JP5231836B2 - Connection structure - Google Patents

Description

  The present invention relates to a connection structure between PCa (precast) members, and more particularly to a connection structure between columns and beams.

  The use of PCa members has been actively promoted for the purpose of rationalizing construction. In the connection between the PCa members, the joint structure between these main bars is important. As a joint structure between main bars, it has been proposed to use a mechanical joint. In this method, the end of each main bar to be connected is inserted and connected to a cylindrical hardware. However, the mechanical joint has a problem in that the position accuracy of the main bars is required because the ends of the main bars are butted together and connected with a cylindrical hardware. In addition, there is a problem that the cost becomes high as long as a cylindrical hardware is required.

  As another joint structure between the main bars, a lap joint has also been proposed in which the main bars to be connected are overlapped with each other. However, in order to ensure the required overlap length, the amount of protrusion of the main bar from the PCa member tends to be long, and the range in which concrete is placed on site is increased. For this reason, the merit using a PCa member may not fully be utilized.

  On the other hand, in connecting a PCa member on a floor or wall with low stress, there has been proposed a method in which reinforcing bars are folded in a loop shape, loop portions are overlapped with each other, and insertion bars are inserted into the loop portions overlapped with each other (Patent Literature). 1). Such a joint structure transmits force between reinforcing bars mainly by supporting pressure. However, in a portion where the stress is large, such as between the column and the beam, and is subjected to many repetitions after yielding, only the transmission by the supporting pressure lacks the force transmission performance, and the structure described in Patent Document 1 is not the same between the column and the beam. It is difficult to apply as it is.

  FIGS. 1 to 3 of Patent Document 2 disclose a structure of a cross-shaped column beam joint, and the beam main bar protrudes from each end of two PCa beam members 2 in a loop shape, and the upper part of the PCa column member is disclosed. A structure is disclosed in which these are superposed within a beam-to-column connection part that is placed on-site. In this structure, the linear part of the beam reinforcement on the outside in the beam width direction is partly overlapped, so that the force transmission between the beam reinforcement by the adhesion between the beam reinforcement and concrete can be achieved to some extent, and the beam reinforcement Because of the loop shape, force transmission between beam main bars by supporting pressure can be achieved.

JP 2000-328704 A Japanese Examined Patent Publication No. 4-14217

  However, in the structure of Patent Document 2, since the beam main bars are superposed in the beam-to-column joint portion placed on the PCa column member in the field, the overlap length of the linear portion is equal to the column width. In some cases, it is difficult to ensure a sufficient overlay length. In addition, because the beam main bars are overlapped in the beam-to-column joints placed on the top of the PCa column members and the concrete is cast there, high-rise buildings using high-strength concrete with strict curing management etc. for the columns Application to things is not very desirable.

  An object of the present invention is to reduce the range of the cast-in-place concrete of the beam while maintaining the force transmission performance between the beam main bars in the connection of the PCa member between the column and the beam.

According to the present invention, in the connection structure for connecting the joint-side PCa member constituting the beam-column joint and the beam-side PCa member constituting the beam, it protrudes in the horizontal direction from the side of the joint-side PCa member. The beam-side reinforcing bars of the joint side, the beam-side reinforcing bars of the beam-side that protrude in the horizontal direction from the end portion of the beam-side PCa member, A pair of first linear portions protruding from the side portion and spaced apart from each other in the beam width direction, and the pair of first straight lines. A pair of second linear portions protruding from the end portion and spaced apart from each other in the beam width direction, and the pair of first linear connecting portions connecting the tip ends of the shape portions. It comprises a second distal end connecting portion connecting the two rectilinear tip, the first straight line of the pair A plurality of joint-side beam main bars having the same shape of the first and second tip connecting portions are arranged in the beam width direction, and the shapes of the pair of second linear portions and the second tip connecting portion are the same, The same number of beam-side beam reinforcements as the joint-side beam reinforcements are arranged in the beam width direction so as to correspond to the respective joint-side beam reinforcements, and the first linear part and the second linear part, A connection structure is provided in which are superimposed on each other.

