Hong Kong International Airport Expansion, Hong Kong, China

Since its opening in 1998, Hong Kong International Airport (HKIA) has been recognized by flyers and industry experts as a global leader in passenger and cargo transport. It is a regional aviation hub for flights between Europe, the Americas, Asia, and Oceania. HKIA handles a significant volume of passengers and freight, placing it among the world's top airports. To accommodate the busy transportation demand, Airport Authority Hong Kong (AAHK) initiated the airport’s expansion into a three-runway system (3RS) began in 2016. The success of this expansion is vital for the airport's future operations and ability to handle passengers and cargo efficiently.

The Hong Kong International Airport was built on an artificial island reclaimed from the sea. Foundation difficulties such as insufficient bearing capacity, detrimental settlement, or troublesome groundwater problems are almost unavoidable. In addition, because of the high traffic volume and tight flight schedule, it's crucial to reduce the inevitability, frequency, or difficulty of maintenance or restoration to ensure successful operations.

Although foundation piles have supported the main structure, significant subgrade differential settlements are highly likely because of underlying weak strata. In addition, punching shear failure of the pavement structure is also possible because of the concentrated stress of the pile heads. To mitigate this issue, the designer incorporated cushion materials between the pavement structure and the pile heads. These materials consist of layers of general and granular fill. In addition, the designer further used high-strength ACETex^® to wrap around these cushion materials to protect them from washing by the groundwater.
Because ACETex^® has exceptional separation and reinforcement properties, it enables the membrane effect to be fully developed in case of loading. The imposed structural stress can then be evenly distributed, thus reducing differential settlement and punching shear, ensuring the concrete pavement's stability.

The constructed facility was placed in service after completion in 2022. Its performance has complied with the expected target, indicating that the use of ACETex^® has successfully fulfilled its intended design function. As a result of the success of this project, the other medium-sized runway also will be temporarily closed. It will perform maintenance procedures following this project's achievement to ensure better future service.