JP5160869B2 - Precast concrete beam joint structure - Google Patents

Description

  The present invention relates to a PCa beam joint structure of a precast concrete (hereinafter referred to as “PCa”) beam and a PCa beam.

  Conventionally, as one method of joining PCa beams and PCa beams, as shown in FIG. 9, precast buried molds 100 and 102 are integrally formed with beams 104 and 106, respectively, as molds outside the building. A method of forming and joining the beam 104 and the beam 106 is known. In this construction method, beam main bars 108 and 110 protruding from the joint end face 104A of the beam 104 and the joint end face 106A of the beam 106 are fixed by the mechanical joint 112, and a shear reinforcement bar 114 is provided around the beam main bars 108 and 110. Arrange the bars. Next, lower and inner molds (not shown) are temporarily installed along the longitudinal direction of the beams 104 and 106 so as to surround the beam main bars 108 and 110, and the cast-in-place concrete is applied from above the mechanical joint 112. The beam 104 and the beam 106 are integrally joined by driving. However, although this method does not require temporary installation and removal work of the outer formwork, temporary and removal work of the lower and inner formwork is required, and improvement in construction efficiency cannot be expected so much.

  On the other hand, Patent Document 1 proposes a precast embedded form with a U-shaped cross section. This precast embedded formwork is an embedded formwork for constructing the beam itself at the site, although it encloses the three directions of the outer side, the lower side, and the inner side, so that the temporary setting of the formwork and the removal work are unnecessary. It is not a buried form for beam joining used when concrete is placed between the beams to join the beams.

  Further, Patent Documents 2 and 3 propose a joint structure in which the beam 118 and the beam 120 are joined without using on-site concrete, as shown in FIGS. 10 and 11. In this joining structure, the beam 120 arranged at the upper end 126A of the column 126 is moved in the horizontal direction or the horizontal direction (arrow A) with respect to the beam 118 integrated with the column 122 and the column 124, and the beam 120 The main beam 128 protruding from the joint end face 120A is inserted into the mechanical joint 130 embedded in the joint end face 118A of the beam 118. Then, mortar (not shown) is injected into the mechanical joint 130 to connect the beam main bar 128 and the beam main bar 132, and the beam 118 and the beam 120 are joined together.

However, since the protruding length of the beam main bar 128 protruding from the joint end surface 120A of the beam 120 is short, when the beam main bar 128 is inserted into the mechanical joint 130, it is necessary to accurately align the positions of the beam 118 and the beam 120. is there.
Japanese Patent Laid-Open No. 5-321326 Japanese Patent Application Laid-Open No. 2004-346587 JP 2004-278257 A

  In view of the above facts, an object of the present invention is to provide a simple joining structure that eliminates the need for on-site formwork when joining a precast concrete beam and a precast concrete beam.

According to one aspect of the present invention, a precast concrete beam joining structure for joining the first precast concrete beam and second precast concrete beam, the first precast concrete beam and the second precast concrete beam of at least one of the opposing end faces, comprising the precast buried formwork Rutotomoni upward is formed along the outer periphery of the end face is open, projects from the end face of the first precast concrete beam to the precast buried formwork in The first beam main reinforcement is inserted into the mechanical joint embedded in the end face of the second precast concrete beam through the precast embedding formwork and connected to the second beam main reinforcement of the second precast concrete beam. the by Da設concrete to the precast buried mold in the first Pureki It is characterized by bonding the said and strike the concrete beam second precast concrete beam.

