The High Voltage Pulse (HVP) has become an efficient emerging technology for preparing recycled aggregates from waste concrete. An experimental device for crushing concrete using high voltage pulsed was produced by HUST. In order to analyze the disintegration mechanism of concrete sample under the high voltage pulse, this paper uses X-ray CT to examine how discharge channels grow within sample during high voltage pulse fragmentation. The discharge channels have a 'trunk-branch' spatial distribution characteristic. Due to the differing electrical properties of aggregates and cement mortar, primarily manifested in their relative permittivity, the electric field strength changes abruptly at their interface. Consequently, discharge channels always propagate along the aggregate surface. This liberation mechanism enables the high voltage pulse crushing process to achieve a higher degree of dissociation than traditional mechanical methods, while preserving the complete structural morphology of the aggregate within the concrete sample.

Concrete fragmentation, High voltage pulse, X-ray CT, Discharge channel.