Passivation and Chloride-Induced Corrosion Behavior of Aluminum Alloys in Pore Solution of Portland Cement Paste

AbstractThe passivation and chloride-induced corrosion behavior of aluminum alloys (AAs) 2014, 5083, and 6061, as a key component in aluminum alloy–concrete composite, were investigated in a pore solution of portland cement paste via electrochemical methods, scanning electron microscopy (SEM), and Raman spectroscopy. Results show that AA6061 presents the highest corrosion resistance due to the formation of uniform α-Al(OH)3 layer on both aluminum matrix and intermetallic phases. AA6061 shows the highest chloride threshold value while exhibiting the lowest corrosion resistance when chloride concentration is above the threshold. Different mechanisms of protection and chloride-induced corrosion for the three aluminum alloys in pore solution are proposed.