JPH03257234A - Connection structure of joint for precast concrete large beam and precast concrete small beam - Google Patents

Abstract

PURPOSE:To facilitate manufacture or the like by integrally forming a bracket provided with an upward facing recessed part opposed to an edge tapered surface of a small beam, in a joint part of a large beam and inserting a small beam edge into the recessed part so as to fill a space between junction surfaces with expansion mortar. CONSTITUTION:A bracket 3, having a recessed part 4 formed of an upward facing tapered surface 4a opposed to a downward facing tapered surface 2a in an edge of a PC small beam 2 and of surfaces 4b, 4c for surrounding right and left side surfaces 2b and a bottom surface 2c is integrally formed in a joint part of a PC large beam 1. After the edge of the beam 2 is inserted into the recessed part 4 of the beam 1 to fill part between the bottom surface 2c of the beam 2 and the bottom surface 4c of the recessed part 4 with level adjusting mortar 5 and a part between the tapered surface 4a and the tapered surface 2a with expansion mortar 6, respectively, concrete is placed in a site in an assembled slab mold frame. Accordingly, junction force of high reliability can be obtained while facilitating assembly work.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention simplifies the production of precast concrete (hereinafter referred to as PC) girders and PC beams, and facilitates the joining of PC girders and PC beams. Moreover, the present invention relates to a connection structure between a PC girder and a PC beam, which ensures the mutual transmission of shear force between the PC girder and PC beam.

[Prior art and problems to be solved by the invention] In recent years, in the construction of buildings, construction methods in which large beams, small beams, etc. are made of PC have been increasingly adopted as a means of shortening the construction period and reducing construction costs. It has become.

However, when both the main beam and the small beams are made of PC, the lower beams of the small beams cannot be fixed to the main beam, unlike the conventional construction method that does not use PC. The PC girders and PC small beams are retracted slightly from the joint surface, and the fixing bars previously embedded in the PC girders and PC small beams are made to protrude into this retracted space, and at the same time as slab concrete is poured, the above spaces are filled with concrete and both PC girders and PC small beams are retracted. How to join beams.

Alternatively, form a seat for the PC girder at the bottom of the joint of the PC girder, place the edge of the PC girder on this seat, and connect the PC girder without an anchor bar.
Various methods have been proposed, such as a method of joining C girders and PC girders.

However, the former joining method in which both anchor bars are protruded from the joint surfaces of the PC girder and PC small beam complicates the production of the PC girder and PC small beam, and the small beam is attached to the receiving seat of the PC girder without anchor bars. The latter joining method, in which the edges of the PC beams are placed, has problems such as poor reliability in transmitting shear force between the PC girders and the PC small beams, and it is difficult to say that either method is a perfect joining method.

The present invention has been made in view of the above-mentioned conventional problems, and is aimed at solving the problems.The present invention simplifies the production of the main beam and the PC beam, and facilitates the joining of the PC main beam and the PC small beam. Moreover, it is an object of the present invention to provide a joint structure between a PC girder and a PC beam in which the shearing force between the PC girder and PC beam can be reliably transmitted. .

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention forms a downwardly tapered surface at the end of the PC beam, and an upwardly tapered surface facing the end of the PC beam at the same inclination angle as the end of the PC beam. A bracket having a concave portion having a surface and a surface surrounding the left and right side surfaces and the bottom surface of the small beam edge is formed integrally with the main beam, and the edge of the PC small beam is inserted into the concave portion of the bracket of the PC large beam, and the connecting surface is It is characterized by a joint structure of PC girders and PC girders whose gaps are filled with expanded mortar.

[For production]

As described above, in the present invention, since both anchoring bars are not protruded from the joint surfaces of the PC girders and PC small beams, the PC girders and PC small beams are simplified and easy to manufacture, and the PC girders and PC girders are
To assemble the small beam, simply insert the end of the small beam into the recess of the joint bracket of the PC girder, so it is easy to assemble as well as disassemble. Then, the downwardly tapered surface of the PC girder's end touches the upwardly tapered surface of the PC girder's joint bracket, so that the shearing force applied to the PC girder is applied to the entire area of the small beam's end due to the holding effect of the tapered surface. is transmitted to the PC girder through the PC girder.
Sufficiently reliable bonding force can be obtained even without fixing bars between the PC beams.

〔Example〕

The present invention will be explained in detail below based on illustrated embodiments.

