JP6416713B2 - Precast concrete beam member and method of introducing prestress into precast concrete beam member - Google Patents

Description

  The present invention is a precast concrete beam member constructed between adjacent column members and having a tension member disposed therein, and the beam member is installed between adjacent column members, and the beam member is prestressed by tension of the tension member. It is about the method of introducing.

  For example, in the method of building a column / beam frame by using precast concrete column members and beam members, joining the beam members to the column members by tension and fixing of the PC steel material that passes through the beam members along the axial direction. After installing the beam member between the adjacent column members, the PC steel material is inserted into the sheath embedded in the beam member, and after the tension of the PC steel material, the end of the PC steel material is fixed to the side surface of the column member, etc. (See Patent Documents 1 to 3).

  Here, if the PC steel material is to be inserted into the sheath of the beam member before laying the beam member between the column members, either end of the PC steel material is stretched in the axial direction of the beam member due to tension. Since it is necessary to make it protrude from an end surface, it becomes impossible to drop a beam member between pillar members. In this relation, the PC steel material is basically inserted into the beam member together with the column member after the beam member is installed (Patent Document 1).

JP 2006-176986 A (paragraphs 0034 to 0041, FIGS. 4 to 10) JP 2009-221692 A (paragraph 0024, FIG. 4) Japanese Utility Model Publication No. 51-45844 (Fig. 5)

  When inserting a PC steel material into a sheath requires a crane or a dedicated pushing machine, as described above, when the PC steel material is inserted into the beam member after the beam member is installed between the column members Since the insertion distance of the PC steel material is the entire length of the beam member, it takes time for the insertion at the site, and the work of inserting the PC steel material into each beam member has to be prolonged.

  When PC steel material is inserted into the sheath after the beam member is installed between the column members and the end of the beam member is fixed to the column member, there is a possibility that an indefinite force is generated in the column member due to the tension of the PC steel material. There is. In this method, each time the beam member is installed, the PC steel material is inserted into the sheath and fixed to the column member. Therefore, the installation of the column member and the beam member must be performed in units of layers.・ This is limited to the laminating method in which the beam frame is built up to the upper layer in units of one layer, and the degree of freedom in building the frame is limited.

  From the above background, the present invention proposes a precast concrete beam member capable of shortening the insertion time of the PC steel material into the beam member and avoiding the generation of an unsteady constant force on the column member, and a method for introducing prestress into the beam member. To do.

The precast concrete beam member of the invention according to claim 1 is a beam member made of precast concrete that is laid between adjacent column members and in which a tension member having a peripheral surface cut is disposed.
One end of the tendon is fixed inside the beam member near one end in the axial direction, and the other end of the tendon is the other end surface in the axial direction of the beam member. A sheath through which the tension member disposed in the other beam member can be inserted at a position where there is no interference with the tension member in the beam member, and the tension member is fixed to the sheath. It is arranged in the section from the end face on the other side to the intermediate part in the axial direction of the beam member, and the end part of the sheath on the intermediate part side communicates with the surface of the beam member.

  One end of the tension member 3 is fixed in advance in the vicinity of one end of the beam member 2 in the axial direction, and the other end of the tension member 3 is on the other side in the axial direction of the beam member 2. By projecting from the end surface, as shown in FIG. 1, FIG. 4, etc., the section protruding from the end surface of the beam member 2 of the tension member 3 penetrates the column member 1 located on that side, and sandwiches the column member 1. If it has a length that reaches the end of the sheath 4 in the opposite beam member 2 (Claim 2), the other end of the tendon 3 is opposed across the column member 1 positioned on that side. Thus, it is possible to continuously insert the beam member 2 (previously erected) and fix it at that position. “Inside the end of the beam member 2” means the inside of the concrete. In this case, the “column member 1” is, as will be described later, in a case where the joining portion 21 continuous with the column member 1 is integrated on the “side where the end portion of the tension member 3 is fixed” (Claim 3), It becomes the junction 21. That is, the “column member 1” referred to in claim 2 includes the “joining portion 21” of claim 3.

  The “end portion of the sheath 4 in the beam member 2” in claim 2 refers to the “end portion on the intermediate portion side in the axial direction of the beam member 2” in “communication with the surface of the beam member 2” in claim 1. If the section protruding from the end face of the beam member 2 of the tendon member 3 has a length that reaches the end of the sheath 4 in the beam member 2 facing the column member 1 located on the side thereof (Claim 2). ), The tension member 3 can be tensioned at the portion protruding from the sheath 4 and can be fixed to the beam member 2.

  The “end surface on the side where the tension member 3 is fixed” in claim 1 is an end surface on the side where the end portion of the tension member 3 in the beam member 2 in which the sheath 4 is embedded is fixed. As will be described later, this end face is connected to the column member 1 on the “side where the end of the tension member 3 is fixed” of the beam member 2 as shown in FIG. When these are integrated (Claim 3), the end portion of the joint portion 21 becomes the end surface on the side where the end portion of the tendon 3 is fixed. In this case, the end of the tendon 3 is fixed in the joint 21 of the beam member 2.

  The end of the tension member 3 on the other side (the preceding beam member 2 side) passes through the column member 1 (joining portion 21) on that side, and passes through the sheath 4 of the beam member 2 positioned at the tip (preceding). To do. The “tensioning material 3 disposed in another beam member 2” inserted through the sheath 4 in claim 1 is a tension previously disposed in the beam member 2 in which the sheath 4 is embedded (previously erected). The tension member 3 is not the member 3 but refers to the tension member 3 that is arranged in advance on the beam member 2 adjacent to the side of the beam member 2 on which the tension member 3 is fixed (constructed later).

  In claim 1, the end of the other side of the tendon 3 is inserted through the sheath 4 in the beam member 2 on that side, and is fixed at that position. It is not necessary to fix both ends to the column member 1, and the generation of an inconstant force on the column member 1 when the end of at least one side of the tension member 3 is fixed to the column member 1 is avoided. . PC steel is mainly used as the tension material 3, but materials capable of introducing tension, such as fiber reinforced plastic, are also used.

