by Bobby Meade, Greenman-Pedersen Inc.; and Sudhir Palle and Theodore Hopwood II, University Of Kentucky
Bridges have been historically designed for a theoretical 50-year service life but in many cases remain in service in excess of 75 years. This article discusses one tool that bridge designers can employ to extend bridge coating service life — the use of hot-dip galvanizing (HDG) and duplex coatings.
by Bobby Meade, Greenman-Pedersen, Inc.; Michael Baase, Kentucky Transportation Cabinet; and Theodore Hopwood Ii and Sudhir Palle, University Of Kentucky
The cost of maintaining a protective coating during the service life of a bridge can approach the cost of the original construction. The authors describe a KYTC-funded research project that assessed steel panels prepared by application of 32 different cleaning methods for quantity and deposition of retained chlorides.
There is a growing demand to use plural-component proportioning equipment to spray 100-percent-solids coatings, which are usually high in viscosity and composed of materials that make them compressible during application. This article explains the more technical aspects of plural-component proportioning, discussing the different technologies and how each handles 100-percent-solids spray coatings.
The author discusses formulation of low-VOC and high-volume-solids coatings with improved performance over currently available commercial products. Waterborne epoxy dispersions show promise in a variety of applications, ranging from garage floor and architectural coatings to heavy-duty industrial coatings.