According to the above configuration, the precast embedded formwork is formed on at least one of the opposing end faces of the first precast concrete beam and the second precast concrete beam, so that on-site formwork, There is no need for temporary work of scaffolds and removal of formwork associated with the frame work. Therefore, the first precast concrete beam and the second precast concrete beam can be integrally joined by a simple construction in which concrete is placed in the precast embedded formwork. Further, reinforcement reinforcement can be arranged from the opening above the precast embedded formwork. Furthermore, since the first beam main bar protrudes from the end face of the first precast concrete beam and the deformable length of the first beam main bar becomes longer, the flexibility of the first beam main bar is increased. Therefore, it becomes easy to join with the 2nd beam main reinforcement, and it can aim at improvement of workability and shortening of a construction period.
In addition, the first beam main reinforcement and the second beam main reinforcement can be connected by inserting the first beam main reinforcement into a mechanical joint embedded in the end face of the second precast concrete beam. Further, since the first beam main bar protrudes from the end surface of the first precast concrete beam, the first beam main bar can be greatly bent with the end surface of the first precast concrete beam as a fulcrum. For this reason, it is possible to absorb assembly errors such as mechanical joints and beam main reinforcing bars, and it is possible to provide a margin in positioning accuracy when the first beam main reinforcing bars are inserted into the mechanical joints.

The invention according to claim 2 is a precast concrete beam joint structure for joining the first precast concrete beam and the second precast concrete beam, the first precast concrete beam and the second precast concrete beam. A precast embedded mold that is formed along at least the outer periphery of the end surface of the first precast concrete beam and is open at the top, and the precast embedded mold includes the first cast A shear reinforcement bar that surrounds the upper and lower first beam main bars projecting from the end face of the precast concrete beam is disposed, and a mechanical joint in which the first beam main bar is inserted is connected to the second precast concrete beam of the second precast concrete beam. Moving toward the beam main bar, inserting the second beam main bar into the mechanical joint, and And connecting the the beam main reinforcement second beam main reinforcement, characterized that you join the first precast concrete beam and the second precast concrete beam to Da設concrete to the precast buried formwork in It is said.

According to said structure, by forming the precast embedding formwork made into the precast in the end surface of at least 1st precast concrete beam among the opposing end surfaces of a 1st precast concrete beam and a 2nd precast concrete beam. In addition, there is no need for on-site formwork, temporary work of scaffolding associated with formwork, and removal of formwork. Therefore, the first precast concrete beam and the second precast concrete beam can be integrally joined by a simple construction in which concrete is placed in the precast embedded formwork. Further, reinforcement reinforcement can be arranged from the opening above the precast embedded formwork. Furthermore, since the first beam main bar protrudes from the end face of the first precast concrete beam and the deformable length of the first beam main bar becomes longer, the flexibility of the first beam main bar is increased. Therefore, it becomes easy to join with the 2nd beam main reinforcement, and it can aim at improvement of workability and shortening of a construction period.
Furthermore, the first beam main reinforcement is inserted into the mechanical joint, and the second joint is inserted into the mechanical joint by moving the mechanical joint toward the second beam main reinforcement. In this way, the first beam principal bar and the second beam principal bar can be connected by moving the mechanical joint.

The invention according to claim 3 is the precast concrete beam joint structure according to claim 2 , wherein the mechanical joint is arranged in the precast embedded formwork .

According to the above configuration , since the first beam main bar and the second beam main bar are connected by the mechanical joint in the precast embedded formwork, the beam main bar can be easily connected. Since the mechanical joint can be operated from above the formwork, workability is improved.

According to a fourth aspect of the invention, the precast concrete beam joint structure according to claim 2, wherein the end face of the second precast concrete beam, said second beam the insertion portion to which the mechanical joint is inserted It is characterized by being formed around the main muscle.

  According to said structure, a 1st beam main reinforcement and a 2nd beam main reinforcement are easily connected by inserting a mechanical coupling in the insertion part formed in the end surface of a 2nd precast concrete beam. Can do. In addition, since the mechanical joint can be operated from above the precast embedded formwork, it is possible to easily connect the beam main bars.

The invention according to claim 5 is the precast concrete beam joint structure according to any one of claims 1 to 4 , wherein the end face of the first precast concrete beam and the end face of the second precast concrete beam. A cotter is formed on at least one of the above.

According to said structure, by providing a cotter in the end surface of a precast concrete beam, stress transmission in a junction part can be made favorable and sufficient joint strength can be ensured.
According to a sixth aspect of the present invention, in the precast concrete beam joint structure according to the first aspect, the upper and lower first beam main bars protrude from the end face of the first precast concrete beam into the precast embedded formwork. It is characterized by doing.
According to said structure, the upper and lower 1st beam main reinforcement protrudes in the precast embedding formwork from the end surface of the 1st precast concrete beam, and the deformable length of the upper and lower 1st beam main reinforcement becomes long. . This increases the flexibility of the upper and lower first beam main bars, so that it is easy to join the second beam main bars. Therefore, it is possible to improve workability and shorten the construction period.

Since this invention set it as said structure, a precast concrete beam and a precast concrete beam can be joined by the simple construction method which does not require the formwork on-site.

  Hereinafter, a PCa beam joint structure according to a first embodiment of the present invention will be described with reference to the drawings. 1 and 2 are schematic views of the first embodiment. In the first embodiment, PCa beams 16 projecting from columns 12 and 14 constituting the frame 10 and an upper end surface 18A of the column 18 are shown. And a PCa beam 20 placed on the butt.

  A beam main bar 22 is arranged in the beam 16, and the beam main bar 22 is inserted into a hollow tubular mechanical joint 26 embedded in the end face 16A. A beam 20 is placed on the upper end surface 18A of the column 18 so as to be movable in the horizontal direction or the horizontal direction (arrow B). Further, the beam 20 is provided with a beam main bar 24 protruding from the end face 20A, and a concrete precast embedded formwork 28 surrounding the protruding beam main bar 24 and opened upward is provided on the end face 20A. The beam main reinforcement 24 protrudes from the front end portion 28 </ b> A of the precast embedded form 28. Furthermore, cotters 30 and 32 are formed on the end face 16A and the end face 20A, respectively.

  As shown in FIG. 2, the connection between the beam main bar 22 and the beam main bar 24 is performed by moving the beam 20 in the horizontal direction or the horizontal direction (arrow B), so that a mechanical joint 26 embedded in the end surface 16 </ b> A of the beam 16. This is done by inserting the beam main bar 24 into Thereafter, cast-in-place concrete is cast in the precast embedded form 28, and the beam 16 and the beam 20 are joined together.

  Here, the end faces 16A and 20A will be described in detail. As shown in FIGS. 3 to 5, a hollow tubular machine in which a beam main bar 22 connected to a beam main bar 24 of the beam 20 is arranged along the longitudinal direction of the beam 16 and embedded in the end surface 16 </ b> A. Each is inserted into the type joint 26. A shear reinforcement bar 34 is arranged around the beam main bar 22 and the mechanical joint 26.

  On the side surface of the beam 16, there are embedded injection hoses 40A and 40B for injecting grout and confirmation hoses 42A and 42B for confirming that the grout is filled. Although not shown, an injection hose and a confirmation hose leading to the inside of each mechanical joint 26 are embedded in the beam 16. Furthermore, the cotter 30 comprised from two recessed parts is comprised by 16 A of end surfaces.

  On the other hand, a precast embedded formwork 28 having a U-shaped cross section that is precast is integrally formed on the end face 20 </ b> A of the beam 20 along the longitudinal direction of the beam 20. A beam main bar 24 is arranged along the longitudinal direction of the beam 20, and a shear reinforcement bar 36 is arranged so as to surround the beam main bar 24. From the end face 20A of the beam 20, the beam main bar 24 protrudes, passes through the precast embedded mold 28, and protrudes from the tip 28A of the precast embedded mold 28. In the precast embedded form 28, a shear reinforcement bar 38 surrounding the beam main bar 24 is arranged close to the end face 20 </ b> A of the beam 20. Further, as shown in FIG. 4, a cotter 32 composed of two concave portions 32A and 32B corresponding to the cotter 30 formed on the end surface 16A of the beam 16 is formed at the center of the end surface 20A of the beam 20. Yes.

  The precast embedding form 28 is a precast embedding form that does not require demolding after casting of concrete, and is sometimes referred to as an outer shell PCa. Further, reinforcing bars and the like may be embedded in the precast embedded form 28 as necessary.

  Next, an example of a method for joining the beam 16 and the beam 20 will be described.

