Development of low-pH cementitious materials for HLRW repositories Resistance against ground waters aggression

作者：Garcia Calvo J L; Hidalgo A; Alonso C; Fernandez Luco L

来源：Cement and Concrete Research, 2010, 40(8): 1290-1297.

DOI：10.1016/j.cemconres.2009.11.008

• Low-pH cements
• Hydration
• Long-term performance
• Radioactive waste

One of the most accepted engineering construction concepts of underground repositories for high radioactive waste considers the use of low-pH cementitious materials. This paper deals with the design of those based on Ordinary Portland Cements with high contents of silica fume and/or fly ashes that modify most of the concrete "standard" properties, the pore fluid composition and the microstructure of the hydrated products. Their resistance to long-term groundwater aggression is also evaluated. The results show that the use of OPC cement binders with high silica content produces low-pH pore waters and the microstructure of these cement pastes is different from the conventional OPC ones, generating C-S-H gels with lower CaO/SiO(2) ratios that possibly bind alkali ions. Leaching tests show a good resistance of low-pH concretes against groundwater aggression although an altered front can be observed.

• 出版日期2010-8