JP2019082005A - Beam-to-column connection structure and construction method thereof - Google Patents

Abstract

To provide a beam-to-column connection structure of a precast concrete column member and a beam member capable of preventing damages on junctions, which requires no sheath with few restrictions on assembly order, and a construction method thereof.SOLUTION: A column member (11) includes: a concrete projection (14) protruding laterally from a column member body (13); a single row reinforcement (15) protruding from the column member body along an upper face and a lower face of the projection; and double row reinforcements (16) extending parallel to the single row reinforcement within the column member body and the projection. A beam member (12) has a beam member main reinforcement (20) which is connected to the single row reinforcement. The beam-to-column connection structure is configured so that the beam member can be inserted laterally between the two column members with the projection passing through between the upper and lower beam member main reinforcement.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a beam-to-column joint structure in which a column and a precast concrete beam member are joined, and a method of constructing the same.

  As a beam-column joint structure in which a precast concrete beam member and a precast concrete beam member are joined, as shown in FIG. 17, the sheath 2 provided on the beam member 1 protrudes from the end face of the beam member 3 A structure is known in which a girder is inserted through the main beam bars 4 provided so as to fill the gaps between the main beam bars 4 and the sheath 2 with grout.

  Further, according to Patent Document 1, the through hole (sheath) provided in the pillar member and the through hole (sheath) provided in the bulging portion of the beam member are mutually aligned, and separate members from both members are used. The structure which inserted the penetration rebar into both through holes and filled the grout in the crevice is indicated. Reinforcing bars that extend into the beam members and do not enter the column members are arranged to be so-called open lap joints with respect to the inserted rebars, both of which become the main bars of the beam.

JP 2012-46960 A

  At the beam-to-column connection, many reinforcing bars such as a column main bar, a beam main bar and a shear reinforcement bar are arranged. Therefore, as shown in FIG. 17, when the sheath 2 whose inner diameter is larger than the outer diameter of the main beam bar 4 is disposed at the beam-to-column joint, the installation space of the reinforcing bar is reduced. In addition, it takes time and effort to fill the grout in the sheath 2, and it is difficult to determine and confirm whether the grout has been filled properly. In particular, when the sheath 2 is horizontal, air is likely to be accumulated in the upper part of the sheath 2 and it is difficult to obtain the adhesion performance between the sheath 2 and the main beam 4. Further, in order to insert the main beam bars 4 into the sheath 2, it is necessary to move the beam member 3 horizontally toward the column member 1, and in order to join the plurality of beam members 3 to the plurality of column members 1, It is necessary to assemble in the order of Therefore, if the order of assembly is incorrect, it will be necessary to rework construction, and if there is a defect (presence of air bubbles, etc.) in some precast concrete members, it will be later than that until replacement or repair of the members is completed. I can not build things that should be assembled. In addition, when an earthquake occurs, breakage is likely to occur in the joint, requiring extensive repair.

  In the beam-to-column joint structure described in Patent Document 1, since the insertion rebar is configured separately from the beam member and the column member, there are few restrictions on the assembly order. However, in other points, the same problem as the beam-to-column connection structure shown in FIG. 17 occurs.

  In view of such problems, in the beam-to-column joint structure in which the column member and the precast concrete beam member are joined to each other, the sheath is unnecessary, the restriction on the assembly order is small, and the joint is damaged. An object of the present invention is to provide a structure that can be suppressed and a method of constructing the same.

  At least some embodiments of the present invention is a beam-column joint structure (10) in which a column member (11) and a precast concrete beam member (12) are joined together, the column member being a column The concrete projecting portion (14) which protrudes laterally from the member main body (13) and has smaller vertical dimensions than the beam, and the upper surface and the lower surface of the projecting portion are arranged along predetermined intervals, respectively. The beam having a single-step barb (15) protruding directly or indirectly from the pillar member body, and a double-step bar (16) extending parallel to the one-step bar at least in the pillar member body and the protrusion The member has a beam member main bar (20) joined to the one-step bar, and the projection, a portion of the one-step bar that protrudes from the column member body, and a portion that protrudes from the beam member body of the beam member main bar A field hit conc Characterized in that it is embedded in the beam end surface portion composed of over preparative (22). Here, that the “one-step muscle“ projects directly or indirectly from the column member body ”” means that the one-step muscle itself protrudes from the column member body or can be attached to the one-step muscle so that it can be connected to the beam member main bar. It means that the mechanical joint protrudes from the column member body.

