Corrosion and Inhibition Performances at the Steel-Mortar Interface. Part 1: A Surface Analytical Investigation

摘要

The present research evaluated the corrosion and inhibition performances of steel-mortar samples with various levels of NaCl and corrosion inhibitors admixed in fresh mortar (0.05M DGP, 0.5M SN, and 0.05M DMEA). FESEM, EDX and XPS were used to analyze the fracture surfaces of the steel-mortar interfacial region for samples exposed to various time periods of ponding by 3% NaCl solution. The admixing of NaCl and the corrosion inhibitors in fresh mortar altered the morphology and microstructure of the hardened mortar at the steel-mortar interfacial region. The admixing of the corrosion inhibitors in fresh mortar increased the risk of carbonation of cement hydrates at the steel-mortar interfacial region, but partially displaced chloride ions. Chloride (either admixed or ingressed) and the admixed corrosion inhibitors facilitated the formation of different cement hydrates and affected chloride binding atthe steel-mortar interfacial region, all of which may affect the steel corrosion and its inhibition.