JPH05179700A - Jointing method of precast girder to precast beam - Google Patents

Abstract

PURPOSE:To join a precast girder with a precast beam to transmit a load securely without using concrete placed at site even in case there is no difference between the heights of both. CONSTITUTION:A cut groove part 3 having a recessed part in an inner wall surface is provided at a joint part with a precast beam 2 in a side surface of a precast girder 1. After dropping an end part of the precast beam 2 having a recessed part 5 in an end surface at a corresponding position to the recessed part 4, high-strength grout material 6 is injected to a gap between the precast girder 1 and the beam 2 and the recessed parts 4, 5 facing each other to solidify and integrate them.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of joining RC precast girders and precast girders in a precast concrete structure building.

[0002]

2. Description of the Related Art Conventional RC precast girders and precast girders are joined to each other by providing a supporting projection B for supporting a girder on a side surface of the girder A as shown in FIG. As shown in FIG. 4, a notch groove D slightly larger than the cross-sectional shape of the beam C is provided at the beam connecting position on the side of the beam A, the end of the beam C is fitted therein, and the grout material G is injected into the gap. Then, the method of fixing the beam C was adopted.

In either method, structurally, the grout material G is not expected as the supporting force for the beam C, and the post-cast concrete E on the upper floor and the supporting projection B from the beam A are used.
Alternatively, the beam C is supported by the concrete portion below the lower end surface of the cut groove portion D.

[0004]

According to the conventional method, it is preferable that there is a sufficient height difference between the large beam and the small beam, but if there is no difference, it is necessary to support the beam under the supporting projection or the cut groove. Since the thickness of the concrete part under the end face was small and the strength was insufficient, it was not possible to support the small beam. Therefore, either the large beam or the small beam, or part of it had to be cast in situ.

Further, in the conventional supporting method, it is necessary to reinforce the supporting projections for supporting the beam or the concrete portion below the lower end surface of the cut groove with reinforcing bars. Particularly, in the supporting projection protruding from the girder. It takes a lot of time and labor to manufacture the precast member, and the formwork becomes complicated, which inevitably results in a high cost.

[0006]

According to the present invention, a cut groove portion 3 having a recess 4 on an inner wall surface is provided at a joint portion of a side surface of a precast girder 1 with a precast beam 2 and the cut groove portion 3 is provided. After dropping the end of the precast girder 2 having a recess 5 on the end face at a position corresponding to the recess 4, a high-strength grout is formed in the gap between the precast girder 1 and the girder 2 and the corresponding recesses 4 and 5. It proposes a method for joining a precast girder and a precast girder in which the material 6 is injected to be solidified and integrated.

[0007]

The high-strength grout material 6 filled and solidified in the gap between the notch 3 of the precast girder 1 and the end of the precast girder 2 and between the opposing recesses 4 and 5 is as if the girder 1
Like a cotter driven between the girder and the girder 2, they will be locked and firmly joined together. Therefore, even if there is no difference in height between the girder 1 and the girder 2, surely without using cast-in-place concrete. It is possible to join the two so that the load can be transmitted.

[0008]

[Example] The beam 2 from the upper end to the lower portion of the joint portion of the precast girder 2 on the side surface of the precast girder 1
A cut groove portion 3 slightly larger than the cross-sectional shape is provided, and one or a plurality of recesses 4 are provided on the inner wall surface of the cut groove portion 3.

The end face of the precast beam 2 is provided with a recess 5 at a position corresponding to the recess 4 on the inner wall surface of the cut groove 3.

When the precast beam 2 is joined, the end of the beam 2 is dropped into the cut groove 3 of the precast girder 1 with a slight gap and placed on the lower end surface of the cut groove 3. A high-strength grout material 6 such as high-strength mortar is injected into the gap between the cut groove 3 of the girder 1 and the end of the girder 2 and the recesses 4 and 5 facing each other, and the girder 2 is fixed to the girder 1. Unify.

The high-strength grout material 6 thus filled and solidified in the gap between the girder 1 and the girder 2 and between the opposing recesses 4 and 5 is as if it were a cotter driven between the girder 1 and the girder 2. As a result, they will be firmly connected.

After that, beam reinforcements 7 and 8 are arranged on the upper ends of the large beam 1 and the small beam 2, and a post-cast concrete 9 integral with the floor slab is placed.

[0013]

As described above, according to the present invention, the high-strength grout material filled and solidified in the gap between the cut groove portion of the precast girder and the precast girder and in the opposing recesses,
Since they are firmly connected like a cotter driven between a large beam and a small beam, even if there is no difference in height between the large beam and the small beam, they are firmly joined together as a precast member without using cast-in-place concrete. It becomes possible.

Moreover, since it is not necessary to provide a supporting projection for supporting the beam, or to reinforce the supporting projection or the concrete portion below the lower end surface of the cut groove portion with a reinforcing bar as in the conventional case, the precast girder is not required to be reinforced. It is easy to manufacture, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a method for joining a large beam and a small beam according to the present invention.

FIG. 2 is a cross-sectional plan view showing a method for joining a girder and a girder according to the present invention.

FIG. 3 is a vertical cross-sectional side view showing a conventional method for connecting a precast girder and a precast girder.

FIG. 4 is a vertical cross-sectional side view showing a method for connecting a conventional precast girder and a precast girder.

[Explanation of symbols]

 1 Precast girder 2 Precast girder 3 Notch groove 4 Recess 5 Recess 6 High-strength grout material 7 Beam reinforcement 8 Beam reinforcement 9 Post-cast concrete

Claims (1)

[Claims] 1. A cut groove portion having a concave portion provided on an inner wall surface thereof is provided at a joint portion of a side surface of a precast girder with a precast beam portion, and the cut groove portion is provided with a concave portion at an end surface at a position corresponding to the concave portion. After dropping the precast girder, a high-strength grout material is injected into the gap between the precast girder and the girder and the corresponding recesses to solidify and integrate the precast girder and the precast girder. Joining method.