Wall construction method

Abstract

To provide a construction method of a wall body capable of suitably constructing the wall body even in the vicinity of an obstacle.SOLUTION: When a wall body having one surface facing the slope of the ground is constructed, one end of a shear reinforcing bar 32 is buried in a concrete panel 31, and a precast plate 3 having the shear reinforcing bar 32 projected from the concrete panel 31 in the out-of-plane direction is arranged so that the shear reinforcing bar 32 is projected to the opposite side of the slope. Thus, an outer shell part on the slope side of the wall body is formed of the concrete panel 31. The remainder of the wall thickness is then formed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] When constructing a reinforced concrete wall, the usual process involves assembling the rebar, assembling the formwork, pouring concrete into the formwork, and then removing the formwork after the concrete has hardened. However, this series of steps involves multiple different types of work, making the work complicated. In addition, there has been a shortage of skilled construction workers in recent years, with a particularly significant decline in the number of carpenters, and it is expected that it will become difficult to secure carpenter personnel in the future.

[0003] On the other hand, Patent Document 1 discloses that the outer shell of a structure is formed by spraying a spraying material such as mortar onto the side, and after the mortar hardens, concrete is poured inside the outer shell to construct the structure. This method makes construction easier by replacing conventional formwork with spraying, and also makes it possible to omit the work of removing the formwork.

[0004] Patent documents 2 and 3 also disclose a construction method in which a panel unit is manufactured by connecting a pair of concrete panels to be used as the inner and outer shell parts of the side wall of a box culvert, the panel unit is transported and installed at the construction site, and then concrete is poured between the concrete panels to construct the side wall of the box culvert. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7139234 [Patent Document 2] Patent No. 6902760 [Patent Document 3] Patent No. 6860167 Summary of the Invention [Problem to be solved by the invention]

[0006] In the method of Patent Document 1, if there is an obstacle near the structure, it may not be possible to ensure a space on the side of the outer shell portion for performing the spraying work on the outer shell portion.

[0007] The methods described in Patent Documents 2 and 3 do not require the spraying work described above, making construction easy even if there are obstacles near the structure. However, when the panel units are transported from a factory or the like on a truck or the like with the concrete panel surfaces upright, they must be made compact due to height restrictions during transportation, and many joints are required between the panel units during construction. Furthermore, when the concrete panels are transported with their surfaces laid horizontally, many holding members are required to connect the concrete panels together to prevent deformation of the concrete panels (especially the upper concrete panels) during transportation, which requires time and cost.

[0008] The present invention has been made in view of the above-mentioned problems, and has an object to provide a wall construction method and the like that allows a wall to be constructed suitably even near an obstacle. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the present invention is a method for constructing a wall, the method comprising: (a) a step in which one side of the wall faces an obstacle, one end of a rod-shaped reinforcing material is embedded in a concrete panel, and a precast plate with the reinforcing material protruding out of the surface of the concrete panel is arranged so that the reinforcing material protrudes on the opposite side of the obstacle, thereby forming an outer shell portion of the wall on the obstacle side using the concrete panel; and (b) a step in which, after forming the outer shell portion of the wall on the obstacle side, the remaining portion of the wall in the wall thickness direction is formed.

[0010] In this invention, a precast panel with one end of a rod-shaped reinforcing member embedded in a concrete panel is used to form the outer shell portion of the wall facing the obstacle, and then the remaining portion of the wall is formed. Using a precast panel as the outer shell portion of the wall facing the obstacle makes construction easy even when the wall is near an obstacle. Furthermore, since rod-shaped reinforcing members such as rebars and separators are already attached to the concrete panel, the effort required to place the reinforcing members is eliminated. Furthermore, a precast panel with one end of the reinforcing member embedded in the concrete panel does not need to maintain its shape when the concrete panel is placed horizontally, and is easier to transport than a panel unit made up of two panels combined together.

[0011] In step (b), it is desirable to construct the wall by forming an outer shell portion of the wall opposite the obstacle, and then pouring concrete between the outer shell portions on both sides of the wall in the wall thickness direction. This allows the outer shell portion to be used as an embedded formwork when pouring concrete, eliminating the need to remove the formwork after the concrete has hardened.

