JPS6155464B2 - - Google Patents

Description

[Detailed description of the invention] In order to protect steel pipe piles driven underwater from corrosion by seawater, etc., a protective cover is constructed by covering the steel pipe piles with FRP pipes and filling the middle with mortar. However, FRP is used for such purposes.
The adhesion between the pipe and mortar is not very strong, so improvement is desired.

To increase the adhesion between FRP pipe and mortar,
Conventionally, attempts have been made to apply sand-containing resin to the inner surface of the FRP pipe after forming it. However, this method has disadvantages such as low productivity due to the increased number of steps, weak adhesion between the sand and resin, tending to spread the sand unevenly, and poor appearance. Apart from this, there is also a method of directly shot blasting or sanding the inner surface of the tube, but this method is still inefficient and damages the inner surface, resulting in a decrease in strength, and in particular, deterioration of the alkali resistance of FRP tubes. This is not desirable because it leads to

For FRP pipes used for the above purposes, by forming uniform inner surface irregularities at the same time as FRP pipe manufacturing, it is possible to easily create a strong adhesion between the filling mortar and the underwater pipe. It is an object of this invention to provide an FRP pipe for the protective cover of piles.

That is, it is made of a molded and cured body of thermosetting resin-impregnated fiber material in the shape of an elongated hollow cylinder, and the thermosetting resin-impregnated fiber material cured layer itself exhibits an uneven shape on the inner peripheral surface of the hollow cylinder of this molded and cured body. Having a skin,
This is an FRP pipe for the protective cover of underwater piles.

This FRP pipe can be manufactured using almost the same conventional manufacturing process, resulting in high productivity.Furthermore, it is easy to obtain FRP pipes of the desired quality.In particular, the inner circumferential surface remains uneven and is not damaged, so it is strong. There is no need to worry about degradation or alkali resistance.

The FRP pipe of the present invention is, of course, similar to conventional pipes in that it is made of a molded and cured body of a thermosetting resin-impregnated fiber material in the shape of an elongated hollow cylinder. In relation to specifying surface properties, "solid skin" refers to Buddhist statues and other objects that have a surface that is made of the same material as the internal substance.
For example, it has the same meaning as being called gold or copper.

Next, as a precaution, an advantageous manufacturing procedure for the above FRP pipe will be described.

That is, FIG. 1 shows an example of the manufacturing process of an FRP pipe by the filament winding method. In this example, a release material tape 4 is further spirally wound around a mandrel 2 which is rotated by a mandrel drive device 1 through a steel tape 3 which is spirally wound, and then a sheet 5 for forming irregularities is further wound in a spiral manner.
A core mold having an uneven outer surface can be obtained by overlapping and winding the cores. A layer of thermosetting resin-impregnated fiber material (hereinafter referred to as resin layer) 6 is wound around the outer periphery of this core mold having an uneven outer surface.Finally, a surface coating tape 7 is wound, and the layer is passed through a heat treatment device 8. possibly
FRP pipe products are obtained.

By removing the mold release material 4 and the unevenness forming sheet 5 from the inner surface of the FRP pipe after removing the mold from the mandrel 2, the inner peripheral surface 6a of the uneven surface resulting from the reverse transfer of the outer surface unevenness of the core mold is removed. This is obtained as shown in FIG.

Here, the release material tape 4 can be used to avoid staining the surface of the steel tape 3 and to facilitate the removal of the finished FRP pipe from the mandrel 2. In the case of a non-permeable type, this allows the release material tape 4 to also function as the release material tape 4, and the release material tape 4 is not necessarily required.

As the unevenness forming sheet 5, in addition to plastics, paper, and rubber tape with an embossed sheet surface, woven fabric, canvas, or wire mesh can also be used. Good and desirable.
Furthermore, if a water-soluble plastic tape such as polyvinyl alcohol is used for the unevenness forming sheet 5, the unevenness forming sheet 5 will be dissolved and removed when it is used as a protective cover for steel pipe piles, so there is no need to separate it after demolding. Therefore, it is preferable because there is no need to perform a removal operation.

Further, a release material may be applied to the unevenness forming sheet 5 in advance in order to improve separation from the resin layer 6.

Needless to say, any material can be selected for the resin layer 6 depending on the purpose of the pipe.

Although only one resin layer 6 is wound in FIG. 1, it may be wound in multiple layers, or in particular, layers of different types, such as a resin concrete layer and an unsaturated polyester resin impregnated fiber material layer, may be laminated. .

The surface coating tape 7 is not necessarily required depending on the use of the pipe, so it is not necessary to wrap it unless the purpose is to improve the appearance or protect the pipe.

Above we have explained the case where FRP pipes for the protective cover of underwater piles are obtained by the filament winding method, but when manufacturing them by the hand lay-up method on a mandrel such as a wooden mold or iron mold, the same steps as above can be used. The forming tape may be wound, and then the resin layer 6 may be wound in the same manner, and the heat treatment may be performed.

According to the present invention, since the adhesion force with the internal filling mortar is advantageously enhanced, it is advantageously suitable for use as a protective cover for underwater piles such as steel pipe piles.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the manufacturing process of an FRP pipe, and FIG. 2 is a partial cross-sectional view of an FRP pipe for a protective cover of an underwater pile. 2... Mandrel, 5... Sheet for forming unevenness,
6...Thermosetting resin impregnated fiber material.

Claims (1)

[Claims] 1. A solid material made of a molded and cured body of a thermosetting resin-impregnated fiber material in the shape of an elongated hollow cylinder, and the thermosetting resin-impregnated fiber material cured layer itself exhibits an uneven shape on the inner circumferential surface of the hollow cylinder of the molded and cured body. FRP pipe for the protective cover of underwater piles, consisting of a material with a bare surface.