  This configuration eliminates the need for a sheath for passing the main bars of the beam to the beam-to-column joint, reduces the installation space of the rebar in the beam-to-column joint caused by using the sheath, and fills the grout in the sheath There is no problem such as the occurrence of trouble and the trouble of confirmation thereof and the deterioration of the adhesion performance between the sheath and the main bar of the beam due to the filling failure of the grout. In addition, since the beam members can be inserted in the lateral direction with respect to the column members, restrictions on the assembly order of the column members and the beam members can be reduced. In addition, the part that functions as the main reinforcement of the beam is divided into a single-step or a part in which the main reinforcement of the beam member and the double reinforcement are doubled, and a part in which the main reinforcement of the beam member is single. Since the bending yield position is at the boundary position, failure occurs in the beam instead of the beam-to-column connection, and repair after failure is relatively easy.

  At least some embodiments of the present invention are characterized in that, in the above-mentioned configuration, a fixing portion (17) is provided at the tip of the two-step muscle.

  According to this configuration, it is possible to prevent the double bar from being pulled out of the concrete portion.

  At least some embodiments of the present invention is characterized in that a cotter (31) is formed on the contact surface of the beam member main body and the beam end surface portion with each other in any of the above configurations. Do.

  According to this configuration, adhesion between the beam member main body and the beam end surface portion becomes more reliable.

  In at least some embodiments of the present invention, in any of the above-described configurations, an end rib (21a) embedded in the surface portion of the beam end is provided to surround the main bar and the first step of the beam member connected to each other. Furthermore, it is characterized by having.

  According to this configuration, it is possible to improve the shear resistance of the beam end (the surface portion of the beam end and the protrusion).

  At least some embodiments of the present invention are a method of constructing a beam-to-column joint structure (10) in which a precast concrete column member (11) and a precast concrete beam member (12) are joined to each other. And a concrete protruding portion (14) which protrudes laterally from the pillar member main body (13) and which has smaller vertical dimensions than the beam and a predetermined distance between each of the upper surface and the lower surface of the protruding portion. The first member (15) directly or indirectly protruding from the pillar member body, and the second member (16) extending parallel to the first step muscle at least in the pillar member body and the projection; Disposing the beam member at a predetermined position, the step of disposing the pillar member at a predetermined position, and the beam member main rebar (20) projecting from the beam member main body (18) so as to be aligned with the first row. The cast-in-place concrete is embedded so as to embed the step, the projecting portion, the portion of the one-step bar that protrudes from the column member body, and the portion of the beam member main bar that protrudes from the beam member body. And (b) constructing the section (22), the beam member main bar is composed of an upper end side beam member main bar (20a) and a lower side beam member main bar (20b), the upper beam member main bar and the lower side beam The member main bars are separated from each other more than the upper and lower dimensions of the protrusion, and the step of arranging the beam members is performed such that the protrusions are inserted between the upper beam member main bars and the lower beam member main bars. And moving the beam member in a direction perpendicular to the extending direction of the column member and the extending direction of the beam member.

  According to this configuration, since the beam members can be inserted into the column members in the lateral direction, the restriction on the assembly order of the column members and the beam members is reduced. Also, since the sheath is not required at the joint, there is no problem with the use of the sheath. In addition, since the bending yield position at the time of the earthquake is not at the end of the beam but at the middle of the beam, repair after breakage is relatively easy.

  In at least some embodiments of the present invention, in the above configuration, the step may be performed after the step of placing the beam member in a predetermined position and before the step of constructing the beam end surface portion (22). The method further comprises the step of joining the bar and the beam bar main bar together by means of a mechanical joint (19), wherein the mechanical joint is arranged prior to the step of arranging the beam bar in a predetermined position. Alternatively, it is temporarily installed so that the one-step muscle is inserted.

  According to this configuration, the mechanical joint can be easily attached.

