Corrosion Initiation Projection for Reinforced Concrete Exposed to Chlorides--Part II: Corrosion Resistant Bars

A model is proposed for projecting the time for, first, reinforcement corrosion initiation and, second, surface cracking of concrete exposed to chlorides.  The approach for the former parameter (corrosion initiation) is based upon the one-dimensional solution to Fick’s second law of diffusion treating all input parameters, including 1) reinforcement cover (x), 2) critical chloride concentration (C_T), 3) surface chloride concentration (C_S), and 4) the effective diffusion coefficient (D) as distributed rather than discrete.  Time to concrete surface cracking, on the other hand, is a function of x and D, which remain distributed here also.  Example calculations are made based upon historically reported data for various structures, and projections are made regarding surface life that should be realized with various materials combinations.