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1、Figure 7 showsthemeasurementresultsofsolublechlorideioncontentthatdirectlyaffectthecorrosionofrebar.图7所示为直接影响钢筋腐蚀的可溶氯离子含量的测试结果。ForsolublechlorideioncontentwithinIcmdepthinconcretefromsurface,thevalueforconcretewithCAlisthealmostsameasforOPCconcrete.在距离试件表面Icm以内的可溶氯离子含量，CA?和OPC混凝土是一样的。However,atthede
2、pthmorethanIcmfromthesurface,thechloridecontentsinallconcreteswithCA2areclearlylessthanofOPCconcrete.然而，距离试件表面ICm以外，CA2混凝土中的氯离子按量明显比OPC混凝土少。TheseresultsindicatethattheconcretesmixedwithCA2areclearlysuperiorinimmobilizationabilityofchlorideioncomparedtotheOPC.这些结果表明含CA2的混凝土固化氯离子的能力明显比OPC混凝土好。Table3sh
3、owstheimmobilizationabilityofchlorideioninbothconcreteswith7%ofCA2andwithOPConlyexposedtotwodifferentmarineenvironments,suchastidalzoneandsubmersionzone.表3显示了含7%CA2和OPC的两种混凝土固化氯离子的能力，这两种混凝土只暴露在两种海洋环境中，如潮汐环境和浸没区。Here,theconcretesarealsoinitiallycuredunderthedifferentconditions,suchaswatercuringfor7da
4、ys,samefor28days,andonlyinatmospherefor28days.这里，混凝土最初也在不同环境下养护，如在水中养护7天，以相同的方法养护28天或者在空气中养护28天。Inconcretewith7%ofCA2,inspiteoftheinitialcuringmethod,chlorideionsignificantlypenetratesupto2cmdepthinconcrete.在含7%CA2的混凝土中，虽然在最初的养护条件下，氯离子的最大渗透距离已达2cmoHowever,atthe2cmordeeperportion,thechlorideionconten
5、tinCA2concretesisclearlylessthanofOPCones.然而，在2cm或者更深的部分，CA2混凝土中氯离子含量明显比OPC混凝土中少。Furthermore,thediffusioncoefficientoftheCA2concretesexposedtotidalzoneshowsalmostthesamevalueregardlessofthecuringmethod,thoughinthecaseofOPCconcrete,thecoefficientofconcretecuredinitiallyunderairisclearlythelargest.此外，
6、暴露在潮汐环境下的CA?混凝土不论在什么养护条件下的扩散系数几乎都一样，即使是OPC混凝土，最初在空气中养护的试件的扩散系数明显是最大的。Theamountofchlorideionatdepthof3cminOPCconcreteislargercomparedtoCA2concrete,regardlessofdifferenceintheinitialcuringmethod.在不计初始养护方法的条件下，与CA2混凝土相比，OpC混凝土在距混凝土试件表面3cm深处的氯离子含量更高，Inaddition,lookingattheeffectsduetodifferencesinexposu
7、reenvironment,bothCA2concretesandOPConesexposedtosubmersionzonehavehigherdiffusioncoefficientthanthoseconcretesattidalzone.此外，就在不同暴露环境下的效果而言，CA?混凝土和OPC混凝土暴露在浸没环境下的扩散系数比在潮汐环境下的高。100 28days28days(Submersion)(Tidal)7daysAircuring ； 28days28days(TidaD(Tidal) (Submersion) (Tidal)7daysr curing(TidaI) (Tid
8、aDExposureFigure 8. Total chloride content and chloride diffusion coefficient (after: year of exposure test)3020SpecimencodeCuringmethodBcposureenvironmentTotalchlorideion(kgm1)Chloridediffusion(cm2year)0.25Deothfromsurface(cm)5.01.0203.04.028daysSubmersionzone8.7215.25035281.0270.1220.0541924CPr28d
9、aysTidalzone10.27.23334320.8190.3220.26717347daysTklalzone11.1255.54726710.4570.0800.0851041AirCiJnngTidalzone8.8585.63237511.2160.1660.034208128daysSubmersionzone13.3977.44313140.2200.1530.3630788CA2-728daysTidalzone12.1385.26909060.1420.2220.24205687dysHdalzone21.4547.69813300.2700.3110.2090442Air
