JP6920985B2 - Beam reinforcement and its reinforcement method - Google Patents

Description

The present invention relates to beam bars constituting the foundation beams of a building and beams connecting columns to each other, and a method of arranging the beams.

When arranging the beam reinforcements that make up the foundation beams of the building and the beams that connect the columns, multiple reinforcing bars are arranged at the site while measuring the pitch between the stirrups over the longitudinal direction of the beam stirrup. A construction method using so-called welded reinforcing bars is applied in order to attach horizontal bars (abdominal muscles) to the vertical bars that make up the bars by binding, etc., and to streamline the work of connecting multiple main bars to the upper, lower, and inner sides of the stirrups. Sometimes. In this welded reinforcing bar, for example, a stirrups and a horizontal reinforcing bar are unitized in advance by welding at a factory or the like, and such a welded reinforcing bar is brought into a site and, for example, an upper unit and a lower unit are connected at the site. By doing so, the closed stirrups are arranged. Then, the beam reinforcements are arranged by arranging the upper end main reinforcement and the lower end main reinforcement inside the upper and lower sides of the closed type stirrups and binding them together.

Here, the reinforcement structure of the beam reinforcement is formed by covering the lower unit in which a plurality of stirrups are unitized by the upper end main reinforcement and the lower end main reinforcement with a cap tie that does not have a hook. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-29249

However, in the beam reinforcement described in Patent Document 1, in addition to the fact that the upper stirrups, which are cap ties, do not have hooks, the reinforcements are arranged with the cap ties slightly wrapped around the lower stirrups. It is unclear whether or not the beam has sufficient strength because it is only used. According to the reinforced concrete reinforcement guideline and commentary 2010 (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 rebar, and the lower part of the rebar is provided with a 135 degree hook. Reinforcing bar arrangement specifications are described in which the stirrups and cap ties are overlapped with a lap joint length of 8d (d is the name of the deformed reinforcing bar). In view of such general specifications, whether or not the strength of the cap tie type beam reinforcement described in Patent Document 1 is sufficient, in other words, the closed type reinforcing bar is provided in such a manner that the upper and lower stirrups are strong. I have to say that it is unclear whether or not it is formed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a beam bar having high strength and excellent workability and a method of arranging the beam bar.

In order to achieve the above object, one aspect of the beam muscle according to the present invention has a U-shape that opens upward, and has a bottom muscle portion and a rising muscle portion that rises upward from the left and right ends of the bottom muscle portion. A lower unit in which one stirrup bar is arranged at a predetermined pitch, and each first stirrup bar is connected to the upper end main bar by full-strength welding inside the upper end of the corresponding rising bar portion on the left and right.
A second stirrups, which have a U-shape that opens downward and have a crown muscle portion and a drooping muscle portion that hangs downward from the left and right ends of the crown muscle portion, are arranged at a predetermined pitch, and each first The two stirrups are connected to the lateral streaks by welding at predetermined positions on the outside of the corresponding left and right sagging muscles, and are composed of an upper unit having no hook at the end of the sagging muscles. Being done
The lower end main bar is connected to the inside of the bent portion at the boundary between the bottom bar portion and the rising bar portion forming the first stirrups.
In a state where the upper unit is covered with the lower unit, the rising muscle portion of the corresponding first stirrups and the sagging muscle portion of the second stirrups are wrapped with a predetermined lap joint length. It is characterized by being.

According to this aspect, the rising muscle portion of the lower unit in which a plurality of first stirrups are integrated by the upper end main muscle and the sagging muscle of the upper unit in which a plurality of second stirrups are integrated by the lateral muscles. By wrapping the portions with a predetermined lap joint length, a beam bar integrated with high strength is formed. Here, "full-strength welding" in which the first stirrups and the upper end main bars are connected in the lower unit is also called "full-strength rebar cross-welding", and the welded portion has a strength equal to or higher than the JIS standard yield point of the stirrups. It means spot welding in which the elongation of the reinforcing bar is equal to or higher than the JIS standard value of the reinforcing bar before welding, and the shear strength of the welded portion is equal to or higher than the short-term allowable tensile strength of the loose bar. In normal spot welding, the welded portion guarantees about 1/3 to 2/3 of the JIS standard yield point of the reinforcing bar. This full-strength welding is a welding method in which normal spot welding is repeated two or more times, and the welding is blunted by performing a second spot welding after one spot welding and before the welded portion is rapidly cooled.

The lower end main bar, which is not necessarily included in the lower unit, is connected to the inside of the bent portion at the boundary between the bottom bar and the rising bar forming the first stirrups. The lower end main bar may also be connected to the first stirrups by full-strength welding, or may be bound by a binding wire or the like. The mode of connecting the lower end main bar to the first stirrups differs depending on the difference in the bar arrangement method described later.

On the other hand, "welding" that connects a plurality of second stirrups and lateral bars in the upper unit means welding in a broad sense, which means general spot welding, in addition to full-strength welding. Further, since the lateral streaks are welded to the plurality of second stirrups in the upper unit, the welded lateral streaks serve as hook substitute bars in the second stirrups. Similarly, in the lower unit, the welded upper end main bar serves as a hook replacement bar in the first stirrups. By providing the horizontal bar which is a hook substitute muscle in this way, the hook can be eliminated from the second stirrups. Similarly, by providing the upper end main bar which is a hook substitute bar, the hook can be eliminated from the first stirrups. The "predetermined lap joint length" means "predetermined lap joint length with hook", and is the concrete design standard strength Fc (Fc = 21N / mm ² etc.) and the type of reinforcing bar (SD295A). , B, SD345, etc.), and is generally set between 20d and 40d (mm) (d is the name of the deformed reinforcing bar).

In addition, another aspect of the beam bar according to the present invention is characterized in that the horizontal bar is connected by full-strength welding at a predetermined position outside the droop bar portion.
According to this aspect, since the second stirrups and the lateral bars are connected by full-strength welding instead of normal spot welding, it is possible to form a beam bar having even higher strength.

In addition, another aspect of the beam bar according to the present invention is characterized in that the lateral bar is connected to the outside of the lower end of the droop bar portion.
According to this aspect, since the lateral muscle is connected to the lower end of the sagging muscle portion of the second rib muscle, the length of this sagging muscle portion is at least between the rising muscle portion of the first rib muscle. It is possible to set the lap joint length to the minimum necessary length, and therefore, it is possible to provide a beam bar in which the amount of reinforcing bars used is suppressed and the material cost is suppressed.

Further, another aspect of the beam bar according to the present invention is characterized in that the horizontal bar is arranged at a position lower than the central position of the height of the beam bar and in the vicinity of the central position.

According to this aspect, by arranging the horizontal streaks at a position lower than the central position of the height of the beam streaks and in the vicinity of the central position, it is possible to form a beam of the bending fracture preceding type, and brittle fracture. Can provide a beam streak to be provided for a suppressed beam. Since the rising muscles of the first rebar and the drooping muscles of the second rebar wrap by a predetermined lap joint length to form the beam, at least from the center position of the height of the beam. In the upper region, the stirrups are double-arranged, and the amount of reinforcing bars (barrel streaks) is larger than in the region below the center position of the height of the beam bars. If the lateral reinforcement is arranged in the region above the center position of the height of the beam reinforcement, the lateral reinforcement is added to the reinforcement amount in addition to the large amount of loose reinforcement as described above, and the bending moment of the upper tension is outstanding. There is a risk that the bending strength at both ends of the beam, which is easy to use, will become too large, and there is a high possibility that the beam will be a shear failure leading type beam. Therefore, by arranging the horizontal bars at a position lower than the center position of the height of the beam bars and in the vicinity of the center position as in this embodiment, the bending strength at both ends of the beam is reduced and the shear fracture precedes. It is possible to easily form a beam that precedes bending fracture instead of a mold. Here, the "neighborhood of the central position" means that the position of h / 2 from the lower part of the beam bar is the central position when the beam formation of the beam bar is h, and the range of h / 4 below the central position is defined as the central position. Means. If the beam formation of the beam is high, it is necessary to arrange reinforcing bars with a minimum amount of reinforcing bars or more in the cross section of the beam. It may be necessary to connect by welding. In such a case, for example, at least the lowest horizontal bar is arranged in the vicinity of the central position below the center position of the height of the beam bar.

Further, one aspect of the method of arranging the beam reinforcements according to the present invention is the first, which has a U-shape that opens upward and has a bottom muscle portion and a rising muscle portion that rises upward from the left and right ends of the bottom muscle portion. The stirrups are arranged at a predetermined pitch, and each of the first stirrups is connected to the upper end main bar by full-strength welding inside the upper end of the corresponding rising bar on the left and right. The lower unit installation process and
A second stirrups, which have a U-shape that opens downward and have a crown muscle portion and a drooping muscle portion that hangs downward from the left and right ends of the crown muscle portion, are arranged at a predetermined pitch, and each first The upper unit, in which the two stirrups are welded to the lateral streaks at predetermined positions outside the corresponding left and right sagging muscles and do not have a hook at the end of the sagging muscles, is attached to the lower part. An upper and lower unit that covers and arranges reinforcements on a unit, and wraps and connects the rising muscle portion of the first stirrups and the sagging muscle portion of the second stirrups with a predetermined lap joint length. Connection process and
It is characterized by having a lower end main bar connecting step of connecting the lower end main bar inside the bent portion of the boundary between the bottom bar portion and the rising bar portion forming the first stirrups.

According to this aspect, for example, the upper unit and the lower unit manufactured in a factory are transported to the site, and at least the rising muscle portion of the first stirrups and the drooping streak portion of the second stirrups are provided with a predetermined lap joint length. By wrapping the beams and assembling them together by binding or the like, the beam reinforcements can be efficiently arranged. In particular, since the lower unit has the upper end main bar, when the second stirrups constituting the upper unit are covered from above the lower unit, the second stirrups can be placed on the upper end main bar. Since the predetermined lap joint length can be automatically formed in this mounted state, there is no need for time-consuming bar arrangement such as wrapping while measuring the lap joint length. In this embodiment, the lower unit does not have the lower end main bar, and therefore, after binding the upper unit and the lower unit, the bottom muscle portion and the rising muscle portion constituting the first stirrups of the lower unit Connect the lower end main bar to the inside of the bending part of the boundary. This connection can be made, for example, by binding. Further, according to this aspect, since the lower unit does not have the lower end main bar, the lower unit is extended when the lower unit having the same weight is manufactured as compared with the case where the lower unit has the lower end main bar. The unit length in the longitudinal direction of the beam bar) can be lengthened.

In addition, another aspect of the method for arranging beam reinforcements according to the present invention has a U-shape that opens upward, and has a bottom muscle portion and a rising muscle portion that rises upward from the left and right ends of the bottom muscle portion. One stirrups are arranged at a predetermined pitch, and each of the first stirrups is connected to the upper end main bar by full-strength welding inside the upper end of the corresponding rising bar on the left and right, and the bottom bar. A lower unit installation step of arranging a lower unit in which the lower end main bar is connected by welding inside the boundary between the portion and the rising bar portion.
A second stirrups, which have a U-shape that opens downward and have a crown muscle portion and a drooping muscle portion that hangs downward from the left and right ends of the crown muscle portion, are arranged at a predetermined pitch, and each first The upper unit, in which the two stirrups are welded to the lateral streaks at predetermined positions outside the corresponding left and right sagging muscles and do not have a hook at the end of the sagging muscles, is attached to the lower part. An upper and lower unit that covers and arranges reinforcements on a unit, and wraps and connects the rising muscle portion of the first stirrups and the sagging muscle portion of the second stirrups with a predetermined lap joint length. It is characterized by having a connection process.

According to this aspect, since the lower unit has both the upper end main bar and the lower end main bar connected to the first stirrups by welding, the upper unit is bound to the lower unit by binding or the like. When assembled, the reinforcement arrangement of the beam reinforcement can be completed. That is, it is possible to eliminate the trouble of further arranging the lower end main reinforcement after assembling the lower unit and the upper unit.

Further, in another aspect of the method of arranging the beam reinforcements according to this aspect, in the upper and lower unit connecting steps, the horizontal reinforcements are placed at a position lower than the central position of the height of the beam reinforcements and in the vicinity of the central position. It is characterized in that it is arranged.
According to this aspect, it is possible to efficiently construct a beam bar for forming a beam which is a bending fracture leading type and has a low possibility of brittle fracture.

As can be understood from the above description, according to the beam bar of the present invention and the method of arranging the beam, it is possible to provide a beam bar having high strength and excellent workability.

It is a process drawing explaining the method of arranging the beam reinforcement which concerns on 1st Embodiment. Following FIG. 1, it is a process diagram for explaining the method of arranging the beam reinforcements according to the first embodiment. Following FIG. 2, it is a process diagram for explaining the method of arranging the beam bars according to the first embodiment, and is a diagram for explaining the beam bars according to the first embodiment. It is a process drawing explaining the method of arranging the beam reinforcement which concerns on 2nd Embodiment. Following FIG. 4, it is a process diagram for explaining the method of arranging the beam bars according to the second embodiment, and is a diagram for explaining the beam bars according to the second embodiment.

