ANALYTICAL CHARACTERIZATION OF THE PASSIVE FILM FORMED ON STEEL IN SOLUTIONS SIMULATING THE CONCRETE INTERSTITIAL ELECTROLYTE

Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) were used to study the effect of chloride (Cl-) and fly ash on behavior of the passive film formed on steel in solutions simulating t he concrete interstitial electrolyte. Results showed the presence of f ly ash and of Cl- led to an increase in the amount of iron oxyhydroxid e (FeOOH) in outer layers of the film and to an increase in the thickn ess and water content of the passive film. Significant differences in composition and thickness were observed between the films formed in pa ste solutions and in calcium hydroxide (Ca[OH](2)) solutions.