Formwork fixing mechanism and wall construction method

Abstract

To provide a formwork fixing mechanism and a wall construction method, etc., that can fix a formwork when filling joint filler material, can minimize interference with work on one side of a wall, and is easy to construct.SOLUTION: A formwork fixing mechanism 3 is used for constructing a liquid barrier sequentially from bottom to top by stacking precast blocks 10 vertically. Each precast block comprises a concrete block body 11 and a plate 12 provided on the inner surface of the block body 11 and projecting upward from the block body 11, in which the plate 12 is used as formwork, and joint filler is filled into the gap between the upper and lower precast blocks 10 to form a joint. The formwork fixing mechanism 3 fixes the plate 12 from the outside by utilizing a female threaded portion 31 provided on the outer surface of the plate 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a formwork fixing mechanism and a method for constructing a wall using the same. [Background technology]

[0002] Walls are sometimes constructed by arranging concrete precast blocks one above the other. For example, Patent Documents 1 and 2 describe an example of the construction of a dike for an LNG (Liquefied Natural Gas) tank, in which concrete precast blocks are arranged one above the other and a filler material is filled between the upper and lower precast blocks to form a joint. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5837118 [Patent Document 2] Patent No. 5837130 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Documents 1 and 2, plates attached to the precast blocks in advance are used as the inner formwork when filling the filler. If these plates bend inward toward the dike when filling the filler, there is a risk of the filler leaking to the inside.

[0005] To prevent this, it is possible to install a plate fixing jig inside the dike. However, the fixing jig becomes a protrusion on the inner surface of the dike, which interferes with construction work inside the dike (for example, air raising of a steel roof).

[0006] Even if the fixing jigs are removed after the joints are formed, removing them normally requires scaffolding inside the dike, which interferes with the equipment work inside the dike. This equipment work is mechanical work, and is a different type of work from the dike construction (civil engineering work), so from the perspective of shortening the construction period, it is desirable to carry out work related to the inner formwork in a way that interferes as little as possible with the equipment work inside the dike.

[0007] In this regard, Figure 15 of Patent Document 1 describes the use of screw steel extending outward from the plate to secure the plate to the outer formwork. However, in Patent Document 1, the precast block must be transported and installed with the long screw steel fixed to the plate, which poses a problem in terms of workability.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a formwork fixing mechanism and a wall construction method that can fix the formwork when filling the joints with filler, minimize interference with construction work on one side of the wall, and are easy to install. [Means for solving the problem]

[0009] The first invention for solving the above-mentioned problems is a formwork fixing mechanism used in constructing a wall from bottom to top by stacking precast blocks each having a concrete block body and a plate attached to one surface of the block body in the thickness direction and protruding upward from the block body, using the plate as a formwork, and filling the gaps between the upper and lower precast blocks with filler to form joints, characterized in that a female threaded portion for fixing the plate from the opposite side of the thickness direction of the block body is provided on the opposite surface of the plate, and the plate is fixed using the female threaded portion.

[0010] According to the present invention, when a plate of precast blocks is used as a formwork on one side and filler material is filled between the upper and lower precast blocks to form a joint, the plate can be fixed from the opposite side of the one side using the female threads, preventing deformation during filling. Furthermore, since the female threads are provided on the opposite side of the plate, the female threads can be prevented from interfering with construction work on one side of the wall, and the work of fixing the plate using the female threads does not interfere with construction work on the other side of the wall. Furthermore, the use of the female threads allows for the retrofitting of threaded steel for fixing the plate, facilitating construction.

