This project is investigating the integrity of wood guardrail posts in strategic locations of Washington state. Guardrail systems protect motorists involved in a crash by dissipating energy and keeping them from leaving the roadway. The guardrail post is an important part of the system. Unfortunately, wood guardrail posts are susceptible to failing during a crash event because of a loss of strength from wood decay. Wood decay may be due to fungal growth or insect intrusion and is difficult to detect by visual inspection alone because decay commonly occurs inside the post. Phase I of this research proposed utilizing a stress wave timing (SWT) device for non-destructive field testing of wood posts. This Phase II study is focusing on quantifying the factors that affect wood post service life in the Northwest, including the post’s age, location, and physical properties such as wood species, treatment method, and lumber grade. WSDOT will be able to use the information provided to consider the need to revise wood treatment specifications and/or design guidance for wood guardrail posts.
Principal Investigator: Adam Phillips, Civil and Environmental Engineering, WSU
Sponsor: WSDOT
WSDOT Technical M0nitor: Brad Manchas
WSDOT Project Monitor: Doug Brodin
Scheduled completion: June 2018