Construction method of concrete wall body and concrete wall body

Abstract

To provide a construction method of a concrete wall body capable of easily constructing a reinforced concrete wall body using a 3D printer and appropriately providing a reinforcing bar cover of the wall body.SOLUTION: A method for constructing a concrete wall body 1 comprises the steps of laminating a cement-based material by a nozzle 62 of a 3D printer 60 to mold a first wall part 10, placing a reinforcing cage 30 on an inner surface side of the first wall part 10, laminating the cement-based material by the nozzle 62 at a position facing the inner surface of the first wall part 10 to mold a second wall part 20, and filling a filling material between the first wall part 10 and the second wall part 20. In the step of shaping the second wall part 20, the nozzle 62 is inclined so that the upper part of the nozzle 62 is farther from the inner surface of the first wall part 10 than the lower end part of the nozzle 62.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a method for constructing a concrete wall and a concrete wall. [Background technology]

[0002] Various techniques have been proposed for constructing concrete structures by layering cement-based materials using 3D printers to create structures. Non-Patent Document 1 describes a method in which a cement-based material is layered using a 3D printer installed in a factory to form a frame, which is then placed around reinforcing bars installed at the construction site, and the space surrounded by the frame is filled with a cement-based filler. Patent Document 1 shows that two laminated bodies are created on either side of a reinforcing bar installed at a construction site using a 3D printer, and a wall is constructed by filling the space between the two laminated bodies with mortar. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-93205 A [Non-patent literature]

[0004] [Non-Patent Document 1] Shimizu Corporation, Utilizing 3D printing technology to build large-scale concrete columns with free-form shapes, [Searched on August 29, 2023], Internet<URL:https: / / www.shimz.co.jp / company / about / news-release / 2021 / 2020053.html> Summary of the Invention [Problem to be solved by the invention]

[0005] In the method of constructing a structure shown in Non-Patent Document 1, it is necessary to transport a frame from a factory to a construction site, and it is also necessary to connect and assemble a plurality of frame bodies at the construction site. In the wall construction method shown in Patent Document 1, the nozzle of the 3D printer is placed far away from the rebar to form the laminate so that it does not come into contact with the rebar installed at the construction site. This makes it difficult to properly cover the rebar in the wall, and is particularly unsuitable for constructing thin walls. The present invention aims to solve the above-mentioned problems and to provide a method for constructing a concrete wall, which can easily construct a reinforced concrete wall using a 3D printer, can provide appropriate rebar cover for the wall, and can also construct a wall with a thin wall thickness. [Means for solving the problem]

[0006] In order to solve the above problems, the first invention is a method for constructing a concrete wall, comprising a first wall forming step of stacking cementitious material discharged from a nozzle of a 3D printer to form a first wall, a reinforcing bar installation step of arranging reinforcing bars on the inner surface side of the first wall, a second wall forming step of stacking the cementitious material discharged from the nozzle at a position facing the inner surface of the first wall to form a second wall, and a filling step of filling a filler between the first wall and the second wall. In the second wall forming step, the cementitious material is discharged from the lower end of the nozzle in a state in which the nozzle is tilted so that a portion above the lower end of the nozzle is separated from the inner surface of the first wall, and the cementitious material is stacked.

[0007] In the method of constructing a concrete wall of the first invention, the first wall section, the reinforcing bar, and the second wall section are constructed in that order from back to front when viewed from the 3D printer, making it easy to construct a reinforced concrete wall using a 3D printer. In addition, in the method for constructing a concrete wall of the first invention, the reinforcing bar is placed after the first wall portion is formed, so that the distance between the first wall portion and the reinforcing bar can be appropriately set. In addition, when forming the second wall portion, the nozzle is tilted, so that the distance between the second wall portion and the reinforcing bar can be appropriately set while avoiding contact between the nozzle and the reinforcing bar. Therefore, in the method for constructing a concrete wall of the first invention, the reinforcing bar cover of the wall can be appropriately provided, and even a wall with a thin wall thickness can be constructed. In the second wall forming process, if the nozzle is tilted so that the upper surface of the layer of cement-based material is inclined downward at an angle of between 10 degrees and 30 degrees with respect to the horizontal plane when viewed from the first wall side, the cement-based material can be layered stably. In addition, as long as contact between the nozzle and the reinforcing bar can be avoided, the inclination angle of the upper surface of the layer of cement-based material does not need to be uniform over the entire second wall portion. In other words, the cement-based material may be layered while changing the inclination angle of the nozzle.

