Joining member and reinforcement structure including the same

Abstract

To exhibit shearing strain property sufficiently and to restrain a design equation for strength calculation from being complicated on composite construction formed by integrally joining a steel member and a concrete-based member.SOLUTION: In a joint member 30 for joining a steel member 10 and a concrete-based member 20, a ratio between a projective area in an acting direction of a shear force of the joint member 30 and a cross-section area D in an acting direction of a shear force acting on the joint member 30 is within a predefined range. When stress is generated in both of the concrete-based member 20 and the steel member 10 by an external force, the joint member 30 has the shape to be broken before the concrete-based member 20 is broken.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a joining member used when integrally joining steel members and concrete members when constructing architectural structures, civil engineering structures, etc., and to a reinforced structure equipped with the same. [Background technology]

[0002] Structures formed by integrally joining steel members and concrete members (referred to as "composite structures" in this specification) are widely used in fields such as architectural and civil engineering structures. At the joints between these steel members and concrete members, a shear stop is essential to ensure reliable and smooth stress transfer between these dissimilar materials. Taking this into consideration, composite structures using studs and perforated steel dowels (dowels are metal fittings that prevent slippage between overlapping members) have traditionally been used.

[0003] In order to improve adhesion between the casting formwork and concrete in such composite structures, a technique has been proposed in the past in which through-holes are formed in the base material of the casting formwork by burring, and multiple small irregular protrusions are formed around the through-holes (see, for example, Patent Document 1). In the casting formwork described in Patent Document 1, through-holes with multiple small protrusions are formed by burring as a means of improving adhesion between the casting formwork and concrete.

[0004] Furthermore, although the small protrusions in the pouring formwork of Patent Document 1 have an uneven shape around the through holes as described above, it is unclear whether they have the function of improving shear strength. Taking note of this fact, a composite structure has been provided that makes it possible to significantly improve the slip-prevention function, shear strength, and rigidity at the joints between steel frame members and concrete members (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-102503 [Patent Document 2] Patent No. 6086452 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in conventional composite structures that combine concrete and steel members, when an external force is applied, the concrete usually breaks before the deformation or fracture of connecting members such as perforated steel dowels or other mechanical shear stoppers. This means that the structure contains members that do not deform sufficiently in response to external forces, and is unable to demonstrate sufficient shear deformation performance (the function or performance of suppressing relative displacement due to shear). In this respect, it is believed that there is room for improvement in conventional composite structures.

[0007] In the above case, the strength of the composite structure is determined by the strength of the concrete members, but this means that the design formula for strength calculations must include the concrete conditions (strength, reinforcement, volume, etc.), which tends to make the formulas more complicated.In addition, because the strength variation of concrete members is greater than that of steel plates, the shear connector of the composite structure may not fail as intended in the design.

[0008] Therefore, an object of the present invention is to provide a connecting member and a reinforced structure equipped with the same, which can fully demonstrate shear deformation performance in a composite structure formed by integrally joining steel members and concrete members, prevents the design formulas for strength calculations from becoming complicated, and has a shear stop that stably results in the intended failure mode. [Means for solving the problem]

[0009] One aspect of the present invention is a joining member for joining a steel member and a concrete member, This connecting member has a ratio of the apparent area of ​​the connecting member along the direction of action of the shear force to the cross-sectional area of ​​the connecting member along the direction of action of the shear force acting on the connecting member that is within a specified range, and is formed in a shape that causes the connecting member to break before the concrete member when stress is generated in both the concrete member and the steel member due to the application of an external force.

[0010] When an external force acts on a connector or a reinforced structure including such a connector, it is common for the concrete member to fail before the connector deforms or breaks. In this case, the moment the concrete member fails, the resistance provided by the connector is inevitably interrupted. Even if the concrete member does not completely fail, commonly used shear connectors resist the shear force tending to move the shear connector and the concrete through bearing pressure. Therefore, it is known that the bearing capacity of the concrete deteriorates when repeated forces are applied due to bearing deformation of the concrete. In this regard, with the connector of the above-described configuration, when stress is generated in both the concrete member and the steel member due to the application of an external force, the connector fails before the concrete member, thereby allowing the shear connector to provide resistance and maintain a state in which it can fully demonstrate its deformation capacity.

