JP4502270B2 - Joint structure of precast concrete beams - Google Patents

Description

  The present invention relates to a joint structure of precast concrete beams.

In the conventional joint structure 22 of precast concrete beams, when the two precast concrete beams 23 and 24 are joined at the center of the beam, as shown in FIG. 26 and 27 are joined together by welding or a mechanical joint 28. In this case, the protruding first-stage main bars 26 and 27 are displaced within the range where fine adjustment is possible due to the installation accuracy of the precast concrete beams 23 and 24 on the precast concrete columns. Needed to match). As another joining structure of precast concrete beams, for example, the invention of Japanese Patent Laid-Open No. 8-93051 is known.
JP-A-8-93051

  However, in the joint structure of the precast concrete beams described above, in order to join the first-stage main bars protruding from the opposed joint end faces by welding or mechanical joints, it is necessary to align the opposed first-stage main bars. .

  This invention is made | formed in view of these problems, The objective is to provide the junction structure of the precast concrete beam which does not need to align the 1 step | paragraph main bars which oppose.

The joint structure of the precast concrete beams for solving the above problems is that the joint end surfaces of the two precast concrete beams that are joined to each other face each other, the one-stage main bar that protrudes from the top and bottom of one joint end surface, and the other joint end surface The first-stage main bars protruding from the top and bottom are not joined, and the joint bars are arranged inside the upper and lower first-stage main bars within the joining interval at the joining end surfaces of the two precast concrete beams ,
Disposed inside the bent portion of the upper joint muscles bent portion of Rutotomoni lower side of the junction muscles and both end portions are bent inwardly each joint muscle with the end of the first stage main reinforcement which projects into the joint gap Is to do .
Further, both ends of the joining bars are bent within the joining interval, and the bent portion of the lower joining muscle is arranged inside the bent portion of the upper joining muscle so as to shorten the joining interval. bent portions of the joint muscles is that joined to.

  It is not necessary to weld the first-stage main bars protruding from the opposite joint end faces of the two precast concrete beams or to join them by mechanical joints, and it is not necessary to align the first-stage main bars. Can improve the performance.

  Embodiments of a precast concrete beam (hereinafter referred to as PC beam) joint structure according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, this PC beam joint structure (hereinafter referred to as “joint structure”) 1 has PC beams 3 and 4 installed on a precast concrete column (hereinafter referred to as “PC column”) 2 at the site. As shown in FIG. 2, there are a structure in which the PC beams 3, 4 formed integrally with the PC pillar 2 are bonded together as shown in FIG. 2, and any of the cases can be applied.

  When these PC beams 3 and 4 are joined, the PC beams 3 and 4 protrude from the opposite joining end surfaces 5 due to the installation accuracy of the PC beams 3 and 4 to the PC pillar 2 and the construction accuracy of the PC pillar 2 (for reasons of construction). If the first-stage main bars 6 and 7 are displaced from each other, alignment is required to join them by welding or mechanical joints. However, according to the present invention, the PC beams 3 and 4 are joined to each other in a state in which the first-stage main bars 6 and 7 protruding from the joining end face 5 are displaced without performing this alignment.

  This “one-step main reinforcing bars are displaced” means that the portions protruding from the joint end face 5 (only the tip portions of the first main reinforcing bars) are the installation accuracy of the PC beams 3 and 4 to the PC column 2 and the PC columns. According to the construction accuracy of 2 and the like, it means that they do not match within the finely adjustable range, and it does not mean that the first stage main bars 6 and 7 are shifted due to a design error or a bar arrangement error. That is, for the reasons described above, it is necessary to make a fine adjustment for alignment that does not match in the state where the tip portions of the first-stage main bars 6 and 7 face each other.

  FIG. 3 shows the joint structure 8 according to the first embodiment. The joint structure 8 includes joint bars 9 on the inner side of the upper first-stage main bars 6 and 7 protruding from the opposite joint end surfaces 5 of the two PC beams 3 and 4 and on the inner side of the lower first-stage main bars 6 and 7. Is arranged, and the on-site cast concrete 10 is placed at the arrangement location.

  The upper and lower first stage main bars 6, 7 protruding from the joint end face 5 of these two PC beams 3, 4 are not directly joined because they are shifted from each other, and are not aligned for direct joining, In this state, the tensile force generated in the first-stage main bar 6 of one PC beam 3 is joined by the joint bar 9 overlapped and laid inside the first-stage main bars 6 and 7. It is transmitted to the first stage main muscle 7. The joining bars 9 are arranged from one first-stage main reinforcement 6 to the other first-stage main reinforcement 7 so as to overlap with the first-stage main reinforcements 6 and 7 in the vertical direction at the arrangement position of the second-stage main reinforcement 11. In this way, even if the first-stage main bars 6 and 7 are displaced from each other, the PC beam 3 can be obtained simply by laying and joining the connecting bars 9 without joining them or taking the trouble of joining them. 4 can be joined together.