[0012] The outer shell portion of the wall opposite the obstacle can be formed by spraying a spray material, or by extrusion molding using a 3D printer. It can also be formed by a precast concrete panel with through holes through which the other ends of the reinforcing members can pass. By these methods, the outer shell portion on the side opposite the obstacle of the wall can be easily formed.

[0013] The remaining portion of the wall body in the wall thickness direction may be entirely formed by spraying a spray material. This will make the construction of the wall even easier and is expected to shorten the process. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a wall construction method and the like that allows a wall to be constructed suitably even near an obstacle. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. [Figure 2] 1A to 1C are diagrams illustrating a method for constructing a wall 1. [Figure 3] A diagram showing precast plate 3. [Figure 4] An example of forming the outer shell part using a 3D printer 200. [Figure 5] FIG. [Figure 6] 1A to 1C are diagrams illustrating a method for constructing a wall 10. [Figure 7] A diagram showing precast plate 2a. [Figure 8] FIG. [Figure 9] 1A to 1C are diagrams illustrating a method for constructing a wall 100. [Figure 10] An example in which a finishing part 5 is provided on the inner surface of the spraying part 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0017] [First embodiment] Figure 1 shows a wall 1 constructed by a construction method according to a first embodiment of the present invention. This wall 1 is the side wall of a box culvert installed in an excavation section of ground 20, and is constructed on the box culvert base 30. A slope of the ground 20 exists near the wall 1 as an obstacle during construction, and one side of the wall 1 faces the slope.

[0018] The wall 1 has the outer shells (buried formwork) on both sides of the wall thickness direction, consisting of the sprayed portion 2 of the sprayed material 21 and the concrete panel 31 of the precast plate 3, and concrete 4 is filled between them. The wall thickness direction corresponds to the left-right direction in Figure 1.

[0019] The sprayed portion 2 is a plate-like portion formed by spraying the sprayed material 21. The sprayed material 21 is made of a cement-based solidifying material such as mortar. Vertical main reinforcements 23 are arranged inside the sprayed portion 2. The main reinforcements 23 are connected to reinforcing bars 301 in the base slab 30. The main reinforcements 23 and reinforcing bars 301 may be connected by any method or at any position, but here we show an example in which they are connected using mechanical joints 24 embedded in the lower end of the sprayed portion 2. Note that the main reinforcements 23 may not be arranged inside the sprayed portion 2, but may be arranged on the back side of the sprayed portion 2, i.e., in the concrete 4. Furthermore, the main reinforcements 23 and reinforcing bars 301 may not be separate entities, and the ends of the reinforcing bars 301 may be extended upward and used as the main reinforcements 23.

[0020] The precast plate 3 is a plate-shaped concrete panel (hereinafter simply referred to as a panel) 31 with one end of a shear reinforcement steel bar 32 embedded inside.

[0021] The shear reinforcement bar 32 is a rod-shaped reinforcing material that has an anchor 321 at one end embedded in the panel 31 and is arranged so as to protrude out of the plane of the panel 31. The anchor 321 is a widened portion of the main body of the shear reinforcement bar 32, and is also provided at the other end of the shear reinforcement bar 32.

[0022] Vertical main reinforcement bars 33 and sleeves 34 are also embedded inside the panel 31. The sleeve 34 is a tubular member that is placed so that its open end is exposed on the bottom surface of the panel 31, and the lower end of the main reinforcement bars 33 is inserted into its upper part. The protruding parts of the reinforcing bars 302 inside the base slab 30 are inserted into the lower part of the sleeve 34. The main reinforcement bars 33 and the reinforcing bars 302 are connected by filling the sleeve 34 with a filler such as mortar.

[0023] In this embodiment, distribution bars 41, 42 are arranged along the opposing surfaces of the spraying section 2 and the panel 31. The distribution bars 41, 42 are horizontal reinforcing bars that extend in the extension direction of the wall body 10 and are embedded in the concrete 4. The extension direction of the wall body 10 corresponds to the normal direction to the paper surface of FIG.

[0024] (2. Construction method of wall 1) 2A and 2B are diagrams illustrating a method for constructing the wall 1. In this embodiment, as shown in FIG. 2A, a base slab 30 is constructed in an excavated portion of the ground 20, and then a precast plate 3 is first placed on the slope side of the ground 20.

