JP2001288848A - Precast concrete beam and connecting method for beam and column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precast concrete beam capable of simply forming a horizontal haunch and a connecting method for the beam and a column. SOLUTION: Main reinforcements are protruded from both end sections of the precast concrete beam 1, and recessed haunch structure sections 5 expanded outward at least on one side face are formed at both end sections.

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 and a method for joining the beam to a column.

[0002]

2. Description of the Related Art In recent years, precast concrete columns and precast concrete beams have been used to improve the efficiency of construction of reinforced concrete structures. Of these, precast concrete beams are used in which the main bars protrude from the ends and are joined to cast-in-place concrete columns or precast concrete columns.

As a method for joining such a precast concrete beam and a column, for example, a conventional example shown in FIG. 14 is known. In this method, a precast concrete beam 24 having a main bar 23 projecting from an end is installed on the head of a precast concrete column 25, and this portion is surrounded by a temporary frame 26 to form a formwork 27, into which concrete is poured. Is what you do.

[0004]

However, the method of joining a precast concrete beam and a column as described above still forms a formwork, and particularly when a horizontal haunch is to be made, it is necessary to assemble and disassemble the formwork. There was a problem that it took time.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a precast concrete beam capable of easily forming a horizontal haunch and a method of joining the beam to a column.

[0006]

Means for achieving the above object are achieved by the invention of claim 1 in which a precast concrete beam having a main reinforcing bar projecting from both ends thereof has at least one outer side at the both ends. An extended concave haunch component is formed, and the invention of claim 2 is the invention according to claim 1, wherein at least the end including the haunch component has a concave portion for casting cast-in-place concrete. The invention according to claim 3, characterized in that the precast concrete beam is formed as a groove, and the precast concrete beam is provided with a concave haunch constituent part having at least one side surface extending outward at both ends. The horizontal haunch formwork is formed by the haunch constituent part by installing the portion on the head of the column, and concrete is poured into the horizontal haunch formwork.

When a precast concrete beam is joined to a column, the haunch components of adjacent precast concrete beams are joined to form a horizontal haunch formwork.
In addition, when the end including the haunch constituent part which has become the concave groove is installed at the head of the pillar, a horizontal haunch formwork can be formed without using a formwork. Further, when concrete is poured into the horizontal haunch formwork to join the precast concrete beam and the column, a horizontal haunch is formed between adjacent precast concrete beams.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a precast concrete beam and a method of joining the beam to a column according to the present invention will be described. First, an embodiment of a precast concrete beam (hereinafter referred to as a PCa beam) will be described.
After that, an embodiment of a method for joining a PCa beam and a column (hereinafter simply referred to as a joining method) will be described. There are first to fifth embodiments of the PCa beam, and in each embodiment, the same configuration will be described with the same reference numeral, and only different configurations will be described with different reference numerals.

FIG. 1 shows a PCa beam 1 according to the first embodiment, which is installed on one side of a plane cross-shaped beam centered on a pillar. This PCa beam 1 has a concrete body 2 having a substantially U-shaped cross section, and a reinforcing cage 3 arranged inside thereof.
It is composed of At both ends of the concrete body 2, a flat octagonal haunch component 5 is formed in which the front ends of both side plates 4 are bent outward. This haunch constituent part 5
The concrete body 2 is formed in a concave shape in which the ends of the concrete body 2 are expanded on both sides, and is sized so as to be combined with the haunch constituting portion of the adjacent PCa beam to form one horizontal haunch.
The lower reinforcing bar 3 is buried in the bottom plate 6 and both side portions are buried in the side plate 4, and the lower main reinforcing bar 7 protrudes from the end of the bottom plate 6 and is bent upward, while the upper main reinforcing bar 8 is in the concrete body 2. It fits in.

FIG. 2 shows a PCa beam 9 according to a second embodiment, and a portion excluding a haunch component 5 is a precast concrete 10 having a protruding upper portion of a reinforced cage. It has the same configuration as PCa beam 1.

