Facile preparation of slag or fly ash geopolymer composite coatings with

FacilepreparationofslagorflyashgeopolymercompositecoatingswithflameresistanceYaChaoWang⇑,JiangPingZhaoCollegeofResourceEngineering,Xi’anUniversityofArchitecture&Technology,Xi’an710055,PRChinahighlights�Slagorflyashgeopolymercompositecoatingexertsflameresistance.�DehydrationofCASAH(I)inslag-basedcoatingisdetected.�Criticalcontentofflyashorslagis25wt%.articleinfoArticlehistory:Received3February2018Receivedinrevisedform3December2018Accepted17January2019Keywords:FlameretardancyFlyashSlagGeopolymerConecalorimeterabstractAmajorconcerninpreparingflameretardantcoatingtodayistocontinuetoimproveitssustainableandecologicalperformance,andgeopolymerizationisconvertingindustrialsolidwastesintochemicallydur-ablecement-likebinderswithexcellentthermalstabilityandnon-combustibility.Therefore,twoseriesofnovelcoatingswerefacilelypreparedviasol-gelmethod,whichcontainedfloatingbeadsofflyashandgranulatedblast-furnaceslag,usingNa2SiO3asthealkali-activator,accompaniedwithorganicmodifierandfilm-formingagentrespectively.Theresultsshowedthatthegeopolymericcoatingtransformedintosiliceouslayerforblockingtransferofheatandmass,leadingtothedecreasesinthevalueofheatreleaserate(HRR)andfiregrowthindex(FGI),andanincreasedfireperformanceindex(FPI).However,theflameretardanteffectofslag-basedcoatingmainlydependedonthedehydrationderivedfromCASAH(I)andamorphous(HO)3ASiAOASi„.Itidentifiedthatanappropriatedosage(25wt%)offlyashorslagwascru-cialtoobtainexcellentflameretardingefficiency.�2019ElsevierLtd.Allrightsreserved.1.Introducti