[0008] In the above-mentioned method for constructing a concrete wall, it is preferable to provide a separator connecting the first wall portion and the second wall portion before filling the gap between the first wall portion and the second wall portion with a filler material, which can prevent the gap between the first wall portion and the second wall portion from changing due to pressure from the filler material. When the separator is configured by connecting parts called peakons connected to both ends of a rod-shaped part, in the first wall portion forming process, a first connecting part is sandwiched between each layer as the cement-based material is stacked, and in the second wall portion forming process, a second connecting part is sandwiched between each layer as the cement-based material is stacked, and the first connecting part and the second connecting part are connected by a rod-shaped part. In addition, when the separator is configured such that both ends of a rod-shaped part are inserted into holes in the wall body and the ends of the rod-shaped parts are assembled to the holes using fixing members such as nuts, in the first wall forming process, a first hole is formed between each layer while stacking the cement-based material, and in the second wall forming process, a second hole is formed between each layer while stacking the cement-based material, and both ends of the rod-shaped part are inserted into the first hole and the second hole, respectively, to assemble them.

[0009] In the first wall forming step, side plate portions protruding from an inner surface of the first wall portion are formed on both lateral edges of the first wall portion, respectively, in the second wall forming step, both lateral edges of the second wall portion are connected to the both side plate portions, respectively, and in the filling step, the filler material may be filled into the space surrounded by the first wall portion and the second wall portion. With this configuration, it is easy to fill the filler material between the first wall portion and the second wall portion.

[0010] In the first wall forming step, a supporting reinforcing bar may be sandwiched between each layer of the cementitious material while stacking the layers, and one end of the supporting reinforcing bar may be protruded from the inner surface side of the first wall. In this configuration, in the reinforcing bar installation step, the reinforcing bar is assembled to the supporting reinforcing bar, which makes it easier to arrange the reinforcing bar on the inner surface side of the first wall.

[0011] In order to solve the above problem, the second invention is a concrete wall comprising a first wall portion, a second wall portion arranged in a position facing the inner surface of the first wall portion, a reinforcing bar arranged between the first wall portion and the second wall portion, and a filler filled between the first wall portion and the second wall portion. The first wall portion and the second wall portion are formed by stacking cement-based materials. In the second wall portion, the cement-based material is stacked with the upper surface of the layer of the cement-based material inclined downward with respect to the horizontal plane when viewed from the first wall portion side.

[0012] When constructing the concrete wall of the second invention using a 3D printer, the first wall section, the reinforcing bar, and the second wall section can be constructed from back to front when viewed from the 3D printer, making it easy to construct a reinforced concrete wall using a 3D printer. Furthermore, when constructing the concrete wall of the second invention using a 3D printer, the first wall portion is formed, and then the reinforcing bar is placed, so that the distance between the first wall portion and the reinforcing bar can be appropriately set. Furthermore, when forming the second wall portion, the nozzle of the 3D printer is tilted, so that the distance between the second wall portion and the reinforcing bar can be appropriately set while avoiding contact between the nozzle and the reinforcing bar. Therefore, in the concrete wall of the second invention, the reinforcing bar cover of the wall can be appropriately provided, and even a wall with a thin wall thickness can be constructed. When the upper surface of the layer of the cementitious material of the second wall portion is inclined downward at an angle between 10 degrees and 30 degrees with respect to the horizontal plane as viewed from the first wall portion, the cementitious material can be stacked stably. Note that the inclination angle of the upper surface of each layer of the cementitious material does not need to be uniform throughout the entire second wall portion.

