to as "PCa") member 12, a pair of outer peripheral connecting bars 28, and filling concrete 16.

[0031] (Outer shell PCa member) As shown in Figures 1 and 2, the outer shell PCa member 12 is a PCa member that forms the outer shell of the concrete column member 10. This outer shell PCa member 12 is formed in a rectangular cross-section and has four sides.

[0032] The outer shell PCa member 12 is cylindrical and, in cross-sectional view, has a hexagonal space 14 on its inside. This space 14 is filled with the concrete 16 described later. The outer shell PCa member 12 also has a pair of outer shell PCa pieces 20 that can be combined with each other.

[0033] (Outer shell PCa piece) The pair of outer shell PCa pieces 20 are PCa members obtained by dividing (halving) the outer shell PCa member 12 in a cross-sectional view, and form the outer shell of the concrete column member 10. The concrete of this pair of outer shell PCa pieces 20 is mixed with a carbon dioxide fixing admixture, which will be described later. Furthermore, the pair of outer shell PCa pieces 20 are cured in a carbonation curing tank, which will be described later, and carbon dioxide is fixed to each outer shell PCa piece 20.

[0034] A pair of outer shell PCa pieces 20, when combined with each other, form a cylindrical outer shell PCa member 12. Specifically, the pair of outer shell PCa pieces 20 are formed in a C-shape (U-shape) in cross-section, and are arranged with their end faces 20E1 abutting against each other at their respective opening ends 20E. Each end face 20E1 is a parallel surface that is substantially parallel to the outer surface (side surface) of the outer shell PCa piece 20 on the opposite side in cross-section.

[0035] In the following, unless otherwise specified, the description will refer to a cross-sectional view of the concrete column member 10 or the outer shell PCa member 12 (outer shell PCa piece 20).

[0036] A recess 22 is formed on the opening side of a pair of outer shell PCa pieces 20. The recess 22 has a bottom surface 22A and a pair of inner surfaces 22B. The bottom surface 22A is located in the center of the recess 22. This bottom surface 22A is a parallel surface that is substantially parallel to the outer surface (side surface) 20A of the outer shell PCa piece 20 on the opposite side of the bottom surface 22A.

[0037] A pair of inner surfaces 22B are positioned on both sides of the bottom surface 22A, connecting the bottom surface 22A to the end surface 20E1. Each inner surface 22B is an inclined surface that slopes with respect to the outer surface (side) 20B of the outer shell PCa piece 20 on the opposite side of the inner surface 22B. These inner surfaces 22B form an installation space for the outer peripheral connecting reinforcement bars 28, which will be described later, on the outer periphery of the space 14.

[0038] Furthermore, cotters or the like may be formed on the bottom surface 22A and the pair of inner surfaces 22B of the recess 22 to enhance integration with the filling concrete 16, which will be described later.

[0039] Multiple main column reinforcements 24 and multiple stirrups (hoop reinforcements) 26 are embedded in the outer periphery of the outer PCa piece 20. The multiple main column reinforcements 24 are arranged along the axial direction of the outer PCa member 12 and are spaced apart in the circumferential direction of the outer PCa member 12. Multiple stirrups 26 are embedded on the outside of these main column reinforcements 24.

[0040] Multiple stirrups 26 are arranged at intervals along the material axis of the outer shell PCa member 12. Each stirrup 26 is bent into a C-shape along the outer circumference of the outer shell PCa piece 20. Both ends of each stirrup 26 protrude into the space 14 from the inner surface 22B of the recess 22 of the outer shell PCa piece 20. Hooks 26F are provided at both ends of the stirrups 26.

[0041] The hook 26F is, for example, a 135-degree hook, formed by bending the end of the stirrup 26 inward at a predetermined angle. The hook 26F is also approximately parallel to the inner surface 22B of the recess 22. Each hook 26F is hooked onto the outer connecting reinforcement 28, which is arranged around the outer perimeter of the space 14, when the pair of outer shell PCa pieces 20 are assembled.

[0042] (Peripheral connecting muscles) A pair of outer perimeter connecting bars (outer perimeter positioning bars) 28 are arranged along the material axis of the outer shell PCa member 12 and serve as reinforcing bars that connect the stirrups 26 of the pair of outer shell PCa pieces 20. These pair of outer perimeter connecting bars 28 are arranged on the outer perimeter of the space 14 formed on the inside when the pair of outer shell PCa pieces 20 are assembled.

[0043] Furthermore, each outer perimeter connecting reinforcement 28 is positioned adjacent to the end portion 20E of the adjacent outer shell PCa piece 20. More specifically, each outer perimeter connecting reinforcement 28 is positioned at the corner formed by the end portion 20E (inner surface 22B) of a pair of combined outer shell PCa pieces 20.

[0044] Each outer perimeter connecting reinforcement bar 28 is positioned between adjacent column main reinforcement bars 24, with a pair of outer shell PCa pieces 20 assembled together. The hooks 26F of the pair of outer shell PCa pieces 20 are hooked onto this outer perimeter connecting reinforcement bar 28.

[0045] More specifically, when a pair of outer shell PCa pieces 20 are assembled, the hooks 26F of the pair of outer shell PCa pieces 20 are partially overlapped to form a ring shape (annular). The outer peripheral connecting reinforcement 28 is positioned (inserted) inside the ring-shaped hooks 26F.

