JPH0434149A - Column and beam connecting method for precast reinforced concrete structure - Google Patents

Abstract

PURPOSE:To enhance the strength of a column beam joint part by protrudingly providing upper and lower two-stage connecting reinforcements on the connecting end surface lower part of a beam, with the lower stage reinforcement being long, and the upper stage reinforcement being short, and further consecutively connecting the upper stage reinforcements through a connecting reinforcement. CONSTITUTION:On the connecting end surface lower parts of each pair of reinforced concrete beams 1, 1' provided opposite to each other, upper and lower two stages of first stage reinforcements 2, 2' and second stage reinforcements 3, 3' are protruded. The first stage reinforcement 2 of the beam 1 is short, and the first stage reinforcement 2' of the beam 1' is long. The second stage reinforcements 3, 3' has only a protruding length necessary for joint. The end parts of the X-directional beams 1, 1' are put on the head part of a column 4, and the first stage reinforcements 2, 2' are butt-welded to each other. Then, the end parts of the Y-directional beams 1, 1' are put on the column 4, the first stage reinforcements 2, 2' are welded to each other, and a connecting reinforcement 5 is interposed between the second stage reinforcements 3, 3' to consecutively connect the both. Thus, the beam lower end parts can be mutually connected and integrated by arranging two stage reinforcements therein.

Description

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

"Prior Art 1 Problems to be Solved by the Invention" Conventionally, as a column-beam connection method for precast reinforced concrete structures, a pair of beam-to-beam joints in the The ends of the precast beams are placed on top of each other, and the opposing beam bottom reinforcements are butted together at the center of the opposing beam end faces to be joined by welding.Then, the ends of the pair of precast beams in the Y direction are placed in the same manner, and the beams are assembled. After joining the lower end reinforcement, the joining method is implemented by arranging reinforcement on the beam in both XY directions and pouring joining concrete at the column-beam joint.

However, in the conventional construction method, when the beam end in the XY direction is placed on column B from above, the end faces of the beam are butt-jointed at the center between the opposing beam ends. Since the bottom reinforcements of the beam are overlapped orthogonally, the bottom reinforcement of the beam must be a single-stage reinforcement (if it is a two-stage reinforcement,
When placing a beam in the Y direction after placing a beam in the Y direction, the beam gets caught in the beam in the X direction and cannot be lowered to a predetermined position), which limits the strength of the joint.

Furthermore, due to manufacturing errors in the precast beams, misalignment occurred at the butt portions of the beam reinforcements, which could not be corrected, especially when large-diameter reinforcing bars were used, and there was a risk that the reinforcing bars could not be joined.

Furthermore, since the column reinforcing bars protrude long above the joint, there is a problem in that it is difficult to perform joining work such as welding.

"Means to solve M target point" This invention aims to solve the above-mentioned conventional problems.

At the bottom of the joint end face of each pair of precast reinforced concrete beams placed opposite each other in the X direction and the Y direction,
The lower end step part and the lower end two-step reinforcing bar are provided in the upper and lower two stages, and the lower end step part of one beam is provided in a short projecting manner, and the lower end step part of the other beam is provided in a long projecting manner. The two-step reinforcement at the bottom of the beam has at least the minimum protrusion length required for connection, and is protruded in a short length so as not to overlap the bottom-step section that intersects when the beams are connected orthogonally, and is made of precast reinforced concrete. Place the end of the beam in the X direction on the head of the column,
At the same time, the lower end and stepped portions are butted and joined, and
This paper proposes a beam-to-column joining method for precast reinforced concrete structures in which connecting reinforcing bars are interposed between the two lower end sections in the Y force direction to join the mutually abutting ends.

``Operation'' When an error occurs in the butt position of the lower end-step portions, the long, easy-to-bend lower end-step portions are bent to align the positions.

When placing a beam in the Y direction, since the two-step reinforcing at the bottom end in the X direction is provided with a short protrusion, the bottom end in the Y direction and the step will not get caught in the two-step reinforcing at the bottom end of the beam in the X direction. It passes through the gap, and as a result, the beam in the Y direction can be placed on the column without any problem.

Therefore, by butting the lower ends in the Y direction and joining them by welding or joining, and then interposing connecting reinforcing bars between the two lower end parts in the XY force directions, the mutual butt ends are joined. , it becomes possible to arrange the bottom reinforcement in two stages, upper and lower.

