Corrosion protection mechanisms of carbon nanotube and zinc-rich epoxy primers on carbon steel in simulated concrete pore solutions in the presence of chloride ions

This study investigates the electrochemical characterization of carbon nanotube and zinc-rich epoxy primers (CNT-ZRPs) on carbon steel in simulated concrete pore (SCP) solutions in the presence of chloride ions. The mechanistic performance of CNT-ZRPs was characterized by adding different zinc content. The electrochemical results indicated a dominant barrier protection effect for the coating with 60 wt%Zn while there was a mixed corrosion protection mechanism for the coating with 70 wt% Zn and a dominant cathodic protection mechanism for coatings with higher zinc content (80 wt% and 90 wt% Zn). These barrier and cathodic protection control mechanisms were characterized quantitatively by electrochemical and high-resolution techniques. (C) 2016 Elsevier Ltd. All rights reserved.