Method for constructing building and joint member used therein

Abstract

To provide a method for constructing buildings efficiently and a joint member used therein.SOLUTION: A building comprises columns and steel beams made of reinforced concrete. This building includes joint members arranged at joints under column portions, with protruding plate portions protruding outward onto an upper edge of a blocking plate. Then, a plate forming a lower surface of a floor slab and slab reinforcement embedded in the floor slab on this plate are arranged by placing an end of the plate on the steel beams and the protruding plate portions. Next, the column portion at the level corresponding to the floor slab is constructed, and the joint member is arranged on this column portion. After repeating the above process to construct the column portions, concrete for the floor slab is placed at a timing independent of the construction of the column portions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a construction method for a building having columns made of reinforced concrete and steel beams, and a joint member used therein. [Background technology]

[0002] Conventionally, RCS buildings with reinforced concrete (RC) columns and steel-frame (S) beams have been known (see, for example, Non-Patent Document 1). The mixed RC column and S beam structure described in Non-Patent Document 1 uses S beams, making it suitable for long-span structures such as warehouses, shopping centers, and office buildings. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Obayashi Corporation, "Technology Introduction: 'Combined RC Column and S Beam Structure'", [online], Obayashi Corporation, [Retrieved January 29, 2024], Internet<URL:https: / / www.obayashi.co.jp / chronicle / database / t82.html> Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, when constructing a building with an RCS structure, reinforced concrete floor slabs are constructed, and then reinforced concrete columns are erected on top of these floor slabs, and this is repeated from the bottom floor onwards. In this case, it is necessary to wait until the concrete in the floor slab hardens and develops strength before constructing the columns above the floor slab. However, the hardening speed of the concrete can be slowed down by weather, etc. This makes it difficult to construct the building efficiently. [Means for solving the problem]

[0005] A construction method for a building that solves the above-mentioned problems is a construction method for a building having columns made of reinforced concrete and steel beams, in which a plate that constructs the underside of a floor slab and slab reinforcing bars that are embedded in the floor slab are placed, and before pouring the concrete for the floor slab, supports fixed to the upper surfaces of the steel beams that support the floor slab are used to adjust the installation direction of formwork for constructing column portions that are higher than the floor slab, and the formwork is used to pour the concrete for the column portions.

[0006] Furthermore, the joint component that solves the above problem is a joint component that is placed at the joint of a building having columns made of reinforced concrete and steel beams, and is equipped with a cover plate that is integrated with the end of the steel beam that supports the floor slab, and a protruding plate portion that protrudes outward at the upper end of the cover plate and on which the end of the plate that constructs the underside of the floor slab is placed. [Effects of the Invention]

[0007] According to the present disclosure, buildings can be constructed efficiently. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a flowchart of a building construction method according to an embodiment. [Figure 2] 1A and 1B are schematic diagrams illustrating a method for constructing a building according to an embodiment, in which (a) shows the column reinforcing bar installation process and (b) shows the system formwork installation process. [Figure 3] 1A and 1B are schematic diagrams illustrating a method for constructing a building according to an embodiment, in which (a) shows the process of pouring concrete into columns, and (b) shows the process of removing the system formwork. [Figure 4] This is an oblique view illustrating the state in which a joint member is placed on top of an upper column portion constructed on a floor slab before concrete is poured in an embodiment. [Figure 5] 10 is a schematic diagram illustrating the process of fixing the main body of a steel beam in the building construction method according to the embodiment. FIG. [Figure 6]FIG. 1 is a schematic diagram illustrating the steps from the deck laying process to the joint concrete pouring process of the building construction method in the embodiment. [Figure 7] 1 is a perspective view of a schematic configuration illustrating the state of the surroundings of the joint member after the joint concrete pouring process in the embodiment has been performed. FIG. [Figure 8] FIG. 2 is a perspective view illustrating the configuration of a joint member in the embodiment, as viewed from above. [Figure 9] FIG. 2 is a front view illustrating the configuration of a joint member in the embodiment. [Figure 10] FIG. 2 is a perspective view illustrating the configuration of a joint member in the embodiment, as viewed from below. [Figure 11] FIG. 1 is a perspective view of a system formwork according to an embodiment. [Figure 12] FIG. 10 is a horizontal cross-sectional view of a column formwork of a system formwork in an embodiment. [Figure 13] 1A and 1B are explanatory diagrams illustrating the configuration of the base part of the installation support member of the system formwork in the embodiment, where (a) is a front view and (b) is a right side view. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, one embodiment of a building construction method will be described with reference to Figures 1 to 13. The building of this embodiment has columns made of reinforced concrete (RC) and beams made of steel (S). Joint members having the configuration described below are placed at the joints of the building.

