JPH06158715A - Joint construction of precast concrete circumferential girder - Google Patents

Abstract

PURPOSE:To omit a form used in the case of condition of precast concrete circumferential girders and to execute joint work simply and easily and to increase joint strength and durability in a joint part. CONSTITUTION:Plane viewed L-shaped vertical walls 10a and 12a and bottom floors 10c and 12c notching the bottom in half are respectively spread on the end connecting a pair of adjacent right and left precast concrete circumferential girders 10 and 12 to each other. Interlocking step sections 10b, 10d, 10e and interlocking step sections 12b, 12d, 12e corresponding to each other are provided to vertical walls 10a and 12a contacted with each other in the case the circumferential girders 10 and 12 are connected to bottom floors 10c and 12c and body end corner sections. Main reinforcing bars 16a, 16b, 17a and 17b are so arranged in a space A after the combination that they are overlapped each other, and a plurality of auxiliary reinforcing bars 18 and 19 and vertical sections 18a and 19a are bound with lateral ties 20 having a plurality of steps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete girder connection structure, and more particularly to a connection structure with improved workability and improved joint strength and durability without the need for a formwork for post-cast concrete. is there.

[0002]

2. Description of the Related Art When connecting precast concrete girders (hereinafter simply referred to as PC girders) to each other at an assembly site, conventionally, as shown in FIGS.
The pair of upper and lower beam main bars 3a and 3b protruding from the joint end surface of the PC are engaged by the splice sleeve 5, and the spiral reinforcement 4 around them is shear-reinforced, and the joint end surfaces of the PC girders 1 and 2 are separated from each other. And placing a pair of molds 8 between the side surfaces of the PC girders 1 and 2 to close the casting space B formed between the two and to postcast concrete inside the space B. By doing so, both the PC girders 1 and 2 were integrally connected.

[0003]

However, in this connection structure, the work of installing and removing the formwork 8 for placing the post-cast concrete is complicated and the workability is poor. . Further, since the beam main bars 3a, 3a or the beam main bars 3b, 3b are engaged with each other by the splice sleeve 5, and the surrounding area is shear-reinforced by the spiral bar (or the hoop bar) 4, post-casting concrete is placed. The space B for the space was narrowed, and there was a problem with the filling property and durability of the post-cast concrete. The present invention solves the above problems, and an object of the present invention is to provide a PC girder connection structure that does not require a formwork or a splice sleeve for connecting PC girders.

[0004]

In order to solve the above-mentioned problems, in the present invention, the end faces of the precast concrete girders are faced with each other at a predetermined interval, and concrete is placed in this interval. In a structure that connects precast concrete girders, a vertical wall with an L-shape in plan view and a bottom floor with a half cutout bottom are stretched on the joint end faces of a pair of left and right adjacent precast concrete girders. A pair of precast concrete girders are provided with vertical step walls, bottom floors, and end faces of the main body, which come into contact with each other, and which have matching step portions, respectively.
A main bar that projects in the axial direction of the beam and that vertically overlaps each other is arranged in a space formed by the end face, the inner surface of the vertical wall, and the upper surface of the bottom floor, and is orthogonal to the main bar in the space and is horizontal. An auxiliary muscle having a vertical portion and a vertical portion is stretched from each vertical wall and the bottom floor, and the vertical portion of the auxiliary muscle is tightly bound by a plurality of upper and lower hoop muscles.

[0005]

In the PC girder of the present invention, a vertical wall and a bottom floor are provided on the joint end faces, and a locking step is provided at the tip of each of them, so that when a pair of left and right PC girders are aligned, the upper part is opened. A box-shaped space is formed, and the main bars are arranged in the axial direction of the beam so that they overlap each other vertically.
Since the vertical part of the auxiliary muscle is configured to be bound by the hoop muscle,
Post-cast concrete can be poured directly from the top of the opening without using a formwork. Therefore, the formwork and splice sleeve shown in the prior art are not required, and simple work can be performed, and the auxiliary girders tightly bound by both main and hoop reinforcements firmly connect the glutes after placing concrete. Therefore, the bonding strength and durability are improved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. 1 to 4 relate to an embodiment of the present invention, and FIG.
C is a perspective view of the girder, FIG. 2 is a plan view of the PC girder, and FIG. 3 is FIG.
FIG. 4 is a vertical sectional view taken along line XX of FIG. 4, and FIG. 4 is a perspective view showing another embodiment. In the figure, a pair of left and right PC girders 10 and 12 have vertical walls 10a and 12a each having an L-shape in plan view at their end faces.
And a bottom floor 10c with a bottom cut in half,
12c. Further, locking step portions 10b and 12b are provided at the tips of the vertical walls 10a and 12a that abut when the PC girders 10 and 12 are united, and the corresponding PC girders are provided. Locking steps 10e and 12e are also provided on the end faces of 10 and 12. Also, the bottom floor 1
The locking steps 1 are also provided in the axial direction at the tips of 0c and 12c, respectively.
0d and 12d are provided and are configured so that they match.

Further, as shown in FIGS. 2 and 3, the end faces of the PC girders 10, 12 have a pair of upper and lower main bars 1 in the axial direction of the beams.
6a, 16b and main reinforcements 17a, 17b are projected, and the main reinforcements 16a and 17a and the main reinforcements 16b and 17b are arranged so as to be vertically overlapped with each other. Furthermore, the main line 16
A, 16b and main muscles 17a, 17b are bent in a C shape so as to surround them, and an auxiliary muscle 18 composed of a horizontal portion and a vertical portion.
And the auxiliary muscles 19 are embedded in the vertical walls 10a, 12a and the floors 10c, 12c, respectively, and the vertical portions 18a and 19a of the exposed portions thereof are both the multistage hoop muscles 20.
Is tied up with. The auxiliary muscles 18 and 19 are vertical walls 10a and 12
A plurality of pieces (five pieces in each case in this embodiment) are attached at equal intervals in the longitudinal direction of a and orthogonal to the main bars 16 and 17.

