Method for constructing a column-beam frame

Abstract

When joining a beam member to a precast concrete column member from the side, grout can be easily filled into the joint space between the column member and the beam member. [Solution] The method for constructing a column-beam frame includes a column member installation step of installing a column member 2, a beam member installation step of moving a beam member 5 laterally and positioning it opposite the tip surface 25f of a protruding portion 25 formed protruding from the side surface of the column member 2 and the end surface 5f of the beam member 5 to form a joint space ZS, and a grout filling step of setting up a joint formwork 90 to close the bottom and sides of the joint space ZS and filling the joint space ZS with grout. In the beam member installation step, the position of the beam member 5 is determined such that when the end surface 5f of the beam member 5 is facing the tip surface 25f of the protruding portion 25, the bottom surface and side surface of the protruding portion 25 and the beam member 5 respectively extend within the same plane.

Description

Technical Field

[0001] The present invention relates to a method for constructing a column-beam framework by joining a column member and a beam member made of precast concrete to construct a column-beam framework.

Background Art

[0002] When constructing a building structure, in order to reduce the construction period, it is widely practiced to fabricate the members constituting the column-beam framework as precast concrete at a factory, transport them to the construction site, and assemble them. Regarding this, for example, in Patent Document 1, a building column-beam joint structure is disclosed in which a PCa (precast concrete) horizontal structure in which a column joint portion and a beam are integrated in advance is horizontally attached on a PCa column of a building. In this building column-beam joint structure, the column joint portion constituting the PCa horizontal structure is directly joined to at least the lower-story PCa column at the column-beam joint, and the beams are directly joined at at least one beam joint portion located between adjacent PCa columns.

[0003] Further, in Patent Document 2, a precast concrete (PC) beam in which the end of the beam main reinforcement protrudes horizontally from the end face, a PC column in which the column main reinforcement is embedded and a joint for connecting the column main reinforcement is embedded at at least the upper end portion of the column main reinforcement, and a rectangular parallelepiped PC joint panel member having a vertical through hole for inserting the column main reinforcement and in which a joint for connecting the beam main reinforcement is embedded. The beam main reinforcement of the PC beam is fixed to the joint for connecting the beam main reinforcement embedded in the PC joint panel member, and the column main reinforcement of the upper-story PC column or a relay reinforcement to be connected to this column main reinforcement is inserted from above into the through hole of the joint panel member, penetrates the PC joint panel member, and is fixed to the joint embedded at the upper end portion of the column main reinforcement of the lower-story PC column. A joint structure of a PC column-beam is disclosed.

[0004] Furthermore, Patent Document 3 discloses a PC column-beam joint structure comprising: a first PC member having a rectangular parallelepiped PC (precast concrete) joint panel section with horizontal through-holes formed for inserting beam main reinforcement, and the PC joint panel section being positioned on a PC column of the lower floor; and second and third PC members having PC beam sections and being positioned on both sides of the PC joint panel section, wherein beam main reinforcement protrudes from the end of the PC beam section of the second PC member, and a joint for connecting beam main reinforcement is embedded in the end of the PC beam section of the third PC member, and the beam main reinforcement protruding from the second PC member is inserted from one end of the through-hole, and its tip protrudes from the other end of the through-hole and is fixed to the joint of the third PC member.

[0005] By the way, when joining two precast concrete members, the two members must be placed facing each other, and grout must be filled into the joint space formed between the surfaces of the two members. However, when joining a precast concrete column member and a beam member, it is not easy to install the joint formwork in a way that prevents grout leakage. The joint formwork is installed along the sides and bottom surfaces of the beam member, so that these sides and bottom surfaces extend horizontally toward the column member. In this case, the end of the joint formwork on the column member side abuts against the surface of the column member, and the joint formwork is positioned perpendicular to the surface of the column member, so that the joint formwork and the surface of the column member are in contact along a line. If grout is to be filled in this state, the joint formwork may not be able to withstand the grout pressure, causing the end of the joint formwork on the column member side to bend outward relative to the joint space, separating the joint formwork from the surface of the column member, and potentially causing the grout to leak out. To suppress this, it is conceivable to join a member that supports the joint formwork from the outside, such as an L-shaped steel, to the surface of the column member, thereby resisting the grout pressure and suppressing grout leakage. However, joining such support members is time-consuming, which may make the grout filling work as a whole not easy. When joining a beam member to a precast concrete column member from the side, there is a need for a method of constructing a column-beam frame that allows for easy filling of the joint space between the column member and the beam member with grout. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-346587 [Patent Document 2] Japanese Patent Publication No. 2004-278257 [Patent Document 3] Japanese Patent Publication No. 2006-22494 [Overview of the project] [Problems that the invention aims to solve]

[0007] The problem that this invention aims to solve is to provide a method for constructing a column-beam frame that allows for easy filling of grout into the joint space between a column member and a beam member when joining a beam member to a precast concrete column member from the side. [Means for solving the problem]

[0008] The present inventors focused on the fact that, as a method for constructing a column-beam frame, efficient joining can be achieved by continuously filling the inside of the beam reinforcement joints embedded in the beam members and the joint formwork between the column members and beam members with grout, and that the vertical accuracy of the column-beam frame can be easily adjusted by joining the other ends of the column members and beam members via a cast-in-place concrete beam section, leading to the present invention. To solve the above problems, the present invention employs the following means. In other words, the present invention provides a method for constructing a column-beam frame, comprising joining precast concrete column members and beam members to construct the column-beam frame, wherein the column member is provided with a projection formed protruding from the side surface of the column member, and includes a column member installation step of installing the column member, a beam member installation step of moving the beam member laterally and positioning it opposite to the end surface of the projection so as to form a joint space between the tip surface of the projection and the end surface of the beam member, and a grout filling step of providing a joint formwork to close the bottom and sides of the joint space and filling the joint space with grout, wherein in the beam member installation step, the position of the beam member is determined such that when the end surface of the beam member is positioned opposite the tip surface of the projection, the lower surface and side surface of the projection and the beam member respectively extend within the same plane. With the above configuration, in the beam member installation process, the beam member is moved laterally and positioned opposite the tip surface of the projection formed protruding from the side surface of the column member and the end surface of the beam member so as to form a joint space. At this time, the position of the beam member is determined such that when the end surface of the beam member is facing the tip surface of the projection, the lower surface and side surface of the projection and the beam member respectively extend within the same plane. Therefore, when a joint formwork is set to close the bottom and sides of the joint space and grout is filled into the joint space, the joint formwork can be set to be in surface contact with each surface by, for example, positioning it so as to straddle the joint space and follow both the lower surface of the projection and the lower surface of the beam member, and so as to straddle the joint space and follow both the side surface of the projection and the side surface of the beam member. As a result, at the contact points on this surface, the joint formwork can be secured from the outside by, for example, by providing fastening bands or frame materials, thus making the installation of the joint formwork easier. Furthermore, since the joint formwork is in contact with each surface as described above, the outflow of grout can be effectively suppressed. This makes it easy to fill the joint with grout. In this way, it becomes possible to realize a method for constructing a column-beam frame in which, when joining a beam member to a precast concrete column member from the side, grout can be easily filled into the joint space between the column member and the beam member.