[0010] (Building construction method: installation of steel materials) Next, a construction method for constructing a building will be described with reference to FIGS. As shown in Fig. 1, first, a column reinforcing bar ground assembling step is carried out (step S11). Specifically, column reinforcing bars R2 to be embedded in the column portions C2 of the target floor of construction are assembled.

[0011] Next, the column reinforcing bar erection process is carried out (step S12). Specifically, as shown in Figure 2(a), the column reinforcing bars R2 assembled in step S11 are integrated with the column reinforcing bars R1 protruding upward from the joint member 20 by bundling or the like. Here, the column reinforcing bars R1 are embedded in the concrete within the joint member 20 and in the column portion C1 of the lower floor directly below the floor to be constructed.

[0012] (Configuration of joint member 20 arranged at the joint of the building) Here, the configuration of the joint member 20 will be described in detail with reference to Figures 8 to 10. Figures 8 to 10 are a perspective view of the joint member 20 as seen from above, a front view, and a perspective view as seen from below, respectively.

[0013] 8 to 10, the joint member 20 includes a tubular closing plate 21 having a square cross section. At the upper end of each corner of this closing plate 21, an L-shaped protruding plate portion 22 is formed that protrudes outward in the horizontal direction. Beam end portions 23, 24, 25, and 26 are fixed to the outer surfaces of each side of the covering plate 21. The beam end portions 23, 24, 25, and 26 are arranged so as to be perpendicular and in a straight line. The beam end portions 23, 24, 25, and 26 are made of H-shaped steel and form the end portions of steel beams 123, 124, 125, and 126, which are made of H-shaped steel and will be described later.

[0014] In this embodiment, the upper flanges of the beam ends 23, 24, 25, and 26 are positioned so as to be at the same height as the upper surface of the cover plate 21. These upper flanges are extended into the interior of the cover plate 21 and integrated to form a cross-shaped inner upper flange 27. The upper end of the above-mentioned cover plate 21 is fixed to the lower surface of this inner upper flange 27 by welding or the like. This inner upper flange 27 is positioned so as to be flush with the above-mentioned protruding plate portion 22.

[0015] As shown in FIG. 9, the lower flanges of the beam ends 23, 24, 25, 26 are located at a height H1 higher than the lowermost end (lower surface) of the covering plate 21. As shown in FIG. 10, a cross-shaped inner lower flange 29 is fixed to the inside of the closing plate 21 at the same height as the lower flanges of the beam ends 23 to 26. Furthermore, four plate-shaped reinforcing members 30 are fixed inside the closing plate 21 so as to extend vertically and be spaced apart from each other so as to be perpendicular to the inner upper flange 27 and the inner lower flange 29 .

[0016] 8, a support column 35 is fixed to the center (the intersection of the cross) of the inner upper flange 27. This support column 35 has four support plates 36 that are spaced apart and approximately perpendicular to each other and fixed to the inner upper flange 27, and a flat plate 37 that extends approximately horizontally. The lower surface of this flat plate 37 is fixed to the upper ends of the multiple support plates 36 by welding, so that the flat plate 37 is supported by the support plates 36. When the above-described joint member 20 is placed in the joint, the column reinforcing bars R2 penetrate through it and the inside is filled with concrete, thereby forming a joint in the building.

[0017] (Building construction method: Construction for pouring concrete) Then, when the above-mentioned column reinforcing bar erection process (step S12) is completed, the system formwork erection process is carried out (step S13). 2(b), in this step, a system formwork 40 is placed around the column reinforcing bars R2. The configuration of this system formwork 40 and the system formwork erection step will be described in detail later.

[0018] Next, a formwork adjustment step is carried out (step S14), which will also be described in detail later.

