JPH0665932A - Joint structure of pc beam and column - Google Patents

Abstract

PURPOSE:To firmly arrange anchor steel rods of a PC beam without use of large columns and easily construct it. CONSTITUTION:Main reinforcing steel rods 5 of the lower end beam protrudes from the end face of a half PC beam 2 and L-shaped anchor steel rods 12 are connected to the front end. A pair of half PC beams 2 are oppositely arranged at both sides of the defined space 11 of concrete columns 3. The L-shaped anchor steel rods 12 are raised up within the defined space 11 by the columns. The main reinforcing steel rods 14 of the upper end beam are laid down without joints, between the half PC beams of both sides. A full PC beam can be used instead of the half PC beam 2. In this case, the anchor steel rods are jointed to the main reinforcing rods of the upper end in these going-down direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete beam (hereinafter referred to as "PC beam") which is an underground beam or a floor beam on each floor.
Abbreviated as ") and a cast-in-place concrete column.

[0002]

2. Description of the Related Art Conventionally, a structure shown in FIG. 6 has been adopted as a joining structure for connecting PC beams arranged via columns. The figure shows the case of an underground beam. That is, the beam main bar 53 is projected from the column joint end surface on the PC beams 52 arranged on both sides of the column mold 51, and after the reinforcement bars (not shown) constituting the column mold 51 and the like are laid out, an anchor is used at the site. Reinforcing bars 54 are joined by reinforcing bar joints 55. A pressure welding or a mechanical joint is used for the reinforcing bar joint 55. A pair of opposing anchor rebars 54
Are joined together with a lap joint (not shown).

[0003]

However, since the straight reinforcing bar is used as the anchor reinforcing bar 54, the anchor reinforcing bar 54 extends horizontally in an attempt to obtain the required fixing length, and accordingly, the anchor reinforcing bar 54 is extended in the horizontal direction. The width of the vertical pillar 51 becomes wider.
When the width of the pillar mold 51 is wide as described above, it is necessary to provide a notch in a floor material, a wall plate, or the like arranged around the pillar mold 51, or the pillar mold 51 projects into the indoor space. Occurs.

It is possible to shorten the fixing length by joining the main beam bars 53 of the PC beams 52 on both sides by pressure contact with each other. In that case, the main beam bars 53 on both sides should be aligned so that their cores are aligned. It is necessary to install the PC beam 52, which makes the construction very difficult. In addition, a special joint is required, which increases the material cost.

An object of the present invention is to provide a PC beam-to-column joining structure in which the anchor rebar of a PC beam can be firmly anchored without increasing the diameter of the column and can be easily constructed. .

[0006]

According to the joining structure of a PC beam and a pillar of the present invention, the lower end beam main bar is projected from the end face of the PC beam,
An L-shaped anchor rebar is joined to its tip. A pair of PC beams are arranged so as to face each other with a concrete column forming space interposed therebetween. The L-shaped anchor rebar is made to stand up in the column forming space.

The PC beam may be a half PC beam in which the upper part of the entire beam cross section is missing. In that case, the upper beam main reinforcement in the beam upper concrete that is placed in the above-mentioned missing portion is bridged across the PC beams on both sides.

[0008]

According to this structure, since the anchor reinforcing bar rises in an L shape, even if a required fixing length is secured, the horizontal protruding length of the anchor reinforcing bar from the end face of the PC beam is shortened by the rising amount. . Therefore, it is not necessary to thicken the column for the reason of embedding the anchor rebar. Also, PCs on both sides
Since the anchor rebars are separately provided on the beams, unlike the structure in which the lower end beam main bars are butt-joined to each other, high accuracy is not required for the installation of the PC beams on both sides, and the horizontal work of the PC beams can be easily performed. Since the L-shaped anchor reinforcing bar is joined to the lower beam main bar, the protruding length of the lower beam main bar is short and the PC beam can be easily transported.

When the PC beam is a half PC beam, the upper end beam main bars are laid across the PC beams on both sides, and therefore the fixing length does not matter. Further, since the upper beam main bars are provided in the post-cast concrete portion, the construction can be easily carried out even with such a configuration of being bridged between the PC beams on both sides.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. The connection structure of this PC beam and the pillar is the underground beam 1
It is a structure in which a pair of opposing half-PC beams 2 constituting the above is joined to a column mold 3 of cast-in-place concrete.

The half-PC beam 2 has a structure in which the upper portion of the entire cross section of the beam 1 is cut off, and the beam upper concrete 4 is cast on site in the missing portion. The reinforcement of the half PC beam 2 is composed of the lower end beam main reinforcement 5 and the stirrup 6, and the upper end 6a of the stirrup 6 is hook-shaped and protrudes from the upper surface of the half PC beam 2 as shown in FIG. The stirrup 6 may be formed in a rectangular shape as in the example of FIG. As shown in FIG. 2, the end portion of the lower beam main bar 5 is slightly projected from the beam joining end surface 2 a of the concrete surface of the half PC beam 2. Further, on the concrete surface of the half PC beam 2, a shear cotter 7 is formed on the end surface 2a and the upper surface.

In the pillar type 3, the base portion 8a (the portion below the level shown by the chain line L in FIG. 1) of the foundation 8 is preliminarily laid on the pile 9 and the half PC beam 2 is laid horizontally. After that, concrete is placed. A base muscle (not shown) is embedded in the base portion 8a of the foundation 8 and the pillar main muscle 10 of the pillar type 3 is formed.
Is set up.

