JP2006183311A - Reinforcing structure of circumference of opening section in reinforced concrete beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing structure of the circumference of an opening section in a reinforced concrete beam capable of reinforcing the circumference of the opening section while increasing workability including bar arrangement workability and shearing proof stress when the opening section such as a through-hole for installation piping or the like is formed in a reinforced concrete construction beam. <P>SOLUTION: When a plurality of diagonal reinforcing bars 6 are arranged to the circumference of the opening section 5 formed in the reinforced concrete construction beam l arranging upper end main bars 2, lower end main bars 3 and shear reinforcing bars 4 thereto, both diagonal reinforcing bars 6 and 6 are made as a set and are arranged by intersecting with each other. Hooks 6a and 6a are formed in both ends of each diagonal reinforcing bar 6, one hook 6a is engaged with the upper end main bars 2, and the other hook 6a is engaged with the lower end main bars 3. A set of the diagonal reinforcing bars 6 and 6 are arranged to both sides of the perpendicular containing the center on the perpendicular cross section at right angles to a material axis of the beam 1, and it is attached to one side of the perpendicular, these diagonal bars are arranged on both sides by holding the opening section 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reinforcing structure around an opening in a reinforced concrete beam that reinforces around the opening when an opening such as a through hole for equipment piping is formed in a reinforced concrete beam.

  When an opening such as a through hole is formed in a beam of reinforced concrete (including SRC structure), reinforcement around the opening is as shown in FIG. As shown in FIG. 20, diagonal bars bent into a Z shape, or a welded wire mesh in which reinforcing bars are combined in two directions as shown in FIG.

  The position and size of the opening are limited by the overall length and completeness of the beam. However, if the opening cross section (diameter) must be increased, or if the opening of the beam is severely stressed When it is necessary to form a part, it is necessary to closely arrange the reinforcing hardware and diagonal stripes, etc., so that it cannot fit around the opening, or the reinforcement of the shear reinforcement bars and the filling of concrete Inhibiting happens.

  To solve the problem of fitting when it is necessary to arrange the reinforcement hardware and diagonal stripes closely, the spiral reinforcement hardware and the diagonal stripes are combined to separate the linear diagonal stripes from the reinforcement hardware. There is a reinforcement method that improves the workability of diagonal reinforcement after arranging reinforcement hardware around the part in advance and can cope with the difference in beam width (see Patent Document 1).

A method of reinforcing concrete efficiently with a small number of steel materials by placing steel materials such as PC steel bars obliquely around the opening and applying prestress to the concrete around the opening by applying tension to the steel. (See Patent Document 2).
JP-A-8-184127 JP 2004-124623 A

  In the method of Patent Document 1, since it is necessary to make it possible to cope with the difference in the beam width of the oblique line, since the hook is formed only at one end part of the oblique line, the other end part where the hook is not formed is simply placed in the concrete. It is only settled. Therefore, the diagonal reinforcement cannot bear the tensile force throughout the beam against the shearing force and bending moment acting on the beam, so the reinforcement of the diagonal reinforcement does not significantly increase the beam strength. .

  In addition, since the spiral reinforcement is used together with the diagonal reinforcement, the amount of steel around the opening increases, which may impair concrete filling properties. In this case, the reinforcement hardware is arranged in advance, and the diagonal reinforcement must be laid after the reinforcement of the shear reinforcement.

  In the method of Patent Document 2, since both ends of the steel material are fixed to the upper and lower ends of the concrete, the steel material can bear a tensile force throughout the beam, so that it is possible to increase the strength of the beam. Although it is thought that there is, the fixing part for fixing the end of the steel material must be formed by cutting out the upper and lower ends of the concrete, so the construction of the formwork becomes complicated and the construction becomes complicated It becomes difficult to ensure the covering of the main bars in the cutout fixing portion.

  In view of the above background, the present invention proposes a reinforcing structure that has good workability including reinforcement workability and can enhance the proof stress of the beam when reinforcing the periphery of the opening.

