【英文标准名称】:StandardPracticeforCalculatingDesignValueTreatmentAdjustmentFactorsforFire-Retardant-TreatedLumber
【原文标准名称】:防火木材的设计值分析调整因素的计算标准规程
【标准号】:ASTMD6841-2003
【标准状态】:现行
【国别】:
【发布日期】:2003
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:D07.07
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:designvalues;fire-retardant;fire-retardanttreatment;lumber;mechanicalproperties;strengthproperty;thermaleffects;
【摘要】:Fire-retardant-treatmentsareusedtoreducetheflame-spreadcharacteristicsofwood.Chemicalsandredryingconditionsemployedintreatmentsareknowntomodifythestrengthpropertiesofthewoodproductbeingtreated.Thispracticegivesproceduresforfire-retardantchemicalmanufacturerstousetocalculatetheeffectsoftheirtreatmentonlumberusedinnormalandelevatedtemperatureserviceconditions.Theeffectoffire-retardanttreatmentsonthestrengthoflumberusedinroofframingapplicationsistimerelated.Inthispractice,thecumulativeeffectonstrengthofannualthermalloadsfromalltemperaturebinsisincreased50timestoestablishtreatmentadjustmentfactorsforfire-retardanttreatedlumberroofframing.TheproceduresofTestMethodD5664employanelevatedtemperatureintendedtoproducestrengthlossesinashortperiodoftime.Althoughtheexposureismuchmoreseverethanthatwhichoccursinanactualroofsystem,thechemicalreactionsthatoccurinthelaboratorytestareconsideredtobethesameasthoseoccurringoverlongperiodsoftimeinthefield.Treatmentadjustmentfactorsdevelopedunderthispracticeapplytolumberinstalledinaccordancewithconstructionpracticesrecommendedbythefire-retardantchemicalmanufacturerwhichincludeavoidanceofdirectwetting,precipitationorfrequentcondensation.Applicationofthispracticeislimitedtoroofapplicationswithdesignconsistentwith1.3.1.1Thispracticecoversproceduresforcalculatingtreatmentadjustmentfactorstobeappliedtodesignvaluesforfire-retardant-treatedlumberusedatambienttemperatures[servicetemperaturesupto1008212;F(388212;C)]andasframinginroofsystems.1.2Thesedesignvaluetreatmentadjustmentfactorsforthepropertiesofextremefiberinbending,tensionparalleltograin,compressionparalleltograin,horizontalshearandmodulusofelasticityarebasedontheresultsofstrengthtestsofmatchedtreatedanduntreatedsmallclearwoodspecimensafterconditioningatnominalroomtemperatures[72176;F(22176;C)]andofothersimilarspecimensafterexposureat150176;F(66176;C).ThetestdataaredevelopedinaccordancewithTestMethodD5664.Guidelinesareprovidedforestablishingadjustmentfactorsforthepropertyofcompressionperpendiculartograinandforconnectiondesignvalues.1.3TreatmentadjustmentfactorsforroofframingapplicationsarebasedoncomputergeneratedthermalloadprofilesfornormalwoodroofconstructionusedinavarietyofclimatesasdefinedbyweathertapesoftheAmericanSocietyofHeating,RefrigeratingandAir-ConditioningEngineers,Inc.(ASHRAE).Thesolarloads,moistureconditions,ventilationratesandotherparametersusedinthecomputermodelwereselectedtorepresenttypicalslopedroofdesigns.Thethermalloadsinthispracticeareapplicabletoroofslopesof3in12orsteeper,toroofsdesignedwithventareasandventlocationsconformingtonationalstandardsofpracticeandtodesignsinwhichthebottomsideoftheroofsheathingisexposedtoventilationair.Fordesignsthatdonothaveoneormoreofthesebase-linefeatures,theapplicabilityofthispracticeneedstobedocumentedbytheuser.1.4TheproceduresofthispracticeparallelthosegiveninPracticeD6305.GeneralreferencesandcommentaryinPracticeD6305arealsoapplicabletothispractice.1.5Thispracticeiswrittenininch-poundunitswithSIunitsprovidedinparenthesesforinformationonly.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortou......
【中国标准分类号】:
【国际标准分类号】:13_220_50;79_040
【页数】:6P.;A4
【正文语种】: