Column-beam joint structure for building

Abstract

To provide a column-beam joint structure that facilitates demolition and recycling of column members and beam members, and also reduces a risk caused by breakage of a tension material.SOLUTION: There is provided a column-beam joint structure, which has a beam member 16 made of precast concrete, a column member 13 to which a lengthwise end of the beam member should be connected and which is made of precast concrete, and a plurality of tension materials 21 for connecting the beam member to the column member. The beam member comprises a wider part 19, which is made larger in width than a lengthwise intermediate part, at its end, and the wider part has the plurality of first through holes 23 formed to insert a plurality of tension materials. A plurality of second through holes 25 are formed in part of the column member aligned with the plurality of first through holes. The respective tension materials are so arranged as to penetrate a tension material insertion hole 27 formed of one of the first through holes and one of the second through holes which are mutually successive, and some of a plurality of tension material insertion holes are filled with a filler 31.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a column-beam joint structure of a building.

Background Art

[0002] In a building with a ramen structure, precast concrete column members and beam members may be used for columns and beams of the building. After the building is demolished, the precast concrete members may be reused as a whole.

[0003] Patent Document 1 discloses a joint structure of precast concrete column-beam members. In this joint structure, a precast concrete beam is fixed to a precast concrete column, and widened portions with an increased beam depth compared to the normal cross-section are provided on the upper and lower surfaces of the beam within a predetermined range from the beam end of the precast concrete beam.

[0004] Patent Document 2 discloses a pressure-bonding joint structure of a column-beam joint made of precast concrete. In this pressure-bonding joint structure, the upper and lower precast concrete columns and the precast concrete beam are pressure-bonded by introducing prestress with unbonded PC steel materials.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a joint structure between a precast beam member having a widened portion and a precast column member as in Patent Document 1, for the purpose of facilitating the disassembly and reuse of the beam member and the column member, it is conceivable to use an unbonded tendon as in Patent Document 2. However, when applying the unbonded tendon of Patent Document 2 to the joint structure of Patent Document 1, when the tendon subjected to tensile force breaks, there is a risk that the beam member may fall or the tendon whose energy has been suddenly released due to the break may scatter around.

[0007] In view of the above background, an object of the present invention is to facilitate the disassembly and reuse of column and beam joint structures, and to reduce the risk when the tendon breaks.

Means for Solving the Problems

[0008] In order to solve the above problems, an aspect of the present invention is a column-beam joint structure, comprising: a beam member (16) made of precast concrete; a column member (13) made of precast concrete to which an end portion in the longitudinal direction of the beam member is to be joined; and a plurality of tendons (21) for joining the beam member to the column member. The beam member has a widened portion (19) widened compared to the intermediate portion in the longitudinal direction at the end portion, and a plurality of first through holes (23) for inserting the plurality of tendons are formed in the widened portion. A plurality of second through holes (25) for inserting the plurality of tendons are formed in a portion of the column member that aligns with the plurality of first through holes. Each of the tendons is arranged so as to penetrate a tendon insertion hole (27) formed by one of the first through holes that are continuous with each other and one of the second through holes. A filler (31) is filled in a part of the plurality of tendon insertion holes.

[0009] According to this aspect, since a part of the tendon insertion hole is filled with a filler, even if the tendon breaks, it is possible to prevent the beam member from falling and the fragments of the broken tendon from falling. Further, since the other part of the tendon insertion hole is not filled with a filler, it is easy to disassemble and reuse the beam member and the column member. Therefore, in the column-beam joint structure, it is possible to facilitate the disassembly and reuse of the members and reduce the risk when the tendon breaks.

[0010] In the above aspect, it is preferable that the filler is filled in the plurality of first through holes and not filled in the plurality of second through holes.

[0011] According to this aspect, in the column member, the tendon is an unbonded tendon, so it is easy to disassemble and reuse the column member. Further, in the widened portion of the beam member, the tendon is a bonded tendon, so even if the tendon breaks, it is possible to prevent the fragments of the broken tendon from falling.

