GFRP Corrosion-Resistant Coating: Ensuring the "Century-Long Lifespan" of the Hong Kong-Zhuhai-Macao Bridge

Recently, as the HZM Bridge continues to operate stably, the key durability technology behind it—glass fibre-reinforced epoxy resin (GFRP) corrosion-resistant coating—has drawn attention.

As the world's longest cross-sea bridge, the HZM Bridge is designed with a service life of 120 years, imposing stringent requirements on the corrosion-resistant technology for its critical steel pipe composite piles. The GFRP corrosion-resistant coating plays an irreplaceable role in this regard.

The GFRP corrosion-resistant coating isolates the steel pipe piles from corrosive media such as seawater, preventing corrosive factors from eroding the steel pipe piles and significantly reducing the occurrence of corrosion, thereby extending the lifespan of the steel piles.  The coating's bond strength to the substrate is more than twice that of similar products domestically and internationally，demonstrating exceptional water resistance and waterproofing capabilities. Additionally, it possesses strong resistance to stress corrosion and pitting corrosion.

From the point of view of actual protection effect, after 10 years of service in the marine environment, the coating thickness retention rate reaches 95%, compared with the traditional anticorrosion programme, the life expectancy has been extended by 3 times, which strongly guarantees the 120-year durable design requirements of the HZMB.