[0046] As a result, the hooks 26F on both sides of the pair of outer shell PCa pieces 20 are connected via a pair of outer perimeter connecting bars 28. In this state, the space 14 enclosed by the pair of outer shell PCa pieces 20 is filled with concrete 16.

[0047] The outer perimeter connecting reinforcement 28 may be used in conjunction with the main reinforcement of the concrete column member 10, or it may be provided separately from the main reinforcement of the concrete column member 10.

[0048] (Filling concrete) For the filling concrete 16, for example, ordinary concrete, cement-reduced concrete, or CCU (Carbon Capture and Utilization) material-utilizing concrete can be used.

[0049] The filling concrete 16 is filled into the space 14 inside the outer shell PCa member 12. A pair of outer perimeter connecting reinforcements 28 and a pair of hooks 26F of outer shell PCa pieces 20 are embedded in this filling concrete 16.

[0050] (Concrete column member manufacturing method) Next, an example of a method for manufacturing (construction) a concrete column member according to this embodiment will be described.

[0051] First, in the outer shell PCa piece manufacturing process, the outer shell PCa piece 20 is manufactured in a factory or similar facility. Specifically, concrete is poured into the formwork with multiple main column reinforcements 24 and stirrups 26 already placed inside.

[0052] In this case, carbon dioxide-absorbing concrete is used as an example for the concrete of the outer shell PCa piece 20. Carbon dioxide-absorbing concrete is mixed with carbon dioxide-fixing admixtures.

[0053] Specifically, in carbon dioxide absorbing concrete, a portion of the cement is replaced with a carbon dioxide fixing admixture. An example of a carbon dioxide fixing admixture is γC2s, which is made from slaked lime. This carbon dioxide fixing admixture has the property of being unresponsive to water and solidifying upon reaction with carbon dioxide. Note that the carbon dioxide fixing admixture is not limited to γC2s and can be changed as appropriate.

[0054] Next, as shown in Figure 3, in the carbonation curing process, the outer PCa piece 20, which is made of carbon dioxide absorbing concrete, is cured in a carbonation curing tank 30 filled with high-concentration carbon dioxide. As a result, the carbon dioxide fixing admixture in the outer PCa piece 20 reacts with carbon dioxide, and the carbon dioxide is absorbed and fixed in the outer PCa piece 20.

[0055] In Figure 3, as an example, multiple outer shell PCa pieces 20 are installed in two stages in a carbonation curing tank 30. The multiple outer shell PCa pieces 20 in the first stage are arranged with their openings (recesses 22) facing upwards and their outer surfaces (sides) 20B facing each other. Each outer shell PCa piece 20 in the first stage is installed on the mounting surface 30A of the carbonation curing tank 30 via multiple spacers 32.

[0056] The second-stage outer shell PCa piece 20 is positioned with its opening (recess 22) facing downwards, straddling the end 20E of the adjacent first-stage outer shell PCa piece 20. The ends 20E (end faces 20E1) on both sides of the second-stage outer shell PCa piece 20 are then placed on the bottom surface 22A of the recess 22 of the adjacent first-stage outer shell PCa piece 20 via spacers 32.

[0057] Here, the ends 20E of adjacent first-stage PCa shell pieces 20 are inserted into the recesses 22 of the second-stage PCa shell piece 20, and the ends 20E on both sides of the second-stage PCa shell piece 20 are respectively inserted into the recesses 22 of adjacent first-stage PCa shell pieces 20. As a result, in this embodiment, the installation height of the second-stage PCa shell piece 20 is lower compared to the case where a single cylindrical PCa shell member is installed on the installation surface 30A of the carbonation curing tank 30.

[0058] Furthermore, the concrete used for the outer PCa piece 20 may be made not only of carbon dioxide absorbing concrete, but also of other types, such as cement-reduced concrete or concrete utilizing CCU materials. This can further reduce carbon dioxide emissions.

[0059] Next, as shown in Figure 2, in the outer shell PCa piece assembly process, for example, at the site or factory, a pair of outer shell PCa pieces 20 are assembled to form the outer shell PCa member 12. Specifically, the end faces 20E1 on both sides of the pair of outer shell PCa pieces 20 are butted together so as to surround the space 14. This prevents leakage of the filling concrete 16 from the gap between the end faces 20E1 of the pair of outer shell PCa pieces 20 when the filling concrete 16 is being filled.

[0060] Alternatively, a restraining band or the like may be wrapped around the pair of outer shell PCa pieces 20, and the end faces 20E1 of the pair of outer shell PCa pieces 20 may be pressed together and restrained. In addition, the gap between the end faces 20E1 of the butted pair of outer shell PCa pieces 20 may be sealed with tape or the like.

[0061] Furthermore, when the pair of outer shell PCa pieces 20 are combined, the hooks 26F on both sides are partially overlapped to form a ring shape. In this state, the outer peripheral connecting reinforcement 28 is inserted inside the ring-shaped hooks 26F. This connects the pair of outer shell PCa pieces 20 via the outer peripheral connecting reinforcement 28.

[0062] In this embodiment, the outer peripheral connecting reinforcement bars 28 are inserted inside the ring-shaped hooks 26F. However, it is also possible to hook the hooks 26F of the outer shell PCa piece 20 onto the outer peripheral connecting reinforcement bars 28 that have been pre-placed (installed).

[0063] Next, as shown in Figure 1, in the concrete filling process, the space 14 surrounded by the pair of outer shell PCa pieces 20 is filled with filling concrete 16 and cured. As a result, the hooks 26F of the pair of outer shell PCa pieces 20 and the pair of outer peripheral connecting bars 28 are embedded in the outer periphery of the filling concrete 16, and the pair of outer shell PCa pieces 20 are integrated via the filling concrete 16.

[0064] (action) Next, the operation of the first embodiment will be described.

[0065] As shown in Figure 1, according to the concrete column member 10 of this embodiment, a pair of outer shell PCa pieces 20 are arranged to surround a space 14. Filling concrete 16 is filled into this space 14. As a result, the pair of outer shell PCa pieces 20 are integrated via the filling concrete 16, and a concrete column member 10 is manufactured with the pair of outer shell PCa pieces 20 as the outer shell.

[0066] Here, each outer shell PCa piece 20 is formed from concrete mixed with a carbon dioxide-fixing admixture, as described above. Therefore, as shown in Figure 3, by curing each outer shell PCa piece 20 in a carbonation curing tank 30, carbon dioxide is fixed in each outer shell PCa piece 20. Thus, carbon dioxide emissions can be reduced.

[0067] In this case, when the outer shell of the concrete column member 10 is formed by a single cylindrical precast concrete (PCa) shell member, the space inside the PCa shell member becomes dead space when it is installed in the carbonation curing tank 30. Therefore, it is difficult to efficiently install multiple PCa shell members in the carbonation curing tank 30.

[0068] In contrast, in this embodiment, the outer shell of the concrete column member 10 is formed by a pair of outer shell PCa pieces 20. Therefore, when the outer shell PCa pieces 20 are installed in the carbonation curing tank 30, dead space is less likely to occur, and multiple outer shell PCa pieces 20 can be efficiently installed in the carbonation curing tank 30.

[0069] Specifically, in the example shown in Figure 3, the ends 20E of adjacent first-stage PCa shell pieces 20 are inserted into the recesses 22 of the second-stage PCa shell piece 20, and the ends 20E on both sides of the second-stage PCa shell piece 20 are respectively inserted into the recesses 22 of the adjacent first-stage PCa shell pieces 20.

[0070] As a result, in this embodiment, the installation height of the second-stage outer shell PCa piece 20 can be lowered compared to the case where one cylindrical outer shell PCa member is installed on the installation surface 30A of the carbonation curing tank 30. Therefore, since multiple outer shell PCa pieces 20 can be efficiently installed in the carbonation curing tank 30, the carbon dioxide fixation efficiency for the outer shell PCa pieces 20, i.e., the outer shell PCa member 12, can be increased.

[0071] Furthermore, by forming the outer shell of the concrete column member 10 with a pair of outer shell PCa pieces 20, the specific surface area of ​​the outer shell PCa pieces 20 that come into contact with carbon dioxide is increased. Therefore, the carbon dioxide fixation efficiency for each outer shell PCa piece 20 can be further enhanced.

[0072] Furthermore, by using cement-reduced concrete or CCU material-utilizing concrete in combination as the filling concrete 16, carbon dioxide emissions can be further reduced.

[0073] Furthermore, the pair of outer shell PCa pieces 20 are assembled with their respective end faces 20E1 butted together. This prevents leakage of the filling concrete 16 when it is filled into the space 14 surrounded by the pair of outer shell PCa pieces 20.

[0074] Furthermore, the pair of outer shell PCa pieces 20 have stirrups 26. Both ends of the stirrups 26 protrude from the outer shell PCa pieces 20 into the space 14. Hooks 26F are provided at both ends of the stirrups 26.

[0075] The hooks 26F of the pair of outer shell PCa pieces 20 are connected via a pair of outer perimeter connecting reinforcements 28. This allows shear force to be transmitted between the pair of outer shell PCa pieces 20 via the stirrups 26 and the outer perimeter connecting reinforcements 28. Therefore, the concrete column member 10 can be efficiently reinforced with shear force.

[0076] Furthermore, when assembling a pair of outer shell PCa pieces 20, connecting each hook 26F via a pair of outer peripheral connecting bars 28 suppresses misalignment of the pair of outer shell PCa pieces 20. Therefore, the manufacturability of the concrete column member 10 is improved.

[0077] (Modification of the first embodiment) The shape of the outer PCa piece 20 can be modified as appropriate. For example, in the modified example shown in Figure 4, the pair of inner surfaces 22B of the recess 22 have a parallel surface 22B1 and an inclined surface 22B2. The parallel surface 22B1 connects the bottom surface 22A of the recess 22 to the inclined surface 22B2. This parallel surface 22B1 is approximately parallel to the outer surface (side surface) 20B of the outer PCa piece 20 on the opposite side of the parallel surface 22B1, so as to reduce the thickness of the outer PCa piece 20. By reducing the thickness of the outer PCa piece 20 in this way, carbon dioxide can penetrate the outer PCa piece 20 more easily, thereby increasing the carbon dioxide fixation efficiency.

