Studies of Threshold Chloride Levels for Localized Carbon Steel Corrosion in Simulated Concrete Pore Solutions Using Coupled Multielectrode Array Sensors

摘要

Threshold chloride levels for localized corrosion of carbon steel material have been studied in three types of simulated concrete pore solutions: NaOH-KOH with pH 11.6, Ca(OH)_2 with pH 12.6, and NaOH-KOH-Ca(OH)_2 with pH 13.3. The nonuniform corrosion rates of carbon steel were measured with coupled multielectrode array sensors (CMAS) when the chloride concentration was changed from 0.0005 to 1 mol/L in each solution. Open circuit potentials were also measured from the coupling joint of the CMAS probes and electrodes made of rebar specimens immersed in the simulated pore solutions to verify the results from the CMAS probes.