[0009] In one embodiment of the present invention, the beam member is formed as a fully precast concrete structure at one beam end joined to the column member, with both the lower main beam reinforcement provided on the lower side and the upper main beam reinforcement provided on the upper side embedded in the concrete, and at the central part of the beam and the other beam end, the lower main beam reinforcement is embedded in the concrete and the upper main beam reinforcement is provided exposed above the concrete, thus forming a half-precast concrete structure. In this configuration, one end of the beam that is joined to the column member is formed as a fully precast concrete structure, with both the lower and upper main beam reinforcements embedded in the concrete. Therefore, when joining the beam member to the column member by joining the main beam reinforcements embedded in the column member to the main beam reinforcements of the beam member, both the lower and upper main beam reinforcements can be used for joining with the main beam reinforcements. Thus, the beam member and the column member can be firmly joined. Furthermore, since the other end of the beam is formed as a half-precast concrete structure, when concrete is poured above it, the floor slab of the upper floor can be formed simultaneously and integrally. Therefore, construction becomes easier, and the beam member and the floor slab can be firmly joined.

[0010] In one embodiment of the present invention, the column member installation step is defined as the column member installed in the column member installation step, and another column member is installed at a position spaced apart from the first column member; and the cast-in-place concrete beam section forming step is defined as the cast-in-place concrete beam section formed by pouring concrete between the other beam end of the beam member opposite to the beam end joined to the first column member and the other column member, thereby joining the other column member and the beam member. The column member installation step, the beam member installation step, the other column member installation step, the grout filling step, and the cast-in-place concrete beam section forming step are repeatedly performed to construct the column-beam frame from bottom to top. With this configuration, in the column member installation process described above, another column member is installed at a position spaced apart from the first column member, and concrete is poured between the other beam end (opposite to the beam end joined to the first column member) and the other column member to form a cast-in-place concrete beam section. This makes it easy to construct a column-beam frame in which one column member and another column member are connected by a beam member. [Effects of the Invention]

[0011] According to the present invention, when joining a beam member to a precast concrete column member from the side, it is possible to provide a method for constructing a column-beam frame that allows grout to be easily filled into the joint space between the column member and the beam member. [Brief explanation of the drawing]

[0012] [Figure 1] This is a longitudinal cross-sectional view showing the configuration of a column-beam frame constructed by applying the column-beam frame construction method according to an embodiment of the present invention. [Figure 2] This is an enlarged longitudinal cross-sectional view of the area indicated by arrow A in Figure 1. [Figure 3] This is a longitudinal cross-sectional view of the area indicated by arrow II in Figure 2. [Figure 4] This is an enlarged longitudinal cross-sectional view of the area indicated by arrow B in Figure 1. [Figure 5] This is a longitudinal cross-sectional view showing the state after one column member has been installed during the construction of the column-beam frame shown in Figure 1. [Figure 6] This is a longitudinal cross-sectional view showing the state after the beam member has been moved laterally from the state shown in Figure 5. [Figure 7] This is a partial longitudinal cross-sectional view showing the beam member moved laterally so that its end face faces the tip face of the protruding part. [Figure 8] This is a top-down plan view of the joint between a column member and a beam member. [Figure 9] This is a schematic diagram showing the flow of grout during the grout filling process. [Figure 10] This is a longitudinal cross-sectional view showing the installation process for other column members. [Figure 11] It is a longitudinal sectional view showing another column member installation step in the method for constructing a column-beam framework according to a modified example of an embodiment of the present invention. [Figure 12] It is a longitudinal sectional view showing a beam member installation step in the method for constructing a column-beam framework according to a modified example of an embodiment of the present invention. [Figure 13] It is a longitudinal sectional view showing a state following FIG. 12 in the method for constructing a column-beam framework according to a modified example of an embodiment of the present invention.

Mode for Carrying Out the Invention

[0013] The present invention is a method for constructing a column-beam framework in which precast concrete column members and beam members are joined to construct a column-beam framework. On the upper side surface of the column member, a protruding portion for positioning the height of the beam member is provided. The protruding portion has the same cross section as the beam member. After inserting a beam bar joint portion embedded in the beam member into the tip of the joint beam main bars protruding from the protruding portion, the inside of the beam bar joint portion and the gap space between the column member and the beam member are filled with grout to join the column member and the beam member. Hereinafter, with reference to the accompanying drawings, a mode for carrying out the method for constructing a column-beam framework according to the present invention will be described based on the drawings. Hereinafter, first, the configuration of the column-beam framework constructed by applying the method for constructing the column-beam framework according to the embodiment of the present invention will be described, and then the method for constructing the column-beam framework will be described. A longitudinal sectional view showing the configuration of the above column-beam framework is shown in FIG. 1. As shown in FIG. 1, the column-beam framework 1 includes a plurality of columns 11 extending in the vertical direction and beams 12 installed between adjacent columns 11 in the horizontal direction. Each column 11 is configured by connecting a plurality of column members 2 in the vertical direction. Each column member 2 is made of precast concrete and has a predetermined length in the vertical direction. Each column member 2 mainly includes a concrete portion 21, column main bars 22 embedded in the concrete portion 21, and a column bar joint portion 23. The concrete portion 21 has, for example, a rectangular cross-sectional shape in plan view. Multiple main reinforcement bars 22 are embedded in the concrete section 21. The number and arrangement of the main reinforcement bars 22 are not limited in any way. The main reinforcement bars 22 extend vertically. The upper ends of the main reinforcement bars 22 protrude upward from the upper surface of the concrete section 21. The lower ends of the main reinforcement bars 22 are inserted into the upper part of the reinforcement bar joint section 23, which is embedded in the lower end of the column member 2.

