ASTM D 7380 : 2008

1.1 This test method covers the procedure for the determination of the number of drops required for a dynamic cone penetrometer with a 5-lb (2.3-kg) drop hammer falling 20 in. (508 mm) to penetrate a certain depth in compacted backfill.

1.2 The device is used in the compaction verification of fine- and coarse-grained soils, granular materials, and weak stabilized or modified material used in subgrade, base layers, and backfill compaction in confined cuts and trenches at shallow depth.

1.3 The test method is not applicable to highly stabilized and cemented materials or granular materials containing a large percentage of aggregates greater than 1.5 in. (37 mm).

1.4 The method is dependent upon knowing the field water content and the user having performed calibration tests to determine cone penetration resistance of various compaction levels and water contents.

1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

Note 1—It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a force (lbf). This standard has been written using the gravitational system of units (lbf) when dealing with the inch-pound system. In this system, the pound (lbf) represents a unit of force (weight). However, the use of balances or scales recording pounds of mass (lbm) or the reading of density in lbm/ft³ shall not be regarded as a nonconformance with this standard.

1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D 6026.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.