An Experimental Study on Determination of Crack Propagation Energy of Rock Materials under Dynamic (Impact) and Static Loading Conditions

Abstract

The Charpy impact test, a widely applied impact strength determination test for variousmaterials such as metals, polymers and cementitious materials was performed to evaluatethe crack propagation energy of 13 different granite type rock materials under the impactload condition. Additionally, crack propagation energies of the granite materials were determinedunder the static load condition to compare the results with those of the Charpyimpact test. The energy levels measured from static load tests were significantly lower thanthose obtained from the dynamic load test that the ratio of energy level under the dynamicloading to energy level under static loading condition was measured to change between 39and 200 for different 13 type of granite materials tested in this study. The crack propagationtime for the chevron-notched specimens under static loading was also measured using professionalsound recording systems. As results of this study have not indicated that the crackpropagation speed and energy values measured from different granite materials have a directrelationship, energy-dependent crack propagation speed was found to be an inherent propertyof rock materials. The Charpy impact test was assessed usable for being a sensitive crackpropagation energy determination method for rock materials. In the context of improvementof the Charpy impact test for rock materials, some issues were pointed out in this study.