Citation
Garcia Calvo, Jose Luis and Hidalgo, A. and Fernandez Luco, L. and Alonso Alonso, Maria Cruz
(2010).
Development of low-pH cementitious materials for HLRW repositories. Resistance against ground waters aggression.
"Cement and Concrete Research", v. 40
(n. 8);
pp. 1290-1297.
ISSN 0008-8846.
https://doi.org/10.1016/j.cemconres.2009.11.008.
Abstract
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/SiO2 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