  The tendon 3 is inserted through the sheath 4 over the entire length of the section in the beam member 2 arranged in advance and the section that protrudes from the beam member 2 and passes through the sheath 4 of the beam member 2 adjacent to the section. Since a tension force is applied to the surface of the previous beam member 2, the peripheral surface of the tension member 3 in the section in the beam member 2 arranged in advance is kept in a state where the adhesion with the surrounding concrete is cut off. In this relation, when the tension material 3 is a PC steel material, an unbonded PC steel material or a pre-grout PC steel material is used, and the case of other materials also conforms to this. When the tension member 3 is tensioned at the point where the sheath 4 is inserted, the end portion on one side of the tension member 3 is fixed in the beam member 2, so that the section other than the end portion is extended.

  The sheath 4 is embedded in a cross section orthogonal to the material axis of the beam member 2 at a position where there is no interference with the tension member 3 inserted in the beam member 2, and the side of the beam member 2 on the side where the tension member 3 is fixed in advance. It arrange | positions in the area from the end surface to the intermediate part of the axial direction of the beam member 2. FIG. Of the total length of the beam member 2, the end of the sheath 4 on the side where the end of the tension member 3 is fixed in advance communicates with the end surface of the beam member 2, and the opposite end is the axial direction of the beam member 2. The end of the tension member 3 that is communicated with any surface of the beam member 2 at the intermediate portion and the sheath 4 is inserted into this surface is fixed. “The end of the sheath 4 on the side where the end of the tendon 3 is fixed beforehand” is connected to the column member 1 on the “side where the end of the tendon 3 is fixed” as shown in FIG. When the joint part 21 of the beam member 2 in which the part 21 is integrated is arranged (Claim 3), the end face of the joint part 21 is obtained.

  As shown in FIG. 3D, which is a cross-sectional view taken along the line ee of FIG. 1, the sheath 4 has a tension member 3 arranged in advance in the beam member 2 in which the beam member 2 is embedded, as shown in FIG. Since the “surface of the beam member 2” communicating with the intermediate portion in the axial direction of the beam member 2 only needs to be at a position where there is no interference with the tension member 3 arranged in advance. , Refers to the upper surface, lower surface, or side surface of the beam member 2. 2 shows an example in which the upper surface of the beam member 2 is the surface, and FIG. 10 shows an example in which the side surface of the beam member 2 is the surface.

  In the sheath 4, basically, the column member 1 (joining portion 21) facing the end surface of the beam member 2 is sandwiched from the end portion of the sheath 4 communicating with the end surface of the beam member 2 in which the sheath 4 is embedded. As the beam member 2 installed on the opposite side (afterwards) moves to the column member 1 side, the tension member 3 protruding from the end face of the beam member 2 is inserted.

  Since the tension member 3 protrudes from the end surface of the beam member 2 on which the tension member 3 to be inserted into the sheath 4 is arranged in advance, the tension member 3 protruding from the end surface of the beam member 2 is provided. As the beam member 2 moves to the column member 1 side, the beam member 2 penetrates through the column member 1 (joining portion 21) and enters the sheath 4 of the beam member 2 that is erected (preceded) to the end of the column member 1. It is inserted (Claim 2, Claim 5). As shown in FIGS. 2 and 10, the tendon 3 inserted through the sheath 4 protrudes from the intermediate portion in the axial direction of the beam member 2, which is the end of the sheath 4 in the beam member 2, to the surface of the beam member 2. And is fixed to the beam member 2.

  According to the second aspect, the movement of the beam member 2 on which the tension member 3 is arranged in advance toward the column member 1 side completes the insertion of the tension member 3 into the sheath 4 of the beam member 2 installed in advance. As described above, the section of the tension member 3 protruding from the end face of the beam member 2 passes through the column member 1 (joint portion 21) located on the side, and reaches the beam member 2 facing the column member 1 therebetween. Although it has length, in Claim 1, the tension | tensile_strength should just protrude from the end surface at the side of the column member 1 of the beam member 2 at least.

  According to the first aspect, it is not always necessary to insert the tension member 3 into the sheath 4 of the beam member 2 facing each other across the column member 1 only by moving the beam member 2 on which the tension member 3 is arranged in advance to the column member 1 side. Alternatively, the portion of the tension member 3 that passes through the column member 1 and reaches the beam member 2 can be separated from the main body of the tension member 3 disposed in advance in the beam member 2. In that case, for example, the separated portion of the tension member 3 is inserted into the sheath 4 from the axially intermediate portion side of the beam member 2 erected in advance, and the tension member 3 protruding from the beam member 2 erected later. It is also possible to fix the tension in the intermediate portion of the preceding beam member 2 after connecting to the main body portion other than the separated portion.

  At least in claim 2, the tension member 3 protruding from the other end face of the beam member 2 is directed to the column member 1 side facing the protruding side of the tension member 3 of the beam member 2 on which the tension member 3 is arranged. By the movement, the beam member 2 is inserted into the sheath 4 of the already installed beam member 2 across the column member 1 (Claim 5). Therefore, the plurality of beam members 2, 2 installed on the same line in the axial direction of the beam member 2 are sequentially column members from the beam member 2 positioned on the side from which the tension member 3 protrudes as shown in FIG. It will be installed between 1 and 1. By moving the beam member 2 in the axial direction, the tension member 3 protruding from the end surface on the moving side can be inserted into the column member 1 located on the side or the sheath 4 of the adjacent beam member 2. As described above, the tension material 3 is made of a material that is not adhered to the peripheral surface.

  Due to the movement of the beam member 2 on which the tension member 3 is arranged to the column member 1 side, the tension member 3 protruding from the end face of the beam member 2 penetrates the column member 1 and If the tendon 3 is inserted into the sheath 4 from the end face, the distal end portion of the tendon 3 can be guided to the inner peripheral surface of the sheath 4 and the sheath 4 itself can be inserted through the sheath 4 due to the rigidity of the tendon 3 itself. . For this reason, basically, the entire length of the protruding section of the tension member 3 can be inserted into the sheath 4 by moving the beam member 2 to the column member 1 side. The end of one side of the tendon 3 is fixed in advance to the end of the beam member 2 moved to the column member 1 side opposite to the moving side. The end portion on the side protruding from 4 is tensioned and fixed on the surface of the beam member 2 in which the sheath 4 is embedded, so that the entire length of the beam member 2 on which the tension member 3 is disposed and the sheath 4 are embedded. Prestress is introduced into the section of the sheath 4 of the beam member 2.

