Slab support structure, and construction method of slab support structure

Abstract

To improve construction workability of a slab support structure suppressing concrete breaking in a side without any floor slab for studs.SOLUTION: A slab support structure is provided with: a steel beam extending in a first direction to support an end part of a floor slab in a second direction intersecting the first direction; and a plurality of studs arranged with an appropriate interval therebetween in the first direction at an upper part of the steel beam. The slab support structure further comprises: a first auxiliary reinforcement bar having a part extending in the second direction at a higher position than that of an apex of the studs, with one end positioned on an upper part of the steel beam as well as a folded part folded downward at the one end; and a second auxiliary reinforcement bar extending in the first direction at a lower position than that of the apex of the studs, and relating to the studs at a side without any floor slab for the studs. A part of the folded part is positioned lower than the apex of the studs and the second auxiliary reinforcement bar relates to a part of the folded part.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a slab support structure in which a floor slab is supported by steel beams, and a construction method for the slab support structure.

Background Art

[0002] Conventionally, as a floor structure for buildings, floor structures in which a reinforced concrete floor slab, a floor slab formed by placing a concrete layer on a deck plate, or the like is installed on an H-shaped steel steel beam have been widely used. In such a floor structure, when a large external force acts on the floor structure due to an earthquake or the like, a phenomenon of lateral buckling of the H-shaped steel may occur. Here, "the H-shaped steel beam laterally buckles" means that the upper part or the lower part of the H-shaped steel beam moves horizontally, or the H-shaped steel beam displaces in the direction of rotation about the material axis. In order to solve such problems, it has been conventionally shown that joining headed studs to steel beams and embedding the headed studs in the concrete of the floor slab to integrate the concrete and the steel beams is effective as a method for suppressing the above-mentioned lateral buckling.

[0003] Here, as shown in Patent Document 1, in a slab support structure in which a floor slab is arranged only on one side of a steel beam, when a large external force acts due to an earthquake or the like, the headed studs tend to displace to the side where the floor slab is not arranged due to the lateral buckling of the H-shaped steel beam, which may cause the concrete on the side without the floor slab relative to the headed studs to be destroyed. In the following description, the term "displacement of the headed stud" in the present specification means that when a large external force acts on the floor structure due to an earthquake or the like, the headed stud displaces to the side where the floor slab is not arranged due to the lateral buckling of the H-shaped steel beam. In view of such problems, Patent Document 1 proposes a slab support structure in which mesh-shaped reinforcing bars are arranged around the headed studs. Such reinforcing bars suppress the displacement of the headed studs, suppress the lateral buckling of the H-shaped steel beam, and consequently suppress the destruction of concrete.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-206812 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Mesh-like reinforcing bars need to interact with headed studs, and therefore it is desirable to place the mesh-like reinforcing bars below the top of the headed studs. However, for example, when using load-bearing bars such as truss bars in a floor slab, attempting to place the mesh-like reinforcing bars from above the construction area may result in interference with the load-bearing bars, making it impossible to place the mesh-like reinforcing bars below the top of the headed studs. In such cases, it is necessary to lengthen the headed studs in the affected area, but if headed studs of different lengths are mixed, construction management becomes complicated, and lengthening all headed studs may lead to increased costs or the risk of not being able to secure sufficient concrete cover thickness on the top surface of the headed studs. In addition, even if the length of the headed studs is lengthened, depending on the position of the headed studs, the mesh-like reinforcing bars may interfere with the headed studs when attempting to place them from above the construction area. This invention was made in view of such problems, and its purpose is to improve the constructability of a slab support structure that suppresses concrete failure on the side of the stud where there is no floor slab. [Means for solving the problem]

[0006] To solve the above problems, a slab support structure according to a first aspect of the present invention comprises: a steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction; and a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, wherein the slab support structure comprises: a first reinforcing bar having a portion extending in the second direction at a position higher than the top of the stud, one end of which is located on the upper part of the steel beam and has a bent portion formed at the one end that bends downward; and a second reinforcing bar extending in the first direction at a position lower than the top of the stud and engaging with the stud on the side of the stud where there is no floor slab, wherein a part of the bent portion is located lower than the top of the stud, and the second reinforcing bar engages with a part of the bent portion.

