Formwork structure for reinforced concrete columns

Abstract

To efficiently form a rectangular cylindrical concrete casting space by smoothly joining and integrating four separate formwork structures that are erected on each side of a reinforced concrete column with a rectangular cross section.SOLUTION: In each support beam joining structure 20, a corner joining piece 21 having a pair of abutment plates 21a, 21a is attached so as to fit from the outside into the right-angle portion between each of end side surfaces 17b, 17b of a pair of adjacent divided support beams 15, 15 arranged at right angles, with an end face 17a of one divided support beam 15 abutting against the end side surface 17b in an area spaced from the end face 17a of the other divided support beam 15. In this way, by joining the end side surfaces 17b, 17b together, it is possible to form an annular support beam 14 that is continuous in a rectangular ring shape.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a formwork structure for a reinforced concrete column. In particular, when constructing by placing an additional reinforced concrete layer around an existing reinforced concrete column having a rectangular cross-sectional shape, or when newly constructing a reinforced concrete column having a rectangular cross-sectional shape, it relates to a formwork structure for a reinforced concrete column to be installed.

Background Art

[0002] As a reinforced concrete column having a rectangular cross-sectional shape, for example, in the work of seismic strengthening of existing reinforced concrete bridge piers constructed several decades or more ago and other old existing reinforced concrete columns, as a general construction method, steel bars are assembled around the existing reinforced concrete columns such as bridge piers, and a formwork is installed, and an RC wrapping method in which additional concrete for reinforcement is placed, or a steel plate wrapping method in which a reinforcing steel plate is wrapped around the existing reinforced concrete columns such as bridge piers, and a solidifying material such as non-shrink mortar or epoxy resin is filled between the wrapped reinforcing steel plate and the concrete body to integrate them is adopted.

[0003] In addition, in the above-mentioned RC wrapping method, when installing a formwork around an existing reinforced concrete column, the outer concrete surface is surface-treated, for example, by a water jet to form an uneven surface, and then an anchor is driven into the surface-treated uneven surface and fixed. At the same time, a separator is attached to the fixed anchor, and the installed formwork is positioned while maintaining a space with a predetermined width between the formwork and the concrete surface through the attached separator. Therefore, when placing the concrete for reinforcement, a large number of anchors need to be driven into the concrete surface so that the installed formwork has sufficient strength to withstand the load due to the internal pressure applied to the formwork, which requires a lot of labor. Furthermore, the work of adjusting the length of each separator connected to a large number of anchors so that a space with a predetermined width can be maintained between the concrete surface and the formwork also requires a lot of labor.

[0004] On the other hand, for example, Patent Document 1 below discloses a formwork device for a prismatic concrete structure that allows the internal pressure load applied to the formwork during concrete pouring to be supported from the outside without using many separators when constructing a new prismatic concrete structure. The formwork device described in Patent Document 1 comprises a pair of formworks having an inner surface corresponding to approximately half of the outer surface of the prismatic concrete structure to be constructed, a plurality of wooden support members attached to the outer periphery of the formwork extending vertically, and a plurality of holding members attached in a rectangular ring shape in the circumferential direction, surrounding the outer periphery of the plurality of wooden support members. The holding members are constructed such that the beam members on the four sides are connected and fixed together at the four intersection corners via corner fixing guides and retrofitting guides. As a result, the internal pressure load applied to the formwork during concrete pouring can be supported from the outside by the holding members attached in a rectangular ring shape in the circumferential direction via the plurality of wooden support members attached to the outer periphery extending vertically. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-181439 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, in the formwork device described in Patent Document 1, the process involves assembling a pair of formwork pieces in a horizontal position in a work area on the ground, separate from the construction site of the rectangular concrete structure, and attaching multiple wooden support members or multiple stages of holding members arranged in a rectangular ring. After forming the formwork device, it is raised vertically using a crane or the like, then lifted and installed at the construction site. As a result, when the scale of the rectangular concrete structure to be constructed increases, the formwork device becomes heavy and bulky, requiring considerable effort to lift and transport it as a whole and to accurately install it at the predetermined construction site. In particular, when constructing a reinforced concrete layer around an existing reinforced concrete column with a rectangular cross-section, structures above the existing reinforced concrete column, such as bridge abutments, get in the way, making it difficult to lift and install the formwork device at the predetermined location.

[0007] For these reasons, even when dealing with large reinforced concrete columns with a rectangular cross-sectional shape, a method has been considered to more easily form a rectangular cylindrical concrete pouring space or a rectangular column-shaped concrete pouring space without using many separators. This method involves forming four segmented formwork structures that are arranged along each face of the rectangular cross-sectional shape, erecting the four segmented formwork structures individually, and then connecting and integrating them at the concrete pouring location to assemble and install a rectangular cylindrical main formwork around the target reinforced concrete column. However, it is believed that by developing a means to more smoothly connect and integrate the four erected segmented formwork structures, it will be possible to form a rectangular cylindrical concrete pouring space or a rectangular column-shaped concrete pouring space using a rectangular cylindrical main formwork even more efficiently.

[0008] The present invention aims to provide a formwork structure for reinforced concrete columns that enables the smooth connection and integration of four segmented formwork structures, each individually erected along each face of a reinforced concrete column having a rectangular cross-sectional shape, thereby enabling the formation of a rectangular cylindrical concrete pouring space or a rectangular columnar concrete pouring space using a main formwork assembled in a rectangular cylindrical shape, in a simpler and more efficient manner. [Means for solving the problem]

