1、Designation: D2844/D2844M 13D2844/D2844M 18Standard Test Method forResistance R-Value and Expansion Pressure of CompactedSoils1This standard is issued under the fixed designation D2844/D2844M; the number immediately following the designation indicates theyear of original adoption or, in the case of
2、revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the procedure for testing both treated and untreated laboratory compact
3、ed soils or aggregates withthe stabilometer and expansion pressure devices to obtain results indicative of performance when placed in the base, subbase, orsubgrade of a road subjected to traffic.1.2 UnitsThe values stated in either SI units or inch-pound units presentedpresented in bracketsbrackets
4、are to be regardedseparately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the standard. However,use of equipment manufactured to be
5、readable in inch-pound units only should not be considered as non-conformance to the testmethod. Many stabilometers and expansion pressure devices are manufactured to be readable in inch-pound units only.1.3 All observed and calculated values shall conform to the guidelines for significant digits an
6、d rounding established in PracticeD6026.1.3.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shallbe rounded to the nearest decimal or significant digits in the specified limits.1.3.2 The procedures used to specify how data are co
7、llected/recorded or calculated, in this standard are regarded as the industrystandard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do notconsider material variation, purpose for obtaining the data, special purpose studies, or
8、any considerations for the users objectives;and 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.1.4 Th
9、is standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior t
10、o use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers
11、 to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction MaterialsD653 Terminology Relating to Soil, Rock, and Contained FluidsD3740 Practice for Minimum Requirements for Agencies Engaged in Testi
12、ng and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD6026 Practice for Using Significant Digits in Geotechnical DataE4 Practices for Force Verification of Testing MachinesE11 Specification for Woven Wire Test Sieve Cloth and Test Sieves1 This test method is under the j
13、urisdiction ofASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.08 on Special and ConstructionControl Tests.Current edition approved Jan. 1, 2013May 1, 2018. Published February 2013May 2018. Originally approved in 1969. Last previous edition approved in 2007201
14、3 as D2844 0713.1. DOI: 10.1520/D2844_D2844M-13.10.1520/D2844_D2844M-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the AS
15、TM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consul
16、t prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, P
17、A 19428-2959. United States12.2 AASHTO Documents:T 190 Test Method for Resistance R-Value and Expansion Pressure of Compacted Soils32.3 ASTM Adjuncts:4Exudation DeviceExpansion Pressure ApparatusStabilometer2.4 CALTRANS Standard:5California Test 103 Method of Test For Calibration of Expansion Pressu
18、re Devices3. Terminology3.1 For definitions of terms in this test method, refer to Terminology D653.4. Significance and Use4.1 This test method is used to measure the potential strength of subgrade, subbase, and base course materials for use in roadand airfield pavements. The R-value is used by some
19、 agencies as criteria for acceptance of aggregates for base course andbituminous courses.4.2 The expansion pressure testing has been used in conjunction with the R-value test to determine cover requirements(thickness) and construction controls to reduce pavement distortion from expansive subgrade so
20、ils.NOTE 1The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of theequipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objectivetesting/s
21、ampling/inspection/etc. Users of this test method are cautioned that compliance with Practice D3740 does not in itself ensure reliable results.Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.5. ApparatusNOTE 2The inch-pound dimensions pres