  First, as shown in FIGS. 3A and 3B, the beam 20 is moved in the horizontal direction or the horizontal direction (arrow B), and the mechanical joint 26 in which the beam main reinforcement 24 of the beam 20 is embedded in the beam 16 is used. And a joint space 44 is formed in the gap between the end face 16A of the beam 16 and the tip end portion 28A of the precast embedded form 28. In addition, an air tube 46 made of an elastic material such as rubber is disposed along the periphery of the joint space 44, and air is blown into the air tube 46 to expand it, thereby sealing the joint space 44. The inner diameter of the mechanical joint 26 does not need to coincide with the outer diameter of the beam main bar 24, and a mechanical joint 26 having an inner diameter somewhat larger than the outer diameter of the beam main bar 24 may be used.

  Next, grout (not shown) is injected from the injection hoses 40A and 40B, the interior of the mechanical joint 26 is filled, and it is confirmed that the grout is filled in the confirmation hoses 42A and 42B. When the grout is hardened, the beam main reinforcement 22 and the beam main reinforcement 24 are integrally connected inside each mechanical joint 26. The grout filling is performed on all mechanical joints 26 embedded in the beam 16.

  Thereafter, the shear reinforcement bars 38 installed in the precast embedded form 28 are arranged at predetermined intervals along the longitudinal direction of the beam main bars 24, and cast-in-place concrete (not shown) is placed in the precast embedded form 28. Set up. After the concrete has hardened, the air is removed from the air tube 46 and contracted, and is removed from the periphery of the joint space 44.

  In this embodiment, after injecting grout into the mechanical joint 26, the cast-in-place concrete is placed in the precast embedded form 28. However, the present invention is not limited to this, and after the concrete is placed, the mechanical joint 26 is placed. The grout may be filled. Further, the joint space 44 is sealed by the air tube 46, but the present invention is not limited to this, and it may be sealed by a sponge-like foaming material. Further, although the shear reinforcement bar 38 is arranged around the beam main bar 24, it is sufficient if the design strength of the beam 20 and the joint strength with the beam 16 can be secured, and fiber reinforced concrete or the like may be placed.

  Next, operations and effects of the PCa beam joint structure according to the first embodiment of the present invention will be described.

  By forming the precast embedded formwork 28 on the end face 20A of the beam 20, the formwork work at the site and the temporary work of the scaffold accompanying the formwork work become unnecessary. Moreover, since the precast embedded formwork 28 is integrated with the beams 16 and 20 after hardening the cast-in-place concrete, it is not necessary to remove it. Such a precast embedded form 28 is particularly effective in a high layer where it is difficult to temporarily set a scaffold. In addition, in this embodiment, as shown in FIGS. 10 and 11, the joint end faces of the beams made of PCa are butted together and joined to each other using a filler such as mortar. Since the cast-in-place concrete adheres to the inner surface and the adhesion area increases, a high bonding strength can be ensured. Furthermore, since the cotters 30 and 32 are formed on the end surfaces 16A and 20A of the beam 16 and the beam 20, the stress transmission at the joint is further improved, and a sufficient joint strength can be ensured.

  Further, in order to insert the beam main reinforcement 24 of the beam 20 into the mechanical joint 26 embedded in the beam 16, considerable accuracy is required for alignment between the beam 16 and the beam 20. Since the projecting beam main reinforcement 24 is surrounded by the precast embedded form 28, a long projection length of the beam main reinforcement 24 is ensured. For this reason, the deformable length of the beam main reinforcing bar 24 is increased, so that the flexibility of the reinforcing bar is increased, and even if the alignment between the beam 16 and the beam 20 is shifted, an external force is applied to the beam main reinforcing bar 24, As shown by the arrow C in FIG. 1, the beam main bar 24 can be easily guided to the mechanical joint 26. Further, assembly errors of the beam main bars 22 and 24 and the mechanical joint 26 at the time of manufacturing the beam 16 or the beam 20 can be absorbed, and a margin can be given to the positioning accuracy between the beam 16 and the beam 20.