  In the invention according to claim 1 of the present application, the opening around the opening formed through the reinforced concrete beam in which the upper and lower main bars and the shear reinforcement bars are arranged in the width direction is inclined with respect to the main bars. In a structure that reinforces using multiple diagonal bars that are arranged in a row, hooks are formed at both ends of the diagonal bars, one hook is engaged with the upper main bar, and the other hook is engaged with the lower main bar. This makes it possible to increase the bearing strength of the beam while increasing the workability of the bar arrangement.

  Since both ends of the diagonal muscles engage with the upper and lower principal bars, the tensile force is transmitted between the diagonal muscles and the upper principal muscles, and between the oblique muscles and the lower principal muscles. With respect to the moment, it becomes possible for the oblique bars to bear the tensile force throughout the beam, and the oblique bars are shown in FIG. 9 together with the upper main bars or the lower main bars and the shear reinforcement bars and the concrete with respect to the shear forces. Form a truss mechanism as shown. In FIGS. 18 and 19 using the same oblique muscle, since the end of the oblique muscle is not engaged with the main muscle, a sufficient tensile force is not transmitted between the oblique muscle and the main muscle.

  For example, as shown in FIG. 9, the upper main reinforcement bears a tensile force against the bending moment when a vertically downward concentrated load acts on the middle part of the beam, and the concrete at the lower end bears a compressive force. However, in the column, it resists by a couple of forces due to the tensile force of the upper and lower main bars of the beam. In order to resist the positive and negative shearing forces that are alternately repeated, the diagonal stripes are arranged in pairs, and are arranged crossing each other.

  With respect to shear force, in the part other than the opening, in FIG. 9, the compression struts formed on the concrete of the beam, which are indicated by diagonal white arrows, and the shear reinforcement such as stirrup, which are indicated by hatched arrows Resist by the truss mechanism composed of the tensile force borne by the muscle and the tensile strength of the upper or lower main bar indicated by the horizontal white arrow, and in the column, the concrete resists by bearing the compressive force .

  Compressive struts formed on the concrete of the beam around the opening where the shear reinforcement is not arranged, the tensile force borne by the diagonal bars, as indicated by the black arrows in FIG. 9, and the tension of the upper and lower main bars Resistes by truss mechanism composed by force. Shear reinforcement bars arranged around the opening also bear the tensile force and reduce the strain on the diagonal lines. The oblique bars serve as shear reinforcement bars around the opening.

  Around the opening where no shear reinforcement is placed, the truss mechanism formed by the diagonal streaks ensures a resistance mechanism against shear force, which improves the shear strength of the beam with the opening and leads to shear failure Since bending fracture can be caused, the deformation performance of the beam after bending yielding is improved, and the energy absorption performance is also improved accordingly.

  Specifically, as shown in claim 2, the diagonal streaks formed as a set of two are centroids of the beam in order to uniformly reinforce the positions of both sides in the length direction of the opening, that is, the width direction of the beam. That is, it is arrange | positioned on the both sides of the vertical surface containing the center on the vertical cross section orthogonal to a material axis. Further, in order to uniformly reinforce the positions of both sides in the width direction of the opening, that is, the length direction of the beam, one side of the vertical surface is arranged on both sides with the opening interposed therebetween.

  In the case of claim 2, a set of diagonal stripes is arranged at four locations around the opening. However, the present invention is not limited to this, and there are two diagonal stripes per set. Is independent, it can be arranged on the vertical section of the beam, inside the shear reinforcement, etc., at a position where it does not interfere with the shear reinforcement or core, and around the main reinforcement Even after shear reinforcement bars and core bars are laid, they can be sewed between them, so the workability of the bar arrangement is not complicated and the flexibility of the bar arrangement procedure is high. .

  In addition, since the member required for reinforcement around the opening is one kind of diagonal reinforcement, reinforcement is completed only by the diagonal reinforcement arrangement, so the arrangement work efficiency is high and the possibility of hindering the filling of concrete is also possible. Absent.