[0013] In the above-mentioned concrete wall structure, it is preferable that one end of a rod-shaped part is sandwiched between each layer of the cementitious material of the first wall portion, and the other end of the rod-shaped part is sandwiched between each layer of the cementitious material of the second wall portion. With this configuration, when filler is filled between the first wall portion and the second wall portion during the process of constructing a concrete wall, it is possible to prevent the distance between the first wall portion and the second wall portion from changing due to pressure from the filler. Effect of the Invention

[0014] In the concrete wall construction method and concrete wall of the present invention, by constructing the first wall section, the reinforcing bar, and the second wall section in that order, it becomes easier to construct a reinforced concrete wall using a 3D printer, and the reinforcing bar cover of the wall can be properly provided, making it possible to construct walls with thin wall thicknesses. [Brief description of the drawings]

[0015] [Figure 1]FIG. 2 is a perspective view showing a wall according to an embodiment of the present invention. [Diagram 2] 1 is a side cross-sectional view showing a wall according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a perspective view showing a foundation installation step according to an embodiment of the present invention. [Figure 4] 6A to 6C are side cross-sectional views showing a first wall portion forming step according to an embodiment of the present invention. [Diagram 5] FIG. 11 is a perspective view showing a first wall portion forming step according to an embodiment of the present invention. [Figure 6] 10A to 10C are cross-sectional plan views showing a first wall portion forming step according to an embodiment of the present invention. [Figure 7] FIG. 2 is a perspective view showing a reinforcing bar installation process according to an embodiment of the present invention. [Figure 8] FIG. 4 is a side cross-sectional view showing a reinforcing bar installation process according to an embodiment of the present invention. [Figure 9] 10A to 10C are side cross-sectional views showing a second wall portion forming step according to an embodiment of the present invention. [Figure 10] 11 is a side cross-sectional view showing a state in which a separator is installed in a second wall portion forming process according to an embodiment of the present invention. FIG. [Figure 11] 4 is a flow chart of a method for constructing a wall according to an embodiment of the present invention. [Figure 12] 10A to 10C are side cross-sectional views showing a first wall portion forming step according to a modified example of the embodiment of the present invention. [Figure 13] 13 is a side cross-sectional view showing a state in which a separator is installed in a second wall portion forming process according to a modified example of an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a wall body according to an embodiment of the present invention. As shown in Figure 1, the wall 1 of this embodiment comprises a foundation portion 50, a first wall portion 10, a second wall portion 20, a reinforcing bar cage 30 arranged between the first wall portion 10 and the second wall portion 20, and filling material 40 filled between the first wall portion 10 and the second wall portion 20. FIG. 3 is a perspective view showing a foundation part installation step according to the embodiment of the present invention. As shown in Fig. 3, the foundation 50 is a concrete block that is placed on the ground and extends in the horizontal direction. A plurality of foundation rebars 51 protrude from the upper surface of the foundation 50. The foundation rebars 51 are disposed in the middle in the front-to-rear direction of the upper surface of the foundation 50, and the plurality of foundation rebars 51 are disposed at intervals in the horizontal direction.

