ASTM D698:12(R2021) pdf free download – Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 f-lb_/ft3 (600 kN-m/m3)).
5.3.1 Oversize Fraction—Soils containing more than 30 % oversize fraction (material retained on the ¾-in. 19-mm) sieve) are a problem. For such soils, there is no ASTM test method to control their compaction and very few laboratories arc equipped to determine the laboratory maximum unit weight (density) of such soils (USD1 Bureau of Reclamation. Denver. CO and U.S. Army Corps of Engineers, Vicksburg. MS). Although Test Methods D4914/t)4914M and D5030/D5030M determine the “field” dry unit weight of such soils, they arc difficult and expensive to perform.
5.3.1.1 One method to design and control the compaction of such soils is to use a test fill to determine the required degree ot compaction and the method to obtain that compaction, followed by use of a method specification to control the compaction. Components of a method specification typically contain the type and size of compaction equipment to be used, the lift thickness, acceptable range in molding water content. and the number of passes.
Note 3—Success in eXecUtifl the compaction control of an earthWork project. especially when a method specification is used. is highly dependent upon the quality and experience of the contractor and inspector.
5.3.1.2 Another method is to apply the use of density correction factors developed by the USD1 Bureau of Reclamation (2. 3) and U.S. Corps of Engineers 14). These correction factors may he applied for soils containing up to about 50 to 70 % oversize fraction. Each agency uses a diticrent term for these density correction factors. The USD1 Bureau of Reclamation uses 0 ratio (or 0—VALUE), while the U.S. Corps of Engineers uses Density Interference Cocflicicnt.
5.3.1.3 The use of the replacement technique (Test Method 1698—78. Method D), in which the oversize fraction is replaced with a finer fraction, is inappropriate to determine the maximum dry unit weight of soils containing oversize fractions (4).
5.3.2 Degradation—Soils containing particles that degrade during compaction are a problem, especially when more degradation occurs during laboratory compaction than field compaction, as is typical. Degradation typically occurs during the compaction of a granular-residual soil or aggregate. When degradation occurs, the maximum dry-unit weight increases so that the laboratory maximum value is not representative of field conditions. Often, in these cases, the maximum dry unit weight is impossible to achieve in the field.
5.3.2.1 Again, for soils subject to degradation. the use of test fills and method specifications may help. Use of replacement techniques is not correct.
5.3.3 Gap Graded—aap-graded soils (soils containing many large particles with limited small particles) are a problem because the compacted soil will have larger voids than usual. To handle these large voids, standard test methods (laboratory or field) typically have to be modified using engineering judgement.
Note 4—The quality of the result produced by this standard is dependent on the competence of the personnel performing it. and the suitability of the equipment and lacilities used. Agencies that meet the criteria of Practice 1)3744) are generally considered capable of competent and ohjcctivc tc-sting/samplinthnspcction. arid the like. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors.