JPH0444544A - Column-beam connecting work in precast reinforced concrete structure - Google Patents

Abstract

PURPOSE:To permit the lower ends of reinforcing bars to be arranged on X-and Y-directional beams in upper and lower two stages by a method in which Y- directional beams are placed, and the X-directional lower end two-stage bars are connected through connecting steel bars. CONSTITUTION:Ends of X-directional beams 1 are placed on the top of a precast or in-situe cast concrete column 4 having projected column bars 5 on its upper part. Ends of Y-directional beams 1' are placed on the top of the column 4 and the lower end one-stage bars 2 and 2' are lapped crossingly. Under the condition, connecting bars 6 are provided in butt joint form between the tips of the lower end two-stage bars 3 of X-directional beams 1 and their both ends are connected.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for joining columns and beams of precast reinforced concrete structures, and particularly to improvements in the lower end reinforcements of the beams to be joined.

"Prior Art and Problems to be Solved by the Invention" Conventionally, as a column-beam connection method for precast reinforced concrete structures, in which the connection point of the beam reinforcement is provided at the center of the beam between the columns, the column head part is After placing the ends of a pair of precast beams in the X direction that are connected to each other by a single beam bottom reinforcement, place the ends of a similar pair of precast beams in the Y direction and intersect the mutual beam bottom reinforcements. Next, a method of joining is carried out by arranging reinforcement at the top of the beam in both the X and Y directions and placing joint concrete at the column-beam joint.

However, in the conventional construction method, the XY force direction beams are orthogonal and the lower end reinforcements of each other are overlapped in a crosswise manner. When placing the beam, the beam got caught on the lower end two-stage reinforcement on the upper side of the beam in the X direction. I didn't get it.

Therefore, there were limitations such as the inability to apply it to high-rise buildings that require many beam reinforcements.

In order to solve the above-mentioned problems of the prior art, the present invention provides a structure in which the lower parts of opposing joint end surfaces are connected to each other by a continuous and integral single-stage lower end reinforcement, and above the single-stage lower end reinforcement. The joint end of a pair of precast reinforced concrete beams facing each other in the horizontal Then, the joint ends of a pair of precast reinforced concrete beams facing each other in the horizontal Y direction are connected by a single-stage bottom reinforcement and a double-stage bottom reinforcement, which are arranged in two continuous upper and lower stages between the lower parts of the opposing joint end surfaces. , proposes a column-beam connection method for a precast reinforced concrete structure in which the two lower end reinforcement bars placed on the head of the column and facing each other in the X direction are connected via connecting reinforcement bars.

"Action J When placing a beam in the Y direction, the lower end two-step reinforcement in the As a result, the beam in the Y direction can be placed on the column without any problem.

After placing the beam in the Y direction, the lower end reinforcement in the X direction is connected via connecting reinforcing bars, which makes it possible to easily arrange the lower end reinforcement in two steps, upper and lower, on the beam in both the X and Y directions. Even if there is a deviation in the protruding positions of the two opposing lower end reinforcing bars, they can be reliably connected and raised together.

In addition, since the tips of the column reinforcements are kept near the upper end of the beam, the beam reinforcements can be easily joined without being obstructed by the column reinforcements from approaching the joint.

"Embodiments" Below, embodiments of the present invention shown in the drawings will be described.
A pair of precast reinforced concrete beams 1.1 placed opposite each other at a required interval in the horizontal
, and on the joint end surface above this lower end two-step reinforcement 2, there are lower end two-step reinforcements 3, 3 each having at least the minimum protrusion length required for the connection, and a beam 1' in the Y direction, which will be described later. 1' is provided in a short protruding manner so as not to overlap the lower end reinforcement when it is arranged orthogonally.

A pair of precast reinforced concrete beams 1' and 1' placed opposite each other in the horizontal Y direction have two upper and lower lower end reinforcing bars 2' and two lower end reinforcing bars 3' between the lower parts of their joint surfaces.
connected by.

