Beam reinforcement and its placement method

Abstract

To provide beam reinforcement with high strength and excellent workability, as well as a method for arranging that reinforcement. [Solution] The beam reinforcement 60 has a lower stirrup unit 30 in which first stirrups 10 having a base reinforcement portion 11 and rising reinforcement portions 12 rising upward from its left and right ends are arranged at a predetermined pitch S, and each first stirrup 10 is connected to the other by full-strength welding of upper main reinforcement 20 on the inside of the upper ends of the corresponding left and right rising reinforcement portions 12; a plurality of second stirrups 40 having a top reinforcement portion 41 and hanging reinforcement portions 42 hanging downward from its left and right ends, and arranged at a predetermined pitch S; and a lower main reinforcement 50 connected to the inside of the bent portion at the boundary between the base reinforcement portion 11 and the rising reinforcement portion 12 that form the first stirrup 10, and in a state in which the plurality of second stirrups 40 are placed over the lower stirrup unit 30, the corresponding rising reinforcement portions 12 and hanging reinforcement portions 42 overlap by a predetermined overlap length.

Description

Technical Field

[0001] The present invention relates to beam reinforcement and its reinforcement method.

Background Art

[0002] When arranging the beam reinforcement that constitutes the foundation beam of a building or the beam connecting columns, at the site, while measuring the pitch between stirrups along the longitudinal direction of the beam reinforcement, a plurality of stirrups are arranged, and transverse bars (web bars) are attached to the longitudinal bars constituting the stirrups by binding or the like, and a plurality of main bars are respectively connected to the upper and lower inner sides of the stirrups. In order to improve the efficiency of the work, a construction method using so-called welded reinforcement may be applied. This welded reinforcement is, for example, a unit formed by pre-welding stirrups and transverse bars at a factory or the like. Such welded reinforcement is carried into the site, and at the site, for example, by connecting the upper unit and the lower unit, a closed-type stirrup is arranged. Then, the upper main bar and the lower main bar are arranged and bound on the upper and lower inner sides of the closed-type stirrup, whereby the beam reinforcement is arranged.

[0003] Here, a beam reinforcement structure and a reinforcement method are proposed, which are formed by covering a lower unit in which a plurality of stirrups are unitized by an upper main bar and a lower main bar with a cap tie without a hook and arranging them (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the beam reinforcement described in Patent Document 1, the upper stirrups, which are cap ties, do not have hooks, and the cap ties are only slightly overlapped with the lower stirrups, so it is unclear whether the beam reinforcement has sufficient strength. Furthermore, according to the Reinforced Concrete Reinforcement Guidelines and Commentary 2021 (Architectural Institute of Japan), in the above-mentioned cap tie type reinforcement, for example, a 135-degree hook is provided at the upper end of the lower stirrups, and the lower stirrups and cap ties are overlapped with a lap splice length of 6d (d is the nominal name for deformed reinforcement).

[0006] In light of these general specifications, it must be said that it is unclear whether the strength of the cap-tie type beam reinforcement described in Patent Document 1 is sufficient, or in other words, whether the upper and lower stirrups form a closed reinforcement structure in a strong manner.

[0007] This invention was made in view of the above problems, and aims to provide beam reinforcement with high strength and excellent workability, as well as a method for arranging that reinforcement. [Means for solving the problem]

[0008] To achieve the above objective, one embodiment of the beam reinforcement according to the present invention is: A lower stirrup unit is formed by first stirrups having an upward-opening U-shape and a base reinforcement section and rising reinforcement sections that rise upward from the left and right ends of the base reinforcement section, arranged at a predetermined pitch, and each of the first stirrups being connected to each other by full-strength welding of the upper main reinforcement at the inner upper ends of the corresponding left and right rising reinforcement sections, It has a U-shape that opens downwards, and has a top reinforcement section and hanging reinforcement sections that hang down from the left and right ends of the top reinforcement section, and is arranged at the predetermined pitch, and a plurality of second stirrups, It has a lower end main reinforcement connected to the inside of the bent portion at the boundary between the bottom reinforcement portion and the rising reinforcement portion that form the first rib, In the state in which the plurality of second ribs are placed over the lower rib unit, the rising portion of the corresponding first rib and the hanging portion of the second rib overlap by a predetermined overlapping length.

[0009] According to this embodiment, the vertical reinforcement portion of the first stirrup and the downward reinforcement portion of the second stirrup of the lower stirrup unit overlap by a predetermined overlap length, resulting in a beam reinforcement that is highly strong and easy to construct.

