Using comprehensive ultrasonic images of the inspected areas bridge managers and engineers can make accurate decisions on steps needed to correct a problem. An imaging technique requires an adequate level of equipment for data acquisition, presentation and representation. However, the system must be suitable for use at bridge sites. Application of an inspection procedure based on a combination of different modalities of ultrasonic imaging was proposed in this paper. The system has been tested on specimens with artificial flaws and implanted fatigue cracks.
Work is in progress to develop a portable imaging unit for full-scale field tests at bridge sites.
Mr. Erhard from the BAM Berlin visited the lecture and after the presentation, we asked him for his opinion. A technique was developed using ultrafast pulse of laser light to generate high frequency ultrasound, and to detect ultrasonic echoes. A completely non-contact method, low energy laser pulse does not damage the coating, making this technique nondestructive. The thickness of coatings as thin as 30 m, and as thick as 400 m was measured. For echo detection, an innovative delay line based pulsed interferometer was used.