JP2006348536A - Shear reinforcement and method of manufacturing this shear reinforcement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shear reinforcement easy in manufacture, while securing the proper cover thickness. <P>SOLUTION: This shear reinforcement 13 has a substantially frame-shaped outer peripheral reinforcement part 13A formed by bending one bar steel, and a substantially frame-shaped inner peripheral reinforcement part 13B arranged in a space surrounded by this outer peripheral reinforcement part 13A. The inner peripheral reinforcement part 13B is formed with a welding part 13B1 of welding mutual both end parts of the bar steel. Thus, since the welding part 13B1 is arranged in the inner peripheral reinforcement part 13B, the proper cover thickness can be secured. A welding node in the welding part 13B1 and a main reinforcement 12B do not interfere when manufacturing a concrete structure 1, and machining for removing the welding node is not required. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shear reinforcement constituting a reinforcing bar structure of a concrete structure, and a method for manufacturing the shear reinforcement.

  Conventionally, for example, in concrete structures such as beams and columns in civil engineering structures and building structures, multiple reinforcing bars are arranged in parallel with each other, and a plurality of shear reinforcement bars are provided in a state of crossing these reinforcing bars to form a reinforcing bar structure And the structure which distribute | arranged this rebar structure inside the concrete structure is known. An example of such a configuration is a concrete structure as shown in FIG. FIG. 4 is a cross-sectional view showing the internal structure of a conventional concrete structure.

  In FIG. 4, the concrete structure 100 has a structure in which an axial section is formed in a columnar shape having a substantially square shape, and a reinforcing bar structure 110 is arranged inside the concrete 120. The concrete structure 100 is formed by forming a reinforcing bar structure 110, surrounding the outer periphery of the reinforcing bar structure 110 with a plate frame (not shown), pouring cement milk, and hardening it.

The reinforcing bar structure 110 includes a plurality of main reinforcing bars 111 and a plurality of shear reinforcing bars 112.
The main bars 111 are steel bars that are substantially parallel to the axial direction of the concrete structure 100, and are sandwiched between the four main bars 111A corresponding to the four corners of the concrete structure 100 and the adjacent main bars 111A at a predetermined interval. 8 main reinforcing bars 111B arranged along the side surface of the concrete structure 100.
The shear reinforcement bars 112 are each formed in a frame shape surrounding the outer periphery of the plurality of main bars 111 and are provided at predetermined intervals along the axial direction of the main bars 111 in a state of being substantially orthogonal to the plurality of main bars 111.

Specifically, the shear reinforcing bar 112 includes an outer peripheral bar 113 and a core bar 114.
The outer circumferential bar 113 is formed by bending one steel bar into a substantially square frame shape surrounding all of the plurality of main bars 111. And the welding part 113A is formed by butting | matching both ends of the said steel bar, and welding by butt welding etc.
The core bar 114 is formed by bending one steel bar into a substantially rectangular frame shape in a state of surrounding the four main bars 111B provided along a pair of opposite side surfaces of the concrete structure 100. . And 114 A of weld parts are formed by butting | matching both ends of the said steel bar, and welding by butt welding etc. FIG.
And the shear reinforcement bar | burr 112 is comprised integrally by overlapping and welding a pair of mutually parallel edge | side of the outer periphery reinforcement | strengthening 113, and a pair of parallel short side | side of the core reinforcement 114.

  However, in such a concrete structure 100 shown in FIG. 4, a welding hump protruding outward in the radial direction of the steel bar is formed in the welded portion 113 </ b> A of the outer periphery reinforcing bar 113. An appropriate cover thickness cannot be ensured.

That is, the cover thickness of the concrete 120 refers to the distance from the side surface of the concrete 120 to the outside of the reinforcing bar structure 110, and has a thickness dimension that is greater than a predetermined dimension that does not corrode the reinforcing bar structure 110 even if the concrete 120 is impregnated with water or the like. Required. Usually, in the case of the concrete structure 100 shown in FIG. 4, this cover thickness is a distance X1 from the outer peripheral edge portion of each side of the outer periphery reinforcing bar 113 to the side surface of the concrete structure 100 facing each side.
However, on one side of the outer periphery reinforcing bar 113 where the welded portion 113A is provided, the cover thickness is not the distance X1 from the outer side of the outer peripheral reinforcing bar 113 to the side surface of the concrete structure 100 facing the one side, but welding. It becomes the distance X2 from the site | part which protruded the outermost part of the welding hump in the part 113A to the side surface of the concrete structure 100 facing the said one side. Then, when the plurality of shear reinforcement bars 112 are arranged with respect to the main bar 111, the positions of the respective welded portions 113 </ b> A are arranged so as to be evenly distributed with respect to the four side surfaces of the concrete structure 100.
For this reason, for the welding hump in the welded portion 113A, the structural design must be performed by adjusting the cover thickness to the distance X2, and the usage amount of the concrete 120 is increased by the protrusion amount (X1-X2) of the welding hump. End up.

In order to solve the problem of such a welding hump, a configuration is known in which the welding hump in the shear reinforcement is removed by forging (for example, see Patent Document 1).
In the configuration described in Patent Document 1, an impact or pressure is applied to a bulge or a burr generated when the end portions of a reinforcing bar are butted and welded, so that the cross section is substantially the same as that of the base material. For this reason, since the flattened reinforcing bar does not have a portion protruding outward, an appropriate cover thickness can be secured when the reinforcing bar is arranged in a concrete structure.

Japanese Patent Laid-Open No. 10-266462 (see page 2, right column-page 3, left column, FIG. 1)

  However, in the configuration described in the above-mentioned Patent Document 1, in order to secure an appropriate cover thickness, forging processing must be performed for each of the plurality of shear reinforcement bars in the manufacture of the shear reinforcement bars. As an example, there is a problem that the manufacturing man-hour increases and the manufacturing efficiency may decrease.

