Performance of Portland cement concretes with 1% nano-Fe3O4 addition: Electrochemical stability under chloride and sulfate environments

• Nano-Fe3O4 (1%) was used as a partial replacement of cement in concrete.
• Concretes were evaluated through impedance spectroscopy and cyclic voltammetry.
• Nano-Fe3O4 concretes presented electrochemical stability, even after ions exposure.

Concretes with 1% nano-Fe3O4 addition aged for 300 days in chloride and sulfur dioxide chambers were analyzed by multiple technics and the performance results were evaluated by impedance spectroscopy and cyclic voltammetry. They exhibited a higher electrochemical stability because of the absence of passive film breakdown and an enhanced electrical resistance to charge transfer. The better properties were resulted from a more homogeneous microstructure produced by the byproducts of the reaction between the cement hydrates and the added nano-material. They were supposed be accumulated in pores and voids.