JP5322802B2 - Reinforced joint structure with open sleeve on one end - Google Patents

Description

  The present invention relates to a reinforcing bar joint structure using an open sleeve on one end side. Specifically, one end side of the sleeve is opened, the other end side is pre-integrated with the first reinforcing bar, and inserted from one end side by a grout injected into the sleeve. The present invention relates to a rebar joint in which the second rebar is joined to the first rebar in the longitudinal direction.

  A large number of reinforcing bars are embedded as reinforcing bars in a precast concrete structure as a wall material or a column material such as a precast concrete panel or a precast concrete column. In these structures, a sleeve-shaped reinforcing bar joint is used for joining reinforcing bars when connecting each other. The sleeve located at the opposite part of the reinforcing bar is filled with grout, and when it is solidified, the sleeve and the reinforcing bar are integrated, and the opposing reinforcing bar is joined via the sleeve.

  By the way, when a concrete structure is arranged up and down and connected, the reinforcing bars for enhancing the proof stress of the structure are buried in the up and down direction. Therefore, when the sleeve is vertically arranged at the position to be the lower end of the structure and the opening faces the lower end edge, and the embedding is performed so that the reinforcing bar protrudes from the upper end edge of the structure, the lower end of the reinforcing bar In a state where is inserted into the upper end opening of the sleeve, a concrete mortar is placed in a mold standing upright to form a structure. Such structures are manufactured as precast products one after another in a well-equipped production plant.

  FIG. 12A shows a concept of joining a pair of opposing reinforcing bars 2 and 4 by a sleeve 41 among a large number of embedded reinforcing bars, and the reinforcing bar 2 is attached to the upper structure 22U shown in FIG. It is buried and a sleeve 41 is arranged in the lower part thereof. The reinforcing bar 4 protrudes from the lower structure 22L, and the head of the reinforcing bar 4 is stored in the sleeve 41 while lowering the upper structure 22U toward the lower structure 22L. When the upper structure descends with the joints 26 secured by the spacers and packings 27 arranged around the upper surface of the lower structure 22L, the grout 3 is injected into the internal space 9 of the sleeve as shown in the figure. This is an example of joining bamboo joints, but a similar structure is disclosed in Japanese Patent Laid-Open No. 7-217022.

  FIG. 13 shows an example of joining screw joint reinforcing bars. When joining the reinforcing bars 2A and 4A as shown in FIG. 13A, the screw 42 formed on the surface of the reinforcing bar is screwed into the screw hole 44 at the upper end opening of the sleeve 43. As shown in (b), the lock nut 45 is hung to prevent the reinforcing bars from loosening, and then embedded in the concrete 47 as shown in (c). Then, the grout 3 is injected into the internal space 9 as in the previous example. An example in which such a screw joint reinforcing bar is employed is described in Japanese Patent Application Laid-Open No. 8-279315.

JP 7-217022 A JP-A-8-279315

  In any of the above-described examples, the reinforcing bars embedded in the structure are embraced by the placed concrete, so that they do not shift in the structure, and there is a particular problem with the integrity with the sleeve under the action of compressive force. There is nothing. However, how to prevent the concrete mortar placed when forming the structure from entering the internal space where the grout is injected from a slight gap at the connecting portion between the reinforcing bar and the sleeve. It has become a challenge. This is because, when the precast structure is shipped from the production factory, if the mortar that has already entered the internal space has solidified, it will hinder the rebar joining work at the construction site.

  In Patent Document 1 described above, a sealing material 46 (see FIG. 12) is placed at the upper end of the sleeve 41 to prevent mortar that would enter between the lower end of the reinforcing bar 2 and the sleeve. . In Patent Document 2, the remaining clearance between the screw 42 and the screw 42 is reduced by screwing with the screw hole 44 formed in the sleeve 43 or screw fitting with the lock nut 45 to suppress passage of mortar or silt. I am doing so. In any case, it is difficult to say that silt or the like transmitted through the reinforcing bars 2 and 2A does not completely enter the sleeve. By the way, threaded joints are manufactured by the rolling method, and are significantly more expensive than unthreaded reinforcing bars. On the other hand, deformed steel bars such as bamboo knots have a relatively simple surface shape, and are inexpensive and widely used because they can be manufactured by rolling bars. However, since the density of the surface pattern is intense, the integrity with the sleeve and the penetration preventing property of the placement mortar are significantly lower than in the case of the threaded bar.