  In the present embodiment, the precast embedded form 28 is formed only on the end face 20A of the beam 20, but the present invention is not limited to this. For example, instead of forming the precast embedded form 28 on the end face 20A, the precast embedded form 28 may be formed on the end face 16A of the beam 16 along the outer periphery of the end face 16A. Also in this case, if the beam 20 is moved in the horizontal direction or the horizontal direction (arrow B), the beam main bar 24 protruding from the end surface 20A of the beam 20 passes through the precast embedded form 28 and reaches the end surface 16A of the beam 16. The main beam 22 and the main beam 24 can be connected by being inserted into the embedded mechanical joint 26. Furthermore, you may form the precast embedding formwork 28 in both the end surface 16A and the end surface 20A. In this case, it is necessary to lengthen the protruding length of the beam main bar 24 protruding from the end face 20A. However, the flexibility of the reinforcing bar is increased correspondingly, and the insertion into the mechanical joint 26 is further facilitated.

  Next, a PCa beam joint structure according to a second embodiment of the present invention will be described. In addition, the thing of the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits suitably and demonstrates.

  As shown in FIGS. 6A and 6B, an insertion hole 48 into which the mechanical joint 26 can be inserted is formed on the end surface 16A of the beam 16, and the bottom wall of the insertion hole 48 is formed inside the insertion hole 48. The main beam bar 22 protruding from 48A is housed. Further, injection hoses 50A and 50B for injecting grout and confirmation hoses 52A and 52B for confirming that the grout is filled are embedded in the side surface of the beam 16 so as to pass through the inside of the insertion hole 48. Although not shown, the beam 16 is embedded with an injection hose and a confirmation hose leading to the inside of each insertion hole 48.

  On the other hand, the end face 20A of the beam 20 is formed with a precast embedded form 28 that opens upward along the outer periphery of the end face 20A, and the beam main bar 24 protruding from the end face 20A is surrounded by the precast embedded form 28. Yes. A mechanical joint 26 is disposed in the precast embedded form 28, and a beam main bar 24 protruding from the end face 20 </ b> A of the beam 20 is inserted into the mechanical joint 26. Further, in the precast embedded form 28, a shear reinforcement bar 38 is arranged close to the end face 20A.

  Next, an example of a method for joining the beam 16 and the beam 20 will be described.

  First, as shown in FIG. 6 (A), the end surface 16A of the beam 16 and the front end portion 28A of the precast embedded form 28 formed on the end surface 20A of the beam 20 are brought into contact with each other, and the gap between the end surface 16A and the front end portion 28A. Then, the joint space 44 is formed, and the joint space 44 is sealed by the air tube 46. At this time, similarly to the first embodiment, the beam 20 may be moved in the horizontal direction or the horizontal direction so that the end face 16A of the beam 16 and the tip end portion 28A of the precast embedded form 28 are brought into contact with each other. In the form, since the beam main reinforcing bar 24 does not protrude from the front end portion 28A of the precast embedded form 28, for example, the end surface 16A and the front end portion 28A may be brought into contact with each other by dropping the beam 20 from above (vertical direction).

  Next, the mechanical joint 26 is moved laterally or horizontally (arrow D) along the beam main bar 24 of the beam 20 and inserted into the insertion hole 48 of the beam 16, and the beam main bar of the beam 16 is inserted into the mechanical joint 26. 22 is inserted. Thereby, the beam main bar 22 and the beam main bar 24 are inserted into the mechanical joint 26, and the beam main bar 22 and the beam main bar 24 are connected. A sponge-like foamable material 54 is disposed in a gap formed between the insertion hole 48 and the mechanical joint 26 so that the grout filled in the insertion hole 48 does not leak into the precast embedded mold 28. And seal. Further, by sealing the gap with the foamable material 54, the grout is filled in the mechanical joint 26 without any gap from the end on the beam 16 side to the end on the beam 20 side of the mechanical joint 26. .

