General Information

Figure 1 shows a cable-stayed bridge that is used by motorcycles, bicycles and pedestrians.

Cable-stayed bridge.
Cable-stayed bridge over a river.
Type Single-span cable-stayed bridge
Main span ≅ 125 m
Deck width ≅ 1.5 m
Girder Steel twin I-girder
Pylon Reinforced concrete (A-type, longitudinal)
Stay cable arrangement Radial (two cable planes)

Grease Coating

Figure 2 shows a stay cable in the main span region.

Stay cable.
Coated stay cable and coated U-bolt clamps.

The stay cable (steel wire rope) and the U-bolt clamps are coated with grease. Figure 3 shows the anchorage region.

Anchorage region.
Anchorage region.

The stay cables are connected to the RC block by turnbuckles and additional cables terminated with U-bolt clamps. All structural members (except the RC block) are grease-coated. Two coated turnbuckles are shown in figure 4.

Coated turnbuckles.
Two turnbuckles coated with grease.

The coat layer is about 5 mm thick. Figure 5 shows the additional cables in the RC block region.

Additional cables (RC block region).
Cables embedded in concrete.

Non-coated regions near the concrete surface are noticeable.

  • What is the purpose of the above shown coating? What are the main pros and cons?
    What are some possible causes for the non-coated regions near the concrete surface?