Multi-technique damage monitoring of concrete beams: Acoustic Emission, Digital Image Correlation, Dynamic Identification

Acoustic Emission (AE), Digital Image Correlation (DIC) and Dynamic Identification (DI) techniques are used to analyse crack formation and propagation in plain concrete pre-notched beam specimens subject to three-point bending. Four dimensional scales are considered and scale effects on fracture energy, bending strength, and AE energy per unit area are investigated. The energy brittleness numbers are calculated for the different beam sizes to characterise the fragility of the specimens. For the larger sample, the principal strain directions obtained by DIC are put in relation with the crack path, while the analysis of resonant frequencies is used to correlate the bending stiffness reduction to the crack advancement.