ASTM_D_5918_-_13.pdf

Designation:D591813Standard Test Methods forFrost Heave and Thaw Weakening Susceptibility of Soils1This standard is issued under the fixed designation D5918;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 These laboratory test methods cover the frost heave andthaw weakening susceptibilities of soil that is tested in thelaboratory by comparing the heave rate and thawed bearingratio2with values in an established classification system.Thistest was developed to classify the frost susceptibility of soilsused in pavements.It should be used for soils where frost-susceptibility considerations,based on particle size such as thelimit of 3%finer than 20 mm in Specification D2940,areuncertain.This is most important for frost-susceptibility crite-ria such as those used by the Corps of Engineers,3that requirea freezing test for aggregates of inconclusive frost classifica-tion.The frost heave susceptibility is determined from theheave rate during freezing.The thaw weakening susceptibilityis determined with the bearing ratio test(see Test MethodD1883).1.2 This is an index test for estimating the relative degree offrost-susceptibility of soils used in pavement systems.It cannotbe used to predict the amount of frost heave nor the strengthafter thawing,nor can it be used for applications involvinglong-term freezing of permafrost or for foundations of refrig-erated structures.1.3 The test methods described are for one specimen anduses manual temperature control.It is suggested that fourspecimens be tested simultaneously and that the temperaturecontrol and data taking be automated using a computer.1.4 All recorded and calculated values shall conform to theguide for significant digits and rounding established in PracticeD6026.1.4.1 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 becommensurate with these considerations.It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering design.1.4.2 Measurements made to more significant digits orbetter sensitivity than specified in this standard shall not beregarded a nonconformance with this standard.1.5 This standard is written using SI units.Inch-pound unitsare provided for convenience.The values stated in inch poundunits may not be exact equivalents;therefore,they shall beused independently of the SI system.Combining values fromthe two systems may result in nonconformance with thisstandard.1.5.1 The gravitational system of inch-pound units is usedwhen dealing with inch-pound units.In this system,the pound(lbf)represents a unit of force(weight),while the unit for massis slugs.The rationalized slug unit is not given,unless dynamic(F=ma)calculations are involved.1.5.2 It is common practice in the engineering/constructionprofession to concurrently use pounds to represent both a unitof mass(lbm)and of force(lbf).This implicitly combines twoseparate systems of units;that is,the absolute system and thegravitational system.It is scientifically undesirable to combinethe use of two separate sets of inch-pound units within a singlestandard.As stated,this standard includes the gravitationalsystem of inch-pound units and does not use/present the slugunit for mass.However,the use of balances or scales recordingpounds of mass(lbm)or recording density in lbm/ft3shall notbe regarded as nonconformance with this standard.1.6 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.1These test methods are under the jurisdiction ofASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.19 on Frozen Soilsand Rock.Current edition approved Feb.1,2013.Published March 2013.Originallyapproved in 1996.Last previous edition approved in 2006 as D5918 06.DOI:10.1520/D5918-13.2Sometimes called California Bearing Ratio(CBR).3The Army Corps of Engineers uses a frost susceptibility classification proce-dure(TM 5-818-2)based on particle size criteria and the Unified Soil ClassificationSystem(MIL-STD-619)field.Furthermore,this test should only be used forseasonal freezing and thawing conditions and not for long-term freezing ofpermafrost or of foundations