[0010] Here, "full-strength welding," which connects the first stirrup and the upper main reinforcement in the lower stirrup unit, is also called "full-strength rebar cross welding." It refers to spot welding in which the welded joint has a strength equal to or greater than the JIS standard yield point of the stirrup, the elongation of the main reinforcement is equal to or greater than the JIS standard value of the rebar before welding, and the shear strength of the welded joint is equal to or greater than the short-term allowable tensile strength of the stirrup. Ordinary spot welding guarantees that the welded joint has a strength of about 1 / 3 to 2 / 3 of the JIS standard yield point of the rebar. This full-strength welding is a welding method that involves repeating ordinary spot welding two or more times, and annealing by performing a second spot weld before the welded joint cools rapidly after the first spot weld.

[0011] Furthermore, the lower main reinforcement, which is not necessarily included in the lower stirrup unit, is connected to the inside of the bent portion at the boundary between the bottom reinforcement portion and the rising reinforcement portion that form the first stirrup. This lower main reinforcement may also be connected to the first stirrup by full-strength welding, or it may be tied with binding wire or the like.

[0012] In this embodiment, the "predetermined overlap length" at which the vertical reinforcement and the vertical reinforcement overlap can be exemplified by, for example, 25d (where d is the designation for the vertical reinforcement or vertical reinforcement) or 40d. Furthermore, in accordance with the description in the Reinforced Concrete Calculation Standards and Commentary (2018), the predetermined overlap length is defined as the overlap length L with a hook. 1h Alternatively, you can set the overlapping length of the straight line to L1.

[0013] Furthermore, other embodiments of the beam reinforcement according to the present invention are: The aforementioned drooping section is characterized by having a straight shape and not having a hook at its tip.

[0014] According to this embodiment, the fact that the hanging reinforcing bar portion has a straight shape without a hook at its tip improves the workability when dropping the U-shaped second stirrup from above the lower stirrup unit. In this embodiment, since the rising reinforcing bar portion and the hanging reinforcing bar portion overlap in a straight line, a predetermined overlap length of 40d is applied.

[0015] Furthermore, other embodiments of the beam reinforcement according to the present invention are: The present invention is characterized in that, when the ends of the other member reinforcements, which are reinforcing bars or anchor bars extending from the ends of other members connected to the beam reinforcement, the second stirrups among the plurality of second stirrups that would normally interfere with the other member reinforcements are shifted to a position where they do not interfere with the other member reinforcements.

[0016] According to this embodiment, among the multiple second stirrups, the second stirrups that are originally located in a position that would interfere with the reinforcement of other members extending from the ends of other members connected to the beam reinforcement are shifted to a position where they do not interfere with the other member reinforcement. This allows the reinforcement of other members to be smoothly inserted into predetermined positions on the beam reinforcement, enabling efficient reinforcement not only for the beam reinforcement but also for the reinforcement of other members connected to the beam reinforcement.

[0017] For example, if the beam reinforcement in this embodiment is the beam reinforcement of a foundation beam, and anchor reinforcement (anchor bolts), which are reinforcement of other members extending from the base plate (or similar) of a column, is inserted into the beam reinforcement, then the second stirrups, which are arranged in the longitudinal direction of the beam reinforcement at predetermined intervals, and which are positioned to interfere with the anchor reinforcement, are shifted in advance to positions where they do not interfere. This allows for smooth reinforcement of the anchor reinforcement of the column base relative to the beam reinforcement of the foundation beam.

[0018] Furthermore, one embodiment of the beam reinforcement method according to the present invention is: A lower stirrup unit is installed, comprising: a lower stirrup unit installation step, in which a first stirrup unit having an upwardly opening U-shape and a base reinforcement portion and rising reinforcement portions rising upward from the left and right ends of the base reinforcement portion is arranged at a predetermined pitch, and each first stirrup unit is connected to the upper main reinforcement by full-strength welding on the inner side of the upper ends of the corresponding left and right rising reinforcement portions; A connection step is to place a plurality of second stirrups, each having a U-shape that opens downwards and comprising a top reinforcement portion and downward-hanging reinforcement portions extending downwards from both ends of the top reinforcement portion, over the lower stirrup unit, and connect the corresponding upright reinforcement portion of the first stirrup and the downward-hanging reinforcement portion of the second stirrup by overlapping them by a predetermined length. The invention is characterized by comprising a lower main reinforcement connection step, in which the lower main reinforcement is connected to the inside of the bent portion at the boundary between the bottom reinforcement portion and the rising reinforcement portion that form the first stirrups.

