https://doi.org/10.1140/epjst/e2012-01590-6
Regular Article
An optical correlation technique for characterizing the crack velocity in concrete
Laboratoire d’Étude des Microstructures et de Mécanique des Matériaux (LEM3), Lorraine University, Ile du Saulcy, 57045 Metz Cedex 1, France
a e-mail: pascal.forquin@univ-lorraine.fr
Received:
15
November
2011
Revised:
13
March
2012
Published online:
7
May
2012
In the present work, an experimental method named “the rocking spalling test” is proposed to investigate the crack-propagation velocity in concrete and rock-like materials under dynamic tensile loading. This method is based on the use of double-notched specimens loaded in spalling tests. A compressive pulse is transmitted to a rectangular specimen by means of a Hopkinson bar. It is reflected as a tensile wave on the opposite free surface of the sample. A large notch provides a rocking effect of the rear part of the specimen whereas a short notch is used to trigger a single unstable crack. This experimental configuration has been optimized through a series of numerical simulations. Finally, a series of tests have been conducted on dry and wet concrete specimens. Crack gauges and ultra-high speed camera coupled to Digital Image Correlation have been used to characterize the crack speed in dry and wet concrete samples.
© EDP Sciences, Springer-Verlag, 2012