22、ented in brackets, found in this section are for equipment commonly available in the United States.5.1 Kneading Compactor, capable of applying an average contact pressure of 24106 110 kPa 350 6 16 psi to the tamper footshown in Fig. 1 and with provisions for maintaining this pressure during changes
23、in sample height. The load-time trace shall befree of “chatter” or evidence of impact-associated changes in slope. The rise time for application of foot pressure, in the range from240 to 2070 kPa 35 to 300 psi, shall be 0.07 to 0.20 seconds. The dwell time, measured at 2070 kPa 300 psi foot pressure
24、, shallbe 0.15 to 0.45 seconds. The pressure-release or removal time shall not be greater than 0.60 seconds.3 Available from American Association of State Highway and Transportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.4 Copies of d
25、etailed drawings of the apparatus shown in Figs. 4 (1 drawing), 7 (4 drawings), 10 and 11 (7 drawings) are available at a nominal cost fromASTM InternationalHeadquarters. Request Adjunct Nos. ADJD284401,ADJD284402, and ADJD284403, respectively.5 Available from State of California Department of Trans
26、portation (CALTRANS), P.O. Box 942873, Sacramento, CA 94273-0001, http:/www.dot.ca.gov. Proving LeverAssembly detailed drawings are available here as well.FIG. 1 Tamper Shoe for Kneading CompactorD2844/D2844M 1825.1.1 The compactor shall include a counter for measuring the number of tamps applied to
27、 a specimen and a mold holder, foruse in compacting specimens, that rotates equally between tamps to give 5 to 7 tamps per revolution of the mold. The holder shallfirmly restrain the mold during compaction. The base of the mold holder shall have a metal plate 100.8 mm 3 3132 in. in diameterand 12.7
28、mm 0.5 in. in height, to which is cemented a rubber disk having a diameter of 100.0 mm 3 1516 in. and a thicknessof 3.2 mm 18 in. The plate shall be an integral part of the base of the mold holder. The compactor shall also include a troughfor feeding the sample into the mold in 20 increments (Fig. 2
29、). Troughs with a semicircular cross section of 39 cm2 6.0 in.2 inarea and 50.8 cm 20 in. in length have proven satisfactory.5.2 Compression Testing Machine, with a minimum capacity of 45 kN 10 000 lbf and satisfying the requirements of PracticesE4.5.3 Mold, 101.6 6 0.05 mm 4.0 6 0.002 in. inside di
30、ameter by 127 6 0.20 mm 5.0 6 0.008 in. high. (See Fig. 3 for surfaceroughness.)5.4 Rubber Disks, 100 mm 3 1516 in. in diameter by 3 mm 18 in. thick and having a durometer hardness of 60 6 15.5.5 Metal Follower, solid-walled, metal specimen follower 100.33 6 0.13 mm 3.95 6 0.005 in. in outside diame
31、ter by 127mm 5.0 in. long.5.6 Exudation Indicator Device, as shown in Fig. 44 and Fig. 5.5.7 Phosphor Bronze Disk, as shown in Fig. 6.5.8 Filter Paper, 100 mm 4.0 in. in diameter and 0.15 mm 0.006 in. thick, with a smooth surface, medium filtering speed,medium retention.5.9 Filter Paper, 110 mm 4.3
32、in. in diameter and 0.15 mm 0.006 in. thick, with a creped surface, medium-fast filtering speed,and medium retention.5.10 Expansion-Pressure Device, with accessories as shown in Fig. 7. 4 There should be at least three of these devices for eachsample to be tested within a days time.FIG. 2 Compactor
33、with Sample Feed TroughD2844/D2844M 1835.11 Deflection Gage, with divisions of 0.002 mm 0.0001 in. and an allen wrench as shown in Fig. 7.5.12 Proving Lever Assembly, as shown in Fig. 8 and Fig. 9.55.13 Stabilometer, with accessories, as shown in Fig. 10 and Fig. 11.45.14 Standard Metal Specimen, 10
34、1.6 mm 4.0 in. in outside diameter by 152.2 mm 6.0 in. high as shown in Fig. 11.5.15 Balance, 5000-g capacity, accurate and readable to 1 g.5.16 Sieves, 25.0 mm 1 in., 19.0 mm 34 in. and 4.75 mm No. 4 conforming to the requirements of Specification E11.5.17 Miscellaneous Equipment, including mixing
35、pans, spoons, spatulas, and gallon cans with close-fitting lids.6. Soil Preparation6.1 Remove any coatings from coarse aggregate and break clay lumps to pass the 4.75-mm No. 4 sieve.6.2 Adjust the soil gradation when material is retained on the 19.0-mm 34-in. sieve. When 75 % or more passes the 19.0
