Material Alternatives for Concrete Structures on Remote Islands: Based on Life-Cycle-Cost Analysis

Abstract

Corrosion is an unavoidable problem for RC structures in harsh marine environment, which encourages the application of high-performance concrete (HPC) and corrosion-resistant reinforcements, such as stainless steel (SS), stainless-clad bimetallic steel (SB) and FRP. Especially, for the RC structures in remote islands or reefs, the use of local materials (coral, sea water, etc.) may bring cost benefits by avoiding the high expansive fee. In this paper, the cost effectiveness of five different material proposals is evaluated and compared based on the life-cycle-cost analysis (LCCA), incorporating not only initial cost but also long-term investment into account. The LCCA results of a 3-floor office building in the South China Sea shows that basically the SB + HPC proposal shows the highest cost benefits considering a 100-year period while the proposals using coral aggregate seawater concrete (CASC) are not that competitive. The sensitivity analysis is performed to address the influence of discount rate and construction-to-material cost ratio.