Title:
Crack Evaluation in Concrete Members Based on
Ultrasonic Spectroscopy
Author(s):
Yasunori Sakata and Masayasu Ohtsu
Publication:
Materials Journal
Volume:
92
Issue:
6
Appears on pages(s):
686-698
Keywords:
cracking (fracturing); nondestructive tests; spectroscopy; ultra-sonic
tests.
DOI:
10.14359/9789
Date:
11/1/1995
Abstract:
A nondestructive evaluation method based on ultrasonic spectroscopy was studied to estimate crack depth in concrete members. A surface method, in which both a transmitter and a receiver were attached to the same surface of a specimen, was investigated. Spectral responses were measured by driving sweep-mode sinusoidal waves from a signal generator Spectral responses due to sweep-mode input are equivalent to Fourier spectra ana-lyzed from impulsive responses. Sweep time was a key parameter to coincide with the spectral response with the Fourier spectrum. Specimens with artificial cracks were tested to study relations between crack depths and spectral responses. Based on these results, depths of bending cracks in plain and reinforced concrete members were estimated and compared with analytical results obtained using the boundary element method (BEM). These experimental and analytical results demonstrate that the present method is promising for evaluation of crack depth in concrete members.