  Even if the section of the tendon 3 protruding from the end face of the beam member 2 has a length that reaches the beam member 2 that has been installed on that side (Claim 2), the tendon 3 is not the sheath 4 either. When the tension member 3 is tensioned on the surface of the beam member 2 on the side through which the tension member 3 is inserted, the tension member 3 straddles the beam member 2 to be installed later and the already installed beam member 2. At the same time that prestress is introduced into the member 2 in the axial direction, the beam members 2 adjacent to each other in the axial direction are joined to each other with the column member 1 interposed therebetween, and the beam member 2 is joined to the column member 1 at the same time. become.

  While the tension member 3 is disposed from one end in the axial direction of one beam member 2 to the other end (end surface), the tension member 3 projects from the other end surface. The sheath 4 is embedded in the section from the end (end surface) on the side where the tendon 3 is fixed to the intermediate portion in the axial direction. As a result, in the section from one end of the beam member 2 to the middle portion, two types of tension members 3 and 2 of the tension member 3 that is arranged in advance and the tension member 3 that is inserted into the sheath 4 afterwards. Will be placed in duplicate.

  As described above, the length of the tension member 3 that is inserted into the sheath 4 later by the movement of the beam member 2 on which the tension member 3 is arranged in advance to the column member 1 side is an embedded section of the sheath 4. 2, it is not necessary to be inserted through the entire length of the beam member 2. Accordingly, the insertion distance of the tendon 3 at the site is shortened, and the insertion time is also shortened.

  Since the beam member 2 is installed between the column members 1 and 1, both ends in the axial direction of the beam member 2 are joined to the column members 1 and 1. Since the end of one side of the tendon 3 is fixed to the end of (No. 1), the end of that side is disposed on the head of the column member 1 as shown in FIG. If the joint portion 21 continuous with the column member 1 is integrated (Claim 3), the volume of one end portion of the beam member 2 can be increased, and the tension member 3 is placed in one end portion of the beam member 2. It is possible to secure a sufficient space for fixing.

  The joint portion 21 corresponds to the head portion and the leg portion of the column member 1 and is a portion that becomes a part of the column member 1 and has a width larger than the width of the main body portion 22 of the beam member 2 excluding the joint portion 21. Therefore, the dense state of the tendon 3 can be relaxed in the joint 21. Since the joining portion 21 is placed on the top end of the pillar member 1 installed or constructed below and joined to the pillar member 1, the joint member 21 is separated from the pillar member 1, but is attached to the pillar member 1. Continuous in the direction. For this reason, at least a restraint bar 1b for restraining the columnar main bar 1a is disposed in the joint portion 21, but by using the gap between the restraint bars 1b and 1b, the tension material 3 in at least one direction is placed on the restraint bar 1b. It becomes possible to arrange | position, avoiding interference with. Hereinafter, when the joint portion 21 is integrated with the beam member 2, a portion other than the joint portion 21 is referred to as a main body portion 22.

  For example, as shown in FIGS. 3A and 12 which are cross-sectional views taken along the line bb in FIG. 1, the joint 21 is disposed in the column member 1 installed between the upper and lower joints 21 and 21. The column main reinforcement 1a is arranged by the straight column main reinforcement 1a passing through the joint portion 21. When the column main reinforcement 1a in the column member 1 passes through the joint portion 21 and is arranged in the joint portion 21, an insertion hole for the column main reinforcement 1a to penetrate is formed at the position of the column main reinforcement 1a of the connection portion 21. Is done. In this case, the column main reinforcing bar 1a is connected to the column main reinforcing bar 1a in the column member 1 mainly by a sleeve joint or the like in the column member 1 other than the joint portion 21. May be buried and the columnar main bars 1a may be connected in the joint 21.

  Further, in the present invention, the joint portion 21 is integrated with the end portion in the axial direction of the beam member 2 in any one of the beam members 2 and 2 constructed in two directions on the plane. Since 21 becomes a part of the beam member 2, the joint portion 21 is an end portion of the beam member 2 that is installed on the side of the opposite end face while the joint portion 21 is placed on the installed column member 1. What is necessary is just to construct between the adjacent pillar members 1 and 1 in which the beam member 2 is installed so that it may be matched with 21. FIG. In this case, the beam member 2 is horizontally moved in the axial direction so that the end surface of the main body portion 22 of the beam member 2 from which the tension member 3 protrudes approaches the joint portion 21 side of the beam member 2 that has been installed. The beam members 2 and 2 arranged in the above can be installed. The column member 1 can be joined to the beam member 2 by dropping a column member made of precast concrete having no leg and head as shown in FIG. 12 onto the joint portion 21 of the already installed beam member 2. become. However, the column member 1 does not necessarily need to be made of precast concrete, and may be constructed with a cast-in-place concrete structure.

  When the column member 1 is a side column in the span direction or the row direction and a corner column, as shown in FIGS. 4, 6, and 7, two-direction tension members 3, 3 are formed in the joint portion 21. The end of the can also be arranged. In these cases, since the beam member 2 is moved in the axial direction of the main body portion 22 as described above, the beam direction 2 (Y direction) in the drawing and is abutted against the beam member 2 (joining portion 21) adjacent to the side, In the span direction (X direction) in the orthogonal direction, the beam member 2 having only the main body portion 22 without the joint portion 21 is erected, and the width of the main body portion 22 is added to the beam member 2 with the junction portion 21 already erected. Matched in the direction.

  The tension member 3 may be arranged in one step in the height direction of the beam member 2, but for the purpose of reducing the tension force to be applied to one tension member 3 or the height in the cross section. A plurality of stages may be arranged for the purpose of adjusting the pre-stress every time. In this case, the end of each tension member 3 on the side of the beam member 2 facing the column member 1 on the side protruding from the end surface of the beam member 2 is inserted through the sheath 4 in the beam member 2, and the beam member 2. It protrudes on the surface of the (claim 4). The surface of the beam member 2 is the upper surface, the lower surface, or the side surface of the beam member 2. The end portion of the tension member 3 that has passed through the sheath 4 in the beam member 2 and protruded from the surface of the beam member 2 is fixed to the surface of the beam member 2 after being given a tension.