  Grouting is injected into the insertion hole 48 from the injection hoses 50A and 50B, and it is confirmed that the grout is filled in the confirmation hoses 52A and 52B. At this time, the mechanical joint 26 is also filled with grout, and the beam main bar 22 of the beam 16 and the beam main bar 24 of the beam 20 are integrally connected. The confirmation that the grout is filled in the mechanical joint 26 may be appropriately performed by a confirmation hole (not shown) formed in the mechanical joint 26. After that, the shear reinforcement bars 38 arranged in the precast embedded form 28 are arranged around the beam main bars 24 and the mechanical joints 26 along the longitudinal direction of the beam 20, and are placed in the precast embedded form 28 in the field. Concrete is placed and the beam 16 and the beam 20 are joined together.

  As in the first embodiment, the joint space 44 is not limited to the air tube 46 and may be sealed with a sponge-like foaming material. Further, although the shear reinforcement bar 38 is arranged around the beam main bar 24 and the mechanical joint 26, it is sufficient if the design strength of the beam 20 and the bonding strength with the beam 16 can be ensured. good.

  Next, functions and effects of the PCa beam joint structure according to the second embodiment of the present invention will be described.

  The mechanical joint 26 is formed on the end face 16 </ b> A of the beam 16 by arranging the mechanical joint 26 in which the beam main reinforcing bars 24 are inserted in the precast embedded form 28 formed on the end face 20 </ b> A of the beam 20. The main beam 22 of the beam 16 is inserted into the mechanical joint 26 simply by moving in the horizontal direction or the horizontal direction (arrow D) toward the insertion hole 48, and the main beam 22 and the main beam 24 are easily connected. be able to. In addition, since the precast embedded mold 28 is open at the top, the mechanical joint 26 is easy to operate. Furthermore, since the projecting length of the beam main bar 24 protruding from the end face 20A of the beam 20 can be secured long, the flexibility of the beam main bar 24 is improved, and the mechanical joint 26 can be easily inserted into the insertion hole 48.

  In the present embodiment, since the beam main reinforcing bar 24 does not protrude from the front end portion 28A of the precast embedded form 28, the end surface 16A of the beam 16 and the front end portion 28A of the precast embedded form frame 28 are brought into contact with each other. There is no need to move 20 laterally or horizontally. For this reason, this embodiment is particularly effective when the lateral or horizontal movement range of the beam 20 is limited. For example, when precast beam members are installed in order along the outer periphery of a building, the beam members are already installed on both sides of the beam member to be installed last. Cannot move horizontally or horizontally. If it is this embodiment, the beam 20 can be arrange | positioned between beam members by dropping the beam 20 from upper direction.

  In the present embodiment, the precast embedded form 28 is formed only on the end face 20A of the beam 20, but the present invention is not limited to this. For example, instead of forming the precast embedded form 28 on the end face 20A, the precast embedded form 28 may be formed on the end face 16A of the beam 16 along the outer periphery of the end face 16A. Also in this case, the main beam 22 can be inserted into the mechanical joint 26 by moving the mechanical joint 26 in the lateral direction or the horizontal direction (arrow D), and the main beam 22 and the main beam 24 are connected. be able to. Moreover, you may form the precast embedding formwork 28 in both the end surface 16A and the end surface 20A similarly to 1st Embodiment.

  Next, a PCa beam joint structure according to a third embodiment of the present invention will be described. In addition, the thing of the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits suitably and demonstrates.

  As shown in FIG. 7, a precast embedded form 28 is formed on the end face 20 </ b> A of the beam 20 along the outer periphery of the end face 20 </ b> A, and a mechanical joint 26 is arranged in the precast embedded form 28. In the mechanical joint 26, a beam main bar 22 protruding from the end surface 16A of the beam 16 and a beam main bar 24 protruding from the end surface 20A of the beam 20 are inserted, and a grout (not shown) filled in the mechanical joint 26 is inserted. ), The beam main bar 22 and the beam main bar 24 are integrally connected. Further, in the precast embedded form 28, a shear reinforcement bar 38 surrounding the beam main bars 22, 24 or the mechanical joint 26 is disposed. Further, on the end face 16A of the beam 16 and the end face 20A of the beam 20, respectively. The cotters 30 and 32 are formed.