[0017] FIG. 5 is a perspective view showing a first wall portion forming step according to the embodiment of the present invention. 5, the first wall portion 10 is erected on the upper surface of the foundation portion 50. The first wall portion 10 is formed with a wall plate portion 11 erected on the rear edge portion of the upper surface of the foundation portion 50, and two side plate portions 12, 12 protruding forward from both lateral edges of the inner surface of the wall plate portion 11. The side plate portions 12 are erected on the lateral edges of the upper surface of the foundation portion 50. FIG. 4 is a side cross-sectional view showing a first wall portion forming step according to an embodiment of the present invention. 4, the first wall portion 10 is formed by layering cement-based materials using a 3D printer 60. The cement-based material is a hydraulic material such as a mortar material or concrete material kneaded with a hydraulic binder, aggregate such as sand, fiber, various admixtures, water, etc. Based on the shape data of the first wall portion 10, the 3D printer 60 forms the first wall portion 10 by repeatedly moving the nozzle 62 along the contour of the first wall portion 10, ejecting cement-based material from the lower end of the nozzle 62, and layering the cement-based material. FIG. 2 is a cross-sectional side view showing a wall according to an embodiment of the present invention. In the first wall portion 10, the cementitious material is layered so that the upper surface of each layer of the cementitious material is horizontal, as shown in Fig. 2. In addition, in the first wall portion 10 of the present embodiment, the cementitious material is layered twice on the inside and outside.

[0018] In this embodiment, a plurality of protrusions 13 extending in the vertical direction are formed at intervals in the horizontal direction on the inner surface of the wall plate portion 11 of the first wall portion 10 as shown in Fig. 5. A plurality of supporting reinforcing bars 15 extending in the front-rear direction are provided at intervals in the vertical direction on the protrusions 13. FIG. 6 is a cross-sectional plan view showing a first wall portion forming step according to an embodiment of the present invention. 6, the tip end of the supporting rebar 15 protrudes from the inner surface of the first wall portion 10, and the base end is embedded in the protruding portion 13. The base end of the supporting rebar 15 is fixed by being inserted into the protruding portion 13 before the cement-based material hardens.

[0019] 1, the second wall portion 20 is erected on the front edge portion of the upper surface of the base portion 50. Both lateral edges of the second wall portion 20 are connected to both side plate portions 12, 12 of the first wall portion 10, respectively. FIG. 9 is a side cross-sectional view showing a second wall portion forming step according to an embodiment of the present invention. As shown in FIG. 9, the second wall portion 20 is formed by layering cement-based materials using a 3D printer 60. Based on the shape data of the second wall portion 20, the 3D printer 60 repeatedly moves the nozzle 62 along the contour of the second wall portion 20, ejecting cement-based material from the outlet at the lower end of the nozzle 62, and layering the cement-based material to form the second wall portion 20. 2, in the second wall portion 20, the upper surface of each layer of the cementitious material is inclined downward with respect to the horizontal plane when viewed from the first wall portion 10 side (rear side). In other words, the upper and lower surfaces of each layer of the cementitious material of the second wall portion 20 are inclined so that the outer surface side of the second wall portion 20 is lower than the inner surface side. In this embodiment, the upper surface of each layer of the cementitious material of the second wall portion 20 is inclined downward at an angle between 10 degrees and 30 degrees with respect to the horizontal plane when viewed from the first wall portion 10 side.

[0020] FIG. 7 is a perspective view showing a reinforcing bar installation process according to an embodiment of the present invention. 1, the reinforcing bar cage 30 is a reinforcing member made by combining a plurality of reinforcing bars (see FIG. 7). The reinforcing bar cage 30 is disposed within an area surrounded by the first wall portion 10 and the second wall portion 20. As shown in Figure 7, the reinforcing bar cage 30 is connected to each foundation reinforcing bar 51 protruding from the upper surface of the foundation portion 50, and is assembled to a plurality of supporting reinforcing bars 15 (see Figure 6) protruding from the inner surface of the first wall portion 10. As shown in Fig. 1, a filler 40, which is a cement-based material, is filled in an area surrounded by a foundation portion 50, a first wall portion 10, and a second wall portion 20 (see Fig. 2). A reinforcing bar cage 30 is embedded in the filler 40.