  The hooks of the diagonal bars are engaged with the upper and lower main bars where the shear reinforcement bars and the core bars are not wound. Since both ends of the oblique muscle are engaged and fixed to the main muscle, the problem of construction complexity and insufficient covering as in the case where tension is applied does not occur.

  The invention according to claim 3 is that hooks formed at both ends of the diagonal stripes arranged at least on one side across the opening portion are used at both ends of a dogleg-shaped diagonal stripe bent at the center in the height direction. One of these is engaged with the upper main bar and the other is engaged with the lower main bar.

  Even when there is not enough space to cross the diagonal bars, the tensile force can be transmitted between the diagonal bars and the upper main bar and between the lower main bars, so that the shearing force and bending moment acting on the beam It becomes possible for the streak to bear the tensile force throughout the beam, and an effect close to that of the invention according to claim 1 can be obtained.

  For example, when the opening is formed in the vicinity of the beam end, there is an advantage of using a dogleg-shaped oblique line when there is not enough space between the opening and the beam end. In that case, the opening comes on the inner corner side of the dogleg, but on the outer corner side, that is, on the column side, there is a risk that the stress transmission in the axial direction of the beam will be insufficient, and in that case, as in claim 5 By connecting the central part in the height direction of the bent oblique line to the anchor line, one end of which is fixed in the column cross section, the stress can be transmitted smoothly.

  In the invention according to claim 4, at least two oblique stripes arranged on one side across the opening are formed with hooks formed at one end of a dogleg-shaped oblique stripe bent at the center in the height direction. One set is used so that the hooks come to the opposite ends, and one diagonal muscle hook is engaged with the upper main muscle, and the other diagonal muscle hook is engaged with the lower main muscle. Is.

  As in the invention according to claim 3, when the opening is formed in the vicinity of the beam end, as in claim 5, the central portion in the height direction of the bent oblique line is fixed in the column cross section. By connecting to the anchor muscle, the stress can be transmitted smoothly.

  The pair of double-shaped diagonal bars used in a set of two functions as a lap joint when embedded in concrete. However, by using anchor bars together, the stress transmission in the axial direction of the beam is smooth. Become.

  The invention according to claim 6 uses a reinforcing bar formed by combining a ring line surrounding the outside of the opening and a plurality of diagonal lines extending vertically above the ring line, and engages a hook of the diagonal line extending upward with the upper main muscle. Then, the hook of the diagonal muscle extending downward is engaged with the lower main muscle, so that a sufficient tensile force is transmitted between the diagonal muscle and the main muscle.

  In this case, the degree of freedom in the bar arrangement procedure is reduced as compared with the invention according to claim 1, but the workability is relatively excellent even when the opening is formed in the vicinity of the beam end, and the diagonal line. As a result, a sufficient tensile force is transmitted between the main reinforcement and the beam, the shear strength of the beam is improved, the deformation performance of the beam after bending yielding is improved, and the energy absorption performance is also improved accordingly.

  By engaging both ends of the oblique muscle with the upper and lower principal bars to transmit the tensile force between the oblique and upper principal bars and between the lower principal bars, the oblique muscles can be applied to the shear force acting on the beam. Since the tensile force can be borne throughout, the diagonal muscles form a truss mechanism with the upper main bars, or the lower main bars and the shear reinforcing bars, and the concrete around the openings where the shear reinforcing bars are not arranged. Can resist shear forces.

  By securing a resistance mechanism against the shearing force due to the diagonal streak, the shear strength of the beam with the opening is improved, and bending failure can occur prior to shearing failure. Performance and energy absorption performance are improved.

  In the invention according to claim 1, since the diagonal reinforcing bars are independent for each line, the reinforcing bars can be arranged even after the shear reinforcing bars and the core reinforcing bars are arranged. There is also a high degree of freedom in the bar arrangement procedure. In addition, since only one type of diagonal reinforcement is required for reinforcement around the opening, the arrangement work efficiency is high and the surroundings of the concrete are not hindered.

