Electrode Process of Rebar in Ca(OH)₂ Solution during Realkalization of Carbonated Concrete

The electrochemical reactions on the rebar during realkalization treatment of carbonated concrete were investigated by using simulation test and electrochemical measurement.The coulomb and the volume of H2 were measured during realkalization treatment,and the electrochemical characteristics of the rebar electrode before and after treatment were compared.The electrode process during the realkalization treatment was discussed according to the experimental results.Results show that the electrochemical reaction on the rebar is closely related with the surface state of rebar electrode.During realkalization treatment,the reduction of ferric oxide or ferrous oxide formed on the surface of rebar will occur in company with the H2 evolution.The realkalization treatment not only resumes the basicity of the carbonated concrete,but also rehabilitates the corroded rebar by reducing the rust to iron.