TTI Research Supervisor:
Nauman Sheikh, P.E.
Texas Transportation Institute
Texas A&M University System
College Station, Texas 77843-3135
(979) 845-8955 [email protected]
Pooled Fund Technical Representative: Dave Olson
Design Policy, Standards and Research Manager
Washington Department of Transportation
P.O. Box 47329
Olympia, WA 98504-7329
(360)705-7952 [email protected]
An inspection manual with sample inspection forms was also developed. It is presented in Appendix A as a standalone document and can be tailored by user agencies for their use.
This research presents an inspection technique for evaluating the structural integrity of weathering steel W-beam guardrail. The inspection technique allows evaluation of the rail without requiring disassembly. Using the technique identified in this research, the researchers also developed an inspection procedure for conducting an in-field inspection.
The inspection is conducted using ultrasonic corrosion thickness gauges. Various in-service samples of weathering steel guardrail from different states were used to develop the appropriate thickness thresholds and inspection procedure.
The inspection procedure prescribes conducting the inspection using a two-level approach. In the first-level, fewer spots are checked along the length of the guardrail system. If a spot fails in the first-level inspection, a second-level inspection is performed. In the second-level inspection, more thorough inspection is performed within a specified distance upstream and downstream of the failed spot.
Not applicable. The inspection methodology was developed in conjunction with FHWA and Washington State DOT.