A Field-Scale Investigation into the Strategic Location of Air Decks for Improved Blasting Performance

Airdeck blasting is a promising technique for improved blast efficiency, reducing explosive consumption, and enhancing fragmentation. Nevertheless, it lacks widespread adoption due to design guideline gaps and differing opinions on air deck placement. This study offers technical guidance based on field experiments to optimise air deck blasting. Full-scale blast experiments were conducted at four distinct limestone benches to evaluate the efficacy of air deck implementation. At Bench-1, experiments were performed using conventional blasting (with full-column charge) and air decks at three strategic air deck positions (i.e., top, mid, and bottom) within blast holes at a selected quarry site. For Benches 2 and 3, comparative fragmentation analyses were conducted between conventional blasts and those utilising air decks positioned in the middle of the explosive column. Furthermore, the impact of multiple mid-air decks within explosive columns was also evaluated at Bench-4. A comparison of blast fragmentation results revealed that fragments obtained through the air decking technique surpassed those from the full-column charge, regardless of air deck placement. Among the tested air deck positions, the single air deck positioned at the middle of the explosive column yielded superior fragmentation results than other locations. In addition, this technique showed a reduction in explosive charge, back break, and toe-related issues.