Steel Bridge-Coating Systems and Their Environmental Impacts: Current Practices and Future Trends

Abstract

Coatings are essential for protecting structural steel bridges from corrosion in harsh environmental conditions. The selection of a suitable coating system can significantly impact the performance and longevity of a bridge as well as its environmental footprint. This study investigates the U.S. and Canada’s environmental ISO corrosivity map and the general environments to which bridges are exposed. Additionally, environmental data and road maintenance practices of transportation departments and the use of de-icing salts were investigated to examine the impact of micro-corrosive environments on bridge elements. The study reviews commonly examined coating systems and their expected service life in moderate and highly corrosive environments. This sheds light on factors influencing coating system selection, such as life-cycle cost analysis and maintenance practices for bridge elements. For the first time to our knowledge, an environmental life-cycle evaluation of one of the most commonly used coating systems with theoretical maintenance scheduling for a bridge project’s expected service life is presented to encourage the use of a quantitative tool for environmental impact assessment of coatings in terms of global warming potential (GWP). Additionally, perspectives on patented state-of-the-art and future steel-protective technologies and their potential role in bridge engineering are reviewed.