Beam reinforcement and bar arrangement method thereof

Abstract

To provide a beam reinforcement with high strength and excellent workability, and a bar arrangement method thereof.SOLUTION: A beam reinforcement 100 is composed of: a lower unit 40 in which stirrups 10 each having a bottom reinforcing part 11 and rising reinforcing parts 12 rising upward from right and left ends of the bottom reinforcing part 11, are arranged at a predetermined pitch s, the stirrups 10 are connected to an upper end main bar 20 by full strength welding to the inside of the upper ends of the corresponding right and left rising reinforcement parts 12; and a cap tie 50 which has a top end reinforcement part 51, and a first hanging reinforcement part 52 and a second hanging reinforcement part 53 hanging downward from both ends of the top end reinforcement part 51. In the cap tie 50, the first hanging reinforcement part 52 includes a first vertical part 52a and a 90 degree hook 52b at a lower end of the first vertical part 52a, the second hanging reinforcement part 53 includes a second vertical part 53a that is longer than the first vertical part 52a and a 90-degree hook 53b at a lower end of the second vertical part 53a, The cap tie 50 is placed over each stirrup 10 of the lower unit 40.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to beam reinforcement bars that form beams connecting foundation beams and columns of a building, and a method of arranging the reinforcement bars.

Background Art

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

[0003] Here, a beam reinforcement bar arrangement structure and an arrangement method have been proposed in which a cap tie without a hook is placed on a lower unit in which a plurality of stirrup bars are unitized with an upper main reinforcement bar and a lower main reinforcement bar and arranged (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 bars described in Patent Document 1, in addition to the upper stirrup bars, which are capties, not having hooks, and the capties are only arranged in a state where they slightly lap the lower stirrup bars, it is unclear whether the beam reinforcement bars have sufficient strength. According to the "Reinforced Concrete Reinforcement Guidelines and Explanation 2021" (Japan Society of Civil Engineers), in the above-described captie-type reinforcement, for example, a 135-degree hook is provided at the upper end of the lower stirrup bar, and a reinforcement specification in which this lower stirrup bar and the captie are overlapped with an overlapping joint length of 6d (d is the name of the deformed bar) is described. In view of such general specifications, it has to be said that it is unclear whether the strength of the captie-type beam reinforcement bars described in Patent Document 1 is sufficient, in other words, whether the upper and lower stirrup bars form a closed-type reinforcement bar in a strong manner.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a beam reinforcement bar with high strength and excellent workability and a reinforcement method thereof.

Means for Solving the Problems

[0007] To achieve the above object, one aspect of the beam reinforcement bar according to the present invention is The stirrup bars having a U-shaped cross-section open upward, including a bottom bar portion and rising bar portions rising upward from the left and right ends of the bottom bar portion, are arranged at a predetermined pitch, and each pair of stirrup bars are connected to the upper main bar by full-strength welding inside the upper ends of the corresponding left and right rising bar portions, forming a lower unit A captie having a top bar portion and first and second hanging bar portions hanging downward from both ends of the top bar portion, wherein the first hanging bar portion includes a first vertical portion and a 90-degree hook at the lower end of the first vertical portion, and the second hanging bar portion includes a second vertical portion longer than the first vertical portion and a 90-degree hook at the lower end of the second vertical portion, and is composed of the captie The lower main bar is connected inside the bent portion at the boundary between the bottom bar portion and the rising bar portion forming the stirrup bar. The cap tie is covered on each rib of the lower unit.

[0008] According to this aspect, the cap tie is covered on the rising rib portion of the lower unit in which a plurality of ribs are integrated by the upper main rib, and the 90-degree hooks of both the first hanging rib portion and the second hanging rib portion of the cap tie enter the inside of the lower unit. As a result, due to the high restraint effect of the cap tie, a beam bar in which the lower unit and the cap tie are integrated with high strength can be formed.

