Alcamines as corrosion inhibitors for reinforced steel and their effect on cement based materials and mortar performance

Abstract

Testing steel in solution has the advantage of avoiding the long time necessary for chlorides to penetrate the concrete cover. The effect of some alcamines, namely TIPA85 and CA92 as corrosion inhibitors for reinforced steel bars in 3.5% NaCl and chloride contaminated saturated concrete pore solution (3.5% NaCl + SCP) was discussed using electrochemical techniques. The characteristic effect of studied compounds on the cement and its mortars was explained by chemical and physical techniques. Results show that alcamines can be used as corrosion inhibitors, grinding aid raw materials and improvers of cement quality. TIPA85 has a higher corrosion inhibition efficiency than CA92 as indicated from the results of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), molecular dynamics simulation and quantum chemical calculation methods. A mixed physical and chemical adsorption mechanism is proposed. Adsorption of these alcamines was found to follow the Langmuir adsorption isotherm.