Influence of chloride acceleration methods on the electrochemical behaviour of superplasticiser admixed reinforced cementitious systems

• Published in: Asian Journal of Civil Engineering
• Main Author: Hemalatha C.; Mohammed M.S.H.S.; Vijayaraghavan R.; Navabshan I.; Kudus S.A.
• Format: Article
• Language: English
• Published: Springer Nature 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85205575472&doi=10.1007%2fs42107-024-01182-x&partnerID=40&md5=fb26ac82fc5fcb93521e6862397e1b32

The presence of chloride ions in concrete is one of the major causes of the corrosion of steel rebar in concrete. The chloride threshold to initiate corrosion in cementitious systems is determined using diffusion and migration-based methods. This study investigates the influence of chloride acceleration methods on the electrochemical behaviour of superplasticiser admixed reinforced Portland pozzolana cementitious systems by conducting an impressed voltage test (IVT) and electrochemical impedance spectroscopy (EIS) technique. The chloride threshold range for crack/corrosion initiation in steel rebars in IVT and EIS techniques is found to be 0.07–0.09% and 0.19%–0.24% respectively. The SEM and EDS analysis of samples collected from the failed specimen of IVT and EIS test exhibits intact microstructure and hydration despite electrochemical acceleration in the tested duration for the control and SP admixed mortar specimens. The performance factors obtained for SP admixed systems for IVT and EIS techniques are in the range of 4–7.35; and 1.4–1.7 respectively. The inconsistent performance factor and chloride threshold values for IVT and EIS techniques suggest the uniqueness of these tests. Impressed voltage electrochemical studies at a lower voltage will be a viable tool to assess the corrosion initiation in the RC systems at a short test duration as compared to the EIS test. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.