Requirements and possible simplifications for multi-ionic transport models - Case of concrete subjected to wetting-drying cycles in marine environment

The results show that when the initial amounts of hydration products are known, the assessment of the chloride binding parameters is not needed. In addition, including reaction kinetics in the model is essential and improves the predictions compared to a pure thermodynamical approach. Moreover, according to sensitivity analysis the boundary layer thickness that reflects the evaporation kinetics and the “intrinsic” permeability are not important parameters for the studied concrete. Updating at each time step the transport properties in order to account for dissolution/ precipitation of mineral species does not change very much the chloride content profiles as well. Furthermore, simulations carried out in saturated conditions provide similar results to those obtained when accounting for wetting-drying cycles for the studied concrete. Then, it may be possible to use a simpler model (ie saturated conditions), and thus avoid the problematic assessment of the “intrinsic” permeability, to predict the service life of a RC structure cast with the concrete studied.