Current Progress in Corrosion Inhibition of Reinforcing Steel in Concrete using Migrating Corrosion Inhibitors

摘要

Several migrating corrosion inhibitors for reinforced concrete were investigated using ASTM G109 and Modified G109. XPS depth profiling showed a 90-100 nm amine-rich layer and chloride ions on the steel rebar surfaces indicating that the modified corrosion inhibitor molecules had suppressed chloride ion interaction and protected the steel rebar passivation layer. There is no indication of corrosion after 400 days of testing. The inhibitor treated samples showed improved resistance polarization (Rp was in the 50 kohm to 60 kohm range, corrosion potentials ranged between -64 mV and -103 mV) and potentiostatic tests showed a significantly lowered corrosion rate. These findings led to investigating the adsorption mechanism where comprehensive testing established a Langmuir adsorption isotherm and verified that chemisorption was responsible for the strong bonding between the inhibitor monolayer and the steel surface.