JP4611065B2 - Method of joining precast reinforced concrete column member and precast reinforced concrete column beam joint block - Google Patents

Description

  The present invention relates to a method for joining a precast reinforced concrete column member and a precast reinforced concrete column beam joint block, and more particularly to a joining method for joining a precast reinforced concrete column beam joint block to a column head of a precast reinforced concrete column member.

  When building a reinforced concrete building using precast reinforced concrete members (in the following description, “precast reinforced concrete” is expressed as “PCa”), it is necessary to join the PCa column member and the PCa beam member on-site. There is. The conventional joining method for that purpose was to build the column beam joint on site. In this joining method, the ends of PCa beam members (usually 2 to 4) to be joined to the stigma of the PCa pillar member are placed, and the beam reinforcing bars projecting from the ends of the PCa beam members are mounted. After joining by an appropriate method, a formwork for placing concrete in the stigma is built, and concrete is put in place in the formwork, so that the stigma of the PCa pillar member and the end of the PCa beam member Integrate with the part. However, in this joining method, a complicated work of joining a large number of beam reinforcing bars in a narrow stigma space is forced. In addition, in order to place concrete at the head of the pillar, a floating formwork must be provided on the outer periphery of the beam-column joint. Therefore, it is not easy to ensure the dimensional accuracy of the beam-column joint, and the quality of the building frame Administrative problems were likely to arise.

  Therefore, a PCa construction method has been proposed in which a PCa column beam joint block in which the column beam joint itself is made into PCa is manufactured and joined to the column head of the PCa column member at the site. A typical example of a PCa beam-column joint block is a block having a height equal to or approximately equal to the beam length of the PCa beam member, and a part of the beam (short beam portion) is formed laterally from the side surface. The end of the PCa beam member is joined to the end of the short beam.

  To join the PCa beam-column joint block to the column head of the PCa column member, the upper end portion of the column main bar protrudes upward from the column head of the PCa column member, while the PCa beam-column joint block has a sheath tube. The column main reinforcement insertion hole for inserting each of the upper end protrusions of the column main reinforcement is formed. When the PCa beam-column joint block is placed on the stigma of the PCa column member installed at the site, the upper end protrusions of the column main bars are inserted into the corresponding column main bar insertion holes, and the stigma and PCa Install joint mortar between the parts. Subsequently, each column main bar insertion hole is filled with a curable filler such as cement grout from the upper end thereof, and the column main bar and the column main bar insertion hole are fixedly joined, so that the PCa column member and the PCa column beam are provided. The joint block is joined.

  According to the PCa method using the PCa beam-column joint block, it is possible to easily secure the dimensional accuracy of the beam-column joint without requiring complicated rebar joining work in a narrow column head space, and quality control of the building frame There are a number of advantages such as being able to reliably However, particularly in a column to which a heavy load is applied, the number of column main bars is large, so that one PCa column member and one PCa column beam joint block are bonded to each of a large number of column main bar insertion holes. In addition, there is a hassle of individually filling curable fillers such as cement grout, and it must be filled securely with care so as not to cause poor filling, so it takes a long time and work There was a problem of increased costs.

In order to solve this problem, the following joining method has been proposed as a method of joining the PCa column beam joint block to the column head of the PCa column member. In the joining method, the upper end protruding portion of the column main bar of the PCa column member is inserted into each column main bar insertion hole of the PCa column beam junction block, and the PCa column beam junction block is placed on the column head of the PCa column member. At this time, by interposing a spacer between them, a joint space is formed between the upper surface of the stigma and the lower surface of the PCa beam-column joint block, and the periphery of the joint space is sealed with a sealing material. Subsequently, the curable filler having high fluidity is injected into the joint space, thereby filling the joint space and the plurality of column main bar insertion holes in one step. Cement grout or the like is used as the curable filler having high fluidity. For example, Japanese Patent Application Laid-Open No. 2001-193150 discloses a document describing this type of bonding method.
JP 2001-193150 A

