Blast-generated fines represent an economical and environmental liability. A possible major source of blast-generated fine material is the dynamic mechanism of crack branching and merging at the tip of a running crack. The research aim is to develop an experimental method for capturing and observing this phenomenon in rock-like specimens. The method includes capturing the dynamic crack propagation in blast-loaded confined mortar cylinders by means of digital high-speed imaging. The research employed a special blast confinement to control the effects that influence dynamic crack development and improve safety. The paper discusses the thus far developed experimental set-up, test results, and points for further improvement.