Significance and Use
5.1 These test methods are used to determine the in-place density of compacted materials in construction of earth embankments, road fills, and structure backfill. For construction control, the test methods can be used as the basis for acceptance of material compacted to a specified unit weight or to a percentage of a maximum unit weight determined by a standard laboratory test method such as determined from Test Methods D698 or D1557, subject to the limitations discussed in 1.4.
5.2 These test methods can be used to determine in-place density of natural soil deposits, aggregates, soil mixtures, or other similar material.
Scope
1.1 These test methods cover the determination of the in-place density of soil and rock using water to fill a lined test pit to determine the volume of the test pit. The use of the word “rock” in these test methods is used to imply that the material being tested will typically contain particles larger than 3 in. [75 mm].
1.2 These test methods are best suited for test pits with a volume between approximately 3 and 100 ft3 [0.08 and 2.83 m3]. In general, the materials tested would have maximum particle sizes over 5 in. [125 mm]. These test methods may be used for larger sized excavations if desirable.
1.2.1 This procedure is usually performed using circular metal templates with inside diameters of 3 ft [0.9 m] or more. Other shapes or materials may be used providing they meet the requirements of these test methods and the guidelines given in Annex A1 for the minimum volume of the test pit.
1.2.2 Test Method D4914 may be used as an alternative method. Its use, however, is usually only practical for volume determination of test pits between approximately 1 and 6 ft3 [0.03 and 0.17 m3].
1.3 The two procedures are described as follows:
1.3.1 Procedure A—In-Place Density and Unit Weight of Total Material (Section 12).
1.3.2 Procedure B—In-Place Density and Unit Weight of Control Fraction (Section 13).
1.4.1 Procedure A is used when the in-place unit weight of total material is to be determined. Procedure A can also be used to determine percent compaction or percent relative density when the maximum particle size present in the in-place material being tested does not exceed the maximum particle size allowed in the laboratory compaction test (Test Methods D698, D1557, D4253, D4254, D4564, and D7382). For Test Methods D698 and D1557 only, the unit weight determined in the laboratory compaction test may be corrected for larger particle sizes in accordance with, and subject to the limitations of, Practice D4718.
1.4.2 Procedure B is used when percent compaction or percent relative density is to be determined and the in-place material contains particles larger than the maximum particle size allowed in the laboratory compaction test or when Practice D4718 is not applicable for the laboratory compaction test. Then the material is considered to consist of two fractions, or portions. The material from the in-place unit weight test is physically divided into a control fraction and an oversize fraction based on a designated sieve size. The unit weight of the control fraction is calculated and compared with the unit weight(s) established by the laboratory compaction test(s).
1.4.3 Normally, the control fraction is the minus No. 4 [4.75-mm] sieve size material for cohesive or nonfree-draining materials and the minus 3-in. [75-mm] sieve size material for cohesionless, free-draining materials. While other sizes are used for the control fraction 3/8 , 3/4-in. [9.5, 19-mm], these test methods have been prepared using only the No. 4 [4.75-mm] and the 3-in. [75-mm] sieve sizes for clarity.
1.5 Any material can be tested, provided the material being tested has sufficient cohesion or particle attraction to maintain stable sides during excavation of the test pit and through completion of this test. It should also be firm enough not to deform or slough due to the minor pressures exerted in digging the hole and filling with water.
1.6 These test methods are generally limited to material in an unsaturated condition and is not recommended for materials that are soft or friable (crumble easily) or in a moisture condition such that water seeps into the excavated hole. The accuracy of the test may be affected for materials that deform easily or that may undergo volume change in the excavated hole from standing or walking near the hole during the test.
1.7 Units—The values stated in either inch-pound units or SI units [presented in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.7.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The slug unit is not given, unless dynamic (F = ma) calculations are involved.
1.7.2 In the engineering profession, it is customary practice to use, interchangeably, units representing both mass and force, unless dynamic calculations (F = Ma) are involved. This implicitly combines two separate systems of units, that is, the absolute system and the gravimetric system. It is scientifically undesirable to combine the use of two separate systems within a single standard. These test methods have been written using inch-pound units (gravimetric system) where the pound (lbf) represents a unit of force (weight); however, conversions are given in the SI system. The use of balances or scales recording pounds of mass (lbm), or the recording of density in lbm/ft3 should not be regarded as nonconformance with this standard.
1.8 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.
1.8.1 The procedures used to specify how data are collected, recorded or calculated in this standard are regarded as the industry standard. In addition they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design.
1.9 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. For a specific hazard statement, see Section 9.
