Service life assessment of timber highway bridges in USA climate zones

Abstract

As engineers begin to estimate life-cycle costs and sustainable design approaches for timber bridges, there is a need for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was jointly administered by the Forest Products Laboratory and the Federal Highway Administration. In depth inspections were conducted using visual and non-destructive evaluation techniques to characterize the condition of the primary bridge components and detect any structural deficiencies. The most popular superstructure system studied in this project was the multiple sawn stringer and plank deck system. This system was evaluated in a number of wood hazard (climate) zones with numerous examples of 60 or 70 year service records. These inspection results will be eventually incorporated into an ongoing national program effort aimed at monitoring the long-term performance of various types of highway bridges in the USA.

Citation

Wacker, James P.; Brashaw, Brian K.; Williamson, Thomas G.; Jones, P. David; Smith, Matthew S.; Hosteng, Travis K.; Strahl, David L.; Coombe, Lola E.; Gopu, V.J. 2014. Service life assessment of timber highway bridges in USA climate zones. In: Proceedings of the World Conference on Timber Engineering, Aug. 10-14, 2014, Quebec City, Canada. p. 8.