JPH01146048A - Method of treating end section for stretching frp reinforcement - Google Patents

Abstract

PURPOSE: To provide the tension end of an FRP reinforcement with strength higher than the strength of a body part by inserting the end of the FRP reinforcement in a compression-deformable pipe, and hardening the inserted end with resin to integrate the pipe and the FRP reinforcement. CONSTITUTION: The end of an FRP reinforcement 1 is inserted in a pipe 3 formed to be compression-deformed by compressive force of a tension chuck, and hardened with resin 4 to integrate the pipe 3 and the FRP reinforcement 1. The tension end of the FRP reinforcement can therefore have strength higher than the strength of a body part.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a method for treating the tensioning end of FRP reinforcement, and in particular, when producing prestressed concrete, FRP reinforcement is used instead of PC steel. FR when attaching to the end
The present invention relates to a method for treating the tensioning end of the P muscle.

[Problems to be solved by conventional techniques and ideas] Tensile testing of conventional FRP bars, or when manufacturing prestressed concrete using these FRP bars - as a method for processing the ends of the FRP bars.

a. There is a method of wrapping the ends of the FRP bars using Phyno (-) and resin. There is a method of inserting the ends of the FRP bars into a pipe (steel pipe) and hardening them with resin. Although the ends of the FRP strips treated by the above method a have the same strength as the main body of the FRP strips, the treatment process takes a long time.

In addition, although it can be used on a trial basis, it is expensive and difficult to actually produce it as a product. Furthermore, the strength of the ends of the FRP bars treated by method b is about 70 degrees, and can be used particularly as tension bars in the production of prestressed concrete. I can't. others.

While processing the ends of FRP bars, attempts have also been made to use them as tension bars during the production of prestressed concrete using special chucks.

In this case, the chuck is modified into a special shape for chucking, but in this case as well, the strength of the end portion of the FRP muscle is limited to about 95 coefficients of the body strength of the main muscle of the FRP muscle.

Therefore, it is necessary to find a solution for processing the tensioning ends of FRP muscles that is easy to process, has a strength greater than that of the main body of the FRP muscles, and can be used with existing chucks. Technical problems arise.

[Failure to solve the problem]

This invention was proposed to solve the above problems, and involves inserting the end of an FRP reinforcement into a pipe that is formed to be compressed and deformed by the compressive force of a tensioning chuck. It is an object of the present invention to provide a method for treating the tensioning end of an FRP reinforcement, which is characterized by curing with a resin and integrating the pipe and the FRP reinforcement.

[Effect]

The FRP fiber end treatment method of the present invention is as follows: 1. For example, an appropriate number of slits are opened in the longitudinal direction of a pipe.

Alternatively, it is made by joining two pipes together and leaving a certain gap between them.

An extremely thin-walled pipe or the like is used, and the ends of the FRP bars are inserted into the pipe, hardened, and integrally joined. Alternatively, as another method, the thin-walled pipe etc. is filled with thermosetting resin in advance and -2 is stored at a temperature below about 15°C, and when used, it is heated at about 806°C to 100°C and the thermosetting resin is filled into the pipe. It is also possible to integrate the pipe and the FRP reinforcement by inserting the end of the FRP reinforcement. When using the FRP reinforcement treated in this way as a tension reinforcement in the production of prestressed concrete, the pipe is chucked using a conventional chuck. In such a case, the compressive force of the chuck compressively deforms the pipe, and this compressive deformation is transmitted to the FRP muscle through the resin within the pipe. In other words, a slit is provided in the longitudinal direction of the pipe.

Alternatively, when joining two pieces of pipe with a gap of one foot between them, the rigidity of the pipe itself is reduced due to the presence of the slit or gap, and therefore the compressive force of the chuck is applied to the pipe. will be compressed and deformed. Furthermore, if the ends of the FRP strips are divided into two or four parts and then cured with resin in the pipe and joined together, the adhesion force will increase, and the untreated ends of the FRP strips will be separated. It is extremely economical because the length of the pipe can be reduced by about 50 to 70 times compared to a conventional pipe. This also applies to pipes formed with extremely thin walls. Thus,
The FRP fiber end portion is formed to have a strength higher than that of the main body portion, and the end portion treatment is extremely simple, which can also contribute to cost reduction.

〔Example〕

Ru. This FRP muscle has a strength corresponding to the tension force, and its diameter and length are different depending on the mode in which it is used. (2) is a part where the end of this FRP strip is cut in half or cut into four parts.

