JP3021512B2 - PC handrail for cantilever slab - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a PC handrail for a cantilever slab.

(Prior Art) Conventionally, a cantilever slab, for example, a concrete handrail portion of a balcony is often cast in place. However, according to this conventional example, it takes a lot of time and labor to construct the handrail portion, such as assembling and dismantling the handrail portion and finishing after placing concrete. In order to solve this problem, the handrails and drains are integrally precast (P
C) has been proposed (JP-A-49-106120).

(Problems to be Solved by the Invention) However, usually, a PC member is placed on a formwork, and then concrete is cast. However, a slight gap is formed between the formwork and the PC member. Concrete will enter the joint, and it will be necessary to repair the joint, that is, the joint between the PC member and the cast-in-place concrete. In order to prevent this, joints may be provided at the joints, but this is not preferable in terms of aesthetics. Furthermore, if there is a problem in the filling property at the time of placing concrete, rainwater or the like penetrates from the joint portion, and stains may occur on the lower surface (ceiling surface) of the slab. Therefore, it is conceivable to use a PC member at the tip rather than the groove portion. However, since the handrail portion and the groove are close to each other, if only the tip is simply made into PC, the possibility of water leakage at the joint is increased.

An object of the present invention is to provide a PC handrail that simplifies construction work, prevents dangers such as water leakage, and can form a cantilevered slab in an aesthetically favorable state.

(Means for Solving the Problems) The feature of the PC handrail 1 for cantilever slab according to the present invention is that the cantilever slab is constituted by being integrated with the slab part 2 cast in place, and the lower end of the PC handrail 1 In addition to forming the thin part, reinforcing bars 3 are arranged inside the PC handrail, and a fixing portion 3a below the reinforcing bar 3 has a length protruding from the lower part of the PC handrail and extending into the slab portion 2. . Further, a lower nut anchor 5 for supporting a mold for forming a groove is provided at a lower portion on the slab side.

The second feature is that the nut anchors 4 and 5 are provided at the upper end of the PC handrail and the lower part on the slab side in order to enhance workability.

The third feature is that the fixing portion 3a of the reinforcing bar is different in height from the adjacent fixing portion 3b, and the reinforcing members 3a and 3b are arranged in a two-stage reinforcing bar. You may.

(Operation) The PC handrail 1 constitutes a handrail of a cantilever slab, and the fixing portions 3a and 3b of the reinforcing bar 3 contribute to integration with the slab portion 2 and form a groove in the lower nut anchor 5. Since the formwork 9 can be supported, the formwork can be easily supported, which contributes to the simplification of construction. In addition, in the upper nut anchor 4 at the upper end of the PC handrail, the hanging hook 8, the mounting hardware M1 of the wall support S or the mounting hardware M of the temporary handrail T are mounted, so that the PC handrail functions as a mounting means. Contributes to ease of operation.

(Example) First, a specific configuration of a cantilever slab will be described with reference to FIG. 1 and FIG.

The cantilever slab comprises a PC handrail 1 according to the present invention and a slab part 2 cast in place.

The lower end 1a of the PC handrail 1 is formed to be thin, and reinforcing bars are arranged inside the PC handrail. Of these, the lower ends of the vertical reinforcing bars 3,... Are fixed at right angles. The fixing portion protrudes horizontally from the thin lower end portion 1a of the PC handrail 1 and extends into the slab portion 2. Reinforcement 3
As shown in FIG. 1, the fixing section 3a is different in height from the adjacent fixing section 3b and is arranged alternately up and down, so that the reinforcing section of the entire fixing section has a two-stage reinforcing arrangement. ing.

Nut anchors 4 and 5 are embedded in the upper end portion of the PC handrail 1 and the lower portion on the slab portion 2 side, respectively. A bolt 6 for fixing a mounting hardware M for supporting the temporary handrail T is screwed into the upper nut anchor 4 on the upper end side. Further, a screw (not shown) for attaching a mounting bracket M1 for supporting one end of the wall support S (FIG. 2) is screwed into the upper nut anchor 4, or a hanging hook 8 (FIG. 3). Screws are attached. A bolt 7 is screwed into the lower nut anchor 5.
A support metal 10 supporting a formwork 9 for forming a groove at the lower end from the bolt 7 is suspended.

