Evaluation of Corrosion Resistant Ferric-Alloys in Chloride Contaminated Concrete

The penetration of chloride ions through concrete can compromise the integrity of
a structure. The chloride concentration, [Cl-], at which the corrosion process initiates is
termed the critical chloride concentration or chloride threshold, [Cl-]th. One of the
purposes of this research was to determine the [Cl-]th for various reinforcing alloys.
Furthermore, the time-to-corrosion (TIC) was measured to determine the time at which
bars become active. Both parameters, [Cl-]th and TTC, were found to be distributed;
therefore, statistical analyses were performed to forecast the probability of activity. A
new experimental procedure was introduced to increase the TTC data set by electrically
isolating the top bars as they became active.
The research also compared the [Cl-] for core samples with those values obtained
from along the top rebar trace. In general, this analysis demonstrated that core sample
[Cr] was lower than at the rebar-trace.