Dynamic fragmentation of concrete using electric discharge impulses

We study dynamic fracture in construction materials induced by electric discharge impulses (EDI) that evaporate self-reactive liquid and produce high pressures in blast holes. Detailed observations utilising a high-speed digital video camera and a three-dimensional finite difference code show cracks generated in cylindrical concrete columns by means of EDI are controlled by direct and reflected waves and widened later by gas pressurisation, just as in the case of conventional blasting. Thus, wave-based analysis developed for blasting using explosives is valid also for EDI crushing, making it an ideal methodology to achieve controlled smooth dynamic fragmentation of construction materials and structures.