JP4355688B2 - Reinforcing bar joints and precast members - Google Patents

Description

  The present invention relates to a reinforcing bar joint including a threaded portion for screwing an end portion of a first reinforcing bar composed of a threaded reinforcing bar, and a sleeve portion that accommodates the end portion of the second reinforcing bar and is fixed with a filler such as mortar. Further, the present invention relates to a precast member in which a plurality of the joints are embedded.

  Patent Document 1 discloses a precast column (precast member). A plurality of first reinforcing bars made of threaded reinforcing bars extending vertically are embedded in the precast column, and a plurality of joints are embedded vertically at the lower end portion thereof.

  The joint has a threaded portion and a sleeve portion extending downward from the threaded portion. The lower end portion of the screw rebar is screwed to the screw portion. The sleeve portion has an internal space, and the lower end thereof opens to the lower surface side of the concrete. A discharge port is formed at the upper end of the sleeve portion, and an injection port is formed at the lower end.

  The precast column further includes a plurality of discharge paths and at least one injection path. The inner end of the discharge passage is connected to the discharge port of the joint, and the outer end is opened on the side surface of the concrete. Moreover, the inner end of the injection path is connected to the inlet of the joint, and the outer end thereof is opened on the side surface of the concrete.

  When joining the precast column to the lower component of the building, suspend the precast column and position it above the lower component, and move upward from the lower component to the internal space of the sleeve portion of the joint. The upper end of the protruding second reinforcing bar is inserted, and a gap serving as a joint space is formed between the lower surface of the precast column and the upper surface of the lower component. In this state, mortar (filler) is injected from the injection path. As a result, the mortar fills the joint space through the joint to which the injection path is connected, and further fills the internal space of all the joints, and then reaches the outer end through the discharge path. The operator confirms the completion of filling by seeing the mortar leaking from the outer end of the discharge path, and finishes the mortar injection work.

As described above, the precast column is joined to the lower component. The lower end part of the 1st reinforcing bar of a precast pillar and the upper end part of the 2nd reinforcing bar of a lower part composition are connected via a joint and mortar.
JP-A-6-322822

  In Patent Document 1, it is ideal that the second rebar of the lower component part and the first rebar of the precast column are located on the same straight line. In this case, the second rebar is the center of the sleeve portion of the joint. A sufficient distance is formed between the outer peripheral surface of the second reinforcing bar and the inner peripheral surface of the sleeve portion, which is located on the axis. Therefore, the mortar can easily pass through the discharge port after filling the internal space of the joint without great resistance and reach the outer end via the discharge path.

  However, the upper end portion of the second rebar may be displaced laterally from the central axis of the sleeve portion of the joint and block the discharge port. In this case, the flow resistance of the mortar passing through the discharge port becomes high, the mortar does not flow smoothly from the discharge port to the discharge path, and there is a disadvantage that it takes time for mortar injection work.

  In order to solve the above-described problems, the present invention includes a screw portion and a sleeve portion connected to the screw portion. The sleeve portion includes an internal space, an open end opposite to the screw portion, and a screw portion side. A state in which the end of the second reinforcing bar is housed in the internal space of the sleeve part, and the end of the first reinforcing bar made of screw reinforcing bars is screwed into the screw part. In the joint in which the first and second reinforcing bars are connected by filling the inner space with a filler, a protrusion is formed on the inner peripheral surface of the sleeve portion. It is arranged on the opening end side from the discharge port, and its circumferential position substantially coincides with the discharge port.

  According to the above configuration, the amount of lateral displacement of the second reinforcing bar with respect to the sleeve portion of the joint is limited by the protrusion formed on the sleeve portion, whereby the inner peripheral surface on the discharge port side of the sleeve portion and the outer peripheral surface of the second reinforcing bar. A sufficient gap can be secured. As a result, when filling the filler in the sleeve, the flow resistance at the discharge port can be kept low, the discharge from the discharge port can be facilitated, and the filling work time of the filler is shortened. Can do.

  Preferably, the protrusion has an inclined surface that becomes higher toward the discharge port. According to this, even when the second rebar enters the sleeve of the joint with a large lateral deviation amount, the lateral deviation amount can be corrected forcibly.

  Preferably, an end of the inclined surface on the opening end side is continuous with an inner peripheral surface of the sleeve portion. According to this, the lateral deviation amount of the second rebar can be corrected more smoothly.