[0009] The present invention relates to a reinforced concrete column formwork structure installed when constructing an existing reinforced concrete column having a rectangular cross-sectional shape by adding a reinforcing reinforced concrete layer around it, or when constructing a new reinforced concrete column having a rectangular cross-sectional shape. The structure comprises a cylindrical main formwork assembled into a rectangular cylindrical shape of a predetermined height by connecting and arranging a plurality of formwork units, and annular support beams attached in multiple stages in a rectangular ring shape in the circumferential direction along the outer circumference of the cylindrical main formwork. The cylindrical main formwork is formed into a rectangular cylindrical shape by joining and integrating four divided main formworks, each arranged along the four faces of the rectangular cross-sectional shape, and the annular support beams are formed in a rectangular ring shape in a continuous manner on the outer circumference of the cylindrical main formwork by joining and integrating four divided support beams, each arranged along the four faces of the rectangular cross-sectional shape. Each of the divided main formworks and divided support beams is assembled on the ground to form a four-part divided formwork structure with the divided main formworks abutting and joining to the divided support beams, and these divisions The split formwork structures are individually erected at the concrete pouring locations and then connected and integrated to form a rectangular cylindrical or rectangular columnar concrete pouring space using the cylindrical main formwork. When the four split formwork structures are connected as a whole, the four split support beams are joined at right angles to each other at the four corner joints of each adjacent pair of split support beams using corner joint pieces having right-angled triangular portions, thereby forming a continuous rectangular annular support beam. The support beam joining structure is such that, at each of the four corner joints where each pair of adjacent divided support beams are joined at a right angle, the end face of one divided support beam is brought into contact with the end side surface in a region spaced apart from the end face of the other divided support beam, and the end sides are joined together as a single unit via a corner joining piece having a pair of contact plates positioned at right angles and capable of contacting these end sides, which are fitted from the outside into the right-angle portion between the respective end sides of these pairs of adjacent divided support beams that are positioned at right angles.The above objective is achieved by providing a formwork structure for reinforced concrete columns that forms a continuous rectangular annular support beam, thereby supporting the load caused by the internal pressure applied to the cylindrical formwork during concrete pouring from the outside by the multiple stages of the continuous rectangular annular support beam that abut against the outer circumference of the cylindrical formwork.

[0010] Furthermore, it is preferable that the formwork structure for reinforced concrete columns of the present invention is made of steel formwork panels.

[0011] Furthermore, in the reinforced concrete column formwork structure of the present invention, it is preferable that the divided support beams are made of large formwork support beams.

[0012] Furthermore, it is preferable that the formwork structure for reinforced concrete columns of the present invention is formed by the formwork units being assembled together as a single unit via the divided support beams, thereby forming the divided main formwork.

[0013] Furthermore, it is preferable that the formwork structure for reinforced concrete columns of the present invention is such that the corner joint piece connects each pair of adjacent segmented support beams at a right angle to each of the four corner joints via fastening bolt members that penetrate and fasten the segmented support beams.

[0014] Furthermore, in the formwork structure for reinforced concrete columns of the present invention, it is preferable that the inner fastening plate, which is attached in close contact to the end side of one of the divided support beams whose end faces abut against it, on the side opposite to the side to which the corner joint piece is joined, is made up of a plurality of segmented plate members arranged in a divided state.

[0015] Furthermore, in the formwork structure for reinforced concrete columns of the present invention, bolt fastening holes are preferably formed in the contact plate of the corner joint piece, and these bolt fastening holes are elongated holes that are elongated in the longitudinal direction of the contact plate. [Effects of the Invention]

[0016] According to the reinforced concrete column formwork structure of the present invention, four segmented formwork structures erected along each face of a reinforced concrete column having a rectangular cross-sectional shape can be smoothly connected and integrated, making it possible to form a rectangular cylindrical concrete pouring space or a rectangular columnar concrete pouring space using a main formwork assembled in a rectangular cylindrical shape more easily and efficiently. [Brief explanation of the drawing]

[0017] [Figure 1] This is a side view along BB in Figure 2 illustrating a reinforcement method for a reinforced concrete column implemented using a formwork structure for reinforced concrete columns according to a preferred embodiment of the present invention. [Figure 2] This is a top view along AA in Figure 1 illustrating a reinforcement method for reinforced concrete columns implemented using a formwork structure for reinforced concrete columns according to a preferred embodiment of the present invention. [Figure 3] This is a cross-sectional view along CC in Figure 1 illustrating a formwork structure for a reinforced concrete column according to a preferred embodiment of the present invention. [Figure 4] Figure 3 is a side view taken from the right, illustrating a formwork structure for a reinforced concrete column according to a preferred embodiment of the present invention. [Figure 5] This is a perspective view from the rear, illustrating a formwork unit made of steel formwork panels. [Figure 6] This is a perspective view illustrating the segmented formwork structure. [Figure 7] This is a perspective view illustrating the segmented support beam. [Figure 8](a) is an enlarged view of part D of FIG. 3 for explaining the joint structure of the support beam, (b) is an enlarged view of part E of (a), and (c) is a cross-sectional view taken along F-F of (a). [Figure 9] (a) to (c) are views for explaining the corner joint piece. (a) is a top view, (b) is an outer side view as seen from the right side of (a), and (c) is an inner side view as seen from the bottom side of (a). [Figure 10] (a) is a front view for explaining the outer fastening plate, and (b) is a front view for explaining the inner fastening plate. [Figure 11] (a) to (c) are process diagrams for explaining the reinforcement method of the reinforced concrete column. [Figure 12] (a) and (b) are process diagrams for explaining the reinforcement method of the reinforced concrete column. [Figure 13] (a) is an enlarged view of part G of FIG. 12(a) for explaining the state where the split main body formwork is lifted and the lower end is supported by the height adjustment support hardware, and (b) is an enlarged view of part H of (a). [Figure 14] (a) is a front view of the height adjustment support hardware, and (b) is a side view.

Mode for Carrying Out the Invention

[0018] A formwork structure 10 for a reinforced concrete column, according to a preferred embodiment of the present invention, is preferably installed to surround an existing reinforced concrete column, for example, a reinforced concrete pier 50 having a rectangular cross-sectional shape, when an additional reinforced concrete layer 51 (see Figure 11) is poured around it. The formwork structure is provided to form a rectangular, annular, cylindrical concrete pouring space (rectangular cylindrical pouring space) 52 (see Figure 3) between the formwork structure and the outer surface of the pier 50. The reinforced concrete column formwork structure 10 of this embodiment allows for the efficient and easy formation of a rectangular tubular concrete pouring space 52 around an existing bridge pier 50 by a simple construction method that involves lifting each of the multiple divided formwork structures 16, which are preferably assembled on the ground in a flat rectangular shape, and installing them around the bridge pier 50, thereby connecting and integrating the divided main formwork 13 into a cylindrical shape. Furthermore, it allows for the load due to the internal pressure applied to the formwork (cylindrical main formwork) 12 during concrete pouring to be firmly and stably supported from the outside without the need for many separators 53 (see Figure 3). In addition, the reinforced concrete column formwork structure 10 of this embodiment allows for the smooth connection and integration of four divided formwork structures 16 erected along each face of the existing bridge pier 50, which is a reinforced concrete column with a rectangular cross-sectional shape, thereby enabling the formation of a rectangular tubular concrete pouring space 52 using a cylindrical main formwork 12 assembled into a rectangular shape, more easily and efficiently.

