CORROSION INHIBITION EFFECT OF CATHODIC PROTECTION ON REINFORCED CONCRETE WITH CORROSION-INDUCED CRACKS PRETREATED WITH THE PRE-INJECTION OF AN ELECTROLYTE SOLUTION AND CRACK INJECTION REPAIR

Abstract

 This study aims to investigate the corrosion inhibition effect of cathodic protection with the pre-injection of an electrolyte solution and crack injection repair as a pretreatment on reinforced concrete with corrosion-induced cracks. A current supply experiment for 244 days was conducted with mortar specimens with corrosion-induced cracks generated by dry-wet cycling. The collected data through the experiment includes the repair condition of the speci-mens, the growth of the corrosion-induced cracks, the amount of cathodic polarization and polarization characteristic of the rebar, and the corrosion mass loss of the rebars. The average corrosion mass loss of the specimens pretreated with the pre-injection of a 10 % calcium nitrite solution and the subsequent injection of ultrafine particle cement was suppressed by 65% compared to the specimens without pretreatments and cathodic protection. This corrosion inhi-bition effect was mainly attributed to the passivation of the corroded rebar by nitrite ions and the improvement of the electrical conductivity between the rebar and surrounding concrete by the electrolyte solution.