JPH10140670A - Reinforcement connecting structure between precast concrete blocks and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement connecting structure and a reinforcement connecting method in which reinforcements arranged respectively in two precast concrete blocks can be firmly connected to each other, and the workability is excellent. SOLUTION: In this reinforcement connecting structure, U-shapedly bent reinforcements 2, 12 are respectively buriedly arranged in two precast concrete blocks 1, 11, and the U-shaped curved parts 2a, 12a are exposed in the vicinity of the joint ends of the concrete blocks. Both the blocks 1, 11 are arranged so that the curved parts 2a, 12a of the reinforcements arranged in the two concrete blocks 1, 11 are confronted with each other from both sides, and a pair of saddle-like lock metal fittings 3, 13 are brought in contact with the inside of the respective curved parts 2a, 12a. These lock metal fittings 3, 13 are connected together through bolts 4 and nuts 5, and fastened so as to introduce a little tension to the reinforcements 2, 12 on both sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure and a connection method of a reinforcing bar buried as a reinforcing material inside a concrete member, and more particularly to a connection structure and a connection of a reinforcing bar at a joint between precast concrete blocks. About the method.

[0002]

2. Description of the Related Art In recent years, in the construction of concrete structures, a construction method using a precast concrete block has been tending to be employed for the purpose of saving labor and improving construction efficiency. In this case, a preformed concrete block, that is, a precast concrete block, which is preformed in a manufacturing yard or a factory provided separately from a place where the structure is to be constructed, is transported to the construction site of the structure, and they are mutually fixed at a predetermined position. It is joined and connected and assembled as a structure. In many cases, a plurality of precast concrete blocks are used as a formwork, and a structure is constructed integrally with concrete cast in a portion surrounded by the blocks.

[0003] When a structure is constructed by joining a plurality of precast concrete blocks in this way, even if rebars are arranged in each block, if the rebars are not connected at the joints of the blocks, the construction is performed. It does not become a reinforcing bar that can effectively resist external force acting on the structure. For this reason, connecting rebars between precast concrete blocks has been considered.

[0004] As a structure or a method for connecting the reinforcing steel between the precast concrete blocks, the following techniques are known. Lap joints Coupler joints Welded or welded joints Splice sleeve joints

[0005] The lap joints mentioned above are the ones most commonly used in the past, in which the joining end faces of two concrete blocks are opposed to each other, and the end of the reinforcing bar exposed from each joining end face. This is a method in which the pieces are overlapped with each other, and a concrete is poured into the connection portion to fix the connection.
This method has the advantage that the construction of the reinforcing bar connection is simple, so that the workability is good and the construction management is easy.

In the coupler joints described above, male threads are provided at the ends of the reinforcing bars to be joined, and the ends of the reinforcing bars are arranged so as to abut each other. The connected cylindrical connecting tool (coupler) is screwed into both rebars and connected. In addition, by using a reinforcing bar in which the convex portion of the peripheral surface of the deformed reinforcing bar has a thread, the length of the reinforcing bar of the connecting portion can be easily adjusted on site, and the cross-section by providing the male screw No loss occurs.

The above-mentioned press-welding or welded joint includes a so-called gas pressure welding method or an enclosure welding method. In this method, both ends of rebars to be connected are abutted, and the portions are connected by welding or heating and pressing.

In the splice sleeve joints described above, cylindrical steel sleeves are attached to both ends of a reinforcing bar to be connected, and mortar grout is injected into a gap between the sleeve and the reinforcing bar. Are joined together by the adhesive force between the mortar reinforcing steel and the steel sleeve.

[0009]

However, the above-described conventional reinforcing joints have the following problems. In the case of the above lap joint, in order to prevent the joint position of a plurality of parallel reinforcing bars from becoming a structural weak point,
It is necessary to disperse the joint positions of the reinforcing bars, but when joining a plurality of reinforcing bars between the precast concrete blocks, the positions of the joints must be all the same. For this reason, there is a problem that it cannot be used as a means for connecting structurally important reinforcing bars. In other words, if lap joints of multiple parallel reinforcing bars are provided at the same position in the axial direction, a large load such as an earthquake will cause cracks in the concrete in this area, causing the reinforcing bars to fall off. The adhesive force of the overlapped and connected portion is lost, and the proof stress of the concrete structure is rapidly reduced. In order to avoid such a situation, the lap joints of the reinforcing bars must be provided dispersed in the axial direction, and are not suitable for connecting the reinforcing bars between the precast concretes.