  In at least some embodiments of the present invention, in any of the above-described method configurations, an end portion surrounding a portion of the main beam member projecting from the beam member main body or a portion of the one-step muscle projecting from the column member main body The rib (21a) is a portion of the portion of the main portion of the beam member projecting from the beam member main body from the beam member main body, or the column member of the portion of the one-step muscle projecting from the column member main body It is temporarily installed in a part from the main body, and is slid to be disposed at a predetermined position after the step of arranging the beam member at a predetermined position and before the step of constructing the surface portion of the beam end. It is characterized by

  According to this configuration, since the end rib can be temporarily installed not at the installation position of the beam but at a precast concrete plant or a work yard of a construction site, the work at the beam installation position can be reduced.

  In at least some embodiments of the present invention, in any of the above method configurations, casting of the cast-in-place concrete of the surface portion of the beam end is integrally performed with casting of cast-in-place concrete of the floor slab (34). The concrete strength of the projection is higher than the concrete strength of the beam member, and the concrete strength of the beam end surface portion and the floor slab is lower than the concrete strength of the beam member.

  According to this configuration, labor can be saved by simultaneously placing the floor slab and the concrete of the surface portion of the beam end. In general, floor slabs can use concrete with lower strength than beams, but according to the method of this configuration, even if such low-strength concrete is used in the surface portion of the beam end, Since the concrete strength of the projection is higher than the concrete strength of the beam member, it is possible to obtain the concrete strength required for the beam as the entire beam end.

  According to the present invention, it is possible to provide a beam-to-column joint structure and its construction method which do not require a sheath, have few restrictions on the assembly order and can suppress damage to the joint.

Explanatory drawing of beam-to-column joint structure according to an embodiment (A: A-A cross section of B figure, B: concrete part shows the cross section along the extension direction of the beam and the column passing through the center of the column Hardware is shown as seen through the concrete from the front.) Explanatory drawing which shows the assembly order of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the assembly order of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the assembly order of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the assembly order of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the assembly order of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the fracture state of the beam-to-column joint structure which concerns on embodiment. Explanatory drawing of the structure of destruction with the beam-column joint structure which concerns on a prior art and embodiment. Explanatory drawing which shows the 1st modification of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the 2nd modification of the beam-to-column joint structure which concerns on embodiment. Explanatory drawing which shows the 3rd modification of the beam-to-column joint structure which concerns on embodiment. Explanatory drawing which shows the 4th modification of the beam-to-column joint structure which concerns on embodiment. Explanatory drawing which shows the 5th modification of the beam-to-column joint structure which concerns on embodiment Explanatory drawing which shows the 6th modification of the beam-to-column joint structure which concerns on embodiment Explanatory drawing showing the 7th modification of the beam-to-column joint structure according to the embodiment (A: A-A cross section of B figure, B: concrete part is a cross section along the extending direction of the beam and the column passing through the center of the column And hardware such as rebar is shown as seen through the concrete part from the front.) Explanatory drawing which shows the 8th modification of the beam-to-column joint structure which concerns on embodiment Explanatory drawing (plan view) which shows the beam-column connection structure which concerns on a prior art

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, hatching showing illustration and a cross section of a column main bar and bars is omitted.

  FIG. 1 shows a beam-column joint structure 10 according to an embodiment. The beam-to-column joint structure 10 has a column member 11 made of precast concrete and a beam member 12 made of precast concrete joined to the column member 11.

  The pillar member 11 constitutes a pillar of a building, and is made of a pillar member main body 13 including a pillar main bar and a rebar not shown in the inside and concrete made to project laterally from the pillar member main body 13 to which the beam member 12 is to be joined. It has a protrusion 14. The concrete of the pillar member body 13 and the concrete of the protrusion 14 may be those having the same strength at the same time or those having the same or different strengths. In the present embodiment, the beam members 12 are joined in the left and right two directions of the column member 11, respectively, but in one direction, in two directions perpendicular to each other, in three directions of T-shape or in four directions of cross shape The members 12 may be joined, and a projection 14 is provided in each of the directions to be joined. The upper and lower dimensions and the width of the protrusion 14 are smaller than the upper and lower dimensions (the beam) and the width of the completed beam.

