Change In Pore Structure And Composition Of Hardened Cement Paste During The Process Of Dissolution

摘要: An understanding about the dissolution phenomena of cement hydrates is important to assess changes in long-term performance radioactive waste disposal facilities. To investigate alteration associated with dissolution, tests ordinary Portland (OPC) were performed. Through observation samples after leaching, it was confirmed that ettringite precipitation increased as portlandite and C-S-H gel progressed. EPMA performed on cross-sections solid phase showed a clear difference between altered unaltered parts. The boundary two parts termed (CH) front. As leaching period became longer, CH front shifted toward inner part sample. A linear relationship derived by plotting distance moved against square root time. This indicated Ca ion movement diffusion.