[0009] The beam bar of this aspect does not require a predetermined lap joint length between the rising rib portion of the rib that wraps around each other and the first hanging rib portion or the second hanging rib portion of the cap tie, and the 90-degree hooks of both the first hanging rib portion and the second hanging rib portion enter the inside of the lower unit, thereby integrating the rib and the cap tie.

[0010] In addition, by making the hook at the lower end of the second vertical portion, which is relatively long with respect to the first vertical portion, a 90-degree hook instead of a 180-degree hook, when the other beam bar (orthogonal bar) connected from the orthogonal direction to the beam bar is a beam bar for a stepped beam or the like, the problem that the upper main rib (fixed bar) of this orthogonal bar is likely to interfere with the 180-degree hook can be solved. That is, in the 180-degree hook, the interference range with the fixed bar of the orthogonal bar extends in the height direction by the length of the hook, but in the 90-degree hook, only the height level of the 90-degree hook becomes the interference range with the orthogonal bar, so the interference range is significantly reduced compared to the 180-degree hook.

[0011] Further, in this aspect, the cap tie has a first hanging rib portion and a second hanging rib portion with different lengths, but for a plurality of ribs, the first hanging rib portions and the second hanging rib portions of the plurality of cap ties may be arranged with their directions (left and right positions) alternated. According to this form, since the cap ties are alternately arranged in a staggered manner with respect to each rib forming the lower unit, a beam bar with uniform left and right rigidity can be formed over the entire length.

[0012] Here, the "full-strength welding" where the upper main reinforcement bars are connected in the lower unit is also referred to as "full-strength rebar intersection welding". It means spot welding where the welded part has a strength above the yield point of the stirrup bars according to JIS standards, the elongation of the rebar is also above the JIS standard value of the rebar before welding, and the shear strength of the welded part is above the short-term allowable tensile strength of the stirrup bars. Note that normal spot welding guarantees that the welded part has about 1 / 3 to 2 / 3 of the yield point of the rebar according to JIS standards. This full-strength welding is achieved by repeating normal spot welding two or more times. It is a welding method that anneals by performing the second spot welding before the welded part rapidly cools after the first spot welding.

[0013] Note that the lower main reinforcement bars, which are not necessarily included in the lower unit, are connected inside the bending part at the boundary between the bottom reinforcement part and the rising reinforcement part that form the stirrup bars. This lower main reinforcement bar may also be connected to the stirrup bars by full-strength welding, or may be tied with a binding wire or the like. The connection mode of the lower main reinforcement bar to the stirrup bars varies depending on the difference in the reinforcement arrangement method described later.

[0014] Also, in the lower unit, the upper main reinforcement bars that are full-strength welded inside the upper end of the rising reinforcement part of the stirrup bars serve as hook replacement bars for the stirrup bars. In this way, by providing the upper main reinforcement bars as hook replacement bars, hooks can be made unnecessary for the stirrup bars.

[0015] Also, in another aspect of the beam reinforcement according to the present invention, The length of the first vertical part is set to a length such that the two upper main reinforcement bars do not interfere with the 90-degree hook when the two upper main reinforcement bars are arranged vertically and lapped.

[0016] According to this aspect, the length of the first vertical portion of the first hanging rib portion of the cap tie is set to a length that does not interfere with the 90-degree hook of the two upper main reinforcement bars when the two upper main reinforcement bars are arranged vertically and lapped. As a result, when lapping the upper main reinforcement bars of the unitized beam bars with each other at a predetermined lapping joint length using a separate upper main reinforcement bar, it is possible to prevent the separate upper main reinforcement bar arranged vertically with respect to the upper main reinforcement bar from interfering with the 90-degree hook, enabling smooth lapping of the unitized beam bars with each other.

[0017] Also, in another aspect of the beam bar according to the present invention, The length of the second vertical portion is characterized in that it is set to a length equal to or greater than the width between the upper main reinforcement bars between the upper main reinforcement bars connected to the left and right rising rib portions.

