Comparison of Visual and Acoustic Emission Observations in a Four Point Bending Experiment on Barre Granite

We present an experimental study in which a pre-notched specimen of Barre Granite was subjected to four point bending under crack mouth opening displacement control. The experimental observations consisted of load–displacement measurements, acoustic emissions, and photography on a macroscopic (~cm) as well as microscopic (~μm) scale. These observations were compared and analysed to better understand process zone development and crack...