ASTM D7380-15

1.1This 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.

1.2The 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.

1.3The 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).

1.4The 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.

1.5The 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.

1.6It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. This standard has been written using the gravitational system of units 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.

1.7All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.

1.8This 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.