  In claim 4, when fixing a plurality of tension members 3 on the same surface, for example, the upper surface side or the lower surface side as shown in FIG. 2, the main body of the plurality of beam members 2. In order to shift the fixing position in the portion 22 in the axial direction, the lengths of the plurality of tension members 3 and 3 are different, and each tension member 3 communicates with the surface of the beam member 2 from a different position in the axial direction of the beam member 2. When fixing a plurality of tension members 3 on the side surfaces on both sides in the width direction as shown in FIG. 10 among the surfaces of the beam member 2, the fixing positions of the plurality of tension members 3 and 3 are set in the height direction. Since it can be made different, it is not necessary to make the lengths of the tension members 3 and 3 in a plurality of stages different.

  In the case of the example shown in FIG. 2, the tension members 3 are arranged in a plurality of stages in the height direction, so that the prestress to be introduced into each part in the height direction on the longitudinal section perpendicular to the material axis of the beam member 2. The amount can be adjusted. Further, since the fixing positions of the plurality of tension members 3 and 3 on the surface of the beam member 2 are different in the axial direction, it is possible to adjust the amount of prestress to be introduced in the axial direction for each axial section. Become.

  The beam member 2 according to claims 1 to 4 is constructed between the column members 1 and 1 adjacent to each other in the axial direction as described above, and the tension member 4 in the beam member 2 is tensioned so that the beam member 2 has a shaft. Prestress is introduced in the direction. Specifically, the protruding section of the tension member 3 protruding from the end face of the beam member 2 passes through the inside of the sheath 4 of the beam member 2 facing the column member 1 on the side and the column member 1 (joining portion 21) therebetween. Prestress is applied to the beam member 2 by being inserted and tensioned at the intermediate portion of the beam member 2 in the axial direction.

  According to this method, the tension member 3 is tensioned and fixed every time the beam member 2 is installed between the column members 1 and 1 adjacent to each other in the axial direction of the beam member 2. Is not necessarily fixed to the column member 1, and it is not always necessary that the column members 1, 1 are installed at both ends in the axial direction of the beam member 2 when the tension member 3 is tensioned. For this reason, the construction method of the frame is not limited to the laminating method in which the frame is constructed in units of one layer, but every time a multi-layered frame is constructed from one side on the plane, it is constructed toward the other side. The construction method in can also become possible, and the freedom of frame construction will increase.

  In particular, when the joint portion 21 is integrated on one side of the beam member 2 in the axial direction (Claim 3), the beam members 2 and 2 arranged on the same line in the axial direction as shown in FIG. The beam member 2 adjacent to the end surface side of the main body portion 22 is first installed while the end surface of the main body portion 22 is directed to the front side in the installation direction, and then the beam adjacent to the joint portion 21 of the already installed beam member 2. The members 2 can be erected sequentially in the axial direction in such a manner that the members 2 are erected so as to abut the end surfaces of the main body 22.

  According to this installation procedure, since the joint portion 21 of the beam member 2 is supported by the installed column member 1 below the beam member 2, the column member 1 below is installed or constructed before the beam member 2 is installed. However, it is possible to select a procedure for installing the beam member 2 adjacent in the axial direction immediately after the installation of the beam member 2 or installing the column member 1 on the beam member 2 immediately after the installation. Therefore, it is possible to construct a frame on the same floor in advance (lamination method), or to construct a structure for all the floors in a part of the plane in advance (built escape method).

  One end of the tendon is fixed inside the beam member near one end in the axial direction, and the other end of the tendon is projected from the other end surface in the axial direction of the beam member. By embedding a sheath in the section of the beam member from the end surface on the side where the tendon material is fixed to the intermediate portion in the axial direction, the tendon material is fixed to the intermediate portion of the beam member adjacent to the protruding side. Therefore, it is not necessary to fix both ends of the tension member to the column member, and generation of static instability force on the column member when fixing at least one end of the tension member to the column member is generated. Can be avoided.

  The tension material that can be inserted into the sheath is the section from one end to the middle of the beam member, and it is not necessary to be inserted through the entire length of the beam member. In addition, the insertion time can be shortened.

FIG. 10 is a plan view showing an example of the arrangement of the beam members in the two directions and the arrangement of the tension members in the beam members in each direction when the column member is the middle column of the frame in FIG. It is an enlarged view. It is the sectional view on the aa line of FIG. 1A is a sectional view taken along the line bb in FIG. 1, FIG. 1B is a sectional view taken along the line cc in FIG. 1, FIG. 1C is a sectional view taken along the line dd in FIG. FIG. FIG. 10 is a plan view showing an example of the arrangement of two-way beam members and the arrangement of the tension members in the beam members in each direction when the column member is a side column on one side in the span direction of the frame in FIG. It is an enlarged view of B part. It is the sectional view on the aa line of FIG. 9 is a plan view showing an example of the arrangement of the tension members in the beam members in each direction and the engagement of the beam members in the two directions when the column member is a side column on one side of the frame in FIG. It is an enlarged view of C part. FIG. 10 is a plan view showing an example of the arrangement of the beam members in the two directions and the arrangement of the tension members in the beam members in each direction when the column member is the corner column of the frame in FIG. It is an enlarged view. It is the sectional view on the aa line of FIG. It is the top view which showed the arrangement | positioning state of the example of a structure which consists of the beam member erected in two directions, and the column member arrange | positioned in the junction part which cross | intersects, and the tension material in a beam member. It is the top view which showed the example of formation of the beam member in the case of fixing a plurality of stages of tension members on the both side surfaces of the beam member (main body part) and the fixation state of the tension members. It is the sectional view on the aa line of FIG. It is the perspective view which showed the point of the bridge | crossing between the column members of the beam member of a row direction, and the insertion of a tension material to the preceding beam member when a junction part is integrated in the one side of the beam member of a row direction. .

