Several hardwood demonstration timber bridges were built by the Pennsylvania Department of Transportation in the early 1990s. These bridge superstructures are of the recently developed stress-laminated deck design type using red oak lumber laminations that were pressure-treated with creosote preservatives. This paper describes the data acquisition system used to monitor seven of these bridge superstructures between 1997 and 2002 and to characterize any effects of cold (winter) temperatures on their structural performance. Prestressing bar forces, a key performance parameter for stress-laminated bridges, stabilized after more than 10 years in service and remained above minimum design threshold levels at six of the seven bridges.
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