[0014] The column reinforcement joint 23 is formed in a cylindrical shape and has an internal space. The column reinforcement joint 23 is positioned so that the axial direction of the cylinder coincides with the vertical direction. The column reinforcement joint 23 is embedded in the concrete section 21. The lower end of the column reinforcement joint 23 is exposed on the lower surface of the concrete section 21, and the internal space of the column reinforcement joint 23 opens downwards. Multiple such column members 2 are connected vertically to form a column 11. Column members 2 located above and below each other are joined by inserting the upper end of the main reinforcement bar 22 of the lower column member 2 into the internal space of the reinforcement bar joint 23 of the upper column member 2 from below, and filling the internal space of the reinforcement bar joint 23 with grout (not shown). In addition, a joint is formed between the concrete portion 21 of the lower column member 2 and the concrete portion 21 of the upper column member 2 by filling it with grout.

[0015] Figure 2 is an enlarged longitudinal cross-sectional view of the area indicated by arrow A in Figure 1. As shown in Figures 1 and 2, each column member 2 is provided with a projection 25 in the vertical direction on the portion facing the end face 5f of the beam member 5, which constitutes the beam 12, as will be described later. The projection 25 protrudes horizontally from the side surface 21s of the concrete portion 21 of the column member 2 toward the beam member 5. The projection 25 is formed integrally with the concrete portion 21. The shape of the projection 25 when viewed from the direction of projection is formed to match the shape of the beam member 5 when viewed from the direction of extension of the beam member 5. More specifically, the shapes of the projection 25 and the lower surface of the beam member 5 match when viewed from the direction of extension of the beam member 5. Also, the shapes of the projection 25 and the side surface of the beam member 5 match when viewed from the direction of extension of the beam member 5. Furthermore, in this embodiment, the shapes of the projection 25 and the upper surface of the beam member 5 match when viewed from the direction of extension of the beam member 5. Thus, the protruding portion 25 has the same shape as the end face 5f of the beam member 5. A recess 25d is formed in the center of the tip surface 25f of the protruding portion 25, so as to be recessed inward from the protruding portion 25, that is, in a direction away from the end surface 5f of the beam member 5. This recess 25d is filled with grout G, which will be used to form the joint Z described later, thereby forming a cotter that will bear the shear force acting between the protruding portion 25 and the grout G that will form the joint Z.

[0016] Furthermore, the column member 2 is provided with multiple connecting beam main reinforcement bars 27A and 27B that protrude from the side, more specifically from the tip surface 25f of the projection 25, toward the beam member 5. The multiple connecting beam main reinforcement bars 27A and 27B are provided so as to penetrate horizontally through the concrete portion 21 and the projection 25. The connecting beam main reinforcement bars 27A are provided at the same height as the upper beam main reinforcement bars 52A of the beam member 5, which will be described later. The connecting beam main reinforcement bars 27B are provided below the connecting beam main reinforcement bars 27A. The connecting beam main reinforcement bars 27B are provided at the same height as the lower beam main reinforcement bars 52B of the beam member 5, which will be described later. Several rib reinforcement bars 28 are embedded near the projection 25, arranged to surround the connecting beam main reinforcement bars 27A and 27B.

[0017] In this embodiment, each beam 12 comprises a beam member 5 and a cast-in-place concrete beam section 7. As shown in Figure 1, the beam member 5 is made of precast concrete, with one beam end 5s (one end of the beam member 5) directly joined to a column member 2A that forms the column 11 shown on the left in Figure 1, and the other beam end 5t (the other end of the beam member 5) joined to another column member 2B that forms the column 11 shown on the right in Figure 1 via a cast-in-place concrete beam section 7. As shown in Figures 1 and 2, the beam member 5 mainly consists of concrete 51, beam main reinforcement 52, beam rib reinforcement 53, and beam reinforcement joint section 54.

[0018] The concrete 51 has, for example, a rectangular cross-sectional shape when viewed from the direction of extension of the beam member 5. The concrete 51 integrally comprises a first concrete section 51A and a second concrete section 51B. The first concrete section 51A forms the concrete 51 on one beam end 5s side. The first concrete section 51A is provided at one beam end 5s of the beam member 5 so as to form the entire cross-section of the beam member 5. As shown in Figure 2, the first concrete section 51A has a through hole 51k formed in the center in the vertical direction, which penetrates the first concrete section 51A in the beam width direction (depth direction in Figure 2), allowing equipment piping and the like to be inserted. In the first concrete section 51A, a recess 51d is formed in the center of the end face 5f facing the tip face 25f of the protruding section 25, so as to be recessed inward from the first concrete section 51A, that is, in the direction away from the tip face 25f of the protruding section 25. This recess 51d is filled with grout G which will form the joint Z described later, and a cotter is formed to bear the shear force acting between the protruding section 25 and the grout G which will form the joint Z. The second concrete section 51B forms the concrete 51 of the central part 5c of the beam and the other end 5t of the beam. The second concrete section 51B is provided only at the lower part of the beam member 5 in the central part 5c of the beam and the other end 5t of the beam in the direction of extension of the beam member 5.

[0019] Figure 3 is a longitudinal cross-sectional view of the area indicated by arrow II in Figure 2. As shown in Figures 2 and 3, the beam main reinforcement 52 comprises multiple upper beam main reinforcement 52A and multiple lower beam main reinforcement 52B. The beam main reinforcement 52 is provided in correspondence with each of the multiple connecting beam main reinforcement 27A and 27B. Each of the upper beam main reinforcement 52A and the lower beam main reinforcement 52B extends in the extension direction (horizontal direction) of the beam member 5. The lower beam main reinforcement 52B is provided below the upper beam main reinforcement 52A. The upper beam main reinforcement 52A is provided above the lower beam main reinforcement 52B. In this embodiment, the upper beam main reinforcement 52A and the lower beam main reinforcement 52B are each arranged in two upper and lower levels. In each level, multiple upper beam main reinforcement 52A and lower beam main reinforcement 52B are provided side by side in the beam width direction. In this embodiment, the diameter and strength of the upper beam main reinforcement 52A and the lower beam main reinforcement 52B are set to be smaller than the diameter and strength of the connecting beam main reinforcement 27A and 27B.