[0078] The inclined surface 22B2 connects the parallel surface 22B1 and the end surface 20E1. Furthermore, the inclined surface 22B2 is inclined relative to the outer surface (side surface) of the outer shell PCa piece 20 on the opposite side of the inclined surface 22B2. This inclined surface 22B2 forms the installation space for the outer peripheral connecting reinforcement bars 28.

[0079] (Second embodiment) Next, a second embodiment will be described. In the second embodiment, components and the like that have the same configuration as in the above embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0080] (Outer shell PCa member) As shown in Figure 5, the outer shell PCa member 12 according to the second embodiment is formed in a rectangular cross-section and has four sides. The outer shell PCa member 12 is cylindrical and has a rectangular space 14 inside. This outer shell PCa member 12 has four divided outer shell PCa pieces 40.

[0081] (Outer shell PCa piece) As shown in Figures 5 and 6, the four outer shell PCa pieces 40 are PCa members obtained by dividing the outer shell PCa member 12 into four parts, and form the outer shell of the concrete column member 10. The concrete of each outer shell PCa piece 40 is mixed with a carbon dioxide fixing admixture. In addition, each outer shell PCa piece 40 is cured in a carbonation curing tank, and carbon dioxide is fixed.

[0082] The four outer shell PCa pieces 40, when combined with each other, form a cylindrical outer shell PCa member 12. Specifically, the four outer shell PCa pieces 40 are triangular in shape and are positioned along the corners of the outer shell PCa member 12.

[0083] Adjacent outer shell PCa pieces 40 are arranged with their respective end faces 40E1 butted together. Each end face 40E1 is a parallel surface that is approximately parallel to the outer surface (side surface) 40A of the outer shell PCa piece 40 on the opposite side of that end face 40E1.

[0084] The inner surface 40B of the outer PCa piece 40 connects the end faces 40E1 on both sides. This inner surface 40B of the outer PCa piece 40 is an inclined surface that slopes relative to the outer surface 40A of the outer PCa piece 40. This inner surface 40B forms the installation space for the outer connecting reinforcement bars 28.

[0085] Furthermore, cotters or the like may be formed on the inner surface 40B of the outer shell PCa piece 40 to enhance its integration with the filling concrete 16.

[0086] Multiple main column reinforcements 42 and multiple hoop reinforcements 44 are embedded in the outer periphery of the outer PCa piece 40. Each hoop reinforcement 44 is bent in an L-shape along the outer periphery of the outer PCa piece 40. Both ends of each hoop reinforcement 44 protrude into the space 14 from the inner surface 40B of the outer PCa piece 40. Hooks 44F are provided at both ends of these hoop reinforcements 44.

[0087] The hooks 44F are approximately parallel to the inner surface 40B of the outer shell PCa piece 40. Each hook 44F is hooked onto the outer connecting reinforcement bars 28 arranged in the space 14 when adjacent outer shell PCa pieces 40 are assembled.

[0088] In this embodiment, the four outer shell PCa pieces 40 have the same configuration, but the configurations of the four outer shell PCa pieces 40 may be different.

[0089] (Peripheral connecting muscles) The four outer perimeter connecting bars (outer perimeter positioning bars) 28 are arranged around the outer perimeter of the space 14 formed inside when the four outer shell PCa pieces 40 are assembled. Each outer perimeter connecting bar 28 is also arranged so as to be adjacent to the end 40E of the adjacent outer shell PCa piece 40. More specifically, each outer perimeter connecting bar 28 is arranged at the corner formed by the end 40E (inner surface 40B) of the adjacent outer shell PCa piece 40.

[0090] Each outer perimeter connecting reinforcement bar 28 is positioned between adjacent column main reinforcement bars 42, with four outer shell PCa pieces 40 assembled together. In addition, each outer perimeter connecting reinforcement bar 28 is hooked onto the hooks 44F of the adjacent outer shell PCa piece 40.

[0091] More specifically, when the four outer shell PCa pieces 40 are assembled, the hooks 44F of adjacent outer shell PCa pieces 40 are partially overlapped to form a ring shape. The outer peripheral connecting reinforcement 28 is positioned (inserted) inside the hooks 44F that are overlapped in this ring shape.

[0092] As a result, the hooks 44F of adjacent outer shell PCa pieces 40 are connected via the outer perimeter connecting reinforcement bars 28. In this state, filling concrete 16 is poured into the space 14 surrounded by the four outer shell PCa pieces 40.

[0093] (action) Next, the operation of the second embodiment will be described.

[0094] As shown in Figures 5 and 6, according to the concrete column member 10 of this embodiment, the four outer shell PCa pieces 40 are arranged to surround the space 14. Filling concrete 16 is filled into this space 14. As a result, the four outer shell PCa pieces 40 are integrated via the filling concrete 16, and a concrete column member 10 is manufactured with the four outer shell PCa pieces 40 as the outer shell.

[0095] In this embodiment, the outer shell of the concrete column member 10 is formed by four outer shell PCa pieces 40. Therefore, when the outer shell PCa pieces 40 are installed in the carbonation curing tank, dead space is less likely to occur, and a pair of outer shell PCa pieces 40 can be efficiently installed in the carbonation curing tank. Thus, in this embodiment, the carbon dioxide fixation efficiency for the outer shell PCa pieces 40, i.e., the outer shell PCa member 12, can be increased.