In the case of a coupler joint, relative displacement occurs without stress between the connected reinforcing bars due to dimensional tolerances between the female screw cut into the coupler and the male screw of the reinforcing bar. In order to prevent this, tension must be introduced between both reinforcing bars or grout such as resin must be injected into the gap between the coupler and the reinforcing bars.
Therefore, there is a problem that the work is complicated and the construction management is complicated. In addition, construction costs are high due to poor workability. Furthermore, if there is a displacement in the arrangement of the reinforcing bars due to an error in the arrangement of the reinforcing bars during the production of the precast concrete block or an error in assembling the concrete block, the position is set so that the coupler can be screwed into both reinforcing bars. There is also a problem that it is difficult to adjust.

[0011] In the case of a joint by a pressure welding method or an enclosure welding method, since both ends of a reinforcing bar to be connected are opposed to each other and connected by welding or heating, it is difficult to perform construction in rainy weather or the like. And there is a problem that it depends on the weather. In addition, there is a problem that workability is poor such as difficulty in construction in a narrow work space, and construction cost tends to be high.

Further, in the case of a splice sleeve joint, mortar grout must be injected into the gap between the sleeve and the reinforcing bar, resulting in poor workability and high construction cost. is there.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to firmly connect the reinforcing bars arranged on each of two precast concrete blocks to each other. Another object of the present invention is to provide a reinforcing bar connection structure and a reinforcing bar connecting method between precast concrete blocks which are excellent in workability.

[0014]

In order to solve the above-mentioned problems, in the rebar connection structure according to the first aspect of the present invention,
Each of the two precast concrete blocks is bent into a U-shape, exposing a curved portion thereof, and both sides of the curved portion have reinforcing bars embedded in the concrete. The curved portions of the reinforcing bars arranged inside face each other, and both side portions thereof are arranged so as to face substantially in opposite directions. Saddle-shaped locking metal fittings abut on the inside of each curved portion of the reinforcing bars. It is assumed that the locking fittings are connected by bolts.

In the rebar connection structure according to the present invention, the rebar placed in the precast concrete block is:
It is formed in a U-shape and both sides are embedded and set in a concrete, and the tensile force is reliably transmitted between the reinforcing metal engaged with the curved portion and the reinforcing bar connected by the bolt. . Further, since the locking fittings are connected to each other by fastening the bolts so as to be attracted to each other, it is possible to reliably and firmly connect the connecting portions without causing relative displacement. Further, since the latches to be engaged with the curved portions of the reinforcing bars arranged on the two precast concrete blocks are saddle-shaped, the position and direction of the latches can be adjusted. Therefore, it is not necessary for the rebars to be connected to face each other with strict accuracy, and the rebars can be easily connected even if there are some errors in the arrangement of rebars and assembly errors during the production of the precast concrete block.

According to a second aspect of the present invention, the curved portion of the U-shaped reinforcing bar is exposed at a side close to a joint end face where the two precast concrete blocks abut, and Moreover, the distal end of the curved portion is disposed at a position slightly retreated from the joint end surface,
The end faces of the joints can be brought into contact with each other or the distance between the end faces can be made extremely close, and the precast concrete
The assembling of the lock is facilitated.

According to a third aspect of the present invention, the precast concrete block according to the present invention is used as a mold for casting concrete of a structure, and is integrated with the concrete to be cast. By exposing the U-shaped reinforcing bar to be connected to a notch provided on the back side of the joint end face of the precast concrete block, thereby forming a concrete in place. And the precast concrete blocks to be joined can be arranged so as to be in contact with each other, so that the finish of the outer surface of the concrete structure can be improved. Also, the joints of the reinforcing bars are embedded in cast-in-place concrete, and the connected reinforcing bars effectively act as reinforcing bars of the concrete structure.