[0020] As shown in Figures 1 and 2, at one end 5s of the beam member 5, both the lower main beam reinforcement 52B and the upper main beam reinforcement 52A are embedded in the first concrete section 51A, forming a fully precast concrete structure. At the central section 5c and the other end 5t of the beam member 5, the lower main beam reinforcement 52B is embedded in the second concrete section 51B, while the upper main beam reinforcement 52A is exposed above the concrete 51, resulting in a half-precast concrete structure. Multiple sets of beam reinforcement bars 53 are provided at intervals in the direction of extension of the beam member 5. Each beam reinforcement bar 53 is provided so as to surround the upper beam main reinforcement bar 52A and the lower beam main reinforcement bar 52B.

[0021] The beam reinforcement joint 54 is formed in a cylindrical shape and has an internal space. The beam reinforcement joint 54 is positioned so that the axial direction of the cylinder coincides with the horizontal direction in which the beam member 5 extends. Multiple beam reinforcement joints 54 are embedded in the first concrete section 51A at one beam end 5s of the beam member 5. The beam reinforcement joints 54 are provided corresponding to each of the multiple main beam reinforcements 52, and at the same time, they are provided corresponding to each of the multiple connecting main beam reinforcements 27A, 27B. As shown in Figure 2, one end 52s of the main beam reinforcement bars 52 (upper main beam reinforcement bar 52A, lower main beam reinforcement bar 52B) embedded in the beam member 5 is inserted into the end of each of the multiple beam reinforcement bar joints 54 on the beam center 5c side (right side in Figure 2). The inner circumferential surface of the beam reinforcement bar joint 54 and the outer circumferential surface of the main beam reinforcement bars 52 are spaced apart in the radial direction of the beam reinforcement bar joint 54, creating a gap between them. Each of the multiple beam reinforcement joints 54 has an end on the beam end 5s side (left side in Figure 2) that is exposed to the end face 5f of the first concrete portion 51A (concrete 51) of the beam member 5, and the internal space of the beam reinforcement joint 54 opens horizontally and communicates with the outside. The ends of the corresponding connecting beam main reinforcements 27A and 27B are inserted into each of the beam reinforcement joints 54 from the beam end 5s side that opens horizontally and communicates with the outside. The inner circumferential surface of the beam reinforcement joint 54 and the outer circumferential surfaces of the connecting beam main reinforcements 27A and 27B are spaced apart in the radial direction of the beam reinforcement joint 54, creating a gap between them.

[0022] A through-hole 54h is provided in the beam reinforcement joint 54, penetrating in a direction perpendicular to the axial direction of the beam reinforcement joint 54, thereby connecting the internal space of the beam reinforcement joint 54 with the outside of the beam reinforcement joint 54. For each beam reinforcement joint 54, the through-hole 54h is provided at both ends in the axial direction of the beam reinforcement joint 54. Thus, in this embodiment, each beam reinforcement joint 54 is provided with two through-holes 54h. In particular, in this embodiment, one of the two through-holes 54h is opened in the axial direction of the beam reinforcement joint 54, in the area where a gap is formed between the inner surface of the beam reinforcement joint 54 and the outer surface of the beam main reinforcement 52 when one end 52s of the beam main reinforcement 52 is inserted. The other through-hole 54h is opened in the axial direction of the beam reinforcement joint 54, in the area where a gap is formed between the inner surface of the beam reinforcement joint 54 and the outer surface of the connecting beam main reinforcement 27A and 27B when the ends of the connecting beam main reinforcement 27A and 27B are inserted.

[0023] In the internal space of each beam reinforcement joint 54, grout G is filled into the gaps between the ends of the connecting beam main reinforcements 27A and 27B and one end 52s of the beam main reinforcement 52 (upper beam main reinforcement 52A, lower beam main reinforcement 52B), the gap between the inner circumferential surface of the beam reinforcement joint 54 and the outer circumferential surface of the beam main reinforcement 52, and the gap between the inner circumferential surface of the beam reinforcement joint 54 and the outer circumferential surfaces of the connecting beam main reinforcements 27A and 27B. Furthermore, the beam member 5 is positioned such that there is a predetermined gap between the end face 5f of one beam end 5s and the tip face 25f of the protruding portion 25 of the column member 2 that is opposite to the end face 5f, which will be explained later as a joint space ZS using Figure 9, etc. A joint Z is formed when grout G is filled into this joint space ZS, which is the gap between the end face 5f and the tip face 25f.

[0024] As described above, in order to fill with grout G, multiple connecting passages 58 are formed in the beam member 5, as shown in Figure 3. In this embodiment, the multiple connecting passages 58 are provided to correspond to all through holes 54h in all beam reinforcement joints 54. Therefore, in this embodiment, two connecting passages 58 are provided for each beam reinforcement joint 54. Each of the multiple connecting passages 58 is provided to communicate with a corresponding through-hole 54h. Each of the multiple connecting passages 58 is connected to a corresponding through-hole 54h. Each of the multiple connecting passages 58 is provided to extend from the through-hole 54h through the interior of the first concrete section 51A to surfaces 51s and 51t other than the end face 5f. The other end of each of the multiple connecting passages 58 is provided to open outwards from surfaces 51s and 51t other than the end face 5f. In this way, each of the multiple connecting passages 58 connects the internal space of the beam reinforcement joint section 54 to the outside of the beam member 5 via the corresponding through-hole 54h of the beam reinforcement joint section 54.

[0025] More specifically, in this embodiment, the internal space of the beam reinforcement joint 54 embedded below the first concrete section 51A is connected to the outside by a connecting passage 58 from the lateral surface 51s (i.e., the side surface) of the first concrete section 51A. The internal space of the beam reinforcement joint 54 embedded above the first concrete section 51A is connected to the outside by a connecting passage 58 from either the lateral surface 51s of the first concrete section 51A or the upward-facing surface 51t (i.e., the top surface) of the first concrete section 51A. Such a connecting passage 58 can be formed by embedding, for example, a pipe material such as a polyvinyl chloride pipe when pouring concrete to form the first concrete portion 51A of the beam member 5. As will be described in detail later, the grout G is filled into the internal space of the multiple beam reinforcement joints 54 from one of the multiple connecting passages 58, which is connected passage 58C (see Figure 2). After the internal space of the multiple beam reinforcement joints 54 is filled with grout G, each of the multiple connecting passages 58 is also filled with grout G.