[0096] Furthermore, by forming the outer shell of the concrete column member 10 with four outer shell PCa pieces 40, the specific surface area of ​​the outer shell PCa pieces 40 that come into contact with carbon dioxide is increased. Therefore, the carbon dioxide fixation efficiency for each outer shell PCa piece 40 can be further increased. Moreover, since each outer shell PCa piece 40 is made smaller, its transportability and lifting capabilities are improved.

[0097] Furthermore, adjacent outer shell PCa pieces 40 are assembled with their respective end faces 40E1 butted together. This prevents leakage of the filling concrete 16 when it is filled into the space 14 surrounded by the four outer shell PCa pieces 40.

[0098] (Modified version of the second embodiment) The shape of the stirrups 44 of the outer PCa piece 40 can be modified as appropriate. For example, in the modified examples shown in Figures 7 and 8, the stirrups 46 are bent into a roughly right-angled triangular ring. Of the three corners of this stirrups 46, one corner is embedded in the outer PCa piece 40. The other two corners of the stirrups 46 are hooks 46F, which protrude from the inner surface 40B of the outer PCa piece 40 and are positioned on the outer periphery of the space 14.

[0099] The hooks 46F of adjacent outer shell PCa pieces 40 are connected via outer perimeter connecting reinforcement 28. This allows shear force to be transmitted between adjacent outer shell PCa pieces 40 via the stirrups 46 and outer perimeter connecting reinforcement 28.

[0100] Next, in the modified examples shown in Figures 9 and 10, the stirrups 48 are bent into a rectangular ring shape. Of the four corners of these stirrups 48, one corner is embedded in the outer PCa piece 40. The other three corners of the stirrups 48 are hooks 48F1 and 48F2, which protrude from the inner surface 40B of the outer PCa piece 40 and are positioned on the outer periphery and in the center of the space 14.

[0101] The hooks (outer hooks) 48F1 of adjacent outer shell PCa pieces 40 are connected via outer perimeter connecting reinforcement bars 28. As a result, shear force is transmitted between adjacent outer shell PCa pieces 40 via the stirrups 48 and outer perimeter connecting reinforcement bars 28.

[0102] Furthermore, in the four outer shell PCa pieces 40, the hooks (central hooks) 48F2 positioned in the center of the space 14 are connected to each other via central connecting bars 34. The central connecting bars (central positioning bars) 34 are arranged along the material axis direction of the outer shell PCa member 12 and serve as reinforcing bars that connect the stirrups 48 of the four outer shell PCa pieces 40. These central connecting bars 34 are positioned in the center of the space 14 formed on the inside when the four outer shell PCa pieces 40 are assembled.

[0103] The hooks 48F2 of the four outer shell PCa pieces 40 are connected via this central connecting reinforcement 34. As a result, shear force is transmitted between the four outer shell PCa pieces 40 via the stirrups 48 and the central connecting reinforcement 34. Therefore, the shear strength of the concrete column member 10 can be increased.

[0104] Next, in the modified examples shown in Figures 11 and 12, the cross-sectional area of ​​the concrete column member 10 is increased, and a portion of the outer shell of the concrete column member 10 is formed by multiple outer shell PCa pieces 40.

[0105] Specifically, the four outer shell PCa pieces 40 are arranged at predetermined intervals. The openings between adjacent outer shell PCa pieces 40 are closed by formwork 50. The space 14 is enclosed by these outer shell PCa pieces 40 and formwork 50.

[0106] Perimeter reinforcement bars 36 and perimeter connecting bars 28 are appropriately placed around the outer perimeter of space 14. The perimeter reinforcement bars 36 and perimeter connecting bars 28 are placed with gaps between the main column reinforcement bars 42 of adjacent outer shell PCa pieces 40. The perimeter reinforcement bars 36 may be, for example, main column reinforcement bars or positioning bars.

[0107] Furthermore, multiple secondary stirrups 60 are arranged in the space 14, surrounding the outer perimeter reinforcement bars 36 and the outer perimeter connecting reinforcement bars 28. The multiple secondary stirrups 60 are embedded in the filling concrete 16. These secondary stirrups 60 are arranged at intervals in the direction of the material axis of the outer shell PCa member 12. The secondary stirrups 60 are formed in a rectangular ring shape and are arranged in a cross shape.

[0108] The formwork 50 is formed in a flat plate shape and is positioned across the ends 40E of adjacent outer shell PCa pieces 40. Furthermore, a stepped portion 52 is formed on the outer surface 40A of the end 40E of the outer shell PCa piece 40 to absorb the thickness of the formwork 50. The stepped portion 52 may be provided as needed and can be omitted as appropriate.

[0109] As shown in Figure 12, the stirrups 44 of each outer shell PCa piece 40 are made longer in proportion to the cross-sectional area of ​​the concrete column member 10. One end of the stirrups 44 is provided with a 135-degree hook 44F that hooks onto the outer perimeter connecting reinforcement 28. In contrast, the other end of the stirrups 44 is a lap splice (straight lap splice) without a hook.

