【英文标准名称】:Rubberandrubberadditives-Determinationoftotalnitrogencontentusinganautomaticanalyser
【原文标准名称】:橡胶和橡胶添加剂.采用自动分析仪对含氮总量的测定
【标准号】:BSISO15672-2000
【标准状态】:现行
【国别】:英国
【发布日期】:2000-10-15
【实施或试行日期】:2000-10-15
【发布单位】:英国标准学会(BSI)
【起草单位】:BSI
【标准类型】:()
【标准水平】:()
【中文主题词】:塑料和橡胶技术;添加剂;化学分析和试验;含量测定;硫化橡胶;橡胶;氮;天然橡胶;合成橡胶
【英文主题词】:Analysis;Chemicalanalysisandtesting;Determinationofcontent;Nitrogen;Nitrogencontent;Rubber;Testing
【摘要】:ThisInternationalStandardspecifiesaninstrumental(automaticanalyser)methodforthedeterminationoftotalnitrogeninrubberandrubberadditives.
【中国标准分类号】:E34
【国际标准分类号】:83_040_20;83_060
【页数】:12P;A4
【正文语种】:英语


【英文标准名称】:StandardTestMethodforDeterminationofLengthChangeofConcreteDuetoAlkali-SilicaReaction
【原文标准名称】:由于碱-硅反应引起的混凝土长度变化测定的标准试验方法
【标准号】:ASTMC1293-2008b
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C09.26
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:aggregate;alkali-silicareactivity;concrete;lengthchange;pozzolan;slag;Aggregate(potentialalkalireactivity);Changeinlength;Concreteaggregates;Expansivealkali-silicareactivity;Silica
【摘要】:Alkali-silicareactionisachemicalinteractionbetweensomesiliceousconstituentsofconcreteaggregatesandhydroxylions(1).Theconcentrationofhydroxylionwithintheconcreteispredominantlycontrolledbytheconcentrationofsodiumandpotassium(2).Thistestmethodisintendedtoevaluatethepotentialofanaggregateorcombinationofanaggregatewithpozzolanorslagtoexpanddeleteriouslyduetoanyformofalkali-silicareactivity(3,4).Whentestinganaggregatewithpozzolanorslag,theresultsareusedtoestablishminimumamountsofthespecificpozzolanorslagneededtopreventdeleteriousexpansion.Pozzolanorslagfromaspecificsourcecanbetestedindividuallyorincombinationwithpozzolanorslagfromothersources.Whenselectingasampleordecidingonthenumberofsamplesfortest,itisimportanttorecognizethevariabilityinlithologyofmaterialfromagivensource,whetheradepositofsand,gravel,orarockformationofanyorigin.Forspecificadvice,seeGuideC295.Thistestmethodisintendedforevaluatingthebehaviorofaggregatesinportlandcementconcretewithanalkali(alkalimetaloxide)contentof5.25kg/m3orinconcretecontainingpozzolanorslagwithanalkalicontentproportionallyreducedfrom5.25kg/m3Na2Oequivalentbytheamountofpozzolanorslagreplacingportlandcement.Thistestmethodassessesthepotentialfordeleteriousexpansionofconcretecausedbyalkali-silicareaction,ofeithercoarseorfineaggregates,fromtestsperformedunderprescribedlaboratorycuringconditionsthatwillprobablydifferfromfieldconditions.Thus,actualfieldperformancewillnotbeduplicatedduetodifferencesinconcretealkalicontent,wettinganddrying,temperature,otherfactors,orcombinationsofthese(5).Resultsoftestsconductedonanaggregateasdescribedhereinshouldformapartofthebasisforadecisionastowhetherprecautionsshouldbetakenagainstexcessiveexpansionduetoalkali-silicareaction.Resultsoftestsconductedoncombinationsofanaggregatewithpozzolansorslagshouldformapartofthebasisforadecisionastowhetherthespecificpozzolanorslag,whenusedintheamounttested,waseffectiveinpreventingexcessiveexpansion.Thesedecisionsshouldbemadebeforeaparticularaggregateisusedinconcreteconstruction.CriteriatodeterminethepotentialdeleteriousnessofexpansionsmeasuredinthistestaregiveninAppendixX1.WhentheexpansionsinthistestmethodaregreaterthanthelimitshowninX1.2,theaggregateorcombinationofaggregatewiththetestedamountofpozzolanorslagispotentiallyalkali-reactive.Supplementalinformationshouldbedevelopedtoconfirmthattheexpansionisactuallyduetoalkali-silicareaction.PetrographicexaminationoftheconcreteprismsshouldbeconductedafterthetestusingPracticeC856toconfirmthatknownreactiveconstituentsarepresentandtoidentifytheproductsofalkali-silicareactivity.Confirmationofalkali-silicareactionisalsoderivedfromtheresultsofthetestmethodsthisproceduresupplements(seeAppendixX1).Ifthesupplementaltestsshowthatagivenaggregateispotentiallydeleteriouslyreactive,additionalstudiesmaybeappropriatetoevaluatepreventivemeasuresinordertoallowsafeuseoftheaggregate.PreventivemeasuresarementionedintheAppendixtoSpecificationC33.Thistestmethoddoesnotaddressthegeneralsuitabilityofpozzolansorslagforuseinconcrete.ThesematerialsshouldcomplywithSpecificationC618,SpecificationC989,orSpecificationC1240.