JPH0261237A - How to join half precast concrete beams to cast-in-place concrete beams - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a half precast concrete beam and a cast-in-place concrete girder that connect a half-precast concrete beam and a cast-in-place concrete girder in a conventional construction method. Regarding the joining method.

[Conventional technology]

In recent years, in the construction of buildings, as a means of saving labor and improving workability, there are many construction methods in which small beams are made of half precast concrete (hereinafter referred to as "half PC"), and this is combined with half precast concrete slabs. It is starting to be adopted.

Here, in conventional reinforced concrete construction, the connection between the half PC small beam and the concrete girder that supports it is
The lower reinforcement of the C beam is 25mm in diameter as per the structural regulations according to the law.
It is fixed within the concrete girder of 2 to 35 times, or a U-shaped fixing bar is separately embedded in the edge of the half PC beam and this is fixed to the concrete girder.

[Problems to be solved by the present invention]

However, the method of extending the extra anchoring length of the lower beam reinforcement from the edge of the half PC beam and fixing it to the concrete girder is difficult when assembling the half PC beam into the girder before concrete pouring. Since the long extra anchoring length of the lower beam of the half PC beam mentioned above touches the upper beam of the girder, it is necessary to incorporate it by moving the upper beam of the girder to one side or bending the lower beam of the girder. The construction is very troublesome, and the method of embedding U-shaped anchoring bars in the half PC beam has a problem in that the U-shaped anchoring bars and the reinforcing bars of the girder do not fit well together.
In view of the above-mentioned problems, the present invention was made with the aim of improving the problem, and the purpose of the present invention is to provide a method for joining a half PC beam and a cast-in-place concrete girder, which is simple and has good workability. .

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention has provided that the edge of a half PC beam, which has a plurality of ribs protruding from the edge without protruding lower reinforcements on the edge surface, is attached to the side joint of a concrete girder cast on-site with the ribs. It is characterized by a method of joining a half PC beam and a cast-in-place concrete beam, in which the concrete beam is inserted into the concrete to a depth not less than the protruding height of the beam, and the concrete beam and slab concrete are poured and joined.

[Function] Half PC beams do not have the long anchorage length of the lower beam reinforcement or the separately embedded anchorage bars protruding from the edge surface, so the half PC beam is similar to the girder before concrete is poured. When it is assembled into the concrete beam, it can be assembled very easily without any hindrance, and after the concrete girder and concrete slab are cast in place, the multiple ribs on the face of the half PC beam cut into the concrete girder. Sufficient bonding strength can be obtained even without fixing the lower beam reinforcement to the main beam.

〔Example〕

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

Figure 1 is a longitudinal sectional view showing the state of a half PC beam and cast-in-place concrete girder after construction, which were joined by the method of the present invention, Figure 2 is a sectional view taken along the line A-A in Figure 1, and Figure 3. 1 is a plan view showing the assembled state of a half PC beam and a concrete girder before casting-in-place concrete-casting.

In the figure, 1 is a half PC beam prefabricated in a factory, and the lower half of the upper beam reinforcement 2, lower beam reinforcement 3, and stirrup 4 are embedded in PC concrete, and the lower half of the beam under the beam is The reinforcing bars 3 do not protrude from the small beam face, but have their ends bent upwards inside the face, and a plurality of horizontal ribs 5 (three in the embodiment) are formed protruding from the face. The small beam upper stirrup 2 is provided with an extra fixing length part, and the above fixed extra length part is initially pulled in and temporarily attached to the stirrup 3 without protruding from the edge surface of the half PC small beam 1.

6 is a concrete girder cast on site, and the girder upper reinforcement 7, girder lower reinforcement 8. The girder stirrups 9 are arranged and the formwork 10 is assembled. Said half PC
The small beam 1 is carried to the site and lifted up, and the small end portion is inserted into a predetermined joint portion of the side surface of the large beam 6 by a depth not less than the protruding height d of the rib 5, and supported by a built-in support.

Next, the upper reinforcements 2 of the half PC beams 1 are pulled out to the top of the concrete girder 6, the upper reinforcements 2 of the half PC beams 1 are overlapped and connected with iron wires 11, and then the concrete beams 12 and When the slab concrete 13 is placed, construction of the half PC slab is completed at the same time as the cast-in-place concrete girder 6 and the half PC small beam 1 are joined.

In the above embodiment, when assembling the half PC beam 1 into the joint of the concrete girder 6, the extra length of the beam upper reinforcements 2 on both sides of the concrete girder 6 that have been pulled out is pulled out and overlapped. However, instead of this, no extra anchoring length was provided in the upper reinforcements 2 of the small beams on both sides of the concrete girder 6, and another anchoring reinforcing bar was attached to the upper reinforcements 2 of the small beams on both sides of the concrete girder 6 to a predetermined overlapping length. It is also possible to provide them, line them up, tie them together, and connect them. Further, the ribs are not limited to the horizontal direction, but may be vertical, or intersect in the vertical and horizontal directions, or may be inclined diagonally.

〔Effect of the invention〕

As explained above, the present invention does not allow lower reinforcements to protrude from the holo surface, and the edge of a half precast concrete beam having a plurality of ribs protruding thereon is attached to the side joint of a cast-in-place concrete girder. The half Pd beam is inserted into the concrete to a depth not less than the protruding height of the concrete beam, and is joined by pouring concrete into the concrete slab. Since there is no protrusion of the anchor bars or the separately embedded anchorage bars, it is extremely easy to incorporate the half Pd beam into the cast-in-place concrete girder without any hindrance, improving workability, and it can be easily integrated into the cast-in-place concrete girder. After pouring slab concrete in place.

Because the plurality of ribs on the face of the half Pd beam cut into the concrete of the main beam, sufficient bonding strength can be obtained even without fixing the beam lowering reinforcement to the main beam.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view showing the state of a half Pd beam and a cast-in-place concrete girder after construction, which were joined by the method of the present invention. FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. 3 is a plan view showing the assembled state of the half Pd beam and the concrete girder before casting-in-place concrete. 1...Half precast concrete beam, 2...
・Upper beam reinforcement, 3...Lower beam reinforcement, 5...Rib, 6
... Cast-in-place concrete girder, 7... Girder upper beam reinforcement, 8... Girder lower beam reinforcement, 12... Girder concrete beam,
13...Slab concrete.

Claims (1)

[Claims] The edge of a half precast concrete beam with multiple ribs protruding from the edge surface without protruding lower ribs.
A half precast concrete beam characterized in that it is inserted into the side joint of a cast-in-place concrete girder by a depth not less than the protruding height of the rib, and the girder concrete and slab concrete are poured and joined. and the method of joining with cast-in-place concrete girders.