矿物掺合料对低水胶比混凝土干缩和自收缩的影响

第39卷第3期2009年5月东南大学学报(自然科学版)JOURNALOFSOUTHEASTUNIVERSITY(NaturalScienceEdition)Vol39No3May2009doi:10.3969/.jissn.1001-0505.2009.03.0301,2122(1,211189)(2,210008):研究了粉煤灰(0%10%30%50%)矿粉(0%10%30%50%)以及硅灰(0%10%20%)对水胶比为024的低水胶比混凝土干缩和自收缩性能的影响规律,并采用双曲线函数的收缩表达式对试验结果进行拟合,定量化地揭示了矿物掺合料对收缩随时间发展趋势的影响,分析了干缩与自收缩的关系.结果表明:粉煤灰有利于减少低水胶比混凝土的干缩,矿粉次之,硅灰略增大混凝土的干缩;粉煤灰有利于减少低水胶比混凝土的自收缩值,矿粉增大了自收缩,硅灰非常明显地增大混凝土自收缩;低水胶比混凝土的自收缩在所测试的干缩中占有很大的比重,而且随着粉煤灰矿粉和硅灰掺量的增加所占的比重均逐渐增大.:干缩;自收缩;矿物掺合料;超高强混凝土;低水胶比:TU528:A:1001-0505(2009)03-0580-06Effectofmineraladmixturesondryingandautogenousshrinkageofconcretewithlowwater-to-binderratioLiuJianzhong1,2SunWei1MiaoChangwen2LiuJiaping2(1JiangsuKeyLaboratoryofCivilEngineeringMaterials,SoutheastUniversity,Nanjing211189,China)(2JiangsuResearchInstituteofBuildingScience,Nanjing210008,China)Abstract:Theinfluencesofflyashwithreplacementpercentagesof0%,10%,30%and50%,groundgranulatedblas-tfurnaceslagwithreplacementpercentagesof0%,10%,30%and50%andsilicafumewithreplacementpercentagesof0%,10%and20%onthedryingandautogenousshrinkageofmortarinsuperhighstrengthconcretewithwater-to-binderratioof024werestudied.Byanalyzingtheshrinkagecurvesfittedfromtheexperimentaldatafortheconcretemixtureswithdifferentmineraladmixturesusinghyperbolicexpression,theinfluencesofmineraladmixturesonthetime-dependentshrinkagebehaviorandtherelationshipbetweendryingandautogenousshrinkagewereinvestigated.Theresultsindicatethatbothflyashandslagobviouslydecreasethedryingshrinkageoftheconcretewithlowwater-to-binderratio,whilesilicafumeincreasesthedryingshrinkagealittle.Ontheotherhand,whiletheautogenousshrinkageisreducedwiththeadditionofflyash,itincreaseswiththeadditionofslagorsilicafume.Theresultsalsoshowthattheproportionofautogenousshrinkagetothedryingshrinkageoftheconcretewithlowwater-to-binderratioisre-markableandmayfurtherincreasewiththecontentofflyash,slagorsilicafume.Keywords:dryingshrinkage;autogenousshrinkage;mineraladmixture;ultrahighstrengthcon-crete;lowwatertobinderratio:2008-10-10.:(1976),,,;(),,,,.:,,,.[J].:,2009,39(3):580-585.[do:i10.3969/.jissn.1001-0505.2009.03.030],100MPa.,,[1-3].,,200MPa[4].,,,.,.,.,,.[5-12],030,025.024,(0%10%30%50%)(0%10%30%50%)(0%10%20%),,,.111:525P,272%,26%,28d987MPa601MPa;:();:(),180%,7d28d666%795%,111%;:();:,25;:PCA()(),202%.1,1.1%w(CaO)w(MgO)w(Fe2O3)w(Al2O3)w(SiO2)w(LOI)63.250.603.545.0121.142.803.180.884.4529.8754.752.6631.568.601.1215.1133.602.371.630.321.010.9789.915.88112,(),.2,4:;10%30%50%;10%30%50%;10%20%.112,024,15%.1325mm25mm280mm,3.2,(20581第3期刘建忠,等:矿物掺合料对低水胶比混凝土干缩和自收缩的影响2%w()w()w()w()w()C10010000011202415C90FA1090100011202415C70FA3070300011202415C50FA5050500011202415C90SL1090010011202415C70SL3070030011202415C50SL5050050011202415C90SF1090001011202415C80SF20800020112024153).20h,,,.,(202)(602)%4h,,1d.,(202)(602)%,.1d,,,.,1d,,1d.2-,,.