  In view of the above-described problems, an object of the present invention is to provide a shear reinforcing bar that can secure an appropriate cover thickness and that can be easily manufactured, and a method for manufacturing the same.

  In order to achieve the above-described object, the shear reinforcement according to the present invention is a shear reinforcement which is provided so as to intersect with a plurality of main bars which are substantially parallel to each other and constitutes a reinforcing bar structure of a concrete structure with the main bars. A substantially frame-shaped outer periphery muscle portion, and a substantially frame-shaped inner periphery muscle portion provided in a space surrounded by the outer periphery muscle portion, wherein the outer periphery muscle portion and the inner periphery muscle portion are One steel bar is bent and formed in a series, and the inner circumferential reinforcing bar portion is provided with a welded portion in which both ends of the steel bar are welded to each other.

According to this invention, since the welded portion is not formed on the outer periphery reinforcing portion, the cover thickness is determined from the outer peripheral edge portion on each side of the outer periphery reinforcing portion to the side surface of the concrete structure facing each side. Can be set uniformly. Thereby, it is possible to ensure an appropriate cover thickness without using extra cement milk.
In addition, since the outer peripheral reinforcing portion and the inner peripheral reinforcing portion are formed in a series by bending one steel bar, a shear reinforcing bar can be easily manufactured. And even if a welding hump is formed in the welding part provided in the inner periphery reinforcement part, the welding hump and main reinforcement in a welding part do not interfere in the case of manufacture of a concrete structure. This eliminates the need for machining for removing the welding humps, and eliminates the need to examine the position of the welded portion in advance in accordance with the arrangement of the main bars in the manufacturing stage of the shear reinforcement bars. For this reason, manufacture of a shear reinforcement becomes easy and it can ensure high manufacturing efficiency.
Therefore, an appropriate cover thickness can be secured, and a shear reinforcing bar can be easily manufactured.

  Here, in the above invention, the outer peripheral muscle portion is formed in a substantially square frame shape, and the inner peripheral muscle portion is formed in a substantially square frame shape that is substantially accommodated in a space surrounded by the outer peripheral muscle portion. The pair of parallel sides of the outer peripheral muscle portion and the pair of parallel sides of the inner peripheral muscle portion substantially overlap each other when viewed from the axial direction of the main muscle, and the pair of sides of the outer peripheral muscle portion. The pair of sides that are substantially orthogonal to the pair of sides and the pair of sides that are substantially perpendicular to the pair of sides in the inner circumference muscle portion do not overlap each other when viewed from the axial direction of the main muscle, and the weld portion is the inner circumference muscle. It is preferable that it is provided on any one side of the pair of sides that do not overlap the outer peripheral muscle portion in the portion.

According to this invention, since the welded portion is provided in the space surrounded by the outer peripheral reinforcing portion, that is, the inner peripheral reinforcing portion, the welded portion does not affect the cover thickness, and unnecessary concrete is used. No need.
And, for example, it is possible to surround all of the plurality of main bars with the outer periphery of the substantially square frame shape with respect to the square columnar concrete structure, and to surround a part of the plurality of main bars with the inner periphery of the concrete structure. Even if an external force is applied from the direction orthogonal to the axis of the structure, a large resistance against the external force can be generated. Thereby, even if a large-scale earthquake generate | occur | produces, the concrete structure can ensure the intensity | strength which can fully be endured.
In addition, the shear reinforcement is a simple structure that can be formed by bending a single steel bar at eight locations so as to draw the shape of a Chinese character “eye” by a single stroke. Efficiency can be greatly improved.
Therefore, the shear reinforcement can improve the vibration resistance strength of the concrete structure and can secure high production efficiency.

  Moreover, in the said invention, the said outer periphery muscle part is formed in substantially square frame shape, and the said inner periphery muscle part is provided in a pair with respect to the said outer periphery muscle part, and is the space enclosed by the said outer periphery muscle part, respectively. A pair of sides that are formed in a substantially rectangular frame shape and are substantially parallel to each other and that are not substantially overlapped with each other, and that are parallel to each other, and the pair of inner periphery lines. The four sides that are substantially orthogonal to the direction in which the pair of inner peripheral muscle portions of the pair are substantially parallel to each other substantially overlap each other when viewed from the axial direction of the main muscle, and the pair of sides that are substantially orthogonal to the pair of sides of the outer peripheral muscle portion. And the four sides other than the four sides in the pair of inner peripheral muscle portions do not overlap with each other when viewed from the axial direction of the main reinforcement, and the welded portion has the outer peripheral muscle portion in the pair of inner peripheral muscle portions. It is provided on any one of the four sides that do not overlap. It is preferred.

According to this invention, since the welded portion is provided in the space surrounded by the outer peripheral reinforcing portion, that is, the inner peripheral reinforcing portion, the welded portion does not affect the cover thickness, and unnecessary concrete is used. No need.
And, for example, for a quadrangular prism-shaped concrete structure, enclose all of the plurality of main bars with a substantially rectangular frame-shaped outer peripheral reinforcement, and surround one of the plurality of main reinforcements with a pair of inner peripheral reinforcements, respectively. Therefore, even when an external force is applied from the direction perpendicular to the axis of the concrete structure, a greater drag can be generated against the external force. Thereby, even if a large-scale earthquake generate | occur | produces, the concrete structure can ensure the intensity | strength which can fully be endured.
In addition, the shear reinforcement is a simple structure that can be formed by bending a single steel bar at 12 locations so as to draw a “six-step ladder” figure with a single stroke. Efficiency can be greatly improved.
Therefore, the shear reinforcement can improve the vibration resistance strength of the concrete structure and can secure high production efficiency.

  In addition, in the said invention, the said outer periphery muscle part is formed in substantially square frame shape, and the said inner periphery muscle part is provided with a pair with respect to the said outer periphery muscle part, and each was enclosed by the said outer periphery muscle part. Formed in a substantially square frame shape that is substantially accommodated in the space, and disposed in a state of being substantially orthogonally overlapped with each other, the outer peripheral muscle portion and the pair of inner peripheral muscle portions in the pair of inner peripheral muscle portions The four sides overlapping each other do not overlap each other when viewed from the axial direction of the main muscle, and the outer peripheral muscle portion and each of the four sides other than the four sides in the pair of inner peripheral muscle portions are the main muscles. It is preferable that the welded portion is provided on any one of the four sides that do not overlap the outer peripheral reinforcing portion in the pair of inner peripheral reinforcing portions.

According to this invention, since the welded portion is provided in the space surrounded by the outer peripheral reinforcing portion, that is, the inner peripheral reinforcing portion, the welded portion does not affect the cover thickness, and unnecessary concrete is used. No need.
For example, for a quadrangular prism-shaped concrete structure, each of the plurality of main bars is surrounded by a substantially square frame-shaped outer periphery of the plurality of main bars, and the pair of inner peripheral bars are crossed with each other. A part can be enclosed. For this reason, when an external force is applied from the direction orthogonal to the axis of the concrete structure, a greater resistance against the external force can be generated. Thereby, even if a large-scale earthquake generate | occur | produces, the concrete structure can ensure the intensity | strength which can fully be endured.
In addition, since the shear reinforcement is a simple structure that can be formed by bending a single steel bar at 12 locations so as to draw the shape of a Chinese character “en” with a single stroke, it can be easily mass-produced and manufactured. Efficiency can be greatly improved.
Therefore, the shear reinforcement can improve the vibration resistance strength of the concrete structure and can secure high production efficiency.

Moreover, this invention can be comprised not only as it concerns on the shear reinforcement mentioned above but as invention of the manufacturing method of a shear reinforcement.
That is, the method for manufacturing a shear reinforcing bar according to the present invention is a method for manufacturing a shear reinforcing bar that is provided so as to intersect with a plurality of main bars that are substantially parallel to each other and that forms a reinforcing bar structure of a concrete structure with the main bars. One steel bar is bent to form a series of a substantially frame-shaped outer periphery muscle portion and a substantially frame-shaped inner periphery muscle portion provided in a space surrounded by the outer periphery muscle portion, In the inner circumference reinforcing portion, both ends of the steel bar are welded to form a welded portion.
According to this method, an appropriate cover thickness can be ensured with a simple configuration, similar to the above-described shear reinforcement.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view showing the internal structure of a reinforced concrete structure according to the first embodiment of the present invention.

(Concrete structure)
In FIG. 1, 1 is a concrete structure, and this concrete structure 1 is used, for example, as a beam or a column in a civil engineering structure or a building structure. The concrete structure 1 is formed in a columnar shape having a substantially square cross section in the axial direction, and has a structure in which a reinforcing bar structure 10 is arranged inside the concrete portion 11. The cover thickness D1 of the concrete part 11 is uniformly set by the distance from the outer peripheral edge part of each side of the outer periphery reinforcing part 13A described later in the reinforcing bar structure 10 to the side surface of the concrete part 11 facing each side. Yes. The reinforcing bar structure 10 includes a plurality of main bars 12 and a plurality of shear reinforcing bars 13.

  The main bars 12 are linear steel bars that are substantially parallel to the axial direction of the concrete structure 1. The main reinforcing bars 12 are sandwiched between the four main reinforcing bars 12A corresponding to the four corners of the concrete structure 1 and the adjacent main reinforcing bars 12A, and two of the main reinforcing bars 12 are arranged along the side surface of the concrete portion 11 at predetermined intervals. It consists of eight main muscles 12B.

  Each of the shear reinforcement bars 13 is formed in a frame shape in which one steel bar is bent at eight locations so as to draw a Chinese character “eye” shape by one stroke, and the main reinforcement 12 is in a state substantially orthogonal to the main reinforcement 12. Are arranged at predetermined intervals along the axial direction. The respective contact portions of the plurality of shear reinforcement bars 13 and the plurality of main bars 12 are integrally connected by, for example, welding or a joining method such as a mechanical joint using bolts and nuts.

Specifically, the shear reinforcing bar 13 includes an outer peripheral bar 13A and an inner bar 13B.
The outer peripheral line 13A is formed in a substantially square frame shape that surrounds all of the main bars 12.
The inner peripheral reinforcement 13B is formed in a substantially rectangular frame shape surrounding the four main reinforcements 12B provided along a pair of opposite side surfaces of the concrete structure 1.
Thereby, a pair of sides parallel to each other in the outer periphery muscle portion 13A and a pair of short sides in the inner periphery muscle portion 13B are substantially parallel and substantially overlapped when viewed from the axial direction of the main muscle 12. In addition, the pair of sides that are substantially orthogonal to the pair of sides in the outer peripheral muscle portion 13A and the pair of long sides in the inner peripheral muscle portion 13B do not overlap with each other when viewed from the axial direction of the main muscle 12, and are in a separated state. ing.

In addition, the state where 13 A of outer periphery muscle parts and the inner periphery muscle part 13B overlap is not restricted to the state which each contact | abuts, but includes the state which has overlapped if it sees from the axial direction of the main muscle 12 although it is non-contact. In addition, the state in which the outer peripheral muscle portion 13A and the inner peripheral muscle portion 13B substantially overlap each other is when one side of the outer peripheral muscle portion 13A and one side of the inner peripheral muscle portion 13B are completely overlapped when viewed from the axial direction of the main muscle 12. In addition, for example, a state in which one side of the inner peripheral line 13B is disposed slightly outside the one side of the outer line 13A and does not completely overlap is also included.
Furthermore, it is good also as a structure which connects the said pair of side of 13 A of outer periphery reinforcement | stripes which mutually overlap, and a pair of short side of 13B of inner periphery reinforcements by welding, respectively. In this case, the strength of the shear reinforcement bar 13 can be increased.

