The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel, which is a complex solid exhibiting incongruent dissolution behaviour. Quintessa has carried out a range of modelling studies for this system using the Raiden reactive geochemistry and transport code.
For example, it has been shown that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most Simulations have been carried out at a reduced 'experimental' scale and at the full repository scale.