Performance assessment of amine group corrosion inhibitors for use in reinforced concrete structures

Abstract

Corrosion of steel reinforcement remains a critical challenge in newlinereinforced concrete structures, particularly in chloride-rich and aggressive newlineenvironments. This study investigates the performance of four amine-based newlinecorrosion inhibitors-Diethanolamine (DEA), Lithium Nitrite, Methyl newlineDiethanolamine (MDEA), and 4-Aminobutyric Acid (GABA)-in mitigating newlinechloride-induced corrosion in reinforced concrete structures under varying newlineenvironmental conditions. A comparative analysis was conducted on Ordinary newlinePortland Cement (OPC), Portland Pozzolana Cement (PPC), and Portland newlineSlag Cement (PSC) systems, incorporating the inhibitors through admixed, newlinemigrating, and electro-injection methods. The experimental results newlinedemonstrate that electro-injection consistently outperformed other methods, newlineachieving up to a 95% reduction in corrosion rates at high chloride newlineconcentrations. newlineMicrostructural analyses, including SEM, EDS, and XRD, revealed newlinethat the inhibitors significantly enhanced the formation of calcium silicate newlinehydrate (C-S-H), leading to denser and more homogeneous cement matrices. newlinePSC systems exhibited superior performance, attributed to their inherent newlinechloride-binding capacity and reduced permeability, which synergized newlineeffectively with the protective action of the inhibitors. Electrochemical tests newlineindicated stable passivation layers on steel reinforcements, with DEA and newlineLithium Nitrite maintaining alkaline environments crucial for corrosion newlinein PSC treated with electro-injected Lithium Nitrite, showcasing the highest newlinedurability among the tested combinations. newline newline