  If the hook of each diagonal muscle is fixed in the state where it is hooked and engaged with the part of the upper and lower principal bars where the shear reinforcement or core does not wrap, the construction is complicated as if tension is applied. The problem of lack of covering does not occur.

  The present invention relates to a reinforced concrete beam 1 in which an upper end main bar 2 and a lower end main bar 3 and a shear reinforcement bar 4 are arranged and an opening 5 is formed in the width direction so as to have two as shown in FIG. The reinforcing structure is reinforced by using a plurality of oblique muscles 6 and 6 arranged in a set and intersecting each other. The beam 1 may be a steel reinforced concrete structure. The shear reinforcing bar 4 includes a core bar and may be independent in a single unit or may be continuous in a spiral shape.

  As shown in FIGS. 1 and 2, the diagonal reinforcement 6 has a length larger than the pitch of the shear reinforcement 4 and is formed with hooks 6a and 6a at both ends, and is engaged with the upper end main reinforcement 2 at one hook 6a. The other hook 6a engages with the lower end main reinforcement 3.

  When the hooks 6a, 6a are engaged with the upper main bar 2 and the lower main bar 3, the concrete covering thickness can be secured, and if the engaged state can be maintained in the concrete, the angle of the hook 6a is 90 °, 135 °, 180 °. As shown in FIGS. 3 to 8 which are cross-sectional views taken along the line xx of FIG. 2, the upper main bar 2 and the lower main bar 3 of the diagonal line 6 on the vertical cross section perpendicular to the material axis of the beam 1 are used. It is decided by the position etc.

  As shown in FIG. 1, two pairs of diagonal stripes 6 and 6 are basically arranged on both sides of the centroid of the beam 1, that is, on both sides of the vertical plane including the center on the vertical section perpendicular to the material axis. One side of the surface is disposed on both sides of the opening 5 (Claim 2), but may be additionally disposed at the position of the vertical surface. The opening 5 is formed by embedding the sleeve 7 at the position, and the shape is not necessarily circular.

  Since each diagonal reinforcement 6 has a length larger than the pitch of the shear reinforcement 4, the pair of diagonal reinforcements 6, 6 does not overlap the shear reinforcement 4 on the vertical cross section of the beam 1. The bar is arranged inside. The elevation (side) of the beam 1 corresponds to the angle of the compression strut so that the tensile force of the oblique muscle 6 can form a truss mechanism with the compression strut formed by the concrete of the beam 1 as shown in FIGS. Intersect each other at an angle of, for example, about 30 ° to 60 ° with respect to the horizontal.

  In FIG. 2, the hooks 6 a and 6 a near the opening 5 of the two pairs of diagonal muscles 6 and 6 arranged on both sides of the opening 5 on the elevation surface of the beam 1 are the positions of the upper main bar 2 and the lower main bar 3. The two diagonal muscles 6 and 6 are arranged so as to cross each other. However, when the hooks 6a and 6a are arranged so that they cross the centroid from the positions of the upper main muscle 2 and the lower main muscle 3, the upper main muscle 2 and There are also cases where the hooks 6a, 6a of the two pairs of oblique muscles 6 and 6 are arranged at a distance from each other at the position of the lower end main reinforcement 3.

  FIG. 3 shows a pair between the upper main bar 2 inside the upper main bar 2 located on the outer side in the width direction of the beam 1 and the lower main bar 3 inside the lower main bar 3 located on the outer side. This is a case where the diagonal stripes 6 and 6 are spanned and the diagonal stripes 6 and 6 are arranged parallel to each other on the vertical cross section of the beam 1.

  FIG. 4 shows a pair of slanted one side of the vertical plane between the upper main bar 2 on the outer side in the width direction of the beam 1 and the inner lower main bar 3, and between the outer lower main bar 3 and the inner upper main bar 2. This is a case where the lines 6 and 6 are spanned, and the diagonal lines 6 and 6 are arranged so as to cross each other on the vertical cross section of the beam 1.

