Electrochemical corrosion evaluation of a steel–concrete system with surface treatment of silicon nanoparticles.

In this research, the contribution of silicon-based nanoparticles (NP) applied superficially on steel–concrete systems, for the passive film improvement was studied. The steel–concrete system was evaluated by electrochemical behavior and durability (physical and chemical properties) generated after such treatment. Corrosion current density (icorr), electrochemical double-layer capacitance (Cdl), coefficient of Warburg impedance (σw), film resistance (Rfilm), and total pore volume were some of the indicators to assess the contribution of NP on the passivity behavior of steels. The systems were fabricated with AISI 1018 carbon steel (CS), and AISI 1018 galvanized steel (GS) embedded in concrete. The water/cement ratio of 0.45 after concrete cured in a dispersion of NP for 24, 48, and 168 h were obtained. The results show that after 48 h of treatment the total pore volume decreases, attributed to reduction of pore interconnection, which was confirmed by the increase in electrical resistivity. Likewise, icorr, Rfilm, and Cdl results supported the passive film enhancement in both steels, which allows to decrease the oxygen on the metal surface, confirmed by σw. [ABSTRACT FROM AUTHOR]