JP2899676B2 - PC method using carbon fiber reinforced plastic flat plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to a PC method using a carbon fiber reinforced plastic, and particularly to a PC method using a carbon fiber reinforced plastic formed in a flat plate shape.

<Conventional technology> Recently, many technologies for using carbon fiber reinforced plastic, which is a new material, for the PC method have been developed.

This is because carbon fiber reinforced plastics are advantageous in that they are lightweight, do not corrode, have high tensile performance, and have low elongation.

However, this kind of conventional technology is an extension of the conventional concept of PC steel bars, and is merely an idea of replacing PC steel bars with carbon fiber reinforced plastic.

Therefore, the conventional invention has not been developed except for a method using a carbon fiber reinforced plastic having a circular cross section.

However, in the case of a material having a circular cross section, a complicated grasping tool and a fixing tool are required when grasping the end and introducing a pulling force.

In particular, carbon fiber reinforced plastics are vulnerable to shearing,
It is inadequate to use fasteners that partially penetrate.

Further, if the cross section is circular, it is inevitable that the concrete must be thicker.

<Object of the present invention> The present invention has been made in order to improve such a point, and it is an object of the present invention to provide a PC method capable of fixing and tensioning by using a fixture which is easy to manufacture and handle. Aim.

Another object of the present invention is to provide a PC method capable of securing an effective thickness even when the covering thickness of concrete is reduced.

<Structure of the present invention> The construction method of the present invention is performed using a flat carbon fiber reinforced plastic as described below and a fixing tool for fixing the same.

<A> Carbon fiber reinforced plastic flat plate In the construction method of the present invention, a carbon fiber reinforced plastic flat plate 1 having a rectangular cross section, not a circular cross section, is used.

That is, a material having a rectangular cross-section and a sufficiently long length can be used after being cut to a length required for the site.

The characteristics and shape of the carbon fiber reinforced plastic flat plate 1 are selected and used according to the use and purpose.

<B> Fixing Tool A fixing tool 2 is necessary to fix the carbon fiber reinforced plastic flat plate 1 to the inside or the end face of the concrete structure.

Carbon fiber reinforced plastic flat plate 1
Since the fixing device 2 is used, the fixing device 2 also uses a device having a flat portion having a fixed length.

For example, as shown in FIG. 1, the fixing device 2 can be configured by preparing a U-shaped plate 21 in which a grooved steel is cut short, and making the outside of the bottom plate 23 of the groove of the U-shaped plate 21 back to back. .

In the center of the U-shaped plate 21, two or four bolts 22 can be penetrated to restrain the two U-shaped plates 21.

The U-shaped plate 21 is formed of a bottom plate 23 and wall plates 24 on both sides of the bottom plate 23. When two bolts 22 are installed, they are arranged in parallel with the wall plate 24.

This is because the carbon fiber reinforced plastic flat plate 1 intersects the fixing device 2 from a direction perpendicular to the wall plate 24 and is fixed.

<C> Mounting of Fixing Device It is extremely easy to mount the fixing device 2 on the carbon fiber reinforced plastic flat plate 1.

That is, the interval between the two U-shaped boards 21 is increased, and
The carbon fiber reinforced plastic flat plate 1 is inserted therebetween in a direction perpendicular to the above.

And U-shaped board 21 and carbon fiber reinforced plastic flat board 1
And an adhesive is applied between them, and at the same time, the three members are integrally restrained by bolts 22.

With such a structure, a sufficiently large adhesive force can be obtained depending on the setting of the contact area between the carbon fiber reinforced plastic flat plate 1 and the U-shaped plate 21.

<Construction method> Next, the construction method of the present invention will be described.

<A> Mounting of Fixing Device The fixing device 2 is mounted with the carbon fiber reinforced plastic flat plate 1 interposed therebetween.

At this time, as described above, the direction of the wall plate 24 of the fixing device 2 is in an attached state at an angle orthogonal to the extension direction of the carbon fiber reinforced plastic flat plate 1.

<B> Arrangement in the formwork The carbon fiber reinforced plastic flat surface 1 and the fixing tool 2 are arranged inside the formwork of the concrete structure.

In the case of a method in which the carbon fiber reinforced plastic flat plate 1 itself does not give an adhesive force to concrete, adopt a configuration in which oil is applied around the carbon fiber reinforced plastic flat plate 1 and covered with a sheath tube. Can be.

<C> Casting concrete In this state, cast concrete and wait for it to harden.

<D> Introduction of tension As a method of introducing tension to the carbon fiber reinforced plastic flat plate 1, concrete is poured after the carbon fiber reinforced plastic flat plate 1 placed in the formwork of the concrete structure is tensioned. Pretension method can be adopted,
A compressive force is introduced into the concrete structure through the carbon fiber reinforced plastic flat plate 1.

A large force acts on the fixing device 2 due to the introduction of such tension or the deformation of the concrete structure due to other phenomena, but this force can be received by the wall plate 24 and can sufficiently withstand it. is there.

<Effects of the Present Invention> The present invention uses a carbon fiber reinforced plastic flat plate having a rectangular cross section instead of a circular cross section as described above, and burying it in concrete.

 Therefore, the following effects can be achieved.

<B> The advantage that carbon fiber reinforced plastic is lightweight and does not corrode can be used as it is for concrete structures.

<B> Particularly, since the carbon fiber reinforced plastic flat plate formed in a thin plate shape is used, the structure of the fixing device can be extremely simplified as compared with the case where a material having a conventional circular cross section is used.

For example, in the illustrated embodiment, the fixing device can be made of a very inexpensive material obtained by simply cutting a commercially available channel steel.

<C> Since the cross section is thin, an effective covering thickness can be secured even if it is arranged closer to the surface of the concrete structure than a circular cross section.

Therefore, when arranging in a curved shape on a bridge or a slab, the arrangement from a state sufficiently close to the upper surface to a state sufficiently close to the lower surface is possible.

Therefore, the upper and lower gaps can be made larger than the material having a circular cross section, which is economical in arrangement.

<D> Since the carbon fiber reinforced plastic is a thin flat plate, it can be bent.

On the other hand, a rod having a circular cross section cannot be bent.

Therefore, the carbon fiber reinforced plastic flat plate of the present invention can be reduced in volume for transportation and storage, and is economical without labor for transportation.

Further, since it is a thin plate, it is easy to cut, and it has the advantage that it can be unrolled at the site and stored in a roll, and can be manufactured to any required length.

[Brief description of the drawings]

FIG. 1: Explanatory drawing of an embodiment of the mounting state of the carbon fiber reinforced plastic flat plate and the fixture of the present invention FIG. 2: Side view of an embodiment of the arrangement state of the carbon fiber reinforced plastic flat plate

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naohiro Ohori 1-3-1 Nishitsurugaoka, Oimachi, Iruma-gun, Saitama (72) Inventor Akira Kobayashi 1-3-1 Nishitsurugaoka, Oimachi, Iruma-gun, Saitama (56) References JP-A-2-266050 (JP, A) JP-A-2-266065 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E04B 5/43 E04C 5/08 E04G 21 / 12-21/12 104

Claims (1)

(57) [Claims] 1. A flat plate made of carbon fiber reinforced plastic is used, and the flat plate is arranged in a form of a concrete structure, and the flat plate is tensioned to introduce a compressive force to the concrete structure by a pretension method. PC construction method using carbon fiber reinforced plastic flat plate.