[0011] The joining member of the above embodiment has the above ratio Visible area / Steel plate cross-sectional area = 1.20~3.45 The shape may be:

[0012] The joining member in the above embodiment may be in the form of a plate and may have a through hole.

[0013] The joining member of the above embodiment may have a protrusion that protrudes in a direction that increases the visible area.

[0014] The joining member of the above embodiment may have one through hole, and a protrusion may be formed around the through hole that protrudes in a direction that increases the visible area.

[0015] The protrusion of the joining member in the above-described embodiment may be formed in a circumferential shape around the through hole.

[0016] The protrusion of the joining member in the above-described embodiment may be formed in a circular shape.

[0017] The protrusion of the joining member in the above-described embodiment may protrude from only one surface of the joining member.

[0018] In the joining member of the above aspect, the protrusions may have a uniform protruding height.

[0019] The width of the plate-like joining member in the above embodiment may be 1.6 to 3 times the diameter of the through-hole.

[0020] A reinforcement structure according to one aspect of the present invention comprises a joining member as described above, and the steel member has a long side and a short side, and the joining members are arranged in multiple numbers in the long side direction of the steel member.

[0021] In the reinforced structure of the above aspect, the concrete member may have a covering thickness of 30 mm or more. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a connecting member having a shear stop that can fully exhibit shear deformation performance in a composite structure formed by integrally joining steel members and concrete members, prevents the design formula for strength calculations from becoming complicated, and stably results in the intended failure mode, and a reinforced structure equipped with the same. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is a diagram schematically illustrating an example of a reinforcing structure according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing an example of a joining member provided on a steel member. [Figure 3]FIG. 1 is a perspective view schematically illustrating an example of a reinforcing structure. [Figure 4] 1A and 1B are diagrams illustrating an example of the structure of a joining member. [Figure 5] FIG. 2A is a diagram illustrating a bearing resistance force acting on a joint member, and FIG. 2B is a diagram illustrating the apparent area of ​​the joint member. [Figure 6] 10A and 10B are diagrams illustrating forces acting on a joining member. [Figure 7] 1A and 1B are diagrams illustrating the restraining function of concrete members on connecting members, showing (A) the case without restraint and (B) the case with restraint. [Figure 8] 7A is a diagram schematically showing the deformation state of the steel plate in the case of FIG. 7A, and FIG. 7B is a diagram schematically showing the deformation state of the steel plate in the case of FIG. 7B. [Figure 9] 1A is a diagram schematically illustrating a state in which a shear force in the X direction acts on a steel plate that is long in the X direction, and FIG. 1B is a diagram schematically illustrating a state in which a shear force in the X direction acts on a steel plate that is long in the height direction. [Figure 10] This is an image of the joint member (steel plate) deformed by shearing action. DETAILED DESCRIPTION OF THE INVENTION

[0024] The configuration of the present invention will be described in detail below based on an example of an embodiment shown in the drawings (see FIG. 1, etc.).

[0025] [Outline of joints and reinforcement structure] A reinforced structure 100 is a structure formed by integrally joining a steel member 10 and a concrete member 20 (see FIG. 1), and is widely used in fields such as architectural structures and civil engineering structures. The steel member 10 is used, for example, as a steel beam in a building (note that only a portion of the steel member 10 is shown in FIGS. 3, 6, 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, 6I, 6J, 6J, 6J, 6JI ...

[0026] The joining member 30 is a member that joins the steel member 10 and the concrete member 20, and by joining the two together, a reinforced structure 100 is formed (see Figs. 1 to 3). The reinforced structure 100 includes a partition made of a steel plate (flat base material) 31. Condition The concrete member 20 includes a flat connecting member 30, one side of which is installed in the steel plate 31 and joined by fillet welds 32 on both the front surface 31f and the back surface (not shown), and a concrete member 20 formed on the front surface 31f of the steel plate 31 with the connecting member 30 embedded. A plurality of connecting members 30 are arranged along the long side 10X of the steel member 10 (see FIG. 1). Each connecting member 30 has a through hole 35. The edge of the through hole 35 is provided with a protruding edge 36 that protrudes upward from one of the front surfaces 31f of the connecting member 30 (see FIG. 2). The through hole 35 is, for example, circular, and the protruding edge 36 has a sleeve-like boss shape that continues circumferentially along the inner periphery of the through hole 35. In this embodiment, the protruding height of the protruding edge 36 from the front surface 31f of the steel plate 31 is uniform (see FIG. 2, etc.), but the height may be intentionally non-uniform. In this embodiment, the flat substrate is formed from a steel plate 31, but the material is not limited to this, and although not shown in the figures, a steel pipe that has been burred or a structural steel that has been burred may also be used.

[0027] In the reinforced structure 100, the shear resistance of the concrete member 20 filled in the through hole 35 prevents the connecting member 30 and the concrete member 20 from slipping apart (see FIG. 3, etc.). The flanges 36 and end 31A of the through hole 35 and the concrete member 20 in their vicinity also function as a shear stopper due to bearing resistance, resulting in high rigidity and improved shear strength. Furthermore, the fillet welds 32 used to join the connecting member 30 to the surface 31f of the steel plate 31 can be performed in advance in a factory or similar facility before the steel plate is transported to the construction site. This avoids on-site welding, allowing for the formation of high-quality joints unaffected by weather conditions such as wind and rain, and shortening the time required for on-site welding.

[0028] Furthermore, by providing the protruding edge 36 at the through hole 35, the rigidity of the connecting member 30 itself is increased, making it less likely to deform, which is effective in improving workability and contributes to improving the strength of the reinforced structure 100. Furthermore, by improving the rigidity of the connecting member 30, deformation due to the heat effect when performing the fillet weld 32 can be prevented.

[0029] The through holes 35 opened in the connecting member 30 can also be used as insertion holes for wire ropes, shackles, etc. when lifting the steel material to which the connecting member 30 is joined with a crane. Furthermore, since reinforcing bars can be inserted into the through holes 35 of the connecting member 30, they can also be used as spacers to hold the position of reinforcing bars when placing reinforcing bars at construction sites of architectural and civil engineering structures.

[0030] Although there are no particular limitations on the processing method used to form the protruding edge 36 of the through hole 35, in this embodiment, it is formed by burring. Burring is a processing technique that uses a punch and a die to raise the inner peripheral edge of a pilot hole formed in a steel plate 31, which is the material of the joining member 30, in the thickness direction of the steel plate 31.

[0031] The steel members 10 constituting the reinforcing structure 100 are not limited to H-shaped steel beams as long as they are made of a material that can be joined by the joining members 30. For example, the beams can be made of any type of steel, such as I-shaped steel, T-shaped steel, angle steel, channel steel, or steel pipes. Alternatively, steel pipes that have been burred or steel sections that have been burred, as described above, can also be used.

[0032] Since reinforcing bars (not shown) can be inserted through the through holes 35 of the connecting member 30, one or more reinforcing bars (not shown) can be inserted into each through hole 35, and the concrete member 20 can be formed on the surface 31f of the steel plate 31 with the connecting member 30 and the reinforcing bars (not shown) embedded. With such a structure, the shear force (which refers to the shear force parallel to the surface 31f of the steel plate 31 and is represented by the symbol F in the figure. The direction in which the shear force F acts (the horizontal direction in this embodiment) is called the shear force acting direction and is represented by the symbol X) can be shared by the reinforcing bars, thereby improving the deformation capacity and providing excellent effects such as improving the resistance of the concrete member 20 to lifting off the steel member 10.

