- Author
-
Knab, L. I.
|
Blessing, G. V.
|
Clifton, J. R.
- Title
- Laboratory Evaluation of Ultrasonics for Crack Detection in Concrete.
- Coporate
- National Bureau of Standards, Washington, DC
- Journal
-
ACI Journal,
17-27,
January/February 1983
- Keywords
-
concretes
|
cracking (fracturing)
|
velocity
- Abstract
- A laboratory study was performed to quantify the capabilities of ultrasonic through-transmission methods to detect cracks in concrete. Pulse velocity and amplitude measurements were taken perpendicular to the crack plane (in cracked concrete) and compared with measurements parallel to the crack plane (in uncracked concrete). The direct path length was 152 mm. Parallel crack surfaces, approximately 0.05 mm apart and having depths of 19, 38, and 57 mm and widths of 152 mm, were fabricated in the specimens. Transducer frequencies of 150 and 54 kHz were used. Concrete specimens with a 28 day compressive strength of about 36 MPa were tested at several ages.