[0021] FIG. 10 is a side cross-sectional view showing a state in which a separator is installed in the second wall portion forming step according to the embodiment of the present invention. In this embodiment, when constructing the wall body 1, a plurality of separators 70 for maintaining a distance between the first wall portion 10 and the second wall portion 20 are provided as shown in FIG. The separator 70 includes a rod-shaped part 73, a first connecting part 71 connected to one end of the rod-shaped part 73, and a second connecting part 72 connected to the other end of the rod-shaped part 73. The first connecting part 71 and the second connecting part 72 are parts having a truncated cone shape called a peakon (P-cone). The first connecting part 71 and the second connecting part 72 are screwed to the end of the rod-shaped part 73, and can be removed from the outer surface side of the first wall part 10 or the second wall part 20 with respect to the rod-shaped part 73. The first connecting part 71 is embedded in the first wall portion 10 by being sandwiched between layers of cement-based material during lamination when the first wall portion 10 is formed. At this time, the inner end surface and the outer end surface of the first connecting part 71 are exposed to the outer surface of the first wall portion 10. The second connecting part 72 is embedded in the second wall portion 20 by being sandwiched between layers of the cement-based material during lamination when the second wall portion 20 is formed. At this time, the inner end surface and the outer end surface of the second connecting part 72 are exposed to the outer surface of the second wall portion 20. The rod-shaped part 73 is a member that connects the first connecting part 71 and the second connecting part 72. Before filling the space between the first wall part 10 and the second wall part 20 with the filler 40 (see FIG. 2), both ends of the rod-shaped part 73 are attached to the first connecting part 71 and the second connecting part 72. 2, after the filler 40 filled between the first wall portion 10 and the second wall portion 20 has hardened, the first connecting part 71 and the second connecting part 72 are detached from the rod-shaped part 73 and pulled out from the first wall portion 10 and the second wall portion 20. The recesses formed in the outer surfaces of the first wall portion 10 and the second wall portion 20 are filled with mortar.

[0022] Next, a method for constructing the wall 1 of this embodiment will be described. Fig. 11 is a flowchart of the method for constructing the wall according to the embodiment of the present invention. In the following description, the flowchart in Fig. 11 will be referred to as appropriate. (Foundation installation process) First, the foundation 50 shown in Fig. 3 is placed on the ground (step S1). The foundation 50 may be formed by placing a formwork on the ground and filling the formwork with a cement-based material, or the foundation 50 may be made in a factory and transported to the construction site. (First wall modeling process) As shown in Fig. 4, a 3D printer 60 is installed in front of the foundation 50 (step S2). The 3D printer 60 has a robot arm 61, and a nozzle 62 is attached to the tip of the robot arm 61. A hose 63 extending from a cement supply device (not shown) is connected to the upper end of the nozzle 62. In the first wall portion forming process, an extension member 64 is provided between the robot arm 61 and the nozzle 62. The extension member 64 extends rearward from the tip of the robot arm 61. The upper end of the nozzle 62 is connected to the rear end of the extension member 64. This allows the nozzle 62 to be positioned rearward of the foundation reinforcing bar 51. FIG. 8 is a side cross-sectional view showing a reinforcing bar installation process according to an embodiment of the present invention. The 3D printer 60 ejects the cementitious material from the lower end of the nozzle 62 while repeatedly moving the nozzle 62 along the contour of the first wall portion 10, and layers the cementitious material to form the first wall portion 10 (step S3). In this embodiment, as shown in Fig. 8, the cementitious material is layered twice, inside and outside, so that the first wall portion 10 can be stably erected. In the first wall forming process, as shown in FIG. 6, a first connecting part 71 is sandwiched between each layer as the cementitious material is being stacked, and the base end portion of the supporting rebar 15 is inserted and fixed before the cementitious material hardens (step S3).