[0033] [Joint material with improved "slip deformation performance"] As described above, in the connecting member 30 connecting the steel member 10 and the concrete member 20, maintaining a state of resistance by the shear stop is important to ensure reliable and smooth stress transfer between these dissimilar materials. When an external force is applied (see FIG. 1 ), it is common for the concrete member 20 to fail before the connecting member 30 deforms or breaks. However, given the above point (the importance of maintaining a state of resistance by the shear stop), the moment the concrete member 20 fails, the state of resistance by the shear stop is inevitably interrupted. Taking this into consideration, in this embodiment, the connecting member 30 is shaped so that when stress is generated in both the concrete member 20 and the steel member 10 due to the application of an external force (see FIG. 1 ), the connecting member 30 fails before the concrete member 20. By incorporating the idea of ​​causing the connecting member 30 to fail before the concrete member 20, it becomes possible to design the connecting member 30 with a focus on its cross-section. Furthermore, by giving the joining member 30 itself a shape and structure that allows it to deform sufficiently, it is possible to prevent brittle fracture and improve shear deformation performance (the function or performance of suppressing relative displacement due to shear).

[0034] When determining the shape and structure of the joining member 30, the shear strength rather than the bending strength within the steel plate plane is used as the deciding factor, so that the shear strength of the steel plate 31 can be maximized up to its limit. For example, if the steel plate 31 is a long, rectangular plate that is long in the shear force acting direction X and the connecting member 30 is a single plate made of the steel plate 31 (see FIG. 9(A)), the strength of the connecting member 30 when a shear force F is applied is mainly influenced by the shear strength (shear stress) of the steel plate 31 (the shear force of the steel plate 31 predominates against a shear force in the shear direction, and bending failure does not occur). In this embodiment, by arranging multiple connecting members 30 in a so-called divided state intermittently, a structure is constructed in which bending strength predominates rather than shear strength (see FIG. 9(B)). However, in a structure with such a long height (h), the bending stress of the steel plate 31 predominates in the shear force acting direction X (the shear direction), and shear failure does not occur. In this regard, in this embodiment, attention is paid to the restraining function of the concrete member 20, and shear failure occurs. This will be described later.

[0035] [Features of reinforced structure (1): High shear transfer performance due to intermittently placed joint members] As described above, in the reinforcement structure 100 of this embodiment, the multiple connecting members 30, each having one through hole 35 per steel plate 31, are arranged intermittently and discontinuously, rather than continuously. Compared to a structure that does not have such a structure (i.e., a structure in which the plates are connected continuously), this structure improves the shear transmission performance (the ability to transmit a force acting in the shear direction) of the steel plate 31 as a whole by adding the bearing resistance of the end face of each steel plate 31 (the face of the side of the steel plate 31 on which the shear force F acts, designated by reference numeral 31A in the figure) and the bearing resistance of the protruding edge portion 36 (resistance corresponding to the shear force acting on the visible portion of the protruding edge portion 36 (designated by reference numeral 36A in FIG. 5)). This can be more easily understood by assuming that when the steel plate 31 is, for example, a single rectangular plate that is long in the shear force acting direction X, the number of edges is small (for example, in the case of a single steel plate 31 like this, there is one edge), and the added amount of shear force F acting on the edge is small. Note that in Figures 5 to 7, the forces acting on the edge surface 31A and the forces acting on the protruding edge portion 36 are indicated by arrows (force lines diagram) and are expressed as "bearing resistance."

[0036] As described above, the reinforcement structure 100 of this embodiment, which has improved shear transmission performance, provides a one-to-one correspondence between the through holes 35 and the flanges 36 (one through hole 35 per flange 36). This allows for increased strength at the front end 36A of the flanges 36, thereby increasing the shear strength per unit and reducing the number of components required compared to conventional techniques. Furthermore, the number of connecting members 30 is reduced, and each component is made smaller, improving workability. Furthermore, the reinforcement structure 100 of this embodiment reduces the amount of welding required, improving construction ease. Furthermore, in a structure with one through hole 35 per steel plate 31, as in this embodiment, the force acting on the concrete member 20 can be distributed between the end surface 31A and the peripheral surface (projected surface) of the flanges 36, i.e., the front end 36A. This makes it easier to ensure overall strength and thereby improve performance.

