Predictive Assessment on the Corrosion Consequences of Reinforced Concrete Frameworks Available Around Bhairahawa City Areas (Nepal) with Half-Cell Potential Measurement

Abstract

A challenge to the long-term durability of reinforced concrete frameworks (RCFs) in urban areas is their corrosive degradation caused by their surrounding factors. This study examines the corrosion status of thirty-four reinforcing steel (RS) samples within the RCFs available in the Bhairahawa city areas of Nepal, using a simple, non-destructive, and in-situ electrochemical method of half-cell potential (EHC) as per the ASTM C876-22b standards. This approach enables prediction of early corrosion activity in steel-reinforced concrete. Average half-cell potential values were used to classify corrosion probability zones as per ASTM C876-22b, i.e., low corrosion risk (LoCR) or less than 10% probability of corrosion, moderate corrosion risk (MoCR) or 10-90% probability of corrosion, and high corrosion risk (HiCR) or greater than 90% probability of corrosion. Results indicate that the RCFs categorized residential roofs and house pillars predominantly (i.e., two-thirds) fall within the LoCR category. Conversely, RCFs categorized within fencing pillars exhibit 66.7% HiCR and 33.3% MoCR. Most of the sewer pipes belonged to MCR, whereas most of the septic tanks are assumed to be LoCR. The study also identifies that structural elements with rough or cracked surfaces and prolonged exposure to moisture are particularly prone to RS within RCFs.