Chloride threshold determination of hybrid inhibitor immersed in simulated concrete pore solution

Abstract

The hybrid inhibitor performs excellently compared to either organic or inorganic inhibitor individually. In the present studies, a fixed amount ie 2 wt% L-arginine (LA) and 0.25 wt% trisodium phosphate dodecahydrate (TSPDH) is considered as hybrid inhibitor and its chloride threshold is determined by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) in simulated concrete pore solution and the formed passive films are characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy after 240 h of immersion. The chloride threshold of this hybrid inhibitor is 6 wt% NaCl, ie, C3 until 216 h of immersion, whereas if the amount is increased, the steel rebar leads to corrode severely.