New Bay Bridge Shows Signs of Rust in Critical Areas
Charles Spiller with the Sacramento Bee reports that CalTran has found signs of corrosion on the new Bay Bridge anchor rods. The rods are hot-dip galvanized and encased in chambers that were meant to be watertight. During the construction of the bridge, however, were subject to a large amount of rainfall. The chambers have since been sealed but are reportedly leaking and subject to moisture. These create conditions that may expose the galvanized steel to wet storage stain. There now appears to be a white residue on the rods, which is a typical sign of wet storage stain. The staining on hot-dip galvanized steel is often superficial despite the presence of a bulky corrosion product. Proper remedial actions should be conducted and coating thickness measurements made to assess the condition of the coating.
The article mentions that the presence of iron in the corrosion products indicates that the underlying steel is now being attacked. This is not necessarily true as the intermetallic layers of a hot-dip galvanized coating aslo contain iron; causing its presence in the analysis.