Early age electrochemical behavior and initial effectiveness of waste-derived Al–Zn hybrid sacrificial anodes on steel bar corrosion control in geopolymer concrete

Abstract

Problems related to waste, particularly metal and battery waste, represent a significant and growing environmental challenge. While recent studies have explored either waste-derived materials in geopolymer concrete or conventional sacrificial anodes for corrosion protection, the integrated application of hybrid waste-based sacrificial anodes with supplementary cementitious systems for effective and sustainable cathodic protection in reinforced concrete remains largely unexplored. This study presents a novel approach by simultaneously utilizing aluminum can waste and used battery materials as an Al-Zn hybrid sacrificial anode system combined with fly ash and rice husk ash–modified geopolymer concrete for corrosion mitigation. The primary objective of this research is to evaluate the effectiveness of waste-based sacrificial anodes in inhibiting reinforcement corrosion while maintaining the mechanical performance of concrete. The study employed an experimental investigation with mechanical property evaluation and electrochemical monitoring. The results of early connection demonstrated that geopolymer concrete containing 6% rice husk ash and 94% fly ash of precursor achieved the optimal performance, exhibiting a depolarization value exceeding 100 mV, reduced corrosion potential in half-cell measurements, and a stable anode current output, confirming effective cathodic protection according to SACP criteria. Corrosion behavior was assessed through half-cell potential and depolarization measurements, while concrete performance was verified using key mechanical and durability indicators. These findings indicate that a waste-based sacrificial anode system offers a promising, environmentally sustainable alternative for corrosion protection in reinforced concrete infrastructure.