  And in the middle of any one of a pair of long sides which do not overlap with the outer periphery reinforcement part 13A in the inner periphery reinforcement part 13B, the welding part 13B1 is provided. The welded portion 13B1 is formed by, for example, butt welding by butting both ends of the steel bar, and has a welding hump protruding outward in the radial direction of the steel bar as shown in FIG.

(Manufacture of concrete structures)
Next, the manufacturing operation of the concrete structure 1 will be described.
The shear reinforcement 13 is manufactured in advance at a factory or the like. That is, one bar is bent at eight locations so as to draw the shape of a Chinese character “eye” by a single stroke, thereby forming a series of outer peripheral streaks 13A and inner peripheral streaks 13B. At this time, the steel bar is bent so that both ends of the steel bar are located in the middle of one of the pair of long sides that do not overlap with the outer peripheral bar 13A in the inner bar 13B. And the both ends of the said steel bar are welded by butt welding etc., welding part 13B1 is formed, and the shear reinforcement 13 is completed. In addition, even if the welding hump is formed in welding part 13B1, the machining for removing this welding hump is not required.

Next, the reinforcing bar structure 10 is constructed on site. That is, a plurality of main bars 12 are arranged in parallel with each other, and a plurality of shear reinforcement bars 13 are arranged at equal intervals along the axial direction of the main bars 12 in a state substantially orthogonal to the main bars 12. To go. At this time, the positions of the respective welded portions 13B1 are arranged so as to be evenly distributed with respect to the four side surfaces of the concrete structure 1.
Here, when the shear reinforcement bar 13 is disposed with respect to the main reinforcing bar 12, the welded part 13B1 in the shear reinforcing bar 13 is provided in the inner peripheral bar part 13B, so that the welding hump and the main bar 12B in the welding part 13B1 Will not interfere. Thereby, in the stage which manufactures the shear reinforcement 13 at a factory, it is not necessary to consider the position of welding part 13B1 according to arrangement | positioning of the main reinforcement 12 in advance.

After constructing the reinforcing bar structure 10, the outer periphery of the reinforcing bar structure 10 is surrounded by a plate frame (not shown), and the concrete part 11 is formed by pouring and hardening cement milk, whereby the concrete structure 1 is completed.
When the outer periphery of the reinforcing bar structure 10 is surrounded by a plate frame (not shown), the distance from each plate surface of the plate frame to the outer peripheral edge portion of the outer peripheral bar portion 13A is set to the distance D1 uniformly. And since the welding part like the past is not formed in 13 A of outer periphery reinforcement parts, in the completed concrete structure 1, the cover thickness of the concrete part 11 is set to D1. That is, unnecessary cement milk is not used.

  In the concrete structure 1 completed as described above, with respect to the columnar concrete structure 1 having a substantially square cross section in the axial direction, the outer peripheral reinforcing portion 13A surrounds all of the plurality of main reinforcing bars 12, and the inner peripheral reinforcing portion. Since 13B surrounds the four main bars 12B, even if an external force is applied from the direction orthogonal to the axis of the concrete structure 1, a large drag force is generated against the external force. Moreover, since the welding part 13B1 is provided in the middle of a pair of long sides that do not overlap with the outer peripheral reinforcing part 13A in the inner peripheral reinforcing part 13B, the shear reinforcing bar 13 is balanced as a whole, and the concrete structure 1 There is no bias in the vibration resistance.

(Operation effect of shear reinforcement)
As described above, the following effects can be achieved in the first embodiment.

  (1) The reinforcing bar structure 10 of the concrete structure 1 is composed of a plurality of main bars 12 that are substantially parallel to each other and shear reinforcing bars 13 that are provided so as to intersect with the main bars 12. The shear reinforcing bar 13 is provided with a substantially frame-shaped outer peripheral bar 13A and a substantially frame-shaped inner bar 13B provided in a space surrounded by the outer bar 13A. Then, the outer peripheral reinforcement 13A and the inner peripheral reinforcement 13B are formed in series by bending one steel bar, and the inner peripheral reinforcement 13B is formed with a welded part 13B1 in which both ends of the steel bar are welded to each other. .

For this reason, since the welded portion is not formed in the outer peripheral reinforcing portion 13A, the cover thickness of the concrete portion 11 is changed from the outer peripheral edge portion of each side of the outer peripheral reinforcing portion 13A to the concrete portion 11 facing the respective sides. It can be set uniformly by the distance D1 to the side surface. Thereby, it is possible to ensure an appropriate cover thickness without using extra cement milk.
Further, since the outer peripheral reinforcing bar portion 13A and the inner peripheral reinforcing bar portion 13B are formed in series by bending one steel bar, the shear reinforcing bar 13 can be easily manufactured. And even if a welding hump is formed in welding part 13B1 provided in inner circumference reinforcing bar part 13B, at the time of manufacture of concrete structure 1, the welding hump and main bar 12B in welding part 13B1 do not interfere. This eliminates the need for machining for removing the welding hump, and eliminates the need for examining the position of the welded portion 13B1 in advance in accordance with the arrangement of the main reinforcing bars 12 in the manufacturing stage of the shear reinforcing bars 13. For this reason, manufacture of the shear reinforcement 13 becomes easy and it can ensure high manufacturing efficiency.
Therefore, an appropriate cover thickness of the concrete portion 11 can be ensured, and the shear reinforcement 13 can be easily manufactured.