[0025] The precast panels 3 are fabricated in advance at a factory or other facility, and then transported to the construction site by truck or other vehicle with the panel 31 facing downwards and the panel surface lying horizontally as shown in Figure 3. They are then installed at the construction site. At this time, the protruding portions of the reinforcing bars 302 protruding from the base slab 30 are inserted into the lower portions of the sleeves 34, and the sleeves 34 are filled with filler to connect the reinforcing bars 302 and the main reinforcement bars 33 as described above. The precast panels 3 are also positioned so that the shear reinforcement bars 32 protrude inward. The "inside" refers to the side opposite the slope of the ground 20 in the wall thickness direction of the wall 1 (the interior side of the box culvert). The side of the slope of the ground 20 in the wall thickness direction of the wall 1 is sometimes referred to as the "outside."

[0026] Next, as shown in Figure 2(b), the placement of the distribution bars 41, 42 and the main reinforcement bars 23 is carried out as described above. In this embodiment, the outer shell portion of the wall 1 is formed in advance using precast plates 3, but the inner shell portion is not yet formed, allowing the placement of the distribution bars 41, 42 and the main reinforcement bars 23 inside the wall 1 with the inside open. This eliminates the need for cumbersome work in a narrow space, such as between the panels of the panel unit described above. In addition, one end of the shear reinforcement bars 32 is already attached to the panel 31, eliminating the need to place the shear reinforcement bars 32.

[0027] In this embodiment, a planar core material 22 is attached to the main reinforcement bars 23 and the distribution bars 41, and as shown in Fig. 2(c), the spraying material 21 is sprayed onto the core material 22 from the inside to form the sprayed portion 2. The other end of the shear reinforcement steel bar 32 is fixed in the sprayed portion 2 by an anchor 321.

[0028] A mesh member or the like can be used as the core material 22, but is not limited to this. Although the core material 22 may be left as is, in this embodiment, the core material 22 is removed after the sprayed material 21 has hardened, and concrete 4 is poured between the sprayed portion 2 and the panel 31 of the precast plate 3, which serve as an embedded formwork, to complete the wall 1 shown in Fig. 1. Because both ends of the shear reinforcement steel 32 are fixed to the sprayed portion 2 and the panel 31, the shear reinforcement steel 32 resists the lateral pressure of the concrete 4 when the concrete 4 is poured, and also functions as a separator (rod-shaped reinforcement material) that maintains the distance between the sprayed portion 2 and the panel 31.

[0029] As described above, in this embodiment, a precast plate 3 with one end of the shear reinforcement bar 32 embedded in the panel 31 is used to form the outer shell portion of the wall 1 on the slope side of the ground 20, and then the remaining portion of the wall 1 in the wall thickness direction is formed. Using the precast plate 3 as the outer shell portion on the slope side facilitates construction even when the wall 1 is near a slope, and further, because the shear reinforcement bar 32 is pre-attached to the panel 31, the effort of arranging the shear reinforcement bar 32 is eliminated. Furthermore, the precast plate 3 with one end of the shear reinforcement bar 32 embedded in the panel 31 does not need to maintain its shape when the panel surface of the panel 31 is laid horizontally, and is easier to transport than a panel unit made up of two panels combined together.

[0030] In addition, in this embodiment, the outer shell portion of the wall 1 opposite the slope can be easily formed by spraying the spraying material 21, and the work of removing the concrete 4 after it hardens can be omitted.

[0031] However, the present invention is not limited to the above embodiment. For example, the configuration of the precast panel 3 is not limited to the above and varies depending on the structure of the box culvert. For example, the height of the panel 31 may be made higher than the sprayed portion 2, and the ends of the main reinforcement 33 may protrude inward from the upper end of the panel 31 and be used to connect to the top slab of the box culvert. In this embodiment, shear reinforcement bars 32 are embedded in the panel 31. However, the ends of the shear reinforcement bars 32 within the panel 31 may be bent into a hook shape and anchored within the panel 31 instead of using anchors 321 that are wider than the panel body. Furthermore, in addition to the shear reinforcement bars 32, separators may be provided to resist the lateral pressure of the concrete 4 during pouring. Furthermore, the core material 22 may be attached to the shear reinforcement bars 32 in advance when the precast panel 3 is manufactured. This eliminates the need for on-site core installation.