  In the connection structure of the present invention, the joint side and the beam side beam main reinforcement are formed in a loop shape including a pair of the first and second linear portions and the first and second tip connecting portions, respectively. As a result, the force between the beam main bars due to the supporting pressure is transmitted, and the force between the beam main bars due to the adhesive force is transmitted by the first linear portion and the second linear portion being overlapped with each other. . Therefore, the force transmission performance between the beam main bars can be improved as compared with the case where the force transmission between the beam main bars is performed only by the adhesive force, and each of the PCa members on the joint side and the beam side beam main bars can be improved. The protruding length of can be shortened. For this reason, the range of the cast-in-place concrete of a beam can be made smaller, maintaining the transmission performance of the force between beam main bars.

  Then, by projecting the joint side beam main reinforcement in the horizontal direction from the side part of the joint side PCa member, the overlapping length is not limited by the width of the joint side PCa member, and the design flexibility is increased. It can be secured. In addition, since the concrete to be cast on site is only the beam end portion on the side of the joint side PCa member, it is not necessary to place the concrete on the column where high strength concrete is required.

  As described above, according to the present invention, in the connection of the PCa member between the column and the beam, the range of the cast-in-place concrete of the beam can be further reduced while maintaining the force transmission performance between the beam main bars.

  1A is a front view (elevated view) of a connection structure A according to an embodiment of the present invention, FIG. 1B is a plan view of the connection structure A, and FIG. 1C is FIG. It is sectional drawing in alignment with line II. FIG. 2A is an exploded perspective view of the connection structure A. FIG.

  The connection structure A includes a joint-side PCa member 1 that constitutes a column-beam joint, a beam-side PCa member 2 that constitutes a beam, and a cast-in-place concrete part 3. In addition, in each figure, the column main reinforcement arrange | positioned by the PCa member 1, the PCa members 1 and 2, and the stirrup arrangement | positioning arrange | positioned at the spot cast-in concrete part 3 are abbreviate | omitting illustration.

  The PCa member 1 has a substantially rectangular parallelepiped shape, and two beam main bars 10 and 11 protrude in the horizontal direction from the side portions (in the case of this example, planar). The two beam main bars 10 are separated from each other in the beam direction (vertical direction), and the two beam main bars 11 are also separated from each other in the beam direction.

  The beam main reinforcing bars 10 are separated from each other in the beam width direction and are substantially parallel to each other, and a pair of linear portions 10a and a tip connecting portion 10b connecting between the tips of the pair of linear portions 10a (between the ends on the PCa member 2 side). , And is formed in a U shape in plan view. A part 10 a ′ of the linear part 10 a is fixed to the concrete portion of the PCa member 1. A conventional technique may be applied as a fixing method in the PCa member. The beam main bar 10 can be formed by bending a single reinforcing bar.

  The main beam 11 has a pair of linear portions 11a that are spaced apart from each other in the beam width direction and are substantially parallel to each other, and a distal end connecting portion 11b that connects the ends of the pair of linear portions 11a. It is formed in a letter shape. A portion 11a ′ of the linear portion 11a is also fixed to the concrete portion of the PCa member 1, and the beam reinforcing bar 11 can also be formed by bending a single reinforcing bar.

  The beam main bars 10 and 11 on the upper side in the beam direction are such that the linear portions 10a and 11a are arranged at substantially equal pitches in the beam width direction, and the beam main bars 10 on the outer side in the beam width direction are relatively It arrange | positions so that the beam main reinforcement 11 of a beam width direction inner side may be enclosed. The same applies to the beam main bars 10 and 11 on the lower side in the beam positive direction.

  The PCa member 2 has a substantially rectangular parallelepiped shape, and two beam main bars 20 and 21 protrude in the horizontal direction from the end portion (in the case of this example, planar). The two main beam bars 20 are separated from each other in the beam direction, and the two main beam bars 21 are also separated from each other in the beam direction.

