Structure and method for producing structure

Abstract

To provide a structure with a simple configuration that firmly joins a beam and a composite slab and has no degradation in performance and a method for producing the structure.SOLUTION: A structure (100) according to the present invention comprises a beam (120), a steel plate (130) placed on an upper surface of the beam (120) and having a predetermined shape, a welding unit (170) that joins the beam (120) and the steel plate (130) by stud plug welding (SPW) and is formed to protrude from the upper surface of the steel plate (130) toward the upside, and concrete (150) casted to cover the welding unit (170) on the upper surface of the steel plate (130).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a structure and a method for manufacturing a structure. [Background technology]

[0002] Generally, the floor structure of a steel-framed building comprises a steel beam (hereinafter simply referred to as "beam") made of H-shaped cross-section steel plate, and a concrete floor slab installed on the top surface of the flange part of the beam (hereinafter, deck composite slabs using composite slab deck plates, reinforced concrete slabs using steel formwork deck plates (flat decks) or deck plates with steel trusses, and other floor slabs are collectively referred to as "composite slabs").

[0003] A floor structure is a combination of a composite slab and a beam, and in order to transmit the live load on the floor of a building and the force applied to the floor during an earthquake to the beam and through the beam to the columns of the building, it is necessary to firmly connect the beam and the composite slab. The most common method of connection is to connect the composite slab and the beam using a shear connector.

[0004] When constructing composite slabs by pouring concrete on-site, composite slab deck plates (hereinafter simply referred to as "deck plates") are widely used as formwork. Although the deck plates of composite slabs do not necessarily need to be fastened (joined) to the beams, they are commonly joined to the beams by welding or other methods to prevent them from being blown up or sliding down due to wind.

[0005] Therefore, two operations are required: a process of fastening the composite slab to the beam and a process of fastening the deck plate to the beam. In addition, when headed studs are used for the shear connectors, the number of work types and management items in the on-site process increases, making it complicated. However, in the case of a composite slab using a deck plate, the deck plate and the concrete are previously joined together, so that the composite slab and the beam can be joined through the deck plate by a single operation of applying burn-out plug welding (hereinafter, this may be referred to as "SPW"), which is a shear connector stronger than normal welding, to the deck plate (see, for example, Patent Document 1). In addition, burn-out plug welding can be performed as the same work type in the process of constructing the deck plate, so that the process and management can be simplified. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-159954 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the joinery method using burn-out plug welding (SPW) can be applied to deck plates in which peaks, valleys, and inclined portions are arranged alternately in the width direction, because the concrete and the deck plate are combined so that they interlock with each other. However, it cannot be applied to flat decks that have flat surfaces without peaks, valleys, etc., because the concrete and the flat deck do not interlock with each other.

[0008] In addition, even when applied to deck plates, the SPW joining method tends to be inferior in terms of fire resistance, load-bearing capacity, and horizontal force transmission performance compared to when headed studs, a common shear connector, are used to join composite slabs and beams.

[0009] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a structure of simple construction that can firmly join a beam and a composite slab and maintain sufficient performance, and a method for manufacturing the structure. [Means for solving the problem]

[0010] In order to solve the above problems, the structure of the present invention comprises a beam, a steel plate having a predetermined shape placed on the upper surface of the beam, a weld portion formed by joining the beam and the steel plate by burn-out plug welding and protruding upward from the upper surface of the steel plate, and concrete poured on the upper surface of the steel plate to cover the weld portion.

[0011] In the structure of the present invention, it is preferable that the welded portion has a head portion whose diameter increases from the bottom toward the top.

[0012] In the structure of the present invention, the head portion is preferably a truncated cone or pyramid having a trapezoidal shape in a side view, the diameter of which increases from the bottom to the top.

[0013] In the structure of the present invention, it is preferable that the head portion has a cylindrical shape with a diameter enlarged upwardly relative to the shaft portion provided below.

[0014] In the structure of the present invention, the head portion preferably has a flange shape.

[0015] In the present invention, a manufacturing method for a structure produced by welding steel plates and beams of a composite slab by burn-out plug welding includes a weld formation process in which the beams and the steel plates are joined by burn-out plug welding and a weld is formed so as to protrude upward from the upper surface of the steel plate, and a concrete pouring process in which concrete is poured on the upper surface of the steel plate to cover the weld.

