The Gray Bridge consists of a stress-laminated deck structure using CCA-treated #2 or better 2x14 rough-sawn Eastern Hemlock laminations. These laminations were placed on edge side by side across the span. High-strength steel bars were placed through prebored holes in the laminations and post-tensioned. The interlaminar friction thus generated allows the deck to act as an orthotropic plate. A 7-year monitoring report is available, which shows excellent performance of the bridge.

Specifications

• Year Constructed: 1991
• Length: 23 ft.
• Width: 23.67 ft.
• Design Live Load: HS20-44
• Wood Species: CCA-Treated Eastern Hemlock
• FRP Tensile Strength: NA
• FRP Tensile Modulus: NA
• FRP Material Suppliers: NA

Sponsored by: US Department of Agriculture Wood in Transportation Initiative, Maine Department of Transportation