  Although not described in detail above, the sleeve is provided with a grout inlet 12 and a residual air outlet 13. As can be seen from both FIG. 12 and FIG. 13, the grout 3 that has been press-fitted rises in the internal space 9 of the sleeve, and at that time, stagnant air is pushed out. This is because it is indispensable for joining the reinforcing bars that the grout is filled without leaving an air reservoir in the internal space. Note that leakage of the grout 3 from the air discharge port also serves as an index for completion of filling. In order to realize such behavior, the grout inlet 12 and the air outlet 13 of the sleeve 41 need to be communicated to the outer surface of the structure. For example, a pipe 14 made of vinyl chloride is embedded in the concrete 47 in advance. .

  In order to ensure the connectivity between the communication pipe 14 such as vinyl chloride and the grout inlet 12 and the air outlet 13, a grout injection cylinder 48 and an air discharge cylinder 49 protruding from the sleeve peripheral wall are provided. Required for each opening edge. Since the sleeve is usually made of cast iron or cast steel, it is not difficult to form them integrally. However, when the sleeve is made of forging, the hollow projecting portion that rises from the peripheral wall 10 such as the grout injection cylinder portion 48 becomes impossible on the principle of molding, so the sleeve of the forged product has not reached the eye. is the current situation.

  A forged product is a plastic processed product to which a high pressure is applied. However, there is a problem that the machinability after forming is remarkably inferior because the voids in the metal are crushed to refine the crystal. Therefore, even if the screw hole portion 44 for using the screw joint reinforcing bars 2A and 4A as shown in FIG. 13 can be formed in the forged sleeve, it is extremely expensive compared to the cast sleeve. .

  The present invention has been made in view of the above problems, and its purpose is to place cast concrete at the connecting portion between the reinforcing bar and the sleeve even if a deformed reinforcing bar such as an inexpensive bamboo reinforcing bar is used instead of the expensive screw reinforcing bar. It is impossible to completely eliminate the intrusion of mortar, and to connect the pipe for communication necessary for application to precast concrete structures, it is impossible to integrally mold the grout injection cylinder and the air discharge cylinder It is also possible to provide a rebar joint structure using an open sleeve on one end side which realizes that it is possible to make a forged sleeve, and that a forged product of the sleeve can be realized to reduce the cost of the rebar joint.

  In the present invention, one end side of the sleeve is opened, while the other end side is preliminarily integrated with the first reinforcing bar, and the second reinforcing bar inserted from the one end side by the grout injected into the sleeve is opposed to the first reinforcing bar in the longitudinal direction. It is applied to rebar joints that are to be joined in a state where As shown in FIG. 1, the sleeve 1 is an iron-based shaped product, and the other end is a solid part having a diameter smaller than the outer diameter of the sleeve and larger than the outer diameter of the first rebar 2. 6 is formed, and the solid portion 6 and the first rebar 2 are integrated by friction welding at the abutting portion between them (see pressure welding burrs 7 and 8). The iron-based shaped product can be made not only of cast iron or cast steel but also of forging.

  Referring to FIGS. 3 and 4, an opening seat 11 is provided on the peripheral wall 10 of the iron-based shaped article to open the grout injection port 12 and the air discharge port 13, but the grout injection that protrudes from the peripheral wall 10 is performed. The cylinder part for air and the cylinder part for air discharge are not formed integrally. Then, as shown in FIG. 1, a grout injection cylinder 15 or an air discharge cylinder 16 is formed in the opening seat 11 and a resin adapter 17 protruding from the peripheral wall of the sleeve 1 is subjected to the friction welding process. Let me sit down.

