Dexter Coffin Bridge Rehabilitation

Carrying thousands of daily commuters along Interstate 91, the Dexter Coffin Bridge is a critical link connecting communities across the Connecticut River and supporting regional travel, commerce, and emergency response. Originally constructed in 1956 and widened in 1991, the 12-span steel structure had developed significant structural deficiencies, including pack rust, flange buckling, and reduced load rating capacity, prompting the Connecticut Department of Transportation (CTDOT) to advance a targeted rehabilitation program.

CHA led the structural assessment, design, and implementation of innovative rehabilitation solutions to restore performance while maintaining live traffic. The scope included deck and substructure repairs, steel strengthening, joint and bearing replacements, and upgrades to lighting and overhead sign structures. To address complex deterioration in critical regions, CHA introduced ultra-high performance concrete (UHPC) as a first-of-its-kind application in Connecticut.

UHPC was used to encase steel girders at areas of concern, strengthening negative moment regions, mitigating flange buckling, and halting pack rust progression. This approach increased load rating capacity while providing a durable barrier against future corrosion, extending the structure’s service life. The design required advanced analysis and careful staging to maintain traffic throughout construction.

By rehabilitating rather than replacing the bridge, the project reduced cost, minimized disruption, and limited environmental impact, preserving a vital commuter corridor while delivering long-term resilience.