ASTM C780-2010 普通及钢筋混凝土砌块用灰浆的预施工及施工评定方法

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【英文标准名称】:StandardTestMethodforPreconstructionandConstructionEvaluationofMortarsforPlainandReinforcedUnitMasonry
【原文标准名称】:普通及钢筋混凝土砌块用灰浆的预施工及施工评定方法
【标准号】:ASTMC780-2010
【标准状态】:现行
【国别】:
【发布日期】:2010
【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】:C12.02
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:合计比率;空气含量;抗压强度;混凝土渗透仪;锥探议;一致性;一致性保持;灰浆;抗拉强度
【英文主题词】:aggregateratio;aircontent;compressivestrength;concretepenetrometer;conepenetrometer;consistency;consistencyretention;mortar;tensilestrength
【摘要】:Duringpreconstructionandconstructionevaluations,useofthesetestmethodsestablishesspecificandoverallperformancecharacteristicsforthemortarsystem.Preconstructiontestingofmortarsprebatchedbyweightprovidesinformationfortheselectionoftheindividualmortarsystembestsuitedforthemasonrytobeconstructed.Therecommendedtestsandtheirsignificanceareasfollows:Consistencydeterminationsbyconepenetration(AnnexA1)allowgagingthewateradditionsforallmortarsincludedinthepreconstructiontestseries.Evenifthemortarconsistencyasmeasuredattheconstructionsiteisatadifferentpenetrationvaluethanthosemeasuredduringthepreconstructiontests,theconepreparationtestservestostandardizewateradditionsformortarsbeingconsideredasalternativesbeforeconstruction.Additionaltestingofmortarwatercontent-consistencyrelationships(AnnexA4)willallowrelatingthesetwofactorstobatch-to-batchvariationsattheconstructionsite.Consistencyretentionbyconepenetration(AnnexA2)usingdisturbedorundisturbedmortarsamplesprovidesameansofestablishingtheearly-agesettingandstiffeningcharacteristicsofthemortars.Becauselaboratorytestingisconductedunderstaticclimaticconditions,consistencyretentiontestresultsreflecttherelativeperformanceofthemortarsystemsundertest.Thesamegeneralrelationshipsareexpectedtoholdduringtestingattheconstructionproject,exceptastheyareinfluencedbyjobsiteweatherconditions.Mortarwater-contentdeterminations(AnnexA4)allowmeasurementofthewatercontentofthemortarmixture.Mortarsprebatchedusingmoistmasonrysandmaybemathematicallyanalyzedformortarwatercontent;however,thistest,whenusedforpreconstructionevaluation,establishestheeffectivenessofthetestmethodandservesasthecontrolorbasefortestsperformedattheconstructionsite.Mortaraggregateratiotesting(AnnexA4)providesamethodfordeterminingtheratioofaggregate-to-cementitiousmaterials.Thesievingoperationemployedduringthistestisincapableofseparatinganindividualcementitiousmaterialwhenmorethanonesuchmaterialisused,butcanaccuratelyestablishtheaggregate-to-cementitiousmaterialsratioofthemixture.Mortarair-contenttesting(AnnexA5)isusefulinestablishingthevalueofthiscomponentofthemortar.Thistestisofparticularimportanceinevaluatingmortarsthatcontainair-entrainingportlandcement,air-entraininglime,masonrycementoranycombinationthereof.Compressivestrengthtesting(AnnexA6)ofmoldedmortarcylindersandcubesestablishesoneofthecharacteristicsofhardenedmortar.Mortarcompressivestrengthtestvaluesarenotrepresentativeoftheactualcompressivestrengthofmortarintheassemblyandarenotappropriateforuseinpredictingthecompressivestrengththatwouldbeattainedbythemortarinthemasonryassembly.Themeasuredcompressivestrengthofamoldedmortarspecimenisalmostalwayslowerthanthestrengthofthesamemortarinthewall,primarilyasaresultofdifferencesinmortarwatercontentandspecimenshape.Mortarcompressivestrengthisinfluencedbymortarwatercontentatthetimeofset.Becausemoldedmortarspecimensarenotincontactwithabsorptivemasonryunitsandarenotsubjectedtoothermechanismsofwaterloss,theyhavehigherwatercontentsthanmortarinthewall.Higherwatercontentsalmostalwaysresultinlowerstrengths.Specimensizeandshapealsoaffectcompressivestrength.Cylindersandcubesexhibitdifferentstrengthsevenwhenmadefromthesamemortarmix.Bothofthesespecimenconfigurationsyieldlowerstrengthsthanwhatwouldbeattainedifaspecimenhavingthesamesizeandconfigurationofatypicalmortarjointcouldbereliablytested.