Electrochemical re-alkalinization applied to carbonated concrete beams samples under the criteria of three standards

Abstract The effect of electrochemical re-alkalinization was evaluated by applying the standards UNE-EN-1504, NACE-SP0107-2007 and NMX-C-553-ONNCCE-2018, on previously carbonated reinforced concrete samples. With the monitoring of the degree of re-alkalinization, through pH and half-cell potential measurements at 7, 14, 21 and 28 days, pH recovery is observed in all cases, obtaining characteristic half-cell potential values in each current application, which confirms the polarization of the steel modifying the thermodynamic condition of the concrete-steel interface and causing chemical changes in the concrete paste. With the NMX-C-553-ONNCCE-2018 standard, the steel was polarized without reaching the overprotection region, avoiding the risk of producing hydrogen and brittleness in the steel.