FIG. 3 shows a PCa beam 11 according to a third embodiment, which is installed on the other side of a cross-shaped beam centered on a pillar. This PCa beam 11 has the same configuration as the PCa beam 1 of FIG. 1 except that the lower main bar 7 and the upper main bar 8 project upward from the end of the concrete body 2 and are bent upward or downward.

FIG. 4 shows a PCa beam 1 according to a fourth embodiment.
2 is installed on one side of a plane L-shaped or plane T-shaped beam centered on a pillar. This PC
The a beam 12 is the same as the PCa beam 1 of FIG. 1 except that only the end of the one side plate 4 is bent outward to form the haunch constituent part 5.
It has the same configuration as

FIG. 5 shows a PCa beam 1 according to a fifth embodiment.
3 is installed on the other side of the plane L-shaped or plane T-shaped beam centered on the pillar. This PC
3 except that only the end of the one side plate 4 is bent outward to form the haunch constituting part 5. The PCa beam 1 shown in FIG.
It has the same configuration as 1.

Also, the PCa beams 11 and 12 shown in FIGS.
As shown in FIG. 2, a portion 13 excluding the haunch component 5 is also a precast concrete 10 in which the upper part of the reinforcing bar cage projects.
(Not shown).

An embodiment of the joining method will be described below. There are first to third embodiments of this embodiment, and the PCa beams 1 and 11 of the first, third to fifth embodiments described above.
12 and 13 are used. Also in this case, similarly to the above, in each embodiment, the same components will be described with the same reference numerals, and only different components will be described with different reference numerals.

FIGS. 6 to 8 show a joining method according to the first embodiment, in which the PCa beams 1 and 11 shown in FIGS. 1 and 3 are joined in a plane cross shape around a column. First, FIG.
As shown in the figure, between precast concrete columns (hereinafter simply referred to as PCa columns) 14 erected on a foundation (other PCa columns).
(The beam is not shown.) When the PCa beam 1 is erected in one direction, its tip is installed opposite to the head of the PCa column 14,
The lower main bars 7 of each other are superposed and arranged inside the column main bar 15.

Next, as shown in FIGS. 7A and 7B, the PCa beam shown in FIG.
When the beam 11 is erected, the haunch components 5 of the PCa beams 1 and 11 are joined at the head of the PCa column 14 to form and form the horizontal haunch formwork 16 and the lower main reinforcing bars 7 of each other cross each other. Then, it is fixed to the pillar inside the pillar main bar 15. The horizontal haunch formwork 16 also serves as a formwork for joining the PCa beam and the PCa column.
A temporary frame to be assembled at the joint of the Ca columns can be omitted.
Next, the reinforcing bar 17 for the haunch is arranged on the formwork 16 for the horizontal haunch, and the PC of FIG.
An L-shaped bar 18 is joined to the upper main bar 8 of the beam 1. On this occasion,
The main bars 8 may be joined linearly via a reinforcing bar.

Next, the stirrups 20 of the PCa column are arranged.
Since the lower main bar 7 and the upper main bar 8 of the PCa beams 1 and 11 are cross-arranged inside the column main bar 15, the four band reinforcing members 19 are wound around the column main bar 15 from four directions as shown in FIG. 8. The adjacent members are welded as described above. When the stirrups 20 are arranged in this manner, concrete is poured into the horizontal haunch formwork 16 and the PCa beams 1 and 11, and the PCa beams 1 and 11 and the PCa pillars 14 are joined.
A horizontal haunch 21 is formed between the beams 1 and 11 (see FIG. 9).

FIGS. 10 and 11 show a joining method according to the second embodiment, in which the PCa beams 11 and 12 shown in FIGS. 3 and 4 are joined in a plane T-shape around a column. This joining method is also the same as above, and the stirrups 20 are arranged so that the two stirrup members 19 are wound around the column main streaks 15 from two directions, and the three haunch components 5 and the temporary closing one direction are closed. Together with the frame 22, the horizontal haunch formwork 16 is formed.

