Durability of Impressed Current Realkalization Treatment Applied on Reinforced Concrete Slabs after 5 years

The aim of this study was to explore the durability of a realkalization treatment using impressed current. Therefore, reinforced concrete slabs were cast and artificially carbonated. Carbonated slabs were then realkalized using an impressed current of 1A/m² of steel following the CEN/TS 14038-1 specification [CEN/TS 14038-1 2005]. The durability of the treatment was determined by several electrochemical measurements and analytical characterizations, at different times after its application, up to 5 years. Rapidly after the treatment, its efficiency was demonstrated both by a realkalization of the concrete matrix revealed by phenolphthalein tests and by a lowering of the corrosion current density values [Tong 2008]. But 5 years after realkalization, including 3.5 years of natural aging, although an alkaline concrete zone was still surrounding the rebars, both the rest potentials and corrosion rate were almost back to their initial values. SEM observations corroborated those results revealing the presence of large corrosion spots on the steel rebars