There are several thousand bridges that are scheduled for maintenance painting both in the State of Tennessee and Missouri. The Caruthersville Bridge (I-155 Mississippi River Bridge) is an on-going project, which is the northern-most bridge over the Lower Mississippi River, with the combined flow of the Upper Mississippi and the Ohio River.
A two-year Federal Highway Administration (FHWA) in-house study was launched in November 2006 to evaluate various coating materials that may be applied as one-coat systems to steel bridges. A total of eight test materials plus two control systems, a 3-coat and a 2-coat, were applied over near-white steel test panels (SSPC-SP10). Their performance has been evaluated for 20 months using electrochemical impedance spectroscopy, surface failure characterizations, rust creepage at scribe, pull-off adhesion, and changes of color and gloss.
Internal linings used for corrosion protection often have to perform under severely corrosive environments. One major concern regarding coating performance is the negative effect of soluble salts on the steel substrate at the time of lining application, particularly for higher temperature lining applications. These salts impact the ability of the applied coating systems to protect the steel in several ways including osmotic coating blistering, promotion of under-film metallic corrosion and lining disbondment.