[0110] By using multiple outer shell PCa pieces 40 and formwork 50 in this manner, the cross-sectional area of ​​the concrete column member 10 can be increased without changing the size of the outer shell PCa pieces 40.

[0111] Furthermore, the hook 44F may be provided not only on one end of the stirrup 44, but also on the other end of the stirrup 44. Also, the hook 44F may be provided only as needed and can be omitted as appropriate. If the hook 44F is omitted, for example, the stirrups 44 of adjacent outer shell PCa pieces 40 may be connected by a hoop clip or the like.

[0112] (Third embodiment) Next, a third embodiment will be described. In the third embodiment, components and the like that have the same configuration as in the above embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0113] As shown in Figures 13 and 14, the outer shell PCa member 12 according to the third embodiment has four outer shell PCa pieces 70. The four outer shell PCa pieces 70 are PCa members obtained by dividing the outer shell PCa member 12 into four parts, and form the outer shell of the concrete column member 10. A carbon dioxide fixing admixture is mixed into the concrete of each outer shell PCa piece 70. In addition, each outer shell PCa piece 70 is cured in a carbonation curing tank, and carbon dioxide is fixed to each outer shell PCa piece 70.

[0114] The four outer shell PCa pieces 70, when combined with each other, form a cylindrical outer shell PCa member 12. Specifically, each outer shell PCa piece 70 is formed in a plate shape along one side of the outer shell PCa member 12 and is arranged across adjacent corners of the outer shell PCa member 12.

[0115] Adjacent outer shell PCa pieces 70 are joined together with their respective ends butted together. Specifically, the end face 70E1 of one adjacent outer shell PCa piece 70 is butted against the inner surface 70B of the end 70E of the other adjacent outer shell PCa piece 70. This prevents the filling concrete 16 from leaking out of the gap between adjacent outer shell PCa pieces 70 when the filling concrete 16 is being filled.

[0116] Furthermore, cotters or the like may be formed on the inner surface 70B of each outer shell PCa piece 70 to enhance its integration with the filling concrete 16.

[0117] Notches 76 are formed at both ends of the outer shell PCa piece 70. These notches 76 create an installation space S for the outer perimeter connecting reinforcement bars 28 on the outer periphery of the space 14. The installation space S is formed diagonally across the outer shell PCa member 12. When installed in the installation space S, the outer perimeter connecting reinforcement bars 28 are positioned adjacent to the ends 70E of adjacent outer shell PCa pieces 70.

[0118] Multiple main column reinforcements 72 and multiple stirrups 74 are embedded in the outer PCa piece 70. The stirrups 74 are arranged along the circumferential direction of the outer PCa member 12. Both ends of the stirrups 74 protrude into the space 14 through the notches 76 of the outer PCa piece 70. Hooks 74F are provided at both ends of the stirrups 74.

[0119] Hook 74F is, for example, a 135-degree hook. Each hook 74F, when combined with adjacent outer shell PCa pieces 70, is hooked onto the outer connecting reinforcement bars 28 that are placed in the installation space S.

[0120] (action) Next, the operation of the third embodiment will be described.

[0121] As shown in Figures 13 and 14, according to the concrete column member 10 of this embodiment, the four outer shell PCa pieces 70 are arranged to surround the space 14. Filling concrete 16 is filled into this space 14. As a result, the four outer shell PCa pieces 70 are integrated via the filling concrete 16, and a concrete column member 10 is manufactured with the four outer shell PCa pieces 70 as the outer shell.

[0122] In this embodiment, the outer shell of the concrete column member 10 is formed by four outer shell PCa pieces 70. Therefore, when the outer shell PCa pieces 70 are installed in the carbonation curing tank, dead space is less likely to occur, and a pair of outer shell PCa pieces 70 can be efficiently installed in the carbonation curing tank. Thus, in this embodiment, the carbon dioxide fixation efficiency for the outer shell PCa pieces 70, i.e., the outer shell PCa member 12, can be increased.

[0123] Furthermore, by forming the outer shell of the concrete column member 10 with four outer shell PCa pieces 70, the specific surface area of ​​the outer shell PCa pieces 70 that come into contact with carbon dioxide is increased. Therefore, the carbon dioxide fixation efficiency for each outer shell PCa piece 70 can be further enhanced. Moreover, since each outer shell PCa piece 70 is made smaller, its transportability and lifting capabilities are improved.

[0124] Furthermore, adjacent outer shell PCa pieces 70 are joined together with their respective ends 70E butted against each other. This prevents leakage of the filling concrete 16 when it is filled into the space 14 surrounded by the four outer shell PCa pieces 70.

[0125] (Fourth embodiment) Next, a fourth embodiment will be described. In the fourth embodiment, components and the like that have the same configuration as in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0126] As shown in Figure 15, the concrete column member 10 according to the fourth embodiment includes a plurality of internal PCa pieces 80. The plurality of internal PCa pieces 80 are formed in a plate shape from precast concrete and are embedded in the filling concrete 16.

[0127] The concrete of each internal PCa piece 80 contains a carbon dioxide-fixing admixture, similar to that of the outer PCa shell member 12. Furthermore, each internal PCa piece 80 is cured in a carbonation curing tank, and carbon dioxide is fixed within each internal PCa piece 80.

