Performance-based assessment of durability and prediction of RC structure service life: transport properties as input data for physical models

This paper deals with an approach based on durability indicators (DIs), intended for the assessment of the durability and the prediction of the service life (SL) of reinforced concrete structures with respect to reinforcement corrosion. The methods of assessment of the DIs, more specifically of the transport properties effective chloride diffusion coefficient and “intrinsic” liquid water permeability, are first investigated. Direct experimental methods, indirect methods based on simple analytical formulas, as well as numerical inverse analysis which involves the same physical models as used for prediction, are compared. Very good agreement is pointed out between the results obtained by the various methods for a broad range of materials. The effect of SCM, as well as of accelerated carbonation in the case of permeability, is also investigated. 1-D numerical models of moisture or ionic isothermal transport are then introduced, where the selected DIs are the main input data. Simulations carried out with the moisture transport model are compared to moisture profiles measured by gamma-ray attenuation, in order to validate the model and the input data (permeability). With regard to chloride ingress, examples of application of the multispecies transport model (saturated conditions) are provided for concentration profile prediction, in lab and in field conditions, as well as SL prediction.