[0019] Furthermore, the reinforced concrete column formwork structure 10 of this embodiment is a formwork structure installed when constructing an additional reinforced concrete layer 51 around an existing reinforced concrete column, such as a reinforced concrete bridge pier 50 having a rectangular cross-sectional shape, and as shown in Figures 3 to 5, it is composed of a cylindrical main formwork 12 assembled into a rectangular cylindrical shape having a rectangular hollow cross-section of a predetermined height by arranging a plurality of formwork units 11 (see Figure 5) in a connected manner, and annular support beams 14 attached in multiple stages in a rectangular ring shape in the circumferential direction along the outer circumference of the cylindrical main formwork 12. The cylindrical main formwork 12 is formed into a rectangular cylindrical shape by joining and integrating four segmented main formworks 13, each positioned along the four rectangular cross-sectional surfaces of the pier 50. The annular support beam 14 is formed in a continuous rectangular annular shape on the outer circumference of the cylindrical main formwork 12 by joining and integrating four segmented support beams 15, each positioned along the four rectangular cross-sectional surfaces of the pier 50. Each segmented main formwork 13 and segmented support beam 15 is assembled on the ground to form a segmented formwork structure 16 (see Figure 6) with the segmented main formwork 13 made of formwork unit 11 in contact with the segmented support beam 15. These segmented formwork structures 16 are then individually erected and connected at the concrete pouring locations, thereby forming a rectangular cylindrical concrete pouring space 52 between the cylindrical main formwork 12 and the existing pier 50. During concrete pouring, the internal pressure load on the cylindrical formwork 12 can be firmly and stably supported from the outside by multiple stages of annular support beams 14 that contact the outer circumference of the cylindrical formwork 12 and are arranged in a continuous rectangular ring shape.

[0020] Furthermore, in this embodiment, as described above, the formwork structure 10 for reinforced concrete columns is formed by assembling each divided main formwork 13 and divided support beam 15 on the ground, thereby forming four divided formwork structures 16 with the divided main formwork 13 abutting against the divided support beam 15. These divided formwork structures 16 are then individually erected at the concrete pouring locations and connected together to form a rectangular cylindrical concrete pouring space 52 between the cylindrical main formwork 12 and the existing bridge pier 50. When the four divided formwork structures 16 are connected together as a single unit, the four divided support beams 15 are joined at right angles to each other at four corner joints between adjacent pairs of divided support beams 15 using corner joint pieces 21 with right-angled triangular portions, as shown in Figure 3. This support beam joint structure 20 forms a rectangular, ring-shaped continuous annular support beam 14. In this embodiment, the support beam joining structure 20 is configured such that, at each of the four corner joints where adjacent pairs of divided support beams 15 are joined at right angles, as shown in Figures 8(a) to (c), the end face 17a of one divided support beam 15 is brought into contact with the end side surface 17b of the other divided support beam 15 in a region spaced apart from the end face 17a. The corner joining piece 21, which has a pair of right-angled contact plates 21a, 21a that can contact these end side surfaces 17b, 17b, is attached from the outside to fit into the right-angle portion between the respective end side surfaces 17b, 17b of these right-angled pairs of adjacent divided support beams 15, 15, thereby joining these end side surfaces 17b, 17b as a single unit and forming a rectangular, annular continuous annular support beam 14.

[0021] Furthermore, in this embodiment, the formwork unit 11 made of steel formwork panels is assembled by being connected as a single unit via the divided support beam 15, as described above, thereby forming the divided main formwork 13.

[0022] Furthermore, in this embodiment, the corner joint piece 21 is configured to allow each pair of adjacent segmented support beams 15 to be joined together at a right angle at four corner joints using fastening bolt members 22 that penetrate and fasten the segmented support beams 15.

[0023] In this embodiment, the formwork units 11 that constitute the cylindrical main formwork 12 and the divided main formwork 13 are preferably made of steel formwork panels known as metal forms. As shown in Figure 5, the steel formwork panel 11 is a known steel formwork member having a height of approximately 55 mm, for example, with a vertically elongated (horizontally elongated) rectangular face plate 11a having a length of approximately 600 to 1800 mm and a width of approximately 200 to 300 mm, to which ribs 11b such as vertical ribs, horizontal ribs, intermediate vertical ribs, and intermediate horizontal ribs are attached in an upright position and joined as a whole. Multiple locking holes 11c such as tie rod holes, U-clip holes, and nail holes are formed in the ribs 11b such as vertical ribs, horizontal ribs, intermediate vertical ribs, and intermediate horizontal ribs at appropriate locations in the steel formwork panel 11. By locking fastening hardware 11d (see Figure 6), such as U-clips or hook bolts, into these locking holes 11c, multiple steel formwork panels 11 are connected vertically and horizontally, preferably forming a rectangular flat plate shape of a predetermined size, thereby forming a divided main formwork 13 having a predetermined height. Four divided main formwork 13s are formed, and as will be described later, in a construction site where a reinforced concrete layer 51 is added around a reinforced concrete bridge pier 50 for reinforcement, these divided main formwork 13s are connected and integrated to form a cylindrical main formwork 12 (see Figure 3) of a predetermined height, preferably having a rectangular hollow cross-section. As the steel formwork panel that becomes such a formwork unit 11, for example, Metalform manufactured by Okaya Building Materials Co., Ltd. can preferably be used.

[0024] An annular support beam 14, which is attached in multiple stages in a rectangular ring shape in the circumferential direction along the outer circumference of a cylindrical main formwork 12 made of multiple steel formwork panels 11, is preferably composed of four divided support beams 15, and these divided support beams 15 can be formed using various steel materials such as H-beams and I-beams. In this embodiment, as shown in Figures 6 and 7, the divided support beams 15 can preferably be formed using support beams specifically for formwork, known as large formwork support beams, and more specifically, they can preferably be formed using "Wide Panel Beams" manufactured by Okaya Building Materials Co., Ltd. The large formwork support beam 15 made of Wide Panel Beams is preferably obtained by connecting a pair of channel steel 15a, each having multiple rectangular through-openings 15b formed at predetermined intervals in the longitudinal direction, back to back with a gap 15c through which bolt members can be inserted, via an end connecting plate 15d.

