Effect of Cathodic Protection on Reinforced Concrete with Fly Ash Using Electrochemical Noise

Abstract

Corrosion of steel reinforcement is the major factor that limits the durability and serviceability performance of reinforced concrete structures. Impressed current cathodic protection (ICCP) is a widely used method to protect steel reinforcements against corrosion. This research aimed to study the effect of cathodic protection on reinforced concrete with fly ash using electrochemical noise (EN). Two types of reinforced concrete mixtures were manufactured; 100% Ordinary Portland Cement (OCP) and replacing 15% of cement using fly ash (OCPFA). The specimens were under-designed protected conditions (−1000 ≤ E ≤ −850 mV vs. Ag/AgCl) and cathodic overprotection (E < −1000 mV vs. Ag/AgCl) by impressed current, and specimens concrete were immersed in a 3.5 wt.% sodium chloride (NaCl) Solution. The analysis of electrochemical noise-time series showed that the mixtures microstructure influenced the corrosion process. Transients of uniform corrosion were observed in the specimens elaborated with (OPC), unlike those elaborated with (OPCFA). This phenomenon marked the difference in the concrete matrix’s hydration products, preventing Cl− ions flow and showing passive current and potential transients in most specimens.

Electrochemical Noise Measurement to Assess Corrosion of Steel Reinforcement in Concrete

“…Recently published work by Garcia-Contreras et al [ 8 ] and Permeh et al [ 9 ] has used ENM techniques to monitor pitting corrosion in post-tensioned bridges and study the effect of fly ash additions on reinforcement subjected to cathodic protection, respectively. A review of electrochemical noise carried out in 2020 by Da-Hai Xia et al [ 10 ] identified the numerous experimental arrangements and models that have been employed in an attempt to achieve near-quantitative evaluation of corrosion rates for a range of environments, including steel in concrete.…”

Special Issue “Corrosion in Concrete: Inhibitors and Coatings”

“…It was evidenced that the phosphating treatment of fibers allows to enhance the bond strength between steel and concrete and improves the corrosion resistance of fibers without affecting their surface morphology. Finally, the paper by Garcia-Contreras et al [ 14 ] studied the effect of impressed current cathodic protection on reinforced concrete manufactured with fly ash as cement replacement. Results evidenced that the microstructure of cementitious matrix strongly influenced the corrosion behavior of steel in concrete.…”