ASTM D7380_D7380M-21 - Standard Test Method for Soil Compaction Determination at Shallow Depths Using 2.3-kg [5-lbm] Dynamic Cone Penetrometer

1.1 This test method covers the procedure for the determination of the number of drops required for a dynamic cone penetrometer with a 2.3-kg [5-lbm] drop hammer falling 508 mm [20 in.] 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 37 mm [1.5 in.].

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 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Within the text of this standard, SI units appear first followed by the inch-pound [or other non-SI] units in brackets. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.

1.6 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 implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. This standard has been written using the absolute 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.

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

1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.