Abstract:
Corrosion of steel in concrete is one of the major causes of structure degradation, requiring expensive maintenance. The using of hot dip galvanized steel (HDGS) has
been recognized as one effective measure to increase the service life of reinforced
concrete structures in marine environmental. However, HDGS corrodes in contact with
high alkaline environment of fresh concrete. Although this initial corrosion process
allows the formation of a protecting layer barrier, the corrosion that occurs initially is harmful and chromate conversion layers are usually used to prevent it.
Due to toxicity of Cr(VI), these kinds of pre-treatments have been forbidden and hybrid
coatings have been proposed as alternatives. To evaluate the performance of these
coatings, beyond the laboratory characterization, in situ tests in real conditions should be performed.
An electrochemical system to measure the macrocell current density (igal) was designed
to evaluate the degradation of HDGS coated samples with different organic-inorganic
hybrid films, embedded in mortar during 70 days, using an automatic data acquisition
system.
This system revealed to be feasible and highly sensitive to coatings degradation. Also,allow distinguishing different hybrid coatings with different thicknesses.
