JPS5846597B2 - Corrosion prevention method for cables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved corrosion protection method for sheathed cables such as suspension cables.

Conventionally, corrosion protection for sheathed cables such as suspension cables has been carried out by filling the sheath with mortar, but in this case, if the cable is bent due to external forces such as wind while in use, the mortar will form near the socket. There was a problem in that cracks formed in the steel and the anticorrosion function was inhibited.

Furthermore, the filling of the mortar is carried out by injecting the mortar through a hole formed in the sheath near the socket on the lower end of the sheathed cable and discharging it from the hole on the upper end. had the disadvantage that air remained and the mortar filling was incomplete.

In order to prevent such incomplete corrosion protection, a highly ductile material such as tar epoxy may be used as the mortar, but in that case the material cost would be very high and thus would be impractical.

The present invention aims to solve these conventional drawbacks, and provides a corrosion prevention method that does not require high material costs and can reliably perform its anticorrosion function.

The present invention provides a method for anticorrosion treatment of a sheathed cable, which includes applying a highly ductile anticorrosion coating to the outer peripheral surface of the cable near the socket, and then injecting mortar through an injection port formed in the sheath near the socket. A double anti-corrosion layer is formed by this method, and the anti-corrosion function is perfected.

In addition, as a specific method for forming a double anti-corrosion layer,
The sheath near the socket at both ends has an injection port close to the socket and a discharge port a predetermined distance away from the socket, and a highly ductile anticorrosive material is injected through the injection port and overflows from the discharge port. After the mortar is discharged from the injection port, an anticorrosion coating is applied to the outer circumferential surface of the cable from the socket to the discharge port, the discharge port is sealed, and mortar is injected from the injection port. .

Hereinafter, the present invention will be explained with reference to drawings of embodiments.

In Fig. 1, 1 is a sheathed cable, a cable 2 is provided with a sheath 3, sockets 4 and 5 are fixed to both ends of the cable 2, and sockets 4 and 5 are attached to the outer peripheral surface of the cable 2 near the sockets 4 and 5. Only a portion 8 coated with a highly ductile corrosion-resistant material is formed.

Further, a mortar injection port 6 and a discharge lower are formed in the sheath 3 at positions close to the sockets 4 and 5.

In this way, anti-corrosion is applied to the outer peripheral surface of the cable near the socket by an appropriate method, and then mortar is injected from the injection port 6 and discharged from the discharge lower, thereby filling the gap 11 between the cable 2 and the sheath 3 with mortar. Fill it with.

The method shown in FIGS. 2 and 3 can be used to form the portion 8 coated with highly ductile anti-corrosion material, and the length of the portion can be set accurately. can.

That is, a discharge port 9 is formed in the sheath 3 at a predetermined distance from the socket, and as shown in FIG. A food material 10 is injected and overflowed from a discharge port 9.

Next, as shown in FIG. 3, the injected corrosion protection 10 is discharged from the injection port 6, leaving the corrosion protection 10 only in the area from the injection port 6 to the end face of the socket 4, and is then hardened.

As a result, a portion 8 coated with corrosion protection is formed on the outer peripheral surface of the cable 2 from the socket 4 to the discharge port 9.

Next, apply anti-corrosion treatment to the cable end on the other end side in the same manner, and after sealing the discharge port 9, resin or cement mortar is injected from the injection port 6 and discharged from the discharge port 1 at the other end. The gap 11 between the cable 2 and the sheath 3 is filled with mortar.

Even if the sheathed cable formed in this way is bent during use and the socket area is bent and the mortar cracks, the outer surface of the cable is coated with a highly ductile anti-corrosion coating. This achieves the anticorrosion function.

Furthermore, since this highly ductile anti-corrosion material is only applied where it is needed and only a small amount is used, the cost of materials does not increase.

In order to confirm the effect of applying this anti-corrosion coating, a comparative test was conducted in the following manner, with and without coating the anti-corrosion coating on the cable.

That is, a bundle of seven wires with seven diameters is used as a cable, and by irradiating it with ultraviolet rays, a temperature change of 30 to 50 degrees Celsius is controlled.
A wazaometer exposure test was conducted in a time cycle and with salt spray applied at a rate of 10 minutes per hour.

As a result, the cables that were not coated with corrosion protection developed rust after 0.2 hours, but the cables that were coated with tar epoxy corrosion protection did not develop rust for 310 hours.

This shows that the method of the present invention provides very good corrosion resistance.

If the method shown in Figs. 2 and 3 is adopted as the method of applying the anti-corrosive material, the preliminary anti-corrosive material can be filled in advance only in the area close to the socket. The problem of residual air bubbles is also eliminated.

Furthermore, since preliminary corrosion protection near the cable end can be performed at the factory during cable manufacture, it can also serve as a temporary corrosion protection until the cable is installed.

[Brief explanation of drawings]

FIG. 1 is a partially cut away longitudinal sectional view of a cable in which the method of the invention is carried out, and FIGS. 2 and 3 are longitudinal sectional views during and after application of a preliminary anticorrosive agent at the end thereof.

Claims (1)

[Claims] 1. In a method for anti-corrosion treatment of a cable with a sheath, a highly ductile anti-corrosion coating is applied to the outer peripheral surface of the cable in the vicinity of the socket, and then mortar is poured into the sheath through an injection port formed in the sheath in the vicinity of the socket. A cable corrosion protection method characterized by injection. 2. In a method of anti-corrosion treatment for sheathed cables, an inlet is formed in the sheath near the socket at both ends on the side close to the socket, and an outlet is formed at a predetermined distance away from the inlet, and the ductile After injecting an anti-corrosion rich in anti-corrosion and allowing it to overflow from the outlet and discharging it from the inlet, the anti-corrosion is applied to the outer circumferential surface of the cable from the socket part to the outlet part, and then the above-mentioned outlet is sealed and A cable corrosion protection method characterized by injecting mortar from the entrance.