[0018] According to this aspect, since the length of the second vertical portion of the second hanging rib portion of the cap tie is set to a length equal to or greater than the width between the upper main reinforcement bars between the upper main reinforcement bars connected to the left and right rising rib portions, after fitting the 90-degree hook of the first hanging rib portion from the lower side of one of the upper main reinforcement bars, while turning the cap tie, the 90-degree hook of the second hanging rib portion is inserted into the web bar, and the cap tie can be arranged with the two 90-degree hooks inserted into the web bar.

[0019] Also, another aspect of the beam bar according to the present invention is Characterized in that the two 90-degree hooks extend in mutually opposite diagonal directions with respect to the vertical plane formed by the top end bar portion, the first vertical portion, and the second vertical portion.

[0020] According to this aspect, since the two 90-degree hooks of the cap tie extend in mutually opposite diagonal directions with respect to the vertical plane formed by the top edge rib portion, the first vertical portion, and the second vertical portion, it becomes possible to make the separation between the tips of both of the two 90-degree hooks longer than the width between the upper main ribs. Even if the length of the second vertical portion of the second hanging rib portion of the cap tie is not set to be longer than the width between the upper main ribs, the cap tie can be laid across the two upper main ribs and arranged using the separation between the two 90-degree hooks of the cap tie.

[0021] Also, one aspect of the method for arranging beam reinforcement bars according to the present invention is a rib having a U-shaped cross-section that opens upward, having a bottom rib portion and rising rib portions that rise upward from the left and right ends of the bottom rib portion, is arranged at a predetermined pitch, and each rib is connected to an upper main rib by full-strength welding inside the upper ends of the corresponding left and right rising rib portions to form a lower unit, a lower unit installation step of arranging the lower unit; a cap tie having a top edge rib portion and first and second hanging rib portions that hang downward from both ends of the top edge rib portion, wherein the first hanging rib portion includes a first vertical portion and a 90-degree hook at the lower end of the first vertical portion, and the second hanging rib portion has a second vertical portion longer than the first vertical portion and a 90-degree hook at the lower end of the second vertical portion, and connecting a plurality of cap ties by covering and arranging them on each rib of the lower unit; a connecting step; a lower main rib connecting step of connecting a lower main rib inside a bent portion at the boundary between the bottom rib portion and the rising rib portion forming the rib, and is characterized by having the steps.

[0022] According to this aspect, for example, the lower unit and the cap tie manufactured at a factory are transported to the site, and with the two 90-degree hooks of the cap tie inserted inside the lower unit, the rising rib portion, the first hanging rib portion, and the second hanging rib portion are assembled by tying or the like, so that the beam reinforcement bars can be efficiently arranged. In particular, since the lower unit has upper main ribs, when the cap tie is placed over the lower unit, the cap tie is locked to the upper main ribs, so that the working efficiency during tying of the reinforcement bars is improved.

[0023] Moreover, in this aspect, since the lower unit does not have a lower-end main bar, after binding the cap tie and the lower unit, the lower-end main bar is connected to the inside of the bending portion at the boundary between the bottom bar portion and the rising bar portion that constitute the web bar of the lower unit. This connection can be made by, for example, binding. Further, according to this aspect, since the lower unit does not have a lower-end main bar, when manufacturing a lower unit of the same weight as compared with the case where the lower unit has a lower-end main bar, the extension of the lower unit (unit length in the longitudinal direction of the beam bar) can be increased.

[0024] Also, another aspect of the method for arranging beam bars according to the present invention is a lower unit installation step of arranging a web bar having a U-shaped cross section open upward, having a bottom bar portion and rising bar portions rising upward from the left and right ends of the bottom bar portion, at a predetermined pitch, and connecting each web bar to an upper-end main bar by full-strength welding inside the upper ends of the corresponding left and right rising bar portions, and connecting a lower-end main bar to the inside of the boundary between the bottom bar portion and the rising bar portion by welding; a connection step of covering and connecting a plurality of cap ties, each having a top-end bar portion, a first hanging bar portion and a second hanging bar portion hanging downward from both ends of the top-end bar portion, wherein the first hanging bar portion includes a first vertical portion and a 90-degree hook at the lower end of the first vertical portion, and the second hanging bar portion includes a second vertical portion longer than the first vertical portion and a 90-degree hook at the lower end of the second vertical portion, over each web bar of the lower unit.