  (2) The outer peripheral streaks 13A are formed in a substantially square frame shape surrounding all the main bars 12. The inner peripheral reinforcement 13B is formed in a substantially rectangular frame shape surrounding the four main reinforcements 12B provided along a pair of opposite side surfaces of the concrete structure 1. As a result, the pair of sides parallel to each other in the outer periphery muscle portion 13A and the pair of short sides in the inner periphery muscle portion 13B are substantially parallel to each other when viewed from the axial direction of the main muscle 12. In addition, the pair of sides that are substantially orthogonal to the pair of sides in the outer peripheral muscle portion 13A and the pair of long sides in the inner peripheral muscle portion 13B are separated from each other without overlapping when viewed from the axial direction of the main muscle 12 It has become. And the welding part 13B1 is provided in any one of a pair of long sides which do not overlap with the outer periphery reinforcement part 13A in the inner periphery reinforcement part 13B.

For this reason, since the welded portion 13B1 is provided in the space surrounded by the outer peripheral reinforcing portion 13A, that is, the inner peripheral reinforcing portion 13B, the welded portion 13B1 does not affect the cover thickness, and unnecessary concrete is used. You don't have to.
For the columnar concrete structure 1 having a substantially square cross section in the axial direction, all of the plurality of main reinforcing bars 12 are surrounded by the outer peripheral reinforcing portion 13A, and the four main reinforcing bars 12B are surrounded by the inner peripheral reinforcing portion 13B. Therefore, even if an external force is applied from the direction orthogonal to the axis of the concrete structure 1, a large resistance against the external force can be generated. Thereby, even if a large-scale earthquake occurs, the concrete structure 1 can ensure the intensity | strength which can fully be endured.
Further, the shear reinforcement bar 13 is bent at eight locations so that a single steel bar is drawn in a single stroke to form the shape of an “eye” of the Chinese character, and the outer peripheral bar 13A and the inner bar 13B are integrally formed. Since it is a simple structure to be formed, mass production can be easily achieved, and manufacturing efficiency can be greatly improved.
Therefore, the shear reinforcement bar 13 can improve the vibration resistance strength of the concrete structure 1 and can ensure high production efficiency.

(3) Welding part 13B1 is provided in the middle of any one of a pair of long sides which do not overlap with outer peripheral reinforcing part 13A in inner peripheral reinforcing part 13B.
For this reason, since the shear reinforcement bars 13 as a whole are balanced, the vibration resistance strength of the concrete structure 1 is not biased. Thereby, the concrete structure 1 can be made into a more stable structure.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the internal structure of the concrete structure according to the second embodiment of the present invention. Note that the concrete structure 2 according to the second embodiment shown in FIG. 2 is different in configuration only in the concrete structure 1 and the reinforcing bar structure 10 according to the first embodiment shown in FIG. The same reference numerals are given to the configurations of and the description is omitted as appropriate.

(Concrete structure)
In FIG. 2, reference numeral 2 denotes a concrete structure. This concrete structure 2 is formed in a columnar shape having a substantially square cross section in the axial direction, and has a structure in which a reinforcing bar structure 20 is arranged inside the concrete portion 11. . The cover thickness D2 of the concrete part 11 is uniformly set by the distance from the outer peripheral edge part of each side of the outer periphery reinforcing part 22A described later in the reinforcing bar structure 20 to the side surface of the concrete part 11 facing each side. Yes. The reinforcing bar structure 20 includes a plurality of main bars 21 and a plurality of shear reinforcing bars 22.

The main bars 21 are sandwiched between the four main bars 21A corresponding to the four corners of the concrete structure 2 and the adjacent main bars 21A, and four of them are arranged along the side surface of the concrete part 11 at predetermined intervals. It consists of the main muscle 21B of the book.
Each of the shear reinforcement bars 22 is formed in a frame shape in which one steel bar is bent at 12 locations so as to draw a “6-ladder” figure by one stroke. 22B.

The outer peripheral line portion 22A is formed in a substantially square frame shape surrounding all of the main bars 21.
The inner peripheral reinforcement 22B is provided as a pair with respect to one outer peripheral reinforcement 22A, that is, two inner peripheral reinforcements 22B are provided for one outer periphery reinforcement 22A. It is formed in a substantially rectangular frame shape that is substantially accommodated in the enclosed space. The pair of inner peripheral streak portions 22B are arranged substantially in parallel with each other so as not to overlap each other.
Thereby, a pair of sides parallel to each other in the outer peripheral muscle portion 22 </ b> A and four short sides in each of the pair of inner peripheral muscle portions 22 </ b> B are substantially overlapped when viewed from the axial direction of the main muscle 21. In addition, the pair of sides that are substantially orthogonal to the pair of sides in the outer peripheral muscle portion 22A and the four long sides in the pair of inner peripheral muscle portions 22B are separated from each other without overlapping when viewed from the axial direction of the main muscle 21. It has become.

In addition, the state where 22 A of outer periphery muscle parts and 22 A of inner periphery muscles overlap is not only the state which each contact | abuts, but the state which has overlapped if it sees from the axial direction of the main muscle 21 although it is non-contact is included. In addition, the state in which the outer circumferential muscle portion 22A and the inner circumferential muscle portion 22B substantially overlap each other means that when viewed from the axial direction of the main muscle 21, one side of the outer circumferential muscle portion 22A and one side of the inner circumferential muscle portion 22B do not completely overlap. In addition, for example, it includes a state in which one side of the inner peripheral streak portion 22B is not completely overlapped, such as being arranged slightly outside of one side of the outer peripheral streak portion 22A.
Furthermore, it is good also as a structure which connects the said pair of edge | side of the outer periphery reinforcement | stripe part 22A which mutually overlaps, and four short sides in a pair of inner periphery reinforcement | stripe part 22B, respectively by welding. In this case, the strength of the shear reinforcement 22 can be increased.

