FUNDAMENTAL STUDY ON CHARACTERISTICS OF ELASTIC WAVES PROPAGATING IN CONCRETE BY WIDE-RANGE ULTRASONIC TESTING

Abstract

 Wide-range ultrasonic testing (WUT) is often used to estimate the grout filling-condition of post-tensioned PC bridges. To improve the accuracy of inspection by WUT, the fundamental characteristics of elastic waves propagating in concrete were examined. Elastic waves transmitted from the probe were propagated in a triangular prism concrete specimen. The propagated elastic waves were analyzed in the study. The result shows that transmitted waves were obviously observed in the range of 20-45° of the incident angle though it decreased in the range of 45-90°. In addition, spectrum peaks in reflected waves indicated 60-90 kHz approximately. The probe placement to observe reflection-waves of the direction angle of smaller than 45° is effective for WUT.