JPH02272151A - Method and tool for anchoring carbon fibre-reinforced plastic flat plate - Google Patents

Abstract

PURPOSE:To anchor carbon fibres without flaws by a method in which a anchoring tool having a pressure-receiving face in the direction of crossing a flat plate is held on the flat plate, dragged in concrete, and anchored by introducing a tension force into it. CONSTITUTION:A bendable rectangular flat plate 1 is cut into a necessary length on site, and U-shaped plates 21 as anchoring tools 2 capable of strongly anchoring the plate 1 without damage for anchoring it to the inside or ends of a concrete structure are clamped to the plate 1 by bolts 22. In this case, the plate-1 is held on the back of the bottom 23 of the plate 21 having a wall plate 24 and a pressure-receiving face 25, in which the face 25 serves as a resistance face against forces when concrete structure is flexed or the plate 1 is tensed. The three bodies can thus be integrated only by clamping the plate 1 held between the paired plates 21 with the bolts 22.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a PC construction method using carbon fibers, and more particularly to a fixing method and fixture for a carbon fiber-reinforced plastic flat plate formed into a flat plate shape.

<Conventional technology> Recently, carbon fiber reinforced plastic, which is said to be a new material, has been
Research and development of technology used in Method C is underway.

It is known that carbon fiber reinforced plastics have the advantages of being lightweight, non-corrosive, having high tensile performance, and low elongation.

However, this type of conventional technology is an extension of the conventional concept of PC steel wire, and is simply an idea of replacing the PC steel wire with carbon fiber reinforced plastic.

Therefore, to date, no method other than using carbon fiber reinforced plastics with a circular cross section has been developed.

<Problems to be Solved by the Present Invention> The following problems exist in the conventional technique of utilizing carbon fiber reinforced plastic in the PC construction method.

(a) When carbon fiber reinforced plastic is used in the PC construction method, the technology for fixing the edges of the carbon fiber reinforced plastic becomes a problem.

In particular, carbon fiber reinforced plastics are susceptible to shearing, so it is inappropriate to use conventional fixing devices that partially bite into them as they are.

For this reason, it is desired to propose a fixing technology that can fix carbon fiber reinforced plastics without damaging them.

<Exposure> Since the cross section of conventional carbon fiber reinforced plastics is circular, there remains the problem that the concrete must be covered thickly.

<Object of the present invention> The present invention was made in order to improve such problems, and the purpose of the present invention is to provide a method for fixing carbon fiber-reinforced plastic flat plates that can be fixed without damaging carbon fibers. The purpose is to provide a method.

Another object of the present invention is to provide a method for fixing a carbon fiber-reinforced plastic flat plate, which can secure the effective thickness even if the covering thickness of concrete is reduced.

A further object of the present invention is to provide a fixing tool for carbon fiber reinforced plastic flat plates that is easy to manufacture and handle and suitable for tensioning and fixing work of carbon fiber reinforced plastic flat plates.

<Structure of the Present Invention> In the present invention, a flat carbon fiber reinforced plastic (carbon fiber reinforced plastic flat plate) as shown below is used, and a fixture for fixing the same is used.

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

By making the cross-sectional shape of the carbon fiber-reinforced plastic flat plate 1 rectangular as in the present invention, bending becomes possible and there is no restriction on shape growth.

Therefore, the carbon fiber-reinforced plastic flat plate 1, which has been formed into a long length in advance at a factory or the like, can be cut into the required length at the site and used.

The characteristics and shape of this carbon fiber reinforced plastic flat plate 1 are selected and used optimally depending on its use and purpose.

<Opening> Fixing device In order to fix the carbon fiber reinforced plastic flat plate 1 to the inside or end face of a concrete structure, it is necessary to use a fixing device that has conditions that allow it to be firmly fixed without damaging the carbon fiber reinforced plastic flat plate 1. Fixture 2 is required.

Therefore, in the present invention, the fixture 2 also has a structure having a flat portion of a certain length.

For example, the fixture 2 shown in FIG. 1.2 will be explained. The fixture 2 consists of a pair of U-shaped plates 21, 21 and bolts 22 that fasten them together.

Each U-shaped plate 21 is made by cutting groove-shaped steel into short lengths to form the bottom plate 23.
, a wall plate 24 formed on both sides of the bottom plate 23, and a pressure receiving surface 25 formed on the wall plate 24.

The back surfaces of the bottom plates 23 of both U-shaped plates 21 serve as surfaces on which the carbon fiber reinforced plastic flat plate 1 is held.

The pressure receiving surface 25 becomes a resistance surface that resists these forces when the carbon fiber reinforced plastic flat plate 1 is tensed or when the concrete structure is deflected, as will be described later.

A plurality of bolts 22 are installed at positions spanning the carbon fiber reinforced plastic flat plate 1 at the center of the bottom surface 23 of each U-shaped plate 21, and pressurize each U-shaped plate 21 in a well-balanced manner.

<C> Attaching the fixture 2 The operation of attaching the fixture 2 to the carbon fiber reinforced plastic flat plate 1 is extremely simple.

That is, this will be explained with reference to FIG. 2. First, while the distance between the pair of U-shaped plates 21 is widened, the carbon fiber reinforced plastic flat plate 1 is inserted from a direction perpendicular to the wall plate 24.

