Sandisfield, Massachusetts, US, received a US$1 million grant in 2017 to rebuild Rugg Bridge following years of wear and tear. The pony truss crossing has carried residents and travellers over the Clam River since 1938. A steel grid/concrete deck weighing 60 lb per square foot created a dead load that was too heavy for the aged structure. MassDOT needed a lightweight option that could balance high performance with the need to preserve the span’s historic character.
MassDOT chose FiberSPAN based on its track record with another state project. In 2013 Composite Advantage supplied the world’s largest FRP composite deck to Haverhill’s Rocks Village vehicle bridge. Built in 1883, the six-span steel truss structure is the state’s oldest movable bridge. Its swing span permits the passage of boats and barges, and the rehabilitation added 18,800 sq.ft. of new driving surface to the bridge. Inspections since the deck’s installation have found panel-to-panel joints, span joints and wear surface in like new condition.
Rugg Bridge totalled 123 ft long with longitudinal steel stringers spaced 6 ft 2 inch on centre. FiberSPAN deck panels were 25 ft 11 inch wide and 10 ft long with a thickness of 7 7/8 inch. The FRP deck and its wear surface, a black Matacryl (aluminium oxide), weighed just 23 lb per square foot. Bolted shear studs connected deck panels to steel stringers and floor beams. Specifications included AASHTO HS-20 vehicle plus impact loading, a 0.9 environmental durability factor, L/500 maximum deflection requirement, a dead load with bending strain/shear strain maximum of 10% and a service load plus dead load with bending strain/shear strain maximum of 20%. The short span opened in May 2018.