Responding to requests from industry, ASTM International Committee D18 on Soil and Rock is developing a proposed new standard for measuring rock abrasivity, which will aid mechanical excavation projects in several ways.
The proposed standard, ASTM 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.
“The proposed standard will help in better equipment selections for a mechanical excavation project and will provide better performance prediction of mechanical excavation machines,” says Dr. Hamid Nazeri, rock mechanics division manager of Advanced Terra Testing Inc. and a member of D18 and the task group.
Dr. Nazeri notes that the proposed new standard will be useful in several ways. It 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 standard will provide information on a machine’s down time and associated cost of possible bit repair/change by providing an index for estimation of bit wear.
Dr. Nazeri also says that the proposed standard 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. Mining and civil engineers, mechanical excavation, drilling contractors, manufacturers of mechanical excavation machines and rock drilling bit/equipment will be the primary users of ASTM WK22313.
Participation from all interested parties, particularly those who use the CERCHAR abrasivity index, is encouraged in the further development of ASTM WK22313.
For technical Information, contact Dr. Hamid Nazeri, Advanced Terra Testing Inc., Lakewood, Colo. (phone: 303-232-8308; hnazeri@terratesting.com); or Bernie Gorski, Natural Resources Canada, Ottawa, Canada (phone: 613-996-3216, bgorski@nrcan.gc.ca). Committee D18 will meet June 14-17 during the June committee week in Vancouver, British Columbia, Canada.
ASTM International welcomes and encourages participation in the development of its standards. ASTM’s open consensus process, using advanced Internet-based standards development tools, ensures worldwide access for all interested individuals. For more information on becoming an ASTM member, please contact Robert Morgan, ASTM International (phone: 610-832-9732; rmorgan@astm.org).
Release #8267/June2009