  However, the following problems are associated with this joining method in which the joint space and the plurality of column main reinforcement insertion holes are filled in one step with a curable filler having high fluidity. In this joining method, the filler injected into the joint space flows into the plurality of column main bar insertion holes from the lower ends of the column main bar insertion holes opened in the joint space, and the plurality of column main bar insertions. The inside of the hole flows from below to above, that is, the filler ascends inside the column main bar insertion hole. The rising speed is influenced by the pressure of the filler at the lower end of the column main reinforcement insertion hole, and the magnitude of the pressure of the column main reinforcement insertion hole opened to the joint space from the injection position of the filler into the joint space. It is influenced by the distance to the lower end position. This is because the flow resistance acts on the filler flowing in the joint space.

  Therefore, in order to quickly fill the joint space and the plurality of pillar main bar insertion holes with the curable filler in one step, the flow resistance acting on the filler flowing in the joint space is minimized. The heights of the top ends of the fillers that respectively rise inside the plurality of column main reinforcement insertion holes must be aligned. For that purpose, it is an essential requirement that the fluidity of the filler is high, but in order to give the cement grout used as a filler a large fluidity, a large amount of water is added to the grout material and a cement grout with a low viscosity is used. Need to be prepared. And as a result of the large amount of kneaded water in the grout material, separation of the grout material and water is likely to occur, the amount of shrinkage of the cement grout during curing is large, and the strength of the cement grout after curing is reduced. Various inconveniences occurred.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a curable filler in a joint space formed between the upper surface of the head of the PCa column member and the lower surface of the PCa column beam joint block. By injecting, the joint between the PCa column member and the PCa beam-column joint block in which the curable filler is filled in the joint space and the plurality of column main bar insertion holes of the PCa beam-column joint block. In the method, a curable filler having good characteristics is used so that the joining operation can be performed quickly.

  In order to achieve the above object, a joining method according to the present invention is a joining method for joining a precast reinforced concrete column beam joint block (PCa column beam joint block) to a stigma of a precast reinforced concrete column member (PCa column member). The upper ends of the plurality of column main bars are projected upward from the column heads of the PCa column members, and the upper ends of the plurality of column main bars are inserted through the PCa column beam joint blocks placed on the column heads of the PCa column members. A plurality of column main bar insertion holes are vertically penetrated, and the PCa column beam joint block is formed on the upper surface of the column head of the PCa column member or the lower surface of the PCa column beam junction block. A protrusion for securing a joint space is formed between the upper surface of the column head of the PCa column member and the lower surface of the PCa beam-column joint block when placed on the column head. The PCa column beam joint block is placed on the head of the PCa column member installed at the site, and at that time, the upper ends of the column main bars of the PCa column member are placed on the PCa column beam junction block. Each of the plurality of column main bar insertion holes is inserted, and the periphery of the joint space formed by placing the PCa column beam joint block on the column head of the PCa column member is sealed with a sealing material, A curable filler having fluidity is injected into the joint space, the curable filler is filled into the joint space, and lower ends of each of the column main reinforcement insertion holes opened in the joint space. To flow into the plurality of column main bar insertion holes, to flow the inside of the plurality of column main bar insertion holes from the bottom to the top, to fill the inside of the plurality of column main bar insertion holes, Ascend inside the column main muscle insertion hole Before the top end at the highest position among the top ends of the curable filler reaches the upper end of the corresponding column main reinforcement insertion hole, the injection of the curable filler is terminated, and the plurality of column main reinforcement insertions are performed. Leaving the unfilled portion in the vicinity of the upper end of the hole as a margin, filling the unfilled portion with a curable filler injected from the upper end of each of the pillar main bar insertion holes, and the curable filler is cured, The plurality of column main bars are fixedly bonded to the plurality of column main bar insertion holes, and the precast column beam joint block is bonded to the column head of the precast column member.

  According to the joining method according to the present invention, as in the conventional joining method, it is good without sacrificing the properties as the filler in order to impart large fluidity to the curable filler such as cement grout. Using a curable filler having characteristics, the joining operation can be completed quickly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a PCa column member and a PCa column beam joint block to be joined by a joining method according to a preferred embodiment of the present invention, and FIG. 2 is a filler for the PCa column beam junction block of FIG. FIG. 3 to FIG. 7 are cross-sectional side views of the PCa column member and the PCa column beam joint block of FIG. 1, and each stage of the joining method according to the preferred embodiment of the present invention. FIG.

  In order to join the PCa column beam joint block to the head of the PCa column member according to the joining method according to the present invention, when the PCa column member and the PCa column beam joint block are produced, they are produced as follows. First, as shown in FIG. 1, the PCa column member 10 projects the upper end portions of the plurality of column main bars 12 upward from the stigma. Further, in the PCa column beam joint block 14 placed on the top of the PCa column member 10, a plurality of column main bar insertion holes 16 for inserting the upper ends of the column main bars 12 of the PCa column member 10 are vertically provided. It penetrates and forms. The PCa column beam joint block 14 in the illustrated example includes a core portion 18 having a shape corresponding to the head of the PCa column member 10 (this core portion 18 is a main body portion of the column beam joint portion), and a side surface of the core portion 18. This is a block in which the short beam portion 20 protruding from the side is integrated, and an end portion of a PCa beam member (not shown) is joined to the tip of the short beam portion 20. The plurality of column main reinforcement insertion holes 16 are formed in the core portion 18 of the PCa beam-column joint block 14.

  The PCa beam-column joint block to be joined to the stigma of the PCa column member using the joining method according to the present invention is not limited to the one in which the short beam portion 20 is integrated with the core portion 18 as in the illustrated example. For example, a block in which half or all of the beams are integrated with the core may be integrated, or a block in which other components such as a part of a floor slab are integrated may be used. That is, it is only necessary to be a block including a core portion which is a main body portion of the column beam joint portion.

  In the illustrated PCa column member 10, the upward protruding length of the column main reinforcement 12 is made larger than the height of the PCa column beam joint block 14, and the PCa column beam joint block 14 is placed on the stigma of the PCa column member 10. When this is done, the tip of the upper end of the columnar reinforcement 12 protrudes upward from the upper surface of the PCa beam-column joint block 14. This is because, after the PCa beam-column joint block 14 is joined to the head of the PCa column member 10, the upper end portion of the column main reinforcement 10 projecting upward from the upper surface of the PCa beam-beam joint block 14, and This is to join the lower end of the column main reinforcement of the PCa column member provided on the upper floor. Therefore, when the PCa column member is not further provided on the upper floor, it is not necessary to project the tip of the upper end portion of the column main bar 12 upward from the upper surface of the PCa column beam joint block 14.

  Further, when the PCa column member 10 or the PCa column beam joint block 14 is manufactured, the upper surface of the column head of the PCa column member 10 is formed on the upper surface of the column head of the PCa column member 10 or the lower surface of the PCa column beam joint block 14. And one or a plurality of protrusions for securing a joint space between the lower surface of the PCa beam-column joint block 14. There are various types of protrusions suitable for this purpose. In the illustrated embodiment, as shown in FIG. 3, one protrusion is provided at the center of the lower surface of the core portion 18 of the PCa beam-column joint block 14. A flat pyramid-shaped projection (convex cotter) 22 is formed, and the joint space 26 is secured by the projection 22. When the protrusion 22 is a convex cotter, for example, if the horizontal cross-sectional dimension of the PCa column member 10 and the horizontal cross-sectional dimension of the core portion 18 of the PCa column beam joint block 16 corresponding thereto are about 1000 × 1000 mm. One convex cotter having a size of 50 × 50 mm to 200 × 200 mm may be formed at the center of the lower surface of the core 18 or the center of the upper surface of the top of the PCa column member 10.

  In the illustrated example of the PCa beam-column joint block 14, the plurality of column main reinforcement insertion holes 16 described above are embedded by embedding a plurality of sheath pipes 26 penetrating the core portion 18 in the vertical direction. Forming. That is, the inner peripheral surface 27 of the columnar muscle insertion hole 16 is defined by the inner peripheral surface 27 of the sheath tube 26. As the sheath tube 26, various known ones can be used. In order to increase the fixing force of the PCa beam-column joint block 14 to the concrete and the fixing force to the curable filler described later. It is desirable to use a deformed sheath tube such as a spiral sheath tube having a spiral rib. Further, a large diameter portion 29 is formed at the upper end of the column main bar insertion hole 16, and the upper end of the sheath tube 26 extends to the lower end of the large diameter portion 29.