[0016] In the method for manufacturing a structure of the present invention, it is preferable that a welding jig having a shape corresponding to the weld portion for forming the weld portion is used in the weld portion forming step. Effect of the Invention

[0017] According to the present invention, it is possible to realize a structure having a simple configuration in which a beam and a composite slab are firmly joined and sufficient performance can be maintained, and a method for manufacturing the structure. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view showing a configuration of a floor structure in a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a state in which a deck plate and a beam in a floor structure according to the first embodiment of the present invention are joined by burn-out plug welding, as viewed obliquely from above. [Diagram 3] FIG. 2 is an enlarged cross-sectional view showing the configuration of a welded portion formed by burn-out plug welding on a floor structure in the first embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view illustrating a method for joining a deck plate and a beam by burn-out plug welding and forming a weld in an embodiment of the present invention. [Diagram 5] 1 is a cross-sectional view showing a configuration of a welding jig for forming a weld in a first embodiment of the present invention. [Figure 6] FIG. 6 is an enlarged cross-sectional view showing a configuration of a welded portion in a second embodiment of the present invention. [Figure 7] FIG. 6 is a cross-sectional view showing a configuration of a welding jig for forming a welded portion in a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A first and second preferred embodiment of the present invention will be described with reference to the drawings. Note that the first and second embodiments described below are merely examples, and various embodiments are possible within the scope of the present invention.

[0020] <First embodiment> A floor structure according to a first embodiment of the present invention will be described with reference to Figs. 1 to 5. Fig. 1 is a cross-sectional view showing the configuration of a floor structure according to the first embodiment of the present invention. Fig. 2 is a perspective view of a deck plate and a beam in a floor structure according to the first embodiment of the present invention joined by burn-out plug welding, as viewed obliquely from above. Fig. 3 is an enlarged cross-sectional view showing the configuration of a welded portion formed by burn-out plug welding on a floor structure according to the first embodiment of the present invention. Fig. 4 is a perspective view for explaining a method of joining a deck plate and a beam by burn-out plug welding and forming a welded portion according to the first embodiment of the present invention. Fig. 5 is a cross-sectional view showing the configuration of a welding jig for forming a welded portion according to the first embodiment of the present invention.

[0021] <Floor structure> As shown in FIG. 1, the floor structure 100 has a steel beam (hereinafter simply referred to as a "beam") 120 made of H-shaped steel as a beam, a composite slab 110 joined to the beam 120, and a weld 170 that increases the joint strength between the beam 120 and the composite slab 110.

[0022] <beam> The beam 120 is an H-shaped steel having a web 121, an upper flange 122 integrally formed at the upper end of the web 121, and a lower flange 123 integrally formed at the lower end of the web 121.

[0023] <Composite slab> The composite slab 110 has a deck plate 130 made of corrugated steel plate and concrete 150 poured integrally to cover the deck plate, and is a concrete floor slab in which the deck plate 130 and the concrete 150 are joined together.

[0024] In addition, in the above description, the composite slab 110 is described as using a deck plate 130 made of corrugated steel plate, but this is not limited to this, and it is also possible to use a flat deck (not shown) made of flat thin steel plate or a deck plate with reinforcing bar trusses.

[0025] <Deck plate> As shown in FIG. 2, the deck plate 130 of the composite slab 110 is a steel plate that is placed on the upper surface of the upper flange 122 of the beam 120 and joined to the upper flange 122 .

[0026] 2, the longitudinal direction of the deck plate 130 is defined as the length direction L, the lateral direction of the deck plate 130 is defined as the width direction W, and the height direction of the deck plate 130 is defined as the up-down direction H. However, these directions are used merely for the convenience of explanation and do not necessarily coincide with the directions when the deck plate 1 is actually used.

[0027] The deck plate 130 is a corrugated steel plate made of a thin steel plate that has been plated with zinc or other plating. However, the deck plate 130 is not limited to this, and may be made of a black steel material or the like that has not been surface-treated.

[0028] The deck plate 130 is manufactured, for example, by roll-forming a flat steel plate using a roll-forming machine. The deck plate 130 is bent at multiple locations by the roll-forming machine. The thickness of the deck plate 130 is preferably 0.5 to 6.0 mm, and in this case, the thickness of the deck plate 130 is, for example, 1.0 mm.

[0029] The deck plate 130 has a configuration in which peaks 131 and valleys 132 are alternately arranged in the width direction W with inclined portions 133 interposed therebetween. The peaks 131 of the deck plate 130 are formed higher in the thickness direction H of the deck plate 130 than the valleys 132, and the distance between the peaks 131 and the valleys 132 defines the height of the deck plate 130. In the deck plate 130, the ends of the adjacent valleys 132 and the ends of the peaks 131 are connected by the inclined portions 133.

