Use of Polymer Overlays or Sealers on New Bridges

5510GPolymer overlays and penetrating deck sealers are used as preventive maintenance options to extend the service life of concrete bridge decks. Overlays and sealers protect concrete structures from deterioration by inhibiting the ingress of chlorides, chemicals, and moisture and by slowing active corrosion. Identifying the optimum time for installation of overlays and sealers is key to maximizing the benefit to cost ratio of this type of maintenance. This report provides an overview and analysis of the use of polymer overlays and penetrating deck sealers to achieve extended service life objectives. It includes a description of the materials used as polymer overlays and sealers; recommended practices for application and installation; additional considerations for construction; service life modeling of various preventive maintenance options; and an analysis of the relative service life costs. The literature indicates that polymer overlays are often applied to bridge decks in good to moderate condition with a median age of 20 years, while for sealers the recommended practice is to apply sealers to new bridge decks 3 to 6 months after construction, with reapplication often scheduled after 4 to 5 years. Service life modeling and life-cycle cost analysis results indicate that the greatest extensions in service life of northern bridges with typical life of 50 years are obtained when sealers are applied shortly after construction and polymer overlays are applied within the first 5 years of service. For bridges with desired service life of 100 years, polymer overlays should be reapplied through the life of the deck, at 25 years interval or less. It is recommended that bridges with desired service life exceeding 50 years be analyzed on a case-by-case basis