  FIG. 8 shows a modified example of the third embodiment in which the precast embedded form 56 is formed on the end surface 16A of the beam 16 in addition to the end surface 20A of the beam 20.

  Precast embedded molds 28 and 56 are formed on the end surface 20A of the beam 20 and the end surface 16A of the beam 16 along the outer periphery of the end surface 20A or the end surface 16A, respectively. 56A is abutted and the joint space 44 is formed. A mechanical joint 26 is disposed in the precast embedded molds 28 and 56, and the main beam 24 protruding from the end face 20 </ b> A of the beam 20 is inserted into one end of the mechanical joint 26, and the other The main beam 22 protruding from the end surface 16A of the beam 16 is inserted into the end, and the main beam 22 and the main beam 24 are integrally connected by a grout (not shown) filled in the mechanical joint 26. Has been. Further, in the precast embedded molds 28 and 56, shear reinforcement bars 38 surrounding the beam main bars 22 and 24 and the mechanical joint 26 are arranged. Further, the end face 16A of the beam 16 and the end face 20A of the beam 20 are arranged on the end face 20A. The cotters 30 and 32 are formed, respectively.

  As shown in FIG. 7 and FIG. 8, the precast embedded formwork may be formed only on the end face 16A of the beam 16 or the end face 20A of the beam 20 as required, or the end face 16A of the beam 16 and the end face of the beam 20 may be formed. You may form in both 20A. Further, the mechanical joint 26 is arranged across the precast embedded form 28 and the precast embedded form 56, but is not limited to this, and the precast embedded form 28 or the precast embedded form 56 as required. The beam main bars 22 and the beam main bars 24 may be connected so as to be within the inner space.

  Next, operations and effects of the PCa beam joint structure according to the third embodiment of the present invention will be described.

  As shown in FIG. 7, by forming the precast embedded formwork 28 on the end face 20A of the beam 20, no on-site formwork or the like is required, and workability is improved. In addition, since the mechanical joint 26 is exposed from the precast embedded formwork 28 by connecting the beam main reinforcement 22 and the beam main reinforcement 24 in the precast embedded formwork 28 having an upper opening, the beam main reinforcement is good. The connection work of 22 and the beam main reinforcement 24 becomes easy. Furthermore, it is not necessary to embed an injection hose or the like for injecting grout into the mechanical joint 26 in the beam 16, and the manufacturing cost of the beam 16 itself can be suppressed.

  Further, if the mechanical joint 26 is arranged close to the end surface 20A of the beam 20, the mechanical joint 26 is moved to the beam 16 after the end surface 16A of the beam 16 and the front end portion 28A of the precast embedded form 28 are brought into contact with each other. The main beam 22 of the beam can be inserted into the mechanical joint 26 simply by moving laterally or horizontally. Further, in the configuration shown in FIG. 8, by forming the precast embedded molds 28 and 56 on the end surfaces 16A and 20A of the beam 16 and the beam 20, respectively, the adhesion area of the cast-in-place concrete increases and the beams 16 and 20 are also formed. Since the cast-in-place concrete is cast across the joint, the joint strength between the beam 16 and the beam 20 is increased, and the stress transmission at the joint is improved.

  In addition, when the precast embedded formwork 28 is formed only on the end face 20A of the beam 20, rainwater or the like is transmitted along the boundary surface between the end face 16A of the beam 16 and the cast-in-place concrete placed on the precast embedded formwork 20A. Although there is a risk of entering the inside of the structure, by forming the precast embedded form 56 on the end face 16A of the beam 16, the entry path for rainwater and the like becomes longer, so that water leakage and the like are suppressed.