[0030] <Concrete> Concrete 150 (FIG. 1) of the composite slab 110 is a part of the composite slab 110 that is poured to cover the deck plate 130 joined to the upper flange 122 of the beam 120 and the welded parts 170 described below. The concrete 150 meshes with a composite mechanism (not shown) of the peaks 131 and valleys 132 of the deck plate 130, and is integrated without shifting in the length direction L, width direction W, or height direction H.

[0031] <Welded parts> The weld portion 170 joins the valley portion 132 of the deck plate 130 and the upper flange 122 of the beam 120 by burn-through plug welding (SPW), and is a protruding portion that protrudes upward from the valley portion 132 of the deck plate 130.

[0032] Here, burn-out plug welding (SPW) is a technique in which an arc welding rod is used to burn out the plate material of the valley portion 132 of the deck plate 130, which is placed in contact with the upper surface of the upper flange 122 of the beam 120, using the arc heat to burn out the plate material of the valley portion 132 and create a hole, and then the deposited metal is melted into the upper flange 122 of the beam 120 while stirring the molten pool that is created in the burned-out hole to form a weld bead, thereby welding the valley portion 132 of the deck plate 130 to the upper flange 122 of the beam 120.

[0033] As shown in FIG. 3, the welded portion 170 joins the upper flange 122 of the beam 120 and the valley portion 132 of the deck plate 130 , and protrudes upward from the upper surface of the valley portion 132 .

[0034] The welded portion 170 has a generally trapezoidal or substantially truncated cone shape in side view, which extends while increasing in diameter from the bottom to the top.

[0035] The welded portion 170 has a height that at least exceeds the valley portion 132 of the deck plate 130 (i.e. exceeds the plate thickness of the deck plate), and has a height that does not reach the peak portion 131 of the deck plate 130. However, this is not limited to this, and the welded portion 170 may have a height that exceeds the peak portion 131 of the deck plate 130 as long as it does not protrude from the top surface of the concrete 150.

[0036] The welded portion 170 has an embedded portion 171 which is roughly almond-shaped or spindle-shaped when viewed from the side and which partially extends into the upper flange 122 of the beam 120, and a head portion 173 which is formed integrally with the embedded portion 171 and which expands in diameter as it extends from bottom to top.

[0037] Thus, in welded portion 170, the entire protruding portion that protrudes upward from the upper surface of valley portion 132 of deck plate 130 constitutes head portion 173. Head portion 173 has a peripheral side surface 173a that is inclined so as to expand in diameter from the bottom to the top, and a top surface 173u that is connected to the upper end of peripheral side surface 173a.

[0038] The top surface 173u of the welded portion 160 is a curved surface formed in an arc shape that is convex upward. However, this is not limited thereto, and the top surface 173u may be a curved surface formed in an arc shape that is concave downward, or may be a flat surface without any irregularities.

[0039] At the peripheral side surface 173a of the head portion 173 of the welded portion 170, the narrower angle α formed between the upper surface of the valley portion 132 of the deck plate 130 and the peripheral side surface 173a is, for example, about 70 degrees. However, this is not limited to this, and the angle α may be various other angles α less than 90 degrees, such as 80 degrees, 60 degrees, 45 degrees, etc., as long as the angle α is inclined so as to increase in diameter from the bottom to the top.

[0040] This allows head portion 173 of weld portion 170 to have the same function as the head of a headed stud bolt (not shown) between the weld portion 170 and concrete 150 being poured.

[0041] <Welding fixture> The welded portion 170 is formed by the above-mentioned burn-out plug welding (SPW) using a welding jig 180 as shown in FIGS.

[0042] Specifically, the welding jig 180 has a cylindrical outer peripheral wall 180g, a circular through hole 181ha in the lower center, an opening 181hb in the upper center with an inner diameter larger than that of the through hole 181ha, and an inclined inner peripheral wall 181s whose diameter increases from the periphery of the through hole 181ha toward the periphery of the opening 181hb. That is, the welding jig 180 has an overall cone-shaped inner space due to the presence of the inner peripheral wall 181s.

[0043] <Method of joining beams and deck plates and forming welds> As shown in FIG. 4, the valley portion 132 of the deck plate 130 is placed on the top surface of the upper flange 122 of the beam 120 so that the valley portion 132 is in intimate contact with the top surface of the upper flange 122 , and then a welding jig 180 is placed at a predetermined position on the top surface of the valley portion 132 .

