Microstructural study on the effectiveness of corrosion inhibitors and GGBS in enhancing the durability of reinforced concrete structures in acid-rich environments

Apstrakt

This research examines the efficiency of various corrosion inhibitors at improving the durability and corrosion resistance of concrete under aggressive conditions. Ordinary Portland Cement (OPC) was supplemented with 40% Ground Granulated Blast Furnace Slag (GGBS) to enhance durability, and manufactured sand and crushed granite were employed as aggregates. Four mixes were made: a control mix (M1) and three mixes with calcium nitrate (M2), sodium nitrate (M3), and diethanolamine (M4) as corrosion inhibitors. The performance of the mixes was tested by Rapid Chloride Penetration Test (RCPT), acid resistance test, Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Analysis (EDAX). The findings indicated that the addition of corrosion inhibitors profoundly decreased chloride ion permeability and enhanced acid-induced degradation resistance. Mix M4, to which diethanolamine had been added, had the lowest value for RCPT (1854 coulombs), weight loss (6.12%), and strength loss (6.76%), reflecting greater resistance to aggressive environments. SEM photographs indicated more compact microstructures in mixes with inhibitors, whereas EDAX analysis established lower chlorine content and greater chemical stability. Generally, the research illustrates that the incorporation of GGBS with suitable corrosion inhibitors, notably diethanolamine, greatly improves the durability and corrosion resistance of concrete, which is ideal for infrastructure in harsh environmental conditions.