[0025] As described later, when the divided support beams 15 are installed in multiple stages (see Figure 4), a through member 15e, for example, made of a square pipe, is inserted through the through opening 15b of the channel steel 15a of the large formwork support beam that forms the divided support beams 15, and the inserted through member 15e is locked to the outer opening edge via a square pipe washer 15f (see Figure 6), thereby enabling the large formwork support beams 15, which are arranged in multiple stages at intervals in the vertical direction, to be connected to one another. Furthermore, at the opening edge on the inside of the through opening 15b (the side facing the divided main formwork 13), a locking fitting 11d, such as a hook bolt, which is locked to a locking hole 11c of the rib 11b of the steel formwork panel 11 that constitutes the divided main formwork 13, is locked via a beam washer 15g (see Figure 6). This makes it possible to form a divided formwork structure 16 by joining a divided main formwork 13, which consists of multiple steel formwork panels 11 assembled in a vertical and horizontal manner to divided support beams 15 arranged in multiple stages, as a single unit through the ground assembly work described later (see Figure 4). The divided support beams 15 are made such that their length can be appropriately adjusted so that it corresponds to the length of one side of the rectangular, continuous annular support beam 14, by joining unit beam materials of a predetermined length as a single unit in the longitudinal direction via end connecting plates 15d attached to the ends (see Figure 7).

[0026] In this embodiment, at a construction site where a reinforced concrete layer is added around a reinforced concrete bridge pier 50, as shown in Figures 1 and 4, four divided formwork structures 16 are formed by, for example, assembling them on the ground in a work area away from the bridge pier 50, supporting them on a plurality of parallel divided support beams 15, and then integrally joining a predetermined number of formwork units 11, which are connected vertically and horizontally, to these divided support beams 15.

[0027] In other words, in the divided formwork structure 16, a predetermined number of multiple steel formwork panels 11, each capable of forming a divided main formwork 13 of a predetermined rectangular shape, are arranged in a vertical and horizontal line with their backs facing upwards and connected, and these multiple steel formwork panels 11 are connected to each other using locking hardware 11d to form a single divided main formwork 13. At the same time, multiple stages of divided support beams 15 are extended parallel to each other on the back side of the formed divided main formwork 13, with one flange surface of each beam contacting the tip of the rib 11b of the steel formwork panel 11 (see Figures 4 and 6). The divided main formwork 13 made of steel formwork panels 11 is then connected to these multiple stages of divided support beams 15 using beam washers 15g and locking hardware 11d such as hook bolts (see Figure 6). This makes it possible to form four segmented formwork structures 16 by ground assembly, each of which is formed by integrally joining segmented main formwork 13, consisting of multiple steel formwork panels 11 arranged vertically and horizontally, to multiple segmented support beams 15 (see Figure 4). Furthermore, with the segmented support beams 15 installed in multiple stages, the through members 15e are inserted and locked into the through openings 15b of the channel steel 15a that constitute the large formwork support beams, thereby connecting these multiple segments of segmented support beams 15 to each other. As a result, the segmented formwork structures 16 can maintain a stable and strong shape-retaining rigidity when each is lifted and erected at the concrete pouring site.

[0028] The four pre-assembled segmented formwork structures 16 are stored in a stacked state, for example, in a section of the construction site away from the bridge piers 50, as shown in Figures 1 and 2. The stored segmented formwork structures 16 are each easily lifted using a lifting machine 60 such as a crane, selected according to their weight and the size of the work area, and individually erected at the concrete pouring locations of the lowest construction rods, where reinforcing bars 54 have been previously placed, to form a reinforcement concrete layer 51 around the lower end of the bridge piers 50, which are reinforced concrete columns to be reinforced. The four erected segmented formwork structures 16 are integrated by a support beam joining structure 20 (see Figure 3), which preferably forms annular support beams 14 that are continuous in a rectangular ring shape in the circumferential direction, by joining the four segmented support beams 15 of each stage at right angles to each other via corner joining pieces 21 which preferably have right-angled triangular portions. The four segmented main formworks 13 are assembled into a cylindrical shape with a rectangular hollow cross-section using locking holes 11c (see Figure 5), such as tie rod holes and U-clip holes, and locking hardware 11d, such as U-clips and hook bolts (see Figure 3), thereby forming a cylindrical main formwork (see Figure 3). This makes it possible to obtain the reinforced concrete column formwork structure 10 of this embodiment, in which the annular support beams 14 and the cylindrical main formwork 12 are integrated.

[0029] Furthermore, in this embodiment, a rectangular cylindrical concrete pouring space 52 of a predetermined width, which is continuous in an annular shape and corresponds to the thickness of the additional reinforced concrete layer 51 to be poured, is formed between the inner formwork surface of the steel formwork panel 11 that constitutes the cylindrical main formwork 12 of the reinforced concrete column formwork structure 10 provided around the preferably lower end portion of the existing bridge pier 50, and the outer surface of the existing bridge pier 50, and serves as the concrete pouring location for the lowest construction rod. Such a rectangular cylindrical concrete casting space 52 of a predetermined width can be accurately maintained on the outer perimeter of the existing bridge pier 50 by, for example, attaching spacer separators 53 (see Figure 3) to the concrete surface on the outer perimeter of the existing bridge pier 50 to ensure a predetermined thickness of the reinforcing reinforced concrete layer, supporting them with anchors or the like that have been previously driven into the bridge pier 50, and arranging them in a balanced manner at multiple appropriate locations. With these spacer separators 53 in place, each divided formwork structure 16 can be installed on the outer perimeter surrounding the existing bridge pier 50, thereby enabling the precise maintenance of a rectangular cylindrical concrete casting space 52 of a predetermined width corresponding to the thickness of the reinforcing reinforced concrete layer 51 on the outer perimeter of the existing bridge pier 50.