[0023] (Reinforcing bar installation process) After the first wall 10 is formed on the top surface of the foundation 50, the reinforcing bar cage 30 is placed on the inner surface side of the first wall as shown in Fig. 7 (step S4). The reinforcing bar cage 30 is connected to each foundation reinforcing bar 51 and is supported by being assembled to each supporting reinforcing bar 15. In addition, as shown in Fig. 9, one end of a rod-shaped part 73 is screwed and connected to the first connecting part 71 (step S4). (Second wall forming process) On the upper surface of the foundation portion 50, facing forward against the inner surface of the first wall portion 10 and in front of the reinforcing bar cage 30, a nozzle 62 of a 3D printer 60 is repeatedly moved along the contour of the second wall portion 20 while ejecting cement-based material from the lower end of the nozzle 62, thereby layering the cement-based material. In the second wall portion forming process, the upper end of the nozzle 62 is directly connected to the tip of a robot arm 61 (see FIG. 4) of a 3D printer 60. In addition, in the second wall portion forming process, the nozzle 62 is inclined so that the upper part of the nozzle 62 is away from the inner surface of the first wall portion 10 relative to the lower end of the nozzle 62. In this manner, when the nozzle 62 is tilted and the cement-based material is ejected from the lower end of the nozzle 62 and the cement-based material is layered, the upper surface of each layer of the cement-based material is inclined downward with respect to the horizontal plane when viewed from the first wall portion 10 side (rear). In this embodiment, the upper surface of each layer of cementitious material is inclined downward at an angle between 10 degrees and 30 degrees with respect to the horizontal plane when viewed from the first wall portion 10 side. Then, the second wall portion 20 is formed by stacking a cement-based material in front of the reinforcing bar cage 30 (step S5). As shown in Fig. 1, both lateral edges of the second wall portion 20 are connected to both side plate portions 12, 12 of the first wall portion 10. As a result, a cylindrical frame is formed on the upper surface of the foundation portion 50 by the first wall portion 10 and the second wall portion 20.

[0024] In the second wall forming step, as shown in Fig. 9, when the height of the first connecting part 71 of the first wall 10 is reached during the process of forming the second wall 20 by stacking the cement-based material, the second connecting part 72 is sandwiched between each layer. Furthermore, the other end of the rod-shaped part 73 is screwed into the second connecting part 72 to connect them (step S5). As a result, the first connecting part 71 and the second connecting part 72 are connected by the rod-shaped part 73 as shown in Fig. 10. In this way, a plurality of separators 70 are provided in the first wall 10 and the second wall 20. Note that one end of the rod-shaped part 73 may be attached to the first connecting part 71 in the first wall portion forming process, and the other end of the rod-shaped part 73 may be attached to the second connecting part 72 in the second wall portion forming process.

[0025] (filling process) As shown in FIG. 2, the space surrounded by the first wall portion 10 and the second wall portion 20 is filled with the filler 40 from above (step S6). After the filler 40 has hardened, the first connecting part 71 shown in Fig. 10 is pulled while being rotated relative to the rod-shaped part 73 from the outside of the first wall part 10, and the first connecting part 71 is pulled out and removed from the first wall part 10. Also, the second connecting part 72 is pulled out and removed from the second wall part 20 from the outside of the second wall part 20 while being rotated relative to the rod-shaped part 73 (step S7). Thereafter, as shown in FIG. 2, the recesses formed in the outer surface of the first wall portion 10 and the recesses formed in the outer surface of the second wall portion 20 are filled with mortar 1a (step S7). In this manner, the reinforced concrete wall 1 shown in FIG. 1 is constructed using the 3D printer 60 (see FIG. 4).

[0026] In the above-described concrete wall 1 and construction method for the wall 1, the first wall section 10, the reinforced concrete cage 30, and the second wall section 20 are constructed in this order from the back to the front when viewed from the 3D printer 60, as shown in FIG. 9, so that the reinforced concrete wall 1 can be easily constructed by the 3D printer 60. In the wall 1 and the method for constructing the wall 1 of this embodiment, as shown in Fig. 7, the reinforcing bar cage 30 is placed after the first wall portion 10 is formed, so that the distance between the first wall portion 10 and the reinforcing bar cage 30 can be appropriately set. In addition, as shown in Fig. 9, when forming the second wall portion 20, the nozzle 62 is tilted, so that the distance between the second wall portion 20 and the reinforcing bar cage 30 can be appropriately set while avoiding contact between the nozzle 62 and the reinforcing bar cage 30. Therefore, in the wall 1 and the method for constructing the wall 1 of this embodiment, as shown in Fig. 2, the reinforcing bar cover of the wall 1 can be appropriately provided, and even a wall 1 with a thin wall thickness can be constructed. Furthermore, in the wall 1 and the method for constructing the wall 1 of this embodiment, the upper surface of each layer of cement-based material is inclined downward at an angle of between 10 degrees and 30 degrees with respect to the horizontal plane when viewed from the first wall portion 10 side, so that the cement-based material can be stacked stably.

