JPS6366969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing precast concrete beams in concrete buildings.

The present invention was developed as part of an initiative to shorten the construction period of concrete buildings, and aims to provide a construction method for precast concrete beams that contributes to shortening the construction period and provides a strong connection to columns. The purpose is

The present invention is particularly suitable for constructing precast concrete beams with large spans of about 10 to 15 m. In addition to supporting the ends of the precast concrete beam, multiple PCs were buried in this precast concrete beam.
Connect each inner end of a PC steel rod for joining that passes through the steel column to each end of the steel rod, and tighten and fix these PC steel rods for joining to the inner flange using double nuts on the inside and outside. The cast concrete beam is supported by the steel column in a stable state, and the inner ends of the anchoring reinforcing bars that pass through the steel column are connected to each exposed end of the main reinforcement of the precast concrete beam, and in this state, the precast concrete slab is assembled. Erection work or installation of floor concrete formwork,
Preparation work for pouring column concrete is carried out, and finally column concrete is poured together with floor concrete to rigidly connect the precast concrete beams to the columns.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, 1 is a steel column that will be erected at the beginning of construction, and in this case, webs 2 ₁ , 2 intersect in a cross shape.
Flanges 3 ₁ , _{3 2 , 3 3 ,}
A cross pillar with 3 _{and 4} points is used.

Attach the bracket 4 to the inner flange 3 ₁ of the steel column 1.
, place the end of the precast concrete beam 5 in the span direction (hereinafter referred to as PC beam 5) on top of it, and secure it with bolts.

A plurality of prestressed steel bars 7 are buried inside the prestressed beam 5 outside the main reinforcing bars 6.
The entire length of the PC beam 5 may be used, or only the end portion may be used.
The end of the main reinforcement 6 slightly protrudes from the end face of the PC beam 5, and the end of the PC steel bar 7 is fixed to a coupler 8 embedded in the end face of the PC beam 5.

If the PC beam 5 is only supported on the bracket 4,
Since the PC beam 5 is unstable and may fall over, the present invention makes the PC beam 5 stable as follows.

The PC steel rod 9 for joining is inserted from the outside through the holes provided in the flange 3 ₂ , the web 2 ₃ or 2 ₄ , and the flange 3 ₁ of the steel column, and its tip is connected to the coupler 8. , a pair of nuts 10, 10 are attached to the PC steel bar 9 for joining before and after the PC steel bar ₉ for joining passes through the inner flange 31.
After connection, the connecting PC steel rod 9 is fixed to the steel column 1 by tightening the flange ₃₁ from the inside and outside with these nuts. Note that by tightening the outer flange 32 with a nut ₁₁ screwed from the outer end of the joining steel rod, the joining PC steel rod 9 is fixed to the steel column 1 even more firmly.

At the exposed end of the main reinforcement 6, a fixing reinforcing bar 12 is inserted from the outside through the web 2 ₃ or 2 ₄ of the steel column 1.
Appropriate means 13 (SBR joint, etc.) for the inner end of
to ensure sufficient anchorage after concrete placement.

With the ends of the PC beams 5 supported by the steel columns 1 in this way, various work such as erection of precast concrete slabs, installation of floor concrete formwork, and column concrete formwork assembly and reinforcement is carried out. , and finally the column concrete 1 along with the floor concrete 14.
5 and rigidly connect the end of the PC beam 5 to the column.

As is clear from the above description, in the present invention,
PC supported on a bracket attached to a steel column
Since the ends of the beams are fixed to the steel columns using PC steel rods for joining, work related to floors and concrete columns can be carried out, which greatly shortens the building construction period. The prestressed steel rod for use in the steel column is passed through the steel column, and is tightened and fixed to the inner flange of the steel column using double nuts on the inside and outside, and this is connected to the prestressed steel rod embedded in the prestressed beam.
Even large-span PC beams can be stably fixed, making it possible not only to perform various intermediate work safely, but also to install anchoring reinforcing bars that penetrate the steel columns, making it possible to stabilize column concrete. It has the advantage of providing a strong joint after pouring.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention;
FIG. 2 is also a cross-sectional view. 1... Steel column, 4... Bracket, 5... PC
Beam, 9...PC steel bar for joining, 12...Reinforcing bar for anchoring.

Claims (1)

[Claims] 1. The end of the precast concrete beam is supported on the bracket attached to the inner flange of the steel column, and each end of a plurality of PC steel bars embedded in this precast concrete beam is attached to the bracket for connection that penetrates the steel column. Connecting each inner end of the PC steel rods, and tightening and fixing these joining PC steel rods to the inner flange with double inner and outer nuts to stably support the precast concrete beam on the steel column, Furthermore, the inner ends of the anchoring reinforcing bars that pass through the steel column are connected to each exposed end of the main reinforcement of the precast concrete beam, and in this state, the precast concrete slab is erected or the formwork for the floor concrete is installed, and the column concrete A construction method for precast concrete beams, which is characterized by performing preparation work for pouring, etc., and finally pouring column concrete together with floor concrete to rigidly connect the precast concrete beams to the columns.