AASHTO T 373M/T 373-17 (2021) describes procedures to evaluate the comparative qualitative corrosion performance of uncoated Corrosion Resistant Reinforcing (CRR) M 334M/M 334 alloy steel bars to those of M 31M/M 31 or other selected reference bars, utilizing electrochemical polarization resistance and potentiodynamic polarization measurements in various test solutions. The test methods evaluate the corrosion performance of the uncoated CRR bars as a function of (1) pH of the environment and (2) concentration of chloride ions, in particular the [Cl?]/[OH?] threshold ratio.