Chloride transport accelerated via modest electromigration as a means to initiate corrosion of the steel reinforcement

Abstract

Specimens with binary (SL, FA) and ternary (T1, T2) concrete mixes (30.5 cm x 12.7 cm x 7.6 cm) were prepared without any chlorides, using a w/cm ratio of 0.41 or lower. Each specimen, reinforced with #3 rebar, have a 0.75 cm concrete cover. The specimens had reservoirs of varying lengths on their top surface. A 10% NaCl solution by weight was introduced into the reservoirs, and electromigration was applied for a period ranging from few weeks to several months to accelerate chloride transport. Corrosion current values were monitored for approximately 1600 days using galvanostatic pulse techniques and converted to mass loss using Faraday’s law. The SL mix specimens showed the highest average corrosion current values, followed by FA, T1, and T2 mix specimens. Despite the prolonged exposure, no visible corrosion such as cracks or surface-reaching corrosion products were observed over the monitoring period.