  The large diameter portion 29 is a top of the curable filler that flows in from the lower end of the column main reinforcement insertion hole 16 and rises when the curable filler is injected into the joint space 26 as described later. When the curable filler is injected from the upper end of the column main reinforcement insertion hole 16 as the final stage of the joining operation, the curable filler can be easily injected using a mug or the like. It is provided for the purpose of doing so. As shown in FIG. 2, the gap s between the inner peripheral surface 27 of the sheath tube 26 and the outer peripheral surface of the columnar main bar 12 is not so large. Therefore, if the large-diameter portion 29 is not provided, the column main bar insertion hole 16 is provided. It is difficult to easily check the top end position of the curable filler inside and to inject the curable filler from the upper end of the column main reinforcement insertion hole 16.

  Further, a curable filler injection hole 28 is formed in the PCa beam-column joint block 14, and this curable filler injection hole 28 extends through the PCa beam-column joint block 14 and has an upper end. And the lower end is opened to the upper surface and lower surface of the core part 18 of the PCa beam-column joint block 14. Therefore, when the PCa column beam joint block 14 is placed on the top of the PCa column member 10 and the joint space 26 described above is defined, the lower end of the curable filler injection hole 28 is in the joint space 26. It becomes an opening. The curable filler injection hole 28 is an injection hole used for injecting a curable filler such as cement grout into the joint space 26 as will be described later.

  In order to construct a reinforced concrete structure using the PCa column member 10 and the PCa column beam joint block 14 described above, the PCa column beam joint block 14 is mounted on the column head of the PCa column member 10 installed at the site. At that time, the upper ends of the plurality of column main bars 12 projecting upward from the stigma of the PCa column member 10 are respectively inserted into the plurality of column main bar insertion holes 16 of the PCa column beam joint block 14. As a result, as shown in FIG. 3, a joint space 26 is defined between the upper surface of the column head of the PCa column member 10 and the lower surface of the PCa column beam joint block 14.

  Subsequently, as shown in FIG. 4, the periphery of the joint space 26 is sealed with a sealing material 30. As the sealing material 30, for example, a kneaded mortar may be used, and other appropriate sealing materials may be used.

  Subsequently, as shown in FIG. 5, a curable filler having fluidity is injected into the joint space 26 through the curable filler injection hole 28. Thus, the curable filler is filled in the joint space 26 and flows into the plurality of column main bar insertion holes 16 from the lower ends of the column main bar insertion holes 16 opened in the joint space 26. The inside of the main bar insertion hole 16 is made to flow from the lower side to the upper side, and the column main bar insertion holes 16 are filled.

As the curable filler having fluidity, various materials can be used, and a particularly preferred specific example is cement grout. In order to inject cement grout from the upper end of the injection hole 28, for example, a grout pump such as a squeeze pump is used, and the discharge port of the grout pump and the upper end of the injection hole 28 are connected by a vinyl chloride pipe or a pressure hose. Good. The amount of kneading water, which is the amount of water mixed into the grout material when preparing cement grout, is such that fresh cement grout immediately after kneading has adequate fluidity, and the cement grout after curing has sufficient compressive strength. It is necessary to obtain an appropriate amount of kneading water as obtained. As a criterion for judging whether or not the amount of water for kneading is appropriate, it is preferable to use the grout flow value of fresh cement grout immediately after kneading, and prepare the grout flow value to be in the range of 200 mm to 300 mm. It has been confirmed that by using the cement grout, the fluidity at the time of injection and the sufficient compressive strength after curing can be achieved. Further, it is more preferable to use a cement grout adjusted so that the grout flow value is in the range of 230 mm to 270 mm. Such cement grout is, for example, the inner diameter of the curable filler injection hole 28 and the grout pump. When the inner diameter of the connecting pipe between the discharge port and the curable filler injection hole 28 is 25 mm, the injection can be satisfactorily injected at a relatively high injection rate of about 8.0 to 9.0 liters per minute. It has been confirmed that a large compressive strength of 100 N / mm ² or more can be obtained as the subsequent compressive strength.