[0025] According to this aspect, since the upper-end main bar and the lower-end main bar of the lower unit are both connected to the web bar by welding, when the cap tie is assembled to the lower unit by binding or the like, the arrangement of the beam bars can be completed. That is, it is possible to eliminate the labor of further arranging the lower-end main bar after assembling the lower unit and the cap tie. Here, the lower-end main bar may be connected to the web bar by full-strength welding or spot welding. [Effects of the Invention]

[0026] As can be understood from the above description, according to the beam reinforcement bars and their reinforcement method of the present invention, beam reinforcement bars with high strength and excellent workability can be provided. [Brief Description of the Drawings]

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0028] Hereinafter, the reinforcement method of the beam reinforcement bars according to each embodiment of the present invention and the beam reinforcement bars formed by each reinforcement method will be described with reference to the accompanying drawings. In the present specification and drawings, substantially the same components may be denoted by the same reference numerals, and redundant descriptions may be omitted.

[0029] [Reinforcement Method and Beam Reinforcement Bars According to the First Embodiment] First, referring to FIGS. 1 to 5, a method for arranging beam reinforcement bars according to the first embodiment and the beam reinforcement bars formed by this arrangement method will be described. Here, FIGS. 1, 3, and 4 are process diagrams for explaining the method for arranging beam reinforcement bars according to the first embodiment in this order, and FIG. 4 is further a diagram for explaining the beam reinforcement bars according to the first embodiment. Also, FIG. 2 is a diagram for explaining a method of arranging cap ties for two upper main reinforcement bars in the order of (a), (b), and (c). As shown in FIG. 1, the method for arranging beam reinforcement bars according to this embodiment is to transport the prefabricated lower unit 40 and cap tie 50 from a factory or the like to the site, and assemble the lower unit 40 and cap tie 50 at the site to arrange the beam reinforcement bars.

[0030] As shown in FIG. 1, the lower unit 40 has a U-shaped cross-section that opens upward, and has a web bar 10 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. The web bars 10 are arranged at a predetermined pitch t1 in the Z direction, which is the longitudinal direction of the beam reinforcement bars, and the web bars 10 are connected to the upper main reinforcement bars 20 inside the upper ends of the corresponding left and right rising reinforcement portions 12 to form a structure.

[0031] Here, the connection between the rising reinforcement portion 12 and the upper main reinforcement bar 20 is made by full-strength welding. This full-strength welding is a welding method that repeats normal spot welding two or more times. By performing the second spot welding before the welded part is rapidly cooled after the first spot welding, it is a stress-relieving welding method. By this full-strength welding, the welded part between the web bar 10 and the upper main reinforcement bar 20 has a strength equal to or higher than the yield point of the JIS standard of the web bar 10, the elongation of the reinforcement bar is also equal to or higher than the JIS standard value of the reinforcement bar before welding, and the shear strength of the welded part is equal to or higher than the short-term allowable tensile strength of the web bar. As a result, the two members are connected with high connection strength.

[0032] The illustrated predetermined pitch t1 is determined from factors such as the required amount of reinforcement bars in the concrete, such as 150 mm, 200 mm, etc. Also, the web bar 10 is formed from, for example, deformed steel bars, and steel bars with diameters of 10 mm (D10), D13, etc. are applied, and this is also determined from factors such as the required amount of reinforcement bars in relation to the above-mentioned predetermined pitch t1.

[0033] The upper main reinforcement bars 20 are applied with deformed steel bars of a predetermined diameter. Since there are two upper main reinforcement bars 20 in the illustrated example, their diameters are set to meet the design bending moment, design shear force, etc. Incidentally, from the perspective of the required amount of steel bars, finally, in the state where the beam is reinforced, one or more additional upper main reinforcement bars 20 may be arranged between the two upper main reinforcement bars 20. For example, in the illustrated example, deformed steel bars such as D19 and D22 can be applied. (The above is the lower unit installation process).

