附知识资料录

千里之行，始于足下朽木易折，金石可镂Word-可编辑附录ResearchonHigh-PerformanceSprayConcreteincoalmineAbstractToproducehigh-performancesprayconcrete,superfinepowdermaterialsincludingsuperfineflyashandsilicafumeetcareincorporatedwithstrength-increasingmaterialssuchassuperplasticizersandrapidsettingagentstoimprovethepropertiesofsprayconcrete.Thecompressivestrengthofhigh-strengthsprayconcrete,madeupbytheoptimumdesignusingauniform,canreachto90MPaattheageof28d.Thepermeabilitygradeofthehighimpermeabilitysprayconcreteisraisedfrom0.4MPato2.0MPaorevenmore.Thereboundlossofthesprayconcreteismarkedlyreducedwiththeadditionofwaterreducerandrapidsettingagents.Accordingtothefinalstatisticsabout150mtunnelconcreteengineeringinacoalmine,thereboundlossisreducedfrom25%～30%to13%,andthelocalreboundlossis5%.Whilehigh-performancesprayconcreteismadeup,propertiesofsprayconcretearetestedandtheimportantinfluencingrulesareinvestigatedwhichindicatehowtheactivityofsuperfineflyashisactivatedbyrapidsettingagent.Keywords:shighperformance;sprayconcrete;superfinepowder;impermeabilityIntroductionAsoneofefficientconstructiontechniquesofspecialconcrete,sprayconcreteisusedwidelyinmanyindustriessuchasarchitecture,metallurgy,transportation,irrigation,coalmineandsoon.Butatpresent,therearesomeundesirablephenomenaincludinglowstrengthgrade,highrebound,seriousdust,lowimpermeability,etc,bywhichtheperformanceandtheusageofsprayconcretearerestricted.Duetothecontinuousprogressofscienceandtechnology,therequirementforsprayconcretethathashighstrength,lowreboundloss,lessdust,outstandingimpermeabilitybecomesurgentlymoreandmore.Tosolvetheseproblems,the千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）mixtureproportionsofhigh-efficientadditivesandhighperformanceconcreteareanalyzed.Onthebasisoftheseanalysessprayconcretespropertiescouldbeimprovedmarkedlyonconditionsofavailableservices,skillandmanagementinmoderndaycoalmining.Simultaneously,engineeringvalueishigherthanever.Topreparehigh-performanceconcretethathashigh-strengthandhighimpermeabilityscientifically,agreatnumberofsystemexperimentswerestudiedonthebasisoflowreboundratioandlessdustsprayconcrete.1ExperimentalToproducethehigh-performancesprayconcretethathaslowreboundloss,highstrengthandhighimpermeability,superplasticizer,silicafume,superfineflyash,superfineself-combustingcoalganguewereincorporatedintotheconcretemixture.Atthesametime,rapidset,increasingviscosityandconsistency,super-lowwatersolidratiowereselectedtoserveasdesignrulesofconcretemixture.Besidestheadditionofsuperfinematerialshavingpozzolanicactivityandafillingrole,asuperplasticizerforwater-reducingandstrength-increasingwasused,too.Withtheactivationofarapidsettingagent,theearlyactivityofflyashincreasedobviously.1.1MaterialsCementGrade425and525PortlandCement.SuperplasticizerFortypeUNF-5non-air-entraininghighefficientwater-reducingagentmadeinTianjinbasedonnaphthalene,theelementalingredientsulphonatednaphthaleneformaldehydecondensationhasawaterreducingrateof19%,andaproportioncontentof0.5%～1%。RapidsettingagentType-ⅠHongxingRapidSettingAgent,initialsettingtimeisnomorethan3min,finalsettingtimeisnomorethan6min.SilicafumeSuppliedbyTangshanSteelPlantwithSiO2contentof95.2%and千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑averageparticlesizeof0.1μm.FlyashSuppliedbydrydustseparatorofthe№2furnaceintheShenhaiheatandpowerplant.Thechemicalcompositionandpropertiesofflyasharegivenintalbe1.Accordingtospecificsurfacearea,flyashisdevidedinto4typeswithspecificsurfaceof471.7,568.3,648.0and704.0(m2/kg)respectively.CoalgangueSelf-combustingcoalganguefromFuxin,whosefinenessis314m2/kganditschemicalcompositionareshowedintable2.Additionally,milledkaoliniteandbentonitewereusedincomparativetests.千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑1.2SpecimensandmethodsThecompressivestrengthofrapidsettingmortarwiththeadditionofdifferentadmixturesweretestedatrequiredagestoassesstheinfluenceofcompoundadmixture,concretespecimensorstrengthtestweresampledfromsprayconcretethatwasmouldedandpreparedonsite,andthensawedintothesizeof100mm×100mm×100mm.Weightmethod:theratioofreboundedconcretetotheoriginalconcretewasusedtoassessreboundlossofsprayconcrete.Impermeabilitywasdetermineddirectlybythepermeabilitygradeofspecimensthathadbeingcuredfor28dinstandardconditions.2ResultsandDiscuss2.1LowreboundlosssprayconcreteWiththeadditionofsuperfineinorganicmaterials,theconsistencyandtheviscosityofcementmortarcouldbeincreasednotably.Thereboundlossanddustofsprayconcretehavebeenreducedtoo.Curvesinfigure1showtheinfluenceoftheproportionalcontentofseveralinorganicpowderstotheworkabilityofcementmortar,whilecementsandratiois1∶2andwatercementratiois0.55.Theconclusionobtainedfromfigure1isthattheviscosityincreasingeffectofkaoliniteandbentoniteishighestinthematerialsused,butisunprofitabletothemechanicalpropertiesofconcretewhilethecontentisratherhigh;Theviscosityin-creasingeffectofself-combustingcoalganguepowderismiddlinginthematerials,butnoharmtothedevelopmentofconcretesstrength;Asforflyash,themorethecontent,thehighertheviscosityincreasingeffect,andtheadditionofflyashisidentifiedtobeusefultoconcretestrength.Table3demonstratestheinfluenceofinorganicpowderandsuper-plasticizertothesettingtimeofcementmortar,whichindicatesthattheadditioninorganic千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）activepowdermaterialsincorporatedwithasuperplasticizerandarapidsettingagentareharmlesstotherapidsettingpropertyofsprayconcrete.Sprayconcretespecimenshadbeensampledfromthesiteandcuredinstandardconditionsuntiltest,andthenthecompressivestrengthwastested(Figure2).Themixmaterialsusedinthecoalmaintunnelinclude425#PortlandCement,HongxingType-1RapidSettingAgent(content3%),UNF-5Superplasticizer,Stone(Maximumsize10mm),MiddleSand(Modulusoffineness2.4);Site-mix-ingproportionratioisC∶S∶G=1∶2.34∶1.91.Figure2demonstratesthatthecompressivestrengthofsprayconcretewiththeadditionofsili-cafumeisbetterthanthatoftheblanksamplenomattertheages,theincreasingratioisevenmorethan50%at28d;Theearlystrengthofthespecimensisroughlyequaltotheblanksamplewhenpulverizedflyashisused,andthestrengthin28dishigherthanthatofblanksampleovbiously;Withtheuseofkaolinite,bentoniteandself-combustingcoalgangue,thestrengthofsprayconcreteisclosetothatoftheblanksample.千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑Theimprovingofthereboundlosswiththeadditionofdifferentinorganicviscosity-increasingmaterialshasbeentestedbyFuxinMineralManagementinthecoalmineconstruction.Table4demonstratesthatitisveryefficienttoreducethereboundlossofsprayconcretebythecoordinationbetweeninorganicpowderandsuperplasticizertoincreasetheviscosityofconcretemixtures.千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑2.2High-strengthSprayConcrete2.2.1Silicafumehigh-strengthsprayconcreteFigure3showsthestrengthofsilicahigh-strengthsprayconcretepreparedbytheoptimumdesignmethod.525#PortlandCementmadeinFushunisused,thecontentofsilicafumeis10%.Cementsandratioofmortaris1∶2,cementcontentofconcreteintestis500kg/m3.Itcanbeacknowledgedfromfigure3thatthemortarstrengthinlaterperiodsismuchlowerthanthatofblandmortar,althoughthestrengthofthemortarwiththeadditionofarapidsettingagentdevelopsspeedwithin1day;Asforthemortarwiththeadditionofsilicafume,thestrengthisratherhighineveryage(81.4MPaattheageof28d).Thestrengthofsprayconcreteconstructedonsitecanreachto63.1MPawhileitsreboundlossis9.2%.2.2.2superfineflyashhigh-strengthsprayconcreteTheoptimumexperimentaldesignofhigh-strengthspraymortarandconcretewiththeadditionofsuperfineflyashcoordinatingisproceededbyuniformdesignmethodwith4factors〔U8(8×42)〕includingwatercementratio(W/C),cementsandratio(C/S),finenessofflyash(S).Thedesignandresults千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑ofthetestisshownintable5,andthefollowingequationsareconcludedfromtable5.Thespecificsurfaceareaofflyashcanreachto1105kg/m3byfurtherpulverization,whichisusedtopreparesprayconcretewithcontentof10%incorporatingwith525#PortlandCement(madeinBenxi,28dstrength61.0MPa,content500kg/m3),rapidsettingagent(content3%)andsuperplasticizer(content1.5%).MixproportionratioisC∶S∶G=1∶1.5∶1.5,W/C=0.28.Thecompressivestrengthofspecimensisshowninfigure4,thecompressivestrengthreachestomorethan90MPaattheageof28d.Additionallyfigure4demonstratesthatthesuperfinepulverizedoperationcausestheearlyactivityofflyashincreasedproperly,especiallywiththeactivatingofrapidsettingagent.千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑Theresultsofanimpermeabilitytestofthesprayconcretewiththeadditionofsuperfineflyashandsuperplasticizerindicatethattheimperme-abilityofsprayconcreteisimprovedobviously(Table6),andcantobeusedintunnelsprayconcreteprojectswherehighpermeabilityresistanceisrequired.千里之行，始于足下朽木易折，金石可镂Word-可编辑千里之行，始于足下朽木易折，金石可镂Word-可编辑山东科技大学学生毕业设计（论文）千里之行，始于足下朽木易折，金石可镂Word-可编辑ConclusionsInorganicpowdermaterialsincludingsuperfineflyashandsilicafumethathaveobviousviscosity-increasingeffectswhicharefitforthepreparationoflowreboundlosssprayconcretecoordinatedwithsuperplasticizerandrapidsettingagent.Thecompressivestrengthatdifferentagesofsprayconcretewiththeadditionofsilicafumeisbetterthanthatofsprayconcretewiththeadditionoftherapidsettingagentonly.Thecompressivestrengthofhigh-strengthsprayconcretewiththeadditionofsilicafumeandsuperplasticizercanreachto81.4MPaafterbeingcuredinstandardcuringconditionfor28d,orreachto63.1MPaintheconditionoftunnelconstructionincoalminesalongwithareboundlossof9.2%.Aftersuperfinepulverization,especiallywiththeactivatingroleofarapidsettingagent,theearlyactivityofflyashisratherincreased.Thecompressivestrengthofultra-high-strengthsp