  Preferably, the protrusion is disposed in the vicinity of the discharge port. Thereby, even if the second rebar is slightly inclined with respect to the sleeve portion, a gap between the inner peripheral surface of the sleeve portion in which the discharge port is formed and the outer peripheral surface of the second rebar can be reliably ensured.

  Preferably, a pair of protrusions are formed apart from each other in the circumferential direction of the sleeve portion, and a flow passage is formed between the pair of protrusions. The flow passage is aligned with the discharge port and is connected to the discharge port. . According to this, since the filler reaches the discharge port via the flow passage formed between the pair of protrusions, the flow resistance can be further reduced. In addition, with this configuration, the protrusion can be formed over a relatively wide angular range in the circumferential direction, and the lateral displacement limiting effect of the second rebar can be ensured.

  Preferably, an injection port is formed in the sleeve portion in the vicinity of the opening end. According to this, since the filling material can be injected from the lateral direction of the joint, the joint can be used in various modes.

  Furthermore, the present invention provides a precast member, a concrete, a plurality of joints described above vertically embedded in a lower end portion of the concrete, a plurality of first reinforcing bars including screw reinforcing bars embedded in the concrete and extending vertically, The joint is disposed with the threaded portion up and the sleeve portion facing down, and the lower end of the first rebar is screwed into the threaded portion, and the open end of the sleeve portion is Open to the lower surface side of the concrete, and the discharge path has an inner end connected to the discharge port of the joint, and an outer end opened to the side of the concrete. The upper ends of the plurality of second reinforcing bars protruding upward from the lower component portion are respectively inserted into the internal spaces of the plurality of joints, and are filled with the filler. According to this, the filling work time of the filler when the precast member is joined to the lower component can be shortened.

  According to the present invention, in a joint provided with a screw portion and a sleeve portion, screwed and connected to the first rebar at the screw portion, and connected to the second rebar by the filler filled in the sleeve portion, The filling time can be shortened.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a precast column 10 (a precast member made of reinforced concrete) includes a concrete 11 having a square cross section and a number of reinforcing bars embedded in the concrete 11 as a basic structure.

  The precast column 10 of this embodiment includes a plurality of vertical screw rebars 12 (first rebars) arranged along the side surface of the concrete 11 as rebars, and an annular shear wound around the screw rebars 12 at intervals. Reinforcing bars (not shown) are provided.

  The precast column 10 further includes the same number of joints 20 as the screw rebar 12. These joints 20 are embedded in the lower end portion of the concrete 11 in a vertical direction. Each joint 20 includes a threaded portion 21 and a sleeve portion 22 that is continuous with the threaded portion 21 in the axial direction and extends downward from the threaded portion 21.

A female screw 21 a is formed on the inner periphery of the screw portion 21 of the joint 20, and the lower end portion of the screw rebar 12 is screwed to the screw portion 21.
The sleeve portion 22 has an internal space 22 a, and a lower end 22 b (open end) of the sleeve portion 22 opens on the lower surface side of the concrete 11. The inner diameter of the sleeve portion 22 increases stepwise from the upper end to the lower end. In other words, the thickness of the sleeve portion 22 is gradually reduced from the upper end toward the lower end. A plurality of annular ribs 22c are formed on the inner periphery of the sleeve portion 22 at intervals in the axial direction for increasing the adhesion strength with a mortar described later.

  In the sleeve portion 22, a discharge port 22d is formed at an upper end portion close to the screw portion 21, and an injection port 22e is formed at a lower end portion. The discharge port 22d and the injection port 22e overlap each other when viewed from the axial direction of the sleeve 22. In other words, the discharge port 22d and the injection port 22e have the same circumferential position.

  The inner end of the straight pipe 16 is inserted and connected to the discharge port 22 d of each joint 20. The outer end of the pipe 16 is open to the side surface of the concrete 11. The internal space of the pipe 16 provides a discharge path 16a.

  The inner end of the straight pipe 18 is inserted and connected to the injection port 22 e of each joint 20, and the outer end thereof opens to the side surface of the concrete 11. The internal space of the tube 18 provides an injection path 18a.

  As best shown in FIGS. 2 and 3, a pair of protrusions 25 are formed on the inner surface of the sleeve portion 22 of the joint 20 below and in the vicinity of the discharge port 22d. Between the pair of protrusions 25, a flow passage 26 is formed that is located directly below the discharge port 22d. In other words, with respect to the circumferential position of the sleeve portion 22, the pair of protrusions 25 substantially match the discharge port 22d, and the flow passage 26 matches the discharge port 22d.