[0034] On the other hand, the cap tie 50 has a top end reinforcement part 51, and a first hanging reinforcement part 52 and a second hanging reinforcement part 53 that hang downward from both ends of the top end reinforcement part 51.

[0035] The first hanging reinforcement part 52 includes a first vertical part 52a with a length of t3 and a 90-degree hook 52b at the lower end of the first vertical part 52a. The second hanging reinforcement part 53 includes a second vertical part 53a that is longer than the first vertical part 52a by a length of t4 and a 90-degree hook 53b at the lower end of the second vertical part 53a.

[0036] Here, the length t3 of the first vertical part 52a (the length between the top end reinforcement part 51 and the 90-degree hook 52b) is set to a length such that the two upper main reinforcement bars 20 and the 90-degree hook 52b do not interfere when the two upper main reinforcement bars 20 are arranged vertically and lapped, that is, t3 ≥ 2 × d1 (d1: the diameter of the upper main reinforcement bar 20). With this length setting, when lapping the upper main reinforcement bars 20 of the unitized beam reinforcements 100 with each other with a separate upper main reinforcement bar at a predetermined lapping length, it is possible to prevent the separate upper main reinforcement bar arranged above and below the upper main reinforcement bar 20 from interfering with the 90-degree hook 52b, and the lapping of the unitized beam reinforcements 100 with each other can be carried out smoothly.

[0037] Also, the length t4 of the second vertical portion 53a (the length between the top edge rib portion 51 and the 90-degree hook 53b) is set to be equal to or greater than the width t2 between the upper main reinforcements 20 (the width outside the two upper main reinforcements 20) between the two upper main reinforcements 20 connected to the left and right rising rib portions 12. With this length setting, after fitting the 90-degree hook 52b of the first drooping rib portion 52 from the lower side of one of the upper main reinforcements 20, while turning the cap tie 50, the 90-degree hook 53b of the second drooping rib portion 53 is inserted into the web 10, so that the two 90-degree hooks 52b and 53b are inserted into the web 10 and the cap tie 50 can be arranged.

[0038] In forming the beam reinforcement, the illustrated lower unit 40 has five web reinforcements 10. Therefore, five cap ties 50 corresponding to each web reinforcement 10 are also prepared. Also, for each web reinforcement 10, the corresponding cap ties 50 are arranged in a staggered pattern with the left and right positions of the first drooping rib portion 52 and the second drooping rib portion 53 alternating in direction, resulting in the arrangement of each cap tie 50 as shown in FIG. 1.

[0039] In the lower unit 40, although the web reinforcement 10 does not have a hook at the end of the rising rib portion 12, since the upper main reinforcement 20 is connected by full-strength welding, this upper main reinforcement 20 becomes a hook substitute rib instead of a hook. In this way, since the upper main reinforcement 20 is connected to the end of the web reinforcement 10 by full-strength welding, good fixing performance of the web reinforcement 10 expected of a hook in the concrete is ensured.

[0040] Incidentally, both the web reinforcements 10 and the cap ties 50 forming the lower unit 40 in the illustrated example are five each. However, from the perspective of constructability such as transportability to the site and handling at the site, it is also possible to have six or more web reinforcements 10 and cap ties 50 and make the unit as long as possible in the Z direction.

[0041] In particular, since the lower unit 40 has only the upper main reinforcement 20 as the main reinforcement and does not have a lower main reinforcement, the weight of the lower unit 40 is relatively light compared to the lower unit applied in the reinforcement method according to the second embodiment described later. Therefore, compared to the lower unit according to the second embodiment having a lower main reinforcement, the lower unit 40 can be made longer in the Z direction. Further, when such a longer lower unit 40 is prepared, for the cap tie 50 as well, the same number of cap ties 50 corresponding to the stirrups 10 of this long lower unit 40 are prepared.

