Assessing Corrosion on Steel Structures Using Corrosion Coulometer

Abstract

Corrosive exposure and subsequent deterioration of weathering steel structures cause strength loss due to cross-section thinning as well as crack susceptibility due to formation of notches that concentrate stresses. Key issues include rapidly drying versus extended wet time surfaces, the relationship of clean versus debris-covered surfaces to corrosion, and disparities between test site and service conditions. An adequate understanding of corrosion, corrosion's relationship to steel structure serviceability, and the ability to monitor, predict, and abate corrosion are important needs for weathering steel structures. To implement these needs, data on corrosive conditions were collected from corrosion coulometers placed on seven structures in varied environments, at one preconstruction site and at two corrosion test sites. An analysis of corrosion processes leading to cross-section thinning, notching, and loss of fatigue strength is presented. Improved service and maintenance, enhanced design methodologies, and cost savings are anticipated outcomes.