JPH03151430A - Building method for reinforced concrete beam using beam formwork of precast concrete - Google Patents

Abstract

PURPOSE:To simplify execution of work by forming a beam formwork having many recessed part on the inner face, placing concrete after supporting the formwork on a prescribed position and arranging beam reinforcement, and retaining the formwork as a finishing member. CONSTITUTION:A formwork 1 constructing a reinforced concrete beam is formed out of precast concrete, and provided with many recessed parts 7 on the inner face. Further, the formwork 1 has U-section or L-section, and is provided with a cutout 5 on the position to receive a small beam 4. Nextly, the formwork 1 is supported on the beam building position, beam reinforcement is arranged inside the formwork 1, and concrete is placed to build the beam. The formwork 1 is retained as a finishing member of the beam, and concrete is filled in the recessed parts 7 not to separate from the formwork. Hereby, execution of work is simplified and the cost can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a precast concrete integral beam formwork with a large number of recesses on the inner surface, which is left as it is as a finishing material for a reinforced concrete beam. This paper relates to a method for constructing reinforced concrete beams using beam formwork.

[Prior art and problems to be solved by the invention] Conventionally, wooden formwork has been generally used as the formwork for reinforced concrete construction, but steel or precast concrete formwork can also be used. It is used depending on finishing conditions, etc.

In any case, these formworks are usually made by assembling flat plate-like formwork in a predetermined position according to the external shape of the structure. The beam formwork is assembled in an L-shape at the beam position, or the bottom punch and side panels are assembled on the floor in a U-shape or L-shape and then hoisted to the post-dyeing position.

Assembling, removing, and cleaning up the formwork mentioned above must be done manually, which requires a great deal of effort and time.Assembling affects the finish of the building, skilled workers are required, and disassembly is dangerous work. There were problems such as.

In view of the above-mentioned problems, the present invention has been made with the aim of improving the above problems, and aims to improve the efficiency of formwork construction, make the work safer, and reduce the construction period and cost.

Another object of the present invention is to provide a method for constructing a reinforced concrete beam using precast concrete beam formwork that can prevent the beam formwork from peeling off.

[Means to solve the problem]

In order to achieve the above object, the present invention supports an integral U-shaped beam form made of precast concrete with a large number of recesses on the inner surface and prepared in advance at a beam construction position, and installs beam reinforcing bars in the beam form. After reinforcing, concrete beams are poured in place,
After the concrete hardens, the beam formwork is left as a finishing material for the beam. It features a method of constructing reinforced concrete beams using precast concrete beam formwork.

[For production]

In the present invention, instead of assembling beam formwork from a flat plate formwork into a U-shape for intermediate beam formwork and an L-shape for wall beam formwork on site, a large number of recesses are provided on the inner surface and pre-assembled. We use the U-shaped or L-shaped integral beam formwork made of precast concrete, and the precast concrete beam formwork in brackets is left as a beam finishing material without being removed after construction is completed.
Formwork work does not require skilled workers, and the labor required for assembling the formwork on site is greatly reduced. Removal and cleanup is time-consuming and there is no need to finish the external surface of the beams, reducing construction time and costs. Safety is ensured, and the concrete spreads through the many recesses provided on the inner surface of the beam formwork, and the beam formwork and poured concrete are integrated, preventing the beam formwork from peeling off as a beam finishing material. be done.

〔Example〕

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

In Fig. 1, l is an intermediate girder form made of precast concrete (hereinafter referred to as PC) prefabricated in a factory, and is integrally formed into a U-shape with a bottom plate 1a and side plates 1b and lb. The dimensions are equal to the size and width of the girder to be constructed, and the length is divided into lengths convenient for transportation and construction.

This PC intermediate beam formwork 1 is tapered at the end 2 that joins to the PC intermediate beam formwork 1' (shown in Figure 3) perpendicular to this, and the PC intermediate beam formworks 1°1 are butted against each other. The end portion 3 is formed at a right angle, and a notch 5 equal to the cross section of the PC beam 4 is formed at a position to receive the PC beam 4 that intersects at right angles, and a cast-in-place concrete 6 (the third
(shown on the lower floor of the figure), a number of recesses 7 are formed to prevent the formwork as a finishing material from peeling off, and there are also recesses on the upper surface of the PC beam 4 to improve the adhesion of cast-in-place concrete 6. A groove 8 is formed. 9 in the figure indicates both side plates 1b and l.
insert into the insert 10 embedded in b, both side plates 1b,
11 is a reinforcing iron plate that prevents breakage of the notch 5, and 12 is an insert for tightening the suspension bolt during construction.