[0030] Furthermore, in this embodiment, temporary work scaffolding 55 for performing various tasks is assembled and installed along each of the four faces of the existing bridge pier 50, which has a rectangular cross-sectional shape, in the outer perimeter area, with a predetermined distance between it and the outer perimeter surface allowing for the installation of reinforcing bars 54 and segmented formwork structures 16. The temporary work scaffolding 55 can preferably be formed using lightweight Darwin scaffolding, which can lift multiple spans as a single unit. Darwin scaffolding preferably has short connecting members so that the spans can be divided. Each segmented formwork structure 16 can be installed outside each face of the bridge pier 50, as needed, by appropriately removing and restoring one or two of the work scaffoldings installed in the outer perimeter area of ​​each of the four faces of the bridge pier 50.

[0031] As shown in Figure 3, the four installed segmented formwork structures 16 are integrated by a support beam joining structure 20, which connects the four segmented support beams 15 at each stage to each of the four corner joints of adjacent pairs of segmented support beams 15 at right angles to each other using corner joint pieces 21 having right-angled triangular portions. This allows for the efficient formation of the reinforced concrete column formwork structure 10 of this embodiment, which includes a cylindrical main formwork 12 assembled into a cylindrical shape with a rectangular hollow cross-section of a predetermined height, and annular support beams 14 that extend in a rectangular ring shape in the circumferential direction along the outer circumference of the cylindrical main formwork 12 and are attached in multiple stages.

[0032] In this embodiment, the corner joining piece 21 constituting the support beam joining structure 20 described above is a steel joining member having a right-angled equilateral triangular planar shape. As shown in Figures 9(a) to (c), it is formed by a pair of vertically elongated (horizontally elongated) rectangular contact plate portions 21a, for example, with a length of about 345 mm and a width of about 129 mm, which are arranged perpendicular to each other and joined by welding or the like, and a pair of right-angled equilateral triangular reinforcing rib plates 21b, which are arranged to straddle the upper or lower edge of each of these contact plates 21a and fixed by welding or the like so as to fit into the inner right-angled portions. Each contact plate 21a has a plurality of bolt fastening holes 21c formed in the center of its width direction at predetermined intervals in the length direction. One end of a fastening bolt member 22 is fastened to these bolt fastening holes 21c for joining the contact plate 21a of the corner joint piece 21 in close contact with the respective end sides 17b, 17b of a pair of adjacent segmented support beams 15, 15. Furthermore, the bolt fastening holes 21c formed in each contact plate 21a are preferably elongated holes that are elongated in the longitudinal direction of the contact plate 21a. This makes it possible to effectively absorb the positional misalignment that occurs when fastening the fastening bolt member 22 to the contact plate 21a when, for example, it is necessary to interpose a length-adjusting plate member between the end face 17a of one segmented support beam 15 and the end side 17b of the other segmented support beam 15 at each corner joint between adjacent segmentsed support beams 15 in order to fine-tune the lateral (horizontal) length of the segmented support beams 15 and segmented formwork structure 16 to match the size of the existing bridge pier 50.

[0033] In order to join each pair of adjacent segmented support beams 15 at right angles using corner joining pieces 21 at the four corner joints of the annular support beam 14, as shown in Figures 3 and 8(a) to 8(c), with four segmented formwork structures 16 erected around the lower end portion of the pier 50, the segmented support beams 15, 15 attached to the outside of the segmented formwork structures 16 are positioned at each corner joint between each pair of adjacent segmented support beams 15 by bringing the end face 17a of one segmented support beam 15 into contact with the end side surface 17b of the other segmented support beam 15 in a region spaced apart from the end face 17a, so that these pairs of segmented support beams 15 are arranged at right angles (see Figure 8(a)). Subsequently, at each corner joint, the corner joint piece 21 is fitted from the outside onto the right-angle portion formed by the end sides 17b of the pair of right-angled divided support beams 15, 15, so that its pair of contact plates 21a, 12a are superimposed on the end sides 17b, 17b of the right-angled divided support beams 15, 15. Then, with the pair of contact plates 21a and 12a of the corner joint piece 21 superimposed on the end sides 17b and 17b of the divided support beams 15, 15, respectively, the fastening bolt member 22 is inserted through the bolt fastening holes 21c of the contact plates 21a and 12a into the gap 15c (see Figure 6) held between the pair of channel steels 15a of the divided support beams 15, 15. This allows the other end of the bolt member to be positioned so that it protrudes from the end side 17b' opposite to the end side 17b to which the corner joint piece 21 is joined (see Figure 8(c)).

[0034] This allows the fastening bolt member 22, which is inserted through the bolt fastening hole 21c and the gap 15c between the pair of channel steel sections 15a, 15a of the divided support beams 15, 15, to be fastened and secured at one end to the contact plates 21a, 21a of the corner joint piece 21 that are in close contact with the end sides 17b, 17b of the divided support beams 15, 15 on the right-angle portion where the corner joint piece 21 is positioned, using washers and nuts, and at the other end to be fastened and secured at the end sides 17b', 17b' on the opposite side of the corner joint piece 21 that are in close contact with the fastening plates 22a, 22b that are in close contact with the corner joint piece 21, using washers and nuts. Furthermore, this makes it possible to firmly fix the fitted corner joint piece 21 to the right-angle portion formed by the end sides 17b of the pair of divided support beams 15, 15 that are positioned at a right angle, when the corner joint piece 21 is fitted from the outside.

[0035] In this embodiment, preferably using three fastening bolt members 22, each pair of adjacent divided support beams 15 are fastened and fixed at four corner joints, as described above, via the corner joint pieces 21, in a state where they are joined at right angles. In this embodiment, the fastening plates 22a and 22b, which are interposed between washers and nuts and attached to the end side surface 17b' opposite to the end side surface 17b' to which the abutment plates 21a and 12a of the corner joint pieces 21 make close contact, are arranged on the outer end side surface 17b' opposite to the side surface of the other divided support beam 15 to which the corner joint piece 21 is joined. The outer fastening plate 22a, which is arranged on the outer end side surface 17b' opposite to the side surface of the other divided support beam 15 to which the end surface 17a abuts, is a single, continuous, horizontally elongated plate member that can fasten three joining bolt members 22 simultaneously, as shown in Figure 10(a). Furthermore, the inner fastening plate 22b, which is attached in close contact with the inner end surface 17b' on the side opposite to the side to which the corner joint piece 21 of one of the divided support beams 15 that abuts the end surface 17a is joined, consists of multiple (two in this embodiment) slotted plate members, which are arranged in a divided state as shown in Figure 10(b), and which allow the three joining bolt members 22 to be fastened in, for example, two locations.

[0036] The inner fastening plate 22b, which is attached in close contact with the inner end side surface 17b' of one of the divided support beams 15 that abuts against the end face 17a, is made up of multiple segmented plate members arranged in a divided state. This makes it possible to arrange each segmented inner fastening plate 22b while avoiding interference with the rib 11b on the back side of the steel formwork panel 11 that constitutes the divided main formwork 13, which is connected to the inner end side surface 17b' of one of the divided support beams 15 with the rib 11b in contact with it. As a result, the other ends of the three fastening bolt members 22 can be fastened and fixed to the inner fastening plate 22b in a state where the inner fastening plate 22b is in close contact with the inner end side surface 17b' in the portion that does not interfere with the rib 11b on the back side, and with the rib 11b on the back side of the steel formwork panel 11 in contact with the inner end side surface 17b'.

[0037] In this embodiment, the support beam joining structure 20 using the corner joining piece 21 connects the four divided support beams 15 of each stage of the four divided formwork structures 16 to form a continuous rectangular annular support beam 14. Furthermore, the divided main formwork 13, consisting of multiple steel formwork panels 11 arranged in a continuous vertical and horizontal manner and supported by the divided support beams 15, is integrated by connecting the steel formwork panels 11 at their side ends using locking hardware 11d such as U-clips and hook bolts, thereby enabling the formation of a cylindrical main formwork 12 with a rectangular hollow cross-section. As a result, the reinforced concrete column formwork structure 10 of this embodiment, which includes a cylindrical main formwork 12 assembled into a cylindrical shape of a predetermined height and annular support beams 14 that extend in a ring shape in the circumferential direction along the outer circumference of the cylindrical main formwork 12 and are installed in multiple stages, surrounds the lower end portion of the existing bridge pier 50 and is installed around it at a predetermined height, and a rectangular cylindrical concrete pouring space 52 is formed between it and the lower end portion of the existing bridge pier 50 while maintaining a predetermined distance. Furthermore, when concrete is poured into the formed cylindrical concrete pouring space 52 at the lower end portion of the bridge pier 50, a reinforcing concrete layer 51 for reinforcing the lowest stage construction rod is added and constructed.

[0038] In this embodiment, the existing bridge pier 50 is, for example, a reinforced concrete column of considerable height. When constructing a reinforced concrete layer 51 for reinforcement around the bridge pier 50 using the reinforced concrete column formwork structure 10 described above, the following reinforced concrete column reinforcement method is implemented, which allows for the use of multiple rotations of the divided main formwork 13 that constitute the cylindrical main formwork 12, moving from the lower part to the upper part of the bridge pier 50. This makes it possible to efficiently construct a reinforced concrete layer 51 for reinforcement around the bridge pier 50.

[0039] In other words, in this embodiment, the reinforcement method for the reinforced concrete column is a reinforcement method using the cylindrical main formwork 12 described above, which is formed into a cylindrical shape of a predetermined height by joining and integrating a plurality of divided main formworks 13 in the circumferential direction, for constructing an additional reinforced concrete layer 51 for reinforcement around an existing reinforced concrete column, which is a bridge pier 50, as shown in Figures 11(a) to (c) and Figures 12(a) and (b). The divided main formworks 13 that constitute the cylindrical main formwork 12 are formed by connecting a plurality of steel formwork panels 11, which are formwork units, as a whole via divided support beams 15 and assembling them to a predetermined height, and preferably are used by rotating them multiple times from the lower part to the upper part of the existing reinforced concrete column, which is a bridge pier 50. After installing a cylindrical main formwork 12 around the lower end portion of the existing bridge pier 50 (see Figure 11(a)), and pouring concrete into the rectangular cylindrical concrete pouring space 52 held between the existing bridge pier 50 and the formwork to form the reinforcing concrete layer 51 of the lowest construction rod (see Figures 11(a) and (b)), the formwork sliding process is performed in which each segmented main formwork 13 of the demolded cylindrical main formwork 12 is slid away from the formed lowest reinforcing concrete layer 51 while remaining in an upright position (Figure (See Figure 11(c)) A worker enters the working space 56 between the lowermost reinforcing concrete layer 51 created thereby and performs a formwork surface scraping process (see Figure 11(c)) in which the inner formwork surface of each divided main formwork 13 is scraped clean. Subsequently, a lifting and repurposing process (see Figure 12(a)) is performed in which the divided main formwork 13, whose inner formwork surface has been scraped clean, is lifted upward and reinstalled as a component of the cylindrical main formwork 12 for forming the reinforcing concrete layer 51 of the next stage of construction rods.

[0040] Furthermore, in this embodiment, the reinforcement method for the reinforced concrete column preferably involves using the divided main formwork 13, which has been repurposed for the next stage of construction rods in the lifting and repurposing process, to pour concrete into the rectangular cylindrical concrete pouring space 52 held between the cylindrical main formwork 12 installed around the existing pier 50 and the existing pier 50, thereby forming the reinforcing concrete layer 51 for the next stage of construction rods. Then, each divided main formwork 13 of the demolded cylindrical main formwork 12 is lowered to the lowest stage of construction rods while remaining in an upright position, and the formed lowest stage of reinforcement is then carried out. The process involves a formwork lowering and moving step (see Figure 12(b)) to move the formwork away from the concrete layer 51, a formwork surface resurfacing step (see Figure 12(b)) in which workers enter the working space 56 between the formwork and the lowest reinforcing concrete layer 51 created by the formwork, and scrape the inner formwork surface of each divided main formwork 13, and then a re-lifting and repurposing step in which the divided main formwork 13, whose inner formwork surface has been scraped, is lifted upward and reinstalled as a component of the cylindrical main formwork 12 for forming the reinforcing concrete layer 51 of the next construction rod.

