Field Analysis of Wood Guardrail Post Decay

Wood guardrail posts can be inspected for decay using a non-destructive testing (NDT) technique called stress wave timing (SWT). This project conducted a field investigation on approximately 500 wood guardrail posts using SWT and then analyzed available data to determine factors that may lead to increased wood decay rates. It was determined that locations with high climate index (> 40) were experiencing higher decay rates. Additionally, poor preservative retention levels were also found to be associated with high decay rates. Impact testing concluded that decay reduces the fracture resistance of wood posts by more than 50%. The results of this report will be useful in considering approaches to managing WSDOT guardrail assets in the future.

Publication Date: 
Friday, August 30, 2019
Publication Number: 
WA-RD 890.1R
Last modified: 
08/30/2019 - 16:08
Adam R. Phillips, Qiyang Luo.
Washington State University. Department of Civil and Environmental Engineering.
Number of Pages: 
Field studies, Guardrails, Posts, Wood, Biodeterioration, Nondestructive tests, Fracture tests, Data analysis, Recommendations.