JP3433496B2 - Precast concrete girder - Google Patents

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 (hereinafter referred to as a PC girder) and a construction method for joining the PC girder with a reinforced concrete column (hereinafter referred to as RC column) and a steel reinforced concrete column (hereinafter referred to as SRC column). It is a thing.

[0002]

2. Description of the Related Art There are two types of frame type PC construction methods, RC type and SRC type. FIG. 9 shows the case of RC system P
The main bar c protruding from the end surface of the PC girder b mounted on the C pillar a is fixed to the pillar-beam joint at the stigma of the PC pillar a,
Post-cast concrete d was placed at the joint to join the columns and beams.

FIG. 10 and FIG. 11 show a method of joining a column beam having an SRC structure, in which a column steel frame e and a beam steel frame end portion f of a large beam are welded or bolted together, and the main beam g of a large beam is also located at the position of the steel frame joint. It was joined or fixed by welding w.

[0004]

However, in the former case, since the columns and beams are made of RC, the number of floors, floor height,
There are restrictions on the span length, etc. In addition, since the beam-column joint is a wet joint, there is a restriction on the construction method that the work on the upper floor cannot be performed unless the concrete work at the joint is completed and the concrete does not exhibit strength.

In the latter case, since a steel frame is used for the girder, R
It is more costly than the C structure, and in addition to joining steel frames, work for joining or fixing main girder bars is required.
In this case, the joint portion of the steel frame and the joint portion of the reinforcing bar come close to each other, which may cause structural inconvenience. The present invention has been proposed in view of the above problems of the prior art, and the object of the present invention is to improve the construction method, have a structurally high reliability, simplify on-site work, and have excellent economical efficiency. It is a point to provide a PC girder and its construction method.

[0006]

In order to achieve the object of the means for solving the problems], PC girder according to the present invention, one to girders concrete
The beam- to- column joint ends at both ends in the longitudinal direction of the projecting beam steel frame are composed of webs and flanges, and the longitudinal middle portion of the beam steel frame is the structurally necessary amount of rebar and the lower part of the equivalent cross section. Consists of only the flange, and the ribs necessary for shear strength are arranged.
It is characterized by

[0007] According to the PC girder according to the present invention, it reinforced concrete Hashirama other in steel reinforced concrete column, before Symbol
A joint steel frame equivalent to the beam-column joint end of the beam steel frame is attached .
Are, the beam-column joint end portion of the beam steel and the cemented steel
Bets are joined by bolting or welding.

[0008]

As described above, the PC girder according to the present invention has both longitudinal ends of the beam steel frame partially protruding from the girder concrete.
Of the beam-column joint end more configuration the web and flange, and the flange and web, RC column or bolting between the flange and web of bonded steel attached to SRC columns,
Alternatively, the columns and beams can be joined together by welding, which makes continuous erection work possible, unlike the case of joining with post-cast concrete.

Further, the middle portion of the beam-to-column joints at both ends of the beam steel frame built in the PC girder is composed of a lower flange having an equivalent cross-section to the structurally necessary amount of reinforcing bar, so that the lower end reinforcing bar at the end of the girder becomes a steel frame. Will be replaced and omitted, so
This eliminates the need for joining and fixing the bottom rebars, simplifies on-site work, and reduces the amount of steel frame in the girder.

Further, by using a steel frame for the beam-column-beam joint, it is possible to cope with an increase in the number of floors, floor height, and span length in terms of structural design.

[0011]

The present invention will be described below with reference to the illustrated embodiments. 1 to 4 show an embodiment of a joining method between RC Column and PC girders, A is a PC girders, beams steel 1 disposed in the concrete portion of the girder A, in the longitudinal direction both end portions c <br/> E Bed 1a and Column joint end more the flange 1b is disposed as protruding from a part girder concrete beams steel
Longitudinally intermediate portion of the 1 'is composed of only and, the lower flange 1b' lower flange 1b section of Ru Tei is formed to have a structure necessary for the main reinforcement amount equivalent section. Further, the ribs 2, which are necessary for shear strength, are arranged so as to partially project above the beam. Reference numeral 3 in the figure is a main bar of the upper end of the PC girder .
The 4 is the PC girder lower auxiliary main reinforcement, the PC girders con
It has been Haisuji only in the cleat portion, the end portion protrudes Tei no <br/>.