  The beam main bars 20 and 21 are provided so as to correspond to the beam main bars 10 and 11, respectively, and the portions protruding from the PCa member 2 have the same shapes as the beam main bars 10 and 11, respectively. That is, the beam main bars 20 are connected to each other in the beam width direction so as to connect the pair of linear portions 20a that are substantially parallel to each other and between the tips of the pair of linear portions 20a (between the ends on the PCa member 1 side). 20b, and is formed in a U shape in plan view. A part 20a ′ of the linear portion 20a is embedded in the concrete portion of the PCa member 2.

  The beam main bar 21 has a pair of linear portions 21a that are spaced apart from each other in the beam width direction and are substantially parallel to each other, and a tip connecting portion 21b that connects the tips of the pair of linear portions 21a. It is formed in a U shape. A part 21 a ′ of the linear part 21 a is also embedded in the concrete part of the PCa member 2.

  The beam main bars 20 and 21 can be formed by bending a single reinforcing bar, but if a fixed length reinforcing bar is used, the beam main bar length may be insufficient. In this case, the reinforcing bars may be added in the concrete portion of the PCa member 2. In this case, the joint structure may be a lap joint, a welded joint, or a mechanical joint.

  Similar to the beam main bars 10 and 11, the beam main bars 20 and 21 on the upper side in the beam direction are such that the straight portions 20a and 21a have substantially the same pitch in the beam width direction as the straight portions 10a and 11a. And the beam main bars 20 relatively outside the beam width direction are arranged so as to surround the beam main bars 21 relatively inside the beam width direction. The same applies to the beam main bars 20 and 21 on the lower side in the beam positive direction.

  As shown in FIGS. 1 (a) and 1 (b) and FIG. 2 (b), the beam main bar 10 and the beam main bar 20, and the beam main bar 11 and the beam main bar 21 are overlapped in the beam direction. By overlapping in the beam direction, the beam width can be made shorter than when overlapping in the beam width direction. In the present embodiment, the beam main bars 20 and 21 are positioned on the upper side of the beam in the beam vertical direction, and the beam main bars 20 and 21 on the lower side in the beam normal direction. Is located above the beam. In the space between the side portion of the PCa member 1 and the end portion of the PCa member 2, the concrete is cast in place to form a spot cast concrete portion 3.

  As shown in FIG.1 (b), the linear part 10a and the linear part 20a are mutually overlapped in the range of length L1, and the linear part 11a and the linear part 21a are mutually overlapped in the range of length L2. Is done. Thereby, the force is transmitted between the beam main bar 10 and the beam main bar 20 and between the beam main bar 11 and the beam main bar 21 by the adhesion force of the cast-in-place concrete part 3 to the concrete. Further, since the beam main bars 10, 11, 20, and 21 each have a loop shape, the force is also transmitted by the support pressure. Since the dependence on the force transmission performance by the adhesion force is reduced by the amount that the force can be transmitted by the support pressure, the lengths L1 and L2 can be shortened. Therefore, the lengths of the beam main bars 10, 11, 20 and 21 can be reduced. In addition, the protruding length from each of the PCa members 1 and 2 can be shortened. Therefore, the range of the cast-in-place concrete portion 3 can be further reduced while maintaining the transmission performance of the force between the beam main bars.

  Further, by projecting the beam main bars 10 and 11 from the side portion of the PCa member 1 in the horizontal direction, the overlapping lengths L1 and L2 are not restricted by the width of the PCa member 1, and the degree of freedom in design can be secured. In addition, since the concrete to be cast in the field is only the beam end on the side of the PCa member 1, it is not necessary to place the concrete on the column where high-strength concrete is required. Moreover, since the joint structure of the beam main bars 10, 11, 20, and 21 is based on a lap joint, the advantage of a lap joint can be enjoyed.

  In addition, although the said embodiment demonstrated the toroidal column beam junction part, it is applicable similarly to a cross-shaped column beam junction part. FIG. 3A is a plan view showing another embodiment of the PCa member 1, which is a PCa member 1 for a cross-shaped column beam joint. In the example of the figure, beam main bars 10 and 11 protrude from the both sides of the PCa member 1 in a loop shape. Each of the beam main bars 10 and 11 can be formed from a single reinforcing bar, and the connection between both end portions of the beam main bars 10 and 11 may be a conventional enclose welding or a mechanical joint. Further, both end portions of the main beam bars 10 and 11 may be fixed.

