Mechanical behavior of steel reinforcement before and after flame spray coating in marine environment

Abstract

Corrosion of steel reinforcement is a major concern for durability of Reinforced Concrete (RC) infrastructure. In particular, corrosion of reinforcement raises important issues for reinforced concrete design and assessment, since it can impair not only the appearance of the structure, affecting the cross sectional area of reinforcement with the subsequent degradation of strength and ductility properties of steel and, ultimately, structural integrity of each structure. As it is widely known, international scientific community up to date, used various methods so as to increase the corrosion resistance of steel. In this context, in the present study, specimens of steel reinforcing bars - B500c class- were examined after flame spray coating with an alloy of aluminum and zinc, without any interference in the chemical composition or in the production mode. More specifically, bare rebars of 12 mm nominal diameter were subdivided in two groups, in reference - as delivered - conditions and after flame spray coating; both groups of rebars were subjected to accelerated corrosion experiments, using impressed current technique, and subsequently their mechanical behavior in uncorroded and corroded conditions. The outcomes attained from the experimental study indicate a positive contribution of this method compared with other studies. Moreover, a comparison is presented between the present study on flame spray coating and our recent studies on application of anticorrosive coatings, such as shot peening treatment.