And U-shaped plate 21 and carbon fiber reinforced plastic flat plate 1
After applying adhesive 3 between them, bolts 22 are tightened to restrain the three members together.

With such a restraining structure, a sufficiently large force can be secured 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 explained.

<A> Attaching the fixing device: Attach the above-mentioned fixing device 2 to the end of the carbon fiber reinforced plastic flat plate 1.

As a result, the wall plate 24 of the fixture 2 is located in a direction perpendicular to the longitudinal direction of the carbon fiber reinforced plastic flat plate 1.

<Opening> Placement in a formwork A carbon fiber-reinforced plastic flat plate 1 with fixtures 2 attached is installed in a formwork of a concrete structure as shown in FIG. 3, for example.

Note that the fixture 2 is omitted in FIG. 3.

Also, when installing the carbon fiber reinforced plastic flat plate 1,
When using a fixing method that does not provide adhesion to concrete (unbonded type), it is preferable to apply oil around the carbon fiber reinforced plastic flat plate 1 in advance and cover it with a sheath pipe.

Kuha〉Place concrete Next, pour concrete into the formwork of the concrete structure, excluding the location where fixture 2 will be installed.

<2> Tension the carbon fiber-reinforced plastic flat plate 1 by pulling the fixture 2 exposed in the unfilled space of the tension concrete with a hydraulic shovel or the like.

<PO> While maintaining the tension applied to the fixed carbon fiber reinforced plastic flat plate 1, the exposed space of the fixture 2 is filled with concrete.

As a result, the fixture 2 is buried in concrete.

After fixing the carbon fiber reinforced plastic flat plate 1,
A large force acts on the fixture 2 due to deformation of the concrete structure 1 or the introduction of tension force to the carbon fiber reinforced plastic flat plate 1.

The force acting on the fixture 2 is opposed by the pressure receiving surface 25 of the wall plate 24 in contact with the concrete structure.

<Effects of the Present Invention> As described above, the present invention uses a carbon fiber-reinforced plastic flat plate having a rectangular cross section instead of a circular cross section, and uses this by embedding it inside concrete.

Therefore, the following effects can be obtained.

After widening the distance between a pair of U-shaped plates, a carbon fiber-reinforced plastic flat plate with a rectangular cross section is inserted, and the three can be restrained together with the simple operation of tightening a bolt.

In this case, if an adhesive is interposed between the contact surfaces of the carbon fiber-reinforced plastic flat plate and the U-shaped plate and they are fastened with bolts, the binding force will further increase. Since each plane is brought into contact and restrained, it is possible to fix the carbon fiber reinforced plastic plane plate without damaging it.

<Exposure> Since carbon fiber reinforced plastic formed into a particularly thin flat plate is used, the structure of the fixing device, which was considered to be complicated, becomes simpler compared to the case of using a conventional material with a circular cross section.

For example, in the illustrated embodiment, commercially available channel steel can be cut into short lengths, making it inexpensive and easy to manufacture.

<C> The fixing device can firmly fix the carbon fiber reinforced plastic flat plate, which is easily sheared, without damaging it.

(2) When the structure of the fixing device is simple, it is not only inexpensive to manufacture, but also easy to handle and assemble, requiring no special skill, and is highly effective in use.

<E> The advantages of carbon fiber, such as being lightweight and non-corrosive, can be directly utilized in concrete structures.

(f) Compared to conventional circular cross-section plates, the carbon fiber reinforced plastic flat plate has a thinner cross section, so it can ensure an effective covering thickness even when placed close to the surface of a concrete structure.

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

This is advantageous in terms of design, as it allows for a larger vertical spacing compared to the conventional case where materials with a circular cross section are installed.

<G> A conventional rod-shaped body with a circular cross section cannot be bent.

On the other hand, since carbon fiber is a thin flat plate and can be bent, the volume for transportation and storage can be reduced, and it is economical because it does not require much effort to transport.

Furthermore, since the carbon fiber reinforced plastic flat plate is a thin plate, it has the advantage that it can be manufactured in any quantity by cutting it into a desired length from a roll on site.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of an embodiment of the present invention, which is a perspective view showing how the carbon fiber-reinforced plastic plane plate and the fixture stand are attached. Figure 2: The vicinity of the fixture buried in the concrete structure. Side view Figure 3: An explanatory diagram of an example of the arrangement of carbon fiber reinforced plastic flat plates

Claims (2)

[Claims] (1) A carbon fiber-reinforced plastic flat plate with a rectangular cross section is used, and a fixture having a pressure-receiving surface in a direction intersecting the carbon fiber-reinforced plastic flat plate is sandwiched and attached in the middle of the carbon fiber-reinforced plastic flat plate. A carbon fiber-reinforced plastic flat plate is buried in concrete, a fixing device is pulled to introduce tensile force to the carbon fiber-reinforced plastic flat plate, and then the fixing device is buried in concrete and fixed. How to fix the face plate. (2) A fixture for holding a carbon fiber-reinforced plastic flat plate with a rectangular cross section, comprising a bottom part for holding the flat part of the carbon fiber-reinforced plastic flat plate, and a pressure-receiving surface that stands up from the bottom and is integrally formed. A fixing device for carbon fiber reinforced plastic flat plates, comprising: a pair of U-shaped plates; and a fastening material that is fastened by butting the bottom surfaces of the pair of U-shaped plates.