  FIG. 1 shows a frame as shown in FIG. 9 which is composed of a column member 1 and precast concrete beam members 2 and 2 installed between adjacent column members 1 and 1, and a peripheral surface is attached inside. The example of arrangement | positioning of the tension material 3 in the inside of the beam member 2 which the cut tension material 3 penetrated is shown. FIG. 1 is an enlarged view of a portion A in FIG. 9 and is arranged in a column member 1 as a middle column and beam members 2 and 2 in two directions as beam members 2 and 2 which are joined to each other in both directions in two directions. The relationship of the tendon 3 to be shown is shown.

  One end of the tension member 3 is fixed to the inside of the beam member 2 near one end in the axial direction, and the other end of the tension member 3 is the end surface on the other side in the axial direction of the beam member 2. Protrude from. In addition, a sheath 4 through which the tensioning material 3 arranged in the other beam member 2 can be inserted is embedded in the beam member 2 at a position where there is no interference with the tensioning material 3, and the tensioning material 3 is fixed to the sheath 4. The end portion on the intermediate portion side of the sheath 4 communicates with the surface of the beam member 2 and is disposed in a section from the end surface of the beam member 2 on the other side to the intermediate portion in the axial direction of the beam member 2. In FIG. 1 which is a plan view and FIG. 2 which is a cross-sectional view along the line aa, a broken line surrounding the tendon 3 indicates the sheath 4. In the beam member 2, in addition to the tendon 3 and the sheath 4, a beam main bar 2 a and a restraint bar 2 b for restraining it are arranged. The “other beam member 2” refers to the beam member 2 adjacent to the side of the beam member 2 in which the sheath 4 is embedded, to which the end of the tendon 3 is fixed.

  The “end surface on the side of the beam member 2 on the side where the tendon 3 is fixed” is an end surface on the side where the end of the tendon 3 is fixed in the axial direction of the beam member 2, and is shown in the example in FIG. Thus, when the joining part 21 continuing to the column member 1 is integrated on the fixing side of the tendon material 3, the end face of the joining part 21 on the side where the end part of the tendon material 3 is fixed is shown in FIG. As shown in FIG. 2, the sheath 4 is embedded from the end surface of the joint portion 21 on the beam member 2 side adjacent to the joint portion 21. In the drawing, the sheath 4 is shown by a broken line in order to distinguish it from the tendon 3 in the beam member 2 regardless of whether the sheath 4 is a cross section or not.

  In FIG. 1 and subsequent figures, a joint portion 21 which is arranged at the head of the column member 1 on one side in the axial direction of the beam member 2 laid in the row direction in FIG. Although an example in the case of integration is shown, it is not always necessary. In the drawing, since the joint portion 21 is integrated with the beam member 2 in the column direction, the joint portion 21 is not integrated with the beam member 2 installed in the span direction.

  The pillar member 1 in a plan view such as FIG. In the drawing, a case is shown in which the joint 21 is integrated on the side of the beam member 2 facing the beam direction (Y direction) in FIG. 9 where the end of the tendon 3 is fixed, but in the span direction (X direction). In some cases, the joint portion 21 is integrated with the beam member 2 facing to the side where the end portion of the tension member 3 is fixed. Since the joint portion 21 of the beam member 2 becomes a part of the column member 1, as shown in FIG. 3A, the column main reinforcement 1 a arranged in the column member 1 when the frame is constructed in the joint portion 21. The restraint muscle 1b is arranged.

  FIG. 1 shows a relationship between a column member 1 which is a middle column to which beam members 2 are joined on both sides in two directions and a beam member 2 in two directions. In the example shown in the drawing, the beam member 2 facing in the column direction is integrated with the column member 1 at its end on the one column member 1 side so that the joining portion 21 continuous in the axial direction is integrated with the column member 1. One end of the member 2 is a joint 21. The beam member 2 in this case is composed of two parts: a main body part 22 excluding the joint part 21 and a joint part 21 integrated with one end of the main body part 22 in the axial direction. There is no joint 21 in the beam member 2 in the span direction.

  When the joint portion 21 is integrated with the beam member 2, it does not matter whether one end of the tension member 3 is fixed on either side in the axial direction of the beam member 2, but it continues to the column member 1. The joining portion 21 to be made can have a width larger than the width of the main body portion 22, and it is easy to secure a space for fixing one end of the tension material 3 in the joining portion 21. The end of one side of the tendon 3 is fixed. An end portion on the fixing side of the tendon 3 is a fixing tool 31 described later.

  When the joint portion 21 is integrated with the beam member 2, the sheath 4 continues in the axial direction from the end surface of the joint portion 21 on the side of the beam member 2 adjacent to the side to the inside of the main body portion 22 as shown in FIG. 1. Buried. When the column member 1 is a middle column, the tension member 3 of the beam member 2 in the span direction also penetrates the column member 1, so that the sheath 4 is embedded between both end surfaces in the span direction in the joint portion 21. The The sheath 4 in the span direction is disposed only in the joint portion 21.

  Since the joint portion 21 is located at one end portion in the axial direction of the beam member 2, it also has a function of fixing the end portion on the fixing side of the tension member 3 arranged in advance in the beam member 2. The tendon 3 protrudes from the end face of the main body 22 opposite to the joint 21 and is inserted into the sheath 4 of the beam member 2 adjacent to the side. In this relationship, the beam member 2 with the joint portion 21 is constructed so as to abut the end surface of the main body portion 22 against the joint portion 21 of the beam member 2 constructed in advance as shown in FIG. Become. Accordingly, the plurality of beam members 2 installed on the same line in the direction of the beam are preceded by the adjacent beam member 2 on the end face side of the main body 22, and the installed beam member 2 is compared with the installed beam member 2. The beam member 2 adjacent to the joint portion 21 side is constructed later with the end face of the main body portion 22 facing the joint portion 21 of the preceding beam member 2.

  Thus, when constructing a frame with the beam member 2 in which the joint portion 21 is integrated, for example, directed in the row direction, the beam member 2 is directed in the row direction with the end face of the main body portion 22 facing the joint portion 21 of the preceding beam member 2. Each time the tension member 3 in the beam member 2 immediately after the installation is inserted into the sheath 4 of the preceding beam member 2 to be tensioned and fixed, it is successively adjacent to the joint 21 of the beam member. The beam members 2 and 2 arranged on the same line can be made continuous by repeating the installation of the beam members 2 to be performed.

