Exposure of U-bend specimens fabricated from 16-mm-diameter 2304 SS to simulate
pore solution with chlorides at ambient temperature and 65°C failed to reveal any
susceptibility to stress corrosion cracking.
The critical chloride concentration required to initiate the corrosion of 2304 SS
specimens polarized to +100 mVSCE while exposed to simulated pore water to which
chlorides were incrementally added ranged from 5.00-9.86 wt percent Cl-.
No definitive corrosion initiation occurred after 929 days for three concrete slab
specimens with 2304 SS reinforcement that were ponded with a Cl- solution. For one
specimen, some momentary activity followed by repassivation occurred.
The Cl- threshold to initiate active corrosion of 2304 SS in concrete was greater than
12.5 kg/m3(4.51 wt percent cement).
An accelerated corrosion test was developed for weathering steel corresponding to a
range of exposure conditions that demonstrated sensitivity to chloride environments.
The protective oxide layer (patina) of weathering steel was degraded above
0.5 wt percent chloride. Above 1 wt percent chloride, the protective oxide was
severely degraded.
Sensors indicated the corrosion rate of coupon material exposed to the same environment.
Sensors allowed direct and immediate observation of the impact of environmental
changes on corrosion rate.
XRD showed that the corrosion products produced in cycle test chambers were similar to
those observed under field conditions.
Bridge cable sensors were capable of monitoring corrosive conditions within suspension
bridge cables and other occluded geometries.