[0044] Then, the arc welding rod 183 to which a voltage has been applied is placed in a vertical position, and the tip of the arc welding rod 183 is brought into contact with the upper surface of the valley portion 132 of the deck plate 130 through the through hole 181 ha of the welding jig 180 .

[0045] Next, the arc welding rod 183 is pulled slightly upward, an arc is thrown from the tip of the arc welding rod 183, and the arc heat is used to burn through the valley portion 132 of the deck plate 130 until a hole of a predetermined size is formed in the upper surface of the valley portion 132.

[0046] Next, the arc welding rod 183 is pushed in until it reaches the upper flange 122 of the beam 120, and the arc welding rod 183 is weaved around the center of the hole by tracing the inside of the hole burned out at the valley portion 132, making two or three rotations, thereby melting the weld metal into the upper flange 122 of the beam 120.

[0047] Thereafter, the deposited metal is adjusted, the arc welding rod 183 is pulled upward to a height required for the weld 170 in the center of the hole, and the weld 170 is formed by removing the slag.

[0048] Finally, the welding jig 180 is removed by breaking it with a hammer or the like, and a weld 170 is formed protruding from the upper surface of the valley portion 132 of the deck plate 130. Note that by providing the welding jig 180 with a hinge or other processing, it is possible to enable repeated use without breaking when the jig is removed.

[0049] In this way, at the weld 170, the valley portion 132 of the deck plate 130 and the upper flange 122 of the beam 120 are joined together by the embedded portion 171, and the head portion 173 protrudes upward a predetermined height from the upper surface of the valley portion 132 of the deck plate 130.

[0050] <Effects> In the above configuration, the floor structure 100 is formed by joining the deck plate 130 and the beams 120 together by the welded portions 170 as described above, and then pouring the concrete 150.

[0051] Since head portions 173 of welded portions 170 protrude from the upper surface of valley portions 132 of deck plate 130, said head portions 173 engage with concrete 150. As a result, in floor structure 100, concrete 150 can be firmly integrated with deck plate 130 without shifting in the length direction L, width direction W, or up-down direction H.

[0052] Thus, the floor structure 100 not only joins the deck plate 130 and the beam 120 by burn-out plug welding (SPW), but also, due to the presence of the head portion 173 of the weld 170 formed by the burn-out plug welding (SPW), it is possible to obtain the same joint strength as a headed stud, as well as fire resistance, load resistance, horizontal force transmission performance, etc.

[0053] The weld 170 of the floor structure 100 has an embedded portion 171 that spans both the valley portion 132 of the deck plate 130 and the upper flange 122 of the beam 120, and a head portion 173 that engages with the concrete 150, so that the force applied to the concrete 150 that forms the floor can be transmitted directly to the beam 120 via the weld 170, in the same way as a headed stud.

[0054] Furthermore, the floor structure 100 can firmly join the deck plate 130 and the beam 120 with just one SPW process, and can also form a weld 170 that has the same function as a headed stud. Therefore, the presence of the weld 170 can simplify the structure of the floor structure 100 itself, and can also simplify the construction process of the floor structure 100.

[0055] <Second embodiment> A second embodiment of the present invention will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is an enlarged cross-sectional view showing the configuration of a welded portion in the second embodiment of the present invention. Fig. 7 is a cross-sectional view showing the configuration of a welding jig for forming a welded portion in the second embodiment of the present invention.

[0056] The second embodiment is similar to the first embodiment except that a weld 270 and a welding jig 280 are used instead of the weld 170, and therefore only the weld 270 and the welding jig 280 will be described here.

[0057] 6, in which the same reference numerals are used to denote parts corresponding to those in FIG. 3, welded portion 270 is formed by burn-out plug welding using a welding jig 280. Welded portion 270 has a different shape from welded portion 170 in the first embodiment, but has the same basic function and performance.

[0058] <Welded parts> Similar to the welded portion 170 in the first embodiment, the welded portion 270 joins the upper flange 122 of the beam 120 and the valley portion 132 of the deck plate 130, and protrudes upward from the upper surface of the valley portion 132 of the deck plate 130.

[0059] The welded portion 270 has a generally T-shape in side view that extends from the bottom to the top. The welded portion 270 has a height that does not reach the peaks 131 of the deck plate 130. However, this is not limited to this, and the welded portion 270 may have a height that exceeds the peaks 131 of the deck plate 130 as long as it does not protrude from the top surface of the concrete 150.

