An Accelerated Approach to Study Corrosion Initiation and Propagation on Specimens Prepared with CRA Rebars

Most corrosion experiments conducted on reinforced concrete are terminated upon corrosion initiation. This paper presents preliminary results on corrosion initiation and propagation on three corrosion resistant alloys (CRAs). Two types of experiments were conducted: CRAs exposed to simulated pore solution (with chloride concentration gradually increased), CRAs embedded in mortar specimens (most with 0.5 w/c ratio) with a reduced cover (~10 mm) exposed to 15% (m/m%) NaCl (initially permanent ponding and later alternate ponding). Three surface conditions were tested on each CRA type: as received, with mill scale, with mill scale then sandblasted. The open circuit potential was monitored over time. Linear polarization resistance and solution resistance were measured periodically. In this research the experiments were not terminated upon corrosion initiation, rather exposure continued to gain a better understand how corrosion propagates. No cracks have appeared on the mortar specimens with the CRA actively corroding.