[0019] According to this embodiment, for example, lower stirrup units manufactured in a factory and multiple second stirrups are transported to the site, the second stirrups corresponding to each first stirrup forming the lower stirrup unit are placed, and the rising and hanging sections are assembled by tying or the like, thereby enabling efficient placement of beam reinforcement. In particular, because the lower stirrup unit has upper main reinforcement, when the second stirrups are placed over the lower stirrup unit from above, the second stirrups are locked to the upper main reinforcement, resulting in improved work efficiency when tying the reinforcement bars together.

[0020] Furthermore, in this embodiment, since the lower stirrup unit does not have a lower main reinforcement, after tying the second stirrup and the lower stirrup unit together, the lower main reinforcement is connected to the inside of the bent portion at the boundary between the bottom reinforcement portion and the rising reinforcement portion that constitute the first stirrup of the lower stirrup unit. This connection can be made, for example, by tying. In addition, according to this embodiment, since the lower stirrup unit does not have a lower main reinforcement, the length of the lower stirrup unit (unit length in the longitudinal direction of the beam reinforcement) can be increased when manufacturing a lower stirrup unit of the same weight compared to the case in which the lower stirrup unit has a lower main reinforcement.

[0021] In addition, another aspect of the method for arranging beam reinforcement bars according to the present invention is that a first web bar having a U-shape opened upward, including a bottom bar portion and rising bar portions rising upward from the left and right ends of the bottom bar portion, is arranged at a predetermined pitch, and each pair of the first web bars is connected to an upper main bar by full-strength welding inside the upper ends of the corresponding rising bar portions on the left and right, and a lower main bar is connected by welding inside the boundary between the bottom bar portion and the rising bar portion, and a lower web bar unit is installed, and a lower web bar unit installation step; a plurality of second web bars having a U-shape opened downward, including a top bar portion and hanging bar portions hanging downward from both ends of the top bar portion, are placed on the lower web bar unit, and the rising bar portions of the corresponding first web bars and the hanging bar portions of the second web bars are connected by lapping with a predetermined overlapping length, and a connecting step.

[0022] According to this aspect, since the lower web bar unit is connected to the first web bar by welding both the upper main bar and the lower main bar, when the second web bar is assembled to the lower web bar unit by bundling or the like, the arrangement of the beam reinforcement bars can be completed. That is, it is possible to eliminate the labor of further arranging the lower main bar after assembling the lower web bar unit and the second web bar. Here, for the first web bar, the lower main bar may be spot welding which is full-strength welding, or spot welding which is not full-strength (welding with a strength of about 1 / 3 to 2 / 3 of the yield load of the web bar).

[0023] In addition, another aspect of the method for arranging beam reinforcement bars according to the present invention is that when arranging the ends of other member bars, which are steel bars or anchor bars extending from the ends of other members to be connected, to the beam reinforcement bars, in the connecting step, among the plurality of second web bars, the second web bars originally located at positions interfering with the other member bars are shifted to positions not interfering with the other member bars.

[0024] According to this embodiment, among the multiple second stirrups, those that are originally located in a position that would interfere with the reinforcement of other members extending from the ends of other members connected to the beam reinforcement can be pre-shifted to a position where they do not interfere with the other reinforcement when forming the beam reinforcement. This allows the other reinforcement to be smoothly inserted into the predetermined position of the beam reinforcement when the beam reinforcement of other members is subsequently laid, enabling efficient reinforcement not only for the beam reinforcement but also for the reinforcement of other members connected to the beam reinforcement. Furthermore, since the multiple second stirrups are each independent and not unitized by, for example, horizontal reinforcement, the second stirrups that interfere with the reinforcement of other members can be easily shifted and laid in a position where they do not interfere. [Effects of the Invention]

[0025] As can be understood from the above explanation, the beam reinforcement and its arrangement method of the present invention can provide beam reinforcement that is highly strong and easy to construct. [Brief explanation of the drawing]

[0026] [Figure 1] This is a process diagram of an example of a beam reinforcement arrangement method according to the embodiment. [Figure 2] Following Figure 1 is a process diagram of an example of a beam reinforcement method according to the embodiment, and is a perspective view of an example of reinforcement according to the embodiment. [Figure 3] This is a perspective view of another example of reinforcement arrangement and reinforcement method according to the embodiment. [Modes for carrying out the invention]

[0027] The beam reinforcement and its arrangement method according to the embodiment will be described below with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0028] [Beam reinforcement according to an embodiment and its reinforcement method] An example of beam reinforcement and its reinforcement method according to the embodiment will be described with reference to Figures 1 to 3. Here, Figure 1 is a process diagram of an example of the beam reinforcement method according to the embodiment, and Figure 2 is a process diagram of an example of the beam reinforcement method according to the embodiment, following Figure 1, and is a perspective view of the example reinforcement according to the embodiment.