Hereinafter, the method of arranging the beam reinforcement and the beam reinforcement formed by each method of arranging the beam according to each embodiment of the present invention will be described with reference to the attached drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Method of arranging beam reinforcement and beam reinforcement according to the first embodiment]
First, with reference to FIGS. 1 to 3, a method of arranging beam reinforcements according to the first embodiment and a beam reinforcement formed by this method of arranging beams will be described. Here, FIGS. 1 to 3 are process diagrams for explaining the method of arranging the beam bars according to the first embodiment in this order, and FIG. 3 further describes the beam bars according to the first embodiment. It is a figure. As shown in FIG. 1, in the method of arranging the beam reinforcements according to the present embodiment, the lower unit 50 and the upper unit 60 are manufactured in advance at a factory or the like and transported to the site, and the lower unit 50 and the upper unit are transported at the site. By assembling 60, the beam reinforcement is arranged.

As shown in FIG. 1, the lower unit 50 has a U-shape that opens upward, and has a bottom muscle portion 11 and a rising muscle portion 12 that rises upward from the left and right ends of the bottom muscle portion 11. The stirrups 10 are arranged at a predetermined pitch s in the Z direction, which is the longitudinal direction of the beam streaks, and the first stirrups 10 are arranged in the upper end main bars 30 inside the upper ends of the corresponding left and right rising streaks 12. It is formed by being connected by.

Here, the connection between the rising bar portion 12 and the upper end main bar 30 is connected by full-strength welding. This full-strength welding is a welding in which normal spot welding is repeated two or more times, and is a welding method in which a second spot welding is performed after one spot welding and before the welded portion is rapidly cooled, thereby quenching. By this full-strength welding, the welded portion of the first stirrup bar 10 and the upper end main bar 30 has strength equal to or higher than the JIS standard yield point of the first stirrup bar 10, and the elongation of the reinforcing bar is also the JIS standard value of the reinforcing bar before welding. As described above, the shear strength of the welded portion is equal to or higher than the short-term allowable tensile strength of the reinforcing bar, and both members are connected with a high connection strength.

The predetermined pitch s shown is determined from the required amount of reinforcing bars in concrete, such as 150 mm and 200 mm. Further, the first stirrups 10 are formed of, for example, deformed steel bars, and reinforcing bars having a diameter of 10 mm (D10), D13, etc. are applied, which is also determined from the required amount of reinforcing bars in relation to the predetermined pitch s.

A deformed steel bar having a predetermined diameter is applied to the upper end main bar 30, and since there are two upper end main bars 30 in the illustrated example, the diameter is set so as to satisfy the design bending moment, the design shearing force, and the like. From the viewpoint of the required amount of reinforcing bars, one or more separate upper end main bars 30 may be arranged between the two upper end main bars 30 in the finally arranged state. For example, in the illustrated example, deformed steel bars such as D19 and D22 can be applied (the above is the lower unit installation step).

On the other hand, the upper unit 60 has a U-shape that opens downward, and has a crown muscle portion 21 and a droop muscle portion 22 that hangs downward from the left and right ends of the crown muscle portion 21. 20 are arranged at a predetermined pitch s in the Z direction, which is the longitudinal direction of the beam bar, like the first stirrup bar 10, and the second stirrups 20 are respectively corresponding left and right sagging muscle portions 22. It is formed by being connected to the horizontal bar 40 by welding at a predetermined position on the outside of the above.

Here, the attachment position of the lateral bar 40 in the drooping muscle portion 22 is the lower end of the drooping muscle portion 22, and the lateral streak 40 is connected to the lower end of the drooping muscle portion 22 by welding. This welding may be normal spot welding, but it is preferably connected by full-strength welding as in the welding of the first stirrups 10 and the upper end main bar 30 in the lower unit 50.

Further, the lower end of the sagging muscle portion 22 of the second stirrups 20 does not have a hook, and the lateral streaks 40 are connected to the ends by welding, so that the lateral streaks 40 replace the hooks. Will be. As described above, although the second stirrups 20 do not have hooks at the ends of the drooping streaks 22, the lateral streaks 40 are connected by welding, preferably by full-strength welding, and thus are expected from hooks. Good fixability of the second stirrups 20 in the concrete is guaranteed. Similarly, in the lower unit 50, although the first stirrups 10 do not have hooks at the ends of the rising streaks 12, the upper end main bars 30 are connected by welding, so that the upper end main bars 30 are connected. Is a hook alternative to the hook. In this way, since the upper end main bar 30 is connected to the end of the first stirrups 10 by full-strength welding, the good fixability of the first stirrup bars 10 expected for the hook in the concrete can be obtained. Guaranteed.