[0019] Next, the pillar concrete pouring process is carried out (step S15). Specifically, as shown in Figure 3(a), concrete is poured from above into a partitioned space inside the system formwork 40. The concrete is then allowed to harden. This forms a column section C2 inside the system formwork 40. The beam section 35 of the joint member 20 is embedded in the lower end of this column section C2. By embedding this beam section 35 in the concrete of the column section C2, the joint member 20 and the column section C2 directly above it are integrated.

[0020] Next, a system formwork removal step is carried out (step S16). Specifically, as shown in Figure 3(b), the system formwork 40 is removed. This exposes the column section C2 of the floor to be constructed, with the column reinforcing bars R2 protruding from above. Then, multiple level adjustment bolts and multiple spaced-apart positioning angles are attached to the upper surface of the formed column section C2. Each level adjustment bolt is positioned so that when the connection member 20 is placed on top, the lower surfaces of the four ends of the cross-shaped inner bottom flange 29 of the connection member 20 will abut against them. Furthermore, the positioning angle is positioned so that one side of the positioning angle will align with a side of the cross-shaped inner bottom flange 29 when the connection member 20 is placed in the correct position.

[0021] (Building construction method: Construction on upper floors) Next, the step of installing the joint members is carried out (step S17). Specifically, as shown in Figure 4, the joint member 20 is placed on the column portion C2. In this case, the column reinforcing bar R2 is positioned within the cover plate 21 so as to avoid the inner lower flange 29 and the inner upper flange 27, and therefore protrudes upward from the joint member 20.

[0022] Furthermore, here, as shown by the two-dot chain line in Figure 9, the joint member 20 is placed so that the lower end of the cover plate 21 fits inside the upper end of the pillar portion C2. Then, the horizontal position of the joint member 20 relative to the pillar portion C2 is adjusted by aligning the positioning angle along the edge of the inner lower flange 29. Furthermore, the amount of engagement of the level adjustment bolt is adjusted so that the joint member 20 placed on the pillar portion C2 stands upright in the vertical direction.

[0023] Next, as shown in Figure 4, a ladder 80 is installed so as to span the pillar portion C2 and the joint member 20. Specifically, the upper end of the ladder 80 is fixed to a support member 81 fixed to the upper flange of the joint member 20, and the lower end of the ladder 80 is fixed to a support member 82 fixed to the pillar portion C2.

[0024] Next, a process for fixing the main body of the steel beam is carried out (step S18). Specifically, as shown in Fig. 5, after the main body portions b1 of the steel beams 123-126 are erected between the beam end portions 23-26 of adjacent joint members 20, the end portions are connected to each other using splice plates, high-strength bolts, etc. Furthermore, if necessary, the beam end portions 23-26 and the main body portions b1 of the steel beams 123-126 are welded together.

[0025] Next, the deck laying and slab reinforcing bar placement process is carried out (step S19). Specifically, as shown in Fig. 6, the deck plate P1 is placed so that its ends rest on the protruding plate portions 22 of the joint members 20 and the steel beams 123 to 126. Then, the slab reinforcing bars are placed on top of the deck plate P1.

[0026] Next, a joint concrete pouring step is carried out (step S20). Specifically, the closing plate 21, the inner lower flange 29, and the column portion C2 of the joint member 20 are used as a formwork for joint concrete, and concrete is poured into these and allowed to harden. 7, the column reinforcing bars R2 that penetrate the inside of the closing plate 21 of the joint member 20 are solidified with concrete. At this time, the end of the deck plate P1 is placed on the end of the protruding plate portion 22 of the joint member 20 and the end of the beam ends 23 to 26. Furthermore, slab reinforcing bars SR1 are placed on the deck plate P1.

[0027] Thereafter, with concrete poured into such joint member 20, column reinforcing bar R2 is changed to column reinforcing bar R1, and the floor to be constructed is set to the floor directly above, and the above-mentioned process (steps S11 to S20) is repeated. In this way, without pouring concrete for the floor slab, column portion C2 of the floor to be constructed, which is located higher than this floor slab, is gradually constructed.

[0028] After that, when the weather remains fine for a while, concrete for the floor slabs is poured. In this case, concrete for the floor slabs of multiple floors may be poured simultaneously. With the above steps, the building is completed.

