5. Conclusion
After detailed experimentation and analysis of blasted fragmentation results, following conclusions
can be drawn. Air deck technique is proved significantly effective in homogeneous concrete block blasting
because it produces more uniform fragmentation with minimum fines and over size blasted material. Sieve
analysis of blasted fragmentation indicates that blasted rock fragmentation produced by airdeck is as
good as produced by full column charge. Airdecks, when placed at middle position of an explosive column produce more uniform blasted rock size distribution compared to that at other positions. It is because, the airdeck at middle position results in multiple impacts of shock wave that leads to an efficient transfer of explosive energy in the
Pak. J. Engg. & Appl. Sci. Vol.17, Jul., 2015
52 surrounding rocks. The results of this work also indicate that the optimum length of airdeck is 20% of
the total length of explosive column.