The main aim of ESR2 is to numerically investigate the chloride transport mechanisms inside the microstructure of AAMs (through the cover material and up to the steel-concrete interface) at different ages, and to obtain the time-dependent permeability and chloride diffusivity parameters suitable to be used in meso-scale simulations. The work of ESR2 will also be based on the developments attained during the 1st year of ESR3, which will bring about the availability of the initial simulated microstructures of AAMs. A detailed understanding of the chloride transport and binding mechanisms in AAMs will be experimentally obtained in ESR8, and will provide the data needed for the development and validation of the model. A lattice Boltzmann multi-ionic reactive transport model will be developed as the framework for the simulations, taking into account transport of moisture and ionic species through the pore structure of AAMs as defined in ESR3. To achieve this, model architectures recently developed in USFD and in TUD will be further extended to account for saturated/unsaturated multi-ionic transport and to consider the chloride binding mechanisms in AAMs. Results will be directly useful in ESR9 to enable specific design of structural elements for service in various exposure conditions.
It is expected to obtain the time-dependent chloride diffusion coefficient. The results will be validated by the results of ESR8 and will be used as input for ESR9.