  As shown in FIG. 5, the adapter 17 has a retaining claw 19 for preventing the adapter 17 from coming off after being seated on the opening seat, and is located on the insertion side of the adapter. Is formed at the tip of a cylindrical neck portion 18 having an outer diameter substantially the same as that of the grout inlet 12 and the air outlet 13 shown in FIG. A plurality of slits 21 extending in the axial direction are formed in the cylindrical neck portion 18 so that the diameter of the diameter 20 is reduced and the diameter is restored after passing.

  According to the present invention, the sleeve is made of an iron-based shaped article, and a solid part having a diameter smaller than the sleeve outer diameter and larger than the outer diameter of the reinforcing bar is formed on the other end side opposite to the one end side of the opening sleeve. Therefore, if friction welding is performed in a state where the solid portion and the end face of the reinforcing bar are in contact with each other, the sleeve and the reinforcing bar can be integrated in advance without enlarging the pressure welding burr. Even if a deformed steel bar such as an inexpensive bamboo joint is used instead of an expensive screw joint, it is possible to completely prevent the structure precast concrete mortar from entering the joint between the reinforcing bar and the sleeve.

  The sleeve of the iron-based shaped article may be made of cast iron, cast steel, or forged. Cast iron is cheaper, cast steel has higher durability than cast iron, and forged has high strength and high productivity. In particular, the mass forging of sleeves promotes cost reduction of rebar joints.

  An opening seat is provided on the peripheral wall of the iron-based modeled product to open the grout inlet and air outlet, but the grout injection cylinder and air exhaust cylinder that protrude from the peripheral wall should not be integrally molded. For example, the forging of the sleeve is promoted.

  If a resin adapter that forms a grout injection cylinder or an air discharge cylinder and protrudes from the sleeve is seated in the opening seat of the peripheral wall after the friction welding between the sleeve and the reinforcing bar, the peripheral wall protrusion during molding Forged sleeves that can hardly be formed can also be used as one-end-opening sleeves for reinforcing steel joints. Precast concrete with various sleeves can be applied to forged sleeves that are difficult to integrally mold the grout injection cylinder and air discharge cylinder protruding from the peripheral wall, and the communication pipe connected to the grout injection and air discharge openings can be applied. The way of introduction to the structure is opened up.

  If a stopper claw is formed at the tip of the cylindrical neck that is provided on the adapter insertion side and has the same diameter as the grout inlet and air outlet, and an axial slit is provided in the cylindrical wall, the stopper claw When passing through the grout inlet and the air outlet, the claw ring can be reduced in diameter, and after the passage, the diameter can be reduced to prevent the adapter from being removed from the opening seat.