  In this case, although the beam member 2 without the joint portion 21 is installed in the span direction, the tension member 3 protrudes from the end surface of the tension member 3 opposite to the fixing side end portion in the beam member 2. Therefore, as shown in FIG. 1, the tension member 3 penetrates the sheath 4 of the joint portion 21 of the beam member 2 in the transverse direction located on the protruding side, and the span-direction beam facing the joint portion 21 therebetween. It is inserted through the sheath 4 of the member 2. In this relation, the beam member 2 in which the tension member 3 protrudes from the end face is erected in the span direction in the same manner as the beam direction, and the sheath 4 into which the tension member 3 of the beam member 2 is inserted is embedded. It is reasonable to lay the member 2 in advance.

  Since the joint portion 21 of the beam member 2 in the beam direction is arranged at the position of the column member 1 on the plane, the column member 1 is manufactured in a form having no leg portion and head when made of precast concrete as described above. Therefore, the column member 1 is installed on the beam member 2 by being dropped onto the joint portion 21 after the beam member 2 is installed in the crosswise direction as shown in FIG. The column main reinforcement 1a of the column member 1 protrudes from, for example, the lower end of the main body (concrete) of the column member 1, passes through the joint portion 21, and is inserted into the column member 1 already installed thereunder. The column main bars 1a in the column member 1 are connected to each other. In this case, an insertion hole for penetrating the column main reinforcement 1 a is formed in the joint portion 21.

  Since the joint portion 21 of the beam member 2 in the row direction is placed on the top end of the column member 1 that has been installed or constructed below, the column below the beam member 2 is installed before the beam member 2 in the row direction is installed. The installation and construction of the member 1 need to be completed. However, after the beam member 2 is installed in the beam direction 2, it is optional whether the beam member 2 adjacent in the axial direction (column direction) is installed or the column member 1 is installed on the beam member 2 after installation. Therefore, it is free to construct the frame on the same floor in advance in all the frames, or to construct the frames for all the floors in advance in the area on one side in the direction of the line in the entire plane of the frame. This “one side in the column direction” refers to the beam member 2 side constructed in advance among the beam members 2 and 2 that are continuous in the column direction 2.

  In FIG. 1, the end of the tension member 3 on the fixing side is fixed in the joint portion 21 of the beam member 2 facing in the direction of the beam, and the support plate 32 is integrated with the end of the tension member 3 on the fixing side. The fixed fixing tool 31 is integrated, and the fixing tool 31 with the pressure bearing plate 32 is embedded in the concrete of the joint 21 and fixed. Reinforcing bars 33 for reinforcing concrete against the bearing stress from the bearing plate 32 are arranged around the tension member 3 on the tension member 3 side of the bearing plate 32. In the drawing, a spiral bar that surrounds each tension member 3 is used as the reinforcing bar 33 in the beam member 2 (main body portion 22), and the two tension members 3 and 3 that are juxtaposed as the reinforcing bar 33 in the joint portion 21 are surrounded. Uses stirrup-like restraint. The tension material 3 having the fixing device 31 at the end fixed to the joint portion 21 is disposed along the axial direction from the joint portion 21 to the entire length of the main body portion 22, and the end portion on the opposite side of the fixing device 31 is the main body portion. 22 protrudes from the end face.

  In the drawing, since the joint portion 21 is integrated on one side of the beam member 2 in the column direction, the beam member 2 facing in the span direction does not have the joint portion 21 as described above. A fixing tool 31 with a pressure bearing plate 32, which is an end portion of the tension member 3 disposed in advance in the beam member 2, is fixed to one end portion in the axial direction.

  The section of the tendon 3 that protrudes from the end face of the beam member 2 (main body portion 22) passes through the column member 1 positioned on the side in principle, and in the beam member 2 opposed to the column member 1 therebetween. It has a length that reaches the end of the sheath 4. The “column member 1” referred to here is the joint 21 when the joint 21 is integrated with the beam member 2. In that case, since the joining portion 21 is a part of the beam member 2, the tension member 3 protruding from the end face of the beam member 2 (main body portion 22) is directly connected to the joining portion 21 of the beam member 2 adjacent to the protruding side. To reach. The section protruding from the end face of the beam member 2 of the tension member 3 has a length that faces the end of the sheath 4 in the adjacent beam member 2 by facing the column member 1 on that side, or reaching the end of the sheath 4 in the adjacent beam member 2. 2, the tension member 3 protruding from the sheath 4 can be tensioned by the jack 7 and fixed to the beam member 2.

  “In principle” means that the section of the tendon 3 that protrudes from the end surface of the main body 22 may not have a length that reaches the end of the sheath 4 in the beam member 2 that faces the tension member 3. It is. In that case, from the portion where the sheath 4 communicates with the surface of the intermediate portion in the axial direction of the beam member 2, a connecting tension material to be connected to the tension material 3 protruding from the end face of the main body portion 22 is inserted, In the state where it is connected to the protruding tension member 3 at or near the protruding portion and is integrated, the integrated tension member 3 at the end of the sheath 4 can be tensioned and fixed.

  The section of the tendon 3 that protrudes from the end face of the main body portion 22 is inserted through the sheath 4 embedded in the beam member 2 adjacent to that side, and the entire length of the tendon 3 is tensioned on the surface of the beam member 2. Therefore, in the beam member 2 where the tendon 3 is disposed in advance, the peripheral surface of the tendon 3 is placed in a state where the adhesion with the surrounding concrete is cut off. For this reason, unbonded PC steel and pre-grout PC steel are mainly used as the tension material 3, but fiber-reinforced plastics can be used if the peripheral surface is not attached.

  As shown in FIG. 1, the tension member to which the fixing device 31 at the end is fixed both in the beam member 2 in the beam direction in which the joints 21 are integrated and in the beam member 2 in the span direction without the joints 21. 3 and the tension material 3 that is inserted into the sheath 4 later, the sheath 4 is shown in a plan view, a longitudinal section, and a sectional view taken along the line dd in FIG. Thus, it is embedded at a position where there is no interference with the tension member 3 arranged in the beam member 2 in advance. In the drawing, the pre-arranged tendon material 3 and the tendon material 3 inserted into the sheath 4 afterwards are arranged on the plane so as not to overlap each other, but may be arranged on the longitudinal section so as not to overlap each other.