[0011] It is desirable that the plate be fixed from the formwork located on the opposite side of the gap by threading the male screw at one end of a bar into the female screw portion and attaching the other end of the bar to the formwork located on the opposite side of the gap. For example, a recess carved upward into the block body is formed in part of the underside of the block body so as to continue in the thickness direction of the block body, and the female screw portion and the bar are placed within the recess of the block body of the upper precast block. This allows the plate on one side of the lower precast block to be fixed from the formwork on the opposite side, preventing deformation of the plate. The recessed portion also ensures space for the female threads and rods. Because the recessed portion is only provided on a portion of the underside of the block body, it also helps prevent an increase in the amount of filler material needed to fill the joints between the upper and lower precast blocks.

[0012] It is also desirable that the plate be fixed to the block body of the upper precast block by attaching a fixing piece provided on the underside of the block body of the upper precast block to the female threaded portion using a bolt screwed into the female threaded portion from the opposite side. For example, a recess carved upward into the block body is formed in part of the underside of the block body so as to continue in the thickness direction of the block body, and the female threaded portion and the fixing piece are positioned within the recess of the block body of the upper precast block. This allows the plate on one side of the lower precast block to be fixed to the block body of the upper precast block, preventing deformation of the plate. The recessed portion also ensures space for the female threads and fixing pieces. Because the recessed portion is only provided on a portion of the underside of the block body, it also prevents the amount of filler material filling between the upper and lower precast blocks from increasing.

[0013] The second invention is a method for constructing a wall, which comprises stacking precast blocks each having a concrete block body and a plate attached to one surface of the block body in the thickness direction and protruding upward from the block body, using the plate as a formwork to fill the gaps between the upper and lower precast blocks with filler to form joints, and then fixing the plate from the opposite side of the block body in the thickness direction using the formwork fixing mechanism of the first invention. [Effects of the Invention]

[0014] The present invention provides a formwork fixing mechanism and a wall construction method that can fix the formwork when filling the joints with filler, minimize interference with construction work on one side of the wall, and are easy to install. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing an LNG tank 100. FIG. [Figure 2] A diagram showing the liquid barrier 1. [Figure 3] A diagram showing block 10. [Figure 4] FIG. 2 is a diagram showing the formwork fixing mechanism 3 and the outer formwork 20. [Figure 5] FIG. 3 is a diagram showing a formwork fixing mechanism 3a. [Figure 6] FIG. 3 is a diagram showing a formwork fixing mechanism 30. [Figure 7] 3A and 3B are diagrams showing a mating protrusion 37 and a mating recess 38. FIG. DETAILED DESCRIPTION OF THE INVENTION

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

[0017] (1.Dike 1) FIG. 1 is a diagram showing an LNG tank 100 including a dike 1 constructed using a formwork fixing mechanism according to an embodiment of the present invention. The LNG tank 100 is an above-ground tank for storing LNG, with the dike 1 installed on a bottom slab 5 and an inner tank and an outer tank made of metal plates or the like installed inside the dike. The dike 1 is a wall installed to prevent LNG from leaking to the outside even if the inner tank or outer tank is damaged. Reference numeral 4 in the figure denotes a steel roof installed on top of the inner tank and outer tank.

[0018] The plane of the dike 1 is circular according to the diameter of the tank. The dike 1 is constructed by arranging concrete precast blocks (hereinafter simply referred to as blocks) 10 on the left and right sides of the periphery of the dike 1 and stacking them in upper and lower layers, and forming joints 2 between adjacent blocks 10 on the left, right, and up and down. The joints 2 are formed by filling the gaps between the blocks 10 with a filler such as mortar or concrete. However, the filler is not limited to these.

[0019] FIG. 2 is a diagram showing a vertical cross section of the dike 1 along its thickness direction, and FIG. 3 is a diagram showing a block 10. As shown in FIG.

[0020] As shown in FIGS. 2 and 3, the block 10 includes a block body 11, a plate 12, and the like.