The reinforcement joint structure by the one end side opening type | mold sleeve which concerns on this invention is shown, (a) is a longitudinal cross-sectional view, (b) is the sectional view on the AA line in (a), (c) is BB in (a). FIG. It is the reinforcing bar joint structure by the one end side opening type | mold sleeve, Comprising: (a) is a top view, (b) is a front view, (c) is a left view, (d) is a right view. It is a state before attaching an adapter to a friction welding product in a reinforcing bar joint structure with one end side opening type sleeve, (a) is a plan view, (b) is a front view, (c) is a left side view, (d) Is a right side view. It is a state before attaching an adapter to a friction welding product applied to a reinforcing bar joint structure with an open-end-side sleeve, wherein (a) is a longitudinal sectional view, and (b) is a sectional view taken along line CC in (a). (C) is the DD sectional view taken on the line in (a). The details of an example of an adapter are shown, (a) is a plan view, (b) is a front view, (c) is a bottom view, (d) is a cross-sectional view taken along line EE in (b), (e) is (c) FF line sectional drawing in (), (f) is GG line sectional drawing in (e), (g) is a whole perspective view. (A) is a perspective view of a state in which an adapter is attached to a friction welding product in which a first reinforcing bar is welded to an open sleeve on the one end side, and (b) is a different example in which only an air discharge port is provided on the peripheral wall and the adapter is attached. The longitudinal cross-sectional view of the friction welding products with an adapter. (A) is the cross-sectional structural example of a precast concrete structure, (b) is sectional drawing showing a mode when lowering an upper precast concrete structure to a lower precast concrete structure. Sectional drawing explaining a mode that grout is inject | poured based on the post grout construction method in the state which accumulated the structure. Sectional drawing showing a mode that a structure was connected based on the pre-grouting method using the friction welding products of a different example. The external view of the structure showing the state of the reinforcement joint preparation at the time of applying the reinforcement joint by the one end side opening type | mold sleeve which concerns on this invention to the left-right direction connection of a beam or a wall panel. Sectional drawing which showed a mode that the joining of a reinforcing bar and the connection of a structure were performed simultaneously also in horizontal connection operation. It is one of the conventional examples given in the background art, (a) is a cross-sectional view of a state before bonding, and (b) is an explanatory view of a grout injection state. In the example of joining the threaded joint reinforcing bar mentioned in the background art, (a) is a sectional view before joining, (b) is a sectional view of the end of the threaded reinforcing bar fixed to the sleeve by a lock nut, (c) is a structure Sectional drawing of a state in which grout is injected for joining of reinforcing bars embedded in the body.

  Below, the reinforcing bar joint structure by the one end side opening type | mold sleeve which concerns on this invention is demonstrated in detail based on drawing showing the embodiment. In FIG. 8, one end side of the cylindrical sleeve 1 opens downward, while the other end side is integrated with the first rebar 2 in advance, and the second rebar 4 inserted from one end side by the grout 3 injected into the sleeve. 2 represents a part of a structure including a reinforcing bar joint 5 which is joined to the first reinforcing bar 2 in a state of facing the first reinforcing bar 2 in the longitudinal direction. The sleeve 1 and the first reinforcing bar 2 are not integrated as shown in FIG. 12 and FIG. 13 mentioned in the background art, but by welding at the butt portion between the solid part and the first reinforcing bar described below. Yes.

  The sleeve 1 of this reinforcing bar joint is a forged product, and the integration of the sleeve 1 and the first reinforcing bar 2 shown in FIGS. 3 (a) and 3 (b) is performed by rotating one or both at a high speed to make a butt surface. This is based on the friction welding method in which the base material is melt-bonded with the heat generated in the substrate. Therefore, a solid portion 6 having a diameter D smaller than the outer diameter of the sleeve 1 and larger than the outer diameter of the reinforcing bar 2 is formed on the other end side of the forged molded product. It is sufficient that the length L of the solid part 6 before the axial welding is normally secured to 10 to 20 millimeters. It is formed. The cross-sectional shape is shown in FIG. 4 (a), but these have a balanced size with respect to the sleeve 1 and contribute to the improvement of the fixing property with the cast concrete.

  By the way, the friction welding is usually applied to a drawn product, a rolled product, a cast product, and a cast steel product, and is not suitable for a forged product whose structure is densified by plasticization. However, the present inventor tried friction welding to overturn the common sense, and confirmed that the strength not to be lost in friction welding between rolled products was demonstrated. Tried to put it to practical use. Incidentally, when the nominal diameter of the reinforcing bar is 32 mm, the outer diameter of the sleeve is 56 mm and the length is, for example, 280 mm. The inner space 9 (see FIG. 1 (a)) is a fastening force exerted by the grout to be filled regardless of the material of the sleeve 1, even though the size can be reduced a little compared to when the sleeve is made of cast iron. The size is determined in order to secure the volume in consideration of the above.