According to a fourth aspect of the present invention, there is provided a method of connecting a reinforcing bar between precast concrete blocks according to the present invention, wherein a saddle-shaped locking member is attached to a curved portion of the reinforcing bar exposed from both sides, and these are bolted. The construction is easy because the rebar is connected firmly by connecting with
Workability becomes extremely good. In addition, work skill and the like are not required, construction management is easy, and since the connection method is purely mechanical, it is less affected by weather and the like. Furthermore, in this method, since two rebars can be connected at the same time, labor saving and improvement in construction efficiency can be obtained.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a reinforcing bar connection structure according to an embodiment of the present invention described in claim 1, claim 2 or claim 3, and FIG. 1 is a schematic perspective view thereof.
FIG. 2 is a plan view (a), a side view (b), and a front view (c) of a main part of the structure.

This connecting structure for reinforcing bars connects the reinforcing bars arranged on both of the two precast concrete blocks 1 and 11 which are erected when joining the two standing upright plate-like concrete blocks. The concrete blocks 1 and 11 are joined so that the vertical joining end faces 1a and 11a abut each other. The joining end surfaces 1a, 1
As shown in FIG. 1, cutout portions 1b and 11b are provided on the back side near 1a.
Are bent in a U-shape, and their curved portions 2a, 12a are exposed in the notches 1b, 11b. And the both sides 2b and 12b of the curved part of these rebars 2 and 12
It is embedded in the inside of the precast concrete blocks 1 and 11 and is fixed by the adhesive force with the concrete.

The two precast concrete blocks 1 and 11 are arranged so that their joining end faces abut each other, so that the surfaces 1d and 1c of the concrete block are arranged.
11d are joined so as to form a continuous plane, and the curved portion 2 of the reinforcing bar bent into the U-shape.
Reference numerals a and 12a are located at positions slightly retreated from the joint end surfaces 1a and 11a, and are arranged so as to face each other with a space therebetween. The two side portions 2b and 12b of the curved portions of the reinforcing bars are arranged facing in opposite directions, and are fixed in the concrete blocks 1 and 11, respectively.

The curved portions 2a, 12 of the two rebars facing each other
The metal fittings 3, 13 made of cast iron, each formed into a semi-disc shape, are fitted into the inside of a. As shown in FIG. 1 and FIG. 2, the locking metal fittings 3 and 13 are provided with groove-shaped concave portions on the arc-shaped outer peripheral portions 3a and 13a in which the curved portions of the rebars 2 and 12 are fitted. And the curved portions 2a, 12
It is a saddle-shaped member that comes into contact with the reinforcing bar from the inside of a. Further, as shown in the plan view (a) and the front view (c) of FIG.
Two bolt holes 3b, 13 penetrating in the center line direction of 3a
The bolt 4 is inserted into these bolt holes 3b, 13b, and a pair of locking fittings 3, 13 which are tightened up by a nut 5 and face each other are connected.

The bolt 4 has male threads cut at both ends, and has a structure in which nuts 5 are screwed into both ends to connect the locking fittings 3, 13. In addition to the structure in which the nuts 5 are screwed into the ends of the bolts 4 as described above, a female screw is previously inserted into the bolt hole 13b of one of the locking members 13. Can be screwed, and a bolt can be directly screwed into this. Further, it is preferable to use a high tension bolt having a large tensile strength as the bolt 4. Furthermore, the above-mentioned locking metal is not limited to cast iron, and the material and the manufacturing method can be arbitrarily selected as long as it has sufficient strength, such as by cutting.

In such a rebar connection structure between precast concrete blocks, rebar connection is performed in the following procedure. Each of the precast concrete blocks 1 and 11 is manufactured in a manufacturing yard or a factory. At the time of manufacturing the blocks, rebars 2 and 12 bent in a U-shape are arranged at predetermined positions, and a curved portion 2 is formed.
Concrete is cast so that a and 12a are exposed and both sides are embedded in the concrete. The precast concrete blocks 1 and 11 carried into the site where the structure is to be constructed are fixed at a predetermined position and temporarily supported. At this time, the curved portions 2a and 12a of the reinforcing bars arranged on the two precast concrete blocks to be connected.
Face each other at a distance from both sides near the joining end face.

As shown in FIG. 3 (a), saddle-shaped stoppers 3 and 13 are brought into contact with the inside of the curved portions 2a and 12a of these reinforcing bars, and the reinforcing bars 2 and 12 are fitted into the grooves of the saddle-shaped portions. The fittings 3 and 13 are attached together. Then, as shown in FIG. 3 (b), the bolt 4 is inserted through the bolt holes 3b, 13b provided in the opposing locking fittings 3, 13, and the nut 5 is screwed into the two locking fittings 3, 3. 13 are connected. Bolt 4
The nut 5 and the nut 5 are tightened so that the curved portions of the rebars 2 and 12 facing each other are attracted to each other, so that the rebars of the two precast concrete blocks 1 and 11 are not loosened. Then, concrete is poured into the joint of the reinforcing bars, and the reinforcing bars 2, 12 and the metal fittings 3, 13 are embedded in the concrete. The rebar connection method of the above procedure is also one embodiment of the invention described in claim 4.

FIG. 4 is a plan view, a front view, and a side view showing a reinforcing bar connection structure according to another embodiment of the present invention. In this rebar connection structure, the rebar 2
The arc-shaped peripheral surfaces of the locking fittings 23 and 33 that are in contact with the inside of the curved portions 22a and 32a of the second and second inclined portions are provided to be inclined with respect to the axis of the bolt hole. Therefore, the reinforcing bars 22 and 32 fitted into the grooves provided along the peripheral surface are provided.
Are bent and engaged with the axis of the bolt 24, and the rebar is bent at an obtuse angle near the boundary between the straight portions 22b and 32b on both sides of the bent portion, and the straight portions 22 on both sides are bent.
b and 32b are substantially parallel to the bolt 24, and the amount of deviation d of the axis is small. That is, as shown in FIG. 4 (a), the curved portions 22a, 32a of the reinforcing bar are bent, and the tips of the rebars are retracted from the bolts 24 connecting the latches 23, 33. It is wound around. Thereby, the reinforcing bars 22, 32 arranged on each of the two precast concrete blocks to be joined are provided.
The straight portions 22b and 32b and the bolts 24 for connecting these are arranged substantially linearly.

In such a reinforcing bar connection structure, the tensile force acting on the reinforcing bar 22 is applied from the linear portion 22b of the reinforcing bar
3. It is transmitted almost straight to the straight portion 32b of the reinforcing bar of the other concrete block via the bolt 24 and the other engaging metal member 33, so as to generate bending stress on the bolt and the reinforcing bar or to cause displacement of the reinforcing bar. The generation of a force to be applied is reduced.

FIG. 5 is a front view and a side view showing a reinforcing bar connection structure according to another embodiment of the present invention. FIG. 6 is a plan view, a front view, and a side view of a lock used in the reinforcing bar connection structure shown in FIG.
Also in this rebar connection structure, similarly to the rebar connection structure shown in FIG. 1 or FIG. 4, the curved portions 42a, 52a of the rebars 42, 52 bent in a U-shape face each other from both sides, and the inside of each curved portion. The fittings 43 and 53 are brought into contact with the first and second fittings. As shown in FIG. 6, this locking metal member has a substantially semi-circular shape with a large thickness, and has a groove-shaped concave portion 43b into which a curved portion of a reinforcing bar is fitted along an arc-shaped outer peripheral portion 43a. Is provided. A groove 43c having a U-shaped cross section is provided on both sides of the semi-disc shape of the locking metal member 43 in the direction of the bisector of the outer peripheral portion 43a. As shown in FIG. 5, bolts 44a and 44b are respectively fitted into the grooves 43c, and nuts 45 are screwed into the grooves 43c so that two locking metal fittings 43 and 53 attached to both of the curved portions of the reinforcing bar facing each other. Connected.