10、curingTklalzone15,206553905000.2330.2730.2600442Table3.Totalchloridecontentandchloridediffusioncoefficient(after1yearofexposuretest)40Figure 8 showsaratiobetweenimmobilizedchlorideionandsolublechlorideoneineachCOnCrete.图8显示了混凝土中固化氯离子和可溶氯离子的比例。Here,theamountofimmobilizedchlorideionisestimatedasthedif
11、ferenceintheamountoftotalchlorideionandtheoneofsolublechlorideion.在这里，认为总氯离子的量与可溶性氯离子的量之差为固化氯离子的量。Intheconcretewith7%ofCA2exposedtotidalzone,thetotalchlorideionseemstoberelativelyhighercomparedtoOPC.暴露在潮汐环境时，与OPC混凝土相比，含7%CA2的混凝土中总氯离子含量相对较高。Theamountofimmobilizedchlorideion,whichisexpressedasapercent
12、ageoftotalchloride,isapproximately42%forconcreteinitiallycuredunderwaterfor28days,43%forconcreteinitiallycuredunderwaterfor7days,and44%forconcreteinitiallycuredunderair.将固化氯离子的量表示为总氯离子含量的百分比形式时，清水养护28天时含量大约为42%,清水养护7天时为43%,在空气中养护时为44%。Also,inthecaseofconcreteexposedtosubmersedzone,whichiscuredinitia
13、llyinwaterfor28days,theimmobilizedchloridepercentageis41%andisalmostthesameasoftheconcreteexposedtotidalzone.同样的，在淹没区时，水养28天时固化氯离子的量为41%,几乎与潮汐环境下相同。Fromtheresultsmentionedabove,itisclearthattheabilitytoimmobilizechlorideionbyCA2inconcretecanbeshownasalmostthesameregardlessofthedifferenceininitialcur
14、ingmethodsandexposureCOndition.由以上结果看，CA2混凝土固化氯离子的能力与初始养护条件和暴露环境关系不大。Ontheotherhand,inthecaseofOPCconcretesexposedtotidalzone,significantdifferenceisnotidentifiedinthetotalamountofchlorideionforeachconcrete.另一方面，对于暴露在潮汐环境下的OPC混凝土，各混凝土中的氯离子含量也没有明显差异However,withrespecttoimmobilizationrate,somedifferen
15、cearisesasfollows;然而，对于氯离子固化率而言，差别如下：(1) forconcreteinitiallycuredinwaterfor28daysandthenexposedintidalzone,theimmobilizationrateis35%,(I)初期水养28天后暴露在潮汐环境下的固化率为35%(2) forconcreteinitiallycuredinwaterfor7daysandthenexposedtotidalzone,theimmobilizationrateis16%,(2)初期水养7天后暴露在潮汐环境下的固化率为16%(3) forconcrete
16、initiallycuredinairfor7days,andthenexposedtotidalzone,theimmobilizationrateis16%.(3)初期在空气中养7天后暴露在潮汐环境下的固化率为16%Inaddition,forconcreteexposedtosubmersedzoneafter28daysofwatercuring,therateofimmobilizationis24%,approximately10%lowerthanthoseexposedtotidalzone,thoughtheamountofthetotalchlorideionislesst
17、hanthoseintidalzone.除此之外，虽然，淹没环境中的氯离子总量比潮汐区少，但水养28天后暴露在淹没环境下的氯离子固化率为24%,比暴露在潮汐环境下相比低了接近10%(.Thelargerthesolublechlorideioncontent,themorepossiblethecorrosionofreinforcingsteelinconcrete.可溶性氯离子含量越多，混凝土中钢筋锈蚀的可能性越大。Fromtheresultsdiscussedabove,theCA2concreteshavehighresistivityagainstchloridepenetratio
18、n.Furthermore,thispropertyislesssensitivetocuringconditioncomparedtotheOPCspecimenwhichneedssufficientinitialcuring.从以上讨论结果可知，CA2混凝土具有相对较高的抗氯离子渗透能力。并且，与OPC混凝土需要在特定环境下养护相比，其对养护条件的敏感性更低,。3.3 EIeCtriCpotentialofrebarinconcreteElectricpotentialchangesofrebarovertimeareshowninFigure9andFigure10.图9和图10所示为
19、钢筋电位随时间的变化。WithrespecttothenaturalpotentialofreinforcingsteelsinBBconcrete,inparticular,thepotentialsignificantlychangestonegativeduringtheinitialsomeperiodofexposureandislowerthan-350mV,whichisconsideredtobeathresholdwherethecorrosionisconsideredtostart,andthenrecoveredtopositivedirectiongradually.
20、对于钢筋在高炉矿渣混凝土中的自然潜力而言，尤其是在最初暴露的某些时期显著的消极变化直到电位低于35OmV时，这被当做亚试开始的阀值，然后逐步恢复到积极地发展方向。InthecaseofusingGGBSasmineraladmixture,apartofthemineralsreactstooxidize.在使用高炉矿渣，氧化反应的一部分，作为矿物外加剂的情况下。Consequently,asconcentrationofoxygeninconcretetemporarilyreduces,thesteelinconcretebecomesanodicwithoutanycorrosion.结
21、果，混凝土中的洋气浓度暂时降低了，钢筋在混凝土中变成了阳极不会受任何腐蚀。Exposure penod (day) Figure 9. Electric POtemiai of rebar at 2cm cover thickness of concrete=0PCCA25% -oCA2-7%-O- CA2-9% - BB - FATidalzoneCov icl)ess 2cm2o SAE) -20od UE3aOntheotherhand,thenaturalpotentialofsteelbarwith2cmofcoverIhicknessinOPCconcretealsochanges
22、tonegativelowerthan-350mVatabout180daysafterexposureleststarts,whichpointsoutclearcommencingofcorrosionofsteel.另一方面，在暴露测试开始后的大约180天时，OPC混凝土中2cm保护层下的钢筋电位也慢慢下降到低于-350mV,这就是钢筋腐蚀开始的明显标志Inaddition,intheconcretewith7%ofCA：,thepotentialofsteelbarswith2cmofcoverthicknesschangestoabout-380mVafter350daysofexp
23、osuretest,whileincaseofconcreteswith5%or9%ofCA?,thepotentialskeeppositiveconditionwherethecorrosioncanbepreventedo此外，含CA27%的混凝土中2cm厚的保护层下的钢筋电位在暴露测试开始后的350天后下降到-38OmV,而在CA?含量为5%和9%时，钢筋电位任然为正，可以抵抗电腐蚀。Regardingtheelectricpotentialofreinforcingsteelbarswith3cmofcoverthickness,thepotentialprofileissimila
24、rtothebarswith2cmofthecover,thatis,thepotentialgraduallychangestonegativedirectionduringfirstafewmonths,thenchangestopositiveasshowninFigure10。当钢筋保护层厚度为3cm时，其其电位变化情况与2cm时相似，即如图10所示，在开始的几个月里钢筋电位慢慢变为负电位，然后再变成正电位。Thereafter,thesituationseemstobeworseonlyincaseofOPCfrom280daysafterexposureteststarted,be
25、causethepotentialofsteelbarchangesagaintothenegativedirection.在暴露测试开始280天后，OPC混凝土中钢筋的情况变得更糟，因为这之后钢筋电位又变成负的了。3.4 Corrosionconditionsofrebar钢筋的腐蚀情况CorrosionarearatioonreinforcingsteelsinconcretesafterIyearofexposuretestisshowninFigure11,whereconcretesareexposedtotidalandsubmersionzones.如图11所示为暴露试验开始一年
26、以后的混凝土中钢筋腐蚀面积比，试验中混凝土分别暴露在潮汐环境和淹没环境下。OnthereinforcingbarsinOPCconcrete,thecorrosionareaisthelargestregardlessofcoverthicknessandexposurecondition,comparingtothebarsinallcasesofCA?concretes.与所有的CA2混凝土试件相比，OPC混凝土中任何保护层厚度和暴露环境下的钢筋腐蚀面积都是最大的。Onthesteelbarsat2cmofthecoverthicknessinOPCconcrete,corrosionha
