Simulating the Pitting Corrosion of Steel Reinforcement in Concrete

The pitting behavior of steel in solid gels made from alkaline solutions containing chloride ions is shown to be markedly different from the behavior that occurs in the solutions themselves. After an induction period during which composition changes take place at the metalgel interface, pitting can start even at bulk chloride levels at which pitting would not occur in solution. Addition of calcium hydroxide to the gel delays the onset of pitting. Portland cement mortar is a less aggressive environment then the alkaline gels, probably because of the formation of a portlandite layer on the steel surface.