[0026] The cast-in-place concrete beam section 7 comprises a first cast-in-place concrete section 71 formed between the other beam end 5t of the beam member 5 and another column member 2B, and a second cast-in-place concrete section 72 formed above the second concrete section 51B of the beam member 5. The first cast-in-place concrete section 71 and the second cast-in-place concrete section 72 are formed integrally. Figure 4 is an enlarged longitudinal cross-sectional view of the area indicated by arrow B in Figure 1. Multiple cylindrical beam reinforcement splices 59 are provided at the location of the protruding portion 25 of the other column member 2B, corresponding to each of the beam main reinforcements 52. The other end 52t of each of the upper beam main reinforcement 52A and the lower beam main reinforcement 52B is inserted into the end of each corresponding beam reinforcement splice 59 on the beam center portion 5c side. The ends of the connecting beam main reinforcements 27A and 27B, which are provided to protrude from the protruding portion 25 of the other column member 2B, are inserted into each of the multiple beam reinforcement splices 59. The first cast-in-place concrete section 71 is formed by pouring concrete on site to embed these upper beam main reinforcement 52A, lower beam main reinforcement 52B, and multiple beam reinforcement splices 59. The second cast-in-place concrete section 72 is formed by pouring concrete on-site at the central part 5c of the beam member 5 and the other end 5t of the beam, so as to embed the upper main beam reinforcement 52A on the second concrete section 51B.

[0027] In the configuration described above, the upper beam main reinforcement 52A and the lower beam main reinforcement 52B are joined to the connecting beam main reinforcement 27A and 27B of the column members 2A and 2B using beam reinforcement splices 54 and 59. Furthermore, as already explained, the diameter and strength of the upper beam main reinforcement 52A and the lower beam main reinforcement 52B are set to be smaller than the diameter and strength of the connecting beam main reinforcement 27A and 27B. In this way, when an earthquake occurs, the position where the plastic hinge occurs moves from the end position P1 of the beam 12 shown in Figure 1 to the end position P2 of the beam reinforcement splices 54 and 59 on the central side of the beam 12, towards the center of the beam 12. This achieves hinge relocation that keeps the column-beam joint within the elastic range.

[0028] Next, we will explain the method for constructing the column-beam frame 1 as described above. To construct the column-beam frame 1, the following steps are carried out on each floor. (Column member installation process) Figure 5 is a longitudinal cross-sectional view showing the state after one column member has been installed when constructing the column-beam frame shown in Figure 1. First, on each floor, one column member 2A is installed in a predetermined position as shown in Figure 5. At this time, if a column member 2A of a lower floor is already installed below the first column member 2A to be installed, the upper end of the main reinforcement bar 22 of the column member 2A of the lower floor is inserted from below into the lower part of the reinforcement bar joint portion 23 of the first column member 2A.

[0029] (Beam member installation process) Next, the beam member 5 is suspended and positioned at a location horizontally opposite to the protruding portion 25 of the first column member 2A. Figure 6 is a longitudinal cross-sectional view showing the state after the beam member has been moved laterally from the state shown in Figure 5. Figure 7 is a partial longitudinal cross-sectional view showing the state after the beam member has been moved laterally and the end face of the beam member is facing the tip face of the protruding part. Figure 8 is a top-down plan view of the joint between the column member and the beam member. Next, the beam member 5 is moved laterally, and the main beam reinforcement bars 27A and 27B protruding from the protruding portion 25 are inserted into each of the multiple beam reinforcement joint portions 54. Then, the beam member 5 is positioned so that the tip surface 25f of the protruding portion 25 of one column member 2A and the end surface 5f of the beam member 5 are separated by a predetermined gap, i.e., a joint space ZS. When the end surface 5f of the beam member 5 is positioned opposite the tip surface 25f of the protruding portion 25, the positions of the lower surface, both sides, and the upper surface of the protruding portion 25 and the beam member 5 are aligned when viewed from the direction of extension of the beam member 5. More specifically, the position of the beam member 5 is adjusted so that the lower surfaces of the protruding portion 25 and the beam member 5, and the sides of the protruding portion 25 and the beam member 5, each extend within the same plane.

[0030] Here, in order to form a joint space ZS, a joint width securing means 81 is provided on either the surface of the column member 2 (the tip surface 25f of the protruding portion 25) or the end surface 5f of the beam member 5, protruding by a predetermined length toward the other, and having a predetermined length, so as to maintain a constant width of the joint Z. In this embodiment, the joint width securing means 81 is formed by screwing a bolt that protrudes by a predetermined length toward the end surface 5f of the beam member 5 into an insert embedded in the protruding portion 25 of the column member 2. When the beam member 5 is moved laterally, the end surface 5f of the beam member 5 is brought into contact with the bolt serving as the joint width securing means 81, so that the tip surface 25f of the protruding portion 25 of one column member 2A and the end surface 5f of the beam member 5 face each other with a predetermined gap between them.

[0031] In this state, the column member 2 and the beam member 5 are joined by the separation suppression means 82. In this embodiment, the separation suppression means 82 includes, for example, an L-shaped fixing bracket 83 bolted to the upper and lower surfaces of the first concrete portion 51A of the beam member 5, and a bolt 84 connecting the fixing bracket 83 to the side surface 21s of the column member 2. Such separation suppression means 82 prevents the column member 2 and the beam member 5 from separating due to the pressure when grout G is later filled into the joint space ZS.

[0032] (Grout filling process) Next, grout G is filled into the joint space ZS between the tip surface 25f of the protruding portion 25 of one column member 2A and the end surface 5f of the beam member 5 to form a joint Z. First, a joint formwork 90 is installed to cover the joint space ZS from below and to the sides (joint formwork installation process). The joint formwork 90 is provided to cover the joint space ZS between the tip surface 25f of the protruding portion 25 of one column member 2A and the end surface 5f of the beam member 5 from below and on both sides. As described above, the position of the beam member 5 is aligned so that the lower surfaces of the protruding portion 25 and the beam member 5, and the side surfaces of the protruding portion 25 and the beam member 5, each extend within the same plane. Therefore, by providing the joint formwork 90 so that it extends within these planes, the joint formwork 90 can be easily installed.