  In the drawing, in order to adjust the amount of prestress introduced for each height in the cross section perpendicular to the material axis of the beam member 2, a plurality of tension members 3 are arranged in the beam member 2 in the height direction. doing. In this case, as shown in FIG. 1 and FIG. 2, when fixing the end of the tension side of all the tension members 3 to the same surface (upper surface or lower surface) of the beam member 2, The lengths are made different, and the fixing positions on the tension side of the tension members 3 in each step are made different in the axial direction of the beam member 2. When fixing the end on the tension side of each tension member 3 to a different surface (side surface) of the beam member 2, it is not necessary to make the lengths of the tension members 3 in each step different.

  In FIG. 1, the tension-side fixing positions of the tension members 3 arranged in the span-direction beam member 2 are different in the axial direction of the beam member 2. The main body portion 22 has the same structure as that of the beam member 2 in the span direction except for the end portion on the fixing side of the tension member 3 in the beam member 2 in the span direction. That is, the arrangement state of the sheath 4 in the beam member 2 in the beam direction and the formation state of the storage portion 2a described later in which the end portions of the sheath 4 are exposed at a plurality of axially intermediate portions of the beam member 2 are the beams in the span direction. Since there is no difference with the member 2, the cross section when the main-body part 22 of the beam member 2 of a row direction is seen in the width direction is the same state as FIG.

  In the example of FIGS. 1 and 2, the tension members 3 are arranged in three stages in the height direction, and the protruding portion (fixing portion) of the tension material 3 protruding from the sheath 4 is fixed on the upper surface of the beam member 2. The length of the three-stage tension material 3 is made different, and the length of the lower-stage tension material 3 is made larger than the length of the upper-stage tension material 3, but the sheath of the tension material 3 as shown in FIG. When fixing the portions protruding from 4 on both sides in the width direction of the beam member 2, it is not necessary to make the lengths of the three-stage tension members 3 different.

  As shown in FIG. 2, when a plurality of stages of tension members 3 are fixed on the upper surface of the beam member 2 (main body portion 22), fixing on the upper surface side of the beam member 3 to fix the end portion on the tension side of the tension member 3. As a space for storing the plate 34 and the fixing device 35 that is locked to the fixing plate 34, a storage portion 2a having a shape in which precast concrete is cut out from the upper surface side is formed, and the inside of the storage portion 2a on the side of the tension material 3 is formed. The fixing plate 34 is locked to the peripheral surface. Further, the sheath 4 arranged at each stage is inclined from the position where the tension members 3 are arranged to the storage portion 2a at the fixing position of each tension member 3 while being curved in a curved shape. Since the storage portion 2a is filled with concrete by fixing the tension material 3 and placing concrete of the slab 5 after the slab reinforcement 6 is arranged, the end portion of the tension material 3, the fixing plate 34, and the fixing tool are filled. 35 is embedded in concrete.

  As shown in FIGS. 10 and 11, when fixing the multi-stage tension members 3 in the example of FIG. 1 to both side surfaces of the beam member 2 (main body portion 22), the cross section of the beam member 2 (main body portion 22). In order to prevent the defect from being lost, protruding fixing portions 2b are formed on both sides of the beam member 2 in the width direction. In FIG. 10, triangular columnar protrusions that gradually increase in width from the end surface side of the beam member 2 where the sheath 4 is exposed to the fixing side of the tension member 3 are added to both sides in the width direction of the beam member 2 (main body portion 22). The beam member 2 (main body portion 22) is formed in a shape, and this triangular columnar protrusion is used as the fixing portion 2b.

  FIG. 4 shows the relationship between the column member 1 which is a side column in the span direction and the beam member 2 in the two directions, in which the beam member 2 is joined to both sides in the column direction and one side in the span direction, which is indicated by B in FIG.

  When the column member 1 is a side column in the span direction, the beam member 2 in the span direction is not joined to the side column (column member 1 (joint portion 21)) from the outer peripheral side of the frame. The end (fixing tool 31) on the fixing side of the tension member 3 inserted into the beam member 2 in the span direction joined from the inner peripheral side of the member is fixed to the column member 1 (joining portion 21). In the example shown in the figure, the joint 21 integrated with the beam member 2 in the beam direction 2 is arranged at the position of the column member 1, so that the end of the tension member 3 inserted through the sheath 4 of the beam member 2 in the span direction As shown in FIG. 4, it is fixed in the joint portion 21 of the beam member 2 in the column direction.

  In this relationship, since the end portion (fixing tool 31) on the fixing side of the two-direction tension members 3 and 3 is fixed in the joint portion 21 of the beam member 2 in the transverse direction, the two-direction tension members 3 and 3 are fixed. As shown in FIG. 4, the fixing tools 31, 31 are arranged on a plane so as not to interfere with each other. In order to prevent the fixing members 31 in the two directions from interfering with each other on the longitudinal cross section, the tension member 3 in the crosswise direction and the tension member 3 in the span direction are, for example, high as shown in FIG. It arrange | positions in the junction part 21 in the state where the level | step difference was attached by the staggered direction.

  In FIG. 4, the end portion (fixing tool 31) is fixed to the joint portion 21 of the beam member 2 in the beam direction, and the arrangement state of the tension members 3 arranged in advance from the joint portion 21 to the main body portion 22 is the same as the example of FIG. 1. Same or similar. The insertion state of the tension member 3 disposed in the beam member 2 installed later, which is inserted into the sheath 4 embedded from the joint portion 21 into the main body portion 22, into the sheath 4 is also an example of FIG. Is the same or similar.

  Since the end portion (fixing tool 31) of the tension member 3 in the span direction is fixed in the joint portion 21 as described above, a section near the end portion of the tension member 3 is disposed in the joint portion 21. The section protruding from the joint portion 21 is inserted into the sheath 4 of the beam member 2 that abuts the joint portion 21 in the span direction. When the tension members 3 are arranged in three steps in the height direction, the arrangement state of the three tension members 3 in the beam member 2 in the span direction is the same as or similar to that in FIG. The arrangement state of the three tendons 3 in 2 is the same as or similar to FIG.