  Further, when cement grout is continuously filled into the plurality of column main reinforcement insertion holes 16 using a grout pump, the column main reinforcement insertion holes 16 closer to the injection holes 28 are filled as shown in FIG. The cement grout rises rapidly and the top of the cement grout rises. Therefore, when the cement grout is injected into the joint space 26, the injection grind and the injection stop are repeated, so that the height of the top of the cement grout to be filled between the columnar muscle insertion holes 16 is increased. It is better not to make a big difference. However, in the present invention, when preparing cement grout, priority is given to the fact that the grout material and water are not separated, the cement grout shrinkage during curing is small, and the strength of the cement grout after curing is large. The fluidity of the cement grout is in accordance with the policy that it is only necessary to be able to inject, so that the height of the top of the cement grout between the plurality of column main muscle insertion holes 16 as shown in FIG. Inconsistency in position is inevitable.

  Therefore, in the present invention, as shown in FIG. 6, the top end at the highest position among the top ends of the curable fillers that respectively rise inside the plurality of column main reinforcement insertion holes 16 corresponds to the corresponding column. Before reaching the upper end of the main bar insertion hole 16, the injection of the curable filler is terminated to leave an unfilled portion in the vicinity of the upper ends of the plurality of column main bar insertion holes 16 as a margin. Further, at that time, since the large diameter portion 19 is formed at the upper end of the column main reinforcement insertion hole 16, the top end of the curable filler such as cement grout rising in the column main reinforcement insertion hole 16 can be visually recognized. This makes it easier to determine when to end the injection of the curable filler.

  Subsequently, as shown in FIG. 7, the non-filling portion left at the upper end of the column main bar insertion hole 16 is filled with a curable filler injected from the upper end of each column main bar insertion hole 16. Is completed. In order to inject the curable filler from the upper end of the column main bar insertion hole 16, for example, a curable filler such as cement grout may be injected from a jug or the like. The diameter portion 19 also facilitates the operation of injecting the curable filler with this mug or the like. Thereafter, by hardening the curable filler, the plurality of column main bars 12 are fixedly bonded to the plurality of column main bar insertion holes 16, and the precast column beam joint block 14 is bonded to the column head of the precast column member 10. Is done.

  As described above, according to the joining method according to the present invention, the curable filler is injected into the joint space formed between the upper surface of the column head of the PCa column member and the lower surface of the PCa column beam joint block. In the joining method of the PCa column member and the PCa beam-column joint block, the curable filler is filled in the joint space and the plurality of column main reinforcement insertion holes of the PCa beam-beam joint block. In order to impart large fluidity to the filler, the bonding operation can be completed quickly using a curable filler having good characteristics without sacrificing the properties as the filler.

It is the perspective view which showed the PCa pillar member and PCa pillar-beam joint block which join by the joining method which concerns on suitable embodiment of this invention. It is an enlarged plan view of the filler injection hole of the PCa column beam joint block of FIG. FIG. 3 is a cross-sectional side view of the PCa column member and the PCa beam-column joint block of FIG. 1, showing one stage of the joining method according to a preferred embodiment of the present invention. FIG. 3 is a cross-sectional side view of the PCa column member and the PCa beam-column joint block of FIG. 1, showing one stage of the joining method according to a preferred embodiment of the present invention. FIG. 3 is a cross-sectional side view of the PCa column member and the PCa beam-column joint block of FIG. 1, showing one stage of the joining method according to a preferred embodiment of the present invention. FIG. 3 is a cross-sectional side view of the PCa column member and the PCa beam-column joint block of FIG. 1, showing one stage of the joining method according to a preferred embodiment of the present invention. FIG. 3 is a cross-sectional side view of the PCa column member and the PCa beam-column joint block of FIG. 1, showing one stage of the joining method according to a preferred embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... PCa column member, 12 ... Column main reinforcement, 14 ... PCa column beam joint block, 16 ... Column main column insertion hole, 22 ... Protrusion, 26 ... Joint space, 28 ... Injection of curable filler Holes 29... Large diameter portion of the column main reinforcement insertion hole 30. Sealing material.