The lower unit 50 and the upper unit 60 in the illustrated example each have five first stirrups 10 and two second stirrups 20 at the same pitch s, but they can be transported to the site. In addition, from the viewpoint of workability such as transportability at the site, the unit may have 6 or more stirrups and be as long as possible in the Z direction.

In particular, since the lower unit 50 has only the upper end main bar 30 as the main bar and does not have the lower end main bar, the lower unit 50 is compared with the lower unit applied by the bar arrangement method according to the second embodiment described later. The weight of is relatively light. Therefore, the lower unit 50 can be made longer in the Z direction than the lower unit according to the second embodiment having the lower end main bar. Further, when a longer lower unit 50 is prepared in this way, the upper unit 60 is also prepared with a length corresponding to the longer lower unit 50.

Next, as shown in FIG. 2, the upper unit 60 is placed over the lower unit 50 to arrange the reinforcing bars, and the corresponding rising muscle portion 12 of the first rib muscle 10 and the hanging muscle portion 22 of the second rib muscle 20 are arranged. Is wrapped and connected with a predetermined lap joint length L (“predetermined lap joint length with hook”) to construct a beam reinforcement intermediate 100'(upper and lower unit connection step).

Here, based on the Architectural Institute of Japan Building Construction Standard Specifications (JASS5) 2009, "Reinforcing Bar Construction", rebars with hooks at the ends are wrapped around each other so as to secure a predetermined lap joint length. The length of the lap joint in the case of connecting by connecting is determined by the design standard strength Fc (Fc = 21N / mm ² etc.) of concrete and the type of reinforcing bar (SD295A, B, SD345 etc.). Therefore, the lap joint length L in the present embodiment can also be set between 20d and 40d (mm) in accordance with this reference.

In this upper and lower unit connecting step, since the lower unit 50 has the upper end main bar 30, when the second stirrups 20 constituting the upper unit 60 are covered from above the lower unit 50, the two upper end main bars A second stirrups 20 can be placed on top of 30. Since a predetermined lap joint length L can be automatically formed in this mounted state, it takes time and effort to wrap the rising muscle portion 12 and the hanging muscle portion 22 while measuring the lap joint length L. No streaks are needed. That is, the beam reinforcement can be arranged with high efficiency while eliminating the need for a jig for fixing the upper unit 60 when measuring the lap joint length L.

Further, as is clear from FIG. 2, in the second stirrups 20, since the lateral streaks 40 are connected to the ends of the sagging muscles 22, the length of the lap joint with the rising streaks 12 is predetermined. With L secured, the length of the drooping muscle portion 22 can be shortened as much as possible. This leads to the reduction of the amount of reinforcing bars in the reinforcement arrangement and leads to the reduction of construction costs. In the illustrated example, the length of the drooping muscle portion 22 is a length corresponding to the lap joint length L.

Next, as shown in FIG. 3, the lower end main bar 70 is arranged and connected to the inside of the bent portion at the boundary between the bottom bar portion 11 and the rising bar portion 12 forming each of the first stirrups 10. The beam reinforcement 100 according to the first embodiment is arranged (lower end main reinforcement connection step). Here, the lower end main bar 70 is connected to the first stirrups 10 by binding with a binding line or the like.

As shown in FIG. 3, in the beam bar 100, the horizontal bar 40 is located below the center position (h / 2) of the height h of the beam bar 100 and is arranged in the vicinity of the center position. .. Here, the "neighborhood of the central position" means a range of less than, for example, downward h / 4 from the central position of the beam reinforcement. In this way, by arranging the horizontal streaks 40 at a position lower than the central position of the height h of the beam streaks 100 and in the vicinity of the central position, it is possible to form a beam of the bending fracture leading type, and the beam is brittle. The beam bar 100 is provided to the beam whose destruction is suppressed. The reason is as follows.

