RECENT TRENDS IN NONDESTRUCTIVE INSPECTIONS IN STATE HIGHWAY AGENCIES. TECHNICAL NOTE

Results of two recent questionnaires, one in 1993 and the other in 1996, reveal that state Departments of Transportation are beginning to shift their priorities to emphasize inspection and rating of infrastructure. Specifically, the use of nondestructive evaluation (NDE) as a tool for maintenance decisions is increasing. In 1993, 94% of the state highway agencies responded to the survey; in 1996, 86% responded. The 1993 survey determined that steel is the material most often inspected with NDE and that concrete NDE techniques need further development. In the 1996 questionnaire, specific inspection information was acquired regarding both steel and concrete members as well as scour. In response to survey results, use of an ultrasonic imaging method for inspecting concrete structures is proposed. Finally, research directions are presented for future NDE development.