RCS Construction Method

Abstract

To provide an RCS construction method for constructing a mixed structure composed of reinforced concrete-constructed (RC) columns and steel construction (S) beams.SOLUTION: An RCS construction method includes the steps of: forming a column main body section (1a) below a connection site, leaving an under-beam space (5), and burying a lug screw bolt (6) at the upper edge of the column main body section so that the upper edge thereof faces the connection site (4); installing a joint fitting (7) at the connection site (4), and fixing and supporting a lower flange (8c) of orthogonal beams (8) of the joint fitting to the lug screw bolt (6); forming a column head section (1b) by placing concrete in a region (R) from the under-beam space (5) to the height position (H) of the top edge of an upper floor slab, including the internal space of the joint fitting, and forming a support section (15) with the lug screw bolt (6) buried below the joint fitting (7); and then connecting and fixing steel beams (2) to a bearing plate (9) of the joint fitting.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an RCS construction method for constructing a mixed structure consisting of reinforced concrete (RC) columns and steel frame (S) beams. [Background technology]

[0002] Conventionally, the RCS construction method is known for constructing a mixed structure consisting of reinforced concrete columns and steel beams, and in this case, metal joints are provided at the joints. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-275432 A [Patent Document 2] JP 2019-78068 A Summary of the Invention [Problem to be solved by the invention]

[0004] The types of connecting metal fittings available include the "hoop type" which has hoops attached to the cross-shaped orthogonal beams, the "cover plate type" which has a cover plate attached to the cross-shaped orthogonal beams, and the "diaphragm type" which has orthogonal beams formed on diaphragms arranged above and below and has a cover plate attached to them.

[0005] Generally, when forming a reinforced concrete column with the main bars extending upward, the RCS construction method is carried out by forming the main column body up to the joint area, installing a metal joint at the joint area, and passing the main bars through the metal joint. In this state, concrete is poured into the internal space of the metal joint to form the column head, and then a steel beam is connected and fixed to the perpendicular beam of the metal joint.

[0006] Conventionally, it has not been easy to accurately install metal joints in the designated positions at the joint area, and even if they were installed accurately, there is a risk of them becoming misaligned when the concrete is poured.

[0007] For this reason, it is desirable for the metal joint to be configured so that it can be easily installed in a positionable state and can be fixed in a stable state, and this is a problem that needs to be solved.

[0008] Furthermore, the metal joints that connect and fix the beams of steel-framed structures are supported at the column capitals formed at the joints, and it is desirable to configure them so that stable support is possible, and this is also a problem that needs to be solved.

[0009] An object of the present invention is to provide an RCS construction method that solves the above problems. [Means for solving the problem]

[0010] The present invention is thus configured as a means for constructing a mixed structure consisting of reinforced concrete columns and steel beams, and includes the steps of forming a reinforced concrete column body with its main bar extended upward toward the joint, leaving a space under the beam below the joint, embedding a lag screw bolt in the upper end of the column body, and bringing the upper end of the lag screw bolt into the joint, and fixing a bearing plate to the end face of an orthogonal beam that is connected to an H-shaped cross section member having upper and lower flanges, and fixing the upper end of the lag screw bolt to the end face of the adjacent beam. the steps of: installing a connecting metal fitting at the joint portion, which has an insertion space created by placing a cover plate between the support plates, and fixing the lower flange of the orthogonal beam to the lag screw bolt to support it, with the main reinforcement passing through the insertion space; forming a column head by pouring concrete into the area from the space under the beam to the height of the top edge of the upper floor slab, including the internal space of the connecting metal fitting, and forming a support part with a lag screw bolt embedded in the column head below the connecting metal fitting; and then connecting and fixing a steel beam to the support plate of the connecting metal fitting.

[0011] In a preferred embodiment of the present invention, with respect to the X-axis and Y-axis which are orthogonal at the center of the cross section of a column having a rectangular cross section, for the main reinforcement arranged near the corners of the rectangle, the lag screw bolts are arranged close to both sides of both axes to form a set of bolt groups, and the set of bolt groups is arranged at locations corresponding to the X-axis and Y-axis extending from the intersection of both axes, and the connecting metal is installed such that the webs of the H-shaped cross section members which constitute the orthogonal beam are aligned along the X-axis and Y-axis.

[0012] The connecting hardware preferably has a lower flange wider than an upper flange, and is configured so that the upper end of the lag screw bolt is fixed to the lower flange with a nut. Effect of the Invention

[0013] According to the present invention, when the joint metal 7 is installed in the joint portion 4, it is configured to be fixed and supported by the lag screw bolt 6, so that it is easy to position it and fix it in a stable state. In particular, when the column head portion 1b is formed by pouring concrete including the joint metal 7, the support portion 15 in which the lag screw bolt 6 with the male thread engaged is embedded is formed under the joint metal 7 in addition to the main reinforcement 3, and a strong structure is formed, which contributes to improving the strength of the column-beam joint. Furthermore, the joint metal 7 connected to the lag screw bolt 6 joined to the support portion 15 has excellent connection strength, and the support portion 15 can firmly support the joint metal 7 not only downward but also horizontally. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing an embodiment of the RCS construction method of the present invention, in which the column body of a reinforced concrete column has been formed and before the metal joints have been installed. [Diagram 2] FIG. 1A is a plan view showing the top surface of a column main body, and FIG. 1B is a perspective view showing the components of a metal joint in an exploded state, relating to an embodiment of the present invention. [Diagram 3]This is an oblique view showing the state in which a connecting metal fitting is installed at the joint portion above the column main body. [Figure 4] This is an oblique view showing a part of a metal joint installed at a joint portion in a broken state. [Diagram 5] 5 is a cross-sectional view taken along line AA in FIG. 4. [Figure 6] 6 is a cross-sectional view taken along line BB in FIG. 5. [Figure 7] FIG. 13 is a perspective view showing the state in which the column capital part has been formed. [Figure 8] A vertical cross-sectional view of a column capital including a connecting metal fitting. [Figure 9] FIG. 13 is a perspective view showing another embodiment of a metal joint. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0016] The present invention relates to an RCS construction method for constructing a mixed structure consisting of reinforced concrete columns 1 and steel beams 2, and is carried out by the following steps.

[0017] (Column body forming process) As in the past, reinforced concrete columns are formed by setting column rebars that extend over the entire height of the column, constructing forms, and pouring concrete, and as shown in Figure 1, a column body 1a that constitutes the main part of the column 1 is formed. Note that hoops are omitted from the drawing.

[0018] The column body 1a is formed toward the joint area 4 with the main reinforcement 3 extended upward. At that time, a space 5 under the beam is left under the joint area 4, and a lag screw bolt 6 is embedded in the upper end of the column body 1a facing the space 5 under the beam.

[0019] Although not shown in the figure, the lag screw bolt 6 is a well-known type having a male thread on the outer periphery and a female threaded hole on the upper end surface, and the lag screw bolt 6 of a predetermined length is embedded in the column main body 1a and is brought into contact with the joint portion 6 with its upper end aligned in height.

[0020] In this case, as shown in Fig. 2(A), with respect to the X-axis and Y-axis that are orthogonal at the center of the cross section of the column main body 1a having a rectangular cross section, the main reinforcement 3 is located near the corner of the rectangle and arranged along the L-shaped line of the corner. On the other hand, the lag screw bolts 6 are arranged close to each other on both sides of the X-axis and the Y-axis, forming a set of bolt groups 6U, and such a set of bolt groups 6U is arranged at four locations corresponding to the X-axis and the Y-axis extending from the intersection of the X-axis and the Y-axis. In the illustrated embodiment, the set of bolt groups 6U is composed of four lag screw bolts, but it may be composed of two lag screw bolts.

[0021] (Metal joint installation process) Next, as shown in FIG. 3, a metal joint 7 is installed at the joint portion 4.

[0022] As shown in Figure 2 (B) and Figures 3 to 6, the connecting metal fitting 7 is formed from steel plate and has an orthogonal beam 8 formed by connecting H-shaped cross-section members at right angles. A support plate 9 is fixed to the end face of the orthogonal beam 8, and a blocking plate 10 is placed between adjacent support plates 9, 9 to form an insertion space 11.

[0023] The H-shaped cross section member constituting the orthogonal beam 8 has an upper flange 8b and a lower flange 8c above and below a web 8a. In this case, the lower flange 8c is formed wider than the upper flange 8b, and a mounting hole 12 is drilled in the lower flange 8c at a position corresponding to the upper end of the lag screw bolt 6.

[0024] Therefore, the joint metal fittings 7 are installed in the joint area 4 so that the webs 8a of the H-shaped cross section members constituting the orthogonal beam 8 are aligned along the X-axis and Y-axis. At this time, with the main reinforcement 3 penetrating the insertion space 11, the lower flanges 8c of the orthogonal beam 8 are supported and fixed on the upper ends of the lag screw bolts 6.

[0025] The means for fixing the lower flange 8c and the lag screw bolt 6 is not particularly limited, but in the illustrated embodiment, as shown in Fig. 6, the lower flange 8c is placed on a support nut 13 screwed into the vicinity of the upper end of the lag screw bolt 6, the upper end of the lag screw bolt 6 extending from the support nut 13 is inserted into the mounting hole 12, and the fastening bolt 14 is screwed into a female threaded hole formed in the end face of the upper end, thereby fixing the lower flange 8c to the lag screw bolt 6. This makes it easy to position and fix the joint metal 7 when it is installed, and also makes it possible to adjust the level of the joint metal 7 by adjusting the support nut 13.

[0026] (Capital formation process) As described above, with the connecting metal fittings 7 fixed at the joint area 4 with the lag screw bolts 6, formwork is assembled and concrete is poured into the area R from the under-beam space 5 to the height position H of the top end of the upper floor slab, including the internal space of the connecting metal fittings 7, as shown in Figures 7 and 8, thereby forming the column capital part 1b.

