ABSTRACT
The fracturing process of granite cubes (400 × 400 × 400 mm3) subjected to blast loading was investigated using data from Digital Image Correlation (DIC) analysis on images captured with a high-speed camera. The four cubes had a centric vertical borehole and an explosive charge (PETN) of weight 12 g or 6 g. Fracture pattern and gas ejection on one of the surfaces of the specimens were studied. Three dominant vertical cracks developed on the observed surface for the two specimens with charge weight 12 g, and one dominant vertical crack for the two specimens with charge 6 g. All four specimens developed one dominant horizontal crack across the surface. The first gas ejection from the surface was seen at time 900 μs to 1400 μs after the detonator initiation. Displacement fields determined by the DIC analysis were used to obtain plots of the surface strain fields, from which the strain concentration zones corresponded well with the locations and directions of the developed cracks.
