混凝土导热系数试验与分析-肖建庄

13120102　　　　　JOURNALOFBUILDINGMATERIALS　Vol.13,No.1Feb.,2010:2009-01-09;:2009-07-06:()(06QH14012);(2008BAK48B03):(1968—),,,,,.E-mail:[e-mail]　　:1007-9629(2010)01-0017-05肖建庄1,2,　宋志文1,　张　枫1(1.,200092;2.,200092):为了研究基于现代施工工艺制成的混凝土导热系数,通过稳态平板导热仪对多种混凝土(包括普通混凝土、高强混凝土、再生混凝土以及配筋混凝土)试件进行了导热系数试验,考察了包括骨料体积分数、水灰比、骨料类型、外掺料掺量、温度、干湿状态及钢筋体积分数等因素对混凝土导热系数的影响;进一步考察了再生粗骨料取代率对再生混凝土导热系数的影响.通过这些因素的显著性分析,得到了各因素对混凝土导热系数影响的显著性大小依次为:干湿状态、再生粗骨料取代率、温度、骨料体积分数、骨料类型、钢筋体积分数、水灰比、掺和料种类.:导热系数;再生粗骨料;显著性分析:TU528.01　　　:A　　　doi:10.3969/j.issn.1007-9629.2010.01.004AnExperimentalStudyonThermalConductivityofConcreteXIAOJian-zhuang1,2,　SONGZHi-wen1,　ZHANGFeng1(1.DepartmentofBuildingEngineering,TongjiUniversity,Shanghai200092,China;2.KeyLaboratoryofAdvancedCivilEngineeringMaterialsofMinistryofEducation,TongjiUniversity,Shanghai200092,China)Abstract:Inordertostudythermalconductivityofconcreteproducedbymodernconstructiontechnology,influencingfactorsonthermalconductivityofnormalstrengthconcrete,highperformanceconcrete,recy-cledconcreteaswellasreinforcedconcretewerequantitativelyinvestigatedbythestableplatethermalcon-ductivitymeter.Seventestingvariables,includingtheaggregatevolumecontent,water-cementratio(mw/mc),typesofaggregate,admixturecontent,temperature,moistureofspecimenandreinforcementvolumecontentwereconsideredinthistest.Withregardtorecycledconcrete,recycledaggregatereplacementper-centagewasalsoconsidered.Thesemaininfluencefactorsonthethermalconductivityofconcretewerein-vestigatedbytheoutstandinganalysis.Theresultsshowthatthesignificanceofthesefactorsisasfollowsfromgreatesttoleast:moisture,recycledcoarseaggregatereplacementratio,temperature,volumefrac-tionsofaggregates,typesofaggregate,volumeratiosofreinforcement,mw/mcandtypesofadmixtures.Keywords:thermalconductivity;recycledcoarseaggregate;outstandinganalysis　　:、、[1-5].[5](),.,,.[6-9],.、(、)、()(),.,,2040[8].,.1　1.1　.,,,.,:Υ=λδΔtS(1):Υ,W;S,m2;δ,m;Δt,℃.(1):λ=ΥδΔtS(2)1.2　250mm×250mm×60mm,28d.1.C-GC1C80,28d86.78MPa,22cm.C30,C3028d38.62MPa.3(RC-GC1,2,3)1.1　Table1　MixproportionsParameterItemmwmc/%TypeofcementitiousmaterialMixproportion/(kg·m-3)WaterCementitiousmaterialFineaggregateCoarseaggregateAdmixtureAggregatevolumecontent,moisture,reinforcementvolumecontentC-GC1,CG-GC1,RC-GC1,2,327Cement16260062611129.68C-GC227Cement2519284347726.42C-GC327Cement3421266241429-mw/mcC-WC143Cement2295336261112-C-WC232Cement1855776261112-TypeofcementitiousmaterialC-KZ127Slag/Cement16290/510626111210.00C-KZ227Slag/Cement162180/420626111210.00C-FMH127Flyash/Cement16290/510626111210.00C-FMH227Flyash/Cement162180/420626111210.00RecycledcoarseaggregatereplacementratioC30,C-ZS1,2,343Cement1653847471072-Reinforcementvolumecontent1%(RC-GC3)Reinforcementvolumecontent3%(RC-GC2)Reinforcementvolumecontent5%(RC-GC1)1　