[0021] The block body 11 is a rectangular plate-shaped member made of concrete. The inner surface of the block body 11 has depressions 111, 112 at the top and bottom. The "inside (inside, inside)" refers to one side in the thickness direction of the block body 11, which in this embodiment refers to the inside side of the tank. The opposite side in the thickness direction of the block body 11 is the outside side of the tank, and will be referred to as the "outside (outer surface, outside)." The inside side of the tank corresponds to the right side in Figures 2 and 3, and the outside side of the tank corresponds to the left side in Figures 2 and 3. The thickness direction of the block body 11 corresponds to the thickness direction of the dike 1.

[0022] The underside of the block body 11 is inclined so that it becomes higher as it goes outward. In addition, in several locations across the width of the block body 11, recessed portions 113 are formed by cutting portions of the underside of the block body 11 upward. The recessed portions 113 continue in the thickness direction from the outer surface to the inner surface of the block body 11. The recessed portions 113 also have the same inclination as the inclination of the underside of the block body 11. The width direction of the block body 11 is perpendicular to the thickness direction of the block body 11 in a plan view, and corresponds to the extension direction of the dike 1 in its plane.

[0023] The plate 12 is a metal plate provided on the inner surface of the block body 11 (one surface in the thickness direction of the block body 11). The plate 12 is provided on the upper part of the block body 11 and protrudes upward from the block body 11. Note that the uppermost block 10 (10a) of the liquid barrier dam 1 does not have a plate 12.

[0024] The lower part of the plate 12 is disposed in a recess 111 of the block body 11 and is fixed to the block body 11 by a flat head screw 114 (see FIG. 4 described later).

[0025] An internal thread portion 31 is provided on the outer surface (opposite the thickness direction of the block body 11) of the upper part of the plate 12. The internal thread portion 31 is a fastener used to secure the plate 12, and in this embodiment is a tubular member such as an insert having an internal thread in its internal space. The axial direction of the internal thread portion 31 is the thickness direction of the block body 11, and multiple internal thread portions 31 are arranged at intervals in the width direction of the block body 11. The engraved portion 113 and the internal thread portion 31 are arranged at corresponding positions in the width direction of the block body 11.

[0026] (2. Construction method of flood barrier 1) In this embodiment, the upper block 10 is lowered by a crane or the like and placed on top of the lower block 10, and the process of forming joints 2 between the upper and lower blocks 10 is repeated to construct the liquid barrier 1 shown in Fig. 2 from bottom to top. By performing the above operations at each position around the periphery of the liquid barrier 1, the liquid barrier 1 is constructed.

[0027] 4(a) and 4(b) are diagrams showing the formwork fixing mechanism 3 and outer formwork 20 according to an embodiment of the present invention, illustrating the state prior to filling the joints 2 with filler during the above-described process. 4(a) and 4(b) respectively show vertical cross sections along the thickness direction of the block body 11 at a position corresponding to the carved portion 113 in the width direction of the block body 11 and at other positions. Hereinafter, the portion of the block body 11 in the width direction other than the carved portion 113 may be referred to as the general portion.

[0028] When the upper block 10 is placed on top of the lower block 10, the upper part of the plate 12 of the lower block 10 is placed in the recess 112 of the upper block 10. By placing the upper and lower parts of the plate 12 in the recesses 112 and 111 of the upper and lower blocks 10, respectively, no protrusions are created by the plate 12 on the inner surface of the dike 1. The lower part of the plate 12 is fixed to the block body 11 by a flat head screw 114. The head of the flat head screw 114 also does not protrude from the plate 12. The shank of the flat head screw 114 is threaded into an insert 115 embedded in the inner surface of the block body 11.

[0029] The plate 12 is provided to seal the gap between the block bodies 11 of the upper and lower blocks 10 from the inside, and functions as an inner formwork when filling the filler material in the joints 2. A sealant such as a sponge may be placed between the plate 12 and the recesses 111, 112 to prevent leakage of the filler material.