[0037] As a specific example of how to achieve the above-described high shear transmission performance, a preferred range for the width B (here, width refers to the length along the shear force acting direction X (see FIG. 6, etc.)) of the steel plate 31 of the joining member 30 is approximately 1.6 to 3 times the diameter of the through hole 35, and a specific numerical example would be 80 to 150 mm per through hole 35 and protruding edge 36. In other words, when a steel plate 31 having a width B in the range of 80 to 150 mm is used for a through hole 35 with a diameter φ of 40 to 60 mm, it is preferable because it makes it easier to position the through holes 35 and the protruding edge 36 at predetermined preferred intervals along the shear force acting direction X. Incidentally, if the width B is shorter than a predetermined value (80 mm in this example), the overall shear force transmission capacity of the connecting members 30 decreases, and therefore, to ensure a predetermined level of shear force transmission capacity or higher, it becomes necessary to arrange more connecting members 30 (if the steel plate width B is less than 80 mm, the shear strength determined by the fracture of the steel plate 31 falls outside the practical range, and the shear strength per steel plate becomes small. Therefore, to obtain the necessary joint strength between the concrete member 20 and the steel member 10, a large number of shear stoppers are required). However, if too many connecting members 30 are arranged, the spacing becomes too small and the strength of the concrete member 20 cannot be ensured, and therefore the relationship "shear strength of the steel plate 31" < "shear strength of the concrete member 20" no longer holds. On the other hand, if the width B is longer than a predetermined value (150 mm in this example), the bearing capacity of the steel plate 31 increases, but the concrete members 20 (e.g., slabs) are, so to speak, cut off by the connecting members 30, making the concrete members 20 held by these connecting members 30 more susceptible to fracture, and the deformation capacity of the steel plate 31 itself is reduced, causing the concrete members 20 to fracture first. Furthermore, if the width B of the connecting members 30 is longer than a predetermined value (150 mm in this example), the welded portions between the steel members 10 and the connecting members 30 increase in size, and the steel plate 31 becomes larger, which increases the cost due to the increased material and labor required.

[0038] In the above description of the width B of the steel plate 31, it was stated that the width is "per one through hole 35 and flange 36." This is because providing multiple flanges 36 (which may be provided on only one side of the steel plate 31, or on both sides) increases the strength of the concrete-based member 20 and allows the width B of the steel plate 31 to be made larger. For example, if there is only one edge, the length of the steel plate 31 can be increased by increasing the number of flanges 36, but this is not simply a multiple of the number of flanges 36. However, by increasing the number of flanges 36, the resistance of the concrete can be increased, and therefore the length of the steel plate 31 can be increased. The shear strength of the steel plate can be increased by the amount that the length of the steel plate 31 is increased.

[0039] [Features of reinforced structure (2): Concrete restrains the upper part of the steel plate, preventing bending of the steel plate] In this embodiment, a reinforcement structure 100 is constructed in which the upper part of the steel plate 31 (for example, the entire part above the fillet weld 32) is covered and restrained by a concrete-based member 20 (in other words, the steel plate 31, which is about to bend, is pressed down from above to prevent it from bending).

[0040] To explain the restraint function with reference to the drawings (see Figures 7 and 8), when a force that causes relative displacement due to shear occurs in the steel member 10 or the concrete member 20, the steel plate 31 tends to bend in-plane when not restrained by the concrete member 20 (see Figures 7(A) and 8(A)). In this case, the stress due to in-plane bending is dominant in the steel plate 31, causing the steel plate 31 to undergo early bending failure. On the other hand, when a force that causes relative displacement due to shear occurs in the steel plate 31 when restrained by the concrete member 20, the steel plate 31 is restrained from bending in-plane by the concrete member 20. In other words, the steel plate 31 is pressed down from above, so that the bending stress at the base of the steel plate 31 (cross section 31d) is suppressed (see Figure 7(B)). Therefore, failure due to bending stress is suppressed until the shear stress at the base of the steel plate causes the steel plate 31 to fracture.