[0012] In the above aspect, one end portion of each of the plurality of tendons is fixed by a fixing member (29) provided on the side end surface (20) of the widened portion, and it is preferable that the filler is filled only in the portion on the side of the side end surface in each of the plurality of first through holes.

[0013] According to this aspect, since the tendon is a bonded tendon in a part of the widened portion of the beam member, even if the tendon breaks, it is possible to prevent the fragments of the broken tendon from falling. Further, compared with the case where the filler fills the entire first through hole, it is easy to reuse the beam member.

[0014] In the above aspect, two of the beam members are provided via the column member, and the tension member insertion hole is formed by one of the first through holes of the beam members that are continuous with each other, one of the second through holes, and one of the first through holes of the other beam member. One end of each of the plurality of tension members is fixed by a fixing member provided on the side end surface of the widened portion of one of the beam members, and the other end of each of the plurality of tension members is fixed by a fixing member provided on the side end surface of the widened portion of the other beam member. The filling material may be filled only in the portion on the side end surface side of each of the plurality of first through holes provided in the widened portion of each beam member.

[0015] According to this aspect, two beam members are coupled to the column member, and the filling material is filled in each of the portions where both ends of the tension member are disposed in the first through holes of the two beam members. Therefore, when the tension member breaks, it is possible to surely prevent the fragments of the broken tension member from falling.

[0016] In the above aspect, it is preferable that the filling material is filled in the portion of the tension member insertion hole corresponding to the gap (33) formed between the column member and the beam member.

[0017] According to this aspect, the filling material can be used as a joint material provided between the column member and the beam member. Further, since the first through hole and the second through hole are not filled with the filling material, the beam member and the column member can be easily disassembled and reused.

[0018] In the above aspect, it is preferable that the filling material is filled in one of the plurality of tension member insertion holes and not filled in the other one of the plurality of tension member insertion holes.

[0019] According to this aspect, since one of the plurality of tension member insertion holes is filled with the filling material, it is possible to prevent the beam member from falling off even when the tension member breaks.

Advantages of the Invention

[0020] According to the above aspect, in the column-beam joint structure of a building, it is possible to facilitate the disassembly and reuse of column members and beam members, and reduce the risk when the tension member breaks.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0022] Hereinafter, with reference to the drawings, some embodiments of the present invention will be described in detail. The present invention is applied to a ramen structure building made of precast concrete composed of reinforced concrete or steel-reinforced concrete.

[0023] ≪First Embodiment≫ First, referring to FIGS. 1 to 3, a first embodiment of the present invention will be described. FIG. 1 is a perspective view showing a main part of a building 1 to which a column-beam joint structure according to the first embodiment is applied. FIG. 2 is a plan view of the column-beam joint structure indicated by the broken line portion of FIG. 1. FIG. 3 is a longitudinal sectional view taken along line III-III of FIG. 2. As shown in FIG. 1, the building 1 is provided with a pile foundation 2. The pile foundation 2 includes a plurality of piles 3 arranged in the X direction (bay direction) and the Y direction (direction between beams) that are orthogonal to each other on a horizontal plane. The building 1 also includes an upper structure 10 constructed on the pile foundation 2 and supported by the pile foundation 2. The upper structure 10 includes a plurality of columns 11 provided at positions corresponding to the piles 3, and a plurality of beams 12 that connect a pair of adjacent columns 11 in the X direction or the Y direction.

[0024] The column 11 is composed of a column member 13 made of precast concrete. In this embodiment, the column 11 of the first floor is formed by one column member 13. In other embodiments, the column main body portion and the joint may be formed by separate members, and the column 11 of the first floor may be formed by two or more precast concrete members.

[0025] Each beam 12 is composed of a beam member 16 made of precast concrete and extends in the X direction or the Y direction. The beam member 16 connects a pair of column members 13. The beam member 16 has a length slightly shorter than the distance between the pair of column members 13. The beam member 16 is disposed between the pair of column members 13. The beam member 16 has a beam body 18 that joins both ends thereof to the pair of column members 13 and spans the pair of column members 13, and a pair of widened portions 19 provided at each of both ends of the beam body 18.