[0032] In this embodiment, the outer shell portion on the inside of the wall 1 is formed by spraying a cement-based solidification material. However, the outer shell portion may also be formed by applying the cement-based solidification material to the core material 22 using a plastering method. As shown in FIG. 4, the outer shell portion may also be constructed by extrusion molding of a modeling material 21a using a 3D printer 200. A cement-based solidification material such as mortar can be used as the modeling material 21a. In these cases, compared to spraying a cement-based solidification material, loss of material due to rebound during spraying can be reduced.

[0033] Alternatively, the outer shell may be constructed using a self-supporting mortar molding method that allows for quick removal. Alternatively, the outer shell may be formed by pouring concrete between a pair of formwork and removing the formwork after the concrete has hardened. These methods also reduce material waste. As such, there are no particular limitations on the method for forming the outer shell, and any method that can be used for on-site construction is sufficient.

[0034] Furthermore, the wall 1 of this embodiment is the side wall of a box culvert facing the slope of an excavated portion of the ground 20, but the construction method of the present invention is applicable to any wall facing an obstacle.

[0035] Other examples of the present invention will be described below as second and third embodiments. The second and third embodiments will be described focusing on differences from the first embodiment, and similar configurations will be denoted by the same reference numerals in the drawings and will not be described again. Furthermore, the configurations described in each embodiment, including the first embodiment, can be combined as necessary.

[0036] [Second embodiment] (1.Wall 10) 5 is a diagram showing a wall 10 constructed by a construction method according to a second embodiment of the present invention. The wall 10 differs from the first embodiment mainly in that a precast plate 2a is used as the inner shell portion instead of the spraying section 2.

[0037] The precast plate 2a is a plate-shaped concrete panel (hereinafter simply referred to as the panel) 25 with recesses 27 and through holes 28. The vertical main reinforcement bars 23 are placed not inside the panel 25 but on the back side of the panel 25, i.e., in the concrete 4. The main reinforcement bars 23 are connected to reinforcing bars 301 in the base slab 30. The main reinforcement bars 23 and reinforcing bars 301 may be connected by any method or at any position, but here we show an example in which they are connected using mechanical joints 24 embedded in the lower end of the concrete 4. As with the above, the main reinforcement bars 23 and reinforcing bars 301 may not be separate bodies, and the ends of the reinforcing bars 301 may be extended upward and used as the main reinforcement bars 23.

[0038] The recess 27 is formed on the inner surface of the panel 25. The through-hole 28 is formed so as to penetrate between the recess 27 and the outer surface of the panel 25.

[0039] The inner end (the other end of the shear reinforcement bar 32) of the shear reinforcement bar 32 protruding from the panel 31 of the precast plate 3 is passed through the through hole 28. This end protrudes into the recess 27. Unlike the first embodiment, an anchor 321 is not formed at this end, and instead a nut 322 is fastened. The nut 322 is housed in the recess 27, and the recess 27 is filled with a hole filling material (not shown) such as mortar, thereby smoothing the inner surface of the panel 25.

[0040] (2. Construction method of wall 10) Figure 6 is a diagram illustrating a method for constructing a wall 10. In this embodiment, as shown in Figure 6(a), a base slab 30 is constructed in an excavated portion of the ground 20, and then a precast plate 3 is installed on the slope side of the ground 20, as in the first embodiment. Then, as shown in Figure 6(b), distribution bars 41, 42 and main reinforcement bars 23 are arranged, and a precast plate 2a is installed at a distance inward from the panel 31 of the precast plate 3, as shown in Figure 6(c).

[0041] The precast plate 2a is fabricated in advance at a factory or the like, and is transported to the construction site by truck or the like with the plate surface laid horizontally as shown in Figure 7, and then installed at the construction site. At this time, the inner ends of the shear reinforcement bars 32 are passed through the through holes 28 of the panel 25 to protrude into the recesses 27, and nuts 322 are tightened to the protruding parts to fill the recesses 27. Thereafter, the panels 25, 31 of the precast plates 2a, 3 are used as buried formwork, and concrete 4 is poured between them to complete the wall 10 shown in Figure 5.

[0042] In this embodiment, the same effects as in the first embodiment can be achieved by using precast plates 3 with one end of shear reinforcement bars 32 embedded in the panels 31 to form the outer shell portion of the wall 10, and then forming the remaining portion of the wall 10 in the wall thickness direction. Furthermore, in this embodiment, the inner shell portion of the wall 10 can be easily formed using precast plates 2a, eliminating the need for demolding after pouring the concrete 4. Furthermore, by using precast plates 2a prefabricated in a factory or the like, on-site work can be further labor-saving. It is also possible to embed the main reinforcement bars 23 and the like in the panels 25 of the precast plates 2a in advance.