[0060] The welded portion 270 has an embedded portion 271 which is roughly almond-shaped or spindle-shaped when viewed from the side and which is partially embedded in the upper flange 122 of the beam 120, a shaft portion 272 which is formed integrally with the embedded portion 271 and extends cylindrically from below to above, and a head portion 273 which is formed integrally with the upper end of the shaft portion 272.

[0061] The shaft portion 272 of the welded portion 270 has the same outer diameter as the embedded portion 271, and extends upward by a predetermined height integrally with the embedded portion 271. The shaft portion 272 has a peripheral side surface 272a that extends straight from the bottom to the top. However, this is not limited thereto, and the shaft portion 272 may have a peripheral side surface that tapers from the bottom to the top, or may have a peripheral side surface that expands in diameter from the bottom to the top.

[0062] Head portion 273 of welded portion 270 is integral with the upper end of shaft portion 272, and has a thin cylindrical shape that expands radially outward. Head portion 273 has an outer diameter larger than shaft portion 272, and protrudes outward more than shaft portion 272, but its height is lower than shaft portion 272.

[0063] The head portion 273 has a peripheral side surface 273a extending straight from the bottom to the top, and a top surface 273u connected to the upper end of the peripheral side surface 273a. However, the head portion 273 is not limited to this, and may have a peripheral side surface that tapers from the bottom to the top, or may have a peripheral side surface that expands in diameter from the bottom to the top.

[0064] The top surface 273u of the welded portion 270 is a curved surface formed in an arc shape that is convex upward. However, this is not limited to this, and the top surface 273u may be a curved surface formed in an arc shape that is concave downward, or a flat surface without any irregularities.

[0065] This allows head portion 273 of weld portion 270 to have a function similar to that of the head of a headed stud bolt (not shown) between the weld portion 270 and concrete 150 being poured.

[0066] As shown in FIG. 7, welding jig 280 used to form welded portion 270 has a cylindrical outer peripheral wall 280g, a circular through hole 281ha in the lower center, an opening 281hb in the upper center having an inner diameter larger than that of through hole 281ha, an inner peripheral wall 281 extending upward from the peripheral edge of through hole 281ha, an annular wall (hereinafter referred to as the "annular wall") 282 extending radially outward from the upper end of inner peripheral wall 281, and an outer peripheral wall 283 extending upward from the outer peripheral end of annular wall 282.

[0067] Here, the inner diameter of outer peripheral wall 283 of welding jig 280 is larger than the inner diameter of inner peripheral wall 281, and the height of outer peripheral wall 283 is smaller than the height of inner peripheral wall 281. Incidentally, the inner diameter of through hole 281ha of welding jig 280 is the same as that of through hole 181ha of welding jig 180 in the first embodiment.

[0068] In other words, the welding jig 280 can form a head portion 273 having a larger outer diameter than the shaft portion 272 at the welded portion 270 due to the difference in size between the inner diameter of the inner peripheral wall 281 and the inner diameter of the outer peripheral wall 283 .

[0069] In the above configuration, the floor structure 100 is formed by joining the deck plate 130 and the beams 120 together by the welded portions 270 as described above, and then pouring the concrete 150.

[0070] Because the shaft 272 and head portion 273 of the welded portion 270 protrude from the upper surface of the valley portion 132 of this deck plate 130, the concrete 150 and the shaft 272 and head portion 273 of the welded portion 270 engage with each other. As a result, in the floor structure 100, the concrete 150 can be firmly integrated with the deck plate 130 without shifting in the length direction L, width direction W, or up-down direction H.

[0071] Thus, the floor structure 100 not only joins the deck plate 130 and the beam 120 by burn-out plug welding (SPW), but also, due to the presence of the shaft portion 272 and head portion 173 of the welded part 270 formed by the burn-out plug welding (SPW), it is possible to obtain the same joint strength, fire resistance, load-bearing capacity, horizontal force transmission performance, etc. as a headed stud.

[0072] The welded part 270 of the floor structure 100 has an embedded part 271 that spans both the valley part 132 of the deck plate 130 and the upper flange 122 of the beam 120, and the shaft part 272 and head part 273 engage with the concrete 150, so that the force applied to the concrete 150 that forms the floor can be transmitted directly to the beam 120 via the welded part 270, in the same way as a headed stud.

