ASTM D5080-20

5.1 The rapid method is performed to quickly evaluate percent compaction and variation from optimum water content of soils used in construction without knowing the value of field water content at the time of the test.

5.2 Test results may be used to determine if the compacted material meets density and water content control values that are specified as a percentage of a standard maximum density and optimum water content such as determined in Method A of Test Methods D698. A three-point compaction curve is used in place of the four- or five-point curve required in Test Methods D698.

5.3 This test method is based on the assumption that a three-point compaction curve is a parabola at the section of the curve close to optimum water content so that the peak point of the curve can be determined mathematically. This assumption results in the major difference between this test method and obtaining the maximum density and optimum water content from a full five-point compaction curve.

5.4 Once the field ovendry water content has been determined in accordance with Test Methods D2216, the values of dry density, dry unit weight, and optimum water content can be calculated (see Note 1).

5.5 This test method can also be used for foundation or borrow area material to compare in-place dry density and unit weight and water content to laboratory maximum dry density and unit weight and optimum water content.

5.6 This test method has the advantage that the maximum density value can be obtained on the same soil excavated during the in-place density test.

1.1 This test method describes the procedure for rapidly determining the percent compaction and the variation from optimum water content of an in-place soil for use in controlling construction of compacted earth. These values are obtained by developing a three-point compaction curve at the same water content as the in-place soil without knowing the value of the water content. The soil used for the compaction curve is normally the same soil removed from the in-place density test. For the remainder of this designation, this test method will be referred to as the 1.2 This test method is normally performed for soils containing more than 15 % fines (minus 75-µm (No. 200) sieve size).

1.3 When gravel-size particles are present in the soil being tested, this test method is limited to a comparison of the minus 4.75-mm (No. 4) sieve-size fraction of the in-place density material to a laboratory compaction test of minus 4.75-mm (No. 4) sieve-size material (Method A of Test Methods D698). Subject to the limitations of Practice D4718/D4718M, this test method is also applicable to comparisons of other sieve-size fractions (for example, Method C of Test Methods D698) or other compactive efforts (for example, Test Methods D1557) if new water content adjustment values are determined (see 6.1 and Appendix X2).

1.4 Units—The values stated in SI units are to be regarded as standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.

1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 unless superseded by this standard.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 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.