[0007] According to this embodiment, the first reinforcing bar, which has a bent portion formed above it, is provided with a second reinforcing bar that engages with the stud at a position lower than the top of the stud, and the first reinforcing bar engages with the second reinforcing bar at the bent portion. Therefore, during construction, there is no interference between the mesh-like reinforcing bar and the load-bearing bars or the stud, as in a structure where mesh-like reinforcing bars are placed above the stud. Furthermore, there is no need to increase the length of the stud. As a result, the constructability of the slab support structure can be improved.

[0008] Furthermore, in this specification, "the second reinforcing bar is involved with the stud" is not limited to a relationship in which the second reinforcing bar and the stud are in direct contact, but also includes a relationship in which the second reinforcing bar is influenced by the stud through a material such as concrete when an external force acts on the slab support structure due to an earthquake or the like. Similarly, the phrase "(the bent portion of the first reinforcing bar) is related to the second reinforcing bar" is not limited to a relationship in which the bent portion and the second reinforcing bar are in direct contact, but also includes a relationship in which the bent portion is influenced by the second reinforcing bar through a material such as concrete when an external force acts on the slab support structure due to an earthquake or the like.

[0009] A second embodiment is characterized in that, in the first embodiment, the portion of the first reinforcing bar that extends in the second direction at a position higher than the top of the stud is at a position higher than the load-bearing bars that constitute the floor slab.

[0010] According to this embodiment, the portion of the first reinforcing bar that extends in the second direction at a position higher than the top of the stud is at a higher position than the load-bearing bars that constitute the floor slab. Therefore, even when arranging the first reinforcing bar to avoid the load-bearing bars, the displacement of the stud can be suppressed by the bent portion of the first reinforcing bar and the second reinforcing bar.

[0011] A slab support structure according to a third embodiment is a slab support structure comprising: a steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction; and a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, wherein the slab support structure comprises a first reinforcing bar having a bent portion formed at one end and the other end facing inward towards the construction area of ​​the floor slab, wherein the bent portion engages with the stud at a position lower than the top of the stud, and the bent portion is fixed to a second reinforcing bar extending in the first direction on the upper part of the steel beam.

[0012] According to this embodiment, since the bent portion of the first reinforcing bar engages with the stud at a position lower than the top of the stud, interference between the mesh-like reinforcing bar and the load-bearing bar or the stud does not occur during construction, unlike in structures where mesh-like reinforcing bars are placed on top of the stud. Furthermore, there is no need to increase the length of the stud. As a result, the constructability of the slab support structure can be improved. Furthermore, since the bent portion is fixed to the second reinforcing bar extending in the first direction at the upper part of the steel beam, the posture of the first reinforcing bar becomes more stable, improving workability and further suppressing the displacement of the studs. Furthermore, in this specification, the phrase "(the bent portion of the first reinforcing bar) is engaged with the stud" is not limited to a relationship in which the bent portion and the stud are in direct contact, but also includes a relationship in which the bent portion is influenced by the stud through a material such as concrete when an external force acts on the slab support structure due to an earthquake or the like.

[0013] A construction method for a slab support structure according to a fourth embodiment is a construction method for a slab support structure comprising: a steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction; and a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, the method comprising: a first step of arranging a first reinforcing bar having a portion extending in the second direction at a position higher than the top of the stud, one end of which is located on the upper part of the steel beam and has a bent portion formed at the one end that bends downward; and a second step of arranging a second reinforcing bar extending in the first direction at a position lower than the top of the stud, which engages with the stud on the side of the stud where there is no floor slab, so as to engage with a part of the bent portion.

[0014] According to this embodiment, the construction is such that the second reinforcing bar engages with the stud at a position lower than the top of the stud, and the first reinforcing bar, on which the bent portion is formed, engages with the second reinforcing bar at the bent portion. Therefore, during construction, there is no interference between the reinforcing bar and the stud, as in the configuration where a mesh-like reinforcing bar is placed on top of the stud. As a result, there is no need to increase the length of the stud, and thus the constructability of the slab support structure can be improved.

[0015] Furthermore, as described above, the phrase "the second reinforcing bar is involved with the stud" is not limited to a relationship in which the second reinforcing bar and the stud are in direct contact, but also includes a relationship in which the second reinforcing bar is influenced by the stud through a material such as concrete when an external force acts on the slab support structure due to an earthquake or the like. Similarly, the phrase "(the bent portion of the first reinforcing bar) is related to the second reinforcing bar" is not limited to a relationship in which the bent portion and the second reinforcing bar are in direct contact, but also includes a relationship in which the bent portion is influenced by the second reinforcing bar through a material such as concrete when an external force acts on the slab support structure due to an earthquake or the like.

