1-Benzyl-4-Phenyl-1H-1,2,3-Triazole as a Green Corrosion Inhibitor for Carbon Steel Reinforcing Bars in Concrete Elements

Abstract

Reinforced concrete (RC) plays a crucial role in the construction of structures around the world. But these structures are frequently subjected to corrosive conditions, which can degrade their structural performance, shorten their service life, resulting in failure with catastrophic consequences. The concrete high pH stabilizes the formation of an oxide passive layer on the rebar. Nevertheless, this protective film can be compromised if the chloride ion concentration threshold is reached at the steel rebar surface, which can occur as the structure ages while exposed to chloride containing environments. Considering growing environmental concerns about the effectiveness of existing corrosion control methods, this study investigates the potential of 1-Benzyl-4-Phenyl-1H-1,2,3-Triazole (BPT), an organic compound, as a green corrosion inhibitor for rebar corrosion. BPT was found to inhibit corrosion of mild steel in acidic environments and has been synthesized in an eco-friendly and sustainable method.The objective of this work is to evaluate the corrosion inhibition of BPT to protect steel reinforcement in simulated marine environments. BPT was evaluated in synthetic pore solution (SPS, 8.33 g/L NaOH + 23.3 g/L KOH + 2.0 g/L Ca(OH)2, pH: 13.6) in the presence of chlorides to determine its optimal concentration. Exposure took place following a modified version of ASTM G180. In addition different electrochemical techniques were used including linear polarization resistance, electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization. Then, mortar specimens containing BPT were tested under accelerated exposure by simulated seawater spray (modified ISO 11474) and the electrochemical response characterized using electrochemical techniques. Also, the physical-mechanical properties were evaluated. The BPT was found to provide different mechanisms to inhibit rebar corrosion including, adsorption on the material (EIS results) and reduced mortar permeability (resistivity and capillary absorption tests). Furthermore, BPT (at the optimal concentration) did not affect the mechanical properties of the mortar.This work highlights the efficacy of an eco-friendly corrosion control technology to extend the service life of critical reinforced concrete structures for a sustainable future.