[0042] Next, a method of arranging the cap ties 50 with respect to the two upper main reinforcements 20 will be described. First, as shown in Fig. 2(a), the cap ties 50 are placed over the two upper main reinforcements 20 in the X1 direction, and after the first vertical portion 52a of the first hanging rib portion 52 is positioned below one of the upper main reinforcements 20, as shown in Fig. 2(b), the cap ties 50 are rotated in the clockwise X2 direction.

[0043] At this time, since the length t4 of the second vertical portion 53a of the second hanging rib portion 53 is set longer than the width t2 between the upper main reinforcements, the posture of the cap ties 50 can be changed while rotating the cap ties 50.

[0044] Furthermore, as shown in Fig. 2(c), by rotating the cap ties 50 in the X3 direction, the top end rib portion 51 is bridged over the two upper main reinforcements 20, and the cap ties 50 are arranged with respect to the two upper main reinforcements 20.

[0045] As shown in Fig. 3, by arranging the corresponding cap ties 50 with respect to each stirrup 10, the beam reinforcement intermediate body 100' is constructed (the above is the connection process).

[0046] In this connection step, since the lower unit 40 has the upper main bars 20, when the cap tie 50 is placed over the lower unit 40 from above, the cap tie 50 can be placed on the two upper main bars 20. And in this placed state, the cap tie 50 can be tied to the upper main bars 20 and the stirrups 10 with a binding wire or the like, so that the beam bars can be arranged with high efficiency.

[0047] Next, as shown in FIG. 4, the lower main bars 30 are arranged and connected inside the bending part at the boundary between the bottom bar part 11 and the rising bar part 12 forming each stirrup 10, whereby the beam bars 100 according to the first embodiment are arranged (lower main bar connection step). Here, the connection of the lower main bars 30 to the stirrups 10 is performed by tying with a binding wire or the like.

[0048] Also, the beam bars 100 do not require the arrangement of transverse bars. Therefore, compared with conventional general beam bars that have transverse bars as an essential component, the amount of steel bars can be reduced as much as possible, and the construction effort is also reduced.

[0049] Also, the cap tie 50 is placed over the rising bar part 12 of the lower unit 40 in which a plurality of stirrups 10 are integrated by the upper main bars 20, and the 90-degree hooks 52b, 53b of both the first hanging bar part 52 and the second hanging bar part 53 of the cap tie 50 enter the inside of the lower unit 40. Thus, due to the high restraint effect of the cap tie 50, a beam bar 100 in which the lower unit 40 and the cap tie 50 are integrated with high strength can be formed.

[0050] Further, by making the hook at the lower end of the second vertical part 53a, which is relatively long with respect to the first vertical part 52a, a 90-degree hook 53b instead of a 180-degree hook, when another beam bar (orthogonal bar not shown) connected from the orthogonal direction to the beam bar 100 is a beam bar for a stepped beam or the like, the problem that the upper main bar (fixed bar) of this orthogonal bar is likely to interfere with the 180-degree hook can be solved. That is, in the case of a 180-degree hook, the interference range with the fixed bar of the orthogonal bar extends in the height direction by the length of the hook, but in the case of a 90-degree hook, only the height level of the 90-degree hook becomes the interference range with the orthogonal bar, so the interference range is significantly reduced compared to the 180-degree hook.

[0051] Furthermore, in the beam bar 100, since a plurality of cap ties 50 are arranged in a staggered pattern alternately with respect to each web bar 10 forming the lower unit 40, a beam bar 100 with uniform left and right rigidity over the entire length is formed. Incidentally, as the reinforcement pattern of the other web bars, there is a form in which all the cap ties 50 are arranged on the same side with respect to the rising bar part 12 on either the right or left side of each web bar 10 forming the lower unit 40, and this form may be applied.