[0033] Figure 9 is a schematic diagram showing the flow of grout in the grout filling process. Next, grout G is filled between the tip surface 25f of the protruding portion 25 of the column member 2A and the end surface 5f of the beam member 5 (grout filling process). In the state after the process of setting the joint formwork 90 as described above, the joint space ZS and the internal space of each beam reinforcement joint 54 are in communication because a gap is formed between the inner circumferential surface of the beam reinforcement joint 54 and the outer circumferential surface of the ends of the connecting beam main reinforcement bars 27A and 27B inserted into the beam reinforcement joint 54. In addition, the internal space of each beam reinforcement joint 54 is in communication with the outside from the surfaces 51s and 51t of the beam member 5 via the through hole 54h and the connecting passage 58 connected thereto. In this way, the joint space ZS, the internal space of each beam reinforcement joint 54, and the connecting passage 58 formed for each beam reinforcement joint 54 are all in communication, forming a single space. In this embodiment, conceptually, grout G is injected into an opening provided on the surface 51s, 51t of the beam member 5 in one of the multiple connecting passages 58, namely passage 58C, thereby filling all parts of the space that are connected as a single space with grout G. By continuing to inject grout G until it is discharged from the openings provided on the surface 51s, 51t of the beam member 5 in all connecting passages 58 other than passage 58C, it can be confirmed that the joint space ZS and the internal space of all beam reinforcement joints 54 are evenly filled with grout G.

[0034] More specifically, as shown in Figures 3 and 9, the filling process begins by press-injecting grout G into one of the multiple connecting passages 58, which is arbitrarily selected as a connecting passage 58C. In the example shown in Figure 3, the beam reinforcement joint 54 located at the bottom, on the right side of the drawing, is designated as one beam reinforcement joint 54C. As shown in Figure 9, one of the two connecting passages 58 provided for the beam reinforcement joint 54C is designated as one connecting passage 58C, and grout G is press-injected into this connecting passage 58C. The grout G is then first filled into the internal space of the beam reinforcement joint 54C via the connecting passage 58C, as indicated by the arrow DR1. The grout G then flows out from the internal space of one beam reinforcement joint 54C into the joint space ZS, as indicated by arrow DR2. At the same time, the grout G is discharged to the outside from the internal space of one beam reinforcement joint 54C through other connecting passages 58 provided in one beam reinforcement joint 54C, other than the one connecting passage 58C, as indicated by arrow DR3. If discharge of grout G to the outside from the connecting passage 58 is confirmed, the openings provided in the surfaces 51s and 51t of the beam member 5 in the connecting passage 58 are closed in order to suppress further discharge of grout G.

[0035] As described above, when grout G flows out from the internal space of one beam reinforcement joint 54C into the joint space ZS, the flowing grout G accumulates and fills the inside of the joint formwork 90 because the joint space ZS is blocked at the bottom and sides by the joint formwork 90. ​​As the filling of grout G into the inside of the joint formwork 90 progresses, the upper surface of the grout G in the joint space ZS rises and reaches the height where the other beam reinforcement joints 54 are located, other than the one beam reinforcement joint 54C. Then, as indicated by arrow DR4, the grout G flows into the internal space of the other beam reinforcement joint 54. The grout G that has flowed into the internal space of the other beam reinforcement joint 54 passes through the connecting passage 58 that communicates with the internal space of the other beam reinforcement joint 54, as indicated by arrow DR5, and is then discharged from the surfaces 51s and 51t of the beam member 5. Regarding the connecting passage 58 where the discharge of grout G to the outside was confirmed, the openings provided on the surfaces 51s and 51t of the beam member 5 are closed. In this manner, the filling of grout G into the first connecting passage 58C continues until the discharge of grout G from all connecting passages 58 except for the first connecting passage 58C is confirmed. After the discharge of grout G from all connecting passages 58 except for the first connecting passage 58C is confirmed, the filling of grout G is stopped.

[0036] (Other column member installation processes) Figure 10 is a longitudinal cross-sectional view showing the installation process for other column members. Next, as shown in Figure 10, another column member 2B is installed at a position spaced apart from the first column member 2A. In this case as well, if a column member 2B of the lower floor is already installed below the other column member 2B to be installed, the upper end of the main reinforcement bar 22 of the column member 2B of the lower floor is inserted from below into the lower part of the reinforcement bar joint portion 23 of the other column member 2B.

[0037] (Concrete beam formation process using cast-in-place concrete) After the other beam member installation processes described above, as shown in Figure 1, concrete is poured between the other beam end 5t of beam member 5 and the other column member 2B, and on the second concrete section 51B of beam member 5 to construct the cast-in-place concrete beam section 7. In this way, the other column member 2B and beam member 5 are joined, and the floor slab of the upper floor is constructed. The column-beam frame 1 is constructed from bottom to top by sequentially repeating the above-described processes of column member installation, beam member installation, grout filling, other column member installation, and on-site cast concrete beam formation on each floor.

