Influence of index angle on specific energy in rock indentation test

Abstract

In the present work, static indentation tests were carried out in six types of rocks namely pink marble, limestone, basalt, steel gray granite, moon white granite and black galaxy granite using commercial drill bits of 35mm, 38mm, 45mm, 48mm diameters, aimed to know the influence of index (rotation)angle on specific energy. From the experimental data, Force-Penetration (F-P) curves were plotted and Specific energy (energy necessary to excavate a unit volume of rock) values were calculated from F-P curves for each bit rock combinations. The specific energies for the rocks (pink marble, limestone) at 30 index angle were found to be much less than the specific energies at other index angles. Similarly the specific energies for the rocks (basalt, steel gray granite, moon white granite and black galaxy granite) at 20 index angle were found to be much less than the specific energies at other index angles. 2015 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.