Page 379 - Corrosion Engineering Principles and Practice

348 C h a p t e r 9 A t m o s p h e r i c C o r r o s i o n 349

FIGURE 9.21 Decreasing corrosion of a sign post as a function of height.
in these studies also leave a visible imprint on many structures adjacent
to roads and highways. The shop sign post shown in Fig. 9.21, for
example, has a decreasing level of coating blistering and peeling as a
function of height while the overpass bridge in New York (Fig. 9.22)
shows a clear imprint of the corrosion due to chloride rich aerosols.

FIGURE 9.22 Corroded overpass steel bridge above the most traveled lane
of a two-lane highway, a telltale symptom of deicing salt corrosion.