[0043] [Third embodiment] 8 is a diagram showing a wall 100 constructed by a construction method according to a third embodiment of the present invention. The wall 100 differs from the first embodiment mainly in that the entire portion of the wall thickness direction, excluding the panel 31 of the precast plate 3, is formed by the sprayed portion 2 of the sprayed material 21. The anchors 321 at the inner ends of the shear reinforcement bars 32, the main reinforcement bars 23, the distribution bars 41, etc. are embedded in the inner part of the sprayed portion 2.

[0044] FIG. 9 is a diagram illustrating a method for constructing a wall 100. In this embodiment, as shown in FIG. 9(a), a base slab 30 is constructed in an excavated portion of the ground 20, and then a precast plate 3 is installed on the slope side of the ground 20, as in the first embodiment. Then, as shown in FIG. 9(b), main reinforcement 23 and distribution reinforcement bars 41, 42 are arranged. After this, the wall 100 is constructed by spraying a spray material 21 onto the inside of the panel 31 of the precast plate 3. The spray material 21 can be concrete with an added quick-setting agent, but is not limited to this.

[0045] In this embodiment, too, the same effect as in the first embodiment can be obtained by using precast plates 3 with one end of shear reinforcement bars 32 embedded in panels 31 to form the outer shell portion of the wall body 100, and then forming the remaining portion in the wall thickness direction of the wall body 100. Furthermore, in this embodiment, there is no need to independently construct the inner shell portion of the wall body 100, which further simplifies the construction of the wall body 100 and is expected to reduce the process compared to the first and second embodiments.

[0046] As shown in Fig. 10, a spraying material may be separately sprayed onto the inner surface of the spraying section 2 to form a finishing section 5. This spraying material may be a different material from the above, such as mortar without the addition of an accelerator, but is not limited to this.

[0047] Furthermore, instead of constructing the wall 100 by spraying the spraying material 21, the wall may be constructed by pouring concrete. In this case, a formwork is installed at a position that corresponds to the inner surface of the wall, and concrete is poured between the formwork and the panel 31. This allows the remaining part of the wall, excluding the panel 31, to be formed. The formwork is removed after the concrete has hardened.

[0048] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications or alterations within the scope of the technical ideas disclosed herein, and it is understood that these modifications also fall within the technical scope of the present invention. [Explanation of symbols]

[0049] 1, 10, 100: Wall 2: Spraying section 2a, 3: Precast plate 4: Concrete 20: Ground 21: Sprayed material 22: Core material 25, 31: Concrete panels 28:Through hole 32: Shear reinforcement bars 200:3D printer

Claims

1. 1. A method of constructing a wall, comprising: One surface of the wall faces the obstacle, a step (a) of embedding one end of a rod-shaped reinforcing material in a concrete panel, and arranging a precast plate with the reinforcing material protruding out of the surface of the concrete panel so that the reinforcing material protrudes on the opposite side of the obstacle, thereby forming an outer shell portion of the wall body on the obstacle side using the concrete panel; a step (b) of forming the remaining part of the wall body in the wall thickness direction after forming the outer shell part of the wall body on the obstacle side; A method for constructing a wall, comprising:

2. 2. A method for constructing a wall according to claim 1, characterized in that in step (b), the wall is constructed by forming an outer shell portion of the wall opposite the obstacle, and then pouring concrete between the outer shell portions on both sides of the wall in the wall thickness direction.

3. 3. The method for constructing a wall according to claim 2, wherein the outer shell portion of the wall opposite the obstacle is formed by spraying a spraying material.

4. The method for constructing a wall according to claim 2, characterized in that the outer shell portion of the wall opposite the obstacle is formed by extrusion molding using a 3D printer.

5. A method for constructing a wall as described in claim 2, characterized in that the outer shell portion of the wall opposite the obstacle is formed from a precast plate having a concrete panel with a through hole through which the other end of the reinforcing material can pass.

6. 2. The method for constructing a wall according to claim 1, wherein the remaining portion of the wall in the wall thickness direction is entirely formed by spraying a spraying material.

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