JPH076227B2 - Joining method of half precast concrete beam and cast-in-place concrete beam. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a half precast concrete beam and a half precast concrete beam and a cast concrete beam for joining a cast-in-place concrete beam of a conventional method. Regarding the joining method.

[Conventional technology]

In recent years, in the construction of buildings, as a means to save labor and improve workability, the beam is made into half precast concrete (hereinafter referred to as half PC) and
Many methods of combining PC-made slabs have been adopted.

Here, the connection between the half PC beam and the concrete girder supporting it is the conventional reinforced concrete construction, where the bottom reinforcement of the half PC beam is from 25 times the diameter of the reinforcing bar according to the structural regulation by law.
It is fixed in the 35 times concrete girder or it is fixed in the concrete girder by embedding a U-shaped fixing streak separately in the small PC girder.

[Problems to be Solved by the Present Invention]

However, from the edge of the above-mentioned half PC beam, extending the anchoring extra length of the beam under the beam, and fixing it to the concrete girder, when incorporating the half PC beam to the girder before concrete placement, Since the long fixing extra length of the under-beam of the half PC beam above hits the over-beam of the beam, the over-beam of the beam must be brought closer to one side, or the under-beam of the beam should be bent to assemble. However, the construction is very troublesome, and the method of embedding the U-shaped anchorage in the half-PC beam has a problem that the U-shaped anchorage and the girder reinforcement are not tightly fitted. In view of the above problems, the present invention has been made to improve this, and an object of the present invention is to provide a method for joining a half PC beam and a cast-in-place concrete beam that are easy and have good workability. .

[Means for Solving the Problems]

The present invention for solving the above-mentioned problems does not project a streak to the stoma surface, and the stylus of the half-PC beam having a plurality of ribs formed to project is formed on the mold face joint portion of the concrete beam to be cast in situ. It is characterized by a method of joining a half-PC small beam and a cast-in-place concrete large beam in which the large beam concrete and the slab concrete are placed and joined by being inserted by a depth not less than the protruding height of the rib.

[Action]

Half-PC beam is not attached to the long beam before the concrete is placed because there is no protrusion of the long anchoring extra length of the beam below the beam and the anchoring line embedded separately. It can be installed very easily without any hindrance, and after casting the girder concrete and slab concrete in place, the ribs on the half PC girder small face bite into the girder concrete to lower the girder. Sufficient bonding strength can be obtained without fixing the streak to the girder.

〔Example〕

 Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 1 is a vertical sectional view showing a state after construction of a half PC beam and a cast-in-place concrete beam joined by the method of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. [Fig. 3] is a plan view showing an assembled state of a half PC beam and a concrete beam before cast-in-place concrete is cast.

In the figure, 1 is a half-PC beam that is manufactured in advance in the factory. The lower half part of the beam upper beam 2, beam lower beam 3, beam beam rib 4 is embedded in PC concrete, The streak 3 does not project from the strut surface, but the end portion is bent upward on the inner side of the stoma surface, and a plurality of horizontal ribs 5 (three in the embodiment) are formed projectingly on the streak surface. . The upper beam 2 of the cross beam is provided with a fixing extra length portion, and the above fixing extra length portion is initially set to the half PC cross beam 1.
It is pulled in without protruding from the forehead surface and temporarily attached to the stirrup 3.

Reference numeral 6 is a concrete girder that is cast on site. At the site, a girder upper bar 7, a girder bottom bar 8 and a girder stirrup bar 9 are arranged, and a form 10 is assembled. The half-PC girder 1 is carried to the site and hoisted, and a small opening portion is inserted into a predetermined joint portion on the side surface of the girder 6 to a depth not less than the protruding height d of the rib 5 and supported by a built-in support.

Next, the upper rib 2 of the half PC beam 1 is replaced with the concrete beam 6
Draw it to the upper part of the slab, put the upper ribs 2 of the half-PC beam 1 on top of each other and tie them together with the iron wire 11.
If the 12 and the slab concrete 13 are cast, the construction of the half PC slab is completed at the same time when the cast-in-place concrete beam 6 and the half PC beam 1 are joined.

In addition, in the above-mentioned embodiment, when the half PC beam 1 is incorporated into the joint portion of the concrete beam 6, the extra fixing portions of the beam strut 2 on both sides of the retracted concrete beam 6 are pulled out and spliced. However, instead, there is no anchoring extra length in the beam upper beam 2 on both sides of the concrete girder 6 and another anchoring reinforcing bar is attached to the beam upper beam 2 on both sides of the concrete beam 6 with a predetermined overlapping length. You may make it provide and it may be made to bind and succeed. Further, the ribs are not limited to the horizontal direction, and may be the vertical direction, may cross in the vertical and horizontal directions, and may be inclined at an angle.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention does not project the bottom streak on the stoma surface, but the stoma of the half precast concrete beam with a plurality of ribs formed on the side surface joint portion of the concrete girder for cast-in-place. Incorporating by inserting only a depth not less than the protruding height of, the large beam concrete and the slab concrete are placed and joined, and the half PC beam is a long fixing extra length part of the lower end streak from the edge face, Alternatively, since there is no protrusion of the anchoring line that is embedded separately, it is extremely easy to install half-PC beam in a cast-in-place concrete girder, and the workability is improved. After casting in place, the half-PC beam will not be fixed to the beam by the ribs on the forehead biting into the beam concrete. But it is possible to obtain a sufficient bonding strength.

[Brief description of drawings]

The drawing shows an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing a state after construction of a half PC beam and a cast-in-place concrete beam joined by the method of the present invention, and FIG. 2 is A- of FIG.
FIG. 3 is a cross-sectional view taken along the line A, and FIG. 3 is a plan view showing an assembled state of the half-PC beam and the concrete beam before the cast-in-place concrete is cast. 1 ... Half precast concrete beam, 2 ... beam upper beam, 3 beam beam lower beam, 5 ... Rib, 6 ... cast-in-place concrete beam, 7 ... beam beam upper beam, 8 ... … Belt girder bottom streak, 12 …… Large beam concrete, 13 …… Slab concrete.

Claims (1)

[Claims] 1. A small precast concrete beam having a plurality of ribs projectingly formed on the forehead without projecting a bottom streak at a side surface joint portion of a concrete girder to be cast in place, and the rib has a protruding height higher than that. A method for joining half-precast concrete girders and cast-in-place concrete girders, characterized in that the girder concrete and the slab concrete are placed and joined at a not-deep depth.