Corrosion of embedded steel remains a major challenge for civil infrastructure, imposing significant economic costs in the United States. Emerging cementitious binders such as portland limestone, calcium aluminate, and calcium sulfoaluminate cements have distinct chemistries that can alter corrosion processes in reinforced concrete. Although reinforcement corrosion has been widely studied, most research has focused on sodium-chloride–induced corrosion in ordinary portland cement (OPC). Current building-code parameters (diffusion coefficients, cover depth, chloride limits) are effective for OPC systems, but alternative binders modify pore solution pH and ionic composition, introducing additional complexity. This study examines the electrochemical behavior of reinforcing steel in simulated pore solutions representing portland-limestone cement, OPC, and calcium sulfoaluminate cement. Solutions were prepared using chemical analyses from pore-press extraction of mortar samples. Corrosion potential and pH of as-received and polished rebar were monitored over 60 days to evaluate the influence of binder chemistry on passivation. Electrochemical impedance spectroscopy (EIS) was performed to understand passive film properties. Potentiodynamic polarization with incremental chloride additions was used to identify the critical chloride threshold for pitting and corrosion rate measurements. Passive film composition will be characterized by X-ray photoelectron spectroscopy (XPS). These results will provide essential data on corrosion performance in non-OPC systems and support the development of standardized test methods for reinforced concrete with alternative binders.