 Next, the construction method of the cantilever slab will be described.

First, as shown in FIGS. 1 and 2, after assembling the mold K of the slab portion 2 on the support P, the upper nut anchor 4 at the upper end portion of the PC handrail 1 having a thin lower end portion 1a. With a crane using the hanging hook 8 screwed into the
The PC handrail 1 is suspended, and the PC handrail 1 is erected on the tip of the formwork K. Then, the PC handrail 1 is attached to another upper nut anchor 4 while being supported by a crane using the hanging hook 8 from the upper nut anchor 4. Install hardware M1. A wall support S is disposed between the mounting hardware M1 and the formwork K1, and the PC handrail 1 is supported by the wall support, so that the PC handrail is kept upright. Then, a mold frame 9 for forming a groove using the lower nut anchor 5 is supported and installed using a support metal 10. Then, after arranging the reinforcement of the slab part 2, slab concrete is poured. After curing, a mounting hardware M is attached to the upper nut anchor 4 at the upper end of the PC handrail 1, the temporary handrail T is fixed thereto, and the support P is erected on the slab 2, and then the formwork is mounted on the support P. K is supported, and the same operation as above is repeated in the following procedure (FIG. 3).

(Effects of the Invention) According to the present invention, since the lower end of the PC handrail is formed to be thin, all the groove portions can be integrally formed with cast-in-place concrete, and the danger of water leakage can be prevented. Can also be provided at the tip of the slab, which is aesthetically preferable. In addition, the use of a PC handrail and the use of a nut anchor eliminates the need for conventional cast-in-place concrete work, facilitating the work of suspending the PC handrail or supporting the formwork for forming the groove, and therefore the slab. Construction is easier and contributes to shortening the construction period. The lower nut anchor facilitates holding of the formwork for forming the groove. If the nut anchors are provided at the upper end of the PC handrail and the lower part on the slab side, the work can be more easily performed because the PC handrail can be temporarily erected during the work of hanging the handrail. As described above, it is easy to hold the mold for forming the groove. If the anchoring portions of the reinforcing bars are arranged in two stages, the concrete of the slab portion can be effectively integrated.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which the PC handrail is standing, FIG. 2 is a front view showing a state in which the PC handrail is supported by a wall support, and FIG. 3 is a front view showing one process of construction. 1 PC handrail 1a Thin bottom end 2 Slab 3 Reinforcing bar 3a, 3b Fixing section 4 Upper nut anchor 5 Lower nut anchor 6, 7 Bolt 9 Formwork for forming the groove 10 ... Support metal fittings K ... Formwork

Claims (3)

(57) [Claims] 1. A PC handrail for forming a cantilever slab composed of a PC handrail and a cast-in-place slab portion, wherein a lower end portion of the PC handrail is formed to be thin.
The PC handrail has reinforcing bars arranged inside, and the fixing part below this reinforcing bar has a length that protrudes from the lower part of the PC handrail and extends into the slab part, and a formwork for forming a groove in the lower part of the slab side A PC handrail for cantilever slabs, wherein a lower nut anchor for supporting is provided. 2. A PC handrail for forming a cantilever slab composed of a PC handrail and a cast-in-place slab portion, wherein a lower end portion of the PC handrail is formed to be thin.
The PC handrail arranges reinforcing bars inside, and the anchoring part below this reinforcing bar has a length that protrudes from the lower part of the PC handrail and extends into the slab part, and a nut anchor is attached to the upper end of the PC handrail,
A PC handrail for a cantilevered slab, wherein a lower nut anchor for supporting a mold for forming a groove is provided at a lower portion of the slab side. 3. The fixing device according to claim 1, wherein the fixing portions of the reinforcing bars have different heights of adjacent fixing portions, and the reinforcing portions of the entire fixing portion are arranged in two steps. PC handrail for holding slab.