The half PC beams 2 are arranged on the base portion 8a so as to face each other in four directions with the column forming space 11 interposed therebetween (see FIG. 3).
After the half PC beams 2 are laid horizontally in this way,
An L-shaped anchor reinforcing bar 12 that stands up in the column forming space 11 is joined to the projecting portion of the lower end beam main bar 5 of the beam 2. The reinforcing bar joint 13 of the anchor reinforcing bar 12 is, for example, a gas pressure welding joint.

The upper end beam main bar 14 of the beam 1 is a half PC beam 2.
After the horizontal crossing, the bars are arranged and fixed to the upper end 6a of the stirrup 6. Further, the upper end beam main bars 14 are bridged between the opposing half PC beams 2 on both sides without joining, and the reinforcing bar joint 15 is arranged at an intermediate position of the half PC beams 2. Stirrup 6
Is also provided between the half PC beam 2 and the column forming space 11 as needed, and a hoop line 16 is provided around the column main line 10 of the column type 3. Arrangement of each part in this way,
A formwork (not shown) is arranged, and the pillar form 3 and the concrete 4 on the upper concrete 4 of the beam 1 are placed.

According to the column-beam joint structure of this construction, the anchor rebar 12 of the half PC beam 2 stands up in an L-shape.
Even if the required fixing length is secured, the PC is
The horizontal protruding length of the anchor rebar 12 from the end surface 2a of the beam 2 is shortened. Therefore, it is not necessary to thicken the column type 3 for the reason of embedding the anchor reinforcing bar. Moreover, since the anchor rebars 12 are separately provided on the half PC beams 2 on both sides,
Unlike the structure in which the lower-end beam main bars 5 of the half-PC beams 2 on both sides are joined to each other, high accuracy is not required for the installation of the half-PC beams 2 on both sides, and the crossing work can be easily performed. Also, no special rebar joints are required.

In this embodiment, the half-PC beam 2 is used as the beam 1. Therefore, the weight is lighter than the full-PC beam, the transportation is easy, and the heavy machine is small. Moreover, the effect of reducing the work on site by using the PC can be obtained. Further, since the reinforcing bar protruding from the end face of the half PC beam 2 is only the lower end beam main bar 5 and the protruding length thereof is also short, it can be easily transported. Since the upper beam main bars 14 are provided in the post-cast concrete portion, the construction can be easily carried out even with the structure of straddling the half PC beams 2 and 2 on both sides.

FIG. 5 shows another embodiment. This example shows beam 1
It uses a full PC beam 2 '. An L-shaped anchor reinforcing bar 12 is joined to the lower beam main bar 5 of the PC beam 2'as in the above-described embodiment. The upper beam main bar 14 'is slightly projected from the end face of the PC beam 2', like the lower beam bar 5,
The L-shaped anchor rebar 12 'is joined by a rebar joint 13'. The anchor rebar 12 ′ is oriented so as to fall in the column forming space 11. In this example, a mechanical joint 13 'is used as the reinforcement joint 13' of the anchor reinforcement 12 '. Even when the full PC beam 2'is used in this way, by joining the L-shaped anchor rebars 12 and 12 ',
The pillar 3 can be made thin, and the work such as laterally straddling the PC beam 2'can be easily performed.

Although each of the above embodiments has been described with respect to an underground beam, the present invention can also be applied to a joint structure of a PC beam and a pillar, such as a floor beam on the upper floor.

[0019]

The joint structure of the PC beam and the pillar according to the present invention has P
Since the lower end beam main bar is projected from the end surface of the C beam and the anchor rebar that rises in an L shape is joined to the tip, the horizontal protruding length of the anchor rebar from the PC beam end surface can be shortened by the amount of the rising, and the column diameter is increased. The anchor rebar can be firmly anchored without being accompanied by. Further, since the anchor rebars are separately provided on the PC beams on both sides, high precision is not required for the installation of the PC beams on both sides, and the lateral crossing work of the PC beams can be easily performed.

In the case of the second aspect of the present invention, the adoption of the half-PC beam reduces the weight during transportation, and since the reinforcing bar protruding from the end surface of the PC beam is only the lower end beam main bar, and the protruding length thereof is short, the transportation is also difficult. It will be easy to handle the PC beams during construction.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of an embodiment of the present invention.

FIG. 2 is a perspective view of the half PC beam.

FIG. 3 is a schematic plan view of the same.

FIG. 4 is a sectional view of a half PC beam according to another embodiment of the present invention.

FIG. 5 is a side view showing a construction-in-progress state of yet another embodiment of the present invention.

FIG. 6 is a cutaway side view of a conventional example.

[Explanation of symbols]

1 ... Underground beam, 2 ... Half PC beam, 3 ... Column type, 4 ... Beam upper concrete, 5 ... Bottom beam main bar, 6 ... Star wrap, 8
... foundation, 8a ... base portion, 10 ... pillar main bar, 11 ... pillar forming space, 12, 12 '... anchor rebar, 13 ... rebar joint,
14,14 '... Main beam of upper beam

Claims (2)

[Claims] 1. A pair of PC beams each having a lower end beam main bar projecting from each of the column joint end faces and facing each other with a column forming space interposed therebetween, and a pair of PC beams being joined to the tips of the lower beam main bars of these PC beams to form a column forming space. A PC beam-to-column joining structure including an L-shaped anchor rebar that rises up in step 1 and a concrete column placed in the column forming space. 2. The PC beam is a half PC beam in which the upper part of the entire beam cross section is missing, and the upper end beam main bar embedded in the beam upper concrete cast in the missing part is between the PC beams on both sides. The joint structure of a PC beam and a pillar according to claim 1, which is bridged over.