  A welded portion 22B1 is formed in the middle of any one of the four long sides that do not overlap with the outer peripheral reinforcing portion 22A in the inner peripheral reinforcing portion 22B. The weld 22B1 is formed by butt welding both ends of the steel bar, for example, by butt welding or the like, and a welding hump protruding outward in the radial direction of the steel bar as shown in FIG. 2 is formed.

(Manufacture of concrete structures)
The manufacturing operation of the concrete structure 2 shown in FIG. 2 is substantially the same as the manufacturing operation of the concrete structure 1 shown in FIG.
In the completed concrete structure 2, the outer peripheral reinforcement 22 </ b> A surrounds all of the plurality of main reinforcements 21 with respect to the columnar concrete structure 2 having a substantially square axial section, and a pair of inner peripheral reinforcements 22 </ b> B respectively. Each of the four main muscles 21B is surrounded. Thereby, when an external force is applied from the direction orthogonal to the axis of the concrete structure 2, a greater drag is generated against the external force than the concrete structure 1 shown in FIG. 1. Further, since the welded portion 22B1 is provided in the middle of any long side that does not overlap with the outer peripheral reinforcing portion 22A in the inner peripheral reinforcing portion 22B, the shear reinforcing bar 22 as a whole is balanced, and the concrete structure 2 There will be no bias in the vibration resistance.

(Operation effect of shear reinforcement)
As described above, in the second embodiment, the following operational effects can be achieved in addition to the operational effects substantially similar to the operational effects (1) and (3) in the first embodiment. .

  (4) The outer peripheral stripe portion 22A is formed in a substantially square frame shape surrounding all of the main stripes 21. A pair of inner circumferential streak portions 22B are provided for one outer perimeter streak portion 22A, each is formed into a substantially rectangular frame shape that is substantially accommodated in a space surrounded by the outer perimeter streak portion 22A, and is substantially parallel to each other. Thus, they are arranged so as not to overlap. Thereby, a pair of sides parallel to each other in the outer peripheral muscle portion 22 </ b> A and four short sides in the pair of inner peripheral muscle portions 22 </ b> B are substantially overlapped when viewed from the axial direction of the main muscle 21. In addition, the pair of sides that are substantially orthogonal to the pair of sides in the outer peripheral muscle portion 22A and the four long sides in the pair of inner peripheral muscle portions 22B are separated from each other without overlapping when viewed from the axial direction of the main muscle 21. It has become. A welded portion 22B1 is formed on any one of the four long sides that do not overlap the outer peripheral reinforcing portion 22A in the inner peripheral reinforcing portion 22B.

For this reason, since the welded portion 22B1 is provided in the space surrounded by the outer peripheral reinforcing portion 22A, that is, the inner peripheral reinforcing portion 22B, the welded portion 22B1 does not affect the cover thickness, and unnecessary concrete is used. You don't have to.
Then, with respect to the columnar concrete structure 2 having a substantially square cross section in the axial direction, all of the plurality of main reinforcing bars 21 are surrounded by the outer peripheral reinforcing bars 22A, and four main reinforcing bars 21B are respectively provided by the pair of inner peripheral reinforcing bars 22B. Surrounding. For this reason, even if an external force is applied from the direction orthogonal to the axis of the concrete structure 2, a greater drag can be generated against the external force. Thereby, the concrete structure 2 can ensure sufficient strength to withstand even if a large earthquake occurs.
Further, the shear reinforcing bar 22 is bent at 12 locations so that a single steel bar is drawn with a single stroke so as to draw a “six-step ladder” figure, and the outer peripheral bar 22A and the inner peripheral bar 22B are integrally formed. Since it is a simple structure to be formed, mass production can be easily achieved, and manufacturing efficiency can be greatly improved.
Therefore, the shear reinforcement 22 can improve the vibration resistance strength of the concrete structure 2 and can ensure high production efficiency.

[Third Embodiment]
Furthermore, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view showing the internal structure of the concrete structure according to the third embodiment of the present invention. The concrete structure 3 according to the third embodiment shown in FIG. 3 is different only in the concrete structure 1 and the reinforcing bar structure 10 according to the first embodiment shown in FIG. The same reference numerals are given to the configurations of and the description is omitted as appropriate.

(Concrete structure)
In FIG. 3, reference numeral 3 denotes a concrete structure. The concrete structure 3 is formed in a columnar shape having a substantially square cross section in the axial direction, and has a structure in which a reinforcing bar structure 30 is arranged inside the concrete portion 11. . The cover thickness D3 of the concrete portion 11 is uniformly set by the distance from the outer peripheral edge portion of each side of the outer circumferential reinforcing bar portion 31A described later in the reinforcing bar structure 30 to the side surface of the concrete portion 11 facing each side. Yes. The reinforcing bar structure 30 includes a plurality of main bars 12 and a plurality of shear reinforcing bars 31.

  Each of the shear reinforcement bars 31 is formed in a frame shape in which one steel bar is bent at 12 locations so as to draw the shape of a Chinese character “en” by one stroke. Part 31B.

  The outer peripheral line portion 31 </ b> A is formed in a substantially square frame shape surrounding all of the main bars 12. The inner periphery 31B is provided as a pair with respect to one outer periphery 31A, that is, two inner periphery 31B is provided for one outer periphery 31A. It is formed in a substantially rectangular frame shape that is substantially accommodated in the enclosed space. The pair of inner circumferential streaks 31B are disposed so as to overlap each other substantially orthogonally. That is, one of the pair of inner peripheral reinforcing bars 31 </ b> B surrounds the four main reinforcing bars 12 </ b> B provided along a pair of side surfaces facing each other of the concrete structure 1. The other of the pair of inner peripheral reinforcing bars 31 </ b> B surrounds the four main reinforcing bars 12 </ b> B provided along the other pair of side surfaces of the concrete structure 1. As a result, the outer periphery 31A and the four short sides of the pair of inner periphery 31B substantially overlap each other when viewed from the axial direction of the main muscle 12. Further, the outer peripheral muscle portion 31 </ b> A and the four long sides of the pair of inner peripheral muscle portions 31 </ b> B are separated from each other without overlapping when viewed from the axial direction of the main muscle 12.