  In all the embodiments described above, the beam main bar 22 of the beam 16 and the beam main bar 24 of the beam 20 are connected by the mechanical joint 26, but the present invention is not limited to this. In particular, in the third embodiment, instead of the mechanical joint 26, the beam main bar 22 and the beam main bar 24 may be welded directly or via an attachment, or at least one of the beam main bar 22 and the beam main bar 24 may be welded. The protruding length may be lengthened and the beam main bars 22 and the beam main bars 24 may be arranged to overlap each other. Moreover, although the beam 14 and the beam 20 made of PCa have been described, it is also applicable to a joint structure in which at least one of the beam 14 and the beam 20 is a half PCa structure. Moreover, the cotters 30 and 32 should just be able to ensure the joint strength of the beam 16 and the beam 20, and are not restricted to the shape of a square frustum shown in FIGS.

  The first to third embodiments of the present invention have been described above, but the present invention is not limited to such embodiments, and the first to third embodiments may be used in combination. Of course, various embodiments can be implemented without departing from the scope of the invention.

It is explanatory drawing which shows the outline of the concrete beam junction structure which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the outline of the concrete beam junction structure which concerns on the 1st Embodiment of this invention. (A), (B) is a top view which shows the concrete beam junction structure which concerns on the 1st Embodiment of this invention. It is the front view and side view which show the junction part of the concrete junction structure which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the junction part of the concrete junction structure which concerns on the 1st Embodiment of this invention. (A), (B) It is a top view which shows the concrete junction structure which concerns on the 2nd Embodiment of this invention. It is a top view which shows the concrete junction structure which concerns on the 3rd Embodiment of this invention. It is a top view which shows the modification of the concrete junction structure which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows the conventional joining structure. It is explanatory drawing which shows the conventional junction structure. It is explanatory drawing which shows the conventional junction structure.

Explanation of symbols

16 beams ( second precast concrete beams)
16A end face (end face of second precast concrete beam)
20 beams ( first precast concrete beam)
20A end face (end face of the first precast concrete beam)
22 Beam reinforcement ( second beam reinforcement)
24 Beam reinforcement ( first beam reinforcement)
26 Mechanical joint 28 Precast embedded form 30 Cotter 32 Cotter 48 Insertion hole (insertion part)
56 Precast buried formwork

Claims (6)

A precast concrete beam joining structure for joining a first precast concrete beam and a second precast concrete beam,
Said face at least one end face of the first precast concrete beam and the second precast concrete beam, comprising a precast buried formwork Rutotomoni upward is formed along the outer periphery of the end face is open,
A first beam main bar projecting from the end face of the first precast concrete beam into the precast embedded formwork is passed through the precast embedded formwork to a mechanical joint embedded in the end face of the second precast concrete beam. insert and connected to the second beam main reinforcement of precast concrete beam of the second, and Da設concrete to the precast buried mold in said first precast concrete beam and the second precast concrete beam Precast concrete beam joint structure characterized by joining. A precast concrete beam joining structure for joining a first precast concrete beam and a second precast concrete beam,
Of the end faces facing each other of the first precast concrete beam and the second precast concrete beam, a precast embedded form formed at least along the outer periphery of the end face of the first precast concrete beam and opened upward. With
In the precast embedded formwork, shear reinforcement bars surrounding the upper and lower first beam main bars protruding from the end face of the first precast concrete beam are arranged,
The mechanical joint with the first beam main reinforcing bar inserted is moved toward the second beam main reinforcing bar of the second precast concrete beam, and the second beam main reinforcing bar is inserted into the mechanical joint to Connecting the first precast concrete beam and the second precast concrete beam by connecting the first beam main reinforcement and the second beam main reinforcement, and placing concrete in the precast embedded formwork. Characteristic precast concrete beam joint structure. The precast concrete beam connection structure according to claim 2, wherein the mechanical joint is disposed in the precast embedded formwork. The precast concrete beam joint structure according to claim 2 , wherein an insertion portion into which the mechanical joint is inserted is formed around the second beam main bar on the end face of the second precast concrete beam. . The precast concrete according to any one of claims 1 to 4, wherein a cotter is formed on at least one of the end face of the first precast concrete beam and the end face of the second precast concrete beam. Beam joint structure. 2. The precast concrete beam joint structure according to claim 1, wherein upper and lower first beam main bars protrude from the end face of the first precast concrete beam into the precast embedded formwork.

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