[0029] (Configuration of System Formwork 40) Here, the configuration of the system formwork 40 used for pouring concrete into the column portions C2 of each floor will be described with reference to Figs. 11 to 13.

[0030] Figure 11 is an overall view of the system formwork 40, and Figure 12 is a horizontal cross-sectional view of the column formwork 41 of the system formwork 40. Also, Figure 13 is an explanatory diagram illustrating the configuration around the base member 53 of the installation support member 50 of the system formwork 40. Here, Figure 13(a) is a front view, and Figure 13(b) is a right side view of Figure 13(a).

[0031] As shown in FIG. 11, the system formwork 40 includes a column formwork 41, a construction support member 50, and a formwork scaffolding 60. As shown in Figure 12, a column formwork 41 has a pair (two) of identically shaped formwork components 42. Each formwork component 42 has a substantially L-shaped cross section. Each formwork component 42 includes a plurality of wales (horizontal battens) 43, a plurality of truss beams (vertical battens) 45, hook straps 44, and two plywood panels 46. Each wale 43 has a substantially L-shaped shape. The hook straps 44 secure the wales 43 and the truss beams 45 together. The wales 43 have a substantially L-shaped horizontal cross section.

[0032] 11, the plurality of wales 43 are arranged spaced apart from one another in the vertical direction, and the plurality of truss beams 45 are arranged spaced apart from one another in the horizontal direction. 12, two plywood panels 46 are fixed to the truss beam 45 so as to form an L-shape. The size of the plywood panels 46 corresponds to the size of the column portions C1 and C2. Therefore, in this embodiment, the plywood panels 46 are formed to a size that will form the column portions C1 and C2 that are sized to fit into the closing plates 21 of the joint members 20.

[0033] As shown in FIG. 11 , the installation support members 50 function as supports and are arranged in two perpendicular directions on different formwork constituent members 42. In this embodiment, two installation support members 50 are provided in the same direction, spaced apart by a distance that allows them to be fixed to the same steel beam 123 (124). Each installation support member 50 includes a long first support member 51, a short second support member 52, and a base member 53. The first and second support members (51, 52) are extendable and can be fixed at any position, and they respectively fix the upper and lower parts of the same truss beam 45. The first and second support members (51, 52) adjust the angle of the truss beam 45 from the horizontal plane, thereby adjusting the vertical angle of the formwork constituent member 42.

[0034] 12, the column formwork 41 further includes a fixing member 47 and a tie rod 48 for fixing the ends of a pair of formwork constituent members 42. The fixing member 47 is a member that fixes the tie rod 48 to the wale 43. The tie rod 48 fixes the ends of adjacent formwork constituent members 42 together by tightening the wing nuts attached to both ends and then driving wedges into the tie rod 48.

[0035] As shown in FIG. 13(a), the base member 53 supports the lower ends of the first and second support members (51, 52). Specifically, as shown in FIG. 13(b), the base member 53 has a U-shape with an open top, and rotatably fixes the lower ends of the first and second support members (51, 52) with bolts or the like.

[0036] As shown in Fig. 11, the formwork scaffolding 60 has an upper scaffolding 61 and a ladder 63. The upper scaffolding 61 and the ladder 63 are fixed to the wales 43 of the formwork constituent members 42. The upper scaffolding 61 is a scaffolding provided above the column formwork 41. The ladder 63 is provided so that a worker can stand on the upper scaffolding 61 to pour concrete through the opening of the column formwork 41, which is open at the top.

[0037] (Details of the erection process and formwork adjustment process using the system formwork 40) In the system formwork erection process in step S13, the system formwork 40 is installed while being assembled.

[0038] Specifically, first, a release agent is applied to the inside surfaces of the plywood 46 of the above-mentioned system formwork 40. Then, the formwork components 42 with the formwork scaffolding 60 attached are placed on top of the joint members 20. In this case, the plywood 46 of the formwork components 42 are placed so as to form a square shape.

[0039] Next, a tie rod 48 is passed through fixing members 47 fixed to the ends of the wales 43 of different formwork components 42. Then, wing nuts attached to both ends of the tie rod 48 are tightened, and a wedge is driven in to secure the ends of the pair of formwork components 42 together.