[0128] Multiple internal PCa pieces 80 are arranged in a stacked state within the space 14 of the outer PCa member 12. Furthermore, the multiple internal PCa pieces 80 are positioned along the material axis of the outer PCa member 12 and are fitted between the inner surfaces 70B of opposing outer PCa pieces 70.

[0129] As shown in Figures 15 and 16, the internal PCa piece 80 has a plurality of through holes 82. The plurality of through holes 82 are circular holes that penetrate the internal PCa piece 80 in the thickness direction and are arranged at intervals in the material axis direction and width direction of the outer shell PCa member 12.

[0130] Multiple internal precast concrete (PCa) pieces 80 have multiple through-holes 82 formed at the same location. This connects the through-holes 82 of adjacent internal PCa pieces 80 when they are stacked. These through-holes 82 are filled with concrete 16. This enhances the integrity between the multiple internal PCa pieces 80 and the concrete 16.

[0131] Multiple grooves 84 are formed on the end face of the inner PCa piece 80 that faces the inner surface 70B of the outer PCa piece 70. The multiple grooves 84 extend in the thickness direction of the inner PCa piece 80 and are spaced apart in the material axis direction of the outer PCa member 12. These grooves 84 are filled with filling concrete 16. This enhances the integrity between the multiple inner PCa pieces 80 and the filling concrete 16.

[0132] (action) Next, the operation of the fourth embodiment will be described.

[0133] As shown in Figure 15, according to the concrete column member 10 of this embodiment, the internal PCa piece 80 is embedded in the filling concrete 16. A carbon dioxide fixing admixture is mixed into the concrete of this internal PCa piece 80. Therefore, by curing the internal PCa piece 80 in a carbonation curing tank, carbon dioxide is absorbed by the internal PCa piece 80. Thus, carbon dioxide emissions can be further reduced.

[0134] Furthermore, the internal PCa piece 80 has multiple through holes 82 and grooves 84 formed within it. By filling these through holes 82 and grooves 84 with filling concrete 16, the integrity between the internal PCa piece 80 and the filling concrete 16 can be enhanced.

[0135] (Modification of the fourth embodiment) Next, a modified example of the fourth embodiment will be described.

[0136] In the modified examples shown in Figures 17 and 18, two internal PCa pieces 80 are placed with a gap between them in the space 14 of the outer PCa member 12. This creates a space for the auxiliary reinforcement bars 86 between the two internal PCa pieces 80.

[0137] The secondary stirrups 86 are integrally provided with the outer PCa piece 70. These secondary stirrups 86 are straight reinforcing bars with hooks 86F at both ends, and the hook 86F at one end is embedded in the center of the outer PCa piece 70. This hook 86F at one end is hooked onto the main column reinforcement 72.

[0138] The secondary ties 86 extend from the inner surface 70B of the outer PCa piece 70 into the space 14. Here, the secondary ties 86 of the outer PCa piece 70, which are located on both sides of the thickness direction of the inner PCa piece 80, are lap-spliced ​​while inserted into the through holes 82 of each inner PCa piece 80.

[0139] On the other hand, the auxiliary reinforcement bars 86 of the outer shell PCa pieces 70, which are positioned on both sides in a direction perpendicular to the thickness direction of the inner PCa piece 80, are lap-spliced ​​and inserted between adjacent inner PCa pieces 80.

[0140] By providing auxiliary reinforcement bars 86 to the outer PCa piece 70 in this manner, the integrity of the outer PCa piece 70, the inner PCa piece 80, and the filling concrete 16 can be enhanced.

[0141] (Fifth embodiment) Next, a fifth embodiment will be described. In the fifth embodiment, components and the like that have the same configuration as in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0142] As shown in Figures 19 and 20, the concrete column member 10 according to the fifth embodiment comprises a first outer shell PCa piece 90 and a pair of outer shell PCa pieces (hereinafter referred to as "second outer shell PCa pieces") 70.

[0143] The first outer shell PCa piece 90 is a PCa member formed by integrating a pair of opposing outer shell PCa pieces 70 (see Figure 13). Specifically, the first outer shell PCa piece 90 is formed in an H shape. Furthermore, the first outer shell PCa piece 90 is formed of concrete mixed with a carbon dioxide fixing admixture. This first outer shell PCa piece 90 has a pair of outer shell portions 90A and a connecting portion 90B.

[0144] The configuration of the pair of outer shell sections 90A is the same as that of the outer shell PCa piece 70. These pair of outer shell sections 90A are connected by a connecting section 90B. The connecting section 90B is formed in a wall shape and connects the central parts of the pair of outer shell sections 90A. Multiple through holes 92 are formed in this connecting section 90B.

[0145] Multiple through-holes 92 are circular holes that penetrate the connecting portion 90B in the thickness direction and are arranged at intervals. By filling these through-holes 92 with filling concrete 16, the unity between the first outer shell PCa piece 90 and the filling concrete 16 is enhanced.

[0146] A pair of second outer shell PCa pieces 70 are positioned opposite the connection portion 90B of the first outer shell PCa piece 90, closing the openings on both sides of the first outer shell PCa piece 90. The space 14 enclosed by the first outer shell PCa piece 90 and the second outer shell PCa piece 70 is then filled with concrete 16.

[0147] In this embodiment, two spaces 14 are formed on both sides of the connection portion 90B of the first outer shell PCa piece 90.