[0026] As shown in FIG. 2, the pair of widened portions 19 project from both sides in the beam width direction from the beam body 18 of the beam member 16 to widen the width of the beam member 16. By providing the widened portions 19 at both ends of the beam body 18, the beam member 16 is widened in the width direction at both ends in the longitudinal direction as compared with the intermediate portion in the longitudinal direction. In other embodiments, the pair of widened portions 19 may project from both sides in the vertical direction from the beam body 18 to expand the beam formation of the beam member 16.

[0027] As described above, the column-beam joint structure of Building 1 is a joint structure between column member 13 and beam member 16. In this embodiment, the column-beam joint structure includes one column member 13 and two beam members 16 provided on both sides of the column member 13. The two beam members 16 are pressure-bonded to the corresponding column member 13 by a tension member 21 arranged so as to extend from the surface (hereinafter referred to as the side end surface 20) opposite to the end surface joined to the column member 13 in the widened portion 19 of one beam member 16 to the side end surface 20 of the widened portion 19 of the other beam member 16. Thereby, the column-beam joint structure of Building 1 becomes a prestressed concrete structure.

[0028] As shown in FIG. 3, a plurality of first through holes 23 for inserting a plurality of tension members 21 are formed in each of the widened portions 19. Each first through hole 23 extends parallel to each other along the beam extending direction of the beam member 16.

[0029] In the column member 13, a second through hole 25 for inserting the tension member 21 is formed at a position aligned with the first through hole 23 formed in the corresponding beam member 16. Each second through hole 25 extends parallel to each other along the width direction of the column member 13. By each second through hole 25 being continuous with each of the corresponding first through holes 23, a plurality of parallel tension member insertion holes 27 penetrating the column-beam joint structure in the width direction are formed so as to be continuous with the column member 13 and the beam member 16. The first through hole 23 and the second through hole 25 may each be defined by a sheath pipe embedded in the beam member 16 and the column member 13.

[0030] The tension member 21 is preferably made of a PC steel bar, a PC steel wire, a PC steel wire rope, a high-strength reinforcing bar, or a rod or cable made of a fiber-reinforced plastic such as an aramid fiber, a carbon fiber, or a glass fiber.

[0031] Each tension member 21 is inserted into each tension member insertion hole 27 and is in a state of being applied with a tensile force. One end portion thereof is fixed to the side end face 20 of the widened portion 19 of one beam member 16 by a fixing member 29, and the other end portion is fixed to the side end face 20 of the widened portion 19 of the other beam member 16. Thereby, prestress is introduced into the column member 13 and the beam member 16, and the widened portions 19 of the respective beam members 16 are respectively compression-bonded to the corresponding column members 13. The fixing member 29 preferably includes a pressure plate (anchor plate), an anchor head supported by the pressure plate, and a wedge for fixing the tension member 21 to the anchor head. Alternatively, the fixing member 29 may be constituted by a pressure plate and a nut supported by the pressure plate and having a female screw that screws into a male screw formed on the tension member 21.

[0032] In the present embodiment, each portion on the side of the side end face 20 of the widened portion 19 in the first through hole 23 formed in each beam member 16, that is, each portion in the vicinity of the fixing member 29, is filled with a filler 31.

[0033] The filler 31 is a fluid material that hardens over time, and may be, for example, non-shrinking mortar or cement milk. It is preferable to employ fiber-reinforced mortar or low-elasticity high-viscosity mortar as the filler 31 so that the filler 31 is difficult to break after hardening.

[0034] For the filler 31, a formwork or a sealing member for regulating the inflow of the filler 31 is disposed at a predetermined position in the first through hole 23, and after the tension member 21 is tensioned and fixed, the first through hole 23 is filled with the filler 31. The sealing member is formed with a through hole having a size that allows only one tension member 21 to be inserted therethrough. The sealing member is preferably constituted by an elastically deformable material such as a non-woven fabric, a sponge, a rubber ring, or a pipe member made of polyvinyl chloride. Thereby, the filler 31 can be provided in the portion on the side of the side end face 20 of the widened portion 19 in the first through hole 23.

