Using the Corner Reflection for Depth Evaluation of Surface Breaking Cracks in Concrete by Ultrasound

Abstract The corner echo is a well-known effect in ultrasonic testing, which allows detection of surface breaking cracks with predominantly perpendicular orientation to the as, for example, corrosion metal pipes or shafts. This formed by two planes, crack and breaks. It can also be classified as half-skip method, since reflection pulse occurs on backwall before at defect takes place. In combination diffraction from tip, sizing. As shown this paper, used civil engineering nondestructive inspection concrete. Commercially available low frequency arrays dry point contact sources generate SH transversal waves sufficient divergence sound field order detect reflections. Ultrasonic line-scans area-scans were acquired linear array flat concrete specimens, data reconstructed Synthetic aperture focusing technique. If angles area reconstruction are chosen accordingly, distinguished other information. thus method deciding whether partial-depth full-depth obtaining statement about depth. paper presents corresponding experimental results obtained specimens artificial test defects induced under controlled conditions.