[0041] Furthermore, in this embodiment, as described above, the reinforcement method for the reinforced concrete column is configured such that temporary scaffolding 55 used when assembling the reinforcing bars 54 and cylindrical main formwork 12 is installed around the existing bridge pier 50, while maintaining space for the cylindrical main formwork 12 to be placed. Preferably, prior to the formwork sliding process or the formwork suspension and movement process, a scaffolding removal process (see Figures 11(c) and 12(b)) is carried out in which a portion of the temporary scaffolding 55 at the lowest construction rod section is removed so as not to hinder the movement of the divided main formwork 13.

[0042] Furthermore, in this embodiment, the reinforcement method for the reinforced concrete column preferably involves installing a cylindrical main formwork 12 around the lower end portion of the existing bridge pier 50, and pouring concrete into the rectangular cylindrical concrete pouring space 52 held between the existing bridge pier 50 and the formwork to form the reinforcing concrete layer 51 of the lowest construction rod. After demolding the divided main formwork 13, as shown in Figures 11(c) and 13(a), (b), the divided main formwork 13 is left in place at a predetermined height position on the surface of the upper end portion of the reinforcing concrete layer 51 of the lowest construction rod in the area where the divided main formwork 13 was demolded. The process involves installing height-adjustable support hardware (see Figures 14(a) and (b)) that uses at least two embedded anchors 57 (see Figure 13(b)) as support members to lock and support the lower end of the divided main formwork 16, and then performing a formwork reuse assembly process (see Figure 12(a)) in which the demolded divided main formwork 16 is lifted up and its lower end is locked to the height-adjustable support hardware 58 (see Figure 13(b)), and the cylindrical main formwork 12 for forming the reinforcing concrete layer 51 of the next stage of construction rods is assembled.

[0043] Here, as shown in Figures 14(a) and (b), the height adjustment support hardware 58 is a locking hardware made of angle steel having, for example, an L-shaped cross-section. One of the surfaces, the joint surface portion 58a, which is positioned in close contact with the surface of the reinforcing concrete layer 51, has a fastening slot 58c into which the adjustment plug 59a of the form tie (registered trademark) 59 is fastened. The fastening slot 58c is formed to extend diagonally in a straight line with respect to the support surface portion 58b to which the lower end of the divided main formwork 13 made of steel formwork panel 11 is locked. This makes it possible to adjust the height position of the support surface portion 58b as appropriate by changing the position of the fastening slot 58c into which the adjustment plug 59a, which is screwed into the embedded anchor 57 (see Figure 13(b)), is fastened.

[0044] Furthermore, in this embodiment, the reinforcement method for the reinforced concrete column preferably involves using the divided main formwork 13, which has been repurposed for the next stage of construction rods in the formwork repurposing assembly process, to pour concrete into the rectangular cylindrical concrete pouring space 52 held between the cylindrical main formwork 12 installed around the existing pier 50 and the existing pier 50, thereby forming the reinforcing concrete layer 51 of the next stage of construction rods. After demolding the divided main formwork 16, the upper end portion of the reinforcing concrete layer 51 of the next stage of construction rods in the area where the divided main formwork 13 was demolded... The system allows for the installation of height adjustment support hardware, which involves attaching height adjustment support hardware 58 (see Figures 14(a), (b)) to secure and support the lower end of the divided main formwork 13 using at least two embedded anchors 57 (see Figure 13(b)) left in place at a fixed height as support members, and a formwork reuse assembly process, in which the demolded divided main formwork 16 is lifted up and its lower end is secured to the adjustment support hardware 58, and then the cylindrical main formwork 12 for forming the reinforcing concrete layer 51 of the next stage of construction rods is assembled.

[0045] Furthermore, in this embodiment, the reinforcement method for reinforced concrete columns is such that, as described above, temporary scaffolding 55 used when assembling the reinforcing bars 54 and cylindrical main formwork 12 is installed around the existing bridge pier 50, maintaining space for the cylindrical main formwork 12 to be placed. Preferably, lifting equipment 61 supported and provided on the upper end of the installed temporary scaffolding 55 is used to lift and lower the divided main formwork 13 that is demolded and reused in the formwork reuse assembly process or the formwork re-reuse assembly process.

[0046] Furthermore, according to the reinforced concrete column formwork structure 10 of this embodiment, which has the above-described configuration, even in the case of large-scale columnar concrete structures (bridge piers) 50, it is possible to assemble them into a rectangular cylindrical shape more easily and accurately without using many separators 53, thereby efficiently and easily forming a rectangular cylindrical concrete pouring space 52, and also making it possible to firmly support the load due to the internal pressure applied to the formwork (cylindrical main formwork) 12 during concrete pouring in a stable state from the outside.

[0047] In other words, according to this embodiment, each divided main formwork 13 and divided support beam 15 is assembled on the ground to form a divided formwork structure 16 in which the divided main formwork 13 made of formwork units (steel formwork panels) 11 abuts against the divided support beam 15. These divided formwork structures 16 are then individually erected at the concrete pouring locations and connected together to form a rectangular cylindrical concrete pouring space 52 between the existing bridge pier 50 and the cylindrical main formwork 12. Since there is no need for large cranes, even when the bridge piers 50 are large in scale, it becomes possible to easily lift individual segmented formwork structures 16 without using large cranes or the like, and efficiently install cylindrical main formwork 12 of a predetermined height around the existing bridge piers 50. Furthermore, when concrete is poured, the load due to the internal pressure applied to the cylindrical main formwork 12 can be firmly and stably supported from the outside by multiple stages of annular support beams 14 that abut the outer circumference of the cylindrical main formwork 12 and are continuous in an annular shape, without the need for many separators.

[0048] Furthermore, according to the reinforced concrete column formwork structure 10 of this embodiment having the above-described configuration, the four segmented formwork structures 16 erected along each face of the bridge pier 50, which is a reinforced concrete column having a rectangular cross-sectional shape, can be smoothly connected and integrated, making it possible to form a rectangular cylindrical concrete pouring space 52 using a cylindrical main formwork 12 assembled in a rectangular cylindrical shape more easily and efficiently.