FIGS. 12 and 13 show a joining method according to the third embodiment, in which the PCa beams 12 and 13 shown in FIGS. 4 and 5 are joined in a plane L-shape around a column. This joining method is also the same as described above, and the stirrups 20 are arranged so that the three stirrup members 19 are wound around the column main streaks 15 from three directions, and the two haunch components 5 and the temporary closing the two directions. Together with the frame 22, the horizontal haunch formwork 16 is formed.

The above joining method can also be performed by using a PCa beam 9 as shown in FIG.

[0022]

According to the present invention, the horizontal haunch formwork can be formed at the head of the pillar by the haunch constituting portion of the adjacent PCa beam.

In the joining work between the PCa beam and the column, the work of separately assembling and disassembling the formwork can be omitted.

The horizontal haunch can be formed between adjacent PCa beams without using a mold.

With the horizontal haunch, the work of arranging reinforcement around the joint can be performed without separately installing a scaffold.

[Brief description of the drawings]

FIG. 1 (1) is a plan view of a PCa beam, and FIG. 1 (2) is a sectional view taken along line AA of (1).

2A is a plan view of a PCa beam, and FIG. 2B is a cross-sectional view taken along line BB of FIG.

3A is a plan view of a PCa beam, and FIG. 3B is a cross-sectional view taken along a line CC of FIG. 3A.

4A is a plan view of a PCa beam, and FIG. 4B is a cross-sectional view taken along a line DD in FIG.

5A is a plan view of a PCa beam, and FIG. 5B is a cross-sectional view taken along line EE of FIG.

FIG. 6A is a plan view in which an end of a PCa beam is placed on the head of a PCa column, and FIG. 6B is a cross-sectional view taken along line FF of FIG.

FIG. 7 (1) is a plan view in which the end of a PCa beam is mounted on the head of a PCa column in a cross shape, (2) is a cross-sectional view taken along line GG of (1), and (3) is (1). FIG. 3 is a sectional view taken along line HH of FIG.

FIGS. 8 (1) and (2) are plan views showing a method of arranging stirrups in a column.

FIG. 9 is a perspective view showing a joint between a PCa beam and a PCa column.

10A is a plan view in which the end of a PCa beam is mounted on the head of a PCa column in a T-shape, FIG. 10B is a cross-sectional view taken along line II of FIG. 10A, and FIG. () Is a sectional view taken along the line JJ.

FIGS. 11 (1) and (2) are plan views showing a method of arranging stirrups.

FIG. 12 (1) is a plan view in which the end of a PCa beam is placed on the head of a PCa column in an L shape, (2) is a cross-sectional view taken along the line KK of (1), and (3) is (1). () Is a sectional view taken along line LL.

FIGS. 13A to 13C are plan views showing a method of arranging stirrups.

14A and 14B are a side view and a plan view showing a conventional bonding method.

[Explanation of symbols]

 1, 9, 11, 12, 13, 24 PCa beam 2 Concrete body 3 Reinforcement cage 4 Side plate 5 Haunch constituent part 6 Bottom plate 7 Lower main bar 8 Upper main bar 10 Precast concrete 14 PCa column 15 Column main bar 16 Horizontal haunch form 17 Haunch Reinforcing bar 18 L-shaped bar 19 Band bar member 20 Band bar 21 Horizontal haunch 22, 26 Temporary frame 23 Main bar 27 Form

Claims (3)

[Claims] 1. A precast concrete beam in which a main reinforcing bar protrudes from both ends, wherein a concave haunch component having at least one side surface extending outward is formed at each end. 2. An end including at least a haunch component,
2. The precast concrete beam according to claim 1, wherein the precast concrete beam has a concave groove for placing cast-in-place concrete. 3. A haunched structure in which a precast concrete beam having a concave haunch component having at least one side surface extending outward is provided at both ends, and an end of the precast concrete beam is installed at the head of a column. A method for joining a precast concrete beam and a column, characterized in that a horizontal haunch form is formed at a portion and concrete is poured into the horizontal haunch form.