[0041] Taking into account the above-mentioned restraining function, as described above, in this embodiment, a structure is used in which one through hole 35 is provided per steel plate 31, and since the width B of the steel plate 31 is smaller than when it is long and continuous (such as a single long rectangular plate that is long in the shear force acting direction X), it is the bending action rather than the shear action that affects the steel plate 31 (if it were long and continuous, shear failure would occur at the cross section 31d that receives the greatest shear action. Since the width B is small, simply applying the formula below would result in bending failure. However, because of the restraining force, bending failure does not occur and shear failure can be assumed). This can be expressed in a simple formula as follows: (Bending of steel plate) < (Shearing of steel plate) It goes without saying that as the width B of the steel plate 31 is increased, this relationship disappears, and problems arise when the steel plate 31 is made long and continuous, such as increased material costs and increased welding work, and the concrete member 20 begins to fracture before the steel plate 31. In other words, the reinforced structure 100 of this embodiment as described above can be said to be a structure in which the concrete member 20, although arranged on the upper side, restrains the bending deformation of the steel plate 31, thereby allowing the steel plate 31 to demonstrate its performance up to the limit of its shear strength, even while the width B of the steel plate 31 remains small.

[0042] From the viewpoint of fully utilizing the restraint function described above, the covering thickness C of the concrete member (meaning the distance from the end face 31B of the steel plate 31 (the end face on the opposite side from the steel member 10) to the top end 21 of the concrete member 20) is preferably at least 30 mm, and more preferably 50 mm or more.

[0043] [Characteristics of reinforced structure (3): A shape in which the joint member breaks before the concrete member] As described above, based on the idea that the connecting member 30 of the reinforced structure 100 of this embodiment breaks before the concrete member 20, (Shear strength of steel plate) < (Shear strength of concrete member) However, specific examples of the shape of the joining member 30 are not particularly limited. In short, the joining member 30 of this embodiment and the reinforcement structure 100 including the same are characterized by the fact that the joining member 30 has such a shape, and specific examples of this idea and examples of shapes and structures realized thereby are as follows.

[0044] Considering the projected area of ​​the steel plate 31 along the shear force acting direction X (see FIG. 5 ; the combined area of ​​the end surface 31A of the steel plate 31 and the visible portion 36A of the protruding edge 36 is referred to as the visible area in this specification and is represented by the symbol A. Note that although hatching is used to make it easier to understand in FIG. 5(B), this does not represent a cross section), and the cross-sectional area D of the cross section 31d of the steel plate 31 (see FIG. 4 ), which is thought to be subjected to the greatest shear force, the ratio between them, i.e., the visible area A / the cross-sectional area D of the steel plate, is expressed as follows: Visible area A / Steel plate cross-sectional area D=1.20~3.45 It is preferable that the ratio is within this range so that the connecting member 30 breaks before the concrete member 20. From this perspective, a connecting member 30 with a ratio value of about 2.55 is even more preferable.

[0045] As described above, the connecting member 30 of this embodiment has a ratio of the cross-sectional area D along the direction of action of shear force F acting on the connecting member 30 to the apparent area A of the connecting member 30 along the direction of action X of the shear force within a predetermined range, and as explained above, by making the shear strength of the connecting member 30 (the steel plate 31) less than the strength of the concrete member, it becomes possible to design the connecting member 30 with the cross-sectional area D of the steel plate 31 as a parameter while making the steel plate 31 more deformable (improving its deformation capacity). Naturally, the protruding edge 36 formed on the connecting member 30 as in this embodiment protrudes in a direction that increases the apparent area A, which affects the design based on the above formula.