The construction drawing is an exploded perspective view of a joint between a PC main beam and a PC small beam according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of the joint state.

In the figure, 1 is the PC beam, and 2 is the P that connects to the PC beam 1.
The C beam 3 is a bracket formed integrally with the PC beam 1 at the joint part of the PC beam 1, and a downwardly tapered surface 2a is formed at the edge of the PC beam 2. , the downward tapered surface 2 of the edge of the PC beam 2
an upwardly tapered surface 4a facing at the same inclination angle as a, and a surface 4b surrounding the left and right side surfaces 2b and bottom surface 2c of the edge of the small beam 2;
.

A recess 4 in which 4b and 4c are formed is provided.

The external shape of the bracket 3 may be a trapezoid with one side vertical in side view as shown in Figures 1 and 2, or a modified triangle with the lower hypotenuse of a right triangle cut vertically as shown in Figure 3. As shown in FIG. 4, a vertically elongated rectangle in side view may also be used.

Assembling the PC girder 1 and PC girder 2 mentioned above.

As shown in FIG. 2, insert the edge of the small beam 2 into the recess 4 of the bracket 3 of the PC girder 1, and align the upper edge of the PC girder 2 with the upper edge of the PC girder 1. To align the upper edge of the PC beam 2 and the upper edge of the PC girder 1, level adjustment mortar 5 is placed in the gap between the bottom surface 2c of the PC beam 2 and the bottom surface 4c of the recess 4. In addition, the upwardly tapered surface 4a of the bracket 4 and the PC
The gap formed between the small beam 2 and the downwardly tapered surface 2a is filled with expanded mortar 6. Thereafter, cast-in-place concrete 8 is poured into the assembled slab formwork 7 to construct a slab.

〔Effect of the invention〕

As explained above, the present invention forms a downwardly tapered surface at the end of the PC beam, and also forms a downwardly tapered surface at the end of the PC beam.
A bracket is formed integrally with the main beam, and has a concave portion having an upwardly tapered surface that faces the tapered surface of the small PC beam at the same angle of inclination, and a surface that surrounds the left and right side surfaces and the bottom of the small beam. A joining structure of a PC girder and a PC girder in which the edge of the beam is inserted into the recess of the bracket of the PC girder, and the gap between the joint surfaces is filled with expanded mortar.
Since both anchoring bars do not protrude from the joint surfaces of the PC girders and PC girders, the PC girders and PC girders are simplified and easy to manufacture. Since the end of the small beam is simply inserted into the recess of the joint bracket, it is easy to assemble and disassemble. Then, the downwardly tapered surface of the PC beam's end touches the upwardly tapered surface of the PC beam's joint bracket, so that the shearing force applied to the PC beam is applied to the entire cross section of the small beam's end due to the holding effect of the tapered surface. Therefore, a sufficiently reliable bonding force can be obtained even without an anchor between the PC girder and PC girder, and the recess of the bracket changes according to the strength of the PC girder. Even if this is not done, the level can be adjusted by applying level adjustment mortar in the gap between the bottom surface 2c of the PC beam 2 and the bottom surface 4c of the recess 4.

[Brief explanation of drawings]

The drawings show nine embodiments of the present invention, and FIG. 1 is an exploded perspective view of a joint between a PC main beam and a PC small beam according to the present invention, FIG. 2 is a longitudinal cross-sectional view of a joined state, FIGS. The figures are side views of examples of brackets having different shapes. DESCRIPTION OF SYMBOLS 1... Precast concrete main beam, 2... Precast concrete small beam, 2a... Downward tapered surface of precast concrete small beam, 3... Bracket, 4... Recessed part of bracket, 4a... Upward direction of bracket Tapered surface, 5...Level adjustment mortar, 6.
... Expanding mortar.

Claims (1)

[Claims] A downwardly tapered surface is formed at the end of the precast concrete beam, and the joint part of the precast concrete girder has an upwardly tapered surface that faces at the same angle of inclination as the end of the precast concrete beam, and an upwardly tapered surface at the end of the precast concrete beam. A bracket provided with a concave portion having a surface surrounding the left and right side surfaces and the bottom surface is formed integrally with the girder, the small end of the precast concrete small beam is inserted into the concave portion of the bracket of the precast concrete girder, and expanding mortar is applied to the gap between the joint surfaces. A joint structure of a precast concrete main beam and a precast concrete small beam characterized by filling.