CEMENT & CONCRETE COMPOSITES (Elsevier Ltd.)
Twenty-two-year investigation of strength development and surface deterioration of cement-treated clay in an in-situ field test
Hidefumi Izuo, Kenichiro Nakarai, Dmitrii A. Kulik
CEMENT & CONCRETE COMPOSITES, Volume 134, November 2022
(https://doi.org/10.1016/j.cemconcomp.2022.104783)
Abstract
The long-term strength development and durability of in-situ cement-treated soil were investigated by physicochemical analysis and geochemical thermodynamic modeling. The measured strength of the volcanic cohesive clay treated with high-sulfate cement continuously increased for five years and then persisted until 22 years. X-ray analysis revealed that the ettringite formation through cement hydration contributed to the early strength, while the stratlingite formation through pozzolanic reaction contributed to the long-term strength. Thermodynamic modeling pointed at the alumina dissolution from the treated clay in an alkaline environment as the main driving force for the pozzolanic reaction. Further, calcium leaching and carbonation caused surface deterioration of the cement-treated soil, thereby decomposing the hydration products and lowering the strength of the treated clay.