Non-contact imaging for surface-opening cracks in concrete with air-coupled sensors

Title: Non-contact imaging for surface-opening cracks in concrete with air-coupled sensors
Author(s): J. Zhu, J. S. Popovics
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 38
Issue: 283
Issue date: 2005-11-01
Publication year: 2005
Pages: 801 - 806
Total Pages: 6
Nb references: 7
Language: English

Abstract: Rapid and accurate non-destructive evaluation (NDE) techniques are needed to assess the in-place condition of concrete structures.
However the time and effort required to perform NDE tests using conventional surface-mounted contact sensors hinder rapid evaluation of large full-scale structures.
The suitability of surface waves and non-contact sensing techniques to detect the presence of concrete defects is examined here.
First, the ability to detect leaky surface waves in concrete with air-coupled sensors is demonstrated.
Surface waves in a concrete slab specimen are generated by an electrically-controlled impact source.
Next, the data and signal processing needed to improve leaky surface wave data, with respect to eventual application to velocity and attenuation images, are demonstrated.
Finally velocity and wave attenuation data collected from a concrete slab specimen that exhibits surface cracking are presented.
Test results show that the proposed energy ratio (attenuation) criterion is more sensitive to existence of cracks than the velocity criterion.

Online publication: 2005-04-12
Classification: Special Issue on Nondestructive Testing in Civil Engineering
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/14292