This test method can be used to determine the in-place density and unit weight of natural inorganic soil deposits, soil-aggregate mixtures, or other similar firm materials.

This test method may be used to determine the density and unit weight of compacted soils used in construction of earth embankments, road fill, and structural backfill. This test method often is used as a basis of acceptance for soils compacted to a specified density or a percentage of maximum density or unit weight, as determined by a standard test method.

The use of this test method is generally limited to soil in an unsaturated condition and is not recommended for soils that are soft or that deform easily. Such soils may undergo a volume change during the application of pressure during testing. This test method may not be suitable for soils containing crushed rock fragments or sharp edge materials which may puncture the rubber membrane.

Note 1—Notwithstanding the statements on precision and bias contained in this test method, the precision of this test method is dependent on the competence of the personnel performing it and the suitability of the equipment and the facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D 3740 does not in itself ensure reliable testing. Reliable testing depends on many factors; Practice D 3740 provides a means of evaluating some of those factors.

1.1 This test method covers the determination of the in-place density and unit weight of compacted or firmly bonded soil using a rubber balloon apparatus.

1.2 This test method is suitable for use as a means of acceptance for compacted fill or embankments constructed of fine-grained soils or granular soils without appreciable amounts of rock or coarse material.

1.3 This test method also may be used for the determination of the in-place density and unit weight of undisturbed or in situ soils, provided the soil will not deform under the pressures imposed during the test.

1.4 This test method is not suitable for use in organic, saturated, or highly plastic soils that would deform under the pressures applied during this test. This test method may require special care for use on (1) soils consisting of unbonded granular materials that will not maintain stable sides in a small hole, (2) soils containing appreciable amounts of coarse material in excess of 1 1/2 in. (37.5 mm), (3) granular soils having high void ratios, or (4) fill materials containing particles with sharp edges. For soils containing appreciable amounts of particles in excess of 1 1/2in. (37.5 mm), Test Methods D 4914 or D 5030 should be used.

1.5 It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a unit of force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. 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/ft ³ should not be regarded as nonconforming with this test method.

1.6 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.