Title: Optimizing Test Parameters for Quantifying Critical Chloride Threshold
Author(s): Naga Pavan Vaddey and David Trejo
Publication: Materials Journal
Appears on pages(s): 53-65
Keywords: chloride test value; critical chloride threshold; open circuit potential
A new method, OCcrit, has been developed at Oregon State University for quantifying critical chloride threshold of steel-cementitious systems. Previous research on this test method focused on identifying a test method for monitoring corrosion initiation and on optimizing criteria for detecting the initiation of steel reinforcement corrosion. This paper reports experimental data used for optimizing various parameters associated with the new test method. The parameters evaluated included water-cementitious materials ratio (w/cm), sand-cement ratio (s/cm), and exposure conditions for the anode specimen. Results indicate that an s/cm of 1.375 is optimal to minimize issues with shrinkage and constructability of the OCcrit anode specimens. Also, results indicate that the optimal conditions for the OCcrit test specimens fabricated with portland cement mortar and conventional steel reinforcement require an exposure solution with a pH of 12.5 and a chloride concentration of 2%, and the anode specimens should be continuously exposed until corrosion initiation. The developed optimal parameters can be used to estimate critical chloride threshold of conventional reinforcement in a practical time frame.