  FIGS. 3 and 4 show examples of bar arrangement when the diagonal line 6 is formed in a C-shape or an inverted C-shape. FIG. 3 and FIG. 4 show examples of bar arrangement when the diagonal line 6 is formed in an S-shape or an inverted S-shape. 5 to 8 show. In addition, a pair of oblique stripes 6 and 6 may be configured by combining the C-shaped oblique stripes 6 and the S-shaped oblique stripes 6.

  5 and 6 show one side of the vertical plane between the upper principal bar 2 on the outer side in the width direction of the beam 1 and the outer lower principal bar 3 and between the inner upper principal bar 2 and the inner lower principal bar 3. FIG. 5 shows the case where the diagonal stripes 6 and 6 are arranged parallel to each other on the vertical cross section of the beam 1, and FIG. 6 shows the case where they are arranged non-parallel.

  FIG. 7 shows a pair of diagonal lines between the upper principal bar 2 on the outer side in the width direction of the beam 1 and the inner lower principal bar 3 and between the outer lower principal bar 3 and the inner upper principal bar 2 on one side of the vertical plane. This is a case where the lines 6 and 6 are spanned, and the diagonal lines 6 and 6 are arranged so as to cross each other on the vertical cross section of the beam 1.

  FIG. 8 shows a case where a pair of oblique muscles 6, 6 are spanned between the upper principal bar 2 on the outer side in the width direction of the beam 1 and the outer lower principal bar 3 on one side of the vertical plane. 6 are arranged to cross each other on the vertical cross section of the beam 1.

  FIG. 10 shows an example of one form of the reinforcing structure when the opening 5 is in the vicinity of the beam end, that is, in the vicinity of the joint between the column 11 and the beam 1.

  In the example of FIG. 10, among the two pairs of diagonal stripes 6 and 6 arranged on both sides of the opening 5, the crossing angle is reduced on the beam end side where there is not enough space. The relationship between the hooks 6a, 6a of the diagonal lines 6 and 6, the upper main bar 2 and the lower main bar 3 is basically the same as in the case of FIG.

  FIG. 11 shows a case where the angle of intersection of a pair of diagonal stripes 6 and 6 is reduced on the opposite side across the opening 5 with respect to the embodiment of FIG. The anchor bars 8 fixed to the concrete in the cross section of the bars 9 and the beams 1 are connected to the intersections of the diagonal bars 6 and 6 on both sides of the opening 5 to compensate for the lack of stress transmission.

  FIG. 12 similarly shows the case where the opening 5 is in the vicinity of the beam end, but corresponds to one embodiment of the present invention, and the height of the diagonal streak 16 used between the opening 5 and the beam end is as shown in FIG. In the direction of the beam (in the direction of beam formation), a diagonal-shaped bar 16 is bent at the center, and one of the hooks (not shown on the elevation) formed at both ends is the upper main bar 2 and the other is the lower main bar 3 Is engaged.

  In this case, the opening 5 comes to the inner corner side bent in the shape of a dogleg, but the central part in the height direction of the bent oblique line 16 is fixed to the anchor line 9 fixed at one end in the concrete section of the column 11. By connecting (corresponding to claim 5), transmission of tensile force is achieved.

  FIG. 13 shows another example of the reinforcement structure around the opening portion using the diagonal stripes 16 of the cross-section, and the diagonal stripes 16 of the cross-section are arranged on both sides so as to sandwich the opening portion 5. The central portion in the height direction is connected to the core muscle 3 by a connecting muscle 19 having hooks formed at both ends to transmit a tensile force.

  In this example, the diagonal stripes 16 are formed on the hoop as shown in Fig. 12 (c), but the center in the height direction bent to the square is slightly narrowed to the inside of the loop. If it puts in, the tether 19 can be stored inside the shear reinforcement 4.

