ASTM International Committee D18 on Soil and Rock is developing a proposed new standard for measuring rock abrasivity. The proposed standard, WK22313, Test Method for Laboratory Determination of Abrasivity of Rock Using the CERCHAR Method, is under the jurisdiction of Subcommittee D18.12 on Rock Mechanics.
ASTM WK22313 covers the determination of rock abrasivity using the CERCHAR abrasivity index, which measures the wear on a steel cone caused by scratching a freshly broken rock surface. “Advances in underground excavation methods, particularly the use of tunnel boring machines, have led to an increasing need for knowledge about the rock abrasivity,” says Bernie Gorski, Geomechanics Project Leader, Natural Resources Canada, subcommittee chair of D18.12 and a WK22313 task group member.
“WK22313 will help in better equipment selections for a mechanical excavation project and will provide better performance prediction of mechanical excavation machines,” says Hamid Nazeri, Rock Mechanics Division Manager, Advanced Terra Testing Inc., and a member of D18 and the task group.
WK22313 will allow for a better assessment of a rock formation’s suitability for mechanical excavation as well as better performance prediction of selected mechanical excavation machines. In addition, the proposed standard will provide information on a machine’s down time and associated cost of possible bit repair/change.
Nazeri says that WK22313 has the potential to reduce the number of legal disputes among contractors, project owners and consultants by providing more knowledge about the physical properties of rock. Participation from all interested parties is encouraged in the further development of ASTM WK22313.
Technical Information: Hamid Nazeri, Advanced Terra Testing Inc., Lakewood, Colo.
Bernie Gorski, Natural Resources Canada, Ottawa, Ontario, Canada
ASTM Staff: Robert Morgan