[0027] In the wall 1 and the method for constructing the wall 1 of this embodiment, when the first wall portion 10 is formed, the supporting rebars 15 are protruded from the inner surface side of the first wall portion 10, as shown in Fig. 6. Then, when the reinforcing bar cage 30 is arranged on the inner surface side of the first wall portion 10, the reinforcing bar cage 30 can be easily arranged in the correct position on the inner surface side of the first wall portion 10 by assembling the reinforcing bar cage 30 to each supporting reinforcing bar 15, as shown in Fig. 7. Furthermore, in the wall 1 and the construction method of the wall 1 of this embodiment, as shown in FIG. 2, the filler 40 is filled into the space surrounded by the first wall portion 10 and the second wall portion 20, so that the filler 40 can be easily filled between the first wall portion 10 and the second wall portion 20. Furthermore, in the wall 1 and the method for constructing the wall 1 of this embodiment, a separator 70 (see FIG. 10) that connects the first wall portion 10 and the second wall portion 20 is provided before filling the filler 40 between the first wall portion 10 and the second wall portion 20. This makes it possible to prevent the gap between the first wall portion 10 and the second wall portion 20 from changing due to the pressure from the filler 40 when filling the space between the first wall portion 10 and the second wall portion 20 with the filler 40.

[0028] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit of the present invention. In this embodiment, the first wall portion 10 is formed by laminating the cementitious material in two layers on the inside and outside as shown in Fig. 2, but the first wall portion 10 may be formed by laminating the cementitious material in two or more layers on the inside and outside, or the first wall portion 10 may be formed by laminating the cementitious material in a single layer. Also, the second wall portion 20 may be formed by laminating the cementitious material in multiple rows on the inside and outside. 1, the first wall portion 10 is formed with the wall plate portion 11 and the side plate portion 12, but the side plate portion 12 does not necessarily have to be formed. Also, the second wall portion 20 may be formed with the side plate portion. Fig. 12 is a side cross-sectional view showing a modified first wall forming step according to an embodiment of the present invention. Fig. 13 is a side cross-sectional view showing a state in which a separator is installed in a modified second wall forming step according to an embodiment of the present invention. Another separator 70A is one that is made of a rod-shaped part 77 and two nuts 78, 78, as shown in FIG. 12. In this configuration, as shown in FIG. 12, in the first wall forming step, a rod-shaped insert member 74 made of resin, rubber, or metal is sandwiched between each layer during lamination of the cement-based material. As shown in FIG. 13, after the first wall 10 hardens, the insert member 74 is pulled out of the first wall 10 to form a first hole 75 in the first wall 10. Similarly, as shown in FIG. 12, a second hole 76 is formed in the second wall 20. Then, both ends of the rod-shaped part 77 are inserted into the first hole 75 and the second hole 76, respectively, and nuts 78 are screwed to the ends of the rod-shaped part 77 on the outer surface side of the first wall 10 and the outer surface side of the second wall 20, to connect both ends of the rod-shaped part 77 to the first wall 10 and the second wall 20, respectively. In this manner, the first wall portion 10 and the second wall portion 20 can be connected by the separator 70A. The wall body 1 may be constructed without providing the separator 70 shown in FIG. In this embodiment, as shown in FIG. 6, the supporting reinforcing bars 15 are provided in the first wall portion 10, but the supporting reinforcing bars 15 do not necessarily have to be provided. [Explanation of symbols]