  The column members 11 each have a single-step muscle 15 and a double-step muscle 16 that constitute a part of the main bar of the beam. The first row reinforcement 15 extends along the upper surface of the protrusion 14 at a predetermined distance, and extends along the lower surface of the protrusion 13 at a predetermined distance, and extends along the lower surface of the protrusion 14 at a predetermined distance. It consists of a lower one-step muscle 15 b protruding from the main body 13. The double bar 16 is composed of an upper upper double bar 16a and a lower double bar 16b extending parallel to the first bar 15 in the column member body 13 and the projection 14. As shown in FIG. 1, when the beam members 12 are joined to the left and right sides of the column member 11, the middle portions of the first row reinforcement 15 and the second row reinforcement 16 are embedded in the column member main body 13, and both ends of the first row reinforcement 15 are It projects from the column member main body 13 and both ends of the double-step bars are embedded in the projecting portion 14. When the beam member 12 is joined to only one side of the column member 11 in the left-right direction, the end portions of the first row reinforcement 15 and the second row string 16 to which the beam member 12 is not joined are fixed to the column member main body 13. Moreover, the fixing | fixed part 17 is provided in the front-end | tip of the two-step reinforcement 16 so that it may not pull out from a concrete part. The fixing unit 17 is formed by fixing the two-step reinforcement 16 to a concrete portion by, for example, hooking the end of the two-step reinforcement 16. The fixing unit 17 may be a fixing metal attached to the tip of the double-step muscle 16.

  Beam member 12 includes a beam member main body 18 including a concrete portion formed of precast concrete, and an end portion projecting from beam member main body 18 so as to be aligned with first step reed 15, and joined to first step reed 15 by mechanical joint 19. And a beam member main bar 20. In the beam member main body 18 in the present embodiment, the dimension of the beam of the building matches the upper dimension and the lower dimension, and the length in the longitudinal direction is shorter than the distance between the two columns. In the beam member main body 18, the middle portion of the beam member main bars 20 and the ribs 21 are embedded. The beam member main reinforcement 20 comprises an upper beam member main reinforcement 20a disposed on the upper side and a lower beam member main reinforcement 20b disposed on the lower side. The first reinforcement 15, the second reinforcement 16 and the beam main reinforcement 20 become the main reinforcement of the beam. Since the end of the double bar 16 where the amount of the main reinforcement of the beam decreases is the bending yield position, the position of the mechanical joint 19 is preferably separated from it and closer to the column member body 13.

  An end extending in a direction orthogonal to the extending direction of the beam member 12 so as to surround the beam member main bars 20 and the single-step beam 15 connected to each other by the mechanical joint 19 between the column member body 13 and the beam member body 18 A partial rib 21a is provided. Further, between the column member main body 13 and the beam member main body 18, the projection 14, the portion of the one-step muscle 15 protruding from the column member main body 13, the portion of the beam member main bar 20 protruding from the beam member main body 18 The beam end surface portion 22 is cast by cast-in-place concrete so as to embed the joint 19. The upper surface, the lower surface, and the pair of side surfaces of the beam end surface portion 22 are flush with the upper surface, the lower surface, and the pair of side surfaces of the beam member main body 18.

Although all of the concrete strengths of the projecting portion 14, the beam member main body 18 and the beam end surface portion 22 may be used as the concrete strength required for the beam, the concrete strength required for the beam for the concrete of the beam member main body 18 (for example, 48 N / mm ² ), and the concrete strength of the projection 14 is higher than the concrete strength required for the beam, for example, the concrete strength required for the column (eg 60 N / mm ² ) The strength may be lower than the strength required for the beam, for example, the strength required for the floor slab (for example, 30 N / mm ² ). In this case, since the concrete of the high strength protrusion 14 is present in the concrete of the low strength beam end surface portion 22, the strength required for the beam as a whole is satisfied.

  Next, with reference to FIGS. 2-6, the construction method of the beam-to-column joint structure 10 which concerns on embodiment is demonstrated. 2 to 6, the ribs 21 other than the end rib 21a are not shown.