[0052] Also, FIG. 5 shows another example of a cap tie. The illustrated cap tie 50A has two 90-degree hooks 52c and 53c of the first hanging bar part 52A and the second hanging bar part 53A extending in mutually opposite diagonal directions (at angles θ1 and θ2 respectively, which can be set to, for example, 45 degrees each) with respect to the vertical plane formed by the top bar part 51, the first vertical part 52a, and the second vertical part 53a.

[0053] According to the cap tie 50A, since the two 90-degree hooks 52c and 53c extend in mutually opposite diagonal directions θ1 and θ2, the separation t5 between the tips of both of the two 90-degree hooks 52c and 53c can be made to have a length equal to or greater than the width t2 between the upper main bars. Even if the length t4' of the second vertical portion 53a of the second hanging rib portion 53A of the cap tie 50A is made to have a length less than the width t2 between the upper main bars, the cap tie 50A can be bridged over the two upper main bars 20 and arranged with reinforcement by utilizing the separation t5 between the two 90-degree hooks 52c and 53c of the cap tie 50A.

[0054] [Reinforcement method for beam bars and beam bars according to the second embodiment] Next, with reference to FIGS. 6 and 7, a reinforcement method for beam bars according to the second embodiment and the beam bars formed by this reinforcement method will be described. Here, FIGS. 6 and 7 are process diagrams for explaining the reinforcement method for beam bars according to the second embodiment in this order, and FIG. 7 is further a diagram for explaining the beam bars according to the second embodiment. As shown in FIG. 6, also in the reinforcement method for beam bars according to the present embodiment, similar to the reinforcement method of the first embodiment, the lower unit 40A and the cap tie 50 which are prefabricated in a factory or the like are transported to the site, and the lower unit 40A and the cap tie 50 are assembled at the site to perform the reinforcement of the beam bars.

[0055] In the following description, by describing the differences from the reinforcement method of the first embodiment, it will be easier to understand the reinforcement method of the second embodiment and the configuration of the beam bars. Therefore, the reinforcement method of the second embodiment and the beam bars will be described while appropriately referring to FIGS. 1, 3, and 4 as well.

[0056] As is clear from comparing FIGS. 1 and 6, in the reinforcement method according to the second embodiment, in addition to the lower unit 40A having the upper main bar 20 by full-strength welding inside the upper ends of the rising rib portions 12 on the left and right of the web bar 10, the lower main bar 30 is also provided by full-strength welding inside the boundary between the bottom rib portion 11 and the rising rib portion 12. That is, it is characterized in that the upper main bar 20 and the lower main bar 30 are simultaneously reinforced by the lower unit installation step.

[0057] Further, unlike the lower unit 40 in the first embodiment, the lower unit 40A in the second embodiment has an increased unit weight by the amount of the lower main reinforcement 30. Therefore, for example, when attempting to manufacture a lower unit 40A with the same weight as the lower unit 40, to ensure the same level of workability, it is necessary to relatively shorten the length in the Z direction, which is the longitudinal direction of the beam reinforcement. For example, while the lower unit 40 in FIG. 1 is provided with five web reinforcements 10 having a predetermined interval t1, the lower unit 40A in FIG. 6 is provided with four web reinforcements 10 having the predetermined interval t1, and for example, the overall weight is approximately the same. In addition, the cap ties 50 are also prepared in four according to the number of web reinforcements 10 of the lower unit 40A.

[0058] As shown in FIG. 7, by covering the lower unit 40A with the cap tie 50 and arranging the reinforcement, and connecting the first hanging reinforcement portion 52, the second hanging reinforcement portion 53, and the rising reinforcement portion 12, etc. by bundling or the like, the arrangement of the beam reinforcement 100A is automatically completed (connection process).

[0059] According to this reinforcement arrangement method, after assembling the lower unit 40A and the cap tie 50, the labor of further arranging the lower main reinforcement 30 can be eliminated, and the beam reinforcement can be arranged with even higher efficiency.

[0060] In addition, other embodiments in which other components are combined, etc. may be possible for the configurations, etc. described in the above embodiments, and the present invention is not limited to the configurations shown here. In this regard, it is possible to make changes without departing from the spirit of the present invention, and it can be appropriately determined according to the application form.

