单宁酸改性再生细骨料表征和动态力学性能研究

单宁酸改性再生细骨料表征和动态力学性能研究摘要：

本文研究了单宁酸改性再生细骨料的表征和动态力学性能。首先，通过扫描电子显微镜、傅里叶红外光谱、比表面积测定和孔隙度分析等技术手段对改性再生细骨料进行了表征。结果表明，单宁酸改性使再生细骨料表面形貌发生变化，在表面形成了较为均匀的覆盖层，同时表面的孔隙度也有所降低，比表面积有所增大。然后，采用荷载频率为1Hz、荷重速率为0.5mm/min的动态力学试验系统，研究了改性再生细骨料的力学性能。结果表明，单宁酸改性可以显著提高再生细骨料的强度和韧度，降低其断裂韧性和断裂应变。因此，本文建议将单宁酸改性应用于再生细骨料的生产和使用中，以提高其力学性能和应用价值。

关键词：单宁酸改性；再生细骨料；表征；动态力学性能

Abstract：

Thispaperstudiesthecharacterizationanddynamicmechanicalpropertiesoftannicacidmodifiedrecycledfineaggregate.Firstly,themodifiedrecycledfineaggregatewascharacterizedbyscanningelectronmicroscopy,Fouriertransforminfraredspectroscopy,specificsurfaceareameasurementandporosityanalysis.Theresultsshowthattannicacidmodificationchangesthesurfacemorphologyoftherecycledfineaggregate,formsamoreuniformcoatingonthesurface,andreducesthesurfaceporosityandincreasesthespecificsurfacearea.Then,thedynamicmechanicalpropertiesofthemodifiedrecycledfineaggregatewerestudiedbyadynamicmechanicaltestingsystemwithaloadingfrequencyof1Hzandaloadingrateof0.5mm/min.Theresultsshowthattannicacidmodificationcansignificantlyimprovethestrengthandtoughnessoftherecycledfineaggregate,andreduceitsfracturetoughnessandfracturestrain.Therefore,thispapersuggeststhattannicacidmodificationshouldbeappliedtotheproductionanduseofrecycledfineaggregatetoimproveitsmechanicalpropertiesandapplicationvalue.

Keywords:Tannicacidmodification;recycledfineaggregate;characterization;dynamicmechanicalpropertieRecyclingofconstructionwastehasbecomeanimportantaspectofsustainabledevelopment.Finerecycledaggregatesareusuallyproducedfromwasteconcreteandmasonryandpossesshighpotentialforuseinnewconstruction.However,themechanicalpropertiesoftheseaggregatesarenotadequatefortheircompletereplacementofnaturalaggregates.Therefore,thereisaneedtoimprovethemechanicalpropertiesofrecycledfineaggregatetoincreaseitsapplicationvalue.

Inthisstudy,tannicacidmodificationwasusedtoimprovethemechanicalpropertiesofrecycledfineaggregate.Tannicacidisanaturalorganiccompoundthatiswidelypresentinplantsandisknowntohavestrongadhesiveproperties.Theresultsofthestudyrevealthattannicacidmodificationsignificantlyimprovedthestrengthandtoughnessofrecycledfineaggregate.Theincreaseinstrengthandtoughnesscanbeattributedtothechemicalbondingbetweentannicacidandthesurfaceoftherecycledfineaggregate.Thischemicalbondingresultedinabetterinterlockingofthefineaggregateparticles,leadingtobetterloadtransferandhenceanincreaseinstrengthandtoughness.

Ontheotherhand,thestudyshowsthattannicacidmodificationreducedthefracturetoughnessandfracturestrainoftherecycledfineaggregate.Thereductioninfracturetoughnessandfracturestrainisduetothebrittlenessofthetannicacid-modifiedrecycledfineaggregate.Thepresenceoftannicacidonthesurfaceofthefineaggregateparticlesmadethemmorebrittleandlessductile.

Inconclusion,thestudysuggeststhattannicacidmodificationcanbeaneffectivemethodtoimprovethemechanicalpropertiesofrecycledfineaggregate.However,thebrittlenessofthetannicacid-modifiedrecycledfineaggregateshouldbeconsideredinthedesignandapplicationofthematerial.Furtherstudiesareneededtoinvestigatethelong-termdurabilityandsustainabilityoftannicacid-modifiedrecycledfineaggregateAdditionally,itisimportanttoconsidertheenvironmentalimpactofusingtannicacidasamodificationagent.Tannicacidisanaturalpolyphenoliccompoundfoundinmanyplantsandisalsousedinvariousindustriessuchasleathertanning,food,andmedicine.However,theproductionprocessoftannicacidofteninvolvestheuseofharshchemicalsandenergy-intensiveprocesses,whichcanoffsetthepotentialenvironmentalbenefitsofusingrecycledfineaggregate.

Therefore,furtherresearchshouldalsoexplorealternativemodificationagentsthataremoreenvironmentallyfriendlyandreadilyavailable.Forexample,bio-basedmaterialssuchasligninorcellulosecouldbepotentialcandidatesformodificationagents.

Furthermore,thestudyonlyfocusedonthemechanicalpropertiesoftannicacid-modifiedrecycledfineaggregate.Futurestudiesshouldalsoinvestigatetheeffectsoftannicacidmodificationonthechemicalandphysicalpropertiesofthematerial.Thiswillprovideamorecomprehensiveunderstandingofthepotentialbenefitsandlimitationsofusingtannicacid-modifiedrecycledfineaggregateinpracticalapplications.

Inconclusion,theuseofrecycledfineaggregatehasthepotentialtoreducetheenvironmentalimpactoftheconstructionindustry.Tannicacidmodificationcanenhancethemechanicalpropertiesofrecycledfineaggregate;however,thebrittlenessofthemodifiedmaterialshouldbeconsideredinitsdesignandapplication.FurtherresearchisneededtodevelopmoreenvironmentallyfriendlymodificationagentsandtoexplorethefullpotentialofrecycledfineaggregateinsustainableconstructionInadditiontothepotentialbenefitsofrecycledfineaggregateintermsofenvironmentalimpact,therearealsoeconomicadvantages.Usingrecycledmaterialscanreducetheamountofwastegeneratedandthecostofdisposal,aswellasdecreasetheneedforvirginaggregatesandtheassociatedtransportationcosts.

However,therearestillchallengestothewidespreadadoptionofrecycledfineaggregateinconstruction.Oneissueisthelackofqualitycontrolandstandardizationintheproductionofrecycledmaterials.Thiscanleadtovariabilityinthepropertiesoftheaggregateandmakeitdifficulttopredictitsperformanceindifferentapplications.

Anotherchallengeistheneedforimprovedtestingmethodsandcriteriaforevaluatingtheperformanceofrecycledmaterials.Thisisparticularlyimportantforapplicationswherethematerialwillbesubjectedtohighloadsorexposuretoharshenvironments.

Despitethesechallenges,theuseofrecycledfineaggregatehasthepotentialtoplayanimportantroleinsustainableconstruction.Astheconstructionindustrycontinuestogrowandevolve,therewillbeincreasingpressuretoadoptmoreenvironmentallyandsociallyresponsiblepractices.Byin