  FIG. 14 shows another embodiment in which, when the opening 5 is in the vicinity of the beam end, not only between the opening 5 and the beam end, but also on the opposite side across the opening 5, Is used. In this case, the dogleg-shaped diagonal stripes 26 on both sides can be replaced with one ring-shaped one, and metal fittings as hooks 26b are fixed on the upper and lower sides, one on the upper main bar 2 and the other on the lower main bar 3 respectively. Can be engaged. Note that the present invention is also applicable when the position of the opening 5 is not near the beam end.

  FIG. 15 shows an embodiment of the fourth aspect of the present invention. As an oblique line used between the opening 5 and the beam end, a hook is attached to one end of a dog-shaped oblique line 36 bent at the center in the height direction. (One that does not appear on the elevation) is used in a pair so that the hooks come to the opposite ends of each other, and the hook of one diagonal line 36 is used as the upper main line 2 The hooks of the other oblique muscle 36 are engaged with the lower end main reinforcement 3.

  Further, the central part in the height direction of the oblique lines 36, 36 is connected to an anchor line 9 whose one end is fixed in the column cross section as in the example of FIG. 11 (corresponding to claim 5). Six overlapping portions of the angled diagonal stripes 36, 36 used as a pair function as a lap joint.

  FIG. 16 corresponds to an embodiment of claim 6 and includes double ring bars 48 and 49 surrounding the outside of the opening and a plurality of oblique bars 46 and vertical bars 47 extending above and below the ring bars 48 and 49. A reinforcing bar 41 is used in combination.

  The hooks of diagonal lines 46 and vertical bars 47 (not shown in the vertical plane) extending upward are engaged with the upper main muscle 2, and the hooks of diagonal lines 46 and vertical bars 47 extending downward are engaged with the lower main bar 3. Thus, a sufficient tensile force is transmitted between these main bars 2 and 3.

It is the perspective view which showed the relationship between the principal muscle and the diagonal muscle around an opening part. It is the elevation view of the beam which showed the reinforcement arrangement | positioning state of an oblique line. FIG. 3 is a cross-sectional view taken along the line xx of FIG. 2 showing a case where a pair of oblique stripes of a C shape are arranged in parallel with each other on one side of a vertical plane of the beam. FIG. 3 is a cross-sectional view taken along the line xx of FIG. 2 showing a case where a set of diagonal stripes of a C shape is crossed with each other on one side of a vertical plane of the beam. FIG. 3 is a cross-sectional view taken along line xx of FIG. 2 showing a case where a set of diagonal S-shaped bars are arranged in parallel to each other on one side of the vertical plane of the beam. FIG. 3 is a cross-sectional view taken along line xx of FIG. 2 illustrating a case where a set of S-shaped diagonal stripes are arranged non-parallel to each other on one side of the vertical plane of the beam. FIG. 3 is a cross-sectional view taken along the line xx of FIG. 2 showing a case where a set of diagonal stripes of an S shape are crossed with each other on one side of a vertical plane of a beam. FIG. 9 is a cross-sectional view taken along line xx of FIG. 2 showing another case where a set of diagonal stripes of an S shape are crossed with each other on one side of the vertical plane of the beam. It is the elevation which showed a mode that a diagonal line | wire forms a truss mechanism with a top main reinforcement, a shear reinforcement bar, and concrete with respect to the shear force which acts on a beam. It is the elevation which showed an example of the reinforcement structure around the opening part of the beam end vicinity. It is the elevation which showed the other example of the reinforcement structure around the opening part of the beam end vicinity. It is the elevation which showed an example of the reinforcement structure around an opening part near the end of a beam using the oblique line of the character of the character. (a) Elevated view showing an example of a reinforcement structure around the opening using a cross-shaped oblique line, (b) is a longitudinal sectional view, (c) a perspective view showing a cross-shaped oblique line It is. It is the elevation which showed the other example of the reinforcement structure around the opening part of the beam end vicinity. It is the elevation which showed the other example of the reinforcement structure around the opening part of the beam end vicinity. It is the elevation which showed the other example of the reinforcement structure around the opening part of the beam end vicinity. (a) is an elevational view showing a conventional method for reinforcing the periphery of the opening by a reinforcing metal piece in which reinforcing bars are assembled in a net-like shape, and (b) is a longitudinal sectional view. (a) is an elevational view showing a conventional method for reinforcing the periphery of the opening by oblique stripes, and (b) is a longitudinal sectional view. (a) is an elevational view showing another conventional method for reinforcing the periphery of the opening by oblique stripes, and (b) is a longitudinal sectional view. (a) is an elevational view showing a conventional method for reinforcing the periphery of the opening with a welded wire mesh, and (b) is a longitudinal sectional view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Beam, 2 ... Top main bar, 3 ... Bottom main bar, 4 ... Shear reinforcement bar, 5 ... Opening, 6 ... Diagonal bar, 6a ... Hook, 7 ... Sleeve, 8 ... Anchor bar, 9 ... Anchor bar, 11 ... Pillar, 16 ... Diagonal muscle of 17, 17 ... Reinforcing bar, 18 ... Core, 19 ... Continuation, 26 ... Diagonal, 26b ... Hook, 36 ... Diagonal , 41 ... Reinforcing bars, 46 ... Diagonal bars, 47 ... Longitudinal bars, 48 ... Ring bars, 49 ... Ring bars