[0029] As shown in Figure 1, the beam reinforcement according to this embodiment is formed by pre-fabricating a lower stirrup unit 30 and a plurality of second stirrups 40 in a factory or the like, transporting them to the site, and then assembling the lower stirrup unit 30 and a plurality (six in the illustrated example) of second stirrups 40 at the site.

[0030] The lower stirrup unit 30 has an upward-opening U-shape, and first stirrups 10, each having a bottom reinforcement portion 11 and rising reinforcement portions 12 that rise upward from the left and right ends of the bottom reinforcement portion 11, are arranged at a predetermined pitch S. Each of the first stirrups 10 is formed by connecting upper end main reinforcements 20 at the upper ends of the corresponding left and right rising reinforcement portions 12.

[0031] Here, the connection between the rising reinforcement section 12 and the upper main reinforcement 20 is made by full-strength welding. This full-strength welding is a welding method that involves repeating normal spot welding two or more times, and performing a second spot weld before the weld cools rapidly after the first spot weld, thereby annealing the weld. With this full-strength welding, the weld between the first stirrup 10 and the upper main reinforcement 20 has a strength equal to or greater than the JIS standard yield point of the first stirrup 10, the elongation of the reinforcement is also equal to or greater than the JIS standard value of the reinforcement before welding, and the shear strength of the weld is equal to or greater than the short-term allowable tensile strength of the stirrup, so that both members are connected with high connection strength.

[0032] The predetermined pitch S shown in the diagram is determined based on the required amount of reinforcing steel in the concrete, such as 150 mm or 200 mm. The first stirrups 10 are formed from deformed steel bars, for example, with reinforcing steel of diameters such as 10 mm (D10) or D13 being used, and this is also determined based on the required amount of reinforcing steel in relation to the predetermined pitch S.

[0033] Deformed steel bars of a predetermined diameter are used for the upper main reinforcement bars 20. In the illustrated example, there are two upper main reinforcement bars 20, and their diameters are set to satisfy the design bending moment and design shear force. From the viewpoint of the required amount of reinforcement, one or more additional upper main reinforcement bars 20 may be placed between the two upper main reinforcement bars 20 in the final reinforcement configuration. For example, in the illustrated example, deformed steel bars such as D19 and D22 can be used (the above describes the lower stirrup unit installation process).

[0034] On the other hand, the second stirrup 40 has a U-shape that opens downwards and has a top reinforcement portion 41 and hanging reinforcement portions 42 with a length t1 that hang down from the left and right ends of the top reinforcement portion 41. As shown in the figure, the hanging reinforcement portions 42 have a straight shape and do not have a hook at their tip (lower end). Here, the second stirrup 40 may also be called a cap tie.

[0035] After the lower stirrup unit 30 is installed on site, as shown in Figure 1, each second stirrup 40 is placed over the lower stirrup unit 30 by dropping it in the X direction, overlapping the rising reinforcement portion 12 of the corresponding first stirrup 10 and the hanging reinforcement portion 42 of the second stirrup 40 by a predetermined overlap length (length t1 of the hanging reinforcement portion 42), and connecting the two by binding or the like.

[0036] Here, since the rising reinforcement section 12 and the hanging reinforcement section 42 overlap in a straight line, a predetermined overlap length of 40d (where d is the designation for the rising reinforcement section 12 or the hanging reinforcement section 42) is applied (connection process).

[0037] In this way, both the rising reinforcement portion 12 of the corresponding first stirrup 10 and the hanging reinforcement portion 42 of the second stirrup 40 are linear in shape and connected in an overlapping position with an overlap length of 40d. Due to the high restraining effect of the second stirrup 40, a high-strength beam reinforcement in which the lower stirrup unit 30 and the second stirrup 40 are integrated with high strength can be formed under good constructability (reinforcement arrangement).

[0038] Furthermore, in the lower stirrup unit 30, although the first stirrup 10 does not have a hook at the end of the rising reinforcement section 12, the upper main reinforcement 20 is connected by full-strength welding, so this upper main reinforcement 20 acts as a hook substitute. In this way, since the upper main reinforcement 20 is connected to the end of the first stirrup 10 by full-strength welding, good anchorage of the stirrup 10 in the concrete, which would be expected from a hook, is guaranteed.

[0039] In the illustrated example, the first stirrups 10 and the second stirrups 40 forming the lower stirrup unit 30 each consist of six pieces. However, from the viewpoint of ease of transport to the site and ease of construction at the site, the first stirrups 10 may have seven or more pieces, making the unit as long as possible in the Z direction, which is the longitudinal direction of the beam reinforcement.

[0040] In particular, since the lower stirrup unit 30 has only an upper main reinforcement 20 as its main reinforcement and no lower main reinforcement, the weight of the lower stirrup unit 30 is relatively lighter compared to, for example, a configuration in which the lower stirrup unit has both an upper and lower main reinforcement. Therefore, the lower stirrup unit 30 can be made even longer in the Z direction, which is the longitudinal direction of the beam reinforcement, compared to a lower stirrup unit that has a lower main reinforcement. Furthermore, if an even longer lower stirrup unit 30 is prepared in this way, the number of second stirrups 40 will also be the same as the number of first stirrups 10 in this longer lower stirrup unit 30.

[0041] Next, as shown in Figure 2, the beam reinforcement 60 is reinforced by placing and connecting the lower main reinforcement bars 50 inside the bent portion at the boundary between the bottom reinforcement portion 11 and the rising reinforcement portion 12 that form each first stirrup 10. Here, the connection of the lower main reinforcement bars 50 to the first stirrup 10 is done by tying with binding wire or the like (lower main reinforcement bar connection process).

[0042] The resulting beam reinforcement 60 eliminates the need for horizontal reinforcement, making it possible to reduce the amount of reinforcement as much as possible compared to conventional beam reinforcement that requires horizontal reinforcement, thus reducing construction time.

[0043] Furthermore, as another example of a beam reinforcement method, the lower stirrup unit may be equipped with both upper and lower main reinforcement bars, and the reinforcement method may include a lower stirrup unit installation step in which the upper and lower main reinforcement bars are automatically placed when the lower stirrup unit is installed on site, and a connection step in which multiple second stirrups are dropped into and placed over the lower stirrup unit, and the corresponding rising reinforcement and hanging reinforcement sections are connected by overlapping by 40d.

[0044] This reinforcement method eliminates the need to further reinforce the lower main reinforcement after connecting the lower stirrup unit and the second stirrup, thus enabling beam reinforcement to be installed with even greater efficiency.

[0045] Next, with reference to Figure 3, yet another example of beam reinforcement and its reinforcement method according to the embodiment will be described.

[0046] The beam reinforcement 60A shown in Figure 3 is a beam reinforcement that forms a foundation beam. When anchor bolts 70 (anchor reinforcement, an example of reinforcement for other members), shown by dashed lines, which fix the base of a column (an example of another member) not shown, erected on this foundation beam, are inserted into the beam reinforcement 60A at a predetermined position, the beam reinforcement is capable of accommodating the case in which some of the second stirrups 40 interfere with the anchor bolts 70 when each of the second stirrups 40 is arranged at a predetermined pitch S.

[0047] The positions in which the anchor bolts 70 are inserted into the beam reinforcement can be determined in advance, and the second stirrups 40, which are originally located in positions that interfere with the anchor bolts 70, can also be identified. Therefore, in the connection process of the reinforcement method, as shown in Figure 3, the beam reinforcement 60A is formed by shifting the second anchor bolts 70, which are located in the interference position, in the Y direction from their original beam reinforcement positions to positions that do not interfere with the anchor bolts 70 (positions S' and S'', where the pitch between them and the left and right second stirrups 40 is different from S).

[0048] For example, since multiple second stirrups 40 are not unitized with horizontal reinforcement, and each second stirrup 40 is a separate reinforcement, the second stirrup 40 that is in a position of interference with the anchor bolt 70 can be smoothly shifted to the desired position.