  First, as shown in FIG. 2, the pillar member 11 which is a precast concrete member in which the concrete of the pillar member main body 13 and the projecting portion 14 is casted in a factory is used to construct a pillar of a building by a crane (not shown) or the like. Place it at the right position.

  Next, as shown in FIG. 3, after temporarily installing the mechanical joint 19 and the end rib 21 a at a portion of the main beam member 20 that protrudes from the beam member main body 18, the beam member 12 is built by a crane or the like. Place the beam at the position where it should be built. Here, the temporary installation of the mechanical joint 19 and the end rib 21a refers to a state in which the beam can be slidably moved with respect to the main beam 20 and the single-step muscle 15. At this time, the beam member 12 is inserted into the column member 11 from the side. That is, the beam member 12 is disposed at a predetermined position by moving in the direction perpendicular to the extending direction of the column member 11 and the extending direction of the beam member 12. Thus, the beam member 12 can be inserted from the side because the distance between the mechanical joint 19 temporarily installed in the upper beam main bar 20a and the mechanical joint 19 temporarily installed in the lower beam main bar 20b. Is larger than the vertical dimension of the protrusion 14 and the column side surface of the beam member main body 18 is from the tip of the protrusion 14 so that the end rib 21a temporarily installed near the beam member main body 18 can pass. This is because they are separated. Thereafter, as shown in FIG. 4, the mechanical joint 19 is slidingly moved to join the one-step bars 15 and the beam member main bars 20 to one another, and the end ribs 21a are slid to a predetermined position to be one-step bars 15 Alternatively, it is bound to the beam member main reinforcement 20.

  Alternatively, the mechanical joint 19 may be temporarily installed on the one-step muscle 15. Alternatively, the end ribs 21a may be temporarily installed in the one-step muscle 15, or the one end muscle 15 and the main beam member 20 may be joined to each other by the mechanical joint 19 without temporarily installing the end ribs 21a. After that, the end ribs 21a may be attached to the single-step bars 15 or the beam main bars 20. In these cases, the beam member 12 may be disposed such that the surface of the beam member main body 18 on the side of the column member 11 abuts on the tip end surface of the protrusion 14.

  Next, as shown in FIG. 5, a mold 23 for placing the beam end surface portion 22 is installed. Although only the form frame 23 is shown installed on the bottom side of the beam end surface layer portion 22, it is also installed on both side surfaces in the width direction of the beam end surface layer portion 22 (the front side and the back side of the sheet). Ru. As shown in FIG. 6, by pouring cast-in-place concrete in the mold 23, the beam end surface portion 22 is formed. When the form 23 is removed, the beam-to-column joint structure 10 is completed as shown in FIG.

  The operation and effect of the beam-column joint structure 10 according to the embodiment will be described.

  Since the sheath 2 as shown in FIG. 17 is not used in the beam-column joint structure 10, the problem caused by using the sheath 2 does not occur. That is, the sheath 2 can prevent the installation space of the reinforcing bar from becoming small and the trouble of filling grout in the sheath 2 and the confirmation thereof become unnecessary, and the adhesion performance between the sheath 2 and the beam main rebar 4 due to filling failure of the grout Does not occur. It also makes it possible to increase the amount of rebar in the joint. Moreover, when the sheath 2 is present, a hose for filling the sheath 2 with grout is necessary, and the hose remains in the structure, but in the beam-column joint structure 10 according to the present embodiment, The structure is more rigid since no hose is required.

  Further, since the beam member 12 can be inserted between the two column members 11 in the lateral direction, the restriction on the assembly order of the column member 11 and the beam member 12 is relaxed. For example, after installing all the column members 11 in the layer, the beam members 12 in the layer can be inserted in any order. Furthermore, even if the height of the column member 11 is two floors (two layers and one section), the beam members 12 of two layers can be inserted after the installation of the column member 11.