[0030] Meanwhile, an outer formwork 20 is placed outside the gap. The outer formwork 20 has a formwork main body 21 on the inner surface of which a spacer 22 is provided. The formwork main body 21 is a strip-shaped plate material that is provided outside the gap between the upper and lower blocks 10 and along the width direction of the block main body 11. The spacer 22 is a plate-shaped member and has a lower spacer part 221 and an upper spacer part 222.

[0031] The spacer lower portion 221 is a strip-shaped plate material provided along the width direction of the block body 11, and its upper end is positioned slightly lower than the general portion of the lower surface of the block body 11 of the upper block 10. The upper end surface of the spacer lower portion 221 is inclined so that it becomes higher as it goes outward.

[0032] The spacer upper part 222 is disposed at a position corresponding to the recessed part 113 of the block body 11 of the upper block 10 so as to cover the recessed part 113 from the outside. The lower end of the spacer upper part 222 is disposed so as to be continuous with the upper end of the spacer lower part 221. The lower end surface of the spacer upper part 222 has a wedge-shaped slope that engages with the upper end surface of the spacer lower part 221.

[0033] On the outer surface of the formwork body 21, girders 23 extending in the width direction of the block body 11 are provided on the top and bottom. Vertical pressing members 24 are arranged on the outside of the upper and lower girders 23. The pressing members 24 are arranged so as to bridge between the upper and lower girders 23.

[0034] The outer formwork 20 is fixed to the outer surfaces of the block bodies 11 of the upper and lower blocks 10 by bolts 25. One end of the bolts 25 is screwed into an insert (not shown) embedded in the outer surface of the block body 11, and the other end of the bolts 25 is attached to the outside of the holding member 24 by an attachment part 26 such as a nut. The bolts 25 are provided in two rows, upper and lower, and each bolt 25 fixes the outer formwork 20 to the block bodies 11 of the upper and lower blocks 10. Note that the configuration and shape of the outer formwork 20 are not limited to those described above. For example, the spacers 22 may be omitted and the formwork bodies 21 may be arranged so as to be in close contact with the block bodies 11 of the upper and lower blocks 10.

[0035] The female thread portion 31 of the plate 12 is disposed within the recessed portion 113 of the upper block 10 when the upper block 10 is disposed on the lower block 10 .

[0036] One end of a separator 32 is attached to the female thread portion 31. The separator 32 is a rod material used to secure the plate 12, and is made of threaded steel or the like. One end of the separator 32 is attached to the female thread portion 31 by threading the male thread at one end of the separator 32 into the female thread on the inner surface of the female thread portion 31. The separator 32 is also placed in the recess 113 of the upper block 10, and the other end of the separator 32 is attached to the outside of the holding member 24 of the outer formwork 20 by an attachment portion 33 such as a nut. In the figure, reference numeral 34 denotes a ceramic contactor provided inside the spacer 22. The ceramic contactor 34 is preferable because it is corrosion-resistant, but other corrosion-resistant materials can be used instead of the ceramic contactor 34.

[0037] In this embodiment, after placing the upper block 10 on top of the lower block 10, one end of the separator 32 is attached to the female thread portion 31 of the plate 12 of the lower block 10, and after placing the outer formwork 20, the other end of the separator 32 is attached to the outer formwork 20 by the attachment portion 33. This allows the plate 12 to be fixed from the outer formwork 20 (outside), preventing the plate 12 from deforming inward when filling the joints 2 with filler without having to perform work inside the dike 1.

[0038] Furthermore, due to the inclination of the general portion and the recessed portion 113 on the underside of the block body 11, air between the upper and lower blocks 10 can be smoothly released to the outside when filling the joint 2 with filler, allowing for dense filling without any air remaining between the blocks 10. However, in some cases, it is also possible to make the general portion and the recessed portion 113 on the underside of the block body 11 horizontal. Also, the upper block 10 may be placed on top of the lower block 10 after the separator 32 and ceramic capacitor 34 have been installed. Because the recessed portion 113 is provided on the underside of the block body 11, the upper block 10 can be placed without any problems even after the separator 32 and ceramic capacitor 34 have been installed.