[0016] A construction method for a slab support structure according to a fifth embodiment is a construction method for a slab support structure comprising: a steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction; and a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, the method comprising: a first step of inserting a first reinforcing bar having a bent portion formed at one end into the construction area of ​​the floor slab from the side with the other end of the first reinforcing bar facing the tip; and a second step of fixing the first reinforcing bar such that the bent portion engages with the stud at a position lower than the top of the stud.

[0017] According to this embodiment, in the first step, the first reinforcing bar, which has a bent portion formed at one end, is inserted from the side into the construction area of ​​the floor slab with the other end of the first reinforcing bar facing the tip. This makes it less likely for the first reinforcing bar to interfere with other reinforcing bars when positioning it. Then, in the second step, the first reinforcing bar is fixed so that the bent portion engages with the stud at a position lower than the top of the stud. Therefore, during construction, there is no interference between the mesh-like reinforcing bar and the load-bearing bars or the stud, as can occur in structures where mesh-like reinforcing bars are placed on top of the stud. Furthermore, there is no need to increase the length of the stud. As a result, the constructability of the slab support structure can be improved. Furthermore, the phrase "(the bent portion of the first reinforcing bar) is involved with the stud" is not limited to a relationship in which the bent portion and the stud are in direct contact, but also includes a relationship in which the bent portion is influenced by the stud through a material such as concrete when an external force acts on the slab support structure due to an earthquake or the like.

[0018] A sixth aspect is characterized in that, in the fifth aspect, the method includes a step of fixing the bent portion to a second reinforcing bar extending in the first direction at an upper portion of the steel beam. According to this aspect, since the method includes the step of fixing the bent portion to the second reinforcing bar extending in the first direction at the upper portion of the steel beam, the posture of the first reinforcing bar is easily stabilized, the workability is further improved, and the displacement of the stud can be further suppressed.

[0019] A seventh aspect is characterized in that, in the fifth or sixth aspect, the floor slab has a convex portion at a bottom portion, and the first reinforcing bar is arranged in an inclined manner so as to avoid the convex portion. According to this aspect, when the floor slab has the convex portion at the bottom portion, the first reinforcing bar can be appropriately arranged. [Brief Description of the Drawings]

[0020] [Figure 1] A perspective view of a steel structure provided with a slab support structure according to the present invention. [Figure 2] A perspective view of a slab support structure according to a first embodiment. [Figure 3] A plan view of the slab support structure according to the first embodiment. [Figure 4] A side sectional view of the slab support structure according to the first embodiment. [Figure 5] A plan view of a slab support structure according to a second embodiment. [Figure 6] A side sectional view of the slab support structure according to the second embodiment. [Figure 7] A plan view of a slab support structure according to a modification of the second embodiment. [Figure 8] A side sectional view of the slab support structure according to the modification of the second embodiment. [Mode for Carrying Out the Invention]

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment, the same components are denoted by the same reference numerals, and only the first embodiment will be described; the description of those components will be omitted in subsequent embodiments. The XYZ coordinate system shown in each figure is a Cartesian coordinate system, where the X direction is an example of a first direction, the Y direction is an example of a second direction that intersects the first direction, and the Z direction represents the vertical direction. Furthermore, to avoid making the diagrams too complex, symbols are only assigned to some of the identical reinforcing bars present in multiple locations, while symbols are omitted for the others. Similarly, to avoid further complexity in the illustrations, hatching of the cross-sections of each component is omitted, and the diagrams primarily show the reinforcing bar structure.

[0022] <<<First Embodiment>>> In Figure 1, reference numeral 10 denotes a steel frame structure, such as a building. The steel frame structure 10 comprises steel columns 12 extending in the Z direction and a plurality of steel beams 14 extending in the X and Y directions relative to the steel columns 12. The steel beams 14 are joined to the steel columns 12. As an example, H-shaped steel is used for the steel beams 14. The floor surface of each floor of the steel frame structure 10 is formed by a reinforced concrete floor slab 16. Furthermore, the buildings to which this invention applies are not limited to those with steel-framed columns and beams (S-structure), but may also include columns made of reinforced concrete (RC-beam-S structure), columns made of steel-reinforced concrete (SRC-beam-S structure), columns made of steel pipes filled with concrete (CFT structure), and the like.

[0023] Figures 2 to 4 show a steel beam 14 that extends in the X direction and supports the +Y end of the floor slab 16, as well as the reinforcement structure around this steel beam 14. Reference numeral 18 denotes the slab support structure. All the reinforcement bars and steel beams shown in each figure constitute the slab support structure 18. In the embodiments described below, a slab support structure including a steel beam 14 supporting the +Y end of the floor slab 16 (referred to as the "first slab support structure") will be described. However, similar structures exist for slab support structures including a steel beam extending in the X direction that supports the -Y end of the floor slab (referred to as the "second slab support structure"), a steel beam extending in the Y direction that supports the +X end of the floor slab (referred to as the "third slab support structure"), and a steel beam extending in the Y direction that supports the -X end of the floor slab 16 (referred to as the "fourth slab support structure"). However, the present invention may be applied to only a part of the first slab support structure, the second slab support structure, the third slab support structure, and the fourth slab support structure.

[0024] In Figures 2 to 4, multiple headed studs 20 are provided on the upper flange 14a of the steel beam 14 at appropriate intervals along the X direction. It is not required that the multiple headed studs 20 be arranged in a strictly straight line along the X direction. Furthermore, the multiple headed studs 20 do not necessarily need to be arranged at equal intervals along the X direction.

[0025] Reference numeral 16 denotes a floor slab. For illustrative purposes, the floor slab 16 is shown as a dashed line (dotted line). Also, the deck plate that constitutes the bottom of the floor slab is not shown in each figure. The reinforcing bars constituting the floor slab 16 include the first truss bars 26, the second truss bars 27, the first slab bars 28, the second slab bars 29, the third slab bars 30, the fourth slab bars 31, connecting bars 34, and auxiliary bars 35, as well as the first reinforcing bars 22, the second reinforcing bars 24, and the third reinforcing bars 25. Of these bars, the first truss bars 26, the second truss bars 27, the first slab bars 28, the second slab bars 29, the third slab bars 30, and the fourth slab bars 31 function as load-bearing bars for the floor slab 16. The third reinforcing bar 25 is included to simplify construction and may be omitted. Please note that the names assigned to each reinforcing bar are examples only and are primarily assigned for convenience to distinguish them; the names assigned to each reinforcing bar do not limit the function of each reinforcing bar. Furthermore, each reinforcing bar can be secured at its intersections by binding with wire or by welding as appropriate, but unless otherwise specified, such explanations will be omitted from this discussion.

[0026] The first truss reinforcement bars 26 have a wavy shape that undulates vertically along the X direction and are provided at predetermined intervals along the Y direction. The second truss reinforcement bars 27 have a wavy shape that undulates vertically along the Y direction and are provided at predetermined intervals along the X direction. On the outer and lower side of the mountain shape formed in the first truss reinforcement 26, there are third slab reinforcement 30 and fourth slab reinforcement 31 extending in the Y direction, and on the inner and upper side of the mountain shape formed in the first truss reinforcement 26, there is a second slab reinforcement 29 extending in the Y direction.

[0027] Above the second slab reinforcement 29, first slab reinforcement 28 extending in the X direction is provided at predetermined intervals along the Y direction. Although only three first slab reinforcement 28 are shown in each figure, in reality, even more first slab reinforcement 28 are provided in the region on the -Y direction side.

[0028] The connecting bars 34 are reinforcing bars that extend the truss structure formed by the first truss bars 26, the second truss bars 27, the second slab bars 29, the third slab bars 30, and the fourth slab bars 31 to the +Y end region of the upper flange 14a, and the auxiliary bars 35 are reinforcing bars that support the above truss structure on the upper surface of the upper flange 14a.

[0029] Above the first slab reinforcement 28, a first reinforcing bar 22 extending in the Y direction is provided. The first reinforcing bar 22 has a portion that extends onto the upper flange 14a of the steel beam 14 and a portion that extends away from the upper flange 14a, and at the end in the +Y direction of the portion that extends onto the upper flange 14a, a bent portion 22a is formed so as to bend downward.