[0027] At this time, since the lag screw bolt 6 has a male thread on the outer periphery, it is embedded in the concrete in an engaged state. Therefore, in the column head 1b, in the portion corresponding to the space under the beam 5 below the joint metal fitting 7, a support portion 15 is formed in which not only the main reinforcement 3 but also the lag screw bolt 6 are embedded in the concrete. As shown in Fig. 2(A), the main reinforcement 3 is embedded in the corner portion of the rectangular cross section, and the bolt group 6U of the lag screw bolt 6 is embedded in four places along the X-axis and Y-axis, so a strong support portion 15 is formed.

[0028] The connecting metal fittings 7, together with the main reinforcement bars 3 inserted vertically, restrain the concrete filled in the internal space, contributing to the formation of compression bundles (struts), and are integrally connected to the column head 1b by embedding the orthogonal beams 8 in the concrete.

[0029] The support part 15 forms a rigid structure with the main reinforcement 3 and the lag screw bolt 6 embedded in concrete, and firmly supports the joint metal 7 by connecting the lag screw bolt 6 to the lower flange 8c of the joint metal 7. This significantly improves the strength of the column-beam joint. The support part 15 not only supports the downward load of the joint metal 7, but also firmly supports the lateral load in the direction in which the joint metal 7 shears the column capital part 1b.

[0030] (Beam connection process) After the above steps, the steel beam 2 is connected and fixed to the bearing plate 9 of the joint metal 7 that is integrally connected to the column capital 1b, as shown in Figure 7. The connection and fixing method is the same as in the conventional method, by welding or other methods.

[0031] (Another embodiment of the metal joint) 9 shows another embodiment of the joint metal 7. The joint metal 7 has a beam connection member 16 with an H-shaped cross section fixed to the support plate 9 by welding or the like. In this case, the beam connection member 16 has upper and lower flanges 16a, 16b formed to the same width, similar to the H-shaped steel that constitutes the beam 2 of a steel-framed structure, and is fixed to the support plate 9 with a horizontal haunch 17 provided on the lower flange 16b.

[0032] Other configurations of the metal joint 7 are similar to those of the above-described embodiment, and as shown in FIG. 9, a steel-framed beam 2 is connected and fixed to the beam connection member 16. [Explanation of symbols]

[0033] 1. Reinforced concrete columns 1a Pillar body 1b Column head 2. Steel beams 3 Main reinforcement 4 Joints 5 Space under the beam 6 Lag screw bolt 7 Joint metal fittings 8 Orthogonal Beams 8a Web 8b Upper flange 8c Lower flange 9. Bearing Plate 10 Covering board 11 Insertion space 12 Mounting hole 13 Support nut 14 Fastening bolt 15 Support part 16 Beam connection member 16a Upper flange 16b Bottom flange 17 Horizontal corbel

Claims

1. This is an RCS construction method that constructs a mixed structure consisting of reinforced concrete columns and steel beams, and in the configuration where metal joints are installed at the joints, a process of forming a reinforced concrete column body with the main bars extended upward toward the joint portion (4), forming the column body portion (1a) so as to leave a space under the beam (5) below the joint portion, embedding a lag screw bolt (6) in the upper end of the column body portion, and bringing the upper end of the lag screw bolt into the joint portion (4); a process of fixing a support plate (9) to the end face of an orthogonal beam (8) formed by connecting H-shaped cross-section members having upper and lower flanges at right angles, and installing a connecting metal fitting (7) having an insertion space provided by placing a cover plate (10) between adjacent support plates at the joint portion (4), and at that time, fixing and supporting the lower flange (8c) of the orthogonal beam (8) to the lag screw bolt (6) with the main reinforcement (3) penetrating the insertion space (11); A step of forming a column capital part (1b) by pouring concrete into an area from the space under the beam (5) to the height position (H) of the top end of the upper floor slab, including the internal space of the connecting metal fittings, and forming a support part (15) with a lag screw bolt (6) embedded in the column capital part below the connecting metal fittings (7); Then, a step of connecting and fixing a steel beam (2) to the support plate (9) of the joint metal is performed.

2. With respect to the X-axis and Y-axis that are perpendicular to each other at the center of the cross section of the column having a rectangular cross section, the lag screw bolts (6) are arranged in the vicinity of the corners of the rectangle, and the lag screw bolts (6) are arranged in close proximity on both sides of the X-axis and Y-axis that are perpendicular to each other at the center of the cross section of the column. The lag screw bolts (6) form a set of bolt groups (6U) with the lag screw bolts arranged in close proximity on both sides of the X-axis and Y-axis that are arranged from the intersection of the X-axis and Y-axis. The RCS construction method according to claim 1, characterized in that the connecting metal (7) is formed by installing the web (8a) of an H-shaped cross-section member constituting the orthogonal beam (8) along the X-axis and Y-axis.

3. The RCS construction method according to claim 1 or 2, characterized in that the connecting metal (7) has a lower flange (8c) formed wider than an upper flange (8b), and the upper end of the lag screw bolt (6) is fixed to the lower flange with a nut (13).

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