Hierarchical life-cycle design of reinforced concrete structures incorporating durability, economic efficiency and green objectives

Current structural design methods mostly emphasize the short-term structural behavior while neglect the long-term performance, social effects and environmental impacts. To address these problems, the Life-Cycle Design (LCD) method considering environmental impacts and structural deterioration could be adopted within the design process to ensure that the structural performance satisfies various objectives. Due to the complexity and the long lifespan of engineering structures, as well as the lack of standardized design approach, studies and application of LCD that cover all the design objectives are limited. This paper proposes a hierarchical LCD method for concrete structures by combining traditional design with green design and other engineering aspects. The design process is divided into six levels that cover the aspects of structural safety and reliability, durability, economic efficiency, local environment, social impacts, and global environment. The proposed design method is then applied to a reinforced concrete highway bridge in marine environment for the purpose of illustration, and a comprehensive comparison between traditional design and the hierarchical LCD approach is made within six design levels. A brief discussion on the hierarchical LCD framework and the future works is presented before conclusions are made.