employee Stella Matuzic takes Gecor reading on the Randolph
The latest readings,
taken in November 2000, show MCI-2000 is still a strong presence
in the Randolph Street bridge in St. Paul, Minnesota. MN-DOT applied
MCI-2000 in an overlay on the westbound lanes in 1986, while the
eastbound lanes were left MCI-free as a control.
Test methods used included
gas chromatography, copper/copper sulfate half-cell, Gecor 6 readings,
and chloride content measurements. Chloride content was used to
predict the corrosion initiation of the rebar in the bridge. Based
on the analyses, it is estimated that the control side will reach
initiation in 2005 and the MCI treated side will reach initiation
Also, the MCI treated
side had zero readings indicating that corrosion was occurring,
and overall the readings were 40% lower than those taken on the
control side. The test data was collected by the Minnesota department
of transportation in 1986 through 1990, by Virginia Tech researchers
in 1991 and 1992, and by American Engineering Testing and Cortec
Corporation employees in November of 2000.
Profometer, American Engineering Testing's Tim Suess detects
the rebar embedded in the concrete..