[0049] In other words, according to this embodiment, when the four divided formwork structures 16 are connected as a single unit, the four divided support beams 15 form a rectangular, continuous annular support beam 14 by the support beam joining structure 20. The support beam joining structure 20 is configured such that at each of the four corner joints where adjacent pairs of divided support beams 15 are joined at a right angle, the end face 17a of one divided support beam 15 abuts against the end side surface 17b of the other divided support beam 15, and the corner joining piece 21 is fitted from the outside into the right-angle portion between the respective end side surfaces 17b, 17b, thereby joining these end side surfaces 17b, 17b as a single unit. Therefore, preferably, by simply fastening the corner joint piece 21 to the right-angle portion between the end sides 17b, 17b using fastening bolt members 22, it becomes possible to more smoothly connect and integrate the four erected segmented formwork structures, making it possible to more efficiently form the rectangular cylindrical concrete pouring space 52 by the cylindrical main formwork 12 assembled in a rectangular cylindrical shape, and also making it possible to firmly support the load due to the internal pressure applied to the cylindrical main formwork 12 during concrete pouring in a stable state from the outside without using many separators, by the multiple stages of annular support beams 14 that abut the outer circumference of the cylindrical main formwork 12 and are continuous in an annular shape.

[0050] It should be noted that the present invention is not limited to the embodiments described above and can be modified in various ways. For example, the formwork structure for reinforced concrete columns of the present invention can be used not only when constructing an additional layer of reinforced concrete around an existing reinforced concrete column, such as a bridge pier, which has a rectangular cross-sectional shape, but also when constructing a new reinforced concrete column, such as a bridge pier, which has a rectangular cross-sectional shape, to form a rectangular column-shaped concrete casting space. The reinforced concrete column does not necessarily have to be a bridge pier; the formwork structure for reinforced concrete columns of the present invention can also be used when reinforcing or constructing other reinforced concrete columns that constitute various structures. [Explanation of Symbols]

[0051] 10. Formwork structure for reinforced concrete columns 11. Steel formwork panels (formwork units) 11a Face plate 11b Rib 11c Locking hole 11d Locking hardware 12. Cylindrical main body formwork 13-part main formwork 14. Annular support beam 15-segment support beam 15a channel steel 15b Through opening 15cm gap 15d End connecting plate 15e Through material 15f Square pipe washer 15g Beam Washer 16 Divided Formwork Structure 17a End face of the segmented support beam 17b End side of the segmented support beam 17b' The end side opposite to the end side to which the corner joint piece is joined. 20. Joint structure of support beams 21 Corner joint piece 21a Contact plate 21b Reinforcement Rib Plate 21c Bolt fastening hole 22 Fastening bolt member 22a External fastening plate 22b Inner fastening plate 50 Bridge piers (reinforced concrete columns) 51 Reinforced concrete layer 52. Rectangular cylindrical concrete pouring space 53 Separator 54 Reinforcement bars 55 Work scaffolding 56 workspace 57 Embedded anchors 58 Height-adjustable support hardware 58a Joint surface part 58b Support surface part 58c Fastening elongated hole 59 Form Tie (Registered Trademark) 59a Adjust Plug 60 Lifting equipment 61 Yang Chong Equipment

Claims

1. A formwork structure for reinforced concrete columns, which is installed when constructing an existing reinforced concrete column having a rectangular cross-sectional shape by adding a reinforcing reinforced concrete layer around it, or when constructing a new reinforced concrete column having a rectangular cross-sectional shape, It is composed of a cylindrical main formwork assembled into a rectangular cylindrical shape of a predetermined height by connecting and arranging multiple formwork units, and annular support beams attached in multiple stages in a rectangular ring shape in the circumferential direction along the outer circumference of the cylindrical main formwork. The cylindrical main formwork is formed into a rectangular cylindrical shape by joining and integrating four segmented main formworks, each positioned along the four sides of a rectangular cross-section, and the annular support beam is formed in a continuous rectangular annular shape on the outer circumference of the cylindrical main formwork by joining and integrating four segmented support beams, each positioned along the four sides of a rectangular cross-section. Each of the aforementioned divided main formwork and divided support beams is assembled on the ground to form four divided formwork structures with the divided main formwork abutting and joining to the divided support beams. These divided formwork structures are then individually erected at the concrete pouring locations and connected together to form a rectangular cylindrical or rectangular columnar concrete pouring space using the cylindrical main formwork. When the four divided formwork structures are connected as a single unit, the four divided support beams are joined at right angles to each other at the four corner joints of each adjacent pair of divided support beams using corner joint pieces having right-angled triangular portions, thereby forming a rectangular, continuous annular support beam. The support beam joining structure is such that, at each of the four corner joints where adjacent pairs of divided support beams are joined at a right angle, the end face of one divided support beam is brought into contact with the end side surface in a region spaced apart from the end face of the other divided support beam. The corner joining piece has a pair of contact plates that are positioned at right angles and can contact these end sides, and is fitted from the outside into the right-angle portion between the respective end sides of these right-angled pairs of adjacent divided support beams, thereby joining the end sides as a single unit and forming the annular support beam that is continuous in a rectangular ring shape. A formwork structure for reinforced concrete columns, wherein the load due to the internal pressure applied to the cylindrical formwork during concrete pouring is supported from the outside by multiple stages of annular support beams that abut the outer circumference of the cylindrical formwork and are continuous in a rectangular ring shape.

2. The formwork structure for reinforced concrete columns according to claim 1, wherein the formwork unit is made of steel formwork panels.

3. The formwork structure for reinforced concrete columns according to claim 1 or 2, wherein the divided support beam is made of a support beam for large formwork.

4. The formwork structure for a reinforced concrete column according to claim 1 or 2, wherein the formwork units are assembled together as a single unit via the divided support beams to form the divided main formwork.

5. The formwork structure for a reinforced concrete column according to claim 1 or 2, wherein the corner joint piece is configured to join each pair of adjacent segmented support beams at a right angle to each of the four corner joints via fastening bolt members that penetrate and fasten the segmented support beams.

6. The formwork structure for a reinforced concrete column according to claim 2, wherein the inner fastening plate, which is attached in close contact to the inner end surface of one of the divided support beams whose end faces abut against the side surface on which the corner joint piece is joined, is made up of a plurality of segmented plate members arranged in a divided state.

7. The formwork structure for reinforced concrete columns according to claim 1 or 2, wherein a bolt fastening hole is formed in the abutment plate of the corner joint piece, and the bolt fastening hole is an elongated hole that is elongated in the longitudinal direction of the abutment plate.

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