Suggested tamping materials for short length blast holes in explosive demolition operations

The purpose of this study was to examine the effects of tamping materials on explosion gas blocking in blast holes. Three materials which were applicable for tamping procedures for the blasting: anhydrite (AD); ultra rapid hardening cement (UC) and glass fiber reinforced cement (GC). The tamping materials mixed with sand were filled in cylindrical paper containers. The wrapped tamping samples were then immerged in water. Temperature and elastic wave velocity during early curing time were measured to investigate the optimum hardening time and physical property change. Uniaxial compression and pushout shear tests were performed to estimate the tamping resistance in the blast hole. Finally, small a scale blast experiment with a cylindrical concrete sample was performed to verify the effectiveness of the suggested tamping materials on the blasting.