  When the sleeve is a forged product, it is not easy to form a protrusion, particularly a hollow protrusion, on the peripheral wall of the cylindrical sleeve, and even if it can be done, the molding cost jumps and the price competitiveness is lost. Therefore, as shown in FIGS. 3C and 3D which are the right side view and the left side view, the opening seat 11 is formed so as to be a seat surface that is extremely low and is in contact with the outer shape of the peripheral wall 10. Note that it is not difficult to open the grout inlet 12 and the air outlet 13 shown in FIG. 4 in the opening seat 11 during the forging process. Therefore, the forged sleeve is integrally formed with the grout injection cylinder 48 and the air discharge cylinder 49 shown in FIGS. 12 and 13 protruding from a virtual seating surface in contact with the outer shape of the peripheral wall 10. I will not let you. In addition, if a core is used for shaping | molding of the internal space 9, it will not become a problem in particular.

  Even if the grout inlet 12 and the air outlet 13 can be opened in the forged sleeve in this way, the communication pipe 14 (see FIG. 8) is stably fixed or connected thereto. Is not easy. Therefore, as shown in FIG. 1 and FIG. 2, a resin adapter 17 that protrudes from the sleeve peripheral wall 10 is formed in the opening seat 11 by forming a grout injection cylinder 15 or an air discharge cylinder 16.

  This adapter may be made of, for example, polyvinyl chloride, which has good moldability, and includes an outer wall having substantially the same diameter as the grout inlet 12 and the air outlet 13 (see FIGS. 1C and 1B). A cylindrical neck 18 having a diameter is provided on the insertion side. Then, a retaining claw 19 shown in FIG. 5 is formed at the tip of the cylindrical neck portion 18 to prevent it from coming off after sitting on the opening seat 11. The claw ring 20 formed by the aligned claws 20 is reduced in diameter when passing through the grout inlet and the air outlet, and can be restored after passing in the axial direction on the cylindrical wall of the cylindrical neck 18. A plurality of extending slits 21 are formed. By the way, each nail has an arrowhead shape and is also formed with a return, so that it functions as a stopper.

  An appearance in which the adapter 17 is attached to the forged sleeve 1 to which the first rebar is friction-welded is shown in FIG. The adapter 17 is attached to the sleeve 1 after the friction welding process and before the precast concrete structure 22 shown in FIG. The adapter can be seated in the opening seat by pushing it in as a one-touch operation as can be seen from the above description. Since the adapter neck requires the deformation of the cylindrical neck portion 18 provided with the retaining claw 19, the adapter 17 is not necessarily made of resin, but an elastic material suitable for locking is selected.

  According to the reinforcing bar joint structure having such a configuration, it is possible to apply an inexpensive deformed reinforcing bar to the one-end-side open type sleeve that has been made into a forged product, and to cast concrete mortar at the connecting portion between the reinforcing bar and the sleeve. Can be completely blocked. In addition, a resin adapter is used to attach the grout injection cylinder or the air discharge cylinder to the grout injection port or the air discharge port, enabling the connection of communication pipes. It is possible to secure the joining of the reinforcing bars.

  The following describes the process of placing the upper precast concrete structure on the lower precast concrete structure and joining the reinforcing bars during the connection of the structures. This operation is not particularly novel, but even with a forged sleeve, the conventional cast sleeve shown in FIG. 12, for example, the grout injection cylinder 48 and the air discharge cylinder 49 are integrally formed on the peripheral wall 10. It shows that it can be constructed in the same way as First, the sleeve and the reinforcing bar are made into a friction welding product 23 as shown in FIG. 6A, and a grout injection cylinder 15 and an air discharge port are connected to the grout injection port 12 and the air discharge port 13 of the sleeve 1. Resin adapters 17 and 17 to be the cylindrical body 16 are attached.

  A large number of them are prepared, and as shown in FIG. 7 (a), with the sleeve 1 facing down, the reinforcing bars 2 are set up (two in the figure), and a formwork (not shown) is arranged at a predetermined position around the periphery. A space is defined to form the structure 22 having a predetermined shape. A small window is opened in the mold, the base end portion is inserted into the adapter 17, and the communication pipe 14 provided with a temporary stopper (not shown) faces the opening. The communication pipe 14 is connected to the grout inlet 12 to the sleeve 1A into which the grout is directly injected, but concrete mortar is applied to the grout inlet 12 of the sleeve 1B that is indirectly filled with grout. A blind lid 24 is applied before being installed.