  FIG. 4 shows a joint structure 12 according to the second embodiment. The joint structure 12 is laid jointly on the ends of the upper and lower first-stage main bars 6 and 7 protruding from the opposite joint end surfaces 5 of the two PC beams 3 and 4 and inside the first-stage main bars 6 and 7. The fixing metal 13 is provided at both ends of the joining bar 9, and the other configuration is the same as that of the joining structure 8 of the first embodiment. Since the fixing metal 13 increases the bonding strength with the cast-in-place concrete 10, the bonding interval (distance between the opposite bonding end faces) 14 between the two PC beams 3 and 4 can be shortened.

  FIG. 5 shows a joint structure 15 according to the third embodiment. The joint structure 15 is formed by bending the tip portions of the upper and lower first-stage main bars 6 and 7 and both end portions of the upper and lower joint bars 9 inward, and the bent joint 16 of the lower joint bar on the upper joint bar. The other configuration is the same as that of the joint structure 8 of the first embodiment. Since the joint strength with the cast-in-place concrete 10 is increased by such bent portions 16 and 17, the joint interval (distance between the joint end faces facing each other) 14 between the two PC beams can be shortened.

  FIG. 6 shows a joint structure 18 according to the fourth embodiment. This joining structure 18 is formed by bending both ends of the upper and lower joining bars 9 inward to form a hoop-like joining bar 19, and the rest is the same as the joining structure 15 of the third embodiment. It is a configuration. In this way, the joint strength between the cast-in-place concrete 10 is increased by the bent portion 20 of the first-stage main reinforcement and the hoop-like joint reinforcement 19, so that the joint interval between the two PC beams 3 and 4 (between the opposing joint end faces). 14) can be shortened.

  FIG. 7 shows a joint structure 21 according to the fifth embodiment. In this joint structure 21, the first-stage principal bars 6, 7 protrude from the upper and lower sides of the opposite joint end faces 5 of the two PC beams 3, 4, and the second-stage principal bars 11 project from the joint end face 5 of one PC beam 3. This is the same as the connection structure 8 of the first embodiment except that this is overlapped and arranged inside the first-stage main reinforcement 7 protruding from the joint end face 5 of the other PC beam 4. This does not place a new connecting bar, but a two-stage main bar 11 protruding from the joint end face 5 of one PC beam 3 replaces the connecting bar 9. This is also not directly joined because the first-stage main bars 6 are displaced from each other, and is not joined for direct joining, and is joined as it is with the two-stage main bars 11 that are overlapped and arranged. The

  Note that the present invention is not limited to the case where the first-stage main bars 6 and 7 are deviated from each other as described above, and can be applied to cases where the first-stage main bars 6 and 7 are not deviated from each other. The two PC beams 3 and 4 are joined without joining the main step bars 6 and 7 to each other.

  Moreover, in the said Example, although the pillar demonstrated by the PC pillar 2, this may not be the PC pillar 2 but an in-situ reinforced concrete pillar.

It is a front view which shows the joining structure of the PC beam installed in the PC pillar in the field. It is a front view which shows the joining structure of the PC beam previously installed in the PC pillar. (1) is sectional drawing of the junction structure of 1st Embodiment, (2) is the top view. (1) is sectional drawing of the junction structure of 2nd Embodiment, (2) is the top view. (1) is sectional drawing of the junction structure of 3rd Embodiment, (2) is the top view. (1) is sectional drawing of the junction structure of 4th Embodiment, (2) is the top view. (1) is sectional drawing of the junction structure of 5th Embodiment, (2) is the top view. It is sectional drawing of the conventional joining structure.

Explanation of symbols

1, 8, 12, 15, 18, 21, 22 Joint structure 2 PC pillar 3, 4, 23, 24 PC beam 5, 25 Joint end face 6, 7, 26, 27 1st stage main bar 9, 19 Joint bar 10 Concrete 11 Two-stage main bar 13 Fixing hardware 14 Joining interval 16, 17, 20 Bent part 28 Mechanical joint

Claims (2)

The joint end faces of the two precast concrete beams that are joined to each other face each other, and the first stage main bar that protrudes from the top and bottom of one joint end face and the first stage main bar that projects from the top and bottom of the other joint end face are not joined. Inside the first stage reinforcing bar , the connecting bars are arranged in the connecting interval at the connecting end surfaces of the two precast concrete beams ,
Disposed inside the bent portion of the upper joint muscles bent portion of Rutotomoni lower side of the junction muscles and both end portions are bent inwardly each joint muscle with the end of the first stage main reinforcement which projects into the joint gap To do,
Precast concrete beam joint structure characterized by And disposed inside the bent portion of the upper joint muscles bent portion of the joint muscles of the lower end portions bent bonding muscle in the joint gap, the joint to hoop so as to shorten the bonding distance The bent parts of the muscles are joined together,
The joint structure of precast concrete beams according to claim 1.

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