[0030] In this embodiment, the first reinforcing bar 22 is placed one between adjacent headed studs 20 in the X direction, but it is not limited to this, and multiple bars may be placed between adjacent headed studs 20. Furthermore, it is not necessary to place the first reinforcing bar 22 in all of the spaces between adjacent headed studs 20.

[0031] A third reinforcing bar 25 extending in the X direction is provided at the starting point of the bend in the bent portion 22a. The third reinforcing bar 25 is located above the height position H1 of the upper surface of the headed stud 20. Furthermore, a second reinforcing bar 24 extending in the X direction is provided below the height position H1 of the upper surface of the headed stud 20 relative to the bent portion 22a. As described above, the headed stud 20 is provided so as to be engaged with the second reinforcing bar 24, and the second reinforcing bar 24 is provided so as to be engaged with the bent portion 22a of the first reinforcing bar 22.

[0032] In the above configuration, if the steel beam 14 attempts to buckle laterally toward the side where the floor slab 16 is not located (the +Y direction in Figures 2 to 4) due to an earthquake or the like, the headed stud 20 will also attempt to displace toward the side where the floor slab 16 is not located. As a result, if the force attempting to displace the headed stud 20 is greater than the load-bearing capacity of the concrete in the floor slab 16, a cone-shaped failure may occur in which the concrete around the headed stud 20 is destroyed, potentially leading to a decrease in the load-bearing capacity of the floor slab 16.

[0033] In this embodiment, the first reinforcing bar 22, the second reinforcing bar 24, and the headed stud 20 are integrated when concrete is poured. Therefore, when the headed stud 20 attempts to displace in the +Y direction, the first reinforcing bar 22 is pulled in the +Y direction via the second reinforcing bar 24. Since an adhesive force is generated between the first reinforcing bar 22 and the concrete, when the headed stud 20 attempts to displace in the +Y direction, this adhesive force counteracts it, thereby suppressing lateral buckling of the steel beam 14 and preventing concrete failure around the headed stud 20.

[0034] As described above, the headed stud 20 is connected to the second reinforcing bar 24, and the second reinforcing bar 24 is connected to the first reinforcing bar 22. Furthermore, the phrase "the second reinforcing bar 24 is involved with the headed stud 20" means that when an external force acts on the slab support structure 18 due to an earthquake or the like, the second reinforcing bar 24 is not limited to the form in which it directly receives the external force from the headed stud 20, but also includes relationships in which the second reinforcing bar 24 is influenced by the headed stud 20 through materials such as concrete. Similarly, the statement that "the bent portion 22a of the first reinforcing bar 22 is related to the second reinforcing bar 24" means that when an external force acts on the slab support structure 18 due to an earthquake or the like, the bent portion 22a is not limited to directly receiving the external force from the second reinforcing bar 24, but also includes relationships in which the bent portion 22a is influenced by the second reinforcing bar 24 through materials such as concrete.

[0035] The construction method for providing the first reinforcing bar 22 and the second reinforcing bar 24 described above, that is, the construction method for the slab support structure 18, includes a first step of arranging the first reinforcing bar 22, and a second step of engaging the second reinforcing bar 24, which is positioned lower than the top of the headed stud 20 and engages with the headed stud 20 on the side where there is no floor slab 16 relative to the headed stud 20, with a part of the bent portion 22a. Furthermore, it is also possible to place the first reinforcing bar 22 first and then the second reinforcing bar 24, or to place the second reinforcing bar 24 first and then the first reinforcing bar 22. Furthermore, when arranging the second reinforcing bar 24, the second reinforcing bar 24 may be tied to the headed stud 20 with wire or the like. Alternatively, a spacer (not shown) may be placed on the upper flange 14a of the steel beam 14, and the second reinforcing bar 24 may be placed on top of the spacer. The second reinforcing bar 24 may also be tied to the bent portion 22a with wire or the like, or fixed by welding.