  The protrusion 25 has a flat inclined surface 25a that becomes higher as it goes upward (as it goes toward the discharge port 22d). The lower end of the inclined surface 25 a is continuous with the inner surface of the sleeve portion 22. The inclined surfaces 25a of the pair of protrusions 25 are on the same plane.

  The precast column 10 having the above-described configuration is joined to the joint portion 30 (lower structure portion of the building) shown in FIG. The joint 30 is a part where a lower-floor precast column and a beam (both not shown) having the same configuration as described above are joined, and between the upper surface of the lower-floor precast column and the end surface of the beam. It is configured by placing concrete 31 in the formed space. The screw rebar 32 (second rebar) of the precast column on the lower floor is embedded in the concrete 31, and the upper end portion protrudes from the upper surface of the concrete 31.

  With the precast pillar 10 suspended and supported, the precast pillar 10 is lowered so that the upper end portion of the screw rebar 32 enters the internal space 22a of the joint 20. Thereby, in the joint 20, the edge parts of the screw rebars 12 and 32 oppose each other. In FIG. 1, the screw rebar 32 is in an ideal position, is aligned with the screw rebar 12, coincides with the central axis of the sleeve 22, and its upper end surface is separated from the lower end surface of the screw rebar 12.

  A spacer (not shown) is previously placed on the upper surface of the concrete 31, and a narrow joint space 40 is formed between the lower surface of the concrete 11 and the upper surface of the concrete 31 by placing the precast pillar 10 on the spacer. .

  Next, the formwork 45 is installed on the upper surface of the concrete 31 along the side surface of the lower end of the concrete 11 of the precast column 10, thereby closing the joint space 40. The joint space 40 may be closed by filling mortar around the joint space 40 instead of the mold 45.

  Next, mortar (filler) is filled. The nozzle of a mortar injector is pressed against the selected one of the plurality of tubes 18 to inject the mortar while applying pressure. The mortar fills the joint space 40 through the injection path 18a of the selected pipe 18 and the internal space 22a of one joint 20. If the injection is continued further, the mortar fills the other unselected injection paths 18a and fills the inner space 22a of all the joints 20, and then reaches the outer end through the discharge path 16a.

  When the mortar reaches the outer end of the discharge passage 16a and leaks, the operator confirms that the mortar filling is completed and finishes the injection. In the above-described injection operation, each time the mortar leaks from the outer ends of the injection path 18a and the discharge path 16a, the outer ends are sequentially closed with plugs.

  When the mortar filled as described above is cured, the joining of the precast column 10 to the joint portion 30 is completed. In this joined state, the screw rebars 12 and 32 are connected to each other via the joint 20 and the mortar filled in the internal space 22a of the joint 20.

  In the process of filling the mortar, when the screw rebar 32 is in an ideal position as shown in FIG. 1, the mortar passes through the discharge port 16a through the discharge port 22d without receiving a large resistance.

  As shown in FIG. 2 or FIG. 3, the flow resistance of the mortar near the discharge port 22d is such that the upper end surface of the screw rebar 32 approaches the lower end surface of the screw rebar 12 and the upper end portion of the screw rebar 32 is the sleeve. It shifts laterally from the central axis of the portion 22 and increases as it approaches the discharge port 22d. However, in this embodiment, the protrusion 25 can prevent an increase in the flow resistance of the mortar, and the mortar can smoothly pass from the discharge port 22d to the discharge path 16a. Therefore, it is possible to avoid an increase in the mortar filling time. . Details will be described below.

2 and 3, when the upper end surface of the screw rebar 32 is in contact with or slightly away from the lower end surface of the screw rebar 12, the mortar has an outer periphery at the upper end portion of the screw rebar 32 as indicated by an arrow. To the discharge port 22d.
In the present embodiment, as shown in FIG. 2, the screw node 32 a of the screw rebar 32 hits the protrusion 25, or the flat portion 32 b hits the protrusion 25 as shown in FIG. Is limited. As a result, the discharge port 22d is not blocked by the screw rebar 32, and a sufficient gap can be secured between the inner peripheral surface of the sleeve portion 22 forming the discharge port 22d and the outer peripheral surface of the screw rebar 32, The mortar can pass through the discharge port 22d without great resistance.

  In the present embodiment, a pair of protrusions 25 are formed, and a gap between the protrusions 25 is provided as a flow passage 26. Therefore, a part of the mortar flows in the axial direction through the flow passage 26 without going around the outer periphery of the screw rebar 32, and is an outlet. 22d can be reached. Thereby, the flow resistance in the vicinity of the mortar outlet 22d can be further reduced.