That is, since the rising bar portion 12 of the first stirrup bar 10 and the drooping streak portion 22 of the second stirrup bar 20 wrap by a predetermined lap joint length L to form the beam bar 100, at least the beam. In the region above the central position (h / 2) of the height h of the bar 100, the stirrups are doubly arranged and below the central position (h / 2) of the height h of the beam bar 100. The amount of reinforcing bars (the amount of stirrups) is larger than that of the area. If the lateral bar 40 is placed in a region above the central position (h / 2) of the height h of the beam bar 100, the horizontal bar 40 is added to the reinforcing bar amount in addition to the large amount of loose bars as described above. , There is a risk that the bending strength at both ends of the beam, where the bending moment of the upper tension is predominant, becomes too large, and there is a high possibility that the beam will be a shear failure leading type beam. Therefore, in the illustrated beam bar 100, the horizontal bar 40 is a region below the central position (h / 2) of the height h of the beam bar 100 and is near the central position, more specifically, downward from the central position, for example. By arranging the beam in a range of less than h / 4, the bending strength at both ends of the beam can be reduced, and it is possible to easily form a beam of the bending fracture leading type instead of the shear fracture leading type.

[Method of arranging beam reinforcement and beam reinforcement according to the second embodiment]
Next, with reference to FIGS. 4 and 5, the method of arranging the beam bars according to the second embodiment and the beam bars formed by this method of arranging the beams will be described. Here, FIGS. 4 and 5 are process diagrams for explaining the method of arranging the beam bars according to the second embodiment in this order, and FIG. 5 further describes the beam bars according to the second embodiment. It is a figure. As shown in FIG. 4, also in the method of arranging the beam reinforcements according to the present embodiment, the lower unit 50A and the upper unit 60A are manufactured in advance at a factory or the like as in the method of arranging the reinforcements of the first embodiment. Is transported to the site, and the lower unit 50A and the upper unit 60A are assembled at the site to arrange the beam reinforcement. In the following description, by describing the differences from the bar arrangement method of the first embodiment, it becomes easy to understand the bar arrangement method of the second embodiment and the structure of the beam reinforcement. The reinforcement arrangement method and the beam reinforcement of the second embodiment will be described with reference to FIG. 3 as appropriate.

As is clear from comparing FIGS. 1 and 4, in the bar arrangement method according to the second embodiment, the lower unit 50A is welded to the inside of the upper ends of the left and right rising bar portions 12 of the first stirrups 10. In addition to having the upper end main bar 30 at the above, the lower end main bar 70 is provided inside the boundary between the bottom bar portion 11 and the rising bar portion 12 by full-strength welding. That is, it is a feature that the upper end main bar 30 and the lower end main bar 70 are simultaneously arranged by the lower unit installation step.

Unlike the lower unit 50 in the first embodiment, the lower unit 50A in the second embodiment has the same weight as the lower unit 50, for example, because the unit weight increases by the amount of having the lower end main bar 70. When trying to manufacture the lower unit 50A, it is necessary to make the length in the Z direction, which is the longitudinal direction of the beam bar, relatively short in order to guarantee the same level of workability. For example, the lower unit 50 in FIG. 1 includes five first stirrups 10 having a predetermined interval s, whereas the lower unit 50A in FIG. 4 has four first stirrups 10 having a predetermined interval s. It is provided with one stirrups 10, for example, the total weight is about the same. The upper unit 60A also includes four second stirrups 20 having a predetermined interval s according to the lower unit 50A.

Therefore, as shown in FIG. 5, the upper unit 60A is placed over the lower unit 50A to arrange the reinforcing bars, and the corresponding rising muscle portion 12 of the first stirrups 10 and the sagging muscle portion 22 of the second stirrup muscle 20 are arranged. By wrapping the beam with a predetermined lap joint length L and connecting them by bundling or the like, the reinforcement arrangement of the beam reinforcement 100A is automatically completed (upper and lower unit connection step).

According to this reinforcement method, it is possible to eliminate the trouble of further arranging the lower end main reinforcement 70 after assembling the lower unit 50A and the upper unit 60A, and it is possible to further arrange the beam reinforcement with higher efficiency. It can be performed.

Further, also in the formed beam bar 100A, the horizontal bar 40 is located below the center position (h / 2) of the height h of the beam bar 100 and is near the center position (less than h / 4 below the center position). By arranging the beam in the range of), the bending strength at both ends of the beam can be reduced, and the beam is used for forming a beam of the bending failure preceding type.

