Abstract
The application of cement-based materials in deep-sea environments presents serious durability challenges due to high hydrostatic pressure and low temperatures. This study reviews previous research and presents new findings from field exposure tests, including a 3-year exposure at 3500 m depth. Portland cement (PC) and blast furnace slag (BFS)-blended systems exhibited severe degradation, with BFS-based specimens showing complete disintegration. Microstructural analysis revealed calcium leaching, C–S–H decalcification, and secondary phase formation such as ettringite and Mg-based hydrates. In contrast, calcium aluminate cement (AC) demonstrated excellent resistance, retaining its shape and chemical integrity even after long-term exposure. Thermodynamic modelling partially supported these observations, indicating hydrate destabilisation at low temperatures. Additional tests confirmed that AC mortar can be stored as slurry and placed underwater without segregation, offering both chemical and practical advantages. Despite these findings, questions remain regarding in-situ mechanical performance, phase transformation behaviour, and binder optimisation. To address these, we have launched a new deep-sea durability research project aimed at identifying and validating next-generation binders for subsea infrastructure.
Keywords
deep-sea durability, supplementary cementitious materials, calcium aluminate cement, phase transformation, thermodynamic modelling.
DOI
10.5703/1288284318120
Recommended Citation
Takahashi, Keisuke; Kawabata, Yuichiro; and Wong, Hong, "Durability of Cement-based Materials in Deep Seas: A Review of Chemical Aspects with New Results" (2025). International Conference on Durability of Concrete Structures. 6.
https://docs.lib.purdue.edu/icdcs/2025/ddm/6
Durability of Cement-based Materials in Deep Seas: A Review of Chemical Aspects with New Results
The application of cement-based materials in deep-sea environments presents serious durability challenges due to high hydrostatic pressure and low temperatures. This study reviews previous research and presents new findings from field exposure tests, including a 3-year exposure at 3500 m depth. Portland cement (PC) and blast furnace slag (BFS)-blended systems exhibited severe degradation, with BFS-based specimens showing complete disintegration. Microstructural analysis revealed calcium leaching, C–S–H decalcification, and secondary phase formation such as ettringite and Mg-based hydrates. In contrast, calcium aluminate cement (AC) demonstrated excellent resistance, retaining its shape and chemical integrity even after long-term exposure. Thermodynamic modelling partially supported these observations, indicating hydrate destabilisation at low temperatures. Additional tests confirmed that AC mortar can be stored as slurry and placed underwater without segregation, offering both chemical and practical advantages. Despite these findings, questions remain regarding in-situ mechanical performance, phase transformation behaviour, and binder optimisation. To address these, we have launched a new deep-sea durability research project aimed at identifying and validating next-generation binders for subsea infrastructure.