[0148] (action) Next, the operation of the fifth embodiment will be described.

[0149] As shown in Figures 19 and 20, according to the concrete column member 10 of this embodiment, the first outer shell PCa piece 90 and the second outer shell PCa piece 70 are arranged to surround the space 14. Filling concrete 16 is filled into this space 14. As a result, the first outer shell PCa piece 90 and the second outer shell PCa piece 70 are integrated via the filling concrete 16, and a concrete column member 10 is manufactured with the outer shell portion 90A of the first outer shell PCa piece 90 and the second outer shell PCa piece 70 as the outer shell.

[0150] Furthermore, the first outer shell PCa piece 90 is formed from concrete mixed with a carbon dioxide-fixing admixture. Therefore, by curing the first outer shell PCa piece 90 in a carbonation curing tank, carbon dioxide is fixed to the first outer shell PCa piece 90. Consequently, carbon dioxide emissions can be reduced.

[0151] Furthermore, in this embodiment, the outer shell of the concrete column member 10 is formed by the first outer shell PCa piece 90 and the pair of second outer shell PCa pieces 70. Therefore, when the first outer shell PCa piece 90 and the pair of second outer shell PCa pieces 70 are installed in the carbonation curing tank, dead space is less likely to occur, and multiple first outer shell PCa pieces 90 and the pair of second outer shell PCa pieces 70 can be efficiently installed in the carbonation curing tank.

[0152] (Modification of the fifth embodiment) Next, a modified example of the fifth embodiment will be described.

[0153] In the modified examples shown in Figures 21 and 22, the secondary stirrups 86 are embedded in the first outer shell PCa piece 90. The secondary stirrups 86 are embedded along the connection portion 90B of the first outer shell PCa piece 90, and hooks 86F provided at both ends are hooked onto the main column reinforcement 72 embedded in the outer shell portion 90A.

[0154] Furthermore, a pair of second outer shell PCa pieces 70 are integrally provided with auxiliary ties 86. The auxiliary ties 86 provided in the pair of second outer shell PCa pieces 70 are then inserted into through holes 92 formed in the connection portion 90B of the first outer shell PCa piece 90 and are joined together.

[0155] By providing auxiliary reinforcement bars 86 to the pair of second outer shell PCa pieces 70 in this manner, the integrity of the first outer shell PCa piece 90, the pair of second outer shell PCa pieces 70, and the filling concrete 16 can be enhanced.

[0156] (modified version) Next, modifications of the first to fifth embodiments described above will be explained. In the following, various modifications will be explained using the first embodiment as an example, but these modifications can be appropriately applied to the second to fifth embodiments described above.

[0157] In the first embodiment described above, the hook 26F of the tie reinforcement 26 is a 135-degree hook. However, the hook 26F of the tie reinforcement 26 is not limited to a 135-degree hook; for example, it could be a 90-degree hook or a 180-degree hook.

[0158] Furthermore, in the first embodiment described above, the pair of outer shell PCa pieces 20 have the same configuration (shape). However, the configuration (shape) of the pair of outer shell PCa pieces 20 is not limited to the same, and may be different.

[0159] Furthermore, in the first embodiment described above, a carbon dioxide-fixing admixture is incorporated into the concrete of each of the pair of outer shell PCa pieces 20. However, the carbon dioxide-fixing admixture can be incorporated into the concrete of at least one of the pair of outer shell PCa pieces 20.

[0160] Although one embodiment of the present invention has been described above, the present invention is not limited to these embodiments, and various modifications may be used in appropriate combinations with one embodiment, and of course, the invention can be implemented in various forms without departing from the spirit of the present invention. [Explanation of symbols]

[0161] 10 Concrete column members 14 Space 16. Filling concrete 20 outer shell PCa pieces 28 Peripheral connecting reinforcement 30 Carbonation Curing Tank 34 Central connecting muscle 80 internal PCa pieces

Claims

1. In a cross-sectional view, the outer shell PCa piece forms a part of the outer shell of a concrete column member, and the carbon dioxide fixing admixture is mixed into the concrete, and the carbon dioxide curing process involves curing the outer shell PCa piece in a carbon dioxide curing tank. A concrete filling step in which filling concrete is filled into the space surrounded by multiple outer shell PCa pieces, A method for manufacturing concrete column members, comprising the following features.

2. Concrete is mixed with a carbon dioxide-fixing admixture, and multiple outer shell PCa pieces are arranged to surround the space, The concrete filling the aforementioned space, A concrete column member equipped with the following features.

3. In a cross-sectional view, the four outer shell PCa pieces are arranged at each corner, In a cross-sectional view, four outer connecting bars are positioned adjacent to the ends of adjacent outer shell PCa pieces and embedded in the filling concrete, In a cross-sectional view, a central connecting reinforcement is positioned in the center of the space and embedded in the concrete filling, Equipped with, The outer shell PCa piece has two adjacent outer peripheral connecting reinforcements at both ends, and a rectangular annular band of reinforcement surrounding the central connecting reinforcement. The concrete column member according to claim 2.

4. The concrete is mixed with a carbon dioxide fixing admixture and includes internal precast concrete pieces embedded in the concrete. The concrete column member according to claim 2.

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