  Since there is no gap in the connecting portion between the reinforcing bar 2 and the sleeve 1, mortar and its silt cannot enter the internal space 9 of the sleeve 1 when mortar is placed. Since the internal space remains the original shape at the time of molding, it does not cause a flow hindrance when injecting grout at the construction site, and the desired joining strength can be exhibited by solidifying the grout filled with a predetermined amount. become.

  As shown in FIG. 7B, the upper precast concrete structure 22 </ b> U is lowered onto the lower precast concrete structure 22 </ b> L by a crane or the like, and the upper ends of the reinforcing bars 4 face the openings 25 of the sleeve 1. The structure 22U is further lowered and placed on the spacer / packing 27 disposed around the joint 26 as shown in FIG. In this example, as described above, there is also the sleeve 1B in which the grout is indirectly filled, so that the mortar is not applied and the flow space of the grout 3 at the joint is secured. As the grout, a high-strength non-shrink mortar or an organic grout agent is used, but it is not limited thereto.

  The grout 3 that has entered the internal space 9 of the sleeve 1 through the injection plug 28, the communication pipe 14, the grout injection cylinder 15, and the grout injection port 12 follows the broken line 29 in the drawing in the direction of the broken arrow. The internal space 9 is filled, and surplus reaches the air discharge port 13 while pushing out the accumulated air, and is discharged out of the structure 22U through the air discharge cylinder 16 and the communication pipe 14. If the overflow grout 30 is confirmed, the sleeve 1 is completely filled, and the presence or absence of the overflow grout 31 from the other communication pipe 14 is also checked. Although not shown, if a plug (not shown) that allows exhaust but prevents overflow of the grout is attached to the opening of the communication pipe 14 connected to the air discharge port 13, the grout can be saved. It is done.

  Incidentally, the adapter 17 is in a state of being fitted to the grout inlet 12 and the air outlet 13, and the grout inlet cylinder 15 and the air outlet cylinder 16 are left in the structure 22 together with the communication pipe 14. Grout remains and solidifies therein, but has no effect on the strength of the structure 22.

  Although the above is described in the example of the post-grouting method, as shown in FIG. 6B, the sleeve 1M having the air discharge cylinder 16 but not the grout injection cylinder may be used. In the case of this sleeve, as shown in FIG. 9, the opening corresponding to the grout inlet is filled with the opening 25 on the one end side of the sleeve 1M before the rebar is inserted. In this example of the pre-grouting method, the sleeve opens at the upper edge of the structure, so that the grout is filled into the internal space by its own weight, and the grout 3 is stirred and pressed in the internal space 9A while the second rebar 4 is being lowered. The diffused and pushed-in air is discharged through the air discharge port 13, the air discharge cylinder 16, and the communication pipe 14 by the grout to be followed. A part of the grout removed by the reinforcing bar overflows from the internal space 9A, but the structures are also joined by solidification of the mortar 32 placed on the joint 26.

  In the forged sleeve 1 described above, an opening seat 11 is provided on the peripheral wall 10 to open the grout injection port 12 and the air discharge port 13, but a grout injection cylinder portion or air that protrudes from the peripheral wall 10 is used. Since the discharge cylinder portion is not integrally formed (see FIGS. 3A and 3B), only the air discharge port 13 is opened in the sleeve 1M shown in FIG. 6B. However, since the air discharge cylinder portion protruding from the peripheral wall 10 is not integrally formed, the sleeve can be easily forged. In the above description, the sleeve has been described as being made of forging. On the other hand, friction welding can be applied even if the sleeve is made of cast iron or cast steel. When the sleeve is made of cast iron or cast steel, it is easy to integrally form the grout injection cylinder 48 (see, for example, FIG. 12) and the air discharge cylinder 49. However, in the case where only the opening seat is formed, the adapter can be used to connect to the communication pipe.