  As shown in FIG. 1, the first reinforcement 15, the second reinforcement 16 and the main reinforcement 20 of the beam member are main reinforcements of the beam, and from the pillar side to the tip of the second reinforcement 16 in each of the upper side and the lower side Alternatively, it is doubled by the beam main bars 20 and the double-step bars 16, and the tip is a single layer of the beam main bars 20. Therefore, the vicinity of the tip of the double bar 16 is a yielding position. During an actual earthquake, bending yield occurs at the positions shown by circles in FIG. Although the bending yield position functions as a hinge, as shown in FIG. 8, in the conventional structure, bending of the main bars of the beam is performed at the middle position of the beam and bending is performed near the column. On the other hand, in the beam-column joint structure 10 according to the present embodiment, a joint of the main bars of the beam (a joint between the one-step bar 15 and the main bar 20 of the beam member) is performed in the vicinity of the column member main body 13 By the center of the beam. Such hinge relocation prevents damage from occurring at the joint between the column and the beam during an earthquake, and causes failure in the beam. Therefore, repair is relatively easy. The amount of brows 15 may be increased to increase the bending strength of the beam end to make hinge relocation more reliable. Also, instead of or in addition to increasing the amount of the first reinforcement 15, the first reinforcement 15 may be a reinforcing bar having a strength higher than that of the second reinforcement 16 and the beam main reinforcement 20 to make the hinge relocation more reliable.

  FIGS. 9-16 shows the modification 1-8 of the beam-to-column joined structure 10 which concerns on the said embodiment, respectively. Members denoted with the same reference numerals as the above embodiment or the already described modified example have the same configuration and operation as the above embodiment except for the portions specifically described below. In the beam-to-column joint structure 10 according to the first to eighth modifications, the end ribs 21a are temporarily installed on the one-step bar 15 side in order to bring the tip end surface of the protrusion 14 into contact with the column side surface of the beam member main body 18. After the beam member 12 is disposed at a predetermined position, the beam member 12 is slid and bound to the one-step reinforcement 15 or the beam member main reinforcement 20 or temporarily installed after the beam member 12 is disposed at a predetermined position without temporary installation. 15 or attached to the beam main bars 20. 9 to 14 and 15B respectively show cross sections corresponding to FIG. 1B in the same manner as the figure.

  The beam-to-column joint structure 10 according to the first modification shown in FIG. 9 is directed to the column member main body 13 above and below the projecting portion 14 on the surface of the beam member main body 18 on the column member main body 13 side. A cotter 31 expanded in a truncated pyramid shape is provided, and a recess 32 having a shape complementary to that of the cotter 31 is formed in the beam end surface layer portion 22 by casting of cast-in-place concrete. The cotter 31 and the recess 32 improve the integrity between the beam member 12 and the beam end surface portion 22. Since the cotters 31 are provided not on the side of the beam member main body 18 in the width direction but on the upper and lower sides (above and below the projecting portion 14), the beam member 12 is placed between the two column members 11 in the lateral direction. It does not inhibit insertion. Further, the mutual connection between the first row reinforcement 15 and the beam member main reinforcement 20 is made by a lap joint. The joints of the above embodiment and the other modified examples (except the fifth modified example) may be changed to known joints such as lap joints and vacant lap joints, and the joint of the first modification example is a machine It may be changed to a known joint such as a joint or a lap joint. Further, an example in which a fixing metal is used as the fixing unit 17 is illustrated.

  With respect to the beam-to-column joint structure 10 according to the second modification shown in FIG. 10, both ends of the double-step bars 16 reach the tip end surface of the projection 14 and the fixing unit 17 is from the projection 14 It differs in the point which is exposed. By configuring in this manner, the dangerous cross section position can be clarified.

  In the beam-column joint structure 10 according to the third modification shown in FIG. 11, both ends of the two-step bar 16 reach the tip end surface of the projection 14 in common with the second modification, but fixing The difference is that the surface of the portion 17 is flush with the tip end surface of the protrusion 14. Since the surface of the fixing unit 17 is flush with the tip end surface of the protrusion 14, the workability is better than in the second modification.

  The beam-column joint structure 10 according to the fourth modification shown in FIG. 12 is a protrusion formed of mortar or the like between the tip end surface of the protrusion 14 and the beam member main body 18 in the third modification. It is different in that a high strength portion 33 which is higher in strength than the concrete of 14 and the beam member main body 18 is provided. The high strength portion 33 improves the integrity of the protrusion 14, the beam member main body 18, and the beam end surface portion 22.