In addition, the state where 31 A of outer periphery muscle parts and the inner periphery muscle part 31B overlap is not only the state which each contact | abuts, but the state which is not contacting but is overlapping if seen from the axial direction of the main muscle 12 is also included. In addition, the state in which the outer circumferential muscle portion 31A and the inner circumferential muscle portion 31B substantially overlap each other means that when viewed from the axial direction of the main muscle 12, one side of the outer circumferential muscle portion 31A and one side of the inner circumferential muscle portion 31B do not completely overlap. In addition, for example, it includes a state in which one side of the inner peripheral line portion 31B is not completely overlapped, such as being arranged slightly outside the one side of the outer peripheral line portion 31A.
Furthermore, it is good also as a structure which connects the 4 short sides in 31 A of outer periphery reinforcement parts which overlap mutually, and a pair of inner periphery reinforcement parts 31B by welding, respectively. In this case, the strength of the shear reinforcement 31 can be increased.

  And the welding part 31B1 is formed in the middle in any one long side among the four long sides which do not overlap with the outer periphery reinforcement part 31A in the inner periphery reinforcement part 31B. This welded portion 31B1 is formed by butt-welding both ends of the steel bar by, for example, butt welding, thereby forming a welding hump protruding outward in the radial direction of the steel bar as shown in FIG. Yes.

(Manufacture of concrete structures)
The manufacturing operation of the concrete structure 3 shown in FIG. 3 is substantially the same as the manufacturing operation of the concrete structure 1 shown in FIG.
In the completed concrete structure 3, with respect to the columnar concrete structure 3 having a substantially square cross section in the axial direction, the outer peripheral reinforcement 31A surrounds all of the plurality of main reinforcing bars 12, and the pair of inner peripheral reinforcement 31B respectively The four main muscles 12B corresponding to each other are crossed with each other. Thereby, when an external force is applied from the direction orthogonal to the axis of the concrete structure 3, a larger drag force is generated against the external force than the concrete structure 1 shown in FIG. Further, since the welded portion 31B1 is provided in the middle of any of the long sides that do not overlap the outer peripheral reinforcing portion 31A in the inner peripheral reinforcing portion 31B, the shear reinforcing bar 31 as a whole is balanced, and the concrete structure 3 There will be no bias in the vibration resistance.

(Operation effect of shear reinforcement)
As described above, in the third embodiment, the following operational effects can be obtained in addition to the operational effects substantially similar to the operational effects (1) and (3) in the first embodiment. .

  (5) The outer peripheral line 31A is formed in a substantially square frame shape surrounding all of the main bars 12. A pair of inner peripheral streak portions 31B are provided for one outer peripheral streak portion 31A, and each of the inner peripheral streak portions 31B is formed in a substantially rectangular frame shape that is substantially accommodated in a space surrounded by the outer peripheral streak portion 31A. And a pair of inner peripheral line | wire part 31B is arrange | positioned in the state which mutually overlaps substantially orthogonally. Thus, the outer peripheral muscle portion 31 </ b> A and the four short sides of the pair of inner peripheral muscle portions 31 </ b> B are substantially overlapped when viewed from the axial direction of the main muscle 12. In addition, the outer peripheral muscle portion 31 </ b> A and the long sides of the pair of inner peripheral muscle portions 31 </ b> B are separated from each other without overlapping each other when viewed from the axial direction of the main muscle 12. And the welding part 31B1 is formed in any one long side among the four long sides which do not overlap with the outer periphery reinforcement part 31A in the inner periphery reinforcement part 31B.

For this reason, since the welded portion 31B1 is provided in the space surrounded by the outer peripheral reinforcing portion 31A, that is, the inner peripheral reinforcing portion 31B, the welded portion 31B1 does not affect the cover thickness, and unnecessary concrete is used. You don't have to.
And with respect to the columnar concrete structure 3 whose axial direction cross section is substantially square, the outer peripheral reinforcement 31A surrounds all of the plurality of main reinforcing bars 12, and the pair of inner peripheral reinforcing bars 31B each include four main reinforcing bars 12B. Each crosses each other. For this reason, when an external force is applied from the direction orthogonal to the axis of the concrete structure 3, a greater drag can be generated against the external force. Thereby, the concrete structure 3 can ensure the strength which can fully endure even if a large-scale earthquake occurs.
In addition, the shear reinforcement bars 31 are bent at 12 locations so that a single steel bar is drawn with a single stroke so as to draw the shape of a Chinese character “enclosed”, and the outer peripheral reinforcement 31A and the inner peripheral reinforcement 31B are integrally formed. Since it is a simple structure to be formed, mass production can be easily achieved, and manufacturing efficiency can be greatly improved.
Therefore, the shear reinforcing bar 31 can improve the vibration resistance strength of the concrete structure 3 and can secure high production efficiency.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.

  For example, in the first to third embodiments, the concrete structures 1 to 3 are formed in a columnar shape with a substantially square cross section in the axial direction. A configuration in which the cross section is formed in various shapes such as a star-shaped column may be employed. Even in these configurations, if the shape of the outer peripheral reinforcement and the inner peripheral reinforcement is matched with the cross-sectional shape of the concrete structure, it is formed into a columnar shape, a triangular prism shape, or the like, and the weld is provided on the inner periphery reinforcement. The same effects as those of the above-described embodiment can be obtained, that is, an appropriate cover thickness can be ensured and a shear reinforcing bar can be easily manufactured.