[0036] As described above, the slab support structure 18 comprises a steel beam 14 extending in a first direction (X direction) and supporting the end of the floor slab 16 in a second direction (Y direction) intersecting the first direction, and a plurality of headed studs 20 provided at appropriate intervals in the first direction (X direction) on the upper part of the steel beam 14. The slab support structure 18 also comprises a first reinforcing bar 22 having a portion extending in the second direction (Y direction) at a position higher than the top of the headed studs 20, with one end located on the upper part of the steel beam 14 and a bent portion 22a formed at the one end that bends downward, and a second reinforcing bar 24 extending in the first direction (X direction) at a position lower than the top of the headed studs 20 and engaging with the headed studs on the side where there is no floor slab 16 relative to the headed studs 20. Furthermore, a portion of the bent portion 22a is located lower than the top of the headed stud 20, and the second reinforcing bar 24 is engaged with a portion of the bent portion 22a. As a result, interference between the mesh-like reinforcing bars and the load-bearing bars or the headed studs 20 does not occur during construction, unlike in structures where the mesh-like reinforcing bars are placed on top of the headed studs 20. Furthermore, there is no need to increase the length of the headed studs 20. In this way, the constructability of the slab support structure 18 can be improved. Furthermore, the reinforcing bars necessary to obtain the effects of such a slab support structure 18 are the first reinforcing bar 22 and the second reinforcing bar 24, and the other reinforcing bars described in the above embodiment are optional.

[0037] Furthermore, the portion of the first reinforcing bar 22 that extends in the second direction (Y direction) at a position higher than the top of the headed stud 20 is at a higher position than the first truss bars 26 and the second truss bars 27 that constitute the floor slab 16. As a result, the displacement of the headed stud 20 can be suppressed by the bent portion 22a of the first reinforcing bar 22 and the second reinforcing bar 24, even while positioning the first reinforcing bar 22 to avoid the first truss bars 26 and the second truss bars 27.

[0038] In this embodiment, the first reinforcing bar 22 is placed at the very top of each reinforcing bar, but this is not limited to this, and other reinforcing bars may be placed above the first reinforcing bar 22.

[0039] <<<Second Embodiment>>> Next, the slab support structure 18A according to the second embodiment will be described with reference to Figures 5 and 6. Note that components identical to those already described in the embodiments described hereafter are denoted by the same reference numerals, and redundant explanations will be avoided. The slab support structure 18A includes a first reinforcing bar 42 in place of the first reinforcing bar 22 in the first embodiment described above. The first reinforcing bar 42 has a bent portion 42a formed at one end in the +Y direction, and is positioned so that the bent portion 42a engages with the headed stud 20 at a position lower than the top of the headed stud 20. The other end of the first reinforcing bar 42, the -Y direction end, is directed towards the inside (-Y direction) of the floor slab 16A.

[0040] The construction method for this slab support structure 18A includes a first step of inserting the first reinforcing bar 42 into the construction area of ​​the floor slab 16A from the side, as indicated by arrow Gs, with the other end of the first reinforcing bar 42 (the end in the -Y direction) facing the tip, and a second step of fixing the first reinforcing bar 42 so that the bent portion 42a engages with the headed stud 20 at a position lower than the top of the headed stud 20. The first reinforcing bar 42 can be fixed in place, for example, by tying the bent portion 42a to the headed stud 20 with wire or the like.

[0041] According to this embodiment, in the first step, the first reinforcing bar 42 is inserted from the side into the construction area of ​​the floor slab 16A, making it less likely for the first reinforcing bar 42 to interfere with other reinforcing bars when positioning it. Then, in the second step, the bent portion 42a engages with the headed stud 20 at a position lower than the top of the headed stud 20. Therefore, during construction, there is no interference between the mesh-like reinforcing bar and the load-bearing bars or the headed stud 20, as in a structure where the mesh-like reinforcing bar is placed on top of the headed stud 20. Furthermore, there is no need to increase the length of the headed stud 20. As a result, the constructability of the slab support structure 18A can be improved. Alternatively, instead of inserting the first reinforcing bar 42 into the construction area of ​​the floor slab 16A from the side, it may be inserted into the construction area of ​​the floor slab 16A from above.

[0042] Furthermore, the second embodiment described above can be modified as shown in the slab support structure 18B in Figure 7. In the slab support structure 18B shown in Figure 7, the bent portions 42a of each of the multiple first reinforcing bars 42 are fixed to the second reinforcing bar 43 that extends in the X direction along the steel beam 14 at the upper part of the steel beam 14. The construction method of the slab support structure 18B includes the steps of arranging the second reinforcing bar 43 and fixing the bent portions 42a of each of the multiple first reinforcing bars 42 to the second reinforcing bar 43. As a more specific example of the construction method in this case, a spacer (not shown) is placed on the upper flange 14a of the steel beam 14, and the second reinforcing bar 43 is placed on top of it. Then, the first reinforcing bar 42 is inserted from the side into the construction area of ​​the floor slab, as explained with reference to Figure 6, and the bent portion 42a of the first reinforcing bar 42 is fixed to the second reinforcing bar 43 with wire or the like. The bent portion 42a is then fixed together with the second reinforcing bar 43 to the headed stud 20 with wire or the like. This construction direction makes it easier to stabilize the posture of the first reinforcing bar 42, resulting in better workability, and also further suppresses the displacement of the headed studs 20.

