ASTM International Committee D18 on Soil and Rock has recently approved a new standard, D 6938, Test Methods for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth). The new standard, which is under the jurisdiction of Subcommittee D18.08 on Special and Construction Control Tests, consolidates the information contained in two other D18.08 standards, D 2922, Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth), and D 3017, Test Method for Water Content of Soil and Rock in Place by Nuclear Methods (Shallow Depth). The result is a single, comprehensive standard that covers the use of nuclear surface moisture density gauges in soils.

“D 6938 provides guidance for the use and selection of nuclear surface moisture-density gauges for testing the dry density, moisture content and level of compaction of soil and soil-aggregate, and for the evaluation of these test results,” says Dan Pratt, a D18.08 subcommittee member and senior nuclear project physicist, Troxler Electronic Laboratories, Inc. Pratt says the standard will be a useful document for field users of nuclear surface moisture-density gauges, quality assurance and design engineers who specify such gauges and gauge manufacturers and service providers.
 
Pratt notes that the subcommittee welcomes participation, comments and suggestions for future revisions of D 6938. While Pratt says that the majority of gauge manufacturers are already active participants in D18.08, he would like to see more participation from gauge users on the subcommittee.
 
“Like all ASTM standards, D 6938 is a living document and several ideas are already being considered for future revisions,” says Pratt. One such idea is what Pratt calls a “synthesis” of D 6938 with D 7013, Guide for Nuclear Surface Moisture and Density Gauge Calibration Facility Setup, with a goal of creating one standard devoted to gauge usage and a second standard devoted to gauge calibration and performance evaluation.
 
For further technical information, contact Dan Pratt, Troxler Electronic Laboratories, Inc., Research Triangle Park, N.C. (phone: 919/314-2707; dpratt@troxlerlabs.com). Committee D18 will meet June 24-27, 2007, at the June Committee Week in Norfolk, Va. For membership or meeting information, contact Robert Morgan, manager, Technical Committee Operations, ASTM International (phone: 610/832-9732; rmorgan@astm.org).

Release #7572