[0040] Next, the installation support member 50 is attached to the column formwork 41. 13, first, a pedestal 71 is placed on the main body b1 of the steel beams 123, 124 in the direction in which the installation support member 50 is to be attached. The pedestal 71 is then fixed to the main body b1 via L-shaped angles 72 arranged in the extension direction of the steel beams 123, 124. Next, a base member 53, to which the lower ends of the first and second support members (51, 52) of the installation support member 50 are attached, is fixed to the pedestal 71.

[0041] In this case, as shown in Figure 12, the position of the base member 53 is adjusted and then fixed to the base 71 so that the first and second support members (51, 52) are attached to the truss beam 45 at the same distance from the perpendicular central axes C5, C6 of the formwork component member 42.

[0042] Then, as shown in FIG. 11, the upper ends of the first support member 51 and the second support member 52 are attached to the upper and lower parts of the same truss beam 45, respectively. Then, in the formwork adjustment process of step S14, the lengths of the first support member 51 and the second support member 52 of the installation support member 50 are adjusted, thereby adjusting the vertical angle of the column formwork 41 of the system formwork 40 in the two orthogonal axial directions.

[0043] (Operation of the embodiment) By fixing the base member 53 of the installation support member 50 to the upper flanges of the steel beams 123, 124, the formwork component member 42 of the system formwork 40 is supported, and the angle of the installation direction (vertical direction) of the system formwork 40 can be adjusted.

[0044] According to this embodiment, the following effects can be obtained. (1) In this embodiment, the deck plate P1 and slab reinforcing bars SR1 of the floor slab are placed on top of the steel beams 123 to 126, and concrete is poured using the system formwork 40. This constructs the column portion C2 located above the floor slab. Therefore, the column portion C2 above the floor slab can be formed and the steel beams 123 to 126 can be erected without waiting for the completion of the time-consuming process of pouring concrete for the floor slab, allowing for efficient construction of the building.

[0045] (2) In this embodiment, the base member 53 of the installation support member 50 of the system formwork 40 is fixed to the main body b1 of the steel beams 123, 124. This allows the vertical angle of the column portion C2 to be adjusted even before the concrete for the floor slab is poured.

[0046] (3) In this embodiment, the joint member 20 placed on the column portions C1, C2 has a protruding plate portion 22 that protrudes outward from the upper end of the closing plate 21. This allows the end of the deck plate P1 that forms the underside of the floor slab to be placed not only on the steel beams 123-126 but also on the protruding plate portion 22 of the joint member 20. Therefore, the concrete that forms the column portions C1, C2 that are fitted into the joint member 20 can be poured without leaking from around the joint member 20.

[0047] (4) In this embodiment, the column beam portion 35 of the joint member 20 is embedded in the lower end of the column portion C2. Furthermore, concrete is poured into the joint member 20 with the column reinforcing bars R1 and R2 of the column portion C2 penetrating the joint member 20 in the vertical direction. This integrates the joint member 20 and the column portions C1 and C2.

[0048] (5) In this embodiment, the joint member 20 has an inner lower flange 29 at a position higher than the lowest end (lower surface) of the covering plate 21 by a height H1. This inner lower flange 29 is placed on the column portion C1, so that the lower end of the joint member 20 is fitted into the upper end of the column portion C1, and concrete can be poured into the covering plate 21, allowing the joint of the building to be efficiently constructed with concrete.

[0049] (6) In this embodiment, the upper surface of the pillar portion C2 is provided with a level adjustment bolt for adjusting the height of the joint member 20 and a positioning angle for positioning the joint member 20. This allows the vertical angle and horizontal position of the pillar portion C2 and the joint member 20 to be efficiently adjusted.

[0050] (7) In this embodiment, the beam ends 23 to 26 constituting the steel beams 123 to 126 are integrally fixed to the joint member 20. As a result, by connecting the main body b1 of the steel beams 123 to 126 to the beam ends 23 to 26 of the joint member 20, the steel beams 123 to 126 can be efficiently connected to the reinforced concrete columns.

[0051] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. In the above embodiment, the joint member 20, which includes the beam ends 23-26 of the steel beams, the L-shaped protruding plate portion 22, and the cross-shaped inner lower flange 29, is arranged in the joint of a building. However, the configuration of the joint member 20 that constitutes the joint is not limited to this. For example, a joint member whose ends are not integrated so that the steel beams can be fixed to the joint member later by welding or the like may be used, or a joint member without the protruding plate portion 22 may be used.