  In the present embodiment, since the inclined surface 25a is formed on the protrusion 25, even if the amount of lateral displacement of the screw rebar 32 with respect to the sleeve portion 22 is large, the screw rebar 32 is guided in the internal space 22a by the guide of the inclined surface 25a. Can be inserted smoothly.

  The present invention is not limited to the above embodiment, and various forms can be adopted. For example, the second rebar that enters the sleeve portion of the joint may be a normal rebar having a vertical rib and a horizontal rib in a lattice shape instead of a screw rebar.

The present invention is applicable not only to precast columns but also to precast walls (precast members).
When mortar is filled in all joints via joint spaces as in the above embodiment, there may be one injection path, and this injection path is connected to the inlet of one selected joint. It may be. In this case, the other joint may not have an inlet.
When filling a mortar into a joint without going through the joint space, the mortar is injected from an injection path connected to each joint.

  The joint for reinforcing bars of the present invention can be used not only for a precast member but also for casting concrete. In this case, not only the discharge port but also the injection port is formed in the sleeve portion. The end of the second reinforcing bar is inserted into the sleeve part in a state where the end of the first reinforcing bar made of screw rebar is screwed into the threaded part. Put on. The mortar injected from the injection port leaks from the discharge port after filling the internal space of the sleeve portion. The effect of the protrusion formed on the joint is the same as that of the above-described embodiment.

It is a longitudinal cross-sectional view of the lower end part of the precast pillar which shows one Embodiment of this invention. It is a figure explaining the effect | action of the protrusion of the joint in the embodiment, (A) is a principal part expanded longitudinal sectional view, (B) is a principal part enlarged flat sectional view. 3A and 3B are views for explaining the action of the protrusion when the position of the screw node of the second reinforcing bar is different from the state of FIG. 2 in the same embodiment, FIG. FIG.

Explanation of symbols

10 Precast pillars (precast members)
11 Concrete 12 Screw rebar (1st rebar)
16a Discharge path 20 Joint 21 Threaded portion 22 Sleeve portion 22a Internal space 22c Open end 22d Discharge port 22e Inlet port 25 Protrusion 25a Inclined surface 26 Flow channel 30 Closure (lower component of the building)
31 Concrete 32 Screw rebar (second rebar)

Claims (6)

A screw portion; and a sleeve portion provided continuously to the screw portion. The sleeve portion includes an internal space, an opening end opposite to the screw portion, and a discharge port formed at an end portion on the screw portion side. Have
By screwing the end of the first rebar made of screw rebar into the threaded portion, and filling the internal space with a filler in the state where the end of the second rebar is accommodated in the internal space of the sleeve portion, In the joint that connects the first and second reinforcing bars,
Reinforcing bar joints characterized in that protrusions are formed on the inner surface of the sleeve portion only in a circumferential position substantially matching the discharge port in the vicinity of the discharge port and on the opening end side of the discharge port. . The joint for reinforcing bars according to claim 1, wherein the protrusion has an inclined surface that becomes higher toward the discharge port, and an end of the inclined surface on the discharge port side is the highest at the protrusion .   The reinforcing bar joint according to claim 2, wherein an end of the inclined surface on the opening end side is continuous with an inner peripheral surface of the sleeve portion. A pair of the protrusions are formed apart from each other in the circumferential direction of the sleeve portion, and a flow passage is formed between the pair of protrusions. The flow passage is aligned with the discharge port and is connected to the discharge port. The joint for reinforcing bars according to claim 3 . The reinforcing joint according to any one of claims 1 to 4 , wherein an injection port is formed in the sleeve portion in the vicinity of the opening end. Concrete, a plurality of joints according to any one of claims 1 to 5 embedded vertically in a lower end portion of the concrete, a plurality of first reinforcing bars made of threaded reinforcing bars embedded in the concrete, and a plurality of first reinforcing bars With a discharge path,
The joint is arranged with the threaded portion up and the sleeve portion facing down, and the lower end portion of the first rebar is screwed into the threaded portion, and the open end of the sleeve portion opens to the lower surface side of the concrete And
The discharge path has an inner end connected to a discharge port of the joint, and an outer end opened to a side surface of the concrete.
When joining to the lower component part, the upper spaces of the plurality of second reinforcing bars protruding upward from the lower component part are respectively inserted into the internal spaces of the plurality of joints and filled with a filler. A precast member.

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