It should be noted that the configuration or the like described in the above embodiment may be another embodiment in which other components are combined, and the present invention is not limited to the configuration shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

10: 1st stirrup muscle, 11: bottom muscle, 12: rising muscle, 20: 2nd stirrup, 21: crown muscle, 22: drooping muscle, 30: upper end main muscle, 40: lateral muscle, 50, 50A: Lower unit, 60, 60A: Upper unit, 70: Lower end main bar, 100, 100A: Beam bar

Claims (7)

The first stirrups, which have a U-shape that opens upward and have a bottom muscle portion and a rising muscle portion that rises upward from the left and right ends of the bottom muscle portion, are arranged at a predetermined pitch, and each of the first stirrups is arranged. A lower unit in which the stirrups are connected to the upper end main bar by full-strength welding inside the upper end of the corresponding rising bar on the left and right.
A second stirrups, which have a U-shape that opens downward and have a crown muscle portion and a drooping muscle portion that hangs downward from the left and right ends of the crown muscle portion, are arranged at a predetermined pitch, and each first The two stirrups are connected to the lateral streaks by welding at predetermined positions on the outside of the corresponding left and right sagging muscles, and are composed of an upper unit having no hook at the end of the sagging muscles. Being done
The lower end main bar is connected to the inside of the bent portion at the boundary between the bottom bar portion and the rising bar portion forming the first stirrups.
In a state where the upper unit is covered with the lower unit, the rising muscle portion of the corresponding first stirrups and the drooping streak portion of the second stirrups wrap with a predetermined lap joint length. Beam reinforcement, which is characterized by being The beam bar according to claim 1, wherein the lateral bar is connected by full-strength welding at a predetermined position outside the droop bar portion. The beam bar according to claim 1 or 2, wherein the horizontal bar is connected to the outside of the lower end of the droop bar portion. The aspect according to any one of claims 1 to 3, wherein the horizontal bar is arranged at a position lower than the central position of the height of the beam bar and in the vicinity of the central position. Beam muscle. The first stirrups, which have a U-shape that opens upward and have a bottom muscle portion and a rising muscle portion that rises upward from the left and right ends of the bottom muscle portion, are arranged at a predetermined pitch, and each of the first stirrups is arranged. A lower unit installation process in which the stirrups are arranged inside the upper ends of the corresponding rising muscles on the left and right by connecting the lower units to the upper end main bars by full-strength welding.
A second stirrups, which have a U-shape that opens downward and have a crown muscle portion and a drooping muscle portion that hangs downward from the left and right ends of the crown muscle portion, are arranged at a predetermined pitch, and each first The upper unit, in which the two stirrups are welded to the lateral streaks at predetermined positions outside the corresponding left and right sagging muscles and do not have a hook at the end of the sagging muscles, is attached to the lower part. An upper and lower unit that covers and arranges reinforcements on a unit, and wraps and connects the rising muscle portion of the first stirrups and the sagging muscle portion of the second stirrups with a predetermined lap joint length. Connection process and
Arrangement of beam bars, which comprises a lower end main bar connecting step of connecting the lower end main bar to the inside of the bent portion of the boundary between the bottom bar portion and the rising bar portion forming the first stirrups. Muscle method. The first stirrups, which have a U-shape that opens upward and have a bottom muscle portion and a rising muscle portion that rises upward from the left and right ends of the bottom muscle portion, are arranged at a predetermined pitch, and each of the first stirrups is arranged. The stirrups are connected to the upper end main bar by full-strength welding inside the upper end of the corresponding rising bar on the left and right, and the lower end main bar is welded inside the boundary between the bottom bar and the rising bar. The lower unit installation process, which arranges the connected lower units, and
A second stirrups, which have a U-shape that opens downward and have a crown muscle portion and a drooping muscle portion that hangs downward from the left and right ends of the crown muscle portion, are arranged at a predetermined pitch, and each first The upper unit, in which the two stirrups are welded to the lateral streaks at predetermined positions outside the corresponding left and right sagging muscles and do not have a hook at the end of the sagging muscles, is attached to the lower part. An upper and lower unit that covers the unit and arranges the reinforcing bars, and wraps and connects the rising muscle portion of the first stirrups and the hanging streak portion of the second stirrups with a predetermined lap joint length. A method of arranging beam reinforcements, which comprises a connection process. The fifth or sixth aspect of the invention, wherein in the upper and lower unit connecting steps, the horizontal streaks are arranged at a position lower than the central position of the height of the beam streaks and in the vicinity of the central position. How to arrange beam reinforcement.

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