  Moreover, in the said 1st thru | or 3rd Embodiment, although welded part 13B1, 22B1, 31B1 was formed by butting | matching both ends of steel bar, for example by butt welding etc., it is not restricted to this. That is, it is good also as a structure which joins the site | part which contacted | abutted the both ends of a steel bar overlapping each other by welding. Even with such a configuration, the same effects as those of the above-described embodiment can be obtained, that is, an appropriate cover thickness can be ensured and a shear reinforcing bar can be easily manufactured. Also, the welding method is not limited to butt welding, and any other welding method such as arc welding or TIG welding can be employed. In addition, it does not matter even if it removes the welding hump formed in welding part 13B1, 22B1, 31B1 conventionally.

  And in the said 1st thru | or 3rd embodiment, welding part 13B1, 22B1, 31B1 is each of the edge | side of the inner periphery reinforcement | stripe part 13B, 22B, 31B which does not overlap with outer periphery reinforcement | stretching part 13A, 22A, 31A, respectively. Although it was set as the structure provided in the center, it is not restricted to this. That is, the positions of the welded portions 13B1, 22B1, and 31B1 may be any positions in the inner peripheral reinforcing portions 13B, 22B, and 31B as long as they are inside the outer peripheral reinforcing portions 13A, 22A, and 31A.

  In addition, the specific structure, the number and dimensions of members, and the manufacturing procedure can be appropriately changed to other configurations and the like as long as the object of the present invention can be achieved.

  The present invention can be used for concrete structures such as beams and pillars in civil engineering structures and building structures.

It is sectional drawing which shows the internal structure of the concrete structure which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the internal structure of the concrete structure which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the internal structure of the concrete structure based on the 3rd Embodiment of this invention. It is sectional drawing which shows the internal structure of the conventional concrete structure.

Explanation of symbols

1, 2, 3 ... Concrete structures 10, 20, 30 ... Reinforcing bar structures 12, 21 ... Main bars 13, 22, 31 ... Shear reinforcement bars 13A, 22A, 31A ... Outer peripheral bars 13B, 22B, 31B ... Inner peripheral bars 13B1, 22B1, 31B1 ... Welded part

Claims (5)

A plurality of main reinforcing bars that are substantially parallel to each other, and are shear reinforcing bars that constitute a reinforcing bar structure of a concrete structure with the main reinforcing bars,
A substantially frame-shaped outer periphery streaks;
A substantially frame-shaped inner periphery reinforcing part provided in a space surrounded by the outer periphery reinforcing part,
The outer periphery and the inner periphery are formed in a series by bending one steel bar,
A shear reinforcement bar, wherein a welded portion in which both end portions of the steel bar are welded to each other is provided on the inner peripheral reinforcing bar portion. The shear reinforcement according to claim 1,
The outer periphery muscle portion is formed in a substantially square frame shape,
The inner periphery muscle portion is formed in a substantially rectangular frame shape that is substantially accommodated in a space surrounded by the outer periphery muscle portion,
A pair of sides parallel to each other in the outer periphery muscle portion and a pair of sides parallel to each other in the inner periphery muscle portion substantially overlap each other when viewed from the axial direction of the main muscle,
The pair of sides that are substantially orthogonal to the pair of sides in the outer periphery muscle portion and the pair of sides that are substantially orthogonal to the pair of sides in the inner periphery muscle portion do not overlap each other when viewed from the axial direction of the main muscle,
The weld reinforcement is provided on any one side of the pair of sides that do not overlap with the outer circumference reinforcement in the inner circumference reinforcement. The shear reinforcement according to claim 1,
The outer periphery muscle portion is formed in a substantially square frame shape,
The inner peripheral line portions are provided as a pair with respect to the outer peripheral line portions, are each formed in a substantially rectangular frame shape that is substantially accommodated in a space surrounded by the outer peripheral line portions, and are substantially parallel to each other. Are arranged in a non-overlapping state,
A pair of sides parallel to each other in the outer periphery muscle portion and four sides substantially orthogonal to a direction in which the pair of inner periphery muscle portions in the pair of inner periphery muscle portions are substantially parallel to each other are viewed from the axial direction of the main muscle. Each approximately overlapping,
A pair of sides that are substantially orthogonal to the pair of sides in the outer peripheral muscle portion and four sides other than the four sides in the pair of inner peripheral muscle portions do not overlap each other when viewed from the axial direction of the main muscle,
The weld reinforcement is provided on any one of the four sides that do not overlap with the outer peripheral reinforcement in the pair of inner peripheral reinforcements. The shear reinforcement according to claim 1,
The outer periphery muscle portion is formed in a substantially square frame shape,
The inner peripheral line portions are provided as a pair with respect to the outer peripheral line portions, are each formed in a substantially rectangular frame shape that is substantially accommodated in a space surrounded by the outer peripheral line portions, and are substantially orthogonal to each other. Arranged in an overlapping state,
The four sides that overlap each other in the pair of inner periphery muscle portions in the pair of inner periphery muscle portions do not overlap each other when viewed from the axial direction of the main muscle,
The outer peripheral muscle portion and each of the four sides other than the four sides in the pair of inner peripheral muscle portions substantially overlap when viewed from the axial direction of the main muscle,
The weld reinforcement is provided on any one of the four sides that do not overlap with the outer peripheral reinforcement in the pair of inner peripheral reinforcements. A method of manufacturing a shear reinforcing bar that is provided to intersect with a plurality of main bars that are substantially parallel to each other and that forms a reinforcing bar structure of a concrete structure with the main bars,
One steel bar is bent to form a series of a substantially frame-shaped outer periphery reinforcing portion and a substantially frame-shaped inner periphery reinforcing portion provided in a space surrounded by the outer periphery reinforcing portion,
A method for manufacturing a shear reinforcing bar, characterized in that a welded portion is formed by welding both end portions of the steel bar in the inner peripheral reinforcing bar portion.

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