When joining the columns and beams, first, as shown in Fig. 1, the ends of the beams 1, 1 in the Then, place the ends of the beams 1' and 1' in the Y direction on the head of the column 4, and connect the single-stage reinforcements 2 and 2' at the lower ends of each other.
Overlap them orthogonally.

When placing the beams 1' and 1' in the Y direction, the lower end two-step reinforcements 3 and 3' in the X direction are provided with short protrusions, so the lower end single-step reinforcement 2' in the Y direction is attached to the lower end two-step reinforcement 3'. Since the beams 1' and 1' in the Y direction pass through the gap between the ends of the beams 1' and 3' without being caught on the pillars 4, the beams 1' and 1' in the Y direction can be placed on the pillars 4 without any problem.

Next, in this state, a connecting reinforcing bar 6 is interposed between the ends of the two-stage reinforcing bars 3, 3 at the lower ends of the beams 1, 1 in the X direction in a butt-like manner, and both ends thereof are joined by welding or jointing.

After arranging the lower end reinforcements of beams 1 and 1' in both the X and Y directions in two stages, upper and lower, as shown in Figure 3,
Arrange upper end reinforcement 7 on 1' and connect the column and beam joints and beams 1 and 1.
While pouring joint concrete on top of ',
Joint concrete is poured integrally at the joint between the beams 1, 1 and 1' and 1'.

In addition, since the protruding tip of the columnar reinforcement 5 is kept at the upper surface position of the beam, the work of joining the lower end two-stage reinforcements 3, 3 can be easily performed without the columnar reinforcement 5 becoming an obstacle.

"Effects of the Invention" As described above, according to the present invention, when a beam in the Y direction is mounted, a short two-step lower reinforcement is provided between the joint end faces of the beam in the X direction, so that the beam in the Y direction is By overlapping the lower end single-stage reinforcement and the lower end two-stage reinforcement in the upper and lower two stages orthogonally to the lower end two-stage reinforcement of the beam in the X direction, the beam in the Y direction can be placed on the column head without any problem.

Also, after placing the beam in the Y direction, the lower end two-step reinforcement in the X direction is
Since they are connected via connecting reinforcing bars, it is possible to easily arrange the lower end reinforcements in two levels, upper and lower, on the beams in both the X7 directions, and even if there is a misalignment in the protruding positions of the opposing two-stage lower end reinforcements. , can be reliably connected together.

In addition, since the tips of the column reinforcements are kept near the upper end of the beam, the beam reinforcement can be easily joined without being obstructed by the column reinforcements from approaching the joint during the joining operation 5.

Therefore, by arranging beam bottom reinforcements in two stages at the column-beam joint, the strength of the column-beam joint of a high-rise building can be strengthened without any restrictions.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are side views sequentially showing the beam-column joining process according to the present invention, and FIG. 4 is a side view showing the reinforcement state of a conventional beam-column joint. 1...Beam in the X direction, 1'...Beam in the Y direction, 2.2'
...Single-stage reinforcement at the bottom end, 3,3' ...Two-stage reinforcement at the bottom end, 4.
・Column, 5... Column reinforcement, 6... Connecting reinforcement, 7... Beam top end reinforcement. Patent applicant: Maeda Construction Industry Co., Ltd. Agent: Minoru Fujii Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1) The lower parts of the opposing joint end surfaces are connected to each other by a continuous and integral lower end single-stage reinforcement, and a short two-stage lower end reinforcement is provided protruding from the joint end surface above the lower end single-stage reinforcement in the horizontal X direction. The joint ends of a pair of precast reinforced concrete beams facing each other are placed on the head of a column with column reinforcement protruding near the upper end of the beam, and then two consecutive upper and lower stages are placed between the lower parts of the opposite joint end faces. Place the joint ends of a pair of precast reinforced concrete beams facing each other in the horizontal Y direction, connected by a single-stage bottom reinforcement and a double-stage bottom reinforcement placed on the head of the column, and connect the bottom ends facing each other in the X direction. A column-beam joining method for precast reinforced concrete structures, which is characterized by joining two-stage reinforcement via connecting reinforcing bars.