Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592


You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Long-term performance monitoring of hardwood timber bridges in Pennsylvania

Source: Res. Pap. FPL-RP-612. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, 2004. 56 pages

Author(s)Wacker, James P.; Calil, Carlito, Jr.; Hislop, Lola E.; Hilbrich Lee, Paula D.; Kainz, James A.

Publication Year: 2004  View PDF »

Category: Research Papers

Abstract: Several hardwood timber bridges were constructed in Pennsylvania during the early 1990s. This report summarizes the long-term field performance of seven stress-laminated deck bridges over a 4-year period beginning August 1997 and ending July 2001. Data collected include lumber moisture content, static load test deflection measurements, and bridge condition assessments. In addition, stressing bar force, temperature, and relative humidity conditions were monitored several times per day by a remote data acquisition system installed at each bridge site. Superstructure lamination moisture content ranged between 20% and 40% after nearly 10 years of service. The field performance of four bridges was unsatisfactory. Loss in prestressing bar force necessitated bar retensioning at the Millcross Road bridge (Lancaster County), and live load deflection limits were exceeded at the Brookson Road (Crawford County), Laurel Run (Huntingdon County), and Jacobs (Huntingdon County) sites. Several serviceability and/or maintenance deficiencies need immediate attention to achieve satisfactory field performance.

Keywords: Stress-laminated deck, timber, wood, highway bridge, red oak, beech, hardwood

File size: 4 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 22107
Current FPL Scientist associated with this product
Wacker, James P.
Research General Engineer

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »

Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »

Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »

Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »