Answering this question requires an understanding of the concrete, the coating and the localized environment; however, epoxy-coated bars are routinely specified for structures with a desired 75 year design life and often for structures with a 100-year design life, given an appropriate concrete.

In environments subjected to marine or deicing salts, corrosion initiates when sufficient chloride ions reach the reinforcing steel. The time for these salts to reach the bars is dependent on the concrete permeability and the amount of cracking in the concrete as well as the exposure conditions.

The permeability of concrete depends on the water-cement ratio as well as the presence of pozzolans including fly ash and silica fume or various concrete additives that impart water resistance. When uncoated reinforcing is placed in cracked concrete, corrosion initiates almost immediately the concrete is placed in contact with the salt solution; thus, the presence of cracks will significantly reduce the repair -free life of a structure.  Epoxy-coated bars have been found to perform well in cracked concrete compared with the use of concrete modifications alone.

To optimize the design life of structures that use epoxy-coated bars, it is recommended that high quality concrete is used with appropriate cover over the reinforcing and that cracks in the concrete are repaired.