Designation:C856−17StandardPracticeforPetrographicExaminationofHardenedConcrete1ThisstandardisissuedunderthefixeddesignationC856;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticeoutlinesproceduresforthepetrographicexaminationofsamplesofhardenedconcrete.Thesamplesexaminedmaybetakenfromconcreteconstructions,theymaybeconcreteproductsorportionsthereof,ortheymaybeconcreteormortarspecimensthathavebeenexposedinnaturalenvironments,ortosimulatedserviceconditions,orsubjectedtolaboratorytests.Thephrase“concreteconstructions”isintendedtoincludeallsortsofobjects,units,orstructuresthathavebeenbuiltofhydrauliccementconcrete.NOTE1—Aphotographicchartofmaterials,phenomena,andreactionproductsdiscussedinSections8–13andTables1-6areavailableasAdjunctC856(ADJCO856).1.2Thepetrographicproceduresoutlinedhereinareappli-cabletotheexaminationofsamplesofalltypesofhardenedhydraulic-cementmixtures,includingconcrete,mortar,grout,plaster,stucco,terrazzo,andthelike.Inthispractice,thematerialforexaminationisdesignatedas“concrete,”eventhoughthecommentarymaybeapplicabletotheothermixtures,unlessthereferenceisspecificallytomediaotherthanconcrete.1.3Thepurposesofandproceduresforpetrographicexami-nationofhardenedconcretearegiveninthefollowingsections:SectionQualificationsofPetrographersandUseofTechnicians4PurposesofExamination5Apparatus6SelectionandUseofApparatus7Samples8ExaminationofSamples9SpecimenPreparation10VisualandStereomicroscopeExamination11PolarizingMicroscopeExamination12PasteFeatures13Report141.4Thevaluesstatedininch-poundunitsaretoberegardedasthestandard.TheSIunitsinparenthesesareprovidedforinformationpurposesonly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishapp...