  The beam / column joint structure 10 according to the fifth modification shown in FIG. 13 is different from the first modification in that the mechanical joint 19 is partially embedded in the column member main body 13. A mechanical joint connected to the end of the first row reinforcement 15 projects from the column member body 13 so that the first row reinforcement 15 can be connected to the main beam member 20. Since the length of the portion of the one-step muscle 15 that protrudes from the column member main body 13 is shortened, the protruding length of the protrusion 14 can also be shortened, and the transportability of the column member 11 is improved.

  The beam / column joint structure 10 according to the sixth modification shown in FIG. 14 is different from the first modification in that the arrangement of the cotter 31 and the recess 32 is reversed. A concave portion 32 is provided on the surface of the beam member main body 18 on the side of the pillar member main body 13, and a cotter 31 having a complementary shape is formed in the concave portion 32 in the beam end surface layer portion 22 by casting on site. Since what is provided in the beam member main body 18 is not the projecting cotter 31 but the concave portion 32, even if the concave portions 32 are provided on both sides in the width direction of the surface of the beam member main body 18 side, the beam member It does not inhibit the insertion of 12 from the lateral direction between the two column members 11. The recess 32 in the sixth modification is provided on the side in the width direction of the surface on the side of the pillar member body 13 of the beam member main body 18 according to the above embodiment or the first to fifth modifications. A cotter 31 of a complementary shape may be formed laterally in the recess 32. When concrete with lower strength than the beam member main body 18 is used for the beam end surface layer portion 22, the cotter 31 of the first modification in which the high strength side is convex is preferable in view of the structure of the cotter 31 of this modification. Although the recess 32 and the cotter 31 of this modification can be provided laterally in the width direction, in that case, rather than providing the recess 32 or the cotter 31 of the first modification in the upper and lower portions where the beam main bars 20 project. Construction is easy.

The beam-column joint structure 10 which concerns on the 7th modification shown in FIG. 15 differs in the point by which the beam end surface layer part 22 and the floor slab 34 are provided integrally by the half precast construction method with respect to the said embodiment. In the beam member main body 18, the upper beam member main bars 20a are exposed from the concrete portion as a precast member, and are embedded in the concrete by casting of cast-in-place concrete for the beam end surface portion 22 and the floor slab 34. The slab bars 35 are installed after the placement of the beam members 12 and before the casting of the cast-in-place concrete. The concrete strength of the beam member body 18 is the concrete strength required for the beam (for example, 48 N / mm ² ), and the concrete strength of the projection 14 is higher than the concrete strength required for the beam, for example, the concrete required for the column It is preferable to set the strength (for example, 60 N / mm ² ) and the concrete strength of the beam end surface portion 22 and the floor slab 34 to be the concrete strength required for the floor slab 34 (for example, 30 N / mm ² ). In this case, at the beam end, since the concrete of the high strength protrusion 14 is present in the concrete of the low strength beam end surface portion 22, the strength required for the beam as a whole is satisfied. Except for the point that the cotter 31 and the recess 32 can not be provided in the upper part between the surface of the beam member main body 18 on the side of the column member body 13 and the beam end surface layer portion 22, the configuration of the other modification is the present modification Applicable

  FIG. 16 is a cross-sectional view of a portion corresponding to the cross section AA of FIG. 15 (B) of the beam-to-column joint structure 10 according to the eighth modification. The beam-column joint structure 10 according to the eighth modification is different from the seventh modification in that the projecting portion 14 and the beam member main body 18 have a flat shape whose dimension in the width direction is longer than the vertical dimension. By making it flat, it is possible to increase the amount of the two-step bar 16, to increase the bending resistance of the beam end, and to ensure the hinge relocation. The beam-to-column joint structure 10 according to the eighth modification may be constructed not by the half precast method but by the same method as the above embodiment. Also, the width of the beam may be larger than the width of the column.

  Although the description of the specific embodiment is finished above, the present invention can be widely modified and implemented without being limited to the above embodiment. The column members may be constructed of cast-in-place concrete. Further, in order to reduce the space required for transporting the column member, the column member main body may be precast concrete, and the concrete of the projecting portion may be cast at a work yard at a construction site.

