Anti-corrosion construction process for bridge cable anchor heads

Introduction to the New Type of Bridge Cable Sealing System

A new cable sealing system is adopted for the cable guide section at the beam end: a rain cover + (the new cable sealing system is installed at the outlet of the pre-embedded steel pipe). At the anchor end, anti-corrosion grease is applied to the anchor surface + anchor protective cover (from top to bottom). The joint with the cable body PE is sealed with silicone + rubber sealing ring.

1. Recommendation: Add a new cable sealing system to the cable guide section at the beam end.

2. Composition of the New Cable Sealing System

The high-strength aluminum alloy airbag sealing system (new cable sealing system) mainly consists of a high-strength aluminum alloy airbag, a transition sealing rubber ring, polyurethane sealant, and viscoelastic anti-corrosion tape. It is a new sealing technology for the joint between the cable body and the pre-embedded guide, independently developed by Zhuzhou Wanquan Technology Co., Ltd.

3. Working Principle of the New Cable Sealing System

The new sealing technology uses a high-strength aluminum alloy airbag filled with pressurized gas to apply pressure to the cable body and the wall of the pre-embedded guide, forming a blocking isolation layer to prevent rainwater and air from entering the pre-embedded guide, achieving a complete seal. The sealing method at the junction of the stay cable and the pre-embedded conduit was changed from contact sealing or adhesive sealing to pressure sealing.

4. Application Performance of the New Cable Sealing System The Ningbo Daxie Second Bridge was installed in December 2012. The first inspection of the entire bridge's sealing system was conducted in June 2014, and a second inspection was conducted in May 2015. After nearly three years of use, not a single cable sealing system failed. This proves that the new cable sealing system is technically mature and reliable, and has high practical value.