  Regardless of the presence or absence of an adapter, if the sleeve is made of an iron-based product that can be friction-welded to the reinforcing bar, even if a deformed steel bar such as an inexpensive bamboo reinforcing bar is used instead of an expensive threaded reinforcing bar, the connection between the reinforcing bar and the sleeve It is possible to completely prevent the pouring concrete mortar from entering the connecting portion. Incidentally, cast iron sleeves are inexpensive, cast steel has higher fracture strength, and forged products are mass-produced despite being high-strength products, which promotes significant cost reduction of reinforced joints.

  The above description is directed to the connection of structures such as precast concrete panels and precast concrete columns in which reinforcing bars are embedded in the vertical direction. By the way, the reinforcing bar joint structure by the one end side opening type sleeve according to the present invention can be applied to a case where a structure in which a reinforcing bar is embedded in a lateral direction such as a precast concrete beam is connected to the left and right. In both cases, the air discharge port is installed in the inner space of the sleeve as deep as possible, and the removal of residual air by the grout is expected.

  Examples of this horizontal connection are shown in FIGS. FIG. 10 is a view of the beam material from the outside of the lateral side, and the friction welding product 23 indicated by a broken line is embedded in the concrete 47. For example, the end port 14a of the communication pipe 14 connected to the air discharge port 13 of the lower sleeve 1A is opened on the side wall surface of the structure 22LT, and the end port of the communication pipe 14 connected to the air discharge port 13 of the upper sleeve 1B. 14b is opened on the upper surface of the structure 22LT. An end port 14c of the communication pipe 14 connected to the grout injection port 12 of the lower sleeve 1A is provided on the side wall surface, and an injection plug 28 is attached thereto, to which a grout supply hose 33 is connected.

  FIG. 11 shows a state in which the grout 3 from the injection plug 28 is filled in the internal space 9 of the sleeve 1A, the communication pipe 14, and the internal space 9 of the other sleeve 1B via the joint 26 and the communication pipe 14. is there. It can be known that there is no residual air when the overflow grouts 30, 31 occur. It is confirmed that the joint 26 is filled by overflowing from the upper end similarly to the communication pipe 14.

  In the case of horizontal connection, usually use a rebar joint with open sleeves on both ends, and a structure that covers a rebar that has been preliminarily covered with a rebar that protrudes from one structure over a rebar that protrudes from the other structure. It is necessary to leave a space at least 1.5 times as long as the sleeve (see, for example, FIG. 9 of JP-A-2008-63729). When this length is 40 centimeters, it can be seen that this is a large space that is incomparable to the case where the joint has a width of 2 to 3 centimeters. This space is covered with a mold after the reinforcing bars are joined via the sleeve, and concrete is placed to connect the structures.

  On the other hand, as shown in FIG. 11, if the reinforcing bar joint by the one end side opening type sleeve is used, the joint volume is remarkably small, and joint filling and reinforcing bar joining work are performed at the same time. Consumed man-hours are drastically reduced. In this epoch-making method, if the grout overflows from the joint before the grout leaks from the end of the communication pipe that is connected to the air discharge port, the joint cover may be applied at that point. Grout injection does not have to be done from the lower sleeve, but in order to increase grout filling at the joint bottom, the rod insertion near the joint bottom and the bubble expelling operation thereby are shallow. It is convenient to inject from the lower sleeve so that it can be done at the moment.

  As can be seen from the above detailed description, the sleeve is made as an iron-based model, and the outer diameter of the reinforcing bar is smaller than the outer diameter of the sleeve on the other end side opposite to the one end side of the sleeve that is opened to insert the first reinforcing bar. Since the solid part having the above diameter is formed, the sleeve and the reinforcing bar can be connected to each other without enlarging the pressure welding burr by rotating the solid part and the end face of the reinforcing bar in contact with each other and friction welding. Can be firmly integrated in advance.

  Since the grout injection cylinder or the air discharge cylinder is formed in the opening seat of the peripheral wall and the resin adapter protruding from the sleeve is seated after the friction welding between the sleeve and the reinforcing bar, the protruding portion is formed on the peripheral wall during molding. Forging sleeves that are not easy to form can also be used as one-end-opening sleeves for reinforcing steel joints. Therefore, it is possible to attach a communication pipe for application to a precast concrete structure, and it is possible to use a forged sleeve that is difficult to integrally form a grout injection cylinder part and an air discharge cylinder part. become able to. As a result, there are no restrictions on the types of reinforcing bars, and it is possible to contribute to a reduction in construction costs by employing inexpensive bamboo joint reinforcing bars.

  A retaining claw that prevents the detachment after sitting on the opening seat is formed at the end of the cylindrical neck that is provided at the insertion side end of the adapter and has an outer diameter substantially the same diameter as the grout inlet and the air outlet. The Since the cylindrical wall has a plurality of slits extending in the axial direction, when the retaining pawl passes through the grout inlet and the air outlet, the diameter of the pawl ring is reduced, and after passing, the diameter is reduced, and the adapter is grouted. Securely locked to the inlet or air outlet. Precast concrete structure that can connect to the grout injection port and the communication pipe connected to the air discharge port even with the forged sleeve that cannot integrally mold the grout injection tube and the air discharge tube protruding from the peripheral wall The way to introduce a new type of sleeve is opened up.

  1, 1A, 1B, 1M ... sleeve, 2 ... first rebar, 3 ... grout, 4 ... second rebar, 5 ... rebar joint, 6 ... solid part, 7, 8 ... pressure welding burr, 10 ... peripheral wall, 11 ... Open seat, 12 ... grout inlet, 13 ... air outlet, 15 ... grouting cylinder, 16 ... air outlet cylinder, 17 ... adapter, 18 ... cylindrical neck, 19 ... retaining claw, 20 ... claw Ring, 21... Slit, 25... Opening on one end side, 48... Grout injection cylinder, 49.

Claims (5)

One end side of the sleeve is open while the other end side is preliminarily integrated with the first rebar, and the second rebar inserted from the one end side by the grout injected into the sleeve is opposed to the first rebar in the longitudinal direction. In the rebar joint that is to be joined with
The sleeve is an iron-based shaped product, and the other end side is formed with a solid part having a diameter smaller than the sleeve outer diameter and greater than or equal to the outer diameter of the reinforcing bar,
The integration of the solid part and the first reinforcing bar is performed by friction welding at the abutting portion of both, and the reinforcing bar joint structure by the one end side opening type sleeve.   The reinforced joint structure according to claim 1, wherein the iron-based shaped article is made of cast iron, cast steel, or forged.   The peripheral wall of the iron-based shaped article is provided with an opening seat to open the grout inlet and the air outlet, but the grout injection cylinder and the air discharge cylinder that protrude from the peripheral wall are integrally molded. 3. A reinforcing bar joint structure according to claim 1 or 2, wherein the one-end opening sleeve is used.   4. A resin adapter that is formed on the opening seat so as to form a grout injection cylinder or an air discharge cylinder and project on a peripheral wall of the sleeve is seated after the friction welding process. The reinforcing bar joint structure by the one end side opening type | mold sleeve described in 1). The adapter has a retaining claw for preventing the adapter from coming off after being seated in the opening seat, and is located on the insertion side of the adapter and has an outer diameter substantially the same as the grout inlet and the air outlet. Formed at the tip of the neck,
A plurality of slits extending in the axial direction are formed in the cylindrical neck so that the claw ring is reduced in diameter when the retaining claw passes through the grout inlet and the air outlet and is restored after passing. The reinforcing bar joint structure according to claim 4, wherein the one-end opening sleeve is used.