ELECTROCHEMICAL REALKALISATION TREATMENT USING IMPRESSED CURRENT FOR THE REPAIR OF CARBPNATED REINFORCED CONCRETE-2.5 YEARS DURABILITY

The aim of this study is to assess the durability performance of an electrochemical realkalisation treatment using impressed current applied on artificially carbonated reinforced concrete slabs. After realkalisation, the slabs were firstly stored in the air conditioned laboratory for 18 months and then exposed for 12 additional months to natural ageing. The treatment efficiency until 30 months after treatment is demonstrated by acid/base indicators tests and quantitative pH determinations of the concrete cover. Non destructive electrochemical measurements (rest potential, linear polarisation resistance, impedance and corrosion current) seem to indicate a decrease of the corrosion activity until 12 months after treatment. However the results after 30 months rather indicate a return to the initial corrosion activity state. The SEM observations show that the corrosion layers have not developed after treatment. No cement matrix transformation due to the realkalisation has been observed.