[5,13].sh(t)=ta+bt(1),t;sh(t)t;a,b.sh(t)=a+bln(t+1)(2)sh(t)=shu(1-aebt)(3),shu.[5],[7].(ACI),ACI209R927d-[14]sh(t)=t35+tshu(4)ACI,,sh(t)=shutA+t(5),A.23312(10%30%50%),3(5).3,(5)582东南大学学报(自然科学版)第39卷--,,R2096.3shuAR2shuAR2C1001235702098979592322096490C90FA101178656099447555361097745C70FA301006664099136538212099145C50FA50800726099059519321099066,,.10%30%50%,46%185%352%,63%91%123%,.,,,;,,;,[5],,.428d80%,28d43%~57%,28d,28d.,48%,10%30%50%47%53%65%,,.,,,,.32310%30%50%,,4(5).34shuAR2shuAR2C1001235702098979592322096490C90SL101175525099049613322096586C70SL301020461099206618208097105C50SL50916468097780622173096113,,.10%30%50%,49%174%258%,,.428d80%~86%,28d47%~62%,,28d,28d.48%,10%30%50%52%61%68%,,.583第3期刘建忠,等:矿物掺合料对低水胶比混凝土干缩和自收缩的影响,,,,,[5],.,,,,.33410%20%,,5(5).45shuAR2shuAR2C1001235702098979592322096490C90SF101228560099017690121099695C80SF201397848097644921170099840,,.10%,20%;10%20%,166%556%.,28d380%;,10%20%,28d70%62%,28d47%,,.10%20%56%66%,,.,SiO2,01m,,50.,,,SiO2Ca(OH)2,,,,.,,,,.41)sh(t)=shut/(A+t),.2),,,50%352%,123%,,.3),,,,50%,258%..4),,,10%20%,166%556%.,584东南大学学报(自然科学版)第39卷..(References)[1]MethaPK,MonteiroPJ.Concrete:microstructure,properties,andmaterials[M].3rded.NewYork:McGraw-Hil,l2005.[2]LappaES.Highstrengthfibrereinforcedconcretestat-icandfatiguebehaviourinbending[D].TheNether-lands:StructuralandBuildingEngineering,DelftUn-iversityofTechnology,2007.[3]YazlclHali.tTheeffectofcuringconditionsoncom-pressivestrengthofultrahighstrengthconcretewithhighvolumemineraladmixtures[J].BuildEnviron-ment,2007,42(5):2083-2089.[4]RichardP,CheyrezyM.Compositionofreactivepow-derconcretes[J].CementandConcreteResearch,1995,25(10):1501-1511.[5].[D].:,2006.[6],,,.[J].,2006,36(7):65-74.LiuJiaping,TianQian,SunWe,ieta.lStudyontheeffectofmineraladmixturesonautogenous-shrinkagedeformationofcemen-tbasedmaterialsanditsmecha-nism[J].IndustrialConstruction,2006,36(7):65-74.(inChinese)[7],,.[J].:,2007,37(2):334-338.ChenBo,ZhangYame,iGuoLiping.Investigationofdryingshrinkageofhighvolumeflyashconcrete[J].JournalofSoutheastUniversity:NaturalScienceEdi-tion,2007,37(2):334-338.(inChinese)[8]YangY,SatoR,KawaiK.Autogenousshrinkageofhigh-strengthconcretecontainingsilicafumeunderdr-yingatearlyages[J].CementandConcreteResearch,