Epoxy Asphalt placements on orthotropic steel decks range from the San Mateo-Hayward bridge, paved in 1967, to the SuTong Bridge, which was completed in 2007 and many others [see last table]. The San Mateo-Hayward pavement lasted over 49 years with no maintenance. Orthotropic decks using epoxy asphalt include bridges paved in Canada, Australia, Brazil, China, South Korea, Thailand and Viet Nam. Several bridges have been paved with Epoxy Asphalt and then, after 25-35 years of successful service, re-paved with the next generation version of Epoxy Asphalt. Epoxy Asphalt has been successfully used in climates with winter temperatures below 0°F (-18°C) and summer deck temperatures reaching 170°F (77°C).

The concrete deck of the heavily traveled Golden Gate Bridge was replaced and paved with no daytime lane closures. Lane shutdown began at 8 PM, paving began at 10 PM and all lanes were opened at 5 AM the next morning. Throughout the night at least one lane was always open in each direction for traffic. Epoxy Asphalt technology helps meet the challenge of replacing old concrete bridge decks with orthotropic steel decks while minimizing traffic interruption. Shop applied Epoxy Asphalt Chip Seal provides a durable skid resistant surfacing that protects each steel plate from wear and corrosion until all plates are in place and welded together. This technique was recently employed on the Macdonald Bridge in Halifax, Nova Scotia during a deck replacement project and the bridge remained open to traffic during daytime commute hours. Epoxy Asphalt concrete provides the long term wearing surface when it is installed after all deck plates are in place. Both the Golden Gate Bridge and the Lions Gate Bridge used this system for their deck replacement projects. The Macdonald Bridge also used Epoxy Asphalt chip seal on the replacement deck sections and a smaller tan-colored aggregate gradation in the Epoxy Asphalt tack coat surfacing for its sidewalks and bikeways as shown on the sides of the 3 lane roadway in the image above.

Properly designed Epoxy Asphalt Pavements for orthotropic steel bridge decks provide a durable surface that resists fatigue cracking in the pavement in the negative moment area above the longitudinal stiffeners. Additionally, the pavement, acting as one element in the composite deck system, reduces deck deflection under load and thus increases the fatigue life of the steel deck plate itself.

On many projects, ChemCo Systems labs can provide accelerated cyclic fatigue testing by making composite specimens to match the design of a specific deck. The composite specimen uses the same pavement thickness and number of lifts as called for and then loads the specimen at 10 hertz cycles to simulate the highest axle loads (including an overweight factor) expected.

1. Test specimen: 14 mm plate 100 mm wide, center point load from underside.
2. Test load: 5kN load @ 10 Hz frequency