The PC wall beam formwork 13 on the outer wall side shown in FIG.
and the side plate 13b are integrally formed in an L-shape, and like the PC intermediate beam 1, the end 14 that joins the PC intermediate beam form or PC wall beam form perpendicular thereto is tapered, and the PCC The abutting ends 15 of the wall frames 13 are formed at right angles, and a notch 16 equal to the cross section of the PC beam 4 is formed at a position to receive the PC beam 4 that intersects at right angles. A large number of recesses 17 are formed for integration with the concrete 6. 18 in the figure is a notch 16
19 is an insert for inserting the reinforcing bar 9, and 20 is an insert for tightening the hanging bolt during construction.

Next, the construction method of the present invention will be explained with reference to FIG.

Figure 3 shows the lower floor after pouring cast-in-place concrete and the upper floor before pouring concrete.

In the construction method of the present invention, first, formwork supports 22, 22 for supporting the PC intermediate girder formwork 1, 1' and the PC wall beam formwork 13, which are perpendicular to each other, are placed at predetermined positions on the constructed slab 21.
', and the PC intermediate girder formwork 1.1' abuts their perpendicular ends 3, and the tapered ends 2 are perpendicular to each other.
Connected to the tapered end 2' of the intermediate girder form 1' and the tapered end 14 of the PC wall beam form, and connected to the PC intermediate girder form 1, 1'.
and PC wall beam formwork 13 are respectively supported on each PC formwork support 22,22'.

Next, in the notch 5 of the PC intermediate girder formwork 1,
The ends of the C beams 4 are rested and supported by the PC beam supports 23, and then the PC middle beam formwork 1°1' PC wall beam formwork 13. In each section surrounded by the PC small beams 4, a pre-fabricated PC slab formwork 24 is attached to the PC middle beam formwork 1.1'
, PC wall formwork 13, and PC beam 4 are supported by PC slab formwork supports 25 over their respective upper edges.

After that, inside the PC middle beam formwork 1, 1', PC wall formwork 1
3 and on the PC slab formwork 24 side, beam reinforcing bars and slab reinforcing bars (both not shown) are arranged, and the PC slab formwork 24
surface, upper surface of pc small beam 4, inside pc intermediate girder formwork 1, 1', p
c. Concrete 6 is cast in place within the wall beam formwork 13, and after the concrete hardens, each support 22, 22', 23
．． 25 is removed, PC intermediate girder formwork 1.1', PC
The slab formwork 24 is left as it is and the construction is completed as shown in the lower floor of FIG.

Note that the PC small beam 4 is connected to the PC middle beam formwork 1, 1.
6 [Effects of the Invention] As explained above, the present invention provides a pre-fabricated precast concrete structure with a large number of recesses on the inner surface. After supporting the integrated beam formwork at the beam construction position and arranging beam reinforcing bars within the beam formwork, beam concrete is poured in place, and after the concrete hardens, the beam is finished without removing the beam formwork. This method is used to construct reinforced concrete beams by leaving the remaining material as a material, and instead of assembling the beam formwork into a U-shape or L-shape from flat plate formwork on site, a large number of recesses are provided on the inner surface and the beam formwork is pre-assembled into a U-shape or an L-shape. A U-shape made of precast concrete.

Alternatively, an L-shaped integral beam form is used, and this precast concrete beam form is left as the beam finishing material, so skilled workers are not required for the formwork work, and the time and effort required to assemble the formwork on site is significantly reduced. This reduces construction time and costs by eliminating the need for removal and cleanup, and the need to finish the external surface of the beam. In addition, work safety is ensured, and the concrete As a result, the beam formwork and concrete are integrated, thereby preventing the beam formwork from peeling off as a beam finishing material.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of a precast concrete intermediate beam form used in the construction method of the present invention, FIG. 2 is a perspective view of a precast concrete wall beam form, and FIG. 3 is a perspective view of a precast concrete wall beam form. FIG. 2 is an elevational view illustrating the construction method of the present invention. 1.1'...Precast concrete intermediate girder formwork, 6...Cast-in-place concrete, 7.17...Concavity, 13...PCC wall mass formwork 22.22'...Precast concrete formwork support.

Claims (1)

[Claims] A pre-fabricated integral beam form made of precast concrete with numerous recesses on the inside surface is supported at the beam construction position.
After arranging beam reinforcing bars in the beam form, beam concrete is cast in place, and after the concrete hardens, the beam form is left as a finishing material for the beam. Method of constructing reinforced concrete beams.