[0039] As described above, according to this embodiment, when the plate 12 of the block 10 is used as an inner formwork and filler material is filled between the upper and lower blocks 10 to form the joint 2, the plate 12 can be secured from the outside using the female threads 31, preventing deformation when the filler material is filled. Furthermore, because the female threads 31 are provided on the outer surface of the plate 12, the female threads 31 can be prevented from interfering with construction work inside the dike 1, and the work of securing the plate 12 using the female threads 31 does not interfere with construction work inside the dike 1. Furthermore, using the female threads 31 allows the separator 32 for securing the plate to be attached later, facilitating construction work.

[0040] In this embodiment, the separator 32 and the female threaded portion 31 secure the plate 12 inside the block 10 to the outer formwork 20, preventing deformation of the plate 12. The recessed portion 113 also ensures space for arranging the female threaded portion 31 and the separator 32. Because the recessed portion 113 is provided on only a portion of the underside of the block body 11, it is possible to prevent an increase in the amount of filler filling the joints 2 between the upper and lower blocks 10. However, in some cases, it is possible to increase the gap between the upper and lower blocks 10 and omit the recessed portion 113.

[0041] However, the present invention is not limited to the above embodiment. For example, the plate 12 is not limited to being made of metal, but may be made of any material, such as a fiber-reinforced mortar board, that can withstand the filling pressure of the filler in the joints 2. Furthermore, the method of fixing the plate 12 from the outside is not limited to using the separator 32 as in the above embodiment.

[0042] As an example, as shown in formwork fixing mechanism 3a in Figure 5, a fixing piece 35 may be provided in a recess 113 on the underside of block body 11 of upper block 10 at a position corresponding to the tip of female thread 31, and the shank of a headed bolt 36 may be screwed into female thread 31 from the outside of fixing piece 35 to attach fixing piece 35 to female thread 31. This also allows plate 12 to be fixed from the outside of block body 11 of upper block 10 and prevents inward deformation when filling joint 2 with filler. As described above, recess 113 ensures space for the female thread 31 and fixing piece 35. However, because fixing piece 35 can be made smaller, it is possible to make cutting portion 113 slightly smaller than previously.

[0043] In this embodiment, the fixing piece 35 is an L-shaped angle bar, one surface of which is fixed to the recessed portion 113 of the block body 11, and the shank of the bolt 36 is passed through the hole 351 on the other surface. The bolt 36 can be screwed in from outside the gap between the upper and lower blocks 10 using a long wrench after the upper block 10 has been placed. The outer formwork 20 can then be attached. Note that the shape of the fixing piece 35 is not limited to the above, and any shape may be used as long as it can be attached to the female threaded portion 31 using the bolt 36 screwed into the female threaded portion 31 from the outside. As described above, it is also possible to enlarge the gap between the upper and lower blocks 10 and omit the recessed portion 113. In this case, the fixing piece 35 is also provided on the underside of the block body 11.

[0044] FIG. 6 shows another example of a formwork fixing mechanism 30 that facilitates the fixing of the plate 12. In the formwork fixing mechanism 30, the upper part of the plate 12 of the lower block 10 is fixed to the block body 11 of the upper block 10 by a mating projection 37 provided on the inner surface of the block body 11 of the upper block 10. The mating projection 37 is fixed to the inner surface of a steel plate 116 placed in a recess 112 of the block body 11. The steel plate 116 is fixed to the inner surface of the block body 11 with the same countersunk screws 114 and inserts 115 as described above. The recess 112 is formed deeper than in the examples shown in FIGS. 4 and 5, so that even with the steel plate 116 and mating projection 37 present, the upper part of the plate 12 placed inside it does not become a protrusion on the inner surface of the dike 1.

[0045] 7 is a diagram showing a horizontal cross section taken along line AA in FIG. 6. As shown in FIG. 7, in this embodiment, protrusions 39 are provided on the outer surface of the plate 12 as fasteners on the plate 12 side. A pair of protrusions 39 are arranged in the width direction of the block body 11, and a fitting recess 38 that fits with the fitting protrusion 37 is formed between these protrusions 39. The fitting protrusion 37 and the fitting recess 38 both have a trapezoidal shape that widens toward the inside. However, the shapes of the fitting protrusion 37 and the fitting recess 38 are not limited to this. Alternatively, the fitting protrusion 37 may be provided on the plate 12, and the fitting recess 38 (protrusion 39) may be provided on the steel plate 116 of the block body 11.

[0046] By fitting the fitting convex portion 37 into the fitting concave portion 38, the top of the plate 12 is fixed from the block body 11 (outside) of the upper block 10, preventing the plate 12 from deforming inward when filling the joint 2 with filler. In this case, the work required to fix the plate 12 is simple, as it is only necessary to insert the fitting convex portion 37 into the fitting concave portion 38 from above when lowering the upper block 10, making construction easy.

[0047] Furthermore, although the formwork fixing mechanism of the present invention has been described using the example of constructing a dike 1 for an LNG tank 100, the formwork fixing mechanism of the present invention can also be applied when constructing other wall structures, and can avoid interference with construction work, etc. being carried out on one side of the wall. "Construction work, etc." includes not only construction work other than facility construction for the LNG tank 100, such as excavation work, but also various other activities (such as various everyday activities) that utilize the space other than construction work.

[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: Liquid dike 2: Joint 3, 3a, 30: Formwork fixing mechanism 10: Block 11: Block body 12: Plate 20: Outer formwork 31: Female thread 32: Separator 35: Fixed piece 36: Bolt 37: Fitting protrusion 38:Mating recess 39: Projection piece 100: LNG tank 111, 112: depressions 113: Engraved section

Claims

1. A formwork fixing mechanism used when building a wall from bottom to top by stacking precast blocks each having a concrete block body and a plate attached to one side of the block body in the thickness direction and protruding upward from the block body, using the plate as a formwork, and filling a filler material into the gaps between the upper and lower precast blocks to form joints, A formwork fixing mechanism characterized in that a female screw portion for fixing the plate from the opposite side in the thickness direction of the block body is provided on the opposite surface of the plate, and the plate is fixed using the female screw portion.

2. The formwork fixing mechanism described in claim 1, characterized in that the plate is fixed from the formwork located on the opposite side of the gap by screwing the male thread at one end of the rod material into the female thread portion and attaching the other end of the rod material to the formwork located on the opposite side of the gap.

3. a recess formed on a part of the lower surface of the block body, the recess being formed by carving the block body upward so as to be continuous in the thickness direction of the block body; 3. The formwork fixing mechanism according to claim 2, wherein the female threaded portion and the rod are disposed within the recessed portion of the block body of the upper precast block.

4. The formwork fixing mechanism described in claim 1, characterized in that the plate is fixed to the block body of the upper precast block by attaching a fixing piece provided on the underside of the block body of the upper precast block to the female threaded portion using a bolt screwed into the female threaded portion from the opposite side.

5. a recess formed on a part of the lower surface of the block body, the recess being formed by carving the block body upward so as to be continuous in the thickness direction of the block body; 5. The formwork fixing mechanism according to claim 4, wherein the female threaded portion and the fixing piece are disposed within the recessed portion of the block body of the upper precast block.

6. A wall is constructed by stacking precast blocks, each having a concrete block body and a plate attached to one side of the block body in the thickness direction and protruding upward from the block body, and using the plate as a formwork to fill the gaps between the upper and lower precast blocks with filler to form joints, from bottom to top.

2. A method for constructing a wall, comprising the steps of: fixing the plate from the opposite side in the thickness direction of the block body by the formwork fixing mechanism according to claim 1.

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