10: Beam-to-column joint structure 11: Column member 12: Beam member 13: Column member main body 14: Protrusive portion 15: One-step bar 16: Two-step bar 17: Fixing portion 18: Beam member main body 19: Mechanical joint 20: Beam member Main reinforcement 21a: End rib 22: Beam end surface 23: Mold 31: Cotter 32: Recess 33: High strength 34: Floor slab

Claims (8)

A beam-column joint structure in which a column member and a beam member made of precast concrete are joined together,
The pillar member protrudes laterally from the pillar member main body, and the concrete protruding portion having a vertical dimension smaller than the length of the beam and the upper surface and the lower surface of the protruding portion are respectively spaced along predetermined intervals. It has a step muscle projecting directly or indirectly from the pillar member main body, and a two-step muscle extending parallel to the first step muscle at least in the pillar member main body and the protrusion.
The beam member has a beam member main bar joined to the one-step bar;
The projecting portion, the portion of the one-step bar protruding from the column member main body, and the portion of the main beam member bar protruding from the beam member main body are embedded in a beam end surface portion made of cast-in-place concrete. Beam-to-column connection structure.   The beam-to-column joint structure according to claim 1, wherein a fixing portion is provided at an end of the two-step bar.   The beam-to-column joint structure according to claim 1 or 2, wherein cotters are formed on the contact surfaces of the beam member main body and the beam end surface portion.   The column according to any one of claims 1 to 3, further comprising an end rib embedded in the surface portion of the beam end, which surrounds the main bar of the beam member and the first row connected to each other. Beam connection structure. A method for constructing a beam-to-column joint structure in which a precast concrete column member and a precast concrete beam member are joined to each other,
From the pillar member main body, a concrete protrusion which protrudes sideward from the pillar member main body and which has a vertical dimension smaller than the beam length and which runs along a predetermined distance between each of the upper surface and the lower surface of the protrusion. Placing the pillar member at a predetermined position, the pillar member having a directly or indirectly projecting one-step muscle and a two-step bar extending parallel to the one-step muscle in at least the pillar member body and the protrusion;
Placing the beam member at a predetermined position, the beam member having a beam member main bar that protrudes from the beam member main body so as to be aligned with the first step;
The cast-in-place concrete is cast so as to embed the projecting portion, the portion of the one-step bar that protrudes from the column member main body, and the portion of the beam member main bar that protrudes from the beam member main body And the step of
The beam member main bar is composed of an upper beam member main bar and a lower beam member main bar, and the upper beam member main bar and the lower beam member main bar are spaced apart from each other more than the upper and lower dimensions of the protrusion.
The step of arranging the beam member is orthogonal to the extending direction of the column member and the extending direction of the beam member such that the protrusion is inserted between the upper beam member main bar and the lower beam member main bar Moving the beam member in the direction of movement. After the step of arranging the beam member in a predetermined position and before the step of constructing the surface portion of the beam end, the step of joining the one-step bar and the main beam of the beam member to each other by a mechanical joint Have
6. The mechanical joint according to claim 5, wherein the mechanical joint is temporarily installed so that the main beam member of the beam member or the one-step bar is inserted before the step of disposing the beam member in a predetermined position. the method of.   An end rib which surrounds a portion of the beam main bar that protrudes from the beam main body or a portion of the one-step bar that protrudes from the column main body is one of the portions of the beam main bar that protrudes from the beam main body. After the step of temporarily installing the portion from the beam member main body or the portion from the pillar member main body of the portion of the one-step muscle projecting from the column member main body, and disposing the beam member at a predetermined position The method according to claim 5 or 6, wherein the method is slid and placed at a predetermined position before the step of constructing the surface portion of the beam end. The cast-in-place concrete in the surface layer of the beam end is integrally performed with the cast-in-place concrete of the floor slab,
The concrete strength of the protrusion is higher than the concrete strength of the beam member, and the concrete strength of the beam end surface portion and the floor slab is lower than the concrete strength of the beam member. The method according to any one of 7.

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