[0052] In the above embodiment, concrete was poured for floor slabs on multiple floors simultaneously. Depending on the weather and the timing of the construction process, concrete pouring for floor slabs may be carried out one by one, or concrete pouring for one or more floor slabs may be started while concrete pouring for other floor slabs is in progress. Even in these cases, concrete pouring for floor slabs can be carried out regardless of the timing of column construction, allowing for efficient construction of buildings.

[0053] In the above embodiment, the column concrete pouring step (step S15) uses the system formwork 40. The column concrete pouring step is not limited to using the system formwork 40, and may be performed using a normal formwork. In the above embodiment, the slab reinforcing bars SR1 are placed after the deck plate P1 is placed. Alternatively, a deck plate integrated with the slab reinforcing bars may be placed.

[0054] In the above embodiment, a building with reinforced concrete columns has been described. The reinforced concrete columns may also be columns of reinforced concrete construction (steel-reinforced concrete construction) with steel frames embedded inside. In this case, the lower end of a steel frame member is fixed onto the column post portion 35 of the joint member 20 embedded in the lower part of the column portion C2, and after placing reinforcing bars around the steel frames, concrete is poured.

[0055] Next, the technical ideas that can be understood from the above-described embodiment and other examples will be described below. (a) The joint member has a configuration in which the end of the steel beam supporting the floor slab is integrated, A construction method according to any one of claims 1 to 3, characterized in that the joint member is placed in the joint below the column member, and then the main body of the steel beam is connected to the end of the joint member, thereby constructing the steel beam.

[0056] (b) The joint member has a configuration in which the closing plate fits into the upper end of the pillar portion, A building construction method as described in claim 2, 3 or (a), characterized in that the joint member fits into the upper end of the column portion, and after adjusting the height and position of the joint member relative to the column portion, concrete is poured inside the cover plate of the joint member. [Explanation of symbols]

[0057] b1...main body, C1, C2...column section, C5, C6...central axis, P1...deck plate, R1, R2...column reinforcing bar, SR1...slab reinforcing bar, 20...joint member, 21...covering plate, 22...projecting plate section, 23, 24, 25, 26...beam end section, 27...inner upper flange, 29...inner lower flange, 30...reinforcing member, 35...stud column section, 36...support plate, 37...flat plate, 40...system formwork, 41...column formwork, 42...formwork component section Materials, 43...Wales, 44...Hook straps, 45...Truss beams, 46...Plywood, 47...Fixing members, 48...Tie rods, 50...Installation support members as supports, 51...First support members, 52...Second support members, 53...Base members, 60...Formwork scaffolding, 61...Upper scaffolding, 63, 80...Ladders, 71...Base, 72...L-shaped angles, 81, 82...Support members, 123, 124, 125, 126...Steel beams.

Claims

1. A construction method for a building having columns made of reinforced concrete and steel beams, Arrange plates that construct the underside of the floor slab and slab reinforcing bars that are embedded in the floor slab; Before pouring the concrete for the floor slab, Using supports fixed to the upper surfaces of the steel beams supporting the floor slab, adjust the vertical direction of formwork for constructing column portions higher than the floor slab; A building construction method characterized by using the formwork to pour concrete into the column portions.

2. A joint member having a protruding plate portion protruding outward from the upper end of the closing plate is disposed at the joint below the pillar portion, The method for constructing a building according to claim 1, characterized in that the plate is laid by placing the ends of the plate on the ends of the steel beams and on the ends of the protruding plate portions, and then the slab reinforcing bars are placed on top of the plate.

3. On the joint member, a column reinforcing bar to be embedded in the column portion constructed directly above the joint member is placed, The column reinforcing bars are covered with the formwork, After adjusting the angles of the two directions perpendicular to the horizontal direction in the formwork using the support, 3. The building construction method according to claim 2, further comprising pouring concrete into the formwork.

4. A joint member to be placed at the joint of a building having a column made of reinforced concrete and a steel beam, A cover plate that is integrated with the end of the steel beam that supports the floor slab, A joint member characterized by having a protruding plate portion that protrudes outward at the upper end of the closing plate and on which the end of a plate that constructs the underside of the floor slab is placed.

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