Claims (6)

  A plurality of slanted bars arranged at an angle with respect to the main bar around the opening formed through the reinforced concrete beam with the upper and lower main bars and shear reinforcement bars penetrating in the width direction It is a reinforcing structure reinforced with a streak, and the diagonal streaks are formed with hooks formed at both ends, and a pair of two are arranged and crossed with each other. A reinforcing structure around an opening in a reinforced concrete beam that engages with a main reinforcement and engages with a lower end main reinforcement at the other hook.   The pair of diagonal bars are arranged on both sides of a vertical plane including the centroid of the beam, and one side of the vertical plane is arranged on both sides of the opening, around the opening in the reinforced concrete beam according to claim 1. Reinforced structure.   A plurality of slanted bars arranged at an angle with respect to the main bar around the opening formed through the reinforced concrete beam with the upper and lower main bars and shear reinforcement bars penetrating in the width direction The reinforcing structure is reinforced by using a streak, and at least one of the oblique streaks arranged on the side sandwiching the opening is hooked to both ends of a crook-shaped slant that is bent at the center in the height direction. A reinforcing structure around an opening in a reinforced concrete beam that has a shape formed by engaging a top main bar in one hook and a bottom main bar in the other hook.   A plurality of slanted bars arranged at an angle with respect to the main bar around the opening formed through the reinforced concrete beam with the upper and lower main bars and shear reinforcement bars penetrating in the width direction It is a reinforcing structure reinforced by using a streak, and at least one of the oblique streaks arranged on the one side across the opening is hooked to one end of a crook-shaped oblique streak bent at the center in the height direction. Is formed, and the two hooks are arranged in a superposed manner so that the hooks are on the opposite ends, and the upper main bar is engaged with the hook of one diagonal line, and the other Reinforcement structure around the opening in a reinforced concrete beam that engages with the main lower end of the diagonal hook.   In the case where the opening is formed in the vicinity of the beam end, the central portion in the height direction of the dog-shaped oblique line used between the opening and the beam end is fixed to the column cross section. The reinforcing structure around the opening in the reinforced concrete beam according to claim 3 or 4, wherein the reinforcing bar is connected to an anchor bar. Extends around the opening formed in the width direction of the reinforced concrete beam with the upper and lower main bars and the shear reinforcement bars, and extends above and below the ring and ring bars surrounding the opening. It is a reinforcing structure using a reinforcing bar formed by combining a plurality of diagonal lines, the diagonal line has a shape in which a hook is formed at an end, and the hook of the diagonal line extending upward is engaged with the upper end main line, A reinforcing structure around an opening in a reinforced concrete beam in which a hook of a diagonal line extending downward is engaged with a bottom main bar.

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