[0073] Furthermore, the floor structure 100 can firmly join the deck plate 130 and the beam 120 with just one SPW, and can also form a weld 270 that has the same function as a headed stud. Therefore, the presence of the weld 270 can simplify the structure of the floor structure 100 itself, and can also simplify the construction process of the floor structure 100.

[0074] <Other embodiments> In the first and second embodiments of the present invention, the case has been described in which weld 170 has head portion 173, and weld 270 has head portion 273. However, the present invention is not limited to this, and weld 170 may be composed of only a shaft portion that extends cylindrically straight upward from embedded portion 171, and weld 270 may be composed of only shaft portion 272 without head portion 273. In other words, head portion 173 and head portion 273 are not essential for weld 170 and weld 270, and it is sufficient if they are welds having a shaft portion that protrudes upward from valley portion 132 of deck plate 130.

[0075] Even in this case, the concrete 150 in the floor structure 100 can engage with the shaft portion of the welded portion 170, or the shaft portion 272 of the welded portion 270, so although the joining condition is inferior to that of the welded portions 170, 270 which have head portions, the concrete 150 can be integrated with the deck plate 130 without shifting horizontally (lengthwise direction L, widthwise direction W) or in the up-down direction H.

[0076] In addition, in the above-mentioned second embodiment, a case has been described in which a thin cylindrical head portion 273 is formed integrally with the shaft portion 272 at the welded portion 270. However, the present invention is not limited to this, and various other shapes of head portions may be provided, such as an umbrella-shaped head portion being formed integrally with the shaft portion 272.

[0077] Furthermore, in the above-mentioned first and second embodiments, the floor structures 100, 200 are described as using only the welds 170, 270, but the present invention is not limited to this, and headed studs may be used in combination with the welds 170, 270. In this case, the floor structures 100, 200 can have a higher joining strength, obtain high fire resistance, and increase their load resistance.

[0078] Furthermore, in the above-mentioned first and second embodiments, floor structures 100, 200 have been described as structures, but the present invention is not limited to this, and can be applied to rooftop structures other than floor structures, and can also be applied to various other objects of application.

[0079] Although the first and second preferred embodiments of the present invention have been described above, the present invention is not limited to the first and second embodiments, and includes all aspects included in the concept of the present invention and the scope of the claims. In addition, each configuration may be appropriately and selectively combined so as to achieve at least a part of the above-mentioned problems and effects. In addition, for example, the shape, material, arrangement, size, etc. of each component in the above-mentioned embodiments may be appropriately changed depending on the specific use mode of the present invention. [Explanation of symbols]

[0080] 100...floor structure, 110...composite slab, 120...beam, 121...web, 122...upper flange, 123...lower flange, 130...deck plate, 131...peak, 132...valley, 133...inclined portion, 150...concrete, 170...welding portion, 171...embedded portion, 173...head portion, 173a...peripheral side surface, 173u...top surface, 180...welding jig, 180g...peripheral wall , 181ha...through hole, 181hb...opening, 181s...inner wall, 183...arc welding rod, 270...welding part, 280...welding jig, 271...embedded part, 272...shaft part, 273...head part, 273a...circumferential side surface, 273u...top surface, 280...welding jig, 280g...outer wall, 281ha...through hole, 281hb...opening, 281...inner wall, 282...annular wall, 283...outer wall.

Claims

1. Beams and A steel plate having a predetermined shape placed on an upper surface of the beam; A weld portion formed by joining the beam and the steel plate by burn-out plug welding and protruding upward from an upper surface of the steel plate; Concrete is poured onto the upper surface of the steel plate so as to cover the welded portion; A structure comprising:

2. The welded portion has a head portion whose diameter increases from the bottom to the top. The structure of claim 1.

3. The head portion is a truncated cone or pyramid having a trapezoidal shape in a side view, the diameter of which increases from the bottom to the top. The structure of claim 2.

4. The head portion has a cylindrical shape with a larger diameter upward than the shaft portion provided below. The structure of claim 1.

5. The head portion has a flange shape. The structure of claim 4.

6. A manufacturing method of a structure manufactured by welding a steel plate of a composite slab and a beam by burn-out plug welding, a weld forming process of joining the beam and the steel plate by burn-out plug welding and forming a weld so as to protrude upward from an upper surface of the steel plate; A concrete pouring process of pouring concrete onto an upper surface of the steel plate so as to cover the welded portion; A method for manufacturing a structure having the above structure.

7. In the weld forming step, A welding jig having a shape corresponding to the welded portion is used to form the welded portion. A method for producing the structure according to claim 6.

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