Fig.1　Descriptionofreinforcementintheconcrete(size:mm)18　　　　　13　1.3　GB10294—1988《》.,,,2.2　Fig.2　Experimentaldeviceforthermalconductivity2　2.1　25℃3.3:.,.3　Fig.3　Effectsofaggregatevolumecontentonthermalconductivity4　Fig.4　Effectsoftypesofaggregatesonthermalconductivity2.2　2,4.4,.,,.[10].2.3　5.5,.:(1),,;(2),,,.5　Fig.5　Effectsofmw/mconthermalconductivity6　Fig.6　Effectsofadmixturesonthermalconductivity2.4　,(,)19　1,:　　　6.6,;,;30%(),.2.5　、、C-GC12.2,C-GC1,,..2　、C-GC1Table2　EffectsoftemperatureandmoistureW/(m·K)Dry25℃50℃80℃Saturated25℃1.681.561.492.482.6　7.7,,.100%(),85%.7　Fig.7　Effectsofrecycledcoarseaggregatereplacementratioonthermalconductivity2.7　8.8,.,,.8　Fig.8　Effectsofreinforcementvolumecontentonthermalconductivity3　3.1　[11]A,Ar,n,1Xij,i=1,2,…,r;j=1,2,…,n.XijN(μi,σ2),Xij.1,Qr:Qr=QE+QA(3):QE;QA.QE/σ2N-rχ2,N=rn;QA/σ2r-1χ2,QE/σ2QA/σ2.:F=QA/(r-1)QE/(N-r)=S2AS2E(4)(r-1,N-r)F,:S2E,S2E=QE/(N-r);S2A,S2A=QA/(r-1).,AF,F,.3.2　,,F3.F,3　Table3　ResultofoutstandinganalysisFactorAggregatevolumecontentTypeofaggregatemwmcTypeofadmixtureTemperatureMoistureRecycledcoarseaggregatereplacementratioReinforcementvolumecontentF3.032.722.430.515.3888.3810.252.51:、、、、、、、.4　1..20　　　　　13　;.2..,.3.;,;30%,.4.;,.5.;;,.6.:、、、、、、、.:[1]　CAMPBELL-ALLEND,THORNECP.Thethermalcon-ductivityofconcrete[J].MagazineofConcreteResearch,1963,15(43):39-48.[2]　HARMATHYTZ.Thermalpropertiesofconcreteatelevat-edtemperatures[J].JournalofMaterials,1970,5(1):47-74.[3]　MARSHALLAL.Thethermalpropertiesofconcrete[J].BuildingScience,1972(7):167-174.[4]　KHANMI,BHATTACHARJEEB.Relationshipbetweenthermalconductivitiesofaggregateandconcrete[A].CivilEngineeringMaterialsandStructures[C].Osmania:OsmaniaUniversityHyderabad,1995.[5]　USBR.Thermalpropertiesofconcrete(BulletinNo1,PartVII)[R].Colorado:[sn],1940.[6]　.[M].:,1991.LIUXing-fa.Analysisofthermalstressinconcretestructure[M].Beijing:People'sCommunicationPublishingHouse,1991.(inChinese)[7]　.[M].:,1995.WUGan-chang.Analysisofthermalstressinsemi-rigidpave-mentstructure[M].Beijing:SciencePress,1995.(inChinese)[8]　.[M].:,1999.ZHUBo-fang.Massconcretethermalstressandthermalcon-trol[M].Beijing:ChinaElectricPowerPress,1999.(inChi-nese)[9]　.[M].:,2001.DONGYu-li.Firesafetydesignonconcretestructure[M].Beijing:SciencePress,2001.(inChinese)[10]