  FIG. 6 shows a relationship between the column member 1 which is a side column in the row direction and the beam member 2 in the two directions, in which the beam member 2 is joined to both sides in the span direction and one side in the row direction, which is indicated by C in FIG.

  When the column member 1 is a side column in the column direction, the beam members 2 and 2 are bonded to the side column (the column member 1 (joining portion 21)) on both sides in the span direction. In this relation, the end portion (fixing tool 31) on the fixing side of the tension member 3 inserted into the beam member 2 in the span direction joined to one side of the side column is connected to the column member 1 (joining portion 21). It is not fixed, but is fixed to the beam member 2 in the span direction that is abutted from the opposite side to the joint portion 21 of the beam member 2 in the row direction, as in the case of the middle pillar in FIG.

  In FIG. 6, the end portion (fixing tool 31) is fixed to the joint portion 21 of the beam member 2 in the row direction, and the arrangement state of the tension members 3 in the row direction arranged in advance from the joint portion 21 to the main body portion 22 is shown in FIG. This is the same as or similar to the example of FIG. However, since the beam member 2 in the row direction is not joined to the side column (joint portion 21) in the row direction from the outer peripheral side of the frame, the sheath 4 is not embedded from the joint portion 21 to the main body portion 22. Only the tension members 3 whose ends are fixed in the main body part 21 are continuously arranged in the joint part 21 and the main body part 22 in the crosswise direction. Since the beam members 2 and 2 are joined to both sides of the column member 1 (joining portion 21) in the span direction, the arrangement state of the tension members 3 and the sheaths 4 in the beam member 2 in the span direction is the same as the example of FIG. Or the same.

  FIG. 7 shows a relationship between the column member 1 which is a corner column to which the beam member 2 is joined and the beam member 2 in two directions, which are indicated by a D portion in FIG. 9 only on one side in the span direction and one side in the row direction.

  When the column member 1 is a corner column, the beam member 2 in the span direction and the beam member 2 in the beam direction are not joined to the column member 1 (joint portion 21) from the outer peripheral side of the frame. The beam member has the same or similar structure as the beam member 2 shown in FIG. 4 at the side column in the span direction (B portion in FIG. 9). Further, the beam member 2 installed in the column direction has the same or similar structure as the beam member 2 shown in FIG. 6 in the side column (C portion in FIG. 9) in the column direction.

  Specifically, the end portion (fixing tool 31) of the tension member 3 inserted into the beam member 2 in the span direction joined to the corner column (the column member 1 (joining portion 21)) from the inner peripheral side of the frame. ) Is fixed to the column member 1 (joint portion 21). The column member 1 (joint portion 21) is also fixed with an end (fixing tool 31) on the fixing side of the tension member 3 in the crossing direction, and the tension member 3 continues from the joint portion 21 to the end surface on the opposite side of the main body portion 22. And projecting from the end face. As in the example of FIG. 6, the sheath 4 is not embedded in the beam member 2 in which the joint portion 21 is disposed at the position of the corner post. The arrangement state of the tension member 3 and the sheath 4 in the beam member 2 in the span direction is the same as or similar to that shown in FIGS.

  The ends (fixing tool 31) of the tension members 3 and 3 inserted into the beam members 2 and 2 installed in the two directions of the span direction and the transverse direction are fixed in the column member 1 (joint portion 21). Thus, as in FIG. 4 in the case of the side pillars in the span direction, the fixing members 31 and 31 of the two-direction tension members 3 and 3 are arranged at positions where they do not interfere with each other on the plane. Also in the longitudinal section, the tension member 3 in the cross direction and the tension member 3 in the span direction are, for example, staggered in the height direction as shown in FIG. 8 which is a sectional view taken along the line aa in FIG. It arrange | positions in the junction part 21. FIG.

1 ... Column member, 1a ... Column main bar, 1b ... Restraint bar,
2 ... Beam member, 2a ... Beam main bar, 2b ... Restraint bar,
21... Joint part, 22... Body part, 2 a... Storage part, 2 b.
3 ... tension material, 31 ... fixing tool, 32 ... bearing plate, 33 ... reinforcing bar, 34 ... fixing plate, 35 ... fixing tool,
4 …… Sheath,
5 ... Slab, 6 ... Slab muscle,
7: Jack.

Claims (5)

It is a beam member made of precast concrete that is laid between adjacent column members, and in which a tension material with a peripheral surface cut off is disposed,
One end of the tendon is fixed to the inside of the beam member near the one end in the axial direction, and the other end of the tendon is the end surface on the other side in the axial direction of the beam member. A sheath that can be inserted into a tension member disposed in another beam member is embedded at a position that protrudes from the beam member and does not interfere with the tension member in the beam member, and the sheath is fixed to the sheath. It is arranged in a section from the end surface on the side to the axial intermediate portion of the beam member, and the end portion of the sheath on the intermediate portion side communicates with the surface of the beam member. Beam member.   The section of the tendon that protrudes from the end face of the beam member has a length that reaches the end of the sheath in the beam member that opposes the pillar member through the pillar member located on the side. It has, The beam member made from precast concrete of Claim 1 characterized by the above-mentioned.   A joint portion arranged on the head of the column member is integrated on one side in the axial direction of the beam member, and a joint portion continuous with the column member is integrated, and an end portion on one side of the tension member is fixed in the joint portion. The precast concrete beam member according to claim 1, wherein the beam member is made of precast concrete.   The tendon is arranged in a plurality of stages in the beam member in the height direction, and the end of each tendon that protrudes from the end face of the beam member is opposed to the beam member on the side. The precast concrete beam member according to claim 2 or 3, wherein the inner sheath is inserted and protrudes from a surface of the beam member. A method in which the beam member according to any one of claims 1 to 4 is installed between adjacent column members, a tension member in the beam member is tensioned, and prestress is introduced in an axial direction of the beam member. Yes,
The protruding section of the tension member protruding from the end face of the beam member is inserted through the sheath of the beam member facing the column member on the side and the column member on the side, and in the axial intermediate portion of the beam member A method of introducing prestress into a precast concrete beam member, wherein the tension member is tensioned and fixed to the beam member.

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