Efeito inibidor dos ânions carboxilato na corrosão de estruturas de concreto armado

Abstract

The corrosion of concrete reinforcement is considered a major problem in construction, or for the maintenance usually difficult to implement and costly or by serious damage, which can lead to complete ruin of structures. Various techniques have been studied to retard corrosion, among which stands out use of additives for corrosion inhibiting effective. In the present study corrosion inhibitors containing carboxilate and benzoate anions were inserted into reinforced concrete to study the electrochemical behavior related to corrosion of these anions. For this were used techniques of accelerated corrosion by modified immersion (CAIM) and electrochemical impedance spectroscopy (EIS). The profiles of the typical behavior of current versus time curves, as well as impedance measurements indicated a corrosion inhibitor behavior associated with the presence of anions in the concrete. Weight loss analysis confirmed the results achieved by CAIM assay as showed a decrease on weight on reinforced of reinforced concrete when in presence of benzoate or carboxilate anions. Moreover, the presence of the carboxylate and benzoate anions suggests a synergic effect against corrosion. Tests were also conducted to evaluate the influence of the presence of inhibitors in the physical properties of the concrete.