钢筋混凝土阴极保护机理及其表征

For the purpose of exploring the mechanism underlying the efficiency of cathodic protection, X-ray diffraction (XRD) coupled with scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) techniques were applied for microstructural analysis of corrosion products and steel/concrete interface. The study shows that cathodic protection is beneficial for the existence of passive film, while more of the common corrosion product Fe3O4 presents for specimens without protection. Besides, corrosion product of Fe3+(O, OH, Cl)－ can be found when chlorides are abundant in concrete. Cathodic protection is helpful for the formation of Ca(OH)2 crystal, thereby keeping the high alkalinity of the steel/paste interface. It is observed that chloride ions are mitigated away from the steel surface. These effects guarantee the efficient protection of steel reinforcement.