Reference numeral B is an RC-made PC column, and the joining steel frame web 5a, the joining steel frame flange 5b and the beam steel frame web 1a and the flange 1b are joined by bolts in the joining steel frame 5 projecting from the column B. Weld and join. In the figure, c is a slab. FIG. 4 shows an embodiment in which the PC girder A is joined to the joining steel frame fixed to the middle portion of the PC column B, and in the figure, 6
The same reference numerals are given to the girder upper end main reinforcement joints and other equivalent parts.

5 to 8 show SRC columns B'and PC girders A.
5 to 7 show the case where the beam steel frame of the PC girder is bolted to the steel frame fixed to the column steel frame 7 of the SRC column B ′, and FIG. 8 shows the case where welding is performed. In the figure, 1b "indicates the upper flange of the beam steel frame, and other parts equivalent to those in the above-mentioned embodiment are designated by the same reference numerals. The upper flange may be arranged on the beam steel frame used for the PC girder.

[0014]

According to the present invention, from girders concrete
Since the beam-column joint ends at both ends in the longitudinal direction of the partially protruded beam steel frame are composed of the web and the flange, the column-beam joint ends are used at the time of assembly to make the columns of the RC structure. Even in this case, columns and beams can be assembled, and continuous erection work can be performed. In addition, by using steel frames at the joints between columns and beams , the number of floors, floor heights, and span lengths can be increased in terms of structural design.

Further, since the longitudinal middle portion of the beam steel frame is constituted by only the lower flange of the structurally necessary reinforcing bar and the equivalent cross section, the lower beam beam is omitted, and the fixing and fixing of the reinforcing bar is not necessary. The work is simplified, there is no fear that the joint between the steel frame and the reinforcing bar will be close to each other, and structural inconvenience will not occur, and the amount of steel frame of the PC girder is reduced, which is economically advantageous.

[0016] According to the onset Ming, pillars before the beam-column joint end portion equivalent joining steel of Kihari steel mounting <br/> Ke in RC columns or SRC Columns, the beam steel and the cemented steel between beam by joining the beam joint end by bolting or welding
The joint part of is a dry joint, which enables continuous erection work and shortens the construction period.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment in which the construction method of the present invention is applied to the joining of a PC girder and an RC column.
The case of joining a large beam is shown.

FIG. 2 is an arrow view of FIG.

FIG. 3 is a perspective view taken along the arrow in FIG.

FIG. 4 is a vertical cross-sectional view showing an embodiment in which the construction method of the present invention is applied to the joining of a PC girder and an RC column, in which the middle portion of the RC column has a P shape.
The case where a C large beam is joined is shown.

FIG. 5 is a vertical cross-sectional view showing an embodiment in which the construction method of the present invention is applied to bolt connection between a PC girder and an SRC column.

FIG. 6 is a view in the direction of the arrow in FIG.

FIG. 7 is a view taken in the direction of the arrow in FIG.

FIG. 8 is a vertical cross-sectional side view showing an example in which the construction method of the present invention is applied to welding and joining a PC girder and an SRC column.

FIG. 9 is a vertical cross-sectional view showing a joint portion between a conventional PC column and a PC girder.

FIG. 10 is a front view showing a joint portion of a conventional column-beam structure having an SRC structure.

11 is a vertical sectional side view of FIG.

[Explanation of symbols]

A PC large beam B PC pillar B'SRC pillar C slab 1 beam steel frame 1a Web 1b flange 1b 'Lower flange 1b ″ upper flange 2 ribs 3 PC main beam upper end main bar 4 PC large beam lower end auxiliary main bar 5 Steel frame for joining 5a Steel web for joining 5b Steel flange for joining 6 Large beam upper main joint 7 pillar steel frame

Claims (2)

(57) [Claims] 1. A beam- to- column joint end at both ends in the longitudinal direction of a beam steel frame partially protruding from a large beam concrete is composed of a web and a flange, and an intermediate portion in the longitudinal direction of the beam steel frame has a structurally necessary rebar amount. It consists only of the lower flange of equivalent cross section,
A precast concrete girder characterized in that the ribs necessary for shear strength are arranged. 2. A reinforced concrete Hashirama other steel rebar con
The cleat pillar, and equivalent bonding steel and the beam-column joint end portion of the front Kihari steel is attached, the beam steel and the cemented steel
Purekya <br/> strike concrete girder according to claim 1, wherein said beam-column joint end is characterized in that it is joined by bolted or welded.