Designation:C1778−16StandardGuideforReducingtheRiskofDeleteriousAlkali-AggregateReactioninConcrete1ThisstandardisissuedunderthefixeddesignationC1778;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisguideprovidesguidanceonhowtoaddressthepotentialfordeleteriousalkaliaggregatereaction(AAR)inconcreteconstruction.Thisguideaddressestheprocessofidentifyingbothpotentiallyalkali-silicareactive(ASR)andalkali-carbonatereactive(ACR)aggregatesthroughstandard-izedtestingproceduresandtheselectionofmitigationoptionstominimizetheriskofexpansionwhenASRaggregatesareusedinconcreteconstruction.MitigationmethodsforASRaggregatesareselectedusingeitherprescriptiveorperformance-basedalternatives.PreventivemeasuresforACRaggregatesarelimitedtoavoidanceofuse.Becausethepotentialfordeleteriousreactionsdependsnotonlyontheconcretemixturebutalsothein-serviceexposure,guidanceisprovidedonthetypeofstructuresandexposureenvironmentswhereAARmaybeofconcern.1.2Units—ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnoncon-formancewiththestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C33/C33MSpecificationforConcreteAggregatesC125TerminologyRelatingtoConcreteandConcreteAg-gregatesC150/C150MSpecificationforPortlandCementC294DescriptiveNomenclatureforConstituentsofCon-creteAggregatesC295GuideforPetrographicExaminationofAggregatesforConcreteC311TestMethodsforSamplingandTe...
