Laboratory induction of accelerated corrosion in rebars of reinforced concrete structures

Abstract

Abstract The study of pathologies in the construction industry are rising and getting more focused in the field of reinforced concrete. In these types of structures, the most common pathologies are: excessive displacement, efflorescence, lack of concreting and cracks and/or crazing, which usually occur due the corrosion of rebars, or due to excess of water and poor cure, respectively. In this study, laboratory tests were performed to accelerate the corrosion process of steel samples. To achieve that, it was used the Tamori's methodology, the electrolytic corrosion. The tests were performed in ten circular reinforced concrete specimens and, due to equipment constrains and time limitations, the specimens were divided in two main groups. The cement used was the Brazilian Portland CP-V ARI and the rebar was CA-50 with a 6.3 mm nominal diameter. After applying a constant electric current in the steel rebars of the reinforced concrete specimens for a certain pre-defined period, it was possible to identify stains and fissures in the faces of the specimens, as well as to measure the corrosion that occurred. To measure the corrosion of the rebars of the specimens, the samples were fractured, the rebars were removed and they were later subject to a thermochemical bath. Finally, it was measured that the rebars had different percentages of corrosion loss when comparing with theoretical values from the literature.