[0029] 1 wall 10 First wall 11 Wall board section 12 Side plate part 13 Protrusion 15 Supporting steel bars 20 Second wall section 40 Filler 50 Foundation 51 Foundation Reinforcement 60 3D Printers 61 Robot Arm 62 Nozzle 63 Hose 64 Extension member 70 Separator 70A Separator 71 First connecting part 72 Second connection part 73 Rod-shaped parts 74 Insertion parts 75 First hole 76 Second hole 77 Rod-shaped parts 78 Nut

Claims

1. a first wall forming process for forming a first wall by stacking cement-based material discharged from a nozzle of a 3D printer; A reinforcing bar installation process for arranging a reinforcing bar on the inner surface side of the first wall portion; a second wall portion forming step of forming a second wall portion by stacking the cement-based material discharged from the nozzle at a position facing an inner surface of the first wall portion; and a filling step of filling a filler material between the first wall portion and the second wall portion, a second wall portion forming step of forming the second wall portion by ejecting the cement-based material from a lower end of the nozzle while tilting the nozzle so that a portion above the lower end of the nozzle is away from an inner surface of the first wall portion, thereby stacking the cement-based material.

2. 2. The method for constructing a concrete wall structure according to claim 1, wherein in the second wall portion forming process, an upper surface of the layer of cement-based material is inclined downward at an angle of between 10 degrees and 30 degrees with respect to a horizontal plane when viewed from the first wall portion side.

3. In the first wall portion forming step, a first connection part is sandwiched between each layer during stacking of the cement-based material; 2. The method for constructing a concrete wall structure according to claim 1, wherein in the second wall portion forming step, a second connecting part is sandwiched between each layer in the middle of stacking the cement-based material, and the first connecting part and the second connecting part are connected by a rod-shaped part.

4. In the first wall portion forming step, a first hole portion is formed between each layer during stacking of the cement-based material, 2. The method for constructing a concrete wall structure according to claim 1, wherein in the second wall forming process, a second hole portion is formed between each layer while stacking the cement-based material, and both ends of a rod-shaped part are inserted into the first hole portion and the second hole portion, respectively, to assemble the rod-shaped part.

5. In the first wall portion forming step, side plate portions protruding from an inner surface of the first wall portion are formed on both lateral edge portions of the first wall portion, In the second wall portion forming step, both lateral edge portions of the second wall portion are connected to the both side plate portions, 2. The method for constructing a concrete wall structure according to claim 1, wherein in the filling step, the filler is filled into a space surrounded by the first wall portion and the second wall portion.

6. In the first wall portion forming step, a supporting reinforcing bar is sandwiched between each layer during stacking of the cement-based material, and one end of the supporting reinforcing bar is made to protrude from the inner surface side of the first wall portion, 2. The method for constructing a concrete wall according to claim 1, wherein in the reinforcing bar installation step, the reinforcing bar is assembled to the supporting reinforcing bar.

7. A first wall portion; A second wall portion disposed at a position facing an inner surface of the first wall portion; A reinforcing bar disposed between the first wall portion and the second wall portion; A filler material is filled between the first wall portion and the second wall portion, The first wall portion and the second wall portion are formed by laminating cement-based materials, A concrete wall structure characterized in that in the second wall portion, the cement-based material is layered with an upper surface of the layer of the cement-based material inclined downward with respect to a horizontal plane when viewed from the first wall portion.

8. 8. The concrete wall structure according to claim 7, wherein in the second wall portion, an upper surface of the cementitious material layer is inclined downward at an angle of between 10 degrees and 30 degrees with respect to a horizontal plane when viewed from the first wall portion side.

9. One end of the rod-shaped part is sandwiched between the layers of the cementitious material of the first wall portion, 8. The concrete wall structure according to claim 7, wherein the other end of the rod-shaped part is sandwiched between each layer of the cementitious material of the second wall portion.

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