ABSTRACT
Singapore’s Deep Tunnel Sewerage System Phase 2 was designed to service the city-state’s southwestern wastewater management region. This project features ~40 km of tunnels, ranging in diameter from 3 m to 6 m. To meet the 100-year design service life, a special concrete mix was developed to combat microbiologically induced corrosion (MIC). Through trans-continental cooperation, concrete samples produced in Singapore were shipped to Kiwa’s “ODOCO” Pilot Plant in Berlin. These samples underwent a comprehensive testing regime involving exposing the concrete to real wastewater at highly aggressive conditions. The objective was to estimate the corrosion rate and sacrificial cover thickness needed to meet the structure’s service life. The samples exhibited favourable MIC resistance, resulting in a minimal sacrificial layer of 35-45 mm. This report describes the specifics of the concrete composition, the testing facility, the methodologies employed, and the resultant outcomes. It offers insights into the innovative materials and methods used to maximize longevity and durability of this infrastructure.
