JPH0323703B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a joint structure for precast reinforced concrete columns and beams (hereinafter referred to as PC columns and PC beams).

(Conventional technology) In the conventional process of joining precast reinforced concrete columns and beams, the bottom reinforcement of the PC beam, whose joint end is mounted on the PC column, is placed at a position beyond the column center line in both the X and Y directions.゜Fold vertically and face the PC
A horizontal reinforcement was placed in the hook-shaped part formed at the intersection of the lower end reinforcements of the beams, and the main reinforcements of the opposing PC beams were restrained via the horizontal reinforcements, and then the column and beam joint concrete was poured.

(Problems to be Solved by the Invention) According to the conventional joining method, it has been proven that the anchoring strength of the lower end reinforcement of the PC beam is good, but the lower end reinforcement of the PC beam in the orthogonal direction However, since the reinforcement had to be placed avoiding the rising position of the lower end reinforcement in the previously set direction, the beam width became wider and highly accurate members were required.

(Means for Solving the Problems) The present invention was proposed to solve these problems.
The joint end of the PC beam, in which the protruding end of the bottom reinforcement is bent horizontally by 90 degrees, is attached to the column head of the PC column.
The bent portions of the lower end reinforcements of the PC beams are placed on the bridge so that they overlap each other, and the longitudinal reinforcement for anchoring is inserted into the overlapped portion of each bent portion, and the longitudinal reinforcement is a restraining tie reinforcement. The present invention relates to a joint structure of precast reinforced concrete columns and beams, characterized in that the precast reinforced concrete columns and beams are fixed, and concrete is cast in the joint spaces of the precast reinforced concrete columns and beams.

(Function) As described above, in the present invention, the protruding end of the lower end reinforcement embedded in the PC beam is bent 90 degrees in the horizontal direction, and the column main reinforcement is protruded from the joint end of the PC beam. When mounted on the head of a column, the bent parts of the protruding ends of the lower end reinforcements of adjacent PC beams overlap each other.
By setting the PC beams, inserting vertical reinforcements into the overlapping parts of the bent parts of the lower end reinforcements of each PC beam, and restraining the longitudinal reinforcements with restraint ties, the lower end reinforcements of each of the PC beams are fixed. It has increased performance and is firmly anchored to the joint concrete placed in the PC column/beam joint space, creating a PC column/beam joint with high strength and rigidity.

(Effect of the invention) As described above, in the precast reinforced concrete column and beam joint structure according to the present invention,
Instead of bending the protruding end of the bottom reinforcement of the PC beam 90° vertically beyond the center line of the column as in conventional methods, we bent it horizontally 90°, and the joint end of the PC beam
When mounted on the head of a PC column, the bent ends of the bottom reinforcements of adjacent PC beams overlap, so the beam width is can be made smaller, and the inside of the PC column and beam joints will not be crowded with reinforcement.

In addition, the end bent part of the lower end reinforcement of the PC beam is connected to the longitudinal reinforcement that constitutes a vertical dowel reinforcement inserted into the overlapped part of the bent part, and the restraining tie reinforcement that restrains this longitudinal reinforcement. Since the lower end reinforcement has good anchoring performance and is firmly anchored to the PC column/beam joint concrete, a structurally reliable PC column/beam joint is constructed.

(Example) The present invention will be described below with reference to the illustrated embodiments.

A is a PC beam in which the thickness of the slab is cut off, and the protruding end of the lower reinforcement 1 of the beam is provided with a bent portion 1a bent at 90 degrees in the horizontal direction. Furthermore, the ribs 2 are buried, and the upper end of the ribs 2 has a hook-shaped portion curved into the protruding portion.

B is a PC column, the lower part of the beam is prefabricated, the column main reinforcement 3 is installed protruding from the column head, and the lower end of the column main reinforcement 3 has a sleeve 4 for connecting the column main reinforcement of the lower PC column.
is installed.

Then, the joint end of the PC beam A is mounted on the capital of the PC column B, and the protruding bent portions 1a of the lower end reinforcements of the adjacent PC beams A are overlapped, and each bent portion 1a is The vertical reinforcements 5 for reinforcing the anchorage are arranged in the vertical direction, and each vertical reinforcement 5
is restrained by the ties 6 to fix the bent portion 1a of the protruding end of the main reinforcement of the PC beam A.

Next, the PC floor plate C is set on the PC beam A, and the beam top end reinforcement 7 is arranged, and then concrete 8 and 9 is poured for the column, beam joint, and slab on the beam, and the PC column B and PC beam A are placed on top of the PC beam A. , PC floorboard C is integrated.

At this time, the anchorage reinforcing vertical reinforcement 5 constituting the longitudinal dowel reinforcement is inserted at the bending point of the protruding end bending portion 1a of the lower end reinforcement of the adjacent PC beam A, and each longitudinal reinforcement 5 is inserted. By being restrained by the stirrups 6, the PC beam A
The fixing performance of the bottom reinforcement has been improved, and the PC columns and beams can be joined together.

Note that instead of the PC floor plate C, the slab C' may be constructed using cast-in-place concrete. 10 in the figure is a slab line.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of the joint between a precast reinforced concrete column and a beam constructed by the method of the present invention, Fig. 2 is a plan view thereof, and Figs. 3 and 4 are longitudinal cross-sectional views of the beam portion, respectively. Figure 5 is a slope view of a PC beam. A...PC beam, B...PC column, 1...bottom reinforcement, 1
a... Bent part of lower end reinforcement, 3... Column main reinforcement, 5... Vertical reinforcement, 6... Strap reinforcement.

Claims (1)

[Claims] 1. The joint end of a PC beam with the protruding end of the lower end reinforcement bent horizontally by 90 degrees to the head of a PC column with a main column reinforcement protruding from the column head is connected to the lower end reinforcement of the adjacent same PC beam. The bent portions of are mounted on each other so as to overlap each other,
Vertical reinforcing bars for anchoring are inserted into the overlapping parts of the respective bent parts, and the longitudinal bars are fixed with restraint bars, and concrete is poured into the joint space between the PC columns and beams. A precast reinforced concrete column and beam joint structure featuring: