Protective Coatings For Highway Structural Steel

This synthesis will be of interest to state department of transportation (DOT) bridge maintenance engineers, coating specialists, chemists, and researchers. Manufacturers and suppliers of corrosion protection products and systems for exposed structural steel on existing bridges will also find it of interest. This synthesis describes current practice regarding maintenance and protection strategies for exposed structural steel on existing bridges. NCHRP Synthesis 251, Lead-Based Paint Removal for Steel Highway Bridges ( 1997), provides a complementary and more in-depth treatment of maintenance issues involving lead-based paint removal. This report of the Transportation Research Board defines the maintenance management systems and decision making criteria used by transportation agencies for maintaining exposed bridge steel. Material selection criteria, surface preparation and application practices, quality control and quality assurance programs, and funding mechanisms are discussed in detail. The impact of recent and proposed environmental and worker protection regulations on current practice is reported. Information for the synthesis was collected by surveying state transportation agencies and by conducting a literature search. Responses to the survey, Appendix C to this document, are published on the Internet as NCHRP Web Document 11.

A current state-of-the-art survey is presented with regard to painting of highway structural steel. A thorough literature review was conducted and an inspection and evaluation made of more than 4,000 paint exposure tests. Paint film thickness measurement studies were made. Specific recommendations are given for selecting typical paint systems on the basis of six environmental zones, which represent the range of severity of environment in which highway steel structures are located in the United States. Model specifications are suggested for surface preparation, application, material procurement, and paint system.

"Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration."