ASTM_D_6951_-_D_6951M_-_09_2015.pdf

Designation:D6951/D6951M09(Reapproved 2015)Standard Test Method forUse of the Dynamic Cone Penetrometer in ShallowPavement Applications1This standard is issued under the fixed designation D6951/D6951M;the number immediately following the designation indicates theyear of original adoption or,in the case of 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.Scope1.1 This test method covers the measurement of the pen-etration rate of the Dynamic Cone Penetrometer with an 8-kg17.6-lb hammer(8-kg 17.6-lb DCP)through undisturbedsoil or compacted materials,or both.The penetration rate maybe related to in situ strength such as an estimated in situ CBR(California Bearing Ratio).A soil density may be estimated(Note 1)if the soil type and moisture content are known.TheDCP described in this test method is typically used forpavement applications.1.2 The test method provides for an optional 4.6-kg 10.1-lb sliding hammer when the use of the 8-kg 17.6-lb slidingmass produces excessive penetration in soft ground conditions.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 8-kg 17.6-lb DCP dynamic cone penetrometer withan 8-kg 17.6-lb hammer(see Fig.1)a device used to assessthe in situ strength of undisturbed soil or compacted materials,or both.2.1.2 sliding attachment(see Fig.1)an optional deviceused in reading the distance the DCP tip has penetrated.It maybe fastened to the anvil or lower rod to hold/slide along aseparate measuring rod,or it may be fastened to the separaterod and slide along a graduated drive rod.3.Summary of Test Method3.1 The operator drives the DCP tip into soil by lifting thesliding hammer to the handle then releasing it.The totalpenetration for a given number of blows is measured andrecorded in mm/blow,which is then used to describe stiffness,estimate an in situ CBR strength from an appropriate correla-tion chart,or other material charcharacteristics.4.Significance and Use4.1 This test method is used to assess in situ strength ofundisturbed soil and compacted materials(or both).Thepenetration rate of the 8-kg 17.6-lb DCP can be used toestimate in-situ CBR(California Bearing Ratio),to identifystrata thickness,shear strength of strata,and other materialcharacteristics.4.1.1 Other test methods exist for DCPs with differenthammer weights and cone tip sizes,which have correlationsthat are unique to the instrument.4.2 The 8-kg 17.6-lb DCP is held vertically and thereforeis typically used in horizontal construction applications,suchas pavements and floor slabs.4.3 This instrument is typically used to assess materialproperties down to a depth of 1000 mm 39 in.below thesurface.The penetration depth can be increased using drive rodextensions.However,if drive rod extensions are used,careshould be taken when using correlations to estimate otherparameters since these correlations are only appropriate forspecific DCPconfigurations.The mass and inertia of the devicewill change and skin friction along drive rod extensions willoccur.4.4 The 8-kg 17.6-lb DCP can be used to estimate thestrength characteristics of fine-and coarse-grained soils,granu-lar construction materials and weak stabilized or modifiedmaterials.The 8-kg 17.6-lb DCP cannot be used in highlystabilized or cemented materials or for granular materialscontaining a large percentage of aggregates greater than 50 mm2 in.1This test method is under the jurisdiction of ASTM Committee E17 on Vehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.41 onPavement Testing and Evaluation.Current edition approved May 1,2015.Published July 2015.Originally approvedin 2003.Last previous edition approved in 2009 as D6951/D6951M 09.DOI:10.1520/D6951_D6951M-09R15.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.5 The 8-kg 17.6-lb DCP can be used to estimate thestrength of in situ materials underlying a bound or highlystabilized layer by first drilling or coring an access hole.NOTE1The DCPmay be used to assess the density of a fairly uniformmaterial by relating density to penetration rate on the same material.Inthis way undercompacted or“soft spots”can be identified,even thoughthe DCP does not measure density directly.24.5.1 A field DCP measurement results