27、vingarearatiosofabout4%and2%ariseundertidalandsubmersedexposureconditions,respectively.保护层厚度为2cm的OPC混凝土中的钢筋，在潮汐区和淹没区的钢筋腐蚀率分别约为4%和2%。Intheconcretewith5%and7%OfCA2,thecorrosionarearatioisslightlylessthan0.5%onrebarat2cmofcoverthicknessattidalzone,andalmostnocorrosionarisesonthebarsat2cmofthecoverincon
28、cretewith9%OfCA2.含CAl5%和7%的混凝土中，保护层厚度为2cm的试件在潮汐区的钢筋腐蚀率略小于0.5%,而CA2含量为9%时试件中的钢筋几乎不受腐蚀。Corrosionofthesteelbarsat3cmofthecoverthicknessisconfirmedasaspotrustinginconcretewith5%CA2andOPC.含量为5%的CA2混凝土和OpC混凝土中钢筋保护层厚度为3cm时会发生点蚀。RegardlessofexposurezoneandincreaseintherateoftheCA2contents,theincidenceofcorr
29、osionwaslessincaseofCA?concrete.在不考虑暴露环境和CA?含量的增加时，CA?混凝土发生腐蚀的情况更少。Theaboveresultsweregenerallyconsistentwithelectricpotentialmeasurementsmentionedabove,excludingonlyconcretewith5%ofCA2inwhichalittlediscrepancyexistsinelectricpotentialandactualcorrosionconditionsonthereinforcements.上面的结果基本符合以上提到的电位测
30、量结果，除了含5%CA2的混凝土，这种混凝土的电位变化和实际腐蚀情况有点差异。Inanycase,itisnecessarytoexaminetheeffectofCA2oncorrosionprotectionofthesteelreinforcementsinconcreteinthelongerdurationoftheexposuretest.不管在什么情况下，都有必要检验暴露试验中CA2混凝土对钢筋抗电腐蚀的长期作用效果。1 year exposureWB=50%CoVerthiCtaTeSS3cmTidal zoneSubmersion zoneCoverthictaiess 2c
31、mSpecimencpde Figure 11. Coos6 area ratio of rebarO OPC CA2-5% CA2-7% CA2-9% BB FASpecimencodeFigure 12. Cartwnation depth of specimens after 14OdayS5105(EE) fdapuOqeUOq3.5 Resistancetocarbonation抗碳化作用Figure12showscarbonationdepthofeachspecimenafter140daysoftheaccelerationtest.图12所示为每个试件140后加速试验的碳化深
32、度。InconcreteswithCA2,thecarbonationissignificantlylesscomparedtoBBorFAconcrete,whileOPCconcretebehavessimilartoUSingCA2.当混凝土中加入CA2时其碳化明显的比高炉矿渣水泥和粉煤灰水泥混凝土低，OPC混凝土的表现与CA2混凝土相似。Fromtheresult,whenusingCA2asamineraladmixture,chloridepenetrationresistanceofconcretecanbeimprovedwithoutreducingtheresistance
33、tothecarbonation.结果看，当采用CA2做矿物外加剂时，可以在提高混凝土的抗氯离子渗透能力的同时不会降低其抗碳化能力。4.CONCLUSIONInthisstudy,inordertograspthefundamentalcharacteristicsoftheconcretemixedwithaCaO2AbO3finepowderasamineraladdmixture,experimentalstudiesarecarriedoutonstrengthproperties,chloridepenetrationcharacteristicsandneutralizationc
34、haracteristics.在这项研究中，为了找出添加了CaO2AK)3细粉后的混凝土的基本特征，进行了抗压强度，氯离子渗透性和中和特性的试验研究。Consequently,thefollowingconclusionswereobtained;试验结果如下所示：(1) ConcretemixedwithCaO2ALO.3,generallyhasthelowerstrengthcomparedtoOPCconcrete,asthecementcontentrelativelyreducesbecauseapartofitisreplacedbyCaO2AI2O3.加入CaO2ALO3后的混
35、凝土，其强度一般比OPC混凝土低，因为混凝土中2ALO3,取代了一部分水泥。Actually,however,thedifferencetendstobeverylesswhenexposedtomarineconditions.然而，实际上，当暴露在海洋环境下之后，差别变得更小。(2) BymixingCaO2A2O3inconcrete,theresistivityagainstchloridepenetrationinmarineenvironmentisimproved.通过加入CaO2ALC3,混凝土抵抗氯离子渗透的能力有所提高。Consequently,replacementupt
36、o9%ofCaO2AI2O3,wasalsopossibletogetgoodresults.即使水泥的取代量达到9%也可以取得较好的效果。(3) TheimmobilizationofchlorideioninconcreteusingCaO2AI2O3isalsosuperiorCOmParedtoOPCConCret力口入Cao2A2O3之后，混凝土固化氯离子的能力也比OPC混凝土强。(4) ImmobilizationofchlorideionsandpenetrationresistanceofconcretecanbeobtainedbyUsingCaO2AI2O3withoutb
37、eingaffectedbythemethodofinitialcuring.混凝土中因添加CaO2A12O3而提高的固化氯离子和抵抗氯离子渗透的能力并不受养护条件的影响。(5) WhenusingCaO2AI2O3inreinforcedconcrete,corrosionprotectionabilityofconcretecanincrease.混凝土中加入CaO2AI2O3后，可以提高其抗腐蚀能力Inotherwords,theincubationperiodofstructureconstructedinthechlorideattackedenvironment,suchassea
38、erea,WiHbeProIOnged.换种说法就是结构在氯离子侵蚀环境，如海洋环境下的正常使用时间会延长。(6) ComparedtoconcreteusingflyashandGGBS,concretewithCaO2AbO3hashigherneutralizationresistanceanditsperformanceissameastheordinarycementconcrete.与粉煤灰和高炉矿渣混凝土相比，加入CaO2ALO3的混凝土的抗中和作用更好，其效果与普通水泥混凝土一样。REFERENCESK.Tabara,K.Yamamoto,M.AshidaandM.Moriok
39、a.,2010.FixationabilityofchlorideionbyhardenedcementaddedwithCaO2A10.(inJapanese),JapanCementAssociation.JCAproceedingsofcementandconcrete,Vol.64:No.64-428:428-434.K.Tabara,K.Miyaguchi,M.MoriokaandK.Takewaka.,2011.Hydrarionbehaviorandfixationabilityofchlorideionbyavarietyofkindsofhardenedcementadded
40、withCaO2A10.(inJapanese),JapanCementAssociation.JCAproceedingsofcementandconcrete,Vol.65:No.65-427:427-434.JSCEG5732003.JSCEStandards.,2004.Measurementmethodfordistributionoftotalchlorideioninconcretestructure.JapanSocietyofCivilEngineers.JournalofMaterials,ConcreteStructuresandPavements,No.767V-64:17-25.
