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TS-3cT260-1AASHTOStandardMethodofTestforSamplingandTestingforChlorideIoninConcreteandConcreteRawMaterialsAASHTODesignation:T260-97(2009)1.SCOPE1.1.Thismethodcoversproceduresforthedeterminationoftheacid-solublechlorideioncontentorthewater-solublechlorideioncontentofaggregates,portlandcement,mortarorconcrete.1.2.Thetotalamountofchlorideisusuallyequaltotheacid-solublechloride.However,organicadditivesormineralsthatcontainacid-insolublechloridemaybepresentinconcreteandconcreterawmaterials.Theseconstituentsmaybecomeacidsolubleduringlong-termexposuretothealkalineenvironmentinconcreteormortar.1.3.Theageofconcretemortar,orhydratedportlandcementatthetimeofsamplingwillhaveanaffectonthewater-solublechlorideioncontent.Therefore,unlessearlyagestudiesaredesired,itisrecommendedthatthematerialbewellcuredandatleast28daysofagebeforesampling.1.4.Thisstandardprovidesforthedeterminationofchlorideioncontentbytwoprocedures:ProcedureA,DeterminationofAcid-SolubleChlorideIonContentandWater-SolubleChlorideIonContentbyPotentiometricTitrationorIon-SelectiveElectrode(LaboratoryTestMethod);andProcedureB,Acid-SolubleChlorideIonbyAtomicAbsorption(LaboratoryTestMethod).1.5.Sulfidesareknowntointerferewiththedeterminationofchloridecontent.Blast-furnaceslagaggregatesandcementscontainsulfidesulfurinconcentrationsthatcancausesuchinterference,whichcanbeeliminatedbytreatmentasnotedinthetestprocedures.OthermaterialsthatproduceastrongodorofH2Swhenacidisaddedtothemshouldbesimilarlytreated.1.6.ThevaluesstatedinSIunitsaretoberegardedasthepreferredstandard.PROCEDUREA—ACID-SOLUBLECHLORIDEIONANDWATER-SOLUBLECHLORIDEIONBYPOTENTIOMETRICTITRATIONORIONSELECTIVEELECTRODE(LABORATORYTESTMETHOD)2.APPARATUS2.1.SamplingequipmentforProceduresAandBarelistedinSections2.1.1or2.1.2.2.1.1.Coredrill.2.1.2.Rotaryimpact-typedrillwithadepthindicatoranddrillorpulverizingbitsofsufficientdiametertoprovidearepresentativesampleofsufficientsizefortesting.©2010bytheAmericanAssociationofStateHighwayandTransportationOfficials.Allrightsreserved.Duplicationisaviolationofapplicablelaw.TS-3cT260-2AASHTO2.1.2.1.Samplecontainerscapableofmaintainingthesampleinanuncontaminatedstate.2.1.2.2.Spoonsofadequatesizetocollectthesamplefromthedrilledholes.2.1.2.3.A“blowout”bulborothersuitablemeansofremovingexcesspulverizedmaterialfromtheholepriortore-drillingoperations.2.1.2.4.Adevicecapableofdeterminingthelocationanddepthofsteelreinforcementto±3mm(±1/8in.).2.2.EquipmentforChemicalTesting:2.2.1.Chlorideionorsilver/sulfideionselectiveelectrodeandmanufacturer-recommendedfillingsolutions.Note1—SuggestedelectrodesaretheOrion96-17CombinationChlorideElectrodeortheOrion94-6Silver/SulfideElectrodeorequivalents.TheSilver/SulfideElectroderequiresuseofanappropriatereferenceelectrode(Orion90-02orequivalent).2.2.2.Amillivoltmetercompatiblewiththeionelectrode.Note2—SuggestedmillivoltmeteristheOrionModel701ADigitalph/mVmeterorequivalent.2.2.3.MagneticstirrerandTeflonstirringbars.2.2.4.Burettewith0.1-mLgraduations.2.2.5.BalancecomplyingwithM231,ClassA.2.2.6.BalancecomplyingwithM231,ClassG2.2.2.7.Hotplate,250to400ºCheatingsurfacetemperature.2.2.8.Glassware,100and250-mLbeakers,filterfunnels,stirringrods,watchglasses,dropper,washbottles.2.2.9.Sieve,U.S.Standard300μm(No.50).2.2.10.WhatmanNo.40andNo.41filterpapers(orequivalent).Note3—Ifequivalentfilterpapersareused,theyshouldbecheckedtoconfirmtheydonotcontainchloride,whichwillcontaminatethesample.3.REAGENTS3.1.ConcentratedHNO3(spgr1.42).3.2.Sodiumchloride,NaCl,reagentgrade(primarystandard).3.3.Standard0.01normalityNaClsolution.DryreagentgradeNaClinanovenat105ºC.Cool,inadesiccator,determinethemassofapproximately0.5844gtothenearest0.0001g,dissolvein©2010bytheAmericanAssociationofStateHighwayandTransportationOfficials.Allrightsreserved.Duplicationisaviolationofapplicablelaw.TS-3cT260-3AASHTOdistilledH2O,andtransfertoa1-Lvolumetricflask.MakeuptothemarkwithdistilledH2Oandmix.Calculatetheexactnormalityasfollows:()actualNaC1()0.01000.5844WN=(1)where:Wactual=actualmassofNaCl,andNNaCl=normalityofNaClsolution.3.4.Standard0.01normalityAgNO3.Determinethemassof1.7gramsofreagentAgNO3,dissolveindistilledH2O,filterintoa1-Lbrownglassbottle,fill,andmixthoroughly.Standardizeagainst25.00mLoftheNaClsolutionbythetitrationmethodgiveninSection5.4.Calculatetheexactnormalityasfollows:()()33NaC1NaC1AgNOAgNOVNNV=(2)where:3AgNON=normalityofAgNO3solution,VNaCl=volume(mL)ofNaClsolution,NNaCl=normalityofNaClsolution,and3AgNOV=volume(mL)ofAgNO3solution.3.5.DistilledWater.Note4—Deionizedwatermaybeusedinplaceofdistilledwaterforsampleswhereextremeprecisionandaccuracyarenotdemanded.3.6.Methylorangeindicator.3.7.Ethanol,denatured,ormethanol,technical.3.8.HydrogenPeroxide(30percent).4.METHODOFSAMPLING4.1.ConcreteSample:4.1.1.Determinethedepthwithintheconcreteforwhichthechloridecontentisdesired.Note5—Aconvenientmethodofdeterminingthelocationanddepthofreinforcementbarsisapachometercapableofdeterminingthelocationanddepthofsteelreinforcementto±3mm(0.125in.).4.1.2.CoreMethod—Drillthecoretochosendepthandretrieve.4.1