模拟国际会议演讲稿

IntroductionThankyouverymuch.Mr.Jiao,foryourkindintroduction.Ladiesandgentlemen,Goodafternoon!MynameisLijia,camefromHarbinEngineeringUniversity.Iamhonoredtohavebeeninvitedtospeakatthisconference.BeforeIstartmyspeech,letmeaskaquestion.Doyouknowwhatcanaffectthepropertiesoffoamconcrete?Doyouthinkhowtoreinforcedthepropertiesoffoamconcrete?Mostoftheinvestigationsonfoamconcreteinthepasthavebeenconfined（被限于）toneatcementpaste,cementpastewithpartialreplacementwithadmixturesandtocement-sandmixes.Today,mytopicisaboutInfluenceoffillertypeonthepropertiesoffoamconcrete.Iwanttoshareourinterestingresearchresultonreinforcedconcreteframewithyou.Thecontentofthispresentationisdividedinto4parts:Insection1,Iwillintroducewhatisthefoamconcrete.Insection2,IwilltalkaboutParametersinvestigatedandmixcompositions.Insection3,IwillgiveEectofwater-solidsratioondesigndensity.Andfinally,Iwillmakeaconclusion.BodythefoamconcreteNow,Iwillintroducethefoamconcrete.Pre-formed（成型的）foamconcreteismanufactured（力口工）byaddingfoam,preparedbyaerating（充气）afoamingagentsolution,tocementpasteorcementmortar（灰浆）.Thecomposition（合成物），physicalproperties（性能）andusesoffoamconcretewerediscussedindetail（详细的）byValore,ShortandKinniburgh,RudnaiandTaylor.Althoughseveralinvestigationshavebeenconductedonthepropertiesoffoamconcrete,mostofthemdealwithcement-sandmixes,neatcementpastewithorwithoutpartialreplacement（局部替换）usingadmixtures（掺合料）.Fewstudiesreportontheinfluenceoffillertypeonthepropertiesoffoamconcrete.Byusingflyash（粉煤灰）asfiller（fineaggregate细骨料）insteadofsand,thehighvolume（体积）utilization（利用）offlyashbecomespossible可能,thusprovidingameansofeco-nomic（经济）andsafedisposal（处理）ofthiswasteproduct.Comparison（比较）ofstrengthofair-curedfoamconcretemadewithcement-sandandcement-flyashformasonry（砌体结构）byDurackandWeiqingshowthatforproductsofcomparabledensity（比较密度）,mixeswithflyashasfineaggregateinplaceofsandgaverelativelyhigherstrength.Parameters（参数）investigatedandmixcompositions（组成成分）Somuchforthefoamconcrete,nowIwillmoveontoParameters（参数）investigatedandmixcompositions.Astheexperimentalprogramme（实验程序）wasaimedatstudyingtheeectofthefillersonthepropertieslikedensity（密度），flowbehaviour（流动特性），waterabsorption（吸水率）andstrengthoffoamconcrete,thefollowingmixeswereinvestigatedbykeepingthebasicfiller-cementratioconstant（恒定不变）at1:1byweight.Thefoamrequiredforthreedensities（密度）offoamconcreteviz.1000,1250,1500kg/m3werearrivedatasperASTMC796-97.Inthecement-sand-flyashmixes50%ofthesandisreplacedwithflyashandinthecement-flyashmixesallthesandisreplacedwithflyash.Effectofwatersolidsratio（水砂比率）ondesigndensityThatbringmetoEffectofwater-solidsratio（水砂比率）ondesigndensity.Ithinkthispartisthemostimportantinmypresentation,Iwillexplainindetail.Asthefoamisaddedtothewetfoamconcretemix,theconsistency（稠度）ofthewetmixisveryimportanttogetthedesigndensity.Fig.2（a）and（b）showthevariationofdensityratio （密度变化率）（measuredfreshdensitydivided（分离）bydesigndensity）withwater-solidsratioformixeswithdifferentfillertypeforeachofthedesigndensities,viz.,1000and1500kg/m3,respectively（分别地）.Itisobservedthatatlowerwater-solidsratios,i.e.,atlowerconsistency,thedensityratioishigherthanunity（个体）.Themixistoostiff（严格地）tomixproperlythuscausingthebubbles（气泡）tobreakduringmixingresultinginincreaseddensity.Athigherwater-solidsratiosthereisalsoanincreaseindensityratioashigherwatercontentsmaketheslurry（泥浆）toothintoholdthebubblesresultinginsegregation（分离）ofthefoamfromthemixalongwithsegregationofthemixitselfthuscausinganincreaseinmeasureddensity.Therefore,asshowninFig.2(a)and(b),adensityratioofunityornearlyunityisachievedonlyataparticularconsistency.Thisconsistencyrequirementforthemixbeforeaddingfoamtoitcanbeexpressedintermsofwater-solidsratio.Itisalsoobservedthatthewater-solidsratiorequiredtoobtainadensityratiovalueofone,dependsonthefillertype.,2@,2@皂ConclusionTheconclusionsdrawnfromthisstudyandsummarizedbelowareapplicable（合适的）tothecharacteristicsofthematerials（材料特性）usedandtherangeofparameters（参数范围）investigated:（i）theconsistencyofpre-formedfoamconcretemixtures（definedasthewater-solidsratioforachievingthetarget（目标）density）mainlydependsonthefillertype,i.e.,relativelyhigherformixeswithflyashasfillercomparedtomixeswithsand;（ii）theflowbehaviourmainlydependsonthefoamvolumeandasthefoamvolumeincreasestheflowdecreases.Foragivendensity,foamconcretewithflyashasfillershowedrelatively（相当的）higherflowvalues;（iii）foragivendensity,anincreaseinflyashcontentofthemixresultsinincreasedstrength.Incomparison（比较）tocement-sandmixes,cement-flyashmixesshowedrelativelyhigherwaterabsorption（吸收）.That,sall.Thankyou!Arethereanyquestions?ThepictureonthisslideisSomuchfor ,nowIwillmoveonto ThisslideshowsthecalculationresultAsweknow,thetargetuserusuallyhastakenalistofcoursesratherthanacourse,soweneedtoextentourprobabilitycalculationformulars.Forexample,supposeT={a,b},Pr[x「T]theprobabilityxoccurswithouteitheranaorbprecedingit;Pr[xT]theprobabilityxoccurswithouteitheranaorbfollowingit.Thisprobabili