Claims (8)

In a joining method for joining a precast reinforced concrete column beam joint block (PCa column beam joint block) to a stigma of a precast reinforced concrete column member (PCa column member),
Plural ends for projecting upper end portions of a plurality of column main bars upward from the column heads of the PCa column members, and inserting the upper end portions of the plurality of column main bars into a PCa column beam joint block placed on the column heads of the PCa column members. The column main bar insertion hole is formed so as to penetrate in the vertical direction, and the PCa column beam joint block is formed on the top surface of the PCa column member or the lower surface of the PCa column beam junction block. Forming a projection for securing joint space between the upper surface of the head of the PCa column member and the lower surface of the PCa column beam joint block when placed;
The PCa beam-column joint block is placed on the stigma of the PCa column member installed on the site, and at that time, the upper ends of the column main bars of the PCa column member are connected to the PCa beam-beam joint block. Insert each through multiple column main muscle insertion holes,
Sealing the periphery of the joint space formed by placing the PCa beam-column joint block on the column head of the PCa column member with a sealing material,
A curable filler having fluidity is injected into the joint space, the curable filler is filled into the joint space, and each of the plurality of column main reinforcement insertion holes opened in the joint space is filled. Flowing into the plurality of column main bar insertion holes from the lower end, causing the inside of the plurality of column main bar insertion holes to flow from below to above, filling the inside of the plurality of column main bar insertion holes,
Before the top end at the highest position among the top ends of the curable fillers respectively rising inside the plurality of column main bar insertion holes reaches the upper end of the corresponding column main bar insertion holes, the curable filling is performed. Finishing the injection of the material, leaving an unfilled portion as a margin in the vicinity of the upper ends of the plurality of column main reinforcement insertion holes,
Filling the non-filling portion with a curable filler that is injected from the upper end of each of the pillar main bar insertion holes,
As the curable filler is cured, the plurality of column main bars are fixedly bonded to the plurality of column main bar insertion holes, and the precast column beam joint block is bonded to the column head of the precast column member. To
The joining method characterized by the above-mentioned.   Forming a large-diameter portion at the upper end of the plurality of column main bar insertion holes for facilitating the visual recognition of the top end position of the curable filler that flows from below to above in the plurality of column main bar insertion holes. The bonding method according to claim 1, wherein:   When injecting the curable filler into the joint space, by repeating injection and injection stop, the top of the curable filler that flows from the bottom to the top inside the plurality of column main bar insertion holes is repeated. The joining method according to claim 1, wherein variation in end positions is reduced.   The joining method according to claim 1, wherein cement grouting is used as the curable filler, and injection into the joint space is performed using a grouting pump.   The joining method according to claim 6, wherein the cement grout is prepared so that a grout flow value is in a range of 200 mm to 300 mm.   The joining method according to claim 1, wherein the projection for securing the joint space is formed as a convex cotter at the center of the lower surface of the PCa beam-column joint block.   A curable filler injection hole is formed which penetrates the PCa beam-column joint block and has a lower end opened on the lower surface of the PCa beam-column joint block, and the curable filler is inserted through the curable filler injection hole. The bonding method according to claim 1, further comprising: injecting into the joint space.   When the PCa column beam joint block is placed on the column head of the PCa column member with the upward protruding length of the column main reinforcement being greater than the height of the PCa column beam junction block, the upper end of the column principal bar The front end of the PCa beam-beam joint block protrudes upward from the upper surface of the PCa beam-column joint block, and after the PCa beam-column joint block is joined to the PCa column member, it protrudes upward from the upper surface of the PCa beam-beam joint block. The joining method according to claim 1, wherein the upper end portion of the column main bar of the PCa column member is joined to the lower end portion of the column main bar of the PCa column member provided on the upper floor.

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