Explanation of Reference Numerals

[0061] 10: Web reinforcement 11: Bottom reinforcement portion 12: Rising reinforcement portion 20: Upper main reinforcement 30: Lower main reinforcement 40, 40A: Lower unit 50, 50A: Cap tie 51: Celestial end rib part 52, 52A: First hanging rib part 52a: First vertical part 52b, 52c: 90-degree hook 53, 53A: Second hanging rib part 53a: Second vertical part 53b, 53c: 90-degree hook 100, 100A: Beam reinforcement

Claims

1. Web bars having a U-shaped opening upward, including a bottom bar portion and rising bar portions rising upward from the left and right ends of the bottom bar portion, are arranged at a predetermined pitch, and each pair of web bars is connected to an upper main bar by full-strength welding inside the upper ends of the corresponding left and right rising bar portions, forming a lower unit; A cap tie having a top bar portion, a first hanging bar portion and a second hanging bar portion hanging downward from both ends of the top bar portion, wherein the first hanging bar portion includes a first vertical portion and a 90-degree hook at the lower end of the first vertical portion, and the second hanging bar portion includes a second vertical portion longer than the first vertical portion and a 90-degree hook at the lower end of the second vertical portion; A lower main bar is connected inside a bent portion at the boundary between the bottom bar portion and the rising bar portion forming the web bar; A beam bar, characterized in that the cap tie is placed over each web bar of the lower unit.

2. The beam bar according to Claim 1, characterized in that the length of the first vertical portion is set such that the two upper main bars and the 90-degree hook do not interfere when the two upper main bars are arranged vertically and lap-jointed.

3. The beam bar according to Claim 2, characterized in that the length of the second vertical portion is set to be equal to or greater than the width between the upper main bars between the upper main bars connected to the left and right rising bar portions.

4. The beam bar according to Claim 1, characterized in that the two 90-degree hooks extend in mutually opposite diagonal directions with respect to the vertical plane formed by the top bar portion, the first vertical portion, and the second vertical portion.

5. A lower unit installation step of arranging a lower unit, in which web bars having a U-shaped opening upward, including a bottom bar portion and rising bar portions rising upward from the left and right ends of the bottom bar portion, are arranged at a predetermined pitch, and each pair of web bars is connected to an upper main bar by full-strength welding inside the upper ends of the corresponding left and right rising bar portions; A cap tie having a top end rib portion and a first hanging rib portion and a second hanging rib portion hanging downward from both ends of the top end rib portion, wherein the first hanging rib portion includes a first vertical portion and a 90-degree hook at the lower end of the first vertical portion, and the second hanging rib portion has a second vertical portion longer than the first vertical portion and a 90-degree hook at the lower end of the second vertical portion. A connecting step of covering and arranging a plurality of cap ties on each rib of the lower unit and connecting them. A method for arranging beam bars, characterized by having a lower main bar connecting step of connecting a lower main bar inside a bending portion at the boundary between the bottom bar portion and the rising bar portion forming the rib.

6. A lower unit installation step of arranging ribs having a U-shaped cross-section open upward, including a bottom bar portion and rising bar portions rising upward from the left and right ends of the bottom bar portion, at a predetermined pitch, and connecting each pair of ribs to an upper main bar by full-strength welding inside the upper ends of the corresponding left and right rising bar portions, and connecting a lower main bar by welding inside the boundary between the bottom bar portion and the rising bar portion. A method for arranging beam bars, characterized by having a connecting step of covering and arranging a plurality of cap ties having a top end rib portion and a first hanging rib portion and a second hanging rib portion hanging downward from both ends of the top end rib portion, wherein the first hanging rib portion includes a first vertical portion and a 90-degree hook at the lower end of the first vertical portion, and the second hanging rib portion has a second vertical portion longer than the first vertical portion and a 90-degree hook at the lower end of the second vertical portion, on each rib of the lower unit and connecting them.

Images