title: Locating and characterizing a crack in concrete with diffuse ultrasound: A four-point bending test.
abstract: This paper describes an original imaging technique, named Locadiff, that benefits from the diffuse effect of ultrasound waves in concrete to detect and locate mechanical changes associated with the opening of pre-existing cracks, and/or to the development of diffuse damage at the tip of the crack. After giving a brief overview of the theoretical model to describe the decorrelation of diffuse waveforms induced by a local change, the article introduces the inversion procedure that produces the three dimensional maps of density of changes. These maps are interpreted in terms of mechanical changes, fracture opening, and damage development. In addition, each fracture is characterized by its effective scattering cross section.
authors.affiliation: ISTerre, CNRS, BP 53, 38041 Grenoble cedex 9, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Larose
authors.affiliation: Swiss Seismological Service, ETH Zurich, Switzerland.
authors.forename: Anne
authors.initials: A
authors.lastname: Obermann
authors.affiliation: Grenoble Institute of Technology, GIPSA-lab, Saint Martin DHeres, France.
authors.forename: Angela
authors.initials: A
authors.lastname: Digulescu
authors.affiliation: Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Planès
authors.affiliation: LMA, UPR CNRS 7051, Univ. Aix-Marseille, Marseille, France.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Chaix
authors.affiliation: LMA, UPR CNRS 7051, Univ. Aix-Marseille, Marseille, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Mazerolle
authors.affiliation: EDF R&D, EDF Lab., Chatou, France.
authors.forename: Gautier
authors.initials: G
authors.lastname: Moreau