[0038] The method for constructing a column-beam frame as described above involves constructing a column-beam frame 1 by joining a precast concrete column member 2 and a beam member 5, wherein the column member 2 is provided with a protruding portion 25 formed to protrude from the side surface 21s of the column member 2, and includes a column member installation step of installing the column member 2, a beam member installation step of moving the beam member 5 laterally and positioning it opposite to the end surface 5f of the protruding portion 25 so as to form a joint space ZS between the end surface 5f of the beam member 5 and the tip surface 25f of the protruding portion 25, and a grout filling step of providing a joint formwork 90 to close the bottom and sides of the joint space ZS and filling the joint space ZS with grout G, wherein in the beam member installation step, the position of the beam member 5 is determined such that when the end surface 5f of the beam member 5 is facing the tip surface 25f of the protruding portion 25, the bottom surface and side surface of the protruding portion 25 and the beam member 5 respectively extend within the same plane. With the above configuration, in the beam member installation process, the beam member 5 is moved laterally and positioned opposite the tip surface 25f of the projection 25 that protrudes from the side surface 21s of the column member 2 and the end surface 5f of the beam member 5, so as to form a joint space ZS. At this time, the position of the beam member 5 is determined such that when the end surface 5f of the beam member 5 is facing the tip surface 25f of the projection 25, the lower surface and side surface of the projection 25 and the beam member 5 respectively extend within the same plane. Therefore, when filling the joint space ZS with grout G by providing a joint formwork 90 to close the bottom and sides of the joint space ZS, the joint formwork 90 can be made to be in surface contact with each surface by, for example, providing it so as to straddle the joint space ZS and follow both the lower surface of the protruding portion 25 and the lower surface of the beam member 5, and so as to straddle the joint space ZS and follow both the side surface of the protruding portion 25 and the side surface of the beam member 5. As a result, at the portion in surface contact, the joint formwork 90 can be secured from the outside by providing, for example, a tightening band or frame material to surround the joint formwork 90 from the outside, making it easy to install the joint formwork 90. ​​Furthermore, as described above, since the joint formwork 90 is in surface contact with each surface, the outflow of grout G can be effectively suppressed. This makes it easy to fill with grout G. In this way, when joining a beam member 5 to a precast concrete column member 2 from the side, it becomes possible to realize a method for constructing a column-beam frame in which grout G can be easily filled into the joint space ZS between the column member 2 and the beam member 5.

[0039] Furthermore, in the beam member 5, at one beam end 5s joined to the column member 2A, both the lower main beam reinforcement 52B provided on the lower side and the upper main beam reinforcement 52A provided on the upper side are embedded in the concrete 51, forming a fully precast concrete structure. At the beam center 5c and the other beam end 5t, the lower main beam reinforcement 52B is embedded in the concrete 51, and the upper main beam reinforcement 52A is provided exposed above the concrete 51, forming a half-precast concrete structure. With this configuration, one beam end 5s, which is joined to the column member 2A, is formed as a fully precast concrete structure in which both the lower beam main reinforcement 52B and the upper beam main reinforcement 52A are embedded in concrete 51. Therefore, when joining the beam member 5 to the column member 2A by joining the joining beam main reinforcement 27A and 27B embedded in the column member 2A to the beam main reinforcement 52A and 52B of the beam member 5, both the lower beam main reinforcement 52B and the upper beam main reinforcement 52A can be used to join with the joining beam main reinforcement 27A and 27B. Thus, the beam member 5 and the column member 2A can be firmly joined. Furthermore, since the other end of the beam (5t) is formed as a half-precast concrete structure, when concrete is poured above it, the floor slab of the upper floor can be formed simultaneously and integrally. Therefore, construction becomes easier, and the beam member 5 and the floor slab can be firmly joined.

[0040] Furthermore, the method for constructing the column-beam frame 1 includes a process of installing another column member, where a column member 2 installed in the column member installation process is designated as one column member 2A, and another column member 2B is installed at a position spaced apart from the first column member 2A; and a process of forming a cast-in-place concrete beam section, where concrete is poured between the other beam end 5t of the beam member 5, opposite to the beam end 5s that is joined to the first column member 2A, and the other column member 2B, thereby forming a cast-in-place concrete beam section 7, and the other column member 2B and the beam member 5 are joined together. The column member installation process, beam member installation process, other column member installation process, grout filling process, and cast-in-place concrete beam section formation process are repeated to construct the column-beam frame 1 from bottom to top. With this configuration, in the column member installation process described above, another column member 2B is installed at a position spaced apart from one column member 2A, and concrete is poured between the other beam end 5t (opposite to the beam end 5s joined to the first column member 2A) and the other column member 2B to form a cast-in-place concrete beam section 7. This makes it easy to construct a column-beam frame 1 in which the first column member 2A and the other column member 2B are connected by a beam member 5.

[0041] (Modified version of the embodiment) Next, a modified example of the column-beam frame construction method shown in the above embodiment is presented. Figure 11 is a longitudinal cross-sectional view showing the process of installing other column members in a method for constructing a column-beam frame according to a modified embodiment of the present invention. As shown in Figure 11, in the method of constructing the column-beam frame in this modified example, after installing one column member 2A in a predetermined position using the same column member installation process as in the above embodiment, another column member installation process is carried out before installing the beam member 5. This involves installing another column member 2C at a position spaced apart from the first column member 2A. At this time, the height of the concrete portion 21 of the installed column member 2C is shorter in the vertical direction than the concrete portion 21 of the first column member 2A. In the subsequent beam member installation process, the beam member 5 is suspended and positioned at a position spaced a certain distance horizontally away from the protruding portion 25 in order to insert the connecting beam main reinforcement bars 27A and 27B protruding from the protruding portion 25 into the beam reinforcement joint portion 54 of the beam member 5. The concrete portion 21 of the column member 2C is set to a height that does not interfere with the beam member 5 and does not hinder the work when carrying out this operation.

[0042] Figure 12 is a longitudinal cross-sectional view showing the beam member installation process in a method for constructing a column-beam frame according to a modified embodiment of the present invention. Next, as shown in Figure 12, the beam member 5 is suspended and positioned horizontally opposite the protruding portion 25 of one column member 2A, in the same manner as the beam member installation process of the above embodiment. Subsequently, the beam member 5 is moved laterally, and the connecting beam main reinforcement bars 27A and 27B protruding from the protruding portion 25 are inserted into each of the multiple beam reinforcement joint portions 54. Then, the beam member 5 is positioned so that it faces the tip surface 25f of the protruding portion 25 of one column member 2A and the end surface 5f of the beam member 5, leaving a predetermined gap, i.e., a joint space ZS, between them. At this time, since the height of the concrete portion 21 of the other column member 2C is set low, the work of joining the beam member 5 to the one column member 2A can be easily carried out.