[0035] The column-beam joint structure of Building 1 is configured as described above. In this embodiment, the filler 31 is filled in the portion on the side of the side end face 20 of the widened portion 19 in the first through hole 23 formed in the beam member 16, and is not filled in the other portions of the tendon insertion hole 27. Therefore, compared with the case where the filler 31 is filled over the entire tendon insertion hole 27 and the tendon 21 is used as a bonded tendon, the disassembly and reuse of the column member 13 and the beam member 16 are facilitated. Further, even when the tendon 21 breaks within the tendon insertion hole 27, the filler 31 can prevent the fragments of the broken tendon 21 from scattering from the opening of the side end face 20 of the widened portion 19 of each beam member 16. Therefore, the possibility of scattering of the broken tendon 21 when the tendon 21 breaks can be reduced.

[0036] <<Second Embodiment>> Next, a second embodiment of the present invention will be described with reference to FIG. 4. In addition, the same reference numerals are given to the same or similar configurations as those in the first embodiment, and redundant descriptions are omitted. This embodiment is different from the first embodiment in that the column-beam joint structure includes one column member 13 and one beam member 16.

[0037] FIG. 4 is a longitudinal sectional view of a column-beam joint structure according to the second embodiment. In this embodiment, the column-beam joint structure has a column member 13 provided along the outer periphery of the building 1 and a beam member 16 whose longitudinal end face is to be joined to the column member 13. The beam member 16 is pressure-bonded to the corresponding column member 13 by a tendon 21 arranged so as to extend from the side end face 20 of the widened portion 19 of the beam member 16 to the side face 32 of the column member 13 on the side opposite to the beam member 16.

[0038] In this embodiment, the filler 31 is filled in the portion on the side of the side end face 20 of the widened portion 19 in the first through hole 23 formed in the beam member 16, and is not filled in the other portions of the tendon insertion hole 27. Therefore, compared with the case where the filler 31 is filled over the entire tendon insertion hole 27, the disassembly and reuse of the column member 13 are facilitated. Further, when the tendon 21 breaks within the tendon insertion hole 27, the filler 31 can prevent the fragments of the broken tendon 21 from scattering from the opening of the side end face 20 of the widened portion 19 of the beam member 16. In this embodiment, since the column member 13 is provided along the outer periphery of the building 1, it is possible to particularly prevent the fragments of the broken tendon 21 from scattering inside the building 1 with respect to the column member 13.

[0039] Note that, in another embodiment, the filler 31 may be filled in the portion on the side opposite to the beam member 16 in the second through hole 25 formed in the column member 13, and may not be filled in the other portions of the tendon insertion hole 27. According to this configuration, when the tendon 21 breaks within the tendon insertion hole 27, it is possible to prevent the fragments of the broken tendon 21 from scattering from the opening of the side face 32 of the column member 13.

[0040] Further, the filler 31 may be filled in both the portion on the side of the side end face 20 of the widened portion 19 in the first through hole 23 formed in the beam member 16 and the portion on the side opposite to the beam member 16 in the second through hole 25 formed in the column member 13, and may not be filled in the other portions of the tendon insertion hole 27. According to this configuration, when the tendon 21 breaks within the tendon insertion hole 27, it is possible to prevent the fragments of the broken tendon 21 from scattering from the opening of the side end face 20 of the widened portion 19 of the beam member 16 and the opening of the side face 32 of the column member 13.

[0041] <<Third Embodiment>> Next, a third embodiment of the present invention will be described with reference to FIG. 5. Note that the same or similar configurations as those in the second embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. This embodiment is different from the second embodiment in that the filler 31 is filled in the entire first through hole 23.

[0042] FIG. 5 is a longitudinal sectional view of the column-beam joint structure according to the third embodiment. As shown in FIG. 5, the filler 31 is filled in the first through-hole 23, but not in the second through-hole 25.

[0043] In this embodiment, when the filler 31 is filled over the entire length of the tendon insertion hole 27 and the tendon 21 is used as a bonded tendon, the disassembly and reuse of the column member 13 are facilitated. Further, when the tendon 21 breaks within the tendon insertion hole 27, the filler 31 can prevent the fragments of the broken tendon 21 from scattering from the opening of the side end face 20 of the widened portion 19 of the beam member 16.

[0044] In another embodiment, a plate-like member may be provided between the column member 13 and the beam member 16. The plate-like member is preferably formed of, for example, a thermoplastic or thermosetting resin. According to this configuration, the adhesion between the column member 13 and the beam member 16 can be improved. Further, it is possible to prevent the filler 31 filled in the first through-hole 23 from leaking between the column member 13 and the beam member 16.

[0045] <<Fourth Embodiment>> Next, a fourth embodiment of the present invention will be described with reference to FIG. 6. The same or similar components as those in the second embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. This embodiment is different from the second embodiment in that the filler 31 is filled between the beam member 16 and the column member 13.

[0046] FIG. 6 is a longitudinal sectional view of the column-beam joint structure according to the fourth embodiment. As shown in FIG. 6, a gap 33 (that is, a joint) is provided between the longitudinal end face of the beam member 16 and the side face of the column member 13 facing the end face. The filler 31 is filled in this gap 33. As a result, the filler 31 is filled in the portion of the tendon insertion hole 27 corresponding to the gap 33. Further, the filler 31 also functions as a joint material provided between the column member 13 and the beam member 16.

[0047] Next, a method for assembling the column-beam joint structure according to the present embodiment will be described. First, an operator disposes the beam member 16 at a predetermined interval (i.e., the gap 33) with respect to the column member 13. Next, a seal member (not shown) is disposed in the first through hole 23 of the beam member 16 and in the second through hole 25 of the column member 13, respectively. Next, the tension member 21 is disposed in the tension member insertion hole 27. At this time, the tension member 21 is inserted through the through holes formed in the seal members in the first through hole 23 and the second through hole 25. Finally, a formwork (not shown) is disposed along the side surfaces of the column member 13 and the beam member 16, and the filler 31 is filled in the gap 33 formed between the side surface of the column member 13 and the end surface of the beam member 16. In this way, since the seal member prevents the filler 31 from flowing into the first through hole 23 and the second through hole 25, the filler 31 can be filled only in the gap 33. It is preferable that a pipe or the like for venting air from the filled filler 31 extends upward in the gap 33.

[0048] In the present embodiment, since the filler 31 is not filled in the first through hole 23 and the second through hole 25, the column member 13 and the beam member 16 are easier to disassemble and reuse as compared with the case where the filler 31 fills the entire tension member insertion hole 27. Further, when the tension member 21 breaks in the first through hole 23, the filler 31 can prevent the fragments of the broken tension member 21 from falling from the opening of the end surface of the column member 13. Similarly, when the tension member 21 breaks in the second through hole 25, the filler 31 can prevent the fragments of the broken tension member 21 from scattering from the opening of the side end surface 20 of the widened portion 19 of the beam member 16.

[0049] Further, since the filler 31 functions as a joint material, it is possible to simultaneously prevent the tension member 21 from falling and adjust the construction error by the joint material, and the construction is easy.

[0050] ≪Fifth Embodiment≫ Next, a fifth embodiment of the present invention will be described with reference to FIG. 7. The same or similar components as those in the second embodiment are denoted by the same reference numerals, and redundant descriptions are omitted. In the present embodiment, the tension member insertion hole 27 is different from the second embodiment in that it includes both an upper tension member insertion hole 27A filled with the filler 31 and a lower tension member insertion hole 27B not filled with the filler 31.

[0051] In the present embodiment, the tension member insertion hole 27 includes an upper tension member insertion hole 27A and a lower tension member insertion hole 27B. The upper tension member insertion hole 27A is formed in the upper portion of the widened portion 19 of the beam member 16, and the lower tension member insertion hole 27B is formed in the lower portion of the widened portion 19 of the beam member 16.

[0052] The upper tension member insertion hole 27A is filled with the filler 31. Thereby, the tension member 21 inserted through the upper tension member insertion hole 27A is used as a bonded tension member adhered to the column member 13 and the beam member 16.

[0053] A ring-shaped sponge member may be provided in a portion around the upper tension member insertion hole 27A on the connection surface of the column member 13 and the beam member 16. Thereby, it is possible to prevent the filler 31 filled in the upper tension member insertion hole 27A from adhering to the connection surface of the column member 13 and the beam member 16. Therefore, the disassembly of the column member 13 and the beam member 16 becomes easy.

[0054] Further, the lower tension member insertion hole 27B is not filled with the filler 31. Thereby, the tension member 21 inserted through the lower tension member insertion hole 27B is used as an unbonded tension member not adhered to the column member 13 and the beam member 16.

[0055] In another embodiment, the lower tension member insertion hole 27B may be filled with the filler 31 and the upper tension member insertion hole 27A may not be filled with the filler 31.

[0056] In this embodiment, since the filler 31 is not filled in the lower tension member insertion hole 27B, it is easier to disassemble the column member 13 and the beam member 16 as compared with the case where the filler 31 is filled in all the tension member insertion holes 27. Further, even when the tension member 21 breaks within the lower tension member insertion hole 27B, since the tension member 21 inserted through the upper tension member insertion hole 27A serves as a bonded tension member, it is possible to prevent the beam member 16 from falling off.

[0057] With the above, the description of the specific embodiment is completed. However, the present invention is not limited to the above embodiment and can be widely modified and implemented. For example, the column beam joint structure may be lightened by making the column member 13 and the beam member 16 of lightweight concrete. Further, the specific configuration, arrangement, quantity, material, procedure, etc. of each member and part can be appropriately changed without departing from the gist of the present invention. On the other hand, not all of the constituent elements shown in the above embodiment are necessarily essential and can be appropriately selected.

Explanation of Reference Numerals

[0058] 13: Column member 16: Beam member 19: Widening portion 20: Side end face 21: Tension member 23: First through hole 25: Second through hole 27: Tension member through hole 29: Fixing member 31: Filler 33: Gap

Claims

1. A column-beam joint structure comprising: a beam member made of precast concrete; a column member made of precast concrete to which an end portion in the longitudinal direction of the beam member is to be joined; a plurality of tension members for joining the beam member to the column member, wherein the beam member has a widened portion at the end portion that is wider than an intermediate portion in the longitudinal direction; a plurality of first through holes for inserting the tension members are formed in the widened portion; a plurality of second through holes for inserting the tension members are formed in a portion of the column member that aligns with the first through holes; each of the tension members is arranged to pass through a tension member insertion hole formed by one of the first through holes that are continuous with each other and one of the second through holes; a column-beam joint structure in which a filling material is filled in a part of the plurality of tension member insertion holes.

2. The column-beam joint structure according to claim 1, wherein the filling material is filled in the plurality of first through holes and is not filled in the plurality of second through holes.

3. One end portion of each of the plurality of tension members is fixed by a fixing member provided on a side end surface of the widened portion; The column-beam joint structure according to claim 2, wherein the filling material is filled only in a portion on the side of the side end surface in each of the plurality of first through holes.

4. Two of the beam members are provided via the column member; The tension member insertion hole is formed by one of the first through holes of one of the beam members that are continuous with each other, one of the second through holes, and one of the first through holes of the other beam member; One end portion of each of the plurality of tension members is fixed by a fixing member provided on a side end surface of the widened portion of one of the beam members, and the other end portion of each of the plurality of tension members is fixed by a fixing member provided on a side end surface of the widened portion of the other beam member; The column-beam joint structure according to claim 3, wherein the filling material is filled only in a portion on the side of the side end surface in each of the plurality of first through holes provided in the widened portion of each of the beam members.

5. The column-beam joint structure according to claim 1, wherein the filling material is filled in a portion of the tension member insertion hole corresponding to a gap formed between the column member and the beam member.

6. The column-beam joint structure according to claim 1, wherein the filling material is filled in one of the plurality of tension member insertion holes and is not filled in another one of the plurality of tension member insertion holes.

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