In FIGS. 1 and 2, (3) is a pipe, and a steel pipe may be used. Thus, sulins (3a) are provided on both sides of the pipe (3) in the longitudinal direction.

In the - example, a steel pipe with an outer diameter of 8 m, a thickness of 1 m11°, and a length of 751 m was used, and the width of the sulin (3a) was set to 1.5. Then, tape or the like is wrapped around the outer surface of the pipe to close the slit (3a), and then a resin that hardens at room temperature is injected into the pipe (3), and the FRP strip (φ3WII) is injected into the pipe (3). ) was inserted into the pipe (3), the resin (4) was cured, and the pipe (3) and the FRP reinforcement (11) were integrally connected with the resin (4).As a result, The pipe (3) of the FRP muscle (1)
When I chucked it and did a tensile test, it was 212k.
l? /d Tonari, FRP muscle (ruptured at the main body of 11).

What is shown in FIGS. 3 and 4 is another embodiment, and in the same figures, the pipes (5) and (5) are divided into two parts. The pipe may be made of a steel pipe like the pipe (3). As shown in FIG.
), insert the FRP muscle (1) into the other pipe (5)
The pipe (5) is fitted with a cap on the split surface of the pipe (5).

At this time, a slight gap (Ll) was provided between both pipes (5) (5), and the resin was cured and the whole was joined together. Then, a tensile strength equivalent to the above tensile strength was obtained. It is.

In another embodiment, a pipe is formed with a thin wall and can be compressed and deformed by the compressive force of a tensioning chuck (not shown), and two FRP reinforcements (the ends of 11 are inserted into the pipe) are used. It is processed into parts or quarters and inserted, as explained in the previous embodiment.

The entire structure may be integrally constructed by injecting a resin and curing it. When the pipe at the end of the FRP reinforcement (1) formed in this way was chucked and pulled, it was found that it had a tensile strength equivalent to the strength of the main body of the FRP reinforcement (1). did.

As yet another embodiment, when the thin-walled pipe is filled with a thermosetting resin in advance and stored at about 150"C or less, and FRP reinforcement (1) is used as the tension reinforcement material. The end of the FRP reinforcement (1) is inserted into the pipe, and heated and cured at approximately 80°C to 100"C to integrally connect the FRP reinforcement and the pipe, forming the tensioned end of the FRP reinforcement. It can also be processed. The tensile strength at this time also obtained the same results as the tensile test described above.

As described above, in the embodiment of the present invention, the end of the FRP reinforcement inserted into the pipe is integrally connected to the pipe by hardening of the resin, and further, when the pipe is chucked with a chuck and tensioned, The compressive force of the chuck compresses and deforms the pipe, and since the whole is integrated, the pipe is compressed and deformed through the hardened resin.

Since the compressive force is transmitted to the FRP reinforcement, reliable chucking is possible, and there is no possibility that the FRP reinforcement (11) will be pulled out. Strength was obtained.

〔Effect of the invention〕

As described in detail in the above embodiments, the present invention has the following advantages:
Conventional P based on the toughness and tension of FRP muscle itself.
Although it can be used as a substitute for C steel, *
When chucking with the chuck, the end of the FRP strip is transmitted to the FRP strip together with the pipe through the resin that has been cured, thus ensuring reliable chucking, and the FRP strip 17
) There is nothing that will pull you out. Therefore, the F
The tensile end of the RP muscle has greater strength than the main body, and
Since edge processing can be done in a simple process, it can also contribute to cost reduction. In addition, when the ends of the FRP strips are cut into two or four parts, cured with resin inside the pipe, and then joined together, the adhesion force increases, and the FR
The length of the pipe is approximately 50 mm compared to the untreated P-stripe end.
The width can be shortened by 704 mm, and therefore the amount of resin used can be reduced accordingly, making it extremely economical.

Furthermore, the present invention can be modified in various ways without departing from the spirit of the invention - and it is natural that the present invention extends to such modifications.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, Fig. 1 is a side view when a pipe with slits is used, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is a diagram of another embodiment. Side view, Figure 4 Prisoner (Bl
is a vertical cross-sectional view explaining the process of dividing the pipe into two and joining them together, and the tel in the figure is a cross-sectional view taken along the line B-B in Figure 3.
Figure 5 IAI (Bl is a side view of the FRP muscle. Symbol explanation

Claims (1)

[Claims] FRP muscle tensioning characterized by inserting the end of the FRP muscle into a pipe formed to be compressed and deformed by the compression force of a tensioning chuck, hardening with resin, and integrating the pipe and FRP muscle. How to treat the ends.