[0043] Figure 13 is a longitudinal cross-sectional view showing a state following Figure 12 in a method for constructing a column-beam frame according to a modified embodiment of the present invention. Next, as shown in Figure 13, a precast concrete column-beam joint member 2J is installed and joined on top of the other column member 2C (column-beam joint member installation process). The column-beam joint member 2J comprises a concrete section 21J and connecting beam main reinforcement bars 27A and 27B embedded in the concrete section 21J. Similar to the column member 2, the column-beam joint member 2J has a protruding section 25 formed protruding from the side surface 21s of the column-beam joint member 2J. In addition, the concrete section 21J has an insertion hole 21h through which the upper end of the column main reinforcement bar 22 of the column member 2C is inserted in the vertical direction. Such a column-beam joint member 2J is installed by placing the concrete portion 21J on top of the concrete portion 21 of another column member 2C. At this time, the upper end of the main reinforcement bar 22 of the column member 2C is inserted through the insertion hole 21h of the concrete portion 21J. In addition, a grout material (not shown) is filled between the concrete portion 21 of the other column member 2C and the concrete portion 21J, and between the insertion hole 21h and the upper end of the main reinforcement bar 22 inserted through the insertion hole 21h. In this way, the other column member 2C is extended upward to the same height as the first column member 2A.

[0044] Subsequently, as in the above embodiment, a joint Z is formed by filling the joint space ZS between the tip surface 25f of the protruding portion 25 of one column member 2A and the end surface 5f of the beam member 5 with grout, thereby joining the one column member 2A and the beam member 5 (grout filling process). Furthermore, concrete is poured between the other beam end 5t of the beam member 5 and the column-beam joint member 2J, and on the second concrete section 51B of the beam member 5 to construct the cast-in-place concrete beam section 7 (cast-in-place concrete beam section formation process).

[0045] The column-beam frame is constructed from bottom to top by sequentially repeating the above-described processes on each floor: the column member installation process, the other column member installation process, the beam member installation process, the grout filling process, the column-beam joint member installation process, and the cast-in-place concrete beam section formation process.

[0046] As described above, the method for constructing the column-beam frame of this modified example further includes: an additional column member installation step in which a column member 2 installed in the column member installation step is designated as one column member 2A, and another column member 2C shorter in height than the first column member 2A is installed at a position spaced apart from the first column member 2A; a column-beam joint member installation step in which a column-beam joint member 2J is installed on top of the other column member 2C after the beam member installation step; and a cast-in-place concrete beam section forming step in which concrete is poured between the other beam end 5t of the beam member 5 opposite to the beam end 5s that is joined to the first column member 2A and the column-beam joint member 2J to form a cast-in-place concrete beam section 7, and the column-beam joint member 2J and the beam member 5 are joined together. The column member installation step, the additional column member installation step, the beam member installation step, the column-beam joint member installation step, the grout filling step, and the cast-in-place concrete beam section forming step are repeatedly performed to construct the column-beam frame 1 from bottom to top. With the above configuration, before installing the beam member 5, both the column member 2A and the other column member 2C, to which the beam ends 5s and 5t of the beam member 5 are joined, can be erected, for example, at the same time. This allows for efficient construction and a reduction in the construction period. Furthermore, since the other column members 2C are shorter in height than the one column member 2A to which the beam member 5 is directly joined, even when the beam member 5 is installed after the other column members 2C have been erected as described above, the possibility of the other column members 2C obstructing the work is reduced. Therefore, construction can be carried out more easily.

[0047] Furthermore, the method for constructing a column-beam frame of the present invention is not limited to the embodiments and modifications described above with reference to the drawings, and various modifications are conceivable within its technical scope. For example, in the above embodiments and modified examples, each step was described as a method for constructing the column-beam frame 1, but the order of implementation and detailed procedures can be changed as appropriate. Furthermore, in the above embodiment, the beam member 5 is formed as a fully precast concrete structure at one beam end 5s, with both the lower beam main reinforcement 52B and the upper beam main reinforcement 52A embedded in the first concrete section 51A, while at the beam center 5c and the other beam end 5t, the lower beam main reinforcement 52B is embedded in the second concrete section 51B and the upper beam main reinforcement 52A is exposed above the concrete 51, thus forming a half-precast concrete structure. However, it is not limited to this. At the other beam end 5t of the beam member 5, similar to the one beam end 5s, both the lower beam main reinforcement 52B and the upper beam main reinforcement 52A may be embedded in the first concrete section 51A, forming a fully precast concrete structure. In addition to the above, it is possible to select or replace the configurations listed in the above embodiments and modifications, or to change them to other configurations as appropriate, as long as it does not deviate from the spirit of the present invention. [Explanation of Symbols]

[0048] 1 Column beam frame 5t Other beam end 2, 2A~2C Column members 51 Concrete 2A Column member 52 Main beam reinforcement 2B, 2C Other column members 52A Upper beam main reinforcement 21s Side 52B Lower beam main reinforcement 25 Protruding section 7 Cast-in-place concrete beam section 25f End surface 90 Joint formwork 5. Beam member G. Grout 5c Beam center Z joint 5f End face ZS joint space 5s One end of the beam

Claims

1. A method for constructing a column-beam frame, comprising joining precast concrete column members and beam members, The column member is provided with a projection that protrudes from the side surface of the column member, The column member installation step involves installing the aforementioned column member, A beam member installation step involves moving the beam member laterally and positioning it so that a joint space is formed between the tip surface of the protruding portion and the end surface of the beam member. The process includes a grout filling step, in which a joint formwork is provided to close the lower and side of the joint space, and grout is filled into the joint space. In the beam member installation process, the position of the beam member is determined such that when the end face of the beam member is facing the tip surface of the protruding portion, the lower surface and side surface of both the protruding portion and the beam member extend within the same plane. A method for constructing a column-beam frame characterized by the following:

2. The beam member is formed as a fully precast concrete structure at one beam end joined to the column member, with both the lower main beam reinforcement located on the lower side and the upper main beam reinforcement located on the upper side embedded in the concrete. At the center of the beam and at the other beam end, the lower main beam reinforcement is embedded in the concrete, while the upper main beam reinforcement is exposed above the concrete, forming a half-precast concrete structure. A method for constructing a column-beam frame according to feature 1.

3. The column member installation step involves setting the column member installed in the column member installation step as one column member, and installing another column member at a position spaced apart from that one column member, A cast-in-place concrete beam formation step is performed, in which concrete is poured between the beam end of the beam member opposite to the beam end joined to the column member and the other column member to form a cast-in-place concrete beam section, and the other column member and the beam member are joined together. This further includes, The column member installation process, the beam member installation process, the other column member installation process, the grout filling process, and the cast-in-place concrete beam section formation process are repeatedly performed to construct the column-beam frame from bottom to top. A method for constructing a column-beam frame according to feature 1.

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