[0043] Furthermore, in the second embodiment described above, if the deck plate constituting the bottom of the floor slab has a protrusion, and a protrusion 45 as shown in Figure 8 is formed on the floor slab, the first reinforcing bar 42 may be modified to be positioned at an angle. Figure 8 shows such a slab support structure 18C, in which the first reinforcing bar 42 is positioned at an angle to avoid the protrusion 45 formed on the bottom of the floor slab 16B. This allows the first reinforcing bar 42 to be positioned appropriately when the floor slab 16B has a protrusion 45 on its bottom. The first reinforcing bar 42 can be tilted at an angle in the first step of inserting it into the construction area of ​​the floor slab 16B from the side with its -Y direction end facing the tip. In this case, the -Y end of the first reinforcing bar 42 may be fixed to other reinforcing bars with wire or the like, or welded, or the first reinforcing bar 42 may be positioned at an angle by placing a spacer (not shown) on the protrusion of the deck plate.

[0044] The present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these modifications are also included within the scope of the present invention. [Explanation of Symbols]

[0045] 10…Steel frame structure 12...Steel column 14…Steel beam 14a…Upper flange 16, 16A, 16B... Floor slabs 18, 18A, 18B, 18C... Slab support structure 20... Studs with heads 22…First reinforcing muscle 22a...Folded section 24…Second reinforcing muscle 25…Third reinforcing muscle 26…First truss reinforcement 27...Second truss reinforcement 28…First slab muscle 29... Second slab muscle 30…Third slab muscle 31…Fourth slab muscle 34…Connecting muscles 42…First reinforcing muscle 42a...Folded section 43…Second reinforcing muscle

Claims

1. A steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction, A slab support structure comprising a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, A reinforcing bar having a portion extending in the second direction at a position higher than the top of the stud, the first reinforcing bar having one end located on the upper part of the steel beam and having a bent portion formed at the one end that bends downward, The system comprises a second reinforcing bar extending in the first direction at a position lower than the top of the stud, and engaging with the stud on the side of the stud where the floor slab is not present, A portion of the bent portion is located lower than the top of the stud. The second reinforcing bar is involved with a part of the bent portion, In the first reinforcing bar, the portion extending in the second direction at a position higher than the top of the stud is at a position higher than the load-bearing bars constituting the floor slab. A slab support structure characterized by the following features.

2. A steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction, A method for constructing a slab support structure comprising a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, A first step of arranging a first reinforcing bar having a portion that extends in the second direction at a position higher than the top of the stud, the first reinforcing bar having one end located on the upper part of the steel beam and having a bent portion formed at the one end that bends downward, The second step includes arranging a second reinforcing bar, which extends in the first direction at a position lower than the top of the stud and engages with the stud on the side of the stud where there is no floor slab, such that it engages with a part of the bent portion, A construction method for a slab support structure characterized by the following features.

3. A steel beam extending in a first direction and supporting the end of a floor slab in a second direction intersecting the first direction, A method for constructing a slab support structure comprising a plurality of studs provided at appropriate intervals in the first direction on the upper part of the steel beam, A first step involves inserting a first reinforcing bar, which has a bent portion formed at one end, into the construction area of ​​the floor slab from the side, with the other end of the first reinforcing bar facing the tip. The second step includes fixing the first reinforcing bar such that the bent portion engages with the stud at a position lower than the top of the stud, A construction method for a slab support structure characterized by the following features.

4. A method for constructing a slab support structure according to claim 3, comprising the step of fixing the bent portion to a second reinforcing bar extending in the first direction at the upper part of the steel beam, A construction method for a slab support structure characterized by the following features.

5. In the construction method for the slab support structure according to claim 3 or claim 4, the floor slab has a protrusion at its bottom, The first reinforcing bar is arranged in an inclined manner so as to avoid the protrusion. A construction method for a slab support structure characterized by the following features.

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