ABSTRACT
In view of the limited chemical fixation capability of portland cement [19], leachability is dependent to a large extent on the physical containment of the waste. Thus, the pore microstructure is of prime importance for evaluating long-term containment. In this paper, the pore microstructure was interpreted by two independent methods: solvent exchange and impedance spectroscopy. In the former method a saturated specimen is immersed in a relatively large volume of solvent that is miscible with the pore solution. The weight loss of the specimen is caused by counter diffusion of the solvent into the specimen and the original pore fluid into the surrounding and it should be related to the transport properties of the specimens.