[0046] According to the reinforcement structure 100 of this embodiment described above, it is possible to fully demonstrate the shear deformation performance in a structure formed by integrally joining a steel member 10 and a concrete member 20, and it is also possible to prevent the design formula for strength calculation from becoming complicated. The characteristics of such a reinforcement structure 100 and its joining member 30 can be described from another perspective as follows. That is, (i) If the connecting member 30 (the steel plate 31) is a long, continuous single plate as in the past, providing a through hole 35 (and a protruding edge portion 36) will increase the contact area between the connecting member 30 and the concrete member 20 by the amount of the through hole 35 (and a protruding edge portion 36). (ii) However, if the connecting member 30 (the steel plate 31) is in the form of such a long, continuous plate, when considering the strength of the connecting member 30, the shear action of the steel plate caused by the shear force F becomes overwhelmingly greater and more dominant than the influence of the bending action. In this regard, as described above, in this embodiment, attention is focused on the restraining function of the concrete member 20, and shear failure is caused to occur.

[0047] The above-described embodiment is a preferred example of the present invention, but is not limited thereto and various modifications are possible within the scope of the present invention. For example, in the above-described embodiment, the flange 36 is provided at the edge of the through hole 35 provided in the connecting member 30 so as to be turned up. However, this is merely one example of a preferred structure for causing the steel plate 31 to be destroyed before the concrete member 20. Although not specifically shown, the steel plate 31 may be provided with only the flange 36 (protrusion) without the through hole 35. In short, the specific shape and structure of the connecting member 30 are not limited as long as they function to ensure a sufficient area for engaging with the concrete member 20 (i.e., the visible area). [Example]

[0048] The inventors have conducted various tests to obtain evidence and verification results for the various theories, formulas, and preferred numerical ranges described above. As a concrete example showing the actual state, an image of (the steel plate 31 of) the joining member 30 deformed by shearing action is shown (see FIG. 10). [Industrial Applicability]

[0049] The joining member according to the present invention and the reinforcement structure including the joining member can be widely used in fields such as the building industry and the civil engineering and construction industry. [Explanation of symbols]

[0050] 10...Steel parts 10X...long side 10Y...short side 20...Concrete materials 21...Top 30... Joint material 31...Steel plate (flat substrate) 31A…Fore side 31B…End face 31d...Section subjected to the greatest shear force 31f…Surface 32...Fill weld 35...Through hole 36…Protrusion (protrusion) 36A...Fitment part of the flange 100...Reinforced structure A: Steel plate visible area B: Width of steel plate C: Cover thickness of concrete members D: Cross-sectional area of ​​the section subjected to the greatest shearing force F...shear force h: Height of resultant force position F...shear force t...Thickness of steel plate X: Shear force acting direction

Claims

1. A joining member that is installed on a steel member and embedded in a concrete member to join the steel member and the concrete member, a ratio of an apparent area of ​​the joining member along the acting direction of the shear force to a cross-sectional area of ​​the joining member along the acting direction of the shear force is 1.20 to 3.45; The joining member is plate-shaped and has a protrusion that protrudes in a direction that increases the visible area, The joining member has a through hole, A joining member, wherein the width of the plate-like joining member is 1.6 to 3 times the diameter of the through hole.

2. 2. The joining member according to claim 1, wherein the joining member has one through hole, and a protrusion is formed around the through hole so as to protrude in a direction that increases the apparent area.

3. The joining member according to claim 2 , wherein the protrusion is formed in a circumferential shape around the through hole.

4. The joining member according to claim 3 , wherein the protrusion is formed in a circular shape.

5. The joining member according to claim 4 , wherein the protrusion protrudes from only one surface of the joining member.

6. The joining member according to claim 5 , wherein the protrusions have a uniform protruding height.

7. 7. A reinforcement structure comprising a joining member according to claim 1, wherein the steel members have long sides and short sides, and a plurality of the joining members are arranged in a partition-like manner along the long side direction of the steel members.

8. 7. A reinforced structure comprising the connecting member according to claim 1, wherein the concrete member has a covering thickness of 30 mm or more.

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