Comparison of experimental and modelled pore solutions of low-pH Ordinary Portland Cement based mix designs

Posiva Oy is constructing one of the world's first long-term nuclear waste repositories in Fin-land. Cementitious materials will be in direct contact with backfill and closure materials. It is assumed that cementitious leachates will interact with backfill and closure materials but not to extent that compromises the long-term safety of the barrier system. In this study, existing modelling tools were compared to experimental samples. Applicability to model the low-pH cementitious materials pore solution compositions was evaluated. Accurate modelling will enable long-term evaluation of the cementitious leachates effect to the backfill and closure materials