Stemming is inert material used to confine energy inside the drill hole. Pea gravel is a common stemming material used for high explosive products for rock breaking. Stemming material used for Nxburst rock breaking cartridges is a finer crush consistency to lock in the gases, which will improve fragmentation for your rock breaking and concrete breaking project. With Nxburst Rock Breaking Cartridges rapidly generating gas and not producing a shockwave, stemming becomes critical to blast to safely break rock. Adequate stemming will help attenuate noise levels and control fly rock. Stemming material is placed on top of the Nxburst Rock Breaking Cartridge which is filled and tamped all the way to the top (collar) of your blast hole. At the minimum, your stemming length should be at least 1.5’. The more adequate stemming material you use while taking your time to appropriately stem and tamp each blast hole will result in safer blast performance. Your holes should always be stemmed for any blasting product. Nxburst is a rapid gas expansion product that deflagrates rather than producing a shock wave. The more effective your stemming is the more controlled and safer your blast will be; thus reducing the exposure and eliminating fly rock concerns when used correctly and appropriately for a given application. Throughout GeoBreak’s Nxburst Training, the importance of stemming is emphasized to produce safe blasting results using Nxburst Rock Breaking Cartridges. During the first day of the classroom based learning, candidates will understand which material for stemming is recommended and which should not be used. The second day where candidates get hands on experience using Nxburst Rock Breaking Cartridges, various stemming material will be used to show which creates the most safe, desirable rock blasting and how to safely tamp the throughout the stemming column with various borehole lengths.