According to such a reinforcing bar connection structure, the reinforcing bars arranged on the two precast concrete blocks can be firmly connected with a simple structure without loosening. Further, since the locking fittings 43, 53 are connected by the two bolts 44a, 44b disposed on both sides of the curved portions 42a, 52a of the reinforcing bars facing each other, the tensile force generated between both reinforcing bars is eccentric. And transmitted in the same plane without the need. In other words, the pulling force is applied from the curved portion 42a of the reinforcing bar to the locking fitting 43, the two bolts 44a and 44b, and the other locking fitting 5
3, the resultant force of the tensile force acting on the two bolts 44a, 44b is in the same plane as the U-shaped reinforcing bars 42, 52. , Without causing bending stress on reinforcing bars or bolts
It is transmitted straight.

Next, a description will be given of a reinforcing bar connection structure between precast concrete blocks according to an embodiment of the present invention. In this embodiment, as shown in a plan view in FIG. 7A, four precast concrete blocks 61 each of which is a substantially vertical plate-like member and has an L-shaped plan view are joined, and each precast concrete block 61 Horizontally arranged reinforcing bars are connected to each other between blocks, and these precast concrete blocks are used as a formwork for cast-in-place concrete of a pier.

As shown in FIG. 7 (b), these precast concrete blocks are provided with horizontal reinforcing bars 62 at substantially equal intervals in the vertical direction, and are connected between all blocks in the circumferential direction. Thereby, a belt reinforcing bar, that is, a reinforcing bar that effectively acts on a shearing force at the time of an earthquake or the like is formed. These reinforcing bars 62 are bent in a U-shape, are arranged so that the curved portions are exposed near the joint end surfaces of the concrete blocks, and the curved portions of the reinforcing bars arranged on each block from both sides are spaced apart from each other. And confront each other. These rebars 62 are connected using the structure shown in FIG. 1 or FIG. 3, and a fitting 63 is fitted inside a curved portion bent into a U-shape, and these are connected to bolts 64. It is connected with the nut 65.

When the precast concrete block 61 is assembled as described above and the horizontal reinforcing bars 62 are connected, as shown in FIG. 8A, the vertical reinforcing bars extend along the inner surface of the joined precast concrete block 61. 66, that is, the main rebar of the pier is arranged. Thereafter, as shown in FIG. 8B, concrete 67 is poured into the area surrounded by the plurality of precast concrete blocks 61, and the main reinforcing bars 66 and the precast concrete blocks 61 are integrated. Such a process is repeated in the vertical direction, and the pier is set up. Although the pier of the above embodiment has a solid section, a large-scale pier generally employs a hollow section as shown in FIG. In such a case, both the outer mold frame and the inner mold frame are made of the precast concrete block 71, and the rebar connection structure according to the present invention can be adopted at the joint of each block.

[0033]

As described above, in the rebar connection structure according to the present invention, the connection portion has a U-shaped rebar,
Since it is a simple structure composed of the locking metal fittings and the bolts and nuts, the workability is good, the work management is easy, and the work cost is low. And two concrete
Since the saddle-shaped locking metal is engaged with the U-shaped reinforcing bar exposed near each joint end face of the lock block, and the locking metal is connected by bolts, the inside of the adjacent concrete block is used. Even if there is some error in the position of the rebar placed in the precast concrete, it is possible to easily cope with it by adjusting the direction of the locking metal.
This makes it easy to manage errors in the arrangement of the reinforcing bars and assembly errors when manufacturing the lock blocks.

Further, the U-shaped rebars to be connected are connected to each other by tightening bolts and nuts for connecting the locking fittings so that they are attracted to each other. It is possible to reliably resist the force and prevent the concrete from cracking. Further, the precast concrete block is used as a formwork for the construction of cast-in-place concrete of the structure, and the connecting portion of the reinforcing steel is provided inside the formwork so that the connecting portion of the reinforcing steel can be formed by cast-in-place concrete of the structure. Can be embedded and integrated.

