Chloride Corrosion of Reinforced Calcium Aluminate Cement Mortar

Abstract

This paper describes a study on the corrosion behavior of steel reinforcement in CAC mortars via electrochemical methods including corrosion potential, electrochemical impedance, and linear polarization evaluation. Results indicate that there is a non-linear relationship between the corrosion degree of steel reinforcement in CAC mortar and the concentration of NaCl solution. The electrochemical parameters of specimens immersed in 3% NaCl solution suddenly drop at 40 days, earlier than 60 days of the reference. And the charge transfer resistivity of the specimen has decreased by 11 orders of magnitude at 40 days, showing an evident corrosion on steel reinforcement. However, it is interesting to notice that the corrosion is delayed by high external chloride concentration. The specimens immersed in 9% and 15% NaCl solutions remain in a relatively stable state within 120 days with slight pitting. The great corrosion protection of CAC concrete to embedded steel bars enables its wide application in marine.

Keywords

electrochemical impedance / calcium aluminate cement mortar / chloride corrosion