fsn_ 1086-lina zhang-2.hydration of portland cement-fp

1、SynthesisofCalciumSilicateHydrateCompoundunderVariedConditionsLinaZHANG1ZongjinLI2XinCHENG3MinglianXIN41.SchoolofMaterialScienceEngineeringUniversityofJinan250022CHINA2.DepartmentofCivilEnvironmentalEngineeringTheHongKon

2、gUniversityofScienceTechnology000000HongKongCHINA3.SchoolofMaterialScienceEngineeringUniversityofJinan250022CHINA4.SchoolofMaterialScienceEngineeringUniversityofJinan250022CHINAAbstractCalciumSilicateHydratecompoundswere

3、synthesizedbythereactionoflimefumedsilica.DifferentreactionconditionswithvariedtemperatureCaSiratioreactiontimewereconductedwiththeproductmphologyacterizedunderSEM.Intermsoftemperatureeffectthecrystallinityathightemperat

4、ureexhibitedexcellentbutpoatlowtemperature.BychangingCaSiratiotheproductobtainedperfmedanalogousunderlowtemperaturewhilediversecompoundsweregainedwhenthetemperaturewaskepthigh.Meoverthereactiontimerequireddifferedtoomuch

5、aswell.Underhightemperaturecircumstanceshtdurationofreactionwassufficientfthegoodqualitycrystalproductproduced.Howeveronlypocrystallinedproductcouldbefmedevenprolongedtimeofthereactionwereconducted.UnderSEMTEMgoodpocryst

6、allinedproductsweredistinguishedacterizedrespectively.iginalityCalciumsilicatehydrateisthemostcrucialhydrationproductofcementbasedmaterial.Duetocomplicatedstructureitsrelevantstudiesunderstingundergoesdeveloping.Basicall

7、yitcouldbeproducedbythehydrationoftricalciumsilicatedicalciumsilicateaswellasvolcanicreactionbetweenlimeadditivessuchasflyashsilicafume.Thecompositionincementbasedmaterialisnmallytoocomplicatedheterogeneousfthesystematic

8、studyofcalciumsilicatehydrate.Consequentlysynthesizedmannerbythevolcanicreactionoflimereactivesilicaised.Aschemicalreactionisaffectedbymanyfactsvariedreactionconditionsaredesignedtohelpunderstthecalciumsilicatehydratecom

9、poundssynthesized.Keywds:calciumsilicatehydratesynthesiscompoundscrystallinity1Crespondingauth:ujn_chengxin@Tel8653182765309Fax8653182765969temperaturehightemperaturegrowthweresimplycarriedoutsimultaneouslytograsptheeffe

10、ctofdifferentcontrollingfactsonthefmationofCSHcompoundsviavolcanicreactionoflimesilicateobtainthebasictrendofcompoundsproducedinvariousconditions.LimefumedsilicawereutilizedtoconductvolcanicreactionunderdifferentCaSi(her

11、einafterreferredtoasCS)valuetemperaturedurationofreactionfthefmationofpossibleCSHsinglecrystalcompounds.AlsotherelationofsuchfmedCSHcompoundswithtobermitewasmentionedtohelpdeepentheunderstingofCSHstructureproperties.2.Ex

12、perimental2.1.MaterialsApparatusMaterialLime(calcinedfromcalciumcarbonate(A.G.Aldrich)at10000Cf3hourssealedinplasticbottle)fumedsilica(A.G.AlfaAesarBETsurfaceareaof385.5m2g)ultrapureH2O(resistivity18??m1deairedf20minutes

13、)ApparatusReact(StainlesssteelflaskwithTeflonbottleinside)oven(SHELLAB14452)2.2.ExperimentalProcessLimefumedsilicaU.P.H2Owerefirstweightedinspecificamountrespectivelythenquicklymixedtogetherevenly.Afterfewminutestheywere

14、rapidlytransferredintoreactscrewedtightly.Suchreactwasthenputintoovenwithtemperaturesetatcertainvaluesteadilyinadvance.Aftercertainperiodoftimethewholeflaskwascooleddownnaturallytoambienttemperature.Theobtainedproductwas

15、vacuumfiltratedwashedbyultrapureH2Ofthreetimesthendriedintheovenat700C800Cf24h.Thefinalproductgainedwaskeptinsealedbottleffurtheracterization.2.3.SampleinfmationThesamplesdesignedunderdifferentCSratiotemperaturedurationo

16、freactionwerelistedinTab.1.Thewatersolidratiohereinwasfixedat50.CSratiovariedfrom0.5to2.0whilethetemperaturewassetat800C2000C.Thedurationofthereactionwasstudiedat64hour1year.Tab.1ListsofsampleinfmationCSGroupAGroupBGroup

17、C0.5T=800CD=64hT=2000CD=64hT=a.t.D=1Y0.831.01.51.71.82.0WhereT=temperatureD=durationa.t.=ambienttemperature2.4.ProductacterizationPowerXraydiffraction(XraydiffractometerhereinafterreferredtoasXRDX’pertPro))wascarriedoutw

18、ithallthesamplesgrindedinagatethoughlytransferredintoAlholderflatted.The2θrangevariedfrom50to800withthescanrateof20min.Scanningelectronmicroscopy(hereinafterreferredtoasSEMJEOL6300)wascarriedoutbyputtingthesamplesontoGaP

19、wafercoatedwithAu.Transmissionelectronmicroscopy(hereinafterreferredtoasTEMJEOL2010F)wasusedbytransferringtheaimingproductontoCugridwithamphouspouscarbonlayer.3.ResultsDiscussion3.1.CompositioneffectThecontemparyundersti

20、ngontheCSratioofCSHwasassumedtobevariedwithincertainranges.ButwhetherthedifferentstartingCScouldinfluencethefmationstructureofCSHnotwasuncertain.BasedonsuchthevariationontheinitialCSatlowerheatedtemperaturewasconducted.F