"Embodiments" Below, embodiments of the present invention shown in the drawings will be described.
At the joint end surfaces of each pair of precast reinforced concrete beams 1.1' arranged opposite to each other in the horizontal XY force directions, lower end reinforcements 2. 2' 3. 3'
is installed protrudingly.

The lower end of the beam 1 - the step 2 is protruded in a short length having at least the minimum protrusion length required for joining, and the lower end of the beam 1' - the step 82' is provided in a long protrusion. Both are 2.2'
The abutting portion is located close to the joining end surface of the beam 1 when the two are butted together.

The two-stage reinforcement 3.3' at the lower end of the upper side of the beams 1 and 1' is.

Beam 1 has at least the minimum protrusion length required for joining, and
, 1' are intersected when they are orthogonally joined -
It is provided in a short protruding manner so as not to overlap the stepped portion 2'.

When joining columns and beams, first, as shown in Fig. 1, a beam 1 in the X direction is placed on the head of a precast reinforced concrete column 4.
.

In this case, if an error occurs in the abutment position between the lower end and the stepped portions 2 and 2',
′ to adjust the position.

Next, as shown in Fig. 2, the end of the beam 1°1' in the Y direction is placed on the head of the column 1, and the lower end and step part 2, 2' are welded together in the same way. A connecting iron H5 is interposed between the lower end two-step reinforcing bars 3 and 3', and the abutted ends are joined to connect them in series.

When placing the beam 1.1' in the Y direction, the two-step reinforcing bars 3, 3' at the lower end in the X direction are provided with short protrusions, so the lower end-step portions 2, 2' in the Y direction are placed on the beam 1 in the X direction. .1' bottom two-step bar 3
, 3', and passes through the gap between the tips 1, and as a result, the beam 1.1' in the Y direction can be placed on the column 4 without any problem.

Furthermore, since the column reinforcements 6 of the columns 4 are provided in a protruding manner so that their tips are located near the upper ends of the beams 1 and 1', it is easy to perform the joining work.

After joining the lower end reinforcements of the beams 1 and 1' in both the X and Y directions in this way in two stages, the upper end reinforcement 7 is arranged on the beams 1 and 1' as shown in figure 's3', and the column-beam joint is Place joint concrete in one piece.

"Effects of the Invention" As described above, according to the present invention, since one of the opposite lower end step portions is protruded long and the other is short, when an error occurs in the butt position of the two, one bend is applied. The position can be easily adjusted by bending the lower end-step part of the long length.

In addition, when placing a beam in the Y direction, the lower end two-step reinforcement in the X direction is provided with a short protrusion, so the lower end step in the Y direction does not get caught on the lower end two-step reinforcement of the beam in the X direction. The beam in the Y direction can be placed on the column without any problem by passing through the gap between the tips.

Therefore, it becomes possible to arrange the beam lower end reinforcements in two stages at the column-beam joint and to connect and integrate them with each other, so that the strength of the column-beam joint can be strengthened without any restrictions.

[Brief explanation of drawings]

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. 1.1' ・Beam + 2. 2'...Bottom end - stepped section, 3.3'...Bottom end reinforcement, 4...Column. 5... Connecting reinforcing bars, 6... Column bars, 7... Beam top end bars. Patent applicant Maeda Construction Industry Co., Ltd. Agent Minoru Fujii Figure 1 @ Figure 2 Figure 3

Claims (1)

[Claims] 1) At the bottom of the joint end face of each pair of precast reinforced concrete beams arranged opposite to each other in the X direction and the Y direction, a lower end single-stage reinforcement and a lower end two-stage reinforcement are protruded in upper and lower two stages,
The single-stage reinforcement at the lower end of one of the beams is protruded in a short length, and the single-stage reinforcement at the lower end of the other beam is provided in a long length, and the two-stage reinforcement at the lower end of the beam has at least a minimum protruding length necessary for joining, In addition, when the beams are connected orthogonally arranged, the beams are protruded in a short length so as not to overlap the single-stage reinforcement at the lower end that intersects, and the end of the beam in the X direction is placed on the head of the precast reinforced concrete column. After butting and joining the lower end single-stage reinforcements, place the ends of the beams in the Y direction, and similarly join the lower end single-stage reinforcements, and interpose connecting reinforcing bars between each of the lower end two-stage reinforcements in the XY direction. A column-beam joining method for precast reinforced concrete structures that is characterized by joining mutual butt ends.