Dynamic fracture and fragmentation of rock-like materials under column charge blasting using electrical explosion of wires

Abstract

By using electrical explosion of metal wires, this study proposed a new experimental method to investigate the dynamic fracture process and fragmentation characteristics of rock-like materials under column charge blasting. A copper wire with a length of 100 mm was prefabricated in a mortar sample measuring 300 mm × 300 mm × 180 mm. High-voltage pulses were injected into the copper wire through an electric explosive device to produce an explosion load that could fracture the mortar sample. By virtue of an ultra-high speed camera, fracture processes on a free surface were observed. Moreover, changes in the fracture zone and fragments under an explosive energy of 1.68–5.67 kJ were studied. The results demonstrated that the crushed zone increased with the rise of explosion energy; however, the volume, perimeter, and breakage angle of the blasting crater, as well as the size of fragments decreased with increasing explosion energy.