Designation:D7070−08StandardTestMethodsforCreepofRockCoreUnderConstantStressandTemperature1ThisstandardisissuedunderthefixeddesignationD7070;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thesetestmethodscoverthecreepbehaviorofintactsoftandhardrockcoreinfixedstatesofstressandtemperature.Theyspecifytheapparatus,instrumentation,andproceduresfordeterminingthestrainasafunctionoftimeundersustainedload.Hardrocksarethosewithamaximumaxialstrainatfailureoflessthan2%.Softrocksincludesuchmaterialsassaltandpotash,whichoftenexhibitverylargestrainatfailure.1.2ThisstandardreplacesandcombinesthefollowingStandardTestMethodsnowtobereferredtoasMethods:Method‘A’(D5341CreepofHardRockCoreSpecimensinUniaxialCompressionatAmbient/ElevatedTemperatures);Method‘B’(D4405CreepofSoftRockCoreSpecimensinUniaxialCompressionatAmbientorElevatedTemperature);andMethod‘C’(D4406CreepofRockCoreSpecimensinTriaxialCompressionatAmbientorElevatedTemperature).1.3AllobservedandcalculatedvaluesshallconformtotheguidelinesforsignificantdigitsandroundingestablishedinPracticeD6026.1.3.1Themethodusedtospecifyhowdataarecollected,calculated,orrecordedinthisstandardisnotdirectlyrelatedtotheaccuracytowhichthedatacanbeappliedindesignorotheruses,orboth.Howoneappliestheresultsobtainedusingthisstandardisbeyonditsscope.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesaremathematicalconversionstoinch-poundunitsthatareprovidedforinforma-tiononlyandarenotconsideredstandard.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesandtodeterminetheapplicabilityofregulatorylimitationspriortouse.Forspecificprecautionarystatements,seeSection7.2.Referenced...