On the other hand, in the rebar connection method according to the present invention,
The number of members used is small, the construction is simple, and the construction management is extremely easy. Also, the construction is less affected by the weather and can be easily constructed even in a relatively narrow work space.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a reinforcing bar connection structure according to an embodiment of the present invention.

FIG. 2 is a plan view, a front view, and a side view of the rebar connection structure shown in FIG.

FIG. 3 is a schematic perspective view showing an operation process in the rebar connection structure shown in FIG. 1;

FIG. 4 is a plan view, a front view, and a side view showing a reinforcing bar connection structure according to another embodiment of the present invention described in claim 1 or 2;

FIG. 5 is a front view and a side view showing a reinforcing bar connection structure according to another embodiment of the present invention described in claim 1 or 2;

FIG. 6 is a plan view, a front view, and a side view of a lock used in the reinforcing bar connection structure shown in FIG. 5;

FIG. 7 is a schematic plan view and a schematic cross-sectional view showing a precast concrete block to which horizontal reinforcing bars are connected by a reinforcing bar connection structure according to an embodiment of the present invention.

8 is a schematic plan view showing a process of constructing a pier using the precast concrete block shown in FIG. 5 as a cast-in-place concrete formwork.

FIG. 9 is a schematic plan view showing another example of a precast concrete block to which horizontal reinforcing bars are connected by a reinforcing bar connection structure according to an embodiment of the present invention.

[Explanation of symbols]

1,11 Precast concrete block 1a, 11a Joining end face 1b, 11b Notch 1c, 11c Back side of precast concrete block 1d, 11d Surface of precast concrete block 2,12 Reinforcing bar 2a, 12a Curved section 2b, 12b Straight section 3, 13 Locking bracket 4 Bolt 5 Nut 22, 32, 42, 52 Reinforcing bar 22a, 32a, 42a, 52a Curved portion 22b, 32b Linear portion 23, 33, 43, 53 Locking bracket 24, 44 Bolt 25, 45 Nut 61 Precast Concrete block 62 Reinforcement 63 Locking bracket 64 Bolt 65 Nut 66 Main rebar 67 Cast-in-place concrete 71 Precast concrete block 72 Cast-in-place concrete

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Manabu Asai 13-4 Arakicho, Shinjuku-ku, Tokyo Sumitomo Construction Co., Ltd.

Claims (4)

[Claims] 1. Each of two precast concrete blocks is bent into a U-shape to expose a curved portion thereof, and both sides of the curved portion have reinforcing bars embedded in the concrete. The curved portions of the reinforcing bars disposed in both the precast concrete blocks face each other, and both side portions thereof are disposed so as to face substantially in opposite directions. Saddle-shaped locking metal fittings are provided inside the respective curved portions of the reinforcing bars. A reinforcing bar connection structure between precast concrete blocks, wherein the metal fittings are connected by bolts. 2. The curved portion of the reinforcing bar is exposed at a position close to a joint end face where the two precast concrete blocks to be joined are abutted, and a tip of the curved portion is located at a position slightly retreated from the joint end surface. The structure for connecting reinforcing bars between precast concrete blocks according to claim 1, wherein the reinforcing bars are arranged in a certain manner. 3. The precast concrete block is used as a formwork for casting concrete of a structure, and is integrated with the concrete to be cast and becomes a part of the structure. 3. The reinforcing bar between the precast concrete blocks according to claim 2, wherein the curved portion of the reinforcing bar is exposed to a cutout portion provided on the back side of the joint end surface of the precast concrete block. Connection structure. 4. Two precast concretes to be joined
A reinforcing bar bent in a U-shape is arranged on each of the blocks so that the curved portion is exposed and both sides of the curved portion are embedded in the concrete. The two precast concrete blocks are arranged so as to face each other, and a saddle-shaped locking member is brought into contact with the inside of the curved portion of the reinforcing bar, and these locking members are connected by bolts, and the bent reinforcing bar is bent. A method of connecting reinforcing bars between precast concrete blocks, wherein the bolts are tightened so as to attract a portion.