  Further, in the above-described embodiment, two types of beam main bars 10 and 11 having different shapes are used, and the beam main bars 10 that are relatively outer in the beam width direction are disposed so as to surround the beam main bars 11 that are relatively inner in the beam width direction. However, a configuration using a plurality of loop-shaped beam main bars having the same shape may be used. FIG. 3B is a plan view showing another aspect of the PCa member 1 and shows a configuration in which a plurality of beam main bars 110 are arranged in the beam width direction. The beam main reinforcing bar 110 includes a pair of linear portions 110a and a tip connecting portion 110b connecting the tips of the pair of linear portions 110a. The pair of linear portions 110a and the tip connecting portions 110b of each beam main reinforcing rod 110 are provided. The shape is common, and in this embodiment, it is formed in a U shape in plan view. The linear portions 110a are arranged in the beam width direction at substantially equal pitches. Although the beam main reinforcement of the PCa member 2 on the beam side is not shown in the figure, the same number of the linear main portion and the tip connecting portion corresponding to each beam main reinforcement 110 corresponds to the beam main reinforcement 110. In the beam width direction as shown. In this case, it is desirable that the shape of the linear portion and the tip connecting portion of the beam main bar of the PCa member 2 on the beam side be exactly the same as the shape of the linear portion 110a and the tip connecting portion 110b of the beam main bar 110, but at least It suffices if the spacing between the pair of linear portions of the beam main bar on the beam side is set so as to be overlapped with the pair of linear portions 110a of the beam main bar 110, respectively.

  In the case of the example in FIG. 3B, it is sufficient to prepare only one type of beam main bar 110 as the beam main bar on the PCa member 1 side, and if one type of beam main bar is also prepared on the PCa member 2 side. There is an advantage of being sufficient. In addition, the overlap length between the respective linear portions can be made the same, and there is an advantage that the required overlap length can be easily obtained between the respective linear portions.

(A) is a front view (elevated view) of the connection structure A according to one embodiment of the present invention, (b) is a plan view of the connection structure A, and (c) is a line II in FIG. It is sectional drawing which follows. (A) is an exploded perspective view of the connection structure A, (b) is a perspective view showing a state in which the beam main bars 10 and 11 and the beam main bars 20 and 21 are overlapped with each other. (A) And (b) is a top view which shows the other aspect of the PCa member 1. FIG.

Explanation of symbols

1, 2 PCa member 3 Cast-in-place concrete part 10, 11, 20, 21 Beam main reinforcement 10a, 11a, 20a, 21a Straight line part 10b, 11b, 20b, 21b Tip connection part

Claims (1)

In the connection structure for connecting the joint-side PCa member constituting the beam-column joint and the beam-side PCa member constituting the beam,
A joint-side beam main bar protruding in a horizontal direction from a side portion of the joint-side PCa member;
A beam-side beam main bar that protrudes in the horizontal direction from the end of the beam-side PCa member, and is overlapped with the joint-side beam main bar and the beam ridge direction;
Concrete placed in a space between the side and the end, and
The joint side beam main reinforcement is
A pair of first linear portions protruding from the side portions and spaced apart from each other in the beam width direction;
A first tip connecting portion connecting between the tips of the pair of first linear portions,
The beam side beam main reinforcement is
A pair of second linear portions protruding from the end portions and spaced apart from each other in the beam width direction;
A second tip connecting portion connecting between the tips of the pair of second linear portions,
A plurality of the joint side beam principal bars having the same shape of the pair of first linear portions and the first tip connecting portion are arranged in the beam width direction,
The shapes of the pair of second linear portions and the second tip connecting portion are common, and the same number of the beam side beam main bars as the joint side beam main bars correspond to the respective joint side beam main bars. Arranged in the beam width direction,
The connection structure, wherein the first linear portion and the second linear portion are overlapped with each other.

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