[0049] By applying the beam reinforcement 60A formed using this reinforcement method, in cases where reinforcement from other members is inserted into the beam reinforcement, it is possible to smoothly insert the reinforcement from other members into the designated position of the beam reinforcement after the beam reinforcement has been formed. Therefore, efficient reinforcement can be achieved, including not only the reinforcement of the beam but also the reinforcement of other members connected to the beam reinforcement.

[0050] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of symbols]

[0051] 10: First rib 11: Bottom muscle 12: Erecting muscles 20: Top main reinforcement 30: Lower rib unit 40: Second rib muscle 41: Top reinforcement section 42: Drooping muscle area 50: Bottom main reinforcement 60,60A: Beam reinforcement 70: Other structural reinforcement (anchor reinforcement, anchor bolts)

Claims

1. A lower stirrup unit is formed by first stirrups having an upward-opening U-shape and a base reinforcement section and rising reinforcement sections that rise upward from the left and right ends of the base reinforcement section, arranged at a predetermined pitch, and each of the first stirrups being connected to each other by full-strength welding of the upper main reinforcement at the inner upper ends of the corresponding left and right rising reinforcement sections, It has a U-shape that opens downwards, and has a top reinforcement section and hanging reinforcement sections that hang down from the left and right ends of the top reinforcement section, and is arranged at the predetermined pitch, and a plurality of second stirrups, It has a lower end main reinforcement connected to the inside of the bent portion at the boundary between the bottom reinforcement portion and the rising reinforcement portion that form the first rib, In a state in which the plurality of second stirrups are placed over the lower stirrup unit, the rising portion of the corresponding first stirrup and the hanging portion of the second stirrup overlap by a predetermined overlap length.

2. The beam reinforcement according to claim 1, characterized in that the hanging reinforcement portion is straight and does not have a hook at its tip.

3. The beam reinforcement according to claim 1 or 2, characterized in that when the ends of the other member reinforcements, which are reinforcing bars or anchor bars extending from the ends of other members to be connected to the beam reinforcement, are arranged, the second stirrups among the plurality of second stirrups that are originally in a position to interfere with the other member reinforcements are shifted to a position where they do not interfere with the other member reinforcements.

4. A lower stirrup unit is installed, comprising: a lower stirrup unit installation step, in which a first stirrup unit having an upwardly opening U-shape and a base reinforcement portion and rising reinforcement portions rising upward from the left and right ends of the base reinforcement portion is arranged at a predetermined pitch, and each first stirrup unit is connected to the upper main reinforcement by full-strength welding on the inner side of the upper ends of the corresponding left and right rising reinforcement portions; A connection step is to place a plurality of second stirrups, each having a U-shape that opens downwards and comprising a top reinforcement portion and downward-hanging reinforcement portions extending downwards from both ends of the top reinforcement portion, over the lower stirrup unit, and connect the corresponding upright reinforcement portion of the first stirrup and the downward-hanging reinforcement portion of the second stirrup by overlapping them by a predetermined length. A method for arranging beam reinforcement, characterized by comprising: a lower end main reinforcement connection step, which involves connecting the lower end main reinforcement to the inside of the bent portion at the boundary between the bottom reinforcement portion and the rising reinforcement portion that form the first stirrups.

5. A lower stirrup unit is installed, comprising: a lower stirrup unit installation step, in which a first stirrup unit having an upwardly opening U-shape and having a bottom reinforcement portion and rising reinforcement portions rising upward from the left and right ends of the bottom reinforcement portion is arranged at a predetermined pitch, each first stirrup is connected to the upper main reinforcement by full-strength welding on the inner side of the upper ends of the corresponding left and right rising reinforcement portions, and the lower main reinforcement is connected by welding on the inner side of the boundary between the bottom reinforcement portion and the rising reinforcement portion; A method for arranging beam reinforcement, characterized by comprising: a connection step of placing a plurality of second stirrups, each having a U-shape that opens downwards and a top reinforcement portion and hanging reinforcement portions that hang downwards from both ends of the top reinforcement portion, over the lower stirrup unit, and connecting the corresponding upright reinforcement portion of the first stirrup and the hanging reinforcement portion of the second stirrup by overlapping them by a predetermined length.

6. The method for arranging beam reinforcement according to claim 4 or 5, characterized in that, when the end of the reinforcement of another member, which is a reinforcing bar or anchor reinforcement extending from the end of the other member to be connected to the beam reinforcement, the connection step involves shifting the second stirrups, which are originally in a position that interferes with the other member reinforcement, to a position that does not interfere with the other member reinforcement.

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