Abstract

Concrete bridge structures most often experience different forms of deterioration, such as surface scaling, spalling, and internal frost damage due to environmental and chemical attacks. Sealers and coatings are used to reduce these forms of concrete deterioration by limiting penetration of water and water-borne deleterious agents, such as chlorides and sulphates. Moreover, sealers and coatings are used to resist chemical attack and corrosion damage due to de-icer and anti-icer chemicals, such as NaCl, CaCl₂, and MgCl₂. They also facilitate moisture vapour transmission, and thus aid rapid drying and mitigate the effects of corrosion. This paper presents the key aspects of sealers and coatings used for the protection of concrete bridge structures. It highlights different types and selection criteria of sealers and coatings, surface preparation and application methods required for applying these products, and their role in protecting concrete. In addition, the different evaluation methods and performance criteria for sealers and coatings are discussed in this paper.

Key words: Bridge structure, chemical attack, concrete, de-icer and anti-icer, durability, freezing and thawing, moisture vapour transmission, wetting and drying, sealer and coating, physical attack.