36、-mm34-in. sieve, use that part of the sample passing the 19.0-mm 34-in. sieve. If less than 75 % of the sample passes the 25.0-mm1-in. sieve, use that part of the sample passing the 25.0-mm 1-in. sieve. See Table 1 for a sample calculation.7. Preparation of Soil Specimens7.1 Thoroughly mix four appr
37、oximately 1200-g 2.7-lb samples of soil with the amount of water estimated to equal one halfto two thirds of the water required to produce saturation as defined in 7.3 and 7.4. Place the samples in covered containers andNOTE 1Inside roughness is obtained by smooth machining inside to required diamet
38、er of 101.6 6 0.05 mm 4.000 6 0.002 in. followed on finaloperation with a boring tool bit ground to a 90 point with sharp point ground flat measuring 0.025 to 0.075 mm 0.001 to 0.003 in. across. Depth ofcut is 0.050 mm 0.002 in. with 0.25 mm 0.010 in. feed using sulfur-based oil coolant.FIG. 3 MoldD
39、2844/D2844M 184FIG. 4 Circular Exudation-Indicator DeviceFIG. 5 Linear Exudation-Indicator DeviceD2844/D2844M 185allow them to stand overnight. Just prior to compaction, mix the samples with the final amount of water required to producesaturation. The first sample is used as a pilot specimen to assi
40、st in determining the final amount of water required.7.2 Weigh out enough material to fabricate a compacted sample 101.6 mm 4.0 in. in diameter by 63 mm 2.5 in. high.Compacted specimens having heights from 62 to 65 mm 2.45 to 2.55 in. are acceptable. Compact the soil into the mold by meansof the kne
41、ading compactor as follows: Place the mold over the mold holder. Adjust the mold for approximately 3-mm 18-in.clearance between the lower edge of the mold and base of the mold holder. A metal angle bracket of 3-mm 18-in. thickness andapproximately 37.5 mm 112 in. length placed on the base of the mol
42、d holder have proven satisfactory. Alternately, tighten theset screw, if available, on the mold holder. Spread the sample along the length of the trough. With the compactor-foot pressure setat 1720 6 170 kPa 250 6 25 psi, feed 75 mm 3.0 in. of the soil from the trough into the mold. Redistribute the
43、 sampleremaining in trough as needed to feed the balance of the soil into the mold in 20 equal increments with one application of the ramafter each increment.Allow 10 additional tamps to level the soil, then place a rubber disk on top of the specimen. Remove the shimfrom under the mold or loosen the
44、 set screw. Apply 100 additional tamps with a foot pressure of 2410 kPa 350 psi. Stopcompacting the soil at any time before 100 tamps if water appears around the bottom of the mold.NOTE 3Use lower compaction pressures when necessary to limit penetration of the ram into the soil to not greater than 6
45、 mm 14 in.7.3 Remove the mold containing the compacted specimen from the compactor. Level the tamped surface by hand tamping witha 38-mm 1.5-in. diameter rod. Remove the rubber disks. Place a phosphor-bronze disk on the tamped surface of the soil and placea 100-mm filter paper on top of the bronze d
46、isk. Invert the mold and place it on the exudation device so that the filter paper is onthe bottom. Place the solid walled, metal specimen follower into the mold. Using the compression testing machine, apply auniformly increasing pressure to the soil at the rate of 8900 N 2000 lbf /min. Water should
47、 be exuded from the soil at 2070 kPa300 psi as evidence that enough moisture is present to produce saturation. Stop the loading and record the exudation pressureto the nearest 10 kPa 1 psi when either five of the six indicator lights on the exudation indicator device are lighted or threeindicator li
48、ghts are lighted and free water is visible around the bottom of the mold. Do not exceed a exudation pressure of 5520kPa 800 psi.7.4 Mold at least two more specimens with different amounts of moisture so that a range of exudation pressures from 690 to5520 kPa 100 to 800 psi is obtained bracketing the
49、 2070 kPa 300 psi value. For some high volume-change soils, additionalspecimens having exudation pressures lower than 690 kPa 100 psi may be necessary to obtain expansion pressures that are lowenough to provide a suitable range of data for a complete expansion pressure analysis of the soil.NOTE 4Occasionally, material from very plastic clay-test specimens will extrude from under the mold and around the follower ram during the loadingope
