Busan-Geoje fixed link: Concrete durability design for the bridgesand tunnels

摘要

The concrete structures of the bridges for the Busan-Geoje Fixed Link (South Korea) shall be designed for 100 years service life.To achieve the 100 years service life for the concrete structures in the envisaged environment is a very demanding task that can not be fulfilled with traditionally used over-simplistic durability approaches which are based on so-called deemed-to-satisfy rules. Examples of such deemed-to satisfy rules are requirements to minimum concrete cover, maximum water/cement ratio, and minimum cement content. These traditional durability approaches provide only qualitative definitions of exposure and they fail to define the design life in relation to durability. This makes it important that similar to the current procedures for structural design, a performance based durability designs is incorporated in the present project which takes into account the probabilistic nature of the environmental aggressivity, the degradation processes and the material properties involved. Therefore, a probabilistic based durability approach has been adopted as part of a rational design basis for the reinforced concrete bridge structures of the Busan-Geoje Fixed Link to document the required service life and the acceptable level of reliability.