In addition to the eight main bars shown in the figure, both PC girders 1
It can be appropriately arranged in the axial direction of the beam near the center of the space A surrounded by 0 and 12. After combining the PC girders 10 and 12 configured as described above, by pouring concrete from the upper part into the space A and solidifying, both PC girders 10 and 12 are placed in the concrete pouring space A. It is integrally connected to the shape in which a vertically long tenon is driven, and is completely integrated. In other words, both PC glutes 10 and 12 are firmly connected by the overlapping main muscles and the auxiliary muscles tightly bound by the hoop muscles 20.

The space A is restricted in its size, and when the beam width of each of the PC girders 10 and 12 is small,
The width of the space A cannot be made large and a large number of beam main bars 16, 1
Since the 7 and the auxiliary muscles 18 and 19 are arranged intricately, the post-cast concrete is difficult to rotate and the filling failure is likely to occur. Therefore, in this case, high fluidity concrete is used. This high-fluidity concrete was developed by the applicant of the present invention, and is a high-performance AE water reducing agent (for example, H
S700 brand name) and limestone powder are concretes that do not cause material separation with good slump flow in the range of 65 to 70 cm. Even if the pouring space A is narrow, it will fully sneak into each part, Prevents defective filling and attaches integrally to the beam main bars 16 and 17,
Demonstrate sufficient strength.

FIG. 4 shows another embodiment in which the form of the auxiliary muscles is different. The auxiliary muscles 18 and 19 each having a concavo-convex shape and an integral loop type are arranged in parallel with each other. The auxiliary muscle 18 of the convex loop is embedded in the vertical wall 10a, while the auxiliary muscle 19 of the concave loop is embedded in the vertical wall 12a and the bottom floor 12c. Then, as shown in the figure, the parallel vertical portions are tightly bound by the hoop muscles 20, respectively. With such a configuration, not only the main muscles are integrated but also the auxiliary muscles are completely integrated, so that the connection between the both PC girders 10 and 12 is further strengthened.

In the PC girder connection structure of the present invention constructed and joined as described above, a vertical wall or a bottom is used instead of the form at the time of joining both PC girders as in the conventional method. The floor will do its job. Therefore, not only is the formwork unnecessary, but also the work of attaching and detaching the formwork is unnecessary, and since it is only necessary to pour concrete into the space A from the opening in the upper part, the construction is easy and the space A
Main bars 16a, 16b, 1 arranged so as to overlap inside
7a, 17b and the auxiliary muscle 18 tightly bound by the hoop muscle 20,
Due to the presence of 19, the joining of both PC girders 10 and 12 is completed. Further, since there is no splice sleeve for engaging the main bars with each other as shown in the prior art, the concrete can flow in well, and the joint strength and durability of the joint portion are improved.

[0012]

As described above, in the joint structure of the precast concrete gaze beam of the present invention, not only the jointing form is unnecessary and the construction is easy, but also the joint strength of the joint portion is improved and the durability is improved. Is enhanced.

[Brief description of drawings]

FIG. 1 is a perspective view of a precast concrete girder according to an embodiment of the present invention.

FIG. 2 is a plan view of a precast concrete girder after uniting according to an embodiment of the present invention.

FIG. 3 is a vertical sectional view taken along line XX of FIG.

FIG. 4 is a perspective view of a precast concrete girder according to another embodiment of the present invention.

FIG. 5 is a perspective view showing a joined state of a conventional precast concrete girder.

FIG. 6 is a plan view showing a joined state of a conventional precast concrete girder.

[Explanation of symbols]

 1 Precast concrete girder (PC girder) 2 Precast concrete girder (PC girder) 3a Main reinforcement (upper) 3b Main reinforcement (lower) 4 Spiral reinforcement (or hoop) 5 Splice sleeve 8 Formwork 10 Precast concrete girder ( PC girder) 10a Vertical wall 10b Locking step 10c Bottom floor 10d Locking step 10e Locking step 12 Precast concrete girder (PC girder) 12a Vertical wall 12b Locking step 12c Bottom floor 12d Locking step Part 12e Locking step 16a Main bar (upper) 16b Main bar (lower) 17a Main bar (upper) 17b Main bar (lower) 18 Auxiliary muscle 18a Vertical part 19 Auxiliary muscle 19a Vertical part 20 Hoop muscle A Space B Space

Claims (1)

[Claims] 1. A structure in which end faces of precast concrete glutes are faced to each other at a predetermined interval and concrete is placed in these gaps to connect the precast concrete glutes to each other. An L-shaped vertical wall in plan view and a bottom floor with a half-bottom cut out are stretched on the joint end faces of the girder, and the vertical wall and the bottom that abut against each other when the pair of left and right precast concrete girders are joined. The floor and the end face of the main body are provided with locking step portions that match each other, and the main bars that project in the axial direction of the beam in the space formed by the end face, the inner surface of the vertical wall, and the bottom floor upper surface, and that overlap each other in the vertical direction are provided. Auxiliary muscles that are arranged in the space and that are orthogonal to the main muscles and that have horizontal and vertical portions are stretched from the respective vertical walls and the bottom floor. A connection structure of precast concrete glutes in which the vertical part of the is tightly bound with upper and lower hoop reinforcements.