ASTM_D_8167_-_D_8167M_-_18a.pdf

Designation:D8167/D8167M18aStandard Test Method forIn-Place Bulk Density of Soil and Soil-Aggregate by a Low-Activity Nuclear Method(Shallow Depth)1This standard is issued under the fixed designation D8167/D8167M;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.Scope*1.1 This test method describes the procedures for measuringin-place bulk density of soil and soil-aggregate using nuclearequipment with radioactive sources(hereafter referred tosimply as“gauges.”)These gauges are distinct from thosedescribed in Test Method D6938 insofar as:1.1.1 These gauges do not contain a system(nuclear orotherwise)for the determination of the water content of thematerial under measurement.1.1.2 These gauges have photon yields sufficiently low as torequire the inclusion of background radiation effects on theresponse during normal operation.1.1.2.1 For the devices described in Test Method D6938,thecontribution of gamma rays detected from the naturally-occurring radioisotopes in most soils(hereafter referred to as“background”)compared to the contribution of gamma raysused by the device to measure in-place bulk density is typicallysmall enough to be negligible in terms of their effect onmeasurement accuracy.However,for these low-activitygauges,the gamma ray yield from the gauge is low enough thatthe background contribution from most soils compared to thecontribution of gamma gays from the gauge is no longernegligible,and changes in this background can adversely affectthe accuracy of the bulk density reading.1.1.2.2 In order to compensate for potentially differingbackground contribution to low-activity gauge measurementsat different test sites,a background reading must be taken inconjunction with gauge measurements obtained at a given testsite.This background reading is utilized in the bulk densitycalculation performed by the gauge with the goal of minimiz-ing these background effects on the density measurementaccuracy.1.2 For limitations see Section 5 on Interferences.1.3 The bulk density of soil and soil-aggregate is measuredby the attenuation of gamma radiation where the source isplaced at a known depth up to 200 mm 8 in.and thedetector(s)remains on the surface(some gauges may reversethis orientation).1.3.1 The bulk density of the test sample in mass per unitvolume is calculated by comparing the detected rate of gammaradiation with previously established calibration data.1.3.2 Neither the dry density nor the water content of thetest sample is measured by this device.However,the results ofthis test can be used with the water content or water mass perunit volume value determined by alternative methods todetermine the dry density of the test sample.1.4 The gauge is calibrated to read the bulk density of soilor soil-aggregate.1.5 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.5.1 For purposes of comparing,a measured or calculatedvalue(s)with specified limits,the measured or calculatedvalue(s)shall be rounded to the nearest decimal or significantdigits in the specified limits.1.5.2 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that should generally be retained.The proce-dures used do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ations for the users objectives;and it is common practice toincrease or reduce significant digits of reported data to com-mensurate with these considerations.It is beyond the scope ofthis standard to consider significant digits used in analysismethods for engineering design.1.6 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues 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.Reporting test results in unitsother than SI shall not be regarded as nonconformance withthis standard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.08 on Special andConstruction Control Tests.Current edition approved Nov.15,2018.Published November 2018.Originallyapproved in 2018.Last previous edition approved in 2018 as D8167/D8167M18.DOI:10.1520/D8167_D8167M18A.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohock