Designation:G13/G13M−13StandardTestMethodforImpactResistanceofPipelineCoatings(LimestoneDropTest)1ThisstandardisissuedunderthefixeddesignationG13/G13M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationoftherelativeresistanceofpipelinecoatingstoimpactbyobservingtheeffectsoffallingstonesoncoatedpipespecimens.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2G12TestMethodforNondestructiveMeasurementofFilmThicknessofPipelineCoatingsonSteel(Withdrawn2013)3G62TestMethodsforHolidayDetectioninPipelineCoat-ings2.2AASHTOStandard:4M80–51(No.67)SpecificationforCoarseAggregateforPortlandCementConcrete3.SummaryofTestMethod3.1Theimpactresistanceofpipelinecoatingsisdeterminedbydroppingweighedamountsofaspecifiedtypeoflimestonethroughachuteontoacoatedpipespecimen.Resultsarereportedasthenumberofdropsrequiredtopiercethroughthecoatingtobaremetal,asdeterminedvisuallyorelectrically.4.SignificanceandUse4.1Thistestmethodisintendedtosimulatetheeffectsofbackfillingafterpipehasbeenplacedinthetrench.Thebackfillisoftenrockysoiland,ifitisunscreenedandthecoatedpipeisunshieldedbysandorotherprotectivepadding,thefallingrocksmayseriouslydamagethecoating.5.Apparatus5.1TheimpactapparatusshallbeessentiallyasshowninFig.1andshallincludethefollowing:5.1.1BoxwithChut...
